tracing: Refactor hist trigger action code
authorTom Zanussi <tom.zanussi@linux.intel.com>
Wed, 13 Feb 2019 23:42:41 +0000 (17:42 -0600)
committerSteven Rostedt (VMware) <rostedt@goodmis.org>
Wed, 20 Feb 2019 18:51:06 +0000 (13:51 -0500)
The hist trigger action code currently implements two essentially
hard-coded pairs of 'actions' - onmax(), which tracks a variable and
saves some event fields when a max is hit, and onmatch(), which is
hard-coded to generate a synthetic event.

These hardcoded pairs (track max/save fields and detect match/generate
synthetic event) should really be decoupled into separate components
that can then be arbitrarily combined.  The first component of each
pair (track max/detect match) is called a 'handler' in the new code,
while the second component (save fields/generate synthetic event) is
called an 'action' in this scheme.

This change refactors the action code to reflect this split by adding
two handlers, HANDLER_ONMATCH and HANDLER_ONMAX, along with two
actions, ACTION_SAVE and ACTION_TRACE.

The new code combines them to produce the existing ONMATCH/TRACE and
ONMAX/SAVE functionality, but doesn't implement the other combinations
now possible.  Future patches will expand these to further useful
cases, such as ONMAX/TRACE, as well as add additional handlers and
actions such as ONCHANGE and SNAPSHOT.

Also, add abbreviated documentation for handlers and actions to
README.

Link: http://lkml.kernel.org/r/98bfdd48c1b4ff29fc5766442f99f5bc3c34b76b.1550100284.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
kernel/trace/trace_events_hist.c

index 449d90cfa151a3444687672f2ffe3f2ef498824b..dfaaad5827974db3f48dd98fc3e7649392d65601 100644 (file)
@@ -313,9 +313,9 @@ struct hist_trigger_data {
        struct field_var_hist           *field_var_hists[SYNTH_FIELDS_MAX];
        unsigned int                    n_field_var_hists;
 
-       struct field_var                *max_vars[SYNTH_FIELDS_MAX];
-       unsigned int                    n_max_vars;
-       unsigned int                    n_max_var_str;
+       struct field_var                *save_vars[SYNTH_FIELDS_MAX];
+       unsigned int                    n_save_vars;
+       unsigned int                    n_save_var_str;
 };
 
 static int synth_event_create(int argc, const char **argv);
@@ -383,11 +383,25 @@ struct action_data;
 
 typedef void (*action_fn_t) (struct hist_trigger_data *hist_data,
                             struct tracing_map_elt *elt, void *rec,
-                            struct ring_buffer_event *rbe,
+                            struct ring_buffer_event *rbe, void *key,
                             struct action_data *data, u64 *var_ref_vals);
 
+enum handler_id {
+       HANDLER_ONMATCH = 1,
+       HANDLER_ONMAX,
+};
+
+enum action_id {
+       ACTION_SAVE = 1,
+       ACTION_TRACE,
+};
+
 struct action_data {
+       enum handler_id         handler;
+       enum action_id          action;
+       char                    *action_name;
        action_fn_t             fn;
+
        unsigned int            n_params;
        char                    *params[SYNTH_FIELDS_MAX];
 
@@ -404,13 +418,11 @@ struct action_data {
                        unsigned int            var_ref_idx;
                        char                    *match_event;
                        char                    *match_event_system;
-                       char                    *synth_event_name;
                        struct synth_event      *synth_event;
                } onmatch;
 
                struct {
                        char                    *var_str;
-                       char                    *fn_name;
                        unsigned int            max_var_ref_idx;
                        struct hist_field       *max_var;
                        struct hist_field       *var;
@@ -1078,7 +1090,7 @@ static struct synth_event *alloc_synth_event(const char *name, int n_fields,
 
 static void action_trace(struct hist_trigger_data *hist_data,
                         struct tracing_map_elt *elt, void *rec,
-                        struct ring_buffer_event *rbe,
+                        struct ring_buffer_event *rbe, void *key,
                         struct action_data *data, u64 *var_ref_vals)
 {
        struct synth_event *event = data->onmatch.synth_event;
@@ -1644,7 +1656,7 @@ find_match_var(struct hist_trigger_data *hist_data, char *var_name)
        for (i = 0; i < hist_data->n_actions; i++) {
                struct action_data *data = hist_data->actions[i];
 
