1 files changed, 14 insertions, 0 deletions

diff --git a/arch/mips/kernel/mcount.S b/arch/mips/kernel/mcount.S
index 522e91c688fc..0a9cfdb271dd 100644
--- a/arch/mips/kernel/mcount.S
+++ b/arch/mips/kernel/mcount.S
@@ -70,6 +70,9 @@ _mcount:
          nop
 
         MCOUNT_SAVE_REGS
+#ifdef KBUILD_MCOUNT_RA_ADDRESS
+        PTR_S   t0, PT_R12(sp)  /* t0 saved the location of the return address(at) by -mmcount-ra-address */
+#endif
 
         move    a0, ra          /* arg1: next ip, selfaddr */
         .globl ftrace_call
@@ -133,11 +136,22 @@ ftrace_stub:
 NESTED(ftrace_graph_caller, PT_SIZE, ra)
 #ifdef CONFIG_DYNAMIC_FTRACE
         PTR_L   a1, PT_R31(sp)  /* load the original ra from the stack */
+#ifdef KBUILD_MCOUNT_RA_ADDRESS
+        PTR_L   t0, PT_R12(sp)  /* load the original t0 from the stack */
+#endif
 #else
         MCOUNT_SAVE_REGS
         move    a1, ra          /* arg2: next ip, selfaddr */
 #endif
+
+#ifdef KBUILD_MCOUNT_RA_ADDRESS
+        bnez    t0, 1f          /* non-leaf func: t0 saved the location of the return address */
+         nop
+        PTR_LA  t0, PT_R1(sp)   /* leaf func: get the location of at(old ra) from our own stack */
+1:      move    a0, t0          /* arg1: the location of the return address */
+#else
         PTR_LA  a0, PT_R1(sp)   /* arg1: &AT -> a0 */
+#endif
         jal     prepare_ftrace_return
 #ifdef CONFIG_FRAME_POINTER
          move   a2, fp          /* arg3: frame pointer */