* [PATCH] samples: Use KSYM_NAME_LEN for fprobe and kprobes
@ 2022-06-07 9:35 Tiezhu Yang
2022-06-07 16:17 ` Masami Hiramatsu
0 siblings, 1 reply; 3+ messages in thread
From: Tiezhu Yang @ 2022-06-07 9:35 UTC (permalink / raw)
To: Masami Hiramatsu, Steven Rostedt; +Cc: Xuefeng Li, linux-kernel
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@loongson.cn>
---
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
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] samples: Use KSYM_NAME_LEN for fprobe and kprobes
2022-06-07 9:35 [PATCH] samples: Use KSYM_NAME_LEN for fprobe and kprobes Tiezhu Yang
@ 2022-06-07 16:17 ` Masami Hiramatsu
2022-06-08 0:20 ` Tiezhu Yang
0 siblings, 1 reply; 3+ messages in thread
From: Masami Hiramatsu @ 2022-06-07 16:17 UTC (permalink / raw)
To: Tiezhu Yang; +Cc: Steven Rostedt, Xuefeng Li, linux-kernel
On Tue, 7 Jun 2022 17:35:36 +0800
Tiezhu Yang <yangtiezhu@loongson.cn> wrote:
> 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.
>
This is good for kprobe and kretprobe examples because it will get
a single symbol name, but not good for the fprobe. It can take
several comma separated symbols.
-----
static int __init fprobe_init(void)
{
...
/* Comma separated symbols */
symbuf = kstrdup(symbol, GFP_KERNEL);
if (!symbuf)
return -ENOMEM;
p = symbuf;
count = 1;
while ((p = strchr(++p, ',')) != NULL)
count++;
pr_info("%d symbols found\n", count);
-----
Can you drop the fprobe_example.c part?
Thank you,
> Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
> ---
> 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
>
--
Masami Hiramatsu (Google) <mhiramat@kernel.org>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] samples: Use KSYM_NAME_LEN for fprobe and kprobes
2022-06-07 16:17 ` Masami Hiramatsu
@ 2022-06-08 0:20 ` Tiezhu Yang
0 siblings, 0 replies; 3+ messages in thread
From: Tiezhu Yang @ 2022-06-08 0:20 UTC (permalink / raw)
To: Masami Hiramatsu (Google); +Cc: Steven Rostedt, Xuefeng Li, linux-kernel
On 06/08/2022 12:17 AM, Masami Hiramatsu (Google) wrote:
> On Tue, 7 Jun 2022 17:35:36 +0800
> Tiezhu Yang <yangtiezhu@loongson.cn> wrote:
>
>> 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.
>>
>
> This is good for kprobe and kretprobe examples because it will get
> a single symbol name, but not good for the fprobe. It can take
> several comma separated symbols.
>
> -----
> static int __init fprobe_init(void)
> {
> ...
> /* Comma separated symbols */
> symbuf = kstrdup(symbol, GFP_KERNEL);
> if (!symbuf)
> return -ENOMEM;
> p = symbuf;
> count = 1;
> while ((p = strchr(++p, ',')) != NULL)
> count++;
>
> pr_info("%d symbols found\n", count);
> -----
>
> Can you drop the fprobe_example.c part?
>
OK, I will send v2 later, thank you.
Thanks,
Tiezhu
^ permalink raw reply [flat|nested] 3+ messages in thread
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2022-06-07 16:17 ` Masami Hiramatsu
2022-06-08 0:20 ` Tiezhu Yang
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