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: riscv-randconfig-r014-20230807 (https://download.01.org/0day-ci/archive/20230808/202308081000.tTL1ElTr-lkp@xxxxxxxxx/config) compiler: clang version 17.0.0 (https://github.com/llvm/llvm-project.git 4a5ac14ee968ff0ad5d2cc1ffa0299048db4c88a) reproduce: (https://download.01.org/0day-ci/archive/20230808/202308081000.tTL1ElTr-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/202308081000.tTL1ElTr-lkp@xxxxxxxxx/ All warnings (new ones prefixed by >>): In file included from arch/riscv/kernel/asm-offsets.c:10: In file included from include/linux/mm.h:7: 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:79: In file included from ./arch/riscv/include/generated/asm/preempt.h:1: In file included from include/asm-generic/preempt.h:5: In file included from include/linux/thread_info.h:23: >> arch/riscv/include/asm/current.h:20:30: warning: no previous extern declaration for non-static variable 'riscv_current_is_tp' [-Wmissing-variable-declarations] 20 | register struct task_struct *riscv_current_is_tp __asm__("tp"); | ^ arch/riscv/include/asm/current.h:20:10: note: declare 'static' if the variable is not intended to be used outside of this translation unit 20 | register struct task_struct *riscv_current_is_tp __asm__("tp"); | ^ >> arch/riscv/include/asm/current.h:36:24: warning: no previous extern declaration for non-static variable 'current_stack_pointer' [-Wmissing-variable-declarations] 36 | register unsigned long current_stack_pointer __asm__("sp"); | ^ arch/riscv/include/asm/current.h:36:10: note: declare 'static' if the variable is not intended to be used outside of this translation unit 36 | register unsigned long current_stack_pointer __asm__("sp"); | ^ 2 warnings generated. -- In file included from arch/riscv/kernel/process.c:10: In file included from include/linux/cpu.h:17: In file included from include/linux/node.h:18: In file included from include/linux/device.h:15: In file included from include/linux/dev_printk.h:16: In file included from include/linux/ratelimit.h:6: In file included from include/linux/sched.h:12: >> arch/riscv/include/asm/current.h:20:30: warning: no previous extern declaration for non-static variable 'riscv_current_is_tp' [-Wmissing-variable-declarations] 20 | register struct task_struct *riscv_current_is_tp __asm__("tp"); | ^ arch/riscv/include/asm/current.h:20:10: note: declare 'static' if the variable is not intended to be used outside of this translation unit 20 | register struct task_struct *riscv_current_is_tp __asm__("tp"); | ^ >> arch/riscv/include/asm/current.h:36:24: warning: no previous extern declaration for non-static variable 'current_stack_pointer' [-Wmissing-variable-declarations] 36 | register unsigned long current_stack_pointer __asm__("sp"); | ^ arch/riscv/include/asm/current.h:36:10: note: declare 'static' if the variable is not intended to be used outside of this translation unit 36 | register unsigned long current_stack_pointer __asm__("sp"); | ^ >> arch/riscv/kernel/process.c:29:24: warning: no previous extern declaration for non-static variable 'gp_in_global' [-Wmissing-variable-declarations] 29 | register unsigned long gp_in_global __asm__("gp"); | ^ arch/riscv/kernel/process.c:29:10: note: declare 'static' if the variable is not intended to be used outside of this translation unit 29 | register unsigned long gp_in_global __asm__("gp"); | ^ 3 warnings generated. -- In file included from arch/riscv/mm/init.c:10: In file included from include/linux/mm.h:7: 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:79: In file included from ./arch/riscv/include/generated/asm/preempt.h:1: In file included from include/asm-generic/preempt.h:5: In file included from include/linux/thread_info.h:23: >> arch/riscv/include/asm/current.h:20:30: warning: no previous extern