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authorZong Li <zong@andestech.com>2018-08-15 11:01:10 +0800
committerGreentime Hu <greentime@andestech.com>2018-09-04 14:45:18 +0800
commit95cd2f7bce9aa712473bba1b5b3f4fdec148baee (patch)
treedb22541157723489503379d7cede8df84c58b0d7 /arch/nds32
parent6b1d6d2fba37129f690ee7e9164f225c55626cac (diff)
nds32/ftrace: Support dynamic function graph tracer
This patch contains the implementation of dynamic function graph tracer. Signed-off-by: Zong Li <zong@andestech.com> Acked-by: Greentime Hu <greentime@andestech.com> Signed-off-by: Greentime Hu <greentime@andestech.com>
Diffstat (limited to 'arch/nds32')
-rw-r--r--arch/nds32/kernel/ftrace.c36
1 files changed, 36 insertions, 0 deletions
diff --git a/arch/nds32/kernel/ftrace.c b/arch/nds32/kernel/ftrace.c
index 3ca676b75d97..a646a8339052 100644
--- a/arch/nds32/kernel/ftrace.c
+++ b/arch/nds32/kernel/ftrace.c
@@ -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 */