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Diffstat (limited to 'kernel/trace/trace_events_hist.c')
| -rw-r--r-- | kernel/trace/trace_events_hist.c | 6017 |
1 files changed, 6017 insertions, 0 deletions
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c new file mode 100644 index 000000000..059a106e6 --- /dev/null +++ b/kernel/trace/trace_events_hist.c @@ -0,0 +1,6017 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * trace_events_hist - trace event hist triggers + * + * Copyright (C) 2015 Tom Zanussi <tom.zanussi@linux.intel.com> + */ + +#include <linux/module.h> +#include <linux/kallsyms.h> +#include <linux/security.h> +#include <linux/mutex.h> +#include <linux/slab.h> +#include <linux/stacktrace.h> +#include <linux/rculist.h> +#include <linux/tracefs.h> + +/* for gfp flag names */ +#include <linux/trace_events.h> +#include <trace/events/mmflags.h> + +#include "tracing_map.h" +#include "trace_synth.h" + +#define ERRORS \ + C(NONE, "No error"), \ + C(DUPLICATE_VAR, "Variable already defined"), \ + C(VAR_NOT_UNIQUE, "Variable name not unique, need to use fully qualified name (subsys.event.var) for variable"), \ + C(TOO_MANY_VARS, "Too many variables defined"), \ + C(MALFORMED_ASSIGNMENT, "Malformed assignment"), \ + C(NAMED_MISMATCH, "Named hist trigger doesn't match existing named trigger (includes variables)"), \ + C(TRIGGER_EEXIST, "Hist trigger already exists"), \ + C(TRIGGER_ENOENT_CLEAR, "Can't clear or continue a nonexistent hist trigger"), \ + C(SET_CLOCK_FAIL, "Couldn't set trace_clock"), \ + C(BAD_FIELD_MODIFIER, "Invalid field modifier"), \ + C(TOO_MANY_SUBEXPR, "Too many subexpressions (3 max)"), \ + C(TIMESTAMP_MISMATCH, "Timestamp units in expression don't match"), \ + C(TOO_MANY_FIELD_VARS, "Too many field variables defined"), \ + C(EVENT_FILE_NOT_FOUND, "Event file not found"), \ + C(HIST_NOT_FOUND, "Matching event histogram not found"), \ + C(HIST_CREATE_FAIL, "Couldn't create histogram for field"), \ + C(SYNTH_VAR_NOT_FOUND, "Couldn't find synthetic variable"), \ + C(SYNTH_EVENT_NOT_FOUND,"Couldn't find synthetic event"), \ + C(SYNTH_TYPE_MISMATCH, "Param type doesn't match synthetic event field type"), \ + C(SYNTH_COUNT_MISMATCH, "Param count doesn't match synthetic event field count"), \ + C(FIELD_VAR_PARSE_FAIL, "Couldn't parse field variable"), \ + C(VAR_CREATE_FIND_FAIL, "Couldn't create or find variable"), \ + C(ONX_NOT_VAR, "For onmax(x) or onchange(x), x must be a variable"), \ + C(ONX_VAR_NOT_FOUND, "Couldn't find onmax or onchange variable"), \ + C(ONX_VAR_CREATE_FAIL, "Couldn't create onmax or onchange variable"), \ + C(FIELD_VAR_CREATE_FAIL,"Couldn't create field variable"), \ + C(TOO_MANY_PARAMS, "Too many action params"), \ + C(PARAM_NOT_FOUND, "Couldn't find param"), \ + C(INVALID_PARAM, "Invalid action param"), \ + C(ACTION_NOT_FOUND, "No action found"), \ + C(NO_SAVE_PARAMS, "No params found for save()"), \ + C(TOO_MANY_SAVE_ACTIONS,"Can't have more than one save() action per hist"), \ + C(ACTION_MISMATCH, "Handler doesn't support action"), \ + C(NO_CLOSING_PAREN, "No closing paren found"), \ + C(SUBSYS_NOT_FOUND, "Missing subsystem"), \ + C(INVALID_SUBSYS_EVENT, "Invalid subsystem or event name"), \ + C(INVALID_REF_KEY, "Using variable references in keys not supported"), \ + C(VAR_NOT_FOUND, "Couldn't find variable"), \ + C(FIELD_NOT_FOUND, "Couldn't find field"), \ + C(EMPTY_ASSIGNMENT, "Empty assignment"), \ + C(INVALID_SORT_MODIFIER,"Invalid sort modifier"), \ + C(EMPTY_SORT_FIELD, "Empty sort field"), \ + C(TOO_MANY_SORT_FIELDS, "Too many sort fields (Max = 2)"), \ + C(INVALID_SORT_FIELD, "Sort field must be a key or a val"), \ + C(INVALID_STR_OPERAND, "String type can not be an operand in expression"), + +#undef C +#define C(a, b) HIST_ERR_##a + +enum { ERRORS }; + +#undef C +#define C(a, b) b + +static const char *err_text[] = { ERRORS }; + +struct hist_field; + +typedef u64 (*hist_field_fn_t) (struct hist_field *field, + struct tracing_map_elt *elt, + struct ring_buffer_event *rbe, + void *event); + +#define HIST_FIELD_OPERANDS_MAX 2 +#define HIST_FIELDS_MAX (TRACING_MAP_FIELDS_MAX + TRACING_MAP_VARS_MAX) +#define HIST_ACTIONS_MAX 8 + +enum field_op_id { + FIELD_OP_NONE, + FIELD_OP_PLUS, + FIELD_OP_MINUS, + FIELD_OP_UNARY_MINUS, +}; + +/* + * A hist_var (histogram variable) contains variable information for + * hist_fields having the HIST_FIELD_FL_VAR or HIST_FIELD_FL_VAR_REF + * flag set. A hist_var has a variable name e.g. ts0, and is + * associated with a given histogram trigger, as specified by + * hist_data. The hist_var idx is the unique index assigned to the + * variable by the hist trigger's tracing_map. The idx is what is + * used to set a variable's value and, by a variable reference, to + * retrieve it. + */ +struct hist_var { + char *name; + struct hist_trigger_data *hist_data; + unsigned int idx; +}; + +struct hist_field { + struct ftrace_event_field *field; + unsigned long flags; + hist_field_fn_t fn; + unsigned int ref; + unsigned int size; + unsigned int offset; + unsigned int is_signed; + const char *type; + struct hist_field *operands[HIST_FIELD_OPERANDS_MAX]; + struct hist_trigger_data *hist_data; + + /* + * Variable fields contain variable-specific info in var. + */ + struct hist_var var; + enum field_op_id operator; + char *system; + char *event_name; + + /* + * The name field is used for EXPR and VAR_REF fields. VAR + * fields contain the variable name in var.name. + */ + char *name; + + /* + * When a histogram trigger is hit, if it has any references + * to variables, the values of those variables are collected + * into a var_ref_vals array by resolve_var_refs(). The + * current value of each variable is read from the tracing_map + * using the hist field's hist_var.idx and entered into the + * var_ref_idx entry i.e. var_ref_vals[var_ref_idx]. + */ + unsigned int var_ref_idx; + bool read_once; + + unsigned int var_str_idx; +}; + +static u64 hist_field_none(struct hist_field *field, + struct tracing_map_elt *elt, + struct ring_buffer_event *rbe, + void *event) +{ + return 0; +} + +static u64 hist_field_counter(struct hist_field *field, + struct tracing_map_elt *elt, + struct ring_buffer_event *rbe, + void *event) +{ + return 1; +} + +static u64 hist_field_string(struct hist_field *hist_field, + struct tracing_map_elt *elt, + struct ring_buffer_event *rbe, + void *event) +{ + char *addr = (char *)(event + hist_field->field->offset); + + return (u64)(unsigned long)addr; +} + +static u64 hist_field_dynstring(struct hist_field *hist_field, + struct tracing_map_elt *elt, + struct ring_buffer_event *rbe, + void *event) +{ + u32 str_item = *(u32 *)(event + hist_field->field->offset); + int str_loc = str_item & 0xffff; + char *addr = (char *)(event + str_loc); + + return (u64)(unsigned long)addr; +} + +static u64 hist_field_pstring(struct hist_field *hist_field, + struct tracing_map_elt *elt, + struct ring_buffer_event *rbe, + void *event) +{ + char **addr = (char **)(event + hist_field->field->offset); + + return (u64)(unsigned long)*addr; +} + +static u64 hist_field_log2(struct hist_field *hist_field, + struct tracing_map_elt *elt, + struct ring_buffer_event *rbe, + void *event) +{ + struct hist_field *operand = hist_field->operands[0]; + + u64 val = operand->fn(operand, elt, rbe, event); + + return (u64) ilog2(roundup_pow_of_two(val)); +} + +static u64 hist_field_plus(struct hist_field *hist_field, + struct tracing_map_elt *elt, + struct ring_buffer_event *rbe, + void *event) +{ + struct hist_field *operand1 = hist_field->operands[0]; + struct hist_field *operand2 = hist_field->operands[1]; + + u64 val1 = operand1->fn(operand1, elt, rbe, event); + u64 val2 = operand2->fn(operand2, elt, rbe, event); + + return val1 + val2; +} + +static u64 hist_field_minus(struct hist_field *hist_field, + struct tracing_map_elt *elt, + struct ring_buffer_event *rbe, + void *event) +{ + struct hist_field *operand1 = hist_field->operands[0]; + struct hist_field *operand2 = hist_field->operands[1]; + + u64 val1 = operand1->fn(operand1, elt, rbe, event); + u64 val2 = operand2->fn(operand2, elt, rbe, event); + + return val1 - val2; +} + +static u64 hist_field_unary_minus(struct hist_field *hist_field, + struct tracing_map_elt *elt, + struct ring_buffer_event *rbe, + void *event) +{ + struct hist_field *operand = hist_field->operands[0]; + + s64 sval = (s64)operand->fn(operand, elt, rbe, event); + u64 val = (u64)-sval; + + return val; +} + +#define DEFINE_HIST_FIELD_FN(type) \ + static u64 hist_field_##type(struct hist_field *hist_field, \ + struct tracing_map_elt *elt, \ + struct ring_buffer_event *rbe, \ + void *event) \ +{ \ + type *addr = (type *)(event + hist_field->field->offset); \ + \ + return (u64)(unsigned long)*addr; \ +} + +DEFINE_HIST_FIELD_FN(s64); +DEFINE_HIST_FIELD_FN(u64); +DEFINE_HIST_FIELD_FN(s32); +DEFINE_HIST_FIELD_FN(u32); +DEFINE_HIST_FIELD_FN(s16); +DEFINE_HIST_FIELD_FN(u16); +DEFINE_HIST_FIELD_FN(s8); +DEFINE_HIST_FIELD_FN(u8); + +#define for_each_hist_field(i, hist_data) \ + for ((i) = 0; (i) < (hist_data)->n_fields; (i)++) + +#define for_each_hist_val_field(i, hist_data) \ + for ((i) = 0; (i) < (hist_data)->n_vals; (i)++) + +#define for_each_hist_key_field(i, hist_data) \ + for ((i) = (hist_data)->n_vals; (i) < (hist_data)->n_fields; (i)++) + +#define HIST_STACKTRACE_DEPTH 16 +#define HIST_STACKTRACE_SIZE (HIST_STACKTRACE_DEPTH * sizeof(unsigned long)) +#define HIST_STACKTRACE_SKIP 5 + +#define HITCOUNT_IDX 0 +#define HIST_KEY_SIZE_MAX (MAX_FILTER_STR_VAL + HIST_STACKTRACE_SIZE) + +enum hist_field_flags { + HIST_FIELD_FL_HITCOUNT = 1 << 0, + HIST_FIELD_FL_KEY = 1 << 1, + HIST_FIELD_FL_STRING = 1 << 2, + HIST_FIELD_FL_HEX = 1 << 3, + HIST_FIELD_FL_SYM = 1 << 4, + HIST_FIELD_FL_SYM_OFFSET = 1 << 5, + HIST_FIELD_FL_EXECNAME = 1 << 6, + HIST_FIELD_FL_SYSCALL = 1 << 7, + HIST_FIELD_FL_STACKTRACE = 1 << 8, + HIST_FIELD_FL_LOG2 = 1 << 9, + HIST_FIELD_FL_TIMESTAMP = 1 << 10, + HIST_FIELD_FL_TIMESTAMP_USECS = 1 << 11, + HIST_FIELD_FL_VAR = 1 << 12, + HIST_FIELD_FL_EXPR = 1 << 13, + HIST_FIELD_FL_VAR_REF = 1 << 14, + HIST_FIELD_FL_CPU = 1 << 15, + HIST_FIELD_FL_ALIAS = 1 << 16, +}; + +struct var_defs { + unsigned int n_vars; + char *name[TRACING_MAP_VARS_MAX]; + char *expr[TRACING_MAP_VARS_MAX]; +}; + +struct hist_trigger_attrs { + char *keys_str; + char *vals_str; + char *sort_key_str; + char *name; + char *clock; + bool pause; + bool cont; + bool clear; + bool ts_in_usecs; + unsigned int map_bits; + + char *assignment_str[TRACING_MAP_VARS_MAX]; + unsigned int n_assignments; + + char *action_str[HIST_ACTIONS_MAX]; + unsigned int n_actions; + + struct var_defs var_defs; +}; + +struct field_var { + struct hist_field *var; + struct hist_field *val; +}; + +struct field_var_hist { + struct hist_trigger_data *hist_data; + char *cmd; +}; + +struct hist_trigger_data { + struct hist_field *fields[HIST_FIELDS_MAX]; + unsigned int n_vals; + unsigned int n_keys; + unsigned int n_fields; + unsigned int n_vars; + unsigned int n_var_str; + unsigned int key_size; + struct tracing_map_sort_key sort_keys[TRACING_MAP_SORT_KEYS_MAX]; + unsigned int n_sort_keys; + struct trace_event_file *event_file; + struct hist_trigger_attrs *attrs; + struct tracing_map *map; + bool enable_timestamps; + bool remove; + struct hist_field *var_refs[TRACING_MAP_VARS_MAX]; + unsigned int n_var_refs; + + struct action_data *actions[HIST_ACTIONS_MAX]; + unsigned int n_actions; + + struct field_var *field_vars[SYNTH_FIELDS_MAX]; + unsigned int n_field_vars; + unsigned int n_field_var_str; + struct field_var_hist *field_var_hists[SYNTH_FIELDS_MAX]; + unsigned int n_field_var_hists; + + struct field_var *save_vars[SYNTH_FIELDS_MAX]; + unsigned int n_save_vars; + unsigned int n_save_var_str; +}; + +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, void *key, + struct action_data *data, u64 *var_ref_vals); + +typedef bool (*check_track_val_fn_t) (u64 track_val, u64 var_val); + +enum handler_id { + HANDLER_ONMATCH = 1, + HANDLER_ONMAX, + HANDLER_ONCHANGE, +}; + +enum action_id { + ACTION_SAVE = 1, + ACTION_TRACE, + ACTION_SNAPSHOT, +}; + +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]; + + /* + * When a histogram trigger is hit, the values of any + * references to variables, including variables being passed + * as parameters to synthetic events, are collected into a + * var_ref_vals array. This var_ref_idx array is an array of + * indices into the var_ref_vals array, one for each synthetic + * event param, and is passed to the synthetic event + * invocation. + */ + unsigned int var_ref_idx[SYNTH_FIELDS_MAX]; + struct synth_event *synth_event; + bool use_trace_keyword; + char *synth_event_name; + + union { + struct { + char *event; + char *event_system; + } match_data; + + struct { + /* + * var_str contains the $-unstripped variable + * name referenced by var_ref, and used when + * printing the action. Because var_ref + * creation is deferred to create_actions(), + * we need a per-action way to save it until + * then, thus var_str. + */ + char *var_str; + + /* + * var_ref refers to the variable being + * tracked e.g onmax($var). + */ + struct hist_field *var_ref; + + /* + * track_var contains the 'invisible' tracking + * variable created to keep the current + * e.g. max value. + */ + struct hist_field *track_var; + + check_track_val_fn_t check_val; + action_fn_t save_data; + } track_data; + }; +}; + +struct track_data { + u64 track_val; + bool updated; + + unsigned int key_len; + void *key; + struct tracing_map_elt elt; + + struct action_data *action_data; + struct hist_trigger_data *hist_data; +}; + +struct hist_elt_data { + char *comm; + u64 *var_ref_vals; + char *field_var_str[SYNTH_FIELDS_MAX]; +}; + +struct snapshot_context { + struct tracing_map_elt *elt; + void *key; +}; + +static void track_data_free(struct track_data *track_data) +{ + struct hist_elt_data *elt_data; + + if (!track_data) + return; + + kfree(track_data->key); + + elt_data = track_data->elt.private_data; + if (elt_data) { + kfree(elt_data->comm); + kfree(elt_data); + } + + kfree(track_data); +} + +static struct track_data *track_data_alloc(unsigned int key_len, + struct action_data *action_data, + struct hist_trigger_data *hist_data) +{ + struct track_data *data = kzalloc(sizeof(*data), GFP_KERNEL); + struct hist_elt_data *elt_data; + + if (!data) + return ERR_PTR(-ENOMEM); + + data->key = kzalloc(key_len, GFP_KERNEL); + if (!data->key) { + track_data_free(data); + return ERR_PTR(-ENOMEM); + } + + data->key_len = key_len; + data->action_data = action_data; + data->hist_data = hist_data; + + elt_data = kzalloc(sizeof(*elt_data), GFP_KERNEL); + if (!elt_data) { + track_data_free(data); + return ERR_PTR(-ENOMEM); + } + + data->elt.private_data = elt_data; + + elt_data->comm = kzalloc(TASK_COMM_LEN, GFP_KERNEL); + if (!elt_data->comm) { + track_data_free(data); + return ERR_PTR(-ENOMEM); + } + + return data; +} + +static char last_cmd[MAX_FILTER_STR_VAL]; +static char last_cmd_loc[MAX_FILTER_STR_VAL]; + +static int errpos(char *str) +{ + return err_pos(last_cmd, str); +} + +static void last_cmd_set(struct trace_event_file *file, char *str) +{ + const char *system = NULL, *name = NULL; + struct trace_event_call *call; + + if (!str) + return; + + strcpy(last_cmd, "hist:"); + strncat(last_cmd, str, MAX_FILTER_STR_VAL - 1 - sizeof("hist:")); + + if (file) { + call = file->event_call; + system = call->class->system; + if (system) { + name = trace_event_name(call); + if (!name) + system = NULL; + } + } + + if (system) + snprintf(last_cmd_loc, MAX_FILTER_STR_VAL, "hist:%s:%s", system, name); +} + +static void hist_err(struct trace_array *tr, u8 err_type, u8 err_pos) +{ + tracing_log_err(tr, last_cmd_loc, last_cmd, err_text, + err_type, err_pos); +} + +static void hist_err_clear(void) +{ + last_cmd[0] = '\0'; + last_cmd_loc[0] = '\0'; +} + +typedef void (*synth_probe_func_t) (void *__data, u64 *var_ref_vals, + unsigned int *var_ref_idx); + +static inline void trace_synth(struct synth_event *event, u64 *var_ref_vals, + unsigned int *var_ref_idx) +{ + struct tracepoint *tp = event->tp; + + if (unlikely(atomic_read(&tp->key.enabled) > 0)) { + struct tracepoint_func *probe_func_ptr; + synth_probe_func_t probe_func; + void *__data; + + if (!(cpu_online(raw_smp_processor_id()))) + return; + + probe_func_ptr = rcu_dereference_sched((tp)->funcs); + if (probe_func_ptr) { + do { + probe_func = probe_func_ptr->func; + __data = probe_func_ptr->data; + probe_func(__data, var_ref_vals, var_ref_idx); + } while ((++probe_func_ptr)->func); + } + } +} + +static void action_trace(struct hist_trigger_data *hist_data, + struct tracing_map_elt *elt, void *rec, + struct ring_buffer_event *rbe, void *key, + struct action_data *data, u64 *var_ref_vals) +{ + struct synth_event *event = data->synth_event; + + trace_synth(event, var_ref_vals, data->var_ref_idx); +} + +struct hist_var_data { + struct list_head list; + struct hist_trigger_data *hist_data; +}; + +static u64 hist_field_timestamp(struct hist_field *hist_field, + struct tracing_map_elt *elt, + struct ring_buffer_event *rbe, + void *event) +{ + struct hist_trigger_data *hist_data = hist_field->hist_data; + struct trace_array *tr = hist_data->event_file->tr; + + u64 ts = ring_buffer_event_time_stamp(rbe); + + if (hist_data->attrs->ts_in_usecs && trace_clock_in_ns(tr)) + ts = ns2usecs(ts); + + return ts; +} + +static u64 hist_field_cpu(struct hist_field *hist_field, + struct tracing_map_elt *elt, + struct ring_buffer_event *rbe, + void *event) +{ + int cpu = smp_processor_id(); + + return cpu; +} + +/** + * check_field_for_var_ref - Check if a VAR_REF field references a variable + * @hist_field: The VAR_REF field to check + * @var_data: The hist trigger that owns the variable + * @var_idx: The trigger variable identifier + * + * Check the given VAR_REF field to see whether or not it references + * the given variable associated with the given trigger. + * + * Return: The VAR_REF field if it does reference the variable, NULL if not + */ +static struct hist_field * +check_field_for_var_ref(struct hist_field *hist_field, + struct hist_trigger_data *var_data, + unsigned int var_idx) +{ + WARN_ON(!