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2 Commits

Author SHA1 Message Date
whatever
acfd874a05 checkpoint for lock lab 2024-11-23 21:39:15 +08:00
Frans Kaashoek
8702675076 lock lab 2024-10-25 09:21:45 -04:00
38 changed files with 1431 additions and 1407 deletions

View File

@ -197,6 +197,7 @@ UPROGS=\
ifeq ($(LAB),syscall)
UPROGS += \
$U/_attack\
@ -260,10 +261,6 @@ UPROGS += \
endif
ifeq ($(LAB),mmap)
UPROGS += \
$U/_mmaptest
endif
ifeq ($(LAB),net)
UPROGS += \

582
]
View File

@ -1,582 +0,0 @@
//
// File-system system calls.
// Mostly argument checking, since we don't trust
// user code, and calls into file.c and fs.c.
//
#include "types.h"
#include "riscv.h"
#include "defs.h"
#include "param.h"
#include "stat.h"
#include "spinlock.h"
#include "proc.h"
#include "fs.h"
#include "sleeplock.h"
#include "file.h"
#include "fcntl.h"
// 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;
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();
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;
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;
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;
return filewrite(f, p, n);
}
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;
}
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);
}
// 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;
if(argstr(0, old, MAXPATH) < 0 || argstr(1, new, MAXPATH) < 0)
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;
}
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);
end_op();
return 0;
bad:
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;
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;
if(argstr(0, path, MAXPATH) < 0)
return -1;
begin_op();
if((dp = nameiparent(path, name)) == 0){
end_op();
return -1;
}
ilock(dp);
// 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->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);
ip->nlink--;
iupdate(ip);
iunlockput(ip);
end_op();
return 0;
bad:
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];
if((dp = nameiparent(path, name)) == 0)
return 0;
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 = ialloc(dp->dev, type)) == 0){
iunlockput(dp);
return 0;
}
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(dirlink(dp, name, ip->inum) < 0)
goto fail;
if(type == T_DIR){
// now that success is guaranteed:
dp->nlink++; // for ".."
iupdate(dp);
}
iunlockput(dp);
return ip;
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;
argint(1, &omode);
if((n = argstr(0, path, MAXPATH)) < 0)
return -1;
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(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(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);
}
iunlock(ip);
end_op();
return fd;
}
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;
}
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;
}
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;
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);
for(i = 0; i < NELEM(argv) && argv[i] != 0; i++)
kfree(argv[i]);
return ret;
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();
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;
}
const struct vma Null= {.addr=0,.len=0,.prot=0,.flags=0,.file=(struct file*)0,.offset=0};
uint64 sys_mmap(void) {
uint64 addr,len;
int prot, flags, fd, offset;
argaddr(0, &addr);
argaddr(1, &len), argint(2, &prot), argint(3, &flags), argint(4, &fd), argint(5, &offset);
struct proc *p = myproc();
struct vma *vma = p->vma;
uint64 ret = p->sz;
for (int i = 0; i < NVMA; ++i) // don't process when it's full
if (vma[i].len == Null.len) { // getting a mem size of 0 seems crazy
vma[i].addr=ret;//addr is always 0, and ret is the position
vma[i].len=len;
vma[i].prot=prot;
vma[i].flags=flags;// which is MAP flags
vma[i].file=p->ofile[fd];
filedup(vma[i].file);//increased ref here
vma[i].offset=offset;
break;
}
p->sz += len;
return ret;
}
uint64 sys_munmap(void) {
uint64 addr,len;
argaddr(0,&addr),argaddr(1,&len);
// well it's possible that the passed addr and len does not match a munmap
return 0;
}
int lazymap(){
struct proc *p=myproc();
uint64 va=PGROUNDDOWN(r_stval());
if(va>=p->sz)
goto err1;
for(int i=0;i<NVMA;++i) {
const uint64 addr=p->vma[i].addr;
const int vma_flag=p->vma[i].prot;
const int offset=p->vma[i].offset;
struct file *file=p->vma[i].file;
struct inode *ip=file->ip;
const int len=p->vma[i].len;
// each addr and len won't intersect with each other, it's defined by sys_mmap process
if(PGROUNDDOWN(addr) + len>= va){// it's considered that addr is page-aligned
char *mem=kalloc();
memset(mem,0,PGSIZE);
if(mem==0)
goto err1;
int pte_flag=0;
if(vma_flag & PROT_READ)
pte_flag|=PTE_R;
if(vma_flag & PROT_WRITE)
pte_flag|=PTE_W;
if(vma_flag & PROT_EXEC)
pte_flag|=PTE_X;
pte_flag|=PTE_U;
if(mappages(p->pagetable,va,PGSIZE,(uint64)mem,pte_flag)<0){
kfree(mem);
goto err1;
}
ilock(ip);
// readi won't increase inode ref
if(!readi(ip,0,(uint64)mem,offset + (va-addr),PGSIZE))
goto err2;
DEBUG();
// file pointer handles ref to inode, so don't increase inode ref there
iunlock(ip);
return 0;
err2:
iunlock(ip);
goto err1;
}
}
err1:
return -1;
}

View File

@ -1 +1 @@
LAB=mmap
LAB=lock

BIN
fs.img.bk Normal file

Binary file not shown.

66
grade-lab-lock Executable file
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@ -0,0 +1,66 @@
#!/usr/bin/env python3
import re
from gradelib import *
r = Runner(save("xv6.out"))
@test(0, "running kalloctest")
def test_kalloctest():
r.run_qemu(shell_script([
'kalloctest'
]), timeout=300)
@test(10, "kalloctest: test1", parent=test_kalloctest)
def test_kalloctest_test1():
r.match('^test1 OK$')
@test(10, "kalloctest: test2", parent=test_kalloctest)
def test_kalloctest_test2():
r.match('^test2 OK$')
@test(10, "kalloctest: test3", parent=test_kalloctest)
def test_kalloctest_test3():
r.match('^test3 OK$')
@test(10, "kalloctest: sbrkmuch")
def test_sbrkmuch():
r.run_qemu(shell_script([
'usertests sbrkmuch'
]), timeout=90)
r.match('^ALL TESTS PASSED$')
@test(0, "running bcachetest")
def test_bcachetest():
r.run_qemu(shell_script([
'bcachetest'
]), timeout=150)
@test(20, "bcachetest: test0", parent=test_bcachetest)
def test_bcachetest_test0():
r.match('^test0: OK$')
@test(10, "bcachetest: test1", parent=test_bcachetest)
def test_bcachetest_test1():
r.match('^test1 OK$')
@test(10, "bcachetest: test2", parent=test_bcachetest)
def test_bcachetest_test2():
r.match('^test2 OK$')
@test(10, "bcachetest: test3", parent=test_bcachetest)
def test_bcachetest_test3():
r.match('^test3 OK$')
@test(19, "usertests")
def test_usertests():
r.run_qemu(shell_script([
'usertests -q'
]), timeout=300)
r.match('^ALL TESTS PASSED$')
@test(1, "time")
def test_time():
check_time()
run_tests()

View File

@ -1,69 +0,0 @@
#!/usr/bin/env python3
import re
from gradelib import *
r = Runner(save("xv6.out"))
@test(0, "running mmaptest")
def test_mmaptest():
r.run_qemu(shell_script([
'mmaptest'
]), timeout=180)
@test(20, "mmaptest: mmap basic", parent=test_mmaptest)
def test_mmaptest_mmap_basic():
r.match('^test basic mmap: OK$')
@test(10, "mmaptest: mmap private", parent=test_mmaptest)
def test_mmaptest_mmap_private():
r.match('^test mmap private: OK$')
@test(10, "mmaptest: mmap read-only", parent=test_mmaptest)
def test_mmaptest_mmap_readonly():
r.match('^test mmap read-only: OK$')
@test(10, "mmaptest: mmap read/write", parent=test_mmaptest)
def test_mmaptest_mmap_readwrite():
r.match('^test mmap read/write: OK$')
@test(10, "mmaptest: mmap dirty", parent=test_mmaptest)
def test_mmaptest_mmap_dirty():
r.match('^test mmap dirty: OK$')
@test(10, "mmaptest: not-mapped unmap", parent=test_mmaptest)
def test_mmaptest_mmap_unmap():
r.match('^test not-mapped unmap: OK$')
@test(10, "mmaptest: lazy access", parent=test_mmaptest)
def test_mmaptest_mmap_unmap():
r.match('^test lazy access: OK$')
@test(10, "mmaptest: two files", parent=test_mmaptest)
def test_mmaptest_mmap_two():
r.match('^test mmap two files: OK$')
@test(40, "mmaptest: fork_test", parent=test_mmaptest)
def test_mmaptest_fork_test():
r.match('^test fork: OK$')
@test(10, "mmaptest: munmap_noaccess", parent=test_mmaptest)
def test_mmaptest_munmap_noaccess():
r.match('^test munmap prevents access: OK$')
@test(10, "mmaptest: read_only_write", parent=test_mmaptest)
def test_mmaptest_read_only_write():
r.match('^test writes to read-only mapped memory: OK$')
@test(19, "usertests")
def test_usertests():
r.run_qemu(shell_script([
'usertests -q'
]), timeout=300)
r.match('^ALL TESTS PASSED$')
@test(1, "time")
def test_time():
check_time()
run_tests()

