From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755252AbaISEce (ORCPT ); Fri, 19 Sep 2014 00:32:34 -0400 Received: from mga11.intel.com ([192.55.52.93]:12395 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753317AbaISEcc (ORCPT ); Fri, 19 Sep 2014 00:32:32 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.04,552,1406617200"; d="scan'208";a="602007056" From: jun.zhang@intel.com To: tj@kernel.org Cc: linux-kernel@vger.kernel.org, zhang jun Subject: [PATCH] workqueue: give a protection when get_work_pwq return NULL. Date: Fri, 19 Sep 2014 12:12:04 +0800 Message-Id: <1411099924-11554-1-git-send-email-jun.zhang@intel.com> X-Mailer: git-send-email 1.7.9.5 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: zhang jun if pwq==NULL, system could panic. next is the panic log. [12973.660792] BUG: unable to handle kernel NULL pointer dereference at 00000004 [12973.668787] IP: [] process_one_work+0x2b/0x3e0 [12973.674735] *pdpt = 00000000304b0001 *pde = 0000000000000000 [12973.681167] Oops: 0000 [#1] PREEMPT SMP [12973.685557] Modules linked in: atomisp_css2400b0_v21 lm3554 ov2722 imx1x5 libmsrlisthelper atmel_mxt_ts vxd392 videobuf_vmalloc videobuf_core lm_dump(O) bcm_bt_lpm hdmi_audio bcm4334x(O) [12973.704154] CPU: 0 PID: 26284 Comm: kworker/0:0 Tainted: G W O 3.10.20-263108-g04ac390 #1 [12973.714070] Hardware name: Intel Corp. VALLEYVIEW C0 PLATFORM/BYT-T FFD8, BIOS BLAKFF81.86C.0099.R41.1406121403 FFD8_IA32_R_2014_24_4_01 06/12/2014 [12973.728846] task: c6e4f620 ti: eda0a000 task.ti: eda0a000 [12973.734878] EIP: 0060:[] EFLAGS: 00010046 CPU: 0 [12973.741010] EIP is at process_one_work+0x2b/0x3e0 [12973.746263] EAX: f364f4c0 EBX: c5267dc8 ECX: 00000000 EDX: 00000000 [12973.753264] ESI: f06fc840 EDI: f06fc840 EBP: eda0bf28 ESP: eda0bef8 [12973.760265] DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068 [12973.766294] CR0: 8005003b CR2: 00000078 CR3: 30798000 CR4: 001007f0 [12973.773295] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000 [12973.780296] DR6: ffff0ff0 DR7: 00000400 [12973.784578] Stack: [12973.786820] f364f4c0 f06fc840 eda0bf1c c1a9d81d c1a9d715 00000000 00000000 00000000 [12973.793547] f364f4c0[12973.793548] f06fc858[12973.793549] f364f4c0[12973.793550] f06fc840[12973.793551] eda0bf54[12973.793552] c125c036[12973.793553] c1a9a337[12973.793554] c6e4f620[12973.793555] [12973.793555] f364f4c0[12973.793556] c6e4f620[12973.793557] c6e4f620[12973.793558] f364f4e0[12973.793559] e73cde84[12973.793560] f06fc840[12973.793561] c125bf40[12973.793562] eda0bfac[12973.793563] [12973.793564] Call Trace: [12973.793567] [12973.793574] [] ? add_preempt_count+0x7d/0xf0 [12973.793575] [12973.793577] [] ? sub_preempt_count+0x55/0xe0 [12973.793579] [12973.793583] [] worker_thread+0xf6/0x310 [12973.793584] [12973.793586] [] ? _raw_spin_unlock_irqrestore+0x47/0x50 [12973.793588] [12973.793590] [] ? rescuer_thread+0x2b0/0x2b0 [12973.793591] [12973.793594] [] kthread+0x94/0xa0 [12973.793596] [12973.793598] [] ? sub_preempt_count+0x55/0xe0 [12973.793600] [12973.793602] [] ret_from_kernel_thread+0x1b/0x28 [12973.793603] [12973.793606] [] ? kthread_create_on_node+0xc0/0xc0 Signed-off-by: zhang jun --- kernel/workqueue.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 5dbe22a..e3baa55 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -1947,9 +1947,19 @@ __acquires(&pool->lock) { struct pool_workqueue *pwq = get_work_pwq(work); struct worker_pool *pool = worker->pool; - bool cpu_intensive = pwq->wq->flags & WQ_CPU_INTENSIVE; int work_color; struct worker *collision; + + if (pwq == NULL) { + pr_err("BUG: pwq is NULL. data: 0x%08lx @ work: 0x%p\n", + atomic_long_read(&work->data), work); + WARN_ON(1); + move_linked_works(work, &worker->scheduled, NULL); + return; + } + + bool cpu_intensive = pwq->wq->flags & WQ_CPU_INTENSIVE; + #ifdef CONFIG_LOCKDEP /* * It is permissible to free the struct work_struct from -- 1.7.9.5