tracing/function-graph-tracer: Drop the useless nmi protection

The function graph tracer used to have a protection against NMI
while entering a function entry tracing. But this is useless now,
this tracer is reentrant and the ring buffer supports the NMI tracing.
We can then drop this protection.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>

diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index d94e1ea..8e96634 100644 (file)
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -417,10 +417,6 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
        unsigned long return_hooker = (unsigned long)
                                &return_to_handler;
 
-       /* Nmi's are currently unsupported */
-       if (unlikely(in_nmi()))
-               return;
-
        if (unlikely(atomic_read(&current->tracing_graph_pause)))
                return;