-               if (data->fn == action_trace) {
+               if (data->handler == HANDLER_ONMATCH) {
                        char *system = data->onmatch.match_event_system;
                        char *event_name = data->onmatch.match_event;
 
@@ -2076,7 +2088,7 @@ static int hist_trigger_elt_data_alloc(struct tracing_map_elt *elt)
                }
        }
 
-       n_str = hist_data->n_field_var_str + hist_data->n_max_var_str;
+       n_str = hist_data->n_field_var_str + hist_data->n_save_var_str;
 
        size = STR_VAR_LEN_MAX;
 
@@ -3050,7 +3062,7 @@ create_field_var_hist(struct hist_trigger_data *target_hist_data,
        int ret;
 
        if (target_hist_data->n_field_var_hists >= SYNTH_FIELDS_MAX) {
-               hist_err_event("onmatch: Too many field variables defined: ",
+               hist_err_event("trace action: Too many field variables defined: ",
                               subsys_name, event_name, field_name);
                return ERR_PTR(-EINVAL);
        }
@@ -3058,7 +3070,7 @@ create_field_var_hist(struct hist_trigger_data *target_hist_data,
        file = event_file(tr, subsys_name, event_name);
 
        if (IS_ERR(file)) {
-               hist_err_event("onmatch: Event file not found: ",
+               hist_err_event("trace action: Event file not found: ",
                               subsys_name, event_name, field_name);
                ret = PTR_ERR(file);
                return ERR_PTR(ret);
@@ -3072,7 +3084,7 @@ create_field_var_hist(struct hist_trigger_data *target_hist_data,
         */
        hist_data = find_compatible_hist(target_hist_data, file);
        if (!hist_data) {
-               hist_err_event("onmatch: Matching event histogram not found: ",
+               hist_err_event("trace action: Matching event histogram not found: ",
                               subsys_name, event_name, field_name);
                return ERR_PTR(-EINVAL);
        }
@@ -3134,7 +3146,7 @@ create_field_var_hist(struct hist_trigger_data *target_hist_data,
                kfree(cmd);
                kfree(var_hist->cmd);
                kfree(var_hist);
-               hist_err_event("onmatch: Couldn't create histogram for field: ",
+               hist_err_event("trace action: Couldn't create histogram for field: ",
                               subsys_name, event_name, field_name);
                return ERR_PTR(ret);
        }
@@ -3147,7 +3159,7 @@ create_field_var_hist(struct hist_trigger_data *target_hist_data,
        if (IS_ERR_OR_NULL(event_var)) {
                kfree(var_hist->cmd);
                kfree(var_hist);
-               hist_err_event("onmatch: Couldn't find synthetic variable: ",
+               hist_err_event("trace action: Couldn't find synthetic variable: ",
                               subsys_name, event_name, field_name);
                return ERR_PTR(-EINVAL);
        }
@@ -3230,8 +3242,8 @@ static void update_max_vars(struct hist_trigger_data *hist_data,
                            struct ring_buffer_event *rbe,
                            void *rec)
 {
-       __update_field_vars(elt, rbe, rec, hist_data->max_vars,
-                           hist_data->n_max_vars, hist_data->n_field_var_str);
+       __update_field_vars(elt, rbe, rec, hist_data->save_vars,
+                           hist_data->n_save_vars, hist_data->n_field_var_str);
 }
 
 static struct hist_field *create_var(struct hist_trigger_data *hist_data,
@@ -3375,9 +3387,9 @@ static void onmax_print(struct seq_file *m,
 
        seq_printf(m, "\n\tmax: %10llu", tracing_map_read_var(elt, max_idx));
 
