diff options
Diffstat (limited to 'kernel/mm/mprotect.c')
| -rw-r--r-- | kernel/mm/mprotect.c | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/kernel/mm/mprotect.c b/kernel/mm/mprotect.c index 88584838e..ef5be8eaa 100644 --- a/kernel/mm/mprotect.c +++ b/kernel/mm/mprotect.c @@ -29,6 +29,8 @@ #include <asm/cacheflush.h> #include <asm/tlbflush.h> +#include "internal.h" + /* * For a prot_numa update we only hold mmap_sem for read so there is a * potential race with faulting where a pmd was temporarily none. This @@ -290,7 +292,8 @@ mprotect_fixup(struct vm_area_struct *vma, struct vm_area_struct **pprev, */ pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT); *pprev = vma_merge(mm, *pprev, start, end, newflags, - vma->anon_vma, vma->vm_file, pgoff, vma_policy(vma)); + vma->anon_vma, vma->vm_file, pgoff, vma_policy(vma), + vma->vm_userfaultfd_ctx); if (*pprev) { vma = *pprev; goto success; @@ -322,6 +325,15 @@ success: change_protection(vma, start, end, vma->vm_page_prot, dirty_accountable, 0); + /* + * Private VM_LOCKED VMA becoming writable: trigger COW to avoid major + * fault on access. + */ + if ((oldflags & (VM_WRITE | VM_SHARED | VM_LOCKED)) == VM_LOCKED && + (newflags & VM_WRITE)) { + populate_vma_page_range(vma, start, end, NULL); + } + vm_stat_account(mm, oldflags, vma->vm_file, -nrpages); vm_stat_account(mm, newflags, vma->vm_file, nrpages); perf_event_mmap(vma); |