View File

@ -238,7 +238,7 @@ def make(*target):
post_make()
def show_command(cmd):
from shlex import quote
from pipes import quote
print("\n$", " ".join(map(quote, cmd)))
def maybe_unlink(*paths):

View File

@ -118,7 +118,9 @@ brelse(struct buf *b)
{
if(!holdingsleep(&b->lock))
panic("brelse");
releasesleep(&b->lock);
acquire(&bcache.lock);
b->refcnt--;
if (b->refcnt == 0) {

View File

@ -237,4 +237,3 @@ void netinit(void);
void net_rx(char *buf, int len);
#endif
#define DEBUG() printf("File %s, Line %d, Function %s\n",__FILE__,__LINE__,__func__);

View File

@ -3,13 +3,3 @@
#define O_RDWR 0x002
#define O_CREATE 0x200
#define O_TRUNC 0x400
#ifdef LAB_MMAP
#define PROT_NONE 0x0
#define PROT_READ 0x1
#define PROT_WRITE 0x2
#define PROT_EXEC 0x4
#define MAP_SHARED 0x01
#define MAP_PRIVATE 0x02
#endif

View File

@ -38,3 +38,4 @@ struct devsw {
extern struct devsw devsw[];
#define CONSOLE 1
#define STATS 2

View File

@ -295,11 +295,11 @@ ilock(struct inode *ip)
struct buf *bp;
struct dinode *dip;
if(ip == 0 || ip->ref < 1)
if(ip == 0 || atomic_read4(&ip->ref) < 1)
panic("ilock");
acquiresleep(&ip->lock);
if(ip->valid == 0){
bp = bread(ip->dev, IBLOCK(ip->inum, sb));
dip = (struct dinode*)bp->data + ip->inum%IPB;
@ -320,7 +320,7 @@ ilock(struct inode *ip)
void
iunlock(struct inode *ip)
{
if(ip == 0 || !holdingsleep(&ip->lock) || ip->ref < 1)
if(ip == 0 || !holdingsleep(&ip->lock) || atomic_read4(&ip->ref) < 1)
panic("iunlock");
releasesleep(&ip->lock);
@ -416,7 +416,6 @@ bmap(struct inode *ip, uint bn)
brelse(bp);
return addr;
}
panic("bmap: out of range");
}
@ -447,7 +446,7 @@ itrunc(struct inode *ip)
bfree(ip->dev, ip->addrs[NDIRECT]);
ip->addrs[NDIRECT] = 0;
}
ip->size = 0;
iupdate(ip);
}
@ -478,6 +477,7 @@ readi(struct inode *ip, int user_dst, uint64 dst, uint off, uint n)
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)

323
kernel/kcsan.c Normal file
View File

@ -0,0 +1,323 @@
#include "types.h"
#include "param.h"
#include "memlayout.h"
#include "spinlock.h"
#include "riscv.h"
#include "proc.h"
#include "defs.h"
//
// Race detector using gcc's thread sanitizer. It delays all stores
// and loads and monitors if any other CPU is using the same address.
// If so, we have a race and print out the backtrace of the thread
// that raced and the thread that set the watchpoint.
//
//
// To run with kcsan:
// make clean
// make KCSAN=1 qemu
//
// The number of watch points.
#define NWATCH (NCPU)
// The number of cycles to delay stores, whatever that means on qemu.
//#define DELAY_CYCLES 20000
#define DELAY_CYCLES 200000
#define MAXTRACE 20
int
trace(uint64 *trace, int maxtrace)
{
uint64 i = 0;
push_off();
uint64 fp = r_fp();
uint64 ra, low = PGROUNDDOWN(fp) + 16, high = PGROUNDUP(fp);
while(!(fp & 7) && fp >= low && fp < high){
ra = *(uint64*)(fp - 8);
fp = *(uint64*)(fp - 16);
trace[i++] = ra;
if(i >= maxtrace)
break;
}
pop_off();
return i;
}
struct watch {
uint64 addr;
int write;
int race;
uint64 trace[MAXTRACE];
int tracesz;
};
struct {
struct spinlock lock;
struct watch points[NWATCH];
int on;
} tsan;
static struct watch*
wp_lookup(uint64 addr)
{
for(struct watch *w = &tsan.points[0]; w < &tsan.points[NWATCH]; w++) {
if(w->addr == addr) {
return w;
}
}
return 0;
}
static int
wp_install(uint64 addr, int write)
{
for(struct watch *w = &tsan.points[0]; w < &tsan.points[NWATCH]; w++) {
if(w->addr == 0) {
w->addr = addr;
w->write = write;
w->tracesz = trace(w->trace, MAXTRACE);
return 1;
}
}
panic("wp_install");
return 0;
}
static void
wp_remove(uint64 addr)
{
for(struct watch *w = &tsan.points[0]; w < &tsan.points[NWATCH]; w++) {
if(w->addr == addr) {
w->addr = 0;
w->tracesz = 0;
return;
}
}
panic("remove");
}
static void
printtrace(uint64 *t, int n)
{
int i;
for(i = 0; i < n; i++) {
printf("%p\n", (void*) t[i]);
}
}
static void
race(char *s, struct watch *w) {
uint64 t[MAXTRACE];
int n;
n = trace(t, MAXTRACE);
printf("== race detected ==\n");
printf("backtrace for racing %s\n", s);
printtrace(t, n);
printf("backtrace for watchpoint:\n");
printtrace(w->trace, w->tracesz);
printf("==========\n");
}
// cycle counter
static inline uint64
r_cycle()
{
uint64 x;
asm volatile("rdcycle %0" : "=r" (x) );
return x;
}
static void delay(void) __attribute__((noinline));
static void delay() {
uint64 stop = r_cycle() + DELAY_CYCLES;
uint64 c = r_cycle();
while(c < stop) {
c = r_cycle();
}
}
static void
kcsan_read(uint64 addr, int sz)
{
struct watch *w;
acquire(&tsan.lock);
if((w = wp_lookup(addr)) != 0) {
if(w->write) {
race("load", w);
}
release(&tsan.lock);
return;
}
release(&tsan.lock);
}
static void
kcsan_write(uint64 addr, int sz)
{
struct watch *w;
acquire(&tsan.lock);
if((w = wp_lookup(addr)) != 0) {
race("store", w);
release(&tsan.lock);
}
// no watchpoint; try to install one
if(wp_install(addr, 1)) {
release(&tsan.lock);
// XXX maybe read value at addr before and after delay to catch
// races of unknown origins (e.g., device).
delay();
acquire(&tsan.lock);
wp_remove(addr);
}
release(&tsan.lock);
}
// tsan.on will only have effect with "make KCSAN=1"
void
kcsaninit(void)
{
initlock(&tsan.lock, "tsan");
tsan.on = 1;
__sync_synchronize();
}
//
// Calls inserted by compiler into kernel binary, except for this file.
//
void
__tsan_init(void)
{
}
void
__tsan_read1(uint64 addr)
{
if(!tsan.on)
return;
// kcsan_read(addr, 1);
}
void
__tsan_read2(uint64 addr)
{
if(!tsan.on)
return;
kcsan_read(addr, 2);
}
void
__tsan_read4(uint64 addr)
{
if(!tsan.on)
return;
kcsan_read(addr, 4);
}
void
__tsan_read8(uint64 addr)
{
if(!tsan.on)
return;
kcsan_read(addr, 8);
}
void
__tsan_read_range(uint64 addr, uint64 size)
{
if(!tsan.on)
return;
kcsan_read(addr, size);
}
void
__tsan_write1(uint64 addr)
{
if(!tsan.on)
return;
// kcsan_write(addr, 1);
}
void
__tsan_write2(uint64 addr)
{
if(!tsan.on)
return;
kcsan_write(addr, 2);
}
void
__tsan_write4(uint64 addr)
{
if(!tsan.on)
return;
kcsan_write(addr, 4);
}
void
__tsan_write8(uint64 addr)
{
if(!tsan.on)
return;
kcsan_write(addr, 8);
}
void
__tsan_write_range(uint64 addr, uint64 size)
{
if(!tsan.on)
return;
kcsan_write(addr, size);
}
void
__tsan_atomic_thread_fence(int order)
{
__sync_synchronize();
}
uint32
__tsan_atomic32_load(uint *ptr, uint *val, int order)
{
uint t;
__atomic_load(ptr, &t, __ATOMIC_SEQ_CST);
return t;
}
void
__tsan_atomic32_store(uint *ptr, uint val, int order)
{
__atomic_store(ptr, &val, __ATOMIC_SEQ_CST);
}
// We don't use this
void
__tsan_func_entry(uint64 pc)
{
}
// We don't use this
void
__tsan_func_exit(void)
{
}

