Hi Nathan, kernel test robot noticed the following build warnings: [auto build test WARNING on ce9ecca0238b140b88f43859b211c9fdfd8e5b70] url: https://github.com/intel-lab-lkp/linux/commits/Nathan-Chancellor/kbuild-Enable-Wincompatible-function-pointer-types-strict-in-W-1/20231003-062107 base: ce9ecca0238b140b88f43859b211c9fdfd8e5b70 patch link: https://lore.kernel.org/r/20231002-enable-wincompatible-function-pointer-types-strict-w-1-v1-1-808ab955d42d%40kernel.org patch subject: [PATCH] kbuild: Enable -Wincompatible-function-pointer-types-strict in W=1 config: um-allnoconfig (https://download.01.org/0day-ci/archive/20231003/202310031340.v1vPh207-lkp@xxxxxxxxx/config) compiler: clang version 17.0.0 (https://github.com/llvm/llvm-project.git 4a5ac14ee968ff0ad5d2cc1ffa0299048db4c88a) reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231003/202310031340.v1vPh207-lkp@xxxxxxxxx/reproduce) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp@xxxxxxxxx> | Closes: https://lore.kernel.org/oe-kbuild-all/202310031340.v1vPh207-lkp@xxxxxxxxx/ All warnings (new ones prefixed by >>): In file included from arch/um/drivers/net_kern.c:9: In file included from include/linux/memblock.h:13: In file included from arch/um/include/asm/dma.h:5: In file included from arch/um/include/asm/io.h:24: include/asm-generic/io.h:547:31: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 547 | val = __raw_readb(PCI_IOBASE + addr); | ~~~~~~~~~~ ^ include/asm-generic/io.h:560:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 560 | val = __le16_to_cpu((__le16 __force)__raw_readw(PCI_IOBASE + addr)); | ~~~~~~~~~~ ^ include/uapi/linux/byteorder/little_endian.h:37:51: note: expanded from macro '__le16_to_cpu' 37 | #define __le16_to_cpu(x) ((__force __u16)(__le16)(x)) | ^ In file included from arch/um/drivers/net_kern.c:9: In file included from include/linux/memblock.h:13: In file included from arch/um/include/asm/dma.h:5: In file included from arch/um/include/asm/io.h:24: include/asm-generic/io.h:573:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 573 | val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr)); | ~~~~~~~~~~ ^ include/uapi/linux/byteorder/little_endian.h:35:51: note: expanded from macro '__le32_to_cpu' 35 | #define __le32_to_cpu(x) ((__force __u32)(__le32)(x)) | ^ In file included from arch/um/drivers/net_kern.c:9: In file included from include/linux/memblock.h:13: In file included from arch/um/include/asm/dma.h:5: In file included from arch/um/include/asm/io.h:24: include/asm-generic/io.h:584:33: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 584 | __raw_writeb(value, PCI_IOBASE + addr); | ~~~~~~~~~~ ^ include/asm-generic/io.h:594:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 594 | __raw_writew((u16 __force)cpu_to_le16(value), PCI_IOBASE + addr); | ~~~~~~~~~~ ^ include/asm-generic/io.h:604:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 604 | __raw_writel((u32 __force)cpu_to_le32(value), PCI_IOBASE + addr); | ~~~~~~~~~~ ^ include/asm-generic/io.h:692:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 692 | readsb(PCI_IOBASE + addr, buffer, count); | ~~~~~~~~~~ ^ include/asm-generic/io.h:700:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 700 | readsw(PCI_IOBASE + addr, buffer, count); | ~~~~~~~~~~ ^ include/asm-generic/io.h:708:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 708 | readsl(PCI_IOBASE + addr, buffer, count); | ~~~~~~~~~~ ^ include/asm-generic/io.h:717:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 717 | writesb(PCI_IOBASE + addr, buffer, count); | ~~~~~~~~~~ ^ include/asm-generic/io.h:726:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 726 | writesw(PCI_IOBASE + addr, buffer, count); | ~~~~~~~~~~ ^ include/asm-generic/io.h:735:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 735 | writesl(PCI_IOBASE + addr, buffer, count); | ~~~~~~~~~~ ^ >> arch/um/drivers/net_kern.c:353:21: warning: incompatible function pointer types initializing 'netdev_tx_t (*)(struct sk_buff *, struct net_device *)' (aka 'enum netdev_tx (*)(struct sk_buff *, struct net_device *)') with an expression of type 'int (struct sk_buff *, struct net_device *)' [-Wincompatible-function-pointer-types-strict] 353 | .ndo_start_xmit = uml_net_start_xmit, | ^~~~~~~~~~~~~~~~~~ 13 warnings generated. vim +353 arch/um/drivers/net_kern.c 2e3f5251ac7168 Jeff Dike 2007-05-06 349 8bb95b39a16ed5 Stephen Hemminger 2009-03-26 350 static const struct net_device_ops uml_netdev_ops = { 8bb95b39a16ed5 Stephen Hemminger 2009-03-26 351 .ndo_open = uml_net_open, 8bb95b39a16ed5 Stephen Hemminger 2009-03-26 352 .ndo_stop = uml_net_close, 8bb95b39a16ed5 Stephen Hemminger 2009-03-26 @353 .ndo_start_xmit = uml_net_start_xmit, afc4b13df14312 Jiri Pirko 2011-08-16 354 .ndo_set_rx_mode = uml_net_set_multicast_list, 8bb95b39a16ed5 Stephen Hemminger 2009-03-26 355 .ndo_tx_timeout = uml_net_tx_timeout, 9337057d433505 Boaz Harrosh 2010-09-29 356 .ndo_set_mac_address = eth_mac_addr, 8bb95b39a16ed5 Stephen Hemminger 2009-03-26 357 .ndo_validate_addr = eth_validate_addr, dd71dc4c335a89 Richard Weinberger 2011-07-25 358 #ifdef CONFIG_NET_POLL_CONTROLLER dd71dc4c335a89 Richard Weinberger 2011-07-25 359 .ndo_poll_controller = uml_net_poll_controller, dd71dc4c335a89 Richard Weinberger 2011-07-25 360 #endif 8bb95b39a16ed5 Stephen Hemminger 2009-03-26 361 }; 8bb95b39a16ed5 Stephen Hemminger 2009-03-26 362 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
