| 1 | /* |
| 2 | * Infrastructure for profiling code inserted by 'gcc -pg'. |
| 3 | * |
| 4 | * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com> |
| 5 | * Copyright (C) 2004-2008 Ingo Molnar <mingo@redhat.com> |
| 6 | * |
| 7 | * Originally ported from the -rt patch by: |
| 8 | * Copyright (C) 2007 Arnaldo Carvalho de Melo <acme@redhat.com> |
| 9 | * |
| 10 | * Based on code in the latency_tracer, that is: |
| 11 | * |
| 12 | * Copyright (C) 2004-2006 Ingo Molnar |
| 13 | * Copyright (C) 2004 William Lee Irwin III |
| 14 | */ |
| 15 | |
| 16 | #include <linux/stop_machine.h> |
| 17 | #include <linux/clocksource.h> |
| 18 | #include <linux/kallsyms.h> |
| 19 | #include <linux/seq_file.h> |
| 20 | #include <linux/suspend.h> |
| 21 | #include <linux/debugfs.h> |
| 22 | #include <linux/hardirq.h> |
| 23 | #include <linux/kthread.h> |
| 24 | #include <linux/uaccess.h> |
| 25 | #include <linux/kprobes.h> |
| 26 | #include <linux/ftrace.h> |
| 27 | #include <linux/sysctl.h> |
| 28 | #include <linux/ctype.h> |
| 29 | #include <linux/list.h> |
| 30 | #include <linux/hash.h> |
| 31 | |
| 32 | #include <trace/events/sched.h> |
| 33 | |
| 34 | #include <asm/ftrace.h> |
| 35 | #include <asm/setup.h> |
| 36 | |
| 37 | #include "trace_output.h" |
| 38 | #include "trace_stat.h" |
| 39 | |
| 40 | #define FTRACE_WARN_ON(cond) \ |
| 41 | do { \ |
| 42 | if (WARN_ON(cond)) \ |
| 43 | ftrace_kill(); \ |
| 44 | } while (0) |
| 45 | |
| 46 | #define FTRACE_WARN_ON_ONCE(cond) \ |
| 47 | do { \ |
| 48 | if (WARN_ON_ONCE(cond)) \ |
| 49 | ftrace_kill(); \ |
| 50 | } while (0) |
| 51 | |
| 52 | /* hash bits for specific function selection */ |
| 53 | #define FTRACE_HASH_BITS 7 |
| 54 | #define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS) |
| 55 | |
| 56 | /* ftrace_enabled is a method to turn ftrace on or off */ |
| 57 | int ftrace_enabled __read_mostly; |
| 58 | static int last_ftrace_enabled; |
| 59 | |
| 60 | /* Quick disabling of function tracer. */ |
| 61 | int function_trace_stop; |
| 62 | |
| 63 | /* |
| 64 | * ftrace_disabled is set when an anomaly is discovered. |
| 65 | * ftrace_disabled is much stronger than ftrace_enabled. |
| 66 | */ |
| 67 | static int ftrace_disabled __read_mostly; |
| 68 | |
| 69 | static DEFINE_MUTEX(ftrace_lock); |
| 70 | |
| 71 | static struct ftrace_ops ftrace_list_end __read_mostly = |
| 72 | { |
| 73 | .func = ftrace_stub, |
| 74 | }; |
| 75 | |
| 76 | static struct ftrace_ops *ftrace_list __read_mostly = &ftrace_list_end; |
| 77 | ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub; |
| 78 | ftrace_func_t __ftrace_trace_function __read_mostly = ftrace_stub; |
| 79 | ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub; |
| 80 | |
| 81 | static void ftrace_list_func(unsigned long ip, unsigned long parent_ip) |
| 82 | { |
| 83 | struct ftrace_ops *op = ftrace_list; |
| 84 | |
| 85 | /* in case someone actually ports this to alpha! */ |
| 86 | read_barrier_depends(); |
| 87 | |
| 88 | while (op != &ftrace_list_end) { |
| 89 | /* silly alpha */ |
| 90 | read_barrier_depends(); |
| 91 | op->func(ip, parent_ip); |
| 92 | op = op->next; |
| 93 | }; |
| 94 | } |
| 95 | |
| 96 | static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip) |
| 97 | { |
| 98 | if (!test_tsk_trace_trace(current)) |
| 99 | return; |
| 100 | |
| 101 | ftrace_pid_function(ip, parent_ip); |
| 102 | } |
| 103 | |
| 104 | static void set_ftrace_pid_function(ftrace_func_t func) |
| 105 | { |
| 106 | /* do not set ftrace_pid_function to itself! */ |
| 107 | if (func != ftrace_pid_func) |
| 108 | ftrace_pid_function = func; |
| 109 | } |
| 110 | |
| 111 | /** |
| 112 | * clear_ftrace_function - reset the ftrace function |
| 113 | * |
| 114 | * This NULLs the ftrace function and in essence stops |
| 115 | * tracing. There may be lag |
| 116 | */ |
| 117 | void clear_ftrace_function(void) |
| 118 | { |
| 119 | ftrace_trace_function = ftrace_stub; |
| 120 | __ftrace_trace_function = ftrace_stub; |
| 121 | ftrace_pid_function = ftrace_stub; |
| 122 | } |
| 123 | |
| 124 | #ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST |
| 125 | /* |
| 126 | * For those archs that do not test ftrace_trace_stop in their |
| 127 | * mcount call site, we need to do it from C. |
| 128 | */ |
| 129 | static void ftrace_test_stop_func(unsigned long ip, unsigned long parent_ip) |
| 130 | { |
| 131 | if (function_trace_stop) |
| 132 | return; |
| 133 | |
| 134 | __ftrace_trace_function(ip, parent_ip); |
| 135 | } |
| 136 | #endif |
| 137 | |
| 138 | static int __register_ftrace_function(struct ftrace_ops *ops) |
| 139 | { |
| 140 | ops->next = ftrace_list; |
| 141 | /* |
| 142 | * We are entering ops into the ftrace_list but another |
| 143 | * CPU might be walking that list. We need to make sure |
| 144 | * the ops->next pointer is valid before another CPU sees |
| 145 | * the ops pointer included into the ftrace_list. |
| 146 | */ |
| 147 | smp_wmb(); |
| 148 | ftrace_list = ops; |
| 149 | |
| 150 | if (ftrace_enabled) { |
| 151 | ftrace_func_t func; |
| 152 | |
| 153 | if (ops->next == &ftrace_list_end) |
| 154 | func = ops->func; |
| 155 | else |
| 156 | func = ftrace_list_func; |
| 157 | |
| 158 | if (ftrace_pid_trace) { |
| 159 | set_ftrace_pid_function(func); |
| 160 | func = ftrace_pid_func; |
| 161 | } |
| 162 | |
| 163 | /* |
| 164 | * For one func, simply call it directly. |
| 165 | * For more than one func, call the chain. |
| 166 | */ |
| 167 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST |
| 168 | ftrace_trace_function = func; |
| 169 | #else |
| 170 | __ftrace_trace_function = func; |
| 171 | ftrace_trace_function = ftrace_test_stop_func; |
| 172 | #endif |
| 173 | } |
| 174 | |
| 175 | return 0; |
| 176 | } |
| 177 | |
| 178 | static int __unregister_ftrace_function(struct ftrace_ops *ops) |
| 179 | { |
| 180 | struct ftrace_ops **p; |
| 181 | |
| 182 | /* |
| 183 | * If we are removing the last function, then simply point |
| 184 | * to the ftrace_stub. |
| 185 | */ |
| 186 | if (ftrace_list == ops && ops->next == &ftrace_list_end) { |
| 187 | ftrace_trace_function = ftrace_stub; |
| 188 | ftrace_list = &ftrace_list_end; |
| 189 | return 0; |
| 190 | } |
| 191 | |
| 192 | for (p = &ftrace_list; *p != &ftrace_list_end; p = &(*p)->next) |
| 193 | if (*p == ops) |
| 194 | break; |
| 195 | |
| 196 | if (*p != ops) |
| 197 | return -1; |
| 198 | |
| 199 | *p = (*p)->next; |
| 200 | |
| 201 | if (ftrace_enabled) { |
| 202 | /* If we only have one func left, then call that directly */ |
| 203 | if (ftrace_list->next == &ftrace_list_end) { |
