linux/kernel/trace/trace_probe.h
<<
>>
Prefs
   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Common header file for probe-based Dynamic events.
   4 *
   5 * This code was copied from kernel/trace/trace_kprobe.h written by
   6 * Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
   7 *
   8 * Updates to make this generic:
   9 * Copyright (C) IBM Corporation, 2010-2011
  10 * Author:     Srikar Dronamraju
  11 */
  12
  13#include <linux/seq_file.h>
  14#include <linux/slab.h>
  15#include <linux/smp.h>
  16#include <linux/tracefs.h>
  17#include <linux/types.h>
  18#include <linux/string.h>
  19#include <linux/ctype.h>
  20#include <linux/ptrace.h>
  21#include <linux/perf_event.h>
  22#include <linux/kprobes.h>
  23#include <linux/stringify.h>
  24#include <linux/limits.h>
  25#include <linux/uaccess.h>
  26#include <linux/bitops.h>
  27#include <asm/bitsperlong.h>
  28
  29#include "trace.h"
  30#include "trace_output.h"
  31
  32#define MAX_TRACE_ARGS          128
  33#define MAX_ARGSTR_LEN          63
  34#define MAX_ARRAY_LEN           64
  35#define MAX_ARG_NAME_LEN        32
  36#define MAX_STRING_SIZE         PATH_MAX
  37
  38/* Reserved field names */
  39#define FIELD_STRING_IP         "__probe_ip"
  40#define FIELD_STRING_RETIP      "__probe_ret_ip"
  41#define FIELD_STRING_FUNC       "__probe_func"
  42
  43#undef DEFINE_FIELD
  44#define DEFINE_FIELD(type, item, name, is_signed)                       \
  45        do {                                                            \
  46                ret = trace_define_field(event_call, #type, name,       \
  47                                         offsetof(typeof(field), item), \
  48                                         sizeof(field.item), is_signed, \
  49                                         FILTER_OTHER);                 \
  50                if (ret)                                                \
  51                        return ret;                                     \
  52        } while (0)
  53
  54
  55/* Flags for trace_probe */
  56#define TP_FLAG_TRACE           1
  57#define TP_FLAG_PROFILE         2
  58
  59/* data_loc: data location, compatible with u32 */
  60#define make_data_loc(len, offs)        \
  61        (((u32)(len) << 16) | ((u32)(offs) & 0xffff))
  62#define get_loc_len(dl)         ((u32)(dl) >> 16)
  63#define get_loc_offs(dl)        ((u32)(dl) & 0xffff)
  64
  65static nokprobe_inline void *get_loc_data(u32 *dl, void *ent)
  66{
  67        return (u8 *)ent + get_loc_offs(*dl);
  68}
  69
  70static nokprobe_inline u32 update_data_loc(u32 loc, int consumed)
  71{
  72        u32 maxlen = get_loc_len(loc);
  73        u32 offset = get_loc_offs(loc);
  74
  75        return make_data_loc(maxlen - consumed, offset + consumed);
  76}
  77
  78/* Printing function type */
  79typedef int (*print_type_func_t)(struct trace_seq *, void *, void *);
  80
  81enum fetch_op {
  82        FETCH_OP_NOP = 0,
  83        // Stage 1 (load) ops
  84        FETCH_OP_REG,           /* Register : .param = offset */
  85        FETCH_OP_STACK,         /* Stack : .param = index */
  86        FETCH_OP_STACKP,        /* Stack pointer */
  87        FETCH_OP_RETVAL,        /* Return value */
  88        FETCH_OP_IMM,           /* Immediate : .immediate */
  89        FETCH_OP_COMM,          /* Current comm */
  90        FETCH_OP_ARG,           /* Function argument : .param */
  91        FETCH_OP_FOFFS,         /* File offset: .immediate */
  92        FETCH_OP_DATA,          /* Allocated data: .data */
  93        // Stage 2 (dereference) op
  94        FETCH_OP_DEREF,         /* Dereference: .offset */
  95        FETCH_OP_UDEREF,        /* User-space Dereference: .offset */
  96        // Stage 3 (store) ops
  97        FETCH_OP_ST_RAW,        /* Raw: .size */
  98        FETCH_OP_ST_MEM,        /* Mem: .offset, .size */
  99        FETCH_OP_ST_UMEM,       /* Mem: .offset, .size */
 100        FETCH_OP_ST_STRING,     /* String: .offset, .size */
 101        FETCH_OP_ST_USTRING,    /* User String: .offset, .size */
 102        // Stage 4 (modify) op
