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// SPDX-License-Identifier: GPL-2.0
* Common header file for probe-based Dynamic events.
* This code was copied from kernel/trace/trace_kprobe.h written by
* Masami Hiramatsu <>
* Updates to make this generic:
* Copyright (C) IBM Corporation, 2010-2011
* Author: Srikar Dronamraju
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/smp.h>
#include <linux/tracefs.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/ctype.h>
#include <linux/ptrace.h>
#include <linux/perf_event.h>
#include <linux/kprobes.h>
#include <linux/stringify.h>
#include <linux/limits.h>
#include <linux/uaccess.h>
#include <linux/bitops.h>
#include <asm/bitsperlong.h>
#include "trace.h"
#include "trace_output.h"
#define MAX_TRACE_ARGS 128
#define MAX_ARGSTR_LEN 63
#define MAX_ARRAY_LEN 64
#define MAX_ARG_NAME_LEN 32
/* Reserved field names */
#define FIELD_STRING_IP "__probe_ip"
#define FIELD_STRING_RETIP "__probe_ret_ip"
#define FIELD_STRING_FUNC "__probe_func"
#define DEFINE_FIELD(type, item, name, is_signed) \
do { \
ret = trace_define_field(event_call, #type, name, \
offsetof(typeof(field), item), \
sizeof(field.item), is_signed, \
if (ret) \
return ret; \
} while (0)
/* Flags for trace_probe */
#define TP_FLAG_TRACE 1
/* data_loc: data location, compatible with u32 */
#define make_data_loc(len, offs) \
(((u32)(len) << 16) | ((u32)(offs) & 0xffff))
#define get_loc_len(dl) ((u32)(dl) >> 16)
#define get_loc_offs(dl) ((u32)(dl) & 0xffff)
static nokprobe_inline void *get_loc_data(u32 *dl, void *ent)
return (u8 *)ent + get_loc_offs(*dl);
static nokprobe_inline u32 update_data_loc(u32 loc, int consumed)
u32 maxlen = get_loc_len(loc);
u32 offset = get_loc_offs(loc);
return make_data_loc(maxlen - consumed, offset + consumed);
/* Printing function type */
typedef int (*print_type_func_t)(struct trace_seq *, void *, void *);
enum fetch_op {
// Stage 1 (load) ops
FETCH_OP_REG, /* Register : .param = offset */
FETCH_OP_STACK, /* Stack : .param = index */
FETCH_OP_STACKP, /* Stack pointer */
FETCH_OP_RETVAL, /* Return value */
FETCH_OP_IMM, /* Immediate : .immediate */
FETCH_OP_COMM, /* Current comm */
FETCH_OP_ARG, /* Function argument : .param */
FETCH_OP_FOFFS, /* File offset: .immediate */
FETCH_OP_DATA, /* Allocated data: .data */
// Stage 2 (dereference) op
FETCH_OP_DEREF, /* Dereference: .offset */
FETCH_OP_UDEREF, /* User-space Dereference: .offset */
// Stage 3 (store) ops
FETCH_OP_ST_RAW, /* Raw: .size */
FETCH_OP_ST_MEM, /* Mem: .offset, .size */
FETCH_OP_ST_UMEM, /* Mem: .offset, .size */
FETCH_OP_ST_STRING, /* String: .offset, .size */
FETCH_OP_ST_USTRING, /* User String: .offset, .size */
// Stage 4 (modify) op
FETCH_OP_MOD_BF, /* Bitfield: .basesize, .lshift, .rshift */
// Stage 5 (loop) op
FETCH_OP_LP_ARRAY, /* Array: .param = loop count */
FETCH_NOP_SYMBOL, /* Unresolved Symbol holder */
struct fetch_insn {
enum fetch_op op;
union {
unsigned int param;
struct {
unsigned int size;
int offset;
struct {
unsigned char basesize;
unsigned char lshift;
unsigned char rshift;
unsigned long immediate;
void *data;
/* fetch + deref*N + store + mod + end <= 16, this allows N=12, enough */
#define FETCH_INSN_MAX 16
/* Fetch type information table */
struct fetch_type {
const char *name; /* Name of type */
size_t size; /* Byte size of type */
