On Mon, Jan 29, 2024 at 9:13 PM Dan Carpenter <dan.carpenter@xxxxxxxxxx> wrote: > > tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master > head: 596764183be8ebb13352b281a442a1f1151c9b06 > commit: ea4df6a5ea81105879ca5549555e231c4596fbc4 [2565/2825] userfaultfd: handle zeropage moves by UFFDIO_MOVE > config: x86_64-randconfig-161-20240129 (https://download.01.org/0day-ci/archive/20240130/202401300107.U8iMAkTl-lkp@xxxxxxxxx/config) > compiler: gcc-7 (Ubuntu 7.5.0-6ubuntu2) 7.5.0 > > 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> > | Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> > | Closes: https://lore.kernel.org/r/202401300107.U8iMAkTl-lkp@xxxxxxxxx/ > > smatch warnings: > mm/userfaultfd.c:983 move_zeropage_pte() warn: inconsistent returns 'dst_ptl'. > > vim +/dst_ptl +983 mm/userfaultfd.c > > ea4df6a5ea8110 Suren Baghdasaryan 2024-01-24 962 static int move_zeropage_pte(struct mm_struct *mm, > ea4df6a5ea8110 Suren Baghdasaryan 2024-01-24 963 struct vm_area_struct *dst_vma, > ea4df6a5ea8110 Suren Baghdasaryan 2024-01-24 964 struct vm_area_struct *src_vma, > ea4df6a5ea8110 Suren Baghdasaryan 2024-01-24 965 unsigned long dst_addr, unsigned long src_addr, > ea4df6a5ea8110 Suren Baghdasaryan 2024-01-24 966 pte_t *dst_pte, pte_t *src_pte, > ea4df6a5ea8110 Suren Baghdasaryan 2024-01-24 967 pte_t orig_dst_pte, pte_t orig_src_pte, > ea4df6a5ea8110 Suren Baghdasaryan 2024-01-24 968 spinlock_t *dst_ptl, spinlock_t *src_ptl) > ea4df6a5ea8110 Suren Baghdasaryan 2024-01-24 969 { > ea4df6a5ea8110 Suren Baghdasaryan 2024-01-24 970 pte_t zero_pte; > ea4df6a5ea8110 Suren Baghdasaryan 2024-01-24 971 > ea4df6a5ea8110 Suren Baghdasaryan 2024-01-24 972 double_pt_lock(dst_ptl, src_ptl); > ea4df6a5ea8110 Suren Baghdasaryan 2024-01-24 973 if (!pte_same(ptep_get(src_pte), orig_src_pte) || > ea4df6a5ea8110 Suren Baghdasaryan 2024-01-24 974 !pte_same(ptep_get(dst_pte), orig_dst_pte)) > ea4df6a5ea8110 Suren Baghdasaryan 2024-01-24 975 return -EAGAIN; > > double_pt_unlock(dst_ptl, src_ptl) before returning? Thanks for reporting and sorry for the delay! Yes, this is definitely a bug. I'll post a fix tomorrow morning. Thanks, Suren. > > ea4df6a5ea8110 Suren Baghdasaryan 2024-01-24 976 > ea4df6a5ea8110 Suren Baghdasaryan 2024-01-24 977 zero_pte = pte_mkspecial(pfn_pte(my_zero_pfn(dst_addr), > ea4df6a5ea8110 Suren Baghdasaryan 2024-01-24 978 dst_vma->vm_page_prot)); > ea4df6a5ea8110 Suren Baghdasaryan 2024-01-24 979 ptep_clear_flush(src_vma, src_addr, src_pte); > ea4df6a5ea8110 Suren Baghdasaryan 2024-01-24 980 set_pte_at(mm, dst_addr, dst_pte, zero_pte); > ea4df6a5ea8110 Suren Baghdasaryan 2024-01-24 981 double_pt_unlock(dst_ptl, src_ptl); > ea4df6a5ea8110 Suren Baghdasaryan 2024-01-24 982 > ea4df6a5ea8110 Suren Baghdasaryan 2024-01-24 @983 return 0; > ea4df6a5ea8110 Suren Baghdasaryan 2024-01-24 984 } > > -- > 0-DAY CI Kernel Test Service > https://github.com/intel/lkp-tests/wiki >