View File

@ -12,6 +12,9 @@ main()
{
if(cpuid() == 0){
consoleinit();
#if defined(LAB_LOCK)
statsinit();
#endif
printfinit();
printf("\n");
printf("xv6 kernel is booting\n");
@ -28,11 +31,17 @@ main()
iinit(); // inode table
fileinit(); // file table
virtio_disk_init(); // emulated hard disk
#ifdef LAB_NET
pci_init();
#endif
userinit(); // first user process
#ifdef KCSAN
kcsaninit();
#endif
__sync_synchronize();
started = 1;
} else {
while(started == 0)
while(atomic_read4((int *) &started) == 0)
;
__sync_synchronize();
printf("hart %d starting\n", cpuid());

View File

@ -68,6 +68,9 @@ pipeclose(struct pipe *pi, int writable)
}
if(pi->readopen == 0 && pi->writeopen == 0){
release(&pi->lock);
#ifdef LAB_LOCK
freelock(&pi->lock);
#endif
kfree((char*)pi);
} else
release(&pi->lock);

View File

@ -273,7 +273,7 @@ growproc(int n)
p->sz = sz;
return 0;
}
extern int lazymap(uint64);
// Create a new process, copying the parent.
// Sets up child kernel stack to return as if from fork() system call.
int
@ -282,35 +282,12 @@ fork(void)
int i, pid;
struct proc *np;
struct proc *p = myproc();
// Allocate process.
if((np = allocproc()) == 0){
return -1;
}
// not lazy anymore, forcefully alloc all pages in VMA
release(&np->lock);
for(int i=0;i<NVMA;++i){
np->vma[i]=p->vma[i];
if(p->vma[i].len==0)
continue;
const int addr=p->vma[i].addr;
const int len=p->vma[i].len;
const int vis=p->vma[i].vis;
filedup(np->vma[i].file);
for(int j=0;j<len;j+=PGSIZE){
const int cur=addr+j;
const int x=j/PGSIZE;
if((1<<x)&vis)
continue;
pte_t *pte=walk(p->pagetable,cur,0);
if(pte!=0 &&(*pte & PTE_V)!=0)
continue;
if(lazymap(cur)<0){
freeproc(np);
return -1;
}
}
}
acquire(&np->lock);
// Copy user memory from parent to child.
if(uvmcopy(p->pagetable, np->pagetable, p->sz) < 0){
freeproc(np);
@ -344,6 +321,7 @@ fork(void)
acquire(&np->lock);
np->state = RUNNABLE;
release(&np->lock);
return pid;
}
@ -365,7 +343,6 @@ reparent(struct proc *p)
// Exit the current process. Does not return.
// An exited process remains in the zombie state
// until its parent calls wait().
extern int munmap(uint64,uint64);
void
exit(int status)
{
@ -387,30 +364,7 @@ exit(int status)
iput(p->cwd);
end_op();
p->cwd = 0;
#ifdef CHECK_IF_VALID_ADDR
int cnt=0;
#endif
for(int i=0;i<NVMA;++i){
int x=0;
for(int j=1;j<NVMA;++j)
if(p->vma[j].addr>p->vma[x].addr)
x=j;
if(p->vma[x].len==0)
break;
#ifdef CHECK_IF_VALID_ADDR
printf("current sz=%lu\n",p->sz);
if(p->vma[x].addr+p->vma[x].len!=p->sz){
printf("addr=%lu,len=%d,cnt=%d\n",p->vma[x].addr,p->vma[x].len,cnt);
panic("invalid addr");
}
++cnt;
#endif
if(p->vma[x].len)
munmap(p->vma[x].addr,p->vma[x].len);
}
#ifdef CHECK_IF_VALID_ADDR
printf("it's still alive, sz=%lu\n",p->sz);
#endif
acquire(&wait_lock);
// Give any children to init.
@ -425,6 +379,7 @@ exit(int status)
p->state = ZOMBIE;
release(&wait_lock);
// Jump into the scheduler, never to return.
sched();
panic("zombie exit");
@ -491,6 +446,7 @@ scheduler(void)
{
struct proc *p;
struct cpu *c = mycpu();
c->proc = 0;
for(;;){
// The most recent process to run may have had interrupts

View File

@ -20,7 +20,7 @@ struct context {
// Per-CPU state.
struct cpu {
struct proc *proc; // The process running on this cpu, or Null.
struct proc *proc; // The process running on this cpu, or null.
struct context context; // swtch() here to enter scheduler().
int noff; // Depth of push_off() nesting.
int intena; // Were interrupts enabled before push_off()?
@ -80,14 +80,7 @@ struct trapframe {
};
enum procstate { UNUSED, USED, SLEEPING, RUNNABLE, RUNNING, ZOMBIE };
#define NVMA 16
struct vma{
uint64 addr;
int len,prot,flags,offset;
struct file *file;
int vis;// validity bitmask used, bit 1 stands for being unmapped, init be 0
// the 0-th bit stands for addr, then 1-st bit stands for addr+PGSIZE, etc
};
// Per-process state
struct proc {
struct spinlock lock;
@ -111,5 +104,4 @@ struct proc {
struct file *ofile[NOFILE]; // Open files
struct inode *cwd; // Current directory
char name[16]; // Process name (debugging)
struct vma vma[NVMA];
};

View File

@ -204,7 +204,7 @@ r_menvcfg()
static inline void
w_menvcfg(uint64 x)
{
// asm volatile("csrw menvcfg, %0" : : "r" (x));
//asm volatile("csrw menvcfg, %0" : : "r" (x));
asm volatile("csrw 0x30a, %0" : : "r" (x));
}
@ -314,6 +314,14 @@ r_sp()
return x;
}
static inline uint64
r_fp()
{
uint64 x;
asm volatile("mv %0, s0" : "=r" (x) );
return x;
}
// read and write tp, the thread pointer, which xv6 uses to hold
// this core's hartid (core number), the index into cpus[].
static inline uint64
@ -354,6 +362,11 @@ typedef uint64 *pagetable_t; // 512 PTEs
#define PGSIZE 4096 // bytes per page
#define PGSHIFT 12 // bits of offset within a page
#ifdef LAB_PGTBL
#define SUPERPGSIZE (2 * (1 << 20)) // bytes per page
#define SUPERPGROUNDUP(sz) (((sz)+SUPERPGSIZE-1) & ~(SUPERPGSIZE-1))
#endif
#define PGROUNDUP(sz) (((sz)+PGSIZE-1) & ~(PGSIZE-1))
#define PGROUNDDOWN(a) (((a)) & ~(PGSIZE-1))
@ -363,6 +376,12 @@ typedef uint64 *pagetable_t; // 512 PTEs
#define PTE_X (1L << 3)
#define PTE_U (1L << 4) // user can access
#if defined(LAB_MMAP) || defined(LAB_PGTBL)
#define PTE_LEAF(pte) (((pte) & PTE_R) | ((pte) & PTE_W) | ((pte) & PTE_X))
#endif
// shift a physical address to the right place for a PTE.
#define PA2PTE(pa) ((((uint64)pa) >> 12) << 10)

