Hi Nick, kernel test robot noticed the following build warnings: [auto build test WARNING on 52a93d39b17dc7eb98b6aa3edb93943248e03b2f] url: https://github.com/intel-lab-lkp/linux/commits/Nick-Desaulniers/Makefile-extrawarn-enable-Wmissing-variable-declarations-for-W-1/20230808-005859 base: 52a93d39b17dc7eb98b6aa3edb93943248e03b2f patch link: https://lore.kernel.org/r/20230807-missing_proto-v2-1-3ae2e188bb0c%40google.com patch subject: [PATCH v2] Makefile.extrawarn: enable -Wmissing-variable-declarations for W=1 config: um-randconfig-r031-20230807 (https://download.01.org/0day-ci/archive/20230808/202308081050.sZEw4cQ5-lkp@xxxxxxxxx/config) compiler: clang version 14.0.6 (https://github.com/llvm/llvm-project.git f28c006a5895fc0e329fe15fead81e37457cb1d1) reproduce: (https://download.01.org/0day-ci/archive/20230808/202308081050.sZEw4cQ5-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/202308081050.sZEw4cQ5-lkp@xxxxxxxxx/ All warnings (new ones prefixed by >>): In file included from scripts/mod/devicetable-offsets.c:3: In file included from include/linux/mod_devicetable.h:14: In file included from include/linux/uuid.h:11: In file included from include/linux/string.h:20: In file included from arch/x86/include/asm/string.h:5: In file included from arch/x86/include/asm/string_64.h:6: In file included from include/linux/jump_label.h:255: In file included from include/linux/atomic.h:7: In file included from arch/x86/include/asm/atomic.h:7: In file included from arch/x86/include/asm/alternative.h:7: >> arch/x86/include/asm/asm.h:208:24: warning: no previous extern declaration for non-static variable 'current_stack_pointer' [-Wmissing-variable-declarations] register unsigned long current_stack_pointer asm(_ASM_SP); ^ arch/x86/include/asm/asm.h:208:10: note: declare 'static' if the variable is not intended to be used outside of this translation unit register unsigned long current_stack_pointer asm(_ASM_SP); ^ 1 warning generated. -- In file included from arch/um/kernel/asm-offsets.c:1: arch/x86/um/shared/sysdep/kernel-offsets.h:9:6: warning: no previous prototype for function 'foo' [-Wmissing-prototypes] void foo(void) ^ arch/x86/um/shared/sysdep/kernel-offsets.h:9:1: note: declare 'static' if the function is not intended to be used outside of this translation unit void foo(void) ^ static In file included from arch/um/kernel/asm-offsets.c:1: In file included from arch/x86/um/shared/sysdep/kernel-offsets.h:3: In file included from include/linux/sched.h:12: In file included from ./arch/um/include/generated/asm/current.h:1: In file included from include/asm-generic/current.h:5: In file included from include/linux/thread_info.h:27: In file included from include/linux/bitops.h:34: In file included from include/asm-generic/bitops/generic-non-atomic.h:7: In file included from arch/x86/um/asm/barrier.h:6: In file included from arch/x86/include/asm/alternative.h:7: >> arch/x86/include/asm/asm.h:208:24: warning: no previous extern declaration for non-static variable 'current_stack_pointer' [-Wmissing-variable-declarations] register unsigned long current_stack_pointer asm(_ASM_SP); ^ arch/x86/include/asm/asm.h:208:10: note: declare 'static' if the variable is not intended to be used outside of this translation unit register unsigned long current_stack_pointer asm(_ASM_SP); ^ 2 warnings generated. -- In file included from arch/um/drivers/hostaudio_kern.c:6: In file included from include/linux/fs.h:6: In file included from include/linux/wait_bit.h:8: In file included from include/linux/wait.h:7: In file included from include/linux/list.h:11: In file included from arch/x86/um/asm/barrier.h:6: In file included from arch/x86/include/asm/alternative.h:7: >> arch/x86/include/asm/asm.h:208:24: warning: no previous extern declaration for non-static variable 'current_stack_pointer' [-Wmissing-variable-declarations] register unsigned long current_stack_pointer asm(_ASM_SP); ^ arch/x86/include/asm/asm.h:208:10: note: declare 'static' if the variable is not intended to be used outside of this translation unit register unsigned long current_stack_pointer asm(_ASM_SP); ^ >> arch/um/drivers/hostaudio_kern.c:316:3: warning: no previous extern declaration for non-static variable 'module_data' [-Wmissing-variable-declarations] } module_data; ^ arch/um/drivers/hostaudio_kern.c:313:1: note: declare 'static' if the variable is not intended to be used outside of this translation unit struct { ^ 2 warnings generated. -- In file included from arch/um/drivers/daemon_kern.c:10: In file included from include/linux/netdevice.h:38: In file included from include/net/net_namespace.h:43: In file included from include/linux/skbuff.h:17: In file included from include/linux/bvec.h:10: In file included from include/linux/highmem.h:12: In file included from include/linux/hardirq.h:11: In file included from arch/um/include/asm/hardirq.h:5: In file included from include/asm-generic/hardirq.h:17: In file included from include/linux/irq.h:20: In file included from include/linux/io.h:13: 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] 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] 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' #define __le16_to_cpu(x) ((__force __u16)(__le16)(x)) ^ In file included from arch/um/drivers/daemon_kern.c:10: In file included from include/linux/netdevice.h:38: In file included from include/net/net_namespace.h:43: In file included from include/linux/skbuff.h:17: In file included from include/linux/bvec.h:10: In file included from include/linux/highmem.h:12: In file included from include/linux/hardirq.h:11: In file included from arch/um/include/asm/hardirq.h:5: In file included from include/asm-generic/hardirq.h:17: In file included from include/linux/irq.h:20: In file included from include/linux/io.h:13: 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] 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' #define __le32_to_cpu(x) ((__force __u32)(__le32)(x)) ^ In file included from arch/um/drivers/daemon_kern.c:10: In file included from include/linux/netdevice.h:38: In file included from include/net/net_namespace.h:43: In file included from include/linux/skbuff.h:17: In file included from include/linux/bvec.h:10: In file included from include/linux/highmem.h:12: In file included from include/linux/hardirq.h:11: In file included from arch/um/include/asm/hardirq.h:5: In file included from include/asm-generic/hardirq.h:17: In file included from include/linux/irq.h:20: In file included from include/linux/io.h:13: 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] __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] __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] __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] 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] 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] 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] 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] 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] writesl(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ In file included from arch/um/drivers/daemon_kern.c:10: In file included from include/linux/netdevice.h:24: In file included from include/linux/timer.h:5: In file included from include/linux/list.h:11: In file included from arch/x86/um/asm/barrier.h:6: In file included from arch/x86/include/asm/alternative.h:7: >> arch/x86/include/asm/asm.h:208:24: warning: no previous extern declaration for non-static variable 'current_stack_pointer' [-Wmissing-variable-declarations] register unsigned long current_stack_pointer asm(_ASM_SP); ^ arch/x86/include/asm/asm.h:208:10: note: declare 'static' if the variable is not intended to be used outside of this translation unit register unsigned long current_stack_pointer asm(_ASM_SP); ^ 13 warnings generated. -- In file included from arch/um/drivers/port_kern.c:7: In file included from include/linux/interrupt.h:11: In file included from include/linux/hardirq.h:11: In file included from arch/um/include/asm/hardirq.h:5: In file included from include/asm-generic/hardirq.h:17: In file included from include/linux/irq.h:20: In file included from include/linux/io.h:13: 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] 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] 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' #define __le16_to_cpu(x) ((__force __u16)(__le16)(x)) ^ In file included from arch/um/drivers/port_kern.c:7: In file included from include/linux/interrupt.h:11: In file included from include/linux/hardirq.h:11: In file included from arch/um/include/asm/hardirq.h:5: In file included from include/asm-generic/hardirq.h:17: In file included from include/linux/irq.h:20: In file included from include/linux/io.h:13: 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] 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' #define __le32_to_cpu(x) ((__force __u32)(__le32)(x)) ^ In file included from arch/um/drivers/port_kern.c:7: In file included from include/linux/interrupt.h:11: In file included from include/linux/hardirq.h:11: In file included from arch/um/include/asm/hardirq.h:5: In file included from include/asm-generic/hardirq.h:17: In file included from include/linux/irq.h:20: In file included from include/linux/io.h:13: 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] __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] __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] __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] 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] 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] 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] 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] 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] writesl(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ >> arch/um/drivers/port_kern.c:147:14: warning: no previous extern declaration for non-static variable 'port_work' [-Wmissing-variable-declarations] DECLARE_WORK(port_work, port_work_proc); ^ arch/um/drivers/port_kern.c:147:1: note: declare 'static' if the variable is not intended to be used outside of this translation unit DECLARE_WORK(port_work, port_work_proc); ^ include/linux/workqueue.h:194:2: note: expanded from macro 'DECLARE_WORK' struct work_struct n = __WORK_INITIALIZER(n, f) ^ In file included from arch/um/drivers/port_kern.c:6: In file included from include/linux/completion.h:12: In file included from include/linux/swait.h:5: In file included from include/linux/list.h:11: In file included from