First successful rust library call

61810

.cargo/config.toml

@@ -0,0 +1,5 @@
+[build]
+target = "riscv64gc-unknown-none-elf"
+
+[target.riscv64-unknown-elf]
+linker = "/opt/riscv/bin/riscv64-unknown-elf-gcc"

.clang-format

@@ -0,0 +1,4 @@
+SortIncludes: Never
+UseTab: Always
+IndentWidth: 4
+TabWidth: 4

.editorconfig

@@ -4,19 +4,4 @@ root = true
 
 [*]
 end_of_line = lf
-insert_final_newline = true
-indent_style = space
-indent_size = 4
-
-[*.{c,h}]
-indent_size = 2
-
-[*.S]
-indent_size = 8
-
-[*.ld]
-indent_size = 2
-
-[Makefile]
 indent_style = tab
-indent_size = 8

.rustfmt.toml

@@ -0,0 +1 @@
+hard_tabs = true

Makefile

@@ -1,5 +1,8 @@
 K=kernel
 U=user
+R=rust
+
+RTARGET = riscv64gc-unknown-none-elf
 
 OBJS = \
   $K/entry.o \
@@ -30,6 +33,9 @@ OBJS = \
   $K/plic.o \
   $K/virtio_disk.o
 
+RLIBS = \
+	$R/foo/target/$(RTARGET)/release/libfoo.a
+
 # riscv64-unknown-elf- or riscv64-linux-gnu-
 # perhaps in /opt/riscv/bin
 #TOOLPREFIX = 
@@ -73,8 +79,8 @@ endif
 
 LDFLAGS = -z max-page-size=4096
 
-$K/kernel: $(OBJS) $K/kernel.ld $U/initcode
-	$(LD) $(LDFLAGS) -T $K/kernel.ld -o $K/kernel $(OBJS) 
+$K/kernel: $(OBJS) $K/kernel.ld $U/initcode rustlibs
+	$(LD) $(LDFLAGS) -T $K/kernel.ld -o $K/kernel $(OBJS) $(RLIBS)
 	$(OBJDUMP) -S $K/kernel > $K/kernel.asm
 	$(OBJDUMP) -t $K/kernel | sed '1,/SYMBOL TABLE/d; s/ .* / /; /^$$/d' > $K/kernel.sym
 
@@ -138,6 +144,9 @@ fs.img: mkfs/mkfs README $(UPROGS)
 
 -include kernel/*.d user/*.d
 
+rustlibs:
+	cargo build -r --manifest-path $R/foo/Cargo.toml
+
 clean: 
 	rm -f *.tex *.dvi *.idx *.aux *.log *.ind *.ilg \
 	*/*.o */*.d */*.asm */*.sym \
@@ -145,6 +154,7 @@ clean:
 	mkfs/mkfs .gdbinit \
         $U/usys.S \
 	$(UPROGS)
+	cargo clean --manifest-path $R/foo/Cargo.toml
 
 # try to generate a unique GDB port
 GDBPORT = $(shell expr `id -u` % 5000 + 25000)

README

@@ -6,7 +6,7 @@ ACKNOWLEDGMENTS
 
 xv6 is inspired by John Lions's Commentary on UNIX 6th Edition (Peer
 to Peer Communications; ISBN: 1-57398-013-7; 1st edition (June 14,
-2000)).  See also https://pdos.csail.mit.edu/6.828/, which provides
+2000)).  See also https://pdos.csail.mit.edu/6.1810/, which provides
 pointers to on-line resources for v6.
 
 The following people have made contributions: Russ Cox (context switching,
@@ -14,29 +14,31 @@ locking), Cliff Frey (MP), Xiao Yu (MP), Nickolai Zeldovich, and Austin
 Clements.
 
 We are also grateful for the bug reports and patches contributed by
-Takahiro Aoyagi, Silas Boyd-Wickizer, Anton Burtsev, Ian Chen, Dan
-Cross, Cody Cutler, Mike CAT, Tej Chajed, Asami Doi, eyalz800, Nelson
-Elhage, Saar Ettinger, Alice Ferrazzi, Nathaniel Filardo, flespark,
-Peter Froehlich, Yakir Goaron, Shivam Handa, Matt Harvey, Bryan Henry,
-jaichenhengjie, Jim Huang, Matúš Jókay, Alexander Kapshuk, Anders
-Kaseorg, kehao95, Wolfgang Keller, Jungwoo Kim, Jonathan Kimmitt,
-Eddie Kohler, Vadim Kolontsov, Austin Liew, l0stman, Pavan
-Maddamsetti, Imbar Marinescu, Yandong Mao, Matan Shabtay, Hitoshi
-Mitake, Carmi Merimovich, Mark Morrissey, mtasm, Joel Nider,
-OptimisticSide, Greg Price, Jude Rich, Ayan Shafqat, Eldar Sehayek,
-Yongming Shen, Fumiya Shigemitsu, Cam Tenny, tyfkda, Warren Toomey,
-Stephen Tu, Rafael Ubal, Amane Uehara, Pablo Ventura, Xi Wang, Keiichi
-Watanabe, Nicolas Wolovick, wxdao, Grant Wu, Jindong Zhang, Icenowy
-Zheng, ZhUyU1997, and Zou Chang Wei.
+Takahiro Aoyagi, Silas Boyd-Wickizer, Anton Burtsev, carlclone, Ian
+Chen, Dan Cross, Cody Cutler, Mike CAT, Tej Chajed, Asami Doi,
+eyalz800, Nelson Elhage, Saar Ettinger, Alice Ferrazzi, Nathaniel
+Filardo, flespark, Peter Froehlich, Yakir Goaron, Shivam Handa, Matt
+Harvey, Bryan Henry, jaichenhengjie, Jim Huang, Matúš Jókay, John
+Jolly, Alexander Kapshuk, Anders Kaseorg, kehao95, Wolfgang Keller,
+Jungwoo Kim, Jonathan Kimmitt, Eddie Kohler, Vadim Kolontsov, Austin
+Liew, l0stman, Pavan Maddamsetti, Imbar Marinescu, Yandong Mao, Matan
+Shabtay, Hitoshi Mitake, Carmi Merimovich, Mark Morrissey, mtasm, Joel
+Nider, Hayato Ohhashi, OptimisticSide, Harry Porter, Greg Price, Jude
+Rich, segfault, Ayan Shafqat, Eldar Sehayek, Yongming Shen, Fumiya
+Shigemitsu, Cam Tenny, tyfkda, Warren Toomey, Stephen Tu, Rafael Ubal,
+Amane Uehara, Pablo Ventura, Xi Wang, WaheedHafez, Keiichi Watanabe,
+Nicolas Wolovick, wxdao, Grant Wu, Jindong Zhang, Icenowy Zheng,
+ZhUyU1997, and Zou Chang Wei.
+
 
 The code in the files that constitute xv6 is
-Copyright 2006-2020 Frans Kaashoek, Robert Morris, and Russ Cox.
+Copyright 2006-2022 Frans Kaashoek, Robert Morris, and Russ Cox.
 
 ERROR REPORTS
 
 Please send errors and suggestions to Frans Kaashoek and Robert Morris
 (kaashoek,rtm@mit.edu).  The main purpose of xv6 is as a teaching
-operating system for MIT's 6.S081, so we are more interested in
+operating system for MIT's 6.1810, so we are more interested in
 simplifications and clarifications than new features.
 
 BUILDING AND RUNNING XV6

kernel/bio.c

@@ -13,7 +13,6 @@
 // * Only one process at a time can use a buffer,
 //     so do not keep them longer than necessary.
 
-
 #include "types.h"
 #include "param.h"
 #include "spinlock.h"
@@ -24,130 +23,116 @@
 #include "buf.h"
 
 struct {
-  struct spinlock lock;
-  struct buf buf[NBUF];
+	struct spinlock lock;
+	struct buf buf[NBUF];
 
-  // Linked list of all buffers, through prev/next.
-  // Sorted by how recently the buffer was used.
-  // head.next is most recent, head.prev is least.
-  struct buf head;
+	// Linked list of all buffers, through prev/next.
+	// Sorted by how recently the buffer was used.
+	// head.next is most recent, head.prev is least.
+	struct buf head;
 } bcache;
 
-void
-binit(void)
-{
-  struct buf *b;
+void binit(void) {
+	struct buf *b;
 
-  initlock(&bcache.lock, "bcache");
+	initlock(&bcache.lock, "bcache");
 
-  // Create linked list of buffers
-  bcache.head.prev = &bcache.head;
-  bcache.head.next = &bcache.head;
-  for(b = bcache.buf; b < bcache.buf+NBUF; b++){
-    b->next = bcache.head.next;
-    b->prev = &bcache.head;
-    initsleeplock(&b->lock, "buffer");
-    bcache.head.next->prev = b;
-    bcache.head.next = b;
-  }
+	// Create linked list of buffers
+	bcache.head.prev = &bcache.head;
+	bcache.head.next = &bcache.head;
+	for (b = bcache.buf; b < bcache.buf + NBUF; b++) {
+		b->next = bcache.head.next;
+		b->prev = &bcache.head;
+		initsleeplock(&b->lock, "buffer");
+		bcache.head.next->prev = b;
+		bcache.head.next = b;
+	}
 }
 
 // Look through buffer cache for block on device dev.
 // If not found, allocate a buffer.
 // In either case, return locked buffer.
-static struct buf*
-bget(uint dev, uint blockno)
-{
-  struct buf *b;
+static struct buf *bget(uint dev, uint blockno) {
+	struct buf *b;
 
-  acquire(&bcache.lock);
+	acquire(&bcache.lock);
 
-  // Is the block already cached?
-  for(b = bcache.head.next; b != &bcache.head; b = b->next){
-    if(b->dev == dev && b->blockno == blockno){
-      b->refcnt++;
-      release(&bcache.lock);
-      acquiresleep(&b->lock);
-      return b;
-    }
-  }
+	// Is the block already cached?
+	for (b = bcache.head.next; b != &bcache.head; b = b->next) {
+		if (b->dev == dev && b->blockno == blockno) {
+			b->refcnt++;
+			release(&bcache.lock);
+			acquiresleep(&b->lock);
+			return b;
+		}
+	}
 
-  // Not cached.
-  // Recycle the least recently used (LRU) unused buffer.
-  for(b = bcache.head.prev; b != &bcache.head; b = b->prev){
-    if(b->refcnt == 0) {
-      b->dev = dev;
-      b->blockno = blockno;
-      b->valid = 0;
-      b->refcnt = 1;
-      release(&bcache.lock);
-      acquiresleep(&b->lock);
-      return b;
-    }
-  }
-  panic("bget: no buffers");
+	// Not cached.
+	// Recycle the least recently used (LRU) unused buffer.
+	for (b = bcache.head.prev; b != &bcache.head; b = b->prev) {
+		if (b->refcnt == 0) {
+			b->dev = dev;
+			b->blockno = blockno;
+			b->valid = 0;
+			b->refcnt = 1;
+			release(&bcache.lock);
+			acquiresleep(&b->lock);
+			return b;
+		}
+	}
+	panic("bget: no buffers");
 }
 
 // Return a locked buf with the contents of the indicated block.
-struct buf*
-bread(uint dev, uint blockno)
-{
-  struct buf *b;
+struct buf *bread(uint dev, uint blockno) {
+	struct buf *b;
 
-  b = bget(dev, blockno);
-  if(!b->valid) {
-    virtio_disk_rw(b, 0);
-    b->valid = 1;
-  }
-  return b;
+	b = bget(dev, blockno);
+	if (!b->valid) {
+		virtio_disk_rw(b, 0);
+		b->valid = 1;
+	}
+	return b;
 }
 
 // Write b's contents to disk.  Must be locked.
-void
-bwrite(struct buf *b)
-{
-  if(!holdingsleep(&b->lock))
-    panic("bwrite");
-  virtio_disk_rw(b, 1);
+void bwrite(struct buf *b) {
+	if (!holdingsleep(&b->lock))
+		panic("bwrite");
+	virtio_disk_rw(b, 1);
 }
 
 // Release a locked buffer.
 // Move to the head of the most-recently-used list.
-void
-brelse(struct buf *b)
-{
-  if(!holdingsleep(&b->lock))
-    panic("brelse");
+void brelse(struct buf *b) {
+	if (!holdingsleep(&b->lock))
+		panic("brelse");
 
-  releasesleep(&b->lock);
+	releasesleep(&b->lock);
 
-  acquire(&bcache.lock);
-  b->refcnt--;
-  if (b->refcnt == 0) {
-    // no one is waiting for it.
-    b->next->prev = b->prev;
-    b->prev->next = b->next;
-    b->next = bcache.head.next;
-    b->prev = &bcache.head;
-    bcache.head.next->prev = b;
-    bcache.head.next = b;
-  }
-  
-  release(&bcache.lock);
+	acquire(&bcache.lock);
+	b->refcnt--;
+	if (b->refcnt == 0) {
+		// no one is waiting for it.
+		b->next->prev = b->prev;
+		b->prev->next = b->next;
+		b->next = bcache.head.next;
+		b->prev = &bcache.head;
+		bcache.head.next->prev = b;
+		bcache.head.next = b;
+	}
+
+	release(&bcache.lock);
 }
 
-void
-bpin(struct buf *b) {
-  acquire(&bcache.lock);
-  b->refcnt++;
-  release(&bcache.lock);
+void bpin(struct buf *b) {
+	acquire(&bcache.lock);
+	b->refcnt++;
+	release(&bcache.lock);
 }
 
-void
-bunpin(struct buf *b) {
-  acquire(&bcache.lock);
-  b->refcnt--;
-  release(&bcache.lock);
+void bunpin(struct buf *b) {
+	acquire(&bcache.lock);
+	b->refcnt--;
+	release(&bcache.lock);
 }
-
-

kernel/console.c

@@ -23,51 +23,49 @@
 #include "proc.h"
 
 #define BACKSPACE 0x100
-#define C(x)  ((x)-'@')  // Control-x
+#define C(x) ((x) - '@') // Control-x
 
 //
 // send one character to the uart.
 // called by printf(), and to echo input characters,
 // but not from write().
 //
-void
-consputc(int c)
-{
-  if(c == BACKSPACE){
-    // if the user typed backspace, overwrite with a space.
-    uartputc_sync('\b'); uartputc_sync(' '); uartputc_sync('\b');
-  } else {
-    uartputc_sync(c);
-  }
+void consputc(int c) {
+	if (c == BACKSPACE) {
+		// if the user typed backspace, overwrite with a space.
+		uartputc_sync('\b');
+		uartputc_sync(' ');
+		uartputc_sync('\b');
+	} else {
+		uartputc_sync(c);
+	}
 }
 
 struct {
-  struct spinlock lock;
-  
-  // input
+	struct spinlock lock;
+
+	// input
 #define INPUT_BUF_SIZE 128
-  char buf[INPUT_BUF_SIZE];
-  uint r;  // Read index
-  uint w;  // Write index
-  uint e;  // Edit index
+	char buf[INPUT_BUF_SIZE];
+	uint r; // Read index
+	uint w; // Write index
+	uint e; // Edit index
 } cons;
 
 //
 // user write()s to the console go here.
 //
-int
-consolewrite(int user_src, uint64 src, int n)
-{
-  int i;
+int consolewrite(int user_src, uint64 src, int n) {
+	int i;
 
-  for(i = 0; i < n; i++){
-    char c;
-    if(either_copyin(&c, user_src, src+i, 1) == -1)
-      break;
-    uartputc(c);
-  }
+	for (i = 0; i < n; i++) {
+		char c;
+		if (either_copyin(&c, user_src, src + i, 1) == -1)
+			break;
+		uartputc(c);
+	}
 
-  return i;
+	return i;
 }
 
 //
@@ -76,54 +74,52 @@ consolewrite(int user_src, uint64 src, int n)
 // user_dist indicates whether dst is a user
 // or kernel address.
 //
-int
-consoleread(int user_dst, uint64 dst, int n)
-{
-  uint target;
-  int c;
-  char cbuf;
+int consoleread(int user_dst, uint64 dst, int n) {
+	uint target;
+	int c;
+	char cbuf;
 
-  target = n;
-  acquire(&cons.lock);
-  while(n > 0){
-    // wait until interrupt handler has put some
-    // input into cons.buffer.
-    while(cons.r == cons.w){
-      if(killed(myproc())){
-        release(&cons.lock);
-        return -1;
-      }
-      sleep(&cons.r, &cons.lock);
-    }
+	target = n;
+	acquire(&cons.lock);
+	while (n > 0) {
+		// wait until interrupt handler has put some
+		// input into cons.buffer.
+		while (cons.r == cons.w) {
+			if (killed(myproc())) {
+				release(&cons.lock);
+				return -1;
+			}
+			sleep(&cons.r, &cons.lock);
+		}
 
-    c = cons.buf[cons.r++ % INPUT_BUF_SIZE];
+		c = cons.buf[cons.r++ % INPUT_BUF_SIZE];
 
-    if(c == C('D')){  // end-of-file
-      if(n < target){
-        // Save ^D for next time, to make sure
-        // caller gets a 0-byte result.
-        cons.r--;
-      }
-      break;
-    }
+		if (c == C('D')) { // end-of-file
+			if (n < target) {
+				// Save ^D for next time, to make sure
+				// caller gets a 0-byte result.
+				cons.r--;
+			}
+			break;
+		}
 
-    // copy the input byte to the user-space buffer.
-    cbuf = c;
-    if(either_copyout(user_dst, dst, &cbuf, 1) == -1)
-      break;
+		// copy the input byte to the user-space buffer.
+		cbuf = c;
+		if (either_copyout(user_dst, dst, &cbuf, 1) == -1)
+			break;
 
-    dst++;
-    --n;
+		dst++;
+		--n;
 
-    if(c == '\n'){
-      // a whole line has arrived, return to
-      // the user-level read().
-      break;
-    }
-  }
-  release(&cons.lock);
+		if (c == '\n') {
+			// a whole line has arrived, return to
+			// the user-level read().
+			break;
+		}
+	}
+	release(&cons.lock);
 
-  return target - n;
+	return target - n;
 }
 
 //
@@ -132,61 +128,57 @@ consoleread(int user_dst, uint64 dst, int n)
 // do erase/kill processing, append to cons.buf,
 // wake up consoleread() if a whole line has arrived.
 //
-void
-consoleintr(int c)
-{
-  acquire(&cons.lock);
+void consoleintr(int c) {
+	acquire(&cons.lock);
 
-  switch(c){
-  case C('P'):  // Print process list.
-    procdump();
-    break;
-  case C('U'):  // Kill line.
-    while(cons.e != cons.w &&
-          cons.buf[(cons.e-1) % INPUT_BUF_SIZE] != '\n'){
-      cons.e--;
-      consputc(BACKSPACE);
-    }
-    break;
-  case C('H'): // Backspace
-  case '\x7f': // Delete key
-    if(cons.e != cons.w){
-      cons.e--;
-      consputc(BACKSPACE);
-    }
-    break;
-  default:
-    if(c != 0 && cons.e-cons.r < INPUT_BUF_SIZE){
-      c = (c == '\r') ? '\n' : c;
+	switch (c) {
+	case C('P'): // Print process list.
+		procdump();
+		break;
+	case C('U'): // Kill line.
+		while (cons.e != cons.w &&
+			   cons.buf[(cons.e - 1) % INPUT_BUF_SIZE] != '\n') {
+			cons.e--;
+			consputc(BACKSPACE);
+		}
+		break;
+	case C('H'): // Backspace
+	case '\x7f': // Delete key
+		if (cons.e != cons.w) {
+			cons.e--;
+			consputc(BACKSPACE);
+		}
+		break;
+	default:
+		if (c != 0 && cons.e - cons.r < INPUT_BUF_SIZE) {
+			c = (c == '\r') ? '\n' : c;
 
-      // echo back to the user.
-      consputc(c);
+			// echo back to the user.
+			consputc(c);
 
-      // store for consumption by consoleread().
-      cons.buf[cons.e++ % INPUT_BUF_SIZE] = c;
+			// store for consumption by consoleread().
+			cons.buf[cons.e++ % INPUT_BUF_SIZE] = c;
 
-      if(c == '\n' || c == C('D') || cons.e-cons.r == INPUT_BUF_SIZE){
-        // wake up consoleread() if a whole line (or end-of-file)
-        // has arrived.
-        cons.w = cons.e;
-        wakeup(&cons.r);
-      }
-    }
-    break;
-  }
-  
-  release(&cons.lock);
+			if (c == '\n' || c == C('D') || cons.e - cons.r == INPUT_BUF_SIZE) {
+				// wake up consoleread() if a whole line (or end-of-file)
+				// has arrived.
+				cons.w = cons.e;
+				wakeup(&cons.r);
+			}
+		}
+		break;
+	}
+
+	release(&cons.lock);
 }
 
-void
-consoleinit(void)
-{
-  initlock(&cons.lock, "cons");
+void consoleinit(void) {
+	initlock(&cons.lock, "cons");
 
-  uartinit();
+	uartinit();
 
-  // connect read and write system calls
-  // to consoleread and consolewrite.
-  devsw[CONSOLE].read = consoleread;
-  devsw[CONSOLE].write = consolewrite;
+	// connect read and write system calls
+	// to consoleread and consolewrite.
+	devsw[CONSOLE].read = consoleread;
+	devsw[CONSOLE].write = consolewrite;
 }

kernel/exec.c

@@ -9,158 +9,155 @@
 
 static int loadseg(pde_t *, uint64, struct inode *, uint, uint);
 
-int flags2perm(int flags)
-{
-    int perm = 0;
-    if(flags & 0x1)
-      perm = PTE_X;
-    if(flags & 0x2)
-      perm |= PTE_W;
-    return perm;
+int flags2perm(int flags) {
+	int perm = 0;
+	if (flags & 0x1)
+		perm = PTE_X;
+	if (flags & 0x2)
+		perm |= PTE_W;
+	return perm;
 }
 
-int
-exec(char *path, char **argv)
-{
-  char *s, *last;
-  int i, off;
-  uint64 argc, sz = 0, sp, ustack[MAXARG], stackbase;
-  struct elfhdr elf;
-  struct inode *ip;
-  struct proghdr ph;
-  pagetable_t pagetable = 0, oldpagetable;
-  struct proc *p = myproc();
+int exec(char *path, char **argv) {
+	char *s, *last;
+	int i, off;
+	uint64 argc, sz = 0, sp, ustack[MAXARG], stackbase;
+	struct elfhdr elf;
+	struct inode *ip;
+	struct proghdr ph;
+	pagetable_t pagetable = 0, oldpagetable;
+	struct proc *p = myproc();
 
-  begin_op();
+	begin_op();
 
-  if((ip = namei(path)) == 0){
-    end_op();
-    return -1;
-  }
-  ilock(ip);
+	if ((ip = namei(path)) == 0) {
+		end_op();
+		return -1;
+	}
+	ilock(ip);
 
-  // Check ELF header
-  if(readi(ip, 0, (uint64)&elf, 0, sizeof(elf)) != sizeof(elf))
-    goto bad;
+	// Check ELF header
+	if (readi(ip, 0, (uint64)&elf, 0, sizeof(elf)) != sizeof(elf))
+		goto bad;
 
-  if(elf.magic != ELF_MAGIC)
-    goto bad;
+	if (elf.magic != ELF_MAGIC)
+		goto bad;
 
-  if((pagetable = proc_pagetable(p)) == 0)
-    goto bad;
+	if ((pagetable = proc_pagetable(p)) == 0)
+		goto bad;
 
-  // Load program into memory.
-  for(i=0, off=elf.phoff; i<elf.phnum; i++, off+=sizeof(ph)){
-    if(readi(ip, 0, (uint64)&ph, off, sizeof(ph)) != sizeof(ph))
-      goto bad;
-    if(ph.type != ELF_PROG_LOAD)
-      continue;
-    if(ph.memsz < ph.filesz)
-      goto bad;
-    if(ph.vaddr + ph.memsz < ph.vaddr)
-      goto bad;
-    if(ph.vaddr % PGSIZE != 0)
-      goto bad;
-    uint64 sz1;
-    if((sz1 = uvmalloc(pagetable, sz, ph.vaddr + ph.memsz, flags2perm(ph.flags))) == 0)
-      goto bad;
-    sz = sz1;
-    if(loadseg(pagetable, ph.vaddr, ip, ph.off, ph.filesz) < 0)
-      goto bad;
-  }
-  iunlockput(ip);
-  end_op();
-  ip = 0;
+	// Load program into memory.
+	for (i = 0, off = elf.phoff; i < elf.phnum; i++, off += sizeof(ph)) {
+		if (readi(ip, 0, (uint64)&ph, off, sizeof(ph)) != sizeof(ph))
+			goto bad;
+		if (ph.type != ELF_PROG_LOAD)
+			continue;
+		if (ph.memsz < ph.filesz)
+			goto bad;
+		if (ph.vaddr + ph.memsz < ph.vaddr)
+			goto bad;
+		if (ph.vaddr % PGSIZE != 0)
+			goto bad;
+		uint64 sz1;
+		if ((sz1 = uvmalloc(pagetable, sz, ph.vaddr + ph.memsz,
+							flags2perm(ph.flags))) == 0)
+			goto bad;
+		sz = sz1;
+		if (loadseg(pagetable, ph.vaddr, ip, ph.off, ph.filesz) < 0)
+			goto bad;
+	}
+	iunlockput(ip);
+	end_op();
+	ip = 0;
 
-  p = myproc();
-  uint64 oldsz = p->sz;
+	p = myproc();
+	uint64 oldsz = p->sz;
 
-  // Allocate two pages at the next page boundary.
-  // Make the first inaccessible as a stack guard.
-  // Use the second as the user stack.
-  sz = PGROUNDUP(sz);
-  uint64 sz1;
-  if((sz1 = uvmalloc(pagetable, sz, sz + 2*PGSIZE, PTE_W)) == 0)
-    goto bad;
-  sz = sz1;
-  uvmclear(pagetable, sz-2*PGSIZE);
-  sp = sz;
-  stackbase = sp - PGSIZE;
+	// Allocate two pages at the next page boundary.
+	// Make the first inaccessible as a stack guard.
+	// Use the second as the user stack.
+	sz = PGROUNDUP(sz);
+	uint64 sz1;
+	if ((sz1 = uvmalloc(pagetable, sz, sz + 2 * PGSIZE, PTE_W)) == 0)
+		goto bad;
+	sz = sz1;
+	uvmclear(pagetable, sz - 2 * PGSIZE);
+	sp = sz;
+	stackbase = sp - PGSIZE;
 
-  // Push argument strings, prepare rest of stack in ustack.
-  for(argc = 0; argv[argc]; argc++) {
-    if(argc >= MAXARG)
-      goto bad;
-    sp -= strlen(argv[argc]) + 1;
-    sp -= sp % 16; // riscv sp must be 16-byte aligned
-    if(sp < stackbase)
-      goto bad;
-    if(copyout(pagetable, sp, argv[argc], strlen(argv[argc]) + 1) < 0)
-      goto bad;
-    ustack[argc] = sp;
-  }
-  ustack[argc] = 0;
+	// Push argument strings, prepare rest of stack in ustack.
+	for (argc = 0; argv[argc]; argc++) {
+		if (argc >= MAXARG)
+			goto bad;
+		sp -= strlen(argv[argc]) + 1;
+		sp -= sp % 16; // riscv sp must be 16-byte aligned
+		if (sp < stackbase)
+			goto bad;
+		if (copyout(pagetable, sp, argv[argc], strlen(argv[argc]) + 1) < 0)
+			goto bad;
+		ustack[argc] = sp;
+	}
+	ustack[argc] = 0;
 
-  // push the array of argv[] pointers.
-  sp -= (argc+1) * sizeof(uint64);
-  sp -= sp % 16;
-  if(sp < stackbase)
-    goto bad;
-  if(copyout(pagetable, sp, (char *)ustack, (argc+1)*sizeof(uint64)) < 0)
-    goto bad;
+	// push the array of argv[] pointers.
+	sp -= (argc + 1) * sizeof(uint64);
+	sp -= sp % 16;
+	if (sp < stackbase)
+		goto bad;
+	if (copyout(pagetable, sp, (char *)ustack, (argc + 1) * sizeof(uint64)) < 0)
+		goto bad;
 
-  // arguments to user main(argc, argv)
-  // argc is returned via the system call return
-  // value, which goes in a0.
-  p->trapframe->a1 = sp;
+	// arguments to user main(argc, argv)
+	// argc is returned via the system call return
+	// value, which goes in a0.
+	p->trapframe->a1 = sp;
 
-  // Save program name for debugging.
-  for(last=s=path; *s; s++)
-    if(*s == '/')
-      last = s+1;
-  safestrcpy(p->name, last, sizeof(p->name));
-    
-  // Commit to the user image.
-  oldpagetable = p->pagetable;
-  p->pagetable = pagetable;
-  p->sz = sz;
-  p->trapframe->epc = elf.entry;  // initial program counter = main
-  p->trapframe->sp = sp; // initial stack pointer
-  proc_freepagetable(oldpagetable, oldsz);
+	// Save program name for debugging.
+	for (last = s = path; *s; s++)
+		if (*s == '/')
+			last = s + 1;
+	safestrcpy(p->name, last, sizeof(p->name));
 
-  return argc; // this ends up in a0, the first argument to main(argc, argv)
+	// Commit to the user image.
+	oldpagetable = p->pagetable;
+	p->pagetable = pagetable;
+	p->sz = sz;
+	p->trapframe->epc = elf.entry; // initial program counter = main
+	p->trapframe->sp = sp;		   // initial stack pointer
+	proc_freepagetable(oldpagetable, oldsz);
 
- bad:
-  if(pagetable)
-    proc_freepagetable(pagetable, sz);
-  if(ip){
-    iunlockput(ip);
-    end_op();
-  }
-  return -1;
+	return argc; // this ends up in a0, the first argument to main(argc, argv)
+
+bad:
+	if (pagetable)
+		proc_freepagetable(pagetable, sz);
+	if (ip) {
+		iunlockput(ip);
+		end_op();
+	}
+	return -1;
 }
 
 // Load a program segment into pagetable at virtual address va.
 // va must be page-aligned
 // and the pages from va to va+sz must already be mapped.
 // Returns 0 on success, -1 on failure.
-static int
-loadseg(pagetable_t pagetable, uint64 va, struct inode *ip, uint offset, uint sz)
-{
-  uint i, n;
-  uint64 pa;
+static int loadseg(pagetable_t pagetable, uint64 va, struct inode *ip,
+				   uint offset, uint sz) {
+	uint i, n;
+	uint64 pa;
 
-  for(i = 0; i < sz; i += PGSIZE){
-    pa = walkaddr(pagetable, va + i);
-    if(pa == 0)
-      panic("loadseg: address should exist");
-    if(sz - i < PGSIZE)
-      n = sz - i;
-    else
-      n = PGSIZE;
-    if(readi(ip, 0, (uint64)pa, offset+i, n) != n)
-      return -1;
-  }
-  
-  return 0;
+	for (i = 0; i < sz; i += PGSIZE) {
+		pa = walkaddr(pagetable, va + i);
+		if (pa == 0)
+			panic("loadseg: address should exist");
+		if (sz - i < PGSIZE)
+			n = sz - i;
+		else
+			n = PGSIZE;
+		if (readi(ip, 0, (uint64)pa, offset + i, n) != n)
+			return -1;
+	}
+
+	return 0;
 }

kernel/file.c

@@ -15,168 +15,151 @@
 
 struct devsw devsw[NDEV];
 struct {
-  struct spinlock lock;
-  struct file file[NFILE];
+	struct spinlock lock;
+	struct file file[NFILE];
 } ftable;
 
-void
-fileinit(void)
-{
-  initlock(&ftable.lock, "ftable");
-}
+void fileinit(void) { initlock(&ftable.lock, "ftable"); }
 
 // Allocate a file structure.
-struct file*
-filealloc(void)
-{
-  struct file *f;
+struct file *filealloc(void) {
+	struct file *f;
 
-  acquire(&ftable.lock);
-  for(f = ftable.file; f < ftable.file + NFILE; f++){
-    if(f->ref == 0){
-      f->ref = 1;
-      release(&ftable.lock);
-      return f;
-    }
-  }
-  release(&ftable.lock);
-  return 0;
+	acquire(&ftable.lock);
+	for (f = ftable.file; f < ftable.file + NFILE; f++) {
+		if (f->ref == 0) {
+			f->ref = 1;
+			release(&ftable.lock);
+			return f;
+		}
+	}
+	release(&ftable.lock);
+	return 0;
 }
 
 // Increment ref count for file f.
-struct file*
-filedup(struct file *f)
-{
-  acquire(&ftable.lock);
-  if(f->ref < 1)
-    panic("filedup");
-  f->ref++;
-  release(&ftable.lock);
-  return f;
+struct file *filedup(struct file *f) {
+	acquire(&ftable.lock);
+	if (f->ref < 1)
+		panic("filedup");
+	f->ref++;
+	release(&ftable.lock);
+	return f;
 }
 
 // Close file f.  (Decrement ref count, close when reaches 0.)
-void
-fileclose(struct file *f)
-{
-  struct file ff;
+void fileclose(struct file *f) {
+	struct file ff;
 
-  acquire(&ftable.lock);
-  if(f->ref < 1)
-    panic("fileclose");
-  if(--f->ref > 0){
-    release(&ftable.lock);
-    return;
-  }
-  ff = *f;
-  f->ref = 0;
-  f->type = FD_NONE;
-  release(&ftable.lock);
+	acquire(&ftable.lock);
+	if (f->ref < 1)
+		panic("fileclose");
+	if (--f->ref > 0) {
+		release(&ftable.lock);
+		return;
+	}
+	ff = *f;
+	f->ref = 0;
+	f->type = FD_NONE;
+	release(&ftable.lock);
 
-  if(ff.type == FD_PIPE){
-    pipeclose(ff.pipe, ff.writable);
-  } else if(ff.type == FD_INODE || ff.type == FD_DEVICE){
-    begin_op();
-    iput(ff.ip);
-    end_op();
-  }
+	if (ff.type == FD_PIPE) {
+		pipeclose(ff.pipe, ff.writable);
+	} else if (ff.type == FD_INODE || ff.type == FD_DEVICE) {
+		begin_op();
+		iput(ff.ip);
+		end_op();
+	}
 }
 
 // Get metadata about file f.
 // addr is a user virtual address, pointing to a struct stat.
-int
-filestat(struct file *f, uint64 addr)
-{
-  struct proc *p = myproc();
-  struct stat st;
-  
-  if(f->type == FD_INODE || f->type == FD_DEVICE){
-    ilock(f->ip);
-    stati(f->ip, &st);
-    iunlock(f->ip);
-    if(copyout(p->pagetable, addr, (char *)&st, sizeof(st)) < 0)
-      return -1;
-    return 0;
-  }
-  return -1;
+int filestat(struct file *f, uint64 addr) {
+	struct proc *p = myproc();
+	struct stat st;
+
+	if (f->type == FD_INODE || f->type == FD_DEVICE) {
+		ilock(f->ip);
+		stati(f->ip, &st);
+		iunlock(f->ip);
+		if (copyout(p->pagetable, addr, (char *)&st, sizeof(st)) < 0)
+			return -1;
+		return 0;
+	}
+	return -1;
 }
 
 // Read from file f.
 // addr is a user virtual address.
-int
-fileread(struct file *f, uint64 addr, int n)
-{
-  int r = 0;
+int fileread(struct file *f, uint64 addr, int n) {
+	int r = 0;
 
-  if(f->readable == 0)
-    return -1;
+	if (f->readable == 0)
+		return -1;
 
-  if(f->type == FD_PIPE){
-    r = piperead(f->pipe, addr, n);
-  } else if(f->type == FD_DEVICE){
-    if(f->major < 0 || f->major >= NDEV || !devsw[f->major].read)
-      return -1;
-    r = devsw[f->major].read(1, addr, n);
-  } else if(f->type == FD_INODE){
-    ilock(f->ip);
-    if((r = readi(f->ip, 1, addr, f->off, n)) > 0)
-      f->off += r;
-    iunlock(f->ip);
-  } else {
-    panic("fileread");
-  }
+	if (f->type == FD_PIPE) {
+		r = piperead(f->pipe, addr, n);
+	} else if (f->type == FD_DEVICE) {
+		if (f->major < 0 || f->major >= NDEV || !devsw[f->major].read)
+			return -1;
+		r = devsw[f->major].read(1, addr, n);
+	} else if (f->type == FD_INODE) {
+		ilock(f->ip);
+		if ((r = readi(f->ip, 1, addr, f->off, n)) > 0)
+			f->off += r;
+		iunlock(f->ip);
+	} else {
+		panic("fileread");
+	}
 
-  return r;
+	return r;
 }
 
 // Write to file f.
 // addr is a user virtual address.
-int
-filewrite(struct file *f, uint64 addr, int n)
-{
-  int r, ret = 0;
+int filewrite(struct file *f, uint64 addr, int n) {
+	int r, ret = 0;
 
-  if(f->writable == 0)
-    return -1;
+	if (f->writable == 0)
+		return -1;
 
-  if(f->type == FD_PIPE){
-    ret = pipewrite(f->pipe, addr, n);
-  } else if(f->type == FD_DEVICE){
-    if(f->major < 0 || f->major >= NDEV || !devsw[f->major].write)
-      return -1;
-    ret = devsw[f->major].write(1, addr, n);
-  } else if(f->type == FD_INODE){
-    // write a few blocks at a time to avoid exceeding
-    // the maximum log transaction size, including
-    // i-node, indirect block, allocation blocks,
-    // and 2 blocks of slop for non-aligned writes.
-    // this really belongs lower down, since writei()
-    // might be writing a device like the console.
-    int max = ((MAXOPBLOCKS-1-1-2) / 2) * BSIZE;
-    int i = 0;
-    while(i < n){
-      int n1 = n - i;
-      if(n1 > max)
-        n1 = max;
+	if (f->type == FD_PIPE) {
+		ret = pipewrite(f->pipe, addr, n);
+	} else if (f->type == FD_DEVICE) {
+		if (f->major < 0 || f->major >= NDEV || !devsw[f->major].write)
+			return -1;
+		ret = devsw[f->major].write(1, addr, n);
+	} else if (f->type == FD_INODE) {
+		// write a few blocks at a time to avoid exceeding
+		// the maximum log transaction size, including
+		// i-node, indirect block, allocation blocks,
+		// and 2 blocks of slop for non-aligned writes.
+		// this really belongs lower down, since writei()
+		// might be writing a device like the console.
+		int max = ((MAXOPBLOCKS - 1 - 1 - 2) / 2) * BSIZE;
+		int i = 0;
+		while (i < n) {
+			int n1 = n - i;
+			if (n1 > max)
+				n1 = max;
 
-      begin_op();
-      ilock(f->ip);
-      if ((r = writei(f->ip, 1, addr + i, f->off, n1)) > 0)
-        f->off += r;
-      iunlock(f->ip);
-      end_op();
+			begin_op();
+			ilock(f->ip);
+			if ((r = writei(f->ip, 1, addr + i, f->off, n1)) > 0)
+				f->off += r;
+			iunlock(f->ip);
+			end_op();
 
-      if(r != n1){
-        // error from writei
-        break;
-      }
-      i += r;
-    }
-    ret = (i == n ? n : -1);
-  } else {
-    panic("filewrite");
-  }
+			if (r != n1) {
+				// error from writei
+				break;
+			}
+			i += r;
+		}
+		ret = (i == n ? n : -1);
+	} else {
+		panic("filewrite");
+	}
 
-  return ret;
+	return ret;
 }
-

kernel/fs.c

@@ -24,84 +24,75 @@
 #define min(a, b) ((a) < (b) ? (a) : (b))
 // there should be one superblock per disk device, but we run with
 // only one device
-struct superblock sb; 
+struct superblock sb;
 
 // Read the super block.
-static void
-readsb(int dev, struct superblock *sb)
-{
-  struct buf *bp;
+static void readsb(int dev, struct superblock *sb) {
+	struct buf *bp;
 
-  bp = bread(dev, 1);
-  memmove(sb, bp->data, sizeof(*sb));
-  brelse(bp);
+	bp = bread(dev, 1);
+	memmove(sb, bp->data, sizeof(*sb));
+	brelse(bp);
 }
 
 // Init fs
-void
-fsinit(int dev) {
-  readsb(dev, &sb);
-  if(sb.magic != FSMAGIC)
-    panic("invalid file system");
-  initlog(dev, &sb);
+void fsinit(int dev) {
+	readsb(dev, &sb);
+	if (sb.magic != FSMAGIC)
+		panic("invalid file system");
+	initlog(dev, &sb);
 }
 
 // Zero a block.
-static void
-bzero(int dev, int bno)
-{
-  struct buf *bp;
+static void bzero(int dev, int bno) {
+	struct buf *bp;
 
-  bp = bread(dev, bno);
-  memset(bp->data, 0, BSIZE);
-  log_write(bp);
-  brelse(bp);
+	bp = bread(dev, bno);
+	memset(bp->data, 0, BSIZE);
+	log_write(bp);
+	brelse(bp);
 }
 
 // Blocks.
 
