Merge tag 'v4.9.209' of git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux...

[platform/kernel/linux-amlogic.git] / mm / mmap.c

diff --git a/mm/mmap.c b/mm/mmap.c
index d221266..6cfc924 100644 (file)
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -964,7 +964,8 @@ again:
  */
 static inline int is_mergeable_vma(struct vm_area_struct *vma,
                                struct file *file, unsigned long vm_flags,
-                               struct vm_userfaultfd_ctx vm_userfaultfd_ctx)
+                               struct vm_userfaultfd_ctx vm_userfaultfd_ctx,
+                               const char __user *anon_name)
 {
        /*
         * VM_SOFTDIRTY should not prevent from VMA merging, if we
@@ -982,6 +983,8 @@ static inline int is_mergeable_vma(struct vm_area_struct *vma,
                return 0;
        if (!is_mergeable_vm_userfaultfd_ctx(vma, vm_userfaultfd_ctx))
                return 0;
+       if (vma_get_anon_name(vma) != anon_name)
+               return 0;
        return 1;
 }
 
@@ -1014,9 +1017,10 @@ static int
 can_vma_merge_before(struct vm_area_struct *vma, unsigned long vm_flags,
                     struct anon_vma *anon_vma, struct file *file,
                     pgoff_t vm_pgoff,
-                    struct vm_userfaultfd_ctx vm_userfaultfd_ctx)
+                    struct vm_userfaultfd_ctx vm_userfaultfd_ctx,
+                    const char __user *anon_name)
 {
-       if (is_mergeable_vma(vma, file, vm_flags, vm_userfaultfd_ctx) &&
+       if (is_mergeable_vma(vma, file, vm_flags, vm_userfaultfd_ctx, anon_name) &&
            is_mergeable_anon_vma(anon_vma, vma->anon_vma, vma)) {
                if (vma->vm_pgoff == vm_pgoff)
                        return 1;
@@ -1035,9 +1039,10 @@ static int
 can_vma_merge_after(struct vm_area_struct *vma, unsigned long vm_flags,
                    struct anon_vma *anon_vma, struct file *file,
                    pgoff_t vm_pgoff,
-                   struct vm_userfaultfd_ctx vm_userfaultfd_ctx)
+                   struct vm_userfaultfd_ctx vm_userfaultfd_ctx,
+                   const char __user *anon_name)
 {
-       if (is_mergeable_vma(vma, file, vm_flags, vm_userfaultfd_ctx) &&
+       if (is_mergeable_vma(vma, file, vm_flags, vm_userfaultfd_ctx, anon_name) &&
            is_mergeable_anon_vma(anon_vma, vma->anon_vma, vma)) {
                pgoff_t vm_pglen;
                vm_pglen = vma_pages(vma);
@@ -1048,9 +1053,9 @@ can_vma_merge_after(struct vm_area_struct *vma, unsigned long vm_flags,
 }
 
 /*
- * Given a mapping request (addr,end,vm_flags,file,pgoff), figure out
- * whether that can be merged with its predecessor or its successor.
- * Or both (it neatly fills a hole).
+ * Given a mapping request (addr,end,vm_flags,file,pgoff,anon_name),
+ * figure out whether that can be merged with its predecessor or its
+ * successor.  Or both (it neatly fills a hole).
  *
  * In most cases - when called for mmap, brk or mremap - [addr,end) is
  * certain not to be mapped by the time vma_merge is called; but when
@@ -1092,7 +1097,8 @@ struct vm_area_struct *vma_merge(struct mm_struct *mm,
                        unsigned long end, unsigned long vm_flags,
                        struct anon_vma *anon_vma, struct file *file,
                        pgoff_t pgoff, struct mempolicy *policy,
-                       struct vm_userfaultfd_ctx vm_userfaultfd_ctx)
+                       struct vm_userfaultfd_ctx vm_userfaultfd_ctx,
+                       const char __user *anon_name)
 {
        pgoff_t pglen = (end - addr) >> PAGE_SHIFT;
        struct vm_area_struct *area, *next;
@@ -1125,7 +1131,8 @@ struct vm_area_struct *vma_merge(struct mm_struct *mm,
                        mpol_equal(vma_policy(prev), policy) &&
                        can_vma_merge_after(prev, vm_flags,
                                            anon_vma, file, pgoff,
-                                           vm_userfaultfd_ctx)) {
+                                           vm_userfaultfd_ctx,
+                                           anon_name)) {
                /*
                 * OK, it can.  Can we now merge in the successor as well?
                 */
@@ -1134,7 +1141,8 @@ struct vm_area_struct *vma_merge(struct mm_struct *mm,
                                can_vma_merge_before(next, vm_flags,
                                                     anon_vma, file,
                                                     pgoff+pglen,
-                                                    vm_userfaultfd_ctx) &&
+                                                    vm_userfaultfd_ctx,
+                                                    anon_name) &&
                                is_mergeable_anon_vma(prev->anon_vma,
                                                      next->anon_vma, NULL)) {
                                                        /* cases 1, 6 */
@@ -1157,7 +1165,8 @@ struct vm_area_struct *vma_merge(struct mm_struct *mm,
                        mpol_equal(policy, vma_policy(next)) &&
                        can_vma_merge_before(next, vm_flags,
                                             anon_vma, file, pgoff+pglen,
-                                            vm_userfaultfd_ctx)) {
+                                            vm_userfaultfd_ctx,
+                                            anon_name)) {
                if (prev && addr < prev->vm_end)        /* case 4 */
                        err = __vma_adjust(prev, prev->vm_start,
                                         addr, prev->vm_pgoff, NULL, next);
@@ -1667,7 +1676,7 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
         * Can we just expand an old mapping?
         */
        vma = vma_merge(mm, prev, addr, addr + len, vm_flags,
-                       NULL, file, pgoff, NULL, NULL_VM_UFFD_CTX);
+                       NULL, file, pgoff, NULL, NULL_VM_UFFD_CTX, NULL);
        if (vma)
                goto out;
 
@@ -2730,6 +2739,7 @@ int do_munmap(struct mm_struct *mm, unsigned long start, size_t len)
 
        return 0;
 }
+EXPORT_SYMBOL(do_munmap);
 
 int vm_munmap(unsigned long start, size_t len)
 {
@@ -2919,7 +2929,7 @@ static int do_brk(unsigned long addr, unsigned long len)
 
        /* Can we just expand an old private anonymous mapping? */
        vma = vma_merge(mm, prev, addr, addr + len, flags,
-                       NULL, NULL, pgoff, NULL, NULL_VM_UFFD_CTX);
+                       NULL, NULL, pgoff, NULL, NULL_VM_UFFD_CTX, NULL);
        if (vma)
                goto out;
 
@@ -3087,7 +3097,7 @@ struct vm_area_struct *copy_vma(struct vm_area_struct **vmap,
                return NULL;    /* should never get here */
        new_vma = vma_merge(mm, prev, addr, addr + len, vma->vm_flags,
                            vma->anon_vma, vma->vm_file, pgoff, vma_policy(vma),
-                           vma->vm_userfaultfd_ctx);
+                           vma->vm_userfaultfd_ctx, vma_get_anon_name(vma));
        if (new_vma) {
                /*
                 * Source vma may have been merged into new_vma