tree: https://git.kernel.org/pub/scm/linux/kernel/git/luto/linux.git x86/kentry head: b0d7a5e5a9b11a6ddb50b90e31877e3cb1f93362 commit: d37c90c782b1cca1fc4f936480dd01dda7f72a88 [5/10] kentry: Simplify the common syscall API config: s390-randconfig-r011-20210321 (attached as .config) compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project 14696baaf4c43fe53f738bc292bbe169eed93d5d) reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # install s390 cross compiling tool for clang build # apt-get install binutils-s390x-linux-gnu # https://git.kernel.org/pub/scm/linux/kernel/git/luto/linux.git/commit/?id... git remote add luto https://git.kernel.org/pub/scm/linux/kernel/git/luto/linux.git git fetch --no-tags luto x86/kentry git checkout d37c90c782b1cca1fc4f936480dd01dda7f72a88 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=s390 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): In file included from arch/s390/kernel/process.c:24: In file included from include/linux/tick.h:8: In file included from include/linux/clockchips.h:14: In file included from include/linux/clocksource.h:21: In file included from arch/s390/include/asm/io.h:80: include/asm-generic/io.h:464:31: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] val = __raw_readb(PCI_IOBASE + addr); ~~~~~~~~~~ ^ include/asm-generic/io.h:477:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] val = __le16_to_cpu((__le16 __force)__raw_readw(PCI_IOBASE + addr)); ~~~~~~~~~~ ^ include/uapi/linux/byteorder/big_endian.h:36:59: note: expanded from macro '__le16_to_cpu' #define __le16_to_cpu(x) __swab16((__force __u16)(__le16)(x)) ^ include/uapi/linux/swab.h:102:54: note: expanded from macro '__swab16' #define __swab16(x) (__u16)__builtin_bswap16((__u16)(x)) ^ In file included from arch/s390/kernel/process.c:24: In file included from include/linux/tick.h:8: In file included from include/linux/clockchips.h:14: In file included from include/linux/clocksource.h:21: In file included from arch/s390/include/asm/io.h:80: include/asm-generic/io.h:490:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr)); ~~~~~~~~~~ ^ include/uapi/linux/byteorder/big_endian.h:34:59: note: expanded from macro '__le32_to_cpu' #define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x)) ^ include/uapi/linux/swab.h:115:54: note: expanded from macro '__swab32' #define __swab32(x) (__u32)__builtin_bswap32((__u32)(x)) ^ In file included from arch/s390/kernel/process.c:24: In file included from include/linux/tick.h:8: In file included from include/linux/clockchips.h:14: In file included from include/linux/clocksource.h:21: In file included from arch/s390/include/asm/io.h:80: include/asm-generic/io.h:501:33: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] __raw_writeb(value, PCI_IOBASE + addr); ~~~~~~~~~~ ^ include/asm-generic/io.h:511:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] __raw_writew((u16 __force)cpu_to_le16(value), PCI_IOBASE + addr); ~~~~~~~~~~ ^ include/asm-generic/io.h:521:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] __raw_writel((u32 __force)cpu_to_le32(value), PCI_IOBASE + addr); ~~~~~~~~~~ ^ include/asm-generic/io.h:609:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] readsb(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ include/asm-generic/io.h:617:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] readsw(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ include/asm-generic/io.h:625:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] readsl(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ include/asm-generic/io.h:634:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] writesb(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ include/asm-generic/io.h:643:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] writesw(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ include/asm-generic/io.h:652:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] writesl(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ syscall_exit_to_user_mode(regs); ^ arch/s390/kernel/process.c:61:2: note: did you mean 'arch_exit_to_user_mode'? include/linux/entry-common.h:232:29: note: 'arch_exit_to_user_mode' declared here static __always_inline void arch_exit_to_user_mode(void); ^ arch/s390/include/asm/entry-common.h:53:32: note: expanded from macro 'arch_exit_to_user_mode' #define arch_exit_to_user_mode arch_exit_to_user_mode ^ 12 warnings and 1 error generated. -- In file included from arch/s390/kernel/syscall.c:34: In file included from include/linux/entry-common.h:6: In file included from include/linux/tracehook.h:50: In file included from include/linux/memcontrol.h:22: In file included from include/linux/writeback.h:14: In file included from include/linux/blk-cgroup.h:23: In file included from include/linux/blkdev.h:26: In file included from include/linux/scatterlist.h:9: In file included from arch/s390/include/asm/io.h:80: include/asm-generic/io.h:464:31: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] val = __raw_readb(PCI_IOBASE + addr); ~~~~~~~~~~ ^ include/asm-generic/io.h:477:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] val = __le16_to_cpu((__le16 __force)__raw_readw(PCI_IOBASE + addr)); ~~~~~~~~~~ ^ include/uapi/linux/byteorder/big_endian.h:36:59: note: expanded from macro '__le16_to_cpu' #define __le16_to_cpu(x) __swab16((__force __u16)(__le16)(x)) ^ include/uapi/linux/swab.h:102:54: note: expanded from macro '__swab16' #define __swab16(x) (__u16)__builtin_bswap16((__u16)(x)) ^ In file included from arch/s390/kernel/syscall.c:34: In file included from include/linux/entry-common.h:6: In file included from include/linux/tracehook.h:50: In file included from include/linux/memcontrol.h:22: In file included from include/linux/writeback.h:14: In file included from include/linux/blk-cgroup.h:23: In file included from include/linux/blkdev.h:26: In file included from include/linux/scatterlist.h:9: In file included from arch/s390/include/asm/io.h:80: include/asm-generic/io.h:490:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr)); ~~~~~~~~~~ ^ include/uapi/linux/byteorder/big_endian.h:34:59: note: expanded from macro '__le32_to_cpu' #define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x)) ^ include/uapi/linux/swab.h:115:54: note: expanded from macro '__swab32' #define __swab32(x) (__u32)__builtin_bswap32((__u32)(x)) ^ In file included from arch/s390/kernel/syscall.c:34: In file included from include/linux/entry-common.h:6: In file included from include/linux/tracehook.h:50: In file included from include/linux/memcontrol.h:22: In file included from include/linux/writeback.h:14: In file included from include/linux/blk-cgroup.h:23: In file included from include/linux/blkdev.h:26: In file included from include/linux/scatterlist.h:9: In file included from arch/s390/include/asm/io.h:80: include/asm-generic/io.h:501:33: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] __raw_writeb(value, PCI_IOBASE + addr); ~~~~~~~~~~ ^ include/asm-generic/io.h:511:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] __raw_writew((u16 __force)cpu_to_le16(value), PCI_IOBASE + addr); ~~~~~~~~~~ ^ include/asm-generic/io.h:521:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] __raw_writel((u32 __force)cpu_to_le32(value), PCI_IOBASE + addr); ~~~~~~~~~~ ^ include/asm-generic/io.h:609:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] readsb(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ include/asm-generic/io.h:617:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] readsw(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ include/asm-generic/io.h:625:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] readsl(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ include/asm-generic/io.h:634:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] writesb(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ include/asm-generic/io.h:643:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] writesw(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ include/asm-generic/io.h:652:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] writesl(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ nr = syscall_enter_from_user_mode_work(regs, nr); ^ syscall_exit_to_user_mode_work(regs); ^ arch/s390/kernel/syscall.c:140:2: note: did you mean 'arch_exit_to_user_mode_work'? include/linux/entry-common.h:190:20: note: 'arch_exit_to_user_mode_work' declared here static inline void arch_exit_to_user_mode_work(struct pt_regs *regs, ^ arch/s390/include/asm/entry-common.h:42:37: note: expanded from macro 'arch_exit_to_user_mode_work' #define arch_exit_to_user_mode_work arch_exit_to_user_mode_work ^ 12 warnings and 2 errors generated. vim +/syscall_exit_to_user_mode +61 arch/s390/kernel/process.c ^1da177e4c3f41 Linus Torvalds 2005-04-16 48 56e62a73702836 Sven Schnelle 2020-11-21 49 void __ret_from_fork(struct task_struct *prev, struct pt_regs *regs) 56e62a73702836 Sven Schnelle 2020-11-21 50 { 56e62a73702836 Sven Schnelle 2020-11-21 51 void (*func)(void *arg); 56e62a73702836 Sven Schnelle 2020-11-21 52 56e62a73702836 Sven Schnelle 2020-11-21 53 schedule_tail(prev); 56e62a73702836 Sven Schnelle 2020-11-21 54 56e62a73702836 Sven Schnelle 2020-11-21 55 if (!user_mode(regs)) { 56e62a73702836 Sven Schnelle 2020-11-21 56 /* Kernel thread */ 56e62a73702836 Sven Schnelle 2020-11-21 57 func = (void *)regs->gprs[9]; 56e62a73702836 Sven Schnelle 2020-11-21 58 func((void *)regs->gprs[10]); 56e62a73702836 Sven Schnelle 2020-11-21 59 } 56e62a73702836 Sven Schnelle 2020-11-21 60 clear_pt_regs_flag(regs, PIF_SYSCALL); 56e62a73702836 Sven Schnelle 2020-11-21 @61 syscall_exit_to_user_mode(regs); 56e62a73702836 Sven Schnelle 2020-11-21 62 } ^1da177e4c3f41 Linus Torvalds 2005-04-16 63 :::::: The code at line 61 was first introduced by commit :::::: 56e62a73702836017564eaacd5212e4d0fa1c01d s390: convert to generic entry :::::: TO: Sven Schnelle <svens(a)linux.ibm.com&gt; :::::: CC: Vasily Gorbik <gor(a)linux.ibm.com&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org