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=-5.4 required=3.0 tests=FROM_LOCAL_HEX, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 18138C010A2 for ; Tue, 5 Nov 2019 11:42:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EC54321D7C for ; Tue, 5 Nov 2019 11:42:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730938AbfKELmM (ORCPT ); Tue, 5 Nov 2019 06:42:12 -0500 Received: from mail-il1-f197.google.com ([209.85.166.197]:44608 "EHLO mail-il1-f197.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730627AbfKELmM (ORCPT ); Tue, 5 Nov 2019 06:42:12 -0500 Received: by mail-il1-f197.google.com with SMTP id 13so18321905iln.11 for ; Tue, 05 Nov 2019 03:42:09 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:date:message-id:subject:from:to; bh=P2JalRCzbuTnz7zbGMtCjjdpNiV9T9DN4NL3TjWGrGM=; b=Oph4m5PqT4LLtoBALVvVWHYCLdzrc7bSYk7VT+VQwf1SwL1/wqYvir4633EWm5nY80 hkLQpLAaxisTZrQfxmzuVFx90MBpz4VD2pSM70WuxdngsSSMpPMp1Kz/oDTYNYvGr1rQ nC0SdbXpJ0DzZA+6WRJSJaOYc+OoCOv2I7eWz8tHCm8bZDhzldH0h7RWPTcdVv3zqtJ3 ttAkH+IJHpwDyqwKptCea4Z7YaYjhr60w+NGDgWA7LiTkWAaRNNRUP9QJ+Gr4NKQ5yr+ cIFAqpOctKWSX/8A3303GscuSeoqnM857qqOMIMV+U71RMxFXiaxmzws5S9TGBLCD1cN Iwmg== X-Gm-Message-State: APjAAAWLqXGeFTi0PuNcKniheWgFlfXt9Sy6n0tP7f1txvcDrOy8cekc S5nfGHohcZmKtpCUzaKSPABtElnSGLj5VINlagh4oPhZLm5G X-Google-Smtp-Source: APXvYqzV0ZbhlU+W8da14/m/I2tCfQgtzi3aU0RAvBeifKHjxtejylfwRZ3agYiW/L+ZVw5cgBDTEq1VIrnFCsvbZONu197m3u4H MIME-Version: 1.0 X-Received: by 2002:a6b:fb0c:: with SMTP id h12mr19050300iog.239.1572954129411; Tue, 05 Nov 2019 03:42:09 -0800 (PST) Date: Tue, 05 Nov 2019 03:42:09 -0800 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <00000000000021be64059697ec8c@google.com> Subject: KCSAN: data-race in perf_event_update_userpage / perf_event_update_userpage From: syzbot To: acme@kernel.org, alexander.shishkin@linux.intel.com, ast@kernel.org, bpf@vger.kernel.org, daniel@iogearbox.net, elver@google.com, jolsa@redhat.com, kafai@fb.com, linux-kernel@vger.kernel.org, mark.rutland@arm.com, mingo@redhat.com, namhyung@kernel.org, netdev@vger.kernel.org, peterz@infradead.org, songliubraving@fb.com, syzkaller-bugs@googlegroups.com, yhs@fb.com Content-Type: text/plain; charset="UTF-8"; format=flowed; delsp=yes Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Hello, syzbot found the following crash on: HEAD commit: 05f22368 x86, kcsan: Enable KCSAN for x86 git tree: https://github.com/google/ktsan.git kcsan console output: https://syzkaller.appspot.com/x/log.txt?x=157a35f8e00000 kernel config: https://syzkaller.appspot.com/x/.config?x=87d111955f40591f dashboard link: https://syzkaller.appspot.com/bug?extid=3d30a087bef7b887dd14 compiler: gcc (GCC) 9.0.0 20181231 (experimental) Unfortunately, I don't have any reproducer for this crash yet. IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+3d30a087bef7b887dd14@syzkaller.appspotmail.com ================================================================== BUG: KCSAN: data-race in perf_event_update_userpage / perf_event_update_userpage write to 0xffff88812403c00c of 4 bytes by task 12674 on cpu 1: perf_event_update_userpage+0x157/0x340 kernel/events/core.c:5405 cpu_clock_event_add+0x3d/0x60 kernel/events/core.c:9672 event_sched_in.isra.0.part.0+0x1d5/0x560 kernel/events/core.c:2367 event_sched_in kernel/events/core.c:2339 [inline] group_sched_in+0xd1/0x2c0 kernel/events/core.c:2403 flexible_sched_in kernel/events/core.c:3418 [inline] flexible_sched_in+0x399/0x540 kernel/events/core.c:3407 visit_groups_merge+0x1d9/0x320 kernel/events/core.c:3366 ctx_flexible_sched_in kernel/events/core.c:3455 [inline] ctx_sched_in+0x1b4/0x360 kernel/events/core.c:3500 perf_event_sched_in+0x77/0xb0 kernel/events/core.c:2512 perf_event_context_sched_in kernel/events/core.c:3540 [inline] __perf_event_task_sched_in+0x354/0x390 kernel/events/core.c:3579 perf_event_task_sched_in include/linux/perf_event.h:1150 [inline] finish_task_switch+0x108/0x260 kernel/sched/core.c:3221 context_switch kernel/sched/core.c:3387 [inline] __schedule+0x319/0x640 kernel/sched/core.c:4069 schedule+0x47/0xd0 kernel/sched/core.c:4136 freezable_schedule include/linux/freezer.h:172 [inline] futex_wait_queue_me+0x18d/0x290 kernel/futex.c:2627 futex_wait+0x19b/0x3f0 kernel/futex.c:2733 write to 0xffff88812403c00c of 4 bytes by task 12673 on cpu 0: perf_event_update_userpage+0x157/0x340 kernel/events/core.c:5405 perf_mmap+0xe00/0xeb0 kernel/events/core.c:5875 call_mmap include/linux/fs.h:1900 [inline] mmap_region+0x83c/0xd50 mm/mmap.c:1806 do_mmap+0x6d4/0xba0 mm/mmap.c:1577 do_mmap_pgoff include/linux/mm.h:2353 [inline] vm_mmap_pgoff+0x12d/0x190 mm/util.c:496 ksys_mmap_pgoff+0x2d8/0x420 mm/mmap.c:1629 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:100 [inline] __se_sys_mmap arch/x86/kernel/sys_x86_64.c:91 [inline] __x64_sys_mmap+0x91/0xc0 arch/x86/kernel/sys_x86_64.c:91 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 12673 Comm: syz-executor.0 Not tainted 5.4.0-rc3+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ================================================================== --- This bug is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@googlegroups.com. syzbot will keep track of this bug report. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot.