From dec4ad86c2fbea062e9ef9caa6d6e79f7c5e0b12 Mon Sep 17 00:00:00 2001 From: David Gibson Date: Thu, 30 Aug 2007 23:56:40 -0700 Subject: hugepage: fix broken check for offset alignment in hugepage mappings For hugepage mappings, the file offset, like the address and size, needs to be aligned to the size of a hugepage. In commit 68589bc353037f233fe510ad9ff432338c95db66, the check for this was moved into prepare_hugepage_range() along with the address and size checks. But since BenH's rework of the get_unmapped_area() paths leading up to commit 4b1d89290b62bb2db476c94c82cf7442aab440c8, prepare_hugepage_range() is only called for MAP_FIXED mappings, not for other mappings. This means we're no longer ever checking for an aligned offset - I've confirmed that mmap() will (apparently) succeed with a misaligned offset on both powerpc and i386 at least. This patch restores the check, removing it from prepare_hugepage_range() and putting it back into hugetlbfs_file_mmap(). I'm putting it there, rather than in the get_unmapped_area() path so it only needs to go in one place, than separately in the half-dozen or so arch-specific implementations of hugetlb_get_unmapped_area(). Signed-off-by: David Gibson Cc: Adam Litke Cc: Andi Kleen Cc: "David S. Miller" Cc: Benjamin Herrenschmidt Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/hugetlbfs/inode.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) (limited to 'fs/hugetlbfs') diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c index c848a191525..950c2fbb815 100644 --- a/fs/hugetlbfs/inode.c +++ b/fs/hugetlbfs/inode.c @@ -82,14 +82,19 @@ static int hugetlbfs_file_mmap(struct file *file, struct vm_area_struct *vma) int ret; /* - * vma alignment has already been checked by prepare_hugepage_range. - * If you add any error returns here, do so after setting VM_HUGETLB, - * so is_vm_hugetlb_page tests below unmap_region go the right way - * when do_mmap_pgoff unwinds (may be important on powerpc and ia64). + * vma address alignment (but not the pgoff alignment) has + * already been checked by prepare_hugepage_range. If you add + * any error returns here, do so after setting VM_HUGETLB, so + * is_vm_hugetlb_page tests below unmap_region go the right + * way when do_mmap_pgoff unwinds (may be important on powerpc + * and ia64). */ vma->vm_flags |= VM_HUGETLB | VM_RESERVED; vma->vm_ops = &hugetlb_vm_ops; + if (vma->vm_pgoff & ~(HPAGE_MASK >> PAGE_SHIFT)) + return -EINVAL; + vma_len = (loff_t)(vma->vm_end - vma->vm_start); mutex_lock(&inode->i_mutex); @@ -132,7 +137,7 @@ hugetlb_get_unmapped_area(struct file *file, unsigned long addr, return -ENOMEM; if (flags & MAP_FIXED) { - if (prepare_hugepage_range(addr, len, pgoff)) + if (prepare_hugepage_range(addr, len)) return -EINVAL; return addr; } -- cgit v1.2.3