(hist_field && hist_field->flags & HIST_FIELD_FL_VAR_REF)); + + if (hist_field && hist_field->var.idx == var_idx && + hist_field->var.hist_data == var_data) + return hist_field; + + return NULL; +} + +/** + * find_var_ref - Check if a trigger has a reference to a trigger variable + * @hist_data: The hist trigger that might have a reference to the variable + * @var_data: The hist trigger that owns the variable + * @var_idx: The trigger variable identifier + * + * Check the list of var_refs[] on the first hist trigger to see + * whether any of them are references to the variable on the second + * trigger. + * + * Return: The VAR_REF field referencing the variable if so, NULL if not + */ +static struct hist_field *find_var_ref(struct hist_trigger_data *hist_data, + struct hist_trigger_data *var_data, + unsigned int var_idx) +{ + struct hist_field *hist_field; + unsigned int i; + + for (i = 0; i < hist_data->n_var_refs; i++) { + hist_field = hist_data->var_refs[i]; + if (check_field_for_var_ref(hist_field, var_data, var_idx)) + return hist_field; + } + + return NULL; +} + +/** + * find_any_var_ref - Check if there is a reference to a given trigger variable + * @hist_data: The hist trigger + * @var_idx: The trigger variable identifier + * + * Check to see whether the given variable is currently referenced by + * any other trigger. + * + * The trigger the variable is defined on is explicitly excluded - the + * assumption being that a self-reference doesn't prevent a trigger + * from being removed. + * + * Return: The VAR_REF field referencing the variable if so, NULL if not + */ +static struct hist_field *find_any_var_ref(struct hist_trigger_data *hist_data, + unsigned int var_idx) +{ + struct trace_array *tr = hist_data->event_file->tr; + struct hist_field *found = NULL; + struct hist_var_data *var_data; + + list_for_each_entry(var_data, &tr->hist_vars, list) { + if (var_data->hist_data == hist_data) + continue; + found = find_var_ref(var_data->hist_data, hist_data, var_idx); + if (found) + break; + } + + return found; +} + +/** + * check_var_refs - Check if there is a reference to any of trigger's variables + * @hist_data: The hist trigger + * + * A trigger can define one or more variables. If any one of them is + * currently referenced by any other trigger, this function will + * determine that. + + * Typically used to determine whether or not a trigger can be removed + * - if there are any references to a trigger's variables, it cannot. + * + * Return: True if there is a reference to any of trigger's variables + */ +static bool check_var_refs(struct hist_trigger_data *hist_data) +{ + struct hist_field *field; + bool found = false; + int i; + + for_each_hist_field(i, hist_data) { + field = hist_data->fields[i]; + if (field && field->flags & HIST_FIELD_FL_VAR) { + if (find_any_var_ref(hist_data, field->var.idx)) { + found = true; + break; + } + } + } + + return found; +} + +static struct hist_var_data *find_hist_vars(struct hist_trigger_data *hist_data) +{ + struct trace_array *tr = hist_data->event_file->tr; + struct hist_var_data *var_data, *found = NULL; + + list_for_each_entry(var_data, &tr->hist_vars, list) { + if (var_data->hist_data == hist_data) { + found = var_data; + break; + } + } + + return found; +} + +static bool field_has_hist_vars(struct hist_field *hist_field, + unsigned int level) +{ + int i; + + if (level > 3) + return false; + + if (!hist_field) + return false; + + if (hist_field->flags & HIST_FIELD_FL_VAR || + hist_field->flags & HIST_FIELD_FL_VAR_REF) + return true; + + for (i = 0; i < HIST_FIELD_OPERANDS_MAX; i++) { + struct hist_field *operand; + + operand = hist_field->operands[i]; + if (field_has_hist_vars(operand, level + 1)) + return true; + } + + return false; +} + +static bool has_hist_vars(struct hist_trigger_data *hist_data) +{ + struct hist_field *hist_field; + int i; + + for_each_hist_field(i, hist_data) { + hist_field = hist_data->fields[i]; + if (field_has_hist_vars(hist_field, 0)) + return true; + } + + return false; +} + +static int save_hist_vars(struct hist_trigger_data *hist_data) +{ + struct trace_array *tr = hist_data->event_file->tr; + struct hist_var_data *var_data; + + var_data = find_hist_vars(hist_data); + if (var_data) + return 0; + + if (tracing_check_open_get_tr(tr)) + return -ENODEV; + + var_data = kzalloc(sizeof(*var_data), GFP_KERNEL); + if (!var_data) { + trace_array_put(tr); + return -ENOMEM; + } + + var_data->hist_data = hist_data; + list_add(&var_data->list, &tr->hist_vars); + + return 0; +} + +static void remove_hist_vars(struct hist_trigger_data *hist_data) +{ + struct trace_array *tr = hist_data->event_file->tr; + struct hist_var_data *var_data; + + var_data = find_hist_vars(hist_data); + if (!var_data) + return; + + if (WARN_ON(check_var_refs(hist_data))) + return; + + list_del(&var_data->list); + + kfree(var_data); + + trace_array_put(tr); +} + +static struct hist_field *find_var_field(struct hist_trigger_data *hist_data, + const char *var_name) +{ + struct hist_field *hist_field, *found = NULL; + int i; + + for_each_hist_field(i, hist_data) { + hist_field = hist_data->fields[i]; + if (hist_field && hist_field->flags & HIST_FIELD_FL_VAR && + strcmp(hist_field->var.name, var_name) == 0) { + found = hist_field; + break; + } + } + + return found; +} + +static struct hist_field *find_var(struct hist_trigger_data *hist_data, + struct trace_event_file *file, + const char *var_name) +{ + struct hist_trigger_data *test_data; + struct event_trigger_data *test; + struct hist_field *hist_field; + + lockdep_assert_held(&event_mutex); + + hist_field = find_var_field(hist_data, var_name); + if (hist_field) + return hist_field; + + list_for_each_entry(test, &file->triggers, list) { + if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) { + test_data = test->private_data; + hist_field = find_var_field(test_data, var_name); + if (hist_field) + return hist_field; + } + } + + return NULL; +} + +static struct trace_event_file *find_var_file(struct trace_array *tr, + char *system, + char *event_name, + char *var_name) +{ + struct hist_trigger_data *var_hist_data; + struct hist_var_data *var_data; + struct trace_event_file *file, *found = NULL; + + if (system) + return find_event_file(tr, system, event_name); + + list_for_each_entry(var_data, &tr->hist_vars, list) { + var_hist_data = var_data->hist_data; + file = var_hist_data->event_file; + if (file == found) + continue; + + if (find_var_field(var_hist_data, var_name)) { + if (found) { + hist_err(tr, HIST_ERR_VAR_NOT_UNIQUE, errpos(var_name)); + return NULL; + } + + found = file; + } + } + + return found; +} + +static struct hist_field *find_file_var(struct trace_event_file *file, + const char *var_name) +{ + struct hist_trigger_data *test_data; + struct event_trigger_data *test; + struct hist_field *hist_field; + + lockdep_assert_held(&event_mutex); + + list_for_each_entry(test, &file->triggers, list) { + if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) { + test_data = test->private_data; + hist_field = find_var_field(test_data, var_name); + if (hist_field) + return hist_field; + } + } + + return NULL; +} + +static struct hist_field * +find_match_var(struct hist_trigger_data *hist_data, char *var_name) +{ + struct trace_array *tr = hist_data->event_file->tr; + struct hist_field *hist_field, *found = NULL; + struct trace_event_file *file; + unsigned int i; + + for (i = 0; i < hist_data->n_actions; i++) { + struct action_data *data = hist_data->actions[i]; + + if (data->handler == HANDLER_ONMATCH) { + char *system = data->match_data.event_system; + char *event_name = data->match_data.event; + + file = find_var_file(tr, system, event_name, var_name); + if (!file) + continue; + hist_field = find_file_var(file, var_name); + if (hist_field) { + if (found) { + hist_err(tr, HIST_ERR_VAR_NOT_UNIQUE, + errpos(var_name)); + return ERR_PTR(-EINVAL); + } + + found = hist_field; + } + } + } + return found; +} + +static struct hist_field *find_event_var(struct hist_trigger_data *hist_data, + char *system, + char *event_name, + char *var_name) +{ + struct trace_array *tr = hist_data->event_file->tr; + struct hist_field *hist_field = NULL; + struct trace_event_file *file; + + if (!system || !event_name) { + hist_field = find_match_var(hist_data, var_name); + if (IS_ERR(hist_field)) + return NULL; + if (hist_field) + return hist_field; + } + + file = find_var_file(tr, system, event_name, var_name); + if (!file) + return NULL; + + hist_field = find_file_var(file, var_name); + + return hist_field; +} + +static u64 hist_field_var_ref(struct hist_field *hist_field, + struct tracing_map_elt *elt, + struct ring_buffer_event *rbe, + void *event) +{ + struct hist_elt_data *elt_data; + u64 var_val = 0; + + if (WARN_ON_ONCE(!elt)) + return var_val; + + elt_data = elt->private_data; + var_val = elt_data->var_ref_vals[hist_field->var_ref_idx]; + + return var_val; +} + +static bool resolve_var_refs(struct hist_trigger_data *hist_data, void *key, + u64 *var_ref_vals, bool self) +{ + struct hist_trigger_data *var_data; + struct tracing_map_elt *var_elt; + struct hist_field *hist_field; + unsigned int i, var_idx; + bool resolved = true; + u64 var_val = 0; + + for (i = 0; i < hist_data->n_var_refs; i++) { + hist_field = hist_data->var_refs[i]; + var_idx = hist_field->var.idx; + var_data = hist_field->var.hist_data; + + if (var_data == NULL) { + resolved = false; + break; + } + + if ((self && var_data != hist_data) || + (!self && var_data == hist_data)) + continue; + + var_elt = tracing_map_lookup(var_data->map, key); + if (!var_elt) { + resolved = false; + break; + } + + if (!tracing_map_var_set(var_elt, var_idx)) { + resolved = false; + break; + } + + if (self || !hist_field->read_once) + var_val = tracing_map_read_var(var_elt, var_idx); + else + var_val = tracing_map_read_var_once(var_elt, var_idx); + + var_ref_vals[i] = var_val; + } + + return resolved; +} + +static const char *hist_field_name(struct hist_field *field, + unsigned int level) +{ + const char *field_name = ""; + + if (WARN_ON_ONCE(!field)) + return field_name; + + if (level > 1) + return field_name; + + if (field->field) + field_name = field->field->name; + else if (field->flags & HIST_FIELD_FL_LOG2 || + field->flags & HIST_FIELD_FL_ALIAS) + field_name = hist_field_name(field->operands[0], ++level); + else if (field->flags & HIST_FIELD_FL_CPU) + field_name = "common_cpu"; + else if (field->flags & HIST_FIELD_FL_EXPR || + field->flags & HIST_FIELD_FL_VAR_REF) { + if (field->system) { + static char full_name[MAX_FILTER_STR_VAL]; + + strcat(full_name, field->system); + strcat(full_name, "."); + strcat(full_name, field->event_name); + strcat(full_name, "."); + strcat(full_name, field->name); + field_name = full_name; + } else + field_name = field->name; + } else if (field->flags & HIST_FIELD_FL_TIMESTAMP) + field_name = "common_timestamp"; + + if (field_name == NULL) + field_name = ""; + + return field_name; +} + +static hist_field_fn_t select_value_fn(int field_size, int field_is_signed) +{ + hist_field_fn_t fn = NULL; + + switch (field_size) { + case 8: + if (field_is_signed) + fn = hist_field_s64; + else + fn = hist_field_u64; + break; + case 4: + if (field_is_signed) + fn = hist_field_s32; + else + fn = hist_field_u32; + break; + case 2: + if (field_is_signed) + fn = hist_field_s16; + else + fn = hist_field_u16; + break; + case 1: + if (field_is_signed) + fn = hist_field_s8; + else + fn = hist_field_u8; + break; + } + + return fn; +} + +static int parse_map_size(char *str) +{ + unsigned long size, map_bits; + int ret; + + ret = kstrtoul(str, 0, &size); + if (ret) + goto out; + + map_bits = ilog2(roundup_pow_of_two(size)); + if (map_bits < TRACING_MAP_BITS_MIN || + map_bits > TRACING_MAP_BITS_MAX) + ret = -EINVAL; + else + ret = map_bits; + out: + return ret; +} + +static void destroy_hist_trigger_attrs(struct hist_trigger_attrs *attrs) +{ + unsigned int i; + + if (!attrs) + return; + + for (i = 0; i < attrs->n_assignments; i++) + kfree(attrs->assignment_str[i]); + + for (i = 0; i < attrs->n_actions; i++) + kfree(attrs->action_str[i]); + + kfree(attrs->name); + kfree(attrs->sort_key_str); + kfree(attrs->keys_str); + kfree(attrs->vals_str); + kfree(attrs->clock); + kfree(attrs); +} + +static int parse_action(char *str, struct hist_trigger_attrs *attrs) +{ + int ret = -EINVAL; + + if (attrs->n_actions >= HIST_ACTIONS_MAX) + return ret; + + if ((str_has_prefix(str, "onmatch(")) || + (str_has_prefix(str, "onmax(")) || + (str_has_prefix(str, "onchange("))) { + attrs->action_str[attrs->n_actions] = kstrdup(str, GFP_KERNEL); + if (!attrs->action_str[attrs->n_actions]) { + ret = -ENOMEM; + return ret; + } + attrs->n_actions++; + ret = 0; + } + return ret; +} + +static int parse_assignment(struct trace_array *tr, + char *str, struct hist_trigger_attrs *attrs) +{ + int len, ret = 0; + + if ((len = str_has_prefix(str, "key=")) || + (len = str_has_prefix(str, "keys="))) { + attrs->keys_str = kstrdup(str + len, GFP_KERNEL); + if (!attrs->keys_str) { + ret = -ENOMEM; + goto out; + } + } else if ((len = str_has_prefix(str, "val=")) || + (len = str_has_prefix(str, "vals=")) || + (len = str_has_prefix(str, "values="))) { + attrs->vals_str = kstrdup(str + len, GFP_KERNEL); + if (!attrs->vals_str) { + ret = -ENOMEM; + goto out; + } + } else if ((len = str_has_prefix(str, "sort="))) { + attrs->sort_key_str = kstrdup(str + len, GFP_KERNEL); + if (!attrs->sort_key_str) { + ret = -ENOMEM; + goto out; + } + } else if (str_has_prefix(str, "name=")) { + attrs->name = kstrdup(str, GFP_KERNEL); + if (!attrs->name) { + ret = -ENOMEM; + goto out; + } + } else if ((len = str_has_prefix(str, "clock="))) { + str += len; + + str = strstrip(str); + attrs->clock = kstrdup(str, GFP_KERNEL); + if (!attrs->clock) { + ret = -ENOMEM; + goto out; + } + } else if ((len = str_has_prefix(str, "size="))) { + int map_bits = parse_map_size(str + len); + + if (map_bits < 0) { + ret = map_bits; + goto out; + } + attrs->map_bits = map_bits; + } else { + char *assignment; + + if (attrs->n_assignments == TRACING_MAP_VARS_MAX) { + hist_err(tr, HIST_ERR_TOO_MANY_VARS, errpos(str)); + ret = -EINVAL; + goto out; + } + + assignment = kstrdup(str, GFP_KERNEL); + if (!assignment) { + ret = -ENOMEM; + goto out; + } + + attrs->assignment_str[attrs->n_assignments++] = assignment; + } + out: + return ret; +} + +static struct hist_trigger_attrs * +parse_hist_trigger_attrs(struct trace_array *tr, char *trigger_str) +{ + struct hist_trigger_attrs *attrs; + int ret = 0; + + attrs = kzalloc(sizeof(*attrs), GFP_KERNEL); + if (!attrs) + return ERR_PTR(-ENOMEM); + + while (trigger_str) { + char *str = strsep(&trigger_str, ":"); + char *rhs; + + rhs = strchr(str, '='); + if (rhs) { + if (!strlen(++rhs)) { + ret = -EINVAL; + hist_err(tr, HIST_ERR_EMPTY_ASSIGNMENT, errpos(str)); + goto free; + } + ret = parse_assignment(tr, str, attrs); + if (ret) + goto free; + } else if (strcmp(str, "pause") == 0) + attrs->pause = true; + else if ((strcmp(str, "cont") == 0) || + (strcmp(str, "continue") == 0)) + attrs->cont = true; + else if (strcmp(str, "clear") == 0) + attrs->clear = true; + else { + ret = parse_action(str, attrs); + if (ret) + goto free; + } + } + + if (!attrs->keys_str) { + ret = -EINVAL; + goto free; + } + + if (!attrs->clock) { + attrs->clock = kstrdup("global", GFP_KERNEL); + if (!attrs->clock) { + ret = -ENOMEM; + goto free; + } + } + + return attrs; + free: + destroy_hist_trigger_attrs(attrs); + + return ERR_PTR(ret); +} + +static inline void save_comm(char *comm, struct task_struct *task) +{ + if (!task->pid) { + strcpy(comm, "<idle>"); + return; + } + + if (WARN_ON_ONCE(task->pid < 0)) { + strcpy(comm, "<XXX>"); + return; + } + + strncpy(comm, task->comm, TASK_COMM_LEN); +} + +static void hist_elt_data_free(struct hist_elt_data *elt_data) +{ + unsigned int i; + + for (i = 0; i < SYNTH_FIELDS_MAX; i++) + kfree(elt_data->field_var_str[i]); + + kfree(elt_data->comm); + kfree(elt_data); +} + +static void hist_trigger_elt_data_free(struct tracing_map_elt *elt) +{ + struct hist_elt_data *elt_data = elt->private_data; + + hist_elt_data_free(elt_data); +} + +static int hist_trigger_elt_data_alloc(struct tracing_map_elt *elt) +{ + struct hist_trigger_data *hist_data = elt->map->private_data; + unsigned int size = TASK_COMM_LEN; + struct hist_elt_data *elt_data; + struct hist_field *key_field; + unsigned int i, n_str; + + elt_data = kzalloc(sizeof(*elt_data), GFP_KERNEL); + if (!elt_data) + return -ENOMEM; + + for_each_hist_key_field(i, hist_data) { + key_field = hist_data->fields[i]; + + if (key_field->flags & HIST_FIELD_FL_EXECNAME) { + elt_data->comm = kzalloc(size, GFP_KERNEL); + if (!elt_data->comm) { + kfree(elt_data); + return -ENOMEM; + } + break; + } + } + + n_str = hist_data->n_field_var_str + hist_data->n_save_var_str + + hist_data->n_var_str; + if (n_str > SYNTH_FIELDS_MAX) { + hist_elt_data_free(elt_data); + return -EINVAL; + } + + BUILD_BUG_ON(STR_VAR_LEN_MAX & (sizeof(u64) - 1)); + + size = STR_VAR_LEN_MAX; + + for (i = 0; i < n_str; i++) { + elt_data->field_var_str[i] = kzalloc(size, GFP_KERNEL); + if (!elt_data->field_var_str[i]) { + hist_elt_data_free(elt_data); + return -ENOMEM; + } + } + + elt->private_data = elt_data; + + return 0; +} + +static void hist_trigger_elt_data_init(struct tracing_map_elt *elt) +{ + struct hist_elt_data *elt_data = elt->private_data; + + if (elt_data->comm) + save_comm(elt_data->comm, current); +} + +static const struct tracing_map_ops hist_trigger_elt_data_ops = { + .elt_alloc = hist_trigger_elt_data_alloc, + .elt_free = hist_trigger_elt_data_free, + .elt_init = hist_trigger_elt_data_init, +}; + +static const char *get_hist_field_flags(struct hist_field *hist_field) +{ + const char *flags_str = NULL; + + if (hist_field->flags & HIST_FIELD_FL_HEX) + flags_str = "hex"; + else if (hist_field->flags & HIST_FIELD_FL_SYM) + flags_str = "sym"; + else if (hist_field->flags & HIST_FIELD_FL_SYM_OFFSET) + flags_str = "sym-offset"; + else if (hist_field->flags & HIST_FIELD_FL_EXECNAME) + flags_str = "execname"; + else if (hist_field->flags & HIST_FIELD_FL_SYSCALL) + flags_str = "syscall"; + else if (hist_field->flags & HIST_FIELD_FL_LOG2) + flags_str = "log2"; + else if (hist_field->flags & HIST_FIELD_FL_TIMESTAMP_USECS) + flags_str = "usecs"; + + return flags_str; +} + +static void expr_field_str(struct hist_field *field, char *expr) +{ + if (field->flags & HIST_FIELD_FL_VAR_REF) + strcat(expr, "$"); + + strcat(expr, hist_field_name(field, 0)); + + if (field->flags && !(field->flags & HIST_FIELD_FL_VAR_REF)) { + const char *flags_str = get_hist_field_flags(field); + + if (flags_str) { + strcat(expr, "."); + strcat(expr, flags_str); + } + } +} + +static char *expr_str(struct hist_field *field, unsigned int level) +{ + char *expr; + + if (level > 1) + return NULL; + + expr = kzalloc(MAX_FILTER_STR_VAL, GFP_KERNEL); + if (!expr) + return NULL; + + if (!field->operands[0]) { + expr_field_str(field, expr); + return expr; + } + + if (field->operator == FIELD_OP_UNARY_MINUS) { + char *subexpr; + + strcat(expr, "-("); + subexpr = expr_str(field->operands[0], ++level); + if (!subexpr) { + kfree(expr); + return NULL; + } + strcat(expr, subexpr); + strcat(expr, ")"); + + kfree(subexpr); + + return expr; + } + + expr_field_str(field->operands[0], expr); + + switch (field->operator) { + case FIELD_OP_MINUS: + strcat(expr, "-"); + break; + case FIELD_OP_PLUS: + strcat(expr, "+"); + break; + default: + kfree(expr); + return NULL; + } + + expr_field_str(field->operands[1], expr); + + return expr; +} + +static int contains_operator(char *str) +{ + enum field_op_id field_op = FIELD_OP_NONE; + char *op; + + op = strpbrk(str, "+-"); + if (!op) + return FIELD_OP_NONE; + + switch (*op) { + case '-': + /* + * Unfortunately, the modifier ".sym-offset" + * can confuse things. + */ + if (op - str >= 4 && !strncmp(op - 4, ".sym-offset", 11)) + return FIELD_OP_NONE; + + if (*str == '-') + field_op = FIELD_OP_UNARY_MINUS; + else + field_op = FIELD_OP_MINUS; + break; + case '+': + field_op = FIELD_OP_PLUS; + break; + default: + break; + } + + return field_op; +} + +static void get_hist_field(struct hist_field *hist_field) +{ + hist_field->ref++; +} + +static void __destroy_hist_field(struct hist_field *hist_field) +{ + if (--hist_field->ref > 1) + return; + + kfree(hist_field->var.name); + kfree(hist_field->name); + kfree(hist_field->type); + + kfree(hist_field->system); + kfree(hist_field->event_name); + + kfree(hist_field); +} + +static void destroy_hist_field(struct hist_field *hist_field, + unsigned int level) +{ + unsigned int i; + + if (level > 3) + return; + + if (!hist_field) + return; + + if (hist_field->flags & HIST_FIELD_FL_VAR_REF) + return; /* var refs will be destroyed separately */ + + for (i = 0; i < HIST_FIELD_OPERANDS_MAX; i++) + destroy_hist_field(hist_field->operands[i], level + 1); + + __destroy_hist_field(hist_field); +} + +static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data, + struct ftrace_event_field *field, + unsigned long flags, + char *var_name) +{ + struct hist_field *hist_field; + + if (field && is_function_field(field)) + return NULL; + + hist_field = kzalloc(sizeof(struct hist_field), GFP_KERNEL); + if (!hist_field) + return NULL; + + hist_field->ref = 1; + + hist_field->hist_data = hist_data; + + if (flags & HIST_FIELD_FL_EXPR || flags & HIST_FIELD_FL_ALIAS) + goto out; /* caller will populate */ + + if (flags & HIST_FIELD_FL_VAR_REF) { + hist_field->fn = hist_field_var_ref; + goto out; + } + + if (flags & HIST_FIELD_FL_HITCOUNT) { + hist_field->fn = hist_field_counter; + hist_field->size = sizeof(u64); + hist_field->type = kstrdup("u64", GFP_KERNEL); + if (!hist_field->type) + goto free; + goto out; + } + + if (flags & HIST_FIELD_FL_STACKTRACE) { + hist_field->fn = hist_field_none; + goto out; + } + + if (flags & HIST_FIELD_FL_LOG2) { + unsigned long fl = flags & ~HIST_FIELD_FL_LOG2; + hist_field->fn = hist_field_log2; + hist_field->operands[0] = create_hist_field(hist_data, field, fl, NULL); + if (!hist_field->operands[0]) + goto free; + hist_field->size = hist_field->operands[0]->size; + hist_field->type = kstrdup(hist_field->operands[0]->type, GFP_KERNEL); + if (!hist_field->type) + goto free; + goto out; + } + + if (flags & HIST_FIELD_FL_TIMESTAMP) { + hist_field->fn = hist_field_timestamp; + hist_field->size = sizeof(u64); + hist_field->type = kstrdup("u64", GFP_KERNEL); + if (!hist_field->type) + goto free; + goto out; + } + + if (flags & HIST_FIELD_FL_CPU) { + hist_field->fn = hist_field_cpu; + hist_field->size = sizeof(int); + hist_field->type = kstrdup("unsigned int", GFP_KERNEL); + if (!hist_field->type) + goto free; + goto out; + } + + if (WARN_ON_ONCE(!field)) + goto out; + + /* Pointers to strings are just pointers and dangerous to dereference */ + if (is_string_field(field) && + (field->filter_type != FILTER_PTR_STRING)) { + flags |= HIST_FIELD_FL_STRING; + + hist_field->size = MAX_FILTER_STR_VAL; + hist_field->type = kstrdup(field->type, GFP_KERNEL); + if (!hist_field->type) + goto free; + + if (field->filter_type == FILTER_STATIC_STRING) { + hist_field->fn = hist_field_string; + hist_field->size = field->size; + } else if (field->filter_type == FILTER_DYN_STRING) + hist_field->fn = hist_field_dynstring; + else + hist_field->fn = hist_field_pstring; + } else { + hist_field->size = field->size; + hist_field->is_signed = field->is_signed; + hist_field->type = kstrdup(field->type, GFP_KERNEL); + if (!hist_field->type) + goto free; + + hist_field->fn = select_value_fn(field->size, + field->is_signed); + if (!hist_field->fn) { + destroy_hist_field(hist_field, 0); + return NULL; + } + } + out: + hist_field->field = field; + hist_field->flags = flags; + + if (var_name) { + hist_field->var.name = kstrdup(var_name, GFP_KERNEL); + if (!hist_field->var.name) + goto free; + } + + return hist_field; + free: + destroy_hist_field(hist_field, 0); + return NULL; +} + +static void destroy_hist_fields(struct hist_trigger_data *hist_data) +{ + unsigned int i; + + for (i = 0; i < HIST_FIELDS_MAX; i++) { + if (hist_data->fields[i]) { + destroy_hist_field(hist_data->fields[i], 0); + hist_data->fields[i] = NULL; + } + } + + for (i = 0; i < hist_data->n_var_refs; i++) { + WARN_ON(!(hist_data->var_refs[i]->flags & HIST_FIELD_FL_VAR_REF)); + __destroy_hist_field(hist_data->var_refs[i]); + hist_data->var_refs[i] = NULL; + } +} + +static int init_var_ref(struct hist_field *ref_field, + struct hist_field *var_field, + char *system, char *event_name) +{ + int err = 0; + + ref_field->var.idx = var_field->var.idx; + ref_field->var.hist_data = var_field->hist_data; + ref_field->size = var_field->size; + ref_field->is_signed = var_field->is_signed; + ref_field->flags |= var_field->flags & + (HIST_FIELD_FL_TIMESTAMP | HIST_FIELD_FL_TIMESTAMP_USECS); + + if (system) { + ref_field->system = kstrdup(system, GFP_KERNEL); + if (!ref_field->system) + return -ENOMEM; + } + + if (event_name) { + ref_field->event_name = kstrdup(event_name, GFP_KERNEL); + if (!ref_field->event_name) { + err = -ENOMEM; + goto free; + } + } + + if (var_field->var.name) { + ref_field->name = kstrdup(var_field->var.name, GFP_KERNEL); + if (!ref_field->name) { + err = -ENOMEM; + goto free; + } + } else if (var_field->name) { + ref_field->name = kstrdup(var_field->name, GFP_KERNEL); + if (!ref_field->name) { + err = -ENOMEM; + goto free; + } + } + + ref_field->type = kstrdup(var_field->type, GFP_KERNEL); + if (!ref_field->type) { + err = -ENOMEM; + goto free; + } + out: + return err; + free: + kfree(ref_field->system); + ref_field->system = NULL; + kfree(ref_field->event_name); + ref_field->event_name = NULL; + kfree(ref_field->name); + ref_field->name = NULL; + + goto out; +} + +static int find_var_ref_idx(struct hist_trigger_data *hist_data, + struct hist_field *var_field) +{ + struct hist_field *ref_field; + int i; + + for (i = 0; i < hist_data->n_var_refs; i++) { + ref_field = hist_data->var_refs[i]; + if (ref_field->var.idx == var_field->var.idx && + ref_field->var.hist_data == var_field->hist_data) + return i; + } + + return -ENOENT; +} + +/** + * create_var_ref - Create a variable reference and attach it to trigger + * @hist_data: The trigger that will be referencing the variable + * @var_field: The VAR field to create a reference to + * @system: The optional system string + * @event_name: The optional event_name string + * + * Given a variable hist_field, create a VAR_REF hist_field that + * represents a reference to it. + * + * This function also adds the reference to the trigger that + * now references the variable. + * + * Return: The VAR_REF field if successful, NULL if not + */ +static struct hist_field *create_var_ref(struct hist_trigger_data *hist_data, + struct hist_field *var_field, + char *system, char *event_name) +{ + unsigned long flags = HIST_FIELD_FL_VAR_REF; + struct hist_field *ref_field; + int i; + + /* Check if the variable already exists */ + for (i = 0; i < hist_data->n_var_refs; i++) { + ref_field = hist_data->var_refs[i]; + if (ref_field->var.idx == var_field->var.idx && + ref_field->var.hist_data == var_field->hist_data) { + get_hist_field(ref_field); + return ref_field; + } + } + /* Sanity check to avoid out-of-bound write on 'hist_data->var_refs' */ + if (hist_data->n_var_refs >= TRACING_MAP_VARS_MAX) + return NULL; + ref_field = create_hist_field(var_field->hist_data, NULL, flags, NULL); + if (ref_field) { + if (init_var_ref(ref_field, var_field, system, event_name)) { + destroy_hist_field(ref_field, 0); + return NULL; + } + + hist_data->var_refs[hist_data->n_var_refs] = ref_field; + ref_field->var_ref_idx = hist_data->n_var_refs++; + } + + return ref_field; +} + +static bool is_var_ref(char *var_name) +{ + if (!var_name || strlen(var_name) < 2 || var_name[0] != '$') + return false; + + return true; +} + +static char *field_name_from_var(struct hist_trigger_data *hist_data, + char *var_name) +{ + char *name, *field; + unsigned int i; + + for (i = 0; i < hist_data->attrs->var_defs.n_vars; i++) { + name = hist_data->attrs->var_defs.name[i]; + + if (strcmp(var_name, name) == 0) { + field = hist_data->attrs->var_defs.expr[i]; + if (contains_operator(field) || is_var_ref(field)) + continue; + return field; + } + } + + return NULL; +} + +static char *local_field_var_ref(struct hist_trigger_data *hist_data, + char *system, char *event_name, + char *var_name) +{ + struct trace_event_call *call; + + if (system && event_name) { + call = hist_data->event_file->event_call; + + if (strcmp(system, call->class->system) != 0) + return NULL; + + if (strcmp(event_name, trace_event_name(call)) != 0) + return NULL; + } + + if (!!system != !!event_name) + return NULL; + + if (!is_var_ref(var_name)) + return NULL; + + var_name++; + + return field_name_from_var(hist_data, var_name); +} + +static struct hist_field *parse_var_ref(struct hist_trigger_data *hist_data, + char *system, char *event_name, + char *var_name) +{ + struct hist_field *var_field = NULL, *ref_field = NULL; + struct trace_array *tr = hist_data->event_file->tr; + + if (!is_var_ref(var_name)) + return NULL; + + var_name++; + + var_field = find_event_var(hist_data, system, event_name, var_name); + if (var_field) + ref_field = create_var_ref(hist_data, var_field, + system, event_name); + + if (!ref_field) + hist_err(tr, HIST_ERR_VAR_NOT_FOUND, errpos(var_name)); + + return ref_field; +} + +static struct ftrace_event_field * +parse_field(struct hist_trigger_data *hist_data, struct trace_event_file *file, + char *field_str, unsigned long *flags) +{ + struct ftrace_event_field *field = NULL; + char *field_name, *modifier, *str; + struct trace_array *tr = file->tr; + + modifier = str = kstrdup(field_str, GFP_KERNEL); + if (!modifier) + return ERR_PTR(-ENOMEM); + + field_name = strsep(&modifier, "."); + if (modifier) { + if (strcmp(modifier, "hex") == 0) + *flags |= HIST_FIELD_FL_HEX; + else if (strcmp(modifier, "sym") == 0) + *flags |= HIST_FIELD_FL_SYM; + else if (strcmp(modifier, "sym-offset") == 0) + *flags |= HIST_FIELD_FL_SYM_OFFSET; + else if ((strcmp(modifier, "execname") == 0) && + (strcmp(field_name, "common_pid") == 0)) + *flags |= HIST_FIELD_FL_EXECNAME; + else if (strcmp(modifier, "syscall") == 0) + *flags |= HIST_FIELD_FL_SYSCALL; + else if (strcmp(modifier, "log2") == 0) + *flags |= HIST_FIELD_FL_LOG2; + else if (strcmp(modifier, "usecs") == 0) + *flags |= HIST_FIELD_FL_TIMESTAMP_USECS; + else { + hist_err(tr, HIST_ERR_BAD_FIELD_MODIFIER, errpos(modifier)); + field = ERR_PTR(-EINVAL); + goto out; + } + } + + if (strcmp(field_name, "common_timestamp") == 0) { + *flags |= HIST_FIELD_FL_TIMESTAMP; + hist_data->enable_timestamps = true; + if (*flags & HIST_FIELD_FL_TIMESTAMP_USECS) + hist_data->attrs->ts_in_usecs = true; + } else if (strcmp(field_name, "common_cpu") == 0) + *flags |= HIST_FIELD_FL_CPU; + else { + field = trace_find_event_field(file->event_call, field_name); + if (!field || !field->size) { + /* + * For backward compatibility, if field_name + * was "cpu", then we treat this the same as + * common_cpu. This also works for "CPU". + */ + if (field && field->filter_type == FILTER_CPU) { + *flags |= HIST_FIELD_FL_CPU; + } else { + hist_err(tr, HIST_ERR_FIELD_NOT_FOUND, + errpos(field_name)); + field = ERR_PTR(-EINVAL); + goto out; + } + } + } + out: + kfree(str); + + return field; +} + +static struct hist_field *create_alias(struct hist_trigger_data *hist_data, + struct hist_field *var_ref, + char *var_name) +{ + struct hist_field *alias = NULL; + unsigned long flags = HIST_FIELD_FL_ALIAS | HIST_FIELD_FL_VAR; + + alias = create_hist_field(hist_data, NULL, flags, var_name); + if (!alias) + return NULL; + + alias->fn = var_ref->fn; + alias->operands[0] = var_ref; + + if (init_var_ref(alias, var_ref, var_ref->system, var_ref->event_name)) { + destroy_hist_field(alias, 0); + return NULL; + } + + alias->var_ref_idx = var_ref->var_ref_idx; + + return alias; +} + +static struct hist_field *parse_atom(struct hist_trigger_data *hist_data, + struct trace_event_file *file, char *str, + unsigned long *flags, char *var_name) +{ + char *s, *ref_system = NULL, *ref_event = NULL, *ref_var = str; + struct ftrace_event_field *field = NULL; + struct hist_field *hist_field = NULL; + int ret = 0; + + s = strchr(str, '.'); + if (s) { + s = strchr(++s, '.'); + if (s) { + ref_system = strsep(&str, "."); + if (!str) { + ret = -EINVAL; + goto out; + } + ref_event = strsep(&str, "."); + if (!str) { + ret = -EINVAL; + goto out; + } + ref_var = str; + } + } + + s = local_field_var_ref(hist_data, ref_system, ref_event, ref_var); + if (!s) { + hist_field = parse_var_ref(hist_data, ref_system, + ref_event, ref_var); + if (hist_field) { + if (var_name) { + hist_field = create_alias(hist_data, hist_field, var_name); + if (!hist_field) { + ret = -ENOMEM; + goto out; + } + } + return hist_field; + } + } else + str = s; + + field = parse_field(hist_data, file, str, flags); + if (IS_ERR(field)) { + ret = PTR_ERR(field); + goto out; + } + + hist_field = create_hist_field(hist_data, field, *flags, var_name); + if (!hist_field) { + ret = -ENOMEM; + goto out; + } + + return hist_field; + out: + return ERR_PTR(ret); +} + +static struct hist_field *parse_expr(struct hist_trigger_data *hist_data, + struct trace_event_file *file, + char *str, unsigned long flags, + char *var_name, unsigned int level); + +static struct hist_field *parse_unary(struct hist_trigger_data *hist_data, + struct trace_event_file *file, + char *str, unsigned long flags, + char *var_name, unsigned int level) +{ + struct hist_field *operand1, *expr = NULL; + unsigned long operand_flags; + int ret = 0; + char *s; + + /* we support only -(xxx) i.e. explicit parens required */ + + if (level > 3) { + hist_err(file->tr, HIST_ERR_TOO_MANY_SUBEXPR, errpos(str)); + ret = -EINVAL; + goto free; + } + + str++; /* skip leading '-' */ + + s = strchr(str, '('); + if (s) + str++; + else { + ret = -EINVAL; + goto free; + } + + s = strrchr(str, ')'); + if (s) + *s = '\0'; + else { + ret = -EINVAL; /* no closing ')' */ + goto free; + } + + flags |= HIST_FIELD_FL_EXPR; + expr = create_hist_field(hist_data, NULL, flags, var_name); + if (!expr) { + ret = -ENOMEM; + goto free; + } + + operand_flags = 0; + operand1 = parse_expr(hist_data, file, str, operand_flags, NULL, ++level); + if (IS_ERR(operand1)) { + ret = PTR_ERR(operand1); + goto free; + } + if (operand1->flags & HIST_FIELD_FL_STRING) { + /* String type can not be the operand of unary operator. */ + hist_err(file->tr, HIST_ERR_INVALID_STR_OPERAND, errpos(str)); + destroy_hist_field(operand1, 0); + ret = -EINVAL; + goto free; + } + + expr->flags |= operand1->flags & + (HIST_FIELD_FL_TIMESTAMP | HIST_FIELD_FL_TIMESTAMP_USECS); + expr->fn = hist_field_unary_minus; + expr->operands[0] = operand1; + expr->size = operand1->size; + expr->is_signed = operand1->is_signed; + expr->operator = FIELD_OP_UNARY_MINUS; + expr->name = expr_str(expr, 0); + expr->type = kstrdup(operand1->type, GFP_KERNEL); + if (!expr->type) { + ret = -ENOMEM; + goto free; + } + + return expr; + free: + destroy_hist_field(expr, 0); + return ERR_PTR(ret); +} + +static int check_expr_operands(struct trace_array *tr, + struct hist_field *operand1, + struct hist_field *operand2) +{ + unsigned long operand1_flags = operand1->flags; + unsigned long operand2_flags = operand2->flags; + + if ((operand1_flags & HIST_FIELD_FL_VAR_REF) || + (operand1_flags & HIST_FIELD_FL_ALIAS)) { + struct hist_field *var; + + var = find_var_field(operand1->var.hist_data, operand1->name); + if (!var) + return -EINVAL; + operand1_flags = var->flags; + } + + if ((operand2_flags & HIST_FIELD_FL_VAR_REF) || + (operand2_flags & HIST_FIELD_FL_ALIAS)) { + struct hist_field *var; + + var = find_var_field(operand2->var.hist_data, operand2->name); + if (!var) + return -EINVAL; + operand2_flags = var->flags; + } + + if ((operand1_flags & HIST_FIELD_FL_TIMESTAMP_USECS) != + (operand2_flags & HIST_FIELD_FL_TIMESTAMP_USECS)) { + hist_err(tr, HIST_ERR_TIMESTAMP_MISMATCH, 0); + return -EINVAL; + } + + return 0; +} + +static struct hist_field *parse_expr(struct hist_trigger_data *hist_data, + struct trace_event_file *file, + char *str, unsigned long flags, + char *var_name, unsigned int level) +{ + struct hist_field *operand1 = NULL, *operand2 = NULL, *expr = NULL; + unsigned long