From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751742AbcIICaN (ORCPT ); Thu, 8 Sep 2016 22:30:13 -0400 Received: from mga06.intel.com ([134.134.136.31]:37005 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750796AbcIICaM (ORCPT ); Thu, 8 Sep 2016 22:30:12 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.30,303,1470726000"; d="scan'208";a="876688804" Date: Fri, 9 Sep 2016 10:26:50 +0800 From: Ye Xiaolong To: chengchao Cc: mingo@kernel.org, oleg@redhat.com, peterz@infradead.org, tj@kernel.org, akpm@linux-foundation.org, chris@chris-wilson.co.uk, linux-kernel@vger.kernel.org, lkp@01.org Subject: Re: [lkp] [sched/core] 3d26b7622f: BUG: unable to handle kernel NULL pointer dereference at 00000001 Message-ID: <20160909022650.GB7131@yexl-desktop> References: <20160909013938.GA7131@yexl-desktop> <427f9112-07e1-2a4d-55f4-93581a9d3ce5@kedacom.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <427f9112-07e1-2a4d-55f4-93581a9d3ce5@kedacom.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, cheng hao, On 09/09, chengchao wrote: >Hi, xiaolong > > where can I find the commit 3d26b7622f3bab689696900ffd33c6dd7849d7c2? This is the commit by 0Day bot for your original email patch sent on Sep 05 where both CONFIG_PREEMPT_NONE and CONFIG_PREEMPT_VOLUNTARY will turn the logic on. +/** + * the caller keeps task_on_rq_queued, so it's more suitable for + * sched_exec on the case when needs migration + */ +void stop_one_cpu_sync(unsigned int cpu, cpu_stop_fn_t fn, void *arg) +{ + struct cpu_stop_work work = { .fn = fn, .arg = arg, .done = NULL }; + + if (!cpu_stop_queue_work(cpu, &work)) + return; + +#if defined(CONFIG_PREEMPT_NONE) || defined(CONFIG_PREEMPT_VOLUNTARY) + /* + * CONFIG_PREEMPT doesn't need call schedule here, because + * preempt_enable already does the similar thing when call + * cpu_stop_queue_work + */ + schedule(); +#endif +} + > config-4.8.0-rc5-00001-g3d26b76: ># CONFIG_PREEMPT_NONE is not set >CONFIG_PREEMPT_VOLUNTARY=y ># CONFIG_PREEMPT is not set > > the patch ("sched/core: simpler function for sched_exec migration") only is on if CONFIG_PREEMPT_NONE=y, >so it doesn't cause the panic when CONFIG_PREEMPT_VOLUNTARY=y. > > >the latest patch is here: >https://lkml.org/lkml/2016/9/7/819 Will you send a formal updated patch to LKML? Then 0day will auto capture and test it. Thanks, Xiaolong > >int stop_one_cpu(unsigned int cpu, cpu_stop_fn_t fn, void *arg) >{ > struct cpu_stop_done done; > struct cpu_stop_work work = { .fn = fn, .arg = arg, .done = &done }; > > cpu_stop_init_done(&done, 1); > if (!cpu_stop_queue_work(cpu, &work)) > return -ENOENT; > >+#if defined(CONFIG_PREEMPT_NONE) >+ /* >+ * let the stopper thread runs as soon as possible, >+ * and keep current TASK_RUNNING. >+ */ >+ scheudle(); >+#endif > wait_for_completion(&done.completion); > return done.ret; >} > >Thanks, >Cheng > >on 09/09/2016 09:39 AM, kernel test robot wrote: >> >> FYI, we noticed the following commit: >> >> https://github.com/0day-ci/linux cheng-chao/sched-core-simpler-function-for-sched_exec-migration/20160905-142452 >> commit 3d26b7622f3bab689696900ffd33c6dd7849d7c2 ("sched/core: simpler function