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Revert "BACKPORT: FROMGIT: mm: improve mprotect(R|W) efficiency on pages referenced once"

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This reverts commit 6c376abc01.

Reason for revert: Breaks CTS

Change-Id: I606cda34b58abb44d2f2bfc085a644dcf8ea7a25
Signed-off-by: Quentin Perret <qperret@google.com>
This commit is contained in:
Quentin Perret
2021-01-18 16:25:49 +00:00
parent 5905c14687
commit e6487e273e
1 changed files with 0 additions and 6 deletions
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6
mm/mprotect.c
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@ -44,8 +44,6 @@ static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
spinlock_t *ptl; spinlock_t *ptl;
unsigned long pages = 0; unsigned long pages = 0;
int target_node = NUMA_NO_NODE; int target_node = NUMA_NO_NODE;
bool anon_writable =
vma_is_anonymous(vma) && (vma->vm_flags & VM_WRITE);
/* /*
* Can be called with only the mmap_sem for reading by * Can be called with only the mmap_sem for reading by
@ -122,11 +120,7 @@ static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
(pte_soft_dirty(ptent) || (pte_soft_dirty(ptent) ||
!(vma->vm_flags & VM_SOFTDIRTY))) { !(vma->vm_flags & VM_SOFTDIRTY))) {
ptent = pte_mkwrite(ptent); ptent = pte_mkwrite(ptent);
} else if (anon_writable &&
page_mapcount(pte_page(ptent)) == 1) {
ptent = pte_mkwrite(ptent);
} }
ptep_modify_prot_commit(mm, addr, pte, ptent); ptep_modify_prot_commit(mm, addr, pte, ptent);
pages++; pages++;
} else if (IS_ENABLED(CONFIG_MIGRATION)) { } else if (IS_ENABLED(CONFIG_MIGRATION)) {