[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>

diff --git a/arch/i386/kernel/e820.c b/arch/i386/kernel/e820.c
index b755255f2721537c16bbf90f9bd827f871c5f693..b704790f79690be9f3f0f0d1e18e1a509f6a335e 100644 (file)
--- 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 ed1512a175ab08e200751ed5078f2373a9b5760f..5f5193401beadea0302538b348dacd1a76b261c7 100644 (file)
--- 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;