tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master head: 44a2f39e611ac0bc1f17c288a583d7f2e5684aa7 commit: 2b58b3f33ba268c00aa7181e203c58fab6661751 [7462/8237] mm/shmem: convert shmem_swapin_page() to shmem_swapin_folio() config: i386-randconfig-a013 (https://download.01.org/0day-ci/archive/20220504/202205040210.LYv9gMu9-lkp@xxxxxxxxx/config) compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project 363b3a645a1e30011cc8da624f13dac5fd915628) 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 # https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=2b58b3f33ba268c00aa7181e203c58fab6661751 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 2b58b3f33ba268c00aa7181e203c58fab6661751 # save the config file mkdir build_dir && cp config build_dir/.config COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=i386 SHELL=/bin/bash If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp@xxxxxxxxx> All warnings (new ones prefixed by >>): >> mm/shmem.c:1704:7: warning: variable 'folio' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized] if (!page) { ^~~~~ mm/shmem.c:1761:6: note: uninitialized use occurs here if (folio) { ^~~~~ mm/shmem.c:1704:3: note: remove the 'if' if its condition is always false if (!page) { ^~~~~~~~~~~~ mm/shmem.c:1685:21: note: initialize the variable 'folio' to silence this warning struct folio *folio; ^ = NULL 1 warning generated. vim +1704 mm/shmem.c bde05d1ccd5126 Hugh Dickins 2012-05-29 1669 ^1da177e4c3f41 Linus Torvalds 2005-04-16 1670 /* c5bf121e4350a9 Vineeth Remanan Pillai 2019-03-05 1671 * Swap in the page pointed to by *pagep. c5bf121e4350a9 Vineeth Remanan Pillai 2019-03-05 1672 * Caller has to make sure that *pagep contains a valid swapped page. c5bf121e4350a9 Vineeth Remanan Pillai 2019-03-05 1673 * Returns 0 and the page in pagep if success. On failure, returns the af44c12fe7c970 Randy Dunlap 2020-08-11 1674 * error code and NULL in *pagep. ^1da177e4c3f41 Linus Torvalds 2005-04-16 1675 */ 2b58b3f33ba268 Matthew Wilcox (Oracle 2022-04-29 1676) static int shmem_swapin_folio(struct inode *inode, pgoff_t index, 2b58b3f33ba268 Matthew Wilcox (Oracle 2022-04-29 1677) struct folio **foliop, enum sgp_type sgp, c5bf121e4350a9 Vineeth Remanan Pillai 2019-03-05 1678 gfp_t gfp, struct vm_area_struct *vma, 2b7403035459c7 Souptick Joarder 2018-08-23 1679 vm_fault_t *fault_type) ^1da177e4c3f41 Linus Torvalds 2005-04-16 1680 { ^1da177e4c3f41 Linus Torvalds 2005-04-16 1681 struct address_space *mapping = inode->i_mapping; 23f919d4ad0eb3 Arnd Bergmann 2016-12-12 1682 struct shmem_inode_info *info = SHMEM_I(inode); 04f94e3fbe1afc Dan Schatzberg 2021-06-28 1683 struct mm_struct *charge_mm = vma ? vma->vm_mm : NULL; 2b58b3f33ba268 Matthew Wilcox (Oracle 2022-04-29 1684) struct page *page; 9a44f3462edc49 Matthew Wilcox (Oracle 2022-04-29 1685) struct folio *folio; ^1da177e4c3f41 Linus Torvalds 2005-04-16 1686 swp_entry_t swap; ^1da177e4c3f41 Linus Torvalds 2005-04-16 1687 int error; 66d2f4d28cd030 Hugh Dickins 2014-07-02 1688 2b58b3f33ba268 Matthew Wilcox (Oracle 2022-04-29 1689) VM_BUG_ON(!