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From:   Justin Stitt <justinstitt@google.com>
Date:   Tue, 3 Oct 2023 16:17:20 -0700
Message-ID: <CAFhGd8o+0KhH2hfOLD=ru+53TPZEfsPUtjRbYOvG_D5zaz-bXg@mail.gmail.com>
Subject: Re: [PATCH 3/5] mlxsw: spectrum: Annotate struct mlxsw_sp_counter_pool
 with __counted_by
To:     Kees Cook <keescook@chromium.org>
Cc:     Ido Schimmel <idosch@nvidia.com>, Petr Machata <petrm@nvidia.com>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>, netdev@vger.kernel.org,
        "Gustavo A. R. Silva" <gustavoars@kernel.org>,
        Nathan Chancellor <nathan@kernel.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Tom Rix <trix@redhat.com>, linux-kernel@vger.kernel.org,
        linux-hardening@vger.kernel.org, llvm@lists.linux.dev
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On Fri, Sep 29, 2023 at 11:08=E2=80=AFAM Kees Cook <keescook@chromium.org> =
wrote:
>
> Prepare for the coming implementation by GCC and Clang of the __counted_b=
y
> attribute. Flexible array members annotated with __counted_by can have
> their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUND=
S
> (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
> functions).
>
> As found with Coccinelle[1], add __counted_by for struct mlxsw_sp_counter=
_pool.
>
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/c=
ounted_by.cocci
>
> Cc: Ido Schimmel <idosch@nvidia.com>
> Cc: Petr Machata <petrm@nvidia.com>
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: Eric Dumazet <edumazet@google.com>
> Cc: Jakub Kicinski <kuba@kernel.org>
> Cc: Paolo Abeni <pabeni@redhat.com>
> Cc: netdev@vger.kernel.org
> Signed-off-by: Kees Cook <keescook@chromium.org>

Reviewed-by: Justin Stitt <justinstitt@google.com>

> ---
>  drivers/net/ethernet/mellanox/mlxsw/spectrum_cnt.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_cnt.c b/drivers=
/net/ethernet/mellanox/mlxsw/spectrum_cnt.c
> index ee59c79156e4..50e591420bd9 100644
> --- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_cnt.c
> +++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_cnt.c
> @@ -24,7 +24,7 @@ struct mlxsw_sp_counter_pool {
>         spinlock_t counter_pool_lock; /* Protects counter pool allocation=
s */
>         atomic_t active_entries_count;
>         unsigned int sub_pools_count;
> -       struct mlxsw_sp_counter_sub_pool sub_pools[];
> +       struct mlxsw_sp_counter_sub_pool sub_pools[] __counted_by(sub_poo=
ls_count);
>  };
>
>  static const struct mlxsw_sp_counter_sub_pool mlxsw_sp_counter_sub_pools=
[] =3D {
> --
> 2.34.1
>
>
Thanks
Justin