[PATCH] lib: remove redundant ftrace flag removal

[PATCH] lib: remove redundant ftrace flag removal

[Mark Rutland]

Since architectures can implement ftrace using a variety of mechanisms,
generic code should always use CC_FLAGS_FTRACE rather than assuming that
ftrace is built using -pg.

Since commit:

  2464a609ded09420 ("ftrace: do not trace library functions")

... lib/Makefile has removed CC_FLAGS_FTRACE from KBUILD_CFLAGS, so ftrace is
disabled for all files under lib/.

Given that, we shouldn't explicitly remove -pg when building
lib/string.o, as this is redundant and bad form.

This patch cleans things up accordingly.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Gary R Hook <gary.hook@amd.com>
Cc: Ingo Molnar <mingo@kernel.org>
---
 lib/Makefile | 4 ----
 1 file changed, 4 deletions(-)

I've verified this atop of v5.3-rc3, where the Makefile removes all of
CC_FLAGS_FTRACE (containing "-pg -mrecord-mcount -mfentry") from the CFLAGS for
building string.o

Mark.

diff --git a/lib/Makefile b/lib/Makefile
index 29c02a924973..c5892807e06f 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -21,10 +21,6 @@ KCOV_INSTRUMENT_dynamic_debug.o := n
 ifdef CONFIG_AMD_MEM_ENCRYPT
 KASAN_SANITIZE_string.o := n
 
-ifdef CONFIG_FUNCTION_TRACER
-CFLAGS_REMOVE_string.o = -pg
-endif
-
 CFLAGS_string.o := $(call cc-option, -fno-stack-protector)
 endif
 
-- 
2.11.0

[tip:x86/cleanups] lib: Remove redundant ftrace flag removal

[tip-bot for Mark Rutland]

Commit-ID:  41b57d1bb8a4084e651c1f9a754fca64952666a0
Gitweb:     https://git.kernel.org/tip/41b57d1bb8a4084e651c1f9a754fca64952666a0
Author:     Mark Rutland <mark.rutland@arm.com>
AuthorDate: Tue, 6 Aug 2019 17:25:39 +0100
Committer:  Borislav Petkov <bp@suse.de>
CommitDate: Wed, 14 Aug 2019 09:48:58 +0200

lib: Remove redundant ftrace flag removal

Since architectures can implement ftrace using a variety of mechanisms,
generic code should always use CC_FLAGS_FTRACE rather than assuming that
ftrace is built using -pg.

Since commit:

  2464a609ded09420 ("ftrace: do not trace library functions")

... lib/Makefile has removed CC_FLAGS_FTRACE from KBUILD_CFLAGS, so ftrace is
disabled for all files under lib/.

Given that, we shouldn't explicitly remove -pg when building
lib/string.o, as this is redundant and bad form.

Clean things up accordingly.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Coly Li <colyli@suse.de>
Cc: Gary R Hook <gary.hook@amd.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Matthew Wilcox <willy@infradead.org>
Link: https://lkml.kernel.org/r/20190806162539.51918-1-mark.rutland@arm.com
---
 lib/Makefile | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/lib/Makefile b/lib/Makefile
index 095601ce371d..34f8a83b2cbd 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -21,10 +21,6 @@ KCOV_INSTRUMENT_dynamic_debug.o := n
 ifdef CONFIG_AMD_MEM_ENCRYPT
 KASAN_SANITIZE_string.o := n
 
-ifdef CONFIG_FUNCTION_TRACER
-CFLAGS_REMOVE_string.o = -pg
-endif
-
 CFLAGS_string.o := $(call cc-option, -fno-stack-protector)
 endif