 // Allocate a zeroed disk block.
 // returns 0 if out of disk space.
-static uint
-balloc(uint dev)
-{
-  int b, bi, m;
-  struct buf *bp;
+static uint balloc(uint dev) {
+	int b, bi, m;
+	struct buf *bp;
 
-  bp = 0;
-  for(b = 0; b < sb.size; b += BPB){
-    bp = bread(dev, BBLOCK(b, sb));
-    for(bi = 0; bi < BPB && b + bi < sb.size; bi++){
-      m = 1 << (bi % 8);
-      if((bp->data[bi/8] & m) == 0){  // Is block free?
-        bp->data[bi/8] |= m;  // Mark block in use.
-        log_write(bp);
-        brelse(bp);
-        bzero(dev, b + bi);
-        return b + bi;
-      }
-    }
-    brelse(bp);
-  }
-  printf("balloc: out of blocks\n");
-  return 0;
+	bp = 0;
+	for (b = 0; b < sb.size; b += BPB) {
+		bp = bread(dev, BBLOCK(b, sb));
+		for (bi = 0; bi < BPB && b + bi < sb.size; bi++) {
+			m = 1 << (bi % 8);
+			if ((bp->data[bi / 8] & m) == 0) { // Is block free?
+				bp->data[bi / 8] |= m;		   // Mark block in use.
+				log_write(bp);
+				brelse(bp);
+				bzero(dev, b + bi);
+				return b + bi;
+			}
+		}
+		brelse(bp);
+	}
+	printf("balloc: out of blocks\n");
+	return 0;
 }
 
 // Free a disk block.
-static void
-bfree(int dev, uint b)
-{
-  struct buf *bp;
-  int bi, m;
+static void bfree(int dev, uint b) {
+	struct buf *bp;
+	int bi, m;
 
-  bp = bread(dev, BBLOCK(b, sb));
-  bi = b % BPB;
-  m = 1 << (bi % 8);
-  if((bp->data[bi/8] & m) == 0)
-    panic("freeing free block");
-  bp->data[bi/8] &= ~m;
-  log_write(bp);
-  brelse(bp);
+	bp = bread(dev, BBLOCK(b, sb));
+	bi = b % BPB;
+	m = 1 << (bi % 8);
+	if ((bp->data[bi / 8] & m) == 0)
+		panic("freeing free block");
+	bp->data[bi / 8] &= ~m;
+	log_write(bp);
+	brelse(bp);
 }
 
 // Inodes.
@@ -174,156 +165,142 @@ bfree(int dev, uint b)
 // read or write that inode's ip->valid, ip->size, ip->type, &c.
 
 struct {
-  struct spinlock lock;
-  struct inode inode[NINODE];
+	struct spinlock lock;
+	struct inode inode[NINODE];
 } itable;
 
-void
-iinit()
-{
-  int i = 0;
-  
-  initlock(&itable.lock, "itable");
-  for(i = 0; i < NINODE; i++) {
-    initsleeplock(&itable.inode[i].lock, "inode");
-  }
+void iinit() {
+	int i = 0;
+
+	initlock(&itable.lock, "itable");
+	for (i = 0; i < NINODE; i++) {
+		initsleeplock(&itable.inode[i].lock, "inode");
+	}
 }
 
-static struct inode* iget(uint dev, uint inum);
+static struct inode *iget(uint dev, uint inum);
 
 // Allocate an inode on device dev.
 // Mark it as allocated by  giving it type type.
 // Returns an unlocked but allocated and referenced inode,
-// or NULL if there is no free inode..
-struct inode*
-ialloc(uint dev, short type)
-{
-  int inum;
-  struct buf *bp;
-  struct dinode *dip;
+// or NULL if there is no free inode.
+struct inode *ialloc(uint dev, short type) {
+	int inum;
+	struct buf *bp;
+	struct dinode *dip;
 
-  for(inum = 1; inum < sb.ninodes; inum++){
-    bp = bread(dev, IBLOCK(inum, sb));
-    dip = (struct dinode*)bp->data + inum%IPB;
-    if(dip->type == 0){  // a free inode
-      memset(dip, 0, sizeof(*dip));
-      dip->type = type;
-      log_write(bp);   // mark it allocated on the disk
-      brelse(bp);
-      return iget(dev, inum);
-    }
-    brelse(bp);
-  }
-  printf("ialloc: no inodes\n");
-  return 0;
+	for (inum = 1; inum < sb.ninodes; inum++) {
+		bp = bread(dev, IBLOCK(inum, sb));
+		dip = (struct dinode *)bp->data + inum % IPB;
+		if (dip->type == 0) { // a free inode
+			memset(dip, 0, sizeof(*dip));
+			dip->type = type;
+			log_write(bp); // mark it allocated on the disk
+			brelse(bp);
+			return iget(dev, inum);
+		}
+		brelse(bp);
+	}
+	printf("ialloc: no inodes\n");
+	return 0;
 }
 
 // Copy a modified in-memory inode to disk.
 // Must be called after every change to an ip->xxx field
 // that lives on disk.
 // Caller must hold ip->lock.
-void
-iupdate(struct inode *ip)
-{
-  struct buf *bp;
-  struct dinode *dip;
+void iupdate(struct inode *ip) {
+	struct buf *bp;
+	struct dinode *dip;
 
-  bp = bread(ip->dev, IBLOCK(ip->inum, sb));
-  dip = (struct dinode*)bp->data + ip->inum%IPB;
-  dip->type = ip->type;
-  dip->major = ip->major;
-  dip->minor = ip->minor;
-  dip->nlink = ip->nlink;
-  dip->size = ip->size;
-  memmove(dip->addrs, ip->addrs, sizeof(ip->addrs));
-  log_write(bp);
-  brelse(bp);
+	bp = bread(ip->dev, IBLOCK(ip->inum, sb));
+	dip = (struct dinode *)bp->data + ip->inum % IPB;
+	dip->type = ip->type;
+	dip->major = ip->major;
+	dip->minor = ip->minor;
+	dip->nlink = ip->nlink;
+	dip->size = ip->size;
+	memmove(dip->addrs, ip->addrs, sizeof(ip->addrs));
+	log_write(bp);
+	brelse(bp);
 }
 
 // Find the inode with number inum on device dev
 // and return the in-memory copy. Does not lock
 // the inode and does not read it from disk.
-static struct inode*
-iget(uint dev, uint inum)
-{
-  struct inode *ip, *empty;
+static struct inode *iget(uint dev, uint inum) {
+	struct inode *ip, *empty;
 
-  acquire(&itable.lock);
+	acquire(&itable.lock);
 
-  // Is the inode already in the table?
-  empty = 0;
-  for(ip = &itable.inode[0]; ip < &itable.inode[NINODE]; ip++){
-    if(ip->ref > 0 && ip->dev == dev && ip->inum == inum){
-      ip->ref++;
-      release(&itable.lock);
-      return ip;
-    }
-    if(empty == 0 && ip->ref == 0)    // Remember empty slot.
-      empty = ip;
-  }
+	// Is the inode already in the table?
+	empty = 0;
+	for (ip = &itable.inode[0]; ip < &itable.inode[NINODE]; ip++) {
+		if (ip->ref > 0 && ip->dev == dev && ip->inum == inum) {
+			ip->ref++;
+			release(&itable.lock);
+			return ip;
+		}
+		if (empty == 0 && ip->ref == 0) // Remember empty slot.
+			empty = ip;
+	}
 
-  // Recycle an inode entry.
-  if(empty == 0)
-    panic("iget: no inodes");
+	// Recycle an inode entry.
+	if (empty == 0)
+		panic("iget: no inodes");
 
-  ip = empty;
-  ip->dev = dev;
-  ip->inum = inum;
-  ip->ref = 1;
-  ip->valid = 0;
-  release(&itable.lock);
+	ip = empty;
+	ip->dev = dev;
+	ip->inum = inum;
+	ip->ref = 1;
+	ip->valid = 0;
+	release(&itable.lock);
 
-  return ip;
+	return ip;
 }
 
 // Increment reference count for ip.
 // Returns ip to enable ip = idup(ip1) idiom.
-struct inode*
-idup(struct inode *ip)
-{
-  acquire(&itable.lock);
-  ip->ref++;
-  release(&itable.lock);
-  return ip;
+struct inode *idup(struct inode *ip) {
+	acquire(&itable.lock);
+	ip->ref++;
+	release(&itable.lock);
+	return ip;
 }
 
 // Lock the given inode.
 // Reads the inode from disk if necessary.
-void
-ilock(struct inode *ip)
-{
-  struct buf *bp;
-  struct dinode *dip;
+void ilock(struct inode *ip) {
+	struct buf *bp;
+	struct dinode *dip;
 
-  if(ip == 0 || ip->ref < 1)
-    panic("ilock");
+	if (ip == 0 || ip->ref < 1)
+		panic("ilock");
 
-  acquiresleep(&ip->lock);
+	acquiresleep(&ip->lock);
 
-  if(ip->valid == 0){
-    bp = bread(ip->dev, IBLOCK(ip->inum, sb));
-    dip = (struct dinode*)bp->data + ip->inum%IPB;
-    ip->type = dip->type;
-    ip->major = dip->major;
-    ip->minor = dip->minor;
-    ip->nlink = dip->nlink;
-    ip->size = dip->size;
-    memmove(ip->addrs, dip->addrs, sizeof(ip->addrs));
-    brelse(bp);
-    ip->valid = 1;
-    if(ip->type == 0)
-      panic("ilock: no type");
-  }
+	if (ip->valid == 0) {
+		bp = bread(ip->dev, IBLOCK(ip->inum, sb));
+		dip = (struct dinode *)bp->data + ip->inum % IPB;
+		ip->type = dip->type;
+		ip->major = dip->major;
+		ip->minor = dip->minor;
+		ip->nlink = dip->nlink;
+		ip->size = dip->size;
+		memmove(ip->addrs, dip->addrs, sizeof(ip->addrs));
+		brelse(bp);
+		ip->valid = 1;
+		if (ip->type == 0)
+			panic("ilock: no type");
+	}
 }
 
 // Unlock the given inode.
-void
-iunlock(struct inode *ip)
-{
-  if(ip == 0 || !holdingsleep(&ip->lock) || ip->ref < 1)
-    panic("iunlock");
+void iunlock(struct inode *ip) {
+	if (ip == 0 || !holdingsleep(&ip->lock) || ip->ref < 1)
+		panic("iunlock");
 
-  releasesleep(&ip->lock);
+	releasesleep(&ip->lock);
 }
 
 // Drop a reference to an in-memory inode.
@@ -333,40 +310,36 @@ iunlock(struct inode *ip)
 // to it, free the inode (and its content) on disk.
 // All calls to iput() must be inside a transaction in
 // case it has to free the inode.
-void
-iput(struct inode *ip)
-{
-  acquire(&itable.lock);
+void iput(struct inode *ip) {
+	acquire(&itable.lock);
 
-  if(ip->ref == 1 && ip->valid && ip->nlink == 0){
-    // inode has no links and no other references: truncate and free.
+	if (ip->ref == 1 && ip->valid && ip->nlink == 0) {
+		// inode has no links and no other references: truncate and free.
 
-    // ip->ref == 1 means no other process can have ip locked,
-    // so this acquiresleep() won't block (or deadlock).
-    acquiresleep(&ip->lock);
+		// ip->ref == 1 means no other process can have ip locked,
+		// so this acquiresleep() won't block (or deadlock).
+		acquiresleep(&ip->lock);
 
-    release(&itable.lock);
+		release(&itable.lock);
 
-    itrunc(ip);
-    ip->type = 0;
-    iupdate(ip);
-    ip->valid = 0;
+		itrunc(ip);
+		ip->type = 0;
+		iupdate(ip);
+		ip->valid = 0;
 
-    releasesleep(&ip->lock);
+		releasesleep(&ip->lock);
 
-    acquire(&itable.lock);
-  }
+		acquire(&itable.lock);
+	}
 
-  ip->ref--;
-  release(&itable.lock);
+	ip->ref--;
+	release(&itable.lock);
 }
 
 // Common idiom: unlock, then put.
-void
-iunlockput(struct inode *ip)
-{
-  iunlock(ip);
-  iput(ip);
+void iunlockput(struct inode *ip) {
+	iunlock(ip);
+	iput(ip);
 }
 
 // Inode content
@@ -379,120 +352,112 @@ iunlockput(struct inode *ip)
 // Return the disk block address of the nth block in inode ip.
 // If there is no such block, bmap allocates one.
 // returns 0 if out of disk space.
-static uint
-bmap(struct inode *ip, uint bn)
-{
-  uint addr, *a;
-  struct buf *bp;
+static uint bmap(struct inode *ip, uint bn) {
+	uint addr, *a;
+	struct buf *bp;
 
-  if(bn < NDIRECT){
-    if((addr = ip->addrs[bn]) == 0){
-      addr = balloc(ip->dev);
-      if(addr == 0)
-        return 0;
-      ip->addrs[bn] = addr;
-    }
-    return addr;
-  }
-  bn -= NDIRECT;
+	if (bn < NDIRECT) {
+		if ((addr = ip->addrs[bn]) == 0) {
+			addr = balloc(ip->dev);
+			if (addr == 0)
+				return 0;
+			ip->addrs[bn] = addr;
+		}
+		return addr;
+	}
+	bn -= NDIRECT;
 
-  if(bn < NINDIRECT){
-    // Load indirect block, allocating if necessary.
-    if((addr = ip->addrs[NDIRECT]) == 0){
-      addr = balloc(ip->dev);
-      if(addr == 0)
-        return 0;
-      ip->addrs[NDIRECT] = addr;
-    }
-    bp = bread(ip->dev, addr);
-    a = (uint*)bp->data;
-    if((addr = a[bn]) == 0){
-      addr = balloc(ip->dev);
-      if(addr){
-        a[bn] = addr;
-        log_write(bp);
-      }
-    }
-    brelse(bp);
-    return addr;
-  }
+	if (bn < NINDIRECT) {
+		// Load indirect block, allocating if necessary.
+		if ((addr = ip->addrs[NDIRECT]) == 0) {
+			addr = balloc(ip->dev);
+			if (addr == 0)
+				return 0;
+			ip->addrs[NDIRECT] = addr;
+		}
+		bp = bread(ip->dev, addr);
+		a = (uint *)bp->data;
+		if ((addr = a[bn]) == 0) {
+			addr = balloc(ip->dev);
+			if (addr) {
+				a[bn] = addr;
+				log_write(bp);
+			}
+		}
+		brelse(bp);
+		return addr;
+	}
 
-  panic("bmap: out of range");
+	panic("bmap: out of range");
 }
 
 // Truncate inode (discard contents).
 // Caller must hold ip->lock.
-void
-itrunc(struct inode *ip)
-{
-  int i, j;
-  struct buf *bp;
-  uint *a;
+void itrunc(struct inode *ip) {
+	int i, j;
+	struct buf *bp;
+	uint *a;
 
-  for(i = 0; i < NDIRECT; i++){
-    if(ip->addrs[i]){
-      bfree(ip->dev, ip->addrs[i]);
-      ip->addrs[i] = 0;
-    }
-  }
+	for (i = 0; i < NDIRECT; i++) {
+		if (ip->addrs[i]) {
+			bfree(ip->dev, ip->addrs[i]);
+			ip->addrs[i] = 0;
+		}
+	}
 
-  if(ip->addrs[NDIRECT]){
-    bp = bread(ip->dev, ip->addrs[NDIRECT]);
-    a = (uint*)bp->data;
-    for(j = 0; j < NINDIRECT; j++){
-      if(a[j])
-        bfree(ip->dev, a[j]);
-    }
-    brelse(bp);
-    bfree(ip->dev, ip->addrs[NDIRECT]);
-    ip->addrs[NDIRECT] = 0;
-  }
+	if (ip->addrs[NDIRECT]) {
+		bp = bread(ip->dev, ip->addrs[NDIRECT]);
+		a = (uint *)bp->data;
+		for (j = 0; j < NINDIRECT; j++) {
+			if (a[j])
+				bfree(ip->dev, a[j]);
+		}
+		brelse(bp);
+		bfree(ip->dev, ip->addrs[NDIRECT]);
+		ip->addrs[NDIRECT] = 0;
+	}
 
-  ip->size = 0;
-  iupdate(ip);
+	ip->size = 0;
+	iupdate(ip);
 }
 
 // Copy stat information from inode.
 // Caller must hold ip->lock.
-void
-stati(struct inode *ip, struct stat *st)
-{
-  st->dev = ip->dev;
-  st->ino = ip->inum;
-  st->type = ip->type;
-  st->nlink = ip->nlink;
-  st->size = ip->size;
+void stati(struct inode *ip, struct stat *st) {
+	st->dev = ip->dev;
+	st->ino = ip->inum;
+	st->type = ip->type;
+	st->nlink = ip->nlink;
+	st->size = ip->size;
 }
 
 // Read data from inode.
 // Caller must hold ip->lock.
 // If user_dst==1, then dst is a user virtual address;
 // otherwise, dst is a kernel address.
-int
-readi(struct inode *ip, int user_dst, uint64 dst, uint off, uint n)
-{
-  uint tot, m;
-  struct buf *bp;
+int readi(struct inode *ip, int user_dst, uint64 dst, uint off, uint n) {
+	uint tot, m;
+	struct buf *bp;
 
-  if(off > ip->size || off + n < off)
-    return 0;
-  if(off + n > ip->size)
-    n = ip->size - off;
+	if (off > ip->size || off + n < off)
+		return 0;
+	if (off + n > ip->size)
+		n = ip->size - off;
 
-  for(tot=0; tot<n; tot+=m, off+=m, dst+=m){
-    uint addr = bmap(ip, off/BSIZE);
-    if(addr == 0)
-      break;
-    bp = bread(ip->dev, addr);
-    m = min(n - tot, BSIZE - off%BSIZE);
-    if(either_copyout(user_dst, dst, bp->data + (off % BSIZE), m) == -1) {
-      brelse(bp);
-      tot = -1;
-      break;
-    }
-    brelse(bp);
-  }
-  return tot;
+	for (tot = 0; tot < n; tot += m, off += m, dst += m) {
+		uint addr = bmap(ip, off / BSIZE);
+		if (addr == 0)
+			break;
+		bp = bread(ip->dev, addr);
+		m = min(n - tot, BSIZE - off % BSIZE);
+		if (either_copyout(user_dst, dst, bp->data + (off % BSIZE), m) == -1) {
+			brelse(bp);
+			tot = -1;
+			break;
+		}
+		brelse(bp);
+	}
+	return tot;
 }
 
 // Write data to inode.
@@ -502,107 +467,97 @@ readi(struct inode *ip, int user_dst, uint64 dst, uint off, uint n)
 // Returns the number of bytes successfully written.
 // If the return value is less than the requested n,
 // there was an error of some kind.
-int
-writei(struct inode *ip, int user_src, uint64 src, uint off, uint n)
-{
-  uint tot, m;
-  struct buf *bp;
+int writei(struct inode *ip, int user_src, uint64 src, uint off, uint n) {
+	uint tot, m;
+	struct buf *bp;
 
-  if(off > ip->size || off + n < off)
-    return -1;
-  if(off + n > MAXFILE*BSIZE)
-    return -1;
+	if (off > ip->size || off + n < off)
+		return -1;
+	if (off + n > MAXFILE * BSIZE)
+		return -1;
 
-  for(tot=0; tot<n; tot+=m, off+=m, src+=m){
-    uint addr = bmap(ip, off/BSIZE);
-    if(addr == 0)
-      break;
-    bp = bread(ip->dev, addr);
-    m = min(n - tot, BSIZE - off%BSIZE);
-    if(either_copyin(bp->data + (off % BSIZE), user_src, src, m) == -1) {
-      brelse(bp);
-      break;
-    }
-    log_write(bp);
-    brelse(bp);
-  }
+	for (tot = 0; tot < n; tot += m, off += m, src += m) {
+		uint addr = bmap(ip, off / BSIZE);
+		if (addr == 0)
+			break;
+		bp = bread(ip->dev, addr);
+		m = min(n - tot, BSIZE - off % BSIZE);
+		if (either_copyin(bp->data + (off % BSIZE), user_src, src, m) == -1) {
+			brelse(bp);
+			break;
+		}
+		log_write(bp);
+		brelse(bp);
+	}
 
-  if(off > ip->size)
-    ip->size = off;
+	if (off > ip->size)
+		ip->size = off;
 
-  // write the i-node back to disk even if the size didn't change
-  // because the loop above might have called bmap() and added a new
-  // block to ip->addrs[].
-  iupdate(ip);
+	// write the i-node back to disk even if the size didn't change
+	// because the loop above might have called bmap() and added a new
+	// block to ip->addrs[].
+	iupdate(ip);
 
-  return tot;
+	return tot;
 }
 
 // Directories
 
-int
-namecmp(const char *s, const char *t)
-{
-  return strncmp(s, t, DIRSIZ);
-}
+int namecmp(const char *s, const char *t) { return strncmp(s, t, DIRSIZ); }
 
 // Look for a directory entry in a directory.
 // If found, set *poff to byte offset of entry.
-struct inode*
-dirlookup(struct inode *dp, char *name, uint *poff)
-{
-  uint off, inum;
-  struct dirent de;
+struct inode *dirlookup(struct inode *dp, char *name, uint *poff) {
+	uint off, inum;
+	struct dirent de;
 
-  if(dp->type != T_DIR)
-    panic("dirlookup not DIR");
+	if (dp->type != T_DIR)
+		panic("dirlookup not DIR");
 
-  for(off = 0; off < dp->size; off += sizeof(de)){
-    if(readi(dp, 0, (uint64)&de, off, sizeof(de)) != sizeof(de))
-      panic("dirlookup read");
-    if(de.inum == 0)
-      continue;
-    if(namecmp(name, de.name) == 0){
-      // entry matches path element
-      if(poff)
-        *poff = off;
-      inum = de.inum;
-      return iget(dp->dev, inum);
-    }
-  }
+	for (off = 0; off < dp->size; off += sizeof(de)) {
+		if (readi(dp, 0, (uint64)&de, off, sizeof(de)) != sizeof(de))
+			panic("dirlookup read");
+		if (de.inum == 0)
+			continue;
+		if (namecmp(name, de.name) == 0) {
+			// entry matches path element
+			if (poff)
+				*poff = off;
+			inum = de.inum;
+			return iget(dp->dev, inum);
+		}
+	}
 
-  return 0;
+	return 0;
 }
 
 // Write a new directory entry (name, inum) into the directory dp.
 // Returns 0 on success, -1 on failure (e.g. out of disk blocks).
-int
-dirlink(struct inode *dp, char *name, uint inum)
-{
-  int off;
-  struct dirent de;
-  struct inode *ip;
+int dirlink(struct inode *dp, char *name, uint inum) {
+	int off;
+	struct dirent de;
+	struct inode *ip;
 
-  // Check that name is not present.
-  if((ip = dirlookup(dp, name, 0)) != 0){
-    iput(ip);
-    return -1;
-  }
+	// Check that name is not present.
+	if ((ip = dirlookup(dp, name, 0)) != 0) {
+		iput(ip);
+		return -1;
+	}
 
-  // Look for an empty dirent.
-  for(off = 0; off < dp->size; off += sizeof(de)){
-    if(readi(dp, 0, (uint64)&de, off, sizeof(de)) != sizeof(de))
-      panic("dirlink read");
-    if(de.inum == 0)
-      break;
-  }
+	// Look for an empty dirent.
+	for (off = 0; off < dp->size; off += sizeof(de)) {
+		if (readi(dp, 0, (uint64)&de, off, sizeof(de)) != sizeof(de))
+			panic("dirlink read");
+		if (de.inum == 0)
+			break;
+	}
 
-  strncpy(de.name, name, DIRSIZ);
-  de.inum = inum;
-  if(writei(dp, 0, (uint64)&de, off, sizeof(de)) != sizeof(de))
-    return -1;
+	strncpy(de.name, name, DIRSIZ);
+	de.inum = inum;
+	if (writei(dp, 0, (uint64)&de, off, sizeof(de)) != sizeof(de))
+		return -1;
 
-  return 0;
+	return 0;
 }
 
 // Paths
@@ -619,79 +574,71 @@ dirlink(struct inode *dp, char *name, uint inum)
 //   skipelem("a", name) = "", setting name = "a"
 //   skipelem("", name) = skipelem("////", name) = 0
 //
-static char*
-skipelem(char *path, char *name)
-{
-  char *s;
-  int len;
+static char *skipelem(char *path, char *name) {
+	char *s;
+	int len;
 
-  while(*path == '/')
-    path++;
-  if(*path == 0)
-    return 0;
-  s = path;
-  while(*path != '/' && *path != 0)
-    path++;
-  len = path - s;
-  if(len >= DIRSIZ)
-    memmove(name, s, DIRSIZ);
-  else {
-    memmove(name, s, len);
-    name[len] = 0;
-  }
-  while(*path == '/')
-    path++;
-  return path;
+	while (*path == '/')
+		path++;
+	if (*path == 0)
+		return 0;
+	s = path;
+	while (*path != '/' && *path != 0)
+		path++;
+	len = path - s;
+	if (len >= DIRSIZ)
+		memmove(name, s, DIRSIZ);
+	else {
+		memmove(name, s, len);
+		name[len] = 0;
+	}
+	while (*path == '/')
+		path++;
+	return path;
 }
 
 // Look up and return the inode for a path name.
 // If parent != 0, return the inode for the parent and copy the final
 // path element into name, which must have room for DIRSIZ bytes.
 // Must be called inside a transaction since it calls iput().
-static struct inode*
-namex(char *path, int nameiparent, char *name)
-{
-  struct inode *ip, *next;
+static struct inode *namex(char *path, int nameiparent, char *name) {
+	struct inode *ip, *next;
 
-  if(*path == '/')
-    ip = iget(ROOTDEV, ROOTINO);
-  else
-    ip = idup(myproc()->cwd);
+	if (*path == '/')
+		ip = iget(ROOTDEV, ROOTINO);
+	else
+		ip = idup(myproc()->cwd);
 
-  while((path = skipelem(path, name)) != 0){
-    ilock(ip);
-    if(ip->type != T_DIR){
-      iunlockput(ip);
-      return 0;
-    }
-    if(nameiparent && *path == '\0'){
-      // Stop one level early.
-      iunlock(ip);
-      return ip;
-    }
-    if((next = dirlookup(ip, name, 0)) == 0){
-      iunlockput(ip);
-      return 0;
-    }
-    iunlockput(ip);
-    ip = next;
-  }
-  if(nameiparent){
-    iput(ip);
-    return 0;
-  }
-  return ip;
+	while ((path = skipelem(path, name)) != 0) {
+		ilock(ip);
+		if (ip->type != T_DIR) {
+			iunlockput(ip);
+			return 0;
+		}
+		if (nameiparent && *path == '\0') {
+			// Stop one level early.
+			iunlock(ip);
+			return ip;
+		}
+		if ((next = dirlookup(ip, name, 0)) == 0) {
+			iunlockput(ip);
+			return 0;
+		}
+		iunlockput(ip);
+		ip = next;
+	}
+	if (nameiparent) {
+		iput(ip);
+		return 0;
+	}
+	return ip;
 }
 
-struct inode*
-namei(char *path)
-{
-  char name[DIRSIZ];
-  return namex(path, 0, name);
+struct inode *namei(char *path) {
+	char name[DIRSIZ];
+	return namex(path, 0, name);
 }
 
-struct inode*
-nameiparent(char *path, char *name)
-{
-  return namex(path, 1, name);
+struct inode *nameiparent(char *path, char *name) {
+	return namex(path, 1, name);
 }

kernel/kalloc.c

@@ -12,71 +12,63 @@
 void freerange(void *pa_start, void *pa_end);
 
 extern char end[]; // first address after kernel.
-                   // defined by kernel.ld.
+				   // defined by kernel.ld.
 
 struct run {
-  struct run *next;
+	struct run *next;
 };
 
 struct {
-  struct spinlock lock;
-  struct run *freelist;
+	struct spinlock lock;
+	struct run *freelist;
 } kmem;
 
-void
-kinit()
-{
-  initlock(&kmem.lock, "kmem");
-  freerange(end, (void*)PHYSTOP);
+void kinit() {
+	initlock(&kmem.lock, "kmem");
+	freerange(end, (void *)PHYSTOP);
 }
 
-void
-freerange(void *pa_start, void *pa_end)
-{
-  char *p;
-  p = (char*)PGROUNDUP((uint64)pa_start);
-  for(; p + PGSIZE <= (char*)pa_end; p += PGSIZE)
-    kfree(p);
+void freerange(void *pa_start, void *pa_end) {
+	char *p;
+	p = (char *)PGROUNDUP((uint64)pa_start);
+	for (; p + PGSIZE <= (char *)pa_end; p += PGSIZE)
+		kfree(p);
 }
 
 // Free the page of physical memory pointed at by pa,
 // which normally should have been returned by a
 // call to kalloc().  (The exception is when
 // initializing the allocator; see kinit above.)
-void
-kfree(void *pa)
-{
-  struct run *r;
+void kfree(void *pa) {
+	struct run *r;
 
-  if(((uint64)pa % PGSIZE) != 0 || (char*)pa < end || (uint64)pa >= PHYSTOP)
-    panic("kfree");
+	if (((uint64)pa % PGSIZE) != 0 || (char *)pa < end || (uint64)pa >= PHYSTOP)
+		panic("kfree");
 
-  // Fill with junk to catch dangling refs.
-  memset(pa, 1, PGSIZE);
+	// Fill with junk to catch dangling refs.
+	memset(pa, 1, PGSIZE);
 
-  r = (struct run*)pa;
+	r = (struct run *)pa;
 
-  acquire(&kmem.lock);
-  r->next = kmem.freelist;
-  kmem.freelist = r;
-  release(&kmem.lock);
+	acquire(&kmem.lock);
+	r->next = kmem.freelist;
+	kmem.freelist = r;
+	release(&kmem.lock);
 }
 
 // Allocate one 4096-byte page of physical memory.
 // Returns a pointer that the kernel can use.
 // Returns 0 if the memory cannot be allocated.
-void *
-kalloc(void)
-{
-  struct run *r;
+void *kalloc(void) {
+	struct run *r;
 
-  acquire(&kmem.lock);
-  r = kmem.freelist;
-  if(r)
-    kmem.freelist = r->next;
-  release(&kmem.lock);
+	acquire(&kmem.lock);
+	r = kmem.freelist;
+	if (r)
+		kmem.freelist = r->next;
+	release(&kmem.lock);
 
-  if(r)
-    memset((char*)r, 5, PGSIZE); // fill with junk
-  return (void*)r;
+	if (r)
+		memset((char *)r, 5, PGSIZE); // fill with junk
+	return (void *)r;
 }

kernel/log.c

@@ -33,173 +33,156 @@
 // Contents of the header block, used for both the on-disk header block
 // and to keep track in memory of logged block# before commit.
 struct logheader {
-  int n;
-  int block[LOGSIZE];
+	int n;
+	int block[LOGSIZE];
 };
 
 struct log {
-  struct spinlock lock;
-  int start;
-  int size;
-  int outstanding; // how many FS sys calls are executing.
-  int committing;  // in commit(), please wait.
-  int dev;
-  struct logheader lh;
+	struct spinlock lock;
+	int start;
+	int size;
+	int outstanding; // how many FS sys calls are executing.
+	int committing;	 // in commit(), please wait.
+	int dev;
+	struct logheader lh;
 };
 struct log log;
 
 static void recover_from_log(void);
 static void commit();
 
-void
-initlog(int dev, struct superblock *sb)
-{
-  if (sizeof(struct logheader) >= BSIZE)
-    panic("initlog: too big logheader");
+void initlog(int dev, struct superblock *sb) {
+	if (sizeof(struct logheader) >= BSIZE)
+		panic("initlog: too big logheader");
 
-  initlock(&log.lock, "log");
-  log.start = sb->logstart;
-  log.size = sb->nlog;
-  log.dev = dev;
-  recover_from_log();
+	initlock(&log.lock, "log");
+	log.start = sb->logstart;
+	log.size = sb->nlog;
+	log.dev = dev;
+	recover_from_log();
 }
 
 // Copy committed blocks from log to their home location
-static void
-install_trans(int recovering)
-{
-  int tail;
+static void install_trans(int recovering) {
+	int tail;
 
-  for (tail = 0; tail < log.lh.n; tail++) {
-    struct buf *lbuf = bread(log.dev, log.start+tail+1); // read log block
-    struct buf *dbuf = bread(log.dev, log.lh.block[tail]); // read dst
-    memmove(dbuf->data, lbuf->data, BSIZE);  // copy block to dst
-    bwrite(dbuf);  // write dst to disk
-    if(recovering == 0)
-      bunpin(dbuf);
-    brelse(lbuf);
-    brelse(dbuf);
-  }
+	for (tail = 0; tail < log.lh.n; tail++) {
+		struct buf *lbuf =
+			bread(log.dev, log.start + tail + 1);			   // read log block
+		struct buf *dbuf = bread(log.dev, log.lh.block[tail]); // read dst
+		memmove(dbuf->data, lbuf->data, BSIZE); // copy block to dst
+		bwrite(dbuf);							// write dst to disk
+		if (recovering == 0)
+			bunpin(dbuf);
+		brelse(lbuf);
+		brelse(dbuf);
+	}
 }
 
 // Read the log header from disk into the in-memory log header
-static void
-read_head(void)
-{
-  struct buf *buf = bread(log.dev, log.start);
-  struct logheader *lh = (struct logheader *) (buf->data);
-  int i;
-  log.lh.n = lh->n;
-  for (i = 0; i < log.lh.n; i++) {
-    log.lh.block[i] = lh->block[i];
-  }
-  brelse(buf);
+static void read_head(void) {
+	struct buf *buf = bread(log.dev, log.start);
+	struct logheader *lh = (struct logheader *)(buf->data);
+	int i;
+	log.lh.n = lh->n;
+	for (i = 0; i < log.lh.n; i++) {
+		log.lh.block[i] = lh->block[i];
+	}
+	brelse(buf);
 }
 
 // Write in-memory log header to disk.
 // This is the true point at which the
 // current transaction commits.
-static void
-write_head(void)
-{
-  struct buf *buf = bread(log.dev, log.start);
-  struct logheader *hb = (struct logheader *) (buf->data);
-  int i;
-  hb->n = log.lh.n;
-  for (i = 0; i < log.lh.n; i++) {
-    hb->block[i] = log.lh.block[i];
-  }
-  bwrite(buf);
-  brelse(buf);
+static void write_head(void) {
+	struct buf *buf = bread(log.dev, log.start);
+	struct logheader *hb = (struct logheader *)(buf->data);
+	int i;
+	hb->n = log.lh.n;
+	for (i = 0; i < log.lh.n; i++) {
+		hb->block[i] = log.lh.block[i];
+	}
+	bwrite(buf);
+	brelse(buf);
 }
 
-static void
-recover_from_log(void)
-{
-  read_head();
-  install_trans(1); // if committed, copy from log to disk
-  log.lh.n = 0;
-  write_head(); // clear the log
+static void recover_from_log(void) {
+	read_head();
+	install_trans(1); // if committed, copy from log to disk
+	log.lh.n = 0;
+	write_head(); // clear the log
 }
 
 // called at the start of each FS system call.
-void
-begin_op(void)
-{
-  acquire(&log.lock);
-  while(1){
-    if(log.committing){
-      sleep(&log, &log.lock);
-    } else if(log.lh.n + (log.outstanding+1)*MAXOPBLOCKS > LOGSIZE){
-      // this op might exhaust log space; wait for commit.
-      sleep(&log, &log.lock);
-    } else {
-      log.outstanding += 1;
-      release(&log.lock);
-      break;
-    }
-  }
+void begin_op(void) {
+	acquire(&log.lock);
+	while (1) {
+		if (log.committing) {
+			sleep(&log, &log.lock);
+		} else if (log.lh.n + (log.outstanding + 1) * MAXOPBLOCKS > LOGSIZE) {
+			// this op might exhaust log space; wait for commit.
+			sleep(&log, &log.lock);
+		} else {
+			log.outstanding += 1;
+			release(&log.lock);
+			break;
+		}
+	}
 }
 
 // called at the end of each FS system call.
 // commits if this was the last outstanding operation.
-void
-end_op(void)
-{
-  int do_commit = 0;
+void end_op(void) {
+	int do_commit = 0;
 
-  acquire(&log.lock);
-  log.outstanding -= 1;
-  if(log.committing)
-    panic("log.committing");
-  if(log.outstanding == 0){
-    do_commit = 1;
-    log.committing = 1;
-  } else {
-    // begin_op() may be waiting for log space,
-    // and decrementing log.outstanding has decreased
-    // the amount of reserved space.
-    wakeup(&log);
-  }
-  release(&log.lock);
+	acquire(&log.lock);
+	log.outstanding -= 1;
+	if (log.committing)
+		panic("log.committing");
+	if (log.outstanding == 0) {
+		do_commit = 1;
+		log.committing = 1;
+	} else {
+		// begin_op() may be waiting for log space,
+		// and decrementing log.outstanding has decreased
+		// the amount of reserved space.
+		wakeup(&log);
+	}
+	release(&log.lock);
 
