Messages in this thread | | | Date | Tue, 9 Sep 2014 16:21:14 -0700 | From | Andrew Morton <> | Subject | Re: [PATCH] mm/sl[aou]b: make kfree() aware of error pointers |
| |
On Tue, 9 Sep 2014 23:25:28 +0200 (CEST) Jiri Kosina <jkosina@suse.cz> wrote:
> kfree() is happy to accept NULL pointer and does nothing in such case. > It's reasonable to expect it to behave the same if ERR_PTR is passed to > it. > > Inspired by a9cfcd63e8d ("ext4: avoid trying to kfree an ERR_PTR > pointer"). > > ... > > --- a/mm/slab.c > +++ b/mm/slab.c > @@ -3612,7 +3612,7 @@ void kfree(const void *objp) > > trace_kfree(_RET_IP_, objp); > > - if (unlikely(ZERO_OR_NULL_PTR(objp))) > + if (unlikely(ZERO_OR_NULL_PTR(objp) || IS_ERR(objp))) > return;
kfree() is quite a hot path to which this will add overhead. And we have (as far as we know) no code which will actually use this at present.
How about a new
kfree_safe(...) { if (IS_ERR(...)) return; if (other-stuff-when-we-think-of-it) return; kfree(...); }
?
| |