tracing/function-graph-tracer: drop the kernel_text_address check

When the function graph tracer picks a return address, it ensures this address
is really a kernel text one by calling __kernel_text_address()

Actually this path has never been taken.Its role was more likely to debug the tracer
on the beginning of its development but this function is wasteful since it is called
for every traced function.

The fault check is already sufficient.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 0 insertions, 7 deletions

diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index d74d75e0952d..18828aee8781 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -491,13 +491,6 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
                 return;
         }
 
-        if (unlikely(!__kernel_text_address(old))) {
-                ftrace_graph_stop();
-                *parent = old;
-                WARN_ON(1);
-                return;
-        }
-
         calltime = cpu_clock(raw_smp_processor_id());
 
         if (push_return_trace(old, calltime,