[PATCH] [133/275] ARM: Ensure predictable endian state on signal handler entry

From: Andi Kleen
Date: Wed Mar 30 2011 - 17:42:25 EST


2.6.35-longterm review patch. If anyone has any objections, please let me know.

------------------
From: Russell King <rmk+kernel@xxxxxxxxxxxxxxxx>

commit 53399053eb505cf541b2405bd9d9bca5ecfb96fb upstream.

Ensure a predictable endian state when entering signal handlers. This
avoids programs which use SETEND to momentarily switch their endian
state from having their signal handlers entered with an unpredictable
endian state.

Acked-by: Dave Martin <dave.martin@xxxxxxxxxx>
Signed-off-by: Russell King <rmk+kernel@xxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>
Signed-off-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>

---
arch/arm/kernel/signal.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

Index: linux-2.6.35.y/arch/arm/kernel/signal.c
===================================================================
--- linux-2.6.35.y.orig/arch/arm/kernel/signal.c 2011-03-29 22:51:14.413354368 -0700
+++ linux-2.6.35.y/arch/arm/kernel/signal.c 2011-03-29 23:03:01.044273450 -0700
@@ -474,7 +474,9 @@
unsigned long handler = (unsigned long)ka->sa.sa_handler;
unsigned long retcode;
int thumb = 0;
- unsigned long cpsr = regs->ARM_cpsr & ~PSR_f;
+ unsigned long cpsr = regs->ARM_cpsr & ~(PSR_f | PSR_E_BIT);
+
+ cpsr |= PSR_ENDSTATE;

/*
* Maybe we need to deliver a 32-bit signal to a 26-bit task.
--
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