From ad2daa85bd50b7ff5c851b80a0b813bdc8d14f8e Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Fri, 10 Jul 2015 15:46:32 +0100 Subject: [PATCH] arm64: entry32: remove pointless register assignment We currently set x27 in compat_sys_sigreturn_wrapper and compat_sys_rt_sigreturn_wrapper, similarly to what we do with r8/why on 32-bit ARM, in an attempt to prevent sigreturns from being restarted. However, on arm64 we have always used pt_regs::syscallno for syscall restarting (for both native and compat tasks), and x27 is never inspected again before being overwritten in kernel_exit. This patch removes the pointless register assignments. Signed-off-by: Mark Rutland Cc: Will Deacon Signed-off-by: Catalin Marinas --- arch/arm64/kernel/entry32.S | 2 -- 1 file changed, 2 deletions(-) diff --git a/arch/arm64/kernel/entry32.S b/arch/arm64/kernel/entry32.S index bd9bfaa9269b..f332d5d1f6b4 100644 --- a/arch/arm64/kernel/entry32.S +++ b/arch/arm64/kernel/entry32.S @@ -32,13 +32,11 @@ ENTRY(compat_sys_sigreturn_wrapper) mov x0, sp - mov x27, #0 // prevent syscall restart handling (why) b compat_sys_sigreturn ENDPROC(compat_sys_sigreturn_wrapper) ENTRY(compat_sys_rt_sigreturn_wrapper) mov x0, sp - mov x27, #0 // prevent syscall restart handling (why) b compat_sys_rt_sigreturn ENDPROC(compat_sys_rt_sigreturn_wrapper)