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| author |   Hugh Dickins <hugh@veritas.com> | 2005-10-29 18:15:55 -0700 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@g5.osdl.org> | 2005-10-29 21:40:36 -0700 |
| commit | 72866f6f277ec0ddd6df7a3b6ecdcf59a28de115 (patch) | |
| tree | a76bb7fb8e092250c4399c20f0c7c973b77cb0bb /mm/memory.c | |
| parent | [PATCH] mm: zap_pte_range dont dirty anon (diff) | |
| download | linux-dev-72866f6f277ec0ddd6df7a3b6ecdcf59a28de115.tar.xz linux-dev-72866f6f277ec0ddd6df7a3b6ecdcf59a28de115.zip | |
[PATCH] mm: anon is already wrprotected
do_anonymous_page's pte_wrprotect causes some confusion: in such a case,
vm_page_prot must already be forcing COW, so must omit write permission, and
so the pte_wrprotect is redundant. Replace it by a comment to that effect,
and reword the comment on unuse_pte which also caused confusion.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'mm/memory.c')
| -rw-r--r-- | mm/memory.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/mm/memory.c b/mm/memory.c index fd5d4c6dc762..13667681cd16 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1768,13 +1768,14 @@ do_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long addr) { pte_t entry; - struct page * page = ZERO_PAGE(addr); - /* Read-only mapping of ZERO_PAGE. */ - entry = pte_wrprotect(mk_pte(ZERO_PAGE(addr), vma->vm_page_prot)); + /* Mapping of ZERO_PAGE - vm_page_prot is readonly */ + entry = mk_pte(ZERO_PAGE(addr), vma->vm_page_prot); /* ..except if it's a write access */ if (write_access) { + struct page *page; + /* Allocate our own private page. */ pte_unmap(page_table); spin_unlock(&mm->page_table_lock); |