[PATCH net] mlxsw: spectrum_acl_erp: Fix const qualifier of delta_clear()

[PATCH net] mlxsw: spectrum_acl_erp: Fix const qualifier of delta_clear()

[Evgenii Burenchev]

mlxsw_sp_acl_erp_delta_clear() takes 'const char *enc_key' but modifies
the memory it points to. This is a logical error in the function
declaration.

The only caller passes a non-const buffer (aentry->ht_key.enc_key), so
the const qualifier is misleading and unnecessary.

Remove const from the enc_key parameter to match the actual usage.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: c22291f7cf45 ("mlxsw: spectrum: acl: Implement delta for ERP")
Signed-off-by: Evgenii Burenchev <evg28bur@yandex.ru>
---
 drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_erp.c  | 2 +-
 drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.h | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_erp.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_erp.c
index cbb272a96359..0d0cd093b3c6 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_erp.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_erp.c
@@ -1118,7 +1118,7 @@ u8 mlxsw_sp_acl_erp_delta_value(const struct mlxsw_sp_acl_erp_delta *delta,
 }
 
 void mlxsw_sp_acl_erp_delta_clear(const struct mlxsw_sp_acl_erp_delta *delta,
-				  const char *enc_key)
+				  char *enc_key)
 {
 	u16 start = delta->start;
 	u8 mask = delta->mask;
diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.h b/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.h
index 010204f73ea4..67cc7a5737dd 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.h
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_tcam.h
@@ -245,7 +245,7 @@ u8 mlxsw_sp_acl_erp_delta_mask(const struct mlxsw_sp_acl_erp_delta *delta);
 u8 mlxsw_sp_acl_erp_delta_value(const struct mlxsw_sp_acl_erp_delta *delta,
 				const char *enc_key);
 void mlxsw_sp_acl_erp_delta_clear(const struct mlxsw_sp_acl_erp_delta *delta,
-				  const char *enc_key);
+				  char *enc_key);
 
 struct mlxsw_sp_acl_erp_mask;
 
-- 
2.43.0

Re: [PATCH net] mlxsw: spectrum_acl_erp: Fix const qualifier of delta_clear()

[Petr Machata]

Evgenii Burenchev <evg28bur@yandex.ru> writes:

> mlxsw_sp_acl_erp_delta_clear() takes 'const char *enc_key' but modifies
> the memory it points to. This is a logical error in the function
> declaration.
>
> The only caller passes a non-const buffer (aentry->ht_key.enc_key), so
> the const qualifier is misleading and unnecessary.
>
> Remove const from the enc_key parameter to match the actual usage.
>
> Found by Linux Verification Center (linuxtesting.org) with SVACE.
>
> Fixes: c22291f7cf45 ("mlxsw: spectrum: acl: Implement delta for ERP")
> Signed-off-by: Evgenii Burenchev <evg28bur@yandex.ru>

Dunno how much of a net material this is, there's no bug to be fixed,
it's a source code cleanliness improvement. But the patch is correct.

Reviewed-by: Petr Machata <petrm@nvidia.com>