diff options
| author | Nick Piggin <nickpiggin@yahoo.com.au> | 2005-09-27 21:45:18 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2005-09-28 07:46:40 -0700 |
| commit | 8b1f3124618b54cf125dea3a074b9cf469117723 (patch) | |
| tree | 19ef8a7fe9cc5b1c46dc973ea151edab4aba2b8a /mm/mremap.c | |
| parent | 95001ee9256df846e374f116c92ca8e0beec1527 (diff) | |
| download | lwn-8b1f3124618b54cf125dea3a074b9cf469117723.tar.gz lwn-8b1f3124618b54cf125dea3a074b9cf469117723.zip | |
[PATCH] mm: move_pte to remap ZERO_PAGE
Move the ZERO_PAGE remapping complexity to the move_pte macro in
asm-generic, have it conditionally depend on
__HAVE_ARCH_MULTIPLE_ZERO_PAGE, which gets defined for MIPS.
For architectures without __HAVE_ARCH_MULTIPLE_ZERO_PAGE, move_pte becomes
a noop.
From: Hugh Dickins <hugh@veritas.com>
Fix nasty little bug we've missed in Nick's mremap move ZERO_PAGE patch.
The "pte" at that point may be a swap entry or a pte_file entry: we must
check pte_present before perhaps corrupting such an entry.
Patch below against 2.6.14-rc2-mm1, but the same bug is in 2.6.14-rc2's
mm/mremap.c, and more dangerous there since it's affecting all arches: I
think the safest course is to send Nick's patch and Yoichi's build fix and
this fix (build tested) on to Linus - so only MIPS can be affected.
Signed-off-by: Nick Piggin <npiggin@suse.de>
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/mremap.c')
| -rw-r--r-- | mm/mremap.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/mm/mremap.c b/mm/mremap.c index a32fed454bd7..f343fc73a8bd 100644 --- a/mm/mremap.c +++ b/mm/mremap.c @@ -141,10 +141,10 @@ move_one_page(struct vm_area_struct *vma, unsigned long old_addr, if (dst) { pte_t pte; pte = ptep_clear_flush(vma, old_addr, src); + /* ZERO_PAGE can be dependant on virtual addr */ - if (pfn_valid(pte_pfn(pte)) && - pte_page(pte) == ZERO_PAGE(old_addr)) - pte = pte_wrprotect(mk_pte(ZERO_PAGE(new_addr), new_vma->vm_page_prot)); + pte = move_pte(pte, new_vma->vm_page_prot, + old_addr, new_addr); set_pte_at(mm, new_addr, dst, pte); } else error = -ENOMEM; |