-       for (i = 0; i < hist_data->n_max_vars; i++) {
-               struct hist_field *save_val = hist_data->max_vars[i]->val;
-               struct hist_field *save_var = hist_data->max_vars[i]->var;
+       for (i = 0; i < hist_data->n_save_vars; i++) {
+               struct hist_field *save_val = hist_data->save_vars[i]->val;
+               struct hist_field *save_var = hist_data->save_vars[i]->var;
                u64 val;
 
                save_var_idx = save_var->var.idx;
@@ -3394,7 +3406,7 @@ static void onmax_print(struct seq_file *m,
 
 static void onmax_save(struct hist_trigger_data *hist_data,
                       struct tracing_map_elt *elt, void *rec,
-                      struct ring_buffer_event *rbe,
+                      struct ring_buffer_event *rbe, void *key,
                       struct action_data *data, u64 *var_ref_vals)
 {
        unsigned int max_idx = data->onmax.max_var->var.idx;
@@ -3421,7 +3433,7 @@ static void onmax_destroy(struct action_data *data)
        destroy_hist_field(data->onmax.var, 0);
 
        kfree(data->onmax.var_str);
-       kfree(data->onmax.fn_name);
+       kfree(data->action_name);
 
        for (i = 0; i < data->n_params; i++)
                kfree(data->params[i]);
@@ -3429,15 +3441,16 @@ static void onmax_destroy(struct action_data *data)
        kfree(data);
 }
 
+static int action_create(struct hist_trigger_data *hist_data,
+                        struct action_data *data);
+
 static int onmax_create(struct hist_trigger_data *hist_data,
                        struct action_data *data)
 {
+       struct hist_field *var_field, *ref_field, *max_var = NULL;
        struct trace_event_file *file = hist_data->event_file;
-       struct hist_field *var_field, *ref_field, *max_var;
        unsigned int var_ref_idx = hist_data->n_var_refs;
-       struct field_var *field_var;
-       char *onmax_var_str, *param;
-       unsigned int i;
+       char *onmax_var_str;
        int ret = 0;
 
        onmax_var_str = data->onmax.var_str;
@@ -3459,8 +3472,8 @@ static int onmax_create(struct hist_trigger_data *hist_data,
 
        data->onmax.var = ref_field;
 
-       data->fn = onmax_save;
        data->onmax.max_var_ref_idx = var_ref_idx;
+
        max_var = create_var(hist_data, file, "max", sizeof(u64), "u64");
        if (IS_ERR(max_var)) {
                hist_err("onmax: Couldn't create onmax variable: ", "max");
@@ -3469,27 +3482,7 @@ static int onmax_create(struct hist_trigger_data *hist_data,
        }
        data->onmax.max_var = max_var;
 
-       for (i = 0; i < data->n_params; i++) {
-               param = kstrdup(data->params[i], GFP_KERNEL);
-               if (!param) {
-                       ret = -ENOMEM;
-                       goto out;
-               }
-
-               field_var = create_target_field_var(hist_data, NULL, NULL, param);
-               if (IS_ERR(field_var)) {
-                       hist_err("onmax: Couldn't create field variable: ", param);
-                       ret = PTR_ERR(field_var);
-                       kfree(param);
-                       goto out;
-               }
-
-               hist_data->max_vars[hist_data->n_max_vars++] = field_var;
-               if (field_var->val->flags & HIST_FIELD_FL_STRING)
-                       hist_data->n_max_var_str++;
-
-               kfree(param);
-       }
+       ret = action_create(hist_data, data);
  out:
        return ret;
 }
@@ -3500,11 +3493,14 @@ static int parse_action_params(char *params, struct action_data *data)
        int ret = 0;
 
        while (params) {
-               if (data->n_params >= SYNTH_FIELDS_MAX)
+               if (data->n_params >= SYNTH_FIELDS_MAX) {
+                       hist_err("Too many action params", "");
                        goto out;
+               }
 
                param = strsep(&params, ",");
                if (!param) {
+                       hist_err("No action param found", "");
                        ret = -EINVAL;
                        goto out;
                }
@@ -3528,10 +3524,71 @@ static int parse_action_params(char *params, struct action_data *data)
        return ret;
 }
 