 103        FETCH_OP_MOD_BF,        /* Bitfield: .basesize, .lshift, .rshift */
 104        // Stage 5 (loop) op
 105        FETCH_OP_LP_ARRAY,      /* Array: .param = loop count */
 106        FETCH_OP_END,
 107        FETCH_NOP_SYMBOL,       /* Unresolved Symbol holder */
 108};
 109
 110struct fetch_insn {
 111        enum fetch_op op;
 112        union {
 113                unsigned int param;
 114                struct {
 115                        unsigned int size;
 116                        int offset;
 117                };
 118                struct {
 119                        unsigned char basesize;
 120                        unsigned char lshift;
 121                        unsigned char rshift;
 122                };
 123                unsigned long immediate;
 124                void *data;
 125        };
 126};
 127
 128/* fetch + deref*N + store + mod + end <= 16, this allows N=12, enough */
 129#define FETCH_INSN_MAX  16
 130#define FETCH_TOKEN_COMM        (-ECOMM)
 131
 132/* Fetch type information table */
 133struct fetch_type {
 134        const char              *name;          /* Name of type */
 135        size_t                  size;           /* Byte size of type */
 136        int                     is_signed;      /* Signed flag */
 137        print_type_func_t       print;          /* Print functions */
 138        const char              *fmt;           /* Fromat string */
 139        const char              *fmttype;       /* Name in format file */
 140};
 141
 142/* For defining macros, define string/string_size types */
 143typedef u32 string;
 144typedef u32 string_size;
 145
 146#define PRINT_TYPE_FUNC_NAME(type)      print_type_##type
 147#define PRINT_TYPE_FMT_NAME(type)       print_type_format_##type
 148
 149/* Printing  in basic type function template */
 150#define DECLARE_BASIC_PRINT_TYPE_FUNC(type)                             \
 151int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, void *data, void *ent);\
 152extern const char PRINT_TYPE_FMT_NAME(type)[]
 153
 154DECLARE_BASIC_PRINT_TYPE_FUNC(u8);
 155DECLARE_BASIC_PRINT_TYPE_FUNC(u16);
 156DECLARE_BASIC_PRINT_TYPE_FUNC(u32);
 157DECLARE_BASIC_PRINT_TYPE_FUNC(u64);
 158DECLARE_BASIC_PRINT_TYPE_FUNC(s8);
 159DECLARE_BASIC_PRINT_TYPE_FUNC(s16);
 160DECLARE_BASIC_PRINT_TYPE_FUNC(s32);
 161DECLARE_BASIC_PRINT_TYPE_FUNC(s64);
 162DECLARE_BASIC_PRINT_TYPE_FUNC(x8);
 163DECLARE_BASIC_PRINT_TYPE_FUNC(x16);
 164DECLARE_BASIC_PRINT_TYPE_FUNC(x32);
 165DECLARE_BASIC_PRINT_TYPE_FUNC(x64);
 166
 167DECLARE_BASIC_PRINT_TYPE_FUNC(string);
 168DECLARE_BASIC_PRINT_TYPE_FUNC(symbol);
 169
 170/* Default (unsigned long) fetch type */
 171#define __DEFAULT_FETCH_TYPE(t) x##t
 172#define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t)
 173#define DEFAULT_FETCH_TYPE _DEFAULT_FETCH_TYPE(BITS_PER_LONG)
 174#define DEFAULT_FETCH_TYPE_STR __stringify(DEFAULT_FETCH_TYPE)
 175
 176#define __ADDR_FETCH_TYPE(t) u##t
 177#define _ADDR_FETCH_TYPE(t) __ADDR_FETCH_TYPE(t)
 178#define ADDR_FETCH_TYPE _ADDR_FETCH_TYPE(BITS_PER_LONG)
 179
 180#define __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype) \
 181        {.name = _name,                         \
 182         .size = _size,                                 \
 183         .is_signed = sign,                             \
 184         .print = PRINT_TYPE_FUNC_NAME(ptype),          \
 185         .fmt = PRINT_TYPE_FMT_NAME(ptype),             \
 186         .fmttype = _fmttype,                           \
 187        }
 188#define _ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype)  \
 189        __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, #_fmttype)
 190#define ASSIGN_FETCH_TYPE(ptype, ftype, sign)                   \
 191        _ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, ptype)
 192
 193/* If ptype is an alias of atype, use this macro (show atype in format) */
 194#define ASSIGN_FETCH_TYPE_ALIAS(ptype, atype, ftype, sign)              \
 195        _ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, atype)
 196
 197#define ASSIGN_FETCH_TYPE_END {}
 198#define MAX_ARRAY_LEN   64
 199
 200#ifdef CONFIG_KPROBE_EVENTS
