diff mbox series

[net,6/8] net/mlx5e: Do not use ptp structure for tx ts stats when not initialized

Message ID 20240522192659.840796-7-tariqt@nvidia.com (mailing list archive)
State Accepted
Commit f55cd31287e5f77f226c91d2f7756bafa0d583ed
Delegated to: Netdev Maintainers
Headers show
Series mlx5 fixes 24-05-22 | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag present in non-next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 905 this patch: 905
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers fail 1 blamed authors not CCed: dtatulea@nvidia.com; 3 maintainers not CCed: dtatulea@nvidia.com richardcochran@gmail.com linux-rdma@vger.kernel.org
netdev/build_clang success Errors and warnings before: 909 this patch: 909
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 909 this patch: 909
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 16 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2024-05-23--12-00 (tests: 1038)

Commit Message

Tariq Toukan May 22, 2024, 7:26 p.m. UTC 
From: Rahul Rameshbabu <rrameshbabu@nvidia.com>

The ptp channel instance is only initialized when ptp traffic is first
processed by the driver. This means that there is a window in between when
port timestamping is enabled and ptp traffic is sent where the ptp channel
instance is not initialized. Accessing statistics during this window will
lead to an access violation (NULL + member offset). Check the validity of
the instance before attempting to query statistics.

  BUG: unable to handle page fault for address: 0000000000003524
  #PF: supervisor read access in kernel mode
  #PF: error_code(0x0000) - not-present page
  PGD 109dfc067 P4D 109dfc067 PUD 1064ef067 PMD 0
  Oops: 0000 [#1] SMP
  CPU: 0 PID: 420 Comm: ethtool Not tainted 6.9.0-rc2-rrameshbabu+ #245
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS Arch Linux 1.16.3-1-1 04/01/204
  RIP: 0010:mlx5e_stats_ts_get+0x4c/0x130
  <snip>
  Call Trace:
   <TASK>
   ? show_regs+0x60/0x70
   ? __die+0x24/0x70
   ? page_fault_oops+0x15f/0x430
   ? do_user_addr_fault+0x2c9/0x5c0
   ? exc_page_fault+0x63/0x110
   ? asm_exc_page_fault+0x27/0x30
   ? mlx5e_stats_ts_get+0x4c/0x130
   ? mlx5e_stats_ts_get+0x20/0x130
   mlx5e_get_ts_stats+0x15/0x20
  <snip>

Fixes: 3579032c08c1 ("net/mlx5e: Implement ethtool hardware timestamping statistics")
Signed-off-by: Rahul Rameshbabu <rrameshbabu@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
---
 drivers/net/ethernet/mellanox/mlx5/core/en_stats.c | 4 ++++
 1 file changed, 4 insertions(+)

Comments

Simon Horman May 23, 2024, 9:48 a.m. UTC | #1 
On Wed, May 22, 2024 at 10:26:57PM +0300, Tariq Toukan wrote:
> From: Rahul Rameshbabu <rrameshbabu@nvidia.com>
> 
> The ptp channel instance is only initialized when ptp traffic is first
> processed by the driver. This means that there is a window in between when
> port timestamping is enabled and ptp traffic is sent where the ptp channel
> instance is not initialized. Accessing statistics during this window will
> lead to an access violation (NULL + member offset). Check the validity of
> the instance before attempting to query statistics.
> 
>   BUG: unable to handle page fault for address: 0000000000003524
>   #PF: supervisor read access in kernel mode
>   #PF: error_code(0x0000) - not-present page
>   PGD 109dfc067 P4D 109dfc067 PUD 1064ef067 PMD 0
>   Oops: 0000 [#1] SMP
>   CPU: 0 PID: 420 Comm: ethtool Not tainted 6.9.0-rc2-rrameshbabu+ #245
>   Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS Arch Linux 1.16.3-1-1 04/01/204
>   RIP: 0010:mlx5e_stats_ts_get+0x4c/0x130
>   <snip>
>   Call Trace:
>    <TASK>
>    ? show_regs+0x60/0x70
>    ? __die+0x24/0x70
>    ? page_fault_oops+0x15f/0x430
>    ? do_user_addr_fault+0x2c9/0x5c0
>    ? exc_page_fault+0x63/0x110
>    ? asm_exc_page_fault+0x27/0x30
>    ? mlx5e_stats_ts_get+0x4c/0x130
>    ? mlx5e_stats_ts_get+0x20/0x130
>    mlx5e_get_ts_stats+0x15/0x20
>   <snip>
> 
> Fixes: 3579032c08c1 ("net/mlx5e: Implement ethtool hardware timestamping statistics")
> Signed-off-by: Rahul Rameshbabu <rrameshbabu@nvidia.com>
> Signed-off-by: Tariq Toukan <tariqt@nvidia.com>

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

Patch

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_stats.c b/drivers/net/ethernet/mellanox/mlx5/core/en_stats.c
index e211c41cec06..e1ed214e8651 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_stats.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_stats.c
@@ -1186,6 +1186,9 @@  void mlx5e_stats_ts_get(struct mlx5e_priv *priv,
 		ts_stats->err = 0;
 		ts_stats->lost = 0;
 
+		if (!ptp)
+			goto out;
+
 		/* Aggregate stats across all TCs */
 		for (i = 0; i < ptp->num_tc; i++) {
 			struct mlx5e_ptp_cq_stats *stats =
@@ -1214,6 +1217,7 @@  void mlx5e_stats_ts_get(struct mlx5e_priv *priv,
 		}
 	}
 
+out:
 	mutex_unlock(&priv->state_lock);
 }