View File

@ -8,12 +8,52 @@
#include "proc.h"
#include "defs.h"
#ifdef LAB_LOCK
#define NLOCK 500
static struct spinlock *locks[NLOCK];
struct spinlock lock_locks;
void
freelock(struct spinlock *lk)
{
acquire(&lock_locks);
int i;
for (i = 0; i < NLOCK; i++) {
if(locks[i] == lk) {
locks[i] = 0;
break;
}
}
release(&lock_locks);
}
static void
findslot(struct spinlock *lk) {
acquire(&lock_locks);
int i;
for (i = 0; i < NLOCK; i++) {
if(locks[i] == 0) {
locks[i] = lk;
release(&lock_locks);
return;
}
}
panic("findslot");
}
#endif
void
initlock(struct spinlock *lk, char *name)
{
lk->name = name;
lk->locked = 0;
lk->cpu = 0;
#ifdef LAB_LOCK
lk->nts = 0;
lk->n = 0;
findslot(lk);
#endif
}
// Acquire the lock.
@ -25,12 +65,21 @@ acquire(struct spinlock *lk)
if(holding(lk))
panic("acquire");
#ifdef LAB_LOCK
__sync_fetch_and_add(&(lk->n), 1);
#endif
// 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)
;
while(__sync_lock_test_and_set(&lk->locked, 1) != 0) {
#ifdef LAB_LOCK
__sync_fetch_and_add(&(lk->nts), 1);
#else
;
#endif
}
// Tell the C compiler and the processor to not move loads or stores
// past this point, to ensure that the critical section's memory
@ -108,3 +157,61 @@ pop_off(void)
if(c->noff == 0 && c->intena)
intr_on();
}
// Read a shared 32-bit value without holding a lock
int
atomic_read4(int *addr) {
uint32 val;
__atomic_load(addr, &val, __ATOMIC_SEQ_CST);
return val;
}
#ifdef LAB_LOCK
int
snprint_lock(char *buf, int sz, struct spinlock *lk)
{
int n = 0;
if(lk->n > 0) {
n = snprintf(buf, sz, "lock: %s: #test-and-set %d #acquire() %d\n",
lk->name, lk->nts, lk->n);
}
return n;
}
int
statslock(char *buf, int sz) {
int n;
int tot = 0;
acquire(&lock_locks);
n = snprintf(buf, sz, "--- lock kmem/bcache stats\n");
for(int i = 0; i < NLOCK; i++) {
if(locks[i] == 0)
break;
if(strncmp(locks[i]->name, "bcache", strlen("bcache")) == 0 ||
strncmp(locks[i]->name, "kmem", strlen("kmem")) == 0) {
tot += locks[i]->nts;
n += snprint_lock(buf +n, sz-n, locks[i]);
}
}
n += snprintf(buf+n, sz-n, "--- top 5 contended locks:\n");
int last = 100000000;
// stupid way to compute top 5 contended locks
for(int t = 0; t < 5; t++) {
int top = 0;
for(int i = 0; i < NLOCK; i++) {
if(locks[i] == 0)
break;
if(locks[i]->nts > locks[top]->nts && locks[i]->nts < last) {
top = i;
}
}
n += snprint_lock(buf+n, sz-n, locks[top]);
last = locks[top]->nts;
}
n += snprintf(buf+n, sz-n, "tot= %d\n", tot);
release(&lock_locks);
return n;
}
#endif

View File

@ -5,5 +5,9 @@ struct spinlock {
// For debugging:
char *name; // Name of lock.
struct cpu *cpu; // The cpu holding the lock.
#ifdef LAB_LOCK
int nts;
int n;
#endif
};

88
kernel/sprintf.c Normal file
View File

@ -0,0 +1,88 @@
#include <stdarg.h>
#include "types.h"
#include "param.h"
#include "spinlock.h"
#include "sleeplock.h"
#include "fs.h"
#include "file.h"
#include "riscv.h"
#include "defs.h"
static char digits[] = "0123456789abcdef";
static int
sputc(char *s, char c)
{
*s = c;
return 1;
}
static int
sprintint(char *s, int xx, int base, int sign)
{
char buf[16];
int i, n;
uint x;
if(sign && (sign = xx < 0))
x = -xx;
else
x = xx;
i = 0;
do {
buf[i++] = digits[x % base];
} while((x /= base) != 0);
if(sign)
buf[i++] = '-';
n = 0;
while(--i >= 0)
n += sputc(s+n, buf[i]);
return n;
}
int
snprintf(char *buf, unsigned long sz, const char *fmt, ...)
{
va_list ap;
int i, c;
int off = 0;
char *s;
va_start(ap, fmt);
for(i = 0; off < sz && (c = fmt[i] & 0xff) != 0; i++){
if(c != '%'){
off += sputc(buf+off, c);
continue;
}
c = fmt[++i] & 0xff;
if(c == 0)
break;
switch(c){
case 'd':
off += sprintint(buf+off, va_arg(ap, int), 10, 1);
break;
case 'x':
off += sprintint(buf+off, va_arg(ap, int), 16, 1);
break;
case 's':
if((s = va_arg(ap, char*)) == 0)
s = "(null)";
for(; *s && off < sz; s++)
off += sputc(buf+off, *s);
break;
case '%':
off += sputc(buf+off, '%');
break;
default:
// Print unknown % sequence to draw attention.
off += sputc(buf+off, '%');
off += sputc(buf+off, c);
break;
}
}
return off;
}

View File

@ -32,6 +32,11 @@ start()
w_mideleg(0xffff);
w_sie(r_sie() | SIE_SEIE | SIE_STIE | SIE_SSIE);
#ifdef KCSAN
// allow supervisor to read cycle counter register
w_mcounteren(r_mcounteren()|0x3);
#endif
// configure Physical Memory Protection to give supervisor mode
// access to all of physical memory.
w_pmpaddr0(0x3fffffffffffffull);

69
kernel/stats.c Normal file
View File

@ -0,0 +1,69 @@
#include <stdarg.h>
#include "types.h"
#include "param.h"
#include "spinlock.h"
#include "sleeplock.h"
#include "fs.h"
#include "file.h"
#include "riscv.h"
#include "defs.h"
#define BUFSZ 4096
static struct {
struct spinlock lock;
char buf[BUFSZ];
int sz;
int off;
} stats;
int statscopyin(char*, int);
int statslock(char*, int);
int
statswrite(int user_src, uint64 src, int n)
{
return -1;
}
int
statsread(int user_dst, uint64 dst, int n)
{
int m;
acquire(&stats.lock);
if(stats.sz == 0) {
#ifdef LAB_PGTBL
stats.sz = statscopyin(stats.buf, BUFSZ);
#endif
#ifdef LAB_LOCK
stats.sz = statslock(stats.buf, BUFSZ);
#endif
}
m = stats.sz - stats.off;
if (m > 0) {
if(m > n)
m = n;
if(either_copyout(user_dst, dst, stats.buf+stats.off, m) != -1) {
stats.off += m;
}
} else {
m = -1;
stats.sz = 0;
stats.off = 0;
}
release(&stats.lock);
return m;
}
void
statsinit(void)
{
initlock(&stats.lock, "stats");
devsw[STATS].read = statsread;
devsw[STATS].write = statswrite;
}

View File

@ -101,8 +101,7 @@ extern uint64 sys_unlink(void);
extern uint64 sys_link(void);
extern uint64 sys_mkdir(void);
extern uint64 sys_close(void);
extern uint64 sys_mmap(void);
extern uint64 sys_munmap(void);
// An array mapping syscall numbers from syscall.h
// to the function that handles the system call.
static uint64 (*syscalls[])(void) = {
@ -127,8 +126,6 @@ static uint64 (*syscalls[])(void) = {
[SYS_link] sys_link,
[SYS_mkdir] sys_mkdir,
[SYS_close] sys_close,
[SYS_mmap] sys_mmap,
[SYS_munmap] sys_munmap
};
void

View File

@ -20,5 +20,3 @@
#define SYS_link 19
#define SYS_mkdir 20
#define SYS_close 21
#define SYS_mmap 22
#define SYS_munmap 23

