tracing/kprobes: Add missing check for skipping symbol counting logic

[PATCH] tracing/kprobes: Add missing check for skipping symbol counting logic

Posted by Nikolay Kuratov 1 year, 7 months ago

In commit b022f0c7e404
("tracing/kprobes: Return EADDRNOTAVAIL when func matches several symbols")
it was already done for symbol in __trace_kprobe_create(), but func in
create_local_trace_kprobe() is also valid usage.
Not doing so leads to ENOENT for module_name:symbol_name
constructions passed over perf_event_open().

Fixes: b022f0c7e404 ("tracing/kprobes: Return EADDRNOTAVAIL when func matches several symbols")
Signed-off-by: Nikolay Kuratov <kniv@yandex-team.ru>
---
 kernel/trace/trace_kprobe.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 16383247bdbf..3f4c9195dc0d 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -1834,7 +1834,7 @@ create_local_trace_kprobe(char *func, void *addr, unsigned long offs,
 	int ret;
 	char *event;
 
-	if (func) {
+	if (func && !strchr(func, ':')) {
 		unsigned int count;
 
 		count = number_of_same_symbols(func);
-- 
2.34.1

Re: [PATCH] tracing/kprobes: Add missing check for skipping symbol counting logic

Posted by Masami Hiramatsu (Google) 1 year, 7 months ago

Hi Nikolay,

Thanks for the patch! But this remind me that I forgot to send a patch
which can solve this issue more generically.

https://lore.kernel.org/all/171338679446.616570.14456856697191949345.stgit@devnote2/

Why I did not send it...? Anyway let me send the update.

Thank you,


On Thu,  4 Jul 2024 19:43:36 +0300
Nikolay Kuratov <kniv@yandex-team.ru> wrote:

> In commit b022f0c7e404
> ("tracing/kprobes: Return EADDRNOTAVAIL when func matches several symbols")
> it was already done for symbol in __trace_kprobe_create(), but func in
> create_local_trace_kprobe() is also valid usage.
> Not doing so leads to ENOENT for module_name:symbol_name
> constructions passed over perf_event_open().
> 
> Fixes: b022f0c7e404 ("tracing/kprobes: Return EADDRNOTAVAIL when func matches several symbols")
> Signed-off-by: Nikolay Kuratov <kniv@yandex-team.ru>
> ---
>  kernel/trace/trace_kprobe.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
> index 16383247bdbf..3f4c9195dc0d 100644
> --- a/kernel/trace/trace_kprobe.c
> +++ b/kernel/trace/trace_kprobe.c
> @@ -1834,7 +1834,7 @@ create_local_trace_kprobe(char *func, void *addr, unsigned long offs,
>  	int ret;
>  	char *event;
>  
> -	if (func) {
> +	if (func && !strchr(func, ':')) {
>  		unsigned int count;
>  
>  		count = number_of_same_symbols(func);
> -- 
> 2.34.1
> 


-- 
Masami Hiramatsu (Google) <mhiramat@kernel.org>