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author | Hugh Dickins <hugh@veritas.com> | 2009-01-06 14:40:10 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-01-06 15:59:07 -0800 |
commit | 2509ef26db4699a5d9fa876e90ddfc107afcab84 (patch) | |
tree | 09e65185142c60b5d766d8b75f3cbc8a65de6a39 | |
parent | 22b31eec63e5f2e219a3ee15f456897272bc73e8 (diff) | |
download | linux-3.10-2509ef26db4699a5d9fa876e90ddfc107afcab84.tar.gz linux-3.10-2509ef26db4699a5d9fa876e90ddfc107afcab84.tar.bz2 linux-3.10-2509ef26db4699a5d9fa876e90ddfc107afcab84.zip |
badpage: zap print_bad_pte on swap and file
Complete zap_pte_range()'s coverage of bad pagetable entries by calling
print_bad_pte() on a pte_file in a linear vma and on a bad swap entry.
That needs free_swap_and_cache() to tell it, which will also have shown
one of those "swap_free" errors (but with much less information).
Similar checks in fork's copy_one_pte()? No, that would be more noisy
than helpful: we'll see them when parent and child exec or exit.
Where do_nonlinear_fault() calls print_bad_pte(): omit !VM_CAN_NONLINEAR
case, that could only be a bug in sys_remap_file_pages(), not a bad pte.
VM_FAULT_OOM rather than VM_FAULT_SIGBUS? Well, okay, that is consistent
with what happens if do_swap_page() operates a bad swap entry; but don't
we have patches to be more careful about killing when VM_FAULT_OOM?
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r-- | include/linux/swap.h | 12 | ||||
-rw-r--r-- | mm/memory.c | 11 | ||||
-rw-r--r-- | mm/swapfile.c | 7 |
3 files changed, 14 insertions, 16 deletions
diff --git a/include/linux/swap.h b/include/linux/swap.h index cbf7fbed3df..91dee50fe26 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -302,7 +302,7 @@ extern swp_entry_t get_swap_page_of_type(int); extern int swap_duplicate(swp_entry_t); extern int valid_swaphandles(swp_entry_t, unsigned long *); extern void swap_free(swp_entry_t); -extern void free_swap_and_cache(swp_entry_t); +extern int free_swap_and_cache(swp_entry_t); extern int swap_type_of(dev_t, sector_t, struct block_device **); extern unsigned int count_swap_pages(int, int); extern sector_t map_swap_page(struct swap_info_struct *, pgoff_t); @@ -352,14 +352,8 @@ static inline void show_swap_cache_info(void) { } -static inline void free_swap_and_cache(swp_entry_t swp) -{ -} - -static inline int swap_duplicate(swp_entry_t swp) -{ - return 0; -} +#define free_swap_and_cache(swp) is_migration_entry(swp) +#define swap_duplicate(swp) is_migration_entry(swp) static inline void swap_free(swp_entry_t swp) { diff --git a/mm/memory.c b/mm/memory.c index 890095f5f36..b273cc12b15 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -810,8 +810,12 @@ static unsigned long zap_pte_range(struct mmu_gather *tlb, */ if (unlikely(details)) continue; - if (!pte_file(ptent)) - free_swap_and_cache(pte_to_swp_entry(ptent)); + if (pte_file(ptent)) { + if (unlikely(!(vma->vm_flags & VM_NONLINEAR))) + print_bad_pte(vma, addr, ptent, NULL); + } else if + (unlikely(!free_swap_and_cache(pte_to_swp_entry(ptent)))) + print_bad_pte(vma, addr, ptent, NULL); pte_clear_not_present_full(mm, addr, pte, tlb->fullmm); } while (pte++, addr += PAGE_SIZE, (addr != end && *zap_work > 0)); @@ -2707,8 +2711,7 @@ static int do_nonlinear_fault(struct mm_struct *mm, struct vm_area_struct *vma, if (!pte_unmap_same(mm, pmd, page_table, orig_pte)) return 0; - if (unlikely(!(vma->vm_flags & VM_NONLINEAR) || - !(vma->vm_flags & VM_CAN_NONLINEAR))) { + if (unlikely(!(vma->vm_flags & VM_NONLINEAR))) { /* * Page table corrupted: show pte and kill process. */ diff --git a/mm/swapfile.c b/mm/swapfile.c index d0052360191..f2874585577 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -571,13 +571,13 @@ int try_to_free_swap(struct page *page) * Free the swap entry like above, but also try to * free the page cache entry if it is the last user. */ -void free_swap_and_cache(swp_entry_t entry) +int free_swap_and_cache(swp_entry_t entry) { - struct swap_info_struct * p; + struct swap_info_struct *p; struct page *page = NULL; if (is_migration_entry(entry)) - return; + return 1; p = swap_info_get(entry); if (p) { @@ -603,6 +603,7 @@ void free_swap_and_cache(swp_entry_t entry) unlock_page(page); page_cache_release(page); } + return p != NULL; } #ifdef CONFIG_HIBERNATION |