View File

@ -503,186 +503,3 @@ sys_pipe(void)
}
return 0;
}
const struct vma Null= {.addr=0,.len=0,.prot=0,.flags=0,.file=(struct file*)0,.offset=0,.vis=0};
uint64 sys_mmap(void) {
uint64 addr,len;
int prot, flags, fd, offset;
argaddr(0, &addr);
argaddr(1, &len), argint(2, &prot), argint(3, &flags), argint(4, &fd), argint(5, &offset);
struct proc *p = myproc();
struct vma *vma = p->vma;
if((!p->ofile[fd]->readable) && (prot & PROT_READ))
goto err1;
if((!p->ofile[fd]->writable) && (prot &PROT_WRITE) && (flags & MAP_SHARED))
goto err1;
uint64 ret = p->sz;
for (int i = 0; i < NVMA; ++i) // don't process when it's full
if (vma[i].len == Null.len) { // getting a mem size of 0 seems crazy
vma[i].addr=ret;//addr is always 0, and ret is the position
vma[i].len=len;
vma[i].prot=prot;
vma[i].flags=flags;// which is MAP flags
vma[i].file=p->ofile[fd];
filedup(vma[i].file);//increased ref here
vma[i].offset=offset;
vma[i].vis=0;
p->sz+=len;
return ret;
}
err1:
return -1;
}
void shrink_vma(){
struct proc *p=myproc();
//DEBUG();
while(1){
int found=0;
int i;
for(i=0;i<NVMA;++i)
if(p->vma[i].vis==-1 && p->vma[i].addr+p->vma[i].len==p->sz){
found=1;
break;
}
if(!found)
break;
#ifdef CHECK_IF_EXISTS
printf("current sz=%lu\n",p->sz);
#endif
p->sz-=p->vma[i].len;
p->vma[i]=Null;
}
}
int munmap(uint64 Argaddr,uint64 Arglen){
struct proc *p=myproc();
// well it's possible that the passed addr and len does not match a munmap
// how do I know that all of the pages of an mmap zone has been removed --using vis
// don't do crazy things like unmap two different mmap area at same time --it's fine, no such operation in test
for(int i=0;i<NVMA;++i){// all of which are changable
uint64 addr=p->vma[i].addr;
const int offset=p->vma[i].offset;
struct file *file=p->vma[i].file;
struct inode *ip=file->ip;
const int len=p->vma[i].len;
int *vis=&p->vma[i].vis;
const int map_flag=p->vma[i].flags;
if(*vis!=-1 && len >0 && PGROUNDDOWN(addr) + len >= Argaddr+Arglen && PGROUNDDOWN(addr) <= Argaddr){
// for(int i=0;i<Arglen;i+=PGSIZE){
// const int cur = Argaddr + i;
// const int x = (cur-addr)/PGSIZE;
// delete it, even if being already deleted
//if((1<<x)&(*vis))
// goto err1; //attempting to visit a dellocated page
// }
for(int i=0;i<Arglen;i+=PGSIZE){
const uint64 cur = Argaddr + i;
const int x = (cur-addr)/PGSIZE;
pte_t *pte=walk(p->pagetable,cur,0);
if(pte!=0 && (*pte & PTE_V)!=0){
// this page may not actually allocated
// wait what happens for uvmunmap, if there's a mmap page between normal pages... --I bet this won't happen
if(map_flag & (MAP_SHARED)){// write back
begin_op(); // don't forget begin_op
ilock(ip);
const uint sz=ip->size;
const int pos=offset+(cur-addr);
const uint remain=sz-pos;
if(writei(ip,1,cur,pos,PGSIZE<remain?PGSIZE:remain)<0)
goto err2;
iunlock(ip);
end_op();
}
uvmunmap(p->pagetable,cur,1,1);
}
*vis |= 1<<x;// add dellocated sign
//kfree((char *)cur); it's not kernel memory space
// delete such memory page
}
int all_clear=1;
for(int i=0;i<len/PGSIZE;++i)
all_clear&=(*vis)>>i;
if(all_clear){ // clear this vma
// wait, what happens if this vma is the highest address?
// and, it's responsible for exit, to call munmap in a dereasing order
//if(p->sz == addr+len)
//p->sz-=len;
// release the file
fileclose(file);
// clean this vma
//p->vma[i]=Null;// well, I don't need those pointers at all...
p->vma[i].vis=-1;
shrink_vma();
}
return 0;
err2:
iunlock(ip);
goto err1;
}
}
err1:
// hey! why did a uint64 func return -1??
return -1; //default not found
}
uint64 sys_munmap(void) {
uint64 Argaddr,Arglen;
argaddr(0,&Argaddr),argaddr(1,&Arglen);
return munmap(Argaddr,Arglen);
}
int lazymap(uint64 va){
struct proc *p=myproc();
if(va>=p->sz)
goto err1;
uint64 scause=r_scause();
for(int i=0;i<NVMA;++i) {
const uint64 addr=p->vma[i].addr;
const int vma_flag=p->vma[i].prot;
const int offset=p->vma[i].offset;
struct file *file=p->vma[i].file;
struct inode *ip=file->ip;
const int len=p->vma[i].len;
const int vis=p->vma[i].vis;
// each addr and len won't intersect with each other, it's defined by sys_mmap process
// it's > not >=, however
// we must make sure that this va is within the range
if(vis!=-1 && len > 0 && PGROUNDDOWN(addr) + len>va && PGROUNDDOWN(addr)<=va){// it's considered that addr is page-aligned
const int x=(va-addr)/PGSIZE;
if((1<<x)&vis)
goto err1;// attempting to visit a dellocated page
if(scause == 13 && (vma_flag & PROT_READ)==0)
goto err1;
if(scause ==15 && (vma_flag & PROT_WRITE)==0)
goto err1;
char *mem=kalloc();
memset(mem,0,PGSIZE);
if(mem==0)
goto err1;
int pte_flag=0;
if(vma_flag & PROT_READ)
pte_flag|=PTE_R;
if(vma_flag & PROT_WRITE)
pte_flag|=PTE_W;
if(vma_flag & PROT_EXEC)
pte_flag|=PTE_X;
pte_flag|=PTE_U;
if(mappages(p->pagetable,va,PGSIZE,(uint64)mem,pte_flag)<0){
kfree(mem);
goto err1;
}
// why I need to call readi??
// oh, that's because I can't get file+offset directly...
ilock(ip);
// readi won't increase inode ref
if(readi(ip,0,(uint64)mem,offset + (va-addr),PGSIZE)<=0)
goto err2;
// file pointer handles ref to inode, so don't increase inode ref there
iunlock(ip);
return 0;
err2:
uvmunmap(p->pagetable,va,1,1);
iunlock(ip);
goto err1;
}
}
err1:
return -1;
}

View File

@ -5,45 +5,62 @@
#include "memlayout.h"
#include "spinlock.h"
#include "proc.h"
uint64 sys_exit(void) {
uint64
sys_exit(void)
{
int n;
argint(0, &n);
exit(n);
return 0; // not reached
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_fork(void)
{
return fork();
}
uint64 sys_wait(void) {
uint64
sys_wait(void)
{
uint64 p;
argaddr(0, &p);
return wait(p);
}
uint64 sys_sbrk(void) {
uint64
sys_sbrk(void)
{
uint64 addr;
int n;
argint(0, &n);
addr = myproc()->sz;
if (growproc(n) < 0)
if(growproc(n) < 0)
return -1;
return addr;
}
uint64 sys_sleep(void) {
uint64
sys_sleep(void)
{
int n;
uint ticks0;
argint(0, &n);
if (n < 0)
if(n < 0)
n = 0;
acquire(&tickslock);
ticks0 = ticks;
while (ticks - ticks0 < n) {
if (killed(myproc())) {
while(ticks - ticks0 < n){
if(killed(myproc())){
release(&tickslock);
return -1;
}
@ -53,17 +70,20 @@ uint64 sys_sleep(void) {
return 0;
}
uint64 sys_kill(void) {
uint64
sys_kill(void)
{
int pid;
argint(0, &pid);
return kill(pid);
}
// return how many clock tick interrupts have occurred
// since start.
uint64 sys_uptime(void) {
uint64
sys_uptime(void)
{
uint xticks;
acquire(&tickslock);
@ -71,4 +91,3 @@ uint64 sys_uptime(void) {
release(&tickslock);
return xticks;
}

View File

@ -15,7 +15,7 @@ extern char trampoline[], uservec[], userret[];
void kernelvec();
extern int devintr();
extern int lazymap(uint64);
void
trapinit(void)
{
@ -65,14 +65,7 @@ usertrap(void)
intr_on();
syscall();
}else if(r_scause() == 13 || r_scause() == 15){ //on handling page fault
if(killed(p))
exit(-1);// for sure?
if(lazymap(PGROUNDDOWN(r_stval()))<0)
setkilled(p);
// kill will call exit(), and exit() will handle munmap
// do I need to call intr_on()? no
}else if((which_dev = devintr()) != 0){
} else if((which_dev = devintr()) != 0){
// ok
} else {
printf("usertrap(): unexpected scause 0x%lx pid=%d\n", r_scause(), p->pid);
@ -84,9 +77,9 @@ usertrap(void)
exit(-1);
// give up the CPU if this is a timer interrupt.
if(which_dev == 2){
if(which_dev == 2)
yield();
}
usertrapret();
}
@ -158,9 +151,9 @@ kerneltrap()
}
// give up the CPU if this is a timer interrupt.
if(which_dev == 2 && myproc() != 0){
if(which_dev == 2 && myproc() != 0)
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);

View File

@ -212,6 +212,28 @@ alloc3_desc(int *idx)
return 0;
}
#ifdef LAB_LOCK
//
// check that there are at most NBUF distinct
// struct buf's, which the lock lab requires.
//
static struct buf *xbufs[NBUF];
static void
checkbuf(struct buf *b)
{
for(int i = 0; i < NBUF; i++){
if(xbufs[i] == b){
return;
}
if(xbufs[i] == 0){
xbufs[i] = b;
return;
}
}
panic("more than NBUF bufs");
}
#endif
void
virtio_disk_rw(struct buf *b, int write)
{
@ -219,6 +241,10 @@ virtio_disk_rw(struct buf *b, int write)
acquire(&disk.vdisk_lock);
#ifdef LAB_LOCK
checkbuf(b);
#endif
// 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.

