[tip:x86/mm] x86: fix 64k corruption-check

[Yinghai Lu <yinghai@kernel.org>]

Commit-ID:  6d7942dc2a70a7e74c352107b150265602671588
Gitweb:     http://git.kernel.org/tip/6d7942dc2a70a7e74c352107b150265602671588
Author:     Yinghai Lu <yinghai@kernel.org>
AuthorDate: Sat, 14 Mar 2009 14:32:41 -0700
Commit:     Ingo Molnar <mingo@elte.hu>
CommitDate: Sun, 15 Mar 2009 07:03:15 +0100

x86: fix 64k corruption-check

Impact: fix boot crash

Need to exit early if the addr is far above 64k.

The crash got exposed by:

  78a8b35: x86: make e820_update_range() handle small range update

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: <stable@kernel.org>
LKML-Reference: <49BC2279.2030101@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>


---
 arch/x86/kernel/check.c |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kernel/check.c b/arch/x86/kernel/check.c
index b617b11..fc999e6 100644
--- a/arch/x86/kernel/check.c
+++ b/arch/x86/kernel/check.c
@@ -86,12 +86,12 @@ void __init setup_bios_corruption_check(void)
 		if (!(addr + 1))
 			break;
 
+		if (addr >= corruption_check_size)
+			break;
+
 		if ((addr + size) > corruption_check_size)
 			size = corruption_check_size - addr;
 
-		if (size == 0)
-			break;
-
 		e820_update_range(addr, size, E820_RAM, E820_RESERVED);
 		scan_areas[num_scan_areas].addr = addr;
 		scan_areas[num_scan_areas].size = size;