Commit d05cdb25 authored by Steven Rostedt's avatar Steven Rostedt Committed by Thomas Gleixner
Browse files

ftrace: fix dynamic ftrace selftest 



With the adding of the configuration changes in the Makefile to prevent
tracing of functions in the ftrace code, all tracing of all the ftrace
code has been removed. Unfortunately, one of the selftests, relied on
a function to be traced. With the new change, the function was no longer
traced and the test failed.

This patch separates out the test function into its own file so that
we can add the "-pg" flag to the compilation of that function and the
adding of the mcount call to that function.

Signed-off-by: default avatarSteven Rostedt <srostedt@redhat.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 06fa75ab

kernel/trace/Makefile

+4 −0
Original line number Diff line number Diff line
@@ -4,6 +4,10 @@ 
ifdef CONFIG_FTRACE

ORIG_CFLAGS := $(KBUILD_CFLAGS)

KBUILD_CFLAGS = $(subst -pg,,$(ORIG_CFLAGS))



# selftest needs instrumentation

CFLAGS_trace_selftest_dynamic.o = -pg

obj-y += trace_selftest_dynamic.o

endif



obj-$(CONFIG_FTRACE) += libftrace.o

kernel/trace/trace.h

+2 −0
Original line number Diff line number Diff line
@@ -244,6 +244,8 @@ extern int unregister_tracer_switch(struct tracer_switch_ops *ops); 


#ifdef CONFIG_DYNAMIC_FTRACE

extern unsigned long ftrace_update_tot_cnt;

#define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func

extern int DYN_FTRACE_TEST_NAME(void);

#endif



#ifdef CONFIG_FTRACE_STARTUP_TEST

kernel/trace/trace_selftest.c

+0 −6
Original line number Diff line number Diff line
@@ -107,14 +107,8 @@ static int trace_test_buffer(struct trace_array *tr, unsigned long *count) 


#ifdef CONFIG_DYNAMIC_FTRACE



#define DYN_FTRACE_TEST_NAME trace_selftest_dynamic_test_func

#define __STR(x) #x

#define STR(x) __STR(x)

static int DYN_FTRACE_TEST_NAME(void)

{

	/* used to call mcount */

	return 0;

}



/* Test dynamic code modification and ftrace filters */

int trace_selftest_startup_dynamic_tracing(struct tracer *trace,

kernel/trace/trace_selftest_dynamic.c

0 → 100644
+7 −0
Original line number Diff line number Diff line 
#include "trace.h"



int DYN_FTRACE_TEST_NAME(void)

{

	/* used to call mcount */

	return 0;

}

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