[PATCH 1/4] signal x86: Propage RF EFLAGS bit throught the signal restore call

From: Jiri Olsa
Date: Wed May 01 2013 - 11:26:55 EST


Adding 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@xxxxxxxxxx>
Tested-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Reviewed-by: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Andi Kleen <andi@xxxxxxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Corey Ashford <cjashfor@xxxxxxxxxxxxxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Vince Weaver <vincent.weaver@xxxxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
---
arch/x86/ia32/ia32_signal.c | 2 --
arch/x86/include/asm/sighandling.h | 4 ++--
arch/x86/kernel/signal.c | 6 ------
3 files changed, 2 insertions(+), 10 deletions(-)

diff --git a/arch/x86/ia32/ia32_signal.c b/arch/x86/ia32/ia32_signal.c
index cf1a471..bccfca6 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>

-#define FIX_EFLAGS __FIX_EFLAGS
-
int copy_siginfo_to_user32(compat_siginfo_t __user *to, siginfo_t *from)
{
int err = 0;
diff --git a/arch/x86/include/asm/sighandling.h b/arch/x86/include/asm/sighandling.h
index beff97f..7a95816 100644
--- a/arch/x86/include/asm/sighandling.h
+++ b/arch/x86/include/asm/sighandling.h
@@ -7,10 +7,10 @@

#include <asm/processor-flags.h>

-#define __FIX_EFLAGS (X86_EFLAGS_AC | X86_EFLAGS_OF | \
+#define FIX_EFLAGS (X86_EFLAGS_AC | X86_EFLAGS_OF | \
X86_EFLAGS_DF | X86_EFLAGS_TF | X86_EFLAGS_SF | \
X86_EFLAGS_ZF | X86_EFLAGS_AF | X86_EFLAGS_PF | \
- X86_EFLAGS_CF)
+ X86_EFLAGS_CF | X86_EFLAGS_RF)

void signal_fault(struct pt_regs *regs, void __user *frame, char *where);

diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 6956299..9df4c0b 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -43,12 +43,6 @@

#include <asm/sigframe.h>

-#ifdef CONFIG_X86_32
-# define FIX_EFLAGS (__FIX_EFLAGS | X86_EFLAGS_RF)
-#else
-# define FIX_EFLAGS __FIX_EFLAGS
-#endif
-
#define COPY(x) do { \
get_user_ex(regs->x, &sc->x); \
} while (0)
--
1.7.11.7

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