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linux / linux / kernel / git / bpf / bpf / 5eb01ddfcfb25e6ebc404a41deae946bde776731 / . / kernel / trace / trace_events_hist.c
blob: 5f6834a2bf4119ef4a30879cac479e0cbc0e5bdf [file] [log] [blame]
// 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.h"
#include "trace_dynevent.h"
#define SYNTH_SYSTEM "synthetic"
#define SYNTH_FIELDS_MAX 32
#define STR_VAR_LEN_MAX 32 /* must be multiple of sizeof(u64) */
#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"),
#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;
};
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 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;
};
static int create_synth_event(int argc, const char **argv);
static int synth_event_show(struct seq_file *m, struct dyn_event *ev);
static int synth_event_release(struct dyn_event *ev);
static bool synth_event_is_busy(struct dyn_event *ev);
static bool synth_event_match(const char *system, const char *event,
int argc, const char **argv, struct dyn_event *ev);
static struct dyn_event_operations synth_event_ops = {
.create = create_synth_event,
.show = synth_event_show,
.is_busy = synth_event_is_busy,
.free = synth_event_release,
.match = synth_event_match,
};
struct synth_field {
char *type;
char *name;
size_t size;
unsigned int offset;
bool is_signed;
bool is_string;
};
struct synth_event {
struct dyn_event devent;
int ref;
char *name;
struct synth_field **fields;
unsigned int n_fields;
unsigned int n_u64;
struct trace_event_class class;
struct trace_event_call call;
struct tracepoint *tp;
struct module *mod;
};
static bool is_synth_event(struct dyn_event *ev)
{
return ev->ops == &synth_event_ops;
}
static struct synth_event *to_synth_event(struct dyn_event *ev)
{
return container_of(ev, struct synth_event, devent);
}
static bool synth_event_is_busy(struct dyn_event *ev)
{
struct synth_event *event = to_synth_event(ev);
return event->ref != 0;
}
static bool synth_event_match(const char *system, const char *event,
int argc, const char **argv, struct dyn_event *ev)
{
struct synth_event *sev = to_synth_event(ev);
return strcmp(sev->name, event) == 0 &&
(!system || strcmp(system, SYNTH_SYSTEM) == 0);
}
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[TRACING_MAP_VARS_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';
}
struct synth_trace_event {
struct trace_entry ent;
u64 fields[];
};
static int synth_event_define_fields(struct trace_event_call *call)
{
struct synth_trace_event trace;
int offset = offsetof(typeof(trace), fields);
struct synth_event *event = call->data;
unsigned int i, size, n_u64;
char *name, *type;
bool is_signed;
int ret = 0;
for (i = 0, n_u64 = 0; i < event->n_fields; i++) {
size = event->fields[i]->size;
is_signed = event->fields[i]->is_signed;
type = event->fields[i]->type;
name = event->fields[i]->name;
ret = trace_define_field(call, type, name, offset, size,
is_signed, FILTER_OTHER);
if (ret)
break;
event->fields[i]->offset = n_u64;
if (event->fields[i]->is_string) {
offset += STR_VAR_LEN_MAX;
n_u64 += STR_VAR_LEN_MAX / sizeof(u64);
} else {
offset += sizeof(u64);
n_u64++;
}
}
event->n_u64 = n_u64;
return ret;
}
static bool synth_field_signed(char *type)
{
if (str_has_prefix(type, "u"))
return false;
if (strcmp(type, "gfp_t") == 0)
return false;
return true;
}
static int synth_field_is_string(char *type)
{
if (strstr(type, "char[") != NULL)
return true;
return false;
}
static int synth_field_string_size(char *type)
{
char buf[4], *end, *start;
unsigned int len;
int size, err;
start = strstr(type, "char[");
if (start == NULL)
return -EINVAL;
start += sizeof("char[") - 1;
end = strchr(type, ']');
if (!end || end < start)
return -EINVAL;
len = end - start;
if (len > 3)
return -EINVAL;
strncpy(buf, start, len);
buf[len] = '\0';
err = kstrtouint(buf, 0, &size);
if (err)
return err;
if (size > STR_VAR_LEN_MAX)
return -EINVAL;
return size;
}
static int synth_field_size(char *type)
{
int size = 0;
if (strcmp(type, "s64") == 0)
size = sizeof(s64);
else if (strcmp(type, "u64") == 0)
size = sizeof(u64);
else if (strcmp(type, "s32") == 0)
size = sizeof(s32);
else if (strcmp(type, "u32") == 0)
size = sizeof(u32);
else if (strcmp(type, "s16") == 0)
size = sizeof(s16);
else if (strcmp(type, "u16") == 0)
size = sizeof(u16);
else if (strcmp(type, "s8") == 0)
size = sizeof(s8);
else if (strcmp(type, "u8") == 0)
size = sizeof(u8);
else if (strcmp(type, "char") == 0)
size = sizeof(char);
else if (strcmp(type, "unsigned char") == 0)
size = sizeof(unsigned char);
else if (strcmp(type, "int") == 0)
size = sizeof(int);
else if (strcmp(type, "unsigned int") == 0)
size = sizeof(unsigned int);
else if (strcmp(type, "long") == 0)
size = sizeof(long);
else if (strcmp(type, "unsigned long") == 0)
size = sizeof(unsigned long);
else if (strcmp(type, "pid_t") == 0)
size = sizeof(pid_t);
else if (strcmp(type, "gfp_t") == 0)
size = sizeof(gfp_t);
else if (synth_field_is_string(type))
size = synth_field_string_size(type);
return size;
}
static const char *synth_field_fmt(char *type)
{
const char *fmt = "%llu";
if (strcmp(type, "s64") == 0)
fmt = "%lld";
else if (strcmp(type, "u64") == 0)
fmt = "%llu";
else if (strcmp(type, "s32") == 0)
fmt = "%d";
else if (strcmp(type, "u32") == 0)
fmt = "%u";
else if (strcmp(type, "s16") == 0)
