From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f199.google.com (mail-pf0-f199.google.com [209.85.192.199]) by kanga.kvack.org (Postfix) with ESMTP id B86186B0005 for ; Fri, 1 Jul 2016 09:55:19 -0400 (EDT) Received: by mail-pf0-f199.google.com with SMTP id 143so237676372pfx.0 for ; Fri, 01 Jul 2016 06:55:19 -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 p190si4275365pfb.185.2016.07.01.06.55.18 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 01 Jul 2016 06:55:18 -0700 (PDT) Received: by mail-pf0-x244.google.com with SMTP id 66so10132885pfy.1 for ; Fri, 01 Jul 2016 06:55:18 -0700 (PDT) From: js1304@gmail.com Subject: [PATCH v2] kasan/quarantine: fix bugs on qlist_move_cache() Date: Fri, 1 Jul 2016 22:55:32 +0900 Message-Id: <1467381332-7282-1-git-send-email-iamjoonsoo.kim@lge.com> In-Reply-To: <57765157.8020909@virtuozzo.com> References: <57765157.8020909@virtuozzo.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. Signed-off-by: Joonsoo Kim --- mm/kasan/quarantine.c | 22 ++++++++-------------- 1 file changed, 8 insertions(+), 14 deletions(-) diff --git a/mm/kasan/quarantine.c b/mm/kasan/quarantine.c index 4973505..061d39b 100644 --- a/mm/kasan/quarantine.c +++ b/mm/kasan/quarantine.c @@ -238,30 +238,24 @@ 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; + struct qlist_node *head = NULL, *tail = NULL; 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