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

3 files changed, 6 insertions, 6 deletions

diff --git a/mm/slab.c b/mm/slab.c
index fa00fd6a644d..b58400285030 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -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);
 
diff --git a/mm/slob.c b/mm/slob.c
index 00003587ebfa..a2d4ab32198d 100644
--- a/mm/slob.c
+++ b/mm/slob.c
@@ -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);
 
diff --git a/mm/slub.c b/mm/slub.c
index a98078bf738b..7ab54ecbd3f3 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -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);