[PATCH 1/2] arm64: Fix static use of function graph

Julien Thierry julien.thierry at arm.com
Wed Nov 1 07:33:43 PDT 2017


Function graph does not work currently when CONFIG_DYNAMIC_TRACE is not
set. This is because ftrace_function_trace is not always set to ftrace_stub
when function_graph is in use.

Do not skip checking of graph tracer functions when ftrace_function_trace
is set.

Signed-off-by: Julien Thierry <julien.thierry at arm.com>
Cc: Catalin Marinas <catalin.marinas at arm.com>
Cc: Will Deacon <will.deacon at arm.com>
Cc: Mark Rutland <mark.rutland at arm.com>
Cc: AKASHI Takahiro <takahiro.akashi at linaro.org>
---
 arch/arm64/kernel/entry-ftrace.S | 12 +++---------
 1 file changed, 3 insertions(+), 9 deletions(-)

diff --git a/arch/arm64/kernel/entry-ftrace.S b/arch/arm64/kernel/entry-ftrace.S
index e1be42e..1175f58 100644
--- a/arch/arm64/kernel/entry-ftrace.S
+++ b/arch/arm64/kernel/entry-ftrace.S
@@ -108,13 +108,8 @@ ENTRY(_mcount)
 	mcount_get_lr	x1		//       function's lr (= parent's pc)
 	blr	x2			//   (*ftrace_trace_function)(pc, lr);

-#ifndef CONFIG_FUNCTION_GRAPH_TRACER
-skip_ftrace_call:			//   return;
-	mcount_exit			// }
-#else
-	mcount_exit			//   return;
-					// }
-skip_ftrace_call:
+skip_ftrace_call:			// }
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
 	ldr_l	x2, ftrace_graph_return
 	cmp	x0, x2			//   if ((ftrace_graph_return
 	b.ne	ftrace_graph_caller	//        != ftrace_stub)
@@ -123,9 +118,8 @@ skip_ftrace_call:
 	adr_l	x0, ftrace_graph_entry_stub //     != ftrace_graph_entry_stub))
 	cmp	x0, x2
 	b.ne	ftrace_graph_caller	//     ftrace_graph_caller();
-
-	mcount_exit
 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
+	mcount_exit
 ENDPROC(_mcount)

 #else /* CONFIG_DYNAMIC_FTRACE */
--
1.9.1



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