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Fix a couple of issues with the stack limit for 32-bit processes on 64-bit

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kernels exposed by the recent fixes to resource limits for 32-bit processes
on 64-bit kernels:
- Let ABIs expose their maximum stack size via a new pointer in sysentvec
  and use that in preference to maxssiz during exec() rather than always
  using maxssiz for all processses.
- Apply the ABI's limit fixup to the previous stack size when adjusting
  RLIMIT_STACK to determine if the existing mapping for the stack needs to
  be grown or shrunk (as well as how much it should be grown or shrunk).

Approved by:	re (kensmith)
This commit is contained in:
jhb 2007-07-12 18:01:31 +00:00
parent 77c677502e
commit ef42e8706b
5 changed files with 33 additions and 21 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
sys/amd64/linux32/linux32_sysvec.c
View File

@ -1023,7 +1023,8 @@ struct sysentvec elf_linux_sysvec = {
VM_PROT_ALL,
linux_copyout_strings,
exec_linux_setregs,
linux32_fixlimit
linux32_fixlimit,
&linux32_maxssiz,
};
static Elf32_Brandinfo linux_brand = {

17
sys/compat/ia32/ia32_sysvec.c
View File

@ -100,6 +100,13 @@ extern struct sysent freebsd32_sysent[];
SYSCTL_NODE(_compat, OID_AUTO, ia32, CTLFLAG_RW, 0, "ia32 mode");
static u_long ia32_maxdsiz = IA32_MAXDSIZ;
SYSCTL_ULONG(_compat_ia32, OID_AUTO, maxdsiz, CTLFLAG_RW, &ia32_maxdsiz, 0, "");
static u_long ia32_maxssiz = IA32_MAXSSIZ;
SYSCTL_ULONG(_compat_ia32, OID_AUTO, maxssiz, CTLFLAG_RW, &ia32_maxssiz, 0, "");
static u_long ia32_maxvmem = IA32_MAXVMEM;
SYSCTL_ULONG(_compat_ia32, OID_AUTO, maxvmem, CTLFLAG_RW, &ia32_maxvmem, 0, "");
struct sysentvec ia32_freebsd_sysvec = {
FREEBSD32_SYS_MAXSYSCALL,
freebsd32_sysent,
@ -126,7 +133,8 @@ struct sysentvec ia32_freebsd_sysvec = {
VM_PROT_ALL,
ia32_copyout_strings,
ia32_setregs,
ia32_fixlimit
ia32_fixlimit,
&ia32_maxssiz
};
@ -273,13 +281,6 @@ ia32_copyout_strings(struct image_params *imgp)
return ((register_t *)stack_base);
}
static u_long ia32_maxdsiz = IA32_MAXDSIZ;
SYSCTL_ULONG(_compat_ia32, OID_AUTO, maxdsiz, CTLFLAG_RW, &ia32_maxdsiz, 0, "");
static u_long ia32_maxssiz = IA32_MAXSSIZ;
SYSCTL_ULONG(_compat_ia32, OID_AUTO, maxssiz, CTLFLAG_RW, &ia32_maxssiz, 0, "");
static u_long ia32_maxvmem = IA32_MAXVMEM;
SYSCTL_ULONG(_compat_ia32, OID_AUTO, maxvmem, CTLFLAG_RW, &ia32_maxvmem, 0, "");
static void
ia32_fixlimit(struct rlimit *rl, int which)
{

