Commit-ID: 05ce5818adee8f8efd0a5ca0d900a6789012516b
Gitweb: http://git.kernel.org/tip/05ce5818adee8f8efd0a5ca0d900a6789012516b
Author: Steven Rostedt <srostedt@xxxxxxxxxx>
AuthorDate: Tue, 24 Mar 2009 00:18:31 -0400
Committer: Steven Rostedt <srostedt@xxxxxxxxxx>
CommitDate: Tue, 24 Mar 2009 09:32:52 -0400
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@xxxxxxxxxx>
---
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 7847806..c81a759 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);
--
To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
|