Hi Dan, kernel test robot noticed the following build warnings:
[auto build test WARNING on kees/for-next/hardening] [also build test WARNING on kees/for-next/pstore kees/for-next/kspp linus/master v6.12 next-20241121] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch#_base_tree_information] url: https://github.com/intel-lab-lkp/linux/commits/Dan-Carpenter/overflow-improve-size_add-mul-for-32bit-systems/20241121-124847 base: https://git.kernel.org/pub/scm/linux/kernel/git/kees/linux.git for-next/hardening patch link: https://lore.kernel.org/r/ebdae636-11f3-4f02-a158-f15bbed2847f%40stanley.mountain patch subject: [PATCH] overflow: improve size_add/mul for 32bit systems config: arm-allnoconfig (https://download.01.org/0day-ci/archive/20241122/[email protected]/config) compiler: clang version 20.0.0git (https://github.com/llvm/llvm-project 592c0fe55f6d9a811028b5f3507be91458ab2713) reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241122/[email protected]/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 <[email protected]> | Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/ All warnings (new ones prefixed by >>): In file included from block/bio.c:5: In file included from include/linux/mm.h:2213: include/linux/vmstat.h:518:36: warning: arithmetic between different enumeration types ('enum node_stat_item' and 'enum lru_list') [-Wenum-enum-conversion] 518 | return node_stat_name(NR_LRU_BASE + lru) + 3; // skip "nr_" | ~~~~~~~~~~~ ^ ~~~ >> block/bio.c:616:17: warning: result of comparison of constant 4294967295 >> with expression of type 'typeof (nr_vecs)' (aka 'unsigned short') is always >> false [-Wtautological-constant-out-of-range-compare] 616 | return kmalloc(struct_size(bio, bi_inline_vecs, nr_vecs), gfp_mask); | ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ include/linux/overflow.h:396:18: note: expanded from macro 'struct_size' 396 | sizeof(*(p)) + flex_array_size(p, member, count), \ | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ include/linux/overflow.h:381:3: note: expanded from macro 'flex_array_size' 381 | size_mul(count, sizeof(*(p)->member) + __must_be_array((p)->member))) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ include/linux/overflow.h:281:11: note: expanded from macro 'size_mul' 281 | (__a >= (u64)SIZE_MAX || __b >= (u64)SIZE_MAX)) \ | ~~~ ^ include/linux/slab.h:884:52: note: expanded from macro 'kmalloc' 884 | #define kmalloc(...) alloc_hooks(kmalloc_noprof(__VA_ARGS__)) | ~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~ include/linux/alloc_tag.h:210:31: note: expanded from macro 'alloc_hooks' 210 | alloc_hooks_tag(&_alloc_tag, _do_alloc); \ | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~ include/linux/alloc_tag.h:202:27: note: expanded from macro 'alloc_hooks_tag' 202 | typeof(_do_alloc) _res = _do_alloc; \ | ^~~~~~~~~ >> block/bio.c:616:17: warning: result of comparison of constant 4294967295 >> with expression of type 'typeof (nr_vecs)' (aka 'unsigned short') is always >> false [-Wtautological-constant-out-of-range-compare] 616 | return kmalloc(struct_size(bio, bi_inline_vecs, nr_vecs), gfp_mask); | ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ include/linux/overflow.h:397:26: note: expanded from macro 'struct_size' 397 | size_add(sizeof(*(p)), flex_array_size(p, member, count))) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ include/linux/overflow.h:381:3: note: expanded from macro 'flex_array_size' 381 | size_mul(count, sizeof(*(p)->member) + __must_be_array((p)->member))) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ include/linux/overflow.h:281:11: note: expanded from macro 'size_mul' 281 | (__a >= (u64)SIZE_MAX || __b >= (u64)SIZE_MAX)) \ | ~~~ ^ note: (skipping 1 expansions in backtrace; use -fmacro-backtrace-limit=0 to see all) include/linux/slab.h:884:52: note: expanded from macro 'kmalloc' 884 | #define kmalloc(...) alloc_hooks(kmalloc_noprof(__VA_ARGS__)) | ~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~ include/linux/alloc_tag.h:210:31: note: expanded from macro 'alloc_hooks' 210 | alloc_hooks_tag(&_alloc_tag, _do_alloc); \ | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~ include/linux/alloc_tag.h:202:27: note: expanded from macro 'alloc_hooks_tag' 202 | typeof(_do_alloc) _res = _do_alloc; \ | ^~~~~~~~~ 3 warnings generated. vim +616 block/bio.c ^1da177e4c3f41 fs/bio.c Linus Torvalds 2005-04-16 593 3175199ab0ac8c block/bio.c Christoph Hellwig 2021-01-26 594 /** 066ff571011d84 block/bio.c Christoph Hellwig 2022-04-06 595 * bio_kmalloc - kmalloc a bio 066ff571011d84 block/bio.c Christoph Hellwig 2022-04-06 596 * @nr_vecs: number of bio_vecs to allocate 3175199ab0ac8c block/bio.c Christoph Hellwig 2021-01-26 597 * @gfp_mask: the GFP_* mask given to the slab allocator 3175199ab0ac8c block/bio.c Christoph Hellwig 2021-01-26 598 * 066ff571011d84 block/bio.c Christoph Hellwig 2022-04-06 599 * Use kmalloc to allocate a bio (including bvecs). The bio must be initialized 066ff571011d84 block/bio.c Christoph Hellwig 2022-04-06 600 * using bio_init() before use. To free a bio returned from this function use 066ff571011d84 block/bio.c Christoph Hellwig 2022-04-06 601 * kfree() after calling bio_uninit(). A bio returned from this function can 066ff571011d84 block/bio.c Christoph Hellwig 2022-04-06 602 * be reused by calling bio_uninit() before calling bio_init() again. 066ff571011d84 block/bio.c Christoph Hellwig 2022-04-06 603 * 066ff571011d84 block/bio.c Christoph Hellwig 2022-04-06 604 * Note that unlike bio_alloc() or bio_alloc_bioset() allocations from this 340e134727c9ad block/bio.c Deming Wang 2022-10-06 605 * function are not backed by a mempool can fail. Do not use this function 066ff571011d84 block/bio.c Christoph Hellwig 2022-04-06 606 * for allocations in the file system I/O path. 3175199ab0ac8c block/bio.c Christoph Hellwig 2021-01-26 607 * 3175199ab0ac8c block/bio.c Christoph Hellwig 2021-01-26 608 * Returns: Pointer to new bio on success, NULL on failure. 3175199ab0ac8c block/bio.c Christoph Hellwig 2021-01-26 609 */ 066ff571011d84 block/bio.c Christoph Hellwig 2022-04-06 610 struct bio *bio_kmalloc(unsigned short nr_vecs, gfp_t gfp_mask) 3175199ab0ac8c block/bio.c Christoph Hellwig 2021-01-26 611 { 3175199ab0ac8c block/bio.c Christoph Hellwig 2021-01-26 612 struct bio *bio; 3175199ab0ac8c block/bio.c Christoph Hellwig 2021-01-26 613 066ff571011d84 block/bio.c Christoph Hellwig 2022-04-06 614 if (nr_vecs > UIO_MAXIOV) 3175199ab0ac8c block/bio.c Christoph Hellwig 2021-01-26 615 return NULL; 066ff571011d84 block/bio.c Christoph Hellwig 2022-04-06 @616 return kmalloc(struct_size(bio, bi_inline_vecs, nr_vecs), gfp_mask); 3175199ab0ac8c block/bio.c Christoph Hellwig 2021-01-26 617 } 3175199ab0ac8c block/bio.c Christoph Hellwig 2021-01-26 618 EXPORT_SYMBOL(bio_kmalloc); 3175199ab0ac8c block/bio.c Christoph Hellwig 2021-01-26 619 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
