[PATCH 29/46] scripts, lto: use CONFIG_LTO for many LTO specific actions

Jiri Slaby (SUSE)
2022-11-14T11:47:30Z

From: Andi Kleen <ak@linux.intel.com>

The clang LTO and the gcc LTO share some changes in Makefiles and build
scripts. Change the common ones to use CONFIG_LTO instead of
CONFIG_LTO_CLANG so that they can be used by gcc too.

[js] fix scripts/link-vmlinux.sh too

Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Michal Marek <michal.lkml@markovi.net>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: linux-kbuild@vger.kernel.org
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Martin Liska <mliska@suse.cz>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
Makefile | 2 +-
include/asm-generic/vmlinux.lds.h | 2 +-
kernel/kallsyms.c | 2 +-
scripts/Makefile.build | 2 +-
scripts/Makefile.lib | 2 +-
scripts/link-vmlinux.sh | 2 +-
scripts/module.lds.S | 2 +-
7 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/Makefile b/Makefile
index 58cd4f5e1c3a..0b723c903819 100644
--- a/Makefile
+++ b/Makefile
@@ -992,7 +992,7 @@ endif
endif
endif

-ifdef CONFIG_LTO
+ifdef CONFIG_LTO_CLANG
KBUILD_CFLAGS += -fno-lto $(CC_FLAGS_LTO)
KBUILD_AFLAGS += -fno-lto
export CC_FLAGS_LTO
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index 3dc5824141cd..5e2179dd41d5 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -96,7 +96,7 @@
* RODATA_MAIN is not used because existing code already defines .rodata.x
* sections to be brought in with rodata.
*/
-#if defined(CONFIG_LD_DEAD_CODE_DATA_ELIMINATION) || defined(CONFIG_LTO_CLANG)
+#if defined(CONFIG_LD_DEAD_CODE_DATA_ELIMINATION) || defined(CONFIG_LTO)
#define TEXT_MAIN .text .text.[0-9a-zA-Z_]*
#define DATA_MAIN .data .data.[0-9a-zA-Z_]* .data..L* .data..compoundliteral* .data.$__unnamed_* .data.$L*
#define SDATA_MAIN .sdata .sdata.[0-9a-zA-Z_]*
diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c
index 60c20f301a6b..1d4557ae090f 100644
--- a/kernel/kallsyms.c
+++ b/kernel/kallsyms.c
@@ -167,7 +167,7 @@ static bool cleanup_symbol_name(char *s)
{
char *res;

- if (!IS_ENABLED(CONFIG_LTO_CLANG))
+ if (!IS_ENABLED(CONFIG_LTO))
return false;

/*
diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 564a20ce2667..0a28e3884efe 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -153,7 +153,7 @@ is-single-obj-m = $(and $(part-of-module),$(filter $@, $(obj-m)),y)

# When a module consists of a single object, there is no reason to keep LLVM IR.
# Make $(LD) covert LLVM IR to ELF here.
-ifdef CONFIG_LTO_CLANG
+ifdef CONFIG_LTO
cmd_ld_single_m = $(if $(is-single-obj-m), ; $(LD) $(ld_flags) -r -o $(tmp-target) $@; mv $(tmp-target) $@)
endif

diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 3aa384cec76b..ac918fd84d96 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -269,7 +269,7 @@ objtool-args = $(objtool-args-y) \
$(if $(delay-objtool), --link) \
$(if $(part-of-module), --module)

-delay-objtool := $(or $(CONFIG_LTO_CLANG),$(CONFIG_X86_KERNEL_IBT))
+delay-objtool := $(or $(CONFIG_LTO),$(CONFIG_X86_KERNEL_IBT))

cmd_objtool = $(if $(objtool-enabled), ; $(objtool) $(objtool-args) $@)
cmd_gen_objtooldep = $(if $(objtool-enabled), { echo ; echo '$@: $$(wildcard $(objtool))' ; } >> $(dot-target).cmd)
diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
index 918470d768e9..652f33be9549 100755
--- a/scripts/link-vmlinux.sh
+++ b/scripts/link-vmlinux.sh
@@ -60,7 +60,7 @@ vmlinux_link()
# skip output file argument
shift

- if is_enabled CONFIG_LTO_CLANG || is_enabled CONFIG_X86_KERNEL_IBT; then
+ if is_enabled CONFIG_LTO || is_enabled CONFIG_X86_KERNEL_IBT; then
# Use vmlinux.o instead of performing the slow LTO link again.
objs=vmlinux.o
libs=
diff --git a/scripts/module.lds.S b/scripts/module.lds.S
index da4bddd26171..b36b0527b0a8 100644
--- a/scripts/module.lds.S
+++ b/scripts/module.lds.S
@@ -27,7 +27,7 @@ SECTIONS {
__kcfi_traps : { KEEP(*(.kcfi_traps)) }
#endif

-#ifdef CONFIG_LTO_CLANG
+#ifdef CONFIG_LTO
/*
* With CONFIG_LTO_CLANG, LLD always enables -fdata-sections and
* -ffunction-sections, which increases the size of the final module.
--
2.38.1