From 9ec5a7d16899ed9062cc4c3dd3a13e1771411ab3 Mon Sep 17 00:00:00 2001 From: Tom Zanussi Date: Mon, 10 Jan 2022 08:04:11 -0600 Subject: tracing: Change event_command func() to parse() The name of the func() callback on event_command is too generic and is easily confused with other callbacks with that name, so change it to something that reflects its actual purpose. In this case, the main purpose of the callback is to parse an event command, so call it parse() instead. Link: https://lkml.kernel.org/r/7784e321840752ed88aac0b349c0c685fc9247b1.1641823001.git.zanussi@kernel.org Signed-off-by: Tom Zanussi Signed-off-by: Steven Rostedt --- kernel/trace/trace_events_trigger.c | 30 +++++++++++++++--------------- 1 file changed, 15 insertions(+), 15 deletions(-) (limited to 'kernel/trace/trace_events_trigger.c') diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c index 3d5c07239a2a..15aae07cbe61 100644 --- a/kernel/trace/trace_events_trigger.c +++ b/kernel/trace/trace_events_trigger.c @@ -245,7 +245,7 @@ int trigger_process_regex(struct trace_event_file *file, char *buff) mutex_lock(&trigger_cmd_mutex); list_for_each_entry(p, &trigger_commands, list) { if (strcmp(p->name, command) == 0) { - ret = p->func(p, file, buff, command, next); + ret = p->parse(p, file, buff, command, next); goto out_unlock; } } @@ -622,7 +622,7 @@ static void unregister_trigger(char *glob, struct event_trigger_ops *ops, } /** - * event_trigger_callback - Generic event_command @func implementation + * event_trigger_parse - Generic event_command @parse implementation * @cmd_ops: The command ops, used for trigger registration * @file: The trace_event_file associated with the event * @glob: The raw string used to register the trigger @@ -632,15 +632,15 @@ static void unregister_trigger(char *glob, struct event_trigger_ops *ops, * Common implementation for event command parsing and trigger * instantiation. * - * Usually used directly as the @func method in event command + * Usually used directly as the @parse method in event command * implementations. * * Return: 0 on success, errno otherwise */ static int -event_trigger_callback(struct event_command *cmd_ops, - struct trace_event_file *file, - char *glob, char *cmd, char *param) +event_trigger_parse(struct event_command *cmd_ops, + struct trace_event_file *file, + char *glob, char *cmd, char *param) { struct event_trigger_data *trigger_data; struct event_trigger_ops *trigger_ops; @@ -1069,7 +1069,7 @@ onoff_get_trigger_ops(char *cmd, char *param) static struct event_command trigger_traceon_cmd = { .name = "traceon", .trigger_type = ETT_TRACE_ONOFF, - .func = event_trigger_callback, + .parse = event_trigger_parse, .reg = register_trigger, .unreg = unregister_trigger, .get_trigger_ops = onoff_get_trigger_ops, @@ -1080,7 +1080,7 @@ static struct event_command trigger_traceoff_cmd = { .name = "traceoff", .trigger_type = ETT_TRACE_ONOFF, .flags = EVENT_CMD_FL_POST_TRIGGER, - .func = event_trigger_callback, + .parse = event_trigger_parse, .reg = register_trigger, .unreg = unregister_trigger, .get_trigger_ops = onoff_get_trigger_ops, @@ -1157,7 +1157,7 @@ snapshot_get_trigger_ops(char *cmd, char *param) static struct event_command trigger_snapshot_cmd = { .name = "snapshot", .trigger_type = ETT_SNAPSHOT, - .func = event_trigger_callback, + .parse = event_trigger_parse, .reg = register_snapshot_trigger, .unreg = unregister_trigger, .get_trigger_ops = snapshot_get_trigger_ops, @@ -1249,7 +1249,7 @@ static struct event_command trigger_stacktrace_cmd = { .name = "stacktrace", .trigger_type = ETT_STACKTRACE, .flags = EVENT_CMD_FL_POST_TRIGGER, - .func = event_trigger_callback, + .parse = event_trigger_parse, .reg = register_trigger, .unreg = unregister_trigger, .get_trigger_ops = stacktrace_get_trigger_ops, @@ -1380,9 +1380,9 @@ static struct event_trigger_ops event_disable_count_trigger_ops = { .free = event_enable_trigger_free, }; -int event_enable_trigger_func(struct event_command *cmd_ops, - struct trace_event_file *file, - char *glob, char *cmd, char *param) +int event_enable_trigger_parse(struct event_command *cmd_ops, + struct trace_event_file *file, + char *glob, char *cmd, char *param) { struct trace_event_file *event_enable_file; struct enable_trigger_data *enable_data; @@ -1628,7 +1628,7 @@ event_enable_get_trigger_ops(char *cmd, char *param) static struct event_command trigger_enable_cmd = { .name = ENABLE_EVENT_STR, .trigger_type = ETT_EVENT_ENABLE, - .func = event_enable_trigger_func, + .parse = event_enable_trigger_parse, .reg = event_enable_register_trigger, .unreg = event_enable_unregister_trigger, .get_trigger_ops = event_enable_get_trigger_ops, @@ -1638,7 +1638,7 @@ static struct event_command trigger_enable_cmd = { static struct event_command trigger_disable_cmd = { .name = DISABLE_EVENT_STR, .trigger_type = ETT_EVENT_ENABLE, - .func = event_enable_trigger_func, + .parse = event_enable_trigger_parse, .reg = event_enable_register_trigger, .unreg = event_enable_unregister_trigger, .get_trigger_ops = event_enable_get_trigger_ops, -- cgit v1.2.3 From fb339e531bfccbd12d49b165f37636e62778b69f Mon Sep 17 00:00:00 2001 From: Tom Zanussi Date: Mon, 10 Jan 2022 08:04:12 -0600 Subject: tracing: Change event_trigger_ops func() to trigger() The name of the func() callback on event_trigger_ops is too generic and is easily confused with other callbacks with that name, so change it to something that reflects its actual purpose. In this case, the main purpose of the callback is to implement an event trigger, so call it trigger() instead. Also add some more documentation to event_trigger_ops describing the callbacks a bit better. Link: https://lkml.kernel.org/r/36ab812e3ee74ee03ae0043fda41a858ee728c00.1641823001.git.zanussi@kernel.org Signed-off-by: Tom Zanussi Signed-off-by: Steven Rostedt --- kernel/trace/trace.h | 19 +++++++++++++++---- kernel/trace/trace_eprobe.c | 2 +- kernel/trace/trace_events_hist.c | 12 ++++++------ kernel/trace/trace_events_trigger.c | 30 +++++++++++++++--------------- 4 files changed, 37 insertions(+), 26 deletions(-) (limited to 'kernel/trace/trace_events_trigger.c') diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 3b2b1bfc686f..13f23082f256 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -1619,10 +1619,20 @@ extern int register_trigger_hist_enable_disable_cmds(void); * The methods in this structure provide per-event trigger hooks for * various trigger operations. * + * The @init and @free methods are used during trigger setup and + * teardown, typically called from an event_command's @parse() + * function implementation. + * + * The @print method is used to print the trigger spec. + * + * The @trigger method is the function that actually implements the + * trigger and is called in the context of the triggering event + * whenever that event occurs. + * * All the methods below, except for @init() and @free(), must be * implemented. * - * @func: The trigger 'probe' function called when the triggering + * @trigger: The trigger 'probe' function called when the triggering * event occurs. The data passed into this callback is the data * that was supplied to the event_command @reg() function that * registered the trigger (see struct event_command) along with @@ -1651,9 +1661,10 @@ extern int register_trigger_hist_enable_disable_cmds(void); * (see trace_event_triggers.c). */ struct event_trigger_ops { - void (*func)(struct event_trigger_data *data, - struct trace_buffer *buffer, void *rec, - struct ring_buffer_event *rbe); + void (*trigger)(struct event_trigger_data *data, + struct trace_buffer *buffer, + void *rec, + struct ring_buffer_event *rbe); int (*init)(struct event_trigger_ops *ops, struct event_trigger_data *data); void (*free)(struct event_trigger_ops *ops, diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c index 84d5bfa34a99..6d363fd8a1e4 100644 --- a/kernel/trace/trace_eprobe.c +++ b/kernel/trace/trace_eprobe.c @@ -543,7 +543,7 @@ static void eprobe_trigger_func(struct event_trigger_data *data, } static struct event_trigger_ops eprobe_trigger_ops = { - .func = eprobe_trigger_func, + .trigger = eprobe_trigger_func, .print = eprobe_trigger_print, .init = eprobe_trigger_init, .free = eprobe_trigger_free, diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index 89bbbbd3a3f5..229ce5c2dfd3 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -5759,7 +5759,7 @@ static void event_hist_trigger_free(struct event_trigger_ops *ops, } static struct event_trigger_ops event_hist_trigger_ops = { - .func = event_hist_trigger, + .trigger = event_hist_trigger, .print = event_hist_trigger_print, .init = event_hist_trigger_init, .free = event_hist_trigger_free, @@ -5793,7 +5793,7 @@ static void event_hist_trigger_named_free(struct event_trigger_ops *ops, } static struct event_trigger_ops event_hist_trigger_named_ops = { - .func = event_hist_trigger, + .trigger = event_hist_trigger, .print = event_hist_trigger_print, .init = event_hist_trigger_named_init, .free = event_hist_trigger_named_free, @@ -6383,28 +6383,28 @@ hist_enable_count_trigger(struct event_trigger_data *data, } static struct event_trigger_ops