perf namespaces: check newns before free

[PATCH] perf namespaces: check newns before free

Posted by zhangjiao2 1 year, 3 months ago

From: zhang jiao <zhangjiao2@cmss.chinamobile.com>

Since newns can be NULL, check it before free

Signed-off-by: zhang jiao <zhangjiao2@cmss.chinamobile.com>
---
 tools/perf/util/namespaces.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/namespaces.c b/tools/perf/util/namespaces.c
index cb185c5659d6..49e20e0a567a 100644
--- a/tools/perf/util/namespaces.c
+++ b/tools/perf/util/namespaces.c
@@ -135,7 +135,8 @@ int nsinfo__init(struct nsinfo *nsi)
 			       &RC_CHK_ACCESS(nsi)->in_pidns, spath);
 
 out:
-	free(newns);
+	if (newns)
+		free(newns);
 	return rv;
 }
 
-- 
2.33.0

Re: [PATCH] perf namespaces: check newns before free

Posted by Thomas Richter 1 year, 3 months ago

On 9/3/24 11:12, zhangjiao2 wrote:
> From: zhang jiao <zhangjiao2@cmss.chinamobile.com>
> 
> Since newns can be NULL, check it before free
> 
> Signed-off-by: zhang jiao <zhangjiao2@cmss.chinamobile.com>
> ---
>  tools/perf/util/namespaces.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/perf/util/namespaces.c b/tools/perf/util/namespaces.c
> index cb185c5659d6..49e20e0a567a 100644
> --- a/tools/perf/util/namespaces.c
> +++ b/tools/perf/util/namespaces.c
> @@ -135,7 +135,8 @@ int nsinfo__init(struct nsinfo *nsi)
>  			       &RC_CHK_ACCESS(nsi)->in_pidns, spath);
>  
>  out:
> -	free(newns);
> +	if (newns)
> +		free(newns);
>  	return rv;
>  }
>  

Ins't zfree() to proper function to use? Also zfree() calls free()
from the C library which can handle a NULL pointer?

Just my opinion.
-- 
Thomas Richter, Dept 3303, IBM s390 Linux Development, Boeblingen, Germany
--
IBM Deutschland Research & Development GmbH

Vorsitzender des Aufsichtsrats: Wolfgang Wendt

Geschäftsführung: David Faller

Sitz der Gesellschaft: Böblingen / Registergericht: Amtsgericht Stuttgart, HRB 243294

Re: [PATCH] perf namespaces: check newns before free

Posted by Namhyung Kim 1 year, 3 months ago

Hello,

On Tue, Sep 03, 2024 at 05:12:08PM +0800, zhangjiao2 wrote:
> From: zhang jiao <zhangjiao2@cmss.chinamobile.com>
> 
> Since newns can be NULL, check it before free
> 
> Signed-off-by: zhang jiao <zhangjiao2@cmss.chinamobile.com>
> ---
>  tools/perf/util/namespaces.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/perf/util/namespaces.c b/tools/perf/util/namespaces.c
> index cb185c5659d6..49e20e0a567a 100644
> --- a/tools/perf/util/namespaces.c
> +++ b/tools/perf/util/namespaces.c
> @@ -135,7 +135,8 @@ int nsinfo__init(struct nsinfo *nsi)
>  			       &RC_CHK_ACCESS(nsi)->in_pidns, spath);
>  
>  out:
> -	free(newns);
> +	if (newns)
> +		free(newns);

It's ok to call free(NULL).

Thanks,
Namhyung


>  	return rv;
>  }
>  
> -- 
> 2.33.0
> 
> 
>