View File

@ -1 +0,0 @@
12

400
user/bcachetest.c Normal file
View File

@ -0,0 +1,400 @@
#include "kernel/fcntl.h"
#include "kernel/param.h"
#include "kernel/types.h"
#include "kernel/stat.h"
#include "kernel/riscv.h"
#include "kernel/fs.h"
#include "user/user.h"
void test0();
void test1();
void test2();
void test3();
#define SZ 4096
char buf[SZ];
int
main(int argc, char *argv[])
{
test0();
test1();
test2();
test3();
exit(0);
}
void
createfile(char *file, int nblock)
{
int fd;
char buf[BSIZE];
int i;
fd = open(file, O_CREATE | O_RDWR);
if(fd < 0){
printf("createfile %s failed\n", file);
exit(-1);
}
for(i = 0; i < nblock; i++) {
if(write(fd, buf, sizeof(buf)) != sizeof(buf)) {
printf("write %s failed\n", file);
exit(-1);
}
}
close(fd);
}
void
readfile(char *file, int nbytes, int inc)
{
char buf[BSIZE];
int fd;
int i;
if(inc > BSIZE) {
printf("readfile: inc too large\n");
exit(-1);
}
if ((fd = open(file, O_RDONLY)) < 0) {
printf("readfile open %s failed\n", file);
exit(-1);
}
for (i = 0; i < nbytes; i += inc) {
if(read(fd, buf, inc) != inc) {
printf("read %s failed for block %d (%d)\n", file, i, nbytes);
exit(-1);
}
}
close(fd);
}
int ntas(int print)
{
int n;
char *c;
if (statistics(buf, SZ) <= 0) {
fprintf(2, "ntas: no stats\n");
}
c = strchr(buf, '=');
n = atoi(c+2);
if(print)
printf("%s", buf);
return n;
}
// Test reading small files concurrently
void
test0()
{
char file[2];
char dir[2];
enum { N = 10, NCHILD = 3 };
int m, n;
dir[0] = '0';
dir[1] = '\0';
file[0] = 'F';
file[1] = '\0';
printf("start test0\n");
for(int i = 0; i < NCHILD; i++){
dir[0] = '0' + i;
mkdir(dir);
if (chdir(dir) < 0) {
printf("chdir failed\n");
exit(1);
}
unlink(file);
createfile(file, N);
if (chdir("..") < 0) {
printf("chdir failed\n");
exit(1);
}
}
m = ntas(0);
for(int i = 0; i < NCHILD; i++){
dir[0] = '0' + i;
int pid = fork();
if(pid < 0){
printf("fork failed");
exit(-1);
}
if(pid == 0){
if (chdir(dir) < 0) {
printf("chdir failed\n");
exit(1);
}
readfile(file, N*BSIZE, 1);
exit(0);
}
}
int status = 0;
for(int i = 0; i < NCHILD; i++){
wait(&status);
if (status != 0) {
printf("FAIL: a child failed\n");
exit(1);
}
}
printf("test0 results:\n");
n = ntas(1);
if (n-m < 500)
printf("test0: OK\n");
else
printf("test0: FAIL\n");
}
// Test bcache evictions by reading a large file concurrently
void test1()
{
char file[3];
enum { N = 200, BIG=100, NCHILD=2 };
printf("start test1\n");
file[0] = 'B';
file[2] = '\0';
for(int i = 0; i < NCHILD; i++){
file[1] = '0' + i;
unlink(file);
if (i == 0) {
createfile(file, BIG);
} else {
createfile(file, 1);
}
}
for(int i = 0; i < NCHILD; i++){
file[1] = '0' + i;
int pid = fork();
if(pid < 0){
printf("fork failed");
exit(-1);
}
if(pid == 0){
if (i==0) {
for (i = 0; i < N; i++) {
readfile(file, BIG*BSIZE, BSIZE);
}
unlink(file);
exit(0);
} else {
for (i = 0; i < N*20; i++) {
readfile(file, 1, BSIZE);
}
unlink(file);
}
exit(0);
}
}
int status = 0;
for(int i = 0; i < NCHILD; i++){
wait(&status);
if (status != 0) {
printf("FAIL: a child failed\n");
exit(1);
}
}
printf("\ntest1 OK\n");
}
//
// test concurrent creates.
//
void
test2()
{
int nc = 4;
char file[16];
printf("start test2\n");
mkdir("d2");
file[0] = 'd';
file[1] = '2';
file[2] = '/';
// remove any stale existing files.
for(int i = 0; i < 50; i++){
for(int ci = 0; ci < nc; ci++){
file[3] = 'a' + ci;
file[4] = '0' + i;
file[5] = '\0';
unlink(file);
}
}
int pids[nc];
for(int ci = 0; ci < nc; ci++){
pids[ci] = fork();
if(pids[ci] < 0){
printf("test2: fork failed\n");
exit(1);
}
if(pids[ci] == 0){
char me = "abcdefghijklmnop"[ci];
int pid = getpid();
int nf = (ci == 0 ? 10 : 15);
// create nf files.
for(int i = 0; i < nf; i++){
file[3] = me;
file[4] = '0' + i;
file[5] = '\0';
int fd = open(file, O_CREATE | O_RDWR);
if(fd < 0){
printf("test2: create %s failed\n", file);
exit(1);
}
int xx = (pid << 16) | i;
for(int nw = 0; nw < 2; nw++){
// the sleep() increases the chance of simultaneous
// calls to bget().
sleep(1);
if(write(fd, &xx, sizeof(xx)) <= 0){
printf("test2: write %s failed\n", file);
exit(1);
}
}
close(fd);
}
// read back the nf files.
for(int i = 0; i < nf; i++){
file[3] = me;
file[4] = '0' + i;
file[5] = '\0';
// printf("r %s\n", file);
int fd = open(file, O_RDWR);
if(fd < 0){
printf("test2: open %s failed\n", file);
exit(1);
}
int xx = (pid << 16) | i;
for(int nr = 0; nr < 2; nr++){
int z = 0;
sleep(1);
int n = read(fd, &z, sizeof(z));
if(n != sizeof(z)){
printf("test2: read %s returned %d, expected %ld\n", file, n, sizeof(z));
exit(1);
}
if(z != xx){
printf("test2: file %s contained %d, not %d\n", file, z, xx);
exit(1);
}
}
close(fd);
}
// delete the nf files.
for(int i = 0; i < nf; i++){
file[3] = me;
file[4] = '0' + i;
file[5] = '\0';
//printf("u %s\n", file);
if(unlink(file) != 0){
printf("test2: unlink %s failed\n", file);
exit(1);
}
}
exit(0);
}
}
int ok = 1;
for(int ci = 0; ci < nc; ci++){
int st = 0;
int ret = wait(&st);
if(ret <= 0){
printf("test2: wait() failed\n");
ok = 0;
}
if(st != 0)
ok = 0;
}
if(ok) {
printf("\ntest2 OK\n");
} else {
printf("test2 failed\n");
}
}
//
// generate big log transactions to check that bget() can
// make use of any of the NBUF buffers for any block number.
//
void
test3()
{
int nc = 5;
char file[16];
printf("start test3\n");
mkdir("d2");
file[0] = 'd';
file[1] = '2';
file[2] = '/';
int pids[nc];
for(int ci = 0; ci < nc; ci++){
pids[ci] = fork();
if(pids[ci] < 0){
printf("test3: fork failed\n");
exit(1);
}
if(pids[ci] == 0){
file[3] = 'a' + ci;
file[4] = '\0';
unlink(file);
int fd = open(file, O_CREATE | O_RDWR);
if(fd < 0){
printf("test3: create %s failed\n", file);
exit(1);
}
write(fd, "x", 1);
static char junk[12*512];
for(int i = 0; i < 12; i++){
sleep(1);
write(fd, junk, sizeof(junk));
}
exit(0);
}
}
int ok = 1;
for(int ci = 0; ci < nc; ci++){
int st = 0;
int ret = wait(&st);
if(ret <= 0){
printf("test3: wait() failed\n");
ok = 0;
}
if(st != 0)
ok = 0;
}
for(int ci = 0; ci < nc; ci++){
file[3] = 'a' + ci;
file[4] = '\0';
unlink(file);
}
if(ok) {
printf("\ntest3 OK\n");
} else {
printf("test3 failed\n");
}
}

View File

@ -18,6 +18,7 @@ main(void)
if(open("console", O_RDWR) < 0){
mknod("console", CONSOLE, 0);
mknod("statistics", STATS, 0);
open("console", O_RDWR);
}
dup(0); // stdout

