[PATCH 6.8 086/172] net/mlx5: Correctly compare pkt reformat ids

Greg Kroah-Hartman
2024-04-15T14:27:47Z

From: Cosmin Ratiu <cratiu@nvidia.com>

[ Upstream commit 9eca93f4d5ab03905516a68683674d9c50ff95bd ]

struct mlx5_pkt_reformat contains a naked union of a u32 id and a
dr_action pointer which is used when the action is SW-managed (when
pkt_reformat.owner is set to MLX5_FLOW_RESOURCE_OWNER_SW). Using id
directly in that case is incorrect, as it maps to the least significant
32 bits of the 64-bit pointer in mlx5_fs_dr_action and not to the pkt
reformat id allocated in firmware.

For the purpose of comparing whether two rules are identical,
interpreting the least significant 32 bits of the mlx5_fs_dr_action
pointer as an id mostly works... until it breaks horribly and produces
the outcome described in [1].

This patch fixes mlx5_flow_dests_cmp to correctly compare ids using
mlx5_fs_dr_action_get_pkt_reformat_id for the SW-managed rules.

Link: https://lore.kernel.org/netdev/ea5264d6-6b55-4449-a602-214c6f509c1e@163.com/T/#u [1]

Fixes: 6a48faeeca10 ("net/mlx5: Add direct rule fs_cmd implementation")
Signed-off-by: Cosmin Ratiu <cratiu@nvidia.com>
Reviewed-by: Mark Bloch <mbloch@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Link: https://lore.kernel.org/r/20240409190820.227554-6-tariqt@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/mellanox/mlx5/core/fs_core.c | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/fs_core.c b/drivers/net/ethernet/mellanox/mlx5/core/fs_core.c
index 2a9421342a503..cf085a478e3e4 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/fs_core.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/fs_core.c
@@ -1664,6 +1664,16 @@ static int create_auto_flow_group(struct mlx5_flow_table *ft,
return err;
}

+static bool mlx5_pkt_reformat_cmp(struct mlx5_pkt_reformat *p1,
+ struct mlx5_pkt_reformat *p2)
+{
+ return p1->owner == p2->owner &&
+ (p1->owner == MLX5_FLOW_RESOURCE_OWNER_FW ?
+ p1->id == p2->id :
+ mlx5_fs_dr_action_get_pkt_reformat_id(p1) ==
+ mlx5_fs_dr_action_get_pkt_reformat_id(p2));
+}
+
static bool mlx5_flow_dests_cmp(struct mlx5_flow_destination *d1,
struct mlx5_flow_destination *d2)
{
@@ -1675,8 +1685,8 @@ static bool mlx5_flow_dests_cmp(struct mlx5_flow_destination *d1,
((d1->vport.flags & MLX5_FLOW_DEST_VPORT_VHCA_ID) ?
(d1->vport.vhca_id == d2->vport.vhca_id) : true) &&
((d1->vport.flags & MLX5_FLOW_DEST_VPORT_REFORMAT_ID) ?
- (d1->vport.pkt_reformat->id ==
- d2->vport.pkt_reformat->id) : true)) ||
+ mlx5_pkt_reformat_cmp(d1->vport.pkt_reformat,
+ d2->vport.pkt_reformat) : true)) ||
(d1->type == MLX5_FLOW_DESTINATION_TYPE_FLOW_TABLE &&
d1->ft == d2->ft) ||
(d1->type == MLX5_FLOW_DESTINATION_TYPE_TIR &&
--
2.43.0