arch/x86/um/asm/barrier.h:6: In file included from arch/x86/include/asm/alternative.h:7: >> arch/x86/include/asm/asm.h:208:24: warning: no previous extern declaration for non-static variable 'current_stack_pointer' [-Wmissing-variable-declarations] register unsigned long current_stack_pointer asm(_ASM_SP); ^ arch/x86/include/asm/asm.h:208:10: note: declare 'static' if the variable is not intended to be used outside of this translation unit register unsigned long current_stack_pointer asm(_ASM_SP); ^ 14 warnings generated. -- In file included from arch/um/drivers/xterm_kern.c:10: In file included from arch/um/include/shared/irq_kern.h:9: In file included from include/linux/interrupt.h:11: In file included from include/linux/hardirq.h:11: In file included from arch/um/include/asm/hardirq.h:5: In file included from include/asm-generic/hardirq.h:17: In file included from include/linux/irq.h:20: In file included from include/linux/io.h:13: 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] 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] 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' #define __le16_to_cpu(x) ((__force __u16)(__le16)(x)) ^ In file included from arch/um/drivers/xterm_kern.c:10: In file included from arch/um/include/shared/irq_kern.h:9: In file included from include/linux/interrupt.h:11: In file included from include/linux/hardirq.h:11: In file included from arch/um/include/asm/hardirq.h:5: In file included from include/asm-generic/hardirq.h:17: In file included from include/linux/irq.h:20: In file included from include/linux/io.h:13: 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] 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' #define __le32_to_cpu(x) ((__force __u32)(__le32)(x)) ^ In file included from arch/um/drivers/xterm_kern.c:10: In file included from arch/um/include/shared/irq_kern.h:9: In file included from include/linux/interrupt.h:11: In file included from include/linux/hardirq.h:11: In file included from arch/um/include/asm/hardirq.h:5: In file included from include/asm-generic/hardirq.h:17: In file included from include/linux/irq.h:20: In file included from include/linux/io.h:13: 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] __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] __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] __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] 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] 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] 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] 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] 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] writesl(PCI_IOBASE + addr, buffer, count); ~~~~~~~~~~ ^ arch/um/drivers/xterm_kern.c:35:5: warning: no previous prototype for function 'xterm_fd' [-Wmissing-prototypes] int xterm_fd(int socket, int *pid_out) ^ arch/um/drivers/xterm_kern.c:35:1: note: declare 'static' if the function is not intended to be used outside of this translation unit int xterm_fd(int socket, int *pid_out) ^ static In file included from arch/um/drivers/xterm_kern.c:6: In file included from include/linux/slab.h:16: In file included from include/linux/gfp.h:7: In file included from include/linux/mmzone.h:8: In file included from include/linux/spinlock.h:56: In file included from include/linux/preempt.h:12: In file included from include/linux/list.h:11: In file included from arch/x86/um/asm/barrier.h:6: In file included from arch/x86/include/asm/alternative.h:7: >> arch/x86/include/asm/asm.h:208:24: warning: no previous extern declaration for non-static variable 'current_stack_pointer' [-Wmissing-variable-declarations] register unsigned long current_stack_pointer asm(_ASM_SP); ^ arch/x86/include/asm/asm.h:208:10: note: declare 'static' if the variable is not intended to be used outside of this translation unit register unsigned long current_stack_pointer asm(_ASM_SP); ^ 14 warnings generated. .. vim +/current_stack_pointer +208 arch/x86/include/asm/asm.h a34746bc43eb63 include/asm-x86/asm.h H. Peter Anvin 2008-02-04 201 f5caf621ee3572 arch/x86/include/asm/asm.h Josh Poimboeuf 2017-09-20 202 /* f5caf621ee3572 arch/x86/include/asm/asm.h Josh Poimboeuf 2017-09-20 203 * This output constraint should be used for any inline asm which has a "call" f5caf621ee3572 arch/x86/include/asm/asm.h Josh Poimboeuf 2017-09-20 204 * instruction. Otherwise the asm may be inserted before the frame pointer f5caf621ee3572 arch/x86/include/asm/asm.h Josh Poimboeuf 2017-09-20 205 * gets set up by the containing function. If you forget to do this, objtool f5caf621ee3572 arch/x86/include/asm/asm.h Josh Poimboeuf 2017-09-20 206 * may print a "call without frame pointer save/setup" warning. f5caf621ee3572 arch/x86/include/asm/asm.h Josh Poimboeuf 2017-09-20 207 */ 196bd485ee4f03 arch/x86/include/asm/asm.h Andrey Ryabinin 2017-09-29 @208 register unsigned long current_stack_pointer asm(_ASM_SP); 196bd485ee4f03 arch/x86/include/asm/asm.h Andrey Ryabinin 2017-09-29 209 #define ASM_CALL_CONSTRAINT "+r" (current_stack_pointer) 28b60197b573cd arch/x86/include/asm/asm.h Borislav Petkov 2020-06-04 210 #endif /* __ASSEMBLY__ */ f5caf621ee3572 arch/x86/include/asm/asm.h Josh Poimboeuf 2017-09-20 211 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
