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 FETCH_OP_ST_USTRING, /* User String: .offset, .size */ 100 // Stage 4 (modify) op 101 FETCH_OP_MOD_BF, /* Bitfield: .basesize, .lshift, .rshift */ 102 // Stage 5 (loop) op 103 FETCH_OP_LP_ARRAY, /* Array: .param = loop count */ 104 FETCH_OP_END, 105 FETCH_NOP_SYMBOL, /* Unresolved Symbol holder */ 106 }; 107 108 struct fetch_insn { 109 enum fetch_op op; 110 union { 111 unsigned int param; 112 struct { 113 unsigned int size; 114 int offset; 115 }; 116 struct { 117 unsigned char basesize; 118 unsigned char lshift; 119 unsigned char rshift; 120 }; 121 unsigned long immediate; 122 void *data; 123 }; 124 }; 125 126 /* fetch + deref*N + store + mod + end <= 16, this allows N=12, enough */ 127 #define FETCH_INSN_MAX 16 128 #define FETCH_TOKEN_COMM (-ECOMM) 129 130 /* Fetch type information table */ 131 struct fetch_type { 132 const char *name; /* Name of type */ 133 size_t size; /* Byte size of type */ 134 int is_signed; /* Signed flag */ 135 print_type_func_t print; /* Print functions */ 136 const char *fmt; /* Fromat string */ 137 const char *fmttype; /* Name in format file */ 138 }; 139 140 /* For defining macros, define string/string_size types */ 141 typedef u32 string; 142 typedef u32 string_size; 143 144 #define PRINT_TYPE_FUNC_NAME(type) print_type_##type 145 #define PRINT_TYPE_FMT_NAME(type) print_type_format_##type 146 147 /* Printing in basic type function template */ 148 #define DECLARE_BASIC_PRINT_TYPE_FUNC(type) \ 149 int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, void *data, void *ent);\ 150 extern const char PRINT_TYPE_FMT_NAME(type)[] 151 152 DECLARE_BASIC_PRINT_TYPE_FUNC(u8); 153 DECLARE_BASIC_PRINT_TYPE_FUNC(u16); 154 DECLARE_BASIC_PRINT_TYPE_FUNC(u32); 155 DECLARE_BASIC_PRINT_TYPE_FUNC(u64); 156 DECLARE_BASIC_PRINT_TYPE_FUNC(s8); 157 DECLARE_BASIC_PRINT_TYPE_FUNC(s16); 158 DECLARE_BASIC_PRINT_TYPE_FUNC(s32); 159 DECLARE_BASIC_PRINT_TYPE_FUNC(s64); 160 DECLARE_BASIC_PRINT_TYPE_FUNC(x8); 161 DECLARE_BASIC_PRINT_TYPE_FUNC(x16); 162 DECLARE_BASIC_PRINT_TYPE_FUNC(x32); 163 DECLARE_BASIC_PRINT_TYPE_FUNC(x64); 164 165 DECLARE_BASIC_PRINT_TYPE_FUNC(string); 166 DECLARE_BASIC_PRINT_TYPE_FUNC(symbol); 167 168 /* Default (unsigned long) fetch type */ 169 #define __DEFAULT_FETCH_TYPE(t) x##t 170 #define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t) 171 #define DEFAULT_FETCH_TYPE _DEFAULT_FETCH_TYPE(BITS_PER_LONG) 172 #define DEFAULT_FETCH_TYPE_STR __stringify(DEFAULT_FETCH_TYPE) 173 174 #define __ADDR_FETCH_TYPE(t) u##t 175 #define _ADDR_FETCH_TYPE(t) __ADDR_FETCH_TYPE(t) 176 #define ADDR_FETCH_TYPE _ADDR_FETCH_TYPE(BITS_PER_LONG) 177 178 #define __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype) \ 179 {.name = _name, \ 180 .size = _size, \ 181 .is_signed = sign, \ 182 .print = PRINT_TYPE_FUNC_NAME(ptype), \ 183 .fmt = PRINT_TYPE_FMT_NAME(ptype), \ 184 .fmttype = _fmttype, \ 185 } 186 #define _ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype) \ 187 __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, #_fmttype) 188 #define ASSIGN_FETCH_TYPE(ptype, ftype, sign) \ 189 _ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, ptype) 190 191 /* If ptype is an alias of atype, use this macro (show atype in format) */ 192 #define ASSIGN_FETCH_TYPE_ALIAS(ptype, atype, ftype, sign) \ 193 _ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, atype) 194 195 #define ASSIGN_FETCH_TYPE_END {} 196 #define MAX_ARRAY_LEN 64 197 198 #ifdef CONFIG_KPROBE_EVENTS 199 bool trace_kprobe_on_func_entry(struct trace_event_call *call); 200 bool trace_kprobe_error_injectable(struct trace_event_call *call); 201 #else 202 static inline bool trace_kprobe_on_func_entry(struct trace_event_call *call) 203 { 204 return false; 205 } 206 207 static inline bool trace_kprobe_error_injectable(struct trace_event_call *call) 208 { 209 return false; 210 } 211 #endif /* CONFIG_KPROBE_EVENTS */ 212 213 struct probe_arg { 214 struct fetch_insn *code; 215 bool dynamic;/* Dynamic array (string) is used */ 216 unsigned int offset; /* Offset from argument entry */ 217 unsigned int count; /* Array count */ 218 const char *name; /* Name of this argument */ 219 const char *comm; /* Command of this argument */ 220 char *fmt; /* Format string if needed */ 221 const struct fetch_type *type; /* Type of this argument */ 222 }; 223 224 struct trace_probe { 225 unsigned int flags; /* For TP_FLAG_* */ 226 struct trace_event_class class; 227 struct trace_event_call call; 228 struct list_head files; 229 ssize_t size; /* trace entry size */ 230 unsigned int nr_args; 231 struct probe_arg args[]; 232 }; 233 234 struct event_file_link { 235 struct trace_event_file *file; 236 struct list_head list; 237 }; 238 239 static inline bool trace_probe_is_enabled(struct trace_probe *tp) 240 { 241 return !!(tp->flags & (TP_FLAG_TRACE | TP_FLAG_PROFILE)); 242 } 243 244 static inline bool trace_probe_is_registered(struct trace_probe *tp) 245 { 246 return !!(tp->flags & TP_FLAG_REGISTERED); 247 } 248 249 /* Check the name is good for event/group/fields */ 250 static inline bool is_good_name(const char *name) 251 { 252 if (!isalpha(*name) && *name != '_') 253 return false; 254 while (*++name != '\0') { 255 if (!isalpha(*name) && !isdigit(*name) && *name != '_') 256 return false; 257 } 258 return true; 259 } 260 261 static inline struct event_file_link * 262 find_event_file_link(struct trace_probe *tp, struct trace_event_file *file) 263 { 264 struct event_file_link *link; 265 266 list_for_each_entry(link, &tp->files, list) 267 if (link->file == file) 268 return link; 269 270 return NULL; 271 } 272 273 #define TPARG_FL_RETURN BIT(0) 274 #define TPARG_FL_KERNEL BIT(1) 275 #define TPARG_FL_FENTRY BIT(2) 276 #define TPARG_FL_MASK GENMASK(2, 0) 277 278 extern int traceprobe_parse_probe_arg(struct trace_probe *tp, int i, 279 char *arg, unsigned int flags); 280 281 extern int traceprobe_update_arg(struct probe_arg *arg); 282 extern void traceprobe_free_probe_arg(struct probe_arg *arg); 283 284 extern int traceprobe_split_symbol_offset(char *symbol, long *offset); 285 int traceprobe_parse_event_name(const char **pevent, const char **pgroup, 286 char *buf, int offset); 287 288 extern int traceprobe_set_print_fmt(struct trace_probe *tp, bool is_return); 289 290 #ifdef CONFIG_PERF_EVENTS 291 extern struct trace_event_call * 292 create_local_trace_kprobe(char *func, void *addr, unsigned long offs, 293 bool is_return); 294 extern void destroy_local_trace_kprobe(struct trace_event_call *event_call); 295 296 extern struct trace_event_call * 297 create_local_trace_uprobe(char *name, unsigned long offs, 298 unsigned long ref_ctr_offset, bool is_return); 299 extern void destroy_local_trace_uprobe(struct trace_event_call *event_call); 300 #endif 301 extern int traceprobe_define_arg_fields(struct