tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: 99613159ad749543621da8238acf1a122880144e commit: 139c949f7f0ac0dd1c0da132675be80e6d76c65d MIPS: ralink: mt7621: add memory detection support date: 10 months ago config: mips-randconfig-r036-20220119 (https://download.01.org/0day-ci/archive/20220119/202201191557.OISJHNMi-lk...) compiler: mipsel-linux-gcc (GCC) 11.2.0 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 # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit... git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git git fetch --no-tags linus master git checkout 139c949f7f0ac0dd1c0da132675be80e6d76c65d # save the config file to linux build tree mkdir build_dir COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross O=build_dir ARCH=mips SHELL=/bin/bash arch/mips/ralink/ If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>): In file included from include/linux/kernel.h:10, from arch/mips/ralink/mt7621.c:8: arch/mips/ralink/mt7621.c: In function 'mt7621_memory_detect': 123 | if (!__builtin_memcmp(dm, dm + size, sizeof(detect_magic))) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ include/linux/compiler.h:58:52: note: in definition of macro '__trace_if_var' 58 | #define __trace_if_var(cond) (__builtin_constant_p(cond) ? (cond) : __trace_if_value(cond)) | ^~~~ arch/mips/ralink/mt7621.c:123:17: note: in expansion of macro 'if' 123 | if (!__builtin_memcmp(dm, dm + size, sizeof(detect_magic))) | ^~ arch/mips/ralink/mt7621.c:54:14: note: at offset 33554432 into source object 'detect_magic' of size 4 54 | static void *detect_magic __initdata = detect_memory_region; | ^~~~~~~~~~~~ In file included from include/linux/kernel.h:10, from arch/mips/ralink/mt7621.c:8: arch/mips/ralink/mt7621.c:129:13: warning: '__builtin_memcmp' reading between 1 and 4 bytes from a region of size 0 [-Wstringop-overread] 129 | __builtin_memcmp(dm, dm + size, sizeof(detect_magic))) { | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ include/linux/compiler.h:69:10: note: in definition of macro '__trace_if_value' 69 | (cond) ? \ | ^~~~ include/linux/compiler.h:56:28: note: in expansion of macro '__trace_if_var' 56 | #define if(cond, ...) if ( __trace_if_var( !!(cond , ## __VA_ARGS__) ) ) | ^~~~~~~~~~~~~~ arch/mips/ralink/mt7621.c:127:9: note: in expansion of macro 'if' 127 | if ((size == 256 * SZ_1M) && | ^~ arch/mips/ralink/mt7621.c:54:14: note: at offset 268435456 into source object 'detect_magic' of size 4 54 | static void *detect_magic __initdata = detect_memory_region; | ^~~~~~~~~~~~ {standard input}: Assembler messages: {standard input}:127: Error: found '(', expected: ')' {standard input}:127: Error: found '(', expected: ')' {standard input}:127: Error: non-constant expression in ".if" statement {standard input}:127: Error: junk at end of line, first unrecognized character is `(' {standard input}:154: Error: found '(', expected: ')' {standard input}:154: Error: found '(', expected: ')' {standard input}:154: Error: non-constant expression in ".if" statement {standard input}:154: Error: junk at end of line, first unrecognized character is `(' vim +/__builtin_memcmp +123 arch/mips/ralink/mt7621.c 116 117 static void __init mt7621_memory_detect(void) 118 { 119 void *dm = &detect_magic; 120 phys_addr_t size; 121 122 for (size = 32 * SZ_1M; size < 256 * SZ_1M; size <<= 1) { 124 break; 125 } 126 127 if ((size == 256 * SZ_1M) && 128 (CPHYSADDR(dm + size) < MT7621_LOWMEM_MAX_SIZE) && 129 __builtin_memcmp(dm, dm + size, sizeof(detect_magic))) { 130 memblock_add(MT7621_LOWMEM_BASE, MT7621_LOWMEM_MAX_SIZE); 131 memblock_add(MT7621_HIGHMEM_BASE, MT7621_HIGHMEM_SIZE); 132 } else { 133 memblock_add(MT7621_LOWMEM_BASE, size); 134 } 135 } 136 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org