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| author |   Jiri Olsa <jolsa@redhat.com> | 2013-05-01 17:25:43 +0200 |
|---|---|---|
| committer |   Ingo Molnar <mingo@kernel.org> | 2013-05-28 08:46:53 +0200 |
| commit | ddd40da4ccbabdd2e941837aa987e08dfa4396b4 (patch) | |
| tree | 90fdbe1cc8420f479bee183a4f223de38fa0dfaa /arch/x86/kernel/signal.c | |
| parent | x86/signals: Clear RF EFLAGS bit for signal handler (diff) | |
| download | linux-dev-ddd40da4ccbabdd2e941837aa987e08dfa4396b4.tar.xz linux-dev-ddd40da4ccbabdd2e941837aa987e08dfa4396b4.zip | |
x86/signals: Merge EFLAGS bit clearing into a single statement
Merging EFLAGS bit clearing into a single statement, to
ensure EFLAGS bits are being cleared in a single instruction.
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Tested-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Frederic Weisbecker <fweisbec@gmail.com>
Originally-Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: Stephane Eranian <eranian@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1367421944-19082-4-git-send-email-jolsa@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/signal.c')
| -rw-r--r-- | arch/x86/kernel/signal.c | 10 |
1 files changed, 3 insertions, 7 deletions
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c index cb12fc9c0642..cf913587d4dd 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)); } |