2022-06-08 08:33:27

by Tiezhu Yang

Subject: [PATCH v2] samples: Use KSYM_NAME_LEN for kprobes

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

Signed-off-by: Tiezhu Yang <[email protected]>
---
samples/kprobes/kprobe_example.c | 5 ++---
samples/kprobes/kretprobe_example.c | 5 ++---
2 files changed, 4 insertions(+), 6 deletions(-)

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

2022-06-21 11:59:50

by Tiezhu Yang

Subject: Re: [PATCH v2] samples: Use KSYM_NAME_LEN for kprobes

Hi Masami,

Are you OK with this version?

[PATCH v2] samples: Use KSYM_NAME_LEN for kprobes
https://lore.kernel.org/lkml/[email protected]/

Thanks,
Tiezhu

2022-06-22 02:12:45

by Masami Hiramatsu

Subject: Re: [PATCH v2] samples: Use KSYM_NAME_LEN for kprobes

Hi,

On Wed, 8 Jun 2022 09:23:22 +0800
Tiezhu Yang <[email protected]> wrote:

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

This looks good to me.

Acked-by: Masami Hiramatsu (Google) <[email protected]>

Thank you!

>
> Signed-off-by: Tiezhu Yang <[email protected]>
> ---
> samples/kprobes/kprobe_example.c | 5 ++---
> samples/kprobes/kretprobe_example.c | 5 ++---
> 2 files changed, 4 insertions(+), 6 deletions(-)
>
> 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
>


--
Masami Hiramatsu (Google) <[email protected]>