*foliop || !xa_is_value(*foliop)); 2b58b3f33ba268 Matthew Wilcox (Oracle 2022-04-29 1690) swap = radix_to_swp_entry(*foliop); 2b58b3f33ba268 Matthew Wilcox (Oracle 2022-04-29 1691) *foliop = NULL; ^1da177e4c3f41 Linus Torvalds 2005-04-16 1692 ^1da177e4c3f41 Linus Torvalds 2005-04-16 1693 /* Look it up and read it in.. */ ec560175c0b6fc Huang Ying 2017-09-06 1694 page = lookup_swap_cache(swap, NULL, 0); 27ab700626f048 Hugh Dickins 2011-07-25 1695 if (!page) { 9e18eb29356b7d Andres Lagar-Cavilla 2016-05-19 1696 /* Or update major stats only when swapin succeeds?? */ 9e18eb29356b7d Andres Lagar-Cavilla 2016-05-19 1697 if (fault_type) { 68da9f055755ee Hugh Dickins 2011-07-25 1698 *fault_type |= VM_FAULT_MAJOR; 9e18eb29356b7d Andres Lagar-Cavilla 2016-05-19 1699 count_vm_event(PGMAJFAULT); 2262185c5b287f Roman Gushchin 2017-07-06 1700 count_memcg_event_mm(charge_mm, PGMAJFAULT); 9e18eb29356b7d Andres Lagar-Cavilla 2016-05-19 1701 } 9e18eb29356b7d Andres Lagar-Cavilla 2016-05-19 1702 /* Here we actually start the io */ 41ffe5d5ceef7f Hugh Dickins 2011-08-03 1703 page = shmem_swapin(swap, gfp, info, index); 27ab700626f048 Hugh Dickins 2011-07-25 @1704 if (!page) { ^1da177e4c3f41 Linus Torvalds 2005-04-16 1705 error = -ENOMEM; 54af60421822bb Hugh Dickins 2011-08-03 1706 goto failed; ^1da177e4c3f41 Linus Torvalds 2005-04-16 1707 } ^1da177e4c3f41 Linus Torvalds 2005-04-16 1708 } 2b58b3f33ba268 Matthew Wilcox (Oracle 2022-04-29 1709) folio = page_folio(page); ^1da177e4c3f41 Linus Torvalds 2005-04-16 1710 ^1da177e4c3f41 Linus Torvalds 2005-04-16 1711 /* We have to do this with page locked to prevent races */ 2b58b3f33ba268 Matthew Wilcox (Oracle 2022-04-29 1712) folio_lock(folio); 2b58b3f33ba268 Matthew Wilcox (Oracle 2022-04-29 1713) if (!folio_test_swapcache(folio) || 2b58b3f33ba268 Matthew Wilcox (Oracle 2022-04-29 1714) folio_swap_entry(folio).val != swap.val || d189922862e03c Hugh Dickins 2012-07-11 1715 !shmem_confirm_swap(mapping, index, swap)) { c5bf121e4350a9 Vineeth Remanan Pillai 2019-03-05 1716 error = -EEXIST; d189922862e03c Hugh Dickins 2012-07-11 1717 goto unlock; bde05d1ccd5126 Hugh Dickins 2012-05-29 1718 } 2b58b3f33ba268 Matthew Wilcox (Oracle 2022-04-29 1719) if (!folio_test_uptodate(folio)) { ^1da177e4c3f41 Linus Torvalds 2005-04-16 1720 error = -EIO; 54af60421822bb Hugh Dickins 2011-08-03 1721 goto failed; ^1da177e4c3f41 Linus Torvalds 2005-04-16 1722 } 2b58b3f33ba268 Matthew Wilcox (Oracle 2022-04-29 1723) folio_wait_writeback(folio); ^1da177e4c3f41 Linus Torvalds 2005-04-16 1724 8a84802e2a2b1a Steven Price 2020-05-13 1725 /* 8a84802e2a2b1a Steven Price 2020-05-13 1726 * Some architectures may have to restore extra metadata to the 2b58b3f33ba268 Matthew Wilcox (Oracle 2022-04-29 1727) * folio after reading from swap. 8a84802e2a2b1a Steven Price 2020-05-13 1728 */ 2b58b3f33ba268 Matthew