declaration for non-static variable 'riscv_current_is_tp' [-Wmissing-variable-declarations] 20 | register struct task_struct *riscv_current_is_tp __asm__("tp"); | ^ arch/riscv/include/asm/current.h:20:10: note: declare 'static' if the variable is not intended to be used outside of this translation unit 20 | register struct task_struct *riscv_current_is_tp __asm__("tp"); | ^ >> arch/riscv/include/asm/current.h:36:24: warning: no previous extern declaration for non-static variable 'current_stack_pointer' [-Wmissing-variable-declarations] 36 | register unsigned long current_stack_pointer __asm__("sp"); | ^ arch/riscv/include/asm/current.h:36:10: note: declare 'static' if the variable is not intended to be used outside of this translation unit 36 | register unsigned long current_stack_pointer __asm__("sp"); | ^ >> arch/riscv/mm/init.c:276:7: warning: no previous extern declaration for non-static variable 'trampoline_pg_dir' [-Wmissing-variable-declarations] 276 | pgd_t trampoline_pg_dir[PTRS_PER_PGD] __page_aligned_bss; | ^ arch/riscv/mm/init.c:276:1: note: declare 'static' if the variable is not intended to be used outside of this translation unit 276 | pgd_t trampoline_pg_dir[PTRS_PER_PGD] __page_aligned_bss; | ^ >> arch/riscv/mm/init.c:279:7: warning: no previous extern declaration for non-static variable 'early_pg_dir' [-Wmissing-variable-declarations] 279 | pgd_t early_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE); | ^ arch/riscv/mm/init.c:279:1: note: declare 'static' if the variable is not intended to be used outside of this translation unit 279 | pgd_t early_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE); | ^ 4 warnings generated. -- drivers/char/ipmi/ipmi_si_platform.c:272:15: warning: cast to smaller integer type 'enum si_type' from 'const void *' [-Wvoid-pointer-to-enum-cast] 272 | io.si_type = (enum si_type) match->data; | ^~~~~~~~~~~~~~~~~~~~~~~~~~ In file included from drivers/char/ipmi/ipmi_si_platform.c:13: In file included from include/linux/module.h:14: In file included from include/linux/buildid.h:5: In file included from include/linux/mm_types.h:8: In file included from include/linux/kref.h:16: In file included from include/linux/spinlock.h:56: In file included from include/linux/preempt.h:79: In file included from ./arch/riscv/include/generated/asm/preempt.h:1: In file included from include/asm-generic/preempt.h:5: In file included from include/linux/thread_info.h:23: >> arch/riscv/include/asm/current.h:20:30: warning: no previous extern declaration for non-static variable 'riscv_current_is_tp' [-Wmissing-variable-declarations] 20 | register struct task_struct *riscv_current_is_tp __asm__("tp"); | ^ arch/riscv/include/asm/current.h:20:10: note: declare 'static' if the variable is not intended to be used outside of this translation unit 20 | register struct task_struct *riscv_current_is_tp __asm__("tp"); | ^ >> arch/riscv/include/asm/current.h:36:24: warning: no previous extern declaration for non-static variable 'current_stack_pointer' [-Wmissing-variable-declarations] 36 | register unsigned long current_stack_pointer __asm__("sp"); | ^ arch/riscv/include/asm/current.h:36:10: note: declare 'static' if the variable is not intended to be used outside of this translation unit 36 | register unsigned long current_stack_pointer __asm__("sp"); | ^ 3 warnings generated. -- >> net/atm/mpc.c:123:21: warning: no previous extern declaration for non-static variable 'mpcs' [-Wmissing-variable-declarations] 123 | struct mpoa_client *mpcs = NULL; /* FIXME */ | ^ net/atm/mpc.c:123:1: note: declare 'static' if the variable is not intended to be used outside of this translation unit 123 | struct mpoa_client *mpcs = NULL; /* FIXME */ | ^ In file included from net/atm/mpc.