for sched_exec migration") >> >> in testcase: trinity >> with following parameters: >> >> runtime: 300s >> >> >> >> >> on test machine: qemu-system-i386 -enable-kvm -smp 2 -m 320M >> >> caused below changes: >> >> >> +------------------------------------------------------------------+----------+------------+ >> | | v4.8-rc5 | 3d26b7622f | >> +------------------------------------------------------------------+----------+------------+ >> | boot_successes | 2271 | 473 | >> | boot_failures | 248 | 654 | >> | genirq:Flags_mismatch_irq##(serial)vs.#(goldfish_pdev_bus) | 248 | 654 | >> | calltrace:SyS_open | 248 | 654 | >> | invoked_oom-killer:gfp_mask=0x | 33 | 32 | >> | Mem-Info | 33 | 32 | >> | BUG:kernel_reboot-without-warning_in_test_stage | 210 | 8 | >> | genirq:Flags_mismatch_irq | 1 | | >> | genirq:Flags_mismatch_irq##(ser | 1 | | >> | genirq:Flags_mismatch_irq##(serial)vs | 1 | | >> | genirq:Flags_mismatch_irq##(serial)vs.#(goldfi | 1 | | >> | genirq:Flags_mismatch_irq##(serial)vs.#(goldfish_pdev_bu | 1 | | >> | warn_alloc_failed+0x | 1 | | >> | Out_of_memory:Kill_process | 1 | 4 | >> | BUG:unable_to_handle_kernel | 0 | 533 | >> | Oops | 0 | 533 | >> | calltrace:smpboot_thread_fn | 0 | 593 | >> | kernel_BUG_at_mm/slub.c | 0 | 531 | >> | invalid_opcode:#[##]SMP | 0 | 536 | >> | EIP_is_at_kfree | 0 | 531 | >> | calltrace:SyS_execve | 0 | 533 | >> | Kernel_panic-not_syncing:Fatal_exception | 0 | 613 | >> | WARNING:at_arch/x86/kernel/traps.c:#do_debug | 0 | 86 | >> | general_protection_fault:#[##]SMP | 0 | 20 | >> | EIP_is_at.brk.pagetables | 0 | 1 | >> | EIP_is_at_do_execveat_common | 0 | 1 | >> | EIP_is_at_copy_strings | 0 | 1 | >> | bounds:#[##]SMP | 0 | 2 | >> | PANIC:double_fault | 0 | 2 | >> | EIP_is_at_elf_format | 0 | 1 | >> | general_protection_fault:#d34[##]SMP | 0 | 1 | >> | EIP_is_at__lock_acquire | 0 | 3 | >> | Kernel_panic-not_syncing:Out_of_memory_and_no_killable_processes | 0 | 1 | >> | WARNING:at_kernel/sched/core.c:#__might_sleep | 0 | 2 | >> | EIP_is_at_unlink_anon_vmas | 0 | 2 | >> | BUG:Bad_rss-counter_state_mm:#idx:#val | 0 | 1 | >> | BUG:non-zero_nr_ptes_on_freeing_mm | 0 | 1 | >> | EIP_is_at_cpu_stopper_thread | 0 | 2 | >> | genirq:Flags_mismatch_irq##(serial)vs.#(goldfish_pdev | 0 | 1 | >> +------------------------------------------------------------------+----------+------------+ >> >> [ 22.622360] BUG: unable to handle kernel NULL pointer dereference at 00000001 >> [ 22.623553] IP: [<5128c004>] 0x5128c004 >> [ 22.624210] *pde = 00000000 >> [ 22.624698] Oops: 0000 [#1] SMP >> [ 22.625223] Modules linked in: >> [ 22.625638] CPU: 1 PID: 15 Comm: migration/1 Not tainted 4.8.0-rc5-00001-g3d26b76 #1 >> [ 22.625638] task: 530910c0 task.stack: 5309a000 >> [ 22.625638] EIP: 0060:[<5128c004>] EFLAGS: 00010246 CPU: 1 >> [ 22.625638] EIP is at 0x5128c004 >> [ 22.625638] EAX: 00000001 EBX: 53790280 ECX: 00000000 EDX: 00000001 >> [ 22.625638] ESI: 5128c000 EDI: 41765d34 EBP: 5309bf04 ESP: 5309bee4 >> [ 22.625638] DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068 >> [ 22.625638] CR0: 80050033 CR2: 00000001 CR3: 01950000 CR4: 00000690 >> [ 22.625638] Stack: >> [ 22.625638] 