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 <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
diff --git a/arch/arm64/kernel/entry32.S b/arch/arm64/kernel/entry32.S
index bd9bfaa..f332d5d 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)