hist_enable_trigger_ops = { - .func = hist_enable_trigger, + .trigger = hist_enable_trigger, .print = event_enable_trigger_print, .init = event_trigger_init, .free = event_enable_trigger_free, }; static struct event_trigger_ops hist_enable_count_trigger_ops = { - .func = hist_enable_count_trigger, + .trigger = hist_enable_count_trigger, .print = event_enable_trigger_print, .init = event_trigger_init, .free = event_enable_trigger_free, }; static struct event_trigger_ops hist_disable_trigger_ops = { - .func = hist_enable_trigger, + .trigger = hist_enable_trigger, .print = event_enable_trigger_print, .init = event_trigger_init, .free = event_enable_trigger_free, }; static struct event_trigger_ops hist_disable_count_trigger_ops = { - .func = hist_enable_count_trigger, + .trigger = hist_enable_count_trigger, .print = event_enable_trigger_print, .init = event_trigger_init, .free = event_enable_trigger_free, diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c index 15aae07cbe61..24aceeb50dc0 100644 --- a/kernel/trace/trace_events_trigger.c +++ b/kernel/trace/trace_events_trigger.c @@ -68,7 +68,7 @@ event_triggers_call(struct trace_event_file *file, if (data->paused) continue; if (!rec) { - data->ops->func(data, buffer, rec, event); + data->ops->trigger(data, buffer, rec, event); continue; } filter = rcu_dereference_sched(data->filter); @@ -78,7 +78,7 @@ event_triggers_call(struct trace_event_file *file, tt |= data->cmd_ops->trigger_type; continue; } - data->ops->func(data, buffer, rec, event); + data->ops->trigger(data, buffer, rec, event); } return tt; } @@ -106,7 +106,7 @@ event_triggers_post_call(struct trace_event_file *file, if (data->paused) continue; if (data->cmd_ops->trigger_type & tt) - data->ops->func(data, NULL, NULL, NULL); + data->ops->trigger(data, NULL, NULL, NULL); } } EXPORT_SYMBOL_GPL(event_triggers_post_call); @@ -1023,28 +1023,28 @@ traceoff_trigger_print(struct seq_file *m, struct event_trigger_ops *ops, } static struct event_trigger_ops traceon_trigger_ops = { - .func = traceon_trigger, + .trigger = traceon_trigger, .print = traceon_trigger_print, .init = event_trigger_init, .free = event_trigger_free, }; static struct event_trigger_ops traceon_count_trigger_ops = { - .func = traceon_count_trigger, + .trigger = traceon_count_trigger, .print = traceon_trigger_print, .init = event_trigger_init, .free = event_trigger_free, }; static struct event_trigger_ops traceoff_trigger_ops = { - .func = traceoff_trigger, + .trigger = traceoff_trigger, .print = traceoff_trigger_print, .init = event_trigger_init, .free = event_trigger_free, }; static struct event_trigger_ops traceoff_count_trigger_ops = { - .func = traceoff_count_trigger, + .trigger = traceoff_count_trigger, .print = traceoff_trigger_print, .init = event_trigger_init, .free = event_trigger_free, @@ -1135,14 +1135,14 @@ snapshot_trigger_print(struct seq_file *m, struct event_trigger_ops *ops, } static struct event_trigger_ops snapshot_trigger_ops = { - .func = snapshot_trigger, + .trigger = snapshot_trigger, .print = snapshot_trigger_print, .init = event_trigger_init, .free = event_trigger_free, }; static struct event_trigger_ops snapshot_count_trigger_ops = { - .func = snapshot_count_trigger, + .trigger = snapshot_count_trigger, .print = snapshot_trigger_print, .init = event_trigger_init, .free = event_trigger_free, @@ -1226,14 +1226,14 @@ stacktrace_trigger_print(struct seq_file *m, struct event_trigger_ops *ops, } static struct event_trigger_ops stacktrace_trigger_ops = { - .func = stacktrace_trigger, + .trigger = stacktrace_trigger, .print = stacktrace_trigger_print, .init = event_trigger_init, .free = event_trigger_free, }; static struct event_trigger_ops stacktrace_count_trigger_ops = { - .func = stacktrace_count_trigger, + .trigger = stacktrace_count_trigger, .print = stacktrace_trigger_print, .init = event_trigger_init, .free = event_trigger_free, @@ -1353,28 +1353,28 @@ void event_enable_trigger_free(struct event_trigger_ops *ops, } static struct event_trigger_ops event_enable_trigger_ops = { - .func = event_enable_trigger, + .trigger = event_enable_trigger, .print = event_enable_trigger_print, .init = event_trigger_init, .free = event_enable_trigger_free, }; static struct event_trigger_ops event_enable_count_trigger_ops = { - .func = event_enable_count_trigger, + .trigger = event_enable_count_trigger, .print = event_enable_trigger_print, .init = event_trigger_init, .free = event_enable_trigger_free, }; static struct event_trigger_ops event_disable_trigger_ops = { - .func = event_enable_trigger, + .trigger = event_enable_trigger, .print = event_enable_trigger_print, .init = event_trigger_init, .free = event_enable_trigger_free, }; static struct event_trigger_ops event_disable_count_trigger_ops = { - .func = event_enable_count_trigger, + .trigger = event_enable_count_trigger, .print = event_enable_trigger_print, .init = event_trigger_init, .free = event_enable_trigger_free, -- cgit v1.2.3 From 2378a2d6b6cf863bdd566aae495336c72bdaec99 Mon Sep 17 00:00:00 2001 From: Tom Zanussi Date: Mon, 10 Jan 2022 08:04:13 -0600 Subject: tracing: Remove ops param from event_command reg()/unreg() callbacks The event_trigger_ops for an event_command are already accessible via event_trigger_data.ops so remove the redundant ops from the callback. Link: https://lkml.kernel.org/r/4c6f2a41820452f9cacddc7634ad442928aa2aa6.1641823001.git.zanussi@kernel.org Signed-off-by: Tom Zanussi Signed-off-by: Steven Rostedt --- kernel/trace/trace.h | 4 ---- kernel/trace/trace_eprobe.c | 12 ++++++------ kernel/trace/trace_events_hist.c | 10 +++++----- kernel/trace/trace_events_trigger.c | 22 +++++++++------------- 4 files changed, 20 insertions(+), 28 deletions(-) (limited to 'kernel/trace/trace_events_trigger.c') diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 13f23082f256..22a1e8635acf 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -1582,11 +1582,9 @@ extern int event_enable_trigger_parse(struct event_command *cmd_ops, struct trace_event_file *file, char *glob, char *cmd, char *param); extern int event_enable_register_trigger(char *glob, - struct event_trigger_ops *ops, struct event_trigger_data *data, struct trace_event_file *file); extern void event_enable_unregister_trigger(char *glob, - struct event_trigger_ops *ops, struct event_trigger_data *test, struct trace_event_file *file); extern void trigger_data_free(struct event_trigger_data *data); @@ -1763,11 +1761,9 @@ struct event_command { char *glob, char *cmd, char *param_and_filter); int (*reg)(char *glob, - struct event_trigger_ops *ops, struct event_trigger_data *data, struct trace_event_file *file); void (*unreg)(char *glob, - struct event_trigger_ops *ops, struct event_trigger_data *data, struct trace_event_file *file); void (*unreg_all)(struct trace_event_file *file); diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c index 6d363fd8a1e4..191db32dec46 100644 --- a/kernel/trace/trace_eprobe.c +++ b/kernel/trace/trace_eprobe.c @@ -556,16 +556,16 @@ static int eprobe_trigger_cmd_parse(struct event_command *cmd_ops, return -1; } -static int eprobe_trigger_reg_func(char *glob, struct event_trigger_ops *ops, - struct event_trigger_data *data, - struct trace_event_file *file) +static int eprobe_trigger_reg_func(char *glob, + struct event_trigger_data *data, + struct trace_event_file *file) { return -1; } -static void eprobe_trigger_unreg_func(char *glob, struct event_trigger_ops *ops, - struct event_trigger_data *data, - struct trace_event_file *file) +static void eprobe_trigger_unreg_func(char *glob, + struct event_trigger_data *data, + struct trace_event_file *file) { } diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index 229ce5c2dfd3..5e6a988a8a51 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -5910,7 +5910,7 @@ static bool hist_trigger_match(struct event_trigger_data *data, return true; } -static int hist_register_trigger(char *glob, struct event_trigger_ops *ops, +static int hist_register_trigger(char *glob, struct event_trigger_data *data, struct trace_event_file *file) { @@ -6062,7 +6062,7 @@ static bool hist_trigger_check_refs(struct event_trigger_data *data, return false; } -static void hist_unregister_trigger(char *glob, struct event_trigger_ops *ops, +static void hist_unregister_trigger(char *glob, struct event_trigger_data *data, struct trace_event_file *file) { @@ -6262,7 +6262,7 @@ static int event_hist_trigger_parse(struct event_command *cmd_ops, goto out_free; } - cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file); + cmd_ops->unreg(glob+1, trigger_data, file); se_name = trace_event_name(file->event_call); se = find_synth_event(se_name); if (se) @@ -6271,7 +6271,7 @@ static int event_hist_trigger_parse(struct event_command *cmd_ops, goto out_free; } - ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file); + ret = cmd_ops->reg(glob, trigger_data, file); /* * The above returns on success the # of triggers registered, * but if it didn't register any it returns zero. Consider no @@ -6314,7 +6314,7 @@ enable: return ret; out_unreg: - cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file); + cmd_ops->unreg(glob+1, trigger_data, file); out_free: if (cmd_ops->set_filter) cmd_ops->set_filter(NULL, trigger_data, NULL); diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c index 24aceeb50dc0..d40b857db572 100644 --- a/kernel/trace/trace_events_trigger.c +++ b/kernel/trace/trace_events_trigger.c @@ -540,7 +540,6 @@ void update_cond_flag(struct trace_event_file *file) /** * register_trigger - Generic event_command @reg implementation * @glob: The raw string used to register the trigger - * @ops: The trigger ops associated with the trigger * @data: Trigger-specific data to associate with the trigger * @file: The trace_event_file associated with the event * @@ -551,7 +550,7 @@ void update_cond_flag(struct trace_event_file *file) * * Return: 0 on success, errno otherwise */ -static int register_trigger(char *glob, struct event_trigger_ops *ops, +static int register_trigger(char *glob, struct event_trigger_data *data, struct trace_event_file *file) { @@ -589,7 +588,6 @@ out: /** * unregister_trigger - Generic event_command @unreg implementation * @glob: The raw string used to register the trigger - * @ops: The trigger ops associated with the trigger * @test: Trigger-specific data used to find the trigger to remove * @file: The trace_event_file associated with the event * @@ -598,7 +596,7 @@ out: * Usually used directly as the @unreg method in event command * implementations. */ -static void unregister_trigger(char *glob, struct event_trigger_ops *ops, +static void unregister_trigger(char *glob, struct event_trigger_data *test, struct trace_event_file *file) { @@ -673,7 +671,7 @@ event_trigger_parse(struct event_command *cmd_ops, INIT_LIST_HEAD(&trigger_data->named_list); if (glob[0] == '!') { - cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file); + cmd_ops->unreg(glob+1, trigger_data, file); kfree(trigger_data); ret = 0; goto out; @@ -708,14 +706,14 @@ event_trigger_parse(struct event_command *cmd_ops, out_reg: /* Up the trigger_data count to make sure reg doesn't free it on failure */ event_trigger_init(trigger_ops, trigger_data); - ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file); + ret = cmd_ops->reg(glob, trigger_data, file); /* * The above returns on success the # of functions enabled, * but if it didn't find any functions it returns zero. * Consider no functions a failure too. */ if (!ret) { - cmd_ops->unreg(glob, trigger_ops, trigger_data, file); + cmd_ops->unreg(glob, trigger_data, file); ret = -ENOENT; } else if (ret > 0) ret = 0; @@ -1116,14 +1114,14 @@ snapshot_count_trigger(struct event_trigger_data *data, } static int -register_snapshot_trigger(char *glob, struct event_trigger_ops *ops, +register_snapshot_trigger(char *glob, struct event_trigger_data *data, struct trace_event_file *file) { if (tracing_alloc_snapshot_instance(file->tr) != 0) return 0; - return register_trigger(glob, ops, data, file); + return register_trigger(glob, data, file); } static int @@ -1455,7 +1453,7 @@ int event_enable_trigger_parse(struct event_command *cmd_ops, trigger_data->private_data = enable_data; if (glob[0] == '!') { - cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file); + cmd_ops->unreg(glob+1, trigger_data, file); kfree(trigger_data); kfree(enable_data); ret = 0; @@ -1502,7 +1500,7 @@ int event_enable_trigger_parse(struct event_command *cmd_ops, ret = trace_event_enable_disable(event_enable_file, 1, 1); if (ret < 0) goto out_put; - ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file); + ret = cmd_ops->reg(glob, trigger_data, file); /* * The above returns on success the # of functions enabled, * but if it didn't find any functions it returns zero. @@ -1532,7 +1530,6 @@ int event_enable_trigger_parse(struct event_command *cmd_ops, } int event_enable_register_trigger(char *glob, - struct event_trigger_ops *ops, struct event_trigger_data *data, struct trace_event_file *file) { @@ -1574,7 +1571,6 @@ out: } void event_enable_unregister_trigger(char *glob, - struct event_trigger_ops *ops, struct event_trigger_data *test, struct trace_event_file *file) { -- cgit v1.2.3 From 86599dbe2c5272588f859858239d1f52321eb0f9 Mon Sep 17 00:00:00 2001 From: Tom Zanussi Date: Mon, 10 Jan 2022 08:04:14 -0600 Subject: tracing: Add helper functions to simplify event_command.parse() callback handling The event_command.parse() callback is responsible for parsing and registering triggers. The existing command implementions for this callback duplicate a lot of the same code, so to clean up and consolidate those implementations, introduce a handful of helper functions for