From: Arnd Bergmann Date: Tue, 17 Dec 2024 08:10:34 +0000 (+0100) Subject: net: phy: avoid undefined behavior in *_led_polarity_set() X-Git-Tag: v6.13-rc4~25^2~12 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=cff865c700711ecc3824b2dfe181637f3ed23c80;p=linux-block.git net: phy: avoid undefined behavior in *_led_polarity_set() gcc runs into undefined behavior at the end of the three led_polarity_set() callback functions if it were called with a zero 'modes' argument and it just ends the function there without returning from it. This gets flagged by 'objtool' as a function that continues on to the next one: drivers/net/phy/aquantia/aquantia_leds.o: warning: objtool: aqr_phy_led_polarity_set+0xf: can't find jump dest instruction at .text+0x5d9 drivers/net/phy/intel-xway.o: warning: objtool: xway_gphy_led_polarity_set() falls through to next function xway_gphy_config_init() drivers/net/phy/mxl-gpy.o: warning: objtool: gpy_led_polarity_set() falls through to next function gpy_led_hw_control_get() There is no point to micro-optimize the behavior here to save a single-digit number of bytes in the kernel, so just change this to a "return -EINVAL" as we do when any unexpected bits are set. Fixes: 1758af47b98c ("net: phy: intel-xway: add support for PHY LEDs") Fixes: 9d55e68b19f2 ("net: phy: aquantia: correctly describe LED polarity override") Fixes: eb89c79c1b8f ("net: phy: mxl-gpy: correctly describe LED polarity") Signed-off-by: Arnd Bergmann Reviewed-by: Andrew Lunn Link: https://patch.msgid.link/20241217081056.238792-1-arnd@kernel.org Signed-off-by: Jakub Kicinski --- diff --git a/drivers/net/phy/aquantia/aquantia_leds.c b/drivers/net/phy/aquantia/aquantia_leds.c index 00ad2313fed3..951f46104eff 100644 --- a/drivers/net/phy/aquantia/aquantia_leds.c +++ b/drivers/net/phy/aquantia/aquantia_leds.c @@ -156,5 +156,5 @@ int aqr_phy_led_polarity_set(struct phy_device *phydev, int index, unsigned long if (force_active_high || force_active_low) return aqr_phy_led_active_low_set(phydev, index, force_active_low); - unreachable(); + return -EINVAL; } diff --git a/drivers/net/phy/intel-xway.c b/drivers/net/phy/intel-xway.c index b672c55a7a4e..e6ed2413e514 100644 --- a/drivers/net/phy/intel-xway.c +++ b/drivers/net/phy/intel-xway.c @@ -529,7 +529,7 @@ static int xway_gphy_led_polarity_set(struct phy_device *phydev, int index, if (force_active_high) return phy_clear_bits(phydev, XWAY_MDIO_LED, XWAY_GPHY_LED_INV(index)); - unreachable(); + return -EINVAL; } static struct phy_driver xway_gphy[] = { diff --git a/drivers/net/phy/mxl-gpy.c b/drivers/net/phy/mxl-gpy.c index db3c1f72b407..a8ccf257c109 100644 --- a/drivers/net/phy/mxl-gpy.c +++ b/drivers/net/phy/mxl-gpy.c @@ -1014,7 +1014,7 @@ static int gpy_led_polarity_set(struct phy_device *phydev, int index, if (force_active_high) return phy_clear_bits(phydev, PHY_LED, PHY_LED_POLARITY(index)); - unreachable(); + return -EINVAL; } static struct phy_driver gpy_drivers[] = {