Re: [PATCH] IB/cm: Remove redundant WARN_ON in cm_free_priv_msg

["Zhijian Li (Fujitsu)" <lizhijian@fujitsu.com>]

On 12/05/2025 18:53, Leon Romanovsky wrote:
> On Fri, May 09, 2025 at 04:18:40PM +0800, Li Zhijian wrote:
>> Sometimes, the blktests triggered this WARN_ON():
>>   ------------[ cut here ]------------
>>   WARNING: CPU: 3 PID: 1330889 at cm.c:353 cm_free_priv_msg+0xaa/0xc0 [ib_cm]
>> ...
>>   CPU: 3 UID: 0 PID: 1330889 Comm: kworker/u16:1 Tainted: G        W  OE      6.13.0-rc3+ #3
>>   Tainted: [W]=WARN, [O]=OOT_MODULE, [E]=UNSIGNED_MODULE
>>   Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
>>   Workqueue: ib_mad1 timeout_sends [ib_core]
>>   RIP: 0010:cm_free_priv_msg+0xaa/0xc0 [ib_cm]
>> ...
>>   Call Trace:
>>    <TASK>
>>    ? cm_free_priv_msg+0xaa/0xc0 [ib_cm]
>>    ? __warn.cold+0x93/0xfa
>>    ? cm_free_priv_msg+0xaa/0xc0 [ib_cm]
>>    ? report_bug+0xff/0x140
>>    ? handle_bug+0x58/0x90
>>    ? exc_invalid_op+0x17/0x70
>>    ? asm_exc_invalid_op+0x1a/0x20
>>    ? cm_free_priv_msg+0xaa/0xc0 [ib_cm]
>>    cm_process_send_error+0x64/0x1f0 [ib_cm]
>>    timeout_sends+0x1e5/0x2d0 [ib_core]
>>    process_one_work+0x156/0x310
>>    worker_thread+0x252/0x390
>>    ? __pfx_worker_thread+0x10/0x10
>>    kthread+0xd2/0x100
>>    ? __pfx_kthread+0x10/0x10
>>    ret_from_fork+0x34/0x50
>>    ? __pfx_kthread+0x10/0x10
>>    ret_from_fork_asm+0x1a/0x30
>>    </TASK>
>>   ---[ end trace 0000000000000000 ]---
>>
>> In cm_process_send_error(), cm_free_priv_msg() will be called
>> when (msg != cm_id_priv->msg) is true. And all other calling to
>> cm_free_priv_msg() cases, msg is always the same as cm_id_priv->msg.
>>
>> So it's safe to remove this WARN_ON
> 
> This patch should fix the issue.
> https://lore.kernel.org/all/0c364c29142f72b7875fdeba51f3c9bd6ca863ee.1745839788.git.leon@kernel.org/
> 7590649ee7af ("IB/cm: Drop lockdep assert and WARN when freeing old msg")


Yeah, thanks for this information.



> 
> Thanks