operand_flags; + int field_op, ret = -EINVAL; + char *sep, *operand1_str; + + if (level > 3) { + hist_err(file->tr, HIST_ERR_TOO_MANY_SUBEXPR, errpos(str)); + return ERR_PTR(-EINVAL); + } + + field_op = contains_operator(str); + + if (field_op == FIELD_OP_NONE) + return parse_atom(hist_data, file, str, &flags, var_name); + + if (field_op == FIELD_OP_UNARY_MINUS) + return parse_unary(hist_data, file, str, flags, var_name, ++level); + + switch (field_op) { + case FIELD_OP_MINUS: + sep = "-"; + break; + case FIELD_OP_PLUS: + sep = "+"; + break; + default: + goto free; + } + + operand1_str = strsep(&str, sep); + if (!operand1_str || !str) + goto free; + + operand_flags = 0; + operand1 = parse_atom(hist_data, file, operand1_str, + &operand_flags, NULL); + if (IS_ERR(operand1)) { + ret = PTR_ERR(operand1); + operand1 = NULL; + goto free; + } + if (operand1->flags & HIST_FIELD_FL_STRING) { + hist_err(file->tr, HIST_ERR_INVALID_STR_OPERAND, errpos(operand1_str)); + ret = -EINVAL; + goto free; + } + + /* rest of string could be another expression e.g. b+c in a+b+c */ + operand_flags = 0; + operand2 = parse_expr(hist_data, file, str, operand_flags, NULL, ++level); + if (IS_ERR(operand2)) { + ret = PTR_ERR(operand2); + operand2 = NULL; + goto free; + } + if (operand2->flags & HIST_FIELD_FL_STRING) { + hist_err(file->tr, HIST_ERR_INVALID_STR_OPERAND, errpos(str)); + ret = -EINVAL; + goto free; + } + + ret = check_expr_operands(file->tr, operand1, operand2); + if (ret) + goto free; + + flags |= HIST_FIELD_FL_EXPR; + + flags |= operand1->flags & + (HIST_FIELD_FL_TIMESTAMP | HIST_FIELD_FL_TIMESTAMP_USECS); + + expr = create_hist_field(hist_data, NULL, flags, var_name); + if (!expr) { + ret = -ENOMEM; + goto free; + } + + operand1->read_once = true; + operand2->read_once = true; + + expr->operands[0] = operand1; + expr->operands[1] = operand2; + + /* The operand sizes should be the same, so just pick one */ + expr->size = operand1->size; + expr->is_signed = operand1->is_signed; + + expr->operator = field_op; + expr->name = expr_str(expr, 0); + expr->type = kstrdup(operand1->type, GFP_KERNEL); + if (!expr->type) { + ret = -ENOMEM; + goto free; + } + + switch (field_op) { + case FIELD_OP_MINUS: + expr->fn = hist_field_minus; + break; + case FIELD_OP_PLUS: + expr->fn = hist_field_plus; + break; + default: + ret = -EINVAL; + goto free; + } + + return expr; + free: + destroy_hist_field(operand1, 0); + destroy_hist_field(operand2, 0); + destroy_hist_field(expr, 0); + + return ERR_PTR(ret); +} + +static char *find_trigger_filter(struct hist_trigger_data *hist_data, + struct trace_event_file *file) +{ + struct event_trigger_data *test; + + lockdep_assert_held(&event_mutex); + + list_for_each_entry(test, &file->triggers, list) { + if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) { + if (test->private_data == hist_data) + return test->filter_str; + } + } + + return NULL; +} + +static struct event_command trigger_hist_cmd; +static int event_hist_trigger_func(struct event_command *cmd_ops, + struct trace_event_file *file, + char *glob, char *cmd, char *param); + +static bool compatible_keys(struct hist_trigger_data *target_hist_data, + struct hist_trigger_data *hist_data, + unsigned int n_keys) +{ + struct hist_field *target_hist_field, *hist_field; + unsigned int n, i, j; + + if (hist_data->n_fields - hist_data->n_vals != n_keys) + return false; + + i = hist_data->n_vals; + j = target_hist_data->n_vals; + + for (n = 0; n < n_keys; n++) { + hist_field = hist_data->fields[i + n]; + target_hist_field = target_hist_data->fields[j + n]; + + if (strcmp(hist_field->type, target_hist_field->type) != 0) + return false; + if (hist_field->size != target_hist_field->size) + return false; + if (hist_field->is_signed != target_hist_field->is_signed) + return false; + } + + return true; +} + +static struct hist_trigger_data * +find_compatible_hist(struct hist_trigger_data *target_hist_data, + struct trace_event_file *file) +{ + struct hist_trigger_data *hist_data; + struct event_trigger_data *test; + unsigned int n_keys; + + lockdep_assert_held(&event_mutex); + + n_keys = target_hist_data->n_fields - target_hist_data->n_vals; + + list_for_each_entry(test, &file->triggers, list) { + if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) { + hist_data = test->private_data; + + if (compatible_keys(target_hist_data, hist_data, n_keys)) + return hist_data; + } + } + + return NULL; +} + +static struct trace_event_file *event_file(struct trace_array *tr, + char *system, char *event_name) +{ + struct trace_event_file *file; + + file = __find_event_file(tr, system, event_name); + if (!file) + return ERR_PTR(-EINVAL); + + return file; +} + +static struct hist_field * +find_synthetic_field_var(struct hist_trigger_data *target_hist_data, + char *system, char *event_name, char *field_name) +{ + struct hist_field *event_var; + char *synthetic_name; + + synthetic_name = kzalloc(MAX_FILTER_STR_VAL, GFP_KERNEL); + if (!synthetic_name) + return ERR_PTR(-ENOMEM); + + strcpy(synthetic_name, "synthetic_"); + strcat(synthetic_name, field_name); + + event_var = find_event_var(target_hist_data, system, event_name, synthetic_name); + + kfree(synthetic_name); + + return event_var; +} + +/** + * create_field_var_hist - Automatically create a histogram and var for a field + * @target_hist_data: The target hist trigger + * @subsys_name: Optional subsystem name + * @event_name: Optional event name + * @field_name: The name of the field (and the resulting variable) + * + * Hist trigger actions fetch data from variables, not directly from + * events. However, for convenience, users are allowed to directly + * specify an event field in an action, which will be automatically + * converted into a variable on their behalf. + + * If a user specifies a field on an event that isn't the event the + * histogram currently being defined (the target event histogram), the + * only way that can be accomplished is if a new hist trigger is + * created and the field variable defined on that. + * + * This function creates a new histogram compatible with the target + * event (meaning a histogram with the same key as the target + * histogram), and creates a variable for the specified field, but + * with 'synthetic_' prepended to the variable name in order to avoid + * collision with normal field variables. + * + * Return: The variable created for the field. + */ +static struct hist_field * +create_field_var_hist(struct hist_trigger_data *target_hist_data, + char *subsys_name, char *event_name, char *field_name) +{ + struct trace_array *tr = target_hist_data->event_file->tr; + struct hist_field *event_var = ERR_PTR(-EINVAL); + struct hist_trigger_data *hist_data; + unsigned int i, n, first = true; + struct field_var_hist *var_hist; + struct trace_event_file *file; + struct hist_field *key_field; + char *saved_filter; + char *cmd; + int ret; + + if (target_hist_data->n_field_var_hists >= SYNTH_FIELDS_MAX) { + hist_err(tr, HIST_ERR_TOO_MANY_FIELD_VARS, errpos(field_name)); + return ERR_PTR(-EINVAL); + } + + file = event_file(tr, subsys_name, event_name); + + if (IS_ERR(file)) { + hist_err(tr, HIST_ERR_EVENT_FILE_NOT_FOUND, errpos(field_name)); + ret = PTR_ERR(file); + return ERR_PTR(ret); + } + + /* + * Look for a histogram compatible with target. We'll use the + * found histogram specification to create a new matching + * histogram with our variable on it. target_hist_data is not + * yet a registered histogram so we can't use that. + */ + hist_data = find_compatible_hist(target_hist_data, file); + if (!hist_data) { + hist_err(tr, HIST_ERR_HIST_NOT_FOUND, errpos(field_name)); + return ERR_PTR(-EINVAL); + } + + /* See if a synthetic field variable has already been created */ + event_var = find_synthetic_field_var(target_hist_data, subsys_name, + event_name, field_name); + if (!IS_ERR_OR_NULL(event_var)) + return event_var; + + var_hist = kzalloc(sizeof(*var_hist), GFP_KERNEL); + if (!var_hist) + return ERR_PTR(-ENOMEM); + + cmd = kzalloc(MAX_FILTER_STR_VAL, GFP_KERNEL); + if (!cmd) { + kfree(var_hist); + return ERR_PTR(-ENOMEM); + } + + /* Use the same keys as the compatible histogram */ + strcat(cmd, "keys="); + + for_each_hist_key_field(i, hist_data) { + key_field = hist_data->fields[i]; + if (!first) + strcat(cmd, ","); + strcat(cmd, key_field->field->name); + first = false; + } + + /* Create the synthetic field variable specification */ + strcat(cmd, ":synthetic_"); + strcat(cmd, field_name); + strcat(cmd, "="); + strcat(cmd, field_name); + + /* Use the same filter as the compatible histogram */ + saved_filter = find_trigger_filter(hist_data, file); + if (saved_filter) { + strcat(cmd, " if "); + strcat(cmd, saved_filter); + } + + var_hist->cmd = kstrdup(cmd, GFP_KERNEL); + if (!var_hist->cmd) { + kfree(cmd); + kfree(var_hist); + return ERR_PTR(-ENOMEM); + } + + /* Save the compatible histogram information */ + var_hist->hist_data = hist_data; + + /* Create the new histogram with our variable */ + ret = event_hist_trigger_func(&trigger_hist_cmd, file, + "", "hist", cmd); + if (ret) { + kfree(cmd); + kfree(var_hist->cmd); + kfree(var_hist); + hist_err(tr, HIST_ERR_HIST_CREATE_FAIL, errpos(field_name)); + return ERR_PTR(ret); + } + + kfree(cmd); + + /* If we can't find the variable, something went wrong */ + event_var = find_synthetic_field_var(target_hist_data, subsys_name, + event_name, field_name); + if (IS_ERR_OR_NULL(event_var)) { + kfree(var_hist->cmd); + kfree(var_hist); + hist_err(tr, HIST_ERR_SYNTH_VAR_NOT_FOUND, errpos(field_name)); + return ERR_PTR(-EINVAL); + } + + n = target_hist_data->n_field_var_hists; + target_hist_data->field_var_hists[n] = var_hist; + target_hist_data->n_field_var_hists++; + + return event_var; +} + +static struct hist_field * +find_target_event_var(struct hist_trigger_data *hist_data, + char *subsys_name, char *event_name, char *var_name) +{ + struct trace_event_file *file = hist_data->event_file; + struct hist_field *hist_field = NULL; + + if (subsys_name) { + struct trace_event_call *call; + + if (!event_name) + return NULL; + + call = file->event_call; + + if (strcmp(subsys_name, call->class->system) != 0) + return NULL; + + if (strcmp(event_name, trace_event_name(call)) != 0) + return NULL; + } + + hist_field = find_var_field(hist_data, var_name); + + return hist_field; +} + +static inline void __update_field_vars(struct tracing_map_elt *elt, + struct ring_buffer_event *rbe, + void *rec, + struct field_var **field_vars, + unsigned int n_field_vars, + unsigned int field_var_str_start) +{ + struct hist_elt_data *elt_data = elt->private_data; + unsigned int i, j, var_idx; + u64 var_val; + + for (i = 0, j = field_var_str_start; i < n_field_vars; i++) { + struct field_var *field_var = field_vars[i]; + struct hist_field *var = field_var->var; + struct hist_field *val = field_var->val; + + var_val = val->fn(val, elt, rbe, rec); + var_idx = var->var.idx; + + if (val->flags & HIST_FIELD_FL_STRING) { + char *str = elt_data->field_var_str[j++]; + char *val_str = (char *)(uintptr_t)var_val; + unsigned int size; + + size = min(val->size, STR_VAR_LEN_MAX); + strscpy(str, val_str, size); + var_val = (u64)(uintptr_t)str; + } + tracing_map_set_var(elt, var_idx, var_val); + } +} + +static void update_field_vars(struct hist_trigger_data *hist_data, + struct tracing_map_elt *elt, + struct ring_buffer_event *rbe, + void *rec) +{ + __update_field_vars(elt, rbe, rec, hist_data->field_vars, + hist_data->n_field_vars, 0); +} + +static void save_track_data_vars(struct hist_trigger_data *hist_data, + struct tracing_map_elt *elt, void *rec, + struct ring_buffer_event *rbe, void *key, + struct action_data *data, u64 *var_ref_vals) +{ + __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, + struct trace_event_file *file, + char *name, int size, const char *type) +{ + struct hist_field *var; + int idx; + + if (find_var(hist_data, file, name) && !hist_data->remove) { + var = ERR_PTR(-EINVAL); + goto out; + } + + var = kzalloc(sizeof(struct hist_field), GFP_KERNEL); + if (!var) { + var = ERR_PTR(-ENOMEM); + goto out; + } + + idx = tracing_map_add_var(hist_data->map); + if (idx < 0) { + kfree(var); + var = ERR_PTR(-EINVAL); + goto out; + } + + var->ref = 1; + var->flags = HIST_FIELD_FL_VAR; + var->var.idx = idx; + var->var.hist_data = var->hist_data = hist_data; + var->size = size; + var->var.name = kstrdup(name, GFP_KERNEL); + var->type = kstrdup(type, GFP_KERNEL); + if (!var->var.name || !var->type) { + kfree(var->var.name); + kfree(var->type); + kfree(var); + var = ERR_PTR(-ENOMEM); + } + out: + return var; +} + +static struct field_var *create_field_var(struct hist_trigger_data *hist_data, + struct trace_event_file *file, + char *field_name) +{ + struct hist_field *val = NULL, *var = NULL; + unsigned long flags = HIST_FIELD_FL_VAR; + struct trace_array *tr = file->tr; + struct field_var *field_var; + int ret = 0; + + if (hist_data->n_field_vars >= SYNTH_FIELDS_MAX) { + hist_err(tr, HIST_ERR_TOO_MANY_FIELD_VARS, errpos(field_name)); + ret = -EINVAL; + goto err; + } + + val = parse_atom(hist_data, file, field_name, &flags, NULL); + if (IS_ERR(val)) { + hist_err(tr, HIST_ERR_FIELD_VAR_PARSE_FAIL, errpos(field_name)); + ret = PTR_ERR(val); + goto err; + } + + var = create_var(hist_data, file, field_name, val->size, val->type); + if (IS_ERR(var)) { + hist_err(tr, HIST_ERR_VAR_CREATE_FIND_FAIL, errpos(field_name)); + kfree(val); + ret = PTR_ERR(var); + goto err; + } + + field_var = kzalloc(sizeof(struct field_var), GFP_KERNEL); + if (!field_var) { + kfree(val); + kfree(var); + ret = -ENOMEM; + goto err; + } + + field_var->var = var; + field_var->val = val; + out: + return field_var; + err: + field_var = ERR_PTR(ret); + goto out; +} + +/** + * create_target_field_var - Automatically create a variable for a field + * @target_hist_data: The target hist trigger + * @subsys_name: Optional subsystem name + * @event_name: Optional event name + * @var_name: The name of the field (and the resulting variable) + * + * Hist trigger actions fetch data from variables, not directly from + * events. However, for convenience, users are allowed to directly + * specify an event field in an action, which will be automatically + * converted into a variable on their behalf. + + * This function creates a field variable with the name var_name on + * the hist trigger currently being defined on the target event. If + * subsys_name and event_name are specified, this function simply + * verifies that they do in fact match the target event subsystem and + * event name. + * + * Return: The variable created for the field. + */ +static struct field_var * +create_target_field_var(struct hist_trigger_data *target_hist_data, + char *subsys_name, char *event_name, char *var_name) +{ + struct trace_event_file *file = target_hist_data->event_file; + + if (subsys_name) { + struct trace_event_call *call; + + if (!event_name) + return NULL; + + call = file->event_call; + + if (strcmp(subsys_name, call->class->system) != 0) + return NULL; + + if (strcmp(event_name, trace_event_name(call)) != 0) + return NULL; + } + + return create_field_var(target_hist_data, file, var_name); +} + +static bool check_track_val_max(u64 track_val, u64 var_val) +{ + if (var_val <= track_val) + return false; + + return true; +} + +static bool check_track_val_changed(u64 track_val, u64 var_val) +{ + if (var_val == track_val) + return false; + + return true; +} + +static u64 get_track_val(struct hist_trigger_data *hist_data, + struct tracing_map_elt *elt, + struct action_data *data) +{ + unsigned int track_var_idx = data->track_data.track_var->var.idx; + u64 track_val; + + track_val = tracing_map_read_var(elt, track_var_idx); + + return track_val; +} + +static void save_track_val(struct hist_trigger_data *hist_data, + struct tracing_map_elt *elt, + struct action_data *data, u64 var_val) +{ + unsigned int track_var_idx = data->track_data.track_var->var.idx; + + tracing_map_set_var(elt, track_var_idx, var_val); +} + +static void save_track_data(struct hist_trigger_data *hist_data, + struct tracing_map_elt *elt, void *rec, + struct ring_buffer_event *rbe, void *key, + struct action_data *data, u64 *var_ref_vals) +{ + if (data->track_data.save_data) + data->track_data.save_data(hist_data, elt, rec, rbe, key, data, var_ref_vals); +} + +static bool check_track_val(struct tracing_map_elt *elt, + struct action_data *data, + u64 var_val) +{ + struct hist_trigger_data *hist_data; + u64 track_val; + + hist_data = data->track_data.track_var->hist_data; + track_val = get_track_val(hist_data, elt, data); + + return data->track_data.check_val(track_val, var_val); +} + +#ifdef CONFIG_TRACER_SNAPSHOT +static bool cond_snapshot_update(struct trace_array *tr, void *cond_data) +{ + /* called with tr->max_lock held */ + struct track_data *track_data = tr->cond_snapshot->cond_data; + struct hist_elt_data *elt_data, *track_elt_data; + struct snapshot_context *context = cond_data; + struct action_data *action; + u64 track_val; + + if (!track_data) + return false; + + action = track_data->action_data; + + track_val = get_track_val(track_data->hist_data, context->elt, + track_data->action_data); + + if (!action->track_data.check_val(track_data->track_val, track_val)) + return false; + + track_data->track_val = track_val; + memcpy(track_data->key, context->key, track_data->key_len); + + elt_data = context->elt->private_data; + track_elt_data = track_data->elt.private_data; + if (elt_data->comm) + strncpy(track_elt_data->comm, elt_data->comm, TASK_COMM_LEN); + + track_data->updated = true; + + return true; +} + +static void save_track_data_snapshot(struct hist_trigger_data *hist_data, + struct tracing_map_elt *elt, void *rec, + struct ring_buffer_event *rbe, void *key, + struct action_data *data, + u64 *var_ref_vals) +{ + struct trace_event_file *file = hist_data->event_file; + struct snapshot_context context; + + context.elt = elt; + context.key = key; + + tracing_snapshot_cond(file->tr, &context); +} + +static void hist_trigger_print_key(struct seq_file *m, + struct hist_trigger_data *hist_data, + void *key, + struct tracing_map_elt *elt); + +static struct action_data *snapshot_action(struct