2.6.39-stable review patch. If anyone has any objections, please let us know.
------------------
From: Bob Liu <lliu...@gmail.com>
commit 8f3b1327aa454bc8283e96bca7669c3c88b83f79 upstream.
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 <lliu...@gmail.com>
Cc: Geert Uytterhoeven <ge...@linux-m68k.org>
Cc: David Howells <dhowe...@redhat.com>
Acked-by: Greg Ungerer <g...@uclinux.org>
Cc: Mike Frysinger <vap...@gentoo.org>
Cc: Bob Liu <lliu...@gmail.com>
Signed-off-by: Andrew Morton <a...@linux-foundation.org>
Signed-off-by: Linus Torvalds <torva...@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gre...@suse.de>
---
mm/nommu.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -1819,10 +1819,13 @@ struct page *follow_page(struct vm_area_
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);
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