fmt = "%d";
else if (strcmp(type, "u16") == 0)
fmt = "%u";
else if (strcmp(type, "s8") == 0)
fmt = "%d";
else if (strcmp(type, "u8") == 0)
fmt = "%u";
else if (strcmp(type, "char") == 0)
fmt = "%d";
else if (strcmp(type, "unsigned char") == 0)
fmt = "%u";
else if (strcmp(type, "int") == 0)
fmt = "%d";
else if (strcmp(type, "unsigned int") == 0)
fmt = "%u";
else if (strcmp(type, "long") == 0)
fmt = "%ld";
else if (strcmp(type, "unsigned long") == 0)
fmt = "%lu";
else if (strcmp(type, "pid_t") == 0)
fmt = "%d";
else if (strcmp(type, "gfp_t") == 0)
fmt = "%x";
else if (synth_field_is_string(type))
fmt = "%s";
return fmt;
}
static void print_synth_event_num_val(struct trace_seq *s,
char *print_fmt, char *name,
int size, u64 val, char *space)
{
switch (size) {
case 1:
trace_seq_printf(s, print_fmt, name, (u8)val, space);
break;
case 2:
trace_seq_printf(s, print_fmt, name, (u16)val, space);
break;
case 4:
trace_seq_printf(s, print_fmt, name, (u32)val, space);
break;
default:
trace_seq_printf(s, print_fmt, name, val, space);
break;
}
}
static enum print_line_t print_synth_event(struct trace_iterator *iter,
int flags,
struct trace_event *event)
{
struct trace_array *tr = iter->tr;
struct trace_seq *s = &iter->seq;
struct synth_trace_event *entry;
struct synth_event *se;
unsigned int i, n_u64;
char print_fmt[32];
const char *fmt;
entry = (struct synth_trace_event *)iter->ent;
se = container_of(event, struct synth_event, call.event);
trace_seq_printf(s, "%s: ", se->name);
for (i = 0, n_u64 = 0; i < se->n_fields; i++) {
if (trace_seq_has_overflowed(s))
goto end;
fmt = synth_field_fmt(se->fields[i]->type);
/* parameter types */
if (tr && tr->trace_flags & TRACE_ITER_VERBOSE)
trace_seq_printf(s, "%s ", fmt);
snprintf(print_fmt, sizeof(print_fmt), "%%s=%s%%s", fmt);
/* parameter values */
if (se->fields[i]->is_string) {
trace_seq_printf(s, print_fmt, se->fields[i]->name,
(char *)&entry->fields[n_u64],
i == se->n_fields - 1 ? "" : " ");
n_u64 += STR_VAR_LEN_MAX / sizeof(u64);
} else {
struct trace_print_flags __flags[] = {
__def_gfpflag_names, {-1, NULL} };
char *space = (i == se->n_fields - 1 ? "" : " ");
print_synth_event_num_val(s, print_fmt,
se->fields[i]->name,
se->fields[i]->size,
entry->fields[n_u64],
space);
if (strcmp(se->fields[i]->type, "gfp_t") == 0) {
trace_seq_puts(s, " (");
trace_print_flags_seq(s, "|",
entry->fields[n_u64],
__flags);
trace_seq_putc(s, ')');
}
n_u64++;
}
}
end:
trace_seq_putc(s, '\n');
return trace_handle_return(s);
}
static struct trace_event_functions synth_event_funcs = {
.trace = print_synth_event
};
static notrace void trace_event_raw_event_synth(void *__data,
u64 *var_ref_vals,
unsigned int *var_ref_idx)
{
struct trace_event_file *trace_file = __data;
struct synth_trace_event *entry;
struct trace_event_buffer fbuffer;
struct trace_buffer *buffer;
struct synth_event *event;
unsigned int i, n_u64, val_idx;
int fields_size = 0;
event = trace_file->event_call->data;
if (trace_trigger_soft_disabled(trace_file))
return;
fields_size = event->n_u64 * sizeof(u64);
/*
* Avoid ring buffer recursion detection, as this event
* is being performed within another event.
*/
buffer = trace_file->tr->array_buffer.buffer;
ring_buffer_nest_start(buffer);
entry = trace_event_buffer_reserve(&fbuffer, trace_file,
sizeof(*entry) + fields_size);
if (!entry)
goto out;
for (i = 0, n_u64 = 0; i < event->n_fields; i++) {
val_idx = var_ref_idx[i];
if (event->fields[i]->is_string) {
char *str_val = (char *)(long)var_ref_vals[val_idx];
char *str_field = (char *)&entry->fields[n_u64];
strscpy(str_field, str_val, STR_VAR_LEN_MAX);
n_u64 += STR_VAR_LEN_MAX / sizeof(u64);
} else {
struct synth_field *field = event->fields[i];
u64 val = var_ref_vals[val_idx];
switch (field->size) {
case 1:
*(u8 *)&entry->fields[n_u64] = (u8)val;
break;
case 2:
*(u16 *)&entry->fields[n_u64] = (u16)val;
break;
case 4:
*(u32 *)&entry->fields[n_u64] = (u32)val;
break;
default:
entry->fields[n_u64] = val;
break;
}
n_u64++;
}
}
trace_event_buffer_commit(&fbuffer);
out:
ring_buffer_nest_end(buffer);
}
static void free_synth_event_print_fmt(struct trace_event_call *call)
{
if (call) {
kfree(call->print_fmt);
call->print_fmt = NULL;
}
}
static int __set_synth_event_print_fmt(struct synth_event *event,
char *buf, int len)
{
const char *fmt;
int pos = 0;
int i;
/* When len=0, we just calculate the needed length */
#define LEN_OR_ZERO (len ? len - pos : 0)
pos += snprintf(buf + pos, LEN_OR_ZERO, "\"");
for (i = 0; i < event->n_fields; i++) {
fmt = synth_field_fmt(event->fields[i]->type);
pos += snprintf(buf + pos, LEN_OR_ZERO, "%s=%s%s",
event->fields[i]->name, fmt,
i == event->n_fields - 1 ? "" : ", ");
}
pos += snprintf(buf + pos, LEN_OR_ZERO, "\"");
for (i = 0; i < event->n_fields; i++) {
pos += snprintf(buf + pos, LEN_OR_ZERO,
", REC->%s", event->fields[i]->name);
}
#undef LEN_OR_ZERO
/* return the length of print_fmt */
return pos;
}
static int set_synth_event_print_fmt(struct trace_event_call *call)
{
struct synth_event *event = call->data;
char *print_fmt;
int len;
/* First: called with 0 length to calculate the needed length */
len = __set_synth_event_print_fmt(event, NULL, 0);
print_fmt = kmalloc(len + 1, GFP_KERNEL);
if (!print_fmt)
return -ENOMEM;
/* Second: actually write the @print_fmt */
__set_synth_event_print_fmt(event, print_fmt, len + 1);
call->print_fmt = print_fmt;
