[PATCH -tip v8 08/13] arm: kprobes: Make a space for regs->ARM_pc at kretprobe_trampoline

[Masami Hiramatsu]

Change kretprobe_trampoline to make a space for regs->ARM_pc so that
kretprobe_trampoline_handler can call instruction_pointer_set()
safely.

Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
---
 arch/arm/probes/kprobes/core.c |    2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm/probes/kprobes/core.c b/arch/arm/probes/kprobes/core.c
index 583f6b1a2a6f..556b1560fb2c 100644
--- a/arch/arm/probes/kprobes/core.c
+++ b/arch/arm/probes/kprobes/core.c
@@ -374,11 +374,13 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self,
 void __naked __kprobes kretprobe_trampoline(void)
 {
 	__asm__ __volatile__ (
+		"sub	sp, sp, #16		\n\t"
 		"stmdb	sp!, {r0 - r11}		\n\t"
 		"mov	r0, sp			\n\t"
 		"bl	trampoline_handler	\n\t"
 		"mov	lr, r0			\n\t"
 		"ldmia	sp!, {r0 - r11}		\n\t"
+		"add	sp, sp, #16		\n\t"
 #ifdef CONFIG_THUMB2_KERNEL
 		"bx	lr			\n\t"
 #else