KVM: arm64: add SYS_DESC()

[karo-tx-linux.git] / mm / madvise.c

diff --git a/mm/madvise.c b/mm/madvise.c
index b530a4986035bac08c12c996600f19fddb597acb..dc5927c812d3d1f9a209fbdbea3a36a61cbde17d 100644 (file)
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -21,6 +21,7 @@
 #include <linux/backing-dev.h>
 #include <linux/swap.h>
 #include <linux/swapops.h>
+#include <linux/shmem_fs.h>
 #include <linux/mmu_notifier.h>
 
 #include <asm/tlb.h>
@@ -92,14 +93,28 @@ static long madvise_behavior(struct vm_area_struct *vma,
        case MADV_MERGEABLE:
        case MADV_UNMERGEABLE:
                error = ksm_madvise(vma, start, end, behavior, &new_flags);
-               if (error)
+               if (error) {
+                       /*
+                        * madvise() returns EAGAIN if kernel resources, such as
+                        * slab, are temporarily unavailable.
+                        */
+                       if (error == -ENOMEM)
+                               error = -EAGAIN;
                        goto out;
+               }
                break;
        case MADV_HUGEPAGE:
        case MADV_NOHUGEPAGE:
                error = hugepage_madvise(vma, &new_flags, behavior);
-               if (error)
+               if (error) {
+                       /*
+                        * madvise() returns EAGAIN if kernel resources, such as
+                        * slab, are temporarily unavailable.
+                        */
+                       if (error == -ENOMEM)
+                               error = -EAGAIN;
                        goto out;
+               }
                break;
        }
 
@@ -120,15 +135,37 @@ static long madvise_behavior(struct vm_area_struct *vma,
        *prev = vma;
 
        if (start != vma->vm_start) {
-               error = split_vma(mm, vma, start, 1);
-               if (error)
+               if (unlikely(mm->map_count >= sysctl_max_map_count)) {
+                       error = -ENOMEM;
                        goto out;
+               }
+               error = __split_vma(mm, vma, start, 1);
+               if (error) {
+                       /*
+                        * madvise() returns EAGAIN if kernel resources, such as
+                        * slab, are temporarily unavailable.
+                        */
+                       if (error == -ENOMEM)
+                               error = -EAGAIN;
+                       goto out;
+               }
        }
 
        if (end != vma->vm_end) {
-               error = split_vma(mm, vma, end, 0);
-               if (error)
+               if (unlikely(mm->map_count >= sysctl_max_map_count)) {
+                       error = -ENOMEM;
+                       goto out;
+               }
+               error = __split_vma(mm, vma, end, 0);
+               if (error) {
+                       /*
+                        * madvise() returns EAGAIN if kernel resources, such as
+                        * slab, are temporarily unavailable.
+                        */
+                       if (error == -ENOMEM)
+                               error = -EAGAIN;
                        goto out;
+               }
        }
 
 success:
@@ -136,10 +173,7 @@ success:
         * vm_flags is protected by the mmap_sem held in write mode.
         */
        vma->vm_flags = new_flags;
-
 out:
-       if (error == -ENOMEM)
-               error = -EAGAIN;
        return error;
 }
 
@@ -479,7 +513,7 @@ static long madvise_dontneed(struct vm_area_struct *vma,
        if (!can_madv_dontneed_vma(vma))
                return -EINVAL;
 
-       madvise_userfault_dontneed(vma, prev, start, end);
+       userfaultfd_remove(vma, prev, start, end);
        zap_page_range(vma, start, end - start);
        return 0;
 }
@@ -520,6 +554,7 @@ static long madvise_remove(struct vm_area_struct *vma,
         * mmap_sem.
         */
        get_file(f);
+       userfaultfd_remove(vma, prev, start, end);
        up_read(&current->mm->mmap_sem);
        error = vfs_fallocate(f,
                                FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,