[PATCH] efi/libstub: Fix build error with libstub

[Zhenzhong Duan]

Got below error during build:

  In file included from drivers/firmware/efi/libstub/efi-stub-helper.c:16:0:
  drivers/firmware/efi/libstub/efi-stub-helper.c: In function âefi_char16_putsâ:
  arch/x86/include/asm/efi.h:355:3: sorry, unimplemented: ms_abi attribute requires -maccumulate-outgoing-args or subtarget optimization implying it
     : __efi64_thunk_map(inst, func, inst, ##__VA_ARGS__))
     ^
  drivers/firmware/efi/libstub/efi-stub-helper.c:37:2: note: in expansion of macro âefi_call_protoâ
    efi_call_proto(efi_table_attr(efi_system_table, con_out),
    ^
  drivers/firmware/efi/libstub/efi-stub-helper.c:37: confused by earlier errors, bailing out

Fix it by adding -maccumulate-outgoing-args for efi libstub build
as suggested by gcc.

Signed-off-by: Zhenzhong Duan <zhenzhong.duan@xxxxxxxxx>
---
 drivers/firmware/efi/libstub/Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile
index cce4a74..25e5d02 100644
--- a/drivers/firmware/efi/libstub/Makefile
+++ b/drivers/firmware/efi/libstub/Makefile
@@ -6,7 +6,7 @@
 # enabled, even if doing so doesn't break the build.
 #
 cflags-$(CONFIG_X86_32)		:= -march=i386
-cflags-$(CONFIG_X86_64)		:= -mcmodel=small
+cflags-$(CONFIG_X86_64)		:= -mcmodel=small -maccumulate-outgoing-args
 cflags-$(CONFIG_X86)		+= -m$(BITS) -D__KERNEL__ \
 				   -fPIC -fno-strict-aliasing -mno-red-zone \
 				   -mno-mmx -mno-sse -fshort-wchar \
-- 
1.8.3.1