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ftrace: Fix global function tracers that are not recursion safe

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If one of the function tracers set by the global ops is not recursion
safe, it can still be called directly without the added recursion
supplied by the ftrace infrastructure.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
This commit is contained in:
Steven Rostedt 2012-11-02 16:58:56 -04:00 committed by Steven Rostedt
parent 05cbbf643b
commit 6350379452
1 changed files with 16 additions and 2 deletions
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18
kernel/trace/ftrace.c
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@ -221,10 +221,24 @@ static void update_global_ops(void)
* registered callers.
*/
if (ftrace_global_list == &ftrace_list_end ||
ftrace_global_list->next == &ftrace_list_end)
ftrace_global_list->next == &ftrace_list_end) {
func = ftrace_global_list->func;
else
/*
* As we are calling the function directly.
* If it does not have recursion protection,
* the function_trace_op needs to be updated
* accordingly.
*/
if (ftrace_global_list->flags & FTRACE_OPS_FL_RECURSION_SAFE)
global_ops.flags |= FTRACE_OPS_FL_RECURSION_SAFE;
else
global_ops.flags &= ~FTRACE_OPS_FL_RECURSION_SAFE;
} else {
func = ftrace_global_list_func;
/* The list has its own recursion protection. */
global_ops.flags |= FTRACE_OPS_FL_RECURSION_SAFE;
}
/* If we filter on pids, update to use the pid function */
if (!list_empty(&ftrace_pids)) {