From: Arnd Bergmann <arnd@arndb.de>
To: Masahiro Yamada <yamada.masahiro@socionext.com>,
Michal Marek <mmarek@suse.com>
Cc: Arnd Bergmann <arnd@arndb.de>,
Namhyung Kim <namhyung.with.foss@gmail.com>,
linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] [v2] kbuild: disable -ffunction-sections on gcc-4.7 with ftrace
Date: Tue, 14 Mar 2017 22:33:27 +0100 [thread overview]
Message-ID: <20170314213410.3762842-1-arnd@arndb.de> (raw)
When ftrace is enabled and we build with gcc-4.7 or older, we
get a warning for each file on architectures that select
CONFIG_LD_DEAD_CODE_DATA_ELIMINATION:
warning: -ffunction-sections disabled; it makes profiling impossible [enabled by default]
This turns off function sections in that specific case, leaving
it enabled for all other configurations.
Fixes: b67067f1176d ("kbuild: allow archs to select link dead code/data elimination")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Namhyung Kim <namhyung.with.foss@gmail.com>
---
Fixed version number in check as pointed out by Namhyung Kim
---
Makefile | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/Makefile b/Makefile
index 6e7e644a0b84..608727d3e47f 100644
--- a/Makefile
+++ b/Makefile
@@ -662,7 +662,11 @@ KBUILD_CFLAGS += -Wextra
KBUILD_CFLAGS += $(call cc-disable-warning,frame-address,)
ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
+ifdef CONFIG_FUNCTION_TRACER
+KBUILD_CFLAGS += $(call cc-ifversion, -ge,0409,$(call cc-option,-ffunction-sections,))
+else
KBUILD_CFLAGS += $(call cc-option,-ffunction-sections,)
+endif
KBUILD_CFLAGS += $(call cc-option,-fdata-sections,)
endif
--
2.9.0
next reply other threads:[~2017-03-14 21:34 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-14 21:33 Arnd Bergmann [this message]
2017-03-14 21:35 ` [PATCH] [v333kbuild: disable -ffunction-sections on gcc-4.7 with ftrace Arnd Bergmann
2017-03-14 21:37 ` [PATCH] [SUBMITTED 20170314] " Arnd Bergmann
2017-03-29 2:07 ` Masahiro Yamada
2017-03-29 9:30 ` Arnd Bergmann
2017-03-30 15:42 ` Masahiro Yamada
2017-03-31 8:48 ` Arnd Bergmann
[not found] ` <CAFzeTN3-=a6n-PEKP5ssCUszYYPu5R5_6uf9DEdptPKEuWOsrQ@mail.gmail.com>
2017-03-31 20:39 ` Arnd Bergmann
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