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authorIngo Molnar <mingo@elte.hu>2008-10-15 13:46:29 +0200
committerIngo Molnar <mingo@elte.hu>2008-10-15 13:46:29 +0200
commitb2aaf8f74cdc84a9182f6cabf198b7763bcb9d40 (patch)
tree53ccb1c2c14751fe69cf93102e76e97021f6df07 /arch/x86/boot/edd.c
parent4f962d4d65923d7b722192e729840cfb79af0a5a (diff)
parent278429cff8809958d25415ba0ed32b59866ab1a8 (diff)
downloadop-kernel-dev-b2aaf8f74cdc84a9182f6cabf198b7763bcb9d40.zip
op-kernel-dev-b2aaf8f74cdc84a9182f6cabf198b7763bcb9d40.tar.gz
Merge branch 'linus' into stackprotector
Conflicts: arch/x86/kernel/Makefile include/asm-x86/pda.h
Diffstat (limited to 'arch/x86/boot/edd.c')
-rw-r--r--arch/x86/boot/edd.c12
1 files changed, 8 insertions, 4 deletions
diff --git a/arch/x86/boot/edd.c b/arch/x86/boot/edd.c
index 03399d6..1aae8f3 100644
--- a/arch/x86/boot/edd.c
+++ b/arch/x86/boot/edd.c
@@ -41,6 +41,7 @@ static u32 read_mbr_sig(u8 devno, struct edd_info *ei, u32 *mbrsig)
char *mbrbuf_ptr, *mbrbuf_end;
u32 buf_base, mbr_base;
extern char _end[];
+ u16 mbr_magic;
sector_size = ei->params.bytes_per_sector;
if (!sector_size)
@@ -58,11 +59,15 @@ static u32 read_mbr_sig(u8 devno, struct edd_info *ei, u32 *mbrsig)
if (mbrbuf_end > (char *)(size_t)boot_params.hdr.heap_end_ptr)
return -1;
+ memset(mbrbuf_ptr, 0, sector_size);
if (read_mbr(devno, mbrbuf_ptr))
return -1;
*mbrsig = *(u32 *)&mbrbuf_ptr[EDD_MBR_SIG_OFFSET];
- return 0;
+ mbr_magic = *(u16 *)&mbrbuf_ptr[510];
+
+ /* check for valid MBR magic */
+ return mbr_magic == 0xAA55 ? 0 : -1;
}
static int get_edd_info(u8 devno, struct edd_info *ei)
@@ -167,9 +172,8 @@ void query_edd(void)
* Scan the BIOS-supported hard disks and query EDD
* information...
*/
- get_edd_info(devno, &ei);
-
- if (boot_params.eddbuf_entries < EDDMAXNR) {
+ if (!get_edd_info(devno, &ei)
+ && boot_params.eddbuf_entries < EDDMAXNR) {
memcpy(edp, &ei, sizeof ei);
edp++;
boot_params.eddbuf_entries++;
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