ARM: ftrace: graph tracer + dynamic ftrace

Support the graph tracer + dynamic ftrace combination on ARM.

Signed-off-by: Rabin Vincent <rabin@rab.in>

1 files changed, 12 insertions, 0 deletions

diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S
index 9f1766211668..aae802ee12f8 100644
--- a/arch/arm/kernel/entry-common.S
+++ b/arch/arm/kernel/entry-common.S
@@ -183,12 +183,24 @@ ENDPROC(ret_from_fork)
 ftrace_call\suffix:
         bl      ftrace_stub
 
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+        .globl ftrace_graph_call\suffix
+ftrace_graph_call\suffix:
+        mov     r0, r0
+#endif
+
         mcount_exit
 .endm
 
 .macro __ftrace_graph_caller
         sub     r0, fp, #4              @ &lr of instrumented routine (&parent)
+#ifdef CONFIG_DYNAMIC_FTRACE
+        @ called from __ftrace_caller, saved in mcount_enter
+        ldr     r1, [sp, #16]           @ instrumented routine (func)
+#else
+        @ called from __mcount, untouched in lr
         mov     r1, lr                  @ instrumented routine (func)
+#endif
         sub     r1, r1, #MCOUNT_INSN_SIZE
         mov     r2, fp                  @ frame pointer
         bl      prepare_ftrace_return