From: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
The stack guard page error case has long incorrectly caused a SIGBUS
rather than a SIGSEGV, but nobody actually noticed until commit
fee7e49d4514 ("mm: propagate error from stack expansion even for guard
page") because that error case was never actually triggered in any
normal situations.
Now that we actually report the error, people noticed the wrong signal
that resulted. So far, only the test suite of libsigsegv seems to have
actually cared, but there are real applications that use libsigsegv, so
let's not wait for any of those to break.
Reported-and-tested-by: Takashi Iwai <tiwai@xxxxxxx>
Tested-by: Jan Engelhardt <jengelh@xxxxxxx>
Acked-by: Heiko Carstens <heiko.carstens@xxxxxxxxxx> # "s390 still compiles and boots"
Cc: linux-arch@xxxxxxxxxxxxxxx
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
---
mm/memory.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/memory.c b/mm/memory.c
index c2a5984..d534374 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3236,7 +3236,7 @@ static int do_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma,
/* Check if we need to add a guard page to the stack */
if (check_stack_guard_page(vma, address) < 0)
- return VM_FAULT_SIGBUS;
+ return VM_FAULT_SIGSEGV;
/* Use the zero-page for reads */
if (!(flags & FAULT_FLAG_WRITE)) {
--
1.8.3.4
--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html