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authorLinus Torvalds <torvalds@g5.osdl.org>2005-12-16 10:21:23 -0800
committerLinus Torvalds <torvalds@g5.osdl.org>2005-12-16 10:21:23 -0800
commit4d7672b46244abffea1953e55688c0ea143dd617 (patch)
tree9f3bdf438bcb0d5f6e723665ced23308fffb8368 /mm
parent281ab031a8c9e5b593142eb4ec59a87faae8676a (diff)
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Make sure we copy pages inserted with "vm_insert_page()" on fork
The logic that decides that a fork() might be able to avoid copying a VM area when it can be re-created by page faults didn't know about the new vm_insert_page() case. Also make some things a bit more anal wrt VM_PFNMAP. Pointed out by Hugh Dickins <hugh@veritas.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/memory.c3
-rw-r--r--mm/mmap.c2
-rw-r--r--mm/mremap.c2
3 files changed, 4 insertions, 3 deletions
diff --git a/mm/memory.c b/mm/memory.c
index d22f78c8a38..d8dde07a365 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -574,7 +574,7 @@ int copy_page_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
* readonly mappings. The tradeoff is that copy_page_range is more
* efficient than faulting.
*/
- if (!(vma->vm_flags & (VM_HUGETLB|VM_NONLINEAR|VM_PFNMAP))) {
+ if (!(vma->vm_flags & (VM_HUGETLB|VM_NONLINEAR|VM_PFNMAP|VM_INSERTPAGE))) {
if (!vma->anon_vma)
return 0;
}
@@ -1228,6 +1228,7 @@ int vm_insert_page(struct vm_area_struct *vma, unsigned long addr, struct page *
return -EFAULT;
if (!page_count(page))
return -EINVAL;
+ vma->vm_flags |= VM_INSERTPAGE;
return insert_page(vma->vm_mm, addr, page, vma->vm_page_prot);
}
EXPORT_SYMBOL(vm_insert_page);
diff --git a/mm/mmap.c b/mm/mmap.c
index 11ca5927d5f..64ba4dbcb7d 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -611,7 +611,7 @@ again: remove_next = 1 + (end > next->vm_end);
* If the vma has a ->close operation then the driver probably needs to release
* per-vma resources, so we don't attempt to merge those.
*/
-#define VM_SPECIAL (VM_IO | VM_DONTCOPY | VM_DONTEXPAND | VM_RESERVED)
+#define VM_SPECIAL (VM_IO | VM_DONTCOPY | VM_DONTEXPAND | VM_RESERVED | VM_PFNMAP)
static inline int is_mergeable_vma(struct vm_area_struct *vma,
struct file *file, unsigned long vm_flags)
diff --git a/mm/mremap.c b/mm/mremap.c
index b535438c363..ddaeee9a0b6 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -323,7 +323,7 @@ unsigned long do_mremap(unsigned long addr,
/* We can't remap across vm area boundaries */
if (old_len > vma->vm_end - addr)
goto out;
- if (vma->vm_flags & VM_DONTEXPAND) {
+ if (vma->vm_flags & (VM_DONTEXPAND | VM_PFNMAP)) {
if (new_len > old_len)
goto out;
}