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Diffstat (limited to 'mm/rmap.c')
-rw-r--r--mm/rmap.c22
1 files changed, 10 insertions, 12 deletions
diff --git a/mm/rmap.c b/mm/rmap.c
index 914d04b98be..2e034a0b89a 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -225,7 +225,9 @@ vma_address(struct page *page, struct vm_area_struct *vma)
/*
* At what user virtual address is page expected in vma? checking that the
- * page matches the vma: currently only used by unuse_process, on anon pages.
+ * page matches the vma: currently only used on anon pages, by unuse_vma;
+ * and by extraordinary checks on anon pages in VM_UNPAGED vmas, taking
+ * care that an mmap of /dev/mem might window free and foreign pages.
*/
unsigned long page_address_in_vma(struct page *page, struct vm_area_struct *vma)
{
@@ -234,7 +236,8 @@ unsigned long page_address_in_vma(struct page *page, struct vm_area_struct *vma)
(void *)page->mapping - PAGE_MAPPING_ANON)
return -EFAULT;
} else if (page->mapping && !(vma->vm_flags & VM_NONLINEAR)) {
- if (vma->vm_file->f_mapping != page->mapping)
+ if (!vma->vm_file ||
+ vma->vm_file->f_mapping != page->mapping)
return -EFAULT;
} else
return -EFAULT;
@@ -529,10 +532,8 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma)
* If the page is mlock()d, we cannot swap it out.
* If it's recently referenced (perhaps page_referenced
* skipped over this mm) then we should reactivate it.
- *
- * Pages belonging to VM_RESERVED regions should not happen here.
*/
- if ((vma->vm_flags & (VM_LOCKED|VM_RESERVED)) ||
+ if ((vma->vm_flags & VM_LOCKED) ||
ptep_clear_flush_young(vma, address, pte)) {
ret = SWAP_FAIL;
goto out_unmap;
@@ -727,7 +728,7 @@ static int try_to_unmap_file(struct page *page)
list_for_each_entry(vma, &mapping->i_mmap_nonlinear,
shared.vm_set.list) {
- if (vma->vm_flags & (VM_LOCKED|VM_RESERVED))
+ if (vma->vm_flags & VM_LOCKED)
continue;
cursor = (unsigned long) vma->vm_private_data;
if (cursor > max_nl_cursor)
@@ -761,7 +762,7 @@ static int try_to_unmap_file(struct page *page)
do {
list_for_each_entry(vma, &mapping->i_mmap_nonlinear,
shared.vm_set.list) {
- if (vma->vm_flags & (VM_LOCKED|VM_RESERVED))
+ if (vma->vm_flags & VM_LOCKED)
continue;
cursor = (unsigned long) vma->vm_private_data;
while ( cursor < max_nl_cursor &&
@@ -783,11 +784,8 @@ static int try_to_unmap_file(struct page *page)
* in locked vmas). Reset cursor on all unreserved nonlinear
* vmas, now forgetting on which ones it had fallen behind.
*/
- list_for_each_entry(vma, &mapping->i_mmap_nonlinear,
- shared.vm_set.list) {
- if (!(vma->vm_flags & VM_RESERVED))
- vma->vm_private_data = NULL;
- }
+ list_for_each_entry(vma, &mapping->i_mmap_nonlinear, shared.vm_set.list)
+ vma->vm_private_data = NULL;
out:
spin_unlock(&mapping->i_mmap_lock);
return ret;