198
user/kalloctest.c Normal file
View File

@ -0,0 +1,198 @@
#include "kernel/param.h"
#include "kernel/types.h"
#include "kernel/stat.h"
#include "kernel/riscv.h"
#include "kernel/memlayout.h"
#include "kernel/fcntl.h"
#include "user/user.h"
#define NCHILD 2
#define N 100000
#define SZ 4096
void test1(void);
void test2(void);
void test3(void);
char buf[SZ];
int countfree();
int
main(int argc, char *argv[])
{
test1();
test2();
test3();
exit(0);
}
int ntas(int print)
{
int n;
char *c;
if (statistics(buf, SZ) <= 0) {
fprintf(2, "ntas: no stats\n");
}
c = strchr(buf, '=');
n = atoi(c+2);
if(print)
printf("%s", buf);
return n;
}
// Test concurrent kallocs and kfrees
void test1(void)
{
void *a, *a1;
int n, m;
printf("start test1\n");
m = ntas(0);
for(int i = 0; i < NCHILD; i++){
int pid = fork();
if(pid < 0){
printf("fork failed");
exit(-1);
}
if(pid == 0){
for(i = 0; i < N; i++) {
a = sbrk(4096);
*(int *)(a+4) = 1;
a1 = sbrk(-4096);
if (a1 != a + 4096) {
printf("test1: FAIL wrong sbrk\n");
exit(1);
}
}
exit(0);
}
}
int status = 0;
for(int i = 0; i < NCHILD; i++){
wait(&status);
if (status != 0) {
printf("FAIL: a child failed\n");
exit(1);
}
}
printf("test1 results:\n");
n = ntas(1);
if(n-m < 10)
printf("test1 OK\n");
else
printf("test1 FAIL\n");
}
// Test stealing
void test2() {
int free0 = countfree();
int free1;
int n = (PHYSTOP-KERNBASE)/PGSIZE;
printf("start test2\n");
printf("total free number of pages: %d (out of %d)\n", free0, n);
if(n - free0 > 1000) {
printf("test2 FAILED: cannot allocate enough memory");
exit(1);
}
for (int i = 0; i < 50; i++) {
free1 = countfree();
if(i % 10 == 9)
printf(".");
if(free1 != free0) {
printf("test2 FAIL: losing pages %d %d\n", free0, free1);
exit(1);
}
}
printf("\ntest2 OK\n");
}
// Test concurrent kalloc/kfree and stealing
void test3(void)
{
uint64 a, a1;
int n, m;
m = ntas(0);
printf("start test3\n");
int pid;
for(int i = 0; i < NCHILD; i++){
pid = fork();
if(pid < 0){
printf("fork failed");
exit(-1);
}
if(pid == 0){
if (i == 0) {
for(i = 0; i < N; i++) {
a = (uint64) sbrk(4096);
if(a == 0xffffffffffffffff){
// no freemem
continue;
}
*(int *)(a+4) = 1;
a1 = (uint64) sbrk(-4096);
if (a1 != a + 4096) {
printf("test3 FAIL: wrong sbrk\n");
exit(1);
}
if ((i + 1) % 10000 == 0) {
printf(".");
}
}
printf("child done %d\n", i);
exit(0);
} else {
while (1) {
int free0 = countfree();
int free1 = countfree();
if(free0 - free1 > 1) {
printf("test3 FAIL: losing pages %d %d\n", free0, free1);
exit(1);
}
}
}
}
}
int status = 0;
for(int i = 0; i < NCHILD-1; i++){
wait(&status);
if (status != 0) {
printf("a child failed\n");
exit(1);
}
}
kill(pid);
n = ntas(1);
if(n-m < 4000)
printf("\ntest3 OK\n");
else
printf("test3 FAIL m %d n %d\n", m, n);
}
//
// countfree() from usertests.c
//
int
countfree()
{
uint64 sz0 = (uint64)sbrk(0);
int n = 0;
while(1){
uint64 a = (uint64) sbrk(4096);
if(a == 0xffffffffffffffff){
break;
}
// modify the memory to make sure it's really allocated.
*(char *)(a + 4096 - 1) = 1;
n += 1;
}
sbrk(-((uint64)sbrk(0) - sz0));
return n;
}

