kernel/trace/trace_probe.h

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