ARM: Ensure predictable endian state on signal handler entry

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@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c
index e7714f367eb83aa0a4b0224e5129ec94c87c3391..962236acfee22d0078ee12a5f38d73a9322446d5 100644 (file)
--- a/arch/arm/kernel/signal.c
+++ b/arch/arm/kernel/signal.c
@@ -389,7 +389,9 @@ 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.