From: kernel test robot <lkp@intel.com>
To: kbuild@lists.01.org
Subject: [linux-next:master 4074/4957] include/linux/mm_inline.h:126:26: warning: Dereference of null pointer [clang-analyzer-core.NullDereference]
Date: Thu, 21 Apr 2022 14:45:00 +0800 [thread overview]
Message-ID: <202204211142.GQLKLSCH-lkp@intel.com> (raw)
[-- Attachment #1: Type: text/plain, Size: 13720 bytes --]
CC: llvm(a)lists.linux.dev
CC: kbuild-all(a)lists.01.org
BCC: lkp(a)intel.com
CC: Linux Memory Management List <linux-mm@kvack.org>
TO: Yu Zhao <yuzhao@google.com>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Linux Memory Management List <linux-mm@kvack.org>
tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
head: f1244c81da13009dbf61cb807f45881501c44789
commit: c81723809cc65cac8155686768dcf75db38f3b57 [4074/4957] mm: multi-gen LRU: groundwork
:::::: branch date: 20 hours ago
:::::: commit date: 4 days ago
config: riscv-randconfig-c006-20220420 (https://download.01.org/0day-ci/archive/20220421/202204211142.GQLKLSCH-lkp(a)intel.com/config)
compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project bac6cd5bf85669e3376610cfc4c4f9ca015e7b9b)
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
# install riscv cross compiling tool for clang build
# apt-get install binutils-riscv64-linux-gnu
# https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=c81723809cc65cac8155686768dcf75db38f3b57
git remote add linux-next https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
git fetch --no-tags linux-next master
git checkout c81723809cc65cac8155686768dcf75db38f3b57
# save the config file
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=riscv clang-analyzer
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
clang-analyzer warnings: (new ones prefixed by >>)
include/linux/minmax.h:104:27: note: expanded from macro 'min_t'
#define min_t(type, x, y) __careful_cmp((type)(x), (type)(y), <)
^
include/linux/minmax.h:37:3: note: expanded from macro '__careful_cmp'
__cmp(x, y, op), \
^
include/linux/minmax.h:28:26: note: expanded from macro '__cmp'
#define __cmp(x, y, op) ((x) op (y) ? (x) : (y))
^
mm/compaction.c:1480:15: note: Assuming '__UNIQUE_ID___x346' is <= '__UNIQUE_ID___y347'
highest = max(pageblock_start_pfn(pfn),
^
include/linux/minmax.h:52:19: note: expanded from macro 'max'
#define max(x, y) __careful_cmp(x, y, >)
^~~~~~~~~~~~~~~~~~~~~~
include/linux/minmax.h:38:3: note: expanded from macro '__careful_cmp'
__cmp_once(x, y, __UNIQUE_ID(__x), __UNIQUE_ID(__y), op))
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/minmax.h:33:3: note: expanded from macro '__cmp_once'
__cmp(unique_x, unique_y, op); })
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/minmax.h:28:26: note: expanded from macro '__cmp'
#define __cmp(x, y, op) ((x) op (y) ? (x) : (y))
^~~~~~~~~~
mm/compaction.c:1480:15: note: '?' condition is false
highest = max(pageblock_start_pfn(pfn),
^
include/linux/minmax.h:52:19: note: expanded from macro 'max'
#define max(x, y) __careful_cmp(x, y, >)
^
include/linux/minmax.h:38:3: note: expanded from macro '__careful_cmp'
__cmp_once(x, y, __UNIQUE_ID(__x), __UNIQUE_ID(__y), op))
^
include/linux/minmax.h:33:3: note: expanded from macro '__cmp_once'
__cmp(unique_x, unique_y, op); })
^
include/linux/minmax.h:28:26: note: expanded from macro '__cmp'
#define __cmp(x, y, op) ((x) op (y) ? (x) : (y))
^
mm/compaction.c:1483:8: note: Assuming 'pfn' is >= 'low_pfn'
if (pfn >= low_pfn) {
^~~~~~~~~~~~~~
mm/compaction.c:1483:4: note: Taking true branch
if (pfn >= low_pfn) {
