On Fri, 17 Nov 2017 10:26:27 +0800 kernel test robot <[email protected]>
wrote:
>
> FYI, we noticed the following commit (built with gcc-6):
>
> commit: c21f87074dc24c9e5a13dc63918b2d30891d190f ("lib/rbtree-test: lower
> default params")
> https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git master
>
> in testcase: boot
Looks like a false positive to me. That commit fiddles with
lib/interval_tree_test.c and lib/rbtree_test.c.
> on test machine: qemu-system-x86_64 -enable-kvm -smp 2 -m 512M
>
> caused below changes (please refer to attached dmesg/kmsg for entire
> log/backtrace):
>
>
> +---------------------------------------------------+------------+------------+
> | | ced2d43150 | c21f87074d
> |
> +---------------------------------------------------+------------+------------+
> | boot_successes | 3 | 2
> |
> | boot_failures | 13 | 14
> |
> | BUG:kernel_hang_in_test_stage | 13 | 14
> |
> | WARNING:at_kernel/events/core.c:#perf_swevent_add | 0 | 14
> |
> | RIP:perf_swevent_add | 0 | 14
> |
> +---------------------------------------------------+------------+------------+
>
>
>
> [ 14.436079] WARNING: CPU: 0 PID: 412 at kernel/events/core.c:7735
> perf_swevent_add+0x90/0xe0
> [ 14.437206] Modules linked in:
> [ 14.437548] CPU: 0 PID: 412 Comm: trinity-main Not tainted
> 4.14.0-rc8-00303-gc21f870 #2
> [ 14.438407] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
> 1.10.2-1 04/01/2014
> [ 14.439350] task: ffff88001c554fc0 task.stack: ffff88001ef30000
> [ 14.440006] RIP: 0010:perf_swevent_add+0x90/0xe0
> [ 14.440546] RSP: 0018:ffff88001ef33c28 EFLAGS: 00010096
> [ 14.441095] RAX: 00000000ffffffff RBX: ffff88001e00d3d8 RCX:
> 0000000000000002
> [ 14.441876] RDX: ffff88001c554fc0 RSI: 0000000000000001 RDI:
> ffff88001e00d3d8
> [ 14.442652] RBP: 0000000000000009 R08: 00000004e4fe313d R09:
> 0000000098260c66
> [ 14.443429] R10: ffff88001ef33c58 R11: 0000000000000002 R12:
> 0000000000000000
> [ 14.444187] R13: 0000000000000000 R14: 0000000000000001 R15:
> ffff88001ed7b508
> [ 14.444931] FS: 00007ff942e15700(0000) GS:ffffffff81c29000(0000)
> knlGS:0000000000000000
> [ 14.445780] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [ 14.446404] CR2: 0000000001697a28 CR3: 000000001dfbb000 CR4:
> 00000000000006b0
> [ 14.447158] Call Trace:
> [ 14.447468] event_sched_in+0xee/0x240
> [ 14.447884] group_sched_in+0x5f/0x1a0
> [ 14.448298] ctx_sched_in+0x363/0x3ca
> [ 14.448758] perf_event_sched_in+0x66/0x6d
> [ 14.449314] ctx_resched+0x9d/0xaf
> [ 14.449716] __perf_install_in_context+0x104/0x137
> [ 14.450225] remote_function+0x1e/0x43
> [ 14.450710] ? rb_free_rcu+0x13/0x13
> [ 14.451109] smp_call_function_single+0x39/0x4a
> [ 14.451644] ? __perf_event_enable+0x182/0x182
> [ 14.452111] task_function_call+0x57/0x95
> [ 14.452605] ? __perf_event_enable+0x182/0x182
> [ 14.453094] perf_install_in_context+0xbe/0x128
> [ 14.453580] SyS_perf_event_open+0xea0/0x11bf
> [ 14.454050] entry_SYSCALL_64_fastpath+0x1e/0xad
> [ 14.454606] RIP: 0033:0x7ff94292a6d9
> [ 14.455002] RSP: 002b:00007ffdb9512bb8 EFLAGS: 00000246 ORIG_RAX:
> 000000000000012a
> [ 14.455852] RAX: ffffffffffffffda RBX: 0000000001695a20 RCX:
> 00007ff94292a6d9
> [ 14.456618] RDX: ffffffffffffffff RSI: 0000000000000000 RDI:
> 000000000141c000
> [ 14.457378] RBP: 0000000000002011 R08: 0000000000000003 R09:
> 0000000000000004
> [ 14.458121] R10: ffffffffffffffff R11: 0000000000000246 R12:
> 00000000000225f1
> [ 14.458919] R13: 0000000000002000 R14: 0000000001695a10 R15:
> 00000000000005f0
> [ 14.459751] Code: 89 ed 49 bc eb 83 b5 80 46 86 c8 61 4c 09 f5 49 0f af ec
> e8 41 a0 fe ff 48 c1 ed 38 4d 8d 64 ed 00 4d 85 e4 75 0e e8 2e a0 fe ff <0f>
> ff bb ea ff ff ff eb 37 e8 20 a0 fe ff 49 8b 6c ed 00 4c 8d
> [ 14.461842] ---[ end trace 43d85185818af4ed ]---
>
that's the WARN_ON_ONCE() in
static int perf_swevent_add(struct perf_event *event, int flags)
{
struct swevent_htable *swhash = this_cpu_ptr(&swevent_htable);
struct hw_perf_event *hwc = &event->hw;
struct hlist_head *head;
if (is_sampling_event(event)) {
hwc->last_period = hwc->sample_period;
perf_swevent_set_period(event);
}
hwc->state = !(flags & PERF_EF_START);
head = find_swevent_head(swhash, event);
if (WARN_ON_ONCE(!head))
return -EINVAL;
hlist_add_head_rcu(&event->hlist_entry, head);
perf_event_update_userpage(event);
return 0;
}
