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| author |   Linus Torvalds <torvalds@g5.osdl.org> | 2005-11-28 14:34:23 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2005-11-28 14:34:23 -0800 |
| commit | 6aab341e0a28aff100a09831c5300a2994b8b986 (patch) | |
| tree | 1af3908275aa5e1b16e80efee554a9a7504c56d4 /mm/fremap.c | |
| parent | [PATCH] drivers/scsi/dpt_i2o.c: fix a NULL pointer dereference (diff) | |
| download | linux-dev-6aab341e0a28aff100a09831c5300a2994b8b986.tar.xz linux-dev-6aab341e0a28aff100a09831c5300a2994b8b986.zip | |
mm: re-architect the VM_UNPAGED logic
This replaces the (in my opinion horrible) VM_UNMAPPED logic with very
explicit support for a "remapped page range" aka VM_PFNMAP. It allows a
VM area to contain an arbitrary range of page table entries that the VM
never touches, and never considers to be normal pages.
Any user of "remap_pfn_range()" automatically gets this new
functionality, and doesn't even have to mark the pages reserved or
indeed mark them any other way. It just works. As a side effect, doing
mmap() on /dev/mem works for arbitrary ranges.
Sparc update from David in the next commit.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'mm/fremap.c')
| -rw-r--r-- | mm/fremap.c | 22 |
1 files changed, 7 insertions, 15 deletions
diff --git a/mm/fremap.c b/mm/fremap.c index 007cbad9331e..f851775e09c2 100644 --- a/mm/fremap.c +++ b/mm/fremap.c @@ -27,24 +27,20 @@ static int zap_pte(struct mm_struct *mm, struct vm_area_struct *vma, struct page *page = NULL; if (pte_present(pte)) { - unsigned long pfn = pte_pfn(pte); - flush_cache_page(vma, addr, pfn); + flush_cache_page(vma, addr, pte_pfn(pte)); pte = ptep_clear_flush(vma, addr, ptep); - if (unlikely(!pfn_valid(pfn))) { - print_bad_pte(vma, pte, addr); - goto out; + page = vm_normal_page(vma, addr, pte); + if (page) { + if (pte_dirty(pte)) + set_page_dirty(page); + page_remove_rmap(page); + page_cache_release(page); } - page = pfn_to_page(pfn); - if (pte_dirty(pte)) - set_page_dirty(page); - page_remove_rmap(page); - page_cache_release(page); } else { if (!pte_file(pte)) free_swap_and_cache(pte_to_swp_entry(pte)); pte_clear(mm, addr, ptep); } -out: return !!page; } @@ -65,8 +61,6 @@ int install_page(struct mm_struct *mm, struct vm_area_struct *vma, pte_t pte_val; spinlock_t *ptl; - BUG_ON(vma->vm_flags & VM_UNPAGED); - pgd = pgd_offset(mm, addr); pud = pud_alloc(mm, pgd, addr); if (!pud) @@ -122,8 +116,6 @@ int install_file_pte(struct mm_struct *mm, struct vm_area_struct *vma, pte_t pte_val; spinlock_t *ptl; - BUG_ON(vma->vm_flags & VM_UNPAGED); - pgd = pgd_offset(mm, addr); pud = pud_alloc(mm, pgd, addr); if (!pud) |