On Fri, Mar 24, 2023 at 08:03:52AM +0300, Dan Carpenter wrote: > tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master > head: 7c4a254d78f89546d0e74a40617ef24c6151c8d1 > commit: e887ecae997ebaaad4d9b93e6a01fd5495ec1bc3 [5496/6100] mm/mmap/vma_merge: set next to NULL if not applicable > config: i386-randconfig-m021 (https://download.01.org/0day-ci/archive/20230324/202303240246.9rvyIPWZ-lkp@xxxxxxxxx/config) > 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> > | Link: https://lore.kernel.org/r/202303240246.9rvyIPWZ-lkp@xxxxxxxxx/ > > smatch warnings: > mm/mmap.c:962 vma_merge() error: uninitialized symbol 'next'. > Hi, sorry for breaking -next (this is the nth report for this :) but this is a mistake that accidentally slipped in a while ago, it was fixed in v3 of the patch series which is currently in mm-unstable and should land in -next when mm is next integrated (no pun intended). See https://lore.kernel.org/all/cover.1679516210.git.lstoakes@xxxxxxxxx for the latest version of the series in question. Thanks for the report and it's really nice to see how many people are on top of these things! > vim +/next +962 mm/mmap.c > > 9760ebffbf5507 Liam R. Howlett 2023-01-20 904 struct vm_area_struct *vma_merge(struct vma_iterator *vmi, struct mm_struct *mm, > ^1da177e4c3f41 Linus Torvalds 2005-04-16 905 struct vm_area_struct *prev, unsigned long addr, > ^1da177e4c3f41 Linus Torvalds 2005-04-16 906 unsigned long end, unsigned long vm_flags, > ^1da177e4c3f41 Linus Torvalds 2005-04-16 907 struct anon_vma *anon_vma, struct file *file, > 19a809afe2fe08 Andrea Arcangeli 2015-09-04 908 pgoff_t pgoff, struct mempolicy *policy, > 9a10064f5625d5 Colin Cross 2022-01-14 909 struct vm_userfaultfd_ctx vm_userfaultfd_ctx, > 5c26f6ac9416b6 Suren Baghdasaryan 2022-03-04 910 struct anon_vma_name *anon_name) > ^1da177e4c3f41 Linus Torvalds 2005-04-16 911 { > ^1da177e4c3f41 Linus Torvalds 2005-04-16 912 pgoff_t pglen = (end - addr) >> PAGE_SHIFT; > 0503ea8f5ba73e Liam R. Howlett 2023-01-20 913 pgoff_t vma_pgoff; > 721076b86904d4 Lorenzo Stoakes 2023-03-21 914 struct vm_area_struct *curr, *next, *res = NULL; > 0503ea8f5ba73e Liam R. Howlett 2023-01-20 915 struct vm_area_struct *vma, *adjust, *remove, *remove2; > eef199440df950 Jakub Matěna 2022-06-03 916 int err = -1; > eef199440df950 Jakub Matěna 2022-06-03 917 bool merge_prev = false; > eef199440df950 Jakub Matěna 2022-06-03 918 bool merge_next = false; > 0503ea8f5ba73e Liam R. Howlett 2023-01-20 919 bool vma_expanded = false; > 0503ea8f5ba73e Liam R. Howlett 2023-01-20 920 struct vma_prepare vp; > 0503ea8f5ba73e Liam R. Howlett 2023-01-20 921 unsigned long vma_end = end; > 27d6788ee67b59 Vlastimil Babka 2023-03-09 922 long adj_start = 0; > 0503ea8f5ba73e Liam R. Howlett 2023-01-20 923 unsigned long vma_start = addr; > ^1da177e4c3f41 Linus Torvalds 2005-04-16 924 > 0503ea8f5ba73e Liam R. Howlett 2023-01-20 925 validate_mm(mm); > ^1da177e4c3f41 Linus Torvalds 2005-04-16 926 /* > ^1da177e4c3f41 Linus Torvalds 2005-04-16 927 * We later require that vma->vm_flags == vm_flags, > ^1da177e4c3f41 Linus Torvalds 2005-04-16 928 * so this tests vma->vm_flags & VM_SPECIAL, too. > ^1da177e4c3f41 Linus Torvalds 2005-04-16 929 */ > ^1da177e4c3f41 Linus Torvalds 2005-04-16 930 if (vm_flags & VM_SPECIAL) > ^1da177e4c3f41 Linus Torvalds 2005-04-16 931 return NULL; > ^1da177e4c3f41 Linus Torvalds 2005-04-16 932 > e887ecae997eba Lorenzo Stoakes 2023-03-21 933 /* Does the input range span an existing VMA? (cases 5 - 8) */ > e887ecae997eba Lorenzo Stoakes 2023-03-21 934 curr = find_vma_intersection(mm, prev ? prev->vm_end : 0, end); > ^1da177e4c3f41 Linus Torvalds 2005-04-16 935 > e887ecae997eba Lorenzo Stoakes 2023-03-21 936 if (curr && end == curr->vm_end) > e887ecae997eba Lorenzo Stoakes 2023-03-21 937 /* Is there is a VMA immediately adjacent (cases 6 - 8)? */ > e887ecae997eba Lorenzo Stoakes 2023-03-21 938 next = vma_lookup(mm, curr->vm_end); > e887ecae997eba Lorenzo Stoakes 2023-03-21 939 else if (!curr) > e887ecae997eba Lorenzo Stoakes 2023-03-21 940 /* Is there a VMA next to a hole (case 1 - 3) or prev (4)? */ > e887ecae997eba Lorenzo Stoakes 2023-03-21 941 next = vma_lookup(mm, end); > > next not initialized on else path. > > 759224a5ffcfa1 Vlastimil Babka 2023-03-09 942 > e86f15ee64d8ee Andrea Arcangeli 2016-10-07 943 /* verify some invariant that must be enforced by the caller */ > e86f15ee64d8ee Andrea Arcangeli 2016-10-07 944 VM_WARN_ON(prev && addr <= prev->vm_start); > 721076b86904d4 Lorenzo Stoakes 2023-03-21 945 VM_WARN_ON(curr && end > curr->vm_end); > e86f15ee64d8ee Andrea Arcangeli 2016-10-07 946 VM_WARN_ON(addr >= end); > e86f15ee64d8ee Andrea Arcangeli 2016-10-07 947 > 0503ea8f5ba73e Liam R. Howlett 2023-01-20 948 if (prev) { > 0503ea8f5ba73e Liam R. Howlett 2023-01-20 949 res = prev; > 0503ea8f5ba73e Liam R. Howlett 2023-01-20 950 vma = prev; > 0503ea8f5ba73e Liam R. Howlett 2023-01-20 951 vma_start = prev->vm_start; > 0503ea8f5ba73e Liam R. Howlett 2023-01-20 952 vma_pgoff = prev->vm_pgoff; > eef199440df950 Jakub Matěna 2022-06-03 953 /* Can we merge the predecessor? */ > 0503ea8f5ba73e Liam R. Howlett 2023-01-20 954 if (prev->vm_end == addr && mpol_equal(vma_policy(prev), policy) > 0503ea8f5ba73e Liam R. Howlett 2023-01-20 955 && can_vma_merge_after(prev, vm_flags, anon_vma, file, > 0503ea8f5ba73e Liam R. Howlett 2023-01-20 956 pgoff, vm_userfaultfd_ctx, anon_name)) { > eef199440df950 Jakub Matěna 2022-06-03 957 merge_prev = true; > 18b098af2890cd Liam R. Howlett 2023-01-20 958 vma_prev(vmi); > eef199440df950 Jakub Matěna 2022-06-03 959 } > 0503ea8f5ba73e Liam R. Howlett 2023-01-20 960 } > eef199440df950 Jakub Matěna 2022-06-03 961 /* Can we merge the successor? */ > e887ecae997eba Lorenzo Stoakes 2023-03-21 @962 if (next && mpol_equal(policy, vma_policy(next)) && > ^^^^ > > ^1da177e4c3f41 Linus Torvalds 2005-04-16 963 can_vma_merge_before(next, vm_flags, > eef199440df950 Jakub Matěna 2022-06-03 964 anon_vma, file, pgoff+pglen, > eef199440df950 Jakub Matěna 2022-06-03 965 vm_userfaultfd_ctx, anon_name)) { > eef199440df950 Jakub Matěna 2022-06-03 966 merge_next = true; > eef199440df950 Jakub Matěna 2022-06-03 967 } > 0503ea8f5ba73e Liam R. Howlett 2023-01-20 968 > > -- > 0-DAY CI Kernel Test Service > https://github.com/intel/lkp-tests >
