From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934226AbeCMPg3 (ORCPT ); Tue, 13 Mar 2018 11:36:29 -0400 Received: from mail.efficios.com ([167.114.142.138]:38036 "EHLO mail.efficios.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934189AbeCMPgX (ORCPT ); Tue, 13 Mar 2018 11:36:23 -0400 Date: Tue, 13 Mar 2018 11:29:54 -0400 (EDT) From: Mathieu Desnoyers To: syzbot , Peter Zijlstra , Ingo Molnar , acme Cc: linux-kernel , "Paul E. McKenney" , rostedt , syzkaller-bugs@googlegroups.com, Alexander Shishkin , Jiri Olsa , Namhyung Kim Message-ID: <280278222.8876.1520954994543.JavaMail.zimbra@efficios.com> In-Reply-To: <001a1140e0de15fc910567464190@google.com> References: <001a1140e0de15fc910567464190@google.com> Subject: Re: WARNING in tracepoint_probe_unregister (2) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-Originating-IP: [167.114.142.138] X-Mailer: Zimbra 8.8.6_GA_1906 (ZimbraWebClient - FF52 (Linux)/8.8.6_GA_1906) Thread-Topic: WARNING in tracepoint_probe_unregister (2) Thread-Index: MdCS0Kg6Q0i+oIRgJu0PDlbYHSDJ6w== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org ----- On Mar 13, 2018, at 3:32 AM, syzbot syzbot+4e9ae7fa46233396f64d@syzkaller.appspotmail.com wrote: > Hello, > > syzbot hit the following crash on bpf-next commit > 6d8cb045cde681e64a5ed80a2ab70be831a7f9b0 (Fri Mar 9 07:46:33 2018 +0000) > bpf: comment why dots in filenames under BPF virtual FS are not allowed Here is the splat on unregister. I suspect this is caused by trying to unregister a tracepoint which is already unregistered (or not yet registered). Thanks, Mathieu > > So far this crash happened 2 times on bpf-next. > Unfortunately, I don't have any reproducer for this crash yet. > Raw console output is attached. > compiler: gcc (GCC) 7.1.1 20170620 > .config is attached. > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+4e9ae7fa46233396f64d@syzkaller.appspotmail.com > It will help syzbot understand when the bug is fixed. See footer for > details. > If you forward the report, please keep this part and the footer. > > RAX: 0000000000000000 RBX: 00007f399ae5c6d4 RCX: 0000000000453e69 > RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000013 > RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000014 > R13: 0000000000000052 R14: 00000000006f0850 R15: 0000000000000000 > WARNING: CPU: 1 PID: 23319 at kernel/tracepoint.c:242 > tracepoint_remove_func kernel/tracepoint.c:242 [inline] > WARNING: CPU: 1 PID: 23319 at kernel/tracepoint.c:242 > tracepoint_probe_unregister+0x6b3/0x870 kernel/tracepoint.c:323 > Kernel panic - not syncing: panic_on_warn set ... > > CPU: 1 PID: 23319 Comm: syz-executor6 Not tainted 4.16.0-rc4+ #28 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > Call Trace: > __dump_stack lib/dump_stack.c:17 [inline] > dump_stack+0x194/0x24d lib/dump_stack.c:53 > panic+0x1e4/0x41c kernel/panic.c:183 > __warn+0x1dc/0x200 kernel/panic.c:547 > report_bug+0x211/0x2d0 lib/bug.c:184 > fixup_bug.part.11+0x37/0x80 arch/x86/kernel/traps.c:178 > fixup_bug arch/x86/kernel/traps.c:247 [inline] > do_error_trap+0x2d7/0x3e0 arch/x86/kernel/traps.c:296 > do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:315 > invalid_op+0x1b/0x40 arch/x86/entry/entry_64.S:986 > RIP: 0010:tracepoint_remove_func kernel/tracepoint.c:242 [inline] > RIP: 0010:tracepoint_probe_unregister+0x6b3/0x870 kernel/tracepoint.c:323 > RSP: 0018:ffff8801c56a74d0 EFLAGS: 00010246 > RAX: 0000000000010000 RBX: 00000000fffffff4 RCX: ffffffff81735193 > RDX: 0000000000010000 RSI: ffffc900057fa000 RDI: 0000000000000286 > RBP: ffff8801c56a75e8 R08: 1ffff10038ad4ded R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801c1132dc0 > R13: 0000000000000000 R14: ffff8801c1132d90 R15: ffff8801c56a75c0 > trace_event_reg+0xed/0x320 kernel/trace/trace_events.c:309 > perf_trace_event_unreg.isra.2+0xad/0x1f0 > kernel/trace/trace_event_perf.c:155 > perf_trace_destroy+0xbc/0x100 kernel/trace/trace_event_perf.c:236 > tp_perf_event_destroy+0x15/0x20 kernel/events/core.c:7963 > _free_event+0x3bd/0x10f0 kernel/events/core.c:4108 > put_event+0x24/0x30 kernel/events/core.c:4191 > perf_event_release_kernel+0x6e8/0xfc0 kernel/events/core.c:4297 > perf_release+0x37/0x50 kernel/events/core.c:4307 > __fput+0x327/0x7e0 fs/file_table.c:209 > ____fput+0x15/0x20 fs/file_table.c:243 > task_work_run+0x199/0x270 kernel/task_work.c:113 > tracehook_notify_resume include/linux/tracehook.h:191 [inline] > exit_to_usermode_loop+0x275/0x2f0 arch/x86/entry/common.c:166 > prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline] > syscall_return_slowpath arch/x86/entry/common.c:265 [inline] > do_syscall_64+0x6ec/0x940 arch/x86/entry/common.c:292 > entry_SYSCALL_64_after_hwframe+0x42/0xb7 > RIP: 0033:0x453e69 > RSP: 002b:00007f399ae5bc68 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 > RAX: 0000000000000000 RBX: 00007f399ae5c6d4 RCX: 0000000000453e69 > RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000013 > RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000014 > R13: 0000000000000052 R14: 00000000006f0850 R15: 0000000000000000 > Dumping ftrace buffer: > (ftrace buffer empty) > Kernel Offset: disabled > Rebooting in 86400 seconds.. > > > --- > This bug is generated by a dumb bot. It may contain errors. > See https://goo.gl/tpsmEJ for details. > Direct all questions to syzkaller@googlegroups.com. > > syzbot will keep track of this bug report. > If you forgot to add the Reported-by tag, once the fix for this bug is > merged > into any tree, please reply to this email with: > #syz fix: exact-commit-title > To mark this as a duplicate of another syzbot report, please reply with: > #syz dup: exact-subject-of-another-report > If it's a one-off invalid bug report, please reply with: > #syz invalid > Note: if the crash happens again, it will cause creation of a new bug > report. > Note: all commands must start from beginning of the line in the email body. -- Mathieu Desnoyers EfficiOS Inc. http://www.efficios.com