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| author | Bob Liu <lliubbo@gmail.com> | 2011-07-08 15:39:46 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-07-08 21:14:44 -0700 |
| commit | 8f3b1327aa454bc8283e96bca7669c3c88b83f79 (patch) | |
| tree | c18f10d34bd41c9eeb74a64d5838ee8b6c0ce817 | |
| parent | f607e7fc5fb94d92030c4527287e9c149ddf9e65 (diff) | |
| download | lwn-8f3b1327aa454bc8283e96bca7669c3c88b83f79.tar.gz lwn-8f3b1327aa454bc8283e96bca7669c3c88b83f79.zip | |
mm/nommu.c: fix remap_pfn_range()
remap_pfn_range() means map physical address pfn<<PAGE_SHIFT to user addr.
For nommu arch it's implemented by vma->vm_start = pfn << PAGE_SHIFT which
is wrong acroding the original meaning of this function. And some driver
developer using remap_pfn_range() with correct parameter will get
unexpected result because vm_start is changed. It should be implementd
like addr = pfn << PAGE_SHIFT but which is meanless on nommu arch, this
patch just make it simply return.
Parameter name and setting of vma->vm_flags also be fixed.
Signed-off-by: Bob Liu <lliubbo@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: David Howells <dhowells@redhat.com>
Acked-by: Greg Ungerer <gerg@uclinux.org>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Bob Liu <lliubbo@gmail.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | mm/nommu.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/mm/nommu.c b/mm/nommu.c index 1fd0c51b10a6..9edc897a3970 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -1813,10 +1813,13 @@ struct page *follow_page(struct vm_area_struct *vma, unsigned long address, return NULL; } -int remap_pfn_range(struct vm_area_struct *vma, unsigned long from, - unsigned long to, unsigned long size, pgprot_t prot) +int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr, + unsigned long pfn, unsigned long size, pgprot_t prot) { - vma->vm_start = vma->vm_pgoff << PAGE_SHIFT; + if (addr != (pfn << PAGE_SHIFT)) + return -EINVAL; + + vma->vm_flags |= VM_IO | VM_RESERVED | VM_PFNMAP; return 0; } EXPORT_SYMBOL(remap_pfn_range); |