Re: [PATCH net 8/9] mlxsw: spectrum_acl_tcam: Fix incorrect list API usage

[Simon Horman <horms@kernel.org>]

On Mon, Apr 22, 2024 at 05:26:01PM +0200, Petr Machata wrote:
> From: Ido Schimmel <idosch@nvidia.com>
> 
> Both the function that migrates all the chunks within a region and the
> function that migrates all the entries within a chunk call
> list_first_entry() on the respective lists without checking that the
> lists are not empty. This is incorrect usage of the API, which leads to
> the following warning [1].
> 
> Fix by returning if the lists are empty as there is nothing to migrate
> in this case.
> 
> [1]
> WARNING: CPU: 0 PID: 6437 at drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.c:1266 mlxsw_sp_acl_tcam_vchunk_migrate_all+0x1f1/0>
> Modules linked in:
> CPU: 0 PID: 6437 Comm: kworker/0:37 Not tainted 6.9.0-rc3-custom-00883-g94a65f079ef6 #39
> Hardware name: Mellanox Technologies Ltd. MSN3700/VMOD0005, BIOS 5.11 01/06/2019
> Workqueue: mlxsw_core mlxsw_sp_acl_tcam_vregion_rehash_work
> RIP: 0010:mlxsw_sp_acl_tcam_vchunk_migrate_all+0x1f1/0x2c0
> [...]
> Call Trace:
>  <TASK>
>  mlxsw_sp_acl_tcam_vregion_rehash_work+0x6c/0x4a0
>  process_one_work+0x151/0x370
>  worker_thread+0x2cb/0x3e0
>  kthread+0xd0/0x100
>  ret_from_fork+0x34/0x50
>  ret_from_fork_asm+0x1a/0x30
>  </TASK>
> 
> Fixes: 6f9579d4e302 ("mlxsw: spectrum_acl: Remember where to continue rehash migration")
> Signed-off-by: Ido Schimmel <idosch@nvidia.com>
> Tested-by: Alexander Zubkov <green@qrator.net>
> Reviewed-by: Petr Machata <petrm@nvidia.com>
> Signed-off-by: Petr Machata <petrm@nvidia.com>

Reviewed-by: Simon Horman <horms@kernel.org>