From: Keir Fraser <Keir.Fraser@cl.cam.ac.uk>
Date: Fri, 23 Sep 2005 04:43:59 +0000 (-0700)
Subject: [PATCH] Fix mmap() of /dev/hpet
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=609725f87709724218047a1049913ed233f79d3c;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git

[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>
---

diff --git a/drivers/char/hpet.c b/drivers/char/hpet.c
index de0379b6d502..c055bb630ffc 100644
--- a/drivers/char/hpet.c
+++ b/drivers/char/hpet.c
@@ -273,7 +273,6 @@ static int hpet_mmap(struct file *file, struct vm_area_struct *vma)
 
 	vma->vm_flags |= VM_IO;
 	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,
 					PAGE_SIZE, vma->vm_page_prot)) {