int is_signed; /* Signed flag */
print_type_func_t print; /* Print functions */
const char *fmt; /* Fromat string */
const char *fmttype; /* Name in format file */
/* For defining macros, define string/string_size types */
typedef u32 string;
typedef u32 string_size;
#define PRINT_TYPE_FUNC_NAME(type) print_type_##type
#define PRINT_TYPE_FMT_NAME(type) print_type_format_##type
/* Printing in basic type function template */
int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, void *data, void *ent);\
extern const char PRINT_TYPE_FMT_NAME(type)[]
/* Default (unsigned long) fetch type */
#define __DEFAULT_FETCH_TYPE(t) x##t
#define __ADDR_FETCH_TYPE(t) u##t
#define __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype) \
{.name = _name, \
.size = _size, \
.is_signed = sign, \
.print = PRINT_TYPE_FUNC_NAME(ptype), \
.fmt = PRINT_TYPE_FMT_NAME(ptype), \
.fmttype = _fmttype, \
#define _ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype) \
__ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, #_fmttype)
#define ASSIGN_FETCH_TYPE(ptype, ftype, sign) \
_ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, ptype)
/* If ptype is an alias of atype, use this macro (show atype in format) */
#define ASSIGN_FETCH_TYPE_ALIAS(ptype, atype, ftype, sign) \
_ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, atype)
#define MAX_ARRAY_LEN 64
bool trace_kprobe_on_func_entry(struct trace_event_call *call);
bool trace_kprobe_error_injectable(struct trace_event_call *call);
static inline bool trace_kprobe_on_func_entry(struct trace_event_call *call)
return false;
static inline bool trace_kprobe_error_injectable(struct trace_event_call *call)
return false;
struct probe_arg {
struct fetch_insn *code;
bool dynamic;/* Dynamic array (string) is used */
unsigned int offset; /* Offset from argument entry */
unsigned int count; /* Array count */
const char *name; /* Name of this argument */
const char *comm; /* Command of this argument */
char *fmt; /* Format string if needed */
const struct fetch_type *type; /* Type of this argument */
struct trace_uprobe_filter {
rwlock_t rwlock;
int nr_systemwide;
struct list_head perf_events;
/* Event call and class holder */
struct trace_probe_event {
unsigned int flags; /* For TP_FLAG_* */
struct trace_event_class class;
struct trace_event_call call;
struct list_head files;
struct list_head probes;
struct trace_uprobe_filter filter[0];
struct trace_probe {
struct list_head list;
struct trace_probe_event *event;
ssize_t size; /* trace entry size */
unsigned int nr_args;
struct probe_arg args[];
struct event_file_link {
struct trace_event_file *file;
struct list_head list;
static inline bool trace_probe_test_flag(struct trace_probe *tp,
unsigned int flag)
return !!(tp->event->flags & flag);
static inline void trace_probe_set_flag(struct trace_probe *tp,
unsigned int flag)
tp->event->flags |= flag;
static inline void trace_probe_clear_flag(struct trace_probe *tp,
unsigned int flag)
tp->event->flags &= ~flag;
static inline bool trace_probe_is_enabled(struct trace_probe *tp)
return trace_probe_test_flag(tp, TP_FLAG_TRACE | TP_FLAG_PROFILE);
static inline const char *trace_probe_name(struct trace_probe *tp)
return trace_event_name(&tp->event->call);
static inline const char *trace_probe_group_name(struct trace_probe *tp)
return tp->event->call.class->system;