implementors to use. This also makes it easier for new commands to be implemented and allows them to focus more on the customizations they provide rather than obscuring and complicating it with boilerplate code. Link: https://lkml.kernel.org/r/c1ff71f594d45177706571132bd3119491097221.1641823001.git.zanussi@kernel.org Signed-off-by: Tom Zanussi Signed-off-by: Steven Rostedt --- kernel/trace/trace.h | 24 +++ kernel/trace/trace_events_trigger.c | 342 ++++++++++++++++++++++++++++++++++++ 2 files changed, 366 insertions(+) (limited to 'kernel/trace/trace_events_trigger.c') diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 22a1e8635acf..d038ddbf1bea 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -1610,6 +1610,30 @@ get_named_trigger_data(struct event_trigger_data *data); extern int register_event_command(struct event_command *cmd); extern int unregister_event_command(struct event_command *cmd); extern int register_trigger_hist_enable_disable_cmds(void); +extern bool event_trigger_check_remove(const char *glob); +extern bool event_trigger_empty_param(const char *param); +extern int event_trigger_separate_filter(char *param_and_filter, char **param, + char **filter, bool param_required); +extern struct event_trigger_data * +event_trigger_alloc(struct event_command *cmd_ops, + char *cmd, + char *param, + void *private_data); +extern int event_trigger_parse_num(char *trigger, + struct event_trigger_data *trigger_data); +extern int event_trigger_set_filter(struct event_command *cmd_ops, + struct trace_event_file *file, + char *param, + struct event_trigger_data *trigger_data); +extern void event_trigger_reset_filter(struct event_command *cmd_ops, + struct event_trigger_data *trigger_data); +extern int event_trigger_register(struct event_command *cmd_ops, + struct trace_event_file *file, + char *glob, + char *cmd, + char *trigger, + struct event_trigger_data *trigger_data, + int *n_registered); /** * struct event_trigger_ops - callbacks for trace event triggers diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c index d40b857db572..d00fee705f9c 100644 --- a/kernel/trace/trace_events_trigger.c +++ b/kernel/trace/trace_events_trigger.c @@ -619,6 +619,348 @@ static void unregister_trigger(char *glob, data->ops->free(data->ops, data); } +/* + * Event trigger parsing helper functions. + * + * These functions help make it easier to write an event trigger + * parsing function i.e. the struct event_command.parse() callback + * function responsible for parsing and registering a trigger command + * written to the 'trigger' file. + * + * A trigger command (or just 'trigger' for short) takes the form: + * [trigger] [if filter] + * + * The struct event_command.parse() callback (and other struct + * event_command functions) refer to several components of a trigger + * command. Those same components are referenced by the event trigger + * parsing helper functions defined below. These components are: + * + * cmd - the trigger command name + * glob - the trigger command name optionally prefaced with '!' + * param_and_filter - text following cmd and ':' + * param - text following cmd and ':' and stripped of filter + * filter - the optional filter text following (and including) 'if' + * + * To illustrate the use of these componenents, here are some concrete + * examples. For the following triggers: + * + * echo 'traceon:5 if pid == 0' > trigger + * - 'traceon' is both cmd and glob + * - '5 if pid == 0' is the param_and_filter + * - '5' is the param + * - 'if pid == 0' is the filter + * + * echo 'enable_event:sys:event:n' > trigger + * - 'enable_event' is both cmd and glob + * - 'sys:event:n' is the param_and_filter + * - 'sys:event:n' is the param + * - there is no filter + * + * echo 'hist:keys=pid if prio > 50' > trigger + * - 'hist' is both cmd and glob + * - 'keys=pid if prio > 50' is the param_and_filter + * - 'keys=pid' is the param + * - 'if prio > 50' is the filter + * + * echo '!enable_event:sys:event:n' > trigger + * - 'enable_event' the cmd + * - '!enable_event' is the glob + * - 'sys:event:n' is the param_and_filter + * - 'sys:event:n' is the param + * - there is no filter + * + * echo 'traceoff' > trigger + * - 'traceoff' is both cmd and glob + * - there is no param_and_filter + * - there is no param + * - there is no filter + * + * There are a few different categories of event trigger covered by + * these helpers: + * + * - triggers that don't require a parameter e.g. traceon + * - triggers that do require a parameter e.g. enable_event and hist + * - triggers that though they may not