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 #define TP_FLAG_REGISTERED 4 59 60 /* data_loc: data location, compatible with u32 */ 61 #define make_data_loc(len, offs) \ 62 (((u32)(len) << 16) | ((u32)(offs) & 0xffff)) 63 #define get_loc_len(dl) ((u32)(dl) >> 16) 64 #define get_loc_offs(dl) ((u32)(dl) & 0xffff) 65 66 static nokprobe_inline void *get_loc_data(u32 *dl, void *ent) 67 { 68 return (u8 *)ent + get_loc_offs(*dl); 69 } 70 71 static nokprobe_inline u32 update_data_loc(u32 loc, int consumed) 72 { 73 u32 maxlen = get_loc_len(loc); 74 u32 offset = get_loc_offs(loc); 75 76 return make_data_loc(maxlen - consumed, offset + consumed); 77 } 78 79 /* Printing function type */ 80 typedef int (*print_type_func_t)(struct trace_seq *, void *, void *); 81 82 enum fetch_op { 83 FETCH_OP_NOP = 0, 84 // Stage 1 (load) ops 85 FETCH_OP_REG, /* Register : .param = offset */ 86 FETCH_OP_STACK, /* Stack : .param = index */ 87 FETCH_OP_STACKP, /* Stack pointer */ 88 FETCH_OP_RETVAL, /* Return value */ 89 FETCH_OP_IMM, /* Immediate : .immediate */ 90 FETCH_OP_COMM, /* Current comm */ 91 FETCH_OP_ARG, /* Function argument : .param */ 92 FETCH_OP_FOFFS, /* File offset: .immediate */ 93 // Stage 2 (dereference) op 94 FETCH_OP_DEREF, /* 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_STRING, /* String: .offset, .size */ 99 // Stage 4 (modify) op 100 FETCH_OP_MOD_BF, /* Bitfield: .basesize, .lshift, .rshift */ 101 // Stage 5 (loop) op 102 FETCH_OP_LP_ARRAY, /* Array: .param = loop count */ 103 FETCH_OP_END, 104 FETCH_NOP_SYMBOL, /* Unresolved Symbol holder */ 105 }; 106 107 struct fetch_insn { 108 enum fetch_op op; 109 union { 110 unsigned int param; 111 struct { 112 unsigned int size; 113 int offset; 114 }; 115 struct { 116 unsigned char basesize; 117 unsigned char lshift; 118 unsigned char rshift; 119 }; 120 unsigned long immediate; 121 void *data; 122 }; 123 }; 124 125 /* fetch + deref*N + store + mod + end <= 16, this allows N=12, enough */ 126 #define FETCH_INSN_MAX 16 127 #define FETCH_TOKEN_COMM (-ECOMM) 128 129 /* Fetch type information table */ 130 struct fetch_type { 131 const char *name; /* Name of type */ 132 size_t size; /* Byte size of type */ 133 int is_signed; /* Signed flag */ 134 print_type_func_t print; /* Print functions */ 135 const char *fmt; /* Fromat string */ 136 const char *fmttype; /* Name in format file */ 137 }; 138 139 /* For defining macros, define string/string_size types */ 140 typedef u32 string; 141 typedef u32 string_size; 142 143 #define PRINT_TYPE_FUNC_NAME(type) print_type_##type 144 #define PRINT_TYPE_FMT_NAME(type) print_type_format_##type 145 146 /* Printing in basic type function template */ 147 #define DECLARE_BASIC_PRINT_TYPE_FUNC(type) \ 148 int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, void *data, void *ent);\ 149 extern const char PRINT_TYPE_FMT_NAME(type)[] 150 151 DECLARE_BASIC_PRINT_TYPE_FUNC(u8); 152 DECLARE_BASIC_PRINT_TYPE_FUNC(u16); 153 DECLARE_BASIC_PRINT_TYPE_FUNC(u32); 154 DECLARE_BASIC_PRINT_TYPE_FUNC(u64); 155 DECLARE_BASIC_PRINT_TYPE_FUNC(s8); 156 DECLARE_BASIC_PRINT_TYPE_FUNC(s16); 157 DECLARE_BASIC_PRINT_TYPE_FUNC(s32); 158 DECLARE_BASIC_PRINT_TYPE_FUNC(s64); 159 DECLARE_BASIC_PRINT_TYPE_FUNC(x8); 160 DECLARE_BASIC_PRINT_TYPE_FUNC(x16); 161 DECLARE_BASIC_PRINT_TYPE_FUNC(x32); 162 DECLARE_BASIC_PRINT_TYPE_FUNC(x64); 163 164 DECLARE_BASIC_PRINT_TYPE_FUNC(string); 165 DECLARE_BASIC_PRINT_TYPE_FUNC(symbol); 166 167 /* Default (unsigned long) fetch type */ 168 #define __DEFAULT_FETCH_TYPE(t) x##t 169 #define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t) 170 #define DEFAULT_FETCH_TYPE _DEFAULT_FETCH_TYPE(BITS_PER_LONG) 171 #define DEFAULT_FETCH_TYPE_STR __stringify(DEFAULT_FETCH_TYPE) 172 173 #define __ADDR_FETCH_TYPE(t) u##t 174 #define _ADDR_FETCH_TYPE(t) __ADDR_FETCH_TYPE(t) 