ARM: Ensure predictable endian state on signal handler entry
Russell King [Sun, 20 Feb 2011 12:22:52 +0000 (12:22 +0000)]
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.

Cc: <stable@kernel.org>
Acked-by: Dave Martin <dave.martin@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/kernel/signal.c

index 907d5a6..abaf844 100644 (file)
@@ -474,7 +474,9 @@ setup_return(struct pt_regs *regs, struct k_sigaction *ka,
        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.