diff options
| author | David Hildenbrand <david@redhat.com> | 2022-11-16 13:26:43 +0300 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2022-12-01 02:58:57 +0300 |
| commit | cdc5021cda194112bc0962d6a0e90b379968c504 (patch) | |
| tree | 12c5231ee46f8a17f2b12d6c80a021c866d2723b /mm/hugetlb.c | |
| parent | 97713a3abe338bb6c968e77264edbb68eb8d932a (diff) | |
| download | linux-cdc5021cda194112bc0962d6a0e90b379968c504.tar.xz | |
mm: add early FAULT_FLAG_UNSHARE consistency checks
For now, FAULT_FLAG_UNSHARE only applies to anonymous pages, which
implies a COW mapping. Let's hide FAULT_FLAG_UNSHARE early if we're not
dealing with a COW mapping, such that we treat it like a read fault as
documented and don't have to worry about the flag throughout all fault
handlers.
While at it, centralize the check for mutual exclusion of
FAULT_FLAG_UNSHARE and FAULT_FLAG_WRITE and just drop the check that
either flag is set in the WP handler.
Link: https://lkml.kernel.org/r/20221116102659.70287-5-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/hugetlb.c')
| -rw-r--r-- | mm/hugetlb.c | 5 |
1 files changed, 0 insertions, 5 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 3fd4570fb8b0..3d381b26d553 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -5316,9 +5316,6 @@ static vm_fault_t hugetlb_wp(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long haddr = address & huge_page_mask(h); struct mmu_notifier_range range; - VM_BUG_ON(unshare && (flags & FOLL_WRITE)); - VM_BUG_ON(!unshare && !(flags & FOLL_WRITE)); - /* * hugetlb does not support FOLL_FORCE-style write faults that keep the * PTE mapped R/O such as maybe_mkwrite() would do. @@ -5328,8 +5325,6 @@ static vm_fault_t hugetlb_wp(struct mm_struct *mm, struct vm_area_struct *vma, /* Let's take out MAP_SHARED mappings first. */ if (vma->vm_flags & VM_MAYSHARE) { - if (unlikely(unshare)) - return 0; set_huge_ptep_writable(vma, haddr, ptep); return 0; } |