static inline struct trace_event_call *
trace_probe_event_call(struct trace_probe *tp)
return &tp->event->call;
static inline struct trace_probe_event *
trace_probe_event_from_call(struct trace_event_call *event_call)
return container_of(event_call, struct trace_probe_event, call);
static inline struct trace_probe *
trace_probe_primary_from_call(struct trace_event_call *call)
struct trace_probe_event *tpe = trace_probe_event_from_call(call);
return list_first_entry(&tpe->probes, struct trace_probe, list);
static inline struct list_head *trace_probe_probe_list(struct trace_probe *tp)
return &tp->event->probes;
static inline bool trace_probe_has_sibling(struct trace_probe *tp)
struct list_head *list = trace_probe_probe_list(tp);
return !list_empty(list) && !list_is_singular(list);
static inline int trace_probe_unregister_event_call(struct trace_probe *tp)
/* tp->event is unregistered in trace_remove_event_call() */
return trace_remove_event_call(&tp->event->call);
static inline bool trace_probe_has_single_file(struct trace_probe *tp)
return !!list_is_singular(&tp->event->files);
int trace_probe_init(struct trace_probe *tp, const char *event,
const char *group, bool alloc_filter);
void trace_probe_cleanup(struct trace_probe *tp);
int trace_probe_append(struct trace_probe *tp, struct trace_probe *to);
void trace_probe_unlink(struct trace_probe *tp);
int trace_probe_register_event_call(struct trace_probe *tp);
int trace_probe_add_file(struct trace_probe *tp, struct trace_event_file *file);
int trace_probe_remove_file(struct trace_probe *tp,
struct trace_event_file *file);
struct event_file_link *trace_probe_get_file_link(struct trace_probe *tp,
struct trace_event_file *file);
int trace_probe_compare_arg_type(struct trace_probe *a, struct trace_probe *b);
bool trace_probe_match_command_args(struct trace_probe *tp,
int argc, const char **argv);
#define trace_probe_for_each_link(pos, tp) \
list_for_each_entry(pos, &(tp)->event->files, list)
#define trace_probe_for_each_link_rcu(pos, tp) \
list_for_each_entry_rcu(pos, &(tp)->event->files, list)
/* Check the name is good for event/group/fields */
static inline bool is_good_name(const char *name)
if (!isalpha(*name) && *name != '_')
return false;
while (*++name != '\0') {
if (!isalpha(*name) && !isdigit(*name) && *name != '_')
return false;
return true;
extern int traceprobe_parse_probe_arg(struct trace_probe *tp, int i,
char *arg, unsigned int flags);
extern int traceprobe_update_arg(struct probe_arg *arg);
extern void traceprobe_free_probe_arg(struct probe_arg *arg);
extern int traceprobe_split_symbol_offset(char *symbol, long *offset);
int traceprobe_parse_event_name(const char **pevent, const char **pgroup,
char *buf, int offset);
extern int traceprobe_set_print_fmt(struct trace_probe *tp, bool is_return);
extern struct trace_event_call *
create_local_trace_kprobe(char *func, void *addr, unsigned long offs,
bool is_return);
extern void destroy_local_trace_kprobe(struct trace_event_call *event_call);
extern struct trace_event_call *
create_local_trace_uprobe(char *name, unsigned long offs,
unsigned long ref_ctr_offset, bool is_return);
extern void destroy_local_trace_uprobe(struct trace_event_call *event_call);
extern int traceprobe_define_arg_fields(struct trace_event_call *event_call,
size_t offset, struct trace_probe *tp);
