diff options
| -rw-r--r-- | include/linux/tracepoint.h | 10 | ||||
| -rw-r--r-- | kernel/trace/bpf_trace.c | 3 | ||||
| -rw-r--r-- | kernel/tracepoint.c | 33 |
3 files changed, 42 insertions, 4 deletions
diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h index 13f65420f188..ab58696d0ddd 100644 --- a/include/linux/tracepoint.h +++ b/include/linux/tracepoint.h @@ -41,7 +41,17 @@ 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); diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 7a52bc172841..f0568b3d6bd1 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -1840,7 +1840,8 @@ static int __bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog * if (prog->aux->max_tp_access > btp->writable_size) return -EINVAL; - return tracepoint_probe_register(tp, (void *)btp->bpf_func, prog); + return tracepoint_probe_register_may_exist(tp, (void *)btp->bpf_func, + prog); } int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog) diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c index 9f478d29b926..976bf8ce8039 100644 --- a/kernel/tracepoint.c +++ b/kernel/tracepoint.c @@ -273,7 +273,8 @@ static void tracepoint_update_call(struct tracepoint *tp, struct tracepoint_func * Add the probe function to a tracepoint. */ static int tracepoint_add_func(struct tracepoint *tp, - struct tracepoint_func *func, int prio) + struct tracepoint_func *func, int prio, + bool warn) { struct tracepoint_func *old, *tp_funcs; int ret; @@ -288,7 +289,7 @@ static int tracepoint_add_func(struct tracepoint *tp, lockdep_is_held(&tracepoints_mutex)); old = func_add(&tp_funcs, func, prio); if (IS_ERR(old)) { - WARN_ON_ONCE(PTR_ERR(old) != -ENOMEM); + WARN_ON_ONCE(warn && PTR_ERR(old) != -ENOMEM); return PTR_ERR(old); } @@ -344,6 +345,32 @@ static int tracepoint_remove_func(struct tracepoint *tp, } /** + * tracepoint_probe_register_prio_may_exist - Connect a probe to a tracepoint with priority + * @tp: tracepoint + * @probe: probe handler + * @data: tracepoint data + * @prio: priority of this function over other registered functions + * + * Same as tracepoint_probe_register_prio() except that it will not warn + * if the tracepoint is already registered. + */ +int tracepoint_probe_register_prio_may_exist(struct tracepoint *tp, void *probe, + void *data, int prio) +{ + struct tracepoint_func tp_func; + int ret; + + mutex_lock(&tracepoints_mutex); + tp_func.func = probe; + tp_func.data = data; + tp_func.prio = prio; + ret = tracepoint_add_func(tp, &tp_func, prio, false); + mutex_unlock(&tracepoints_mutex); + return ret; +} +EXPORT_SYMBOL_GPL(tracepoint_probe_register_prio_may_exist); + +/** * tracepoint_probe_register_prio - Connect a probe to a tracepoint with priority * @tp: tracepoint * @probe: probe handler @@ -366,7 +393,7 @@ int tracepoint_probe_register_prio(struct tracepoint *tp, void *probe, tp_func.func = probe; tp_func.data = data; tp_func.prio = prio; - ret = tracepoint_add_func(tp, &tp_func, prio); + ret = tracepoint_add_func(tp, &tp_func, prio, true); mutex_unlock(&tracepoints_mutex); return ret; } |