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* [PATCH] perf bpf: return value with unlocking in perf_env__find_btf()
@ 2019-04-22  8:01 Bo YU
  2019-04-22  9:36 ` Jiri Olsa
  0 siblings, 1 reply; 3+ messages in thread
From: Bo YU @ 2019-04-22  8:01 UTC (permalink / raw)
  To: peterz, acme, alexander.shishkin, jolsa, namhyung, ast, daniel,
	kafai, songliubraving, yhs, adrian.hunter
  Cc: Bo YU, linux-kernel, netdev, bpf

In perf_env__find_btf(), returning without unlocking
"env->bpf_progs.lock". There may be cause lockdep issue.

DEtected by CoversityScan, CID# 1444762:(program hangs(LOCK))

Fixes: 2db7b1e0bd49d: (perf bpf: Return NULL when RB tree lookup fails in perf_env__find_btf())
Signed-off-by: Bo YU <tsu.yubo@gmail.com>
---
 tools/perf/util/env.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/util/env.c b/tools/perf/util/env.c
index 9494f9dc61ec..6a3eaf7d9353 100644
--- a/tools/perf/util/env.c
+++ b/tools/perf/util/env.c
@@ -115,8 +115,8 @@ struct btf_node *perf_env__find_btf(struct perf_env *env, __u32 btf_id)
 	}
 	node = NULL;
 
-	up_read(&env->bpf_progs.lock);
 out:
+	up_read(&env->bpf_progs.lock);
 	return node;
 }
 
-- 
2.11.0


^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH] perf bpf: return value with unlocking in perf_env__find_btf()
  2019-04-22  8:01 [PATCH] perf bpf: return value with unlocking in perf_env__find_btf() Bo YU
@ 2019-04-22  9:36 ` Jiri Olsa
  2019-04-22 14:29   ` Arnaldo Carvalho de Melo
  0 siblings, 1 reply; 3+ messages in thread
From: Jiri Olsa @ 2019-04-22  9:36 UTC (permalink / raw)
  To: Bo YU
  Cc: peterz, acme, alexander.shishkin, namhyung, ast, daniel, kafai,
	songliubraving, yhs, adrian.hunter, linux-kernel, netdev, bpf

On Mon, Apr 22, 2019 at 04:01:38AM -0400, Bo YU wrote:
> In perf_env__find_btf(), returning without unlocking
> "env->bpf_progs.lock". There may be cause lockdep issue.
> 
> DEtected by CoversityScan, CID# 1444762:(program hangs(LOCK))
> 
> Fixes: 2db7b1e0bd49d: (perf bpf: Return NULL when RB tree lookup fails in perf_env__find_btf())

ugh, sry about that

Acked-by: Jiri Olsa <jolsa@kernel.org>

thanks,
jirka

> Signed-off-by: Bo YU <tsu.yubo@gmail.com>
> ---
>  tools/perf/util/env.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tools/perf/util/env.c b/tools/perf/util/env.c
> index 9494f9dc61ec..6a3eaf7d9353 100644
> --- a/tools/perf/util/env.c
> +++ b/tools/perf/util/env.c
> @@ -115,8 +115,8 @@ struct btf_node *perf_env__find_btf(struct perf_env *env, __u32 btf_id)
>  	}
>  	node = NULL;
>  
> -	up_read(&env->bpf_progs.lock);
>  out:
> +	up_read(&env->bpf_progs.lock);
>  	return node;
>  }
>  
> -- 
> 2.11.0
> 

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH] perf bpf: return value with unlocking in perf_env__find_btf()
  2019-04-22  9:36 ` Jiri Olsa
@ 2019-04-22 14:29   ` Arnaldo Carvalho de Melo
  0 siblings, 0 replies; 3+ messages in thread
From: Arnaldo Carvalho de Melo @ 2019-04-22 14:29 UTC (permalink / raw)
  To: Jiri Olsa
  Cc: Bo YU, peterz, alexander.shishkin, namhyung, ast, daniel, kafai,
	songliubraving, yhs, adrian.hunter, linux-kernel, netdev, bpf

Em Mon, Apr 22, 2019 at 11:36:29AM +0200, Jiri Olsa escreveu:
> On Mon, Apr 22, 2019 at 04:01:38AM -0400, Bo YU wrote:
> > In perf_env__find_btf(), returning without unlocking
> > "env->bpf_progs.lock". There may be cause lockdep issue.
> > 
> > DEtected by CoversityScan, CID# 1444762:(program hangs(LOCK))
> > 
> > Fixes: 2db7b1e0bd49d: (perf bpf: Return NULL when RB tree lookup fails in perf_env__find_btf())
> 
> ugh, sry about that

Brown paper bag on the part of everybody involved indeed :-\
 
> Acked-by: Jiri Olsa <jolsa@kernel.org>

Applied.

Thanks,

- Arnaldo
 
> thanks,
> jirka
> 
> > Signed-off-by: Bo YU <tsu.yubo@gmail.com>
> > ---
> >  tools/perf/util/env.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/tools/perf/util/env.c b/tools/perf/util/env.c
> > index 9494f9dc61ec..6a3eaf7d9353 100644
> > --- a/tools/perf/util/env.c
> > +++ b/tools/perf/util/env.c
> > @@ -115,8 +115,8 @@ struct btf_node *perf_env__find_btf(struct perf_env *env, __u32 btf_id)
> >  	}
> >  	node = NULL;
> >  
> > -	up_read(&env->bpf_progs.lock);
> >  out:
> > +	up_read(&env->bpf_progs.lock);
> >  	return node;
> >  }
> >  
> > -- 
> > 2.11.0
> > 

-- 

- Arnaldo

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2019-04-22 14:29 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
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2019-04-22  8:01 [PATCH] perf bpf: return value with unlocking in perf_env__find_btf() Bo YU
2019-04-22  9:36 ` Jiri Olsa
2019-04-22 14:29   ` Arnaldo Carvalho de Melo

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