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| author |   Steven Rostedt <srostedt@redhat.com> | 2009-03-24 00:18:31 -0400 |
|---|---|---|
| committer | Steven Rostedt <srostedt@redhat.com> | 2009-03-24 09:32:52 -0400 |
| commit | 05ce5818adee8f8efd0a5ca0d900a6789012516b (patch) | |
| tree | 81c90288dd1da4291b5e3ee154756b2d7745c248 /kernel/trace/ftrace.c | |
| parent | function-graph: moved the timestamp from arch to generic code (diff) | |
| download | linux-dev-05ce5818adee8f8efd0a5ca0d900a6789012516b.tar.xz linux-dev-05ce5818adee8f8efd0a5ca0d900a6789012516b.zip | |
function-graph: prevent more than one tracer registering
Impact: prevent crash due to multiple function graph tracers
The function graph tracer can currently only handle a single tracer
being registered. If another tracer registers with the function
graph tracer it can crash the system.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Diffstat (limited to '')
| -rw-r--r-- | kernel/trace/ftrace.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 7847806eefef..c81a759fbf76 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -2643,6 +2643,12 @@ int register_ftrace_graph(trace_func_graph_ret_t retfunc, mutex_lock(&ftrace_lock); + /* we currently allow only one tracer registered at a time */ + if (atomic_read(&ftrace_graph_active)) { + ret = -EBUSY; + goto out; + } + ftrace_suspend_notifier.notifier_call = ftrace_suspend_notifier_call; register_pm_notifier(&ftrace_suspend_notifier); |