13
sys/kern/kern_exec.c
View File

@ -894,6 +894,7 @@ exec_new_vmspace(imgp, sv)
struct vmspace *vmspace = p->p_vmspace;
vm_offset_t stack_addr;
vm_map_t map;
u_long ssiz;
imgp->vmspace_destroyed = 1;
imgp->sysent = sv;
@ -919,8 +920,12 @@ exec_new_vmspace(imgp, sv)
}
/* Allocate a new stack */
stack_addr = sv->sv_usrstack - maxssiz;
error = vm_map_stack(map, stack_addr, (vm_size_t)maxssiz,
if (sv->sv_maxssiz != NULL)
ssiz = *sv->sv_maxssiz;
else
ssiz = maxssiz;
stack_addr = sv->sv_usrstack - ssiz;
error = vm_map_stack(map, stack_addr, (vm_size_t)ssiz,
sv->sv_stackprot, VM_PROT_ALL, MAP_STACK_GROWS_DOWN);
if (error)
return (error);
@ -928,7 +933,7 @@ exec_new_vmspace(imgp, sv)
#ifdef __ia64__
/* Allocate a new register stack */
stack_addr = IA64_BACKINGSTORE;
error = vm_map_stack(map, stack_addr, (vm_size_t)maxssiz,
error = vm_map_stack(map, stack_addr, (vm_size_t)ssiz,
sv->sv_stackprot, VM_PROT_ALL, MAP_STACK_GROWS_UP);
if (error)
return (error);
@ -939,7 +944,7 @@ exec_new_vmspace(imgp, sv)
* process stack so we can check the stack rlimit.
*/
vmspace->vm_ssize = sgrowsiz >> PAGE_SHIFT;
vmspace->vm_maxsaddr = (char *)sv->sv_usrstack - maxssiz;
vmspace->vm_maxsaddr = (char *)sv->sv_usrstack - ssiz;
return (0);
}

20
sys/kern/kern_resource.c
View File

@ -657,7 +657,7 @@ kern_setrlimit(td, which, limp)
struct plimit *newlim, *oldlim;
struct proc *p;
register struct rlimit *alimp;
rlim_t oldssiz;
struct rlimit oldssiz;
int error;
if (which >= RLIM_NLIMITS)
@ -671,7 +671,7 @@ kern_setrlimit(td, which, limp)
if (limp->rlim_max < 0)
limp->rlim_max = RLIM_INFINITY;
oldssiz = 0;
oldssiz.rlim_cur = 0;
p = td->td_proc;
newlim = lim_alloc();
PROC_LOCK(p);
@ -711,7 +711,10 @@ kern_setrlimit(td, which, limp)
limp->rlim_cur = maxssiz;
if (limp->rlim_max > maxssiz)
limp->rlim_max = maxssiz;
oldssiz = alimp->rlim_cur;
oldssiz = *alimp;
if (td->td_proc->p_sysent->sv_fixlimit != NULL)
td->td_proc->p_sysent->sv_fixlimit(&oldssiz,
RLIMIT_STACK);
break;
case RLIMIT_NOFILE:
@ -745,20 +748,21 @@ kern_setrlimit(td, which, limp)
* "rlim_cur" bytes accessible. If stack limit is going
* up make more accessible, if going down make inaccessible.
*/
if (limp->rlim_cur != oldssiz) {
if (limp->rlim_cur != oldssiz.rlim_cur) {
vm_offset_t addr;
vm_size_t size;
vm_prot_t prot;
if (limp->rlim_cur > oldssiz) {
if (limp->rlim_cur > oldssiz.rlim_cur) {
prot = p->p_sysent->sv_stackprot;
size = limp->rlim_cur - oldssiz;
size = limp->rlim_cur - oldssiz.rlim_cur;
addr = p->p_sysent->sv_usrstack -
limp->rlim_cur;
} else {
prot = VM_PROT_NONE;
size = oldssiz - limp->rlim_cur;
addr = p->p_sysent->sv_usrstack - oldssiz;
size = oldssiz.rlim_cur - limp->rlim_cur;
addr = p->p_sysent->sv_usrstack -
oldssiz.rlim_cur;
}
addr = trunc_page(addr);
size = round_page(size);

1
sys/sys/sysent.h
View File

@ -99,6 +99,7 @@ struct sysentvec {
register_t *(*sv_copyout_strings)(struct image_params *);
void (*sv_setregs)(struct thread *, u_long, u_long, u_long);
void (*sv_fixlimit)(struct rlimit *, int);
u_long *sv_maxssiz;
};
#ifdef _KERNEL