hist_trigger_data *hist_data) +{ + unsigned int i; + + if (!hist_data->n_actions) + return NULL; + + for (i = 0; i < hist_data->n_actions; i++) { + struct action_data *data = hist_data->actions[i]; + + if (data->action == ACTION_SNAPSHOT) + return data; + } + + return NULL; +} + +static void track_data_snapshot_print(struct seq_file *m, + struct hist_trigger_data *hist_data) +{ + struct trace_event_file *file = hist_data->event_file; + struct track_data *track_data; + struct action_data *action; + + track_data = tracing_cond_snapshot_data(file->tr); + if (!track_data) + return; + + if (!track_data->updated) + return; + + action = snapshot_action(hist_data); + if (!action) + return; + + seq_puts(m, "\nSnapshot taken (see tracing/snapshot). Details:\n"); + seq_printf(m, "\ttriggering value { %s(%s) }: %10llu", + action->handler == HANDLER_ONMAX ? "onmax" : "onchange", + action->track_data.var_str, track_data->track_val); + + seq_puts(m, "\ttriggered by event with key: "); + hist_trigger_print_key(m, hist_data, track_data->key, &track_data->elt); + seq_putc(m, '\n'); +} +#else +static bool cond_snapshot_update(struct trace_array *tr, void *cond_data) +{ + return false; +} +static void save_track_data_snapshot(struct hist_trigger_data *hist_data, + struct tracing_map_elt *elt, void *rec, + struct ring_buffer_event *rbe, void *key, + struct action_data *data, + u64 *var_ref_vals) {} +static void track_data_snapshot_print(struct seq_file *m, + struct hist_trigger_data *hist_data) {} +#endif /* CONFIG_TRACER_SNAPSHOT */ + +static void track_data_print(struct seq_file *m, + struct hist_trigger_data *hist_data, + struct tracing_map_elt *elt, + struct action_data *data) +{ + u64 track_val = get_track_val(hist_data, elt, data); + unsigned int i, save_var_idx; + + if (data->handler == HANDLER_ONMAX) + seq_printf(m, "\n\tmax: %10llu", track_val); + else if (data->handler == HANDLER_ONCHANGE) + seq_printf(m, "\n\tchanged: %10llu", track_val); + + if (data->action == ACTION_SNAPSHOT) + return; + + 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; + + val = tracing_map_read_var(elt, save_var_idx); + + if (save_val->flags & HIST_FIELD_FL_STRING) { + seq_printf(m, " %s: %-32s", save_var->var.name, + (char *)(uintptr_t)(val)); + } else + seq_printf(m, " %s: %10llu", save_var->var.name, val); + } +} + +static void ontrack_action(struct hist_trigger_data *hist_data, + struct tracing_map_elt *elt, void *rec, + struct ring_buffer_event *rbe, void *key, + struct action_data *data, u64 *var_ref_vals) +{ + u64 var_val = var_ref_vals[data->track_data.var_ref->var_ref_idx]; + + if (check_track_val(elt, data, var_val)) { + save_track_val(hist_data, elt, data, var_val); + save_track_data(hist_data, elt, rec, rbe, key, data, var_ref_vals); + } +} + +static void action_data_destroy(struct action_data *data) +{ + unsigned int i; + + lockdep_assert_held(&event_mutex); + + kfree(data->action_name); + + for (i = 0; i < data->n_params; i++) + kfree(data->params[i]); + + if (data->synth_event) + data->synth_event->ref--; + + kfree(data->synth_event_name); + + kfree(data); +} + +static void track_data_destroy(struct hist_trigger_data *hist_data, + struct action_data *data) +{ + struct trace_event_file *file = hist_data->event_file; + + destroy_hist_field(data->track_data.track_var, 0); + + if (data->action == ACTION_SNAPSHOT) { + struct track_data *track_data; + + track_data = tracing_cond_snapshot_data(file->tr); + if (track_data && track_data->hist_data == hist_data) { + tracing_snapshot_cond_disable(file->tr); + track_data_free(track_data); + } + } + + kfree(data->track_data.var_str); + + action_data_destroy(data); +} + +static int action_create(struct hist_trigger_data *hist_data, + struct action_data *data); + +static int track_data_create(struct hist_trigger_data *hist_data, + struct action_data *data) +{ + struct hist_field *var_field, *ref_field, *track_var = NULL; + struct trace_event_file *file = hist_data->event_file; + struct trace_array *tr = file->tr; + char *track_data_var_str; + int ret = 0; + + track_data_var_str = data->track_data.var_str; + if (track_data_var_str[0] != '$') { + hist_err(tr, HIST_ERR_ONX_NOT_VAR, errpos(track_data_var_str)); + return -EINVAL; + } + track_data_var_str++; + + var_field = find_target_event_var(hist_data, NULL, NULL, track_data_var_str); + if (!var_field) { + hist_err(tr, HIST_ERR_ONX_VAR_NOT_FOUND, errpos(track_data_var_str)); + return -EINVAL; + } + + ref_field = create_var_ref(hist_data, var_field, NULL, NULL); + if (!ref_field) + return -ENOMEM; + + data->track_data.var_ref = ref_field; + + if (data->handler == HANDLER_ONMAX) + track_var = create_var(hist_data, file, "__max", sizeof(u64), "u64"); + if (IS_ERR(track_var)) { + hist_err(tr, HIST_ERR_ONX_VAR_CREATE_FAIL, 0); + ret = PTR_ERR(track_var); + goto out; + } + + if (data->handler == HANDLER_ONCHANGE) + track_var = create_var(hist_data, file, "__change", sizeof(u64), "u64"); + if (IS_ERR(track_var)) { + hist_err(tr, HIST_ERR_ONX_VAR_CREATE_FAIL, 0); + ret = PTR_ERR(track_var); + goto out; + } + data->track_data.track_var = track_var; + + ret = action_create(hist_data, data); + out: + return ret; +} + +static int parse_action_params(struct trace_array *tr, char *params, + struct action_data *data) +{ + char *param, *saved_param; + bool first_param = true; + int ret = 0; + + while (params) { + if (data->n_params >= SYNTH_FIELDS_MAX) { + hist_err(tr, HIST_ERR_TOO_MANY_PARAMS, 0); + ret = -EINVAL; + goto out; + } + + param = strsep(¶ms, ","); + if (!param) { + hist_err(tr, HIST_ERR_PARAM_NOT_FOUND, 0); + ret = -EINVAL; + goto out; + } + + param = strstrip(param); + if (strlen(param) < 2) { + hist_err(tr, HIST_ERR_INVALID_PARAM, errpos(param)); + ret = -EINVAL; + goto out; + } + + saved_param = kstrdup(param, GFP_KERNEL); + if (!saved_param) { + ret = -ENOMEM; + goto out; + } + + if (first_param && data->use_trace_keyword) { + data->synth_event_name = saved_param; + first_param = false; + continue; + } + first_param = false; + + data->params[data->n_params++] = saved_param; + } + out: + return ret; +} + +static int action_parse(struct trace_array *tr, char *str, struct action_data *data, + enum handler_id handler) +{ + char *action_name; + int ret = 0; + + strsep(&str, "."); + if (!str) { + hist_err(tr, HIST_ERR_ACTION_NOT_FOUND, 0); + ret = -EINVAL; + goto out; + } + + action_name = strsep(&str, "("); + if (!action_name || !str) { + hist_err(tr, HIST_ERR_ACTION_NOT_FOUND, 0); + ret = -EINVAL; + goto out; + } + + if (str_has_prefix(action_name, "save")) { + char *params = strsep(&str, ")"); + + if (!params) { + hist_err(tr, HIST_ERR_NO_SAVE_PARAMS, 0); + ret = -EINVAL; + goto out; + } + + ret = parse_action_params(tr, params, data); + if (ret) + goto out; + + if (handler == HANDLER_ONMAX) + data->track_data.check_val = check_track_val_max; + else if (handler == HANDLER_ONCHANGE) + data->track_data.check_val = check_track_val_changed; + else { + hist_err(tr, HIST_ERR_ACTION_MISMATCH, errpos(action_name)); + ret = -EINVAL; + goto out; + } + + data->track_data.save_data = save_track_data_vars; + data->fn = ontrack_action; + data->action = ACTION_SAVE; + } else if (str_has_prefix(action_name, "snapshot")) { + char *params = strsep(&str, ")"); + + if (!str) { + hist_err(tr, HIST_ERR_NO_CLOSING_PAREN, errpos(params)); + ret = -EINVAL; + goto out; + } + + if (handler == HANDLER_ONMAX) + data->track_data.check_val = check_track_val_max; + else if (handler == HANDLER_ONCHANGE) + data->track_data.check_val = check_track_val_changed; + else { + hist_err(tr, HIST_ERR_ACTION_MISMATCH, errpos(action_name)); + ret = -EINVAL; + goto out; + } + + data->track_data.save_data = save_track_data_snapshot; + data->fn = ontrack_action; + data->action = ACTION_SNAPSHOT; + } else { + char *params = strsep(&str, ")"); + + if (str_has_prefix(action_name, "trace")) + data->use_trace_keyword = true; + + if (params) { + ret = parse_action_params(tr, params, data); + if (ret) + goto out; + } + + if (handler == HANDLER_ONMAX) + data->track_data.check_val = check_track_val_max; + else if (handler == HANDLER_ONCHANGE) + data->track_data.check_val = check_track_val_changed; + + if (handler != HANDLER_ONMATCH) { + data->track_data.save_data = action_trace; + data->fn = ontrack_action; + } else + 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 *track_data_parse(struct hist_trigger_data *hist_data, + char *str, enum handler_id handler) +{ + struct action_data *data; + int ret = -EINVAL; + char *var_str; + + data = kzalloc(sizeof(*data), GFP_KERNEL); + if (!data) + return ERR_PTR(-ENOMEM); + + var_str = strsep(&str, ")"); + if (!var_str || !str) { + ret = -EINVAL; + goto free; + } + + data->track_data.var_str = kstrdup(var_str, GFP_KERNEL); + if (!data->track_data.var_str) { + ret = -ENOMEM; + goto free; + } + + ret = action_parse(hist_data->event_file->tr, str, data, handler); + if (ret) + goto free; + out: + return data; + free: + track_data_destroy(hist_data, data); + data = ERR_PTR(ret); + goto out; +} + +static void onmatch_destroy(struct action_data *data) +{ + kfree(data->match_data.event); + kfree(data->match_data.event_system); + + action_data_destroy(data); +} + +static void destroy_field_var(struct field_var *field_var) +{ + if (!field_var) + return; + + destroy_hist_field(field_var->var, 0); + destroy_hist_field(field_var->val, 0); + + kfree(field_var); +} + +static void destroy_field_vars(struct hist_trigger_data *hist_data) +{ + unsigned int i; + + for (i = 0; i < hist_data->n_field_vars; i++) + destroy_field_var(hist_data->field_vars[i]); + + for (i = 0; i < hist_data->n_save_vars; i++) + destroy_field_var(hist_data->save_vars[i]); +} + +static void save_field_var(struct hist_trigger_data *hist_data, + struct field_var *field_var) +{ + hist_data->field_vars[hist_data->n_field_vars++] = field_var; + + if (field_var->val->flags & HIST_FIELD_FL_STRING) + hist_data->n_field_var_str++; +} + + +static int check_synth_field(struct synth_event *event, + struct hist_field *hist_field, + unsigned int field_pos) +{ + struct synth_field *field; + + if (field_pos >= event->n_fields) + return -EINVAL; + + field = event->fields[field_pos]; + + /* + * A dynamic string synth field can accept static or + * dynamic. A static string synth field can only accept a + * same-sized static string, which is checked for later. + */ + if (strstr(hist_field->type, "char[") && field->is_string + && field->is_dynamic) + return 0; + + if (strcmp(field->type, hist_field->type) != 0) { + if (field->size != hist_field->size || + (!field->is_string && field->is_signed != hist_field->is_signed)) + return -EINVAL; + } + + return 0; +} + +static struct hist_field * +trace_action_find_var(struct hist_trigger_data *hist_data, + struct action_data *data, + char *system, char *event, char *var) +{ + struct trace_array *tr = hist_data->event_file->tr; + struct hist_field *hist_field; + + var++; /* skip '$' */ + + hist_field = find_target_event_var(hist_data, system, event, var); + if (!hist_field) { + if (!system && data->handler == HANDLER_ONMATCH) { + system = data->match_data.event_system; + event = data->match_data.event; + } + + hist_field = find_event_var(hist_data, system, event, var); + } + + if (!hist_field) + hist_err(tr, HIST_ERR_PARAM_NOT_FOUND, errpos(var)); + + return hist_field; +} + +static struct hist_field * +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; + + /* + * First try to create a field var on the target event (the + * currently being defined). This will create a variable for + * unqualified fields on the target event, or if qualified, + * target fields that have qualified names matching the target. + */ + field_var = create_target_field_var(hist_data, system, event, var); + + if (field_var && !IS_ERR(field_var)) { + save_field_var(hist_data, field_var); + hist_field = field_var->var; + } else { + field_var = NULL; + /* + * If no explicit system.event is specfied, default to + * looking for fields on the onmatch(system.event.xxx) + * event. + */ + if (!system && data->handler == HANDLER_ONMATCH) { + system = data->match_data.event_system; + event = data->match_data.event; + } + + if (!event) + goto free; + /* + * At this point, we're looking at a field on another + * event. Because we can't modify a hist trigger on + * another event to add a variable for a field, we need + * to create a new trigger on that event and create the + * variable at the same time. + */ + hist_field = create_field_var_hist(hist_data, system, event, var); + if (IS_ERR(hist_field)) + goto free; + } + out: + return hist_field; + free: + destroy_field_var(field_var); + hist_field = NULL; + goto out; +} + +static int trace_action_create(struct hist_trigger_data *hist_data, + struct action_data *data) +{ + struct trace_array *tr = hist_data->event_file->tr; + char *event_name, *param, *system = NULL; + struct hist_field *hist_field, *var_ref; + unsigned int i; + unsigned int field_pos = 0; + struct synth_event *event; + char *synth_event_name; + int var_ref_idx, ret = 0; + + lockdep_assert_held(&event_mutex); + + /* Sanity check to avoid out-of-bound write on 'data->var_ref_idx' */ + if (data->n_params > SYNTH_FIELDS_MAX) + return -EINVAL; + + if (data->use_trace_keyword) + synth_event_name = data->synth_event_name; + else + synth_event_name = data->action_name; + + event = find_synth_event(synth_event_name); + if (!event) { + hist_err(tr, HIST_ERR_SYNTH_EVENT_NOT_FOUND, errpos(synth_event_name)); + return -EINVAL; + } + + event->ref++; + + for (i = 0; i < data->n_params; i++) { + char *p; + + p = param = kstrdup(data->params[i], GFP_KERNEL); + if (!param) { + ret = -ENOMEM; + goto err; + } + + system = strsep(¶m, "."); + if (!param) { + param = (char *)system; + system = event_name = NULL; + } else { + event_name = strsep(¶m, "."); + if (!param) { + kfree(p); + ret = -EINVAL; + goto err; + } + } + + if (param[0] == '$') + hist_field = trace_action_find_var(hist_data, data, + system, event_name, + param); + else + hist_field = trace_action_create_field_var(hist_data, + data, + system, + event_name, + param); + + if (!hist_field) { + kfree(p); + ret = -EINVAL; + goto err; + } + + if (check_synth_field(event, hist_field, field_pos) == 0) { + var_ref = create_var_ref(hist_data, hist_field, + system, event_name); + if (!var_ref) { + kfree(p); + ret = -ENOMEM; + goto err; + } + + var_ref_idx = find_var_ref_idx(hist_data, var_ref); + if (WARN_ON(var_ref_idx < 0)) { + kfree(p); + ret = var_ref_idx; + goto err; + } + + data->var_ref_idx[i] = var_ref_idx; + + field_pos++; + kfree(p); + continue; + } + + hist_err(tr, HIST_ERR_SYNTH_TYPE_MISMATCH, errpos(param)); + kfree(p); + ret = -EINVAL; + goto err; + } + + if (field_pos != event->n_fields) { + hist_err(tr, HIST_ERR_SYNTH_COUNT_MISMATCH, errpos(event->name)); + ret = -EINVAL; + goto err; + } + + data->synth_event = event; + out: + return ret; + err: + event->ref--; + + goto out; +} + +static int action_create(struct hist_trigger_data *hist_data, + struct action_data *data) +{ + struct trace_event_file *file = hist_data->event_file; + struct trace_array *tr = file->tr; + struct track_data *track_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_SNAPSHOT) { + track_data = track_data_alloc(hist_data->key_size, data, hist_data); + if (IS_ERR(track_data)) { + ret = PTR_ERR(track_data); + goto out; + } + + ret = tracing_snapshot_cond_enable(file->tr, track_data, + cond_snapshot_update); + if (ret) + track_data_free(track_data); + + goto out; + } + + if (data->action == ACTION_SAVE) { + if (hist_data->n_save_vars) { + ret = -EEXIST; + hist_err(tr, HIST_ERR_TOO_MANY_SAVE_ACTIONS, 0); + 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(tr, HIST_ERR_FIELD_VAR_CREATE_FAIL, + errpos(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; + struct action_data *data; + int ret = -EINVAL; + + data = kzalloc(sizeof(*data), GFP_KERNEL); + if (!data) + return ERR_PTR(-ENOMEM); + + match_event = strsep(&str, ")"); + if (!match_event || !str) { + hist_err(tr, HIST_ERR_NO_CLOSING_PAREN, errpos(match_event)); + goto free; + } + + match_event_system = strsep(&match_event, "."); + if (!match_event) { + hist_err(tr, HIST_ERR_SUBSYS_NOT_FOUND, errpos(match_event_system)); + goto free; + } + + if (IS_ERR(event_file(tr, match_event_system, match_event))) { + hist_err(tr, HIST_ERR_INVALID_SUBSYS_EVENT, errpos(match_event)); + goto free; + } + + data->match_data.event = kstrdup(match_event, GFP_KERNEL); + if (!data->match_data.event) { + ret = -ENOMEM; + goto free; + } + + data->match_data.event_system = kstrdup(match_event_system, GFP_KERNEL); + if (!data->match_data.event_system) { + ret = -ENOMEM; + goto free; + } + + ret = action_parse(tr, str, data, HANDLER_ONMATCH); + if (ret) + goto free; + out: + return data; + free: + onmatch_destroy(data); + data = ERR_PTR(ret); + goto out; +} + +static int create_hitcount_val(struct hist_trigger_data *hist_data) +{ + hist_data->fields[HITCOUNT_IDX] = + create_hist_field(hist_data, NULL, HIST_FIELD_FL_HITCOUNT, NULL); + if (!hist_data->fields[HITCOUNT_IDX]) + return -ENOMEM; + + hist_data->n_vals++; + hist_data->n_fields++; + + if (WARN_ON(hist_data->n_vals > TRACING_MAP_VALS_MAX)) + return -EINVAL; + + return 0; +} + +static int __create_val_field(struct hist_trigger_data *hist_data, + unsigned int val_idx, + struct trace_event_file *file, + char *var_name, char *field_str, + unsigned long flags) +{ + struct hist_field *hist_field; + int ret = 0; + + hist_field = parse_expr(hist_data, file, field_str, flags, var_name, 0); + if (IS_ERR(hist_field)) { + ret = PTR_ERR(hist_field); + goto out; + } + + hist_data->fields[val_idx] = hist_field; + + ++hist_data->n_vals; + ++hist_data->n_fields; + + if (WARN_ON(hist_data->n_vals > TRACING_MAP_VALS_MAX + TRACING_MAP_VARS_MAX)) + ret = -EINVAL; + out: + return ret; +} + +static int create_val_field(struct hist_trigger_data *hist_data, + unsigned int val_idx, + struct trace_event_file *file, + char *field_str) +{ + if (WARN_ON(val_idx >= TRACING_MAP_VALS_MAX)) + return -EINVAL; + + return __create_val_field(hist_data, val_idx, file, NULL, field_str, 0); +} + +static int create_var_field(struct