3 files changed, 12 insertions, 1 deletions

diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S
index 826682abed1d..43ceb3f454bf 100644
--- a/arch/x86/kernel/entry_32.S
+++ b/arch/x86/kernel/entry_32.S
@@ -1196,6 +1196,9 @@ ENTRY(mcount)
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
         cmpl $ftrace_stub, ftrace_graph_return
         jnz ftrace_graph_caller
+
+        cmpl $ftrace_graph_entry_stub, ftrace_graph_entry
+        jnz ftrace_graph_caller
 #endif
 .globl ftrace_stub
 ftrace_stub:
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 9060ba6497e2..54e0bbdccb99 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -120,6 +120,9 @@ ENTRY(mcount)
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
         cmpq $ftrace_stub, ftrace_graph_return
         jnz ftrace_graph_caller
+
+        cmpq $ftrace_graph_entry_stub, ftrace_graph_entry
+        jnz ftrace_graph_caller
 #endif
 
 .globl ftrace_stub
diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index adba8e9a427c..d278ad2ebda2 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -425,6 +425,7 @@ static void pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret)
         trace->calltime = current->ret_stack[index].calltime;
         trace->overrun = atomic_read(&current->trace_overrun);
         trace->depth = index;
+        barrier();
         current->curr_ret_stack--;
 }
 
@@ -506,7 +507,11 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
         }
 
         trace.func = self_addr;
-        ftrace_graph_entry(&trace);
 
+        /* Only trace if the calling function expects to */
+        if (!ftrace_graph_entry(&trace)) {
+                current->curr_ret_stack--;
+                *parent = old;
+        }
 }
 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */