Hi Nguyen, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on staging/staging-testing] url: https://github.com/0day-ci/linux/commits/Nguyen-Dinh-Phi/staging-vc04_services-make-a-couple-of-functions-static/20220131-151209 base: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git 64b2d6ffff862c0e7278198b4229e42e1abb3bb1 config: x86_64-buildonly-randconfig-r004-20220131 (https://download.01.org/0day-ci/archive/20220131/202201311820.inNbCM0H-lkp@xxxxxxxxx/config) compiler: gcc-9 (Debian 9.3.0-22) 9.3.0 reproduce (this is a W=1 build): # https://github.com/0day-ci/linux/commit/1b64825a2b5b3312ae309c1714239df049b018ac git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Nguyen-Dinh-Phi/staging-vc04_services-make-a-couple-of-functions-static/20220131-151209 git checkout 1b64825a2b5b3312ae309c1714239df049b018ac # save the config file to linux build tree mkdir build_dir make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash drivers/staging/vc04_services/ If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp@xxxxxxxxx> All warnings (new ones prefixed by >>): In file included from include/linux/string.h:253, from include/linux/bitmap.h:11, from include/linux/cpumask.h:12, from arch/x86/include/asm/cpumask.h:5, from arch/x86/include/asm/msr.h:11, from arch/x86/include/asm/processor.h:22, from arch/x86/include/asm/timex.h:5, from include/linux/timex.h:65, from include/linux/time32.h:13, from include/linux/time.h:60, from include/linux/stat.h:19, from include/linux/module.h:13, from drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c:8: In function 'memcpy', inlined from 'free_pagelist' at drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c:434:4, inlined from 'vchiq_complete_bulk' at drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c:650:3: >> include/linux/fortify-string.h:41:29: warning: argument 2 null where non-null expected [-Wnonnull] 41 | #define __underlying_memcpy __builtin_memcpy | ^ include/linux/fortify-string.h:225:9: note: in expansion of macro '__underlying_memcpy' 225 | return __underlying_memcpy(p, q, size); | ^~~~~~~~~~~~~~~~~~~ drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c: In function 'vchiq_complete_bulk': include/linux/fortify-string.h:41:29: note: in a call to built-in function '__builtin_memcpy' 41 | #define __underlying_memcpy __builtin_memcpy | ^ include/linux/fortify-string.h:225:9: note: in expansion of macro '__underlying_memcpy' 225 | return __underlying_memcpy(p, q, size); | ^~~~~~~~~~~~~~~~~~~ vim +41 include/linux/fortify-string.h 3009f891bb9f32 Kees Cook 2021-08-02 26 a28a6e860c6cf2 Francis Laniel 2021-02-25 27 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS) a28a6e860c6cf2 Francis Laniel 2021-02-25 28 extern void *__underlying_memchr(const void *p, int c, __kernel_size_t size) __RENAME(memchr); a28a6e860c6cf2 Francis Laniel 2021-02-25 29 extern int __underlying_memcmp(const void *p, const void *q, __kernel_size_t size) __RENAME(memcmp); a28a6e860c6cf2 Francis Laniel 2021-02-25 30 extern void *__underlying_memcpy(void *p, const void *q, __kernel_size_t size) __RENAME(memcpy); a28a6e860c6cf2 Francis Laniel 2021-02-25 31 extern void *__underlying_memmove(void *p, const void *q, __kernel_size_t size) __RENAME(memmove); a28a6e860c6cf2 Francis Laniel 2021-02-25 32 extern void *__underlying_memset(void *p, int c, __kernel_size_t size) __RENAME(memset); a28a6e860c6cf2 Francis Laniel 2021-02-25 33 extern char *__underlying_strcat(char *p, const char *q) __RENAME(strcat); a28a6e860c6cf2 Francis Laniel 2021-02-25 34 extern char *__underlying_strcpy(char *p, const char *q) __RENAME(strcpy); a28a6e860c6cf2 Francis Laniel 2021-02-25 35 extern __kernel_size_t __underlying_strlen(const char *p) __RENAME(strlen); a28a6e860c6cf2 Francis Laniel 2021-02-25 36 extern char *__underlying_strncat(char *p, const char *q, __kernel_size_t count) __RENAME(strncat); a28a6e860c6cf2 Francis Laniel 2021-02-25 37 extern char *__underlying_strncpy(char *p, const char *q, __kernel_size_t size) __RENAME(strncpy); a28a6e860c6cf2 Francis Laniel 2021-02-25 38 #else a28a6e860c6cf2 Francis Laniel 2021-02-25 39 #define __underlying_memchr __builtin_memchr a28a6e860c6cf2 Francis Laniel 2021-02-25 40 #define __underlying_memcmp __builtin_memcmp a28a6e860c6cf2 Francis Laniel 2021-02-25 @41 #define __underlying_memcpy __builtin_memcpy a28a6e860c6cf2 Francis Laniel 2021-02-25 42 #define __underlying_memmove __builtin_memmove a28a6e860c6cf2 Francis Laniel 2021-02-25 43 #define __underlying_memset __builtin_memset a28a6e860c6cf2 Francis Laniel 2021-02-25 44 #define __underlying_strcat __builtin_strcat a28a6e860c6cf2 Francis Laniel 2021-02-25 45 #define __underlying_strcpy __builtin_strcpy a28a6e860c6cf2 Francis Laniel 2021-02-25 46 #define __underlying_strlen __builtin_strlen a28a6e860c6cf2 Francis Laniel 2021-02-25 47 #define __underlying_strncat __builtin_strncat a28a6e860c6cf2 Francis Laniel 2021-02-25 48 #define __underlying_strncpy __builtin_strncpy a28a6e860c6cf2 Francis Laniel 2021-02-25 49 #endif a28a6e860c6cf2 Francis Laniel 2021-02-25 50 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx