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authorDavid Gibson <david@gibson.dropbear.id.au>2007-08-30 23:56:40 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-08-31 01:42:23 -0700
commitdec4ad86c2fbea062e9ef9caa6d6e79f7c5e0b12 (patch)
tree9882d3b1f59fb293cf0f70afc80bdc7bb1e0021e /fs
parent4a58448b0a375f7198de34dd0d3e2881afeaf025 (diff)
downloadlinux-linaro-dec4ad86c2fbea062e9ef9caa6d6e79f7c5e0b12.tar.gz
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 <david@gibson.dropbear.id.au> Cc: Adam Litke <agl@us.ibm.com> Cc: Andi Kleen <ak@suse.de> Cc: "David S. Miller" <davem@davemloft.net> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs')
-rw-r--r--fs/hugetlbfs/inode.c15
1 files changed, 10 insertions, 5 deletions
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;
}