From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D449DC433E1 for ; Thu, 18 Jun 2020 20:12:48 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id A4DEE207E8 for ; Thu, 18 Jun 2020 20:12:48 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A4DEE207E8 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linutronix.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 2528D8D005B; Thu, 18 Jun 2020 16:12:48 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 1DBCE8D0052; Thu, 18 Jun 2020 16:12:48 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0CD018D005B; Thu, 18 Jun 2020 16:12:48 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0214.hostedemail.com [216.40.44.214]) by kanga.kvack.org (Postfix) with ESMTP id E540D8D0052 for ; Thu, 18 Jun 2020 16:12:47 -0400 (EDT) Received: from smtpin10.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id A00B082499B9 for ; Thu, 18 Jun 2020 20:12:47 +0000 (UTC) X-FDA: 76943430774.10.tree33_0803d8d26e13 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin10.hostedemail.com (Postfix) with ESMTP id 7E0A62D71EC for ; Thu, 18 Jun 2020 20:12:47 +0000 (UTC) X-HE-Tag: tree33_0803d8d26e13 X-Filterd-Recvd-Size: 3512 Received: from Galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by imf27.hostedemail.com (Postfix) with ESMTP for ; Thu, 18 Jun 2020 20:12:46 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=flow.W.breakpoint.cc) by Galois.linutronix.de with esmtp (Exim 4.80) (envelope-from ) id 1jm0tv-00028j-9P; Thu, 18 Jun 2020 22:12:43 +0200 From: Sebastian Andrzej Siewior To: linux-mm@kvack.org Cc: Christopher Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton , Thomas Gleixner , Sebastian Andrzej Siewior Subject: [PATCH 1/2] slub: Cure list_slab_objects() from double fix Date: Thu, 18 Jun 2020 22:12:33 +0200 Message-Id: <20200618201234.795692-1-bigeasy@linutronix.de> X-Mailer: git-send-email 2.27.0 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Rspamd-Queue-Id: 7E0A62D71EC X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam03 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: According to Christopher Lameter two fixes have been merged for the same problem. As far as I can tell, the code does not acquire the list_lock and invoke kmalloc(). list_slab_objects() misses an unlock (the counterpart to get_map()) and the memory allocated in free_partial() isn't used. Revert the mentioned commit. Fixes: aa456c7aebb14 ("slub: remove kmalloc under list_lock from list_slab_= objects() V2") Link: https://lkml.kernel.org/r/alpine.DEB.2.22.394.2006181501480.12014@www= .lameter.com Signed-off-by: Sebastian Andrzej Siewior --- mm/slub.c | 19 ++++--------------- 1 file changed, 4 insertions(+), 15 deletions(-) diff --git a/mm/slub.c b/mm/slub.c index b8f798b50d44d..72195cafbb503 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -3766,15 +3766,13 @@ static int kmem_cache_open(struct kmem_cache *s, sl= ab_flags_t flags) } =20 static void list_slab_objects(struct kmem_cache *s, struct page *page, - const char *text, unsigned long *map) + const char *text) { #ifdef CONFIG_SLUB_DEBUG void *addr =3D page_address(page); + unsigned long *map; void *p; =20 - if (!map) - return; - slab_err(s, page, text, s->name); slab_lock(page); =20 @@ -3786,6 +3784,7 @@ static void list_slab_objects(struct kmem_cache *s, s= truct page *page, print_tracking(s, p); } } + put_map(map); slab_unlock(page); #endif } @@ -3799,11 +3798,6 @@ static void free_partial(struct kmem_cache *s, struc= t kmem_cache_node *n) { LIST_HEAD(discard); struct page *page, *h; - unsigned long *map =3D NULL; - -#ifdef CONFIG_SLUB_DEBUG - map =3D bitmap_alloc(oo_objects(s->max), GFP_KERNEL); -#endif =20 BUG_ON(irqs_disabled()); spin_lock_irq(&n->list_lock); @@ -3813,16 +3807,11 @@ static void free_partial(struct kmem_cache *s, stru= ct kmem_cache_node *n) list_add(&page->slab_list, &discard); } else { list_slab_objects(s, page, - "Objects remaining in %s on __kmem_cache_shutdown()", - map); + "Objects remaining in %s on __kmem_cache_shutdown()"); } } spin_unlock_irq(&n->list_lock); =20 -#ifdef CONFIG_SLUB_DEBUG - bitmap_free(map); -#endif - list_for_each_entry_safe(page, h, &discard, slab_list) discard_slab(s, page); } --=20 2.27.0