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Commit 95cd2f7b authored by Zong Li's avatar Zong Li Committed by Greentime Hu
Browse files

nds32/ftrace: Support dynamic function graph tracer 



This patch contains the implementation of dynamic function graph tracer.

Signed-off-by: default avatarZong Li <zong@andestech.com>
Acked-by: default avatarGreentime Hu <greentime@andestech.com>
Signed-off-by: default avatarGreentime Hu <greentime@andestech.com>
parent 6b1d6d2f

arch/nds32/kernel/ftrace.c

+36 −0
Original line number Diff line number Diff line
@@ -74,6 +74,14 @@ void _ftrace_caller(unsigned long parent_ip) 
		"nop			\n\t"

		"nop			\n\t");



#ifdef CONFIG_FUNCTION_GRAPH_TRACER

	/* a placeholder for the call to ftrace_graph_caller */

	__asm__ __volatile__ (

		"ftrace_graph_call:	\n\t"

		"nop			\n\t"

		"nop			\n\t"

		"nop			\n\t");

#endif

	/* restore all state needed by the compiler epilogue */

}
@@ -258,4 +266,32 @@ void __naked return_to_handler(void) 
		"lmw.bim $r0,[$sp],$r1,#0x0  \n\t");

}



#ifdef CONFIG_DYNAMIC_FTRACE

extern unsigned long ftrace_graph_call;



static int ftrace_modify_graph_caller(bool enable)

{

	unsigned long pc = (unsigned long)&ftrace_graph_call;

	unsigned long nop_insn[3] = {INSN_NOP, INSN_NOP, INSN_NOP};

	unsigned long call_insn[3] = {INSN_NOP, INSN_NOP, INSN_NOP};



	ftrace_gen_call_insn(call_insn, (unsigned long)ftrace_graph_caller);



	if (enable)

		return ftrace_modify_code(pc, nop_insn, call_insn, true);

	else

		return ftrace_modify_code(pc, call_insn, nop_insn, true);

}



int ftrace_enable_ftrace_graph_caller(void)

{

	return ftrace_modify_graph_caller(true);

}



int ftrace_disable_ftrace_graph_caller(void)

{

	return ftrace_modify_graph_caller(false);

}

#endif /* CONFIG_DYNAMIC_FTRACE */



#endif /* CONFIG_FUNCTION_GRAPH_TRACER */