-static struct action_data *onmax_parse(char *str)
+static int action_parse(char *str, struct action_data *data,
+                       enum handler_id handler)
+{
+       char *action_name;
+       int ret = 0;
+
+       strsep(&str, ".");
+       if (!str) {
+               hist_err("action parsing: No action found", "");
+               ret = -EINVAL;
+               goto out;
+       }
+
+       action_name = strsep(&str, "(");
+       if (!action_name || !str) {
+               hist_err("action parsing: No action found", "");
+               ret = -EINVAL;
+               goto out;
+       }
+
+       if (str_has_prefix(action_name, "save")) {
+               char *params = strsep(&str, ")");
+
+               if (!params) {
+                       hist_err("action parsing: No params found for %s", "save");
+                       ret = -EINVAL;
+                       goto out;
+               }
+
+               ret = parse_action_params(params, data);
+               if (ret)
+                       goto out;
+
+               if (handler == HANDLER_ONMAX)
+                       data->fn = onmax_save;
+
+               data->action = ACTION_SAVE;
+       } else {
+               char *params = strsep(&str, ")");
+
+               if (params) {
+                       ret = parse_action_params(params, data);
+                       if (ret)
+                               goto out;
+               }
+
+               data->fn = action_trace;
+               data->action = ACTION_TRACE;
+       }
+
+       data->action_name = kstrdup(action_name, GFP_KERNEL);
+       if (!data->action_name) {
+               ret = -ENOMEM;
+               goto out;
+       }
+
+       data->handler = handler;
+ out:
+       return ret;
+}
+
+static struct action_data *onmax_parse(char *str, enum handler_id handler)
 {
-       char *onmax_fn_name, *onmax_var_str;
        struct action_data *data;
+       char *onmax_var_str;
        int ret = -EINVAL;
 
        data = kzalloc(sizeof(*data), GFP_KERNEL);
@@ -3550,33 +3607,9 @@ static struct action_data *onmax_parse(char *str)
                goto free;
        }
 
-       strsep(&str, ".");
-       if (!str)
-               goto free;
-
-       onmax_fn_name = strsep(&str, "(");
-       if (!onmax_fn_name || !str)
-               goto free;
-
-       if (str_has_prefix(onmax_fn_name, "save")) {
-               char *params = strsep(&str, ")");
-
-               if (!params) {
-                       ret = -EINVAL;
-                       goto free;
-               }
-
-               ret = parse_action_params(params, data);
-               if (ret)
-                       goto free;
-       } else
-               goto free;
-
-       data->onmax.fn_name = kstrdup(onmax_fn_name, GFP_KERNEL);
-       if (!data->onmax.fn_name) {
-               ret = -ENOMEM;
+       ret = action_parse(str, data, handler);
+       if (ret)
                goto free;
-       }
  out:
        return data;
  free:
@@ -3593,7 +3626,7 @@ static void onmatch_destroy(struct action_data *data)
 
        kfree(data->onmatch.match_event);
        kfree(data->onmatch.match_event_system);
-       kfree(data->onmatch.synth_event_name);
+       kfree(data->action_name);
 
        for (i = 0; i < data->n_params; i++)
                kfree(data->params[i]);
@@ -3651,8 +3684,9 @@ static int check_synth_field(struct synth_event *event,
 }
 
 static struct hist_field *
-onmatch_find_var(struct hist_trigger_data *hist_data, struct action_data *data,
-                char *system, char *event, char *var)
+trace_action_find_var(struct hist_trigger_data *hist_data,
+                     struct action_data *data,
+                     char *system, char *event, char *var)
 {
        struct hist_field *hist_field;
 
