2023-01-06 00:24:31

by Kees Cook

Subject: [PATCH] mlxsw: spectrum_router: Replace 0-length array with flexible array

Zero-length arrays are deprecated[1]. Replace struct
mlxsw_sp_nexthop_group_info's "nexthops" 0-length array with a flexible
array. Detected with GCC 13, using -fstrict-flex-arrays=3:

drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c: In function 'mlxsw_sp_nexthop_group_hash_obj':
drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:3278:38: warning: array subscript i is outside array bounds of 'struct mlxsw_sp_nexthop[0]' [-Warray-bounds=]
3278 | val ^= jhash(&nh->ifindex, sizeof(nh->ifindex), seed);
| ^~~~~~~~~~~~
drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:2954:33: note: while referencing 'nexthops'
2954 | struct mlxsw_sp_nexthop nexthops[0];
| ^~~~~~~~

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays

Cc: Ido Schimmel <[email protected]>
Cc: Petr Machata <[email protected]>
Cc: "David S. Miller" <[email protected]>
Cc: Eric Dumazet <[email protected]>
Cc: Jakub Kicinski <[email protected]>
Cc: Paolo Abeni <[email protected]>
Cc: "Gustavo A. R. Silva" <[email protected]>
Cc: [email protected]
Signed-off-by: Kees Cook <[email protected]>
---
drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
index c22c3ac4e2a1..09e32778b012 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
@@ -2951,7 +2951,7 @@ struct mlxsw_sp_nexthop_group_info {
gateway:1, /* routes using the group use a gateway */
is_resilient:1;
struct list_head list; /* member in nh_res_grp_list */
- struct mlxsw_sp_nexthop nexthops[0];
+ struct mlxsw_sp_nexthop nexthops[];
#define nh_rif nexthops[0].rif
};

--
2.34.1

2023-01-06 10:25:38

by Ido Schimmel

Subject: Re: [PATCH] mlxsw: spectrum_router: Replace 0-length array with flexible array

On Thu, Jan 05, 2023 at 03:22:29PM -0800, Kees Cook wrote:
> Zero-length arrays are deprecated[1]. Replace struct
> mlxsw_sp_nexthop_group_info's "nexthops" 0-length array with a flexible
> array. Detected with GCC 13, using -fstrict-flex-arrays=3:
>
> drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c: In function 'mlxsw_sp_nexthop_group_hash_obj':
> drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:3278:38: warning: array subscript i is outside array bounds of 'struct mlxsw_sp_nexthop[0]' [-Warray-bounds=]
> 3278 | val ^= jhash(&nh->ifindex, sizeof(nh->ifindex), seed);
> | ^~~~~~~~~~~~
> drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:2954:33: note: while referencing 'nexthops'
> 2954 | struct mlxsw_sp_nexthop nexthops[0];
> | ^~~~~~~~
>
> [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays
>
> Cc: Ido Schimmel <[email protected]>
> Cc: Petr Machata <[email protected]>
> Cc: "David S. Miller" <[email protected]>
> Cc: Eric Dumazet <[email protected]>
> Cc: Jakub Kicinski <[email protected]>
> Cc: Paolo Abeni <[email protected]>
> Cc: "Gustavo A. R. Silva" <[email protected]>
> Cc: [email protected]
> Signed-off-by: Kees Cook <[email protected]>

Reviewed-by: Ido Schimmel <[email protected]>

Thanks

2023-01-06 11:26:33

by Petr Machata

Subject: Re: [PATCH] mlxsw: spectrum_router: Replace 0-length array with flexible array

Kees Cook <[email protected]> writes:

> Zero-length arrays are deprecated[1]. Replace struct
> mlxsw_sp_nexthop_group_info's "nexthops" 0-length array with a flexible
> array. Detected with GCC 13, using -fstrict-flex-arrays=3:
>
> drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c: In function 'mlxsw_sp_nexthop_group_hash_obj':
> drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:3278:38: warning: array subscript i is outside array bounds of 'struct mlxsw_sp_nexthop[0]' [-Warray-bounds=]
> 3278 | val ^= jhash(&nh->ifindex, sizeof(nh->ifindex), seed);
> | ^~~~~~~~~~~~
> drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:2954:33: note: while referencing 'nexthops'
> 2954 | struct mlxsw_sp_nexthop nexthops[0];
> | ^~~~~~~~
>
> [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays
>
> Cc: Ido Schimmel <[email protected]>
> Cc: Petr Machata <[email protected]>
> Cc: "David S. Miller" <[email protected]>
> Cc: Eric Dumazet <[email protected]>
> Cc: Jakub Kicinski <[email protected]>
> Cc: Paolo Abeni <[email protected]>
> Cc: "Gustavo A. R. Silva" <[email protected]>
> Cc: [email protected]
> Signed-off-by: Kees Cook <[email protected]>
> ---
> drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
> index c22c3ac4e2a1..09e32778b012 100644
> --- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
> +++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
> @@ -2951,7 +2951,7 @@ struct mlxsw_sp_nexthop_group_info {
> gateway:1, /* routes using the group use a gateway */
> is_resilient:1;
> struct list_head list; /* member in nh_res_grp_list */
> - struct mlxsw_sp_nexthop nexthops[0];
> + struct mlxsw_sp_nexthop nexthops[];
> #define nh_rif nexthops[0].rif
> };

Thanks. I'll pass this through our nightly and report back.

