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-rw-r--r--mm/mmap.c19
1 files changed, 12 insertions, 7 deletions
diff --git a/mm/mmap.c b/mm/mmap.c
index e66a0b524af..eea8eefd51a 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -64,6 +64,13 @@ pgprot_t protection_map[16] = {
__S000, __S001, __S010, __S011, __S100, __S101, __S110, __S111
};
+pgprot_t vm_get_page_prot(unsigned long vm_flags)
+{
+ return protection_map[vm_flags &
+ (VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)];
+}
+EXPORT_SYMBOL(vm_get_page_prot);
+
int sysctl_overcommit_memory = OVERCOMMIT_GUESS; /* heuristic overcommit */
int sysctl_overcommit_ratio = 50; /* default is 50% */
int sysctl_max_map_count __read_mostly = DEFAULT_MAX_MAP_COUNT;
@@ -109,7 +116,7 @@ int __vm_enough_memory(long pages, int cap_sys_admin)
* which are reclaimable, under pressure. The dentry
* cache and most inode caches should fall into this
*/
- free += atomic_read(&slab_reclaim_pages);
+ free += global_page_state(NR_SLAB_RECLAIMABLE);
/*
* Leave the last 3% for root
@@ -1098,12 +1105,6 @@ munmap_back:
goto free_vma;
}
- /* Don't make the VMA automatically writable if it's shared, but the
- * backer wishes to know when pages are first written to */
- if (vma->vm_ops && vma->vm_ops->page_mkwrite)
- vma->vm_page_prot =
- protection_map[vm_flags & (VM_READ|VM_WRITE|VM_EXEC)];
-
/* We set VM_ACCOUNT in a shared mapping's vm_flags, to inform
* shmem_zero_setup (perhaps called through /dev/zero's ->mmap)
* that memory reservation must be checked; but that reservation
@@ -1121,6 +1122,10 @@ munmap_back:
pgoff = vma->vm_pgoff;
vm_flags = vma->vm_flags;
+ if (vma_wants_writenotify(vma))
+ vma->vm_page_prot =
+ protection_map[vm_flags & (VM_READ|VM_WRITE|VM_EXEC)];
+
if (!file || !vma_merge(mm, prev, addr, vma->vm_end,
vma->vm_flags, NULL, file, pgoff, vma_policy(vma))) {
file = vma->vm_file;