^
mm/compaction.c:1487:5: note: Execution continues on line 1502
break;
^
mm/compaction.c:1502:7: note: Assuming pointer value is null
if (!page && high_pfn) {
^~~~~
mm/compaction.c:1502:7: note: Assuming 'page' is null
if (!page && high_pfn) {
^~~~~
mm/compaction.c:1502:7: note: Left side of '&&' is true
mm/compaction.c:1502:16: note: 'high_pfn' is 0
if (!page && high_pfn) {
^~~~~~~~
mm/compaction.c:1502:3: note: Taking false branch
if (!page && high_pfn) {
^
mm/compaction.c:1510:3: note: Calling 'move_freelist_head'
move_freelist_head(freelist, freepage);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
mm/compaction.c:1335:6: note: Assuming the condition is true
if (!list_is_last(freelist, &freepage->lru)) {
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
mm/compaction.c:1335:2: note: Taking true branch
if (!list_is_last(freelist, &freepage->lru)) {
^
mm/compaction.c:1336:3: note: Calling 'list_cut_before'
list_cut_before(&sublist, freelist, &freepage->lru);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/list.h:430:6: note: Assuming 'entry' is equal to field 'next'
if (head->next == entry) {
^~~~~~~~~~~~~~~~~~~
include/linux/list.h:430:2: note: Taking true branch
if (head->next == entry) {
^
include/linux/list.h:432:3: note: Returning without writing to 'head->prev'
return;
^
mm/compaction.c:1336:3: note: Returning from 'list_cut_before'
list_cut_before(&sublist, freelist, &freepage->lru);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
mm/compaction.c:1337:3: note: Calling 'list_splice_tail'
list_splice_tail(&sublist, freelist);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/list.h:476:2: note: Taking true branch
if (!list_empty(list))
^
include/linux/list.h:477:23: note: Passing null pointer value via 2nd parameter 'prev'
__list_splice(list, head->prev, head);
^~~~~~~~~~
include/linux/list.h:477:3: note: Calling '__list_splice'
__list_splice(list, head->prev, head);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/list.h:450:13: note: Access to field 'next' results in a dereference of a null pointer (loaded from variable 'prev')
prev->next = first;
~~~~ ^
>> include/linux/mm_inline.h:126:26: warning: Dereference of null pointer [clang-analyzer-core.NullDereference]
unsigned long max_seq = lruvec->lrugen.max_seq;
^
mm/compaction.c:823:2: note: Loop condition is false. Execution continues on line 838
while (unlikely(too_many_isolated(pgdat))) {
^
mm/compaction.c:840:6: note: Assuming field 'direct_compaction' is false
if (cc->direct_compaction && (cc->mode == MIGRATE_ASYNC)) {
^~~~~~~~~~~~~~~~~~~~~
mm/compaction.c:840:28: note: Left side of '&&' is false
if (cc->direct_compaction && (cc->mode == MIGRATE_ASYNC)) {
^
mm/compaction.c:846:9: note: Assuming 'low_pfn' is < 'end_pfn'
for (; low_pfn < end_pfn; low_pfn++) {
^~~~~~~~~~~~~~~~~
mm/compaction.c:846:2: note: Loop condition is true. Entering loop body
for (; low_pfn < end_pfn; low_pfn++) {
^
mm/compaction.c:848:7: note: 'skip_on_failure' is false
if (skip_on_failure && low_pfn >= next_skip_pfn) {
^~~~~~~~~~~~~~~
mm/compaction.c:848:23: note: Left side of '&&' is false
if (skip_on_failure && low_pfn >= next_skip_pfn) {
^
mm/compaction.c:875:7: note: Assuming the condition is false
if (!(low_pfn % SWAP_CLUSTER_MAX)) {
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
mm/compaction.c:875:3: note: Taking false branch
if (!(low_pfn % SWAP_CLUSTER_MAX)) {
^
mm/compaction.c:901:8: note: 'valid_page' is null
if (!valid_page && IS_ALIGNED(low_pfn, pageblock_nr_pages)) {
^~~~~~~~~~