return 0;
}
static void free_synth_field(struct synth_field *field)
{
kfree(field->type);
kfree(field->name);
kfree(field);
}
static struct synth_field *parse_synth_field(int argc, const char **argv,
int *consumed)
{
struct synth_field *field;
const char *prefix = NULL, *field_type = argv[0], *field_name, *array;
int len, ret = 0;
if (field_type[0] == ';')
field_type++;
if (!strcmp(field_type, "unsigned")) {
if (argc < 3)
return ERR_PTR(-EINVAL);
prefix = "unsigned ";
field_type = argv[1];
field_name = argv[2];
*consumed = 3;
} else {
field_name = argv[1];
*consumed = 2;
}
field = kzalloc(sizeof(*field), GFP_KERNEL);
if (!field)
return ERR_PTR(-ENOMEM);
len = strlen(field_name);
array = strchr(field_name, '[');
if (array)
len -= strlen(array);
else if (field_name[len - 1] == ';')
len--;
field->name = kmemdup_nul(field_name, len, GFP_KERNEL);
if (!field->name) {
ret = -ENOMEM;
goto free;
}
if (field_type[0] == ';')
field_type++;
len = strlen(field_type) + 1;
if (array)
len += strlen(array);
if (prefix)
len += strlen(prefix);
field->type = kzalloc(len, GFP_KERNEL);
if (!field->type) {
ret = -ENOMEM;
goto free;
}
if (prefix)
strcat(field->type, prefix);
strcat(field->type, field_type);
if (array) {
strcat(field->type, array);
if (field->type[len - 1] == ';')
field->type[len - 1] = '\0';
}
field->size = synth_field_size(field->type);
if (!field->size) {
ret = -EINVAL;
goto free;
}
if (synth_field_is_string(field->type))
field->is_string = true;
field->is_signed = synth_field_signed(field->type);
out:
return field;
free:
free_synth_field(field);
field = ERR_PTR(ret);
goto out;
}
static void free_synth_tracepoint(struct tracepoint *tp)
{
if (!tp)
return;
kfree(tp->name);
kfree(tp);
}
static struct tracepoint *alloc_synth_tracepoint(char *name)
{
struct tracepoint *tp;
tp = kzalloc(sizeof(*tp), GFP_KERNEL);
if (!tp)
return ERR_PTR(-ENOMEM);
tp->name = kstrdup(name, GFP_KERNEL);
if (!tp->name) {
kfree(tp);
return ERR_PTR(-ENOMEM);
}
return tp;
}
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 struct synth_event *find_synth_event(const char *name)
{
struct dyn_event *pos;
struct synth_event *event;
for_each_dyn_event(pos) {
if (!is_synth_event(pos))
continue;
event = to_synth_event(pos);
if (strcmp(event->name, name) == 0)
return event;
}
return NULL;
}
static struct trace_event_fields synth_event_fields_array[] = {
{ .type = TRACE_FUNCTION_TYPE,
.define_fields = synth_event_define_fields },
{}
};
static int register_synth_event(struct synth_event *event)
{
struct trace_event_call *call = &event->call;
int ret = 0;
event->call.class = &event->class;
event->class.system = kstrdup(SYNTH_SYSTEM, GFP_KERNEL);
if (!event->class.system) {
ret = -ENOMEM;
goto out;
}
event->tp = alloc_synth_tracepoint(event->name);
if (IS_ERR(event->tp)) {
ret = PTR_ERR(event->tp);
event->tp = NULL;
goto out;
}
INIT_LIST_HEAD(&call->class->fields);
call->event.funcs = &synth_event_funcs;
call->class->fields_array = synth_event_fields_array;
ret = register_trace_event(&call->event);
if (!ret) {
ret = -ENODEV;
goto out;
}
call->flags = TRACE_EVENT_FL_TRACEPOINT;
call->class->reg = trace_event_reg;
call->class->probe = trace_event_raw_event_synth;
call->data = event;
call->tp = event->tp;
ret = trace_add_event_call(call);
if (ret) {
pr_warn("Failed to register synthetic event: %s\n",
trace_event_name(call));
goto err;
}
ret = set_synth_event_print_fmt(call);
if (ret < 0) {
trace_remove_event_call(call);
goto err;
}
out:
return ret;
err:
unregister_trace_event(&call->event);
goto out;
}
static int unregister_synth_event(struct synth_event *event)
{
struct trace_event_call *call = &event->call;
int ret;
ret = trace_remove_event_call(call);
return ret;
}
static void free_synth_event(struct synth_event *event)
{
unsigned int i;
if (!event)
return;
for (i = 0; i < event->n_fields; i++)
free_synth_field(event->fields[i]);
kfree(event->fields);
kfree(event->name);
kfree(event->class.system);
free_synth_tracepoint(event->tp);
free_synth_event_print_fmt(&event->call);
kfree(event);
}
static struct synth_event *alloc_synth_event(const char *name, int n_fields,
struct synth_field **fields)
{
struct synth_event *event;
unsigned int i;
event = kzalloc(sizeof(*event), GFP_KERNEL);
if (!event) {
event = ERR_PTR(-ENOMEM);
goto out;
}
event->name = kstrdup(name, GFP_KERNEL);
if (!event->name) {
kfree(event);
event = ERR_PTR(-ENOMEM);
goto out;
}
event->fields = kcalloc(n_fields, sizeof(*event->fields), GFP_KERNEL);
if (!event->fields) {
free_synth_event(event);
event = ERR_PTR(-ENOMEM);
goto out;
}
dyn_event_init(&event->devent, &synth_event_ops);
for (i = 0; i < n_fields; i++)
event->fields[i] = fields[i];
event->n_fields = n_fields;
out:
return event;
}
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 int synth_event_check_arg_fn(void *data)
{
struct dynevent_arg_pair *arg_pair = data;
int size;
size = synth_field_size((char *)arg_pair->lhs);
return size ? 0 : -EINVAL;
}
/**
* synth_event_add_field - Add a new field to a synthetic event cmd
* @cmd: A pointer to the dynevent_cmd struct representing the new event
* @type: The type of the new field to add
* @name: The name of the new field to add
*
* Add a new field to a synthetic event cmd object. Field ordering is in
* the same order the fields are added.