@@ -3660,7 +3694,7 @@ onmatch_find_var(struct hist_trigger_data *hist_data, struct action_data *data,
 
        hist_field = find_target_event_var(hist_data, system, event, var);
        if (!hist_field) {
-               if (!system) {
+               if (!system && data->handler == HANDLER_ONMATCH) {
                        system = data->onmatch.match_event_system;
                        event = data->onmatch.match_event;
                }
@@ -3669,15 +3703,15 @@ onmatch_find_var(struct hist_trigger_data *hist_data, struct action_data *data,
        }
 
        if (!hist_field)
-               hist_err_event("onmatch: Couldn't find onmatch param: $", system, event, var);
+               hist_err_event("trace action: Couldn't find param: $", system, event, var);
 
        return hist_field;
 }
 
 static struct hist_field *
-onmatch_create_field_var(struct hist_trigger_data *hist_data,
-                        struct action_data *data, char *system,
-                        char *event, char *var)
+trace_action_create_field_var(struct hist_trigger_data *hist_data,
+                             struct action_data *data, char *system,
+                             char *event, char *var)
 {
        struct hist_field *hist_field = NULL;
        struct field_var *field_var;
@@ -3700,7 +3734,7 @@ onmatch_create_field_var(struct hist_trigger_data *hist_data,
                 * looking for fields on the onmatch(system.event.xxx)
                 * event.
                 */
-               if (!system) {
+               if (!system && data->handler == HANDLER_ONMATCH) {
                        system = data->onmatch.match_event_system;
                        event = data->onmatch.match_event;
                }
@@ -3724,9 +3758,8 @@ onmatch_create_field_var(struct hist_trigger_data *hist_data,
        goto out;
 }
 
-static int onmatch_create(struct hist_trigger_data *hist_data,
-                         struct trace_event_file *file,
-                         struct action_data *data)
+static int trace_action_create(struct hist_trigger_data *hist_data,
+                              struct action_data *data)
 {
        char *event_name, *param, *system = NULL;
        struct hist_field *hist_field, *var_ref;
@@ -3737,11 +3770,12 @@ static int onmatch_create(struct hist_trigger_data *hist_data,
 
        lockdep_assert_held(&event_mutex);
 
-       event = find_synth_event(data->onmatch.synth_event_name);
+       event = find_synth_event(data->action_name);
        if (!event) {
-               hist_err("onmatch: Couldn't find synthetic event: ", data->onmatch.synth_event_name);
+               hist_err("trace action: Couldn't find synthetic event: ", data->action_name);
                return -EINVAL;
        }
+
        event->ref++;
 
        var_ref_idx = hist_data->n_var_refs;
@@ -3769,13 +3803,15 @@ static int onmatch_create(struct hist_trigger_data *hist_data,
                }
 
                if (param[0] == '$')
-                       hist_field = onmatch_find_var(hist_data, data, system,
-                                                     event_name, param);
+                       hist_field = trace_action_find_var(hist_data, data,
+                                                          system, event_name,
+                                                          param);
                else
-                       hist_field = onmatch_create_field_var(hist_data, data,
-                                                             system,
-                                                             event_name,
-                                                             param);
+                       hist_field = trace_action_create_field_var(hist_data,
+                                                                  data,
+                                                                  system,
+                                                                  event_name,
+                                                                  param);
 
                if (!hist_field) {
                        kfree(p);
@@ -3797,7 +3833,7 @@ static int onmatch_create(struct hist_trigger_data *hist_data,
                        continue;
                }
 
-               hist_err_event("onmatch: Param type doesn't match synthetic event field type: ",
+               hist_err_event("trace action: Param type doesn't match synthetic event field type: ",
                               system, event_name, param);
                kfree(p);
                ret = -EINVAL;
@@ -3805,12 +3841,11 @@ static int onmatch_create(struct hist_trigger_data *hist_data,
        }
 
        if (field_pos != event->n_fields) {
-               hist_err("onmatch: Param count doesn't match synthetic event field count: ", event->name);
+               hist_err("trace action: Param count doesn't match synthetic event field count: ", event->name);
                ret = -EINVAL;
                goto err;
        }
 
