tree: https://github.com/ammarfaizi2/linux-block akpm/mm/mm-unstable head: a8da2493d983a10242e6c9d71c6e828aafa5baf8 commit: d68dde0dc6f8b8d09357a32473db8881173b10b0 [160/254] mm,thp,rmap: subpages_mapcount of PTE-mapped subpages config: i386-randconfig-m021 compiler: gcc-11 (Debian 11.3.0-8) 11.3.0 If you fix the issue, kindly add following tag where applicable | Reported-by: kernel test robot <lkp@xxxxxxxxx> | Reported-by: Dan Carpenter <error27@xxxxxxxxx> smatch warnings: mm/rmap.c:1325 page_add_anon_rmap() error: uninitialized symbol 'first'. vim +/first +1325 mm/rmap.c 9617d95e6e9ffd Nicholas Piggin 2006-01-06 1278 void page_add_anon_rmap(struct page *page, 14f9135d547060 David Hildenbrand 2022-05-09 1279 struct vm_area_struct *vma, unsigned long address, rmap_t flags) 9617d95e6e9ffd Nicholas Piggin 2006-01-06 1280 { 5b3276bc4a2e01 Hugh Dickins 2022-11-02 1281 struct compound_mapcounts mapcounts; 5b3276bc4a2e01 Hugh Dickins 2022-11-02 1282 int nr = 0, nr_pmdmapped = 0; d281ee61451835 Kirill A. Shutemov 2016-01-15 1283 bool compound = flags & RMAP_COMPOUND; 53f9263baba69f Kirill A. Shutemov 2016-01-15 1284 bool first; ^^^^^^^^^^ 53f9263baba69f Kirill A. Shutemov 2016-01-15 1285 be5d0a74c62d8d Johannes Weiner 2020-06-03 1286 if (unlikely(PageKsm(page))) be5d0a74c62d8d Johannes Weiner 2020-06-03 1287 lock_page_memcg(page); be5d0a74c62d8d Johannes Weiner 2020-06-03 1288 d68dde0dc6f8b8 Hugh Dickins 2022-11-18 1289 if (likely(!compound /* page is mapped by PTE */)) { 84e6cb5a201a85 Hugh Dickins 2022-11-09 1290 first = atomic_inc_and_test(&page->_mapcount); 84e6cb5a201a85 Hugh Dickins 2022-11-09 1291 nr = first; d68dde0dc6f8b8 Hugh Dickins 2022-11-18 1292 if (first && PageCompound(page)) { d68dde0dc6f8b8 Hugh Dickins 2022-11-18 1293 struct page *head = compound_head(page); d68dde0dc6f8b8 Hugh Dickins 2022-11-18 1294 d68dde0dc6f8b8 Hugh Dickins 2022-11-18 1295 lock_compound_mapcounts(head, &mapcounts); d68dde0dc6f8b8 Hugh Dickins 2022-11-18 1296 mapcounts.subpages_mapcount++; d68dde0dc6f8b8 Hugh Dickins 2022-11-18 1297 nr = !mapcounts.compound_mapcount; d68dde0dc6f8b8 Hugh Dickins 2022-11-18 1298 unlock_compound_mapcounts(head, &mapcounts); d68dde0dc6f8b8 Hugh Dickins 2022-11-18 1299 } d68dde0dc6f8b8 Hugh Dickins 2022-11-18 1300 } else if (PageTransHuge(page)) { d68dde0dc6f8b8 Hugh Dickins 2022-11-18 1301 /* That test is redundant: it's for safety or to optimize out */ 84e6cb5a201a85 Hugh Dickins 2022-11-09 1302 5b3276bc4a2e01 Hugh Dickins 2022-11-02 1303 lock_compound_mapcounts(page, &mapcounts); 5b3276bc4a2e01 Hugh Dickins 2022-11-02 1304 first = !mapcounts.compound_mapcount; 5b3276bc4a2e01 Hugh Dickins 2022-11-02 1305 mapcounts.compound_mapcount++; 5b3276bc4a2e01 Hugh Dickins 2022-11-02 1306 if (first) { d68dde0dc6f8b8 Hugh Dickins 2022-11-18 1307 nr_pmdmapped = thp_nr_pages(page); d68dde0dc6f8b8 Hugh Dickins 2022-11-18 1308 nr = nr_pmdmapped - mapcounts.subpages_mapcount; 5b3276bc4a2e01 Hugh Dickins 2022-11-02 1309 } 5b3276bc4a2e01 Hugh Dickins 2022-11-02 1310 unlock_compound_mapcounts(page, &mapcounts); 53f9263baba69f Kirill A. Shutemov 2016-01-15 1311 } No else path. bde3d57e6cec9c Hugh Dickins 2022-11-02 1312 6c287605fd5646 David Hildenbrand 2022-05-09 1313 VM_BUG_ON_PAGE(!first && (flags & RMAP_EXCLUSIVE), page); ^^^^^ Uninitialized. 6c287605fd5646 David Hildenbrand 2022-05-09 1314 VM_BUG_ON_PAGE(!first && PageAnonExclusive(page), page); 53f9263baba69f Kirill A. Shutemov 2016-01-15 1315 5b3276bc4a2e01 Hugh Dickins 2022-11-02 1316 if (nr_pmdmapped) 5b3276bc4a2e01 Hugh Dickins 2022-11-02 1317 __mod_lruvec_page_state(page, NR_ANON_THPS, nr_pmdmapped); 5b3276bc4a2e01 Hugh Dickins 2022-11-02 1318 if (nr) be5d0a74c62d8d Johannes Weiner 2020-06-03 1319 __mod_lruvec_page_state(page, NR_ANON_MAPPED, nr); 5ad6468801d28c Hugh Dickins 2009-12-14 1320 cea86fe246b694 Hugh Dickins 2022-02-14 1321 if (unlikely(PageKsm(page))) be5d0a74c62d8d Johannes Weiner 2020-06-03 1322 unlock_page_memcg(page); 53f9263baba69f Kirill A. Shutemov 2016-01-15 1323 5dbe0af47f8a8f Hugh Dickins 2011-05-28 1324 /* address might be in next vma when migration races vma_adjust */ cea86fe246b694 Hugh Dickins 2022-02-14 @1325 else if (first) d281ee61451835 Kirill A. Shutemov 2016-01-15 1326 __page_set_anon_rmap(page, vma, address, 14f9135d547060 David Hildenbrand 2022-05-09 1327 !!(flags & RMAP_EXCLUSIVE)); 69029cd550284e KAMEZAWA Hiroyuki 2008-07-25 1328 else c97a9e10eaee32 Nicholas Piggin 2007-05-16 1329 __page_check_anon_rmap(page, vma, address); cea86fe246b694 Hugh Dickins 2022-02-14 1330 cea86fe246b694 Hugh Dickins 2022-02-14 1331 mlock_vma_page(page, vma, compound); ^1da177e4c3f41 Linus Torvalds 2005-04-16 1332 } -- 0-DAY CI Kernel Test Service https://01.org/lkp