-  if(do_commit){
-    // call commit w/o holding locks, since not allowed
-    // to sleep with locks.
-    commit();
-    acquire(&log.lock);
-    log.committing = 0;
-    wakeup(&log);
-    release(&log.lock);
-  }
+	if (do_commit) {
+		// call commit w/o holding locks, since not allowed
+		// to sleep with locks.
+		commit();
+		acquire(&log.lock);
+		log.committing = 0;
+		wakeup(&log);
+		release(&log.lock);
+	}
 }
 
 // Copy modified blocks from cache to log.
-static void
-write_log(void)
-{
-  int tail;
+static void write_log(void) {
+	int tail;
 
-  for (tail = 0; tail < log.lh.n; tail++) {
-    struct buf *to = bread(log.dev, log.start+tail+1); // log block
-    struct buf *from = bread(log.dev, log.lh.block[tail]); // cache block
-    memmove(to->data, from->data, BSIZE);
-    bwrite(to);  // write the log
-    brelse(from);
-    brelse(to);
-  }
+	for (tail = 0; tail < log.lh.n; tail++) {
+		struct buf *to = bread(log.dev, log.start + tail + 1); // log block
+		struct buf *from = bread(log.dev, log.lh.block[tail]); // cache block
+		memmove(to->data, from->data, BSIZE);
+		bwrite(to); // write the log
+		brelse(from);
+		brelse(to);
+	}
 }
 
-static void
-commit()
-{
-  if (log.lh.n > 0) {
-    write_log();     // Write modified blocks from cache to log
-    write_head();    // Write header to disk -- the real commit
-    install_trans(0); // Now install writes to home locations
-    log.lh.n = 0;
-    write_head();    // Erase the transaction from the log
-  }
+static void commit() {
+	if (log.lh.n > 0) {
+		write_log();	  // Write modified blocks from cache to log
+		write_head();	  // Write header to disk -- the real commit
+		install_trans(0); // Now install writes to home locations
+		log.lh.n = 0;
+		write_head(); // Erase the transaction from the log
+	}
 }
 
 // Caller has modified b->data and is done with the buffer.
@@ -211,26 +194,23 @@ commit()
 //   modify bp->data[]
 //   log_write(bp)
 //   brelse(bp)
-void
-log_write(struct buf *b)
-{
-  int i;
+void log_write(struct buf *b) {
+	int i;
 
-  acquire(&log.lock);
-  if (log.lh.n >= LOGSIZE || log.lh.n >= log.size - 1)
-    panic("too big a transaction");
-  if (log.outstanding < 1)
-    panic("log_write outside of trans");
+	acquire(&log.lock);
+	if (log.lh.n >= LOGSIZE || log.lh.n >= log.size - 1)
+		panic("too big a transaction");
+	if (log.outstanding < 1)
+		panic("log_write outside of trans");
 
-  for (i = 0; i < log.lh.n; i++) {
-    if (log.lh.block[i] == b->blockno)   // log absorption
-      break;
-  }
-  log.lh.block[i] = b->blockno;
-  if (i == log.lh.n) {  // Add new block to log?
-    bpin(b);
-    log.lh.n++;
-  }
-  release(&log.lock);
+	for (i = 0; i < log.lh.n; i++) {
+		if (log.lh.block[i] == b->blockno) // log absorption
+			break;
+	}
+	log.lh.block[i] = b->blockno;
+	if (i == log.lh.n) { // Add new block to log?
+		bpin(b);
+		log.lh.n++;
+	}
+	release(&log.lock);
 }
-

kernel/main.c

@@ -3,43 +3,46 @@
 #include "memlayout.h"
 #include "riscv.h"
 #include "defs.h"
+#include <stdint.h>
+
+extern int32_t add(int32_t right, int32_t left);
 
 volatile static int started = 0;
 
 // start() jumps here in supervisor mode on all CPUs.
-void
-main()
-{
-  if(cpuid() == 0){
-    consoleinit();
-    printfinit();
-    printf("\n");
-    printf("xv6 kernel is booting\n");
-    printf("\n");
-    kinit();         // physical page allocator
-    kvminit();       // create kernel page table
-    kvminithart();   // turn on paging
-    procinit();      // process table
-    trapinit();      // trap vectors
-    trapinithart();  // install kernel trap vector
-    plicinit();      // set up interrupt controller
-    plicinithart();  // ask PLIC for device interrupts
-    binit();         // buffer cache
-    iinit();         // inode table
-    fileinit();      // file table
-    virtio_disk_init(); // emulated hard disk
-    userinit();      // first user process
-    __sync_synchronize();
-    started = 1;
-  } else {
-    while(started == 0)
-      ;
-    __sync_synchronize();
-    printf("hart %d starting\n", cpuid());
-    kvminithart();    // turn on paging
-    trapinithart();   // install kernel trap vector
-    plicinithart();   // ask PLIC for device interrupts
-  }
+void main() {
+	if (cpuid() == 0) {
+		consoleinit();
+		printfinit();
+		printf("\n");
+		printf("xv6 kernel is booting\n");
+		printf("\n");
+		printf("rust library call: add(1, 2) = %d\n", add(1, 2));
+		printf("\n");
+		kinit();			// physical page allocator
+		kvminit();			// create kernel page table
+		kvminithart();		// turn on paging
+		procinit();			// process table
+		trapinit();			// trap vectors
+		trapinithart();		// install kernel trap vector
+		plicinit();			// set up interrupt controller
+		plicinithart();		// ask PLIC for device interrupts
+		binit();			// buffer cache
+		iinit();			// inode table
+		fileinit();			// file table
+		virtio_disk_init(); // emulated hard disk
+		userinit();			// first user process
+		__sync_synchronize();
+		started = 1;
+	} else {
+		while (started == 0)
+			;
+		__sync_synchronize();
+		printf("hart %d starting\n", cpuid());
+		kvminithart();	// turn on paging
+		trapinithart(); // install kernel trap vector
+		plicinithart(); // ask PLIC for device interrupts
+	}
 
-  scheduler();        
+	scheduler();
 }

kernel/pipe.c

@@ -11,120 +11,112 @@
 #define PIPESIZE 512
 
 struct pipe {
-  struct spinlock lock;
-  char data[PIPESIZE];
-  uint nread;     // number of bytes read
-  uint nwrite;    // number of bytes written
-  int readopen;   // read fd is still open
-  int writeopen;  // write fd is still open
+	struct spinlock lock;
+	char data[PIPESIZE];
+	uint nread;	   // number of bytes read
+	uint nwrite;   // number of bytes written
+	int readopen;  // read fd is still open
+	int writeopen; // write fd is still open
 };
 
-int
-pipealloc(struct file **f0, struct file **f1)
-{
-  struct pipe *pi;
+int pipealloc(struct file **f0, struct file **f1) {
+	struct pipe *pi;
 
-  pi = 0;
-  *f0 = *f1 = 0;
-  if((*f0 = filealloc()) == 0 || (*f1 = filealloc()) == 0)
-    goto bad;
-  if((pi = (struct pipe*)kalloc()) == 0)
-    goto bad;
-  pi->readopen = 1;
-  pi->writeopen = 1;
-  pi->nwrite = 0;
-  pi->nread = 0;
-  initlock(&pi->lock, "pipe");
-  (*f0)->type = FD_PIPE;
-  (*f0)->readable = 1;
-  (*f0)->writable = 0;
-  (*f0)->pipe = pi;
-  (*f1)->type = FD_PIPE;
-  (*f1)->readable = 0;
-  (*f1)->writable = 1;
-  (*f1)->pipe = pi;
-  return 0;
+	pi = 0;
+	*f0 = *f1 = 0;
+	if ((*f0 = filealloc()) == 0 || (*f1 = filealloc()) == 0)
+		goto bad;
+	if ((pi = (struct pipe *)kalloc()) == 0)
+		goto bad;
+	pi->readopen = 1;
+	pi->writeopen = 1;
+	pi->nwrite = 0;
+	pi->nread = 0;
+	initlock(&pi->lock, "pipe");
+	(*f0)->type = FD_PIPE;
+	(*f0)->readable = 1;
+	(*f0)->writable = 0;
+	(*f0)->pipe = pi;
+	(*f1)->type = FD_PIPE;
+	(*f1)->readable = 0;
+	(*f1)->writable = 1;
+	(*f1)->pipe = pi;
+	return 0;
 
- bad:
-  if(pi)
-    kfree((char*)pi);
-  if(*f0)
-    fileclose(*f0);
-  if(*f1)
-    fileclose(*f1);
-  return -1;
+bad:
+	if (pi)
+		kfree((char *)pi);
+	if (*f0)
+		fileclose(*f0);
+	if (*f1)
+		fileclose(*f1);
+	return -1;
 }
 
-void
-pipeclose(struct pipe *pi, int writable)
-{
-  acquire(&pi->lock);
-  if(writable){
-    pi->writeopen = 0;
-    wakeup(&pi->nread);
-  } else {
-    pi->readopen = 0;
-    wakeup(&pi->nwrite);
-  }
-  if(pi->readopen == 0 && pi->writeopen == 0){
-    release(&pi->lock);
-    kfree((char*)pi);
-  } else
-    release(&pi->lock);
+void pipeclose(struct pipe *pi, int writable) {
+	acquire(&pi->lock);
+	if (writable) {
+		pi->writeopen = 0;
+		wakeup(&pi->nread);
+	} else {
+		pi->readopen = 0;
+		wakeup(&pi->nwrite);
+	}
+	if (pi->readopen == 0 && pi->writeopen == 0) {
+		release(&pi->lock);
+		kfree((char *)pi);
+	} else
+		release(&pi->lock);
 }
 
-int
-pipewrite(struct pipe *pi, uint64 addr, int n)
-{
-  int i = 0;
-  struct proc *pr = myproc();
+int pipewrite(struct pipe *pi, uint64 addr, int n) {
+	int i = 0;
+	struct proc *pr = myproc();
 
-  acquire(&pi->lock);
-  while(i < n){
-    if(pi->readopen == 0 || killed(pr)){
-      release(&pi->lock);
-      return -1;
-    }
-    if(pi->nwrite == pi->nread + PIPESIZE){ //DOC: pipewrite-full
-      wakeup(&pi->nread);
-      sleep(&pi->nwrite, &pi->lock);
-    } else {
-      char ch;
-      if(copyin(pr->pagetable, &ch, addr + i, 1) == -1)
-        break;
-      pi->data[pi->nwrite++ % PIPESIZE] = ch;
-      i++;
-    }
-  }
-  wakeup(&pi->nread);
-  release(&pi->lock);
+	acquire(&pi->lock);
+	while (i < n) {
+		if (pi->readopen == 0 || killed(pr)) {
+			release(&pi->lock);
+			return -1;
+		}
+		if (pi->nwrite == pi->nread + PIPESIZE) { // DOC: pipewrite-full
+			wakeup(&pi->nread);
+			sleep(&pi->nwrite, &pi->lock);
+		} else {
+			char ch;
+			if (copyin(pr->pagetable, &ch, addr + i, 1) == -1)
+				break;
+			pi->data[pi->nwrite++ % PIPESIZE] = ch;
+			i++;
+		}
+	}
+	wakeup(&pi->nread);
+	release(&pi->lock);
 
-  return i;
+	return i;
 }
 
-int
-piperead(struct pipe *pi, uint64 addr, int n)
-{
-  int i;
-  struct proc *pr = myproc();
-  char ch;
+int piperead(struct pipe *pi, uint64 addr, int n) {
+	int i;
+	struct proc *pr = myproc();
+	char ch;
 
-  acquire(&pi->lock);
-  while(pi->nread == pi->nwrite && pi->writeopen){  //DOC: pipe-empty
-    if(killed(pr)){
-      release(&pi->lock);
-      return -1;
-    }
-    sleep(&pi->nread, &pi->lock); //DOC: piperead-sleep
-  }
-  for(i = 0; i < n; i++){  //DOC: piperead-copy
-    if(pi->nread == pi->nwrite)
-      break;
-    ch = pi->data[pi->nread++ % PIPESIZE];
-    if(copyout(pr->pagetable, addr + i, &ch, 1) == -1)
-      break;
-  }
-  wakeup(&pi->nwrite);  //DOC: piperead-wakeup
-  release(&pi->lock);
-  return i;
+	acquire(&pi->lock);
+	while (pi->nread == pi->nwrite && pi->writeopen) { // DOC: pipe-empty
+		if (killed(pr)) {
+			release(&pi->lock);
+			return -1;
+		}
+		sleep(&pi->nread, &pi->lock); // DOC: piperead-sleep
+	}
+	for (i = 0; i < n; i++) { // DOC: piperead-copy
+		if (pi->nread == pi->nwrite)
+			break;
+		ch = pi->data[pi->nread++ % PIPESIZE];
+		if (copyout(pr->pagetable, addr + i, &ch, 1) == -1)
+			break;
+	}
+	wakeup(&pi->nwrite); // DOC: piperead-wakeup
+	release(&pi->lock);
+	return i;
 }

kernel/plic.c

@@ -8,40 +8,32 @@
 // the riscv Platform Level Interrupt Controller (PLIC).
 //
 
-void
-plicinit(void)
-{
-  // set desired IRQ priorities non-zero (otherwise disabled).
-  *(uint32*)(PLIC + UART0_IRQ*4) = 1;
-  *(uint32*)(PLIC + VIRTIO0_IRQ*4) = 1;
+void plicinit(void) {
+	// set desired IRQ priorities non-zero (otherwise disabled).
+	*(uint32 *)(PLIC + UART0_IRQ * 4) = 1;
+	*(uint32 *)(PLIC + VIRTIO0_IRQ * 4) = 1;
 }
 
-void
-plicinithart(void)
-{
-  int hart = cpuid();
-  
-  // set enable bits for this hart's S-mode
-  // for the uart and virtio disk.
-  *(uint32*)PLIC_SENABLE(hart) = (1 << UART0_IRQ) | (1 << VIRTIO0_IRQ);
+void plicinithart(void) {
+	int hart = cpuid();
 
-  // set this hart's S-mode priority threshold to 0.
-  *(uint32*)PLIC_SPRIORITY(hart) = 0;
+	// set enable bits for this hart's S-mode
+	// for the uart and virtio disk.
+	*(uint32 *)PLIC_SENABLE(hart) = (1 << UART0_IRQ) | (1 << VIRTIO0_IRQ);
+
+	// set this hart's S-mode priority threshold to 0.
+	*(uint32 *)PLIC_SPRIORITY(hart) = 0;
 }
 
 // ask the PLIC what interrupt we should serve.
-int
-plic_claim(void)
-{
-  int hart = cpuid();
-  int irq = *(uint32*)PLIC_SCLAIM(hart);
-  return irq;
+int plic_claim(void) {
+	int hart = cpuid();
+	int irq = *(uint32 *)PLIC_SCLAIM(hart);
+	return irq;
 }
 
 // tell the PLIC we've served this IRQ.
-void
-plic_complete(int irq)
-{
-  int hart = cpuid();
-  *(uint32*)PLIC_SCLAIM(hart) = irq;
+void plic_complete(int irq) {
+	int hart = cpuid();
+	*(uint32 *)PLIC_SCLAIM(hart) = irq;
 }

kernel/printf.c

@@ -19,117 +19,107 @@ volatile int panicked = 0;
 
 // lock to avoid interleaving concurrent printf's.
 static struct {
-  struct spinlock lock;
-  int locking;
+	struct spinlock lock;
+	int locking;
 } pr;
 
 static char digits[] = "0123456789abcdef";
 
-static void
-printint(int xx, int base, int sign)
-{
-  char buf[16];
-  int i;
-  uint x;
+static void printint(int xx, int base, int sign) {
+	char buf[16];
+	int i;
+	uint x;
 
-  if(sign && (sign = xx < 0))
-    x = -xx;
-  else
-    x = xx;
+	if (sign && (sign = xx < 0))
+		x = -xx;
+	else
+		x = xx;
 
-  i = 0;
-  do {
-    buf[i++] = digits[x % base];
-  } while((x /= base) != 0);
+	i = 0;
+	do {
+		buf[i++] = digits[x % base];
+	} while ((x /= base) != 0);
 
-  if(sign)
-    buf[i++] = '-';
+	if (sign)
+		buf[i++] = '-';
 
-  while(--i >= 0)
-    consputc(buf[i]);
+	while (--i >= 0)
+		consputc(buf[i]);
 }
 
-static void
-printptr(uint64 x)
-{
-  int i;
-  consputc('0');
-  consputc('x');
-  for (i = 0; i < (sizeof(uint64) * 2); i++, x <<= 4)
-    consputc(digits[x >> (sizeof(uint64) * 8 - 4)]);
+static void printptr(uint64 x) {
+	int i;
+	consputc('0');
+	consputc('x');
+	for (i = 0; i < (sizeof(uint64) * 2); i++, x <<= 4)
+		consputc(digits[x >> (sizeof(uint64) * 8 - 4)]);
 }
 
 // Print to the console. only understands %d, %x, %p, %s.
-void
-printf(char *fmt, ...)
-{
-  va_list ap;
-  int i, c, locking;
-  char *s;
+void printf(char *fmt, ...) {
+	va_list ap;
+	int i, c, locking;
+	char *s;
 
-  locking = pr.locking;
-  if(locking)
-    acquire(&pr.lock);
+	locking = pr.locking;
+	if (locking)
+		acquire(&pr.lock);
 
-  if (fmt == 0)
-    panic("null fmt");
+	if (fmt == 0)
+		panic("null fmt");
 
-  va_start(ap, fmt);
-  for(i = 0; (c = fmt[i] & 0xff) != 0; i++){
-    if(c != '%'){
-      consputc(c);
-      continue;
-    }
-    c = fmt[++i] & 0xff;
-    if(c == 0)
-      break;
-    switch(c){
-    case 'd':
-      printint(va_arg(ap, int), 10, 1);
-      break;
-    case 'x':
-      printint(va_arg(ap, int), 16, 1);
-      break;
-    case 'p':
-      printptr(va_arg(ap, uint64));
-      break;
-    case 's':
-      if((s = va_arg(ap, char*)) == 0)
-        s = "(null)";
-      for(; *s; s++)
-        consputc(*s);
-      break;
-    case '%':
-      consputc('%');
-      break;
-    default:
-      // Print unknown % sequence to draw attention.
-      consputc('%');
-      consputc(c);
-      break;
-    }
-  }
-  va_end(ap);
+	va_start(ap, fmt);
+	for (i = 0; (c = fmt[i] & 0xff) != 0; i++) {
+		if (c != '%') {
+			consputc(c);
+			continue;
+		}
+		c = fmt[++i] & 0xff;
+		if (c == 0)
+			break;
+		switch (c) {
+		case 'd':
+			printint(va_arg(ap, int), 10, 1);
+			break;
+		case 'x':
+			printint(va_arg(ap, int), 16, 1);
+			break;
+		case 'p':
+			printptr(va_arg(ap, uint64));
+			break;
+		case 's':
+			if ((s = va_arg(ap, char *)) == 0)
+				s = "(null)";
+			for (; *s; s++)
+				consputc(*s);
+			break;
+		case '%':
+			consputc('%');
+			break;
+		default:
+			// Print unknown % sequence to draw attention.
+			consputc('%');
+			consputc(c);
+			break;
+		}
+	}
+	va_end(ap);
 
-  if(locking)
-    release(&pr.lock);
+	if (locking)
+		release(&pr.lock);
 }
 
-void
-panic(char *s)
-{
-  pr.locking = 0;
-  printf("panic: ");
-  printf(s);
-  printf("\n");
-  panicked = 1; // freeze uart output from other CPUs
-  for(;;)
-    ;
+void panic(char *s) {
+	pr.locking = 0;
+	printf("panic: ");
+	printf(s);
+	printf("\n");
+	panicked = 1; // freeze uart output from other CPUs
+	for (;;)
+		;
 }
 
-void
-printfinit(void)
-{
-  initlock(&pr.lock, "pr");
-  pr.locking = 1;
+void printfinit(void) {
+	initlock(&pr.lock, "pr");
+	pr.locking = 1;
 }

kernel/ramdisk.c

@@ -12,34 +12,29 @@
 #include "fs.h"
 #include "buf.h"
 
-void
-ramdiskinit(void)
-{
-}
+void ramdiskinit(void) {}
 
 // If B_DIRTY is set, write buf to disk, clear B_DIRTY, set B_VALID.
 // Else if B_VALID is not set, read buf from disk, set B_VALID.
-void
-ramdiskrw(struct buf *b)
-{
-  if(!holdingsleep(&b->lock))
-    panic("ramdiskrw: buf not locked");
-  if((b->flags & (B_VALID|B_DIRTY)) == B_VALID)
-    panic("ramdiskrw: nothing to do");
+void ramdiskrw(struct buf *b) {
+	if (!holdingsleep(&b->lock))
+		panic("ramdiskrw: buf not locked");
+	if ((b->flags & (B_VALID | B_DIRTY)) == B_VALID)
+		panic("ramdiskrw: nothing to do");
 
-  if(b->blockno >= FSSIZE)
-    panic("ramdiskrw: blockno too big");
+	if (b->blockno >= FSSIZE)
+		panic("ramdiskrw: blockno too big");
 
-  uint64 diskaddr = b->blockno * BSIZE;
-  char *addr = (char *)RAMDISK + diskaddr;
+	uint64 diskaddr = b->blockno * BSIZE;
+	char *addr = (char *)RAMDISK + diskaddr;
 
-  if(b->flags & B_DIRTY){
-    // write
-    memmove(addr, b->data, BSIZE);
-    b->flags &= ~B_DIRTY;
-  } else {
-    // read
-    memmove(b->data, addr, BSIZE);
-    b->flags |= B_VALID;
-  }
+	if (b->flags & B_DIRTY) {
+		// write
+		memmove(addr, b->data, BSIZE);
+		b->flags &= ~B_DIRTY;
+	} else {
+		// read
+		memmove(b->data, addr, BSIZE);
+		b->flags |= B_VALID;
+	}
 }

kernel/sleeplock.c

@@ -9,47 +9,36 @@
 #include "proc.h"
 #include "sleeplock.h"
 
-void
-initsleeplock(struct sleeplock *lk, char *name)
-{
-  initlock(&lk->lk, "sleep lock");
-  lk->name = name;
-  lk->locked = 0;
-  lk->pid = 0;
+void initsleeplock(struct sleeplock *lk, char *name) {
+	initlock(&lk->lk, "sleep lock");
+	lk->name = name;
+	lk->locked = 0;
+	lk->pid = 0;
 }
 
-void
-acquiresleep(struct sleeplock *lk)
-{
-  acquire(&lk->lk);
-  while (lk->locked) {
-    sleep(lk, &lk->lk);
-  }
-  lk->locked = 1;
-  lk->pid = myproc()->pid;
-  release(&lk->lk);
+void acquiresleep(struct sleeplock *lk) {
+	acquire(&lk->lk);
+	while (lk->locked) {
+		sleep(lk, &lk->lk);
+	}
+	lk->locked = 1;
+	lk->pid = myproc()->pid;
+	release(&lk->lk);
 }
 
-void
-releasesleep(struct sleeplock *lk)
-{
-  acquire(&lk->lk);
-  lk->locked = 0;
-  lk->pid = 0;
-  wakeup(lk);
-  release(&lk->lk);
+void releasesleep(struct sleeplock *lk) {
+	acquire(&lk->lk);
+	lk->locked = 0;
+	lk->pid = 0;
+	wakeup(lk);
+	release(&lk->lk);
 }
 
-int
-holdingsleep(struct sleeplock *lk)
-{
-  int r;
-  
-  acquire(&lk->lk);
-  r = lk->locked && (lk->pid == myproc()->pid);
-  release(&lk->lk);
-  return r;
+int holdingsleep(struct sleeplock *lk) {
+	int r;
+
+	acquire(&lk->lk);
+	r = lk->locked && (lk->pid == myproc()->pid);
+	release(&lk->lk);
+	return r;
 }
-
-
-

kernel/spinlock.c

@@ -8,103 +8,91 @@
 #include "proc.h"
 #include "defs.h"
 
-void
-initlock(struct spinlock *lk, char *name)
-{
-  lk->name = name;
-  lk->locked = 0;
-  lk->cpu = 0;
+void initlock(struct spinlock *lk, char *name) {
+	lk->name = name;
+	lk->locked = 0;
+	lk->cpu = 0;
 }
 
 // Acquire the lock.
 // Loops (spins) until the lock is acquired.
-void
-acquire(struct spinlock *lk)
-{
-  push_off(); // disable interrupts to avoid deadlock.
-  if(holding(lk))
-    panic("acquire");
+void acquire(struct spinlock *lk) {
+	push_off(); // disable interrupts to avoid deadlock.
+	if (holding(lk))
+		panic("acquire");
 
-  // On RISC-V, sync_lock_test_and_set turns into an atomic swap:
-  //   a5 = 1
-  //   s1 = &lk->locked
-  //   amoswap.w.aq a5, a5, (s1)
-  while(__sync_lock_test_and_set(&lk->locked, 1) != 0)
-    ;
+	// On RISC-V, sync_lock_test_and_set turns into an atomic swap:
+	//   a5 = 1
+	//   s1 = &lk->locked
+	//   amoswap.w.aq a5, a5, (s1)
+	while (__sync_lock_test_and_set(&lk->locked, 1) != 0)
+		;
 
-  // Tell the C compiler and the processor to not move loads or stores
-  // past this point, to ensure that the critical section's memory
-  // references happen strictly after the lock is acquired.
-  // On RISC-V, this emits a fence instruction.
-  __sync_synchronize();
+	// Tell the C compiler and the processor to not move loads or stores
+	// past this point, to ensure that the critical section's memory
+	// references happen strictly after the lock is acquired.
+	// On RISC-V, this emits a fence instruction.
+	__sync_synchronize();
 
-  // Record info about lock acquisition for holding() and debugging.
-  lk->cpu = mycpu();
+	// Record info about lock acquisition for holding() and debugging.
+	lk->cpu = mycpu();
 }
 
 // Release the lock.
-void
-release(struct spinlock *lk)
-{
-  if(!holding(lk))
-    panic("release");
+void release(struct spinlock *lk) {
+	if (!holding(lk))
+		panic("release");
 
-  lk->cpu = 0;
+	lk->cpu = 0;
 
-  // Tell the C compiler and the CPU to not move loads or stores
-  // past this point, to ensure that all the stores in the critical
-  // section are visible to other CPUs before the lock is released,
-  // and that loads in the critical section occur strictly before
-  // the lock is released.
-  // On RISC-V, this emits a fence instruction.
-  __sync_synchronize();
+	// Tell the C compiler and the CPU to not move loads or stores
+	// past this point, to ensure that all the stores in the critical
+	// section are visible to other CPUs before the lock is released,
+	// and that loads in the critical section occur strictly before
+	// the lock is released.
+	// On RISC-V, this emits a fence instruction.
+	__sync_synchronize();
 
-  // Release the lock, equivalent to lk->locked = 0.
-  // This code doesn't use a C assignment, since the C standard
-  // implies that an assignment might be implemented with
-  // multiple store instructions.
-  // On RISC-V, sync_lock_release turns into an atomic swap:
-  //   s1 = &lk->locked
-  //   amoswap.w zero, zero, (s1)
-  __sync_lock_release(&lk->locked);
+	// Release the lock, equivalent to lk->locked = 0.
+	// This code doesn't use a C assignment, since the C standard
+	// implies that an assignment might be implemented with
+	// multiple store instructions.
+	// On RISC-V, sync_lock_release turns into an atomic swap:
+	//   s1 = &lk->locked
+	//   amoswap.w zero, zero, (s1)
+	__sync_lock_release(&lk->locked);
 
-  pop_off();
+	pop_off();
 }
 
 // Check whether this cpu is holding the lock.
 // Interrupts must be off.
-int
-holding(struct spinlock *lk)
-{
-  int r;
-  r = (lk->locked && lk->cpu == mycpu());
-  return r;
+int holding(struct spinlock *lk) {
+	int r;
+	r = (lk->locked && lk->cpu == mycpu());
+	return r;
 }
 
 // push_off/pop_off are like intr_off()/intr_on() except that they are matched:
 // it takes two pop_off()s to undo two push_off()s.  Also, if interrupts
 // are initially off, then push_off, pop_off leaves them off.
 
-void
-push_off(void)
-{
-  int old = intr_get();
+void push_off(void) {
+	int old = intr_get();
 
-  intr_off();
-  if(mycpu()->noff == 0)
-    mycpu()->intena = old;
-  mycpu()->noff += 1;
+	intr_off();
+	if (mycpu()->noff == 0)
+		mycpu()->intena = old;
+	mycpu()->noff += 1;
 }
 
-void
-pop_off(void)
-{
-  struct cpu *c = mycpu();
-  if(intr_get())
-    panic("pop_off - interruptible");
-  if(c->noff < 1)
-    panic("pop_off");
-  c->noff -= 1;
-  if(c->noff == 0 && c->intena)
-    intr_on();
+void pop_off(void) {
+	struct cpu *c = mycpu();
+	if (intr_get())
+		panic("pop_off - interruptible");
+	if (c->noff < 1)
+		panic("pop_off");
+	c->noff -= 1;
+	if (c->noff == 0 && c->intena)
+		intr_on();
 }

kernel/start.c

@@ -8,7 +8,7 @@ void main();
 void timerinit();
 
 // entry.S needs one stack per CPU.
-__attribute__ ((aligned (16))) char stack0[4096 * NCPU];
+__attribute__((aligned(16))) char stack0[4096 * NCPU];
 
 // a scratch area per CPU for machine-mode timer interrupts.
 uint64 timer_scratch[NCPU][5];
@@ -17,41 +17,39 @@ uint64 timer_scratch[NCPU][5];
 extern void timervec();
 
 // entry.S jumps here in machine mode on stack0.
-void
-start()
-{
-  // set M Previous Privilege mode to Supervisor, for mret.
-  unsigned long x = r_mstatus();
-  x &= ~MSTATUS_MPP_MASK;
-  x |= MSTATUS_MPP_S;
-  w_mstatus(x);
+void start() {
+	// set M Previous Privilege mode to Supervisor, for mret.
+	unsigned long x = r_mstatus();
+	x &= ~MSTATUS_MPP_MASK;
+	x |= MSTATUS_MPP_S;
+	w_mstatus(x);
 
-  // set M Exception Program Counter to main, for mret.
-  // requires gcc -mcmodel=medany
-  w_mepc((uint64)main);
+	// set M Exception Program Counter to main, for mret.
+	// requires gcc -mcmodel=medany
+	w_mepc((uint64)main);
 
-  // disable paging for now.
-  w_satp(0);
+	// disable paging for now.
+	w_satp(0);
 
-  // delegate all interrupts and exceptions to supervisor mode.
-  w_medeleg(0xffff);
-  w_mideleg(0xffff);
-  w_sie(r_sie() | SIE_SEIE | SIE_STIE | SIE_SSIE);
+	// delegate all interrupts and exceptions to supervisor mode.
+	w_medeleg(0xffff);
+	w_mideleg(0xffff);
+	w_sie(r_sie() | SIE_SEIE | SIE_STIE | SIE_SSIE);
 
-  // configure Physical Memory Protection to give supervisor mode
-  // access to all of physical memory.
-  w_pmpaddr0(0x3fffffffffffffull);
-  w_pmpcfg0(0xf);
+	// configure Physical Memory Protection to give supervisor mode
+	// access to all of physical memory.
+	w_pmpaddr0(0x3fffffffffffffull);
+	w_pmpcfg0(0xf);
 
-  // ask for clock interrupts.
-  timerinit();
+	// ask for clock interrupts.
+	timerinit();
 
-  // keep each CPU's hartid in its tp register, for cpuid().
-  int id = r_mhartid();
-  w_tp(id);
+	// keep each CPU's hartid in its tp register, for cpuid().
+	int id = r_mhartid();
+	w_tp(id);
 
-  // switch to supervisor mode and jump to main().
-  asm volatile("mret");
+	// switch to supervisor mode and jump to main().
+	asm volatile("mret");
 }
 
 // arrange to receive timer interrupts.
@@ -59,31 +57,29 @@ start()
 // at timervec in kernelvec.S,
 // which turns them into software interrupts for
 // devintr() in trap.c.
-void
-timerinit()
-{
-  // each CPU has a separate source of timer interrupts.
-  int id = r_mhartid();
+void timerinit() {
+	// each CPU has a separate source of timer interrupts.
+	int id = r_mhartid();
 
-  // ask the CLINT for a timer interrupt.
-  int interval = 1000000; // cycles; about 1/10th second in qemu.
-  *(uint64*)CLINT_MTIMECMP(id) = *(uint64*)CLINT_MTIME + interval;
+	// ask the CLINT for a timer interrupt.
+	int interval = 1000000; // cycles; about 1/10th second in qemu.
+	*(uint64 *)CLINT_MTIMECMP(id) = *(uint64 *)CLINT_MTIME + interval;
 
-  // prepare information in scratch[] for timervec.
-  // scratch[0..2] : space for timervec to save registers.
-  // scratch[3] : address of CLINT MTIMECMP register.
-  // scratch[4] : desired interval (in cycles) between timer interrupts.
-  uint64 *scratch = &timer_scratch[id][0];
-  scratch[3] = CLINT_MTIMECMP(id);
-  scratch[4] = interval;
-  w_mscratch((uint64)scratch);
+	// prepare information in scratch[] for timervec.
+	// scratch[0..2] : space for timervec to save registers.
+	// scratch[3] : address of CLINT MTIMECMP register.
+	// scratch[4] : desired interval (in cycles) between timer interrupts.
+	uint64 *scratch = &timer_scratch[id][0];
+	scratch[3] = CLINT_MTIMECMP(id);
+	scratch[4] = interval;
+	w_mscratch((uint64)scratch);
 
-  // set the machine-mode trap handler.
-  w_mtvec((uint64)timervec);
+	// set the machine-mode trap handler.
+	w_mtvec((uint64)timervec);
 
-  // enable machine-mode interrupts.
-  w_mstatus(r_mstatus() | MSTATUS_MIE);
+	// enable machine-mode interrupts.
+	w_mstatus(r_mstatus() | MSTATUS_MIE);
 
-  // enable machine-mode timer interrupts.
-  w_mie(r_mie() | MIE_MTIE);
+	// enable machine-mode timer interrupts.
+	w_mie(r_mie() | MIE_MTIE);
 }

kernel/string.c

@@ -1,107 +1,90 @@
 #include "types.h"
 
-void*
-memset(void *dst, int c, uint n)
-{
-  char *cdst = (char *) dst;
-  int i;
-  for(i = 0; i < n; i++){
-    cdst[i] = c;
-  }
-  return dst;
+void *memset(void *dst, int c, uint n) {
+	char *cdst = (char *)dst;
+	int i;
+	for (i = 0; i < n; i++) {
+		cdst[i] = c;
+	}
+	return dst;
 }
 
-int
-memcmp(const void *v1, const void *v2, uint n)
-{
-  const uchar *s1, *s2;
+int memcmp(const void *v1, const void *v2, uint n) {
+	const uchar *s1, *s2;
 
-  s1 = v1;
-  s2 = v2;
-  while(n-- > 0){
-    if(*s1 != *s2)
-      return *s1 - *s2;
-    s1++, s2++;
-  }
+	s1 = v1;
+	s2 = v2;
+	while (n-- > 0) {
+		if (*s1 != *s2)
+			return *s1 - *s2;
+		s1++, s2++;
+	}
 
-  return 0;
+	return 0;
 }
 
-void*
-memmove(void *dst, const void *src, uint n)
-{
-  const char *s;
-  char *d;
+void *memmove(void *dst, const void *src, uint n) {
+	const char *s;
+	char *d;
 
-  if(n == 0)
-    return dst;
-  
-  s = src;
-  d = dst;
-  if(s < d && s + n > d){
-    s += n;
-    d += n;
-    while(n-- > 0)
-      *--d = *--s;
-  } else
-    while(n-- > 0)
-      *d++ = *s++;
+	if (n == 0)
+		return dst;
 
-  return dst;
+	s = src;
+	d = dst;
+	if (s < d && s + n > d) {
+		s += n;
+		d += n;
+		while (n-- > 0)
+			*--d = *--s;
+	} else
+		while (n-- > 0)
+			*d++ = *s++;
+
+	return dst;
 }
 
 // memcpy exists to placate GCC.  Use memmove.
-void*
-memcpy(void *dst, const void *src, uint n)
-{
-  return memmove(dst, src, n);
+void *memcpy(void *dst, const void *src, uint n) {
+	return memmove(dst, src, n);
 }
 
-int
-strncmp(const char *p, const char *q, uint n)
-{
-  while(n > 0 && *p && *p == *q)
-    n--, p++, q++;
-  if(n == 0)
-    return 0;
-  return (uchar)*p - (uchar)*q;
+int strncmp(const char *p, const char *q, uint n) {
+	while (n > 0 && *p && *p == *q)
+		n--, p++, q++;
+	if (n == 0)
+		return 0;
+	return (uchar)*p - (uchar)*q;
 }
 
-char*
-strncpy(char *s, const char *t, int n)
-{
-  char *os;
+char *strncpy(char *s, const char *t, int n) {
+	char *os;
 
-  os = s;
-  while(n-- > 0 && (*s++ = *t++) != 0)
-    ;
-  while(n-- > 0)
-    *s++ = 0;
-  return os;
+	os = s;
+	while (n-- > 0 && (*s++ = *t++) != 0)
+		;
+	while (n-- > 0)
+		*s++ = 0;
+	return os;
 }
 
 // Like strncpy but guaranteed to NUL-terminate.
-char*
-safestrcpy(char *s, const char *t, int n)
-{
-  char *os;
+char *safestrcpy(char *s, const char *t, int n) {
+	char *os;
 
-  os = s;
-  if(n <= 0)
-    return os;
-  while(--n > 0 && (*s++ = *t++) != 0)
-    ;
-  *s = 0;
-  return os;
+	os = s;
+	if (n <= 0)
+		return os;
+	while (--n > 0 && (*s++ = *t++) != 0)
+		;
+	*s = 0;
+	return os;
 }
 
-int
-strlen(const char *s)
-{
-  int n;
+int strlen(const char *s) {
+	int n;
 
-  for(n = 0; s[n]; n++)
-    ;
-  return n;
+	for (n = 0; s[n]; n++)
+		;
+	return n;
 }
-

kernel/syscall.c

@@ -8,77 +8,63 @@
 #include "defs.h"
 
 // Fetch the uint64 at addr from the current process.
-int
-fetchaddr(uint64 addr, uint64 *ip)
-{
-  struct proc *p = myproc();
-  if(addr >= p->sz || addr+sizeof(uint64) > p->sz) // both tests needed, in case of overflow
-    return -1;
-  if(copyin(p->pagetable, (char *)ip, addr, sizeof(*ip)) != 0)
-    return -1;
-  return 0;
+int fetchaddr(uint64 addr, uint64 *ip) {
+	struct proc *p = myproc();
+	if (addr >= p->sz ||
+		addr + sizeof(uint64) > p->sz) // both tests needed, in case of overflow
+		return -1;
+	if (copyin(p->pagetable, (char *)ip, addr, sizeof(*ip)) != 0)
+		return -1;
+	return 0;
 }
 
