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>
[bwh: Backported to 3.2: s/__pa_symbol/virt_to_phys/]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index bee75a6052a4bcc8c4c72788f2f11620a2fff80a..e56da773f504b41b0b953e2f41e4ecda06791536 100644 (file)
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -424,7 +424,7 @@ 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_x86_check_reserved_size(&start, &size,