*
* See synth_field_size() for available types. If field_name contains
* [n] the field is considered to be an array.
*
* Return: 0 if successful, error otherwise.
*/
int synth_event_add_field(struct dynevent_cmd *cmd, const char *type,
const char *name)
{
struct dynevent_arg_pair arg_pair;
int ret;
if (cmd->type != DYNEVENT_TYPE_SYNTH)
return -EINVAL;
if (!type || !name)
return -EINVAL;
dynevent_arg_pair_init(&arg_pair, 0, ';');
arg_pair.lhs = type;
arg_pair.rhs = name;
ret = dynevent_arg_pair_add(cmd, &arg_pair, synth_event_check_arg_fn);
if (ret)
return ret;
if (++cmd->n_fields > SYNTH_FIELDS_MAX)
ret = -EINVAL;
return ret;
}
EXPORT_SYMBOL_GPL(synth_event_add_field);
/**
* synth_event_add_field_str - Add a new field to a synthetic event cmd
* @cmd: A pointer to the dynevent_cmd struct representing the new event
* @type_name: The type and name of the new field to add, as a single string
*
* Add a new field to a synthetic event cmd object, as a single
* string. The @type_name string is expected to be of the form 'type
* name', which will be appended by ';'. No sanity checking is done -
* what's passed in is assumed to already be well-formed. Field
* ordering is in the same order the fields are added.
*
* See synth_field_size() for available types. If field_name contains
* [n] the field is considered to be an array.
*
* Return: 0 if successful, error otherwise.
*/
int synth_event_add_field_str(struct dynevent_cmd *cmd, const char *type_name)
{
struct dynevent_arg arg;
int ret;
if (cmd->type != DYNEVENT_TYPE_SYNTH)
return -EINVAL;
if (!type_name)
return -EINVAL;
dynevent_arg_init(&arg, ';');
arg.str = type_name;
ret = dynevent_arg_add(cmd, &arg, NULL);
if (ret)
return ret;
if (++cmd->n_fields > SYNTH_FIELDS_MAX)
ret = -EINVAL;
return ret;
}
EXPORT_SYMBOL_GPL(synth_event_add_field_str);
/**
* synth_event_add_fields - Add multiple fields to a synthetic event cmd
* @cmd: A pointer to the dynevent_cmd struct representing the new event
* @fields: An array of type/name field descriptions
* @n_fields: The number of field descriptions contained in the fields array
*
* Add a new set of fields to a synthetic event cmd object. The event
* fields that will be defined for the event should be passed in as an
* array of struct synth_field_desc, and the number of elements in the
* array passed in as n_fields. Field ordering will retain the
* ordering given in the fields array.
*
* See synth_field_size() for available types. If field_name contains
* [n] the field is considered to be an array.
*
* Return: 0 if successful, error otherwise.
*/
int synth_event_add_fields(struct dynevent_cmd *cmd,
struct synth_field_desc *fields,
unsigned int n_fields)
{
unsigned int i;
int ret = 0;
for (i = 0; i < n_fields; i++) {
if (fields[i].type == NULL || fields[i].name == NULL) {
ret = -EINVAL;
break;
}
ret = synth_event_add_field(cmd, fields[i].type, fields[i].name);
if (ret)
break;
}
return ret;
}
EXPORT_SYMBOL_GPL(synth_event_add_fields);
/**
* __synth_event_gen_cmd_start - Start a synthetic event command from arg list
* @cmd: A pointer to the dynevent_cmd struct representing the new event
* @name: The name of the synthetic event
* @mod: The module creating the event, NULL if not created from a module
* @args: Variable number of arg (pairs), one pair for each field
*
* NOTE: Users normally won't want to call this function directly, but
* rather use the synth_event_gen_cmd_start() wrapper, which
* automatically adds a NULL to the end of the arg list. If this
* function is used directly, make sure the last arg in the variable
* arg list is NULL.
*
* Generate a synthetic event command to be executed by
* synth_event_gen_cmd_end(). This function can be used to generate
* the complete command or only the first part of it; in the latter
* case, synth_event_add_field(), synth_event_add_field_str(), or
* synth_event_add_fields() can be used to add more fields following
* this.
*
* There should be an even number variable args, each pair consisting
* of a type followed by a field name.
*
* See synth_field_size() for available types. If field_name contains
* [n] the field is considered to be an array.
*
* Return: 0 if successful, error otherwise.
*/
int __synth_event_gen_cmd_start(struct dynevent_cmd *cmd, const char *name,
struct module *mod, ...)
{
struct dynevent_arg arg;
va_list args;
int ret;
cmd->event_name = name;
cmd->private_data = mod;
if (cmd->type != DYNEVENT_TYPE_SYNTH)
return -EINVAL;
dynevent_arg_init(&arg, 0);
arg.str = name;
ret = dynevent_arg_add(cmd, &arg, NULL);
if (ret)
return ret;
va_start(args, mod);
for (;;) {
const char *type, *name;
type = va_arg(args, const char *);
if (!type)
break;
name = va_arg(args, const char *);
if (!name)
break;
if (++cmd->n_fields > SYNTH_FIELDS_MAX) {
ret = -EINVAL;
break;
}
ret = synth_event_add_field(cmd, type, name);
if (ret)
break;
}
va_end(args);
return ret;
}
EXPORT_SYMBOL_GPL(__synth_event_gen_cmd_start);
/**
* synth_event_gen_cmd_array_start - Start synthetic event command from an array
* @cmd: A pointer to the dynevent_cmd struct representing the new event
* @name: The name of the synthetic event
* @fields: An array of type/name field descriptions
* @n_fields: The number of field descriptions contained in the fields array
*
* Generate a synthetic event command to be executed by
* synth_event_gen_cmd_end(). This function can be used to generate
* the complete command or only the first part of it; in the latter
* case, synth_event_add_field(), synth_event_add_field_str(), or
* synth_event_add_fields() can be used to add more fields following
* this.
