name : trace_custom_events.h /* SPDX-License-Identifier: GPL-2.0 */ /* * This is similar to the trace_events.h file, but is to only * create custom trace events to be attached to existing tracepoints. * Where as the TRACE_EVENT() macro (from trace_events.h) will create * both the trace event and the tracepoint it will attach the event to, * TRACE_CUSTOM_EVENT() is to create only a custom version of an existing * trace event (created by TRACE_EVENT() or DEFINE_EVENT()), and will * be placed in the "custom" system. */ #include <linux/trace_events.h> /* All custom events are placed in the custom group */ #undef TRACE_SYSTEM #define TRACE_SYSTEM custom #ifndef TRACE_SYSTEM_VAR #define TRACE_SYSTEM_VAR TRACE_SYSTEM #endif /* The init stage creates the system string and enum mappings */ #include "stages/init.h" #undef TRACE_CUSTOM_EVENT #define TRACE_CUSTOM_EVENT(name, proto, args, tstruct, assign, print) \ DECLARE_CUSTOM_EVENT_CLASS(name, \ PARAMS(proto), \ PARAMS(args), \ PARAMS(tstruct), \ PARAMS(assign), \ PARAMS(print)); \ DEFINE_CUSTOM_EVENT(name, name, PARAMS(proto), PARAMS(args)); /* Stage 1 creates the structure of the recorded event layout */ #include "stages/stage1_struct_define.h" #undef DECLARE_CUSTOM_EVENT_CLASS #define DECLARE_CUSTOM_EVENT_CLASS(name, proto, args, tstruct, assign, print) \ struct trace_custom_event_raw_##name { \ struct trace_entry ent; \ tstruct \ char __data[]; \ }; \ \ static struct trace_event_class custom_event_class_##name; #undef DEFINE_CUSTOM_EVENT #define DEFINE_CUSTOM_EVENT(template, name, proto, args) \ static struct trace_event_call __used \ __attribute__((__aligned__(4))) custom_event_##name #include TRACE_INCLUDE(TRACE_INCLUDE_FILE) /* Stage 2 creates the custom class */ #include "stages/stage2_data_offsets.h" #undef DECLARE_CUSTOM_EVENT_CLASS #define DECLARE_CUSTOM_EVENT_CLASS(call, proto, args, tstruct, assign, print) \ struct trace_custom_event_data_offsets_##call { \ tstruct; \ }; #undef DEFINE_CUSTOM_EVENT #define DEFINE_CUSTOM_EVENT(template, name, proto, args) #include TRACE_INCLUDE(TRACE_INCLUDE_FILE) /* Stage 3 create the way to print the custom event */ #include "stages/stage3_trace_output.h" #undef DECLARE_CUSTOM_EVENT_CLASS #define DECLARE_CUSTOM_EVENT_CLASS(call, proto, args, tstruct, assign, print) \ static notrace enum print_line_t \ trace_custom_raw_output_##call(struct trace_iterator *iter, int flags, \ struct trace_event *trace_event) \ { \ struct trace_seq *s = &iter->seq; \ struct trace_seq __maybe_unused *p = &iter->tmp_seq; \ struct trace_custom_event_raw_##call *field; \ int ret; \ \ field = (typeof(field))iter->ent; \ \ ret = trace_raw_output_prep(iter, trace_event); \ if (ret != TRACE_TYPE_HANDLED) \ return ret; \ \ trace_event_printf(iter, print); \ \ return trace_handle_return(s); \ } \ static struct trace_event_functions trace_custom_event_type_funcs_##call = { \ .trace = trace_custom_raw_output_##call, \ }; #include TRACE_INCLUDE(TRACE_INCLUDE_FILE) /* Stage 4 creates the offset layout for the fields */ #include "stages/stage4_event_fields.h" #undef DECLARE_CUSTOM_EVENT_CLASS #define DECLARE_CUSTOM_EVENT_CLASS(call, proto, args, tstruct, func, print) \ static struct trace_event_fields trace_custom_event_fields_##call[] = { \ tstruct \ {} }; #include TRACE_INCLUDE(TRACE_INCLUDE_FILE) /* Stage 