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vm_map_growstack(): handle max protection for stacks

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Do not assume that protection is same as max_protection.  Store both in
offset, packed in the same way as the prot syscall parameter.

Reviewed by:	alc, markj (previous version)
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D41099
This commit is contained in:
Konstantin Belousov 2023-07-25 16:56:29 +03:00
parent 0fb6aae7f0
commit aa928a5216
1 changed files with 5 additions and 4 deletions
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9
sys/vm/vm_map.c
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@ -4605,7 +4605,7 @@ vm_map_stack_locked(vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize,
* object offset.
*/
gap_entry->next_read = sgp;
gap_entry->offset = prot;
gap_entry->offset = prot | PROT_MAX(max);
} else {
(void)vm_map_delete(map, bot, top);
}
@ -4625,7 +4625,7 @@ vm_map_growstack(vm_map_t map, vm_offset_t addr, vm_map_entry_t gap_entry)
struct ucred *cred;
vm_offset_t gap_end, gap_start, grow_start;
vm_size_t grow_amount, guard, max_grow;
vm_prot_t prot;
vm_prot_t prot, max;
rlim_t lmemlim, stacklim, vmemlim;
int rv, rv1 __diagused;
bool gap_deleted, grow_down, is_procstack;
@ -4770,7 +4770,8 @@ vm_map_growstack(vm_map_t map, vm_offset_t addr, vm_map_entry_t gap_entry)
* The gap_entry "offset" field is overloaded. See
* vm_map_stack_locked().
*/
prot = gap_entry->offset;
prot = PROT_EXTRACT(gap_entry->offset);
max = PROT_MAX_EXTRACT(gap_entry->offset);
grow_start = gap_entry->end - grow_amount;
if (gap_entry->start + grow_amount == gap_entry->end) {
@ -4784,7 +4785,7 @@ vm_map_growstack(vm_map_t map, vm_offset_t addr, vm_map_entry_t gap_entry)
gap_deleted = false;
}
rv = vm_map_insert(map, NULL, 0, grow_start,
grow_start + grow_amount, prot, prot, MAP_STACK_GROWS_DOWN);
grow_start + grow_amount, prot, max, MAP_STACK_GROWS_DOWN);
if (rv != KERN_SUCCESS) {
if (gap_deleted) {
rv1 = vm_map_insert(map, NULL, 0, gap_start,