Re: [PATCH] kmemleak: Never return a pointer you didn't 'get'

[Catalin Marinas <catalin.marinas@arm.com>]

On Thu, 2011-04-21 at 12:39 +0100, Phil Carmody wrote:
> Old - If you don't get the last pointer that you looked at, then it will
> still be put, as there's no way of knowing you didn't get it.
> 
> New - If you didn't get it, then it refers to something deleted, and
> your work is done, so return NULL.
> 
> Signed-off-by: Phil Carmody <ext-phil.2.carmody@nokia.com>

Good catch. But I think the code may look slightly simpler as below:

diff --git a/mm/kmemleak.c b/mm/kmemleak.c
index c1d5867..aacee45 100644
--- a/mm/kmemleak.c
+++ b/mm/kmemleak.c
@@ -1414,9 +1414,12 @@ static void *kmemleak_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 	++(*pos);
 
 	list_for_each_continue_rcu(n, &object_list) {
-		next_obj = list_entry(n, struct kmemleak_object, object_list);
-		if (get_object(next_obj))
+		struct kmemleak_object *obj =
+			list_entry(n, struct kmemleak_object, object_list);
+		if (get_object(obj)) {
+			next_obj = obj;
 			break;
+		}
 	}
 
 	put_object(prev_obj);


Thanks.

-- 
Catalin