175 #define ADDR_FETCH_TYPE _ADDR_FETCH_TYPE(BITS_PER_LONG) 176 177 #define __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype) \ 178 {.name = _name, \ 179 .size = _size, \ 180 .is_signed = sign, \ 181 .print = PRINT_TYPE_FUNC_NAME(ptype), \ 182 .fmt = PRINT_TYPE_FMT_NAME(ptype), \ 183 .fmttype = _fmttype, \ 184 } 185 #define _ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype) \ 186 __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, #_fmttype) 187 #define ASSIGN_FETCH_TYPE(ptype, ftype, sign) \ 188 _ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, ptype) 189 190 /* If ptype is an alias of atype, use this macro (show atype in format) */ 191 #define ASSIGN_FETCH_TYPE_ALIAS(ptype, atype, ftype, sign) \ 192 _ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, atype) 193 194 #define ASSIGN_FETCH_TYPE_END {} 195 #define MAX_ARRAY_LEN 64 196 197 #ifdef CONFIG_KPROBE_EVENTS 198 bool trace_kprobe_on_func_entry(struct trace_event_call *call); 199 bool trace_kprobe_error_injectable(struct trace_event_call *call); 200 #else 201 static inline bool trace_kprobe_on_func_entry(struct trace_event_call *call) 202 { 203 return false; 204 } 205 206 static inline bool trace_kprobe_error_injectable(struct trace_event_call *call) 207 { 208 return false; 209 } 210 #endif /* CONFIG_KPROBE_EVENTS */ 211 212 struct probe_arg { 213 struct fetch_insn *code; 214 bool dynamic;/* Dynamic array (string) is used */ 215 unsigned int offset; /* Offset from argument entry */ 216 unsigned int count; /* Array count */ 217 const char *name; /* Name of this argument */ 218 const char *comm; /* Command of this argument */ 219 char *fmt; /* Format string if needed */ 220 const struct fetch_type *type; /* Type of this argument */ 221 }; 222 223 struct trace_probe { 224 unsigned int flags; /* For TP_FLAG_* */ 225 struct trace_event_class class; 226 struct trace_event_call call; 227 struct list_head files; 228 ssize_t size; /* trace entry size */ 229 unsigned int nr_args; 230 struct probe_arg args[]; 231 }; 232 233 struct event_file_link { 234 struct trace_event_file *file; 235 struct list_head list; 236 }; 237 238 static inline bool trace_probe_is_enabled(struct trace_probe *tp) 239 { 240 return !!(tp->flags & (TP_FLAG_TRACE | TP_FLAG_PROFILE)); 241 } 242 243 static inline bool trace_probe_is_registered(struct trace_probe *tp) 244 { 245 return !!(tp->flags & TP_FLAG_REGISTERED); 246 } 247 248 /* Check the name is good for event/group/fields */ 249 static inline bool is_good_name(const char *name) 250 { 251 if (!isalpha(*name) && *name != '_') 252 return false; 253 while (*++name != '\0') { 254 if (!isalpha(*name) && !isdigit(*name) && *name != '_') 255 return false; 256 } 257 return true; 258 } 259 260 static inline struct event_file_link * 261 find_event_file_link(struct trace_probe *tp, struct trace_event_file *file) 262 { 263 struct event_file_link *link; 264 265 list_for_each_entry(link, &tp->files, list) 266 if (link->file == file) 267 return link; 268 269 return NULL; 270 } 271 272 #define TPARG_FL_RETURN BIT(0) 273 #define TPARG_FL_KERNEL BIT(1) 274 #define TPARG_FL_FENTRY BIT(2) 275 #define TPARG_FL_MASK GENMASK(2, 0) 276 277 extern int traceprobe_parse_probe_arg(struct trace_probe *tp, int i, 278 char *arg, unsigned int flags); 279 280 extern int traceprobe_update_arg(struct probe_arg *arg); 281 extern void traceprobe_free_probe_arg(struct probe_arg *arg); 282 283 extern int traceprobe_split_symbol_offset(char *symbol, long *offset); 284 int traceprobe_parse_event_name(const char **pevent, const char **pgroup, 285 char *buf, int offset); 286 287 extern int traceprobe_set_print_fmt(struct trace_probe *tp, bool is_return); 288 289 #ifdef CONFIG_PERF_EVENTS 290 extern struct trace_event_call * 291 create_local_trace_kprobe(char *func, void *addr, unsigned long offs, 292 bool is_return); 293 extern void destroy_local_trace_kprobe(struct trace_event_call *event_call); 294 295 extern struct trace_event_call * 296 create_local_trace_uprobe(char *name, unsigned long offs, 297 unsigned long ref_ctr_offset, bool is_return); 298 extern void destroy_local_trace_uprobe(struct trace_event_call *event_call); 299 #endif 300 extern int traceprobe_define_arg_fields(struct trace_event_call *event_call, 301 size_t offset, struct trace_probe *tp); 302 303 #undef ERRORS 304 #define ERRORS \ 305 C(FILE_NOT_FOUND, "Failed to find the given file"), \ 306 C(NO_REGULAR_FILE, "Not a regular file"), \ 307 C(BAD_REFCNT, "Invalid reference counter offset"), \ 308 C(REFCNT_OPEN_BRACE, "Reference counter brace is not closed"), \ 309 C(BAD_REFCNT_SUFFIX, "Reference counter has wrong suffix"), \ 310 C(BAD_UPROBE_OFFS, "Invalid uprobe offset"), \ 311 C(MAXACT_NO_KPROBE, "Maxactive is not for kprobe"), \ 312 C(BAD_MAXACT, "Invalid maxactive number"), \ 313 C(MAXACT_TOO_BIG, "Maxactive is too big"), \ 314 C(BAD_PROBE_ADDR, "Invalid probed address or symbol"), \ 315 C(BAD_RETPROBE, "Retprobe address must be an function entry"), \ 316 C(NO_GROUP_NAME, "Group name is not specified"), \ 317 C(GROUP_TOO_LONG, "Group name is too long"), \ 318 C(BAD_GROUP_NAME, "Group name must follow the same rules as C identifiers"), \ 319 C(NO_EVENT_NAME, "Event name is not specified"), \ 320 C(EVENT_TOO_LONG, "Event name is too long"), \ 321 C(BAD_EVENT_NAME, "Event name must follow the same rules as C identifiers"), \ 322 C(RETVAL_ON_PROBE, "$retval is not available on probe"), \ 323 C(BAD_STACK_NUM, "Invalid stack number"), \ 324 C(BAD_ARG_NUM, "Invalid argument number"), \ 325 C(BAD_VAR, "Invalid $-valiable specified"), \ 326 C(BAD_REG_NAME, "Invalid register name"), \ 327 C(BAD_MEM_ADDR, "Invalid memory address"), \ 328 C(FILE_ON_KPROBE, "File offset is not available with kprobe"), \ 329 C(BAD_FILE_OFFS, "Invalid file offset value"), \ 330 C(SYM_ON_UPROBE, "Symbol is not available with uprobe"), \ 331 C(TOO_MANY_OPS, "Dereference is too much nested"), \ 332 C(DEREF_NEED_BRACE, "Dereference needs a brace"), \ 333 C(BAD_DEREF_OFFS, "Invalid dereference offset"), \ 334 C(DEREF_OPEN_BRACE, "Dereference brace is not closed"), \ 335 C(COMM_CANT_DEREF, "$comm can not be dereferenced"), \ 336 C(BAD_FETCH_ARG, "Invalid fetch argument"), \ 337 C(ARRAY_NO_CLOSE, "Array is not closed"), \ 338 C(BAD_ARRAY_SUFFIX, "Array has wrong suffix"), \ 339 C(BAD_ARRAY_NUM, "Invalid array size"), \ 340 C(ARRAY_TOO_BIG, "Array number is too big"), \ 341 C(BAD_TYPE, "Unknown type is specified"), \ 342 C(BAD_STRING, "String accepts only memory argument"), \ 343 C(BAD_BITFIELD, "Invalid bitfield"), \ 344 C(ARG_NAME_TOO_LONG, "Argument name is too long"), \ 345 C(NO_ARG_NAME, "Argument name is not specified"), \ 346 C(BAD_ARG_NAME, "Argument name must follow the same rules as C identifiers"), \ 347 C(USED_ARG_NAME, "This argument name is already used"), \ 348 C(ARG_TOO_LONG, "Argument expression is too long"), \ 349 C(NO_ARG_BODY, "No argument expression"), \ 350 C(BAD_INSN_BNDRY, "Probe point is not an instruction boundary"),\ 351 C(FAIL_REG_PROBE, "Failed to register probe event"), 352 353 #undef C 354 #define C(a, b) TP_ERR_##a 355 356 /* Define TP_ERR_ */ 357 enum { ERRORS }; 358 359 /* Error text is defined in trace_probe.c */ 360 361 struct trace_probe_log { 362 const char *subsystem; 363 const char **argv; 364 int argc; 365 int index; 366 }; 367 368 void trace_probe_log_init(const char *subsystem, int argc, const char **argv); 369 void trace_probe_log_set_index(int index); 370 void trace_probe_log_clear(void); 371 void __trace_probe_log_err(int offset, int err); 372 373 #define trace_probe_log_err(offs, err) \ 374 __trace_probe_log_err(offs, TP_ERR_##err) 375