-       data->fn = action_trace;
        data->onmatch.synth_event = event;
        data->onmatch.var_ref_idx = var_ref_idx;
  out:
@@ -3821,10 +3856,58 @@ static int onmatch_create(struct hist_trigger_data *hist_data,
        goto out;
 }
 
+static int action_create(struct hist_trigger_data *hist_data,
+                        struct action_data *data)
+{
+       struct field_var *field_var;
+       unsigned int i;
+       char *param;
+       int ret = 0;
+
+       if (data->action == ACTION_TRACE)
+               return trace_action_create(hist_data, data);
+
+       if (data->action == ACTION_SAVE) {
+               if (hist_data->n_save_vars) {
+                       ret = -EEXIST;
+                       hist_err("save action: Can't have more than one save() action per hist", "");
+                       goto out;
+               }
+
+               for (i = 0; i < data->n_params; i++) {
+                       param = kstrdup(data->params[i], GFP_KERNEL);
+                       if (!param) {
+                               ret = -ENOMEM;
+                               goto out;
+                       }
+
+                       field_var = create_target_field_var(hist_data, NULL, NULL, param);
+                       if (IS_ERR(field_var)) {
+                               hist_err("save action: Couldn't create field variable: ", param);
+                               ret = PTR_ERR(field_var);
+                               kfree(param);
+                               goto out;
+                       }
+
+                       hist_data->save_vars[hist_data->n_save_vars++] = field_var;
+                       if (field_var->val->flags & HIST_FIELD_FL_STRING)
+                               hist_data->n_save_var_str++;
+                       kfree(param);
+               }
+       }
+ out:
+       return ret;
+}
+
+static int onmatch_create(struct hist_trigger_data *hist_data,
+                         struct action_data *data)
+{
+       return action_create(hist_data, data);
+}
+
 static struct action_data *onmatch_parse(struct trace_array *tr, char *str)
 {
        char *match_event, *match_event_system;
-       char *synth_event_name, *params;
        struct action_data *data;
        int ret = -EINVAL;
 
@@ -3862,31 +3945,7 @@ static struct action_data *onmatch_parse(struct trace_array *tr, char *str)
                goto free;
        }
 
-       strsep(&str, ".");
-       if (!str) {
-               hist_err("onmatch: Missing . after onmatch(): ", str);
-               goto free;
-       }
-
-       synth_event_name = strsep(&str, "(");
-       if (!synth_event_name || !str) {
-               hist_err("onmatch: Missing opening paramlist paren: ", synth_event_name);
-               goto free;
-       }
-
-       data->onmatch.synth_event_name = kstrdup(synth_event_name, GFP_KERNEL);
-       if (!data->onmatch.synth_event_name) {
-               ret = -ENOMEM;
-               goto free;
-       }
-
-       params = strsep(&str, ")");
-       if (!params || !str || (str && strlen(str))) {
-               hist_err("onmatch: Missing closing paramlist paren: ", params);
-               goto free;
-       }
-
-       ret = parse_action_params(params, data);
+       ret = action_parse(str, data, HANDLER_ONMATCH);
        if (ret)
                goto free;
  out:
@@ -4326,9 +4385,9 @@ static void destroy_actions(struct hist_trigger_data *hist_data)
        for (i = 0; i < hist_data->n_actions; i++) {
                struct action_data *data = hist_data->actions[i];
 
-               if (data->fn == action_trace)
+               if (data->handler == HANDLER_ONMATCH)
                        onmatch_destroy(data);
-               else if (data->fn == onmax_save)
+               else if (data->handler == HANDLER_ONMAX)
                        onmax_destroy(data);
                else
                        kfree(data);
@@ -4355,16 +4414,14 @@ static int parse_actions(struct hist_trigger_data *hist_data)
                                ret = PTR_ERR(data);
                                break;
                        }
-                       data->fn = action_trace;
                } else if ((len = str_has_prefix(str, "onmax("))) {
                        char *action_str = str + len;
 