53790280 410c5173 00000001 537902b0 53790284 530910c0 530023c0 41761ca0 >> [ 22.625638] 5309bf1c 410543d3 00000000 5301da60 530023c0 410542e0 5309bfa4 410513e0 >> [ 22.625638] 00000001 00000001 530023c0 00000000 00000000 dead4ead ffffffff ffffffff >> [ 22.625638] Call Trace: >> [ 22.625638] [<410c5173>] ? cpu_stopper_thread+0x73/0xf0 >> [ 22.625638] [<410543d3>] smpboot_thread_fn+0xf3/0x1e0 >> [ 22.625638] [<410542e0>] ? sort_range+0x20/0x20 >> [ 22.625638] [<410513e0>] kthread+0xa0/0xc0 >> [ 22.625638] [<41543e46>] ? wait_for_common+0xa6/0x150 >> [ 22.625638] [<415483e2>] ret_from_kernel_thread+0xe/0x24 >> [ 22.625638] [<41051340>] ? kthread_create_on_node+0x160/0x160 >> [ 22.625638] Code: 00 00 00 95 a1 7c 37 73 00 00 00 46 02 00 00 6c f5 bd 3f 7b 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 80 e4 1a 53 <02> 00 00 00 00 00 00 00 00 00 00 00 9d 6e ac 57 6c 6b 70 2f 6c >> [ 22.625638] EIP: [<5128c004>] 0x5128c004 SS:ESP 0068:5309bee4 >> [ 22.625638] CR2: 0000000000000001 >> [ 22.625638] ---[ end trace d07782e5cdd90364 ]--- >> [ 22.623351] ------------[ cut here ]------------ >> [ 22.623351] kernel BUG at mm/slub.c:3851! >> [ 22.623351] invalid opcode: 0000 [#2] SMP >> [ 22.623351] Modules linked in: >> [ 22.623351] CPU: 0 PID: 267 Comm: sh Tainted: G D 4.8.0-rc5-00001-g3d26b76 #1 >> [ 22.623351] task: 531ae480 task.stack: 5128c000 >> [ 22.623351] EIP: 0060:[<411268d3>] EFLAGS: 00010246 CPU: 0 >> [ 22.623351] EIP is at kfree+0x193/0x1a0 >> [ 22.623351] EAX: 00000000 EBX: 539cc1a0 ECX: 00000000 EDX: 00000000 >> [ 22.623351] ESI: 37740000 EDI: 5128df08 EBP: 5128dec4 ESP: 5128deb0 >> [ 22.623351] DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068 >> [ 22.623351] CR0: 80050033 CR2: 377d358c CR3: 125e6000 CR4: 00000690 >> [ 22.623351] Stack: >> [ 22.623351] 377d4000 00002000 530aee00 37740000 525e0480 5128df24 41184169 530aee00 >> [ 22.623351] 00000000 00000005 00000000 00000000 00000000 000930a0 00000000 00000000 >> [ 22.623351] ffffffff 377d5608 00000001 377a61bf 5140f300 520ca8c0 5128df08 5128df08 >> [ 22.623351] Call Trace: >> [ 22.623351] [<41184169>] load_elf_binary+0xb69/0xbc0 >> [ 22.623351] [<4113ddf2>] search_binary_handler+0x62/0x1a0 >> [ 22.623351] [<4113e4f3>] do_execveat_common+0x5c3/0x760 >> [ 22.623351] [<4113e8ff>] SyS_execve+0x1f/0x30 >> [ 22.623351] [<410012a5>] do_int80_syscall_32+0x45/0x110 >> [ 22.623351] [<415484d0>] entry_INT80_32+0x2c/0x2c >> [ 22.623351] Code: ff 40 18 eb b6 8d 76 00 6a 01 57 89 da 89 f0 89 f9 e8 12 fb ff ff 58 5a eb a1 8d b6 00 00 00 00 8b 43 14 a8 01 0f 85 7c ff ff ff <0f> 0b 8d 74 26 00 8d bc 27 00 00 00 00 55 89 e5 57 56 53 89 d7 >> [ 22.623351] EIP: [<411268d3>] kfree+0x193/0x1a0 SS:ESP 0068:5128deb0 >> [ 22.651614] ---[ end trace d07782e5cdd90365 ]--- >> [ 22.651616] Kernel panic - not syncing: Fatal exception >> [ 22.654918] Shutting down cpus with NMI >> [ 22.654918] Kernel Offset: disabled >> >> >> >> To reproduce: >> >> git clone git://git.kernel.org/pub/scm/linux/kernel/git/wfg/lkp-tests.git >> cd lkp-tests >> bin/lkp install job.yaml # job file is attached in this email >> bin/lkp run job.yaml >> >> >> >> Thanks, >> Xiaolong >>