2023-01-06 16:57:08

by Gustavo A. R. Silva

Subject: Re: [PATCH] mlxsw: spectrum_router: Replace 0-length array with flexible array

On Thu, Jan 05, 2023 at 03:22:29PM -0800, Kees Cook wrote:
> Zero-length arrays are deprecated[1]. Replace struct
> mlxsw_sp_nexthop_group_info's "nexthops" 0-length array with a flexible
> array. Detected with GCC 13, using -fstrict-flex-arrays=3:
>
> drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c: In function 'mlxsw_sp_nexthop_group_hash_obj':
> drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:3278:38: warning: array subscript i is outside array bounds of 'struct mlxsw_sp_nexthop[0]' [-Warray-bounds=]
> 3278 | val ^= jhash(&nh->ifindex, sizeof(nh->ifindex), seed);
> | ^~~~~~~~~~~~
> drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:2954:33: note: while referencing 'nexthops'
> 2954 | struct mlxsw_sp_nexthop nexthops[0];
> | ^~~~~~~~
>
> [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays
>
> Cc: Ido Schimmel <[email protected]>
> Cc: Petr Machata <[email protected]>
> Cc: "David S. Miller" <[email protected]>
> Cc: Eric Dumazet <[email protected]>
> Cc: Jakub Kicinski <[email protected]>
> Cc: Paolo Abeni <[email protected]>
> Cc: "Gustavo A. R. Silva" <[email protected]>
> Cc: [email protected]
> Signed-off-by: Kees Cook <[email protected]>

Reviewed-by: Gustavo A. R. Silva <[email protected]>

Thanks!
--
Gustavo

> ---
> drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
> index c22c3ac4e2a1..09e32778b012 100644
> --- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
> +++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
> @@ -2951,7 +2951,7 @@ struct mlxsw_sp_nexthop_group_info {
> gateway:1, /* routes using the group use a gateway */
> is_resilient:1;
> struct list_head list; /* member in nh_res_grp_list */
> - struct mlxsw_sp_nexthop nexthops[0];
> + struct mlxsw_sp_nexthop nexthops[];
> #define nh_rif nexthops[0].rif
> };
>
> --
> 2.34.1
>

2023-01-07 23:05:21

by Petr Machata

Subject: Re: [PATCH] mlxsw: spectrum_router: Replace 0-length array with flexible array

Petr Machata <[email protected]> writes:

> Kees Cook <[email protected]> writes:
>
>> Zero-length arrays are deprecated[1]. Replace struct
>> mlxsw_sp_nexthop_group_info's "nexthops" 0-length array with a flexible
>> array.

[...]

> Thanks. I'll pass this through our nightly and report back.

Looking good.

Tested-by: Petr Machata <[email protected]>

2023-01-09 08:14:10

by patchwork-bot+netdevbpf

Subject: Re: [PATCH] mlxsw: spectrum_router: Replace 0-length array with flexible array

Hello:

This patch was applied to netdev/net.git (master)
by David S. Miller <[email protected]>:

On Thu, 5 Jan 2023 15:22:29 -0800 you wrote:
> Zero-length arrays are deprecated[1]. Replace struct
> mlxsw_sp_nexthop_group_info's "nexthops" 0-length array with a flexible
> array. Detected with GCC 13, using -fstrict-flex-arrays=3:
>
> drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c: In function 'mlxsw_sp_nexthop_group_hash_obj':
> drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:3278:38: warning: array subscript i is outside array bounds of 'struct mlxsw_sp_nexthop[0]' [-Warray-bounds=]
> 3278 | val ^= jhash(&nh->ifindex, sizeof(nh->ifindex), seed);
> | ^~~~~~~~~~~~
> drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:2954:33: note: while referencing 'nexthops'
> 2954 | struct mlxsw_sp_nexthop nexthops[0];
> | ^~~~~~~~
>
> [...]

Here is the summary with links:
- mlxsw: spectrum_router: Replace 0-length array with flexible array
https://git.kernel.org/netdev/net/c/2ab6478d1266

You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html