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From 69e4a800e255147d8e9fb52eaab8d6b29a33ebcf Mon Sep 17 00:00:00 2001
From: Sami Tolvanen <samitolvanen@google.com>
Date: Tue, 16 Apr 2019 14:40:00 -0700
Subject: [PATCH 21/24] g86, vdso: disable LTO only for vDSO
Remove the undefined DISABLE_LTO flag from the vDSO, and filter out
CC_FLAGS_LTO flags instead where needed. Note that while we could use
Clang's LTO for the 64-bit vDSO, it won't add noticeable benefit for
the small amount of C code.
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
---
arch/x86/entry/vdso/Makefile | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/arch/x86/entry/vdso/Makefile b/arch/x86/entry/vdso/Makefile
index 04e65f0698f6..67f60662830a 100644
--- a/arch/x86/entry/vdso/Makefile
+++ b/arch/x86/entry/vdso/Makefile
@@ -9,8 +9,6 @@ ARCH_REL_TYPE_ABS := R_X86_64_JUMP_SLOT|R_X86_64_GLOB_DAT|R_X86_64_RELATIVE|
ARCH_REL_TYPE_ABS += R_386_GLOB_DAT|R_386_JMP_SLOT|R_386_RELATIVE
include $(srctree)/lib/vdso/Makefile
-KBUILD_CFLAGS += $(DISABLE_LTO)
-
# Sanitizer runtimes are unavailable and cannot be linked here.
KASAN_SANITIZE := n
UBSAN_SANITIZE := n
@@ -92,7 +90,7 @@ ifneq ($(RETPOLINE_VDSO_CFLAGS),)
endif
endif
-$(vobjs): KBUILD_CFLAGS := $(filter-out $(GCC_PLUGINS_CFLAGS) $(RETPOLINE_CFLAGS),$(KBUILD_CFLAGS)) $(CFL)
+$(vobjs): KBUILD_CFLAGS := $(filter-out $(CC_FLAGS_LTO) $(GCC_PLUGINS_CFLAGS) $(RETPOLINE_CFLAGS),$(KBUILD_CFLAGS)) $(CFL)
#
# vDSO code runs in userspace and -pg doesn't help with profiling anyway.
@@ -150,6 +148,7 @@ KBUILD_CFLAGS_32 := $(filter-out -fno-pic,$(KBUILD_CFLAGS_32))
KBUILD_CFLAGS_32 := $(filter-out -mfentry,$(KBUILD_CFLAGS_32))
KBUILD_CFLAGS_32 := $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS_32))
KBUILD_CFLAGS_32 := $(filter-out $(RETPOLINE_CFLAGS),$(KBUILD_CFLAGS_32))
+KBUILD_CFLAGS_32 := $(filter-out $(CC_FLAGS_LTO),$(KBUILD_CFLAGS_32))
KBUILD_CFLAGS_32 += -m32 -msoft-float -mregparm=0 -fpic
KBUILD_CFLAGS_32 += $(call cc-option, -fno-stack-protector)
KBUILD_CFLAGS_32 += $(call cc-option, -foptimize-sibling-calls)
--
2.28.0
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