From 7eab14de73a8028f770e703962c5437a2b0dda82 Mon Sep 17 00:00:00 2001 From: Alexander Lobakin Date: Sat, 16 Jan 2021 16:13:22 +0000 Subject: mdio, phy: fix -Wshadow warnings triggered by nested container_of() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit container_of() macro hides a local variable '__mptr' inside. This becomes a problem when several container_of() are nested in each other within single line or plain macros. As C preprocessor doesn't support generating random variable names, the sole solution is to avoid defining macros that consist only of container_of() calls, or they will self-shadow '__mptr' each time: In file included from ./include/linux/bitmap.h:10, from drivers/net/phy/phy_device.c:12: drivers/net/phy/phy_device.c: In function ‘phy_device_release’: ./include/linux/kernel.h:693:8: warning: declaration of ‘__mptr’ shadows a previous local [-Wshadow] 693 | void *__mptr = (void *)(ptr); \ | ^~~~~~ ./include/linux/phy.h:647:26: note: in expansion of macro ‘container_of’ 647 | #define to_phy_device(d) container_of(to_mdio_device(d), \ | ^~~~~~~~~~~~ ./include/linux/mdio.h:52:27: note: in expansion of macro ‘container_of’ 52 | #define to_mdio_device(d) container_of(d, struct mdio_device, dev) | ^~~~~~~~~~~~ ./include/linux/phy.h:647:39: note: in expansion of macro ‘to_mdio_device’ 647 | #define to_phy_device(d) container_of(to_mdio_device(d), \ | ^~~~~~~~~~~~~~ drivers/net/phy/phy_device.c:217:8: note: in expansion of macro ‘to_phy_device’ 217 | kfree(to_phy_device(dev)); | ^~~~~~~~~~~~~ ./include/linux/kernel.h:693:8: note: shadowed declaration is here 693 | void *__mptr = (void *)(ptr); \ | ^~~~~~ ./include/linux/phy.h:647:26: note: in expansion of macro ‘container_of’ 647 | #define to_phy_device(d) container_of(to_mdio_device(d), \ | ^~~~~~~~~~~~ drivers/net/phy/phy_device.c:217:8: note: in expansion of macro ‘to_phy_device’ 217 | kfree(to_phy_device(dev)); | ^~~~~~~~~~~~~ As they are declared in header files, these warnings are highly repetitive and very annoying (along with the one from linux/pci.h). Convert the related macros from linux/{mdio,phy}.h to static inlines to avoid self-shadowing and potentially improve bug-catching. No functional changes implied. Signed-off-by: Alexander Lobakin Reviewed-by: Andrew Lunn Link: https://lore.kernel.org/r/20210116161246.67075-1-alobakin@pm.me Signed-off-by: Jakub Kicinski --- include/linux/phy.h | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'include/linux/phy.h') diff --git a/include/linux/phy.h b/include/linux/phy.h index 24fcc6456a9e..bc323fbdd21e 100644 --- a/include/linux/phy.h +++ b/include/linux/phy.h @@ -648,8 +648,11 @@ struct phy_device { const struct macsec_ops *macsec_ops; #endif }; -#define to_phy_device(d) container_of(to_mdio_device(d), \ - struct phy_device, mdio) + +static inline struct phy_device *to_phy_device(const struct device *dev) +{ + return container_of(to_mdio_device(dev), struct phy_device, mdio); +} /** * struct phy_tdr_config - Configuration of a TDR raw test -- cgit