#undef ERRORS
#define ERRORS \
C(FILE_NOT_FOUND, "Failed to find the given file"), \
C(NO_REGULAR_FILE, "Not a regular file"), \
C(BAD_REFCNT, "Invalid reference counter offset"), \
C(REFCNT_OPEN_BRACE, "Reference counter brace is not closed"), \
C(BAD_REFCNT_SUFFIX, "Reference counter has wrong suffix"), \
C(BAD_UPROBE_OFFS, "Invalid uprobe offset"), \
C(MAXACT_NO_KPROBE, "Maxactive is not for kprobe"), \
C(BAD_MAXACT, "Invalid maxactive number"), \
C(MAXACT_TOO_BIG, "Maxactive is too big"), \
C(BAD_PROBE_ADDR, "Invalid probed address or symbol"), \
C(BAD_RETPROBE, "Retprobe address must be an function entry"), \
C(NO_GROUP_NAME, "Group name is not specified"), \
C(GROUP_TOO_LONG, "Group name is too long"), \
C(BAD_GROUP_NAME, "Group name must follow the same rules as C identifiers"), \
C(NO_EVENT_NAME, "Event name is not specified"), \
C(EVENT_TOO_LONG, "Event name is too long"), \
C(BAD_EVENT_NAME, "Event name must follow the same rules as C identifiers"), \
C(RETVAL_ON_PROBE, "$retval is not available on probe"), \
C(BAD_STACK_NUM, "Invalid stack number"), \
C(BAD_ARG_NUM, "Invalid argument number"), \
C(BAD_VAR, "Invalid $-valiable specified"), \
C(BAD_REG_NAME, "Invalid register name"), \
C(BAD_MEM_ADDR, "Invalid memory address"), \
C(BAD_IMM, "Invalid immediate value"), \
C(IMMSTR_NO_CLOSE, "String is not closed with '\"'"), \
C(FILE_ON_KPROBE, "File offset is not available with kprobe"), \
C(BAD_FILE_OFFS, "Invalid file offset value"), \
C(SYM_ON_UPROBE, "Symbol is not available with uprobe"), \
C(TOO_MANY_OPS, "Dereference is too much nested"), \
C(DEREF_NEED_BRACE, "Dereference needs a brace"), \
C(BAD_DEREF_OFFS, "Invalid dereference offset"), \
C(DEREF_OPEN_BRACE, "Dereference brace is not closed"), \
C(COMM_CANT_DEREF, "$comm can not be dereferenced"), \
C(BAD_FETCH_ARG, "Invalid fetch argument"), \
C(ARRAY_NO_CLOSE, "Array is not closed"), \
C(BAD_ARRAY_SUFFIX, "Array has wrong suffix"), \
C(BAD_ARRAY_NUM, "Invalid array size"), \
C(ARRAY_TOO_BIG, "Array number is too big"), \
C(BAD_TYPE, "Unknown type is specified"), \
C(BAD_STRING, "String accepts only memory argument"), \
C(BAD_BITFIELD, "Invalid bitfield"), \
C(ARG_NAME_TOO_LONG, "Argument name is too long"), \
C(NO_ARG_NAME, "Argument name is not specified"), \
C(BAD_ARG_NAME, "Argument name must follow the same rules as C identifiers"), \
C(USED_ARG_NAME, "This argument name is already used"), \
C(ARG_TOO_LONG, "Argument expression is too long"), \
C(NO_ARG_BODY, "No argument expression"), \
C(BAD_INSN_BNDRY, "Probe point is not an instruction boundary"),\
C(FAIL_REG_PROBE, "Failed to register probe event"),\
C(DIFF_PROBE_TYPE, "Probe type is different from existing probe"),\
C(DIFF_ARG_TYPE, "Argument type or name is different from existing probe"),\
C(SAME_PROBE, "There is already the exact same probe event"),
#undef C
#define C(a, b) TP_ERR_##a
/* Define TP_ERR_ */
enum { ERRORS };
/* Error text is defined in trace_probe.c */
struct trace_probe_log {
const char *subsystem;
const char **argv;
int argc;
int index;
void trace_probe_log_init(const char *subsystem, int argc, const char **argv);
void trace_probe_log_set_index(int index);
void trace_probe_log_clear(void);
void __trace_probe_log_err(int offset, int err);
#define trace_probe_log_err(offs, err) \
__trace_probe_log_err(offs, TP_ERR_##err)