diff mbox series

[net-next,V2,02/14] net/mlx5e: SHAMPO, Fix incorrect page release

Message ID 20240603212219.1037656-3-tariqt@nvidia.com (mailing list archive)
State Accepted
Commit 70bd03b89f20b9bbe51a7f73c4950565a17a45f7
Delegated to: Netdev Maintainers
Headers show
Series net/mlx5e: SHAMPO, Enable HW GRO once more | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 901 this patch: 901
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers warning 1 maintainers not CCed: linux-rdma@vger.kernel.org
netdev/build_clang success Errors and warnings before: 905 this patch: 905
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: 905 this patch: 905
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 9 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-2024-06-04--18-00 (tests: 1045)

Commit Message

Tariq Toukan June 3, 2024, 9:22 p.m. UTC 
From: Dragos Tatulea <dtatulea@nvidia.com>

Under the following conditions:
1) No skb created yet
2) header_size == 0 (no SHAMPO header)
3) header_index + 1 % MLX5E_SHAMPO_WQ_HEADER_PER_PAGE == 0 (this is the
   last page fragment of a SHAMPO header page)

a new skb is formed with a page that is NOT a SHAMPO header page (it
is a regular data page). Further down in the same function
(mlx5e_handle_rx_cqe_mpwrq_shampo()), a SHAMPO header page from
header_index is released. This is wrong and it leads to SHAMPO header
pages being released more than once.

Fixes: 6f5742846053 ("net/mlx5e: RX, Enable skb page recycling through the page_pool")
Signed-off-by: Dragos Tatulea <dtatulea@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
---
 drivers/net/ethernet/mellanox/mlx5/core/en_rx.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Comments

Jakub Kicinski June 6, 2024, 3:20 a.m. UTC | #1 
On Tue, 4 Jun 2024 00:22:07 +0300 Tariq Toukan wrote:
> Fixes: 6f5742846053 ("net/mlx5e: RX, Enable skb page recycling through the page_pool")

Why is this still here?! If the bad code path cannot be hit without
applying patches later in the series, it's not a fix. Let me remove
this for you when applying so y'all don't descend on me for "hating
vendors" :|
Tariq Toukan June 6, 2024, 5:32 a.m. UTC | #2 
On 06/06/2024 6:20, Jakub Kicinski wrote:
> On Tue, 4 Jun 2024 00:22:07 +0300 Tariq Toukan wrote:
>> Fixes: 6f5742846053 ("net/mlx5e: RX, Enable skb page recycling through the page_pool")
> 
> Why is this still here?!

It shouldn't, I planned to remove it, but missed it eventually.

> If the bad code path cannot be hit without
> applying patches later in the series, it's not a fix. Let me remove
> this for you when applying 

Yes please. Thanks.

> so y'all don't descend on me for "hating
> vendors" :|
diff mbox series

Patch

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
index 369d101bf03c..1ddfa00f923f 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
@@ -2369,7 +2369,8 @@  static void mlx5e_handle_rx_cqe_mpwrq_shampo(struct mlx5e_rq *rq, struct mlx5_cq
 	if (flush)
 		mlx5e_shampo_flush_skb(rq, cqe, match);
 free_hd_entry:
-	mlx5e_free_rx_shampo_hd_entry(rq, header_index);
+	if (likely(head_size))
+		mlx5e_free_rx_shampo_hd_entry(rq, header_index);
 mpwrq_cqe_out:
 	if (likely(wi->consumed_strides < rq->mpwqe.num_strides))
 		return;