diff options
Diffstat (limited to 'include/linux/tracepoint.h')
| -rw-r--r-- | include/linux/tracepoint.h | 25 |
1 files changed, 16 insertions, 9 deletions
diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h index 444aa73037f1..bff2f76aeff7 100644 --- a/include/linux/tracepoint.h +++ b/include/linux/tracepoint.h @@ -42,7 +42,17 @@ extern int tracepoint_probe_register_prio(struct tracepoint *tp, void *probe, void *data, int prio); extern int +tracepoint_probe_register_prio_may_exist(struct tracepoint *tp, void *probe, void *data, + int prio); +extern int tracepoint_probe_unregister(struct tracepoint *tp, void *probe, void *data); +static inline int +tracepoint_probe_register_may_exist(struct tracepoint *tp, void *probe, + void *data) +{ + return tracepoint_probe_register_prio_may_exist(tp, probe, data, + TRACEPOINT_DEFAULT_PRIO); +} extern void for_each_kernel_tracepoint(void (*fct)(struct tracepoint *tp, void *priv), void *priv); @@ -223,12 +233,11 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p) * not add unwanted padding between the beginning of the section and the * structure. Force alignment to the same alignment as the section start. * - * When lockdep is enabled, we make sure to always do the RCU portions of - * the tracepoint code, regardless of whether tracing is on. However, - * don't check if the condition is false, due to interaction with idle - * instrumentation. This lets us find RCU issues triggered with tracepoints - * even when this tracepoint is off. This code has no purpose other than - * poking RCU a bit. + * When lockdep is enabled, we make sure to always test if RCU is + * "watching" regardless if the tracepoint is enabled or not. Tracepoints + * require RCU to be active, and it should always warn at the tracepoint + * site if it is not watching, as it will need to be active when the + * tracepoint is enabled. */ #define __DECLARE_TRACE(name, proto, args, cond, data_proto, data_args) \ extern struct tracepoint __tracepoint_##name; \ @@ -240,9 +249,7 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p) TP_ARGS(data_args), \ TP_CONDITION(cond), 0); \ if (IS_ENABLED(CONFIG_LOCKDEP) && (cond)) { \ - rcu_read_lock_sched_notrace(); \ - rcu_dereference_sched(__tracepoint_##name.funcs);\ - rcu_read_unlock_sched_notrace(); \ + WARN_ON_ONCE(!rcu_is_watching()); \ } \ } \ __DECLARE_TRACE_RCU(name, PARAMS(proto), PARAMS(args), \ |