Wilcox (Oracle 2022-04-29 1729) arch_swap_restore(swap, folio); 8a84802e2a2b1a Steven Price 2020-05-13 1730 8d657a77c6fe46 Matthew Wilcox (Oracle 2022-04-29 1731) if (shmem_should_replace_folio(folio, gfp)) { bde05d1ccd5126 Hugh Dickins 2012-05-29 1732 error = shmem_replace_page(&page, gfp, info, index); bde05d1ccd5126 Hugh Dickins 2012-05-29 1733 if (error) 54af60421822bb Hugh Dickins 2011-08-03 1734 goto failed; ^1da177e4c3f41 Linus Torvalds 2005-04-16 1735 } 27ab700626f048 Hugh Dickins 2011-07-25 1736 9a44f3462edc49 Matthew Wilcox (Oracle 2022-04-29 1737) error = shmem_add_to_page_cache(folio, mapping, index, 3fea5a499d57de Johannes Weiner 2020-06-03 1738 swp_to_radix_entry(swap), gfp, 3fea5a499d57de Johannes Weiner 2020-06-03 1739 charge_mm); 3fea5a499d57de Johannes Weiner 2020-06-03 1740 if (error) 54af60421822bb Hugh Dickins 2011-08-03 1741 goto failed; 00501b531c4723 Johannes Weiner 2014-08-08 1742 4595ef88d13613 Kirill A. Shutemov 2016-07-26 1743 spin_lock_irq(&info->lock); 285b2c4fdd69ea Hugh Dickins 2011-08-03 1744 info->swapped--; 54af60421822bb Hugh Dickins 2011-08-03 1745 shmem_recalc_inode(inode); 4595ef88d13613 Kirill A. Shutemov 2016-07-26 1746 spin_unlock_irq(&info->lock); 54af60421822bb Hugh Dickins 2011-08-03 1747 66d2f4d28cd030 Hugh Dickins 2014-07-02 1748 if (sgp == SGP_WRITE) 2b58b3f33ba268 Matthew Wilcox (Oracle 2022-04-29 1749) folio_mark_accessed(folio); 66d2f4d28cd030 Hugh Dickins 2014-07-02 1750 2b58b3f33ba268 Matthew Wilcox (Oracle 2022-04-29 1751) delete_from_swap_cache(&folio->page); 2b58b3f33ba268 Matthew Wilcox (Oracle 2022-04-29 1752) folio_mark_dirty(folio); 27ab700626f048 Hugh Dickins 2011-07-25 1753 swap_free(swap); 27ab700626f048 Hugh Dickins 2011-07-25 1754 2b58b3f33ba268 Matthew Wilcox (Oracle 2022-04-29 1755) *foliop = folio; c5bf121e4350a9 Vineeth Remanan Pillai 2019-03-05 1756 return 0; c5bf121e4350a9 Vineeth Remanan Pillai 2019-03-05 1757 failed: c5bf121e4350a9 Vineeth Remanan Pillai 2019-03-05 1758 if (!shmem_confirm_swap(mapping, index, swap)) c5bf121e4350a9 Vineeth Remanan Pillai 2019-03-05 1759 error = -EEXIST; c5bf121e4350a9 Vineeth Remanan Pillai 2019-03-05 1760 unlock: 2b58b3f33ba268 Matthew Wilcox (Oracle 2022-04-29 1761) if (folio) { 2b58b3f33ba268 Matthew Wilcox (Oracle 2022-04-29 1762) folio_unlock(folio); 2b58b3f33ba268 Matthew Wilcox (Oracle 2022-04-29 1763) folio_put(folio); c5bf121e4350a9 Vineeth Remanan Pillai 2019-03-05 1764 } c5bf121e4350a9 Vineeth Remanan Pillai 2019-03-05 1765 c5bf121e4350a9 Vineeth Remanan Pillai 2019-03-05 1766 return error; c5bf121e4350a9 Vineeth Remanan Pillai 2019-03-05 1767 } c5bf121e4350a9 Vineeth Remanan Pillai 2019-03-05 1768 :::::: The code at line 1704 was first introduced by commit :::::: 27ab700626f048407e9466d389a43c7d3aa45967 tmpfs: simplify filepage/swappage :::::: TO: Hugh Dickins <hughd@xxxxxxxxxx> :::::: CC: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> -- 0-DAY CI Kernel Test Service https://01.org/lkp