 // Fetch the nul-terminated string at addr from the current process.
 // Returns length of string, not including nul, or -1 for error.
-int
-fetchstr(uint64 addr, char *buf, int max)
-{
-  struct proc *p = myproc();
-  if(copyinstr(p->pagetable, buf, addr, max) < 0)
-    return -1;
-  return strlen(buf);
+int fetchstr(uint64 addr, char *buf, int max) {
+	struct proc *p = myproc();
+	if (copyinstr(p->pagetable, buf, addr, max) < 0)
+		return -1;
+	return strlen(buf);
 }
 
-static uint64
-argraw(int n)
-{
-  struct proc *p = myproc();
-  switch (n) {
-  case 0:
-    return p->trapframe->a0;
-  case 1:
-    return p->trapframe->a1;
-  case 2:
-    return p->trapframe->a2;
-  case 3:
-    return p->trapframe->a3;
-  case 4:
-    return p->trapframe->a4;
-  case 5:
-    return p->trapframe->a5;
-  }
-  panic("argraw");
-  return -1;
+static uint64 argraw(int n) {
+	struct proc *p = myproc();
+	switch (n) {
+	case 0:
+		return p->trapframe->a0;
+	case 1:
+		return p->trapframe->a1;
+	case 2:
+		return p->trapframe->a2;
+	case 3:
+		return p->trapframe->a3;
+	case 4:
+		return p->trapframe->a4;
+	case 5:
+		return p->trapframe->a5;
+	}
+	panic("argraw");
+	return -1;
 }
 
 // Fetch the nth 32-bit system call argument.
-void
-argint(int n, int *ip)
-{
-  *ip = argraw(n);
-}
+void argint(int n, int *ip) { *ip = argraw(n); }
 
 // Retrieve an argument as a pointer.
 // Doesn't check for legality, since
 // copyin/copyout will do that.
-void
-argaddr(int n, uint64 *ip)
-{
-  *ip = argraw(n);
-}
+void argaddr(int n, uint64 *ip) { *ip = argraw(n); }
 
 // Fetch the nth word-sized system call argument as a null-terminated string.
 // Copies into buf, at most max.
 // Returns string length if OK (including nul), -1 if error.
-int
-argstr(int n, char *buf, int max)
-{
-  uint64 addr;
-  argaddr(n, &addr);
-  return fetchstr(addr, buf, max);
+int argstr(int n, char *buf, int max) {
+	uint64 addr;
+	argaddr(n, &addr);
+	return fetchstr(addr, buf, max);
 }
 
+// Prototypes for the functions that handle system calls.
 extern uint64 sys_fork(void);
 extern uint64 sys_exit(void);
 extern uint64 sys_wait(void);
@@ -101,42 +87,29 @@ extern uint64 sys_link(void);
 extern uint64 sys_mkdir(void);
 extern uint64 sys_close(void);
 
+// An array mapping syscall numbers from syscall.h
+// to the function that handles the system call.
 static uint64 (*syscalls[])(void) = {
-[SYS_fork]    sys_fork,
-[SYS_exit]    sys_exit,
-[SYS_wait]    sys_wait,
-[SYS_pipe]    sys_pipe,
-[SYS_read]    sys_read,
-[SYS_kill]    sys_kill,
-[SYS_exec]    sys_exec,
-[SYS_fstat]   sys_fstat,
-[SYS_chdir]   sys_chdir,
-[SYS_dup]     sys_dup,
-[SYS_getpid]  sys_getpid,
-[SYS_sbrk]    sys_sbrk,
-[SYS_sleep]   sys_sleep,
-[SYS_uptime]  sys_uptime,
-[SYS_open]    sys_open,
-[SYS_write]   sys_write,
-[SYS_mknod]   sys_mknod,
-[SYS_unlink]  sys_unlink,
-[SYS_link]    sys_link,
-[SYS_mkdir]   sys_mkdir,
-[SYS_close]   sys_close,
+	[SYS_fork] sys_fork,   [SYS_exit] sys_exit,		[SYS_wait] sys_wait,
+	[SYS_pipe] sys_pipe,   [SYS_read] sys_read,		[SYS_kill] sys_kill,
+	[SYS_exec] sys_exec,   [SYS_fstat] sys_fstat,	[SYS_chdir] sys_chdir,
+	[SYS_dup] sys_dup,	   [SYS_getpid] sys_getpid, [SYS_sbrk] sys_sbrk,
+	[SYS_sleep] sys_sleep, [SYS_uptime] sys_uptime, [SYS_open] sys_open,
+	[SYS_write] sys_write, [SYS_mknod] sys_mknod,	[SYS_unlink] sys_unlink,
+	[SYS_link] sys_link,   [SYS_mkdir] sys_mkdir,	[SYS_close] sys_close,
 };
 
-void
-syscall(void)
-{
-  int num;
-  struct proc *p = myproc();
+void syscall(void) {
+	int num;
+	struct proc *p = myproc();
 
-  num = p->trapframe->a7;
-  if(num > 0 && num < NELEM(syscalls) && syscalls[num]) {
-    p->trapframe->a0 = syscalls[num]();
-  } else {
-    printf("%d %s: unknown sys call %d\n",
-            p->pid, p->name, num);
-    p->trapframe->a0 = -1;
-  }
+	num = p->trapframe->a7;
+	if (num > 0 && num < NELEM(syscalls) && syscalls[num]) {
+		// Use num to lookup the system call function for num, call it,
+		// and store its return value in p->trapframe->a0
+		p->trapframe->a0 = syscalls[num]();
+	} else {
+		printf("%d %s: unknown sys call %d\n", p->pid, p->name, num);
+		p->trapframe->a0 = -1;
+	}
 }

kernel/sysfile.c

@@ -18,488 +18,455 @@
 
 // Fetch the nth word-sized system call argument as a file descriptor
 // and return both the descriptor and the corresponding struct file.
-static int
-argfd(int n, int *pfd, struct file **pf)
-{
-  int fd;
-  struct file *f;
+static int argfd(int n, int *pfd, struct file **pf) {
+	int fd;
+	struct file *f;
 
-  argint(n, &fd);
-  if(fd < 0 || fd >= NOFILE || (f=myproc()->ofile[fd]) == 0)
-    return -1;
-  if(pfd)
-    *pfd = fd;
-  if(pf)
-    *pf = f;
-  return 0;
+	argint(n, &fd);
+	if (fd < 0 || fd >= NOFILE || (f = myproc()->ofile[fd]) == 0)
+		return -1;
+	if (pfd)
+		*pfd = fd;
+	if (pf)
+		*pf = f;
+	return 0;
 }
 
 // Allocate a file descriptor for the given file.
 // Takes over file reference from caller on success.
-static int
-fdalloc(struct file *f)
-{
-  int fd;
-  struct proc *p = myproc();
+static int fdalloc(struct file *f) {
+	int fd;
+	struct proc *p = myproc();
 
-  for(fd = 0; fd < NOFILE; fd++){
-    if(p->ofile[fd] == 0){
-      p->ofile[fd] = f;
-      return fd;
-    }
-  }
-  return -1;
+	for (fd = 0; fd < NOFILE; fd++) {
+		if (p->ofile[fd] == 0) {
+			p->ofile[fd] = f;
+			return fd;
+		}
+	}
+	return -1;
 }
 
-uint64
-sys_dup(void)
-{
-  struct file *f;
-  int fd;
+uint64 sys_dup(void) {
+	struct file *f;
+	int fd;
 
-  if(argfd(0, 0, &f) < 0)
-    return -1;
-  if((fd=fdalloc(f)) < 0)
-    return -1;
-  filedup(f);
-  return fd;
+	if (argfd(0, 0, &f) < 0)
+		return -1;
+	if ((fd = fdalloc(f)) < 0)
+		return -1;
+	filedup(f);
+	return fd;
 }
 
-uint64
-sys_read(void)
-{
-  struct file *f;
-  int n;
-  uint64 p;
+uint64 sys_read(void) {
+	struct file *f;
+	int n;
+	uint64 p;
 
-  argaddr(1, &p);
-  argint(2, &n);
-  if(argfd(0, 0, &f) < 0)
-    return -1;
-  return fileread(f, p, n);
+	argaddr(1, &p);
+	argint(2, &n);
+	if (argfd(0, 0, &f) < 0)
+		return -1;
+	return fileread(f, p, n);
 }
 
-uint64
-sys_write(void)
-{
-  struct file *f;
-  int n;
-  uint64 p;
-  
-  argaddr(1, &p);
-  argint(2, &n);
-  if(argfd(0, 0, &f) < 0)
-    return -1;
+uint64 sys_write(void) {
+	struct file *f;
+	int n;
+	uint64 p;
 
-  return filewrite(f, p, n);
+	argaddr(1, &p);
+	argint(2, &n);
+	if (argfd(0, 0, &f) < 0)
+		return -1;
+
+	return filewrite(f, p, n);
 }
 
-uint64
-sys_close(void)
-{
-  int fd;
-  struct file *f;
+uint64 sys_close(void) {
+	int fd;
+	struct file *f;
 
-  if(argfd(0, &fd, &f) < 0)
-    return -1;
-  myproc()->ofile[fd] = 0;
-  fileclose(f);
-  return 0;
+	if (argfd(0, &fd, &f) < 0)
+		return -1;
+	myproc()->ofile[fd] = 0;
+	fileclose(f);
+	return 0;
 }
 
-uint64
-sys_fstat(void)
-{
-  struct file *f;
-  uint64 st; // user pointer to struct stat
+uint64 sys_fstat(void) {
+	struct file *f;
+	uint64 st; // user pointer to struct stat
 
-  argaddr(1, &st);
-  if(argfd(0, 0, &f) < 0)
-    return -1;
-  return filestat(f, st);
+	argaddr(1, &st);
+	if (argfd(0, 0, &f) < 0)
+		return -1;
+	return filestat(f, st);
 }
 
 // Create the path new as a link to the same inode as old.
-uint64
-sys_link(void)
-{
-  char name[DIRSIZ], new[MAXPATH], old[MAXPATH];
-  struct inode *dp, *ip;
+uint64 sys_link(void) {
+	char name[DIRSIZ], new[MAXPATH], old[MAXPATH];
+	struct inode *dp, *ip;
 
-  if(argstr(0, old, MAXPATH) < 0 || argstr(1, new, MAXPATH) < 0)
-    return -1;
+	if (argstr(0, old, MAXPATH) < 0 || argstr(1, new, MAXPATH) < 0)
+		return -1;
 
-  begin_op();
-  if((ip = namei(old)) == 0){
-    end_op();
-    return -1;
-  }
+	begin_op();
+	if ((ip = namei(old)) == 0) {
+		end_op();
+		return -1;
+	}
 
-  ilock(ip);
-  if(ip->type == T_DIR){
-    iunlockput(ip);
-    end_op();
-    return -1;
-  }
+	ilock(ip);
+	if (ip->type == T_DIR) {
+		iunlockput(ip);
+		end_op();
+		return -1;
+	}
 
-  ip->nlink++;
-  iupdate(ip);
-  iunlock(ip);
+	ip->nlink++;
+	iupdate(ip);
+	iunlock(ip);
 
-  if((dp = nameiparent(new, name)) == 0)
-    goto bad;
-  ilock(dp);
-  if(dp->dev != ip->dev || dirlink(dp, name, ip->inum) < 0){
-    iunlockput(dp);
-    goto bad;
-  }
-  iunlockput(dp);
-  iput(ip);
+	if ((dp = nameiparent(new, name)) == 0)
+		goto bad;
+	ilock(dp);
+	if (dp->dev != ip->dev || dirlink(dp, name, ip->inum) < 0) {
+		iunlockput(dp);
+		goto bad;
+	}
+	iunlockput(dp);
+	iput(ip);
 
-  end_op();
+	end_op();
 
-  return 0;
+	return 0;
 
 bad:
-  ilock(ip);
-  ip->nlink--;
-  iupdate(ip);
-  iunlockput(ip);
-  end_op();
-  return -1;
+	ilock(ip);
+	ip->nlink--;
+	iupdate(ip);
+	iunlockput(ip);
+	end_op();
+	return -1;
 }
 
 // Is the directory dp empty except for "." and ".." ?
-static int
-isdirempty(struct inode *dp)
-{
-  int off;
-  struct dirent de;
+static int isdirempty(struct inode *dp) {
+	int off;
+	struct dirent de;
 
-  for(off=2*sizeof(de); off<dp->size; off+=sizeof(de)){
-    if(readi(dp, 0, (uint64)&de, off, sizeof(de)) != sizeof(de))
-      panic("isdirempty: readi");
-    if(de.inum != 0)
-      return 0;
-  }
-  return 1;
+	for (off = 2 * sizeof(de); off < dp->size; off += sizeof(de)) {
+		if (readi(dp, 0, (uint64)&de, off, sizeof(de)) != sizeof(de))
+			panic("isdirempty: readi");
+		if (de.inum != 0)
+			return 0;
+	}
+	return 1;
 }
 
-uint64
-sys_unlink(void)
-{
-  struct inode *ip, *dp;
-  struct dirent de;
-  char name[DIRSIZ], path[MAXPATH];
-  uint off;
+uint64 sys_unlink(void) {
+	struct inode *ip, *dp;
+	struct dirent de;
+	char name[DIRSIZ], path[MAXPATH];
+	uint off;
 
-  if(argstr(0, path, MAXPATH) < 0)
-    return -1;
+	if (argstr(0, path, MAXPATH) < 0)
+		return -1;
 
-  begin_op();
-  if((dp = nameiparent(path, name)) == 0){
-    end_op();
-    return -1;
-  }
+	begin_op();
+	if ((dp = nameiparent(path, name)) == 0) {
+		end_op();
+		return -1;
+	}
 
-  ilock(dp);
+	ilock(dp);
 
-  // Cannot unlink "." or "..".
-  if(namecmp(name, ".") == 0 || namecmp(name, "..") == 0)
-    goto bad;
+	// Cannot unlink "." or "..".
+	if (namecmp(name, ".") == 0 || namecmp(name, "..") == 0)
+		goto bad;
 
-  if((ip = dirlookup(dp, name, &off)) == 0)
-    goto bad;
-  ilock(ip);
+	if ((ip = dirlookup(dp, name, &off)) == 0)
+		goto bad;
+	ilock(ip);
 
-  if(ip->nlink < 1)
-    panic("unlink: nlink < 1");
-  if(ip->type == T_DIR && !isdirempty(ip)){
-    iunlockput(ip);
-    goto bad;
-  }
+	if (ip->nlink < 1)
+		panic("unlink: nlink < 1");
+	if (ip->type == T_DIR && !isdirempty(ip)) {
+		iunlockput(ip);
+		goto bad;
+	}
 
-  memset(&de, 0, sizeof(de));
-  if(writei(dp, 0, (uint64)&de, off, sizeof(de)) != sizeof(de))
-    panic("unlink: writei");
-  if(ip->type == T_DIR){
-    dp->nlink--;
-    iupdate(dp);
-  }
-  iunlockput(dp);
+	memset(&de, 0, sizeof(de));
+	if (writei(dp, 0, (uint64)&de, off, sizeof(de)) != sizeof(de))
+		panic("unlink: writei");
+	if (ip->type == T_DIR) {
+		dp->nlink--;
+		iupdate(dp);
+	}
+	iunlockput(dp);
 
-  ip->nlink--;
-  iupdate(ip);
-  iunlockput(ip);
+	ip->nlink--;
+	iupdate(ip);
+	iunlockput(ip);
 
-  end_op();
+	end_op();
 
-  return 0;
+	return 0;
 
 bad:
-  iunlockput(dp);
-  end_op();
-  return -1;
+	iunlockput(dp);
+	end_op();
+	return -1;
 }
 
-static struct inode*
-create(char *path, short type, short major, short minor)
-{
-  struct inode *ip, *dp;
-  char name[DIRSIZ];
+static struct inode *create(char *path, short type, short major, short minor) {
+	struct inode *ip, *dp;
+	char name[DIRSIZ];
 
-  if((dp = nameiparent(path, name)) == 0)
-    return 0;
+	if ((dp = nameiparent(path, name)) == 0)
+		return 0;
 
-  ilock(dp);
+	ilock(dp);
 
-  if((ip = dirlookup(dp, name, 0)) != 0){
-    iunlockput(dp);
-    ilock(ip);
-    if(type == T_FILE && (ip->type == T_FILE || ip->type == T_DEVICE))
-      return ip;
-    iunlockput(ip);
-    return 0;
-  }
+	if ((ip = dirlookup(dp, name, 0)) != 0) {
+		iunlockput(dp);
+		ilock(ip);
+		if (type == T_FILE && (ip->type == T_FILE || ip->type == T_DEVICE))
+			return ip;
+		iunlockput(ip);
+		return 0;
+	}
 
-  if((ip = ialloc(dp->dev, type)) == 0){
-    iunlockput(dp);
-    return 0;
-  }
+	if ((ip = ialloc(dp->dev, type)) == 0) {
+		iunlockput(dp);
+		return 0;
+	}
 
-  ilock(ip);
-  ip->major = major;
-  ip->minor = minor;
-  ip->nlink = 1;
-  iupdate(ip);
+	ilock(ip);
+	ip->major = major;
+	ip->minor = minor;
+	ip->nlink = 1;
+	iupdate(ip);
 
-  if(type == T_DIR){  // Create . and .. entries.
-    // No ip->nlink++ for ".": avoid cyclic ref count.
-    if(dirlink(ip, ".", ip->inum) < 0 || dirlink(ip, "..", dp->inum) < 0)
-      goto fail;
-  }
+	if (type == T_DIR) { // Create . and .. entries.
+		// No ip->nlink++ for ".": avoid cyclic ref count.
+		if (dirlink(ip, ".", ip->inum) < 0 || dirlink(ip, "..", dp->inum) < 0)
+			goto fail;
+	}
 
-  if(dirlink(dp, name, ip->inum) < 0)
-    goto fail;
+	if (dirlink(dp, name, ip->inum) < 0)
+		goto fail;
 
-  if(type == T_DIR){
-    // now that success is guaranteed:
-    dp->nlink++;  // for ".."
-    iupdate(dp);
-  }
+	if (type == T_DIR) {
+		// now that success is guaranteed:
+		dp->nlink++; // for ".."
+		iupdate(dp);
+	}
 
-  iunlockput(dp);
+	iunlockput(dp);
 
-  return ip;
+	return ip;
 
- fail:
-  // something went wrong. de-allocate ip.
-  ip->nlink = 0;
-  iupdate(ip);
-  iunlockput(ip);
-  iunlockput(dp);
-  return 0;
+fail:
+	// something went wrong. de-allocate ip.
+	ip->nlink = 0;
+	iupdate(ip);
+	iunlockput(ip);
+	iunlockput(dp);
+	return 0;
 }
 
-uint64
-sys_open(void)
-{
-  char path[MAXPATH];
-  int fd, omode;
-  struct file *f;
-  struct inode *ip;
-  int n;
+uint64 sys_open(void) {
+	char path[MAXPATH];
+	int fd, omode;
+	struct file *f;
+	struct inode *ip;
+	int n;
 
-  argint(1, &omode);
-  if((n = argstr(0, path, MAXPATH)) < 0)
-    return -1;
+	argint(1, &omode);
+	if ((n = argstr(0, path, MAXPATH)) < 0)
+		return -1;
 
-  begin_op();
+	begin_op();
 
-  if(omode & O_CREATE){
-    ip = create(path, T_FILE, 0, 0);
-    if(ip == 0){
-      end_op();
-      return -1;
-    }
-  } else {
-    if((ip = namei(path)) == 0){
-      end_op();
-      return -1;
-    }
-    ilock(ip);
-    if(ip->type == T_DIR && omode != O_RDONLY){
-      iunlockput(ip);
-      end_op();
-      return -1;
-    }
-  }
+	if (omode & O_CREATE) {
+		ip = create(path, T_FILE, 0, 0);
+		if (ip == 0) {
+			end_op();
+			return -1;
+		}
+	} else {
+		if ((ip = namei(path)) == 0) {
+			end_op();
+			return -1;
+		}
+		ilock(ip);
+		if (ip->type == T_DIR && omode != O_RDONLY) {
+			iunlockput(ip);
+			end_op();
+			return -1;
+		}
+	}
 
-  if(ip->type == T_DEVICE && (ip->major < 0 || ip->major >= NDEV)){
-    iunlockput(ip);
-    end_op();
-    return -1;
-  }
+	if (ip->type == T_DEVICE && (ip->major < 0 || ip->major >= NDEV)) {
+		iunlockput(ip);
+		end_op();
+		return -1;
+	}
 
-  if((f = filealloc()) == 0 || (fd = fdalloc(f)) < 0){
-    if(f)
-      fileclose(f);
-    iunlockput(ip);
-    end_op();
-    return -1;
-  }
+	if ((f = filealloc()) == 0 || (fd = fdalloc(f)) < 0) {
+		if (f)
+			fileclose(f);
+		iunlockput(ip);
+		end_op();
+		return -1;
+	}
 
-  if(ip->type == T_DEVICE){
-    f->type = FD_DEVICE;
-    f->major = ip->major;
-  } else {
-    f->type = FD_INODE;
-    f->off = 0;
-  }
-  f->ip = ip;
-  f->readable = !(omode & O_WRONLY);
-  f->writable = (omode & O_WRONLY) || (omode & O_RDWR);
+	if (ip->type == T_DEVICE) {
+		f->type = FD_DEVICE;
+		f->major = ip->major;
+	} else {
+		f->type = FD_INODE;
+		f->off = 0;
+	}
+	f->ip = ip;
+	f->readable = !(omode & O_WRONLY);
+	f->writable = (omode & O_WRONLY) || (omode & O_RDWR);
 
-  if((omode & O_TRUNC) && ip->type == T_FILE){
-    itrunc(ip);
-  }
+	if ((omode & O_TRUNC) && ip->type == T_FILE) {
+		itrunc(ip);
+	}
 
-  iunlock(ip);
-  end_op();
+	iunlock(ip);
+	end_op();
 
-  return fd;
+	return fd;
 }
 
-uint64
-sys_mkdir(void)
-{
-  char path[MAXPATH];
-  struct inode *ip;
+uint64 sys_mkdir(void) {
+	char path[MAXPATH];
+	struct inode *ip;
 
-  begin_op();
-  if(argstr(0, path, MAXPATH) < 0 || (ip = create(path, T_DIR, 0, 0)) == 0){
-    end_op();
-    return -1;
-  }
-  iunlockput(ip);
-  end_op();
-  return 0;
+	begin_op();
+	if (argstr(0, path, MAXPATH) < 0 || (ip = create(path, T_DIR, 0, 0)) == 0) {
+		end_op();
+		return -1;
+	}
+	iunlockput(ip);
+	end_op();
+	return 0;
 }
 
-uint64
-sys_mknod(void)
-{
-  struct inode *ip;
-  char path[MAXPATH];
-  int major, minor;
+uint64 sys_mknod(void) {
+	struct inode *ip;
+	char path[MAXPATH];
+	int major, minor;
 
-  begin_op();
-  argint(1, &major);
-  argint(2, &minor);
-  if((argstr(0, path, MAXPATH)) < 0 ||
-     (ip = create(path, T_DEVICE, major, minor)) == 0){
-    end_op();
-    return -1;
-  }
-  iunlockput(ip);
-  end_op();
-  return 0;
+	begin_op();
+	argint(1, &major);
+	argint(2, &minor);
+	if ((argstr(0, path, MAXPATH)) < 0 ||
+		(ip = create(path, T_DEVICE, major, minor)) == 0) {
+		end_op();
+		return -1;
+	}
+	iunlockput(ip);
+	end_op();
+	return 0;
 }
 
-uint64
-sys_chdir(void)
-{
-  char path[MAXPATH];
-  struct inode *ip;
-  struct proc *p = myproc();
-  
-  begin_op();
-  if(argstr(0, path, MAXPATH) < 0 || (ip = namei(path)) == 0){
-    end_op();
-    return -1;
-  }
-  ilock(ip);
-  if(ip->type != T_DIR){
-    iunlockput(ip);
-    end_op();
-    return -1;
-  }
-  iunlock(ip);
-  iput(p->cwd);
-  end_op();
-  p->cwd = ip;
-  return 0;
+uint64 sys_chdir(void) {
+	char path[MAXPATH];
+	struct inode *ip;
+	struct proc *p = myproc();
+
+	begin_op();
+	if (argstr(0, path, MAXPATH) < 0 || (ip = namei(path)) == 0) {
+		end_op();
+		return -1;
+	}
+	ilock(ip);
+	if (ip->type != T_DIR) {
+		iunlockput(ip);
+		end_op();
+		return -1;
+	}
+	iunlock(ip);
+	iput(p->cwd);
+	end_op();
+	p->cwd = ip;
+	return 0;
 }
 
-uint64
-sys_exec(void)
-{
-  char path[MAXPATH], *argv[MAXARG];
-  int i;
-  uint64 uargv, uarg;
+uint64 sys_exec(void) {
+	char path[MAXPATH], *argv[MAXARG];
+	int i;
+	uint64 uargv, uarg;
 
-  argaddr(1, &uargv);
-  if(argstr(0, path, MAXPATH) < 0) {
-    return -1;
-  }
-  memset(argv, 0, sizeof(argv));
-  for(i=0;; i++){
-    if(i >= NELEM(argv)){
-      goto bad;
-    }
-    if(fetchaddr(uargv+sizeof(uint64)*i, (uint64*)&uarg) < 0){
-      goto bad;
-    }
-    if(uarg == 0){
-      argv[i] = 0;
-      break;
-    }
-    argv[i] = kalloc();
-    if(argv[i] == 0)
-      goto bad;
-    if(fetchstr(uarg, argv[i], PGSIZE) < 0)
-      goto bad;
-  }
+	argaddr(1, &uargv);
+	if (argstr(0, path, MAXPATH) < 0) {
+		return -1;
+	}
+	memset(argv, 0, sizeof(argv));
+	for (i = 0;; i++) {
+		if (i >= NELEM(argv)) {
+			goto bad;
+		}
+		if (fetchaddr(uargv + sizeof(uint64) * i, (uint64 *)&uarg) < 0) {
+			goto bad;
+		}
+		if (uarg == 0) {
+			argv[i] = 0;
+			break;
+		}
+		argv[i] = kalloc();
+		if (argv[i] == 0)
+			goto bad;
+		if (fetchstr(uarg, argv[i], PGSIZE) < 0)
+			goto bad;
+	}
 
-  int ret = exec(path, argv);
+	int ret = exec(path, argv);
 
-  for(i = 0; i < NELEM(argv) && argv[i] != 0; i++)
-    kfree(argv[i]);
+	for (i = 0; i < NELEM(argv) && argv[i] != 0; i++)
+		kfree(argv[i]);
 
-  return ret;
+	return ret;
 
- bad:
-  for(i = 0; i < NELEM(argv) && argv[i] != 0; i++)
-    kfree(argv[i]);
-  return -1;
+bad:
+	for (i = 0; i < NELEM(argv) && argv[i] != 0; i++)
+		kfree(argv[i]);
+	return -1;
 }
 
-uint64
-sys_pipe(void)
-{
-  uint64 fdarray; // user pointer to array of two integers
-  struct file *rf, *wf;
-  int fd0, fd1;
-  struct proc *p = myproc();
+uint64 sys_pipe(void) {
+	uint64 fdarray; // user pointer to array of two integers
+	struct file *rf, *wf;
+	int fd0, fd1;
+	struct proc *p = myproc();
 
-  argaddr(0, &fdarray);
-  if(pipealloc(&rf, &wf) < 0)
-    return -1;
-  fd0 = -1;
-  if((fd0 = fdalloc(rf)) < 0 || (fd1 = fdalloc(wf)) < 0){
-    if(fd0 >= 0)
-      p->ofile[fd0] = 0;
-    fileclose(rf);
-    fileclose(wf);
-    return -1;
-  }
-  if(copyout(p->pagetable, fdarray, (char*)&fd0, sizeof(fd0)) < 0 ||
-     copyout(p->pagetable, fdarray+sizeof(fd0), (char *)&fd1, sizeof(fd1)) < 0){
-    p->ofile[fd0] = 0;
-    p->ofile[fd1] = 0;
-    fileclose(rf);
-    fileclose(wf);
-    return -1;
-  }
-  return 0;
+	argaddr(0, &fdarray);
+	if (pipealloc(&rf, &wf) < 0)
+		return -1;
+	fd0 = -1;
+	if ((fd0 = fdalloc(rf)) < 0 || (fd1 = fdalloc(wf)) < 0) {
+		if (fd0 >= 0)
+			p->ofile[fd0] = 0;
+		fileclose(rf);
+		fileclose(wf);
+		return -1;
+	}
+	if (copyout(p->pagetable, fdarray, (char *)&fd0, sizeof(fd0)) < 0 ||
+		copyout(p->pagetable, fdarray + sizeof(fd0), (char *)&fd1,
+				sizeof(fd1)) < 0) {
+		p->ofile[fd0] = 0;
+		p->ofile[fd1] = 0;
+		fileclose(rf);
+		fileclose(wf);
+		return -1;
+	}
+	return 0;
 }

kernel/sysproc.c

@@ -6,86 +6,66 @@
 #include "spinlock.h"
 #include "proc.h"
 
-uint64
-sys_exit(void)
-{
-  int n;
-  argint(0, &n);
-  exit(n);
-  return 0;  // not reached
+uint64 sys_exit(void) {
+	int n;
+	argint(0, &n);
+	exit(n);
+	return 0; // not reached
 }
 
-uint64
-sys_getpid(void)
-{
-  return myproc()->pid;
+uint64 sys_getpid(void) { return myproc()->pid; }
+
+uint64 sys_fork(void) { return fork(); }
+
+uint64 sys_wait(void) {
+	uint64 p;
+	argaddr(0, &p);
+	return wait(p);
 }
 
-uint64
-sys_fork(void)
-{
-  return fork();
+uint64 sys_sbrk(void) {
+	uint64 addr;
+	int n;
+
+	argint(0, &n);
+	addr = myproc()->sz;
+	if (growproc(n) < 0)
+		return -1;
+	return addr;
 }
 
-uint64
-sys_wait(void)
-{
-  uint64 p;
-  argaddr(0, &p);
-  return wait(p);
+uint64 sys_sleep(void) {
+	int n;
+	uint ticks0;
+
+	argint(0, &n);
+	acquire(&tickslock);
+	ticks0 = ticks;
+	while (ticks - ticks0 < n) {
+		if (killed(myproc())) {
+			release(&tickslock);
+			return -1;
+		}
+		sleep(&ticks, &tickslock);
+	}
+	release(&tickslock);
+	return 0;
 }
 
-uint64
-sys_sbrk(void)
-{
-  uint64 addr;
-  int n;
+uint64 sys_kill(void) {
+	int pid;
 
-  argint(0, &n);
-  addr = myproc()->sz;
-  if(growproc(n) < 0)
-    return -1;
-  return addr;
-}
-
-uint64
-sys_sleep(void)
-{
-  int n;
-  uint ticks0;
-
-  argint(0, &n);
-  acquire(&tickslock);
-  ticks0 = ticks;
-  while(ticks - ticks0 < n){
-    if(killed(myproc())){
-      release(&tickslock);
-      return -1;
-    }
-    sleep(&ticks, &tickslock);
-  }
-  release(&tickslock);
-  return 0;
-}
-
-uint64
-sys_kill(void)
-{
-  int pid;
-
-  argint(0, &pid);
-  return kill(pid);
+	argint(0, &pid);
+	return kill(pid);
 }
 
 // return how many clock tick interrupts have occurred
 // since start.
-uint64
-sys_uptime(void)
-{
-  uint xticks;
+uint64 sys_uptime(void) {
+	uint xticks;
 
-  acquire(&tickslock);
-  xticks = ticks;
-  release(&tickslock);
-  return xticks;
+	acquire(&tickslock);
+	xticks = ticks;
+	release(&tickslock);
+	return xticks;
 }

kernel/trampoline.S

@@ -80,9 +80,18 @@ uservec:
         # load the address of usertrap(), from p->trapframe->kernel_trap
         ld t0, 16(a0)
 
-        # load the kernel page table, from p->trapframe->kernel_satp
+
+        # fetch the kernel page table address, from p->trapframe->kernel_satp.
         ld t1, 0(a0)
+
+        # wait for any previous memory operations to complete, so that
+        # they use the user page table.
+        sfence.vma zero, zero
+
+        # install the kernel page table.
         csrw satp, t1
+
+        # flush now-stale user entries from the TLB.
         sfence.vma zero, zero
 
         # jump to usertrap(), which does not return
@@ -96,6 +105,7 @@ userret:
         # a0: user page table, for satp.
 
         # switch to the user page table.
+        sfence.vma zero, zero
         csrw satp, a0
         sfence.vma zero, zero
 

kernel/trap.c

@@ -16,157 +16,141 @@ void kernelvec();
 
 extern int devintr();
 
-void
-trapinit(void)
-{
-  initlock(&tickslock, "time");
-}
+void trapinit(void) { initlock(&tickslock, "time"); }
 
 // set up to take exceptions and traps while in the kernel.
-void
-trapinithart(void)
-{
-  w_stvec((uint64)kernelvec);
-}
+void trapinithart(void) { w_stvec((uint64)kernelvec); }
 
 //
 // handle an interrupt, exception, or system call from user space.
 // called from trampoline.S
 //
-void
-usertrap(void)
-{
-  int which_dev = 0;
+void usertrap(void) {
+	int which_dev = 0;
 
-  if((r_sstatus() & SSTATUS_SPP) != 0)
-    panic("usertrap: not from user mode");
+	if ((r_sstatus() & SSTATUS_SPP) != 0)
+		panic("usertrap: not from user mode");
 
-  // send interrupts and exceptions to kerneltrap(),
-  // since we're now in the kernel.
-  w_stvec((uint64)kernelvec);
+	// send interrupts and exceptions to kerneltrap(),
+	// since we're now in the kernel.
+	w_stvec((uint64)kernelvec);
 
-  struct proc *p = myproc();
-  
-  // save user program counter.
-  p->trapframe->epc = r_sepc();
-  
-  if(r_scause() == 8){
-    // system call
+	struct proc *p = myproc();
 
-    if(killed(p))
-      exit(-1);
+	// save user program counter.
+	p->trapframe->epc = r_sepc();
 
-    // sepc points to the ecall instruction,
-    // but we want to return to the next instruction.
-    p->trapframe->epc += 4;
+	if (r_scause() == 8) {
+		// system call
 
-    // an interrupt will change sepc, scause, and sstatus,
-    // so enable only now that we're done with those registers.
-    intr_on();
+		if (killed(p))
+			exit(-1);
 
-    syscall();
-  } else if((which_dev = devintr()) != 0){
-    // ok
-  } else {
-    printf("usertrap(): unexpected scause %p pid=%d\n", r_scause(), p->pid);
-    printf("            sepc=%p stval=%p\n", r_sepc(), r_stval());
-    setkilled(p);
-  }
+		// sepc points to the ecall instruction,
+		// but we want to return to the next instruction.
+		p->trapframe->epc += 4;
 
-  if(killed(p))
-    exit(-1);
+		// an interrupt will change sepc, scause, and sstatus,
+		// so enable only now that we're done with those registers.
+		intr_on();
 
-  // give up the CPU if this is a timer interrupt.
-  if(which_dev == 2)
-    yield();
+		syscall();
+	} else if ((which_dev = devintr()) != 0) {
+		// ok
+	} else {
+		printf("usertrap(): unexpected scause %p pid=%d\n", r_scause(), p->pid);
+		printf("            sepc=%p stval=%p\n", r_sepc(), r_stval());
+		setkilled(p);
+	}
 
-  usertrapret();
+	if (killed(p))
+		exit(-1);
+
+	// give up the CPU if this is a timer interrupt.
+	if (which_dev == 2)
+		yield();
+
+	usertrapret();
 }
 
 //
 // return to user space
 //
-void
-usertrapret(void)
-{
-  struct proc *p = myproc();
+void usertrapret(void) {
+	struct proc *p = myproc();
 
-  // we're about to switch the destination of traps from
-  // kerneltrap() to usertrap(), so turn off interrupts until
-  // we're back in user space, where usertrap() is correct.
-  intr_off();
+	// we're about to switch the destination of traps from
+	// kerneltrap() to usertrap(), so turn off interrupts until
+	// we're back in user space, where usertrap() is correct.
+	intr_off();
 
-  // send syscalls, interrupts, and exceptions to uservec in trampoline.S
-  uint64 trampoline_uservec = TRAMPOLINE + (uservec - trampoline);
-  w_stvec(trampoline_uservec);
+	// send syscalls, interrupts, and exceptions to uservec in trampoline.S
+	uint64 trampoline_uservec = TRAMPOLINE + (uservec - trampoline);
+	w_stvec(trampoline_uservec);
 
-  // set up trapframe values that uservec will need when
-  // the process next traps into the kernel.
-  p->trapframe->kernel_satp = r_satp();         // kernel page table
-  p->trapframe->kernel_sp = p->kstack + PGSIZE; // process's kernel stack
-  p->trapframe->kernel_trap = (uint64)usertrap;
-  p->trapframe->kernel_hartid = r_tp();         // hartid for cpuid()
+	// set up trapframe values that uservec will need when
+	// the process next traps into the kernel.
+	p->trapframe->kernel_satp = r_satp();		  // kernel page table
+	p->trapframe->kernel_sp = p->kstack + PGSIZE; // process's kernel stack
+	p->trapframe->kernel_trap = (uint64)usertrap;
+	p->trapframe->kernel_hartid = r_tp(); // hartid for cpuid()
 
-  // set up the registers that trampoline.S's sret will use
-  // to get to user space.
-  
-  // set S Previous Privilege mode to User.
-  unsigned long x = r_sstatus();
-  x &= ~SSTATUS_SPP; // clear SPP to 0 for user mode
-  x |= SSTATUS_SPIE; // enable interrupts in user mode
-  w_sstatus(x);
+	// set up the registers that trampoline.S's sret will use
+	// to get to user space.
 
