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prevent longjmp / forkret from writing over tf->edi

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This commit is contained in:
rtm 2006-07-18 19:22:37 +00:00
parent 0dd4253747
commit bd228a8156
3 changed files with 9 additions and 6 deletions
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5
pipe.c
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@ -61,6 +61,8 @@ pipe_alloc(struct fd **fd1, struct fd **fd2)
void void
pipe_close(struct pipe *p, int writeable) pipe_close(struct pipe *p, int writeable)
{ {
acquire(&p->lock);
if(writeable){ if(writeable){
p->writeopen = 0; p->writeopen = 0;
wakeup(&p->readp); wakeup(&p->readp);
@ -68,6 +70,9 @@ pipe_close(struct pipe *p, int writeable)
p->readopen = 0; p->readopen = 0;
wakeup(&p->writep); wakeup(&p->writep);
} }
release(&p->lock);
if(p->readopen == 0 && p->writeopen == 0) if(p->readopen == 0 && p->writeopen == 0)
kfree((char *) p, PAGE); kfree((char *) p, PAGE);
} }

2
proc.c
View file

@ -109,7 +109,7 @@ copyproc(struct proc* p)
// Set up new jmpbuf to start executing at forkret (see below). // Set up new jmpbuf to start executing at forkret (see below).
memset(&np->jmpbuf, 0, sizeof np->jmpbuf); memset(&np->jmpbuf, 0, sizeof np->jmpbuf);
np->jmpbuf.eip = (uint)forkret; np->jmpbuf.eip = (uint)forkret;
np->jmpbuf.esp = (uint)np->tf; np->jmpbuf.esp = (uint)np->tf - 4;
// Copy file descriptors // Copy file descriptors
for(i = 0; i < NOFILE; i++){ for(i = 0; i < NOFILE; i++){

8
syscall.c
View file

@ -13,8 +13,7 @@
* System call number in %eax. * System call number in %eax.
* Arguments on the stack, from the user call to the C * Arguments on the stack, from the user call to the C
* library system call function. The saved user %esp points * library system call function. The saved user %esp points
* to a saved frame pointer, a program counter, and then * to a saved program counter, and then the first argument.
* the first argument.
* *
* Return value? Error indication? Errno? * Return value? Error indication? Errno?
*/ */
@ -56,11 +55,11 @@ fetcharg(int argno, void *ip)
} }
int int
putint(struct proc *p, uint addr, int ip) putint(struct proc *p, uint addr, int x)
{ {
if(addr > p->sz - 4) if(addr > p->sz - 4)
return -1; return -1;
memmove(p->mem + addr, &ip, 4); memmove(p->mem + addr, &x, 4);
return 0; return 0;
} }
@ -269,7 +268,6 @@ syscall(void)
int num = cp->tf->eax; int num = cp->tf->eax;
int ret = -1; int ret = -1;
//cprintf("%x sys %d\n", cp, num);
switch(num){ switch(num){
case SYS_fork: case SYS_fork:
ret = sys_fork(); ret = sys_fork();