*
* The event fields that will be defined for the event should be
* passed in as an array of struct synth_field_desc, and the number of
* elements in the array passed in as n_fields. Field ordering will
* retain the ordering given in the fields array.
*
* See synth_field_size() for available types. If field_name contains
* [n] the field is considered to be an array.
*
* Return: 0 if successful, error otherwise.
*/
int synth_event_gen_cmd_array_start(struct dynevent_cmd *cmd, const char *name,
struct module *mod,
struct synth_field_desc *fields,
unsigned int n_fields)
{
struct dynevent_arg arg;
unsigned int i;
int ret = 0;
cmd->event_name = name;
cmd->private_data = mod;
if (cmd->type != DYNEVENT_TYPE_SYNTH)
return -EINVAL;
if (n_fields > SYNTH_FIELDS_MAX)
return -EINVAL;
dynevent_arg_init(&arg, 0);
arg.str = name;
ret = dynevent_arg_add(cmd, &arg, NULL);
if (ret)
return ret;
for (i = 0; i < n_fields; i++) {
if (fields[i].type == NULL || fields[i].name == NULL)
return -EINVAL;
ret = synth_event_add_field(cmd, fields[i].type, fields[i].name);
if (ret)
break;
}
return ret;
}
EXPORT_SYMBOL_GPL(synth_event_gen_cmd_array_start);
static int __create_synth_event(int argc, const char *name, const char **argv)
{
struct synth_field *field, *fields[SYNTH_FIELDS_MAX];
struct synth_event *event = NULL;
int i, consumed = 0, n_fields = 0, ret = 0;
/*
* Argument syntax:
* - Add synthetic event: <event_name> field[;field] ...
* - Remove synthetic event: !<event_name> field[;field] ...
* where 'field' = type field_name
*/
if (name[0] == '\0' || argc < 1)
return -EINVAL;
mutex_lock(&event_mutex);
event = find_synth_event(name);
if (event) {
ret = -EEXIST;
goto out;
}
for (i = 0; i < argc - 1; i++) {
if (strcmp(argv[i], ";") == 0)
continue;
if (n_fields == SYNTH_FIELDS_MAX) {
ret = -EINVAL;
goto err;
}
field = parse_synth_field(argc - i, &argv[i], &consumed);
if (IS_ERR(field)) {
ret = PTR_ERR(field);
goto err;
}
fields[n_fields++] = field;
i += consumed - 1;
}
if (i < argc && strcmp(argv[i], ";") != 0) {
ret = -EINVAL;
goto err;
}
event = alloc_synth_event(name, n_fields, fields);
if (IS_ERR(event)) {
ret = PTR_ERR(event);
event = NULL;
goto err;
}
ret = register_synth_event(event);
if (!ret)
dyn_event_add(&event->devent);
else
free_synth_event(event);
out:
mutex_unlock(&event_mutex);
return ret;
err:
for (i = 0; i < n_fields; i++)
free_synth_field(fields[i]);
goto out;
}
/**
* synth_event_create - Create a new synthetic event
* @name: The name of the new sythetic event
* @fields: An array of type/name field descriptions
* @n_fields: The number of field descriptions contained in the fields array
* @mod: The module creating the event, NULL if not created from a module
*
* Create a new synthetic event with the given name under the
* trace/events/synthetic/ directory. The event fields that will be
* defined for the event should be passed in as an array of struct
* synth_field_desc, and the number elements in the array passed in as
* n_fields. Field ordering will retain the ordering given in the
* fields array.
*
* If the new synthetic event is being created from a module, the mod
* param must be non-NULL. This will ensure that the trace buffer
* won't contain unreadable events.
*
* The new synth event should be deleted using synth_event_delete()
* function. The new synthetic event can be generated from modules or
* other kernel code using trace_synth_event() and related functions.
*
* Return: 0 if successful, error otherwise.
*/
int synth_event_create(const char *name, struct synth_field_desc *fields,
unsigned int n_fields, struct module *mod)
{
struct dynevent_cmd cmd;
char *buf;
int ret;
buf = kzalloc(MAX_DYNEVENT_CMD_LEN, GFP_KERNEL);
if (!buf)
return -ENOMEM;
synth_event_cmd_init(&cmd, buf, MAX_DYNEVENT_CMD_LEN);
ret = synth_event_gen_cmd_array_start(&cmd, name, mod,
fields, n_fields);
if (ret)
goto out;
ret = synth_event_gen_cmd_end(&cmd);
out:
kfree(buf);
return ret;
}
EXPORT_SYMBOL_GPL(synth_event_create);
static int destroy_synth_event(struct synth_event *se)
{
int ret;
if (se->ref)
ret = -EBUSY;
else {
ret = unregister_synth_event(se);
if (!ret) {
dyn_event_remove(&se->devent);
free_synth_event(se);
}
}
return ret;
}
/**
* synth_event_delete - Delete a synthetic event
* @event_name: The name of the new sythetic event
*
* Delete a synthetic event that was created with synth_event_create().
*
* Return: 0 if successful, error otherwise.
*/
int synth_event_delete(const char *event_name)
{
struct synth_event *se = NULL;
struct module *mod = NULL;
int ret = -ENOENT;
mutex_lock(&event_mutex);
se = find_synth_event(event_name);
if (se) {
mod = se->mod;
ret = destroy_synth_event(se);
}
mutex_unlock(&event_mutex);
if (mod) {
mutex_lock(&trace_types_lock);
/*
* It is safest to reset the ring buffer if the module
* being unloaded registered any events that were
* used. The only worry is if a new module gets
* loaded, and takes on the same id as the events of
* this module. When printing out the buffer, traced
* events left over from this module may be passed to
* the new module events and unexpected results may
* occur.
