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| author | Chen, Kenneth W <kenneth.w.chen@intel.com> | 2006-10-04 02:15:24 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-10-04 07:55:12 -0700 |
| commit | fe1668ae5bf0145014c71797febd9ad5670d5d05 (patch) | |
| tree | a1ad042a0c9b604653ca24645358fe31d1bbcfd6 /mm/hugetlb.c | |
| parent | e80ee884ae0e3794ef2b65a18a767d502ad712ee (diff) | |
| download | linux-fe1668ae5bf0145014c71797febd9ad5670d5d05.tar.gz | |
[PATCH] enforce proper tlb flush in unmap_hugepage_range
Spotted by Hugh that hugetlb page is free'ed back to global pool before performing any TLB flush in unmap_hugepage_range(). This potentially allow threads to abuse free-alloc race condition. The generic tlb gather code is unsuitable to use by hugetlb, I just open coded a page gathering list and delayed put_page until tlb flush is performed. Cc: Hugh Dickins <hugh@veritas.com> Signed-off-by: Ken Chen <kenneth.w.chen@intel.com> Acked-by: William Irwin <wli@holomorphy.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'mm/hugetlb.c')
| -rw-r--r-- | mm/hugetlb.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 7c7d03dbf73d..1d709ff528e1 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -364,6 +364,8 @@ void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, pte_t *ptep; pte_t pte; struct page *page; + struct page *tmp; + LIST_HEAD(page_list); WARN_ON(!is_vm_hugetlb_page(vma)); BUG_ON(start & ~HPAGE_MASK); @@ -384,12 +386,16 @@ void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, continue; page = pte_page(pte); - put_page(page); + list_add(&page->lru, &page_list); add_mm_counter(mm, file_rss, (int) -(HPAGE_SIZE / PAGE_SIZE)); } spin_unlock(&mm->page_table_lock); flush_tlb_range(vma, start, end); + list_for_each_entry_safe(page, tmp, &page_list, lru) { + list_del(&page->lru); + put_page(page); + } } static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma, |