[PATCH 3.12 009/133] x86/efi: Fix off-by-one bug in EFI Boot Services reservation

Greg Kroah-Hartman
2014-02-04T22:31:30Z

From: Dave Young <dyoung@redhat.com>

commit a7f84f03f660d93574ac88835d056c0d6468aebe upstream.

Current code check boot service region with kernel text region by:
start+size >= __pa_symbol(_text)
The end of the above region should be start + size - 1 instead.

I see this problem in ovmf + Fedora 19 grub boot:
text start: 1000000 md start: 800000 md size: 800000

Signed-off-by: Dave Young <dyoung@redhat.com>
Acked-by: Borislav Petkov <bp@suse.de>
Acked-by: Toshi Kani <toshi.kani@hp.com>
Tested-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
arch/x86/platform/efi/efi.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -440,7 +440,7 @@ void __init efi_reserve_boot_services(vo
* - Not within any part of the kernel
* - Not the bios reserved area
*/
- if ((start+size >= __pa_symbol(_text)
+ if ((start + size > __pa_symbol(_text)
&& start <= __pa_symbol(_end)) ||
!e820_all_mapped(start, start+size, E820_RAM) ||
memblock_is_region_reserved(start, size)) {