From: Alexandre Rusev <arusev@ru.mvista.com>
Date: Tue, 26 Feb 2008 17:42:10 +0000 (+0100)
Subject: [ARM] 4839/1: fixes kernel Oops in /dev/mem device driver for memory map with PHYS_OFF
X-Git-Tag: v2.6.25-rc4~128^2~4
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9ae3ae0bebb9a3a348dc233229008b126014889d;p=linux-2.6

[ARM] 4839/1: fixes kernel Oops in /dev/mem device driver for memory map with PHYS_OFF

"cat /dev/mem" may cause kernel Oops for boards with PHYS_OFFSET != 0
because character device is mapped to addresses starting from zero
and there is no protection against such situation.
Patch just add this.

Signed-off-by: Alexandre Rusev <arusev@ru.mvista.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---

diff --git a/arch/arm/mm/mmap.c b/arch/arm/mm/mmap.c
index 2728b0e7d2..3f6dc40b83 100644
--- a/arch/arm/mm/mmap.c
+++ b/arch/arm/mm/mmap.c
@@ -120,6 +120,8 @@ full_search:
  */
 int valid_phys_addr_range(unsigned long addr, size_t size)
 {
+	if (addr < PHYS_OFFSET)
+		return 0;
 	if (addr + size > __pa(high_memory))
 		return 0;