Kyle Swenson | 8d8f654 | 2021-03-15 11:02:55 -0600 | [diff] [blame] | 1 | /* |
| 2 | * Common header file for probe-based Dynamic events. |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify |
| 5 | * it under the terms of the GNU General Public License version 2 as |
| 6 | * published by the Free Software Foundation. |
| 7 | * |
| 8 | * This program is distributed in the hope that it will be useful, |
| 9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 11 | * GNU General Public License for more details. |
| 12 | * |
| 13 | * You should have received a copy of the GNU General Public License |
| 14 | * along with this program; if not, write to the Free Software |
| 15 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 16 | * |
| 17 | * This code was copied from kernel/trace/trace_kprobe.h written by |
| 18 | * Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> |
| 19 | * |
| 20 | * Updates to make this generic: |
| 21 | * Copyright (C) IBM Corporation, 2010-2011 |
| 22 | * Author: Srikar Dronamraju |
| 23 | */ |
| 24 | |
| 25 | #include <linux/seq_file.h> |
| 26 | #include <linux/slab.h> |
| 27 | #include <linux/smp.h> |
| 28 | #include <linux/tracefs.h> |
| 29 | #include <linux/types.h> |
| 30 | #include <linux/string.h> |
| 31 | #include <linux/ctype.h> |
| 32 | #include <linux/ptrace.h> |
| 33 | #include <linux/perf_event.h> |
| 34 | #include <linux/kprobes.h> |
| 35 | #include <linux/stringify.h> |
| 36 | #include <linux/limits.h> |
| 37 | #include <linux/uaccess.h> |
| 38 | #include <asm/bitsperlong.h> |
| 39 | |
| 40 | #include "trace.h" |
| 41 | #include "trace_output.h" |
| 42 | |
| 43 | #define MAX_TRACE_ARGS 128 |
| 44 | #define MAX_ARGSTR_LEN 63 |
| 45 | #define MAX_EVENT_NAME_LEN 64 |
| 46 | #define MAX_STRING_SIZE PATH_MAX |
| 47 | |
| 48 | /* Reserved field names */ |
| 49 | #define FIELD_STRING_IP "__probe_ip" |
| 50 | #define FIELD_STRING_RETIP "__probe_ret_ip" |
| 51 | #define FIELD_STRING_FUNC "__probe_func" |
| 52 | |
| 53 | #undef DEFINE_FIELD |
| 54 | #define DEFINE_FIELD(type, item, name, is_signed) \ |
| 55 | do { \ |
| 56 | ret = trace_define_field(event_call, #type, name, \ |
| 57 | offsetof(typeof(field), item), \ |
| 58 | sizeof(field.item), is_signed, \ |
| 59 | FILTER_OTHER); \ |
| 60 | if (ret) \ |
| 61 | return ret; \ |
| 62 | } while (0) |
| 63 | |
| 64 | |
| 65 | /* Flags for trace_probe */ |
| 66 | #define TP_FLAG_TRACE 1 |
| 67 | #define TP_FLAG_PROFILE 2 |
| 68 | #define TP_FLAG_REGISTERED 4 |
| 69 | |
| 70 | |
| 71 | /* data_rloc: data relative location, compatible with u32 */ |
| 72 | #define make_data_rloc(len, roffs) \ |
| 73 | (((u32)(len) << 16) | ((u32)(roffs) & 0xffff)) |
| 74 | #define get_rloc_len(dl) ((u32)(dl) >> 16) |
| 75 | #define get_rloc_offs(dl) ((u32)(dl) & 0xffff) |
| 76 | |
| 77 | /* |
| 78 | * Convert data_rloc to data_loc: |
| 79 | * data_rloc stores the offset from data_rloc itself, but data_loc |
