From f28bc3c32c059ab4d13f52155fabd3e20f477f65 Mon Sep 17 00:00:00 2001 From: Vasily Gorbik Date: Mon, 6 Aug 2018 15:17:42 +0200 Subject: tracing: Handle CC_FLAGS_FTRACE more accurately CC_FLAGS_FTRACE is exported and later used to remove ftrace relevant build flags from files which should be built without ftrace support. For that reason add -mfentry to CC_FLAGS_FTRACE as well. That fixes a problem with vdso32 build on s390, where -mfentry could not be used together with -m31 flag. At the same time flags like -pg and -mfentry are not relevant for asm files, so avoid adding them to KBUILD_AFLAGS. Introduce CC_FLAGS_USING instead of CC_USING_FENTRY to collect -DCC_USING_FENTRY (and future alike) which are relevant for both KBUILD_CFLAGS and KBUILD_AFLAGS. Link: http://lkml.kernel.org/r/patch-1.thread-aa7b8d.git-42971afe87de.your-ad-here.call-01533557518-ext-9465@work.hours Signed-off-by: Vasily Gorbik Signed-off-by: Steven Rostedt (VMware) --- Makefile | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) (limited to 'Makefile') diff --git a/Makefile b/Makefile index 67d9d20f8564..489de42d30c7 100644 --- a/Makefile +++ b/Makefile @@ -743,12 +743,15 @@ ifdef CONFIG_FUNCTION_TRACER ifndef CC_FLAGS_FTRACE CC_FLAGS_FTRACE := -pg endif -export CC_FLAGS_FTRACE ifdef CONFIG_HAVE_FENTRY -CC_USING_FENTRY := $(call cc-option, -mfentry -DCC_USING_FENTRY) + ifeq ($(call cc-option-yn, -mfentry),y) + CC_FLAGS_FTRACE += -mfentry + CC_FLAGS_USING += -DCC_USING_FENTRY + endif endif -KBUILD_CFLAGS += $(CC_FLAGS_FTRACE) $(CC_USING_FENTRY) -KBUILD_AFLAGS += $(CC_USING_FENTRY) +export CC_FLAGS_FTRACE +KBUILD_CFLAGS += $(CC_FLAGS_FTRACE) $(CC_FLAGS_USING) +KBUILD_AFLAGS += $(CC_FLAGS_USING) ifdef CONFIG_DYNAMIC_FTRACE ifdef CONFIG_HAVE_C_RECORDMCOUNT BUILD_C_RECORDMCOUNT := y -- cgit v1.2.3 From 07d0408120216b60625c9a5b8012d1c3a907984d Mon Sep 17 00:00:00 2001 From: Vasily Gorbik Date: Mon, 6 Aug 2018 15:17:44 +0200 Subject: tracing: Avoid calling cc-option -mrecord-mcount for every Makefile Currently if CONFIG_FTRACE_MCOUNT_RECORD is enabled -mrecord-mcount compiler flag support is tested for every Makefile. Top 4 cc-option usages: 511 -mrecord-mcount 11 -fno-stack-protector 9 -Wno-override-init 2 -fsched-pressure To address that move cc-option from scripts/Makefile.build to top Makefile and export CC_USING_RECORD_MCOUNT to be used in original place. While doing that also add -mrecord-mcount to CC_FLAGS_FTRACE (if gcc actually supports it). Link: http://lkml.kernel.org/r/patch-2.thread-aa7b8d.git-de935bace15a.your-ad-here.call-01533557518-ext-9465@work.hours Acked-by: Andi Kleen Signed-off-by: Vasily Gorbik Signed-off-by: Steven Rostedt (VMware) --- Makefile | 7 +++++++ scripts/Makefile.build | 9 +++------ 2 files changed, 10 insertions(+), 6 deletions(-) (limited to 'Makefile') diff --git a/Makefile b/Makefile index 489de42d30c7..2c92ebf59a34 100644 --- a/Makefile +++ b/Makefile @@ -743,6 +743,13 @@ ifdef CONFIG_FUNCTION_TRACER ifndef CC_FLAGS_FTRACE CC_FLAGS_FTRACE := -pg endif +ifdef CONFIG_FTRACE_MCOUNT_RECORD + # gcc 5 supports generating the mcount tables directly + ifeq ($(call cc-option-yn,-mrecord-mcount),y) + CC_FLAGS_FTRACE += -mrecord-mcount + export