ftrace_call as global symbol in ftrace_caller(), this
will cause function:stacktrace can not work well.
i.e. echo do_IRQ:stacktrace > set_ftrace_filte

Signed-off-by: YuanJunQing <yuanjunqin...@163.com>
---
 arch/mips/kernel/mcount.S | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/arch/mips/kernel/mcount.S b/arch/mips/kernel/mcount.S
index cff52b283e03..cd5545764e5f 100644
--- a/arch/mips/kernel/mcount.S
+++ b/arch/mips/kernel/mcount.S
@@ -87,8 +87,15 @@ EXPORT_SYMBOL(_mcount)
        PTR_LA   t1, _etext
        sltu     t3, t1, a0     /* t3 = (a0 > _etext) */
        or       t1, t2, t3
+       PTR_LA   t2, stlab-4    /* t2: "function:stacktrace" return address */
+       move     a1, AT         /* arg2: parent's return address */
        beqz     t1, ftrace_call
-        nop
+        nop                    /* "function:stacktrace" return address */
+stlab:
+       PTR_LA  t2, stlab-4
+       /* ftrace_call_end: ftrace_call return address */
+       beq     t2,ra, ftrace_call_end
+       nop
 #if defined(KBUILD_MCOUNT_RA_ADDRESS) && defined(CONFIG_32BIT)
        PTR_SUBU a0, a0, 16     /* arg1: adjust to module's recorded callsite */
 #else
@@ -98,7 +105,9 @@ EXPORT_SYMBOL(_mcount)
        .globl ftrace_call
 ftrace_call:
        nop     /* a placeholder for the call to a real tracing function */
-        move   a1, AT          /* arg2: parent's return address */
+       move    ra, t2          /* t2: "function:stacktrace" return address */
+
+ftrace_call_end:
 
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
        .globl ftrace_graph_call
-- 
2.17.1

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