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Diffstat (limited to 'samples/kprobes/kretprobe_example.c')
-rw-r--r--samples/kprobes/kretprobe_example.c13
1 files changed, 7 insertions, 6 deletions
diff --git a/samples/kprobes/kretprobe_example.c b/samples/kprobes/kretprobe_example.c
index 186315ca88b3..cbf16542d84e 100644
--- a/samples/kprobes/kretprobe_example.c
+++ b/samples/kprobes/kretprobe_example.c
@@ -8,10 +8,10 @@
*
* usage: insmod kretprobe_example.ko func=<func_name>
*
- * If no func_name is specified, _do_fork is instrumented
+ * If no func_name is specified, kernel_clone is instrumented
*
* For more information on theory of operation of kretprobes, see
- * Documentation/kprobes.txt
+ * Documentation/trace/kprobes.rst
*
* Build and insert the kernel module as done in the kprobe example.
* You will see the trace data in /var/log/messages and on the console
@@ -23,11 +23,10 @@
#include <linux/module.h>
#include <linux/kprobes.h>
#include <linux/ktime.h>
-#include <linux/limits.h>
#include <linux/sched.h>
-static char func_name[NAME_MAX] = "_do_fork";
-module_param_string(func, func_name, NAME_MAX, S_IRUGO);
+static char func_name[KSYM_NAME_LEN] = "kernel_clone";
+module_param_string(func, func_name, KSYM_NAME_LEN, 0644);
MODULE_PARM_DESC(func, "Function to kretprobe; this module will report the"
" function's execution time");
@@ -48,6 +47,7 @@ static int entry_handler(struct kretprobe_instance *ri, struct pt_regs *regs)
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 +67,7 @@ static int ret_handler(struct kretprobe_instance *ri, struct pt_regs *regs)
func_name, retval, (long long)delta);
return 0;
}
+NOKPROBE_SYMBOL(ret_handler);
static struct kretprobe my_kretprobe = {
.handler = ret_handler,
@@ -84,7 +85,7 @@ static int __init kretprobe_init(void)
ret = register_kretprobe(&my_kretprobe);
if (ret < 0) {
pr_err("register_kretprobe failed, returned %d\n", ret);
- return -1;
+ return ret;
}
pr_info("Planted return probe at %s: %p\n",
my_kretprobe.kp.symbol_name, my_kretprobe.kp.addr);