diff options
Diffstat (limited to 'include/linux/trace_events.h')
| -rw-r--r-- | include/linux/trace_events.h | 56 |
1 files changed, 48 insertions, 8 deletions
diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h index 536c80ff7ad9..af44e7c2d577 100644 --- a/include/linux/trace_events.h +++ b/include/linux/trace_events.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0 */ #ifndef _LINUX_TRACE_EVENT_H #define _LINUX_TRACE_EVENT_H @@ -173,6 +174,11 @@ enum trace_reg { TRACE_REG_PERF_UNREGISTER, TRACE_REG_PERF_OPEN, TRACE_REG_PERF_CLOSE, + /* + * These (ADD/DEL) use a 'boolean' return value, where 1 (true) means a + * custom action was taken and the default action is not to be + * performed. + */ TRACE_REG_PERF_ADD, TRACE_REG_PERF_DEL, #endif @@ -217,7 +223,6 @@ enum { TRACE_EVENT_FL_CAP_ANY_BIT, TRACE_EVENT_FL_NO_SET_FILTER_BIT, TRACE_EVENT_FL_IGNORE_ENABLE_BIT, - TRACE_EVENT_FL_WAS_ENABLED_BIT, TRACE_EVENT_FL_TRACEPOINT_BIT, TRACE_EVENT_FL_KPROBE_BIT, TRACE_EVENT_FL_UPROBE_BIT, @@ -229,9 +234,6 @@ enum { * CAP_ANY - Any user can enable for perf * NO_SET_FILTER - Set when filter has error and is to be ignored * IGNORE_ENABLE - For trace internal events, do not enable with debugfs file - * WAS_ENABLED - Set and stays set when an event was ever enabled - * (used for module unloading, if a module event is enabled, - * it is best to clear the buffers that used it). * TRACEPOINT - Event is a tracepoint * KPROBE - Event is a kprobe * UPROBE - Event is a uprobe @@ -241,7 +243,6 @@ enum { TRACE_EVENT_FL_CAP_ANY = (1 << TRACE_EVENT_FL_CAP_ANY_BIT), TRACE_EVENT_FL_NO_SET_FILTER = (1 << TRACE_EVENT_FL_NO_SET_FILTER_BIT), TRACE_EVENT_FL_IGNORE_ENABLE = (1 << TRACE_EVENT_FL_IGNORE_ENABLE_BIT), - TRACE_EVENT_FL_WAS_ENABLED = (1 << TRACE_EVENT_FL_WAS_ENABLED_BIT), TRACE_EVENT_FL_TRACEPOINT = (1 << TRACE_EVENT_FL_TRACEPOINT_BIT), TRACE_EVENT_FL_KPROBE = (1 << TRACE_EVENT_FL_KPROBE_BIT), TRACE_EVENT_FL_UPROBE = (1 << TRACE_EVENT_FL_UPROBE_BIT), @@ -276,13 +277,37 @@ struct trace_event_call { #ifdef CONFIG_PERF_EVENTS int perf_refcount; struct hlist_head __percpu *perf_events; - struct bpf_prog *prog; + struct bpf_prog_array __rcu *prog_array; int (*perf_perm)(struct trace_event_call *, struct perf_event *); #endif }; +#ifdef CONFIG_PERF_EVENTS +static inline bool bpf_prog_array_valid(struct trace_event_call *call) +{ + /* + * This inline function checks whether call->prog_array + * is valid or not. The function is called in various places, + * outside rcu_read_lock/unlock, as a heuristic to speed up execution. + * + * If this function returns true, and later call->prog_array + * becomes false inside rcu_read_lock/unlock region, + * we bail out then. If this function return false, + * there is a risk that we might miss a few events if the checking + * were delayed until inside rcu_read_lock/unlock region and + * call->prog_array happened to become non-NULL then. + * + * Here, READ_ONCE() is used instead of rcu_access_pointer(). + * rcu_access_pointer() requires the actual definition of + * "struct bpf_prog_array" while READ_ONCE() only needs + * a declaration of the same type. + */ + return !!READ_ONCE(call->prog_array); +} +#endif + static inline const char * trace_event_name(struct trace_event_call *call) { @@ -306,6 +331,7 @@ enum { EVENT_FILE_FL_TRIGGER_MODE_BIT, EVENT_FILE_FL_TRIGGER_COND_BIT, EVENT_FILE_FL_PID_FILTER_BIT, + EVENT_FILE_FL_WAS_ENABLED_BIT, }; /* @@ -321,6 +347,7 @@ enum { * TRIGGER_MODE - When set, invoke the triggers associated with the event * TRIGGER_COND - When set, one or more triggers has an associated filter * PID_FILTER - When set, the event is filtered based on pid + * WAS_ENABLED - Set when enabled to know to clear trace on module removal */ enum { EVENT_FILE_FL_ENABLED = (1 << EVENT_FILE_FL_ENABLED_BIT), @@ -333,6 +360,7 @@ enum { EVENT_FILE_FL_TRIGGER_MODE = (1 << EVENT_FILE_FL_TRIGGER_MODE_BIT), EVENT_FILE_FL_TRIGGER_COND = (1 << EVENT_FILE_FL_TRIGGER_COND_BIT), EVENT_FILE_FL_PID_FILTER = (1 << EVENT_FILE_FL_PID_FILTER_BIT), + EVENT_FILE_FL_WAS_ENABLED = (1 << EVENT_FILE_FL_WAS_ENABLED_BIT), }; struct trace_event_file { @@ -436,12 +464,23 @@ trace_trigger_soft_disabled(struct trace_event_file *file) } #ifdef CONFIG_BPF_EVENTS -unsigned int trace_call_bpf(struct bpf_prog *prog, void *ctx); +unsigned int trace_call_bpf(struct trace_event_call *call, void *ctx); +int perf_event_attach_bpf_prog(struct perf_event *event, struct bpf_prog *prog); +void perf_event_detach_bpf_prog(struct perf_event *event); #else -static inline unsigned int trace_call_bpf(struct bpf_prog *prog, void *ctx) +static inline unsigned int trace_call_bpf(struct trace_event_call *call, void *ctx) { return 1; } + +static inline int +perf_event_attach_bpf_prog(struct perf_event *event, struct bpf_prog *prog) +{ + return -EOPNOTSUPP; +} + +static inline void perf_event_detach_bpf_prog(struct perf_event *event) { } + #endif enum { @@ -512,6 +551,7 @@ perf_trace_buf_submit(void *raw_data, int size, int rctx, u16 type, { perf_tp_event(type, count, raw_data, size, regs, head, rctx, task); } + #endif #endif /* _LINUX_TRACE_EVENT_H */ |