Commit 2121db74 authored by Pekka Enberg's avatar Pekka Enberg Committed by Ingo Molnar
Browse files

kmemtrace: trace kfree() calls with NULL or zero-length objects 



Impact: also output kfree(NULL) entries

This patch moves the trace_kfree() calls before the ZERO_OR_NULL_PTR
check so that we can trace call-sites that call kfree() with NULL many
times which might be an indication of a bug.

Signed-off-by: default avatarPekka Enberg <penberg@cs.helsinki.fi>
Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
LKML-Reference: <1237971957.30175.18.camel@penberg-laptop>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent c826e3cd

mm/slab.c

+2 −2
Original line number Diff line number Diff line
@@ -3773,6 +3773,8 @@ void kfree(const void *objp) 
	struct kmem_cache *c;

	unsigned long flags;



	trace_kfree(_RET_IP_, objp);



	if (unlikely(ZERO_OR_NULL_PTR(objp)))

		return;

	local_irq_save(flags);
@@ -3782,8 +3784,6 @@ void kfree(const void *objp) 
	debug_check_no_obj_freed(objp, obj_size(c));

	__cache_free(c, (void *)objp);

	local_irq_restore(flags);



	trace_kfree(_RET_IP_, objp);

}

EXPORT_SYMBOL(kfree);

mm/slob.c

+2 −2
Original line number Diff line number Diff line
@@ -514,6 +514,8 @@ void kfree(const void *block) 
{

	struct slob_page *sp;



	trace_kfree(_RET_IP_, block);



	if (unlikely(ZERO_OR_NULL_PTR(block)))

		return;
@@ -524,8 +526,6 @@ void kfree(const void *block) 
		slob_free(m, *m + align);

	} else

		put_page(&sp->page);



	trace_kfree(_RET_IP_, block);

}

EXPORT_SYMBOL(kfree);

mm/slub.c

+2 −2
Original line number Diff line number Diff line
@@ -2792,6 +2792,8 @@ void kfree(const void *x) 
	struct page *page;

	void *object = (void *)x;



	trace_kfree(_RET_IP_, x);



	if (unlikely(ZERO_OR_NULL_PTR(x)))

		return;
@@ -2802,8 +2804,6 @@ void kfree(const void *x) 
		return;

	}

	slab_free(page->slab, page, object, _RET_IP_);



	trace_kfree(_RET_IP_, x);

}

EXPORT_SYMBOL(kfree);

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