hist_trigger_data *hist_data, + unsigned int val_idx, + struct trace_event_file *file, + char *var_name, char *expr_str) +{ + struct trace_array *tr = hist_data->event_file->tr; + unsigned long flags = 0; + int ret; + + if (WARN_ON(val_idx >= TRACING_MAP_VALS_MAX + TRACING_MAP_VARS_MAX)) + return -EINVAL; + + if (find_var(hist_data, file, var_name) && !hist_data->remove) { + hist_err(tr, HIST_ERR_DUPLICATE_VAR, errpos(var_name)); + return -EINVAL; + } + + flags |= HIST_FIELD_FL_VAR; + hist_data->n_vars++; + if (WARN_ON(hist_data->n_vars > TRACING_MAP_VARS_MAX)) + return -EINVAL; + + ret = __create_val_field(hist_data, val_idx, file, var_name, expr_str, flags); + + if (!ret && hist_data->fields[val_idx]->flags & HIST_FIELD_FL_STRING) + hist_data->fields[val_idx]->var_str_idx = hist_data->n_var_str++; + + return ret; +} + +static int create_val_fields(struct hist_trigger_data *hist_data, + struct trace_event_file *file) +{ + char *fields_str, *field_str; + unsigned int i, j = 1; + int ret; + + ret = create_hitcount_val(hist_data); + if (ret) + goto out; + + fields_str = hist_data->attrs->vals_str; + if (!fields_str) + goto out; + + for (i = 0, j = 1; i < TRACING_MAP_VALS_MAX && + j < TRACING_MAP_VALS_MAX; i++) { + field_str = strsep(&fields_str, ","); + if (!field_str) + break; + + if (strcmp(field_str, "hitcount") == 0) + continue; + + ret = create_val_field(hist_data, j++, file, field_str); + if (ret) + goto out; + } + + if (fields_str && (strcmp(fields_str, "hitcount") != 0)) + ret = -EINVAL; + out: + return ret; +} + +static int create_key_field(struct hist_trigger_data *hist_data, + unsigned int key_idx, + unsigned int key_offset, + struct trace_event_file *file, + char *field_str) +{ + struct trace_array *tr = hist_data->event_file->tr; + struct hist_field *hist_field = NULL; + unsigned long flags = 0; + unsigned int key_size; + int ret = 0; + + if (WARN_ON(key_idx >= HIST_FIELDS_MAX)) + return -EINVAL; + + flags |= HIST_FIELD_FL_KEY; + + if (strcmp(field_str, "stacktrace") == 0) { + flags |= HIST_FIELD_FL_STACKTRACE; + key_size = sizeof(unsigned long) * HIST_STACKTRACE_DEPTH; + hist_field = create_hist_field(hist_data, NULL, flags, NULL); + } else { + hist_field = parse_expr(hist_data, file, field_str, flags, + NULL, 0); + if (IS_ERR(hist_field)) { + ret = PTR_ERR(hist_field); + goto out; + } + + if (field_has_hist_vars(hist_field, 0)) { + hist_err(tr, HIST_ERR_INVALID_REF_KEY, errpos(field_str)); + destroy_hist_field(hist_field, 0); + ret = -EINVAL; + goto out; + } + + key_size = hist_field->size; + } + + hist_data->fields[key_idx] = hist_field; + + key_size = ALIGN(key_size, sizeof(u64)); + hist_data->fields[key_idx]->size = key_size; + hist_data->fields[key_idx]->offset = key_offset; + + hist_data->key_size += key_size; + + if (hist_data->key_size > HIST_KEY_SIZE_MAX) { + ret = -EINVAL; + goto out; + } + + hist_data->n_keys++; + hist_data->n_fields++; + + if (WARN_ON(hist_data->n_keys > TRACING_MAP_KEYS_MAX)) + return -EINVAL; + + ret = key_size; + out: + return ret; +} + +static int create_key_fields(struct hist_trigger_data *hist_data, + struct trace_event_file *file) +{ + unsigned int i, key_offset = 0, n_vals = hist_data->n_vals; + char *fields_str, *field_str; + int ret = -EINVAL; + + fields_str = hist_data->attrs->keys_str; + if (!fields_str) + goto out; + + for (i = n_vals; i < n_vals + TRACING_MAP_KEYS_MAX; i++) { + field_str = strsep(&fields_str, ","); + if (!field_str) + break; + ret = create_key_field(hist_data, i, key_offset, + file, field_str); + if (ret < 0) + goto out; + key_offset += ret; + } + if (fields_str) { + ret = -EINVAL; + goto out; + } + ret = 0; + out: + return ret; +} + +static int create_var_fields(struct hist_trigger_data *hist_data, + struct trace_event_file *file) +{ + unsigned int i, j = hist_data->n_vals; + int ret = 0; + + unsigned int n_vars = hist_data->attrs->var_defs.n_vars; + + for (i = 0; i < n_vars; i++) { + char *var_name = hist_data->attrs->var_defs.name[i]; + char *expr = hist_data->attrs->var_defs.expr[i]; + + ret = create_var_field(hist_data, j++, file, var_name, expr); + if (ret) + goto out; + } + out: + return ret; +} + +static void free_var_defs(struct hist_trigger_data *hist_data) +{ + unsigned int i; + + for (i = 0; i < hist_data->attrs->var_defs.n_vars; i++) { + kfree(hist_data->attrs->var_defs.name[i]); + kfree(hist_data->attrs->var_defs.expr[i]); + } + + hist_data->attrs->var_defs.n_vars = 0; +} + +static int parse_var_defs(struct hist_trigger_data *hist_data) +{ + struct trace_array *tr = hist_data->event_file->tr; + char *s, *str, *var_name, *field_str; + unsigned int i, j, n_vars = 0; + int ret = 0; + + for (i = 0; i < hist_data->attrs->n_assignments; i++) { + str = hist_data->attrs->assignment_str[i]; + for (j = 0; j < TRACING_MAP_VARS_MAX; j++) { + field_str = strsep(&str, ","); + if (!field_str) + break; + + var_name = strsep(&field_str, "="); + if (!var_name || !field_str) { + hist_err(tr, HIST_ERR_MALFORMED_ASSIGNMENT, + errpos(var_name)); + ret = -EINVAL; + goto free; + } + + if (n_vars == TRACING_MAP_VARS_MAX) { + hist_err(tr, HIST_ERR_TOO_MANY_VARS, errpos(var_name)); + ret = -EINVAL; + goto free; + } + + s = kstrdup(var_name, GFP_KERNEL); + if (!s) { + ret = -ENOMEM; + goto free; + } + hist_data->attrs->var_defs.name[n_vars] = s; + + s = kstrdup(field_str, GFP_KERNEL); + if (!s) { + kfree(hist_data->attrs->var_defs.name[n_vars]); + hist_data->attrs->var_defs.name[n_vars] = NULL; + ret = -ENOMEM; + goto free; + } + hist_data->attrs->var_defs.expr[n_vars++] = s; + + hist_data->attrs->var_defs.n_vars = n_vars; + } + } + + return ret; + free: + free_var_defs(hist_data); + + return ret; +} + +static int create_hist_fields(struct hist_trigger_data *hist_data, + struct trace_event_file *file) +{ + int ret; + + ret = parse_var_defs(hist_data); + if (ret) + goto out; + + ret = create_val_fields(hist_data, file); + if (ret) + goto out; + + ret = create_var_fields(hist_data, file); + if (ret) + goto out; + + ret = create_key_fields(hist_data, file); + if (ret) + goto out; + out: + free_var_defs(hist_data); + + return ret; +} + +static int is_descending(struct trace_array *tr, const char *str) +{ + if (!str) + return 0; + + if (strcmp(str, "descending") == 0) + return 1; + + if (strcmp(str, "ascending") == 0) + return 0; + + hist_err(tr, HIST_ERR_INVALID_SORT_MODIFIER, errpos((char *)str)); + + return -EINVAL; +} + +static int create_sort_keys(struct hist_trigger_data *hist_data) +{ + struct trace_array *tr = hist_data->event_file->tr; + char *fields_str = hist_data->attrs->sort_key_str; + struct tracing_map_sort_key *sort_key; + int descending, ret = 0; + unsigned int i, j, k; + + hist_data->n_sort_keys = 1; /* we always have at least one, hitcount */ + + if (!fields_str) + goto out; + + for (i = 0; i < TRACING_MAP_SORT_KEYS_MAX; i++) { + struct hist_field *hist_field; + char *field_str, *field_name; + const char *test_name; + + sort_key = &hist_data->sort_keys[i]; + + field_str = strsep(&fields_str, ","); + if (!field_str) + break; + + if (!*field_str) { + ret = -EINVAL; + hist_err(tr, HIST_ERR_EMPTY_SORT_FIELD, errpos("sort=")); + break; + } + + if ((i == TRACING_MAP_SORT_KEYS_MAX - 1) && fields_str) { + hist_err(tr, HIST_ERR_TOO_MANY_SORT_FIELDS, errpos("sort=")); + ret = -EINVAL; + break; + } + + field_name = strsep(&field_str, "."); + if (!field_name || !*field_name) { + ret = -EINVAL; + hist_err(tr, HIST_ERR_EMPTY_SORT_FIELD, errpos("sort=")); + break; + } + + if (strcmp(field_name, "hitcount") == 0) { + descending = is_descending(tr, field_str); + if (descending < 0) { + ret = descending; + break; + } + sort_key->descending = descending; + continue; + } + + for (j = 1, k = 1; j < hist_data->n_fields; j++) { + unsigned int idx; + + hist_field = hist_data->fields[j]; + if (hist_field->flags & HIST_FIELD_FL_VAR) + continue; + + idx = k++; + + test_name = hist_field_name(hist_field, 0); + + if (strcmp(field_name, test_name) == 0) { + sort_key->field_idx = idx; + descending = is_descending(tr, field_str); + if (descending < 0) { + ret = descending; + goto out; + } + sort_key->descending = descending; + break; + } + } + if (j == hist_data->n_fields) { + ret = -EINVAL; + hist_err(tr, HIST_ERR_INVALID_SORT_FIELD, errpos(field_name)); + break; + } + } + + hist_data->n_sort_keys = i; + out: + return ret; +} + +static void destroy_actions(struct hist_trigger_data *hist_data) +{ + unsigned int i; + + for (i = 0; i < hist_data->n_actions; i++) { + struct action_data *data = hist_data->actions[i]; + + if (data->handler == HANDLER_ONMATCH) + onmatch_destroy(data); + else if (data->handler == HANDLER_ONMAX || + data->handler == HANDLER_ONCHANGE) + track_data_destroy(hist_data, data); + else + kfree(data); + } +} + +static int parse_actions(struct hist_trigger_data *hist_data) +{ + struct trace_array *tr = hist_data->event_file->tr; + struct action_data *data; + unsigned int i; + int ret = 0; + char *str; + int len; + + for (i = 0; i < hist_data->attrs->n_actions; i++) { + str = hist_data->attrs->action_str[i]; + + if ((len = str_has_prefix(str, "onmatch("))) { + char *action_str = str + len; + + data = onmatch_parse(tr, action_str); + if (IS_ERR(data)) { + ret = PTR_ERR(data); + break; + } + } else if ((len = str_has_prefix(str, "onmax("))) { + char *action_str = str + len; + + data = track_data_parse(hist_data, action_str, + HANDLER_ONMAX); + if (IS_ERR(data)) { + ret = PTR_ERR(data); + break; + } + } else if ((len = str_has_prefix(str, "onchange("))) { + char *action_str = str + len; + + data = track_data_parse(hist_data, action_str, + HANDLER_ONCHANGE); + if (IS_ERR(data)) { + ret = PTR_ERR(data); + break; + } + } else { + ret = -EINVAL; + break; + } + + hist_data->actions[hist_data->n_actions++] = data; + } + + return ret; +} + +static int create_actions(struct hist_trigger_data *hist_data) +{ + struct action_data *data; + unsigned int i; + int ret = 0; + + for (i = 0; i < hist_data->attrs->n_actions; i++) { + data = hist_data->actions[i]; + + if (data->handler == HANDLER_ONMATCH) { + ret = onmatch_create(hist_data, data); + if (ret) + break; + } else if (data->handler == HANDLER_ONMAX || + data->handler == HANDLER_ONCHANGE) { + ret = track_data_create(hist_data, data); + if (ret) + break; + } else { + ret = -EINVAL; + break; + } + } + + return ret; +} + +static void print_actions(struct seq_file *m, + struct hist_trigger_data *hist_data, + struct tracing_map_elt *elt) +{ + unsigned int i; + + for (i = 0; i < hist_data->n_actions; i++) { + struct action_data *data = hist_data->actions[i]; + + if (data->action == ACTION_SNAPSHOT) + continue; + + if (data->handler == HANDLER_ONMAX || + data->handler == HANDLER_ONCHANGE) + track_data_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) { + if (data->use_trace_keyword) + seq_printf(m, "%s", data->synth_event_name); + for (i = 0; i < data->n_params; i++) { + if (i || data->use_trace_keyword) + seq_puts(m, ","); + seq_printf(m, "%s", data->params[i]); + } + } +} + +static void print_track_data_spec(struct seq_file *m, + struct hist_trigger_data *hist_data, + struct action_data *data) +{ + if (data->handler == HANDLER_ONMAX) + seq_puts(m, ":onmax("); + else if (data->handler == HANDLER_ONCHANGE) + seq_puts(m, ":onchange("); + seq_printf(m, "%s", data->track_data.var_str); + seq_printf(m, ").%s(", data->action_name); + + print_action_spec(m, hist_data, data); + + seq_puts(m, ")"); +} + +static void print_onmatch_spec(struct seq_file *m, + struct hist_trigger_data *hist_data, + struct action_data *data) +{ + seq_printf(m, ":onmatch(%s.%s).", data->match_data.event_system, + data->match_data.event); + + seq_printf(m, "%s(", data->action_name); + + print_action_spec(m, hist_data, data); + + seq_puts(m, ")"); +} + +static bool actions_match(struct hist_trigger_data *hist_data, + struct hist_trigger_data *hist_data_test) +{ + unsigned int i, j; + + if (hist_data->n_actions != hist_data_test->n_actions) + return false; + + for (i = 0; i < hist_data->n_actions; i++) { + struct action_data *data = hist_data->actions[i]; + struct action_data *data_test = hist_data_test->actions[i]; + char *action_name, *action_name_test; + + if (data->handler != data_test->handler) + return false; + if (data->action != data_test->action) + return false; + + if (data->n_params != data_test->n_params) + return false; + + for (j = 0; j < data->n_params; j++) { + if (strcmp(data->params[j], data_test->params[j]) != 0) + return false; + } + + if (data->use_trace_keyword) + action_name = data->synth_event_name; + else + action_name = data->action_name; + + if (data_test->use_trace_keyword) + action_name_test = data_test->synth_event_name; + else + action_name_test = data_test->action_name; + + if (strcmp(action_name, action_name_test) != 0) + return false; + + if (data->handler == HANDLER_ONMATCH) { + if (strcmp(data->match_data.event_system, + data_test->match_data.event_system) != 0) + return false; + if (strcmp(data->match_data.event, + data_test->match_data.event) != 0) + return false; + } else if (data->handler == HANDLER_ONMAX || + data->handler == HANDLER_ONCHANGE) { + if (strcmp(data->track_data.var_str, + data_test->track_data.var_str) != 0) + return false; + } + } + + return true; +} + + +static void print_actions_spec(struct seq_file *m, + struct hist_trigger_data *hist_data) +{ + unsigned int i; + + for (i = 0; i < hist_data->n_actions; i++) { + struct action_data *data = hist_data->actions[i]; + + if (data->handler == HANDLER_ONMATCH) + print_onmatch_spec(m, hist_data, data); + else if (data->handler == HANDLER_ONMAX || + data->handler == HANDLER_ONCHANGE) + print_track_data_spec(m, hist_data, data); + } +} + +static void destroy_field_var_hists(struct hist_trigger_data *hist_data) +{ + unsigned int i; + + for (i = 0; i < hist_data->n_field_var_hists; i++) { + kfree(hist_data->field_var_hists[i]->cmd); + kfree(hist_data->field_var_hists[i]); + } +} + +static void destroy_hist_data(struct hist_trigger_data *hist_data) +{ + if (!hist_data) + return; + + destroy_hist_trigger_attrs(hist_data->attrs); + destroy_hist_fields(hist_data); + tracing_map_destroy(hist_data->map); + + destroy_actions(hist_data); + destroy_field_vars(hist_data); + destroy_field_var_hists(hist_data); + + kfree(hist_data); +} + +static int create_tracing_map_fields(struct hist_trigger_data *hist_data) +{ + struct tracing_map *map = hist_data->map; + struct ftrace_event_field *field; + struct hist_field *hist_field; + int i, idx = 0; + + for_each_hist_field(i, hist_data) { + hist_field = hist_data->fields[i]; + if (hist_field->flags & HIST_FIELD_FL_KEY) { + tracing_map_cmp_fn_t cmp_fn; + + field = hist_field->field; + + if (hist_field->flags & HIST_FIELD_FL_STACKTRACE) + cmp_fn = tracing_map_cmp_none; + else if (!field || hist_field->flags & HIST_FIELD_FL_CPU) + cmp_fn = tracing_map_cmp_num(hist_field->size, + hist_field->is_signed); + else if (is_string_field(field)) + cmp_fn = tracing_map_cmp_string; + else + cmp_fn = tracing_map_cmp_num(field->size, + field->is_signed); + idx = tracing_map_add_key_field(map, + hist_field->offset, + cmp_fn); + } else if (!(hist_field->flags & HIST_FIELD_FL_VAR)) + idx = tracing_map_add_sum_field(map); + + if (idx < 0) + return idx; + + if (hist_field->flags & HIST_FIELD_FL_VAR) { + idx = tracing_map_add_var(map); + if (idx < 0) + return idx; + hist_field->var.idx = idx; + hist_field->var.hist_data = hist_data; + } + } + + return 0; +} + +static struct hist_trigger_data * +create_hist_data(unsigned int map_bits, + struct hist_trigger_attrs *attrs, + struct trace_event_file *file, + bool remove) +{ + const struct tracing_map_ops *map_ops = NULL; + struct hist_trigger_data *hist_data; + int ret = 0; + + hist_data = kzalloc(sizeof(*hist_data), GFP_KERNEL); + if (!hist_data) + return ERR_PTR(-ENOMEM); + + hist_data->attrs = attrs; + hist_data->remove = remove; + hist_data->event_file = file; + + ret = parse_actions(hist_data); + if (ret) + goto free; + + ret = create_hist_fields(hist_data, file); + if (ret) + goto free; + + ret = create_sort_keys(hist_data); + if (ret) + goto free; + + map_ops = &hist_trigger_elt_data_ops; + + hist_data->map = tracing_map_create(map_bits, hist_data->key_size, + map_ops, hist_data); + if (IS_ERR(hist_data->map)) { + ret = PTR_ERR(hist_data->map); + hist_data->map = NULL; + goto free; + } + + ret = create_tracing_map_fields(hist_data); + if (ret) + goto free; + out: + return hist_data; + free: + hist_data->attrs = NULL; + + destroy_hist_data(hist_data); + + hist_data = ERR_PTR(ret); + + goto out; +} + +static void hist_trigger_elt_update(struct hist_trigger_data *hist_data, + struct tracing_map_elt *elt, void *rec, + struct ring_buffer_event *rbe, + u64 *var_ref_vals) +{ + struct hist_elt_data *elt_data; + struct hist_field *hist_field; + unsigned int i, var_idx; + u64 hist_val; + + elt_data = elt->private_data; + elt_data->var_ref_vals = var_ref_vals; + + for_each_hist_val_field(i, hist_data) { + hist_field = hist_data->fields[i]; + hist_val = hist_field->fn(hist_field, elt, rbe, rec); + if (hist_field->flags & HIST_FIELD_FL_VAR) { + var_idx = hist_field->var.idx; + + if (hist_field->flags & HIST_FIELD_FL_STRING) { + unsigned int str_start, var_str_idx, idx; + char *str, *val_str; + unsigned int size; + + str_start = hist_data->n_field_var_str + + hist_data->n_save_var_str; + var_str_idx = hist_field->var_str_idx; + idx = str_start + var_str_idx; + + str = elt_data->field_var_str[idx]; + val_str = (char *)(uintptr_t)hist_val; + + size = min(hist_field->size, STR_VAR_LEN_MAX); + strscpy(str, val_str, size); + + hist_val = (u64)(uintptr_t)str; + } + tracing_map_set_var(elt, var_idx, hist_val); + continue; + } + tracing_map_update_sum(elt, i, hist_val); + } + + for_each_hist_key_field(i, hist_data) { + hist_field = hist_data->fields[i]; + if (hist_field->flags & HIST_FIELD_FL_VAR) { + hist_val = hist_field->fn(hist_field, elt, rbe, rec); + var_idx = hist_field->var.idx; + tracing_map_set_var(elt, var_idx, hist_val); + } + } + + update_field_vars(hist_data, elt, rbe, rec); +} + +static inline void add_to_key(char *compound_key, void *key, + struct hist_field *key_field, void *rec) +{ + size_t size = key_field->size; + + if (key_field->flags & HIST_FIELD_FL_STRING) { + struct ftrace_event_field *field; + + field = key_field->field; + if (field->filter_type == FILTER_DYN_STRING) + size = *(u32 *)(rec + field->offset) >> 16; + else if (field->filter_type == FILTER_STATIC_STRING) + size = field->size; + + /* ensure NULL-termination */ + if (size > key_field->size - 1) + size = key_field->size - 1; + + strncpy(compound_key + key_field->offset, (char *)key, size); + } else + memcpy(compound_key + key_field->offset, key, size); +} + +static void +hist_trigger_actions(struct hist_trigger_data *hist_data, + struct tracing_map_elt *elt, void *rec, + 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, key, data, var_ref_vals); + } +} + +static void event_hist_trigger(struct event_trigger_data *data, void *rec, + struct ring_buffer_event *rbe) +{ + struct hist_trigger_data *hist_data = data->private_data; + bool use_compound_key = (hist_data->n_keys > 1); + unsigned long entries[HIST_STACKTRACE_DEPTH]; + u64 var_ref_vals[TRACING_MAP_VARS_MAX]; + char compound_key[HIST_KEY_SIZE_MAX]; + struct tracing_map_elt *elt = NULL; + struct hist_field *key_field; + u64 field_contents; + void *key = NULL; + unsigned int i; + + memset(compound_key, 0, hist_data->key_size); + + for_each_hist_key_field(i, hist_data) { + key_field = hist_data->fields[i]; + + if (key_field->flags & HIST_FIELD_FL_STACKTRACE) { + memset(entries, 0, HIST_STACKTRACE_SIZE); + stack_trace_save(entries, HIST_STACKTRACE_DEPTH, + HIST_STACKTRACE_SKIP); + key = entries; + } else { + field_contents = key_field->fn(key_field, elt, rbe, rec); + if (key_field->flags & HIST_FIELD_FL_STRING) { + key = (void *)(unsigned long)field_contents; + use_compound_key = true; + } else + key = (void *)&field_contents; + } + + if (use_compound_key) + add_to_key(compound_key, key, key_field, rec); + } + + if (use_compound_key) + key = compound_key; + + if (hist_data->n_var_refs && + !resolve_var_refs(hist_data, key, var_ref_vals, false)) + return; + + elt = tracing_map_insert(hist_data->map, key); + if (!elt) + return; + + 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, key, var_ref_vals); +} + +static void hist_trigger_stacktrace_print(struct seq_file *m, + unsigned long *stacktrace_entries, + unsigned int max_entries) +{ + char str[KSYM_SYMBOL_LEN]; + unsigned int spaces = 8; + unsigned int i; + + for (i = 0; i < max_entries; i++) { + if (!stacktrace_entries[i]) + return; + + seq_printf(m, "%*c", 1 + spaces, ' '); + sprint_symbol(str, stacktrace_entries[i]); + seq_printf(m, "%s\n", str); + } +} + +static void hist_trigger_print_key(struct seq_file *m, + struct hist_trigger_data *hist_data, + void *key, + struct tracing_map_elt *elt) +{ + struct hist_field *key_field; + char str[KSYM_SYMBOL_LEN]; + bool multiline = false; + const char *field_name; + unsigned int i; + u64 uval; + + seq_puts(m, "{ "); + + for_each_hist_key_field(i, hist_data) { + key_field = hist_data->fields[i]; + + if (i > hist_data->n_vals) + seq_puts(m, ", "); + + field_name = hist_field_name(key_field, 0); + + if (key_field->flags & HIST_FIELD_FL_HEX) { + uval = *(u64 *)(key + key_field->offset); + seq_printf(m, "%s: %llx", field_name, uval); + } else if (key_field->flags & HIST_FIELD_FL_SYM) { + uval = *(u64 *)(key + key_field->offset); + sprint_symbol_no_offset(str, uval); + seq_printf(m, "%s: [%llx] %-45s", field_name, + uval, str); + } else if (key_field->flags & HIST_FIELD_FL_SYM_OFFSET) { + uval = *(u64 *)(key + key_field->offset); + sprint_symbol(str, uval); + seq_printf(m, "%s: [%llx] %-55s", field_name, + uval, str); + } else if (key_field->flags & HIST_FIELD_FL_EXECNAME) { + struct hist_elt_data *elt_data = elt->private_data; + char *comm; + + if (WARN_ON_ONCE(!elt_data)) + return; + + comm = elt_data->comm; + + uval = *(u64 *)(key + key_field->offset); + seq_printf(m, "%s: %-16s[%10llu]", field_name, + comm, uval); + } else if (key_field->flags & HIST_FIELD_FL_SYSCALL) { + const char *syscall_name; + + uval = *(u64 *)(key + key_field->offset); + syscall_name = get_syscall_name(uval); + if (!syscall_name) + syscall_name = "unknown_syscall"; + + seq_printf(m, "%s: %-30s[%3llu]", field_name, + syscall_name, uval); + } else if (key_field->flags & HIST_FIELD_FL_STACKTRACE) { + seq_puts(m, "stacktrace:\n"); + hist_trigger_stacktrace_print(m, + key + key_field->offset, + HIST_STACKTRACE_DEPTH); + multiline = true; + } else if (key_field->flags & HIST_FIELD_FL_LOG2) { + seq_printf(m, "%s: ~ 2^%-2llu", field_name, + *(u64 *)(key + key_field->offset)); + } else if (key_field->flags & HIST_FIELD_FL_STRING) { + seq_printf(m, "%s: %-50s", field_name, + (char *)(key + key_field->offset)); + } else { + uval = *(u64 *)(key + key_field->offset); + seq_printf(m, "%s: %10llu", field_name, uval); + } + } + + if (!multiline) + seq_puts(m, " "); + + seq_puts(m, "}"); +} + +static void hist_trigger_entry_print(struct seq_file *m, + struct hist_trigger_data *hist_data, + void *key, + struct tracing_map_elt *elt) +{ + const char *field_name; + unsigned int i; + + hist_trigger_print_key(m, hist_data, key, elt); + + seq_printf(m, " hitcount: %10llu", + tracing_map_read_sum(elt, HITCOUNT_IDX)); + + for (i = 1; i < hist_data->n_vals; i++) { + field_name = hist_field_name(hist_data->fields[i], 0); + + if (hist_data->fields[i]->flags & HIST_FIELD_FL_VAR || + hist_data->fields[i]->flags & HIST_FIELD_FL_EXPR) + continue; + + if (hist_data->fields[i]->flags & HIST_FIELD_FL_HEX) { + seq_printf(m, " %s: %10llx", field_name, + tracing_map_read_sum(elt, i)); + } else { + seq_printf(m, " %s: %10llu", field_name, + tracing_map_read_sum(elt, i)); + } + } + + print_actions(m, hist_data, elt); + + seq_puts(m, "\n"); +} + +static int print_entries(struct seq_file *m, + struct hist_trigger_data *hist_data) +{ + struct tracing_map_sort_entry **sort_entries = NULL; + struct tracing_map *map = hist_data->map; + int i, n_entries; + + n_entries = tracing_map_sort_entries(map, hist_data->sort_keys, + hist_data->n_sort_keys, + &sort_entries); + if (n_entries < 0) + return n_entries; + + for (i = 0; i < n_entries; i++) + hist_trigger_entry_print(m, hist_data, + sort_entries[i]->key, + sort_entries[i]->elt); + + tracing_map_destroy_sort_entries(sort_entries, n_entries); + + return n_entries; +} + +static void hist_trigger_show(struct seq_file *m, + struct event_trigger_data *data, int n) +{ + struct hist_trigger_data *hist_data; + int n_entries; + + if (n > 0) + seq_puts(m, "\n\n"); + + seq_puts(m, "# event histogram\n#\n# trigger info: "); + data->ops->print(m, data->ops, data); + seq_puts(m, "#\n\n"); + + hist_data = data->private_data; + n_entries = print_entries(m, hist_data); + if (n_entries < 0) + n_entries = 0; + + track_data_snapshot_print(m, hist_data); + + seq_printf(m, "\nTotals:\n Hits: %llu\n Entries: %u\n Dropped: %llu\n", + (u64)atomic64_read(&hist_data->map->hits), + n_entries, (u64)atomic64_read(&hist_data->map->drops)); +} + +static int hist_show(struct seq_file *m, void *v) +{ + struct event_trigger_data *data; + struct trace_event_file *event_file; + int n = 0, ret = 0; + + mutex_lock(&event_mutex); + + event_file = event_file_data(m->private); + if (unlikely(!event_file)) { + ret = -ENODEV; + goto out_unlock; + } + + list_for_each_entry(data, &event_file->triggers, list) { + if (data->cmd_ops->trigger_type == ETT_EVENT_HIST) + hist_trigger_show(m, data, n++); + } + + out_unlock: + mutex_unlock(&event_mutex); + + return ret; +} + +static int event_hist_open(struct inode *inode, struct file *file) +{ + int ret; + + ret = security_locked_down(LOCKDOWN_TRACEFS); + if (ret) + return ret; + + return single_open(file, hist_show, file); +} + +const struct file_operations event_hist_fops = { + .open = event_hist_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +#ifdef CONFIG_HIST_TRIGGERS_DEBUG +static void hist_field_debug_show_flags(struct seq_file *m, + unsigned long flags) +{ + seq_puts(m, " flags:\n"); + + if (flags & HIST_FIELD_FL_KEY) + seq_puts(m, " HIST_FIELD_FL_KEY\n"); + else if (flags & HIST_FIELD_FL_HITCOUNT) + seq_puts(m, " VAL: HIST_FIELD_FL_HITCOUNT\n"); + else if (flags & HIST_FIELD_FL_VAR) + seq_puts(m, " HIST_FIELD_FL_VAR\n"); + else if (flags & HIST_FIELD_FL_VAR_REF) + seq_puts(m, " HIST_FIELD_FL_VAR_REF\n"); + else + seq_puts(m, " VAL: normal u64 value\n"); + + if (flags & HIST_FIELD_FL_ALIAS) + seq_puts(m, " HIST_FIELD_FL_ALIAS\n"); +} + +static int hist_field_debug_show(struct seq_file *m, + struct hist_field *field, unsigned long flags) +{ + if ((field->flags & flags) != flags) { + seq_printf(m, "ERROR: bad flags - %lx\n", flags); + return -EINVAL; + } + + hist_field_debug_show_flags(m, field->flags); + if (field->field) + seq_printf(m, " ftrace_event_field name: %s\n", + field->field->name); + + if (field->flags & HIST_FIELD_FL_VAR) { + seq_printf(m, " var.name: %s\n", field->var.name); + seq_printf(m, " var.idx (into tracing_map_elt.vars[]): %u\n", + field->var.idx); + } + + if (field->flags & HIST_FIELD_FL_ALIAS) + seq_printf(m, " var_ref_idx (into hist_data->var_refs[]): %u\n", + field->var_ref_idx); + + if (field->flags & HIST_FIELD_FL_VAR_REF) { + seq_printf(m, " name: %s\n", field->name); + seq_printf(m, " var.idx (into tracing_map_elt.vars[]): %u\n", + field->var.idx); + seq_printf(m, " var.hist_data: %p\n", field->var.hist_data); + seq_printf(m, " var_ref_idx (into hist_data->var_refs[]): %u\n", + field->var_ref_idx); + if (field->system) + seq_printf(m, " system: %s\n", field->system); + if (field->event_name) + seq_printf(m, " event_name: %s\n", field->event_name); + } + + seq_printf(m, " type: %s\n", field->type); + seq_printf(m, " size: %u\n", field->size); + seq_printf(m, " is_signed: %u\n", field->is_signed); + + return 0; +} + +static int field_var_debug_show(struct seq_file *m, + struct field_var *field_var, unsigned int i, + bool save_vars) +{ + const char *vars_name = save_vars ? "save_vars" : "field_vars"; + struct hist_field *field; + int ret = 0; + + seq_printf(m, "\n hist_data->%s[%d]:\n", vars_name, i); + + field = field_var->var; + + seq_printf(m, "\n %s[%d].var:\n", vars_name, i); + + hist_field_debug_show_flags(m, field->flags); + seq_printf(m, " var.name: %s\n", field->var.name); + seq_printf(m, " var.idx (into tracing_map_elt.vars[]): %u\n", + field->var.idx); + + field = field_var->val; + + seq_printf(m, "\n %s[%d].val:\n", vars_name, i); + if (field->field) + seq_printf(m, " ftrace_event_field name: %s\n", + field->field->name); + else { + ret = -EINVAL; + goto out; + } + + seq_printf(m, " type: %s\n", field->type); + seq_printf(m, " size: %u\n", field->size); + seq_printf(m, " is_signed: %u\n", field->is_signed); +out: + return ret; +} + +static int hist_action_debug_show(struct seq_file *m, + struct action_data *data, int i) +{ + int ret = 0; + + if (data->handler == HANDLER_ONMAX || + data->handler == HANDLER_ONCHANGE) { + seq_printf(m, "\n hist_data->actions[%d].track_data.var_ref:\n", i); + ret = hist_field_debug_show(m, data->track_data.var_ref, + HIST_FIELD_FL_VAR_REF); + if (ret) + goto out; + + seq_printf(m, "\n hist_data->actions[%d].track_data.track_var:\n", i); + ret = hist_field_debug_show(m, data->track_data.track_var, + HIST_FIELD_FL_VAR); + if (ret) + goto out; + } + + if (data->handler == HANDLER_ONMATCH) { + seq_printf(m, "\n hist_data->actions[%d].match_data.event_system: %s\n", + i, data->match_data.event_system); + seq_printf(m, " hist_data->actions[%d].match_data.event: %s\n", + i, data->match_data.event); + } +out: + return ret; +} + +static int hist_actions_debug_show(struct seq_file *m, + struct hist_trigger_data *hist_data) +{ + int i, ret = 0; + + if (hist_data->n_actions) + seq_puts(m, "\n action tracking variables (for onmax()/onchange()/onmatch()):\n"); + + for (i = 0; i < hist_data->n_actions; i++) { + struct action_data *action = hist_data->actions[i]; + + ret = hist_action_debug_show(m, action, i); + if (ret) + goto out; + } + + if (hist_data->n_save_vars) + seq_puts(m, "\n save action variables (save() params):\n"); + + for (i = 0; i < hist_data->n_save_vars; i++) { + ret = field_var_debug_show(m, hist_data->save_vars[i], i, true); + if (ret) + goto out; + } +out: + return ret; +} + +static void hist_trigger_debug_show(struct seq_file *m, + struct event_trigger_data *data, int n) +{ + struct hist_trigger_data *hist_data; + int i, ret; + + if (n > 0) + seq_puts(m, "\n\n"); + + seq_puts(m, "# event histogram\n#\n# trigger info: "); + data->ops->print(m, data->ops, data); + seq_puts(m, "#\n\n"); + + hist_data = data->private_data; + + seq_printf(m, "hist_data: %p\n\n", hist_data); + seq_printf(m, " n_vals: %u\n", hist_data->n_vals); + seq_printf(m, " n_keys: %u\n", hist_data->n_keys); + seq_printf(m, " n_fields: %u\n", hist_data->n_fields); + + seq_puts(m, "\n val fields:\n\n"); + + seq_puts(m, " hist_data->fields[0]:\n"); + ret = hist_field_debug_show(m, hist_data->fields[0], + HIST_FIELD_FL_HITCOUNT); + if (ret) + return; + + for (i = 1; i < hist_data->n_vals; i++) { + seq_printf(m, "\n hist_data->fields[%d]:\n", i); + ret = hist_field_debug_show(m, hist_data->fields[i], 0); + if (ret) + return; + } + + seq_puts(m, "\n key fields:\n"); + + for (i = hist_data->n_vals; i < hist_data->n_fields; i++) { + seq_printf(m, "\n hist_data->fields[%d]:\n", i); + ret = hist_field_debug_show(m, hist_data->fields[i], + HIST_FIELD_FL_KEY); + if (ret) + return; + } + + if (hist_data->n_var_refs) + seq_puts(m, "\n variable reference fields:\n"); + + for (i = 0; i < hist_data->n_var_refs; i++) { + seq_printf(m, "\n hist_data->var_refs[%d]:\n", i); + ret = hist_field_debug_show(m, hist_data->var_refs[i], + HIST_FIELD_FL_VAR_REF); + if (ret) + return; + } + + if (hist_data->n_field_vars) + seq_puts(m, "\n field variables:\n"); + + for (i = 0; i < hist_data->n_field_vars; i++) { + ret = field_var_debug_show(m, hist_data->field_vars[i], i, false); + if (ret) + return; + } + + ret = hist_actions_debug_show(m, hist_data); + if (ret) + return; +} + +static int hist_debug_show(struct seq_file *m, void *v) +{ + struct event_trigger_data *data; + struct trace_event_file *event_file; + int n = 0, ret = 0; + + mutex_lock(&event_mutex); + + event_file = event_file_data(m->private); + if (unlikely(!event_file)) { + ret = -ENODEV; + goto out_unlock; + } + + list_for_each_entry(data, &event_file->triggers, list) { + if (data->cmd_ops->trigger_type == ETT_EVENT_HIST) + hist_trigger_debug_show(m, data, n++); + } + + out_unlock: + mutex_unlock(&event_mutex); + + return ret; +} + +static int event_hist_debug_open(struct inode *inode, struct file *file) +{ + int ret; + + ret = security_locked_down(LOCKDOWN_TRACEFS); + if (ret) + return ret; + + return single_open(file, hist_debug_show, file); +} + +const struct file_operations event_hist_debug_fops = { + .open = event_hist_debug_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; +#endif + +static void hist_field_print(struct seq_file *m, struct hist_field *hist_field) +{ + const char *field_name = hist_field_name(hist_field, 0); + + if (hist_field->var.name) + seq_printf(m, "%s=", hist_field->var.name); + + if (hist_field->flags & HIST_FIELD_FL_CPU) + seq_puts(m, "common_cpu"); + else if (field_name) { + if (hist_field->flags & HIST_FIELD_FL_VAR_REF || + hist_field->flags & HIST_FIELD_FL_ALIAS) + seq_putc(m, '$'); + seq_printf(m, "%s", field_name); + } else if (hist_field->flags & HIST_FIELD_FL_TIMESTAMP) + seq_puts(m, "common_timestamp"); + + if (hist_field->flags) { + if (!(hist_field->flags & HIST_FIELD_FL_VAR_REF) && + !(hist_field->flags & HIST_FIELD_FL_EXPR)) { + const char *flags = get_hist_field_flags(hist_field); + + if (flags) + seq_printf(m, ".