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=-16.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 D0D23C432BE for ; Mon, 30 Aug 2021 07:17:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AB2D760F8F for ; Mon, 30 Aug 2021 07:17:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233631AbhH3HSD (ORCPT ); Mon, 30 Aug 2021 03:18:03 -0400 Received: from mailout2.samsung.com ([203.254.224.25]:64211 "EHLO mailout2.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232321AbhH3HSC (ORCPT ); Mon, 30 Aug 2021 03:18:02 -0400 Received: from epcas1p4.samsung.com (unknown [182.195.41.48]) by mailout2.samsung.com (KnoxPortal) with ESMTP id 20210830071707epoutp025dee6994fb1ea3493466cced3a9e9d6e~gBFTSyPTL1867018670epoutp02V for ; Mon, 30 Aug 2021 07:17:07 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 mailout2.samsung.com 20210830071707epoutp025dee6994fb1ea3493466cced3a9e9d6e~gBFTSyPTL1867018670epoutp02V DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=samsung.com; s=mail20170921; t=1630307827; bh=ZDC2xTZuSK55t0V8aQf8pSsiEvOfn0p17TQ+RPhTN00=; h=Subject:Reply-To:From:To:CC:Date:References:From; b=q8FKjjnWc3HAzu9KggIx8wdo56JNtDrQwtHoTqUJ9tL6T0Qw7gpwu3AxUPPaVmoRv xTVZKiv1TT2rTPobqkA2H9pHopKnETuPEkI4bo6jm+5ZVlrySbxv2D3Gix9j2hKjGp 74ExJJG2FsVUFwaVYWWe1xpXTxVlmS33ZcSpBgr8= Received: from epsnrtp3.localdomain (unknown [182.195.42.164]) by epcas1p1.samsung.com (KnoxPortal) with ESMTP id 20210830071707epcas1p14a94340ed0469b9e88ba6636143c9c20~gBFS-YQYW1777517775epcas1p1r; Mon, 30 Aug 2021 07:17:07 +0000 (GMT) Received: from epsmges1p5.samsung.com (unknown [182.195.38.243]) by epsnrtp3.localdomain (Postfix) with ESMTP id 4GyhTY0LgWz4x9Q9; Mon, 30 Aug 2021 07:17:05 +0000 (GMT) X-AuditID: b6c32a39-6a7ff70000002618-77-612c85ee86b6 Received: from epcas1p1.samsung.com ( [182.195.41.45]) by epsmges1p5.samsung.com (Symantec Messaging Gateway) with SMTP id 89.53.09752.EE58C216; Mon, 30 Aug 2021 16:17:02 +0900 (KST) Mime-Version: 1.0 Subject: [PATCH] printk: use kvmalloc instead of kmalloc for devkmsg_user Reply-To: ytk.lee@samsung.com Sender: =?UTF-8?B?7J207Jqp7YOd?= From: =?UTF-8?B?7J207Jqp7YOd?= To: "pmladek@suse.com" , "senozhatsky@chromium.org" , "rostedt@goodmis.org" , "john.ogness@linutronix.de" , "linux-kernel@vger.kernel.org" CC: =?UTF-8?B?7J207Jqp7YOd?= X-Priority: 3 X-Content-Kind-Code: NORMAL X-Drm-Type: N,general X-Msg-Generator: Mail X-Msg-Type: PERSONAL X-Reply-Demand: N Message-ID: <20210830071701epcms1p70f72ae10940bc407a3c33746d20da771@epcms1p7> Date: Mon, 30 Aug 2021 16:17:01 +0900 X-CMS-MailID: 20210830071701epcms1p70f72ae10940bc407a3c33746d20da771 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" X-Sendblock-Type: SVC_REQ_APPROVE CMS-TYPE: 101P X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFvrFKsWRmVeSWpSXmKPExsWy7bCmru67Vp1Eg6NbBCy2XZnPaHF51xw2 i/+Pv7Ja7Ot4wGSxe+MiNovH67kd2DxmN1xk8WjZd4vd4925c+wefVtWMXqs33KVxePzJrkA tqhsm4zUxJTUIoXUvOT8lMy8dFsl7+B453hTMwNDXUNLC3MlhbzE3FRbJRefAF23zBygK5QU yhJzSoFCAYnFxUr6djZF+aUlqQoZ+cUltkqpBSk5BWYFesWJucWleel6eaklVoYGBkamQIUJ 