-                       data = onmax_parse(action_str);
+                       data = onmax_parse(action_str, HANDLER_ONMAX);
                        if (IS_ERR(data)) {
                                ret = PTR_ERR(data);
                                break;
                        }
-                       data->fn = onmax_save;
                } else {
                        ret = -EINVAL;
                        break;
@@ -4376,8 +4433,7 @@ static int parse_actions(struct hist_trigger_data *hist_data)
        return ret;
 }
 
-static int create_actions(struct hist_trigger_data *hist_data,
-                         struct trace_event_file *file)
+static int create_actions(struct hist_trigger_data *hist_data)
 {
        struct action_data *data;
        unsigned int i;
@@ -4386,14 +4442,17 @@ static int create_actions(struct hist_trigger_data *hist_data,
        for (i = 0; i < hist_data->attrs->n_actions; i++) {
                data = hist_data->actions[i];
 
-               if (data->fn == action_trace) {
-                       ret = onmatch_create(hist_data, file, data);
+               if (data->handler == HANDLER_ONMATCH) {
+                       ret = onmatch_create(hist_data, data);
                        if (ret)
-                               return ret;
-               } else if (data->fn == onmax_save) {
+                               break;
+               } else if (data->handler == HANDLER_ONMAX) {
                        ret = onmax_create(hist_data, data);
                        if (ret)
-                               return ret;
+                               break;
+               } else {
+                       ret = -EINVAL;
+                       break;
                }
        }
 
@@ -4409,26 +4468,42 @@ static void print_actions(struct seq_file *m,
        for (i = 0; i < hist_data->n_actions; i++) {
                struct action_data *data = hist_data->actions[i];
 
-               if (data->fn == onmax_save)
+               if (data->handler == HANDLER_ONMAX)
                        onmax_print(m, hist_data, elt, data);
        }
 }
 
+static void print_action_spec(struct seq_file *m,
+                             struct hist_trigger_data *hist_data,
+                             struct action_data *data)
+{
+       unsigned int i;
+
+       if (data->action == ACTION_SAVE) {
+               for (i = 0; i < hist_data->n_save_vars; i++) {
+                       seq_printf(m, "%s", hist_data->save_vars[i]->var->var.name);
+                       if (i < hist_data->n_save_vars - 1)
+                               seq_puts(m, ",");
+               }
+       } else if (data->action == ACTION_TRACE) {
+               for (i = 0; i < data->n_params; i++) {
+                       if (i)
+                               seq_puts(m, ",");
+                       seq_printf(m, "%s", data->params[i]);
+               }
+       }
+}
+
 static void print_onmax_spec(struct seq_file *m,
                             struct hist_trigger_data *hist_data,
                             struct action_data *data)
 {
-       unsigned int i;
-
        seq_puts(m, ":onmax(");
        seq_printf(m, "%s", data->onmax.var_str);
-       seq_printf(m, ").%s(", data->onmax.fn_name);
+       seq_printf(m, ").%s(", data->action_name);
+
+       print_action_spec(m, hist_data, data);
 
-       for (i = 0; i < hist_data->n_max_vars; i++) {
-               seq_printf(m, "%s", hist_data->max_vars[i]->var->var.name);
-               if (i < hist_data->n_max_vars - 1)
-                       seq_puts(m, ",");
-       }
        seq_puts(m, ")");
 }
 
@@ -4436,18 +4511,12 @@ static void print_onmatch_spec(struct seq_file *m,
                               struct hist_trigger_data *hist_data,
                               struct action_data *data)
 {
-       unsigned int i;
-
        seq_printf(m, ":onmatch(%s.%s).", data->onmatch.match_event_system,
                   data->onmatch.match_event);
 
-       seq_printf(m, "%s(", data->onmatch.synth_event->name);
+       seq_printf(m, "%s(", data->action_name);
 
