From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f197.google.com (mail-pf0-f197.google.com [209.85.192.197]) by kanga.kvack.org (Postfix) with ESMTP id 5E8896B0005 for ; Fri, 1 Jul 2016 10:02:01 -0400 (EDT) Received: by mail-pf0-f197.google.com with SMTP id e189so237507195pfa.2 for ; Fri, 01 Jul 2016 07:02:01 -0700 (PDT) Received: from mail-pf0-x244.google.com (mail-pf0-x244.google.com. [2607:f8b0:400e:c00::244]) by mx.google.com with ESMTPS id qj5si4330592pac.289.2016.07.01.07.02.00 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 01 Jul 2016 07:02:00 -0700 (PDT) Received: by mail-pf0-x244.google.com with SMTP id c74so10161165pfb.0 for ; Fri, 01 Jul 2016 07:02:00 -0700 (PDT) From: js1304@gmail.com Subject: [PATCH v3] kasan/quarantine: fix bugs on qlist_move_cache() Date: Fri, 1 Jul 2016 23:02:13 +0900 Message-Id: <1467381733-18314-1-git-send-email-iamjoonsoo.kim@lge.com> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: Andrey Ryabinin , Alexander Potapenko , Dmitry Vyukov , kasan-dev@googlegroups.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Joonsoo Kim From: Joonsoo Kim There are two bugs on qlist_move_cache(). One is that qlist's tail isn't set properly. curr->next can be NULL since it is singly linked list and NULL value on tail is invalid if there is one item on qlist. Another one is that if cache is matched, qlist_put() is called and it will set curr->next to NULL. It would cause to stop the loop prematurely. These problems come from complicated implementation so I'd like to re-implement it completely. Implementation in this patch is really simple. Iterate all qlist_nodes and put them to appropriate list. Unfortunately, I got this bug sometime ago and lose oops message. But, the bug looks trivial and no need to attach oops. v3: fix build warning Signed-off-by: Joonsoo Kim --- mm/kasan/quarantine.c | 21 +++++++-------------- 1 file changed, 7 insertions(+), 14 deletions(-) diff --git a/mm/kasan/quarantine.c b/mm/kasan/quarantine.c index 4973505..cf92494 100644 --- a/mm/kasan/quarantine.c +++ b/mm/kasan/quarantine.c @@ -238,30 +238,23 @@ static void qlist_move_cache(struct qlist_head *from, struct qlist_head *to, struct kmem_cache *cache) { - struct qlist_node *prev = NULL, *curr; + struct qlist_node *curr; if (unlikely(qlist_empty(from))) return; curr = from->head; + qlist_init(from); while (curr) { struct qlist_node *qlink = curr; struct kmem_cache *obj_cache = qlink_to_cache(qlink); - if (obj_cache == cache) { - if (unlikely(from->head == qlink)) { - from->head = curr->next; - prev = curr; - } else - prev->next = curr->next; - if (unlikely(from->tail == qlink)) - from->tail = curr->next; - from->bytes -= cache->size; - qlist_put(to, qlink, cache->size); - } else { - prev = curr; - } curr = curr->next; + + if (obj_cache == cache) + qlist_put(to, qlink, cache->size); + else + qlist_put(from, qlink, cache->size); } } -- 1.9.1 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org