2RkdO1+xFDwRqNi5cyVzA+Mt3i5GTg4JAROJWWsmMYLYQgI7GCX+bQrrYuTg4BUQlPi7Qxgk LCzgKbFg5kFmkLCQgKxEa68KRNhM4nXPFCYQmw1oyo7Hf4FKuDhEBLqZJNpn3GEFSTALGEn0 rtjICLGKV2JG+1MWCFtaYvvyrVBxUYmbq9+yw9jvj82HiotItN47ywxhC0o8+LkbKi4lMf3k DjaQZRIC8xklDv3cwA7hdDBKfPn6kg2iylzi2YYWsKm8Ar4SO54+AbuIRUBV4vXURVDbXCT+ dC9mgrhUW2LZwtdgXzILaEqs36UPUaIosfP3XEaIEj6Jd197WGGe2THvCRNMTfOJXqi4uMS9 eX1Q4z0klndPZoOEbaDE1ok3WCcwys9CBO8sJItnISxewMi8ilEstaA4Nz212LDAFB6hyfm5 mxjBiVDLcgfj9Lcf9A4xMnEwHmKU4GBWEuHNfqOVKMSbklhZlVqUH19UmpNafIjRFOjlicxS osn5wFScVxJvaGJpYGJmZGJhbGlspiTOy/hKJlFIID2xJDU7NbUgtQimj4mDU6qBKahaWaxU wE1Uslt47a+vLkx5bIw2r59kO+73zJS4HL9YYdOSjqoTTXY/+Bquhz6q+cke8PVt2mfBj183 s5v1XfZ+HsKsM7NMhfGOToH8dZU3b7ZvibK/UX7meHDOV95l/N+TT82qnc2dVLUy+ZDsmh0L s+c97Zse0iAqqTRT8NEXG4ulO2+yqmvkpuid97PJLeBf/f1h9NYP08WZ4qRvrY2pagzoeWtv Veds8lKh9lG7BM/9OXNC16/QXC0u6M4+4yLDZ8uHST+el4rtPbbjPNf67JXZdv2OZe2Rp+62 PsrrtBdtTdZ9WanwuFT/ztlySY4JzIu+5h64sYV16r+NE+NqFc8cezIrsGL2BX9JJZbijERD Leai4kQApVj8Vg0EAAA= DLP-Filter: Pass X-CFilter-Loop: Reflected X-CMS-RootMailID: 20210830071701epcms1p70f72ae10940bc407a3c33746d20da771 References: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Size of struct devkmsg_user increased to 16784 by commit 896fbe20b4e2 (=22printk: use the lockless ringbuffer=22) so order3(32kb) is needed for kmalloc. Under stress conditions the kernel may temporary fail to allocate 32k with kmalloc. Use kvmalloc instead of kmalloc to aviod this issue. qseecomd invoked oom-killer: gfp_mask=3D0x40cc0(GFP_KERNEL=7C__GFP_COMP), o= rder=3D3, oom_score_adj=3D-1000 Call trace: dump_backtrace+0x0/0x34c dump_stack_lvl+0xd4/0x16c dump_header+0x5c/0x338 out_of_memory+0x374/0x4cc __alloc_pages_slowpath+0xbc8/0x1130 __alloc_pages_nodemask+0x170/0x1b0 kmalloc_order+0x5c/0x24c devkmsg_open+0x1f4/0x558 memory_open+0x94/0xf0 chrdev_open+0x288/0x3dc do_dentry_open+0x2b4/0x618 path_openat+0xce4/0xfa8 do_filp_open+0xb0/0x164 do_sys_openat2+0xa8/0x264 __arm64_sys_openat+0x70/0xa0 el0_svc_common+0xc4/0x270 el0_svc+0x34/0x9c el0_sync_handler+0x88/0xf0 el0_sync+0x1bc/0x200 DMA32: 4521*4kB (UMEC) 1377*8kB (UMECH) 73*16kB (UM) 0*32kB 0*64kB 0*128kB= 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB =3D 30268kB Normal: 2490*4kB (UMEH) 277*8kB (UMH) 27*16kB (UH) 1*32kB (H) 0*64kB 0*128= kB 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB =3D 12640kB Signed-off-by: Yong-Taek Lee --- kernel/printk/printk.c =7C 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index 142a58d124d9..8ba1602232ec 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c =40=40 -862,7 +862,7 =40=40 static int devkmsg_open(struct inode *inode, st= ruct file *file) return err; =7D - user =3D kmalloc(sizeof(struct devkmsg_user), GFP_KERNEL); + user =3D kvmalloc(sizeof(struct devkmsg_user), GFP_KERNEL); if (=21user) return -ENOMEM; =40=40 -892,7 +892,7 =40=40 static int devkmsg_release(struct inode *inode,= struct file *file) ratelimit_state_exit(&user->rs); mutex_destroy(&user->lock); - kfree(user); + kvfree(user); return 0; =7D -- 2.17.1 =C2=A0