-       for (i = 0; i < data->n_params; i++) {
-               if (i)
-                       seq_puts(m, ",");
-               seq_printf(m, "%s", data->params[i]);
-       }
+       print_action_spec(m, hist_data, data);
 
        seq_puts(m, ")");
 }
@@ -4464,7 +4533,9 @@ static bool actions_match(struct hist_trigger_data *hist_data,
                struct action_data *data = hist_data->actions[i];
                struct action_data *data_test = hist_data_test->actions[i];
 
-               if (data->fn != data_test->fn)
+               if (data->handler != data_test->handler)
+                       return false;
+               if (data->action != data_test->action)
                        return false;
 
                if (data->n_params != data_test->n_params)
@@ -4475,23 +4546,20 @@ static bool actions_match(struct hist_trigger_data *hist_data,
                                return false;
                }
 
-               if (data->fn == action_trace) {
-                       if (strcmp(data->onmatch.synth_event_name,
-                                  data_test->onmatch.synth_event_name) != 0)
-                               return false;
+               if (strcmp(data->action_name, data_test->action_name) != 0)
+                       return false;
+
+               if (data->handler == HANDLER_ONMATCH) {
                        if (strcmp(data->onmatch.match_event_system,
                                   data_test->onmatch.match_event_system) != 0)
                                return false;
                        if (strcmp(data->onmatch.match_event,
                                   data_test->onmatch.match_event) != 0)
                                return false;
-               } else if (data->fn == onmax_save) {
+               } else if (data->handler == HANDLER_ONMAX) {
                        if (strcmp(data->onmax.var_str,
                                   data_test->onmax.var_str) != 0)
                                return false;
-                       if (strcmp(data->onmax.fn_name,
-                                  data_test->onmax.fn_name) != 0)
-                               return false;
                }
        }
 
@@ -4507,9 +4575,9 @@ static void print_actions_spec(struct seq_file *m,
        for (i = 0; i < hist_data->n_actions; i++) {
                struct action_data *data = hist_data->actions[i];
 
-               if (data->fn == action_trace)
+               if (data->handler == HANDLER_ONMATCH)
                        print_onmatch_spec(m, hist_data, data);
-               else if (data->fn == onmax_save)
+               else if (data->handler == HANDLER_ONMAX)
                        print_onmax_spec(m, hist_data, data);
        }
 }
@@ -4703,14 +4771,15 @@ static inline void add_to_key(char *compound_key, void *key,
 static void
 hist_trigger_actions(struct hist_trigger_data *hist_data,
                     struct tracing_map_elt *elt, void *rec,
-                    struct ring_buffer_event *rbe, u64 *var_ref_vals)
+                    struct ring_buffer_event *rbe, void *key,
+                    u64 *var_ref_vals)
 {
        struct action_data *data;
        unsigned int i;
 
        for (i = 0; i < hist_data->n_actions; i++) {
                data = hist_data->actions[i];
-               data->fn(hist_data, elt, rec, rbe, data, var_ref_vals);
+               data->fn(hist_data, elt, rec, rbe, key, data, var_ref_vals);
        }
 }
 
@@ -4771,7 +4840,7 @@ static void event_hist_trigger(struct event_trigger_data *data, void *rec,
        hist_trigger_elt_update(hist_data, elt, rec, rbe, var_ref_vals);
 
        if (resolve_var_refs(hist_data, key, var_ref_vals, true))
-               hist_trigger_actions(hist_data, elt, rec, rbe, var_ref_vals);
+               hist_trigger_actions(hist_data, elt, rec, rbe, key, var_ref_vals);
 }
 
 static void hist_trigger_stacktrace_print(struct seq_file *m,
@@ -5683,7 +5752,7 @@ static int event_hist_trigger_func(struct event_command *cmd_ops,
        if (has_hist_vars(hist_data))
                save_hist_vars(hist_data);
 
-       ret = create_actions(hist_data, file);
+       ret = create_actions(hist_data);
        if (ret)
                goto out_unreg;