x86/efi: Fix off-by-one bug in EFI Boot Services reservation

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>

diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index 3474a2c..6033be9 100644 (file)
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -438,7 +438,7 @@ void __init efi_reserve_boot_services(void)
                 * - 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)) {