On 22/01/2024 17:19, Ryan Roberts wrote: > On 12/01/2024 10:14, Kefeng Wang wrote: >> >> >> On 2024/1/12 13:03, kernel test robot wrote: >>> Hi Matthew, >>> >>> kernel test robot noticed the following build warnings: >>> >>> [auto build test WARNING on akpm-mm/mm-everything] >>> >>> url: >>> https://github.com/intel-lab-lkp/linux/commits/Matthew-Wilcox-Oracle/mm-Add-pfn_swap_entry_folio/20240111-232757 >>> base: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything >>> patch link: >>> https://lore.kernel.org/r/20240111152429.3374566-9-willy%40infradead.org >>> patch subject: [PATCH v3 08/10] mm: Convert to should_zap_page() to >>> should_zap_folio() >>> config: arm-milbeaut_m10v_defconfig >>> (https://download.01.org/0day-ci/archive/20240112/202401121250.A221BL2D-lkp@xxxxxxxxx/config) >>> compiler: clang version 16.0.4 (https://github.com/llvm/llvm-project.git >>> ae42196bc493ffe877a7e3dff8be32035dea4d07) >>> reproduce (this is a W=1 build): >>> (https://download.01.org/0day-ci/archive/20240112/202401121250.A221BL2D-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/202401121250.A221BL2D-lkp@xxxxxxxxx/ >>> >>> All warnings (new ones prefixed by >>): >>> >>>>> mm/memory.c:1451:8: warning: variable 'folio' is used uninitialized whenever >>>>> 'if' condition is false [-Wsometimes-uninitialized] >>> if (page) >>> ^~~~ >>> mm/memory.c:1454:44: note: uninitialized use occurs here >>> if (unlikely(!should_zap_folio(details, folio))) >>> ^~~~~ >>> include/linux/compiler.h:77:42: note: expanded from macro 'unlikely' >>> # define unlikely(x) __builtin_expect(!!(x), 0) >>> ^ >>> mm/memory.c:1451:4: note: remove the 'if' if its condition is always true >>> if (page) >>> ^~~~~~~~~ >>> mm/memory.c:1438:22: note: initialize the variable 'folio' to silence this >>> warning >>> struct folio *folio; >>> ^ >>> = NULL >> >> Hi Andrew, please help to squash following change, thanks. > > I just independently found this issue during coincidental review of the code. > It's still a problem in mm-unstable, so wondered if you missed the request, Andrew? Sorry - please ignore this - I was confused. I see that it is infact applied to mm-unstable. > >> >> diff --git a/mm/memory.c b/mm/memory.c >> index 998237b5600f..5e88d5379127 100644 >> --- a/mm/memory.c >> +++ b/mm/memory.c >> @@ -1435,7 +1435,7 @@ static unsigned long zap_pte_range(struct mmu_gather *tlb, >> arch_enter_lazy_mmu_mode(); >> do { >> pte_t ptent = ptep_get(pte); >> - struct folio *folio; >> + struct folio *folio = NULL; >> struct page *page; >> >> if (pte_none(ptent)) >> >> >> >
