From bd472c794bbf6771c3fc1c58f188bc16c393d2fe Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Thu, 7 Dec 2006 02:14:08 +0100 Subject: [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 Signed-off-by: Rusty Russell Signed-off-by: Andi Kleen Cc: Jeremy Fitzhardinge Cc: Andi Kleen Signed-off-by: Andrew Morton --- arch/i386/kernel/e820.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) (limited to 'arch/i386/kernel/e820.c') 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 #include #include +#include #include #include @@ -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) { -- cgit v1.2.3-70-g09d2