[PATCH] tracepoint: Print the function symbol when tracepoint_debug is set

[PATCH] tracepoint: Print the function symbol when tracepoint_debug is set

[Huang Shijie]

When tracepoint_debug is set, we may get the output in kernel log:
     [  380.013843] Probe 0 : 00000000f0d68cda

It is not readable, so change to print the function symbol.
After this patch, the output may becomes:
     [   54.930567] Probe 0 : perf_trace_sched_wakeup_template

Reviewed-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Huang Shijie <shijie@os.amperecomputing.com>
---
 kernel/tracepoint.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c
index 1848ce7e2976..82bef4b9400a 100644
--- a/kernel/tracepoint.c
+++ b/kernel/tracepoint.c
@@ -127,7 +127,7 @@ static void debug_print_probes(struct tracepoint_func *funcs)
 		return;
 
 	for (i = 0; funcs[i].func; i++)
-		printk(KERN_DEBUG "Probe %d : %p\n", i, funcs[i].func);
+		printk(KERN_DEBUG "Probe %d : %ps\n", i, funcs[i].func);
 }
 
 static struct tracepoint_func *
-- 
2.40.1

Re: [PATCH] tracepoint: Print the function symbol when tracepoint_debug is set

[Steven Rostedt]

Can you resend this with linux-trace-kernel@vger.kernel.org please.

I probably should update the MAINTAINERS file and place this and
include/linux/tracepoint.h under TRACING.

-- Steve


On Tue,  4 Mar 2025 18:18:43 +0800
Huang Shijie <shijie@os.amperecomputing.com> wrote:

> When tracepoint_debug is set, we may get the output in kernel log:
>      [  380.013843] Probe 0 : 00000000f0d68cda
> 
> It is not readable, so change to print the function symbol.
> After this patch, the output may becomes:
>      [   54.930567] Probe 0 : perf_trace_sched_wakeup_template
> 
> Reviewed-by: Christoph Lameter <cl@linux.com>
> Signed-off-by: Huang Shijie <shijie@os.amperecomputing.com>
> ---
>  kernel/tracepoint.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c
> index 1848ce7e2976..82bef4b9400a 100644
> --- a/kernel/tracepoint.c
> +++ b/kernel/tracepoint.c
> @@ -127,7 +127,7 @@ static void debug_print_probes(struct tracepoint_func *funcs)
>  		return;
>  
>  	for (i = 0; funcs[i].func; i++)
> -		printk(KERN_DEBUG "Probe %d : %p\n", i, funcs[i].func);
> +		printk(KERN_DEBUG "Probe %d : %ps\n", i, funcs[i].func);
>  }
>  
>  static struct tracepoint_func *