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Diffstat (limited to 'mm/madvise.c')
-rw-r--r--mm/madvise.c61
1 files changed, 50 insertions, 11 deletions
diff --git a/mm/madvise.c b/mm/madvise.c
index 0e3828eae9f8..dc5927c812d3 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -10,6 +10,7 @@
#include <linux/syscalls.h>
#include <linux/mempolicy.h>
#include <linux/page-isolation.h>
+#include <linux/userfaultfd_k.h>
#include <linux/hugetlb.h>
#include <linux/falloc.h>
#include <linux/sched.h>
@@ -20,10 +21,13 @@
#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>
+#include "internal.h"
+
/*
* Any behaviour which results in changes to the vma->vm_flags needs to
* take mmap_sem for writing. Others, which simply traverse vmas, need
@@ -89,14 +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;
}
@@ -117,15 +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:
@@ -133,10 +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;
}
@@ -473,10 +510,11 @@ static long madvise_dontneed(struct vm_area_struct *vma,
unsigned long start, unsigned long end)
{
*prev = vma;
- if (vma->vm_flags & (VM_LOCKED|VM_HUGETLB|VM_PFNMAP))
+ if (!can_madv_dontneed_vma(vma))
return -EINVAL;
- zap_page_range(vma, start, end - start, NULL);
+ userfaultfd_remove(vma, prev, start, end);
+ zap_page_range(vma, start, end - start);
return 0;
}
@@ -516,6 +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,