Commit 7391dd19 authored by Masami Hiramatsu's avatar Masami Hiramatsu Committed by Steven Rostedt (VMware)
Browse files

arm: kprobes: Make space for instruction pointer on stack 

Since arm's __kretprobe_trampoline() saves partial 'pt_regs' on the
stack, 'regs->ARM_pc' (instruction pointer) is not accessible from
the kretprobe handler. This means if instruction_pointer_set() is
used from kretprobe handler, it will break the data on the stack.

Make space for instruction pointer (ARM_pc) on the stack in the
__kretprobe_trampoline() for fixing this problem.

Link: https://lkml.kernel.org/r/163163052262.489837.10327621053231461255.stgit@devnote2



Signed-off-by: default avatarMasami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
parent c1f76fe5

arch/arm/probes/kprobes/core.c

+2 −0
Original line number Diff line number Diff line
@@ -376,11 +376,13 @@ 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