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Diffstat (limited to 'kernel/trace/ftrace.c')
-rw-r--r--kernel/trace/ftrace.c31
1 files changed, 24 insertions, 7 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index d017c2c82c4..1ee417fcbfa 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -109,12 +109,18 @@ ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip);
static void ftrace_global_list_func(unsigned long ip,
unsigned long parent_ip)
{
- struct ftrace_ops *op = rcu_dereference_raw(ftrace_global_list); /*see above*/
+ struct ftrace_ops *op;
+
+ if (unlikely(trace_recursion_test(TRACE_GLOBAL_BIT)))
+ return;
+ trace_recursion_set(TRACE_GLOBAL_BIT);
+ op = rcu_dereference_raw(ftrace_global_list); /*see above*/
while (op != &ftrace_list_end) {
op->func(ip, parent_ip);
op = rcu_dereference_raw(op->next); /*see above*/
};
+ trace_recursion_clear(TRACE_GLOBAL_BIT);
}
static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip)
@@ -1638,12 +1644,12 @@ static void ftrace_startup_enable(int command)
ftrace_run_update_code(command);
}
-static void ftrace_startup(struct ftrace_ops *ops, int command)
+static int ftrace_startup(struct ftrace_ops *ops, int command)
{
bool hash_enable = true;
if (unlikely(ftrace_disabled))
- return;
+ return -ENODEV;
ftrace_start_up++;
command |= FTRACE_ENABLE_CALLS;
@@ -1662,6 +1668,8 @@ static void ftrace_startup(struct ftrace_ops *ops, int command)
ftrace_hash_rec_enable(ops, 1);
ftrace_startup_enable(command);
+
+ return 0;
}
static void ftrace_shutdown(struct ftrace_ops *ops, int command)
@@ -2501,7 +2509,7 @@ static void __enable_ftrace_function_probe(void)
ret = __register_ftrace_function(&trace_probe_ops);
if (!ret)
- ftrace_startup(&trace_probe_ops, 0);
+ ret = ftrace_startup(&trace_probe_ops, 0);
ftrace_probe_registered = 1;
}
@@ -3466,7 +3474,11 @@ device_initcall(ftrace_nodyn_init);
static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; }
static inline void ftrace_startup_enable(int command) { }
/* Keep as macros so we do not need to define the commands */
-# define ftrace_startup(ops, command) do { } while (0)
+# define ftrace_startup(ops, command) \
+ ({ \
+ (ops)->flags |= FTRACE_OPS_FL_ENABLED; \
+ 0; \
+ })
# define ftrace_shutdown(ops, command) do { } while (0)
# define ftrace_startup_sysctl() do { } while (0)
# define ftrace_shutdown_sysctl() do { } while (0)
@@ -3484,6 +3496,10 @@ ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip)
{
struct ftrace_ops *op;
+ if (unlikely(trace_recursion_test(TRACE_INTERNAL_BIT)))
+ return;
+
+ trace_recursion_set(TRACE_INTERNAL_BIT);
/*
* Some of the ops may be dynamically allocated,
* they must be freed after a synchronize_sched().
@@ -3496,6 +3512,7 @@ ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip)
op = rcu_dereference_raw(op->next);
};
preempt_enable_notrace();
+ trace_recursion_clear(TRACE_INTERNAL_BIT);
}
static void clear_ftrace_swapper(void)
@@ -3799,7 +3816,7 @@ int register_ftrace_function(struct ftrace_ops *ops)
ret = __register_ftrace_function(ops);
if (!ret)
- ftrace_startup(ops, 0);
+ ret = ftrace_startup(ops, 0);
out_unlock:
@@ -4045,7 +4062,7 @@ int register_ftrace_graph(trace_func_graph_ret_t retfunc,
ftrace_graph_return = retfunc;
ftrace_graph_entry = entryfunc;
- ftrace_startup(&global_ops, FTRACE_START_FUNC_RET);
+ ret = ftrace_startup(&global_ops, FTRACE_START_FUNC_RET);
out:
mutex_unlock(&ftrace_lock);