From bd472c794bbf6771c3fc1c58f188bc16c393d2fe Mon Sep 17 00:00:00 2001
From: Rusty Russell <rusty@rustcorp.com.au>
Date: Thu, 7 Dec 2006 02:14:08 +0100
Subject: [PATCH] [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>
---
arch/i386/kernel/e820.c | 10 +++++++++-
arch/i386/pci/pcbios.c | 11 +++++++++--
2 files changed, 18 insertions(+), 3 deletions(-)
diff --git a/arch/i386/kernel/e820.c b/arch/i386/kernel/e820.c
index b755255f27215..b704790f79690 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)
{
diff --git a/arch/i386/pci/pcbios.c b/arch/i386/pci/pcbios.c
index ed1512a175ab0..5f5193401bead 100644
--- a/arch/i386/pci/pcbios.c
+++ b/arch/i386/pci/pcbios.c
@@ -5,6 +5,7 @@
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/module.h>
+#include <linux/uaccess.h>
#include "pci.h"
#include "pci-functions.h"
@@ -314,6 +315,10 @@ static struct pci_raw_ops * __devinit pci_find_bios(void)
for (check = (union bios32 *) __va(0xe0000);
check <= (union bios32 *) __va(0xffff0);
++check) {
+ long sig;
+ if (probe_kernel_address(&check->fields.signature, sig))
+ continue;
+
if (check->fields.signature != BIOS32_SIGNATURE)
continue;
length = check->fields.length * 16;
@@ -331,11 +336,13 @@ static struct pci_raw_ops * __devinit pci_find_bios(void)
}
DBG("PCI: BIOS32 Service Directory structure at 0x%p\n", check);
if (check->fields.entry >= 0x100000) {
- printk("PCI: BIOS32 entry (0x%p) in high memory, cannot use.\n", check);
+ printk("PCI: BIOS32 entry (0x%p) in high memory, "
+ "cannot use.\n", check);
return NULL;
} else {
unsigned long bios32_entry = check->fields.entry;
- DBG("PCI: BIOS32 Service Directory entry at 0x%lx\n", bios32_entry);
+ DBG("PCI: BIOS32 Service Directory entry at 0x%lx\n",
+ bios32_entry);
bios32_indirect.address = bios32_entry + PAGE_OFFSET;
if (check_pcibios())
return &pci_bios_access;
--
2.30.2