From 8f8d6bc6ec9510a3bd8d97e011c7dc6008a7355d Mon Sep 17 00:00:00 2001 From: Bob Liu Date: Fri, 8 Jul 2011 15:39:46 -0700 Subject: [PATCH] mm/nommu.c: fix remap_pfn_range() [ upstream commit 8f3b1327aa454bc8283e96bca7669c3c88b83f79 ] remap_pfn_range() means map physical address pfn<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 Cc: Geert Uytterhoeven Cc: David Howells Acked-by: Greg Ungerer Cc: Mike Frysinger Cc: Bob Liu Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Andi Kleen --- mm/nommu.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/mm/nommu.c b/mm/nommu.c index 3e185488741..fbdb2e76675 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -1747,10 +1747,13 @@ 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); -- 2.11.4.GIT