Re: [PATCH 2/2] HID: uclogic: Fix a work->entry not empty bug in __queue_work()

["José Expósito" <jose.exposito89@gmail.com>]

On Thu, Sep 21, 2023 at 09:38:24PM +0800, Jinjie Ruan wrote:
> When CONFIG_HID_UCLOGIC=y and CONFIG_KUNIT_ALL_TESTS=y, launch
> kernel and then the below work->entry not empty bug occurs.
> 
> In hid_test_uclogic_exec_event_hook_test(), the filter->work is not
> initialized to be added to p.event_hooks->list, and then the
> schedule_work() in uclogic_exec_event_hook() will call __queue_work(),
> which check whether the work->entry is empty and cause the below
> warning call trace.
> 
> So call INIT_WORK() with a fake work to solve the issue. After applying
> this patch, the below work->entry not empty bug never occurs.
> 
>  WARNING: CPU: 0 PID: 2177 at kernel/workqueue.c:1787 __queue_work.part.0+0x780/0xad0
>  Modules linked in:
>  CPU: 0 PID: 2177 Comm: kunit_try_catch Tainted: G    B   W        N 6.6.0-rc2+ #30
>  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
>  RIP: 0010:__queue_work.part.0+0x780/0xad0
>  Code: 44 24 20 0f b6 00 84 c0 74 08 3c 03 0f 8e 52 03 00 00 f6 83 00 01 00 00 02 74 6f 4c 89 ef e8 c7 d8 f1 02 f3 90 e9 e5 f8 ff ff <0f> 0b e9 63 fc ff ff 89 e9 49 8d 57 68 4c 89 e6 4c 89 ff 83 c9 02
>  RSP: 0000:ffff888102bb7ce8 EFLAGS: 00010086
>  RAX: 0000000000000000 RBX: ffff888106b8e460 RCX: ffffffff84141cc7
>  RDX: 1ffff11020d71c8c RSI: 0000000000000004 RDI: ffff8881001d0118
>  RBP: dffffc0000000000 R08: 0000000000000001 R09: ffffed1020576f92
>  R10: 0000000000000003 R11: ffff888102bb7980 R12: ffff888106b8e458
>  R13: ffff888119c38800 R14: 0000000000000000 R15: ffff8881001d0100
>  FS:  0000000000000000(0000) GS:ffff888119c00000(0000) knlGS:0000000000000000
>  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>  CR2: ffff888119506000 CR3: 0000000005286001 CR4: 0000000000770ef0
>  DR0: ffffffff8fdd6ce0 DR1: ffffffff8fdd6ce1 DR2: ffffffff8fdd6ce3
>  DR3: ffffffff8fdd6ce5 DR6: 00000000fffe0ff0 DR7: 0000000000000600
>  PKRU: 55555554
>  Call Trace:
>   <TASK>
>   ? __warn+0xc9/0x260
>   ? __queue_work.part.0+0x780/0xad0
>   ? report_bug+0x345/0x400
>   ? handle_bug+0x3c/0x70
>   ? exc_invalid_op+0x14/0x40
>   ? asm_exc_invalid_op+0x16/0x20
>   ? _raw_spin_lock+0x87/0xe0
>   ? __queue_work.part.0+0x780/0xad0
>   ? __queue_work.part.0+0x249/0xad0
>   queue_work_on+0x48/0x50
>   uclogic_exec_event_hook.isra.0+0xf7/0x160
>   hid_test_uclogic_exec_event_hook_test+0x2f1/0x5d0
>   ? try_to_wake_up+0x151/0x13e0
>   ? uclogic_exec_event_hook.isra.0+0x160/0x160
>   ? _raw_spin_lock_irqsave+0x8d/0xe0
>   ? __sched_text_end+0xa/0xa
>   ? __sched_text_end+0xa/0xa
>   ? migrate_enable+0x260/0x260
>   ? kunit_try_run_case_cleanup+0xe0/0xe0
>   kunit_generic_run_threadfn_adapter+0x4a/0x90
>   ? kunit_try_catch_throw+0x80/0x80
>   kthread+0x2b5/0x380
>   ? kthread_complete_and_exit+0x20/0x20
>   ret_from_fork+0x2d/0x70
>   ? kthread_complete_and_exit+0x20/0x20
>   ret_from_fork_asm+0x11/0x20
>   </TASK>
> 
> Fixes: a251d6576d2a ("HID: uclogic: Handle wireless device reconnection")
> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>

Reviewed-by: José Expósito <jose.exposito89@gmail.com>

> ---
>  drivers/hid/hid-uclogic-core-test.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/drivers/hid/hid-uclogic-core-test.c b/drivers/hid/hid-uclogic-core-test.c
> index 2bb916226a38..cb274cde3ad2 100644
> --- a/drivers/hid/hid-uclogic-core-test.c
> +++ b/drivers/hid/hid-uclogic-core-test.c
> @@ -56,6 +56,11 @@ static struct uclogic_raw_event_hook_test test_events[] = {
>  	},
>  };
>  
> +static void fake_work(struct work_struct *work)
> +{
> +
> +}
> +
>  static void hid_test_uclogic_exec_event_hook_test(struct kunit *test)
>  {
>  	struct uclogic_params p = {0, };
> @@ -77,6 +82,8 @@ static void hid_test_uclogic_exec_event_hook_test(struct kunit *test)
>  		KUNIT_ASSERT_NOT_ERR_OR_NULL(test, filter->event);
>  		memcpy(filter->event, &hook_events[n].event[0], filter->size);
>  
> +		INIT_WORK(&filter->work, fake_work);
> +
>  		list_add_tail(&filter->list, &p.event_hooks->list);
>  	}
>  
> -- 
> 2.34.1
>