| 80 | * stores the offset from event entry. |
| 81 | */ |
| 82 | #define convert_rloc_to_loc(dl, offs) ((u32)(dl) + (offs)) |
| 83 | |
| 84 | static nokprobe_inline void *get_rloc_data(u32 *dl) |
| 85 | { |
| 86 | return (u8 *)dl + get_rloc_offs(*dl); |
| 87 | } |
| 88 | |
| 89 | /* For data_loc conversion */ |
| 90 | static nokprobe_inline void *get_loc_data(u32 *dl, void *ent) |
| 91 | { |
| 92 | return (u8 *)ent + get_rloc_offs(*dl); |
| 93 | } |
| 94 | |
| 95 | /* Data fetch function type */ |
| 96 | typedef void (*fetch_func_t)(struct pt_regs *, void *, void *); |
| 97 | /* Printing function type */ |
| 98 | typedef int (*print_type_func_t)(struct trace_seq *, const char *, void *, void *); |
| 99 | |
| 100 | /* Fetch types */ |
| 101 | enum { |
| 102 | FETCH_MTD_reg = 0, |
| 103 | FETCH_MTD_stack, |
| 104 | FETCH_MTD_retval, |
| 105 | FETCH_MTD_memory, |
| 106 | FETCH_MTD_symbol, |
| 107 | FETCH_MTD_deref, |
| 108 | FETCH_MTD_bitfield, |
| 109 | FETCH_MTD_file_offset, |
| 110 | FETCH_MTD_END, |
| 111 | }; |
| 112 | |
| 113 | /* Fetch type information table */ |
| 114 | struct fetch_type { |
| 115 | const char *name; /* Name of type */ |
| 116 | size_t size; /* Byte size of type */ |
| 117 | int is_signed; /* Signed flag */ |
| 118 | print_type_func_t print; /* Print functions */ |
| 119 | const char *fmt; /* Fromat string */ |
| 120 | const char *fmttype; /* Name in format file */ |
| 121 | /* Fetch functions */ |
| 122 | fetch_func_t fetch[FETCH_MTD_END]; |
| 123 | }; |
| 124 | |
| 125 | struct fetch_param { |
| 126 | fetch_func_t fn; |
| 127 | void *data; |
| 128 | }; |
| 129 | |
| 130 | /* For defining macros, define string/string_size types */ |
| 131 | typedef u32 string; |
| 132 | typedef u32 string_size; |
| 133 | |
| 134 | #define PRINT_TYPE_FUNC_NAME(type) print_type_##type |
| 135 | #define PRINT_TYPE_FMT_NAME(type) print_type_format_##type |
| 136 | |
| 137 | /* Printing in basic type function template */ |
| 138 | #define DECLARE_BASIC_PRINT_TYPE_FUNC(type) \ |
| 139 | int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, const char *name, \ |
| 140 | void *data, void *ent); \ |
| 141 | extern const char PRINT_TYPE_FMT_NAME(type)[] |
| 142 | |
| 143 | DECLARE_BASIC_PRINT_TYPE_FUNC(u8); |
| 144 | DECLARE_BASIC_PRINT_TYPE_FUNC(u16); |
| 145 | DECLARE_BASIC_PRINT_TYPE_FUNC(u32); |
| 146 | DECLARE_BASIC_PRINT_TYPE_FUNC(u64); |
| 147 | DECLARE_BASIC_PRINT_TYPE_FUNC(s8); |
| 148 | DECLARE_BASIC_PRINT_TYPE_FUNC(s16); |
| 149 | DECLARE_BASIC_PRINT_TYPE_FUNC(s32); |
| 150 | DECLARE_BASIC_PRINT_TYPE_FUNC(s64); |
| 151 | DECLARE_BASIC_PRINT_TYPE_FUNC(string); |
| 152 | |
| 153 | #define FETCH_FUNC_NAME(method, type) fetch_##method##_##type |
| 154 | |
| 155 | /* Declare macro for basic types */ |
| 156 | #define DECLARE_FETCH_FUNC(method, type) \ |
| 157 | extern void FETCH_FUNC_NAME(method, type)(struct pt_regs *regs, \ |