%s", flags); + } + } +} + +static int event_hist_trigger_print(struct seq_file *m, + struct event_trigger_ops *ops, + struct event_trigger_data *data) +{ + struct hist_trigger_data *hist_data = data->private_data; + struct hist_field *field; + bool have_var = false; + unsigned int i; + + seq_puts(m, "hist:"); + + if (data->name) + seq_printf(m, "%s:", data->name); + + seq_puts(m, "keys="); + + for_each_hist_key_field(i, hist_data) { + field = hist_data->fields[i]; + + if (i > hist_data->n_vals) + seq_puts(m, ","); + + if (field->flags & HIST_FIELD_FL_STACKTRACE) + seq_puts(m, "stacktrace"); + else + hist_field_print(m, field); + } + + seq_puts(m, ":vals="); + + for_each_hist_val_field(i, hist_data) { + field = hist_data->fields[i]; + if (field->flags & HIST_FIELD_FL_VAR) { + have_var = true; + continue; + } + + if (i == HITCOUNT_IDX) + seq_puts(m, "hitcount"); + else { + seq_puts(m, ","); + hist_field_print(m, field); + } + } + + if (have_var) { + unsigned int n = 0; + + seq_puts(m, ":"); + + for_each_hist_val_field(i, hist_data) { + field = hist_data->fields[i]; + + if (field->flags & HIST_FIELD_FL_VAR) { + if (n++) + seq_puts(m, ","); + hist_field_print(m, field); + } + } + } + + seq_puts(m, ":sort="); + + for (i = 0; i < hist_data->n_sort_keys; i++) { + struct tracing_map_sort_key *sort_key; + unsigned int idx, first_key_idx; + + /* skip VAR vals */ + first_key_idx = hist_data->n_vals - hist_data->n_vars; + + sort_key = &hist_data->sort_keys[i]; + idx = sort_key->field_idx; + + if (WARN_ON(idx >= HIST_FIELDS_MAX)) + return -EINVAL; + + if (i > 0) + seq_puts(m, ","); + + if (idx == HITCOUNT_IDX) + seq_puts(m, "hitcount"); + else { + if (idx >= first_key_idx) + idx += hist_data->n_vars; + hist_field_print(m, hist_data->fields[idx]); + } + + if (sort_key->descending) + seq_puts(m, ".descending"); + } + seq_printf(m, ":size=%u", (1 << hist_data->map->map_bits)); + if (hist_data->enable_timestamps) + seq_printf(m, ":clock=%s", hist_data->attrs->clock); + + print_actions_spec(m, hist_data); + + if (data->filter_str) + seq_printf(m, " if %s", data->filter_str); + + if (data->paused) + seq_puts(m, " [paused]"); + else + seq_puts(m, " [active]"); + + seq_putc(m, '\n'); + + return 0; +} + +static int event_hist_trigger_init(struct event_trigger_ops *ops, + struct event_trigger_data *data) +{ + struct hist_trigger_data *hist_data = data->private_data; + + if (!data->ref && hist_data->attrs->name) + save_named_trigger(hist_data->attrs->name, data); + + data->ref++; + + return 0; +} + +static void unregister_field_var_hists(struct hist_trigger_data *hist_data) +{ + struct trace_event_file *file; + unsigned int i; + char *cmd; + int ret; + + for (i = 0; i < hist_data->n_field_var_hists; i++) { + file = hist_data->field_var_hists[i]->hist_data->event_file; + cmd = hist_data->field_var_hists[i]->cmd; + ret = event_hist_trigger_func(&trigger_hist_cmd, file, + "!hist", "hist", cmd); + } +} + +static void event_hist_trigger_free(struct event_trigger_ops *ops, + struct event_trigger_data *data) +{ + struct hist_trigger_data *hist_data = data->private_data; + + if (WARN_ON_ONCE(data->ref <= 0)) + return; + + data->ref--; + if (!data->ref) { + if (data->name) + del_named_trigger(data); + + trigger_data_free(data); + + remove_hist_vars(hist_data); + + unregister_field_var_hists(hist_data); + + destroy_hist_data(hist_data); + } +} + +static struct event_trigger_ops event_hist_trigger_ops = { + .func = event_hist_trigger, + .print = event_hist_trigger_print, + .init = event_hist_trigger_init, + .free = event_hist_trigger_free, +}; + +static int event_hist_trigger_named_init(struct event_trigger_ops *ops, + struct event_trigger_data *data) +{ + data->ref++; + + save_named_trigger(data->named_data->name, data); + + event_hist_trigger_init(ops, data->named_data); + + return 0; +} + +static void event_hist_trigger_named_free(struct event_trigger_ops *ops, + struct event_trigger_data *data) +{ + if (WARN_ON_ONCE(data->ref <= 0)) + return; + + event_hist_trigger_free(ops, data->named_data); + + data->ref--; + if (!data->ref) { + del_named_trigger(data); + trigger_data_free(data); + } +} + +static struct event_trigger_ops event_hist_trigger_named_ops = { + .func = event_hist_trigger, + .print = event_hist_trigger_print, + .init = event_hist_trigger_named_init, + .free = event_hist_trigger_named_free, +}; + +static struct event_trigger_ops *event_hist_get_trigger_ops(char *cmd, + char *param) +{ + return &event_hist_trigger_ops; +} + +static void hist_clear(struct event_trigger_data *data) +{ + struct hist_trigger_data *hist_data = data->private_data; + + if (data->name) + pause_named_trigger(data); + + tracepoint_synchronize_unregister(); + + tracing_map_clear(hist_data->map); + + if (data->name) + unpause_named_trigger(data); +} + +static bool compatible_field(struct ftrace_event_field *field, + struct ftrace_event_field *test_field) +{ + if (field == test_field) + return true; + if (field == NULL || test_field == NULL) + return false; + if (strcmp(field->name, test_field->name) != 0) + return false; + if (strcmp(field->type, test_field->type) != 0) + return false; + if (field->size != test_field->size) + return false; + if (field->is_signed != test_field->is_signed) + return false; + + return true; +} + +static bool hist_trigger_match(struct event_trigger_data *data, + struct event_trigger_data *data_test, + struct event_trigger_data *named_data, + bool ignore_filter) +{ + struct tracing_map_sort_key *sort_key, *sort_key_test; + struct hist_trigger_data *hist_data, *hist_data_test; + struct hist_field *key_field, *key_field_test; + unsigned int i; + + if (named_data && (named_data != data_test) && + (named_data != data_test->named_data)) + return false; + + if (!named_data && is_named_trigger(data_test)) + return false; + + hist_data = data->private_data; + hist_data_test = data_test->private_data; + + if (hist_data->n_vals != hist_data_test->n_vals || + hist_data->n_fields != hist_data_test->n_fields || + hist_data->n_sort_keys != hist_data_test->n_sort_keys) + return false; + + if (!ignore_filter) { + if ((data->filter_str && !data_test->filter_str) || + (!data->filter_str && data_test->filter_str)) + return false; + } + + for_each_hist_field(i, hist_data) { + key_field = hist_data->fields[i]; + key_field_test = hist_data_test->fields[i]; + + if (key_field->flags != key_field_test->flags) + return false; + if (!compatible_field(key_field->field, key_field_test->field)) + return false; + if (key_field->offset != key_field_test->offset) + return false; + if (key_field->size != key_field_test->size) + return false; + if (key_field->is_signed != key_field_test->is_signed) + return false; + if (!!key_field->var.name != !!key_field_test->var.name) + return false; + if (key_field->var.name && + strcmp(key_field->var.name, key_field_test->var.name) != 0) + return false; + } + + for (i = 0; i < hist_data->n_sort_keys; i++) { + sort_key = &hist_data->sort_keys[i]; + sort_key_test = &hist_data_test->sort_keys[i]; + + if (sort_key->field_idx != sort_key_test->field_idx || + sort_key->descending != sort_key_test->descending) + return false; + } + + if (!ignore_filter && data->filter_str && + (strcmp(data->filter_str, data_test->filter_str) != 0)) + return false; + + if (!actions_match(hist_data, hist_data_test)) + return false; + + return true; +} + +static int hist_register_trigger(char *glob, struct event_trigger_ops *ops, + struct event_trigger_data *data, + struct trace_event_file *file) +{ + struct hist_trigger_data *hist_data = data->private_data; + struct event_trigger_data *test, *named_data = NULL; + struct trace_array *tr = file->tr; + int ret = 0; + + if (hist_data->attrs->name) { + named_data = find_named_trigger(hist_data->attrs->name); + if (named_data) { + if (!hist_trigger_match(data, named_data, named_data, + true)) { + hist_err(tr, HIST_ERR_NAMED_MISMATCH, errpos(hist_data->attrs->name)); + ret = -EINVAL; + goto out; + } + } + } + + if (hist_data->attrs->name && !named_data) + goto new; + + lockdep_assert_held(&event_mutex); + + list_for_each_entry(test, &file->triggers, list) { + if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) { + if (!hist_trigger_match(data, test, named_data, false)) + continue; + if (hist_data->attrs->pause) + test->paused = true; + else if (hist_data->attrs->cont) + test->paused = false; + else if (hist_data->attrs->clear) + hist_clear(test); + else { + hist_err(tr, HIST_ERR_TRIGGER_EEXIST, 0); + ret = -EEXIST; + } + goto out; + } + } + new: + if (hist_data->attrs->cont || hist_data->attrs->clear) { + hist_err(tr, HIST_ERR_TRIGGER_ENOENT_CLEAR, 0); + ret = -ENOENT; + goto out; + } + + if (hist_data->attrs->pause) + data->paused = true; + + if (named_data) { + data->private_data = named_data->private_data; + set_named_trigger_data(data, named_data); + data->ops = &event_hist_trigger_named_ops; + } + + if (data->ops->init) { + ret = data->ops->init(data->ops, data); + if (ret < 0) + goto out; + } + + if (hist_data->enable_timestamps) { + char *clock = hist_data->attrs->clock; + + ret = tracing_set_clock(file->tr, hist_data->attrs->clock); + if (ret) { + hist_err(tr, HIST_ERR_SET_CLOCK_FAIL, errpos(clock)); + goto out; + } + + tracing_set_time_stamp_abs(file->tr, true); + } + + if (named_data) + destroy_hist_data(hist_data); + + ret++; + out: + return ret; +} + +static int hist_trigger_enable(struct event_trigger_data *data, + struct trace_event_file *file) +{ + int ret = 0; + + list_add_tail_rcu(&data->list, &file->triggers); + + update_cond_flag(file); + + if (trace_event_trigger_enable_disable(file, 1) < 0) { + list_del_rcu(&data->list); + update_cond_flag(file); + ret--; + } + + return ret; +} + +static bool have_hist_trigger_match(struct event_trigger_data *data, + struct trace_event_file *file) +{ + struct hist_trigger_data *hist_data = data->private_data; + struct event_trigger_data *test, *named_data = NULL; + bool match = false; + + lockdep_assert_held(&event_mutex); + + if (hist_data->attrs->name) + named_data = find_named_trigger(hist_data->attrs->name); + + list_for_each_entry(test, &file->triggers, list) { + if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) { + if (hist_trigger_match(data, test, named_data, false)) { + match = true; + break; + } + } + } + + return match; +} + +static bool hist_trigger_check_refs(struct event_trigger_data *data, + struct trace_event_file *file) +{ + struct hist_trigger_data *hist_data = data->private_data; + struct event_trigger_data *test, *named_data = NULL; + + lockdep_assert_held(&event_mutex); + + if (hist_data->attrs->name) + named_data = find_named_trigger(hist_data->attrs->name); + + list_for_each_entry(test, &file->triggers, list) { + if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) { + if (!hist_trigger_match(data, test, named_data, false)) + continue; + hist_data = test->private_data; + if (check_var_refs(hist_data)) + return true; + break; + } + } + + return false; +} + +static void hist_unregister_trigger(char *glob, struct event_trigger_ops *ops, + struct event_trigger_data *data, + struct trace_event_file *file) +{ + struct hist_trigger_data *hist_data = data->private_data; + struct event_trigger_data *test, *named_data = NULL; + bool unregistered = false; + + lockdep_assert_held(&event_mutex); + + if (hist_data->attrs->name) + named_data = find_named_trigger(hist_data->attrs->name); + + list_for_each_entry(test, &file->triggers, list) { + if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) { + if (!hist_trigger_match(data, test, named_data, false)) + continue; + unregistered = true; + list_del_rcu(&test->list); + trace_event_trigger_enable_disable(file, 0); + update_cond_flag(file); + break; + } + } + + if (unregistered && test->ops->free) + test->ops->free(test->ops, test); + + if (hist_data->enable_timestamps) { + if (!hist_data->remove || unregistered) + tracing_set_time_stamp_abs(file->tr, false); + } +} + +static bool hist_file_check_refs(struct trace_event_file *file) +{ + struct hist_trigger_data *hist_data; + struct event_trigger_data *test; + + lockdep_assert_held(&event_mutex); + + list_for_each_entry(test, &file->triggers, list) { + if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) { + hist_data = test->private_data; + if (check_var_refs(hist_data)) + return true; + } + } + + return false; +} + +static void hist_unreg_all(struct trace_event_file *file) +{ + struct event_trigger_data *test, *n; + struct hist_trigger_data *hist_data; + struct synth_event *se; + const char *se_name; + + lockdep_assert_held(&event_mutex); + + if (hist_file_check_refs(file)) + return; + + list_for_each_entry_safe(test, n, &file->triggers, list) { + if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) { + hist_data = test->private_data; + list_del_rcu(&test->list); + trace_event_trigger_enable_disable(file, 0); + + se_name = trace_event_name(file->event_call); + se = find_synth_event(se_name); + if (se) + se->ref--; + + update_cond_flag(file); + if (hist_data->enable_timestamps) + tracing_set_time_stamp_abs(file->tr, false); + if (test->ops->free) + test->ops->free(test->ops, test); + } + } +} + +static int event_hist_trigger_func(struct event_command *cmd_ops, + struct trace_event_file *file, + char *glob, char *cmd, char *param) +{ + unsigned int hist_trigger_bits = TRACING_MAP_BITS_DEFAULT; + struct event_trigger_data *trigger_data; + struct hist_trigger_attrs *attrs; + struct event_trigger_ops *trigger_ops; + struct hist_trigger_data *hist_data; + struct synth_event *se; + const char *se_name; + bool remove = false; + char *trigger, *p; + int ret = 0; + + lockdep_assert_held(&event_mutex); + + if (glob && strlen(glob)) { + hist_err_clear(); + last_cmd_set(file, param); + } + + if (!param) + return -EINVAL; + + if (glob[0] == '!') + remove = true; + + /* + * separate the trigger from the filter (k:v [if filter]) + * allowing for whitespace in the trigger + */ + p = trigger = param; + do { + p = strstr(p, "if"); + if (!p) + break; + if (p == param) + return -EINVAL; + if (*(p - 1) != ' ' && *(p - 1) != '\t') { + p++; + continue; + } + if (p >= param + strlen(param) - (sizeof("if") - 1) - 1) + return -EINVAL; + if (*(p + sizeof("if") - 1) != ' ' && *(p + sizeof("if") - 1) != '\t') { + p++; + continue; + } + break; + } while (p); + + if (!p) + param = NULL; + else { + *(p - 1) = '\0'; + param = strstrip(p); + trigger = strstrip(trigger); + } + + attrs = parse_hist_trigger_attrs(file->tr, trigger); + if (IS_ERR(attrs)) + return PTR_ERR(attrs); + + if (attrs->map_bits) + hist_trigger_bits = attrs->map_bits; + + hist_data = create_hist_data(hist_trigger_bits, attrs, file, remove); + if (IS_ERR(hist_data)) { + destroy_hist_trigger_attrs(attrs); + return PTR_ERR(hist_data); + } + + trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger); + + trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL); + if (!trigger_data) { + ret = -ENOMEM; + goto out_free; + } + + trigger_data->count = -1; + trigger_data->ops = trigger_ops; + trigger_data->cmd_ops = cmd_ops; + + INIT_LIST_HEAD(&trigger_data->list); + RCU_INIT_POINTER(trigger_data->filter, NULL); + + trigger_data->private_data = hist_data; + + /* if param is non-empty, it's supposed to be a filter */ + if (param && cmd_ops->set_filter) { + ret = cmd_ops->set_filter(param, trigger_data, file); + if (ret < 0) + goto out_free; + } + + if (remove) { + if (!have_hist_trigger_match(trigger_data, file)) + goto out_free; + + if (hist_trigger_check_refs(trigger_data, file)) { + ret = -EBUSY; + goto out_free; + } + + cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file); + se_name = trace_event_name(file->event_call); + se = find_synth_event(se_name); + if (se) + se->ref--; + ret = 0; + goto out_free; + } + + ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file); + /* + * The above returns on success the # of triggers registered, + * but if it didn't register any it returns zero. Consider no + * triggers registered a failure too. + */ + if (!ret) { + if (!(attrs->pause || attrs->cont || attrs->clear)) + ret = -ENOENT; + goto out_free; + } else if (ret < 0) + goto out_free; + + if (get_named_trigger_data(trigger_data)) + goto enable; + + ret = create_actions(hist_data); + if (ret) + goto out_unreg; + + if (has_hist_vars(hist_data) || hist_data->n_var_refs) { + ret = save_hist_vars(hist_data); + if (ret) + goto out_unreg; + } + + ret = tracing_map_init(hist_data->map); + if (ret) + goto out_unreg; +enable: + ret = hist_trigger_enable(trigger_data, file); + if (ret) + goto out_unreg; + + se_name = trace_event_name(file->event_call); + se = find_synth_event(se_name); + if (se) + se->ref++; + /* Just return zero, not the number of registered triggers */ + ret = 0; + out: + if (ret == 0 && glob[0]) + hist_err_clear(); + + return ret; + out_unreg: + cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file); + out_free: + if (cmd_ops->set_filter) + cmd_ops->set_filter(NULL, trigger_data, NULL); + + remove_hist_vars(hist_data); + + kfree(trigger_data); + + destroy_hist_data(hist_data); + goto out; +} + +static struct event_command trigger_hist_cmd = { + .name = "hist", + .trigger_type = ETT_EVENT_HIST, + .flags = EVENT_CMD_FL_NEEDS_REC, + .func = event_hist_trigger_func, + .reg = hist_register_trigger, + .unreg = hist_unregister_trigger, + .unreg_all = hist_unreg_all, + .get_trigger_ops = event_hist_get_trigger_ops, + .set_filter = set_trigger_filter, +}; + +__init int register_trigger_hist_cmd(void) +{ + int ret; + + ret = register_event_command(&trigger_hist_cmd); + WARN_ON(ret < 0); + + return ret; +} + +static void +hist_enable_trigger(struct event_trigger_data *data, void *rec, + struct ring_buffer_event *event) +{ + struct enable_trigger_data *enable_data = data->private_data; + struct event_trigger_data *test; + + list_for_each_entry_rcu(test, &enable_data->file->triggers, list, + lockdep_is_held(&event_mutex)) { + if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) { + if (enable_data->enable) + test->paused = false; + else + test->paused = true; + } + } +} + +static void +hist_enable_count_trigger(struct event_trigger_data *data, void *rec, + struct ring_buffer_event *event) +{ + if (!data->count) + return; + + if (data->count != -1) + (data->count)--; + + hist_enable_trigger(data, rec, event); +} + +static struct event_trigger_ops hist_enable_trigger_ops = { + .func = 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, + .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, + .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, + .print = event_enable_trigger_print, + .init = event_trigger_init, + .free = event_enable_trigger_free, +}; + +static struct event_trigger_ops * +hist_enable_get_trigger_ops(char *cmd, char *param) +{ + struct event_trigger_ops *ops; + bool enable; + + enable = (strcmp(cmd, ENABLE_HIST_STR) == 0); + + if (enable) + ops = param ? &hist_enable_count_trigger_ops : + &hist_enable_trigger_ops; + else + ops = param ? &hist_disable_count_trigger_ops : + &hist_disable_trigger_ops; + + return ops; +} + +static void hist_enable_unreg_all(struct trace_event_file *file) +{ + struct event_trigger_data *test, *n; + + list_for_each_entry_safe(test, n, &file->triggers, list) { + if (test->cmd_ops->trigger_type == ETT_HIST_ENABLE) { + list_del_rcu(&test->list); + update_cond_flag(file); + trace_event_trigger_enable_disable(file, 0); + if (test->ops->free) + test->ops->free(test->ops, test); + } + } +} + +static struct event_command trigger_hist_enable_cmd = { + .name = ENABLE_HIST_STR, + .trigger_type = ETT_HIST_ENABLE, + .func = event_enable_trigger_func, + .reg = event_enable_register_trigger, + .unreg = event_enable_unregister_trigger, + .unreg_all = hist_enable_unreg_all, + .get_trigger_ops = hist_enable_get_trigger_ops, + .set_filter = set_trigger_filter, +}; + +static struct event_command trigger_hist_disable_cmd = { + .name = DISABLE_HIST_STR, + .trigger_type = ETT_HIST_ENABLE, + .func = event_enable_trigger_func, + .reg = event_enable_register_trigger, + .unreg = event_enable_unregister_trigger, + .unreg_all = hist_enable_unreg_all, + .get_trigger_ops = hist_enable_get_trigger_ops, + .set_filter = set_trigger_filter, +}; + +static __init void unregister_trigger_hist_enable_disable_cmds(void) +{ + unregister_event_command(&trigger_hist_enable_cmd); + unregister_event_command(&trigger_hist_disable_cmd); +} + +__init int register_trigger_hist_enable_disable_cmds(void) +{ + int ret; + + ret = register_event_command(&trigger_hist_enable_cmd); + if (WARN_ON(ret < 0)) + return ret; + ret = register_event_command(&trigger_hist_disable_cmd); + if (WARN_ON(ret < 0)) + unregister_trigger_hist_enable_disable_cmds(); + + return ret; +} |