require a param may support an + * optional 'n' param (n = number of times the trigger should fire) + * e.g.: traceon:5 or enable_event:sys:event:n + * - triggers that do not support an 'n' param e.g. hist + * + * These functions can be used or ignored as necessary - it all + * depends on the complexity of the trigger, and the granularity of + * the functions supported reflects the fact that some implementations + * may need to customize certain aspects of their implementations and + * won't need certain functions. For instance, the hist trigger + * implementation doesn't use event_trigger_separate_filter() because + * it has special requirements for handling the filter. + */ + +/** + * event_trigger_check_remove - check whether an event trigger specifies remove + * @glob: The trigger command string, with optional remove(!) operator + * + * The event trigger callback implementations pass in 'glob' as a + * parameter. This is the command name either with or without a + * remove(!) operator. This function simply parses the glob and + * determines whether the command corresponds to a trigger removal or + * a trigger addition. + * + * Return: true if this is a remove command, false otherwise + */ +bool event_trigger_check_remove(const char *glob) +{ + return (glob && glob[0] == '!') ? true : false; +} + +/** + * event_trigger_empty_param - check whether the param is empty + * @param: The trigger param string + * + * The event trigger callback implementations pass in 'param' as a + * parameter. This corresponds to the string following the command + * name minus the command name. This function can be called by a + * callback implementation for any command that requires a param; a + * callback that doesn't require a param can ignore it. + * + * Return: true if this is an empty param, false otherwise + */ +bool event_trigger_empty_param(const char *param) +{ + return !param; +} + +/** + * event_trigger_separate_filter - separate an event trigger from a filter + * @param: The param string containing trigger and possibly filter + * @trigger: outparam, will be filled with a pointer to the trigger + * @filter: outparam, will be filled with a pointer to the filter + * @param_required: Specifies whether or not the param string is required + * + * Given a param string of the form '[trigger] [if filter]', this + * function separates the filter from the trigger and returns the + * trigger in *trigger and the filter in *filter. Either the *trigger + * or the *filter may be set to NULL by this function - if not set to + * NULL, they will contain strings corresponding to the trigger and + * filter. + * + * There are two cases that need to be handled with respect to the + * passed-in param: either the param is required, or it is not + * required. If @param_required is set, and there's no param, it will + * return -EINVAL. If @param_required is not set and there's a param + * that starts with a number, that corresponds to the case of a + * trigger with :n (n = number of times the trigger should fire) and + * the parsing continues normally; otherwise the function just returns + * and assumes param just contains a filter and there's nothing else + * to do. + * + * Return: 0 on success, errno otherwise + */ +int event_trigger_separate_filter(char *param_and_filter, char **param, + char **filter, bool param_required) +{ + int ret = 0; + + *param = *filter = NULL; + + if (!param_and_filter) { + if (param_required) + ret = -EINVAL; + goto out; + } + + /* + * Here we check for an optional param. The only legal + * optional param is :n, and if that's the case, continue + * below. Otherwise we assume what's left is a filter and + * return it as the filter string for the caller to deal with. + */ + if (!param_required && param_and_filter && !isdigit(param_and_filter[0])) { + *filter = param_and_filter; + goto out; + } + + /* + * Separate the param from the filter (param [if filter]). + * Here we have either an optional :n param or a required + * param and an optional filter. + */ + *param = strsep(¶m_and_filter, " \t"); + + /* + * Here we have a filter, though it may be empty. + */ + if (param_and_filter) { + *filter = skip_spaces(param_and_filter); + if (!