-  // set S Exception Program Counter to the saved user pc.
-  w_sepc(p->trapframe->epc);
+	// set S Previous Privilege mode to User.
+	unsigned long x = r_sstatus();
+	x &= ~SSTATUS_SPP; // clear SPP to 0 for user mode
+	x |= SSTATUS_SPIE; // enable interrupts in user mode
+	w_sstatus(x);
 
-  // tell trampoline.S the user page table to switch to.
-  uint64 satp = MAKE_SATP(p->pagetable);
+	// set S Exception Program Counter to the saved user pc.
+	w_sepc(p->trapframe->epc);
 
-  // jump to userret in trampoline.S at the top of memory, which 
-  // switches to the user page table, restores user registers,
-  // and switches to user mode with sret.
-  uint64 trampoline_userret = TRAMPOLINE + (userret - trampoline);
-  ((void (*)(uint64))trampoline_userret)(satp);
+	// tell trampoline.S the user page table to switch to.
+	uint64 satp = MAKE_SATP(p->pagetable);
+
+	// jump to userret in trampoline.S at the top of memory, which
+	// switches to the user page table, restores user registers,
+	// and switches to user mode with sret.
+	uint64 trampoline_userret = TRAMPOLINE + (userret - trampoline);
+	((void (*)(uint64))trampoline_userret)(satp);
 }
 
 // interrupts and exceptions from kernel code go here via kernelvec,
 // on whatever the current kernel stack is.
-void 
-kerneltrap()
-{
-  int which_dev = 0;
-  uint64 sepc = r_sepc();
-  uint64 sstatus = r_sstatus();
-  uint64 scause = r_scause();
-  
-  if((sstatus & SSTATUS_SPP) == 0)
-    panic("kerneltrap: not from supervisor mode");
-  if(intr_get() != 0)
-    panic("kerneltrap: interrupts enabled");
+void kerneltrap() {
+	int which_dev = 0;
+	uint64 sepc = r_sepc();
+	uint64 sstatus = r_sstatus();
+	uint64 scause = r_scause();
 
-  if((which_dev = devintr()) == 0){
-    printf("scause %p\n", scause);
-    printf("sepc=%p stval=%p\n", r_sepc(), r_stval());
-    panic("kerneltrap");
-  }
+	if ((sstatus & SSTATUS_SPP) == 0)
+		panic("kerneltrap: not from supervisor mode");
+	if (intr_get() != 0)
+		panic("kerneltrap: interrupts enabled");
 
-  // give up the CPU if this is a timer interrupt.
-  if(which_dev == 2 && myproc() != 0 && myproc()->state == RUNNING)
-    yield();
+	if ((which_dev = devintr()) == 0) {
+		printf("scause %p\n", scause);
+		printf("sepc=%p stval=%p\n", r_sepc(), r_stval());
+		panic("kerneltrap");
+	}
 
-  // the yield() may have caused some traps to occur,
-  // so restore trap registers for use by kernelvec.S's sepc instruction.
-  w_sepc(sepc);
-  w_sstatus(sstatus);
+	// give up the CPU if this is a timer interrupt.
+	if (which_dev == 2 && myproc() != 0 && myproc()->state == RUNNING)
+		yield();
+
+	// the yield() may have caused some traps to occur,
+	// so restore trap registers for use by kernelvec.S's sepc instruction.
+	w_sepc(sepc);
+	w_sstatus(sstatus);
 }
 
-void
-clockintr()
-{
-  acquire(&tickslock);
-  ticks++;
-  wakeup(&ticks);
-  release(&tickslock);
+void clockintr() {
+	acquire(&tickslock);
+	ticks++;
+	wakeup(&ticks);
+	release(&tickslock);
 }
 
 // check if it's an external interrupt or software interrupt,
@@ -174,48 +158,44 @@ clockintr()
 // returns 2 if timer interrupt,
 // 1 if other device,
 // 0 if not recognized.
-int
-devintr()
-{
-  uint64 scause = r_scause();
+int devintr() {
+	uint64 scause = r_scause();
 
-  if((scause & 0x8000000000000000L) &&
-     (scause & 0xff) == 9){
-    // this is a supervisor external interrupt, via PLIC.
+	if ((scause & 0x8000000000000000L) && (scause & 0xff) == 9) {
+		// this is a supervisor external interrupt, via PLIC.
 
-    // irq indicates which device interrupted.
-    int irq = plic_claim();
+		// irq indicates which device interrupted.
+		int irq = plic_claim();
 
-    if(irq == UART0_IRQ){
-      uartintr();
-    } else if(irq == VIRTIO0_IRQ){
-      virtio_disk_intr();
-    } else if(irq){
-      printf("unexpected interrupt irq=%d\n", irq);
-    }
+		if (irq == UART0_IRQ) {
+			uartintr();
+		} else if (irq == VIRTIO0_IRQ) {
+			virtio_disk_intr();
+		} else if (irq) {
+			printf("unexpected interrupt irq=%d\n", irq);
+		}
 
-    // the PLIC allows each device to raise at most one
-    // interrupt at a time; tell the PLIC the device is
-    // now allowed to interrupt again.
-    if(irq)
-      plic_complete(irq);
+		// the PLIC allows each device to raise at most one
+		// interrupt at a time; tell the PLIC the device is
+		// now allowed to interrupt again.
+		if (irq)
+			plic_complete(irq);
 
-    return 1;
-  } else if(scause == 0x8000000000000001L){
-    // software interrupt from a machine-mode timer interrupt,
-    // forwarded by timervec in kernelvec.S.
+		return 1;
+	} else if (scause == 0x8000000000000001L) {
+		// software interrupt from a machine-mode timer interrupt,
+		// forwarded by timervec in kernelvec.S.
 
-    if(cpuid() == 0){
-      clockintr();
-    }
-    
-    // acknowledge the software interrupt by clearing
-    // the SSIP bit in sip.
-    w_sip(r_sip() & ~2);
+		if (cpuid() == 0) {
+			clockintr();
+		}
 
-    return 2;
-  } else {
-    return 0;
-  }
+		// acknowledge the software interrupt by clearing
+		// the SSIP bit in sip.
+		w_sip(r_sip() & ~2);
+
+		return 2;
+	} else {
+		return 0;
+	}
 }
-

kernel/uart.c

@@ -19,21 +19,21 @@
 // some have different meanings for
 // read vs write.
 // see http://byterunner.com/16550.html
-#define RHR 0                 // receive holding register (for input bytes)
-#define THR 0                 // transmit holding register (for output bytes)
-#define IER 1                 // interrupt enable register
-#define IER_RX_ENABLE (1<<0)
-#define IER_TX_ENABLE (1<<1)
-#define FCR 2                 // FIFO control register
-#define FCR_FIFO_ENABLE (1<<0)
-#define FCR_FIFO_CLEAR (3<<1) // clear the content of the two FIFOs
-#define ISR 2                 // interrupt status register
-#define LCR 3                 // line control register
-#define LCR_EIGHT_BITS (3<<0)
-#define LCR_BAUD_LATCH (1<<7) // special mode to set baud rate
-#define LSR 5                 // line status register
-#define LSR_RX_READY (1<<0)   // input is waiting to be read from RHR
-#define LSR_TX_IDLE (1<<5)    // THR can accept another character to send
+#define RHR 0 // receive holding register (for input bytes)
+#define THR 0 // transmit holding register (for output bytes)
+#define IER 1 // interrupt enable register
+#define IER_RX_ENABLE (1 << 0)
+#define IER_TX_ENABLE (1 << 1)
+#define FCR 2 // FIFO control register
+#define FCR_FIFO_ENABLE (1 << 0)
+#define FCR_FIFO_CLEAR (3 << 1) // clear the content of the two FIFOs
+#define ISR 2					// interrupt status register
+#define LCR 3					// line control register
+#define LCR_EIGHT_BITS (3 << 0)
+#define LCR_BAUD_LATCH (1 << 7) // special mode to set baud rate
+#define LSR 5					// line status register
+#define LSR_RX_READY (1 << 0)	// input is waiting to be read from RHR
+#define LSR_TX_IDLE (1 << 5)	// THR can accept another character to send
 
 #define ReadReg(reg) (*(Reg(reg)))
 #define WriteReg(reg, v) (*(Reg(reg)) = (v))
@@ -49,32 +49,30 @@ extern volatile int panicked; // from printf.c
 
 void uartstart();
 
-void
-uartinit(void)
-{
-  // disable interrupts.
-  WriteReg(IER, 0x00);
+void uartinit(void) {
+	// disable interrupts.
+	WriteReg(IER, 0x00);
 
-  // special mode to set baud rate.
-  WriteReg(LCR, LCR_BAUD_LATCH);
+	// special mode to set baud rate.
+	WriteReg(LCR, LCR_BAUD_LATCH);
 
-  // LSB for baud rate of 38.4K.
-  WriteReg(0, 0x03);
+	// LSB for baud rate of 38.4K.
+	WriteReg(0, 0x03);
 
-  // MSB for baud rate of 38.4K.
-  WriteReg(1, 0x00);
+	// MSB for baud rate of 38.4K.
+	WriteReg(1, 0x00);
 
-  // leave set-baud mode,
-  // and set word length to 8 bits, no parity.
-  WriteReg(LCR, LCR_EIGHT_BITS);
+	// leave set-baud mode,
+	// and set word length to 8 bits, no parity.
+	WriteReg(LCR, LCR_EIGHT_BITS);
 
-  // reset and enable FIFOs.
-  WriteReg(FCR, FCR_FIFO_ENABLE | FCR_FIFO_CLEAR);
+	// reset and enable FIFOs.
+	WriteReg(FCR, FCR_FIFO_ENABLE | FCR_FIFO_CLEAR);
 
-  // enable transmit and receive interrupts.
-  WriteReg(IER, IER_TX_ENABLE | IER_RX_ENABLE);
+	// enable transmit and receive interrupts.
+	WriteReg(IER, IER_TX_ENABLE | IER_RX_ENABLE);
 
-  initlock(&uart_tx_lock, "uart");
+	initlock(&uart_tx_lock, "uart");
 }
 
 // add a character to the output buffer and tell the
@@ -83,108 +81,97 @@ uartinit(void)
 // because it may block, it can't be called
 // from interrupts; it's only suitable for use
 // by write().
-void
-uartputc(int c)
-{
-  acquire(&uart_tx_lock);
+void uartputc(int c) {
+	acquire(&uart_tx_lock);
 
-  if(panicked){
-    for(;;)
-      ;
-  }
-  while(uart_tx_w == uart_tx_r + UART_TX_BUF_SIZE){
-    // buffer is full.
-    // wait for uartstart() to open up space in the buffer.
-    sleep(&uart_tx_r, &uart_tx_lock);
-  }
-  uart_tx_buf[uart_tx_w % UART_TX_BUF_SIZE] = c;
-  uart_tx_w += 1;
-  uartstart();
-  release(&uart_tx_lock);
+	if (panicked) {
+		for (;;)
+			;
+	}
+	while (uart_tx_w == uart_tx_r + UART_TX_BUF_SIZE) {
+		// buffer is full.
+		// wait for uartstart() to open up space in the buffer.
+		sleep(&uart_tx_r, &uart_tx_lock);
+	}
+	uart_tx_buf[uart_tx_w % UART_TX_BUF_SIZE] = c;
+	uart_tx_w += 1;
+	uartstart();
+	release(&uart_tx_lock);
 }
 
-
-// alternate version of uartputc() that doesn't 
+// alternate version of uartputc() that doesn't
 // use interrupts, for use by kernel printf() and
 // to echo characters. it spins waiting for the uart's
 // output register to be empty.
-void
-uartputc_sync(int c)
-{
-  push_off();
+void uartputc_sync(int c) {
+	push_off();
 
-  if(panicked){
-    for(;;)
-      ;
-  }
+	if (panicked) {
+		for (;;)
+			;
+	}
 
-  // wait for Transmit Holding Empty to be set in LSR.
-  while((ReadReg(LSR) & LSR_TX_IDLE) == 0)
-    ;
-  WriteReg(THR, c);
+	// wait for Transmit Holding Empty to be set in LSR.
+	while ((ReadReg(LSR) & LSR_TX_IDLE) == 0)
+		;
+	WriteReg(THR, c);
 
-  pop_off();
+	pop_off();
 }
 
 // if the UART is idle, and a character is waiting
 // in the transmit buffer, send it.
 // caller must hold uart_tx_lock.
 // called from both the top- and bottom-half.
-void
-uartstart()
-{
-  while(1){
-    if(uart_tx_w == uart_tx_r){
-      // transmit buffer is empty.
-      return;
-    }
-    
-    if((ReadReg(LSR) & LSR_TX_IDLE) == 0){
-      // the UART transmit holding register is full,
-      // so we cannot give it another byte.
-      // it will interrupt when it's ready for a new byte.
-      return;
-    }
-    
-    int c = uart_tx_buf[uart_tx_r % UART_TX_BUF_SIZE];
-    uart_tx_r += 1;
-    
-    // maybe uartputc() is waiting for space in the buffer.
-    wakeup(&uart_tx_r);
-    
-    WriteReg(THR, c);
-  }
+void uartstart() {
+	while (1) {
+		if (uart_tx_w == uart_tx_r) {
+			// transmit buffer is empty.
+			return;
+		}
+
+		if ((ReadReg(LSR) & LSR_TX_IDLE) == 0) {
+			// the UART transmit holding register is full,
+			// so we cannot give it another byte.
+			// it will interrupt when it's ready for a new byte.
+			return;
+		}
+
+		int c = uart_tx_buf[uart_tx_r % UART_TX_BUF_SIZE];
+		uart_tx_r += 1;
+
+		// maybe uartputc() is waiting for space in the buffer.
+		wakeup(&uart_tx_r);
+
+		WriteReg(THR, c);
+	}
 }
 
 // read one input character from the UART.
 // return -1 if none is waiting.
-int
-uartgetc(void)
-{
-  if(ReadReg(LSR) & 0x01){
-    // input data is ready.
-    return ReadReg(RHR);
-  } else {
-    return -1;
-  }
+int uartgetc(void) {
+	if (ReadReg(LSR) & 0x01) {
+		// input data is ready.
+		return ReadReg(RHR);
+	} else {
+		return -1;
+	}
 }
 
 // handle a uart interrupt, raised because input has
 // arrived, or the uart is ready for more output, or
 // both. called from devintr().
-void
-uartintr(void)
-{
-  // read and process incoming characters.
-  while(1){
-    int c = uartgetc();
-    if(c == -1)
-      break;
-    consoleintr(c);
-  }
+void uartintr(void) {
+	// read and process incoming characters.
+	while (1) {
+		int c = uartgetc();
+		if (c == -1)
+			break;
+		consoleintr(c);
+	}
 
-  // send buffered characters.
-  acquire(&uart_tx_lock);
-  uartstart();
-  release(&uart_tx_lock);
+	// send buffered characters.
+	acquire(&uart_tx_lock);
+	uartstart();
+	release(&uart_tx_lock);
 }

kernel/virtio_disk.c

@@ -2,7 +2,8 @@
 // driver for qemu's virtio disk device.
 // uses qemu's mmio interface to virtio.
 //
-// qemu ... -drive file=fs.img,if=none,format=raw,id=x0 -device virtio-blk-device,drive=x0,bus=virtio-mmio-bus.0
+// qemu ... -drive file=fs.img,if=none,format=raw,id=x0 -device
+// virtio-blk-device,drive=x0,bus=virtio-mmio-bus.0
 //
 
 #include "types.h"
@@ -20,308 +21,293 @@
 #define R(r) ((volatile uint32 *)(VIRTIO0 + (r)))
 
 static struct disk {
-  // a set (not a ring) of DMA descriptors, with which the
-  // driver tells the device where to read and write individual
-  // disk operations. there are NUM descriptors.
-  // most commands consist of a "chain" (a linked list) of a couple of
-  // these descriptors.
-  struct virtq_desc *desc;
+	// a set (not a ring) of DMA descriptors, with which the
+	// driver tells the device where to read and write individual
+	// disk operations. there are NUM descriptors.
+	// most commands consist of a "chain" (a linked list) of a couple of
+	// these descriptors.
+	struct virtq_desc *desc;
 
-  // a ring in which the driver writes descriptor numbers
-  // that the driver would like the device to process.  it only
-  // includes the head descriptor of each chain. the ring has
-  // NUM elements.
-  struct virtq_avail *avail;
+	// a ring in which the driver writes descriptor numbers
+	// that the driver would like the device to process.  it only
+	// includes the head descriptor of each chain. the ring has
+	// NUM elements.
+	struct virtq_avail *avail;
 
-  // a ring in which the device writes descriptor numbers that
-  // the device has finished processing (just the head of each chain).
-  // there are NUM used ring entries.
-  struct virtq_used *used;
+	// a ring in which the device writes descriptor numbers that
+	// the device has finished processing (just the head of each chain).
+	// there are NUM used ring entries.
+	struct virtq_used *used;
 
-  // our own book-keeping.
-  char free[NUM];  // is a descriptor free?
-  uint16 used_idx; // we've looked this far in used[2..NUM].
+	// our own book-keeping.
+	char free[NUM];	 // is a descriptor free?
+	uint16 used_idx; // we've looked this far in used[2..NUM].
 
-  // track info about in-flight operations,
-  // for use when completion interrupt arrives.
-  // indexed by first descriptor index of chain.
-  struct {
-    struct buf *b;
-    char status;
-  } info[NUM];
+	// track info about in-flight operations,
+	// for use when completion interrupt arrives.
+	// indexed by first descriptor index of chain.
+	struct {
+		struct buf *b;
+		char status;
+	} info[NUM];
+
+	// disk command headers.
+	// one-for-one with descriptors, for convenience.
+	struct virtio_blk_req ops[NUM];
+
+	struct spinlock vdisk_lock;
 
-  // disk command headers.
-  // one-for-one with descriptors, for convenience.
-  struct virtio_blk_req ops[NUM];
-  
-  struct spinlock vdisk_lock;
-  
 } disk;
 
-void
-virtio_disk_init(void)
-{
-  uint32 status = 0;
+void virtio_disk_init(void) {
+	uint32 status = 0;
 
-  initlock(&disk.vdisk_lock, "virtio_disk");
+	initlock(&disk.vdisk_lock, "virtio_disk");
 
-  if(*R(VIRTIO_MMIO_MAGIC_VALUE) != 0x74726976 ||
-     *R(VIRTIO_MMIO_VERSION) != 2 ||
-     *R(VIRTIO_MMIO_DEVICE_ID) != 2 ||
-     *R(VIRTIO_MMIO_VENDOR_ID) != 0x554d4551){
-    panic("could not find virtio disk");
-  }
-  
-  // reset device
-  *R(VIRTIO_MMIO_STATUS) = status;
+	if (*R(VIRTIO_MMIO_MAGIC_VALUE) != 0x74726976 ||
+		*R(VIRTIO_MMIO_VERSION) != 2 || *R(VIRTIO_MMIO_DEVICE_ID) != 2 ||
+		*R(VIRTIO_MMIO_VENDOR_ID) != 0x554d4551) {
+		panic("could not find virtio disk");
+	}
 
-  // set ACKNOWLEDGE status bit
-  status |= VIRTIO_CONFIG_S_ACKNOWLEDGE;
-  *R(VIRTIO_MMIO_STATUS) = status;
+	// reset device
+	*R(VIRTIO_MMIO_STATUS) = status;
 
-  // set DRIVER status bit
-  status |= VIRTIO_CONFIG_S_DRIVER;
-  *R(VIRTIO_MMIO_STATUS) = status;
+	// set ACKNOWLEDGE status bit
+	status |= VIRTIO_CONFIG_S_ACKNOWLEDGE;
+	*R(VIRTIO_MMIO_STATUS) = status;
 
-  // negotiate features
-  uint64 features = *R(VIRTIO_MMIO_DEVICE_FEATURES);
-  features &= ~(1 << VIRTIO_BLK_F_RO);
-  features &= ~(1 << VIRTIO_BLK_F_SCSI);
-  features &= ~(1 << VIRTIO_BLK_F_CONFIG_WCE);
-  features &= ~(1 << VIRTIO_BLK_F_MQ);
-  features &= ~(1 << VIRTIO_F_ANY_LAYOUT);
-  features &= ~(1 << VIRTIO_RING_F_EVENT_IDX);
-  features &= ~(1 << VIRTIO_RING_F_INDIRECT_DESC);
-  *R(VIRTIO_MMIO_DRIVER_FEATURES) = features;
+	// set DRIVER status bit
+	status |= VIRTIO_CONFIG_S_DRIVER;
+	*R(VIRTIO_MMIO_STATUS) = status;
 
-  // tell device that feature negotiation is complete.
-  status |= VIRTIO_CONFIG_S_FEATURES_OK;
-  *R(VIRTIO_MMIO_STATUS) = status;
+	// negotiate features
+	uint64 features = *R(VIRTIO_MMIO_DEVICE_FEATURES);
+	features &= ~(1 << VIRTIO_BLK_F_RO);
+	features &= ~(1 << VIRTIO_BLK_F_SCSI);
+	features &= ~(1 << VIRTIO_BLK_F_CONFIG_WCE);
+	features &= ~(1 << VIRTIO_BLK_F_MQ);
+	features &= ~(1 << VIRTIO_F_ANY_LAYOUT);
+	features &= ~(1 << VIRTIO_RING_F_EVENT_IDX);
+	features &= ~(1 << VIRTIO_RING_F_INDIRECT_DESC);
+	*R(VIRTIO_MMIO_DRIVER_FEATURES) = features;
 
-  // re-read status to ensure FEATURES_OK is set.
-  status = *R(VIRTIO_MMIO_STATUS);
-  if(!(status & VIRTIO_CONFIG_S_FEATURES_OK))
-    panic("virtio disk FEATURES_OK unset");
+	// tell device that feature negotiation is complete.
+	status |= VIRTIO_CONFIG_S_FEATURES_OK;
+	*R(VIRTIO_MMIO_STATUS) = status;
 
-  // initialize queue 0.
-  *R(VIRTIO_MMIO_QUEUE_SEL) = 0;
+	// re-read status to ensure FEATURES_OK is set.
+	status = *R(VIRTIO_MMIO_STATUS);
+	if (!(status & VIRTIO_CONFIG_S_FEATURES_OK))
+		panic("virtio disk FEATURES_OK unset");
 
-  // ensure queue 0 is not in use.
-  if(*R(VIRTIO_MMIO_QUEUE_READY))
-    panic("virtio disk should not be ready");
+	// initialize queue 0.
+	*R(VIRTIO_MMIO_QUEUE_SEL) = 0;
 
-  // check maximum queue size.
-  uint32 max = *R(VIRTIO_MMIO_QUEUE_NUM_MAX);
-  if(max == 0)
-    panic("virtio disk has no queue 0");
-  if(max < NUM)
-    panic("virtio disk max queue too short");
+	// ensure queue 0 is not in use.
+	if (*R(VIRTIO_MMIO_QUEUE_READY))
+		panic("virtio disk should not be ready");
 
-  // allocate and zero queue memory.
-  disk.desc = kalloc();
-  disk.avail = kalloc();
-  disk.used = kalloc();
-  if(!disk.desc || !disk.avail || !disk.used)
-    panic("virtio disk kalloc");
-  memset(disk.desc, 0, PGSIZE);
-  memset(disk.avail, 0, PGSIZE);
-  memset(disk.used, 0, PGSIZE);
+	// check maximum queue size.
+	uint32 max = *R(VIRTIO_MMIO_QUEUE_NUM_MAX);
+	if (max == 0)
+		panic("virtio disk has no queue 0");
+	if (max < NUM)
+		panic("virtio disk max queue too short");
 
-  // set queue size.
-  *R(VIRTIO_MMIO_QUEUE_NUM) = NUM;
+	// allocate and zero queue memory.
+	disk.desc = kalloc();
+	disk.avail = kalloc();
+	disk.used = kalloc();
+	if (!disk.desc || !disk.avail || !disk.used)
+		panic("virtio disk kalloc");
+	memset(disk.desc, 0, PGSIZE);
+	memset(disk.avail, 0, PGSIZE);
+	memset(disk.used, 0, PGSIZE);
 
-  // write physical addresses.
-  *R(VIRTIO_MMIO_QUEUE_DESC_LOW) = (uint64)disk.desc;
-  *R(VIRTIO_MMIO_QUEUE_DESC_HIGH) = (uint64)disk.desc >> 32;
-  *R(VIRTIO_MMIO_DRIVER_DESC_LOW) = (uint64)disk.avail;
-  *R(VIRTIO_MMIO_DRIVER_DESC_HIGH) = (uint64)disk.avail >> 32;
-  *R(VIRTIO_MMIO_DEVICE_DESC_LOW) = (uint64)disk.used;
-  *R(VIRTIO_MMIO_DEVICE_DESC_HIGH) = (uint64)disk.used >> 32;
+	// set queue size.
+	*R(VIRTIO_MMIO_QUEUE_NUM) = NUM;
 
-  // queue is ready.
-  *R(VIRTIO_MMIO_QUEUE_READY) = 0x1;
+	// write physical addresses.
+	*R(VIRTIO_MMIO_QUEUE_DESC_LOW) = (uint64)disk.desc;
+	*R(VIRTIO_MMIO_QUEUE_DESC_HIGH) = (uint64)disk.desc >> 32;
+	*R(VIRTIO_MMIO_DRIVER_DESC_LOW) = (uint64)disk.avail;
+	*R(VIRTIO_MMIO_DRIVER_DESC_HIGH) = (uint64)disk.avail >> 32;
+	*R(VIRTIO_MMIO_DEVICE_DESC_LOW) = (uint64)disk.used;
+	*R(VIRTIO_MMIO_DEVICE_DESC_HIGH) = (uint64)disk.used >> 32;
 
-  // all NUM descriptors start out unused.
-  for(int i = 0; i < NUM; i++)
-    disk.free[i] = 1;
+	// queue is ready.
+	*R(VIRTIO_MMIO_QUEUE_READY) = 0x1;
 
-  // tell device we're completely ready.
-  status |= VIRTIO_CONFIG_S_DRIVER_OK;
-  *R(VIRTIO_MMIO_STATUS) = status;
+	// all NUM descriptors start out unused.
+	for (int i = 0; i < NUM; i++)
+		disk.free[i] = 1;
 
-  // plic.c and trap.c arrange for interrupts from VIRTIO0_IRQ.
+	// tell device we're completely ready.
+	status |= VIRTIO_CONFIG_S_DRIVER_OK;
+	*R(VIRTIO_MMIO_STATUS) = status;
+
+	// plic.c and trap.c arrange for interrupts from VIRTIO0_IRQ.
 }
 
 // find a free descriptor, mark it non-free, return its index.
-static int
-alloc_desc()
-{
-  for(int i = 0; i < NUM; i++){
-    if(disk.free[i]){
-      disk.free[i] = 0;
-      return i;
-    }
-  }
-  return -1;
+static int alloc_desc() {
+	for (int i = 0; i < NUM; i++) {
+		if (disk.free[i]) {
+			disk.free[i] = 0;
+			return i;
+		}
+	}
+	return -1;
 }
 
 // mark a descriptor as free.
-static void
-free_desc(int i)
-{
-  if(i >= NUM)
-    panic("free_desc 1");
-  if(disk.free[i])
-    panic("free_desc 2");
-  disk.desc[i].addr = 0;
-  disk.desc[i].len = 0;
-  disk.desc[i].flags = 0;
-  disk.desc[i].next = 0;
-  disk.free[i] = 1;
-  wakeup(&disk.free[0]);
+static void free_desc(int i) {
+	if (i >= NUM)
+		panic("free_desc 1");
+	if (disk.free[i])
+		panic("free_desc 2");
+	disk.desc[i].addr = 0;
+	disk.desc[i].len = 0;
+	disk.desc[i].flags = 0;
+	disk.desc[i].next = 0;
+	disk.free[i] = 1;
+	wakeup(&disk.free[0]);
 }
 
 // free a chain of descriptors.
-static void
-free_chain(int i)
-{
-  while(1){
-    int flag = disk.desc[i].flags;
-    int nxt = disk.desc[i].next;
-    free_desc(i);
-    if(flag & VRING_DESC_F_NEXT)
-      i = nxt;
-    else
-      break;
-  }
+static void free_chain(int i) {
+	while (1) {
+		int flag = disk.desc[i].flags;
+		int nxt = disk.desc[i].next;
+		free_desc(i);
+		if (flag & VRING_DESC_F_NEXT)
+			i = nxt;
+		else
+			break;
+	}
 }
 
 // allocate three descriptors (they need not be contiguous).
 // disk transfers always use three descriptors.
-static int
-alloc3_desc(int *idx)
-{
-  for(int i = 0; i < 3; i++){
-    idx[i] = alloc_desc();
-    if(idx[i] < 0){
-      for(int j = 0; j < i; j++)
-        free_desc(idx[j]);
-      return -1;
-    }
-  }
-  return 0;
+static int alloc3_desc(int *idx) {
+	for (int i = 0; i < 3; i++) {
+		idx[i] = alloc_desc();
+		if (idx[i] < 0) {
+			for (int j = 0; j < i; j++)
+				free_desc(idx[j]);
+			return -1;
+		}
+	}
+	return 0;
 }
 
-void
-virtio_disk_rw(struct buf *b, int write)
-{
-  uint64 sector = b->blockno * (BSIZE / 512);
+void virtio_disk_rw(struct buf *b, int write) {
+	uint64 sector = b->blockno * (BSIZE / 512);
 
-  acquire(&disk.vdisk_lock);
+	acquire(&disk.vdisk_lock);
 
-  // the spec's Section 5.2 says that legacy block operations use
-  // three descriptors: one for type/reserved/sector, one for the
-  // data, one for a 1-byte status result.
+	// the spec's Section 5.2 says that legacy block operations use
+	// three descriptors: one for type/reserved/sector, one for the
+	// data, one for a 1-byte status result.
 
-  // allocate the three descriptors.
-  int idx[3];
-  while(1){
-    if(alloc3_desc(idx) == 0) {
-      break;
-    }
-    sleep(&disk.free[0], &disk.vdisk_lock);
-  }
+	// allocate the three descriptors.
+	int idx[3];
+	while (1) {
+		if (alloc3_desc(idx) == 0) {
+			break;
+		}
+		sleep(&disk.free[0], &disk.vdisk_lock);
+	}
 
-  // format the three descriptors.
-  // qemu's virtio-blk.c reads them.
+	// format the three descriptors.
+	// qemu's virtio-blk.c reads them.
 
-  struct virtio_blk_req *buf0 = &disk.ops[idx[0]];
+	struct virtio_blk_req *buf0 = &disk.ops[idx[0]];
 
-  if(write)
-    buf0->type = VIRTIO_BLK_T_OUT; // write the disk
-  else
-    buf0->type = VIRTIO_BLK_T_IN; // read the disk
-  buf0->reserved = 0;
-  buf0->sector = sector;
+	if (write)
+		buf0->type = VIRTIO_BLK_T_OUT; // write the disk
+	else
+		buf0->type = VIRTIO_BLK_T_IN; // read the disk
+	buf0->reserved = 0;
+	buf0->sector = sector;
 
-  disk.desc[idx[0]].addr = (uint64) buf0;
-  disk.desc[idx[0]].len = sizeof(struct virtio_blk_req);
-  disk.desc[idx[0]].flags = VRING_DESC_F_NEXT;
-  disk.desc[idx[0]].next = idx[1];
+	disk.desc[idx[0]].addr = (uint64)buf0;
+	disk.desc[idx[0]].len = sizeof(struct virtio_blk_req);
+	disk.desc[idx[0]].flags = VRING_DESC_F_NEXT;
+	disk.desc[idx[0]].next = idx[1];
 
-  disk.desc[idx[1]].addr = (uint64) b->data;
-  disk.desc[idx[1]].len = BSIZE;
-  if(write)
-    disk.desc[idx[1]].flags = 0; // device reads b->data
-  else
-    disk.desc[idx[1]].flags = VRING_DESC_F_WRITE; // device writes b->data
-  disk.desc[idx[1]].flags |= VRING_DESC_F_NEXT;
-  disk.desc[idx[1]].next = idx[2];
+	disk.desc[idx[1]].addr = (uint64)b->data;
+	disk.desc[idx[1]].len = BSIZE;
+	if (write)
+		disk.desc[idx[1]].flags = 0; // device reads b->data
+	else
+		disk.desc[idx[1]].flags = VRING_DESC_F_WRITE; // device writes b->data
+	disk.desc[idx[1]].flags |= VRING_DESC_F_NEXT;
+	disk.desc[idx[1]].next = idx[2];
 
-  disk.info[idx[0]].status = 0xff; // device writes 0 on success
-  disk.desc[idx[2]].addr = (uint64) &disk.info[idx[0]].status;
-  disk.desc[idx[2]].len = 1;
-  disk.desc[idx[2]].flags = VRING_DESC_F_WRITE; // device writes the status
-  disk.desc[idx[2]].next = 0;
+	disk.info[idx[0]].status = 0xff; // device writes 0 on success
+	disk.desc[idx[2]].addr = (uint64)&disk.info[idx[0]].status;
+	disk.desc[idx[2]].len = 1;
+	disk.desc[idx[2]].flags = VRING_DESC_F_WRITE; // device writes the status
+	disk.desc[idx[2]].next = 0;
 
-  // record struct buf for virtio_disk_intr().
-  b->disk = 1;
-  disk.info[idx[0]].b = b;
+	// record struct buf for virtio_disk_intr().
+	b->disk = 1;
+	disk.info[idx[0]].b = b;
 
-  // tell the device the first index in our chain of descriptors.
-  disk.avail->ring[disk.avail->idx % NUM] = idx[0];
+	// tell the device the first index in our chain of descriptors.
+	disk.avail->ring[disk.avail->idx % NUM] = idx[0];
 
-  __sync_synchronize();
+	__sync_synchronize();
 
-  // tell the device another avail ring entry is available.
-  disk.avail->idx += 1; // not % NUM ...
+	// tell the device another avail ring entry is available.
+	disk.avail->idx += 1; // not % NUM ...
 
-  __sync_synchronize();
+	__sync_synchronize();
 
-  *R(VIRTIO_MMIO_QUEUE_NOTIFY) = 0; // value is queue number
+	*R(VIRTIO_MMIO_QUEUE_NOTIFY) = 0; // value is queue number
 
-  // Wait for virtio_disk_intr() to say request has finished.
-  while(b->disk == 1) {
-    sleep(b, &disk.vdisk_lock);
-  }
+	// Wait for virtio_disk_intr() to say request has finished.
+	while (b->disk == 1) {
+		sleep(b, &disk.vdisk_lock);
+	}
 
-  disk.info[idx[0]].b = 0;
-  free_chain(idx[0]);
+	disk.info[idx[0]].b = 0;
+	free_chain(idx[0]);
 
-  release(&disk.vdisk_lock);
+	release(&disk.vdisk_lock);
 }
 
-void
-virtio_disk_intr()
-{
-  acquire(&disk.vdisk_lock);
+void virtio_disk_intr() {
+	acquire(&disk.vdisk_lock);
 
-  // the device won't raise another interrupt until we tell it
-  // we've seen this interrupt, which the following line does.
-  // this may race with the device writing new entries to
-  // the "used" ring, in which case we may process the new
-  // completion entries in this interrupt, and have nothing to do
-  // in the next interrupt, which is harmless.
-  *R(VIRTIO_MMIO_INTERRUPT_ACK) = *R(VIRTIO_MMIO_INTERRUPT_STATUS) & 0x3;
+	// the device won't raise another interrupt until we tell it
+	// we've seen this interrupt, which the following line does.
+	// this may race with the device writing new entries to
+	// the "used" ring, in which case we may process the new
+	// completion entries in this interrupt, and have nothing to do
+	// in the next interrupt, which is harmless.
+	*R(VIRTIO_MMIO_INTERRUPT_ACK) = *R(VIRTIO_MMIO_INTERRUPT_STATUS) & 0x3;
 
-  __sync_synchronize();
+	__sync_synchronize();
 
-  // the device increments disk.used->idx when it
-  // adds an entry to the used ring.
+	// the device increments disk.used->idx when it
+	// adds an entry to the used ring.
 
