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/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
  65 static nokprobe_inline void *get_loc_data(u32 *dl, void *ent)
  66 {
  67         return (u8 *)ent + get_loc_offs(*dl);
  68 }
  69
  70 static 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 */
  79 typedef int (*print_type_func_t)(struct trace_seq *, void *, void *);
  80
  81 enum 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
 110 struct 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 */
 133 struct 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 */
 143 typedef u32 string;
 144 typedef 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)                             \
 151 int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, void *data, void *ent);\
 152 extern const char PRINT_TYPE_FMT_NAME(type)[]
 153
 154 DECLARE_BASIC_PRINT_TYPE_FUNC(u8);
 155 DECLARE_BASIC_PRINT_TYPE_FUNC(u16);
 156 DECLARE_BASIC_PRINT_TYPE_FUNC(u32);
 157 DECLARE_BASIC_PRINT_TYPE_FUNC(u64);
 158 DECLARE_BASIC_PRINT_TYPE_FUNC(s8);
 159 DECLARE_BASIC_PRINT_TYPE_FUNC(s16);
 160 DECLARE_BASIC_PRINT_TYPE_FUNC(s32);
 161 DECLARE_BASIC_PRINT_TYPE_FUNC(s64);
 162 DECLARE_BASIC_PRINT_TYPE_FUNC(x8);
 163 DECLARE_BASIC_PRINT_TYPE_FUNC(x16);
 164 DECLARE_BASIC_PRINT_TYPE_FUNC(x32);
 165 DECLARE_BASIC_PRINT_TYPE_FUNC(x64);
 166
 167 DECLARE_BASIC_PRINT_TYPE_FUNC(string);
 168 DECLARE_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
 201 bool trace_kprobe_on_func_entry(struct trace_event_call *call);
 202 bool trace_kprobe_error_injectable(struct trace_event_call *call);
 203 #else
 204 static inline bool trace_kprobe_on_func_entry(struct trace_event_call *call)
 205 {
 206         return false;
 207 }
 208
 209 static inline bool trace_kprobe_error_injectable(struct trace_event_call *call)
 210 {
 211         return false;
 212 }
 213 #endif /* CONFIG_KPROBE_EVENTS */
 214
 215 struct 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
 226 struct 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 */
 233 struct 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
 242 struct 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
 250 struct event_file_link {
 251         struct trace_event_file         *file;
 252         struct list_head                list;
 253 };
 254
 255 static inline bool trace_probe_test_flag(struct trace_probe *tp,
 256                                          unsigned int flag)
 257 {
 258         return !!(tp->event->flags & flag);
 259 }
 260
 261 static inline void trace_probe_set_flag(struct trace_probe *tp,
 262                                         unsigned int flag)
 263 {
 264         tp->event->flags |= flag;
 265 }
 266
 267 static inline void trace_probe_clear_flag(struct trace_probe *tp,
 268                                           unsigned int flag)
 269 {
 270         tp->event->flags &= ~flag;
 271 }
 272
 273 static 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
 278 static inline const char *trace_probe_name(struct trace_probe *tp)
 279 {
 280         return trace_event_name(&tp->event->call);
 281 }
 282
 283 static inline const char *trace_probe_group_name(struct trace_probe *tp)
 284 {
 285         return tp->event->call.class->system;
 286 }
 287
 288 static inline struct trace_event_call *
 289         trace_probe_event_call(struct trace_probe *tp)
 290 {
 291         return &tp->event->call;
 292 }
 293
 294 static inline struct trace_probe_event *
 295 trace_probe_event_from_call(struct trace_event_call *event_call)
 296 {
 297         return container_of(event_call, struct trace_probe_event, call);
 298 }
 299
 300 static inline struct trace_probe *
 301 trace_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
 308 static inline struct list_head *trace_probe_probe_list(struct trace_probe *tp)
 309 {
 310         return &tp->event->probes;
 311 }
 312
 313 static 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
 320 static 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
 326 static inline bool trace_probe_has_single_file(struct trace_probe *tp)
 327 {
 328         return !!list_is_singular(&tp->event->files);
 329 }
 330
 331 int trace_probe_init(struct trace_probe *tp, const char *event,
 332                      const char *group, bool alloc_filter);
 333 void trace_probe_cleanup(struct trace_probe *tp);
 334 int trace_probe_append(struct trace_probe *tp, struct trace_probe *to);
 335 void trace_probe_unlink(struct trace_probe *tp);
 336 int trace_probe_register_event_call(struct trace_probe *tp);
 337 int trace_probe_add_file(struct trace_probe *tp, struct trace_event_file *file);
 338 int trace_probe_remove_file(struct trace_probe *tp,
 339                             struct trace_event_file *file);
 340 struct event_file_link *trace_probe_get_file_link(struct trace_probe *tp,
 341                                                 struct trace_event_file *file);
 342 int trace_probe_compare_arg_type(struct trace_probe *a, struct trace_probe *b);
 343 bool 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 */
 352 static 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
 368 extern int traceprobe_parse_probe_arg(struct trace_probe *tp, int i,
 369                                 char *arg, unsigned int flags);
 370
 371 extern int traceprobe_update_arg(struct probe_arg *arg);
 372 extern void traceprobe_free_probe_arg(struct probe_arg *arg);
 373
 374 extern int traceprobe_split_symbol_offset(char *symbol, long *offset);
 375 int traceprobe_parse_event_name(const char **pevent, const char **pgroup,
 376                                 char *buf, int offset);
 377
 378 extern int traceprobe_set_print_fmt(struct trace_probe *tp, bool is_return);
 379
 380 #ifdef CONFIG_PERF_EVENTS
 381 extern struct trace_event_call *
 382 create_local_trace_kprobe(char *func, void *addr, unsigned long offs,
 383                           bool is_return);
 384 extern void destroy_local_trace_kprobe(struct trace_event_call *event_call);
 385
 386 extern struct trace_event_call *
 387 create_local_trace_uprobe(char *name, unsigned long offs,
 388                           unsigned long ref_ctr_offset, bool is_return);
 389 extern void destroy_local_trace_uprobe(struct trace_event_call *event_call);
 390 #endif
 391 extern 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_ */
 453 enum { ERRORS };
 454
 455 /* Error text is defined in trace_probe.c */
 456
 457 struct trace_probe_log {
 458         const char      *subsystem;
 459         const char      **argv;
 460         int             argc;
 461         int             index;
 462 };
 463
 464 void trace_probe_log_init(const char *subsystem, int argc, const char **argv);
 465 void trace_probe_log_set_index(int index);
 466 void trace_probe_log_clear(void);
 467 void __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)