*/
tracing_reset_all_online_cpus();
mutex_unlock(&trace_types_lock);
}
return ret;
}
EXPORT_SYMBOL_GPL(synth_event_delete);
static int create_or_delete_synth_event(int argc, char **argv)
{
const char *name = argv[0];
int ret;
/* trace_run_command() ensures argc != 0 */
if (name[0] == '!') {
ret = synth_event_delete(name + 1);
return ret;
}
ret = __create_synth_event(argc - 1, name, (const char **)argv + 1);
return ret == -ECANCELED ? -EINVAL : ret;
}
static int synth_event_run_command(struct dynevent_cmd *cmd)
{
struct synth_event *se;
int ret;
ret = trace_run_command(cmd->seq.buffer, create_or_delete_synth_event);
if (ret)
return ret;
se = find_synth_event(cmd->event_name);
if (WARN_ON(!se))
return -ENOENT;
se->mod = cmd->private_data;
return ret;
}
/**
* synth_event_cmd_init - Initialize a synthetic event command object
* @cmd: A pointer to the dynevent_cmd struct representing the new event
* @buf: A pointer to the buffer used to build the command
* @maxlen: The length of the buffer passed in @buf
*
* Initialize a synthetic event command object. Use this before
* calling any of the other dyenvent_cmd functions.
*/
void synth_event_cmd_init(struct dynevent_cmd *cmd, char *buf, int maxlen)
{
dynevent_cmd_init(cmd, buf, maxlen, DYNEVENT_TYPE_SYNTH,
synth_event_run_command);
}
EXPORT_SYMBOL_GPL(synth_event_cmd_init);
static inline int
__synth_event_trace_start(struct trace_event_file *file,
struct synth_event_trace_state *trace_state)
{
int entry_size, fields_size = 0;
int ret = 0;
memset(trace_state, '\0', sizeof(*trace_state));
/*
* Normal event tracing doesn't get called at all unless the
* ENABLED bit is set (which attaches the probe thus allowing
* this code to be called, etc). Because this is called
* directly by the user, we don't have that but we still need
* to honor not logging when disabled. For the the iterated
* trace case, we save the enabed state upon start and just
* ignore the following data calls.
*/
if (!(file->flags & EVENT_FILE_FL_ENABLED) ||
trace_trigger_soft_disabled(file)) {
trace_state->disabled = true;
ret = -ENOENT;
goto out;
}
trace_state->event = file->event_call->data;
fields_size = trace_state->event->n_u64 * sizeof(u64);
/*
* Avoid ring buffer recursion detection, as this event
* is being performed within another event.
*/
trace_state->buffer = file->tr->array_buffer.buffer;
ring_buffer_nest_start(trace_state->buffer);
entry_size = sizeof(*trace_state->entry) + fields_size;
trace_state->entry = trace_event_buffer_reserve(&trace_state->fbuffer,
file,
entry_size);
if (!trace_state->entry) {
ring_buffer_nest_end(trace_state->buffer);
ret = -EINVAL;
}
out:
return ret;
}
static inline void
__synth_event_trace_end(struct synth_event_trace_state *trace_state)
{
trace_event_buffer_commit(&trace_state->fbuffer);
ring_buffer_nest_end(trace_state->buffer);
}
/**
* synth_event_trace - Trace a synthetic event
* @file: The trace_event_file representing the synthetic event
* @n_vals: The number of values in vals
* @args: Variable number of args containing the event values
*
* Trace a synthetic event using the values passed in the variable
* argument list.
*
* The argument list should be a list 'n_vals' u64 values. The number
* of vals must match the number of field in the synthetic event, and
* must be in the same order as the synthetic event fields.
*
* All vals should be cast to u64, and string vals are just pointers
* to strings, cast to u64. Strings will be copied into space
* reserved in the event for the string, using these pointers.
*
* Return: 0 on success, err otherwise.
*/
int synth_event_trace(struct trace_event_file *file, unsigned int n_vals, ...)
{
struct synth_event_trace_state state;
unsigned int i, n_u64;
va_list args;
int ret;
ret = __synth_event_trace_start(file, &state);
if (ret) {
if (ret == -ENOENT)
ret = 0; /* just disabled, not really an error */
return ret;
}
if (n_vals != state.event->n_fields) {
ret = -EINVAL;
goto out;
}
va_start(args, n_vals);
for (i = 0, n_u64 = 0; i < state.event->n_fields; i++) {
u64 val;
val = va_arg(args, u64);
if (state.event->fields[i]->is_string) {
char *str_val = (char *)(long)val;
char *str_field = (char *)&state.entry->fields[n_u64];
strscpy(str_field, str_val, STR_VAR_LEN_MAX);
n_u64 += STR_VAR_LEN_MAX / sizeof(u64);
} else {
struct synth_field *field = state.event->fields[i];
switch (field->size) {
case 1:
*(u8 *)&state.entry->fields[n_u64] = (u8)val;
break;
case 2:
*(u16 *)&state.entry->fields[n_u64] = (u16)val;
break;
case 4:
*(u32 *)&state.entry->fields[n_u64] = (u32)val;
break;
default:
state.entry->fields[n_u64] = val;
break;
}
n_u64++;
}
}
va_end(args);
out:
__synth_event_trace_end(&state);
return ret;
}
EXPORT_SYMBOL_GPL(synth_event_trace);
/**
* synth_event_trace_array - Trace a synthetic event from an array
* @file: The trace_event_file representing the synthetic event
* @vals: Array of values
* @n_vals: The number of values in vals
*
* Trace a synthetic event using the values passed in as 'vals'.
*
* The 'vals' array is just an array of 'n_vals' u64. The number of
* vals must match the number of field in the synthetic event, and
* must be in the same order as the synthetic event fields.
*
* All vals should be cast to u64, and string vals are just pointers
* to strings, cast to u64. Strings will be copied into space
* reserved in the event for the string, using these pointers.
*
* Return: 0 on success, err otherwise.
