[PATCH 2/4] kprobes/x86: use instruction_pointer and instruction_pointer_set

From: Jisheng Zhang
Date: Mon Aug 19 2019 - 07:36:53 EST


This is to make the kprobe_ftrace_handler() common, so we can move it
to common code in next patch.

Signed-off-by: Jisheng Zhang <Jisheng.Zhang@xxxxxxxxxxxxx>
---
arch/x86/kernel/kprobes/ftrace.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kernel/kprobes/ftrace.c b/arch/x86/kernel/kprobes/ftrace.c
index 681a4b36e9bb..c2ad0b9259ca 100644
--- a/arch/x86/kernel/kprobes/ftrace.c
+++ b/arch/x86/kernel/kprobes/ftrace.c
@@ -28,9 +28,9 @@ void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
if (kprobe_running()) {
kprobes_inc_nmissed_count(p);
} else {
- unsigned long orig_ip = regs->ip;
+ unsigned long orig_ip = instruction_pointer(regs);
/* Kprobe handler expects regs->ip = ip + 1 as breakpoint hit */
- regs->ip = ip + sizeof(kprobe_opcode_t);
+ instruction_pointer_set(regs, ip + sizeof(kprobe_opcode_t));

__this_cpu_write(current_kprobe, p);
kcb->kprobe_status = KPROBE_HIT_ACTIVE;
@@ -39,12 +39,13 @@ void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
* Emulate singlestep (and also recover regs->ip)
* as if there is a 5byte nop
*/
- regs->ip = (unsigned long)p->addr + MCOUNT_INSN_SIZE;
+ instruction_pointer_set(regs,
+ (unsigned long)p->addr + MCOUNT_INSN_SIZE);
if (unlikely(p->post_handler)) {
kcb->kprobe_status = KPROBE_HIT_SSDONE;
p->post_handler(p, regs, 0);
}
- regs->ip = orig_ip;
+ instruction_pointer_set(regs, orig_ip);
}
/*
* If pre_handler returns !0, it changes regs->ip. We have to
--
2.23.0.rc1