Messages in this thread Patch in this message | | | From | Jiri Olsa <> | Subject | [PATCH 3/6] signal x86: Merge EFLAGS bit clearing into single statement | Date | Sun, 10 Mar 2013 19:41:08 +0100 |
| |
Merging EFLAGS bit clearing into a single statement, to ensure EFLAGS bits being cleared in single instruction.
Signed-off-by: Jiri Olsa <jolsa@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> 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: Peter Zijlstra <a.p.zijlstra@chello.nl> 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> --- 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
| |