Messages in this thread | | | Date | Tue, 13 Mar 2018 11:29:51 -0400 (EDT) | From | Mathieu Desnoyers <> | Subject | Re: WARNING in tracepoint_probe_register_prio (2) |
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----- On Mar 12, 2018, at 9:59 PM, syzbot syzbot+9c0d616860575a73166a@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
Hi,
Here is a WARN_ON() splat in tracepoint.c, which I suspect is caused by perf trying to register the same probe twice to the tracepoint API. We got another splat on unregister too, which I will forward in a separate email.
Thoughts ?
Thanks,
Mathieu
> > So far this crash happened 6 times on bpf-next, upstream. > C reproducer is attached. > syzkaller reproducer is attached. > 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+9c0d616860575a73166a@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: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441dd9 > RDX: 00000000ffffffff RSI: 0000000000000000 RDI: 0000000020348f88 > RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000032 > R10: 0000000000000003 R11: 0000000000000246 R12: 0000000000000004 > R13: ffffffffffffffff R14: 0000000000000000 R15: 0000000000000000 > WARNING: CPU: 0 PID: 4185 at kernel/tracepoint.c:210 tracepoint_add_func > kernel/tracepoint.c:210 [inline] > WARNING: CPU: 0 PID: 4185 at kernel/tracepoint.c:210 > tracepoint_probe_register_prio+0x397/0x9a0 kernel/tracepoint.c:282 > Kernel panic - not syncing: panic_on_warn set ... > > CPU: 0 PID: 4185 Comm: syzkaller994063 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_add_func kernel/tracepoint.c:210 [inline] > RIP: 0010:tracepoint_probe_register_prio+0x397/0x9a0 kernel/tracepoint.c:282 > RSP: 0018:ffff8801bbc87468 EFLAGS: 00010293 > RAX: ffff8801b5a3c680 RBX: 00000000fffffff4 RCX: ffffffff81735e67 > RDX: 0000000000000000 RSI: ffffffff86f42a00 RDI: 0000000000000286 > RBP: ffff8801bbc87570 R08: 1ffff10037790de1 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 > R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8801bbc87548 > tracepoint_probe_register+0x2a/0x40 kernel/tracepoint.c:303 > trace_event_reg+0x167/0x320 kernel/trace/trace_events.c:305 > perf_trace_event_reg kernel/trace/trace_event_perf.c:122 [inline] > perf_trace_event_init kernel/trace/trace_event_perf.c:197 [inline] > perf_trace_init+0x4ef/0xab0 kernel/trace/trace_event_perf.c:221 > perf_tp_event_init+0x7d/0xf0 kernel/events/core.c:7979 > perf_try_init_event+0xc9/0x2a0 kernel/events/core.c:9240 > perf_init_event kernel/events/core.c:9278 [inline] > perf_event_alloc+0x1cc6/0x2b00 kernel/events/core.c:9542 > SYSC_perf_event_open+0x84e/0x2e00 kernel/events/core.c:9997 > SyS_perf_event_open+0x39/0x50 kernel/events/core.c:9883 > do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 > entry_SYSCALL_64_after_hwframe+0x42/0xb7 > RIP: 0033:0x441dd9 > RSP: 002b:00007ffcca452388 EFLAGS: 00000246 ORIG_RAX: 000000000000012a > RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441dd9 > RDX: 00000000ffffffff RSI: 0000000000000000 RDI: 0000000020348f88 > RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000032 > R10: 0000000000000003 R11: 0000000000000246 R12: 0000000000000004 > R13: ffffffffffffffff R14: 0000000000000000 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 > If you want to test a patch for this bug, please reply with: > #syz test: git://repo/address.git branch > and provide the patch inline or as an attachment. > 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
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