Re: [PATCH 38/46] selinux: One function call less in five functions after null pointer detection

Paul Moore
2017-03-29T15:39:09Z

On Sun, Jan 15, 2017 at 10:38 AM, SF Markus Elfring
<elfring@users.sourceforge.net> wrote:
> From: Markus Elfring <elfring@users.sourceforge.net>
> Date: Sun, 15 Jan 2017 11:28:02 +0100
>
> Call the function "kfree" at the end only after it was determined
> that the passed parameter contained a non-null pointer.
>
> Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
> ---
> security/selinux/ss/policydb.c | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/security/selinux/ss/policydb.c b/security/selinux/ss/policydb.c
> index faa6ecc2450d..88730b372277 100644
> --- a/security/selinux/ss/policydb.c
> +++ b/security/selinux/ss/policydb.c
> @@ -620,8 +620,8 @@ static int common_destroy(void *key, void *datum, void *p)
> comdatum = datum;
> hashtab_map(comdatum->permissions.table, perm_destroy, NULL);
> hashtab_destroy(comdatum->permissions.table);
> + kfree(datum);
> }
> - kfree(datum);
> return 0;
> }

I'm dropping this patch because it really doesn't do much other than
add some code churn. I suppose you can argue it removes one
conditional if datum is NULL, but that is such a corner case I'm not
worried about it.

If I were to merge this, I would probably expect "kfree(datum)" to be
converted to "kfree(comdatum)" (and similar in the cases below).

> @@ -675,8 +675,8 @@ static int cls_destroy(void *key, void *datum, void *p)
> kfree(ctemp);
> }
> kfree(cladatum->comkey);
> + kfree(datum);
> }
> - kfree(datum);
> return 0;
> }
>
> @@ -689,8 +689,8 @@ static int role_destroy(void *key, void *datum, void *p)
> role = datum;
> ebitmap_destroy(&role->dominates);
> ebitmap_destroy(&role->types);
> + kfree(datum);
> }
> - kfree(datum);
> return 0;
> }
>
> @@ -712,8 +712,8 @@ static int user_destroy(void *key, void *datum, void *p)
> ebitmap_destroy(&usrdatum->range.level[0].cat);
> ebitmap_destroy(&usrdatum->range.level[1].cat);
> ebitmap_destroy(&usrdatum->dfltlevel.cat);
> + kfree(datum);
> }
> - kfree(datum);
> return 0;
> }
>
> @@ -726,8 +726,8 @@ static int sens_destroy(void *key, void *datum, void *p)
> levdatum = datum;
> ebitmap_destroy(&levdatum->level->cat);
> kfree(levdatum->level);
> + kfree(datum);
> }
> - kfree(datum);
> return 0;
> }
>
> --
> 2.11.0
>

--
paul moore