CC_USING_RECORD_MCOUNT := 1 + endif +endif ifdef CONFIG_HAVE_FENTRY ifeq ($(call cc-option-yn, -mfentry),y) CC_FLAGS_FTRACE += -mfentry diff --git a/scripts/Makefile.build b/scripts/Makefile.build index 514ed63ff571..42ecb8cf7666 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -206,11 +206,8 @@ cmd_modversions_c = \ endif ifdef CONFIG_FTRACE_MCOUNT_RECORD -# gcc 5 supports generating the mcount tables directly -ifneq ($(call cc-option,-mrecord-mcount,y),y) -KBUILD_CFLAGS += -mrecord-mcount -else -# else do it all manually +ifndef CC_USING_RECORD_MCOUNT +# compiler will not generate __mcount_loc use recordmcount or recordmcount.pl ifdef BUILD_C_RECORDMCOUNT ifeq ("$(origin RECORDMCOUNT_WARN)", "command line") RECORDMCOUNT_FLAGS = -w @@ -239,7 +236,7 @@ cmd_record_mcount = \ "$(CC_FLAGS_FTRACE)" ]; then \ $(sub_cmd_record_mcount) \ fi; -endif # -record-mcount +endif # CC_USING_RECORD_MCOUNT endif # CONFIG_FTRACE_MCOUNT_RECORD ifdef CONFIG_STACK_VALIDATION -- cgit v1.2.3 From 2f4df0017baedd535254d987c6b10f855f1fb11f Mon Sep 17 00:00:00 2001 From: Vasily Gorbik Date: Mon, 6 Aug 2018 15:17:46 +0200 Subject: tracing: Add -mcount-nop option support -mcount-nop gcc option generates the calls to the profiling functions as nops which allows to avoid patching mcount jump with NOP instructions initially. -mcount-nop gcc option will be activated if platform selects HAVE_NOP_MCOUNT and gcc actually supports it. In addition to that CC_USING_NOP_MCOUNT is defined and could be used by architectures to adapt ftrace patching behavior. Link: http://lkml.kernel.org/r/patch-3.thread-aa7b8d.git-e02ed2dc082b.your-ad-here.call-01533557518-ext-9465@work.hours Signed-off-by: Vasily Gorbik Signed-off-by: Steven Rostedt (VMware) --- Makefile | 6 ++++++ kernel/trace/Kconfig | 5 +++++ kernel/trace/ftrace.c | 2 ++ 3 files changed, 13 insertions(+) (limited to 'Makefile') diff --git a/Makefile b/Makefile index 2c92ebf59a34..c5b0cd7f3c2a 100644 --- a/Makefile +++ b/Makefile @@ -749,6 +749,12 @@ ifdef CONFIG_FTRACE_MCOUNT_RECORD CC_FLAGS_FTRACE += -mrecord-mcount export CC_USING_RECORD_MCOUNT := 1 endif + ifdef CONFIG_HAVE_NOP_MCOUNT + ifeq ($(call cc-option-yn, -mnop-mcount),y) + CC_FLAGS_FTRACE += -mnop-mcount + CC_FLAGS_USING += -DCC_USING_NOP_MCOUNT + endif + endif endif ifdef CONFIG_HAVE_FENTRY ifeq ($(call cc-option-yn, -mfentry),y) diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 036cec1fcd24..fd6754b88f87 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -47,6 +47,11 @@ config HAVE_FENTRY help Arch supports the gcc options -pg with -mfentry +config HAVE_NOP_MCOUNT + bool + help + Arch supports the gcc options -pg with -mrecord-mcount and -nop-mcount + config HAVE_C_RECORDMCOUNT bool help diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 48b5b466ec7a..468e8527e979 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -2950,12 +2950,14 @@ static int ftrace_update_code(struct module *mod, struct ftrace_page *new_pgs) p = &pg->records[i]; p->flags = rec_flags; +#ifndef CC_USING_NOP_MCOUNT /* * Do the initial record conversion from mcount jump * to the NOP instructions. */ if (!ftrace_code_disable(mod, p)) break; +#endif update_cnt++; } -- cgit v1.2.3