5 creates the helper function for dynamic fields */ #include "stages/stage5_get_offsets.h" #undef DECLARE_CUSTOM_EVENT_CLASS #define DECLARE_CUSTOM_EVENT_CLASS(call, proto, args, tstruct, assign, print) \ static inline notrace int trace_custom_event_get_offsets_##call( \ struct trace_custom_event_data_offsets_##call *__data_offsets, proto) \ { \ int __data_size = 0; \ int __maybe_unused __item_length; \ struct trace_custom_event_raw_##call __maybe_unused *entry; \ \ tstruct; \ \ return __data_size; \ } #include TRACE_INCLUDE(TRACE_INCLUDE_FILE) /* Stage 6 creates the probe function that records the event */ #include "stages/stage6_event_callback.h" #undef DECLARE_CUSTOM_EVENT_CLASS #define DECLARE_CUSTOM_EVENT_CLASS(call, proto, args, tstruct, assign, print) \ \ static notrace void \ trace_custom_event_raw_event_##call(void *__data, proto) \ { \ struct trace_event_file *trace_file = __data; \ struct trace_custom_event_data_offsets_##call __maybe_unused __data_offsets; \ struct trace_event_buffer fbuffer; \ struct trace_custom_event_raw_##call *entry; \ int __data_size; \ \ if (trace_trigger_soft_disabled(trace_file)) \ return; \ \ __data_size = trace_custom_event_get_offsets_##call(&__data_offsets, args); \ \ entry = trace_event_buffer_reserve(&fbuffer, trace_file, \ sizeof(*entry) + __data_size); \ \ if (!entry) \ return; \ \ tstruct \ \ { assign; } \ \ trace_event_buffer_commit(&fbuffer); \ } /* * The ftrace_test_custom_probe is compiled out, it is only here as a build time check * to make sure that if the tracepoint handling changes, the ftrace probe will * fail to compile unless it too is updated. */ #undef DEFINE_CUSTOM_EVENT #define DEFINE_CUSTOM_EVENT(template, call, proto, args) \ static inline void ftrace_test_custom_probe_##call(void) \ { \ check_trace_callback_type_##call(trace_custom_event_raw_event_##template); \ } #include TRACE_INCLUDE(TRACE_INCLUDE_FILE) /* Stage 7 creates the actual class and event structure for the custom event */ #include "stages/stage7_class_define.h" #undef DECLARE_CUSTOM_EVENT_CLASS #define DECLARE_CUSTOM_EVENT_CLASS(call, proto, args, tstruct, assign, print) \ static char custom_print_fmt_##call[] = print; \ static struct trace_event_class __used __refdata custom_event_class_##call = { \ .system = TRACE_SYSTEM_STRING, \ .fields_array = trace_custom_event_fields_##call, \ .fields = LIST_HEAD_INIT(custom_event_class_##call.fields),\ .raw_init = trace_event_raw_init, \ .probe = trace_custom_event_raw_event_##call, \ .reg = trace_event_reg, \ }; #undef DEFINE_CUSTOM_EVENT #define DEFINE_CUSTOM_EVENT(template, call, proto, args) \ \ static struct trace_event_call __used custom_event_##call = { \ .name = #call, \ .class = &custom_event_class_##template, \ .event.funcs = &trace_custom_event_type_funcs_##template, \ .print_fmt = custom_print_fmt_##template, \ .flags = TRACE_EVENT_FL_CUSTOM, \ }; \ static inline int trace_custom_event_##call##_update(struct tracepoint *tp) \ { \ if (tp->name && strcmp(tp->name, #call) == 0) { \ custom_event_##call.tp = tp; \ custom_event_##call.flags = TRACE_EVENT_FL_TRACEPOINT; \ return 1; \ } \ return 0; \ } \ static struct trace_event_call __used \ __section("_ftrace_events") *__custom_event_##call = &custom_event_##call #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)