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:79: In file included from ./arch/riscv/include/generated/asm/preempt.h:1: In file included from include/asm-generic/preempt.h:5: In file included from include/linux/thread_info.h:23: >> arch/riscv/include/asm/current.h:20:30: warning: no previous extern declaration for non-static variable 'riscv_current_is_tp' [-Wmissing-variable-declarations] 20 | register struct task_struct *riscv_current_is_tp __asm__("tp"); | ^ arch/riscv/include/asm/current.h:20:10: note: declare 'static' if the variable is not intended to be used outside of this translation unit 20 | register struct task_struct *riscv_current_is_tp __asm__("tp"); | ^ >> arch/riscv/include/asm/current.h:36:24: warning: no previous extern declaration for non-static variable 'current_stack_pointer' [-Wmissing-variable-declarations] 36 | register unsigned long current_stack_pointer __asm__("sp"); | ^ arch/riscv/include/asm/current.h:36:10: note: declare 'static' if the variable is not intended to be used outside of this translation unit 36 | register unsigned long current_stack_pointer __asm__("sp"); | ^ 3 warnings generated. -- >> net/llc/llc_conn.c:44:5: warning: no previous extern declaration for non-static variable 'sysctl_llc2_ack_timeout' [-Wmissing-variable-declarations] 44 | int sysctl_llc2_ack_timeout = LLC2_ACK_TIME * HZ; | ^ net/llc/llc_conn.c:44:1: note: declare 'static' if the variable is not intended to be used outside of this translation unit 44 | int sysctl_llc2_ack_timeout = LLC2_ACK_TIME * HZ; | ^ >> net/llc/llc_conn.c:45:5: warning: no previous extern declaration for non-static variable 'sysctl_llc2_p_timeout' [-Wmissing-variable-declarations] 45 | int sysctl_llc2_p_timeout = LLC2_P_TIME * HZ; | ^ net/llc/llc_conn.c:45:1: note: declare 'static' if the variable is not intended to be used outside of this translation unit 45 | int sysctl_llc2_p_timeout = LLC2_P_TIME * HZ; | ^ >> net/llc/llc_conn.c:46:5: warning: no previous extern declaration for non-static variable 'sysctl_llc2_rej_timeout' [-Wmissing-variable-declarations] 46 | int sysctl_llc2_rej_timeout = LLC2_REJ_TIME * HZ; | ^ net/llc/llc_conn.c:46:1: note: declare 'static' if the variable is not intended to be used outside of this translation unit 46 | int sysctl_llc2_rej_timeout = LLC2_REJ_TIME * HZ; | ^ >> net/llc/llc_conn.c:47:5: warning: no previous extern declaration for non-static variable 'sysctl_llc2_busy_timeout' [-Wmissing-variable-declarations] 47 | int sysctl_llc2_busy_timeout = LLC2_BUSY_TIME * HZ; | ^ net/llc/llc_conn.c:47:1: note: declare 'static' if the variable is not intended to be used outside of this translation unit 47 | int sysctl_llc2_busy_timeout = LLC2_BUSY_TIME * HZ; | ^ In file included from net/llc/llc_conn.c:16: 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:79: In file included from ./arch/riscv/include/generated/asm/preempt.h:1: In file included from include/asm-generic/preempt.h:5: In file included from include/linux/thread_info.h:23: >> arch/riscv/include/asm/current.h:20:30: warning: no previous extern declaration for non-static variable 'riscv_current_is_tp' [-Wmissing-variable-declarations] 20 | register struct task_struct *riscv_current_is_tp __asm__("tp"); | ^ arch/riscv/include/asm/current.h:20:10: note: declare 'static' if the variable is not intended to be used outside of this translation unit 20 | register struct task_struct *riscv_current_is_tp __asm__("tp"); | ^ >> arch/riscv/include/asm/current.h:36:24: warning: no previous extern declaration for non-static variable 'current_stack_pointer' [-Wmissing-variable-declarations] 36 | register unsigned long current_stack_pointer __asm__("sp"); | ^ arch/riscv/include/asm/current.h:36:10: note: declare 'static' if the variable is not intended to be used outside of this translation unit 36 | register unsigned long current_stack_pointer __asm__("sp"); | ^ 6 warnings