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authorRusty Russell <rusty@rustcorp.com.au>2006-12-07 02:14:08 +0100
committerAndi Kleen <andi@basil.nowhere.org>2006-12-07 02:14:08 +0100
commitbd472c794bbf6771c3fc1c58f188bc16c393d2fe (patch)
treea7f45422f7df7fa2cd394dcaabe71cb592c2b7da /arch/i386/kernel/e820.c
parentda181a8b3916aa7f2e3c5775d2bd2fe3454cf82d (diff)
[PATCH] paravirt: Be careful about touching BIOS address space
BIOS ROM areas may not be mapped into the guest address space, so be careful when touching those addresses to make sure they appear to be mapped. [akpm@osdl.org: fix unused var warning] AK: Changed __get_user to probe_kernel_address Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andi Kleen <ak@suse.de> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org>
Diffstat (limited to 'arch/i386/kernel/e820.c')
-rw-r--r--arch/i386/kernel/e820.c10
1 files changed, 9 insertions, 1 deletions
diff --git a/arch/i386/kernel/e820.c b/arch/i386/kernel/e820.c
index b755255f272..b704790f796 100644
--- a/arch/i386/kernel/e820.c
+++ b/arch/i386/kernel/e820.c
@@ -9,6 +9,7 @@
#include <linux/mm.h>
#include <linux/efi.h>
#include <linux/pfn.h>
+#include <linux/uaccess.h>
#include <asm/pgtable.h>
#include <asm/page.h>
@@ -155,7 +156,14 @@ static struct resource standard_io_resources[] = { {
.flags = IORESOURCE_BUSY | IORESOURCE_IO
} };
-#define romsignature(x) (*(unsigned short *)(x) == 0xaa55)
+static int romsignature(const unsigned char *x)
+{
+ unsigned short sig;
+ int ret = 0;
+ if (probe_kernel_address((const unsigned short *)x, sig) == 0)
+ ret = (sig == 0xaa55);
+ return ret;
+}
static int __init romchecksum(unsigned char *rom, unsigned long length)
{