View File

@ -1,444 +0,0 @@
#include "kernel/param.h"
#include "kernel/fcntl.h"
#include "kernel/types.h"
#include "kernel/stat.h"
#include "kernel/riscv.h"
#include "kernel/fs.h"
#include "user/user.h"
void mmap_test();
void fork_test();
void more_test();
char buf[PGSIZE];
#define MAP_FAILED ((char *) -1)
int
main(int argc, char *argv[])
{
mmap_test();
fork_test();
more_test();
printf("mmaptest: all tests succeeded\n");
exit(0);
}
void
err(char *why)
{
printf("mmaptest failure: %s, pid=%d\n", why, getpid());
exit(1);
}
//
// check the content of the two mapped pages.
//
void
_v1(char *p)
{
int i;
for (i = 0; i < PGSIZE*2; i++) {
if (i < PGSIZE + (PGSIZE/2)) {
if (p[i] != 'A') {
printf("mismatch at %d, wanted 'A', got 0x%x\n", i, p[i]);
err("v1 mismatch (1)");
}
} else {
if (p[i] != 0) {
printf("mismatch at %d, wanted zero, got 0x%x\n", i, p[i]);
err("v1 mismatch (2)");
}
}
}
}
//
// create a file to be mapped, containing
// 1.5 pages of 'A' and half a page of zeros.
//
void
makefile(const char *f)
{
int i;
int n = PGSIZE/BSIZE;
unlink(f);
int fd = open(f, O_WRONLY | O_CREATE);
if (fd == -1)
err("open");
memset(buf, 'A', BSIZE);
// write 1.5 page
for (i = 0; i < n + n/2; i++) {
if (write(fd, buf, BSIZE) != BSIZE)
err("write 0 makefile");
}
if (close(fd) == -1)
err("close");
}
void
mmap_test(void)
{
int fd;
int i;
const char * const f = "mmap.dur";
//
// create a file with known content, map it into memory, check that
// the mapped memory has the same bytes as originally written to the
// file.
//
makefile(f);
if ((fd = open(f, O_RDONLY)) == -1)
err("open (1)");
printf("test basic mmap\n");
//
// this call to mmap() asks the kernel to map the content
// of open file fd into the address space. the first
// 0 argument indicates that the kernel should choose the
// virtual address. the second argument indicates how many
// bytes to map. the third argument indicates that the
// mapped memory should be read-only. the fourth argument
// indicates that, if the process modifies the mapped memory,
// that the modifications should not be written back to
// the file nor shared with other processes mapping the
// same file (of course in this case updates are prohibited
// due to PROT_READ). the fifth argument is the file descriptor
// of the file to be mapped. the last argument is the starting
// offset in the file.
//
char *p = mmap(0, PGSIZE*2, PROT_READ, MAP_PRIVATE, fd, 0);
if (p == MAP_FAILED)
err("mmap (1)");
_v1(p);
if (munmap(p, PGSIZE*2) == -1)
err("munmap (1)");
printf("test basic mmap: OK\n");
printf("test mmap private\n");
// should be able to map file opened read-only with private writable
// mapping
p = mmap(0, PGSIZE*2, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
if (p == MAP_FAILED)
err("mmap (2)");
if (close(fd) == -1)
err("close (1)");
_v1(p);
for (i = 0; i < PGSIZE*2; i++)
p[i] = 'Z';
if (munmap(p, PGSIZE*2) == -1)
err("munmap (2)");
close(fd);
// file should not have been modified.
if((fd = open(f, O_RDONLY)) < 0) err("open");
if(read(fd, buf, PGSIZE) != PGSIZE) err("read");
if(buf[0] != 'A')
err("write to MAP_PRIVATE was written to file");
if(read(fd, buf, PGSIZE) != PGSIZE/2) err("read");
if(buf[0] != 'A')
err("write to MAP_PRIVATE was written to file");
close(fd);
printf("test mmap private: OK\n");
printf("test mmap read-only\n");
// check that mmap doesn't allow read/write mapping of a
// file opened read-only.
if ((fd = open(f, O_RDONLY)) == -1)
err("open (2)");
p = mmap(0, PGSIZE*2, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
if (p != MAP_FAILED)
err("mmap (3)");
if (close(fd) == -1)
err("close (2)");
printf("test mmap read-only: OK\n");
printf("test mmap read/write\n");
// check that mmap does allow read/write mapping of a
// file opened read/write.
if ((fd = open(f, O_RDWR)) == -1)
err("open (3)");
p = mmap(0, PGSIZE*3, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
if (p == MAP_FAILED)
err("mmap (4)");
if (close(fd) == -1)
err("close (3)");
// check that the mapping still works after close(fd).
_v1(p);
// write the mapped memory.
for (i = 0; i < PGSIZE; i++)
p[i] = 'B';
for (i = PGSIZE; i < PGSIZE*2; i++)
p[i] = 'C';
// unmap just the first two of three pages of mapped memory.
if (munmap(p, PGSIZE*2) == -1)
err("munmap (3)");
printf("test mmap read/write: OK\n");
printf("test mmap dirty\n");
// check that the writes to the mapped memory were
// written to the file.
if ((fd = open(f, O_RDONLY)) == -1)
err("open (4)");
if(read(fd, buf, PGSIZE) != PGSIZE)
err("dirty read #1");
for (i = 0; i < PGSIZE; i++){
if (buf[i] != 'B')
err("file page 0 does not contain modifications");
}
if(read(fd, buf, PGSIZE) != PGSIZE/2)
err("dirty read #2");
for (i = 0; i < PGSIZE/2; i++){
if (buf[i] != 'C')
err("file page 1 does not contain modifications");
}
if (close(fd) == -1)
err("close (4)");
printf("test mmap dirty: OK\n");
printf("test not-mapped unmap\n");
// unmap the rest of the mapped memory.
if (munmap(p+PGSIZE*2, PGSIZE) == -1)
err("munmap (4)");
printf("test not-mapped unmap: OK\n");
printf("test lazy access\n");
if(unlink(f) != 0) err("unlink");
makefile(f);
if ((fd = open(f, O_RDWR)) == -1)
err("open");
p = mmap(0, PGSIZE*2, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
if (p == MAP_FAILED)
err("mmap");
close(fd);
// mmap() should not have read the file at this point,
// so that the file modification we're about to make
// ought to be visible to a subsequent read of the
// mapped memory.
if((fd = open(f, O_RDWR)) == -1)
err("open");
if(write(fd, "m", 1) != 1)
err("write");
close(fd);
if(*p != 'm')
err("read was not lazy");
if(munmap(p, PGSIZE*2) == -1)
err("munmap");
printf("test lazy access: OK\n");
printf("test mmap two files\n");
//
// mmap two different files at the same time.
//
int fd1;
if((fd1 = open("mmap1", O_RDWR|O_CREATE)) < 0)
err("open (5)");
if(write(fd1, "12345", 5) != 5)
err("write (1)");
char *p1 = mmap(0, PGSIZE, PROT_READ, MAP_PRIVATE, fd1, 0);
if(p1 == MAP_FAILED)
err("mmap (5)");
if (close(fd1) == -1)
err("close (5)");
if (unlink("mmap1") == -1)
err("unlink (1)");
int fd2;
if((fd2 = open("mmap2", O_RDWR|O_CREATE)) < 0)
err("open (6)");
if(write(fd2, "67890", 5) != 5)
err("write (2)");
char *p2 = mmap(0, PGSIZE, PROT_READ, MAP_PRIVATE, fd2, 0);
if(p2 == MAP_FAILED)
err("mmap (6)");
if (close(fd2) == -1)
err("close (6)");
if (unlink("mmap2") == -1)
err("unlink (2)");
if(memcmp(p1, "12345", 5) != 0)
err("mmap1 mismatch");
if(memcmp(p2, "67890", 5) != 0)
err("mmap2 mismatch");
if (munmap(p1, PGSIZE) == -1)
err("munmap (5)");
if(memcmp(p2, "67890", 5) != 0)
err("mmap2 mismatch (2)");
if (munmap(p2, PGSIZE) == -1)
err("munmap (6)");
printf("test mmap two files: OK\n");
}
//
// mmap a file, then fork.
// check that the child sees the mapped file.
//
void
fork_test(void)
{
int fd;
int pid;
const char * const f = "mmap.dur";
printf("test fork\n");
// mmap the file twice.
makefile(f);
if ((fd = open(f, O_RDONLY)) == -1)
err("open (7)");
if (unlink(f) == -1)
err("unlink (3)");
char *p1 = mmap(0, PGSIZE*2, PROT_READ, MAP_SHARED, fd, 0);
if (p1 == MAP_FAILED)
err("mmap (7)");
char *p2 = mmap(0, PGSIZE*2, PROT_READ, MAP_SHARED, fd, 0);
if (p2 == MAP_FAILED)
err("mmap (8)");
// read just 2nd page.
if(*(p1+PGSIZE) != 'A')
err("fork mismatch (1)");
if((pid = fork()) < 0)
err("fork");
if (pid == 0) {
_v1(p1);
if (munmap(p1, PGSIZE) == -1) // just the first page
err("munmap (7)");
exit(0); // tell the parent that the mapping looks OK.
}
int status = -1;
wait(&status);
if(status != 0){
printf("fork_test failed\n");
exit(1);
}
// check that the parent's mappings are still there.
_v1(p1);
_v1(p2);
printf("test fork: OK\n");
}
void
more_test()
{
int fd, pid;
char *p;
const char * const f = "mmap.dur";
printf("test munmap prevents access\n");
makefile(f);
if ((fd = open(f, O_RDWR)) == -1)
err("open");
p = mmap(0, PGSIZE*2, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
if (p == MAP_FAILED)
err("mmap");
close(fd);
*p = 'X';
*(p+PGSIZE) = 'Y';
pid = fork();
if(pid < 0) err("fork");
if(pid == 0){
*p = 'a';
*(p+PGSIZE) = 'b';
if(munmap(p+PGSIZE, PGSIZE) == -1)
err("munmap");
// this should cause a fatal fault
printf("*(p+PGSIZE) = %x\n", *(p+PGSIZE));
exit(0);
}
int st = 0;
wait(&st);
if(st != -1)
err("child #1 read unmapped memory");
pid = fork();
if(pid < 0) err("fork");
if(pid == 0){
*p = 'c';
*(p+PGSIZE) = 'd';
if(munmap(p, PGSIZE) == -1)
err("munmap");
// this should cause a fatal fault
printf("*p = %x\n", *p);
exit(0);
}
st = 0;
wait(&st);
if(st != -1)
err("child #2 read unmapped memory");
// parent should still be able to access the memory.
*p = 'P';
*(p+PGSIZE) = 'Q';
if(munmap(p, PGSIZE) == -1)
err("munmap");
*(p+PGSIZE) = 'R';
if(munmap(p+PGSIZE, PGSIZE) == -1)
err("munmap");
// read the file, check that the first page starts
// with P and the second page with R.
fd = open(f, O_RDONLY);
if(fd < 0) err("open");
if(read(fd, buf, PGSIZE) != PGSIZE) err("read");
if(buf[0] != 'P') err("first byte of file is wrong");
if(read(fd, buf, PGSIZE) != PGSIZE/2) err("read");
if(buf[0] != 'R') err("first byte of 2nd page of file is wrong");
close(fd);
printf("test munmap prevents access: OK\n");
printf("test writes to read-only mapped memory\n");
makefile(f);
pid = fork();
if(pid < 0) err("fork");
if(pid == 0){
if ((fd = open(f, O_RDWR)) == -1)
err("open");
p = mmap(0, PGSIZE*2, PROT_READ, MAP_SHARED, fd, 0);
if (p == MAP_FAILED)
err("mmap");
// this should cause a fatal fault
*p = 0;
exit(*p);
}
st = 0;
wait(&st);
if(st != -1)
err("child wrote read-only mapping");
printf("test writes to read-only mapped memory: OK\n");
}

24
user/statistics.c Normal file
View File

@ -0,0 +1,24 @@
#include "kernel/types.h"
#include "kernel/stat.h"
#include "kernel/fcntl.h"
#include "user/user.h"
int
statistics(void *buf, int sz)
{
int fd, i, n;
fd = open("statistics", O_RDONLY);
if(fd < 0) {
fprintf(2, "stats: open failed\n");
exit(1);
}
for (i = 0; i < sz; ) {
if ((n = read(fd, buf+i, sz-i)) < 0) {
break;
}
i += n;
}
close(fd);
return i;
}

24
user/stats.c Normal file
View File

@ -0,0 +1,24 @@
#include "kernel/types.h"
#include "kernel/stat.h"
#include "kernel/fcntl.h"
#include "user/user.h"
#define SZ 4096
char buf[SZ];
int
main(void)
{
int i, n;
while (1) {
n = statistics(buf, SZ);
for (i = 0; i < n; i++) {
write(1, buf+i, 1);
}
if (n != SZ)
break;
}
exit(0);
}

View File

@ -1,9 +1,6 @@
#ifdef LAB_MMAP
typedef unsigned long size_t;
typedef long int off_t;
void *mmap(void*,size_t,int,int,int,off_t);
int munmap(void*,size_t);
#endif
struct stat;
@ -62,5 +59,3 @@ int statistics(void*, int);
// umalloc.c
void* malloc(uint);
void free(void*);
#define DEBUG() printf("File %s, Line %d, Function %s\n",__FILE__,__LINE__,__func__);

View File

@ -36,5 +36,3 @@ entry("getpid");
entry("sbrk");
entry("sleep");
entry("uptime");
entry("mmap");
entry("munmap");