Hi Jakub, kernel test robot noticed the following build warnings: [auto build test WARNING on bpf-next/master] url: https://github.com/intel-lab-lkp/linux/commits/Jakub-Sitnicki/bpf-Add-dynptr-type-for-skb-metadata/20250731-183157 base: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master patch link: https://lore.kernel.org/r/20250731-skb-metadata-thru-dynptr-v5-2-f02f6b5688dc%40cloudflare.com patch subject: [PATCH bpf-next v5 2/9] bpf: Enable read/write access to skb metadata through a dynptr config: i386-buildonly-randconfig-005-20250801 (https://download.01.org/0day-ci/archive/20250801/202508010501.YGP8iOar-lkp@xxxxxxxxx/config) compiler: gcc-12 (Debian 12.2.0-14+deb12u1) 12.2.0 reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250801/202508010501.YGP8iOar-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/202508010501.YGP8iOar-lkp@xxxxxxxxx/ All warnings (new ones prefixed by >>): kernel/bpf/helpers.c: In function '____bpf_snprintf': kernel/bpf/helpers.c:1069:9: warning: function '____bpf_snprintf' might be a candidate for 'gnu_printf' format attribute [-Wsuggest-attribute=format] 1069 | err = bstr_printf(str, str_size, fmt, data.bin_args); | ^~~ In file included from include/linux/string.h:382, from arch/x86/include/asm/page_32.h:18, from arch/x86/include/asm/page.h:14, from arch/x86/include/asm/processor.h:20, from arch/x86/include/asm/timex.h:5, from include/linux/timex.h:67, from include/linux/time32.h:13, from include/linux/time.h:60, from include/linux/jiffies.h:10, from include/linux/ktime.h:25, from include/linux/timer.h:6, from include/linux/workqueue.h:9, from include/linux/bpf.h:10, from kernel/bpf/helpers.c:4: kernel/bpf/helpers.c: In function '__bpf_dynptr_read': >> include/linux/fortify-string.h:115:33: warning: argument 2 null where non-null expected [-Wnonnull] 115 | #define __underlying_memmove __builtin_memmove | ^ include/linux/fortify-string.h:645:9: note: in expansion of macro '__underlying_memmove' 645 | __underlying_##op(p, q, __copy_size); \ | ^~~~~~~~~~~~~ include/linux/fortify-string.h:694:27: note: in expansion of macro '__fortify_memcpy_chk' 694 | #define memmove(p, q, s) __fortify_memcpy_chk(p, q, s, \ | ^~~~~~~~~~~~~~~~~~~~ kernel/bpf/helpers.c:1784:17: note: in expansion of macro 'memmove' 1784 | memmove(dst, bpf_skb_meta_pointer(src->data, src->offset + offset), len); | ^~~~~~~ include/linux/fortify-string.h:115:33: note: in a call to built-in function '__builtin_memmove' 115 | #define __underlying_memmove __builtin_memmove | ^ include/linux/fortify-string.h:645:9: note: in expansion of macro '__underlying_memmove' 645 | __underlying_##op(p, q, __copy_size); \ | ^~~~~~~~~~~~~ include/linux/fortify-string.h:694:27: note: in expansion of macro '__fortify_memcpy_chk' 694 | #define memmove(p, q, s) __fortify_memcpy_chk(p, q, s, \ | ^~~~~~~~~~~~~~~~~~~~ kernel/bpf/helpers.c:1784:17: note: in expansion of macro 'memmove' 1784 | memmove(dst, bpf_skb_meta_pointer(src->data, src->offset + offset), len); | ^~~~~~~ kernel/bpf/helpers.c: In function '__bpf_dynptr_write': include/linux/fortify-string.h:115:33: warning: argument 1 null where non-null expected [-Wnonnull] 115 | #define __underlying_memmove __builtin_memmove | ^ include/linux/fortify-string.h:645:9: note: in expansion of macro '__underlying_memmove' 645 | __underlying_##op(p, q, __copy_size); \ | ^~~~~~~~~~~~~ include/linux/fortify-string.h:694:27: note: in expansion of macro '__fortify_memcpy_chk' 694 | #define memmove(p, q, s) __fortify_memcpy_chk(p, q, s, \ | ^~~~~~~~~~~~~~~~~~~~ kernel/bpf/helpers.c:1845:17: note: in expansion of macro 'memmove' 1845 | memmove(bpf_skb_meta_pointer(dst->data, dst->offset + offset), src, len); | ^~~~~~~ include/linux/fortify-string.h:115:33: note: in a call to built-in function '__builtin_memmove' 115 | #define __underlying_memmove __builtin_memmove | ^ include/linux/fortify-string.h:645:9: note: in expansion of macro '__underlying_memmove' 645 | __underlying_##op(p, q, __copy_size); \ | ^~~~~~~~~~~~~ include/linux/fortify-string.h:694:27: note: in expansion of macro '__fortify_memcpy_chk' 694 | #define memmove(p, q, s) __fortify_memcpy_chk(p, q, s, \ | ^~~~~~~~~~~~~~~~~~~~ kernel/bpf/helpers.c:1845:17: note: in expansion of macro 'memmove' 1845 | memmove(bpf_skb_meta_pointer(dst->data, dst->offset + offset), src, len); | ^~~~~~~ vim +115 include/linux/fortify-string.h 78a498c3a227f2 Alexander Potapenko 2022-10-24 103 78a498c3a227f2 Alexander Potapenko 2022-10-24 104 #if defined(__SANITIZE_MEMORY__) 78a498c3a227f2 Alexander Potapenko 2022-10-24 105 /* 78a498c3a227f2 Alexander Potapenko 2022-10-24 106 * For KMSAN builds all memcpy/memset/memmove calls should be replaced by the 78a498c3a227f2 Alexander Potapenko 2022-10-24 107 * corresponding __msan_XXX functions. 78a498c3a227f2 Alexander Potapenko 2022-10-24 108 */ 78a498c3a227f2 Alexander Potapenko 2022-10-24 109 #include <linux/kmsan_string.h> 78a498c3a227f2 Alexander Potapenko 2022-10-24 110 #define __underlying_memcpy __msan_memcpy 78a498c3a227f2 Alexander Potapenko 2022-10-24 111 #define __underlying_memmove __msan_memmove 78a498c3a227f2 Alexander Potapenko 2022-10-24 112 #define __underlying_memset __msan_memset 78a498c3a227f2 Alexander Potapenko 2022-10-24 113 #else a28a6e860c6cf2 Francis Laniel 2021-02-25 114 #define __underlying_memcpy __builtin_memcpy a28a6e860c6cf2 Francis Laniel 2021-02-25 @115 #define __underlying_memmove __builtin_memmove a28a6e860c6cf2 Francis Laniel 2021-02-25 116 #define __underlying_memset __builtin_memset 78a498c3a227f2 Alexander Potapenko 2022-10-24 117 #endif 78a498c3a227f2 Alexander Potapenko 2022-10-24 118 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