generated. -- drivers/i2c/busses/i2c-bcm-iproc.c:1039:3: warning: cast to smaller integer type 'enum bcm_iproc_i2c_type' from 'const void *' [-Wvoid-pointer-to-enum-cast] 1039 | (enum bcm_iproc_i2c_type)of_device_get_match_data(&pdev->dev); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ In file included from drivers/i2c/busses/i2c-bcm-iproc.c:4: In file included from include/linux/delay.h:23: In file included from include/linux/sched.h:12: >> arch/riscv/include/asm/current.h:20:30: warning: no previous extern declaration for non-static variable 'riscv_current_is_tp' [-Wmissing-variable-declarations] 20 | register struct task_struct *riscv_current_is_tp __asm__("tp"); | ^ arch/riscv/include/asm/current.h:20:10: note: declare 'static' if the variable is not intended to be used outside of this translation unit 20 | register struct task_struct *riscv_current_is_tp __asm__("tp"); | ^ >> arch/riscv/include/asm/current.h:36:24: warning: no previous extern declaration for non-static variable 'current_stack_pointer' [-Wmissing-variable-declarations] 36 | register unsigned long current_stack_pointer __asm__("sp"); | ^ arch/riscv/include/asm/current.h:36:10: note: declare 'static' if the variable is not intended to be used outside of this translation unit 36 | register unsigned long current_stack_pointer __asm__("sp"); | ^ 3 warnings generated. -- >> drivers/i2c/busses/i2c-amd756.c:286:20: warning: no previous extern declaration for non-static variable 'amd756_smbus' [-Wmissing-variable-declarations] 286 | struct i2c_adapter amd756_smbus = { | ^ drivers/i2c/busses/i2c-amd756.c:286:1: note: declare 'static' if the variable is not intended to be used outside of this translation unit 286 | struct i2c_adapter amd756_smbus = { | ^ In file included from drivers/i2c/busses/i2c-amd756.c:25: In file included from include/linux/module.h:14: In file included from include/linux/buildid.h:5: In file included from include/linux/mm_types.h:8: In file included from include/linux/kref.h:16: In file included from include/linux/spinlock.h:56: In file included from include/linux/preempt.h:79: In file included from ./arch/riscv/include/generated/asm/preempt.h:1: In file included from include/asm-generic/preempt.h:5: In file included from include/linux/thread_info.h:23: >> arch/riscv/include/asm/current.h:20:30: warning: no previous extern declaration for non-static variable 'riscv_current_is_tp' [-Wmissing-variable-declarations] 20 | register struct task_struct *riscv_current_is_tp __asm__("tp"); | ^ arch/riscv/include/asm/current.h:20:10: note: declare 'static' if the variable is not intended to be used outside of this translation unit 20 | register struct task_struct *riscv_current_is_tp __asm__("tp"); | ^ >> arch/riscv/include/asm/current.h:36:24: warning: no previous extern declaration for non-static variable 'current_stack_pointer' [-Wmissing-variable-declarations] 36 | register unsigned long current_stack_pointer __asm__("sp"); | ^ arch/riscv/include/asm/current.h:36:10: note: declare 'static' if the variable is not intended to be used outside of this translation unit 36 | register unsigned long current_stack_pointer __asm__("sp"); | ^ 3 warnings generated. -- drivers/i2c/busses/i2c-rcar.c:1066:18: warning: cast to smaller integer type 'enum rcar_i2c_type' from 'const void *' [-Wvoid-pointer-to-enum-cast] 1066 | priv->devtype = (enum rcar_i2c_type)of_device_get_match_data(dev); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ In file included from drivers/i2c/busses/i2c-rcar.c:15: In file included from include/linux/clk.h:14: In file included from include/linux/notifier.h:14: In file included from include/linux/mutex.h:14: >> arch/riscv/include/asm/current.h:20:30: warning: no previous extern declaration for non-static variable 'riscv_current_is_tp' [-Wmissing-variable-declarations] 20 | register struct task_struct *riscv_current_is_tp __asm__("tp"); | ^ arch/riscv/include/asm/current.h:20:10: note: declare 'static' if the variable is not intended to be used outside of this translation unit 20 | register struct task_struct *riscv_current_is_tp __asm__("tp"); | ^ >> arch/riscv/include/asm/current.h:36:24: warning: no previous extern declaration for non-static variable 'current_stack_pointer' [-Wmissing-variable-declarations] 36 | register unsigned long current_stack_pointer __asm__("sp"); | ^ arch/riscv/include/asm/current.h:36:10: note: declare 'static' if the variable is not intended to be used outside of this translation unit 36 | register unsigned long current_stack_pointer __asm__("sp"); | ^ 3 warnings generated. -- scripts/genksyms/parse.y: warning: 9 shift/reduce conflicts [-Wconflicts-sr] scripts/genksyms/parse.y: warning: 5 reduce/reduce conflicts [-Wconflicts-rr] scripts/genksyms/parse.y: note: rerun with option '-Wcounterexamples' to generate conflict counterexamples In file included from arch/riscv/kernel/asm-offsets.c:10: In file included from include/linux/mm.h:7: 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:79: In file included from ./arch/riscv/include/generated/asm/preempt.h:1: In file included from include/asm-generic/preempt.h:5: In file included from include/linux/thread_info.h:23: >> arch/riscv/include/asm/current.h:20:30: warning: no previous extern declaration for non-static variable 'riscv_current_is_tp' [-Wmissing-variable-declarations] 20 | register struct task_struct *riscv_current_is_tp __asm__("tp"); | ^ arch/riscv/include/asm/current.h:20:10: note: declare 'static' if the variable is not intended to be used outside of this translation unit 20 | register struct task_struct *riscv_current_is_tp __asm__("tp"); | ^ >> arch/riscv/include/asm/current.h:36:24: warning: no previous extern declaration for non-static variable 'current_stack_pointer' [-Wmissing-variable-declarations] 36 | register unsigned long current_stack_pointer __asm__("sp"); | ^ arch/riscv/include/asm/current.h:36:10: note: declare 'static' if the variable is not intended to be used outside of this translation unit 36 | register unsigned long current_stack_pointer __asm__("sp"); | ^ 2 warnings generated. vim +/riscv_current_is_tp +20 arch/riscv/include/asm/current.h 7db91e57a0acde Palmer Dabbelt 2017-07-10 19 52e7c52d2ded59 Palmer Dabbelt 2020-02-27 @20 register struct task_struct *riscv_current_is_tp __asm__("tp"); 52e7c52d2ded59 Palmer Dabbelt 2020-02-27 21 7db91e57a0acde Palmer Dabbelt 2017-07-10 22 /* 7db91e57a0acde Palmer Dabbelt 2017-07-10 23 * This only works because "struct thread_info" is at offset 0 from "struct 7db91e57a0acde Palmer Dabbelt 2017-07-10 24 * task_struct". This constraint seems to be necessary on other architectures 7db91e57a0acde Palmer Dabbelt 2017-07-10 25 * as well, but __switch_to enforces it. We can't check TASK_TI here because 7db91e57a0acde Palmer Dabbelt 2017-07-10 26 * <asm/asm-offsets.h> includes this, and I can't get the definition of "struct 7db91e57a0acde Palmer Dabbelt 2017-07-10 27 * task_struct" here due to some header ordering problems. 7db91e57a0acde Palmer Dabbelt 2017-07-10 28 */ 7db91e57a0acde Palmer Dabbelt 2017-07-10 29 static __always_inline struct task_struct *get_current(void) 7db91e57a0acde Palmer Dabbelt 2017-07-10 30 { 52e7c52d2ded59 Palmer Dabbelt 2020-02-27 31 return riscv_current_is_tp; 7db91e57a0acde Palmer Dabbelt 2017-07-10 32 } 7db91e57a0acde Palmer Dabbelt 2017-07-10 33 7db91e57a0acde Palmer Dabbelt 2017-07-10 34 #define current get_current() 7db91e57a0acde Palmer Dabbelt 2017-07-10 35 fdecfea09328b3 Kees Cook 2022-02-23 @36 register unsigned long current_stack_pointer __asm__("sp"); fdecfea09328b3 Kees Cook 2022-02-23 37 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