 201bool trace_kprobe_on_func_entry(struct trace_event_call *call);
 202bool trace_kprobe_error_injectable(struct trace_event_call *call);
 203#else
 204static inline bool trace_kprobe_on_func_entry(struct trace_event_call *call)
 205{
 206        return false;
 207}
 208
 209static inline bool trace_kprobe_error_injectable(struct trace_event_call *call)
 210{
 211        return false;
 212}
 213#endif /* CONFIG_KPROBE_EVENTS */
 214
 215struct probe_arg {
 216        struct fetch_insn       *code;
 217        bool                    dynamic;/* Dynamic array (string) is used */
 218        unsigned int            offset; /* Offset from argument entry */
 219        unsigned int            count;  /* Array count */
 220        const char              *name;  /* Name of this argument */
 221        const char              *comm;  /* Command of this argument */
 222        char                    *fmt;   /* Format string if needed */
 223        const struct fetch_type *type;  /* Type of this argument */
 224};
 225
 226struct trace_uprobe_filter {
 227        rwlock_t                rwlock;
 228        int                     nr_systemwide;
 229        struct list_head        perf_events;
 230};
 231
 232/* Event call and class holder */
 233struct trace_probe_event {
 234        unsigned int                    flags;  /* For TP_FLAG_* */
 235        struct trace_event_class        class;
 236        struct trace_event_call         call;
 237        struct list_head                files;
 238        struct list_head                probes;
 239        struct trace_uprobe_filter      filter[0];
 240};
 241
 242struct trace_probe {
 243        struct list_head                list;
 244        struct trace_probe_event        *event;
 245        ssize_t                         size;   /* trace entry size */
 246        unsigned int                    nr_args;
 247        struct probe_arg                args[];
 248};
 249
 250struct event_file_link {
 251        struct trace_event_file         *file;
 252        struct list_head                list;
 253};
 254
 255static inline bool trace_probe_test_flag(struct trace_probe *tp,
 256                                         unsigned int flag)
 257{
 258        return !!(tp->event->flags & flag);
 259}
 260
 261static inline void trace_probe_set_flag(struct trace_probe *tp,
 262                                        unsigned int flag)
 263{
 264        tp->event->flags |= flag;
 265}
 266
 267static inline void trace_probe_clear_flag(struct trace_probe *tp,
 268                                          unsigned int flag)
 269{
 270        tp->event->flags &= ~flag;
 271}
 272
 273static inline bool trace_probe_is_enabled(struct trace_probe *tp)
 274{
 275        return trace_probe_test_flag(tp, TP_FLAG_TRACE | TP_FLAG_PROFILE);
 276}
 277
 278static inline const char *trace_probe_name(struct trace_probe *tp)
 279{
 280        return trace_event_name(&tp->event->call);
 281}
 282
 283static inline const char *trace_probe_group_name(struct trace_probe *tp)
 284{
 285        return tp->event->call.class->system;
 286}
 287
 288static inline struct trace_event_call *
 289        trace_probe_event_call(struct trace_probe *tp)
 290{
 291        return &tp->event->call;
 292}
 293
 294static inline struct trace_probe_event *
 295trace_probe_event_from_call(struct trace_event_call *event_call)
 296{
 297        return container_of(event_call, struct trace_probe_event, call);
 298}
 299
 300static inline struct trace_probe *
 301trace_probe_primary_from_call(struct trace_event_call *call)
 302{
 303        struct trace_probe_event *tpe = trace_probe_event_from_call(call);
 304
 305        return list_first_entry(&tpe->probes, struct trace_probe, list);
 306}
 307
 308static inline struct list_head *trace_probe_probe_list(struct trace_probe *tp)
 309{
 310        return &tp->event->probes;
 311}
 312
 313static inline bool trace_probe_has_sibling(struct trace_probe *tp)
 314{
 315        struct list_head *list = trace_probe_probe_list(tp);
 316
 317        return !list_empty(list) && !list_is_singular(list);
 318}
 319
