ARM: 7065/1: kexec: ensure new kernel is entered in ARM state

Commit 540b5738 ("ARM: 6999/1: head, zImage: Always Enter the kernel in
ARM state") mandates that the kernel should be entered in ARM state.

If a Thumb-2 kernel kexecs a new kernel image, we need to ensure that
we change state when branching to the new code. This patch replaces a
mov pc, lr with a bx lr on Thumb-2 kernels so that we transition to ARM
state if need be.

Reviewed-by: Dave Martin <dave.martin@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

diff --git a/arch/arm/kernel/relocate_kernel.S b/arch/arm/kernel/relocate_kernel.S
index 9cf4cbf..d0cdedf 100644 (file)
--- a/arch/arm/kernel/relocate_kernel.S
+++ b/arch/arm/kernel/relocate_kernel.S
@@ -57,7 +57,8 @@ relocate_new_kernel:
        mov r0,#0
        ldr r1,kexec_mach_type
        ldr r2,kexec_boot_atags
-       mov pc,lr
+ ARM(  mov pc, lr      )
+ THUMB(        bx lr           )
 
        .align