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| author | Steven Rostedt (Red Hat) <rostedt@goodmis.org> | 2014-07-15 11:05:12 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-07-28 08:08:20 -0700 |
| commit | 1462165dcc4952d085d2458b64ba60eaab6453cc (patch) | |
| tree | 6b182a323d7932a8af6ef15baecad0843b1f08f7 | |
| parent | 7d88bf615c1bfea0b42ac3a18ccd9d84a60b2ccc (diff) | |
| download | lwn-1462165dcc4952d085d2458b64ba60eaab6453cc.tar.gz lwn-1462165dcc4952d085d2458b64ba60eaab6453cc.zip | |
tracing: Fix graph tracer with stack tracer on other archs
commit 5f8bf2d263a20b986225ae1ed7d6759dc4b93af9 upstream.
Running my ftrace tests on PowerPC, it failed the test that checks
if function_graph tracer is affected by the stack tracer. It was.
Looking into this, I found that the update_function_graph_func()
must be called even if the trampoline function is not changed.
This is because archs like PowerPC do not support ftrace_ops being
passed by assembly and instead uses a helper function (what the
trampoline function points to). Since this function is not changed
even when multiple ftrace_ops are added to the code, the test that
falls out before calling update_function_graph_func() will miss that
the update must still be done.
Call update_function_graph_function() for all calls to
update_ftrace_function()
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | kernel/trace/ftrace.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 4a54a25afa2f..5aeac5338b30 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -325,12 +325,12 @@ static void update_ftrace_function(void) func = ftrace_ops_list_func; } + update_function_graph_func(); + /* If there's no change, then do nothing more here */ if (ftrace_trace_function == func) return; - update_function_graph_func(); - /* * If we are using the list function, it doesn't care * about the function_trace_ops. |