Commit 609725f8 authored Sep 22, 2005 by Keir Fraser Committed by Linus Torvalds Sep 22, 2005

[PATCH] Fix mmap() of /dev/hpet



The address passed to io_remap_pfn_range() in hpet_mmap() does not need to
be converted using __pa(): it is already a physical address.  This bug was
found and the patch suggested by Clay Harris.

I introduced this particular bug when making io_remap_pfn_range changes a
few months ago.  In fact mmap()ing /dev/hpet has *never* previously worked:
before my changes __pa() was being executed on an ioremap()ed virtual
address, which is also invalid.

Signed-off-by: Keir Fraser <keir@xensource.com>
Cc: Robert Picco <Robert.Picco@hp.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

parent 7243cc05

drivers/char/hpet.c

+0 −1

Original line number	Original line	Diff line number	Diff line
	@@ -273,7 +273,6 @@ static int hpet_mmap(struct file file, struct vm_area_struct vma)

	vma->vm_flags \|= VM_IO;		vma->vm_flags \|= VM_IO;
	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);		vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
	addr = __pa(addr);

	if (io_remap_pfn_range(vma, vma->vm_start, addr >> PAGE_SHIFT,		if (io_remap_pfn_range(vma, vma->vm_start, addr >> PAGE_SHIFT,
	PAGE_SIZE, vma->vm_page_prot)) {		PAGE_SIZE, vma->vm_page_prot)) {

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