Hi Hao, kernel test robot noticed the following build errors: [auto build test ERROR on akpm-mm/mm-everything] url: https://github.com/intel-lab-lkp/linux/commits/Hao-Ge/mm-alloc_tag-Fix-panic-when-CONFIG_KASAN-enabled-and-CONFIG_KASAN_VMALLOC-not-enabled/20241211-110206 base: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything patch link: https://lore.kernel.org/r/20241211025755.56173-1-hao.ge%40linux.dev patch subject: [PATCH v3] mm/alloc_tag: Fix panic when CONFIG_KASAN enabled and CONFIG_KASAN_VMALLOC not enabled config: i386-buildonly-randconfig-005-20241211 (https://download.01.org/0day-ci/archive/20241212/202412120143.l3g6vx8b-lkp@xxxxxxxxx/config) compiler: gcc-12 (Debian 12.2.0-14) 12.2.0 reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241212/202412120143.l3g6vx8b-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/202412120143.l3g6vx8b-lkp@xxxxxxxxx/ All errors (new ones prefixed by >>): lib/alloc_tag.c: In function 'vm_module_tags_populate': >> lib/alloc_tag.c:409:40: error: 'KASAN_SHADOW_SCALE_SHIFT' undeclared (first use in this function) 409 | (2 << KASAN_SHADOW_SCALE_SHIFT) - 1) >> KASAN_SHADOW_SCALE_SHIFT; | ^~~~~~~~~~~~~~~~~~~~~~~~ lib/alloc_tag.c:409:40: note: each undeclared identifier is reported only once for each function it appears in vim +/KASAN_SHADOW_SCALE_SHIFT +409 lib/alloc_tag.c 402 403 static int vm_module_tags_populate(void) 404 { 405 unsigned long phys_end = ALIGN_DOWN(module_tags.start_addr, PAGE_SIZE) + 406 (vm_module_tags->nr_pages << PAGE_SHIFT); 407 unsigned long new_end = module_tags.start_addr + module_tags.size; 408 unsigned long phys_idx = (vm_module_tags->nr_pages + > 409 (2 << KASAN_SHADOW_SCALE_SHIFT) - 1) >> KASAN_SHADOW_SCALE_SHIFT; 410 unsigned long new_idx = 0; 411 412 if (phys_end < new_end) { 413 struct page **next_page = vm_module_tags->pages + vm_module_tags->nr_pages; 414 unsigned long more_pages; 415 unsigned long nr; 416 417 more_pages = ALIGN(new_end - phys_end, PAGE_SIZE) >> PAGE_SHIFT; 418 nr = alloc_pages_bulk_array_node(GFP_KERNEL | __GFP_NOWARN, 419 NUMA_NO_NODE, more_pages, next_page); 420 if (nr < more_pages || 421 vmap_pages_range(phys_end, phys_end + (nr << PAGE_SHIFT), PAGE_KERNEL, 422 next_page, PAGE_SHIFT) < 0) { 423 /* Clean up and error out */ 424 for (int i = 0; i < nr; i++) 425 __free_page(next_page[i]); 426 return -ENOMEM; 427 } 428 429 vm_module_tags->nr_pages += nr; 430 431 new_idx = (vm_module_tags->nr_pages + 432 (2 << KASAN_SHADOW_SCALE_SHIFT) - 1) >> KASAN_SHADOW_SCALE_SHIFT; 433 434 /* 435 * Kasan allocates 1 byte of shadow for every 8 bytes of data. 436 * When kasan_alloc_module_shadow allocates shadow memory, 437 * its unit of allocation is a page. 438 * Therefore, here we need to align to MODULE_ALIGN. 439 * 440 * For every KASAN_SHADOW_SCALE_SHIFT, a shadow page is allocated. 441 * So, we determine whether to allocate based on whether the 442 * number of pages falls within the scope of the same KASAN_SHADOW_SCALE_SHIFT. 443 */ 444 if (phys_idx != new_idx) 445 kasan_alloc_module_shadow((void *)round_up(phys_end, MODULE_ALIGN), 446 (new_idx - phys_idx) * MODULE_ALIGN, 447 GFP_KERNEL); 448 } 449 450 /* 451 * Mark the pages as accessible, now that they are mapped. 452 * With hardware tag-based KASAN, marking is skipped for 453 * non-VM_ALLOC mappings, see __kasan_unpoison_vmalloc(). 454 */ 455 kasan_unpoison_vmalloc((void *)module_tags.start_addr, 456 new_end - module_tags.start_addr, 457 KASAN_VMALLOC_PROT_NORMAL); 458 459 return 0; 460 } 461 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