| 158 | void *data, void *dest) |
| 159 | |
| 160 | #define DECLARE_BASIC_FETCH_FUNCS(method) \ |
| 161 | DECLARE_FETCH_FUNC(method, u8); \ |
| 162 | DECLARE_FETCH_FUNC(method, u16); \ |
| 163 | DECLARE_FETCH_FUNC(method, u32); \ |
| 164 | DECLARE_FETCH_FUNC(method, u64) |
| 165 | |
| 166 | DECLARE_BASIC_FETCH_FUNCS(reg); |
| 167 | #define fetch_reg_string NULL |
| 168 | #define fetch_reg_string_size NULL |
| 169 | |
| 170 | DECLARE_BASIC_FETCH_FUNCS(retval); |
| 171 | #define fetch_retval_string NULL |
| 172 | #define fetch_retval_string_size NULL |
| 173 | |
| 174 | DECLARE_BASIC_FETCH_FUNCS(symbol); |
| 175 | DECLARE_FETCH_FUNC(symbol, string); |
| 176 | DECLARE_FETCH_FUNC(symbol, string_size); |
| 177 | |
| 178 | DECLARE_BASIC_FETCH_FUNCS(deref); |
| 179 | DECLARE_FETCH_FUNC(deref, string); |
| 180 | DECLARE_FETCH_FUNC(deref, string_size); |
| 181 | |
| 182 | DECLARE_BASIC_FETCH_FUNCS(bitfield); |
| 183 | #define fetch_bitfield_string NULL |
| 184 | #define fetch_bitfield_string_size NULL |
| 185 | |
| 186 | /* |
| 187 | * Define macro for basic types - we don't need to define s* types, because |
| 188 | * we have to care only about bitwidth at recording time. |
| 189 | */ |
| 190 | #define DEFINE_BASIC_FETCH_FUNCS(method) \ |
| 191 | DEFINE_FETCH_##method(u8) \ |
| 192 | DEFINE_FETCH_##method(u16) \ |
| 193 | DEFINE_FETCH_##method(u32) \ |
| 194 | DEFINE_FETCH_##method(u64) |
| 195 | |
| 196 | /* Default (unsigned long) fetch type */ |
| 197 | #define __DEFAULT_FETCH_TYPE(t) u##t |
| 198 | #define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t) |
| 199 | #define DEFAULT_FETCH_TYPE _DEFAULT_FETCH_TYPE(BITS_PER_LONG) |
| 200 | #define DEFAULT_FETCH_TYPE_STR __stringify(DEFAULT_FETCH_TYPE) |
| 201 | |
| 202 | #define ASSIGN_FETCH_FUNC(method, type) \ |
| 203 | [FETCH_MTD_##method] = FETCH_FUNC_NAME(method, type) |
| 204 | |
| 205 | #define __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype) \ |
| 206 | {.name = _name, \ |
| 207 | .size = _size, \ |
| 208 | .is_signed = sign, \ |
| 209 | .print = PRINT_TYPE_FUNC_NAME(ptype), \ |
| 210 | .fmt = PRINT_TYPE_FMT_NAME(ptype), \ |
| 211 | .fmttype = _fmttype, \ |
| 212 | .fetch = { \ |
| 213 | ASSIGN_FETCH_FUNC(reg, ftype), \ |
| 214 | ASSIGN_FETCH_FUNC(stack, ftype), \ |
| 215 | ASSIGN_FETCH_FUNC(retval, ftype), \ |
| 216 | ASSIGN_FETCH_FUNC(memory, ftype), \ |
| 217 | ASSIGN_FETCH_FUNC(symbol, ftype), \ |
| 218 | ASSIGN_FETCH_FUNC(deref, ftype), \ |
| 219 | ASSIGN_FETCH_FUNC(bitfield, ftype), \ |
| 220 | ASSIGN_FETCH_FUNC(file_offset, ftype), \ |
| 221 | } \ |
| 222 | } |
| 223 | |
| 224 | #define ASSIGN_FETCH_TYPE(ptype, ftype, sign) \ |
| 225 | __ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, #ptype) |
| 226 | |
| 227 | #define ASSIGN_FETCH_TYPE_END {} |
| 228 | |
| 229 | #define FETCH_TYPE_STRING 0 |
| 230 | #define FETCH_TYPE_STRSIZE 1 |
| 231 | |
| 232 | #ifdef CONFIG_KPROBE_EVENT |
| 233 | struct symbol_cache; |
