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authorBob Liu <lliubbo@gmail.com>2011-07-08 15:39:46 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2011-07-08 21:14:44 -0700
commit8f3b1327aa454bc8283e96bca7669c3c88b83f79 (patch)
treec18f10d34bd41c9eeb74a64d5838ee8b6c0ce817
parentf607e7fc5fb94d92030c4527287e9c149ddf9e65 (diff)
downloadlinux-linaro-8f3b1327aa454bc8283e96bca7669c3c88b83f79.tar.gz
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.c9
1 files changed, 6 insertions, 3 deletions
diff --git a/mm/nommu.c b/mm/nommu.c
index 1fd0c51b10a..9edc897a397 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);