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authorSteven Rostedt <srostedt@redhat.com>2012-11-02 16:58:56 -0400
committerSteven Rostedt <rostedt@goodmis.org>2013-01-22 23:37:57 -0500
commit6350379452ccaeaa71734adf57dec2ebc9207849 (patch)
tree58873a5c9c3d7c2b9b29d56482a87a4392ecb8a2 /kernel/trace
parent05cbbf643b8eea1be21082c53cdb856d1dc6d765 (diff)
downloadblackbird-op-linux-6350379452ccaeaa71734adf57dec2ebc9207849.tar.gz
blackbird-op-linux-6350379452ccaeaa71734adf57dec2ebc9207849.zip
ftrace: Fix global function tracers that are not recursion safe
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>
Diffstat (limited to 'kernel/trace')
-rw-r--r--kernel/trace/ftrace.c18
1 files changed, 16 insertions, 2 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 6e34dc162fe1..789cbec24e81 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -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)) {
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