Commit dec4ad86 authored by David Gibson's avatar David Gibson Committed by Linus Torvalds
Browse files

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 68589bc3, 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 4b1d8929

, 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: default avatarDavid 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: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 4a58448b
......@@ -367,7 +367,7 @@ 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;
}
......
......@@ -75,10 +75,8 @@ int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep)
* Don't actually need to do any preparation, but need to make sure
* the address is in the right region.
*/
int prepare_hugepage_range(unsigned long addr, unsigned long len, pgoff_t pgoff)
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)
......@@ -151,7 +149,7 @@ unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr, u
/* Handle MAP_FIXED */
if (flags & MAP_FIXED) {
if (prepare_hugepage_range(addr, len, pgoff))
if (prepare_hugepage_range(addr, len))
return -EINVAL;
return addr;
}
......
......@@ -175,7 +175,7 @@ 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;
}
......
......@@ -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;
}
......
......@@ -66,11 +66,8 @@ void hugetlb_free_pgd_range(struct mmu_gather **tlb, unsigned long addr,
* 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 @@ static inline int prepare_hugepage_range(unsigned long addr, unsigned long len,
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 @@ static inline unsigned long hugetlb_total_pages(void)
#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; })
......
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