From: Adam Litke Date: Wed, 12 Nov 2008 21:24:56 +0000 (-0800) Subject: hugetlb: make unmap_ref_private multi-size-aware X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=7526674de0c921e7f1e9b6f71a1f9d832557b554;p=GitHub%2Fmt8127%2Fandroid_kernel_alcatel_ttab.git hugetlb: make unmap_ref_private multi-size-aware Oops. Part of the hugetlb private reservation code was not fully converted to use hstates. When a huge page must be unmapped from VMAs due to a failed COW, HPAGE_SIZE is used in the call to unmap_hugepage_range() regardless of the page size being used. This works if the VMA is using the default huge page size. Otherwise we might unmap too much, too little, or trigger a BUG_ON. Rare but serious -- fix it. Signed-off-by: Adam Litke Cc: Jon Tollefson Cc: Mel Gorman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/mm/hugetlb.c b/mm/hugetlb.c index d143ab67be44..6058b53dcb89 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -1796,6 +1796,7 @@ void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, static int unmap_ref_private(struct mm_struct *mm, struct vm_area_struct *vma, struct page *page, unsigned long address) { + struct hstate *h = hstate_vma(vma); struct vm_area_struct *iter_vma; struct address_space *mapping; struct prio_tree_iter iter; @@ -1805,7 +1806,7 @@ static int unmap_ref_private(struct mm_struct *mm, struct vm_area_struct *vma, * vm_pgoff is in PAGE_SIZE units, hence the different calculation * from page cache lookup which is in HPAGE_SIZE units. */ - address = address & huge_page_mask(hstate_vma(vma)); + address = address & huge_page_mask(h); pgoff = ((address - vma->vm_start) >> PAGE_SHIFT) + (vma->vm_pgoff >> PAGE_SHIFT); mapping = (struct address_space *)page_private(page); @@ -1824,7 +1825,7 @@ static int unmap_ref_private(struct mm_struct *mm, struct vm_area_struct *vma, */ if (!is_vma_resv_set(iter_vma, HPAGE_RESV_OWNER)) unmap_hugepage_range(iter_vma, - address, address + HPAGE_SIZE, + address, address + huge_page_size(h), page); }