Re: [PATCH net-next] octeontx2: fix -Wnonnull warning

[Sunil Kovvuri]

On Tue, Mar 23, 2021 at 6:26 PM Arnd Bergmann <arnd@xxxxxxxxxx> wrote:
>
> From: Arnd Bergmann <arnd@xxxxxxxx>
>
> When compile testing this driver on a platform on which probe() is
> known to fail at compile time, gcc warns about the cgx_lmactype_string[]
> array being uninitialized:
>
> In function 'strncpy',
>     inlined from 'link_status_user_format' at /git/arm-soc/drivers/net/ethernet/marvell/octeontx2/af/cgx.c:838:2,
>     inlined from 'cgx_link_change_handler' at /git/arm-soc/drivers/net/ethernet/marvell/octeontx2/af/cgx.c:853:2:
> include/linux/fortify-string.h:27:30: error: argument 2 null where non-null expected [-Werror=nonnull]
>    27 | #define __underlying_strncpy __builtin_strncpy
>
> Address this by turning the runtime initialization into a fixed array,
> which should also produce better code.
>
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> ---
>  .../net/ethernet/marvell/octeontx2/af/cgx.c   | 60 +++++++++----------
>  1 file changed, 28 insertions(+), 32 deletions(-)
>
> diff --git a/drivers/net/ethernet/marvell/octeontx2/af/cgx.c b/drivers/net/ethernet/marvell/octeontx2/af/cgx.c
> index 9caa375d01b1..ea5a033a1d0b 100644
> --- a/drivers/net/ethernet/marvell/octeontx2/af/cgx.c
> +++ b/drivers/net/ethernet/marvell/octeontx2/af/cgx.c
> @@ -30,10 +30,35 @@
>  static LIST_HEAD(cgx_list);
>
>  /* Convert firmware speed encoding to user format(Mbps) */
> -static u32 cgx_speed_mbps[CGX_LINK_SPEED_MAX];
> +static const u32 cgx_speed_mbps[CGX_LINK_SPEED_MAX] = {
> +       [CGX_LINK_NONE] = 0,
> +       [CGX_LINK_10M] = 10,
> +       [CGX_LINK_100M] = 100,
> +       [CGX_LINK_1G] = 1000,
> +       [CGX_LINK_2HG] = 2500,
> +       [CGX_LINK_5G] = 5000,
> +       [CGX_LINK_10G] = 10000,
> +       [CGX_LINK_20G] = 20000,
> +       [CGX_LINK_25G] = 25000,
> +       [CGX_LINK_40G] = 40000,
> +       [CGX_LINK_50G] = 50000,
> +       [CGX_LINK_80G] = 80000,
> +       [CGX_LINK_100G] = 100000,
> +};
>
>  /* Convert firmware lmac type encoding to string */
> -static char *cgx_lmactype_string[LMAC_MODE_MAX];
> +static const char *cgx_lmactype_string[LMAC_MODE_MAX] = {
> +       [LMAC_MODE_SGMII] = "SGMII",
> +       [LMAC_MODE_XAUI] = "XAUI",
> +       [LMAC_MODE_RXAUI] = "RXAUI",
> +       [LMAC_MODE_10G_R] = "10G_R",
> +       [LMAC_MODE_40G_R] = "40G_R",
> +       [LMAC_MODE_QSGMII] = "QSGMII",
> +       [LMAC_MODE_25G_R] = "25G_R",
> +       [LMAC_MODE_50G_R] = "50G_R",
> +       [LMAC_MODE_100G_R] = "100G_R",
> +       [LMAC_MODE_USXGMII] = "USXGMII",
> +};
>
>  /* CGX PHY management internal APIs */
>  static int cgx_fwi_link_change(struct cgx *cgx, int lmac_id, bool en);
> @@ -657,34 +682,6 @@ int cgx_fwi_cmd_generic(u64 req, u64 *resp, struct cgx *cgx, int lmac_id)
>         return err;
>  }
>
> -static inline void cgx_link_usertable_init(void)
> -{
> -       cgx_speed_mbps[CGX_LINK_NONE] = 0;
> -       cgx_speed_mbps[CGX_LINK_10M] = 10;
> -       cgx_speed_mbps[CGX_LINK_100M] = 100;
> -       cgx_speed_mbps[CGX_LINK_1G] = 1000;
> -       cgx_speed_mbps[CGX_LINK_2HG] = 2500;
> -       cgx_speed_mbps[CGX_LINK_5G] = 5000;
> -       cgx_speed_mbps[CGX_LINK_10G] = 10000;
> -       cgx_speed_mbps[CGX_LINK_20G] = 20000;
> -       cgx_speed_mbps[CGX_LINK_25G] = 25000;
> -       cgx_speed_mbps[CGX_LINK_40G] = 40000;
> -       cgx_speed_mbps[CGX_LINK_50G] = 50000;
> -       cgx_speed_mbps[CGX_LINK_80G] = 80000;
> -       cgx_speed_mbps[CGX_LINK_100G] = 100000;
> -
> -       cgx_lmactype_string[LMAC_MODE_SGMII] = "SGMII";
> -       cgx_lmactype_string[LMAC_MODE_XAUI] = "XAUI";
> -       cgx_lmactype_string[LMAC_MODE_RXAUI] = "RXAUI";
> -       cgx_lmactype_string[LMAC_MODE_10G_R] = "10G_R";
> -       cgx_lmactype_string[LMAC_MODE_40G_R] = "40G_R";
> -       cgx_lmactype_string[LMAC_MODE_QSGMII] = "QSGMII";
> -       cgx_lmactype_string[LMAC_MODE_25G_R] = "25G_R";
> -       cgx_lmactype_string[LMAC_MODE_50G_R] = "50G_R";
> -       cgx_lmactype_string[LMAC_MODE_100G_R] = "100G_R";
> -       cgx_lmactype_string[LMAC_MODE_USXGMII] = "USXGMII";
> -}
> -
>  static int cgx_link_usertable_index_map(int speed)
>  {
>         switch (speed) {
> @@ -826,7 +823,7 @@ static inline void link_status_user_format(u64 lstat,
>                                            struct cgx_link_user_info *linfo,
>                                            struct cgx *cgx, u8 lmac_id)
>  {
> -       char *lmac_string;
> +       const char *lmac_string;
>
>         linfo->link_up = FIELD_GET(RESP_LINKSTAT_UP, lstat);
>         linfo->full_duplex = FIELD_GET(RESP_LINKSTAT_FDUPLEX, lstat);
> @@ -1375,7 +1372,6 @@ static int cgx_probe(struct pci_dev *pdev, const struct pci_device_id *id)
>
>         list_add(&cgx->cgx_list, &cgx_list);
>
> -       cgx_link_usertable_init();
>
>         cgx_populate_features(cgx);
>
> --
> 2.29.2
>

Looks good to me, thanks for the fix.

Acked-by: Sunil Goutham <sgoutham@xxxxxxxxxxx>