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| author |   Peter Xu <peterx@redhat.com> | 2022-09-30 20:25:55 -0400 |
|---|---|---|
| committer |   Andrew Morton <akpm@linux-foundation.org> | 2022-10-12 15:56:46 -0700 |
| commit | 515778e2d790652a38a24554fdb7f21420d91efc (patch) | |
| tree | 0e5e96ac55e5d986733bbd2d60746eab134792d7 /mm | |
| parent | mm/mmap: preallocate maple nodes for brk vma expansion (diff) | |
| download | linux-dev-515778e2d790652a38a24554fdb7f21420d91efc.tar.xz linux-dev-515778e2d790652a38a24554fdb7f21420d91efc.zip | |
mm/uffd: fix warning without PTE_MARKER_UFFD_WP compiled in
When PTE_MARKER_UFFD_WP not configured, it's still possible to reach pte
marker code and trigger an warning. Add a few CONFIG_PTE_MARKER_UFFD_WP
ifdefs to make sure the code won't be reached when not compiled in.
Link: https://lkml.kernel.org/r/YzeR+R6b4bwBlBHh@x1n
Fixes: b1f9e876862d ("mm/uffd: enable write protection for shmem & hugetlbfs")
Signed-off-by: Peter Xu <peterx@redhat.com>
Reported-by: <syzbot+2b9b4f0895be09a6dec3@syzkaller.appspotmail.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Brian Geffon <bgeffon@google.com>
Cc: Edward Liaw <edliaw@google.com>
Cc: Liu Shixin <liushixin2@huawei.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/hugetlb.c | 4 | ||||
| -rw-r--r-- | mm/memory.c | 2 | ||||
| -rw-r--r-- | mm/mprotect.c | 2 |
3 files changed, 8 insertions, 0 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 41d3aa077837..9a910612336d 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -5096,6 +5096,7 @@ static void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct * unmapped and its refcount is dropped, so just clear pte here. */ if (unlikely(!pte_present(pte))) { +#ifdef CONFIG_PTE_MARKER_UFFD_WP /* * If the pte was wr-protected by uffd-wp in any of the * swap forms, meanwhile the caller does not want to @@ -5107,6 +5108,7 @@ static void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct set_huge_pte_at(mm, address, ptep, make_pte_marker(PTE_MARKER_UFFD_WP)); else +#endif huge_pte_clear(mm, address, ptep, sz); spin_unlock(ptl); continue; @@ -5135,11 +5137,13 @@ static void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct tlb_remove_huge_tlb_entry(h, tlb, ptep, address); if (huge_pte_dirty(pte)) set_page_dirty(page); +#ifdef CONFIG_PTE_MARKER_UFFD_WP /* Leave a uffd-wp pte marker if needed */ if (huge_pte_uffd_wp(pte) && !(zap_flags & ZAP_FLAG_DROP_MARKER)) set_huge_pte_at(mm, address, ptep, make_pte_marker(PTE_MARKER_UFFD_WP)); +#endif hugetlb_count_sub(pages_per_huge_page(h), mm); page_remove_rmap(page, vma, true); diff --git a/mm/memory.c b/mm/memory.c index df678fa30cdb..2c7723ea4371 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1393,10 +1393,12 @@ zap_install_uffd_wp_if_needed(struct vm_area_struct *vma, unsigned long addr, pte_t *pte, struct zap_details *details, pte_t pteval) { +#ifdef CONFIG_PTE_MARKER_UFFD_WP if (zap_drop_file_uffd_wp(details)) return; pte_install_uffd_wp_if_needed(vma, addr, pte, pteval); +#endif } static unsigned long zap_pte_range(struct mmu_gather *tlb, diff --git a/mm/mprotect.c b/mm/mprotect.c index 461dcbd4f21a..668bfaa6ed2a 100644 --- a/mm/mprotect.c +++ b/mm/mprotect.c @@ -267,6 +267,7 @@ static unsigned long change_pte_range(struct mmu_gather *tlb, } else { /* It must be an none page, or what else?.. */ WARN_ON_ONCE(!pte_none(oldpte)); +#ifdef CONFIG_PTE_MARKER_UFFD_WP if (unlikely(uffd_wp && !vma_is_anonymous(vma))) { /* * For file-backed mem, we need to be able to @@ -278,6 +279,7 @@ static unsigned long change_pte_range(struct mmu_gather *tlb, make_pte_marker(PTE_MARKER_UFFD_WP)); pages++; } +#endif } } while (pte++, addr += PAGE_SIZE, addr != end); arch_leave_lazy_mmu_mode(); |