mm/compaction.c:901:7: note: Left side of '&&' is true
if (!valid_page && IS_ALIGNED(low_pfn, pageblock_nr_pages)) {
^
mm/compaction.c:901:42: note: '?' condition is false
if (!valid_page && IS_ALIGNED(low_pfn, pageblock_nr_pages)) {
^
include/linux/pageblock-flags.h:55:36: note: expanded from macro 'pageblock_nr_pages'
#define pageblock_nr_pages (1UL << pageblock_order)
^
include/linux/pageblock-flags.h:44:26: note: expanded from macro 'pageblock_order'
#define pageblock_order min_t(unsigned int, HUGETLB_PAGE_ORDER, MAX_ORDER - 1)
^
include/linux/minmax.h:104:27: note: expanded from macro 'min_t'
#define min_t(type, x, y) __careful_cmp((type)(x), (type)(y), <)
^
include/linux/minmax.h:37:3: note: expanded from macro '__careful_cmp'
__cmp(x, y, op), \
^
include/linux/minmax.h:28:26: note: expanded from macro '__cmp'
#define __cmp(x, y, op) ((x) op (y) ? (x) : (y))
^
mm/compaction.c:901:22: note: Assuming the condition is false
if (!valid_page && IS_ALIGNED(low_pfn, pageblock_nr_pages)) {
^
include/linux/align.h:13:28: note: expanded from macro 'IS_ALIGNED'
#define IS_ALIGNED(x, a) (((x) & ((typeof(x))@ - 1)) == 0)
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
mm/compaction.c:901:3: note: Taking false branch
if (!valid_page && IS_ALIGNED(low_pfn, pageblock_nr_pages)) {
^
mm/compaction.c:910:7: note: Assuming the condition is false
if (PageHuge(page) && cc->alloc_contig) {
^~~~~~~~~~~~~~
mm/compaction.c:910:22: note: Left side of '&&' is false
if (PageHuge(page) && cc->alloc_contig) {
^
mm/compaction.c:948:3: note: Taking false branch
if (PageBuddy(page)) {
^
mm/compaction.c:969:7: note: Assuming the condition is false
if (PageCompound(page) && !cc->alloc_contig) {
^~~~~~~~~~~~~~~~~~
mm/compaction.c:969:26: note: Left side of '&&' is false
if (PageCompound(page) && !cc->alloc_contig) {
^
mm/compaction.c:982:7: note: Assuming the condition is false
if (!PageLRU(page)) {
^~~~~~~~~~~~~~
mm/compaction.c:982:3: note: Taking false branch
if (!PageLRU(page)) {
^
mm/compaction.c:1007:7: note: Assuming 'mapping' is non-null
if (!mapping && page_count(page) > page_mapcount(page))
^~~~~~~~
mm/compaction.c:1007:16: note: Left side of '&&' is false
if (!mapping && page_count(page) > page_mapcount(page))
^
mm/compaction.c:1014:7: note: Assuming the condition is false
if (!(cc->gfp_mask & __GFP_FS) && mapping)
^~~~~~~~~~~~~~~~~~~~~~~~~~
mm/compaction.c:1014:34: note: Left side of '&&' is false
if (!(cc->gfp_mask & __GFP_FS) && mapping)
^
mm/compaction.c:1022:16: note: Assuming the condition is false
if (unlikely(!get_page_unless_zero(page)))
^
include/linux/compiler.h:78:42: note: expanded from macro 'unlikely'
# define unlikely(x) __builtin_expect(!!(x), 0)
vim +126 include/linux/mm_inline.h
c81723809cc65c Yu Zhao 2022-04-13 123
c81723809cc65c Yu Zhao 2022-04-13 124 static inline bool lru_gen_is_active(struct lruvec *lruvec, int gen)
c81723809cc65c Yu Zhao 2022-04-13 125 {
c81723809cc65c Yu Zhao 2022-04-13 @126 unsigned long max_seq = lruvec->lrugen.max_seq;
c81723809cc65c Yu Zhao 2022-04-13 127
c81723809cc65c Yu Zhao 2022-04-13 128 VM_BUG_ON(gen >= MAX_NR_GENS);
c81723809cc65c Yu Zhao 2022-04-13 129
c81723809cc65c Yu Zhao 2022-04-13 130 /* see the comment on MIN_NR_GENS */
c81723809cc65c Yu Zhao 2022-04-13 131 return gen == lru_gen_from_seq(max_seq) || gen == lru_gen_from_seq(max_seq - 1);
c81723809cc65c Yu Zhao 2022-04-13 132 }
c81723809cc65c Yu Zhao 2022-04-13 133
--
0-DAY CI Kernel Test Service
https://01.org/lkp
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