diff options
Diffstat (limited to 'mm/userfaultfd.c')
-rw-r--r-- | mm/userfaultfd.c | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c index 640ff2bd9a69..e8758304a9f3 100644 --- a/mm/userfaultfd.c +++ b/mm/userfaultfd.c @@ -53,6 +53,8 @@ static int mcopy_atomic_pte(struct mm_struct *dst_mm, /* don't free the page */ goto out; } + + flush_dcache_page(page); } else { page = *pagep; *pagep = NULL; @@ -175,6 +177,7 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm, unsigned long dst_start, unsigned long src_start, unsigned long len, + bool *mmap_changing, bool zeropage) { int vm_alloc_shared = dst_vma->vm_flags & VM_SHARED; @@ -306,6 +309,15 @@ retry: goto out; } down_read(&dst_mm->mmap_sem); + /* + * If memory mappings are changing because of non-cooperative + * operation (e.g. mremap) running in parallel, bail out and + * request the user to retry later + */ + if (mmap_changing && READ_ONCE(*mmap_changing)) { + err = -EAGAIN; + break; + } dst_vma = NULL; goto retry; @@ -387,6 +399,7 @@ extern ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm, unsigned long dst_start, unsigned long src_start, unsigned long len, + bool *mmap_changing, bool zeropage); #endif /* CONFIG_HUGETLB_PAGE */ @@ -504,7 +517,8 @@ retry: */ if (is_vm_hugetlb_page(dst_vma)) return __mcopy_atomic_hugetlb(dst_mm, dst_vma, dst_start, - src_start, len, zeropage); + src_start, len, mmap_changing, + zeropage); if (!vma_is_anonymous(dst_vma) && !vma_is_shmem(dst_vma)) goto out_unlock; @@ -572,6 +586,7 @@ retry: err = -EFAULT; goto out; } + flush_dcache_page(page); goto retry; } else BUG_ON(page); |