 320static inline int trace_probe_unregister_event_call(struct trace_probe *tp)
 321{
 322        /* tp->event is unregistered in trace_remove_event_call() */
 323        return trace_remove_event_call(&tp->event->call);
 324}
 325
 326static inline bool trace_probe_has_single_file(struct trace_probe *tp)
 327{
 328        return !!list_is_singular(&tp->event->files);
 329}
 330
 331int trace_probe_init(struct trace_probe *tp, const char *event,
 332                     const char *group, bool alloc_filter);
 333void trace_probe_cleanup(struct trace_probe *tp);
 334int trace_probe_append(struct trace_probe *tp, struct trace_probe *to);
 335void trace_probe_unlink(struct trace_probe *tp);
 336int trace_probe_register_event_call(struct trace_probe *tp);
 337int trace_probe_add_file(struct trace_probe *tp, struct trace_event_file *file);
 338int trace_probe_remove_file(struct trace_probe *tp,
 339                            struct trace_event_file *file);
 340struct event_file_link *trace_probe_get_file_link(struct trace_probe *tp,
 341                                                struct trace_event_file *file);
 342int trace_probe_compare_arg_type(struct trace_probe *a, struct trace_probe *b);
 343bool trace_probe_match_command_args(struct trace_probe *tp,
 344                                    int argc, const char **argv);
 345
 346#define trace_probe_for_each_link(pos, tp)      \
 347        list_for_each_entry(pos, &(tp)->event->files, list)
 348#define trace_probe_for_each_link_rcu(pos, tp)  \
 349        list_for_each_entry_rcu(pos, &(tp)->event->files, list)
 350
 351/* Check the name is good for event/group/fields */
 352static inline bool is_good_name(const char *name)
 353{
 354        if (!isalpha(*name) && *name != '_')
 355                return false;
 356        while (*++name != '\0') {
 357                if (!isalpha(*name) && !isdigit(*name) && *name != '_')
 358                        return false;
 359        }
 360        return true;
 361}
 362
 363#define TPARG_FL_RETURN BIT(0)
 364#define TPARG_FL_KERNEL BIT(1)
 365#define TPARG_FL_FENTRY BIT(2)
 366#define TPARG_FL_MASK   GENMASK(2, 0)
 367
 368extern int traceprobe_parse_probe_arg(struct trace_probe *tp, int i,
 369                                char *arg, unsigned int flags);
 370
 371extern int traceprobe_update_arg(struct probe_arg *arg);
 372extern void traceprobe_free_probe_arg(struct probe_arg *arg);
 373
 374extern int traceprobe_split_symbol_offset(char *symbol, long *offset);
 375int traceprobe_parse_event_name(const char **pevent, const char **pgroup,
 376                                char *buf, int offset);
 377
 378extern int traceprobe_set_print_fmt(struct trace_probe *tp, bool is_return);
 379
 380#ifdef CONFIG_PERF_EVENTS
 381extern struct trace_event_call *
 382create_local_trace_kprobe(char *func, void *addr, unsigned long offs,
 383                          bool is_return);
 384extern void destroy_local_trace_kprobe(struct trace_event_call *event_call);
 385
 386extern struct trace_event_call *
 387create_local_trace_uprobe(char *name, unsigned long offs,
 388                          unsigned long ref_ctr_offset, bool is_return);
 389extern void destroy_local_trace_uprobe(struct trace_event_call *event_call);
 390#endif
 391extern int traceprobe_define_arg_fields(struct trace_event_call *event_call,
 392                                        size_t offset, struct trace_probe *tp);
 393
 394#undef ERRORS
 395#define ERRORS  \
 396        C(FILE_NOT_FOUND,       "Failed to find the given file"),       \
 397        C(NO_REGULAR_FILE,      "Not a regular file"),                  \
 398        C(BAD_REFCNT,           "Invalid reference counter offset"),    \
 399        C(REFCNT_OPEN_BRACE,    "Reference counter brace is not closed"), \
 400        C(BAD_REFCNT_SUFFIX,    "Reference counter has wrong suffix"),  \
 401        C(BAD_UPROBE_OFFS,      "Invalid uprobe offset"),               \
 402        C(MAXACT_NO_KPROBE,     "Maxactive is not for kprobe"),         \
 403        C(BAD_MAXACT,           "Invalid maxactive number"),            \
 404        C(MAXACT_TOO_BIG,       "Maxactive is too big"),                \