*/
int synth_event_trace_array(struct trace_event_file *file, u64 *vals,
unsigned int n_vals)
{
struct synth_event_trace_state state;
unsigned int i, n_u64;
int ret;
ret = __synth_event_trace_start(file, &state);
if (ret) {
if (ret == -ENOENT)
ret = 0; /* just disabled, not really an error */
return ret;
}
if (n_vals != state.event->n_fields) {
ret = -EINVAL;
goto out;
}
for (i = 0, n_u64 = 0; i < state.event->n_fields; i++) {
if (state.event->fields[i]->is_string) {
char *str_val = (char *)(long)vals[i];
char *str_field = (char *)&state.entry->fields[n_u64];
strscpy(str_field, str_val, STR_VAR_LEN_MAX);
n_u64 += STR_VAR_LEN_MAX / sizeof(u64);
} else {
struct synth_field *field = state.event->fields[i];
u64 val = vals[i];
switch (field->size) {
case 1:
*(u8 *)&state.entry->fields[n_u64] = (u8)val;
break;
case 2:
*(u16 *)&state.entry->fields[n_u64] = (u16)val;
break;
case 4:
*(u32 *)&state.entry->fields[n_u64] = (u32)val;
break;
default:
state.entry->fields[n_u64] = val;
break;
}
n_u64++;
}
}
out:
__synth_event_trace_end(&state);
return ret;
}
EXPORT_SYMBOL_GPL(synth_event_trace_array);
/**
* synth_event_trace_start - Start piecewise synthetic event trace
* @file: The trace_event_file representing the synthetic event
* @trace_state: A pointer to object tracking the piecewise trace state
*
* Start the trace of a synthetic event field-by-field rather than all
* at once.
*
* This function 'opens' an event trace, which means space is reserved
* for the event in the trace buffer, after which the event's
* individual field values can be set through either
* synth_event_add_next_val() or synth_event_add_val().
*
* A pointer to a trace_state object is passed in, which will keep
* track of the current event trace state until the event trace is
* closed (and the event finally traced) using
* synth_event_trace_end().
*
* Note that synth_event_trace_end() must be called after all values
* have been added for each event trace, regardless of whether adding
* all field values succeeded or not.
*
* Note also that for a given event trace, all fields must be added
* using either synth_event_add_next_val() or synth_event_add_val()
* but not both together or interleaved.
*
* Return: 0 on success, err otherwise.
*/
int synth_event_trace_start(struct trace_event_file *file,
struct synth_event_trace_state *trace_state)
{
int ret;
if (!trace_state)
return -EINVAL;
ret = __synth_event_trace_start(file, trace_state);
if (ret == -ENOENT)
ret = 0; /* just disabled, not really an error */
return ret;
}
EXPORT_SYMBOL_GPL(synth_event_trace_start);
static int __synth_event_add_val(const char *field_name, u64 val,
struct synth_event_trace_state *trace_state)
{
struct synth_field *field = NULL;
struct synth_trace_event *entry;
struct synth_event *event;
int i, ret = 0;
if (!trace_state) {
ret = -EINVAL;
goto out;
}
/* can't mix add_next_synth_val() with add_synth_val() */
if (field_name) {
if (trace_state->add_next) {
ret = -EINVAL;
goto out;
}
trace_state->add_name = true;
} else {
if (trace_state->add_name) {
ret = -EINVAL;
goto out;
}
trace_state->add_next = true;
}
if (trace_state->disabled)
goto out;
event = trace_state->event;
if (trace_state->add_name) {
for (i = 0; i < event->n_fields; i++) {
field = event->fields[i];
if (strcmp(field->name, field_name) == 0)
break;
}
if (!field) {
ret = -EINVAL;
goto out;
}
} else {
if (trace_state->cur_field >= event->n_fields) {
ret = -EINVAL;
goto out;
}
field = event->fields[trace_state->cur_field++];
}
entry = trace_state->entry;
if (field->is_string) {
char *str_val = (char *)(long)val;
char *str_field;
if (!str_val) {
ret = -EINVAL;
goto out;
}
str_field = (char *)&entry->fields[field->offset];
strscpy(str_field, str_val, STR_VAR_LEN_MAX);
} else {
switch (field->size) {
case 1:
*(u8 *)&trace_state->entry->fields[field->offset] = (u8)val;
break;
case 2:
*(u16 *)&trace_state->entry->fields[field->offset] = (u16)val;
break;
case 4:
*(u32 *)&trace_state->entry->fields[field->offset] = (u32)val;
break;
default:
trace_state->entry->fields[field->offset] = val;
break;
}
}
out:
return ret;
}
/**
* synth_event_add_next_val - Add the next field's value to an open synth trace
* @val: The value to set the next field to
* @trace_state: A pointer to object tracking the piecewise trace state
*
* Set the value of the next field in an event that's been opened by
* synth_event_trace_start().
*
* The val param should be the value cast to u64. If the value points
* to a string, the val param should be a char * cast to u64.
*
* This function assumes all the fields in an event are to be set one
* after another - successive calls to this function are made, one for
* each field, in the order of the fields in the event, until all
* fields have been set. If you'd rather set each field individually
* without regard to ordering, synth_event_add_val() can be used
* instead.
*
* Note however that synth_event_add_next_val() and
* synth_event_add_val() can't be intermixed for a given event trace -
* one or the other but not both can be used at the same time.
*
* Note also that synth_event_trace_end() must be called after all
* values have been added for each event trace, regardless of whether
* adding all field values succeeded or not.
*
* Return: 0 on success, err otherwise.
*/
int synth_event_add_next_val(u64 val,
struct synth_event_trace_state *trace_state)
{
return __synth_event_add_val(NULL, val, trace_state);
}
EXPORT_SYMBOL_GPL(synth_event_add_next_val);
/**
* synth_event_add_val - Add a named field's value to an open synth trace
* @field_name: The name of the synthetic event field value to set
* @val: The value to set the next field to
* @trace_state: A pointer to object tracking the piecewise trace state
*
* Set the value of the named field in an event that's been opened by
* synth_event_trace_start().
*
* The val param should be the value cast to u64. If the value points
* to a string, the val param should be a char * cast to u64.
*
* This function looks up the field name, and if found, sets the field
* to the specified value. This lookup makes this function more
* expensive than synth_event_add_next_val(), so use that or the
* none-piecewise synth_event_trace() instead if efficiency is more
* important.
