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hugepage: fix broken check for offset alignment in hugepage mappings

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For hugepage mappings, the file offset, like the address and size, needs to
be aligned to the size of a hugepage.

In commit 68589bc353, 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 4b1d89290b, 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>
This commit is contained in:
David Gibson
2007-08-30 23:56:40 -07:00
committed by Linus Torvalds
parent 4a58448b0a
commit dec4ad86c2
5 changed files with 17 additions and 18 deletions
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15
fs/hugetlbfs/inode.c
View File

@@ -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;
}