**filter) + *filter = NULL; + } +out: + return ret; +} + +/** + * event_trigger_alloc - allocate and init event_trigger_data for a trigger + * @cmd_ops: The event_command operations for the trigger + * @cmd: The cmd string + * @param: The param string + * @private_data: User data to associate with the event trigger + * + * Allocate an event_trigger_data instance and initialize it. The + * @cmd_ops are used along with the @cmd and @param to get the + * trigger_ops to assign to the event_trigger_data. @private_data can + * also be passed in and associated with the event_trigger_data. + * + * Use event_trigger_free() to free an event_trigger_data object. + * + * Return: The trigger_data object success, NULL otherwise + */ +struct event_trigger_data *event_trigger_alloc(struct event_command *cmd_ops, + char *cmd, + char *param, + void *private_data) +{ + struct event_trigger_data *trigger_data; + struct event_trigger_ops *trigger_ops; + + trigger_ops = cmd_ops->get_trigger_ops(cmd, param); + + trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL); + if (!trigger_data) + return NULL; + + trigger_data->count = -1; + trigger_data->ops = trigger_ops; + trigger_data->cmd_ops = cmd_ops; + trigger_data->private_data = private_data; + + INIT_LIST_HEAD(&trigger_data->list); + INIT_LIST_HEAD(&trigger_data->named_list); + RCU_INIT_POINTER(trigger_data->filter, NULL); + + return trigger_data; +} + +/** + * event_trigger_parse_num - parse and return the number param for a trigger + * @param: The param string + * @trigger_data: The trigger_data for the trigger + * + * Parse the :n (n = number of times the trigger should fire) param + * and set the count variable in the trigger_data to the parsed count. + * + * Return: 0 on success, errno otherwise + */ +int event_trigger_parse_num(char *param, + struct event_trigger_data *trigger_data) +{ + char *number; + int ret = 0; + + if (param) { + number = strsep(¶m, ":"); + + if (!strlen(number)) + return -EINVAL; + + /* + * We use the callback data field (which is a pointer) + * as our counter. + */ + ret = kstrtoul(number, 0, &trigger_data->count); + } + + return ret; +} + +/** + * event_trigger_set_filter - set an event trigger's filter + * @cmd_ops: The event_command operations for the trigger + * @file: The event file for the trigger's event + * @param: The string containing the filter + * @trigger_data: The trigger_data for the trigger + * + * Set the filter for the trigger. If the filter is NULL, just return + * without error. + * + * Return: 0 on success, errno otherwise + */ +int event_trigger_set_filter(struct event_command *cmd_ops, + struct trace_event_file *file, + char *param, + struct event_trigger_data *trigger_data) +{ + if (param && cmd_ops->set_filter) + return cmd_ops->set_filter(param, trigger_data, file); + + return 0; +} + +/** + * event_trigger_reset_filter - reset an event trigger's filter + * @cmd_ops: The event_command operations for the trigger + * @trigger_data: The trigger_data for the trigger + * + * Reset the filter for the trigger to no filter. + */ +void event_trigger_reset_filter(struct event_command *cmd_ops, + struct event_trigger_data *trigger_data) +{ + if (cmd_ops->set_filter) + cmd_ops->set_filter(NULL, trigger_data, NULL); +} + +/** + * event_trigger_register - register an event trigger + * @cmd_ops: The event_command operations for the trigger + * @file: The event file for the trigger's event + * @glob: The trigger command string, with optional remove(!) operator + * @cmd: The cmd string + * @param: The param string + * @trigger_data: The trigger_data for the trigger + * @n_registered: optional outparam, the number of triggers registered + * + * Register an event trigger. The @cmd_ops are used to call the + * cmd_ops->reg() function which actually does the registration. The + * cmd_ops->reg() function returns the number of triggers registered, + * which is assigned to n_registered, if n_registered is non-NULL. + * + * Return: 0 on success, errno otherwise + */ +int event_trigger_register(struct event_command *cmd_ops, + struct trace_event_file *file, + char *glob, + char *cmd, + char *param, + struct event_trigger_data *trigger_data, + int *n_registered) +{ + int ret; + + if (n_registered) + *n_registered = 0; + + ret = cmd_ops->reg(glob, trigger_data, file); + /* + * The above returns on success the # of functions enabled, + * but if it didn't find any functions it returns zero. + * Consider no functions a failure too. + */ + if (!ret) { + cmd_ops->unreg(glob, trigger_data, file); + ret = -ENOENT; + } else if (ret > 0) { + if (n_registered) + *n_registered = ret; + /* Just return zero, not the number of enabled functions */ + ret = 0; + } + + return ret; +} + +/* + * End event trigger parsing helper functions. + */ + /** * event_trigger_parse - Generic event_command @parse implementation * @cmd_ops: The command ops, used for trigger registration -- cgit v1.2.3