path: root/arch/x86/ia32
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authorJiri Olsa <jolsa@redhat.com>2013-05-01 17:25:41 +0200
committerIngo Molnar <mingo@kernel.org>2013-05-28 08:46:50 +0200
commit5e219b3c671b34b2d79468fe89c44c0460c0f02b (patch)
tree3eddae1e4122a5f7d9d6e4f8561ec01eae14124d /arch/x86/ia32
parente4aa937ec75df0eea0bee03bffa3303ad36c986b (diff)
x86/signals: Propagate RF EFLAGS bit through the signal restore call
While porting Vince's perf overflow tests I found perf event breakpoint overflow does not work properly. I found the x86 RF EFLAG bit not being set when returning from debug exception after triggering signal handler. Which is exactly what you get when you set perf breakpoint overflow SIGIO handler. This patch and the next two patches fix the underlying bugs. This patch adds the RF EFLAGS bit to be restored on return from signal from the original register context before the signal was entered. This will prevent the RF flag to disappear when returning from exception due to the signal handler being executed. 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/1367421944-19082-2-git-send-email-jolsa@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/ia32')
1 files changed, 0 insertions, 2 deletions
diff --git a/arch/x86/ia32/ia32_signal.c b/arch/x86/ia32/ia32_signal.c
index cf1a471a18a..bccfca68430 100644
--- a/arch/x86/ia32/ia32_signal.c
+++ b/arch/x86/ia32/ia32_signal.c
@@ -34,8 +34,6 @@
#include <asm/sys_ia32.h>
#include <asm/smap.h>
int copy_siginfo_to_user32(compat_siginfo_t __user *to, siginfo_t *from)
int err = 0;