[patch V4 part 1 18/36] samples/kprobes: Add __kprobes and NOKPROBE_SYMBOL() for handlers.

Thomas Gleixner
2020-05-05T14:14:00Z

From: Masami Hiramatsu <mhiramat@kernel.org>

Add __kprobes and NOKPROBE_SYMBOL() for sample kprobe handlers.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/158523421177.24735.16273975317343670204.stgit@devnote2

---
samples/kprobes/kprobe_example.c | 6 ++++--
samples/kprobes/kretprobe_example.c | 2 ++
2 files changed, 6 insertions(+), 2 deletions(-)

--- a/samples/kprobes/kprobe_example.c
+++ b/samples/kprobes/kprobe_example.c
@@ -25,7 +25,7 @@ static struct kprobe kp = {
};

/* kprobe pre_handler: called just before the probed instruction is executed */
-static int handler_pre(struct kprobe *p, struct pt_regs *regs)
+static int __kprobes handler_pre(struct kprobe *p, struct pt_regs *regs)
{
#ifdef CONFIG_X86
pr_info("<%s> pre_handler: p->addr = 0x%p, ip = %lx, flags = 0x%lx\n",
@@ -54,7 +54,7 @@ static int handler_pre(struct kprobe *p,
}

/* kprobe post_handler: called after the probed instruction is executed */
-static void handler_post(struct kprobe *p, struct pt_regs *regs,
+static void __kprobes handler_post(struct kprobe *p, struct pt_regs *regs,
unsigned long flags)
{
#ifdef CONFIG_X86
@@ -90,6 +90,8 @@ static int handler_fault(struct kprobe *
/* Return 0 because we don't handle the fault. */
return 0;
}
+/* NOKPROBE_SYMBOL() is also available */
+NOKPROBE_SYMBOL(handler_fault);

static int __init kprobe_init(void)
{
--- a/samples/kprobes/kretprobe_example.c
+++ b/samples/kprobes/kretprobe_example.c
@@ -48,6 +48,7 @@ static int entry_handler(struct kretprob
data->entry_stamp = ktime_get();
return 0;
}
+NOKPROBE_SYMBOL(entry_handler);

/*
* Return-probe handler: Log the return value and duration. Duration may turn
@@ -67,6 +68,7 @@ static int ret_handler(struct kretprobe_
func_name, retval, (long long)delta);
return 0;
}
+NOKPROBE_SYMBOL(ret_handler);

static struct kretprobe my_kretprobe = {
.handler = ret_handler,