-  while(disk.used_idx != disk.used->idx){
-    __sync_synchronize();
-    int id = disk.used->ring[disk.used_idx % NUM].id;
+	while (disk.used_idx != disk.used->idx) {
+		__sync_synchronize();
+		int id = disk.used->ring[disk.used_idx % NUM].id;
 
-    if(disk.info[id].status != 0)
-      panic("virtio_disk_intr status");
+		if (disk.info[id].status != 0)
+			panic("virtio_disk_intr status");
 
-    struct buf *b = disk.info[id].b;
-    b->disk = 0;   // disk is done with buf
-    wakeup(b);
+		struct buf *b = disk.info[id].b;
+		b->disk = 0; // disk is done with buf
+		wakeup(b);
 
-    disk.used_idx += 1;
-  }
+		disk.used_idx += 1;
+	}
 
-  release(&disk.vdisk_lock);
+	release(&disk.vdisk_lock);
 }

kernel/vm.c

@@ -11,58 +11,56 @@
  */
 pagetable_t kernel_pagetable;
 
-extern char etext[];  // kernel.ld sets this to end of kernel code.
+extern char etext[]; // kernel.ld sets this to end of kernel code.
 
 extern char trampoline[]; // trampoline.S
 
 // Make a direct-map page table for the kernel.
-pagetable_t
-kvmmake(void)
-{
-  pagetable_t kpgtbl;
+pagetable_t kvmmake(void) {
+	pagetable_t kpgtbl;
 
-  kpgtbl = (pagetable_t) kalloc();
-  memset(kpgtbl, 0, PGSIZE);
+	kpgtbl = (pagetable_t)kalloc();
+	memset(kpgtbl, 0, PGSIZE);
 
-  // uart registers
-  kvmmap(kpgtbl, UART0, UART0, PGSIZE, PTE_R | PTE_W);
+	// uart registers
+	kvmmap(kpgtbl, UART0, UART0, PGSIZE, PTE_R | PTE_W);
 
-  // virtio mmio disk interface
-  kvmmap(kpgtbl, VIRTIO0, VIRTIO0, PGSIZE, PTE_R | PTE_W);
+	// virtio mmio disk interface
+	kvmmap(kpgtbl, VIRTIO0, VIRTIO0, PGSIZE, PTE_R | PTE_W);
 
-  // PLIC
-  kvmmap(kpgtbl, PLIC, PLIC, 0x400000, PTE_R | PTE_W);
+	// PLIC
+	kvmmap(kpgtbl, PLIC, PLIC, 0x400000, PTE_R | PTE_W);
 
-  // map kernel text executable and read-only.
-  kvmmap(kpgtbl, KERNBASE, KERNBASE, (uint64)etext-KERNBASE, PTE_R | PTE_X);
+	// map kernel text executable and read-only.
+	kvmmap(kpgtbl, KERNBASE, KERNBASE, (uint64)etext - KERNBASE, PTE_R | PTE_X);
 
-  // map kernel data and the physical RAM we'll make use of.
-  kvmmap(kpgtbl, (uint64)etext, (uint64)etext, PHYSTOP-(uint64)etext, PTE_R | PTE_W);
+	// map kernel data and the physical RAM we'll make use of.
+	kvmmap(kpgtbl, (uint64)etext, (uint64)etext, PHYSTOP - (uint64)etext,
+		   PTE_R | PTE_W);
 
-  // map the trampoline for trap entry/exit to
-  // the highest virtual address in the kernel.
-  kvmmap(kpgtbl, TRAMPOLINE, (uint64)trampoline, PGSIZE, PTE_R | PTE_X);
+	// map the trampoline for trap entry/exit to
+	// the highest virtual address in the kernel.
+	kvmmap(kpgtbl, TRAMPOLINE, (uint64)trampoline, PGSIZE, PTE_R | PTE_X);
 
-  // allocate and map a kernel stack for each process.
-  proc_mapstacks(kpgtbl);
-  
-  return kpgtbl;
+	// allocate and map a kernel stack for each process.
+	proc_mapstacks(kpgtbl);
+
+	return kpgtbl;
 }
 
 // Initialize the one kernel_pagetable
-void
-kvminit(void)
-{
-  kernel_pagetable = kvmmake();
-}
+void kvminit(void) { kernel_pagetable = kvmmake(); }
 
 // Switch h/w page table register to the kernel's page table,
 // and enable paging.
-void
-kvminithart()
-{
-  w_satp(MAKE_SATP(kernel_pagetable));
-  sfence_vma();
+void kvminithart() {
+	// wait for any previous writes to the page table memory to finish.
+	sfence_vma();
+
+	w_satp(MAKE_SATP(kernel_pagetable));
+
+	// flush stale entries from the TLB.
+	sfence_vma();
 }
 
 // Return the address of the PTE in page table pagetable
@@ -77,218 +75,198 @@ kvminithart()
 //   21..29 -- 9 bits of level-1 index.
 //   12..20 -- 9 bits of level-0 index.
 //    0..11 -- 12 bits of byte offset within the page.
-pte_t *
-walk(pagetable_t pagetable, uint64 va, int alloc)
-{
-  if(va >= MAXVA)
-    panic("walk");
+pte_t *walk(pagetable_t pagetable, uint64 va, int alloc) {
+	if (va >= MAXVA)
+		panic("walk");
 
-  for(int level = 2; level > 0; level--) {
-    pte_t *pte = &pagetable[PX(level, va)];
-    if(*pte & PTE_V) {
-      pagetable = (pagetable_t)PTE2PA(*pte);
-    } else {
-      if(!alloc || (pagetable = (pde_t*)kalloc()) == 0)
-        return 0;
-      memset(pagetable, 0, PGSIZE);
-      *pte = PA2PTE(pagetable) | PTE_V;
-    }
-  }
-  return &pagetable[PX(0, va)];
+	for (int level = 2; level > 0; level--) {
+		pte_t *pte = &pagetable[PX(level, va)];
+		if (*pte & PTE_V) {
+			pagetable = (pagetable_t)PTE2PA(*pte);
+		} else {
+			if (!alloc || (pagetable = (pde_t *)kalloc()) == 0)
+				return 0;
+			memset(pagetable, 0, PGSIZE);
+			*pte = PA2PTE(pagetable) | PTE_V;
+		}
+	}
+	return &pagetable[PX(0, va)];
 }
 
 // Look up a virtual address, return the physical address,
 // or 0 if not mapped.
 // Can only be used to look up user pages.
-uint64
-walkaddr(pagetable_t pagetable, uint64 va)
-{
-  pte_t *pte;
-  uint64 pa;
+uint64 walkaddr(pagetable_t pagetable, uint64 va) {
+	pte_t *pte;
+	uint64 pa;
 
-  if(va >= MAXVA)
-    return 0;
+	if (va >= MAXVA)
+		return 0;
 
-  pte = walk(pagetable, va, 0);
-  if(pte == 0)
-    return 0;
-  if((*pte & PTE_V) == 0)
-    return 0;
-  if((*pte & PTE_U) == 0)
-    return 0;
-  pa = PTE2PA(*pte);
-  return pa;
+	pte = walk(pagetable, va, 0);
+	if (pte == 0)
+		return 0;
+	if ((*pte & PTE_V) == 0)
+		return 0;
+	if ((*pte & PTE_U) == 0)
+		return 0;
+	pa = PTE2PA(*pte);
+	return pa;
 }
 
 // add a mapping to the kernel page table.
 // only used when booting.
 // does not flush TLB or enable paging.
-void
-kvmmap(pagetable_t kpgtbl, uint64 va, uint64 pa, uint64 sz, int perm)
-{
-  if(mappages(kpgtbl, va, sz, pa, perm) != 0)
-    panic("kvmmap");
+void kvmmap(pagetable_t kpgtbl, uint64 va, uint64 pa, uint64 sz, int perm) {
+	if (mappages(kpgtbl, va, sz, pa, perm) != 0)
+		panic("kvmmap");
 }
 
 // Create PTEs for virtual addresses starting at va that refer to
 // physical addresses starting at pa. va and size might not
 // be page-aligned. Returns 0 on success, -1 if walk() couldn't
 // allocate a needed page-table page.
-int
-mappages(pagetable_t pagetable, uint64 va, uint64 size, uint64 pa, int perm)
-{
-  uint64 a, last;
-  pte_t *pte;
+int mappages(pagetable_t pagetable, uint64 va, uint64 size, uint64 pa,
+			 int perm) {
+	uint64 a, last;
+	pte_t *pte;
 
-  if(size == 0)
-    panic("mappages: size");
-  
-  a = PGROUNDDOWN(va);
-  last = PGROUNDDOWN(va + size - 1);
-  for(;;){
-    if((pte = walk(pagetable, a, 1)) == 0)
-      return -1;
-    if(*pte & PTE_V)
-      panic("mappages: remap");
-    *pte = PA2PTE(pa) | perm | PTE_V;
-    if(a == last)
-      break;
-    a += PGSIZE;
-    pa += PGSIZE;
-  }
-  return 0;
+	if (size == 0)
+		panic("mappages: size");
+
+	a = PGROUNDDOWN(va);
+	last = PGROUNDDOWN(va + size - 1);
+	for (;;) {
+		if ((pte = walk(pagetable, a, 1)) == 0)
+			return -1;
+		if (*pte & PTE_V)
+			panic("mappages: remap");
+		*pte = PA2PTE(pa) | perm | PTE_V;
+		if (a == last)
+			break;
+		a += PGSIZE;
+		pa += PGSIZE;
+	}
+	return 0;
 }
 
 // Remove npages of mappings starting from va. va must be
 // page-aligned. The mappings must exist.
 // Optionally free the physical memory.
-void
-uvmunmap(pagetable_t pagetable, uint64 va, uint64 npages, int do_free)
-{
-  uint64 a;
-  pte_t *pte;
+void uvmunmap(pagetable_t pagetable, uint64 va, uint64 npages, int do_free) {
+	uint64 a;
+	pte_t *pte;
 
-  if((va % PGSIZE) != 0)
-    panic("uvmunmap: not aligned");
+	if ((va % PGSIZE) != 0)
+		panic("uvmunmap: not aligned");
 
-  for(a = va; a < va + npages*PGSIZE; a += PGSIZE){
-    if((pte = walk(pagetable, a, 0)) == 0)
-      panic("uvmunmap: walk");
-    if((*pte & PTE_V) == 0)
-      panic("uvmunmap: not mapped");
-    if(PTE_FLAGS(*pte) == PTE_V)
-      panic("uvmunmap: not a leaf");
-    if(do_free){
-      uint64 pa = PTE2PA(*pte);
-      kfree((void*)pa);
-    }
-    *pte = 0;
-  }
+	for (a = va; a < va + npages * PGSIZE; a += PGSIZE) {
+		if ((pte = walk(pagetable, a, 0)) == 0)
+			panic("uvmunmap: walk");
+		if ((*pte & PTE_V) == 0)
+			panic("uvmunmap: not mapped");
+		if (PTE_FLAGS(*pte) == PTE_V)
+			panic("uvmunmap: not a leaf");
+		if (do_free) {
+			uint64 pa = PTE2PA(*pte);
+			kfree((void *)pa);
+		}
+		*pte = 0;
+	}
 }
 
 // create an empty user page table.
 // returns 0 if out of memory.
-pagetable_t
-uvmcreate()
-{
-  pagetable_t pagetable;
-  pagetable = (pagetable_t) kalloc();
-  if(pagetable == 0)
-    return 0;
-  memset(pagetable, 0, PGSIZE);
-  return pagetable;
+pagetable_t uvmcreate() {
+	pagetable_t pagetable;
+	pagetable = (pagetable_t)kalloc();
+	if (pagetable == 0)
+		return 0;
+	memset(pagetable, 0, PGSIZE);
+	return pagetable;
 }
 
 // Load the user initcode into address 0 of pagetable,
 // for the very first process.
 // sz must be less than a page.
-void
-uvmfirst(pagetable_t pagetable, uchar *src, uint sz)
-{
-  char *mem;
+void uvmfirst(pagetable_t pagetable, uchar *src, uint sz) {
+	char *mem;
 
-  if(sz >= PGSIZE)
-    panic("uvmfirst: more than a page");
-  mem = kalloc();
-  memset(mem, 0, PGSIZE);
-  mappages(pagetable, 0, PGSIZE, (uint64)mem, PTE_W|PTE_R|PTE_X|PTE_U);
-  memmove(mem, src, sz);
+	if (sz >= PGSIZE)
+		panic("uvmfirst: more than a page");
+	mem = kalloc();
+	memset(mem, 0, PGSIZE);
+	mappages(pagetable, 0, PGSIZE, (uint64)mem, PTE_W | PTE_R | PTE_X | PTE_U);
+	memmove(mem, src, sz);
 }
 
 // Allocate PTEs and physical memory to grow process from oldsz to
 // newsz, which need not be page aligned.  Returns new size or 0 on error.
-uint64
-uvmalloc(pagetable_t pagetable, uint64 oldsz, uint64 newsz, int xperm)
-{
-  char *mem;
-  uint64 a;
+uint64 uvmalloc(pagetable_t pagetable, uint64 oldsz, uint64 newsz, int xperm) {
+	char *mem;
+	uint64 a;
 
-  if(newsz < oldsz)
-    return oldsz;
+	if (newsz < oldsz)
+		return oldsz;
 
-  oldsz = PGROUNDUP(oldsz);
-  for(a = oldsz; a < newsz; a += PGSIZE){
-    mem = kalloc();
-    if(mem == 0){
-      uvmdealloc(pagetable, a, oldsz);
-      return 0;
-    }
-    memset(mem, 0, PGSIZE);
-    if(mappages(pagetable, a, PGSIZE, (uint64)mem, PTE_R|PTE_U|xperm) != 0){
-      kfree(mem);
-      uvmdealloc(pagetable, a, oldsz);
-      return 0;
-    }
-  }
-  return newsz;
+	oldsz = PGROUNDUP(oldsz);
+	for (a = oldsz; a < newsz; a += PGSIZE) {
+		mem = kalloc();
+		if (mem == 0) {
+			uvmdealloc(pagetable, a, oldsz);
+			return 0;
+		}
+		memset(mem, 0, PGSIZE);
+		if (mappages(pagetable, a, PGSIZE, (uint64)mem,
+					 PTE_R | PTE_U | xperm) != 0) {
+			kfree(mem);
+			uvmdealloc(pagetable, a, oldsz);
+			return 0;
+		}
+	}
+	return newsz;
 }
 
 // Deallocate user pages to bring the process size from oldsz to
 // newsz.  oldsz and newsz need not be page-aligned, nor does newsz
 // need to be less than oldsz.  oldsz can be larger than the actual
 // process size.  Returns the new process size.
-uint64
-uvmdealloc(pagetable_t pagetable, uint64 oldsz, uint64 newsz)
-{
-  if(newsz >= oldsz)
-    return oldsz;
+uint64 uvmdealloc(pagetable_t pagetable, uint64 oldsz, uint64 newsz) {
+	if (newsz >= oldsz)
+		return oldsz;
 
-  if(PGROUNDUP(newsz) < PGROUNDUP(oldsz)){
-    int npages = (PGROUNDUP(oldsz) - PGROUNDUP(newsz)) / PGSIZE;
-    uvmunmap(pagetable, PGROUNDUP(newsz), npages, 1);
-  }
+	if (PGROUNDUP(newsz) < PGROUNDUP(oldsz)) {
+		int npages = (PGROUNDUP(oldsz) - PGROUNDUP(newsz)) / PGSIZE;
+		uvmunmap(pagetable, PGROUNDUP(newsz), npages, 1);
+	}
 
-  return newsz;
+	return newsz;
 }
 
 // Recursively free page-table pages.
 // All leaf mappings must already have been removed.
-void
-freewalk(pagetable_t pagetable)
-{
-  // there are 2^9 = 512 PTEs in a page table.
-  for(int i = 0; i < 512; i++){
-    pte_t pte = pagetable[i];
-    if((pte & PTE_V) && (pte & (PTE_R|PTE_W|PTE_X)) == 0){
-      // this PTE points to a lower-level page table.
-      uint64 child = PTE2PA(pte);
-      freewalk((pagetable_t)child);
-      pagetable[i] = 0;
-    } else if(pte & PTE_V){
-      panic("freewalk: leaf");
-    }
-  }
-  kfree((void*)pagetable);
+void freewalk(pagetable_t pagetable) {
+	// there are 2^9 = 512 PTEs in a page table.
+	for (int i = 0; i < 512; i++) {
+		pte_t pte = pagetable[i];
+		if ((pte & PTE_V) && (pte & (PTE_R | PTE_W | PTE_X)) == 0) {
+			// this PTE points to a lower-level page table.
+			uint64 child = PTE2PA(pte);
+			freewalk((pagetable_t)child);
+			pagetable[i] = 0;
+		} else if (pte & PTE_V) {
+			panic("freewalk: leaf");
+		}
+	}
+	kfree((void *)pagetable);
 }
 
 // Free user memory pages,
 // then free page-table pages.
-void
-uvmfree(pagetable_t pagetable, uint64 sz)
-{
-  if(sz > 0)
-    uvmunmap(pagetable, 0, PGROUNDUP(sz)/PGSIZE, 1);
-  freewalk(pagetable);
+void uvmfree(pagetable_t pagetable, uint64 sz) {
+	if (sz > 0)
+		uvmunmap(pagetable, 0, PGROUNDUP(sz) / PGSIZE, 1);
+	freewalk(pagetable);
 }
 
 // Given a parent process's page table, copy
@@ -297,138 +275,128 @@ uvmfree(pagetable_t pagetable, uint64 sz)
 // physical memory.
 // returns 0 on success, -1 on failure.
 // frees any allocated pages on failure.
-int
-uvmcopy(pagetable_t old, pagetable_t new, uint64 sz)
-{
-  pte_t *pte;
-  uint64 pa, i;
-  uint flags;
-  char *mem;
+int uvmcopy(pagetable_t old, pagetable_t new, uint64 sz) {
+	pte_t *pte;
+	uint64 pa, i;
+	uint flags;
+	char *mem;
 
-  for(i = 0; i < sz; i += PGSIZE){
-    if((pte = walk(old, i, 0)) == 0)
-      panic("uvmcopy: pte should exist");
-    if((*pte & PTE_V) == 0)
-      panic("uvmcopy: page not present");
-    pa = PTE2PA(*pte);
-    flags = PTE_FLAGS(*pte);
-    if((mem = kalloc()) == 0)
-      goto err;
-    memmove(mem, (char*)pa, PGSIZE);
-    if(mappages(new, i, PGSIZE, (uint64)mem, flags) != 0){
-      kfree(mem);
-      goto err;
-    }
-  }
-  return 0;
+	for (i = 0; i < sz; i += PGSIZE) {
+		if ((pte = walk(old, i, 0)) == 0)
+			panic("uvmcopy: pte should exist");
+		if ((*pte & PTE_V) == 0)
+			panic("uvmcopy: page not present");
+		pa = PTE2PA(*pte);
+		flags = PTE_FLAGS(*pte);
+		if ((mem = kalloc()) == 0)
+			goto err;
+		memmove(mem, (char *)pa, PGSIZE);
+		if (mappages(new, i, PGSIZE, (uint64)mem, flags) != 0) {
+			kfree(mem);
+			goto err;
+		}
+	}
+	return 0;
 
- err:
-  uvmunmap(new, 0, i / PGSIZE, 1);
-  return -1;
+err:
+	uvmunmap(new, 0, i / PGSIZE, 1);
+	return -1;
 }
 
 // mark a PTE invalid for user access.
 // used by exec for the user stack guard page.
-void
-uvmclear(pagetable_t pagetable, uint64 va)
-{
-  pte_t *pte;
-  
-  pte = walk(pagetable, va, 0);
-  if(pte == 0)
-    panic("uvmclear");
-  *pte &= ~PTE_U;
+void uvmclear(pagetable_t pagetable, uint64 va) {
+	pte_t *pte;
+
+	pte = walk(pagetable, va, 0);
+	if (pte == 0)
+		panic("uvmclear");
+	*pte &= ~PTE_U;
 }
 
 // Copy from kernel to user.
 // Copy len bytes from src to virtual address dstva in a given page table.
 // Return 0 on success, -1 on error.
-int
-copyout(pagetable_t pagetable, uint64 dstva, char *src, uint64 len)
-{
-  uint64 n, va0, pa0;
+int copyout(pagetable_t pagetable, uint64 dstva, char *src, uint64 len) {
+	uint64 n, va0, pa0;
 
-  while(len > 0){
-    va0 = PGROUNDDOWN(dstva);
-    pa0 = walkaddr(pagetable, va0);
-    if(pa0 == 0)
-      return -1;
-    n = PGSIZE - (dstva - va0);
-    if(n > len)
-      n = len;
-    memmove((void *)(pa0 + (dstva - va0)), src, n);
+	while (len > 0) {
+		va0 = PGROUNDDOWN(dstva);
+		pa0 = walkaddr(pagetable, va0);
+		if (pa0 == 0)
+			return -1;
+		n = PGSIZE - (dstva - va0);
+		if (n > len)
+			n = len;
+		memmove((void *)(pa0 + (dstva - va0)), src, n);
 
-    len -= n;
-    src += n;
-    dstva = va0 + PGSIZE;
-  }
-  return 0;
+		len -= n;
+		src += n;
+		dstva = va0 + PGSIZE;
+	}
+	return 0;
 }
 
 // Copy from user to kernel.
 // Copy len bytes to dst from virtual address srcva in a given page table.
 // Return 0 on success, -1 on error.
-int
-copyin(pagetable_t pagetable, char *dst, uint64 srcva, uint64 len)
-{
-  uint64 n, va0, pa0;
+int copyin(pagetable_t pagetable, char *dst, uint64 srcva, uint64 len) {
+	uint64 n, va0, pa0;
 
-  while(len > 0){
-    va0 = PGROUNDDOWN(srcva);
-    pa0 = walkaddr(pagetable, va0);
-    if(pa0 == 0)
-      return -1;
-    n = PGSIZE - (srcva - va0);
-    if(n > len)
-      n = len;
-    memmove(dst, (void *)(pa0 + (srcva - va0)), n);
+	while (len > 0) {
+		va0 = PGROUNDDOWN(srcva);
+		pa0 = walkaddr(pagetable, va0);
+		if (pa0 == 0)
+			return -1;
+		n = PGSIZE - (srcva - va0);
+		if (n > len)
+			n = len;
+		memmove(dst, (void *)(pa0 + (srcva - va0)), n);
 
-    len -= n;
-    dst += n;
-    srcva = va0 + PGSIZE;
-  }
-  return 0;
+		len -= n;
+		dst += n;
+		srcva = va0 + PGSIZE;
+	}
+	return 0;
 }
 
 // Copy a null-terminated string from user to kernel.
 // Copy bytes to dst from virtual address srcva in a given page table,
 // until a '\0', or max.
 // Return 0 on success, -1 on error.
-int
-copyinstr(pagetable_t pagetable, char *dst, uint64 srcva, uint64 max)
-{
-  uint64 n, va0, pa0;
-  int got_null = 0;
+int copyinstr(pagetable_t pagetable, char *dst, uint64 srcva, uint64 max) {
+	uint64 n, va0, pa0;
+	int got_null = 0;
 
-  while(got_null == 0 && max > 0){
-    va0 = PGROUNDDOWN(srcva);
-    pa0 = walkaddr(pagetable, va0);
-    if(pa0 == 0)
-      return -1;
-    n = PGSIZE - (srcva - va0);
-    if(n > max)
-      n = max;
+	while (got_null == 0 && max > 0) {
+		va0 = PGROUNDDOWN(srcva);
+		pa0 = walkaddr(pagetable, va0);
+		if (pa0 == 0)
+			return -1;
+		n = PGSIZE - (srcva - va0);
+		if (n > max)
+			n = max;
 
-    char *p = (char *) (pa0 + (srcva - va0));
-    while(n > 0){
-      if(*p == '\0'){
-        *dst = '\0';
-        got_null = 1;
-        break;
-      } else {
-        *dst = *p;
-      }
-      --n;
-      --max;
-      p++;
-      dst++;
-    }
+		char *p = (char *)(pa0 + (srcva - va0));
+		while (n > 0) {
+			if (*p == '\0') {
+				*dst = '\0';
+				got_null = 1;
+				break;
+			} else {
+				*dst = *p;
+			}
+			--n;
+			--max;
+			p++;
+			dst++;
+		}
 
-    srcva = va0 + PGSIZE;
-  }
-  if(got_null){
-    return 0;
-  } else {
-    return -1;
-  }
+		srcva = va0 + PGSIZE;
+	}
+	if (got_null) {
+		return 0;
+	} else {
+		return -1;
+	}
 }

mkfs/mkfs.c

@@ -5,14 +5,19 @@
 #include <fcntl.h>
 #include <assert.h>
 
-#define stat xv6_stat  // avoid clash with host struct stat
+#define stat xv6_stat // avoid clash with host struct stat
 #include "kernel/types.h"
 #include "kernel/fs.h"
 #include "kernel/stat.h"
 #include "kernel/param.h"
 
 #ifndef static_assert
-#define static_assert(a, b) do { switch (0) case 0: case (a): ; } while (0)
+#define static_assert(a, b)                                                    \
+	do {                                                                       \
+		switch (0)                                                             \
+		case 0:                                                                \
+		case (a):;                                                             \
+	} while (0)
 #endif
 
 #define NINODES 200
@@ -20,11 +25,11 @@
 // Disk layout:
 // [ boot block | sb block | log | inode blocks | free bit map | data blocks ]
 
-int nbitmap = FSSIZE/(BSIZE*8) + 1;
+int nbitmap = FSSIZE / (BSIZE * 8) + 1;
 int ninodeblocks = NINODES / IPB + 1;
 int nlog = LOGSIZE;
-int nmeta;    // Number of meta blocks (boot, sb, nlog, inode, bitmap)
-int nblocks;  // Number of data blocks
+int nmeta;	 // Number of meta blocks (boot, sb, nlog, inode, bitmap)
+int nblocks; // Number of data blocks
 
 int fsfd;
 struct superblock sb;
@@ -32,10 +37,9 @@ char zeroes[BSIZE];
 uint freeinode = 1;
 uint freeblock;
 
-
 void balloc(int);
-void wsect(uint, void*);
-void winode(uint, struct dinode*);
+void wsect(uint, void *);
+void winode(uint, struct dinode *);
 void rinode(uint inum, struct dinode *ip);
 void rsect(uint sec, void *buf);
 uint ialloc(ushort type);
@@ -43,259 +47,237 @@ void iappend(uint inum, void *p, int n);
 void die(const char *);
 
 // convert to riscv byte order
-ushort
-xshort(ushort x)
-{
-  ushort y;
-  uchar *a = (uchar*)&y;
-  a[0] = x;
-  a[1] = x >> 8;
-  return y;
+ushort xshort(ushort x) {
+	ushort y;
+	uchar *a = (uchar *)&y;
+	a[0] = x;
+	a[1] = x >> 8;
+	return y;
 }
 
-uint
-xint(uint x)
-{
-  uint y;
-  uchar *a = (uchar*)&y;
-  a[0] = x;
-  a[1] = x >> 8;
-  a[2] = x >> 16;
-  a[3] = x >> 24;
-  return y;
+uint xint(uint x) {
+	uint y;
+	uchar *a = (uchar *)&y;
+	a[0] = x;
+	a[1] = x >> 8;
+	a[2] = x >> 16;
+	a[3] = x >> 24;
+	return y;
 }
 
-int
-main(int argc, char *argv[])
-{
-  int i, cc, fd;
-  uint rootino, inum, off;
-  struct dirent de;
-  char buf[BSIZE];
-  struct dinode din;
+int main(int argc, char *argv[]) {
+	int i, cc, fd;
+	uint rootino, inum, off;
+	struct dirent de;
+	char buf[BSIZE];
+	struct dinode din;
 
+	static_assert(sizeof(int) == 4, "Integers must be 4 bytes!");
 
-  static_assert(sizeof(int) == 4, "Integers must be 4 bytes!");
+	if (argc < 2) {
+		fprintf(stderr, "Usage: mkfs fs.img files...\n");
+		exit(1);
+	}
 
-  if(argc < 2){
-    fprintf(stderr, "Usage: mkfs fs.img files...\n");
-    exit(1);
-  }
+	assert((BSIZE % sizeof(struct dinode)) == 0);
+	assert((BSIZE % sizeof(struct dirent)) == 0);
 
-  assert((BSIZE % sizeof(struct dinode)) == 0);
-  assert((BSIZE % sizeof(struct dirent)) == 0);
+	fsfd = open(argv[1], O_RDWR | O_CREAT | O_TRUNC, 0666);
+	if (fsfd < 0)
+		die(argv[1]);
 
-  fsfd = open(argv[1], O_RDWR|O_CREAT|O_TRUNC, 0666);
-  if(fsfd < 0)
-    die(argv[1]);
+	// 1 fs block = 1 disk sector
+	nmeta = 2 + nlog + ninodeblocks + nbitmap;
+	nblocks = FSSIZE - nmeta;
 
-  // 1 fs block = 1 disk sector
-  nmeta = 2 + nlog + ninodeblocks + nbitmap;
-  nblocks = FSSIZE - nmeta;
+	sb.magic = FSMAGIC;
+	sb.size = xint(FSSIZE);
+	sb.nblocks = xint(nblocks);
+	sb.ninodes = xint(NINODES);
+	sb.nlog = xint(nlog);
+	sb.logstart = xint(2);
+	sb.inodestart = xint(2 + nlog);
+	sb.bmapstart = xint(2 + nlog + ninodeblocks);
 
-  sb.magic = FSMAGIC;
-  sb.size = xint(FSSIZE);
-  sb.nblocks = xint(nblocks);
-  sb.ninodes = xint(NINODES);
-  sb.nlog = xint(nlog);
-  sb.logstart = xint(2);
-  sb.inodestart = xint(2+nlog);
-  sb.bmapstart = xint(2+nlog+ninodeblocks);
+	printf("nmeta %d (boot, super, log blocks %u inode blocks %u, bitmap "
+		   "blocks %u) blocks %d total %d\n",
+		   nmeta, nlog, ninodeblocks, nbitmap, nblocks, FSSIZE);
 
-  printf("nmeta %d (boot, super, log blocks %u inode blocks %u, bitmap blocks %u) blocks %d total %d\n",
-         nmeta, nlog, ninodeblocks, nbitmap, nblocks, FSSIZE);
+	freeblock = nmeta; // the first free block that we can allocate
 
-  freeblock = nmeta;     // the first free block that we can allocate
+	for (i = 0; i < FSSIZE; i++)
+		wsect(i, zeroes);
 
-  for(i = 0; i < FSSIZE; i++)
-    wsect(i, zeroes);
+	memset(buf, 0, sizeof(buf));
+	memmove(buf, &sb, sizeof(sb));
+	wsect(1, buf);
 
-  memset(buf, 0, sizeof(buf));
-  memmove(buf, &sb, sizeof(sb));
-  wsect(1, buf);
+	rootino = ialloc(T_DIR);
+	assert(rootino == ROOTINO);
 
-  rootino = ialloc(T_DIR);
-  assert(rootino == ROOTINO);
+	bzero(&de, sizeof(de));
+	de.inum = xshort(rootino);
+	strcpy(de.name, ".");
+	iappend(rootino, &de, sizeof(de));
 
-  bzero(&de, sizeof(de));
-  de.inum = xshort(rootino);
-  strcpy(de.name, ".");
-  iappend(rootino, &de, sizeof(de));
+	bzero(&de, sizeof(de));
+	de.inum = xshort(rootino);
+	strcpy(de.name, "..");
+	iappend(rootino, &de, sizeof(de));
 
-  bzero(&de, sizeof(de));
-  de.inum = xshort(rootino);
-  strcpy(de.name, "..");
-  iappend(rootino, &de, sizeof(de));
+	for (i = 2; i < argc; i++) {
+		// get rid of "user/"
+		char *shortname;
+		if (strncmp(argv[i], "user/", 5) == 0)
+			shortname = argv[i] + 5;
+		else
+			shortname = argv[i];
 
-  for(i = 2; i < argc; i++){
-    // get rid of "user/"
-    char *shortname;
-    if(strncmp(argv[i], "user/", 5) == 0)
-      shortname = argv[i] + 5;
-    else
-      shortname = argv[i];
-    
-    assert(index(shortname, '/') == 0);
+		assert(index(shortname, '/') == 0);
 
-    if((fd = open(argv[i], 0)) < 0)
-      die(argv[i]);
+		if ((fd = open(argv[i], 0)) < 0)
+			die(argv[i]);
 
-    // Skip leading _ in name when writing to file system.
-    // The binaries are named _rm, _cat, etc. to keep the
-    // build operating system from trying to execute them
-    // in place of system binaries like rm and cat.
-    if(shortname[0] == '_')
-      shortname += 1;
+		// Skip leading _ in name when writing to file system.
+		// The binaries are named _rm, _cat, etc. to keep the
+		// build operating system from trying to execute them
+		// in place of system binaries like rm and cat.
+		if (shortname[0] == '_')
+			shortname += 1;
 
-    inum = ialloc(T_FILE);
+		inum = ialloc(T_FILE);
 
-    bzero(&de, sizeof(de));
-    de.inum = xshort(inum);
-    strncpy(de.name, shortname, DIRSIZ);
-    iappend(rootino, &de, sizeof(de));
+		bzero(&de, sizeof(de));
+		de.inum = xshort(inum);
+		strncpy(de.name, shortname, DIRSIZ);
+		iappend(rootino, &de, sizeof(de));
 
-    while((cc = read(fd, buf, sizeof(buf))) > 0)
-      iappend(inum, buf, cc);
+		while ((cc = read(fd, buf, sizeof(buf))) > 0)
+			iappend(inum, buf, cc);
 
-    close(fd);
-  }
+		close(fd);
+	}
 
-  // fix size of root inode dir
-  rinode(rootino, &din);
-  off = xint(din.size);
-  off = ((off/BSIZE) + 1) * BSIZE;
-  din.size = xint(off);
-  winode(rootino, &din);
+	// fix size of root inode dir
+	rinode(rootino, &din);
+	off = xint(din.size);
+	off = ((off / BSIZE) + 1) * BSIZE;
+	din.size = xint(off);
+	winode(rootino, &din);
 
-  balloc(freeblock);
+	balloc(freeblock);
 
-  exit(0);
+	exit(0);
 }
 
-void
-wsect(uint sec, void *buf)
-{
-  if(lseek(fsfd, sec * BSIZE, 0) != sec * BSIZE)
-    die("lseek");
-  if(write(fsfd, buf, BSIZE) != BSIZE)
-    die("write");
+void wsect(uint sec, void *buf) {
+	if (lseek(fsfd, sec * BSIZE, 0) != sec * BSIZE)
+		die("lseek");
+	if (write(fsfd, buf, BSIZE) != BSIZE)
+		die("write");
 }
 
-void
-winode(uint inum, struct dinode *ip)
-{
-  char buf[BSIZE];
-  uint bn;
-  struct dinode *dip;
+void winode(uint inum, struct dinode *ip) {
+	char buf[BSIZE];
+	uint bn;
+	struct dinode *dip;
 
-  bn = IBLOCK(inum, sb);
-  rsect(bn, buf);
-  dip = ((struct dinode*)buf) + (inum % IPB);
-  *dip = *ip;
-  wsect(bn, buf);
+	bn = IBLOCK(inum, sb);
+	rsect(bn, buf);
+	dip = ((struct dinode *)buf) + (inum % IPB);
+	*dip = *ip;
+	wsect(bn, buf);
 }
 
-void
-rinode(uint inum, struct dinode *ip)
-{
-  char buf[BSIZE];
-  uint bn;
-  struct dinode *dip;
+void rinode(uint inum, struct dinode *ip) {
+	char buf[BSIZE];
+	uint bn;
+	struct dinode *dip;
 
-  bn = IBLOCK(inum, sb);
-  rsect(bn, buf);
-  dip = ((struct dinode*)buf) + (inum % IPB);
-  *ip = *dip;
+	bn = IBLOCK(inum, sb);
+	rsect(bn, buf);
+	dip = ((struct dinode *)buf) + (inum % IPB);
+	*ip = *dip;
 }
 
-void
-rsect(uint sec, void *buf)
-{
-  if(lseek(fsfd, sec * BSIZE, 0) != sec * BSIZE)
-    die("lseek");
-  if(read(fsfd, buf, BSIZE) != BSIZE)
-    die("read");
+void rsect(uint sec, void *buf) {
+	if (lseek(fsfd, sec * BSIZE, 0) != sec * BSIZE)
+		die("lseek");
+	if (read(fsfd, buf, BSIZE) != BSIZE)
+		die("read");
 }
 
-uint
-ialloc(ushort type)
-{
-  uint inum = freeinode++;
-  struct dinode din;
+uint ialloc(ushort type) {
+	uint inum = freeinode++;
+	struct dinode din;
 
-  bzero(&din, sizeof(din));
-  din.type = xshort(type);
-  din.nlink = xshort(1);
-  din.size = xint(0);
-  winode(inum, &din);
-  return inum;
+	bzero(&din, sizeof(din));
+	din.type = xshort(type);
+	din.nlink = xshort(1);
+	din.size = xint(0);
+	winode(inum, &din);
+	return inum;
 }
 
-void
-balloc(int used)
-{
-  uchar buf[BSIZE];
-  int i;
+void balloc(int used) {
+	uchar buf[BSIZE];
+	int i;
 
-  printf("balloc: first %d blocks have been allocated\n", used);
-  assert(used < BSIZE*8);
-  bzero(buf, BSIZE);
-  for(i = 0; i < used; i++){
-    buf[i/8] = buf[i/8] | (0x1 << (i%8));
-  }
-  printf("balloc: write bitmap block at sector %d\n", sb.bmapstart);
-  wsect(sb.bmapstart, buf);
+	printf("balloc: first %d blocks have been allocated\n", used);
+	assert(used < BSIZE * 8);
+	bzero(buf, BSIZE);
+	for (i = 0; i < used; i++) {
+		buf[i / 8] = buf[i / 8] | (0x1 << (i % 8));
+	}
+	printf("balloc: write bitmap block at sector %d\n", sb.bmapstart);
+	wsect(sb.bmapstart, buf);
 }
 
 #define min(a, b) ((a) < (b) ? (a) : (b))
 
-void
-iappend(uint inum, void *xp, int n)
-{
-  char *p = (char*)xp;
-  uint fbn, off, n1;
-  struct dinode din;
-  char buf[BSIZE];
-  uint indirect[NINDIRECT];
-  uint x;
+void iappend(uint inum, void *xp, int n) {
+	char *p = (char *)xp;
+	uint fbn, off, n1;
+	struct dinode din;
+	char buf[BSIZE];
+	uint indirect[NINDIRECT];
+	uint x;
 
-  rinode(inum, &din);
-  off = xint(din.size);
-  // printf("append inum %d at off %d sz %d\n", inum, off, n);
-  while(n > 0){
-    fbn = off / BSIZE;
-    assert(fbn < MAXFILE);
-    if(fbn < NDIRECT){
-      if(xint(din.addrs[fbn]) == 0){
-        din.addrs[fbn] = xint(freeblock++);
-      }
-      x = xint(din.addrs[fbn]);
-    } else {
-      if(xint(din.addrs[NDIRECT]) == 0){
-        din.addrs[NDIRECT] = xint(freeblock++);
-      }
-      rsect(xint(din.addrs[NDIRECT]), (char*)indirect);
-      if(indirect[fbn - NDIRECT] == 0){
-        indirect[fbn - NDIRECT] = xint(freeblock++);
-        wsect(xint(din.addrs[NDIRECT]), (char*)indirect);
-      }
-      x = xint(indirect[fbn-NDIRECT]);
-    }
-    n1 = min(n, (fbn + 1) * BSIZE - off);
-    rsect(x, buf);
-    bcopy(p, buf + off - (fbn * BSIZE), n1);
-    wsect(x, buf);
-    n -= n1;
-    off += n1;
-    p += n1;
-  }
-  din.size = xint(off);
-  winode(inum, &din);
+	rinode(inum, &din);
+	off = xint(din.size);
+	// printf("append inum %d at off %d sz %d\n", inum, off, n);
+	while (n > 0) {
+		fbn = off / BSIZE;
+		assert(fbn < MAXFILE);
+		if (fbn < NDIRECT) {
+			if (xint(din.addrs[fbn]) == 0) {
+				din.addrs[fbn] = xint(freeblock++);
+			}
+			x = xint(din.addrs[fbn]);
+		} else {
+			if (xint(din.addrs[NDIRECT]) == 0) {
+				din.addrs[NDIRECT] = xint(freeblock++);
+			}
+			rsect(xint(din.addrs[NDIRECT]), (char *)indirect);
+			if (indirect[fbn - NDIRECT] == 0) {
+				indirect[fbn - NDIRECT] = xint(freeblock++);
+				wsect(xint(din.addrs[NDIRECT]), (char *)indirect);
+			}
+			x = xint(indirect[fbn - NDIRECT]);
+		}
+		n1 = min(n, (fbn + 1) * BSIZE - off);
+		rsect(x, buf);
+		bcopy(p, buf + off - (fbn * BSIZE), n1);
+		wsect(x, buf);
+		n -= n1;
+		off += n1;
+		p += n1;
+	}
+	din.size = xint(off);
+	winode(inum, &din);
 }
 
-void
-die(const char *s)
-{
-  perror(s);
-  exit(1);
+void die(const char *s) {
+	perror(s);
+	exit(1);
 }

rust/foo/.gitignore

@@ -0,0 +1 @@
+/target

rust/foo/Cargo.lock

@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "foo"
+version = "0.1.0"

rust/foo/Cargo.toml

@@ -0,0 +1,14 @@
+[package]
+name = "foo"
+version = "0.1.0"
+edition = "2021"
+
+[lib]
+crate-type = [ "staticlib" ]
+
+[profile.release]
+panic = "abort"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]

rust/foo/src/lib.rs

@@ -0,0 +1,13 @@
+#![no_std]
+#![crate_type = "staticlib"]
+
+#[no_mangle]
+pub extern "C" fn add(left: i32, right: i32) -> i32 {
+	left + right
+}
+
+#[panic_handler]
+#[no_mangle]
+fn panic(_info: &core::panic::PanicInfo) -> ! {
+	loop {}
+}

user/cat.c

@@ -4,40 +4,36 @@
 
 char buf[512];
 
-void
-cat(int fd)
-{
-  int n;
+void cat(int fd) {
+	int n;
 
-  while((n = read(fd, buf, sizeof(buf))) > 0) {
-    if (write(1, buf, n) != n) {
-      fprintf(2, "cat: write error\n");
-      exit(1);
-    }
-  }
-  if(n < 0){
-    fprintf(2, "cat: read error\n");
-    exit(1);
-  }
+	while ((n = read(fd, buf, sizeof(buf))) > 0) {
+		if (write(1, buf, n) != n) {
+			fprintf(2, "cat: write error\n");
+			exit(1);
+		}
+	}
+	if (n < 0) {
+		fprintf(2, "cat: read error\n");
+		exit(1);
+	}
 }
 
-int
-main(int argc, char *argv[])
-{
-  int fd, i;
+int main(int argc, char *argv[]) {
+	int fd, i;
 
-  if(argc <= 1){
-    cat(0);
-    exit(0);
-  }
+	if (argc <= 1) {
+		cat(0);
+		exit(0);
+	}
 
-  for(i = 1; i < argc; i++){
-    if((fd = open(argv[i], 0)) < 0){
-      fprintf(2, "cat: cannot open %s\n", argv[i]);
-      exit(1);
-    }
-    cat(fd);
-    close(fd);
-  }
-  exit(0);
+	for (i = 1; i < argc; i++) {
+		if ((fd = open(argv[i], 0)) < 0) {
+			fprintf(2, "cat: cannot open %s\n", argv[i]);
+			exit(1);
+		}
+		cat(fd);
+		close(fd);
+	}
+	exit(0);
 }

user/echo.c

@@ -2,18 +2,16 @@
 #include "kernel/stat.h"
 #include "user/user.h"
 
