[PATCH 3.8 018/124] x86/efi: Fix off-by-one bug in EFI Boot Services reservation

From: Kamal Mostafa
Date: Mon Feb 10 2014 - 15:18:49 EST


3.8.13.18 -stable review patch. If anyone has any objections, please let me know.

------------------

From: Dave Young <dyoung@xxxxxxxxxx>

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@xxxxxxxxxx>
Acked-by: Borislav Petkov <bp@xxxxxxx>
Acked-by: Toshi Kani <toshi.kani@xxxxxx>
Tested-by: Toshi Kani <toshi.kani@xxxxxx>
Signed-off-by: Matt Fleming <matt.fleming@xxxxxxxxx>
[ kamal: backport to 3.8 (virt_to_phys instead of __pa_symbol) ]
Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
---
arch/x86/platform/efi/efi.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index 2a5d329..b826ce8 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -428,7 +428,7 @@ void __init efi_reserve_boot_services(void)
* - Not within any part of the kernel
* - Not the bios reserved area
*/
- if ((start+size >= virt_to_phys(_text)
+ if ((start + size > virt_to_phys(_text)
&& start <= virt_to_phys(_end)) ||
!e820_all_mapped(start, start+size, E820_RAM) ||
memblock_is_region_reserved(start, size)) {
--
1.8.3.2

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