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author | David Hildenbrand <david@redhat.com> | 2022-11-08 18:46:49 +0100 |
---|---|---|
committer | Andrew Morton <akpm@linux-foundation.org> | 2022-11-30 15:58:49 -0800 |
commit | eb309ec89953d6a3e8e35a3a577bab13893858d8 (patch) | |
tree | 6d51e48da1a5e5731731898d23bae7ae8921d9ee | |
parent | c27f479ef5428f691787fb6fe3703a70e931ae8c (diff) | |
download | linux-stable-eb309ec89953d6a3e8e35a3a577bab13893858d8.tar.gz linux-stable-eb309ec89953d6a3e8e35a3a577bab13893858d8.tar.bz2 linux-stable-eb309ec89953d6a3e8e35a3a577bab13893858d8.zip |
mm/mprotect: factor out check whether manual PTE write upgrades are required
Let's factor the check out into vma_wants_manual_pte_write_upgrade(), to be
reused in NUMA hinting fault context soon.
Link: https://lkml.kernel.org/r/20221108174652.198904-5-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nadav Amit <namit@vmware.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
-rw-r--r-- | include/linux/mm.h | 16 | ||||
-rw-r--r-- | mm/mprotect.c | 17 |
2 files changed, 18 insertions, 15 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h index d33639be3db3..e203e8a83e2d 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2088,6 +2088,20 @@ extern unsigned long move_page_tables(struct vm_area_struct *vma, #define MM_CP_UFFD_WP_ALL (MM_CP_UFFD_WP | \ MM_CP_UFFD_WP_RESOLVE) +int vma_wants_writenotify(struct vm_area_struct *vma, pgprot_t vm_page_prot); +static inline bool vma_wants_manual_pte_write_upgrade(struct vm_area_struct *vma) +{ + /* + * We want to check manually if we can change individual PTEs writable + * if we can't do that automatically for all PTEs in a mapping. For + * private mappings, that's always the case when we have write + * permissions as we properly have to handle COW. + */ + if (vma->vm_flags & VM_SHARED) + return vma_wants_writenotify(vma, vma->vm_page_prot); + return !!(vma->vm_flags & VM_WRITE); + +} extern unsigned long change_protection(struct mmu_gather *tlb, struct vm_area_struct *vma, unsigned long start, unsigned long end, pgprot_t newprot, @@ -2227,8 +2241,6 @@ static inline int pte_devmap(pte_t pte) } #endif -int vma_wants_writenotify(struct vm_area_struct *vma, pgprot_t vm_page_prot); - extern pte_t *__get_locked_pte(struct mm_struct *mm, unsigned long addr, spinlock_t **ptl); static inline pte_t *get_locked_pte(struct mm_struct *mm, unsigned long addr, diff --git a/mm/mprotect.c b/mm/mprotect.c index 72aabffb7871..fe22db2c9cdd 100644 --- a/mm/mprotect.c +++ b/mm/mprotect.c @@ -558,8 +558,8 @@ mprotect_fixup(struct mmu_gather *tlb, struct vm_area_struct *vma, struct mm_struct *mm = vma->vm_mm; unsigned long oldflags = vma->vm_flags; long nrpages = (end - start) >> PAGE_SHIFT; + unsigned int mm_cp_flags = 0; unsigned long charged = 0; - bool try_change_writable; pgoff_t pgoff; int error; @@ -637,20 +637,11 @@ success: * held in write mode. */ vma->vm_flags = newflags; - /* - * We want to check manually if we can change individual PTEs writable - * if we can't do that automatically for all PTEs in a mapping. For - * private mappings, that's always the case when we have write - * permissions as we properly have to handle COW. - */ - if (vma->vm_flags & VM_SHARED) - try_change_writable = vma_wants_writenotify(vma, vma->vm_page_prot); - else - try_change_writable = !!(vma->vm_flags & VM_WRITE); + if (vma_wants_manual_pte_write_upgrade(vma)) + mm_cp_flags |= MM_CP_TRY_CHANGE_WRITABLE; vma_set_page_prot(vma); - change_protection(tlb, vma, start, end, vma->vm_page_prot, - try_change_writable ? MM_CP_TRY_CHANGE_WRITABLE : 0); + change_protection(tlb, vma, start, end, vma->vm_page_prot, mm_cp_flags); /* * Private VM_LOCKED VMA becoming writable: trigger COW to avoid major |