Merging EFLAGS bit clearing into a single statement, to
ensure EFLAGS bits being cleared in single instruction.
Signed-off-by: Jiri Olsa <jo...@redhat.com>
Cc: Thomas Gleixner <t...@linutronix.de>
Cc: H. Peter Anvin <h...@zytor.com>
Cc: Andi Kleen <a...@firstfloor.org>
Cc: Oleg Nesterov <o...@redhat.com>
Cc: Arnaldo Carvalho de Melo <a...@ghostprotocols.net>
Cc: Peter Zijlstra <a.p.zijls...@chello.nl>
Cc: Ingo Molnar <mi...@elte.hu>
Cc: Paul Mackerras <pau...@samba.org>
Cc: Corey Ashford <cjash...@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweis...@gmail.com>
Cc: Vince Weaver <vincent.wea...@maine.edu>
Cc: Stephane Eranian <eran...@google.com>
---
arch/x86/kernel/signal.c | 10 +++-------
1 file changed, 3 insertions(+), 7 deletions(-)
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index cb12fc9..cf91358 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -662,21 +662,17 @@ handle_signal(struct ksignal *ksig, struct pt_regs *regs)
if (!failed) {
/*
* Clear the direction flag as per the ABI for function entry.
- */
- regs->flags &= ~X86_EFLAGS_DF;
- /*
+ *
* Clear RF when entering the signal handler, because
* it might disable possible debug exception from the
* signal handler.
- */
- regs->flags &= ~X86_EFLAGS_RF;
- /*
+ *
* Clear TF when entering the signal handler, but
* notify any tracer that was single-stepping it.
* The tracer may want to single-step inside the
* handler too.
*/
- regs->flags &= ~X86_EFLAGS_TF;
+ regs->flags &= ~(X86_EFLAGS_DF|X86_EFLAGS_RF|X86_EFLAGS_TF);
}
signal_setup_done(failed, ksig, test_thread_flag(TIF_SINGLESTEP));
}
--
1.7.11.7
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