Re: [PATCH net] device property: change device_get_phy_mode() to prevent signedess bugs
From: Andy Shevchenko
Date: Fri Jan 31 2020 - 03:12:25 EST
On Fri, Jan 31, 2020 at 7:03 AM Dan Carpenter <dan.carpenter@xxxxxxxxxx> wrote:
>
> The device_get_phy_mode() was returning negative error codes on
> failure and positive phy_interface_t values on success. The problem is
> that the phy_interface_t type is an enum which GCC treats as unsigned.
> This lead to recurring signedness bugs where we check "if (phy_mode < 0)"
> and "phy_mode" is unsigned.
>
> In the commit 0c65b2b90d13 ("net: of_get_phy_mode: Change API to solve
> int/unit warnings") we updated of_get_phy_mode() take a pointer to
> phy_mode and only return zero on success and negatives on failure. This
> patch does the same thing for device_get_phy_mode(). Plus it's just
> nice for the API to be the same in both places.
>
For device property API changes
Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
> Fixes: b9f0b2f634c0 ("net: stmmac: platform: fix probe for ACPI devices")
> Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> ---
> This is a change to drivers/base/ but all the users are ethernet drivers
> so probably it makes sense for Dave to take this?
>
> Also this fixes a bug in stmmac. If you wanted I could make a one
> liner fix for that and then write this change on top of that. The bug
> is only in v5.6 so it doesn't affect old kernels.
>
> drivers/base/property.c | 13 +++++++++++--
> drivers/net/ethernet/apm/xgene-v2/main.c | 9 ++++-----
> drivers/net/ethernet/apm/xgene-v2/main.h | 2 +-
> drivers/net/ethernet/apm/xgene/xgene_enet_main.c | 6 +++---
> drivers/net/ethernet/apm/xgene/xgene_enet_main.h | 2 +-
> drivers/net/ethernet/smsc/smsc911x.c | 8 +++-----
> drivers/net/ethernet/socionext/netsec.c | 5 ++---
> drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c | 6 +++---
> include/linux/property.h | 3 ++-
> 9 files changed, 30 insertions(+), 24 deletions(-)
>
> diff --git a/drivers/base/property.c b/drivers/base/property.c
> index 511f6d7acdfe..8854cfbd213b 100644
> --- a/drivers/base/property.c
> +++ b/drivers/base/property.c
> @@ -863,9 +863,18 @@ EXPORT_SYMBOL_GPL(fwnode_get_phy_mode);
> * 'phy-connection-type', and return its index in phy_modes table, or errno in
> * error case.
> */
> -int device_get_phy_mode(struct device *dev)
> +int device_get_phy_mode(struct device *dev, phy_interface_t *interface)
> {
> - return fwnode_get_phy_mode(dev_fwnode(dev));
> + int mode;
> +
> + *interface = PHY_INTERFACE_MODE_NA;
> +
> + mode = fwnode_get_phy_mode(dev_fwnode(dev));
> + if (mode < 0)
> + return mode;
> +
> + *interface = mode;
> + return 0;
> }
> EXPORT_SYMBOL_GPL(device_get_phy_mode);
>
> diff --git a/drivers/net/ethernet/apm/xgene-v2/main.c b/drivers/net/ethernet/apm/xgene-v2/main.c
> index c48f60996761..706602918dd1 100644
> --- a/drivers/net/ethernet/apm/xgene-v2/main.c
> +++ b/drivers/net/ethernet/apm/xgene-v2/main.c
> @@ -15,7 +15,7 @@ static int xge_get_resources(struct xge_pdata *pdata)
> {
> struct platform_device *pdev;
> struct net_device *ndev;
> - int phy_mode, ret = 0;
> + int ret = 0;
> struct resource *res;
> struct device *dev;
>
> @@ -41,12 +41,11 @@ static int xge_get_resources(struct xge_pdata *pdata)
>
> memcpy(ndev->perm_addr, ndev->dev_addr, ndev->addr_len);
>
> - phy_mode = device_get_phy_mode(dev);
> - if (phy_mode < 0) {
> + ret = device_get_phy_mode(dev, &pdata->resources.phy_mode);
> + if (ret) {
> dev_err(dev, "Unable to get phy-connection-type\n");
> - return phy_mode;
> + return ret;
> }
> - pdata->resources.phy_mode = phy_mode;
>
> if (pdata->resources.phy_mode != PHY_INTERFACE_MODE_RGMII) {
> dev_err(dev, "Incorrect phy-connection-type specified\n");
> diff --git a/drivers/net/ethernet/apm/xgene-v2/main.h b/drivers/net/ethernet/apm/xgene-v2/main.h
> index d41439d2709d..d687f0185908 100644
> --- a/drivers/net/ethernet/apm/xgene-v2/main.h
> +++ b/drivers/net/ethernet/apm/xgene-v2/main.h
> @@ -35,7 +35,7 @@
>
> struct xge_resource {
> void __iomem *base_addr;
> - int phy_mode;
> + phy_interface_t phy_mode;
> u32 irq;
> };
>
