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>
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index e6a71c8..3a19b03 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -66,11 +66,8 @@
* If the arch doesn't supply something else, assume that hugepage
* size aligned regions are ok without further preparation.
*/
-static inline int prepare_hugepage_range(unsigned long addr, unsigned long len,
- pgoff_t pgoff)
+static inline int prepare_hugepage_range(unsigned long addr, unsigned long len)
{
- if (pgoff & (~HPAGE_MASK >> PAGE_SHIFT))
- return -EINVAL;
if (len & ~HPAGE_MASK)
return -EINVAL;
if (addr & ~HPAGE_MASK)
@@ -78,8 +75,7 @@
return 0;
}
#else
-int prepare_hugepage_range(unsigned long addr, unsigned long len,
- pgoff_t pgoff);
+int prepare_hugepage_range(unsigned long addr, unsigned long len);
#endif
#ifndef ARCH_HAS_SETCLEAR_HUGE_PTE
@@ -117,7 +113,7 @@
#define hugetlb_report_meminfo(buf) 0
#define hugetlb_report_node_meminfo(n, buf) 0
#define follow_huge_pmd(mm, addr, pmd, write) NULL
-#define prepare_hugepage_range(addr,len,pgoff) (-EINVAL)
+#define prepare_hugepage_range(addr,len) (-EINVAL)
#define pmd_huge(x) 0
#define is_hugepage_only_range(mm, addr, len) 0
#define hugetlb_free_pgd_range(tlb, addr, end, floor, ceiling) ({BUG(); 0; })