btrfs: remove duplicated include in block-group.c

[linux-2.6-microblaze.git] / mm / userfaultfd.c

diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c
index bd96855..512576e 100644 (file)
--- a/mm/userfaultfd.c
+++ b/mm/userfaultfd.c
@@ -53,7 +53,8 @@ static int mcopy_atomic_pte(struct mm_struct *dst_mm,
                            struct vm_area_struct *dst_vma,
                            unsigned long dst_addr,
                            unsigned long src_addr,
-                           struct page **pagep)
+                           struct page **pagep,
+                           bool wp_copy)
 {
        struct mem_cgroup *memcg;
        pte_t _dst_pte, *dst_pte;
@@ -99,9 +100,13 @@ static int mcopy_atomic_pte(struct mm_struct *dst_mm,
        if (mem_cgroup_try_charge(page, dst_mm, GFP_KERNEL, &memcg, false))
                goto out_release;
 
-       _dst_pte = mk_pte(page, dst_vma->vm_page_prot);
-       if (dst_vma->vm_flags & VM_WRITE)
-               _dst_pte = pte_mkwrite(pte_mkdirty(_dst_pte));
+       _dst_pte = pte_mkdirty(mk_pte(page, dst_vma->vm_page_prot));
+       if (dst_vma->vm_flags & VM_WRITE) {
+               if (wp_copy)
+                       _dst_pte = pte_mkuffd_wp(_dst_pte);
+               else
+                       _dst_pte = pte_mkwrite(_dst_pte);
+       }
 
        dst_pte = pte_offset_map_lock(dst_mm, dst_pmd, dst_addr, &ptl);
        if (dst_vma->vm_file) {
@@ -415,7 +420,8 @@ static __always_inline ssize_t mfill_atomic_pte(struct mm_struct *dst_mm,
                                                unsigned long dst_addr,
                                                unsigned long src_addr,
                                                struct page **page,
-                                               bool zeropage)
+                                               bool zeropage,
+                                               bool wp_copy)
 {
        ssize_t err;
 
@@ -432,11 +438,13 @@ static __always_inline ssize_t mfill_atomic_pte(struct mm_struct *dst_mm,
        if (!(dst_vma->vm_flags & VM_SHARED)) {
                if (!zeropage)
                        err = mcopy_atomic_pte(dst_mm, dst_pmd, dst_vma,
-                                              dst_addr, src_addr, page);
+                                              dst_addr, src_addr, page,
+                                              wp_copy);
                else
                        err = mfill_zeropage_pte(dst_mm, dst_pmd,
                                                 dst_vma, dst_addr);
        } else {
+               VM_WARN_ON_ONCE(wp_copy);
                if (!zeropage)
                        err = shmem_mcopy_atomic_pte(dst_mm, dst_pmd,
                                                     dst_vma, dst_addr,
@@ -454,7 +462,8 @@ static __always_inline ssize_t __mcopy_atomic(struct mm_struct *dst_mm,
                                              unsigned long src_start,
                                              unsigned long len,
                                              bool zeropage,
-                                             bool *mmap_changing)
+                                             bool *mmap_changing,
+                                             __u64 mode)
 {
        struct vm_area_struct *dst_vma;
        ssize_t err;
@@ -462,6 +471,7 @@ static __always_inline ssize_t __mcopy_atomic(struct mm_struct *dst_mm,
        unsigned long src_addr, dst_addr;
        long copied;
        struct page *page;
+       bool wp_copy;
 
        /*
         * Sanitize the command parameters:
@@ -507,6 +517,14 @@ retry:
            dst_vma->vm_flags & VM_SHARED))
                goto out_unlock;
 
+       /*
+        * validate 'mode' now that we know the dst_vma: don't allow
+        * a wrprotect copy if the userfaultfd didn't register as WP.
+        */
+       wp_copy = mode & UFFDIO_COPY_MODE_WP;
+       if (wp_copy && !(dst_vma->vm_flags & VM_UFFD_WP))
+               goto out_unlock;
+
        /*
         * If this is a HUGETLB vma, pass off to appropriate routine
         */
@@ -562,7 +580,7 @@ retry:
                BUG_ON(pmd_trans_huge(*dst_pmd));
 
                err = mfill_atomic_pte(dst_mm, dst_pmd, dst_vma, dst_addr,
-                                      src_addr, &page, zeropage);
+                                      src_addr, &page, zeropage, wp_copy);
                cond_resched();
 
                if (unlikely(err == -ENOENT)) {
@@ -609,14 +627,68 @@ out:
 
 ssize_t mcopy_atomic(struct mm_struct *dst_mm, unsigned long dst_start,
                     unsigned long src_start, unsigned long len,
-                    bool *mmap_changing)
+                    bool *mmap_changing, __u64 mode)
 {
        return __mcopy_atomic(dst_mm, dst_start, src_start, len, false,
-                             mmap_changing);
+                             mmap_changing, mode);
 }
 
 ssize_t mfill_zeropage(struct mm_struct *dst_mm, unsigned long start,
                       unsigned long len, bool *mmap_changing)
 {
-       return __mcopy_atomic(dst_mm, start, 0, len, true, mmap_changing);
+       return __mcopy_atomic(dst_mm, start, 0, len, true, mmap_changing, 0);
+}
+
+int mwriteprotect_range(struct mm_struct *dst_mm, unsigned long start,
+                       unsigned long len, bool enable_wp, bool *mmap_changing)
+{
+       struct vm_area_struct *dst_vma;
+       pgprot_t newprot;
+       int err;
+
+       /*
+        * Sanitize the command parameters:
+        */
+       BUG_ON(start & ~PAGE_MASK);
+       BUG_ON(len & ~PAGE_MASK);
+
+       /* Does the address range wrap, or is the span zero-sized? */
+       BUG_ON(start + len <= start);
+
+       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
+        */
+       err = -EAGAIN;
+       if (mmap_changing && READ_ONCE(*mmap_changing))
+               goto out_unlock;
+
+       err = -ENOENT;
+       dst_vma = find_dst_vma(dst_mm, start, len);
+       /*
+        * Make sure the vma is not shared, that the dst range is
+        * both valid and fully within a single existing vma.
+        */
+       if (!dst_vma || (dst_vma->vm_flags & VM_SHARED))
+               goto out_unlock;
+       if (!userfaultfd_wp(dst_vma))
+               goto out_unlock;
+       if (!vma_is_anonymous(dst_vma))
+               goto out_unlock;
+
+       if (enable_wp)
+               newprot = vm_get_page_prot(dst_vma->vm_flags & ~(VM_WRITE));
+       else
+               newprot = vm_get_page_prot(dst_vma->vm_flags);
+
+       change_protection(dst_vma, start, start + len, newprot,
+                         enable_wp ? MM_CP_UFFD_WP : MM_CP_UFFD_WP_RESOLVE);
+
+       err = 0;
+out_unlock:
+       up_read(&dst_mm->mmap_sem);
+       return err;
 }