This is a note to let you know that I've just added the patch titled
vm: make stack guard page errors return VM_FAULT_SIGSEGV rather than SIGBUS
to the 3.18-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
vm-make-stack-guard-page-errors-return-vm_fault_sigsegv-rather-than-sigbus.patch
and it can be found in the queue-3.18 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 9c145c56d0c8a0b62e48c8d71e055ad0fb2012ba Mon Sep 17 00:00:00 2001
From: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Date: Thu, 29 Jan 2015 11:15:17 -0800
Subject: vm: make stack guard page errors return VM_FAULT_SIGSEGV rather than SIGBUS
From: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
commit 9c145c56d0c8a0b62e48c8d71e055ad0fb2012ba upstream.
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
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
mm/memory.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2645,7 +2645,7 @@ static int do_anonymous_page(struct mm_s
/* 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)) {
Patches currently in stable-queue which might be from torvalds@xxxxxxxxxxxxxxxxxxxx are
queue-3.18/arc-mm-fix-build-failure.patch
queue-3.18/vm-make-stack-guard-page-errors-return-vm_fault_sigsegv-rather-than-sigbus.patch
queue-3.18/vm-add-vm_fault_sigsegv-handling-support.patch
queue-3.18/x86-build-replace-perl-script-with-shell-script.patch
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