> diff --git a/drivers/net/ethernet/apm/xgene/xgene_enet_main.c b/drivers/net/ethernet/apm/xgene/xgene_enet_main.c
> index 6aee2f0fc0db..da35e70ccceb 100644
> --- a/drivers/net/ethernet/apm/xgene/xgene_enet_main.c
> +++ b/drivers/net/ethernet/apm/xgene/xgene_enet_main.c
> @@ -1736,10 +1736,10 @@ static int xgene_enet_get_resources(struct xgene_enet_pdata *pdata)
>
> memcpy(ndev->perm_addr, ndev->dev_addr, ndev->addr_len);
>
> - pdata->phy_mode = device_get_phy_mode(dev);
> - if (pdata->phy_mode < 0) {
> + ret = device_get_phy_mode(dev, &pdata->phy_mode);
> + if (ret) {
> dev_err(dev, "Unable to get phy-connection-type\n");
> - return pdata->phy_mode;
> + return ret;
> }
> if (!phy_interface_mode_is_rgmii(pdata->phy_mode) &&
> pdata->phy_mode != PHY_INTERFACE_MODE_SGMII &&
> diff --git a/drivers/net/ethernet/apm/xgene/xgene_enet_main.h b/drivers/net/ethernet/apm/xgene/xgene_enet_main.h
> index 18f4923b1723..600cddf1942d 100644
> --- a/drivers/net/ethernet/apm/xgene/xgene_enet_main.h
> +++ b/drivers/net/ethernet/apm/xgene/xgene_enet_main.h
> @@ -209,7 +209,7 @@ struct xgene_enet_pdata {
> void __iomem *pcs_addr;
> void __iomem *ring_csr_addr;
> void __iomem *ring_cmd_addr;
> - int phy_mode;
> + phy_interface_t phy_mode;
> enum xgene_enet_rm rm;
> struct xgene_enet_cle cle;
> u64 *extd_stats;
> diff --git a/drivers/net/ethernet/smsc/smsc911x.c b/drivers/net/ethernet/smsc/smsc911x.c
> index 49a6a9167af4..2d773e5e67f8 100644
> --- a/drivers/net/ethernet/smsc/smsc911x.c
> +++ b/drivers/net/ethernet/smsc/smsc911x.c
> @@ -2361,14 +2361,12 @@ static const struct smsc911x_ops shifted_smsc911x_ops = {
> static int smsc911x_probe_config(struct smsc911x_platform_config *config,
> struct device *dev)
> {
> - int phy_interface;
> u32 width = 0;
> int err;
>
> - phy_interface = device_get_phy_mode(dev);
> - if (phy_interface < 0)
> - phy_interface = PHY_INTERFACE_MODE_NA;
> - config->phy_interface = phy_interface;
> + err = device_get_phy_mode(dev, &config->phy_interface);
> + if (err)
> + config->phy_interface = PHY_INTERFACE_MODE_NA;
>
> device_get_mac_address(dev, config->mac, ETH_ALEN);
>
> diff --git a/drivers/net/ethernet/socionext/netsec.c b/drivers/net/ethernet/socionext/netsec.c
> index e8224b543dfc..95ff91230523 100644
> --- a/drivers/net/ethernet/socionext/netsec.c
> +++ b/drivers/net/ethernet/socionext/netsec.c
> @@ -1994,10 +1994,9 @@ static int netsec_probe(struct platform_device *pdev)
> priv->msg_enable = NETIF_MSG_TX_ERR | NETIF_MSG_HW | NETIF_MSG_DRV |
> NETIF_MSG_LINK | NETIF_MSG_PROBE;
>
> - priv->phy_interface = device_get_phy_mode(&pdev->dev);
> - if ((int)priv->phy_interface < 0) {
> + ret = device_get_phy_mode(&pdev->dev, &priv->phy_interface);
> + if (ret) {
> dev_err(&pdev->dev, "missing required property 'phy-mode'\n");
> - ret = -ENODEV;
> goto free_ndev;
> }
>
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
> index d10ac54bf385..aa77c332ea1d 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
> @@ -412,9 +412,9 @@ stmmac_probe_config_dt(struct platform_device *pdev, const char **mac)
> *mac = NULL;
> }
>
> - plat->phy_interface = device_get_phy_mode(&pdev->dev);
> - if (plat->phy_interface < 0)
> - return ERR_PTR(plat->phy_interface);
> + rc = device_get_phy_mode(&pdev->dev, &plat->phy_interface);
> + if (rc)
> + return ERR_PTR(rc);
>
> plat->interface = stmmac_of_get_mac_mode(np);
> if (plat->interface < 0)
> diff --git a/include/linux/property.h b/include/linux/property.h
> index d86de017c689..2ffe9842c997 100644
> --- a/include/linux/property.h
> +++ b/include/linux/property.h
> @@ -12,6 +12,7 @@
>
> #include <linux/bits.h>
> #include <linux/fwnode.h>
> +#include <linux/phy.h>
> #include <linux/types.h>
>
> struct device;
> @@ -368,7 +369,7 @@ enum dev_dma_attr device_get_dma_attr(struct device *dev);
>
> const void *device_get_match_data(struct device *dev);
>
> -int device_get_phy_mode(struct device *dev);
> +int device_get_phy_mode(struct device *dev, phy_interface_t *interface);
>
> void *device_get_mac_address(struct device *dev, char *addr, int alen);
>
> --
> 2.11.0
>
--
With Best Regards,
Andy Shevchenko