Hi Matthew, kernel test robot noticed the following build warnings: [auto build test WARNING on akpm-mm/mm-everything] [also build test WARNING on linus/master v6.5-rc7 next-20230824] [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/Matthew-Wilcox-Oracle/hugetlb-Remove-a-few-calls-to-page_folio/20230823-002932 base: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything patch link: https://lore.kernel.org/r/20230822162808.4131399-2-willy%40infradead.org patch subject: [PATCH 2/3] hugetlb: Remove a few calls to page_folio() config: s390-randconfig-001-20230824 (https://download.01.org/0day-ci/archive/20230824/202308242115.E2LcVeIB-lkp@xxxxxxxxx/config) compiler: clang version 17.0.0 (https://github.com/llvm/llvm-project.git 4a5ac14ee968ff0ad5d2cc1ffa0299048db4c88a) reproduce: (https://download.01.org/0day-ci/archive/20230824/202308242115.E2LcVeIB-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/202308242115.E2LcVeIB-lkp@xxxxxxxxx/ All warnings (new ones prefixed by >>): In file included from mm/hugetlb.c:19: In file included from include/linux/memblock.h:13: In file included from arch/s390/include/asm/dma.h:5: In file included from include/linux/io.h:13: In file included from arch/s390/include/asm/io.h:78: include/asm-generic/io.h:547:31: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 547 | val = __raw_readb(PCI_IOBASE + addr); | ~~~~~~~~~~ ^ include/asm-generic/io.h:560:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 560 | val = __le16_to_cpu((__le16 __force)__raw_readw(PCI_IOBASE + addr)); | ~~~~~~~~~~ ^ include/uapi/linux/byteorder/big_endian.h:37:59: note: expanded from macro '__le16_to_cpu' 37 | #define __le16_to_cpu(x) __swab16((__force __u16)(__le16)(x)) | ^ include/uapi/linux/swab.h:102:54: note: expanded from macro '__swab16' 102 | #define __swab16(x) (__u16)__builtin_bswap16((__u16)(x)) | ^ In file included from mm/hugetlb.c:19: In file included from include/linux/memblock.h:13: In file included from arch/s390/include/asm/dma.h:5: In file included from include/linux/io.h:13: In file included from arch/s390/include/asm/io.h:78: include/asm-generic/io.h:573:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 573 | val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr)); | ~~~~~~~~~~ ^ include/uapi/linux/byteorder/big_endian.h:35:59: note: expanded from macro '__le32_to_cpu' 35 | #define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x)) | ^ include/uapi/linux/swab.h:115:54: note: expanded from macro '__swab32' 115 | #define __swab32(x) (__u32)__builtin_bswap32((__u32)(x)) | ^ In file included from mm/hugetlb.c:19: In file included from include/linux/memblock.h:13: In file included from arch/s390/include/asm/dma.h:5: In file included from include/linux/io.h:13: In file included from arch/s390/include/asm/io.h:78: include/asm-generic/io.h:584:33: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 584 | __raw_writeb(value, PCI_IOBASE + addr); | ~~~~~~~~~~ ^ include/asm-generic/io.h:594:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 594 | __raw_writew((u16 __force)cpu_to_le16(value), PCI_IOBASE + addr); | ~~~~~~~~~~ ^ include/asm-generic/io.h:604:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 604 | __raw_writel((u32 __force)cpu_to_le32(value), PCI_IOBASE + addr); | ~~~~~~~~~~ ^ include/asm-generic/io.h:692:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 692 | readsb(PCI_IOBASE + addr, buffer, count); | ~~~~~~~~~~ ^ include/asm-generic/io.h:700:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 700 | readsw(PCI_IOBASE + addr, buffer, count); | ~~~~~~~~~~ ^ include/asm-generic/io.h:708:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 708 | readsl(PCI_IOBASE + addr, buffer, count); | ~~~~~~~~~~ ^ include/asm-generic/io.h:717:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 717 | writesb(PCI_IOBASE + addr, buffer, count); | ~~~~~~~~~~ ^ include/asm-generic/io.h:726:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 726 | writesw(PCI_IOBASE + addr, buffer, count); | ~~~~~~~~~~ ^ include/asm-generic/io.h:735:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic] 735 | writesl(PCI_IOBASE + addr, buffer, count); | ~~~~~~~~~~ ^ >> mm/hugetlb.c:2232:32: warning: variable 'folio' is used uninitialized whenever '&&' condition is false [-Wsometimes-uninitialized] 2232 | for_each_node_mask_to_free(h, nr_nodes, node, nodes_allowed) { | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ mm/hugetlb.c:1469:3: note: expanded from macro 'for_each_node_mask_to_free' 1469 | nr_nodes > 0 && \ | ^~~~~~~~~~~~ mm/hugetlb.c:2246:10: note: uninitialized use occurs here 2246 | return &folio->page; | ^~~~~ mm/hugetlb.c:2232:32: note: remove the '&&' if its condition is always true 2232 | for_each_node_mask_to_free(h, nr_nodes, node, nodes_allowed) { | ^ mm/hugetlb.c:2229:21: note: initialize the variable 'folio' to silence this warning 2229 | struct folio *folio; | ^ | = NULL 13 warnings generated. vim +2232 mm/hugetlb.c b2261026825ed3 Joonsoo Kim 2013-09-11 2216 e8c5c8249878fb Lee Schermerhorn 2009-09-21 2217 /* 10c6ec49802b17 Mike Kravetz 2021-05-04 2218 * Remove huge page from pool from next node to free. Attempt to keep 10c6ec49802b17 Mike Kravetz 2021-05-04 2219 * persistent huge pages more or less balanced over allowed nodes. 10c6ec49802b17 Mike Kravetz 2021-05-04 2220 * This routine only 'removes' the hugetlb page. The caller must make 10c6ec49802b17 Mike Kravetz 2021-05-04 2221 * an additional call to free the page to low level allocators. e8c5c8249878fb Lee Schermerhorn 2009-09-21 2222 * Called with hugetlb_lock locked. e8c5c8249878fb Lee Schermerhorn 2009-09-21 2223 */ 10c6ec49802b17 Mike Kravetz 2021-05-04 2224 static struct page *remove_pool_huge_page(struct hstate *h, 10c6ec49802b17 Mike Kravetz 2021-05-04 2225 nodemask_t *nodes_allowed, 6ae11b278bca1c Lee Schermerhorn 2009-12-14 2226 bool acct_surplus) e8c5c8249878fb Lee Schermerhorn 2009-09-21 2227 { b2261026825ed3 Joonsoo Kim 2013-09-11 2228 int nr_nodes, node; cfd5082b514765 Sidhartha Kumar 2022-11-29 2229 struct folio *folio; e8c5c8249878fb Lee Schermerhorn 2009-09-21 2230 9487ca60fd7fa2 Mike Kravetz 2021-05-04 2231 lockdep_assert_held(&hugetlb_lock); b2261026825ed3 Joonsoo Kim 2013-09-11 @2232 for_each_node_mask_to_free(h, nr_nodes, node, nodes_allowed) { 685f345708096e Lee Schermerhorn 2009-09-21 2233 /* 685f345708096e Lee Schermerhorn 2009-09-21 2234 * If we're returning unused surplus pages, only examine 685f345708096e Lee Schermerhorn 2009-09-21 2235 * nodes with surplus pages. 685f345708096e Lee Schermerhorn 2009-09-21 2236 */ b2261026825ed3 Joonsoo Kim 2013-09-11 2237 if ((!acct_surplus || h->surplus_huge_pages_node[node]) && b2261026825ed3 Joonsoo Kim 2013-09-11 2238 !list_empty(&h->hugepage_freelists[node])) { e601ce76a2aabd Matthew Wilcox (Oracle 2023-08-22 2239) folio = list_entry(h->hugepage_freelists[node].next, e601ce76a2aabd Matthew Wilcox (Oracle 2023-08-22 2240) struct folio, lru); cfd5082b514765 Sidhartha Kumar 2022-11-29 2241 remove_hugetlb_folio(h, folio, acct_surplus); 9a76db09970938 Lee Schermerhorn 2009-12-14 2242 break; e8c5c8249878fb Lee Schermerhorn 2009-09-21 2243 } b2261026825ed3 Joonsoo Kim 2013-09-11 2244 } e8c5c8249878fb Lee Schermerhorn 2009-09-21 2245 e601ce76a2aabd Matthew Wilcox (Oracle 2023-08-22 2246) return &folio->page; e8c5c8249878fb Lee Schermerhorn 2009-09-21 2247 } e8c5c8249878fb Lee Schermerhorn 2009-09-21 2248 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
