[tip:x86/asm] x86: Call do_notify_resume() with interrupts enabled

From: tip-bot for Srikar Dronamraju
Date: Tue Dec 06 2011 - 04:42:25 EST


Commit-ID: 3596ff4e6b2aff8a28c69af389d5046090a53330
Gitweb: http://git.kernel.org/tip/3596ff4e6b2aff8a28c69af389d5046090a53330
Author: Srikar Dronamraju <srikar@xxxxxxxxxxxxxxxxxx>
AuthorDate: Tue, 25 Oct 2011 19:48:12 +0530
Committer: Ingo Molnar <mingo@xxxxxxx>
CommitDate: Tue, 6 Dec 2011 08:20:34 +0100

x86: Call do_notify_resume() with interrupts enabled

do_notify_resume() gets called with interrupts disabled on x86_32. This
is different from the x86_64 behavior, where interrupts are enabled at
the time.

Queries on lkml on this issue hasn't yielded any clear answer. Lets make
x86_32 behave the same as x86_64, unless there is a real reason to
maintain status quo.

Please refer https://lkml.org/lkml/2011/9/27/130 for more
details.

A similar change was suggested in ARM:

https://lkml.org/lkml/2011/8/25/231

My 32-bit machine works fine (tm) with this patch.

Signed-off-by: Srikar Dronamraju <srikar@xxxxxxxxxxxxxxxxxx>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/20111025141812.GA21225@xxxxxxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
---
arch/x86/kernel/entry_32.S | 4 ++++
1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S
index f3f6f53..22d0e21 100644
--- a/arch/x86/kernel/entry_32.S
+++ b/arch/x86/kernel/entry_32.S
@@ -625,6 +625,8 @@ work_notifysig: # deal with pending signals and
movl %esp, %eax
jne work_notifysig_v86 # returning to kernel-space or
# vm86-space
+ TRACE_IRQS_ON
+ ENABLE_INTERRUPTS(CLBR_NONE)
xorl %edx, %edx
call do_notify_resume
jmp resume_userspace_sig
@@ -638,6 +640,8 @@ work_notifysig_v86:
#else
movl %esp, %eax
#endif
+ TRACE_IRQS_ON
+ ENABLE_INTERRUPTS(CLBR_NONE)
xorl %edx, %edx
call do_notify_resume
jmp resume_userspace_sig
--
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