*
* Note however that synth_event_add_next_val() and
* synth_event_add_val() can't be intermixed for a given event trace -
* one or the other but not both can be used at the same time.
*
* Note also that synth_event_trace_end() must be called after all
* values have been added for each event trace, regardless of whether
* adding all field values succeeded or not.
*
* Return: 0 on success, err otherwise.
*/
int synth_event_add_val(const char *field_name, u64 val,
struct synth_event_trace_state *trace_state)
{
return __synth_event_add_val(field_name, val, trace_state);
}
EXPORT_SYMBOL_GPL(synth_event_add_val);
/**
* synth_event_trace_end - End piecewise synthetic event trace
* @trace_state: A pointer to object tracking the piecewise trace state
*
* End the trace of a synthetic event opened by
* synth_event_trace__start().
*
* This function 'closes' an event trace, which basically means that
* it commits the reserved event and cleans up other loose ends.
*
* A pointer to a trace_state object is passed in, which will keep
* track of the current event trace state opened with
* synth_event_trace_start().
*
* Note that this function must be called after all values have been
* added for each event trace, regardless of whether adding all field
* values succeeded or not.
*
* Return: 0 on success, err otherwise.
*/
int synth_event_trace_end(struct synth_event_trace_state *trace_state)
{
if (!trace_state)
return -EINVAL;
__synth_event_trace_end(trace_state);
return 0;
}
EXPORT_SYMBOL_GPL(synth_event_trace_end);
static int create_synth_event(int argc, const char **argv)
{
const char *name = argv[0];
int len;
if (name[0] != 's' || name[1] != ':')
return -ECANCELED;
name += 2;
/* This interface accepts group name prefix */
if (strchr(name, '/')) {
len = str_has_prefix(name, SYNTH_SYSTEM "/");
if (len == 0)
return -EINVAL;
name += len;
}
return __create_synth_event(argc - 1, name, argv + 1);
}
static int synth_event_release(struct dyn_event *ev)
{
struct synth_event *event = to_synth_event(ev);
int ret;
if (event->ref)
return -EBUSY;
ret = unregister_synth_event(event);
if (ret)
return ret;
dyn_event_remove(ev);
free_synth_event(event);
return 0;
}
static int __synth_event_show(struct seq_file *m, struct synth_event *event)
{
struct synth_field *field;
unsigned int i;
seq_printf(m, "%s\t", event->name);
for (i = 0; i < event->n_fields; i++) {
field = event->fields[i];
/* parameter values */
seq_printf(m, "%s %s%s", field->type, field->name,
i == event->n_fields - 1 ? "" : "; ");
}
seq_putc(m, '\n');
return 0;
}
static int synth_event_show(struct seq_file *m, struct dyn_event *ev)
{
struct synth_event *event = to_synth_event(ev);
seq_printf(m, "s:%s/", event->class.system);
return __synth_event_show(m, event);
}
static int synth_events_seq_show(struct seq_file *m, void *v)
{
struct dyn_event *ev = v;
if (!is_synth_event(ev))
return 0;
return __synth_event_show(m, to_synth_event(ev));
}
static const struct seq_operations synth_events_seq_op = {
.start = dyn_event_seq_start,
.next = dyn_event_seq_next,
.stop = dyn_event_seq_stop,
.show = synth_events_seq_show,
};
static int synth_events_open(struct inode *inode, struct file *file)
{
int ret;
ret = security_locked_down(LOCKDOWN_TRACEFS);
if (ret)
return ret;
if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
ret = dyn_events_release_all(&synth_event_ops);
if (ret < 0)
return ret;
}
return seq_open(file, &synth_events_seq_op);
}
static ssize_t synth_events_write(struct file *file,
const char __user *buffer,
size_t count, loff_t *ppos)
{
return trace_parse_run_command(file, buffer, count, ppos,
create_or_delete_synth_event);
}
static const struct file_operations synth_events_fops = {
.open = synth_events_open,
.write = synth_events_write,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
};
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 (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 = "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;
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 '-':
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);
}
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);
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;
if (is_string_field(field)) {
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;
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);
kfree(ref_field->event_name);
kfree(ref_field->name);
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;
}
}
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, "cpu") == 0)
*flags |= HIST_FIELD_FL_CPU;
else {
field = trace_find_event_field(file->event_call, field_name);
if (!field || !field->size) {
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;
}
expr->flags |= operand1->flags &
(HIST_FIELD_FL_TIMESTAMP | HIST_FIELD_FL_TIMESTAMP_USECS);
expr->fn = hist_field_unary_minus;
expr->operands[0] = operand1;
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;
}
/* 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;
}
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;
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;
strscpy(str, val_str, STR_VAR_LEN_MAX);
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->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);
goto out;
}
param = strsep(&params, ",");
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]);
}
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];
if (strcmp(field->type, hist_field->type) != 0) {
if (field->size != hist_field->size ||
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;
}
/*
* 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);
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(&param, ".");
if (!param) {
param = (char *)system;
system = event_name = NULL;
} else {
event_name = strsep(&param, ".");
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)) {
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;
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;
return __create_val_field(hist_data, val_idx, file, var_name, expr_str, flags);
}
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]);
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)
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;
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_PTR_STRING)
size = strlen(key);
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,
};
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, "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;
if (has_hist_vars(hist_data))
save_hist_vars(hist_data);
ret = create_actions(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)
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;
}
static __init int trace_events_hist_init(void)
{
struct dentry *entry = NULL;
struct dentry *d_tracer;
int err = 0;
err = dyn_event_register(&synth_event_ops);
if (err) {
pr_warn("Could not register synth_event_ops\n");
return err;
}
d_tracer = tracing_init_dentry();
if (IS_ERR(d_tracer)) {
err = PTR_ERR(d_tracer);
goto err;
}
entry = tracefs_create_file("synthetic_events", 0644, d_tracer,
NULL, &synth_events_fops);
if (!entry) {
err = -ENODEV;
goto err;
}
return err;
err:
pr_warn("Could not create tracefs 'synthetic_events' entry\n");
return err;
}
fs_initcall(trace_events_hist_init);