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-rw-r--r--kernel/trace/ftrace.c18
1 files changed, 14 insertions, 4 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 67708f46baae..8ce9eefc5bb4 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1441,12 +1441,22 @@ ftrace_hash_move(struct ftrace_ops *ops, int enable,
* the hashes are freed with call_rcu_sched().
*/
static int
-ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip)
+ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs)
{
struct ftrace_hash *filter_hash;
struct ftrace_hash *notrace_hash;
int ret;
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
+ /*
+ * There's a small race when adding ops that the ftrace handler
+ * that wants regs, may be called without them. We can not
+ * allow that handler to be called if regs is NULL.
+ */
+ if (regs == NULL && (ops->flags & FTRACE_OPS_FL_SAVE_REGS))
+ return 0;
+#endif
+
filter_hash = rcu_dereference_raw_notrace(ops->filter_hash);
notrace_hash = rcu_dereference_raw_notrace(ops->notrace_hash);
@@ -4218,7 +4228,7 @@ static inline void ftrace_startup_enable(int command) { }
# define ftrace_shutdown_sysctl() do { } while (0)
static inline int
-ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip)
+ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs)
{
return 1;
}
@@ -4241,7 +4251,7 @@ ftrace_ops_control_func(unsigned long ip, unsigned long parent_ip,
do_for_each_ftrace_op(op, ftrace_control_list) {
if (!(op->flags & FTRACE_OPS_FL_STUB) &&
!ftrace_function_local_disabled(op) &&
- ftrace_ops_test(op, ip))
+ ftrace_ops_test(op, ip, regs))
op->func(ip, parent_ip, op, regs);
} while_for_each_ftrace_op(op);
trace_recursion_clear(TRACE_CONTROL_BIT);
@@ -4274,7 +4284,7 @@ __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
*/
preempt_disable_notrace();
do_for_each_ftrace_op(op, ftrace_ops_list) {
- if (ftrace_ops_test(op, ip))
+ if (ftrace_ops_test(op, ip, regs))
op->func(ip, parent_ip, op, regs);
} while_for_each_ftrace_op(op);
preempt_enable_notrace();
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