Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752985AbdGGJIf (ORCPT ); Fri, 7 Jul 2017 05:08:35 -0400 Received: from mail-pf0-f195.google.com ([209.85.192.195]:33244 "EHLO mail-pf0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752626AbdGGJIa (ORCPT ); Fri, 7 Jul 2017 05:08:30 -0400 From: Wanpeng Li X-Google-Original-From: Wanpeng Li To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Peter Zijlstra , Wanpeng Li , Thomas Gleixner , Luiz Capitulino , Frederic Weisbecker , Rik van Riel Subject: [PATCH v2] sched/cputime: Fix using smp_processor_id() in preemptible Date: Fri, 7 Jul 2017 02:08:25 -0700 Message-Id: <1499418505-14754-1-git-send-email-wanpeng.li@hotmail.com> X-Mailer: git-send-email 2.7.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1667 Lines: 55 From: Wanpeng Li BUG: using smp_processor_id() in preemptible [00000000] code: 99-trinity/181 caller is debug_smp_processor_id+0x17/0x19 CPU: 0 PID: 181 Comm: 99-trinity Not tainted 4.12.0-01059-g2a42eb9 #1 Call Trace: dump_stack+0x82/0xb8 check_preemption_disabled+0xd1/0xe3 debug_smp_processor_id+0x17/0x19 vtime_delta+0xd/0x2c task_cputime+0x89/0xdb thread_group_cputime+0x11b/0x1ed thread_group_cputime_adjusted+0x1f/0x47 wait_consider_task+0x2a9/0xaf9 ? lock_acquire+0x97/0xa4 do_wait+0xdf/0x1f4 SYSC_wait4+0x8e/0xb5 ? list_add+0x34/0x34 SyS_wait4+0x9/0xb do_syscall_64+0x70/0x82 entry_SYSCALL64_slow_path+0x25/0x25 This patch fixes it by replacing sched_clock_cpu() in vtime_delta() by local_clock() for effectively raw_smp_processor_id(). Reported-by: Xiaolong Ye Cc: Thomas Gleixner Cc: Luiz Capitulino Cc: Frederic Weisbecker Cc: Rik van Riel Cc: Peter Zijlstra Cc: Ingo Molnar Signed-off-by: Wanpeng Li --- v1 -> v2: * replace sched_clock_cpu() by local_clock() kernel/sched/cputime.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c index 6e3ea4a..d86b94e 100644 --- a/kernel/sched/cputime.c +++ b/kernel/sched/cputime.c @@ -683,7 +683,7 @@ static u64 vtime_delta(struct vtime *vtime) { unsigned long long clock; - clock = sched_clock_cpu(smp_processor_id()); + clock = local_clock(); if (clock < vtime->starttime) return 0; -- 2.7.4