Commit 8f3b1327 authored by Bob Liu's avatar Bob Liu Committed by Linus Torvalds

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: default avatarBob Liu <lliubbo@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: David Howells <dhowells@redhat.com>
Acked-by: default avatarGreg Ungerer <gerg@uclinux.org>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Bob Liu <lliubbo@gmail.com>
Cc: <stable@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent f607e7fc
...@@ -1813,10 +1813,13 @@ struct page *follow_page(struct vm_area_struct *vma, unsigned long address, ...@@ -1813,10 +1813,13 @@ struct page *follow_page(struct vm_area_struct *vma, unsigned long address,
return NULL; return NULL;
} }
int remap_pfn_range(struct vm_area_struct *vma, unsigned long from, int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr,
unsigned long to, unsigned long size, pgprot_t prot) 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; return 0;
} }
EXPORT_SYMBOL(remap_pfn_range); EXPORT_SYMBOL(remap_pfn_range);
......
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