This is a note to let you know that I've just added the patch titled
uprobes, x86: Fix _TIF_UPROBE vs _TIF_NOTIFY_RESUME
to the 3.14-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:
uprobes-x86-fix-_tif_uprobe-vs-_tif_notify_resume.patch
and it can be found in the queue-3.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 82975bc6a6df743b9a01810fb32cb65d0ec5d60b Mon Sep 17 00:00:00 2001
From: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
Date: Fri, 21 Nov 2014 13:26:07 -0800
Subject: uprobes, x86: Fix _TIF_UPROBE vs _TIF_NOTIFY_RESUME
From: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
commit 82975bc6a6df743b9a01810fb32cb65d0ec5d60b upstream.
x86 call do_notify_resume on paranoid returns if TIF_UPROBE is set but
not on non-paranoid returns. I suspect that this is a mistake and that
the code only works because int3 is paranoid.
Setting _TIF_NOTIFY_RESUME in the uprobe code was probably a workaround
for the x86 bug. With that bug fixed, we can remove _TIF_NOTIFY_RESUME
from the uprobes code.
Reported-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Acked-by: Srikar Dronamraju <srikar@xxxxxxxxxxxxxxxxxx>
Acked-by: Borislav Petkov <bp@xxxxxxx>
Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/include/asm/thread_info.h | 2 +-
kernel/events/uprobes.c | 1 -
2 files changed, 1 insertion(+), 2 deletions(-)
--- a/arch/x86/include/asm/thread_info.h
+++ b/arch/x86/include/asm/thread_info.h
@@ -144,7 +144,7 @@ struct thread_info {
/* Only used for 64 bit */
#define _TIF_DO_NOTIFY_MASK \
(_TIF_SIGPENDING | _TIF_MCE_NOTIFY | _TIF_NOTIFY_RESUME | \
- _TIF_USER_RETURN_NOTIFY)
+ _TIF_USER_RETURN_NOTIFY | _TIF_UPROBE)
/* flags to check in __switch_to() */
#define _TIF_WORK_CTXSW \
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -1621,7 +1621,6 @@ bool uprobe_deny_signal(void)
if (__fatal_signal_pending(t) || arch_uprobe_xol_was_trapped(t)) {
utask->state = UTASK_SSTEP_TRAPPED;
set_tsk_thread_flag(t, TIF_UPROBE);
- set_tsk_thread_flag(t, TIF_NOTIFY_RESUME);
}
}
Patches currently in stable-queue which might be from luto@xxxxxxxxxxxxxx are
queue-3.14/x86-mm-set-nx-across-entire-pmd-at-boot.patch
queue-3.14/uprobes-x86-fix-_tif_uprobe-vs-_tif_notify_resume.patch
queue-3.14/x86_64-traps-stop-using-ist-for-ss.patch
queue-3.14/x86_64-traps-fix-the-espfix64-df-fixup-and-rewrite-it-in-c.patch
queue-3.14/x86_64-traps-rework-bad_iret.patch
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