tree: https://git.kernel.org/pub/scm/linux/kernel/git/rppt/linux.git memblock/iterators-cleanup/v3 head: f0d593460d044672ca2ea065efc283e30dd23ef1 commit: 3efd016ce3025d16da91568f97de6f0006281657 [10/17] memblock: reduce number of parameters in for_each_mem_range() config: powerpc-defconfig (attached as .config) compiler: powerpc64-linux-gcc (GCC) 9.3.0 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 git checkout 3efd016ce3025d16da91568f97de6f0006281657 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=powerpc If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): arch/powerpc/kexec/file_load_64.c: In function '__locate_mem_hole_bottom_up': 354 | MEMBLOCK_NONE, &start, &end, NULL) { | ^ In file included from arch/powerpc/kexec/file_load_64.c:21: include/linux/memblock.h:211: note: macro "for_each_mem_range" defined here 211 | #define for_each_mem_range(i, p_start, p_end) \ | 353 | for_each_mem_range(i, &memblock.memory, NULL, NUMA_NO_NODE, | ^~~~~~~~~~~~~~~~~~ | crash_mem_range arch/powerpc/kexec/file_load_64.c:353:2: note: each undeclared identifier is reported only once for each function it appears in 353 | for_each_mem_range(i, &memblock.memory, NULL, NUMA_NO_NODE, | ^ | ; 354 | MEMBLOCK_NONE, &start, &end, NULL) { | ~ 351 | u64 i; | ^ 350 | phys_addr_t start, end; | ^~~ 350 | phys_addr_t start, end; | ^~~~~ 349 | int ret = -EADDRNOTAVAIL; | ^~~ arch/powerpc/kexec/file_load_64.c:385:1: error: no return statement in function returning non-void [-Werror=return-type] 385 | } | ^ cc1: all warnings being treated as errors vim +/for_each_mem_range +354 arch/powerpc/kexec/file_load_64.c b8e55a3e5c2088 Hari Bathini 2020-07-29 335 b8e55a3e5c2088 Hari Bathini 2020-07-29 336 /** b8e55a3e5c2088 Hari Bathini 2020-07-29 337 * __locate_mem_hole_bottom_up - Looks bottom up for a large enough memory hole b8e55a3e5c2088 Hari Bathini 2020-07-29 338 * in the memory regions between buf_min & buf_max b8e55a3e5c2088 Hari Bathini 2020-07-29 339 * for the buffer. If found, sets kbuf->mem. b8e55a3e5c2088 Hari Bathini 2020-07-29 340 * @kbuf: Buffer contents and memory parameters. b8e55a3e5c2088 Hari Bathini 2020-07-29 341 * @buf_min: Minimum address for the buffer. b8e55a3e5c2088 Hari Bathini 2020-07-29 342 * @buf_max: Maximum address for the buffer. b8e55a3e5c2088 Hari Bathini 2020-07-29 343 * b8e55a3e5c2088 Hari Bathini 2020-07-29 344 * Returns 0 on success, negative errno on error. b8e55a3e5c2088 Hari Bathini 2020-07-29 345 */ b8e55a3e5c2088 Hari Bathini 2020-07-29 346 static int __locate_mem_hole_bottom_up(struct kexec_buf *kbuf, b8e55a3e5c2088 Hari Bathini 2020-07-29 347 u64 buf_min, u64 buf_max) b8e55a3e5c2088 Hari Bathini 2020-07-29 348 { b8e55a3e5c2088 Hari Bathini 2020-07-29 @349 int ret = -EADDRNOTAVAIL; b8e55a3e5c2088 Hari Bathini 2020-07-29 @350 phys_addr_t start, end; b8e55a3e5c2088 Hari Bathini 2020-07-29 @351 u64 i; b8e55a3e5c2088 Hari Bathini 2020-07-29 352 b8e55a3e5c2088 Hari Bathini 2020-07-29 @353 for_each_mem_range(i, &memblock.memory, NULL, NUMA_NO_NODE, b8e55a3e5c2088 Hari Bathini 2020-07-29 @354 MEMBLOCK_NONE, &start, &end, NULL) { b8e55a3e5c2088 Hari Bathini 2020-07-29 355 /* b8e55a3e5c2088 Hari Bathini 2020-07-29 356 * memblock uses [start, end) convention while it is b8e55a3e5c2088 Hari Bathini 2020-07-29 357 * [start, end] here. Fix the off-by-one to have the b8e55a3e5c2088 Hari Bathini 2020-07-29 358 * same convention. b8e55a3e5c2088 Hari Bathini 2020-07-29 359 */ b8e55a3e5c2088 Hari Bathini 2020-07-29 360 end -= 1; b8e55a3e5c2088 Hari Bathini 2020-07-29 361 b8e55a3e5c2088 Hari Bathini 2020-07-29 362 if (end < buf_min) b8e55a3e5c2088 Hari Bathini 2020-07-29 363 continue; b8e55a3e5c2088 Hari Bathini 2020-07-29 364 b8e55a3e5c2088 Hari Bathini 2020-07-29 365 /* Memory hole not found */ b8e55a3e5c2088 Hari Bathini 2020-07-29 366 if (start > buf_max) b8e55a3e5c2088 Hari Bathini 2020-07-29 367 break; b8e55a3e5c2088 Hari Bathini 2020-07-29 368 b8e55a3e5c2088 Hari Bathini 2020-07-29 369 /* Adjust memory region based on the given range */ b8e55a3e5c2088 Hari Bathini 2020-07-29 370 if (start < buf_min) b8e55a3e5c2088 Hari Bathini 2020-07-29 371 start = buf_min; b8e55a3e5c2088 Hari Bathini 2020-07-29 372 if (end > buf_max) b8e55a3e5c2088 Hari Bathini 2020-07-29 373 end = buf_max; b8e55a3e5c2088 Hari Bathini 2020-07-29 374 b8e55a3e5c2088 Hari Bathini 2020-07-29 375 start = ALIGN(start, kbuf->buf_align); b8e55a3e5c2088 Hari Bathini 2020-07-29 376 if (start < end && (end - start + 1) >= kbuf->memsz) { b8e55a3e5c2088 Hari Bathini 2020-07-29 377 /* Suitable memory range found. Set kbuf->mem */ b8e55a3e5c2088 Hari Bathini 2020-07-29 378 kbuf->mem = start; b8e55a3e5c2088 Hari Bathini 2020-07-29 379 ret = 0; b8e55a3e5c2088 Hari Bathini 2020-07-29 380 break; b8e55a3e5c2088 Hari Bathini 2020-07-29 381 } b8e55a3e5c2088 Hari Bathini 2020-07-29 382 } b8e55a3e5c2088 Hari Bathini 2020-07-29 383 b8e55a3e5c2088 Hari Bathini 2020-07-29 384 return ret; b8e55a3e5c2088 Hari Bathini 2020-07-29 385 } b8e55a3e5c2088 Hari Bathini 2020-07-29 386 :::::: The code at line 354 was first introduced by commit :::::: b8e55a3e5c208862eacded5aad822184f89f85d9 powerpc/kexec_file: Avoid stomping memory used by special regions :::::: TO: Hari Bathini <hbathini(a)linux.ibm.com&gt; :::::: CC: Michael Ellerman <mpe(a)ellerman.id.au&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org