-int
-main(int argc, char *argv[])
-{
-  int i;
+int main(int argc, char *argv[]) {
+	int i;
 
-  for(i = 1; i < argc; i++){
-    write(1, argv[i], strlen(argv[i]));
-    if(i + 1 < argc){
-      write(1, " ", 1);
-    } else {
-      write(1, "\n", 1);
-    }
-  }
-  exit(0);
+	for (i = 1; i < argc; i++) {
+		write(1, argv[i], strlen(argv[i]));
+		if (i + 1 < argc) {
+			write(1, " ", 1);
+		} else {
+			write(1, "\n", 1);
+		}
+	}
+	exit(0);
 }

user/forktest.c

@@ -5,52 +5,44 @@
 #include "kernel/stat.h"
 #include "user/user.h"
 
-#define N  1000
+#define N 1000
 
-void
-print(const char *s)
-{
-  write(1, s, strlen(s));
+void print(const char *s) { write(1, s, strlen(s)); }
+
+void forktest(void) {
+	int n, pid;
+
+	print("fork test\n");
+
+	for (n = 0; n < N; n++) {
+		pid = fork();
+		if (pid < 0)
+			break;
+		if (pid == 0)
+			exit(0);
+	}
+
+	if (n == N) {
+		print("fork claimed to work N times!\n");
+		exit(1);
+	}
+
+	for (; n > 0; n--) {
+		if (wait(0) < 0) {
+			print("wait stopped early\n");
+			exit(1);
+		}
+	}
+
+	if (wait(0) != -1) {
+		print("wait got too many\n");
+		exit(1);
+	}
+
+	print("fork test OK\n");
 }
 
-void
-forktest(void)
-{
-  int n, pid;
-
-  print("fork test\n");
-
-  for(n=0; n<N; n++){
-    pid = fork();
-    if(pid < 0)
-      break;
-    if(pid == 0)
-      exit(0);
-  }
-
-  if(n == N){
-    print("fork claimed to work N times!\n");
-    exit(1);
-  }
-
-  for(; n > 0; n--){
-    if(wait(0) < 0){
-      print("wait stopped early\n");
-      exit(1);
-    }
-  }
-
-  if(wait(0) != -1){
-    print("wait got too many\n");
-    exit(1);
-  }
-
-  print("fork test OK\n");
-}
-
-int
-main(void)
-{
-  forktest();
-  exit(0);
+int main(void) {
+	forktest();
+	exit(0);
 }

user/grep.c

@@ -5,102 +5,93 @@
 #include "user/user.h"
 
 char buf[1024];
-int match(char*, char*);
+int match(char *, char *);
 
-void
-grep(char *pattern, int fd)
-{
-  int n, m;
-  char *p, *q;
+void grep(char *pattern, int fd) {
+	int n, m;
+	char *p, *q;
 
-  m = 0;
-  while((n = read(fd, buf+m, sizeof(buf)-m-1)) > 0){
-    m += n;
-    buf[m] = '\0';
-    p = buf;
-    while((q = strchr(p, '\n')) != 0){
-      *q = 0;
-      if(match(pattern, p)){
-        *q = '\n';
-        write(1, p, q+1 - p);
-      }
-      p = q+1;
-    }
-    if(m > 0){
-      m -= p - buf;
-      memmove(buf, p, m);
-    }
-  }
+	m = 0;
+	while ((n = read(fd, buf + m, sizeof(buf) - m - 1)) > 0) {
+		m += n;
+		buf[m] = '\0';
+		p = buf;
+		while ((q = strchr(p, '\n')) != 0) {
+			*q = 0;
+			if (match(pattern, p)) {
+				*q = '\n';
+				write(1, p, q + 1 - p);
+			}
+			p = q + 1;
+		}
+		if (m > 0) {
+			m -= p - buf;
+			memmove(buf, p, m);
+		}
+	}
 }
 
-int
-main(int argc, char *argv[])
-{
-  int fd, i;
-  char *pattern;
+int main(int argc, char *argv[]) {
+	int fd, i;
+	char *pattern;
 
-  if(argc <= 1){
-    fprintf(2, "usage: grep pattern [file ...]\n");
-    exit(1);
-  }
-  pattern = argv[1];
+	if (argc <= 1) {
+		fprintf(2, "usage: grep pattern [file ...]\n");
+		exit(1);
+	}
+	pattern = argv[1];
 
-  if(argc <= 2){
-    grep(pattern, 0);
-    exit(0);
-  }
+	if (argc <= 2) {
+		grep(pattern, 0);
+		exit(0);
+	}
 
-  for(i = 2; i < argc; i++){
-    if((fd = open(argv[i], 0)) < 0){
-      printf("grep: cannot open %s\n", argv[i]);
-      exit(1);
-    }
-    grep(pattern, fd);
-    close(fd);
-  }
-  exit(0);
+	for (i = 2; i < argc; i++) {
+		if ((fd = open(argv[i], 0)) < 0) {
+			printf("grep: cannot open %s\n", argv[i]);
+			exit(1);
+		}
+		grep(pattern, fd);
+		close(fd);
+	}
+	exit(0);
 }
 
 // Regexp matcher from Kernighan & Pike,
 // The Practice of Programming, Chapter 9, or
 // https://www.cs.princeton.edu/courses/archive/spr09/cos333/beautiful.html
 
-int matchhere(char*, char*);
-int matchstar(int, char*, char*);
+int matchhere(char *, char *);
+int matchstar(int, char *, char *);
 
-int
-match(char *re, char *text)
-{
-  if(re[0] == '^')
-    return matchhere(re+1, text);
-  do{  // must look at empty string
-    if(matchhere(re, text))
-      return 1;
-  }while(*text++ != '\0');
-  return 0;
+int match(char *re, char *text) {
+	if (re[0] == '^')
+		return matchhere(re + 1, text);
+	do { // must look at empty string
+		if (matchhere(re, text))
+			return 1;
+	} while (*text++ != '\0');
+	return 0;
 }
 
 // matchhere: search for re at beginning of text
-int matchhere(char *re, char *text)
-{
-  if(re[0] == '\0')
-    return 1;
-  if(re[1] == '*')
-    return matchstar(re[0], re+2, text);
-  if(re[0] == '$' && re[1] == '\0')
-    return *text == '\0';
-  if(*text!='\0' && (re[0]=='.' || re[0]==*text))
-    return matchhere(re+1, text+1);
-  return 0;
+int matchhere(char *re, char *text) {
+	if (re[0] == '\0')
+		return 1;
+	if (re[1] == '*')
+		return matchstar(re[0], re + 2, text);
+	if (re[0] == '$' && re[1] == '\0')
+		return *text == '\0';
+	if (*text != '\0' && (re[0] == '.' || re[0] == *text))
+		return matchhere(re + 1, text + 1);
+	return 0;
 }
 
 // matchstar: search for c*re at beginning of text
-int matchstar(int c, char *re, char *text)
-{
-  do{  // a * matches zero or more instances
-    if(matchhere(re, text))
-      return 1;
-  }while(*text!='\0' && (*text++==c || c=='.'));
-  return 0;
+int matchstar(int c, char *re, char *text) {
+	do { // a * matches zero or more instances
+		if (matchhere(re, text))
+			return 1;
+	} while (*text != '\0' && (*text++ == c || c == '.'));
+	return 0;
 }
-

user/grind.c

@@ -13,338 +13,328 @@
 #include "kernel/riscv.h"
 
 // from FreeBSD.
-int
-do_rand(unsigned long *ctx)
-{
-/*
- * Compute x = (7^5 * x) mod (2^31 - 1)
- * without overflowing 31 bits:
- *      (2^31 - 1) = 127773 * (7^5) + 2836
- * From "Random number generators: good ones are hard to find",
- * Park and Miller, Communications of the ACM, vol. 31, no. 10,
- * October 1988, p. 1195.
- */
-    long hi, lo, x;
+int do_rand(unsigned long *ctx) {
+	/*
+	 * Compute x = (7^5 * x) mod (2^31 - 1)
+	 * without overflowing 31 bits:
+	 *      (2^31 - 1) = 127773 * (7^5) + 2836
+	 * From "Random number generators: good ones are hard to find",
+	 * Park and Miller, Communications of the ACM, vol. 31, no. 10,
+	 * October 1988, p. 1195.
+	 */
+	long hi, lo, x;
 
-    /* Transform to [1, 0x7ffffffe] range. */
-    x = (*ctx % 0x7ffffffe) + 1;
-    hi = x / 127773;
-    lo = x % 127773;
-    x = 16807 * lo - 2836 * hi;
-    if (x < 0)
-        x += 0x7fffffff;
-    /* Transform to [0, 0x7ffffffd] range. */
-    x--;
-    *ctx = x;
-    return (x);
+	/* Transform to [1, 0x7ffffffe] range. */
+	x = (*ctx % 0x7ffffffe) + 1;
+	hi = x / 127773;
+	lo = x % 127773;
+	x = 16807 * lo - 2836 * hi;
+	if (x < 0)
+		x += 0x7fffffff;
+	/* Transform to [0, 0x7ffffffd] range. */
+	x--;
+	*ctx = x;
+	return (x);
 }
 
 unsigned long rand_next = 1;
 
-int
-rand(void)
-{
-    return (do_rand(&rand_next));
+int rand(void) { return (do_rand(&rand_next)); }
+
+void go(int which_child) {
+	int fd = -1;
+	static char buf[999];
+	char *break0 = sbrk(0);
+	uint64 iters = 0;
+
+	mkdir("grindir");
+	if (chdir("grindir") != 0) {
+		printf("grind: chdir grindir failed\n");
+		exit(1);
+	}
+	chdir("/");
+
+	while (1) {
+		iters++;
+		if ((iters % 500) == 0)
+			write(1, which_child ? "B" : "A", 1);
+		int what = rand() % 23;
+		if (what == 1) {
+			close(open("grindir/../a", O_CREATE | O_RDWR));
+		} else if (what == 2) {
+			close(open("grindir/../grindir/../b", O_CREATE | O_RDWR));
+		} else if (what == 3) {
+			unlink("grindir/../a");
+		} else if (what == 4) {
+			if (chdir("grindir") != 0) {
+				printf("grind: chdir grindir failed\n");
+				exit(1);
+			}
+			unlink("../b");
+			chdir("/");
+		} else if (what == 5) {
+			close(fd);
+			fd = open("/grindir/../a", O_CREATE | O_RDWR);
+		} else if (what == 6) {
+			close(fd);
+			fd = open("/./grindir/./../b", O_CREATE | O_RDWR);
+		} else if (what == 7) {
+			write(fd, buf, sizeof(buf));
+		} else if (what == 8) {
+			read(fd, buf, sizeof(buf));
+		} else if (what == 9) {
+			mkdir("grindir/../a");
+			close(open("a/../a/./a", O_CREATE | O_RDWR));
+			unlink("a/a");
+		} else if (what == 10) {
+			mkdir("/../b");
+			close(open("grindir/../b/b", O_CREATE | O_RDWR));
+			unlink("b/b");
+		} else if (what == 11) {
+			unlink("b");
+			link("../grindir/./../a", "../b");
+		} else if (what == 12) {
+			unlink("../grindir/../a");
+			link(".././b", "/grindir/../a");
+		} else if (what == 13) {
+			int pid = fork();
+			if (pid == 0) {
+				exit(0);
+			} else if (pid < 0) {
+				printf("grind: fork failed\n");
+				exit(1);
+			}
+			wait(0);
+		} else if (what == 14) {
+			int pid = fork();
+			if (pid == 0) {
+				fork();
+				fork();
+				exit(0);
+			} else if (pid < 0) {
+				printf("grind: fork failed\n");
+				exit(1);
+			}
+			wait(0);
+		} else if (what == 15) {
+			sbrk(6011);
+		} else if (what == 16) {
+			if (sbrk(0) > break0)
+				sbrk(-(sbrk(0) - break0));
+		} else if (what == 17) {
+			int pid = fork();
+			if (pid == 0) {
+				close(open("a", O_CREATE | O_RDWR));
+				exit(0);
+			} else if (pid < 0) {
+				printf("grind: fork failed\n");
+				exit(1);
+			}
+			if (chdir("../grindir/..") != 0) {
+				printf("grind: chdir failed\n");
+				exit(1);
+			}
+			kill(pid);
+			wait(0);
+		} else if (what == 18) {
+			int pid = fork();
+			if (pid == 0) {
+				kill(getpid());
+				exit(0);
+			} else if (pid < 0) {
+				printf("grind: fork failed\n");
+				exit(1);
+			}
+			wait(0);
+		} else if (what == 19) {
+			int fds[2];
+			if (pipe(fds) < 0) {
+				printf("grind: pipe failed\n");
+				exit(1);
+			}
+			int pid = fork();
+			if (pid == 0) {
+				fork();
+				fork();
+				if (write(fds[1], "x", 1) != 1)
+					printf("grind: pipe write failed\n");
+				char c;
+				if (read(fds[0], &c, 1) != 1)
+					printf("grind: pipe read failed\n");
+				exit(0);
+			} else if (pid < 0) {
+				printf("grind: fork failed\n");
+				exit(1);
+			}
+			close(fds[0]);
+			close(fds[1]);
+			wait(0);
+		} else if (what == 20) {
+			int pid = fork();
+			if (pid == 0) {
+				unlink("a");
+				mkdir("a");
+				chdir("a");
+				unlink("../a");
+				fd = open("x", O_CREATE | O_RDWR);
+				unlink("x");
+				exit(0);
+			} else if (pid < 0) {
+				printf("grind: fork failed\n");
+				exit(1);
+			}
+			wait(0);
+		} else if (what == 21) {
+			unlink("c");
+			// should always succeed. check that there are free i-nodes,
+			// file descriptors, blocks.
+			int fd1 = open("c", O_CREATE | O_RDWR);
+			if (fd1 < 0) {
+				printf("grind: create c failed\n");
+				exit(1);
+			}
+			if (write(fd1, "x", 1) != 1) {
+				printf("grind: write c failed\n");
+				exit(1);
+			}
+			struct stat st;
+			if (fstat(fd1, &st) != 0) {
+				printf("grind: fstat failed\n");
+				exit(1);
+			}
+			if (st.size != 1) {
+				printf("grind: fstat reports wrong size %d\n", (int)st.size);
+				exit(1);
+			}
+			if (st.ino > 200) {
+				printf("grind: fstat reports crazy i-number %d\n", st.ino);
+				exit(1);
+			}
+			close(fd1);
+			unlink("c");
+		} else if (what == 22) {
+			// echo hi | cat
+			int aa[2], bb[2];
+			if (pipe(aa) < 0) {
+				fprintf(2, "grind: pipe failed\n");
+				exit(1);
+			}
+			if (pipe(bb) < 0) {
+				fprintf(2, "grind: pipe failed\n");
+				exit(1);
+			}
+			int pid1 = fork();
+			if (pid1 == 0) {
+				close(bb[0]);
+				close(bb[1]);
+				close(aa[0]);
+				close(1);
+				if (dup(aa[1]) != 1) {
+					fprintf(2, "grind: dup failed\n");
+					exit(1);
+				}
+				close(aa[1]);
+				char *args[3] = {"echo", "hi", 0};
+				exec("grindir/../echo", args);
+				fprintf(2, "grind: echo: not found\n");
+				exit(2);
+			} else if (pid1 < 0) {
+				fprintf(2, "grind: fork failed\n");
+				exit(3);
+			}
+			int pid2 = fork();
+			if (pid2 == 0) {
+				close(aa[1]);
+				close(bb[0]);
+				close(0);
+				if (dup(aa[0]) != 0) {
+					fprintf(2, "grind: dup failed\n");
+					exit(4);
+				}
+				close(aa[0]);
+				close(1);
+				if (dup(bb[1]) != 1) {
+					fprintf(2, "grind: dup failed\n");
+					exit(5);
+				}
+				close(bb[1]);
+				char *args[2] = {"cat", 0};
+				exec("/cat", args);
+				fprintf(2, "grind: cat: not found\n");
+				exit(6);
+			} else if (pid2 < 0) {
+				fprintf(2, "grind: fork failed\n");
+				exit(7);
+			}
+			close(aa[0]);
+			close(aa[1]);
+			close(bb[1]);
+			char buf[4] = {0, 0, 0, 0};
+			read(bb[0], buf + 0, 1);
+			read(bb[0], buf + 1, 1);
+			read(bb[0], buf + 2, 1);
+			close(bb[0]);
+			int st1, st2;
+			wait(&st1);
+			wait(&st2);
+			if (st1 != 0 || st2 != 0 || strcmp(buf, "hi\n") != 0) {
+				printf("grind: exec pipeline failed %d %d \"%s\"\n", st1, st2,
+					   buf);
+				exit(1);
+			}
+		}
+	}
 }
 
-void
-go(int which_child)
-{
-  int fd = -1;
-  static char buf[999];
-  char *break0 = sbrk(0);
-  uint64 iters = 0;
+void iter() {
+	unlink("a");
+	unlink("b");
 
-  mkdir("grindir");
-  if(chdir("grindir") != 0){
-    printf("grind: chdir grindir failed\n");
-    exit(1);
-  }
-  chdir("/");
-  
-  while(1){
-    iters++;
-    if((iters % 500) == 0)
-      write(1, which_child?"B":"A", 1);
-    int what = rand() % 23;
-    if(what == 1){
-      close(open("grindir/../a", O_CREATE|O_RDWR));
-    } else if(what == 2){
-      close(open("grindir/../grindir/../b", O_CREATE|O_RDWR));
-    } else if(what == 3){
-      unlink("grindir/../a");
-    } else if(what == 4){
-      if(chdir("grindir") != 0){
-        printf("grind: chdir grindir failed\n");
-        exit(1);
-      }
-      unlink("../b");
-      chdir("/");
-    } else if(what == 5){
-      close(fd);
-      fd = open("/grindir/../a", O_CREATE|O_RDWR);
-    } else if(what == 6){
-      close(fd);
-      fd = open("/./grindir/./../b", O_CREATE|O_RDWR);
-    } else if(what == 7){
-      write(fd, buf, sizeof(buf));
-    } else if(what == 8){
-      read(fd, buf, sizeof(buf));
-    } else if(what == 9){
-      mkdir("grindir/../a");
-      close(open("a/../a/./a", O_CREATE|O_RDWR));
-      unlink("a/a");
-    } else if(what == 10){
-      mkdir("/../b");
-      close(open("grindir/../b/b", O_CREATE|O_RDWR));
-      unlink("b/b");
-    } else if(what == 11){
-      unlink("b");
-      link("../grindir/./../a", "../b");
-    } else if(what == 12){
-      unlink("../grindir/../a");
-      link(".././b", "/grindir/../a");
-    } else if(what == 13){
-      int pid = fork();
-      if(pid == 0){
-        exit(0);
-      } else if(pid < 0){
-        printf("grind: fork failed\n");
-        exit(1);
-      }
-      wait(0);
-    } else if(what == 14){
-      int pid = fork();
-      if(pid == 0){
-        fork();
-        fork();
-        exit(0);
-      } else if(pid < 0){
-        printf("grind: fork failed\n");
-        exit(1);
-      }
-      wait(0);
-    } else if(what == 15){
-      sbrk(6011);
-    } else if(what == 16){
-      if(sbrk(0) > break0)
-        sbrk(-(sbrk(0) - break0));
-    } else if(what == 17){
-      int pid = fork();
-      if(pid == 0){
-        close(open("a", O_CREATE|O_RDWR));
-        exit(0);
-      } else if(pid < 0){
-        printf("grind: fork failed\n");
-        exit(1);
-      }
-      if(chdir("../grindir/..") != 0){
-        printf("grind: chdir failed\n");
-        exit(1);
-      }
-      kill(pid);
-      wait(0);
-    } else if(what == 18){
-      int pid = fork();
-      if(pid == 0){
-        kill(getpid());
-        exit(0);
-      } else if(pid < 0){
-        printf("grind: fork failed\n");
-        exit(1);
-      }
-      wait(0);
-    } else if(what == 19){
-      int fds[2];
-      if(pipe(fds) < 0){
-        printf("grind: pipe failed\n");
-        exit(1);
-      }
-      int pid = fork();
-      if(pid == 0){
-        fork();
-        fork();
-        if(write(fds[1], "x", 1) != 1)
-          printf("grind: pipe write failed\n");
-        char c;
-        if(read(fds[0], &c, 1) != 1)
-          printf("grind: pipe read failed\n");
-        exit(0);
-      } else if(pid < 0){
-        printf("grind: fork failed\n");
-        exit(1);
-      }
-      close(fds[0]);
-      close(fds[1]);
-      wait(0);
-    } else if(what == 20){
-      int pid = fork();
-      if(pid == 0){
-        unlink("a");
-        mkdir("a");
-        chdir("a");
-        unlink("../a");
-        fd = open("x", O_CREATE|O_RDWR);
-        unlink("x");
-        exit(0);
-      } else if(pid < 0){
-        printf("grind: fork failed\n");
-        exit(1);
-      }
-      wait(0);
-    } else if(what == 21){
-      unlink("c");
-      // should always succeed. check that there are free i-nodes,
-      // file descriptors, blocks.
-      int fd1 = open("c", O_CREATE|O_RDWR);
-      if(fd1 < 0){
-        printf("grind: create c failed\n");
-        exit(1);
-      }
-      if(write(fd1, "x", 1) != 1){
-        printf("grind: write c failed\n");
-        exit(1);
-      }
-      struct stat st;
-      if(fstat(fd1, &st) != 0){
-        printf("grind: fstat failed\n");
-        exit(1);
-      }
-      if(st.size != 1){
-        printf("grind: fstat reports wrong size %d\n", (int)st.size);
-        exit(1);
-      }
-      if(st.ino > 200){
-        printf("grind: fstat reports crazy i-number %d\n", st.ino);
-        exit(1);
-      }
-      close(fd1);
-      unlink("c");
-    } else if(what == 22){
-      // echo hi | cat
-      int aa[2], bb[2];
-      if(pipe(aa) < 0){
-        fprintf(2, "grind: pipe failed\n");
-        exit(1);
-      }
-      if(pipe(bb) < 0){
-        fprintf(2, "grind: pipe failed\n");
-        exit(1);
-      }
-      int pid1 = fork();
-      if(pid1 == 0){
-        close(bb[0]);
-        close(bb[1]);
-        close(aa[0]);
-        close(1);
-        if(dup(aa[1]) != 1){
-          fprintf(2, "grind: dup failed\n");
-          exit(1);
-        }
-        close(aa[1]);
-        char *args[3] = { "echo", "hi", 0 };
-        exec("grindir/../echo", args);
-        fprintf(2, "grind: echo: not found\n");
-        exit(2);
-      } else if(pid1 < 0){
-        fprintf(2, "grind: fork failed\n");
-        exit(3);
-      }
-      int pid2 = fork();
-      if(pid2 == 0){
-        close(aa[1]);
-        close(bb[0]);
-        close(0);
-        if(dup(aa[0]) != 0){
-          fprintf(2, "grind: dup failed\n");
-          exit(4);
-        }
-        close(aa[0]);
-        close(1);
-        if(dup(bb[1]) != 1){
-          fprintf(2, "grind: dup failed\n");
-          exit(5);
-        }
-        close(bb[1]);
-        char *args[2] = { "cat", 0 };
-        exec("/cat", args);
-        fprintf(2, "grind: cat: not found\n");
-        exit(6);
-      } else if(pid2 < 0){
-        fprintf(2, "grind: fork failed\n");
-        exit(7);
-      }
-      close(aa[0]);
-      close(aa[1]);
-      close(bb[1]);
-      char buf[4] = { 0, 0, 0, 0 };
-      read(bb[0], buf+0, 1);
-      read(bb[0], buf+1, 1);
-      read(bb[0], buf+2, 1);
-      close(bb[0]);
-      int st1, st2;
-      wait(&st1);
-      wait(&st2);
-      if(st1 != 0 || st2 != 0 || strcmp(buf, "hi\n") != 0){
-        printf("grind: exec pipeline failed %d %d \"%s\"\n", st1, st2, buf);
-        exit(1);
-      }
-    }
-  }
+	int pid1 = fork();
+	if (pid1 < 0) {
+		printf("grind: fork failed\n");
+		exit(1);
+	}
+	if (pid1 == 0) {
+		rand_next ^= 31;
+		go(0);
+		exit(0);
+	}
+
+	int pid2 = fork();
+	if (pid2 < 0) {
+		printf("grind: fork failed\n");
+		exit(1);
+	}
+	if (pid2 == 0) {
+		rand_next ^= 7177;
+		go(1);
+		exit(0);
+	}
+
+	int st1 = -1;
+	wait(&st1);
+	if (st1 != 0) {
+		kill(pid1);
+		kill(pid2);
+	}
+	int st2 = -1;
+	wait(&st2);
+
+	exit(0);
 }
 
-void
-iter()
-{
-  unlink("a");
-  unlink("b");
-  
-  int pid1 = fork();
-  if(pid1 < 0){
-    printf("grind: fork failed\n");
-    exit(1);
-  }
-  if(pid1 == 0){
-    rand_next = 31;
-    go(0);
-    exit(0);
-  }
-
-  int pid2 = fork();
-  if(pid2 < 0){
-    printf("grind: fork failed\n");
-    exit(1);
-  }
-  if(pid2 == 0){
-    rand_next = 7177;
-    go(1);
-    exit(0);
-  }
-
-  int st1 = -1;
-  wait(&st1);
-  if(st1 != 0){
-    kill(pid1);
-    kill(pid2);
-  }
-  int st2 = -1;
-  wait(&st2);
-
-  exit(0);
-}
-
-int
-main()
-{
-  while(1){
-    int pid = fork();
-    if(pid == 0){
-      iter();
-      exit(0);
-    }
-    if(pid > 0){
-      wait(0);
-    }
-    sleep(20);
-  }
+int main() {
+	while (1) {
+		int pid = fork();
+		if (pid == 0) {
+			iter();
+			exit(0);
+		}
+		if (pid > 0) {
+			wait(0);
+		}
+		sleep(20);
+		rand_next += 1;
+	}
 }

user/init.c

@@ -9,46 +9,44 @@
 #include "user/user.h"
 #include "kernel/fcntl.h"
 
-char *argv[] = { "sh", 0 };
+char *argv[] = {"sh", 0};
 
-int
-main(void)
-{
-  int pid, wpid;
+int main(void) {
+	int pid, wpid;
 
-  if(open("console", O_RDWR) < 0){
-    mknod("console", CONSOLE, 0);
-    open("console", O_RDWR);
-  }
-  dup(0);  // stdout
-  dup(0);  // stderr
+	if (open("console", O_RDWR) < 0) {
+		mknod("console", CONSOLE, 0);
+		open("console", O_RDWR);
+	}
+	dup(0); // stdout
+	dup(0); // stderr
 
-  for(;;){
-    printf("init: starting sh\n");
-    pid = fork();
-    if(pid < 0){
-      printf("init: fork failed\n");
-      exit(1);
-    }
-    if(pid == 0){
-      exec("sh", argv);
-      printf("init: exec sh failed\n");
-      exit(1);
-    }
+	for (;;) {
+		printf("init: starting sh\n");
+		pid = fork();
+		if (pid < 0) {
+			printf("init: fork failed\n");
+			exit(1);
+		}
+		if (pid == 0) {
+			exec("sh", argv);
+			printf("init: exec sh failed\n");
+			exit(1);
+		}
 
-    for(;;){
-      // this call to wait() returns if the shell exits,
-      // or if a parentless process exits.
-      wpid = wait((int *) 0);
-      if(wpid == pid){
-        // the shell exited; restart it.
-        break;
-      } else if(wpid < 0){
-        printf("init: wait returned an error\n");
-        exit(1);
-      } else {
-        // it was a parentless process; do nothing.
-      }
-    }
-  }
+		for (;;) {
+			// this call to wait() returns if the shell exits,
+			// or if a parentless process exits.
+			wpid = wait((int *)0);
+			if (wpid == pid) {
+				// the shell exited; restart it.
+				break;
+			} else if (wpid < 0) {
+				printf("init: wait returned an error\n");
+				exit(1);
+			} else {
+				// it was a parentless process; do nothing.
+			}
+		}
+	}
 }

user/kill.c

@@ -2,16 +2,14 @@
 #include "kernel/stat.h"
 #include "user/user.h"
 
-int
-main(int argc, char **argv)
-{
-  int i;
+int main(int argc, char **argv) {
+	int i;
 
-  if(argc < 2){
-    fprintf(2, "usage: kill pid...\n");
-    exit(1);
-  }
-  for(i=1; i<argc; i++)
-    kill(atoi(argv[i]));
-  exit(0);
+	if (argc < 2) {
+		fprintf(2, "usage: kill pid...\n");
+		exit(1);
+	}
+	for (i = 1; i < argc; i++)
+		kill(atoi(argv[i]));
+	exit(0);
 }

user/ln.c

@@ -2,14 +2,12 @@
 #include "kernel/stat.h"
 #include "user/user.h"
 
-int
-main(int argc, char *argv[])
-{
-  if(argc != 3){
-    fprintf(2, "Usage: ln old new\n");
-    exit(1);
-  }
-  if(link(argv[1], argv[2]) < 0)
-    fprintf(2, "link %s %s: failed\n", argv[1], argv[2]);
-  exit(0);
+int main(int argc, char *argv[]) {
+	if (argc != 3) {
+		fprintf(2, "Usage: ln old new\n");
+		exit(1);
+	}
+	if (link(argv[1], argv[2]) < 0)
+		fprintf(2, "link %s %s: failed\n", argv[1], argv[2]);
+	exit(0);
 }

user/ls.c

@@ -3,84 +3,78 @@
 #include "user/user.h"
 #include "kernel/fs.h"
 
-char*
-fmtname(char *path)
-{
-  static char buf[DIRSIZ+1];
-  char *p;
+char *fmtname(char *path) {
+	static char buf[DIRSIZ + 1];
+	char *p;
 
-  // Find first character after last slash.
-  for(p=path+strlen(path); p >= path && *p != '/'; p--)
-    ;
-  p++;
+	// Find first character after last slash.
+	for (p = path + strlen(path); p >= path && *p != '/'; p--)
+		;
+	p++;
 
-  // Return blank-padded name.
-  if(strlen(p) >= DIRSIZ)
-    return p;
-  memmove(buf, p, strlen(p));
-  memset(buf+strlen(p), ' ', DIRSIZ-strlen(p));
-  return buf;
+	// Return blank-padded name.
+	if (strlen(p) >= DIRSIZ)
+		return p;
+	memmove(buf, p, strlen(p));
+	memset(buf + strlen(p), ' ', DIRSIZ - strlen(p));
+	return buf;
 }
 
-void
-ls(char *path)
-{
-  char buf[512], *p;
-  int fd;
-  struct dirent de;
-  struct stat st;
+void ls(char *path) {
+	char buf[512], *p;
+	int fd;
+	struct dirent de;
+	struct stat st;
 
-  if((fd = open(path, 0)) < 0){
-    fprintf(2, "ls: cannot open %s\n", path);
-    return;
-  }
+	if ((fd = open(path, 0)) < 0) {
+		fprintf(2, "ls: cannot open %s\n", path);
+		return;
+	}
 
-  if(fstat(fd, &st) < 0){
-    fprintf(2, "ls: cannot stat %s\n", path);
-    close(fd);
-    return;
-  }
+	if (fstat(fd, &st) < 0) {
+		fprintf(2, "ls: cannot stat %s\n", path);
+		close(fd);
+		return;
+	}
 
-  switch(st.type){
-  case T_DEVICE:
-  case T_FILE:
-    printf("%s %d %d %l\n", fmtname(path), st.type, st.ino, st.size);
-    break;
+	switch (st.type) {
+	case T_DEVICE:
+	case T_FILE:
+		printf("%s %d %d %l\n", fmtname(path), st.type, st.ino, st.size);
+		break;
 
-  case T_DIR:
-    if(strlen(path) + 1 + DIRSIZ + 1 > sizeof buf){
-      printf("ls: path too long\n");
-      break;
-    }
-    strcpy(buf, path);
-    p = buf+strlen(buf);
-    *p++ = '/';
-    while(read(fd, &de, sizeof(de)) == sizeof(de)){
-      if(de.inum == 0)
-        continue;
-      memmove(p, de.name, DIRSIZ);
-      p[DIRSIZ] = 0;
-      if(stat(buf, &st) < 0){
-        printf("ls: cannot stat %s\n", buf);
-        continue;
-      }
-      printf("%s %d %d %d\n", fmtname(buf), st.type, st.ino, st.size);
-    }
-    break;
-  }
-  close(fd);
+	case T_DIR:
+		if (strlen(path) + 1 + DIRSIZ + 1 > sizeof buf) {
+			printf("ls: path too long\n");
+			break;
+		}
+		strcpy(buf, path);
+		p = buf + strlen(buf);
+		*p++ = '/';
+		while (read(fd, &de, sizeof(de)) == sizeof(de)) {
+			if (de.inum == 0)
+				continue;
+			memmove(p, de.name, DIRSIZ);
+			p[DIRSIZ] = 0;
+			if (stat(buf, &st) < 0) {
+				printf("ls: cannot stat %s\n", buf);
+				continue;
+			}
+			printf("%s %d %d %d\n", fmtname(buf), st.type, st.ino, st.size);
+		}
+		break;
+	}
+	close(fd);
 }
 
-int
-main(int argc, char *argv[])
-{
-  int i;
+int main(int argc, char *argv[]) {
+	int i;
 
-  if(argc < 2){
-    ls(".");
-    exit(0);
-  }
-  for(i=1; i<argc; i++)
-    ls(argv[i]);
-  exit(0);
+	if (argc < 2) {
+		ls(".");
+		exit(0);
+	}
+	for (i = 1; i < argc; i++)
+		ls(argv[i]);
+	exit(0);
 }

user/mkdir.c

@@ -2,22 +2,20 @@
 #include "kernel/stat.h"
 #include "user/user.h"
 
-int
-main(int argc, char *argv[])
-{
-  int i;
+int main(int argc, char *argv[]) {
+	int i;
 
-  if(argc < 2){
-    fprintf(2, "Usage: mkdir files...\n");
-    exit(1);
-  }
+	if (argc < 2) {
+		fprintf(2, "Usage: mkdir files...\n");
+		exit(1);
+	}
 
-  for(i = 1; i < argc; i++){
-    if(mkdir(argv[i]) < 0){
-      fprintf(2, "mkdir: %s failed to create\n", argv[i]);
-      break;
-    }
-  }
+	for (i = 1; i < argc; i++) {
+		if (mkdir(argv[i]) < 0) {
+			fprintf(2, "mkdir: %s failed to create\n", argv[i]);
+			break;
+		}
+	}
 
-  exit(0);
+	exit(0);
 }

user/printf.c

@@ -6,108 +6,95 @@
 
 static char digits[] = "0123456789ABCDEF";
 
-static void
-putc(int fd, char c)
-{
-  write(fd, &c, 1);
+static void putc(int fd, char c) { write(fd, &c, 1); }
+
+static void printint(int fd, int xx, int base, int sgn) {
+	char buf[16];
+	int i, neg;
+	uint x;
+
+	neg = 0;
+	if (sgn && xx < 0) {
+		neg = 1;
+		x = -xx;
+	} else {
+		x = xx;
+	}
+
+	i = 0;
+	do {
+		buf[i++] = digits[x % base];
+	} while ((x /= base) != 0);
+	if (neg)
+		buf[i++] = '-';
+
+	while (--i >= 0)
+		putc(fd, buf[i]);
 }
 
-static void
-printint(int fd, int xx, int base, int sgn)
-{
-  char buf[16];
-  int i, neg;
-  uint x;
-
-  neg = 0;
-  if(sgn && xx < 0){
-    neg = 1;
-    x = -xx;
-  } else {
-    x = xx;
-  }
-
-  i = 0;
-  do{
-    buf[i++] = digits[x % base];
-  }while((x /= base) != 0);
-  if(neg)
-    buf[i++] = '-';
-
-  while(--i >= 0)
-    putc(fd, buf[i]);
-}
-
-static void
-printptr(int fd, uint64 x) {
-  int i;
-  putc(fd, '0');
-  putc(fd, 'x');
-  for (i = 0; i < (sizeof(uint64) * 2); i++, x <<= 4)
-    putc(fd, digits[x >> (sizeof(uint64) * 8 - 4)]);
+static void printptr(int fd, uint64 x) {
+	int i;
+	putc(fd, '0');
+	putc(fd, 'x');
+	for (i = 0; i < (sizeof(uint64) * 2); i++, x <<= 4)
+		putc(fd, digits[x >> (sizeof(uint64) * 8 - 4)]);
 }
 
 // Print to the given fd. Only understands %d, %x, %p, %s.
-void
-vprintf(int fd, const char *fmt, va_list ap)
-{
-  char *s;
-  int c, i, state;
+void vprintf(int fd, const char *fmt, va_list ap) {
+	char *s;
+	int c, i, state;
 
-  state = 0;
-  for(i = 0; fmt[i]; i++){
-    c = fmt[i] & 0xff;
-    if(state == 0){
-      if(c == '%'){
-        state = '%';
-      } else {
-        putc(fd, c);
-      }
-    } else if(state == '%'){
-      if(c == 'd'){
-        printint(fd, va_arg(ap, int), 10, 1);
-      } else if(c == 'l') {
-        printint(fd, va_arg(ap, uint64), 10, 0);
-      } else if(c == 'x') {
-        printint(fd, va_arg(ap, int), 16, 0);
-      } else if(c == 'p') {
-        printptr(fd, va_arg(ap, uint64));
-      } else if(c == 's'){
-        s = va_arg(ap, char*);
-        if(s == 0)
-          s = "(null)";
-        while(*s != 0){
-          putc(fd, *s);
-          s++;
-        }
-      } else if(c == 'c'){
-        putc(fd, va_arg(ap, uint));
-      } else if(c == '%'){
-        putc(fd, c);
-      } else {
-        // Unknown % sequence.  Print it to draw attention.
-        putc(fd, '%');
-        putc(fd, c);
-      }
-      state = 0;
-    }
-  }
+	state = 0;
+	for (i = 0; fmt[i]; i++) {
+		c = fmt[i] & 0xff;
+		if (state == 0) {
+			if (c == '%') {
+				state = '%';
+			} else {
+				putc(fd, c);
+			}
+		} else if (state == '%') {
+			if (c == 'd') {
+				printint(fd, va_arg(ap, int), 10, 1);
+			} else if (c == 'l') {
+				printint(fd, va_arg(ap, uint64), 10, 0);
+			} else if (c == 'x') {
+				printint(fd, va_arg(ap, int), 16, 0);
+			} else if (c == 'p') {
+				printptr(fd, va_arg(ap, uint64));
+			} else if (c == 's') {
+				s = va_arg(ap, char *);
+				if (s == 0)
+					s = "(null)";
+				while (*s != 0) {
+					putc(fd, *s);
+					s++;
+				}
+			} else if (c == 'c') {
+				putc(fd, va_arg(ap, uint));
+			} else if (c == '%') {
+				putc(fd, c);
+			} else {
+				// Unknown % sequence.  Print it to draw attention.
+				putc(fd, '%');
+				putc(fd, c);
+			}
+			state = 0;
+		}
+	}
 }
 
-void
-fprintf(int fd, const char *fmt, ...)
-{
-  va_list ap;
+void fprintf(int fd, const char *fmt, ...) {
+	va_list ap;
 
-  va_start(ap, fmt);
-  vprintf(fd, fmt, ap);
+	va_start(ap, fmt);
+	vprintf(fd, fmt, ap);
 }
 
-void
-printf(const char *fmt, ...)
-{
-  va_list ap;
+void printf(const char *fmt, ...) {
+	va_list ap;
 
-  va_start(ap, fmt);
-  vprintf(1, fmt, ap);
+	va_start(ap, fmt);
+	vprintf(1, fmt, ap);
 }

user/rm.c

@@ -2,22 +2,20 @@
 #include "kernel/stat.h"
 #include "user/user.h"
 
-int
-main(int argc, char *argv[])
-{
-  int i;
+int main(int argc, char *argv[]) {
+	int i;
 
-  if(argc < 2){
-    fprintf(2, "Usage: rm files...\n");
-    exit(1);
-  }
+	if (argc < 2) {
+		fprintf(2, "Usage: rm files...\n");
+		exit(1);
+	}
 
-  for(i = 1; i < argc; i++){
-    if(unlink(argv[i]) < 0){
-      fprintf(2, "rm: %s failed to delete\n", argv[i]);
-      break;
-    }
-  }
+	for (i = 1; i < argc; i++) {
+		if (unlink(argv[i]) < 0) {
+			fprintf(2, "rm: %s failed to delete\n", argv[i]);
+			break;
+		}
+	}
 
-  exit(0);
+	exit(0);
 }

user/sh.c

@@ -5,490 +5,453 @@
 #include "kernel/fcntl.h"
 
 // Parsed command representation
-#define EXEC  1
+#define EXEC 1
 #define REDIR 2
-#define PIPE  3
-#define LIST  4
-#define BACK  5
+#define PIPE 3
+#define LIST 4
+#define BACK 5
 
 #define MAXARGS 10
 
 struct cmd {
-  int type;
+	int type;
 };
 
 struct execcmd {
-  int type;
-  char *argv[MAXARGS];
-  char *eargv[MAXARGS];
+	int type;
+	char *argv[MAXARGS];
+	char *eargv[MAXARGS];
 };
 
 struct redircmd {
-  int type;
-  struct cmd *cmd;
-  char *file;
-  char *efile;
-  int mode;
-  int fd;
+	int type;
+	struct cmd *cmd;
+	char *file;
+	char *efile;
+	int mode;
+	int fd;
 };
 
 struct pipecmd {
-  int type;
-  struct cmd *left;
-  struct cmd *right;
+	int type;
+	struct cmd *left;
+	struct cmd *right;
 };
 
 struct listcmd {
-  int type;
-  struct cmd *left;
-  struct cmd *right;
+	int type;
+	struct cmd *left;
+	struct cmd *right;
 };
 
 struct backcmd {
-  int type;
-  struct cmd *cmd;
+	int type;
+	struct cmd *cmd;
 };
 
-int fork1(void);  // Fork but panics on failure.
-void panic(char*);
-struct cmd *parsecmd(char*);
-void runcmd(struct cmd*) __attribute__((noreturn));
+int fork1(void); // Fork but panics on failure.
+void panic(char *);
+struct cmd *parsecmd(char *);
+void runcmd(struct cmd *) __attribute__((noreturn));
 
 // Execute cmd.  Never returns.
-void
-runcmd(struct cmd *cmd)
-{
-  int p[2];
-  struct backcmd *bcmd;
-  struct execcmd *ecmd;
-  struct listcmd *lcmd;
-  struct pipecmd *pcmd;
-  struct redircmd *rcmd;
+void runcmd(struct cmd *cmd) {
+	int p[2];
+	struct backcmd *bcmd;
+	struct execcmd *ecmd;
+	struct listcmd *lcmd;
+	struct pipecmd *pcmd;
+	struct redircmd *rcmd;
 
-  if(cmd == 0)
-    exit(1);
+	if (cmd == 0)
+		exit(1);
 
-  switch(cmd->type){
-  default:
-    panic("runcmd");
+	switch (cmd->type) {
+	default:
+		panic("runcmd");
 
-  case EXEC:
-    ecmd = (struct execcmd*)cmd;
-    if(ecmd->argv[0] == 0)
-      exit(1);
-    exec(ecmd->argv[0], ecmd->argv);
-    fprintf(2, "exec %s failed\n", ecmd->argv[0]);
-    break;
+	case EXEC:
+		ecmd = (struct execcmd *)cmd;
+		if (ecmd->argv[0] == 0)
+			exit(1);
+		exec(ecmd->argv[0], ecmd->argv);
+		fprintf(2, "exec %s failed\n", ecmd->argv[0]);
+		break;
 
-  case REDIR:
-    rcmd = (struct redircmd*)cmd;
-    close(rcmd->fd);
-    if(open(rcmd->file, rcmd->mode) < 0){
-      fprintf(2, "open %s failed\n", rcmd->file);
-      exit(1);
-    }
-    runcmd(rcmd->cmd);
-    break;
+	case REDIR:
+		rcmd = (struct redircmd *)cmd;
+		close(rcmd->fd);
+		if (open(rcmd->file, rcmd->mode) < 0) {
+			fprintf(2, "open %s failed\n", rcmd->file);
+			exit(1);
+		}
+		runcmd(rcmd->cmd);
+		break;
 
-  case LIST:
-    lcmd = (struct listcmd*)cmd;
-    if(fork1() == 0)
-      runcmd(lcmd->left);
-    wait(0);
-    runcmd(lcmd->right);
-    break;
+	case LIST:
+		lcmd = (struct listcmd *)cmd;
+		if (fork1() == 0)
+			runcmd(lcmd->left);
+		wait(0);
+		runcmd(lcmd->right);
+		break;
 
-  case PIPE:
-    pcmd = (struct pipecmd*)cmd;
-    if(pipe(p) < 0)
-      panic("pipe");
-    if(fork1() == 0){
-      close(1);
-      dup(p[1]);
-      close(p[0]);
-      close(p[1]);
-      runcmd(pcmd->left);
-    }
-    if(fork1() == 0){
-      close(0);
-      dup(p[0]);
-      close(p[0]);
-      close(p[1]);
-      runcmd(pcmd->right);
-    }
-    close(p[0]);
-    close(p[1]);
-    wait(0);
-    wait(0);
-    break;
+	case PIPE:
+		pcmd = (struct pipecmd *)cmd;
+		if (pipe(p) < 0)
+			panic("pipe");
+		if (fork1() == 0) {
+			close(1);
+			dup(p[1]);
+			close(p[0]);
+			close(p[1]);
+			runcmd(pcmd->left);
+		}
+		if (fork1() == 0) {
+			close(0);
+			dup(p[0]);
+			close(p[0]);
+			close(p[1]);
+			runcmd(pcmd->right);
+		}
+		close(p[0]);
+		close(p[1]);
+		wait(0);
+		wait(0);
+		break;
 
-  case BACK:
-    bcmd = (struct backcmd*)cmd;
-    if(fork1() == 0)
-      runcmd(bcmd->cmd);
-    break;
-  }
-  exit(0);
+	case BACK:
+		bcmd = (struct backcmd *)cmd;
+		if (fork1() == 0)
+			runcmd(bcmd->cmd);
+		break;
+	}
+	exit(0);
 }
 
-int
-getcmd(char *buf, int nbuf)
-{
-  write(2, "$ ", 2);
-  memset(buf, 0, nbuf);
-  gets(buf, nbuf);
-  if(buf[0] == 0) // EOF
-    return -1;
-  return 0;
+int getcmd(char *buf, int nbuf) {
+	write(2, "$ ", 2);
+	memset(buf, 0, nbuf);
+	gets(buf, nbuf);
+	if (buf[0] == 0) // EOF
+		return -1;
+	return 0;
 }
 
-int
-main(void)
-{
-  static char buf[100];
-  int fd;
+int main(void) {
+	static char buf[100];
+	int fd;
 
-  // Ensure that three file descriptors are open.
-  while((fd = open("console", O_RDWR)) >= 0){
-    if(fd >= 3){
-      close(fd);
-      break;
-    }
-  }
+	// Ensure that three file descriptors are open.
+	while ((fd = open("console", O_RDWR)) >= 0) {
+		if (fd >= 3) {
+			close(fd);
+			break;
+		}
+	}
 
-  // Read and run input commands.
-  while(getcmd(buf, sizeof(buf)) >= 0){
-    if(buf[0] == 'c' && buf[1] == 'd' && buf[2] == ' '){
-      // Chdir must be called by the parent, not the child.
-      buf[strlen(buf)-1] = 0;  // chop \n
-      if(chdir(buf+3) < 0)
-        fprintf(2, "cannot cd %s\n", buf+3);
-      continue;
-    }
-    if(fork1() == 0)
-      runcmd(parsecmd(buf));
-    wait(0);
-  }
-  exit(0);
+	// Read and run input commands.
+	while (getcmd(buf, sizeof(buf)) >= 0) {
+		if (buf[0] == 'c' && buf[1] == 'd' && buf[2] == ' ') {
+			// Chdir must be called by the parent, not the child.
+			buf[strlen(buf) - 1] = 0; // chop \n
+			if (chdir(buf + 3) < 0)
+				fprintf(2, "cannot cd %s\n", buf + 3);
+			continue;
+		}
+		if (fork1() == 0)
+			runcmd(parsecmd(buf));
+		wait(0);
+	}
+	exit(0);
 }
 
-void
-panic(char *s)
-{
-  fprintf(2, "%s\n", s);
-  exit(1);
+void panic(char *s) {
+	fprintf(2, "%s\n", s);
+	exit(1);
 }
 
-int
-fork1(void)
-{
-  int pid;
+int fork1(void) {
+	int pid;
 
-  pid = fork();
-  if(pid == -1)
-    panic("fork");
-  return pid;
+	pid = fork();
+	if (pid == -1)
+		panic("fork");
+	return pid;
 }
 
-//PAGEBREAK!
-// Constructors
+// PAGEBREAK!
+//  Constructors
 
-struct cmd*
-execcmd(void)
-{
-  struct execcmd *cmd;
+struct cmd *execcmd(void) {
+	struct execcmd *cmd;
 
-  cmd = malloc(sizeof(*cmd));
-  memset(cmd, 0, sizeof(*cmd));
-  cmd->type = EXEC;
-  return (struct cmd*)cmd;
+	cmd = malloc(sizeof(*cmd));
+	memset(cmd, 0, sizeof(*cmd));
+	cmd->type = EXEC;
+	return (struct cmd *)cmd;
 }
 
-struct cmd*
-redircmd(struct cmd *subcmd, char *file, char *efile, int mode, int fd)
-{
-  struct redircmd *cmd;
+struct cmd *redircmd(struct cmd *subcmd, char *file, char *efile, int mode,
+					 int fd) {
+	struct redircmd *cmd;
 
-  cmd = malloc(sizeof(*cmd));
-  memset(cmd, 0, sizeof(*cmd));
-  cmd->type = REDIR;
-  cmd->cmd = subcmd;
-  cmd->file = file;
-  cmd->efile = efile;
-  cmd->mode = mode;
-  cmd->fd = fd;
-  return (struct cmd*)cmd;
+	cmd = malloc(sizeof(*cmd));
+	memset(cmd, 0, sizeof(*cmd));
+	cmd->type = REDIR;
+	cmd->cmd = subcmd;
+	cmd->file = file;
+	cmd->efile = efile;
+	cmd->mode = mode;
+	cmd->fd = fd;
+	return (struct cmd *)cmd;
 }
 
-struct cmd*
-pipecmd(struct cmd *left, struct cmd *right)
-{
-  struct pipecmd *cmd;
+struct cmd *pipecmd(struct cmd *left, struct cmd *right) {
+	struct pipecmd *cmd;
 
-  cmd = malloc(sizeof(*cmd));
-  memset(cmd, 0, sizeof(*cmd));
-  cmd->type = PIPE;
-  cmd->left = left;
-  cmd->right = right;
-  return (struct cmd*)cmd;
+	cmd = malloc(sizeof(*cmd));
+	memset(cmd, 0, sizeof(*cmd));
+	cmd->type = PIPE;
+	cmd->left = left;
+	cmd->right = right;
+	return (struct cmd *)cmd;
 }
 
-struct cmd*
-listcmd(struct cmd *left, struct cmd *right)
-{
-  struct listcmd *cmd;
+struct cmd *listcmd(struct cmd *left, struct cmd *right) {
+	struct listcmd *cmd;
 
-  cmd = malloc(sizeof(*cmd));
-  memset(cmd, 0, sizeof(*cmd));
-  cmd->type = LIST;
-  cmd->left = left;
-  cmd->right = right;
-  return (struct cmd*)cmd;
+	cmd = malloc(sizeof(*cmd));
+	memset(cmd, 0, sizeof(*cmd));
+	cmd->type = LIST;
+	cmd->left = left;
+	cmd->right = right;
+	return (struct cmd *)cmd;
 }
 
-struct cmd*
-backcmd(struct cmd *subcmd)
-{
-  struct backcmd *cmd;
+struct cmd *backcmd(struct cmd *subcmd) {
+	struct backcmd *cmd;
 
-  cmd = malloc(sizeof(*cmd));
-  memset(cmd, 0, sizeof(*cmd));
-  cmd->type = BACK;
-  cmd->cmd = subcmd;
-  return (struct cmd*)cmd;
+	cmd = malloc(sizeof(*cmd));
+	memset(cmd, 0, sizeof(*cmd));
+	cmd->type = BACK;
+	cmd->cmd = subcmd;
+	return (struct cmd *)cmd;
 }
-//PAGEBREAK!
-// Parsing
+// PAGEBREAK!
+//  Parsing
 
 char whitespace[] = " \t\r\n\v";
 char symbols[] = "<|>&;()";
 
-int
-gettoken(char **ps, char *es, char **q, char **eq)
-{
-  char *s;
-  int ret;
+int gettoken(char **ps, char *es, char **q, char **eq) {
+	char *s;
+	int ret;
 
-  s = *ps;
-  while(s < es && strchr(whitespace, *s))
-    s++;
-  if(q)
-    *q = s;
-  ret = *s;
-  switch(*s){
-  case 0:
-    break;
-  case '|':
-  case '(':
-  case ')':
-  case ';':
-  case '&':
-  case '<':
-    s++;
-    break;
-  case '>':
-    s++;
-    if(*s == '>'){
-      ret = '+';
-      s++;
-    }
-    break;
-  default:
-    ret = 'a';
-    while(s < es && !strchr(whitespace, *s) && !strchr(symbols, *s))
-      s++;
-    break;
-  }
-  if(eq)
-    *eq = s;
+	s = *ps;
+	while (s < es && strchr(whitespace, *s))
+		s++;
+	if (q)
+		*q = s;
+	ret = *s;
+	switch (*s) {
+	case 0:
+		break;
+	case '|':
+	case '(':
+	case ')':
+	case ';':
+	case '&':
+	case '<':
+		s++;
+		break;
+	case '>':
+		s++;
+		if (*s == '>') {
+			ret = '+';
+			s++;
+		}
+		break;
+	default:
+		ret = 'a';
+		while (s < es && !strchr(whitespace, *s) && !strchr(symbols, *s))
+			s++;
+		break;
+	}
+	if (eq)
+		*eq = s;
 
-  while(s < es && strchr(whitespace, *s))
-    s++;
-  *ps = s;
-  return ret;
+	while (s < es && strchr(whitespace, *s))
+		s++;
+	*ps = s;
+	return ret;
 }
 
-int
-peek(char **ps, char *es, char *toks)
-{
-  char *s;
+int peek(char **ps, char *es, char *toks) {
+	char *s;
 
-  s = *ps;
-  while(s < es && strchr(whitespace, *s))
-    s++;
-  *ps = s;
-  return *s && strchr(toks, *s);
+	s = *ps;
+	while (s < es && strchr(whitespace, *s))
+		s++;
+	*ps = s;
+	return *s && strchr(toks, *s);
 }
 
-struct cmd *parseline(char**, char*);
-struct cmd *parsepipe(char**, char*);
-struct cmd *parseexec(char**, char*);
-struct cmd *nulterminate(struct cmd*);
+struct cmd *parseline(char **, char *);
+struct cmd *parsepipe(char **, char *);
+struct cmd *parseexec(char **, char *);
+struct cmd *nulterminate(struct cmd *);
 
-struct cmd*
-parsecmd(char *s)
-{
-  char *es;
-  struct cmd *cmd;
+struct cmd *parsecmd(char *s) {
+	char *es;
+	struct cmd *cmd;
 
-  es = s + strlen(s);
-  cmd = parseline(&s, es);
-  peek(&s, es, "");
-  if(s != es){
-    fprintf(2, "leftovers: %s\n", s);
-    panic("syntax");
-  }
-  nulterminate(cmd);
-  return cmd;
+	es = s + strlen(s);
+	cmd = parseline(&s, es);
+	peek(&s, es, "");
+	if (s != es) {
+		fprintf(2, "leftovers: %s\n", s);
+		panic("syntax");
+	}
+	nulterminate(cmd);
+	return cmd;
 }
 
-struct cmd*
-parseline(char **ps, char *es)
-{
-  struct cmd *cmd;
+struct cmd *parseline(char **ps, char *es) {
+	struct cmd *cmd;
 
-  cmd = parsepipe(ps, es);
-  while(peek(ps, es, "&")){
-    gettoken(ps, es, 0, 0);
-    cmd = backcmd(cmd);
-  }
-  if(peek(ps, es, ";")){
-    gettoken(ps, es, 0, 0);
-    cmd = listcmd(cmd, parseline(ps, es));
-  }
-  return cmd;
+	cmd = parsepipe(ps, es);
+	while (peek(ps, es, "&")) {
+		gettoken(ps, es, 0, 0);
+		cmd = backcmd(cmd);
+	}
+	if (peek(ps, es, ";")) {
+		gettoken(ps, es, 0, 0);
+		cmd = listcmd(cmd, parseline(ps, es));
+	}
+	return cmd;
 }
 
-struct cmd*
-parsepipe(char **ps, char *es)
-{
-  struct cmd *cmd;
+struct cmd *parsepipe(char **ps, char *es) {
+	struct cmd *cmd;
 
-  cmd = parseexec(ps, es);
-  if(peek(ps, es, "|")){
-    gettoken(ps, es, 0, 0);
-    cmd = pipecmd(cmd, parsepipe(ps, es));
-  }
-  return cmd;
+	cmd = parseexec(ps, es);
+	if (peek(ps, es, "|")) {
+		gettoken(ps, es, 0, 0);
+		cmd = pipecmd(cmd, parsepipe(ps, es));
+	}
+	return cmd;
 }
 
-struct cmd*
-parseredirs(struct cmd *cmd, char **ps, char *es)
-{
-  int tok;
-  char *q, *eq;
+struct cmd *parseredirs(struct cmd *cmd, char **ps, char *es) {
+	int tok;
+	char *q, *eq;
 
-  while(peek(ps, es, "<>")){
-    tok = gettoken(ps, es, 0, 0);
-    if(gettoken(ps, es, &q, &eq) != 'a')
-      panic("missing file for redirection");
-    switch(tok){
-    case '<':
-      cmd = redircmd(cmd, q, eq, O_RDONLY, 0);
-      break;
-    case '>':
-      cmd = redircmd(cmd, q, eq, O_WRONLY|O_CREATE|O_TRUNC, 1);
-      break;
-    case '+':  // >>
-      cmd = redircmd(cmd, q, eq, O_WRONLY|O_CREATE, 1);
-      break;
-    }
-  }
-  return cmd;
+	while (peek(ps, es, "<>")) {
+		tok = gettoken(ps, es, 0, 0);
+		if (gettoken(ps, es, &q, &eq) != 'a')
+			panic("missing file for redirection");
+		switch (tok) {
+		case '<':
+			cmd = redircmd(cmd, q, eq, O_RDONLY, 0);
+			break;
+		case '>':
+			cmd = redircmd(cmd, q, eq, O_WRONLY | O_CREATE | O_TRUNC, 1);
+			break;
+		case '+': // >>
+			cmd = redircmd(cmd, q, eq, O_WRONLY | O_CREATE, 1);
+			break;
+		}
+	}
+	return cmd;
 }
 
-struct cmd*
-parseblock(char **ps, char *es)
-{
-  struct cmd *cmd;
+struct cmd *parseblock(char **ps, char *es) {
+	struct cmd *cmd;
 
-  if(!peek(ps, es, "("))
-    panic("parseblock");
-  gettoken(ps, es, 0, 0);
-  cmd = parseline(ps, es);
-  if(!peek(ps, es, ")"))
-    panic("syntax - missing )");
-  gettoken(ps, es, 0, 0);
-  cmd = parseredirs(cmd, ps, es);
-  return cmd;
+	if (!peek(ps, es, "("))
+		panic("parseblock");
+	gettoken(ps, es, 0, 0);
+	cmd = parseline(ps, es);
+	if (!peek(ps, es, ")"))
+		panic("syntax - missing )");
+	gettoken(ps, es, 0, 0);
+	cmd = parseredirs(cmd, ps, es);
+	return cmd;
 }
 
-struct cmd*
-parseexec(char **ps, char *es)
-{
-  char *q, *eq;
-  int tok, argc;
-  struct execcmd *cmd;
-  struct cmd *ret;
+struct cmd *parseexec(char **ps, char *es) {
+	char *q, *eq;
+	int tok, argc;
+	struct execcmd *cmd;
+	struct cmd *ret;
 
-  if(peek(ps, es, "("))
-    return parseblock(ps, es);
+	if (peek(ps, es, "("))
+		return parseblock(ps, es);
 
-  ret = execcmd();
-  cmd = (struct execcmd*)ret;
+	ret = execcmd();
+	cmd = (struct execcmd *)ret;
 
-  argc = 0;
-  ret = parseredirs(ret, ps, es);
-  while(!peek(ps, es, "|)&;")){
-    if((tok=gettoken(ps, es, &q, &eq)) == 0)
-      break;
-    if(tok != 'a')
-      panic("syntax");
-    cmd->argv[argc] = q;
-    cmd->eargv[argc] = eq;
-    argc++;
-    if(argc >= MAXARGS)
-      panic("too many args");
-    ret = parseredirs(ret, ps, es);
-  }
-  cmd->argv[argc] = 0;
-  cmd->eargv[argc] = 0;
-  return ret;
+	argc = 0;
+	ret = parseredirs(ret, ps, es);
+	while (!peek(ps, es, "|)&;")) {
+		if ((tok = gettoken(ps, es, &q, &eq)) == 0)
+			break;
+		if (tok != 'a')
+			panic("syntax");
+		cmd->argv[argc] = q;
+		cmd->eargv[argc] = eq;
+		argc++;
+		if (argc >= MAXARGS)
+			panic("too many args");
+		ret = parseredirs(ret, ps, es);
+	}
+	cmd->argv[argc] = 0;
+	cmd->eargv[argc] = 0;
+	return ret;
 }
 
 // NUL-terminate all the counted strings.
-struct cmd*
-nulterminate(struct cmd *cmd)
-{
-  int i;
-  struct backcmd *bcmd;
-  struct execcmd *ecmd;
-  struct listcmd *lcmd;
-  struct pipecmd *pcmd;
-  struct redircmd *rcmd;
+struct cmd *nulterminate(struct cmd *cmd) {
+	int i;
+	struct backcmd *bcmd;
+	struct execcmd *ecmd;
+	struct listcmd *lcmd;
+	struct pipecmd *pcmd;
+	struct redircmd *rcmd;
 
-  if(cmd == 0)
-    return 0;
+	if (cmd == 0)
+		return 0;
 
-  switch(cmd->type){
-  case EXEC:
-    ecmd = (struct execcmd*)cmd;
-    for(i=0; ecmd->argv[i]; i++)
-      *ecmd->eargv[i] = 0;
-    break;
+	switch (cmd->type) {
+	case EXEC:
+		ecmd = (struct execcmd *)cmd;
+		for (i = 0; ecmd->argv[i]; i++)
+			*ecmd->eargv[i] = 0;
+		break;
 
-  case REDIR:
-    rcmd = (struct redircmd*)cmd;
-    nulterminate(rcmd->cmd);
-    *rcmd->efile = 0;
-    break;
+	case REDIR:
+		rcmd = (struct redircmd *)cmd;
+		nulterminate(rcmd->cmd);
+		*rcmd->efile = 0;
+		break;
 
-  case PIPE:
-    pcmd = (struct pipecmd*)cmd;
-    nulterminate(pcmd->left);
-    nulterminate(pcmd->right);
-    break;
+	case PIPE:
+		pcmd = (struct pipecmd *)cmd;
+		nulterminate(pcmd->left);
+		nulterminate(pcmd->right);
+		break;
 
-  case LIST:
-    lcmd = (struct listcmd*)cmd;
-    nulterminate(lcmd->left);
-    nulterminate(lcmd->right);
-    break;
+	case LIST:
+		lcmd = (struct listcmd *)cmd;
+		nulterminate(lcmd->left);
+		nulterminate(lcmd->right);
+		break;
 
-  case BACK:
-    bcmd = (struct backcmd*)cmd;
-    nulterminate(bcmd->cmd);
-    break;
-  }
-  return cmd;
+	case BACK:
+		bcmd = (struct backcmd *)cmd;
+		nulterminate(bcmd->cmd);
+		break;
+	}
+	return cmd;
 }

user/stressfs.c

@@ -13,37 +13,35 @@
 #include "kernel/fs.h"
 #include "kernel/fcntl.h"
 
-int
-main(int argc, char *argv[])
-{
-  int fd, i;
-  char path[] = "stressfs0";
-  char data[512];
+int main(int argc, char *argv[]) {
+	int fd, i;
+	char path[] = "stressfs0";
+	char data[512];
 
-  printf("stressfs starting\n");
-  memset(data, 'a', sizeof(data));
+	printf("stressfs starting\n");
+	memset(data, 'a', sizeof(data));
 
-  for(i = 0; i < 4; i++)
-    if(fork() > 0)
-      break;
+	for (i = 0; i < 4; i++)
+		if (fork() > 0)
+			break;
 
-  printf("write %d\n", i);
+	printf("write %d\n", i);
 
-  path[8] += i;
-  fd = open(path, O_CREATE | O_RDWR);
-  for(i = 0; i < 20; i++)
-//    printf(fd, "%d\n", i);
-    write(fd, data, sizeof(data));
-  close(fd);
+	path[8] += i;
+	fd = open(path, O_CREATE | O_RDWR);
+	for (i = 0; i < 20; i++)
+		//    printf(fd, "%d\n", i);
+		write(fd, data, sizeof(data));
+	close(fd);
 
-  printf("read\n");
+	printf("read\n");
 
-  fd = open(path, O_RDONLY);
-  for (i = 0; i < 20; i++)
-    read(fd, data, sizeof(data));
-  close(fd);
+	fd = open(path, O_RDONLY);
+	for (i = 0; i < 20; i++)
+		read(fd, data, sizeof(data));
+	close(fd);
 
-  wait(0);
+	wait(0);
 
-  exit(0);
+	exit(0);
 }

user/ulib.c

@@ -6,142 +6,118 @@
 //
 // wrapper so that it's OK if main() does not call exit().
 //
-void
-_main()
-{
-  extern int main();
-  main();
-  exit(0);
+void _main() {
+	extern int main();
+	main();
+	exit(0);
 }
 
-char*
-strcpy(char *s, const char *t)
-{
-  char *os;
+char *strcpy(char *s, const char *t) {
+	char *os;
 
-  os = s;
-  while((*s++ = *t++) != 0)
-    ;
-  return os;
+	os = s;
+	while ((*s++ = *t++) != 0)
+		;
+	return os;
 }
 
-int
-strcmp(const char *p, const char *q)
-{
-  while(*p && *p == *q)
-    p++, q++;
-  return (uchar)*p - (uchar)*q;
+int strcmp(const char *p, const char *q) {
+	while (*p && *p == *q)
+		p++, q++;
+	return (uchar)*p - (uchar)*q;
 }
 
-uint
-strlen(const char *s)
-{
-  int n;
+uint strlen(const char *s) {
+	int n;
 
-  for(n = 0; s[n]; n++)
-    ;
-  return n;
+	for (n = 0; s[n]; n++)
+		;
+	return n;
 }
 
-void*
-memset(void *dst, int c, uint n)
-{
-  char *cdst = (char *) dst;
-  int i;
-  for(i = 0; i < n; i++){
-    cdst[i] = c;
-  }
-  return dst;
+void *memset(void *dst, int c, uint n) {
+	char *cdst = (char *)dst;
+	int i;
+	for (i = 0; i < n; i++) {
+		cdst[i] = c;
+	}
+	return dst;
 }
 
-char*
-strchr(const char *s, char c)
-{
-  for(; *s; s++)
-    if(*s == c)
-      return (char*)s;
-  return 0;
+char *strchr(const char *s, char c) {
+	for (; *s; s++)
+		if (*s == c)
+			return (char *)s;
+	return 0;
 }
 
-char*
-gets(char *buf, int max)
-{
-  int i, cc;
-  char c;
+char *gets(char *buf, int max) {
+	int i, cc;
+	char c;
 
-  for(i=0; i+1 < max; ){
-    cc = read(0, &c, 1);
-    if(cc < 1)
-      break;
-    buf[i++] = c;
-    if(c == '\n' || c == '\r')
-      break;
-  }
-  buf[i] = '\0';
-  return buf;
+	for (i = 0; i + 1 < max;) {
+		cc = read(0, &c, 1);
+		if (cc < 1)
+			break;
+		buf[i++] = c;
+		if (c == '\n' || c == '\r')
+			break;
+	}
+	buf[i] = '\0';
+	return buf;
 }
 
-int
-stat(const char *n, struct stat *st)
-{
-  int fd;
-  int r;
+int stat(const char *n, struct stat *st) {
+	int fd;
+	int r;
 
-  fd = open(n, O_RDONLY);
-  if(fd < 0)
-    return -1;
-  r = fstat(fd, st);
-  close(fd);
-  return r;
+	fd = open(n, O_RDONLY);
+	if (fd < 0)
+		return -1;
+	r = fstat(fd, st);
+	close(fd);
+	return r;
 }
 
-int
-atoi(const char *s)
-{
-  int n;
+int atoi(const char *s) {
+	int n;
 
-  n = 0;
-  while('0' <= *s && *s <= '9')
-    n = n*10 + *s++ - '0';
-  return n;
+	n = 0;
+	while ('0' <= *s && *s <= '9')
+		n = n * 10 + *s++ - '0';
+	return n;
 }
 
-void*
-memmove(void *vdst, const void *vsrc, int n)
-{
-  char *dst;
-  const char *src;
+void *memmove(void *vdst, const void *vsrc, int n) {
+	char *dst;
+	const char *src;
 
-  dst = vdst;
-  src = vsrc;
-  if (src > dst) {
-    while(n-- > 0)
-      *dst++ = *src++;
-  } else {
-    dst += n;
-    src += n;
-    while(n-- > 0)
-      *--dst = *--src;
-  }
-  return vdst;
+	dst = vdst;
+	src = vsrc;
+	if (src > dst) {
+		while (n-- > 0)
+			*dst++ = *src++;
+	} else {
+		dst += n;
+		src += n;
+		while (n-- > 0)
+			*--dst = *--src;
+	}
+	return vdst;
 }
 
-int
-memcmp(const void *s1, const void *s2, uint n)
-{
-  const char *p1 = s1, *p2 = s2;
-  while (n-- > 0) {
-    if (*p1 != *p2) {
-      return *p1 - *p2;
-    }
-    p1++;
-    p2++;
-  }
-  return 0;
+int memcmp(const void *s1, const void *s2, uint n) {
+	const char *p1 = s1, *p2 = s2;
+	while (n-- > 0) {
+		if (*p1 != *p2) {
+			return *p1 - *p2;
+		}
+		p1++;
+		p2++;
+	}
+	return 0;
 }
 
-void *
-memcpy(void *dst, const void *src, uint n)
-{
-  return memmove(dst, src, n);
+void *memcpy(void *dst, const void *src, uint n) {
+	return memmove(dst, src, n);
 }

user/umalloc.c

@@ -9,11 +9,11 @@
 typedef long Align;
 
 union header {
-  struct {
-    union header *ptr;
-    uint size;
-  } s;
-  Align x;
+	struct {
+		union header *ptr;
+		uint size;
+	} s;
+	Align x;
 };
 
 typedef union header Header;
@@ -21,70 +21,64 @@ typedef union header Header;
 static Header base;
 static Header *freep;
 
-void
-free(void *ap)
-{
-  Header *bp, *p;
+void free(void *ap) {
+	Header *bp, *p;
 
-  bp = (Header*)ap - 1;
-  for(p = freep; !(bp > p && bp < p->s.ptr); p = p->s.ptr)
-    if(p >= p->s.ptr && (bp > p || bp < p->s.ptr))
-      break;
-  if(bp + bp->s.size == p->s.ptr){
-    bp->s.size += p->s.ptr->s.size;
-    bp->s.ptr = p->s.ptr->s.ptr;
-  } else
-    bp->s.ptr = p->s.ptr;
-  if(p + p->s.size == bp){
-    p->s.size += bp->s.size;
-    p->s.ptr = bp->s.ptr;
-  } else
-    p->s.ptr = bp;
-  freep = p;
+	bp = (Header *)ap - 1;
+	for (p = freep; !(bp > p && bp < p->s.ptr); p = p->s.ptr)
+		if (p >= p->s.ptr && (bp > p || bp < p->s.ptr))
+			break;
+	if (bp + bp->s.size == p->s.ptr) {
+		bp->s.size += p->s.ptr->s.size;
+		bp->s.ptr = p->s.ptr->s.ptr;
+	} else
+		bp->s.ptr = p->s.ptr;
+	if (p + p->s.size == bp) {
+		p->s.size += bp->s.size;
+		p->s.ptr = bp->s.ptr;
+	} else
+		p->s.ptr = bp;
+	freep = p;
 }
 
-static Header*
-morecore(uint nu)
-{
-  char *p;
-  Header *hp;
+static Header *morecore(uint nu) {
+	char *p;
+	Header *hp;
 
-  if(nu < 4096)
-    nu = 4096;
-  p = sbrk(nu * sizeof(Header));
-  if(p == (char*)-1)
-    return 0;
-  hp = (Header*)p;
-  hp->s.size = nu;
-  free((void*)(hp + 1));
-  return freep;
+	if (nu < 4096)
+		nu = 4096;
+	p = sbrk(nu * sizeof(Header));
+	if (p == (char *)-1)
+		return 0;
+	hp = (Header *)p;
+	hp->s.size = nu;
+	free((void *)(hp + 1));
+	return freep;
 }
 
-void*
-malloc(uint nbytes)
-{
-  Header *p, *prevp;
-  uint nunits;
+void *malloc(uint nbytes) {
+	Header *p, *prevp;
+	uint nunits;
 
-  nunits = (nbytes + sizeof(Header) - 1)/sizeof(Header) + 1;
-  if((prevp = freep) == 0){
-    base.s.ptr = freep = prevp = &base;
-    base.s.size = 0;
-  }
-  for(p = prevp->s.ptr; ; prevp = p, p = p->s.ptr){
-    if(p->s.size >= nunits){
-      if(p->s.size == nunits)
-        prevp->s.ptr = p->s.ptr;
-      else {
-        p->s.size -= nunits;
-        p += p->s.size;
-        p->s.size = nunits;
-      }
-      freep = prevp;
-      return (void*)(p + 1);
-    }
-    if(p == freep)
-      if((p = morecore(nunits)) == 0)
-        return 0;
-  }
+	nunits = (nbytes + sizeof(Header) - 1) / sizeof(Header) + 1;
+	if ((prevp = freep) == 0) {
+		base.s.ptr = freep = prevp = &base;
+		base.s.size = 0;
+	}
+	for (p = prevp->s.ptr;; prevp = p, p = p->s.ptr) {
+		if (p->s.size >= nunits) {
+			if (p->s.size == nunits)
+				prevp->s.ptr = p->s.ptr;
+			else {
+				p->s.size -= nunits;
+				p += p->s.size;
+				p->s.size = nunits;
+			}
+			freep = prevp;
+			return (void *)(p + 1);
+		}
+		if (p == freep)
+			if ((p = morecore(nunits)) == 0)
+				return 0;
+	}
 }

user/wc.c

@@ -4,51 +4,47 @@
 
 char buf[512];
 
-void
-wc(int fd, char *name)
-{
-  int i, n;
-  int l, w, c, inword;
+void wc(int fd, char *name) {
+	int i, n;
+	int l, w, c, inword;
 
-  l = w = c = 0;
-  inword = 0;
-  while((n = read(fd, buf, sizeof(buf))) > 0){
-    for(i=0; i<n; i++){
-      c++;
-      if(buf[i] == '\n')
-        l++;
-      if(strchr(" \r\t\n\v", buf[i]))
-        inword = 0;
-      else if(!inword){
-        w++;
-        inword = 1;
-      }
-    }
-  }
-  if(n < 0){
-    printf("wc: read error\n");
-    exit(1);
-  }
-  printf("%d %d %d %s\n", l, w, c, name);
+	l = w = c = 0;
+	inword = 0;
+	while ((n = read(fd, buf, sizeof(buf))) > 0) {
+		for (i = 0; i < n; i++) {
+			c++;
+			if (buf[i] == '\n')
+				l++;
+			if (strchr(" \r\t\n\v", buf[i]))
+				inword = 0;
+			else if (!inword) {
+				w++;
+				inword = 1;
+			}
+		}
+	}
+	if (n < 0) {
+		printf("wc: read error\n");
+		exit(1);
+	}
+	printf("%d %d %d %s\n", l, w, c, name);
 }
 
-int
-main(int argc, char *argv[])
-{
-  int fd, i;
+int main(int argc, char *argv[]) {
+	int fd, i;
 
-  if(argc <= 1){
-    wc(0, "");
-    exit(0);
-  }
+	if (argc <= 1) {
+		wc(0, "");
+		exit(0);
+	}
 
-  for(i = 1; i < argc; i++){
-    if((fd = open(argv[i], 0)) < 0){
-      printf("wc: cannot open %s\n", argv[i]);
-      exit(1);
-    }
-    wc(fd, argv[i]);
-    close(fd);
-  }
-  exit(0);
+	for (i = 1; i < argc; i++) {
+		if ((fd = open(argv[i], 0)) < 0) {
+			printf("wc: cannot open %s\n", argv[i]);
+			exit(1);
+		}
+		wc(fd, argv[i]);
+		close(fd);
+	}
+	exit(0);
 }

user/zombie.c

@@ -5,10 +5,8 @@
 #include "kernel/stat.h"
 #include "user/user.h"
 
-int
-main(void)
-{
-  if(fork() > 0)
-    sleep(5);  // Let child exit before parent.
-  exit(0);
+int main(void) {
+	if (fork() > 0)
+		sleep(5); // Let child exit before parent.
+	exit(0);
 }