 405        C(BAD_PROBE_ADDR,       "Invalid probed address or symbol"),    \
 406        C(BAD_RETPROBE,         "Retprobe address must be an function entry"), \
 407        C(NO_GROUP_NAME,        "Group name is not specified"),         \
 408        C(GROUP_TOO_LONG,       "Group name is too long"),              \
 409        C(BAD_GROUP_NAME,       "Group name must follow the same rules as C identifiers"), \
 410        C(NO_EVENT_NAME,        "Event name is not specified"),         \
 411        C(EVENT_TOO_LONG,       "Event name is too long"),              \
 412        C(BAD_EVENT_NAME,       "Event name must follow the same rules as C identifiers"), \
 413        C(RETVAL_ON_PROBE,      "$retval is not available on probe"),   \
 414        C(BAD_STACK_NUM,        "Invalid stack number"),                \
 415        C(BAD_ARG_NUM,          "Invalid argument number"),             \
 416        C(BAD_VAR,              "Invalid $-valiable specified"),        \
 417        C(BAD_REG_NAME,         "Invalid register name"),               \
 418        C(BAD_MEM_ADDR,         "Invalid memory address"),              \
 419        C(BAD_IMM,              "Invalid immediate value"),             \
 420        C(IMMSTR_NO_CLOSE,      "String is not closed with '\"'"),      \
 421        C(FILE_ON_KPROBE,       "File offset is not available with kprobe"), \
 422        C(BAD_FILE_OFFS,        "Invalid file offset value"),           \
 423        C(SYM_ON_UPROBE,        "Symbol is not available with uprobe"), \
 424        C(TOO_MANY_OPS,         "Dereference is too much nested"),      \
 425        C(DEREF_NEED_BRACE,     "Dereference needs a brace"),           \
 426        C(BAD_DEREF_OFFS,       "Invalid dereference offset"),          \
 427        C(DEREF_OPEN_BRACE,     "Dereference brace is not closed"),     \
 428        C(COMM_CANT_DEREF,      "$comm can not be dereferenced"),       \
 429        C(BAD_FETCH_ARG,        "Invalid fetch argument"),              \
 430        C(ARRAY_NO_CLOSE,       "Array is not closed"),                 \
 431        C(BAD_ARRAY_SUFFIX,     "Array has wrong suffix"),              \
 432        C(BAD_ARRAY_NUM,        "Invalid array size"),                  \
 433        C(ARRAY_TOO_BIG,        "Array number is too big"),             \
 434        C(BAD_TYPE,             "Unknown type is specified"),           \
 435        C(BAD_STRING,           "String accepts only memory argument"), \
 436        C(BAD_BITFIELD,         "Invalid bitfield"),                    \
 437        C(ARG_NAME_TOO_LONG,    "Argument name is too long"),           \
 438        C(NO_ARG_NAME,          "Argument name is not specified"),      \
 439        C(BAD_ARG_NAME,         "Argument name must follow the same rules as C identifiers"), \
 440        C(USED_ARG_NAME,        "This argument name is already used"),  \
 441        C(ARG_TOO_LONG,         "Argument expression is too long"),     \
 442        C(NO_ARG_BODY,          "No argument expression"),              \
 443        C(BAD_INSN_BNDRY,       "Probe point is not an instruction boundary"),\
 444        C(FAIL_REG_PROBE,       "Failed to register probe event"),\
 445        C(DIFF_PROBE_TYPE,      "Probe type is different from existing probe"),\
 446        C(DIFF_ARG_TYPE,        "Argument type or name is different from existing probe"),\
 447        C(SAME_PROBE,           "There is already the exact same probe event"),
 448
 449#undef C
 450#define C(a, b)         TP_ERR_##a
 451
 452/* Define TP_ERR_ */
 453enum { ERRORS };
 454
 455/* Error text is defined in trace_probe.c */
 456
 457struct trace_probe_log {
 458        const char      *subsystem;
 459        const char      **argv;
 460        int             argc;
 461        int             index;
 462};
 463
 464void trace_probe_log_init(const char *subsystem, int argc, const char **argv);
 465void trace_probe_log_set_index(int index);
 466void trace_probe_log_clear(void);
 467void __trace_probe_log_err(int offset, int err);
 468
 469#define trace_probe_log_err(offs, err)  \
 470        __trace_probe_log_err(offs, TP_ERR_##err)
 471