trace_event_call *event_call, 302 size_t offset, struct trace_probe *tp); 303 304 #undef ERRORS 305 #define ERRORS \ 306 C(FILE_NOT_FOUND, "Failed to find the given file"), \ 307 C(NO_REGULAR_FILE, "Not a regular file"), \ 308 C(BAD_REFCNT, "Invalid reference counter offset"), \ 309 C(REFCNT_OPEN_BRACE, "Reference counter brace is not closed"), \ 310 C(BAD_REFCNT_SUFFIX, "Reference counter has wrong suffix"), \ 311 C(BAD_UPROBE_OFFS, "Invalid uprobe offset"), \ 312 C(MAXACT_NO_KPROBE, "Maxactive is not for kprobe"), \ 313 C(BAD_MAXACT, "Invalid maxactive number"), \ 314 C(MAXACT_TOO_BIG, "Maxactive is too big"), \ 315 C(BAD_PROBE_ADDR, "Invalid probed address or symbol"), \ 316 C(BAD_RETPROBE, "Retprobe address must be an function entry"), \ 317 C(NO_GROUP_NAME, "Group name is not specified"), \ 318 C(GROUP_TOO_LONG, "Group name is too long"), \ 319 C(BAD_GROUP_NAME, "Group name must follow the same rules as C identifiers"), \ 320 C(NO_EVENT_NAME, "Event name is not specified"), \ 321 C(EVENT_TOO_LONG, "Event name is too long"), \ 322 C(BAD_EVENT_NAME, "Event name must follow the same rules as C identifiers"), \ 323 C(RETVAL_ON_PROBE, "$retval is not available on probe"), \ 324 C(BAD_STACK_NUM, "Invalid stack number"), \ 325 C(BAD_ARG_NUM, "Invalid argument number"), \ 326 C(BAD_VAR, "Invalid $-valiable specified"), \ 327 C(BAD_REG_NAME, "Invalid register name"), \ 328 C(BAD_MEM_ADDR, "Invalid memory address"), \ 329 C(FILE_ON_KPROBE, "File offset is not available with kprobe"), \ 330 C(BAD_FILE_OFFS, "Invalid file offset value"), \ 331 C(SYM_ON_UPROBE, "Symbol is not available with uprobe"), \ 332 C(TOO_MANY_OPS, "Dereference is too much nested"), \ 333 C(DEREF_NEED_BRACE, "Dereference needs a brace"), \ 334 C(BAD_DEREF_OFFS, "Invalid dereference offset"), \ 335 C(DEREF_OPEN_BRACE, "Dereference brace is not closed"), \ 336 C(COMM_CANT_DEREF, "$comm can not be dereferenced"), \ 337 C(BAD_FETCH_ARG, "Invalid fetch argument"), \ 338 C(ARRAY_NO_CLOSE, "Array is not closed"), \ 339 C(BAD_ARRAY_SUFFIX, "Array has wrong suffix"), \ 340 C(BAD_ARRAY_NUM, "Invalid array size"), \ 341 C(ARRAY_TOO_BIG, "Array number is too big"), \ 342 C(BAD_TYPE, "Unknown type is specified"), \ 343 C(BAD_STRING, "String accepts only memory argument"), \ 344 C(BAD_BITFIELD, "Invalid bitfield"), \ 345 C(ARG_NAME_TOO_LONG, "Argument name is too long"), \ 346 C(NO_ARG_NAME, "Argument name is not specified"), \ 347 C(BAD_ARG_NAME, "Argument name must follow the same rules as C identifiers"), \ 348 C(USED_ARG_NAME, "This argument name is already used"), \ 349 C(ARG_TOO_LONG, "Argument expression is too long"), \ 350 C(NO_ARG_BODY, "No argument expression"), \ 351 C(BAD_INSN_BNDRY, "Probe point is not an instruction boundary"),\ 352 C(FAIL_REG_PROBE, "Failed to register probe event"), 353 354 #undef C 355 #define C(a, b) TP_ERR_##a 356 357 /* Define TP_ERR_ */ 358 enum { ERRORS }; 359 360 /* Error text is defined in trace_probe.c */ 361 362 struct trace_probe_log { 363 const char *subsystem; 364 const char **argv; 365 int argc; 366 int index; 367 }; 368 369 void trace_probe_log_init(const char *subsystem, int argc, const char **argv); 370 void trace_probe_log_set_index(int index); 371 void trace_probe_log_clear(void); 372 void __trace_probe_log_err(int offset, int err); 373 374 #define trace_probe_log_err(offs, err) \ 375 __trace_probe_log_err(offs, TP_ERR_##err) 376