[PATCH] samples: Use KSYM_NAME_LEN for fprobe and kprobes

From: Tiezhu Yang
Date: Tue Jun 07 2022 - 05:36:25 EST


It is better and enough to use KSYM_NAME_LEN for fprobe and kprobes
in samples, no need to define and use the other values.

Signed-off-by: Tiezhu Yang <yangtiezhu@xxxxxxxxxxx>
---
samples/fprobe/fprobe_example.c | 9 ++++-----
samples/kprobes/kprobe_example.c | 5 ++---
samples/kprobes/kretprobe_example.c | 5 ++---
3 files changed, 8 insertions(+), 11 deletions(-)

diff --git a/samples/fprobe/fprobe_example.c b/samples/fprobe/fprobe_example.c
index 24d3cf1..1ed1a69 100644
--- a/samples/fprobe/fprobe_example.c
+++ b/samples/fprobe/fprobe_example.c
@@ -19,13 +19,12 @@
#include <linux/slab.h>

#define BACKTRACE_DEPTH 16
-#define MAX_SYMBOL_LEN 4096
struct fprobe sample_probe;

-static char symbol[MAX_SYMBOL_LEN] = "kernel_clone";
-module_param_string(symbol, symbol, sizeof(symbol), 0644);
-static char nosymbol[MAX_SYMBOL_LEN] = "";
-module_param_string(nosymbol, nosymbol, sizeof(nosymbol), 0644);
+static char symbol[KSYM_NAME_LEN] = "kernel_clone";
+module_param_string(symbol, symbol, KSYM_NAME_LEN, 0644);
+static char nosymbol[KSYM_NAME_LEN] = "";
+module_param_string(nosymbol, nosymbol, KSYM_NAME_LEN, 0644);
static bool stackdump = true;
module_param(stackdump, bool, 0644);

diff --git a/samples/kprobes/kprobe_example.c b/samples/kprobes/kprobe_example.c
index f991a66..fd346f5 100644
--- a/samples/kprobes/kprobe_example.c
+++ b/samples/kprobes/kprobe_example.c
@@ -16,9 +16,8 @@
#include <linux/module.h>
#include <linux/kprobes.h>

-#define MAX_SYMBOL_LEN 64
-static char symbol[MAX_SYMBOL_LEN] = "kernel_clone";
-module_param_string(symbol, symbol, sizeof(symbol), 0644);
+static char symbol[KSYM_NAME_LEN] = "kernel_clone";
+module_param_string(symbol, symbol, KSYM_NAME_LEN, 0644);

/* For each probe you need to allocate a kprobe structure */
static struct kprobe kp = {
diff --git a/samples/kprobes/kretprobe_example.c b/samples/kprobes/kretprobe_example.c
index 228321e..cbf1654 100644
--- a/samples/kprobes/kretprobe_example.c
+++ b/samples/kprobes/kretprobe_example.c
@@ -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] = "kernel_clone";
-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");

--
2.1.0