| 234 | unsigned long update_symbol_cache(struct symbol_cache *sc); |
| 235 | void free_symbol_cache(struct symbol_cache *sc); |
| 236 | struct symbol_cache *alloc_symbol_cache(const char *sym, long offset); |
| 237 | #else |
| 238 | /* uprobes do not support symbol fetch methods */ |
| 239 | #define fetch_symbol_u8 NULL |
| 240 | #define fetch_symbol_u16 NULL |
| 241 | #define fetch_symbol_u32 NULL |
| 242 | #define fetch_symbol_u64 NULL |
| 243 | #define fetch_symbol_string NULL |
| 244 | #define fetch_symbol_string_size NULL |
| 245 | |
| 246 | struct symbol_cache { |
| 247 | }; |
| 248 | static inline unsigned long __used update_symbol_cache(struct symbol_cache *sc) |
| 249 | { |
| 250 | return 0; |
| 251 | } |
| 252 | |
| 253 | static inline void __used free_symbol_cache(struct symbol_cache *sc) |
| 254 | { |
| 255 | } |
| 256 | |
| 257 | static inline struct symbol_cache * __used |
| 258 | alloc_symbol_cache(const char *sym, long offset) |
| 259 | { |
| 260 | return NULL; |
| 261 | } |
| 262 | #endif /* CONFIG_KPROBE_EVENT */ |
| 263 | |
| 264 | struct probe_arg { |
| 265 | struct fetch_param fetch; |
| 266 | struct fetch_param fetch_size; |
| 267 | unsigned int offset; /* Offset from argument entry */ |
| 268 | const char *name; /* Name of this argument */ |
| 269 | const char *comm; /* Command of this argument */ |
| 270 | const struct fetch_type *type; /* Type of this argument */ |
| 271 | }; |
| 272 | |
| 273 | struct trace_probe { |
| 274 | unsigned int flags; /* For TP_FLAG_* */ |
| 275 | struct trace_event_class class; |
| 276 | struct trace_event_call call; |
| 277 | struct list_head files; |
| 278 | ssize_t size; /* trace entry size */ |
| 279 | unsigned int nr_args; |
| 280 | struct probe_arg args[]; |
| 281 | }; |
| 282 | |
| 283 | struct event_file_link { |
| 284 | struct trace_event_file *file; |
| 285 | struct list_head list; |
| 286 | }; |
| 287 | |
| 288 | static inline bool trace_probe_is_enabled(struct trace_probe *tp) |
| 289 | { |
| 290 | return !!(tp->flags & (TP_FLAG_TRACE | TP_FLAG_PROFILE)); |
| 291 | } |
| 292 | |
| 293 | static inline bool trace_probe_is_registered(struct trace_probe *tp) |
| 294 | { |
| 295 | return !!(tp->flags & TP_FLAG_REGISTERED); |
| 296 | } |
| 297 | |
| 298 | static nokprobe_inline void call_fetch(struct fetch_param *fprm, |
| 299 | struct pt_regs *regs, void *dest) |
| 300 | { |
| 301 | return fprm->fn(regs, fprm->data, dest); |
| 302 | } |
| 303 | |
| 304 | /* Check the name is good for event/group/fields */ |
| 305 | static inline bool is_good_name(const char *name) |
| 306 | { |
| 307 | if (!isalpha(*name) && *name != '_') |
| 308 | return false; |
| 309 | while (*++name != '\0') { |
| 310 | if (!isalpha(*name) && !isdigit(*name) && *name != '_') |
| 311 | return false; |
| 312 | } |
| 313 | return true; |
| 314 | } |
| 315 | |
| 316 | static inline struct event_file_link * |
| 317 | find_event_file_link(struct trace_probe *tp, struct trace_event_file *file) |
| 318 | { |
| 319 | struct event_file_link *link; |
| 320 | |
| 321 | list_for_each_entry(link, &tp->files, list) |
| 322 | if (link->file == file) |
| 323 | return link; |
| 324 | |
| 325 | return NULL; |
| 326 | } |
| 327 | |
| 328 | extern int traceprobe_parse_probe_arg(char *arg, ssize_t *size, |
| 329 | struct probe_arg *parg, bool is_return, bool is_kprobe, |
| 330 | const struct fetch_type *ftbl); |
| 331 | |
| 332 | extern int traceprobe_conflict_field_name(const char *name, |
| 333 | struct probe_arg *args, int narg); |
| 334 | |
| 335 | extern void traceprobe_update_arg(struct probe_arg *arg); |
| 336 | extern void traceprobe_free_probe_arg(struct probe_arg *arg); |
| 337 | |
| 338 | extern int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset); |
| 339 | |
| 340 | extern ssize_t traceprobe_probes_write(struct file *file, |
| 341 | const char __user *buffer, size_t count, loff_t *ppos, |
| 342 | int (*createfn)(int, char**)); |
| 343 | |
| 344 | extern int traceprobe_command(const char *buf, int (*createfn)(int, char**)); |
| 345 | |
| 346 | /* Sum up total data length for dynamic arraies (strings) */ |
| 347 | static nokprobe_inline int |
| 348 | __get_data_size(struct trace_probe *tp, struct pt_regs *regs) |
| 349 | { |
| 350 | int i, ret = 0; |
| 351 | u32 len; |
| 352 | |
| 353 | for (i = 0; i < tp->nr_args; i++) |
| 354 | if (unlikely(tp->args[i].fetch_size.fn)) { |
| 355 | call_fetch(&tp->args[i].fetch_size, regs, &len); |
| 356 | ret += len; |
| 357 | } |
| 358 | |
| 359 | return ret; |
| 360 | } |
| 361 | |
| 362 | /* Store the value of each argument */ |
| 363 | static nokprobe_inline void |
| 364 | store_trace_args(int ent_size, struct trace_probe *tp, struct pt_regs *regs, |
| 365 | u8 *data, int maxlen) |
| 366 | { |
| 367 | int i; |
| 368 | u32 end = tp->size; |
| 369 | u32 *dl; /* Data (relative) location */ |
| 370 | |
| 371 | for (i = 0; i < tp->nr_args; i++) { |
| 372 | if (unlikely(tp->args[i].fetch_size.fn)) { |
| 373 | /* |
| 374 | * First, we set the relative location and |
| 375 | * maximum data length to *dl |
| 376 | */ |
| 377 | dl = (u32 *)(data + tp->args[i].offset); |
| 378 | *dl = make_data_rloc(maxlen, end - tp->args[i].offset); |
| 379 | /* Then try to fetch string or dynamic array data */ |
| 380 | call_fetch(&tp->args[i].fetch, regs, dl); |
| 381 | /* Reduce maximum length */ |
| 382 | end += get_rloc_len(*dl); |
| 383 | maxlen -= get_rloc_len(*dl); |
| 384 | /* Trick here, convert data_rloc to data_loc */ |
| 385 | *dl = convert_rloc_to_loc(*dl, |
| 386 | ent_size + tp->args[i].offset); |
| 387 | } else |
| 388 | /* Just fetching data normally */ |
| 389 | call_fetch(&tp->args[i].fetch, regs, |
| 390 | data + tp->args[i].offset); |
| 391 | } |
| 392 | } |
| 393 | |
| 394 | extern int set_print_fmt(struct trace_probe *tp, bool is_return); |