| 204 | ftrace_func_t func = ftrace_list->func; |
| 205 | |
| 206 | if (ftrace_pid_trace) { |
| 207 | set_ftrace_pid_function(func); |
| 208 | func = ftrace_pid_func; |
| 209 | } |
| 210 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST |
| 211 | ftrace_trace_function = func; |
| 212 | #else |
| 213 | __ftrace_trace_function = func; |
| 214 | #endif |
| 215 | } |
| 216 | } |
| 217 | |
| 218 | return 0; |
| 219 | } |
| 220 | |
| 221 | static void ftrace_update_pid_func(void) |
| 222 | { |
| 223 | ftrace_func_t func; |
| 224 | |
| 225 | if (ftrace_trace_function == ftrace_stub) |
| 226 | return; |
| 227 | |
| 228 | func = ftrace_trace_function; |
| 229 | |
| 230 | if (ftrace_pid_trace) { |
| 231 | set_ftrace_pid_function(func); |
| 232 | func = ftrace_pid_func; |
| 233 | } else { |
| 234 | if (func == ftrace_pid_func) |
| 235 | func = ftrace_pid_function; |
| 236 | } |
| 237 | |
| 238 | #ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST |
| 239 | ftrace_trace_function = func; |
| 240 | #else |
| 241 | __ftrace_trace_function = func; |
| 242 | #endif |
| 243 | } |
| 244 | |
| 245 | #ifdef CONFIG_FUNCTION_PROFILER |
| 246 | struct ftrace_profile { |
| 247 | struct hlist_node node; |
| 248 | unsigned long ip; |
| 249 | unsigned long counter; |
| 250 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
| 251 | unsigned long long time; |
| 252 | #endif |
| 253 | }; |
| 254 | |
| 255 | struct ftrace_profile_page { |
| 256 | struct ftrace_profile_page *next; |
| 257 | unsigned long index; |
| 258 | struct ftrace_profile records[]; |
| 259 | }; |
| 260 | |
| 261 | struct ftrace_profile_stat { |
| 262 | atomic_t disabled; |
| 263 | struct hlist_head *hash; |
| 264 | struct ftrace_profile_page *pages; |
| 265 | struct ftrace_profile_page *start; |
| 266 | struct tracer_stat stat; |
| 267 | }; |
| 268 | |
| 269 | #define PROFILE_RECORDS_SIZE \ |
| 270 | (PAGE_SIZE - offsetof(struct ftrace_profile_page, records)) |
| 271 | |
| 272 | #define PROFILES_PER_PAGE \ |
| 273 | (PROFILE_RECORDS_SIZE / sizeof(struct ftrace_profile)) |
| 274 | |
| 275 | static int ftrace_profile_bits __read_mostly; |
| 276 | static int ftrace_profile_enabled __read_mostly; |
| 277 | |
| 278 | /* ftrace_profile_lock - synchronize the enable and disable of the profiler */ |
| 279 | static DEFINE_MUTEX(ftrace_profile_lock); |
| 280 | |
| 281 | static DEFINE_PER_CPU(struct ftrace_profile_stat, ftrace_profile_stats); |
| 282 | |
| 283 | #define FTRACE_PROFILE_HASH_SIZE 1024 /* must be power of 2 */ |
| 284 | |
| 285 | static void * |
| 286 | function_stat_next(void *v, int idx) |
| 287 | { |
| 288 | struct ftrace_profile *rec = v; |
| 289 | struct ftrace_profile_page *pg; |
| 290 | |
| 291 | pg = (struct ftrace_profile_page *)((unsigned long)rec & PAGE_MASK); |
| 292 | |
| 293 | again: |
| 294 | rec++; |
| 295 | if ((void *)rec >= (void *)&pg->records[pg->index]) { |
| 296 | pg = pg->next; |
| 297 | if (!pg) |
| 298 | return NULL; |
| 299 | rec = &pg->records[0]; |
| 300 | if (!rec->counter) |
| 301 | goto again; |
| 302 | } |
| 303 | |
| 304 | return rec; |
| 305 | } |
| 306 | |
| 307 | static void *function_stat_start(struct tracer_stat *trace) |
| 308 | { |
| 309 | struct ftrace_profile_stat *stat = |
| 310 | container_of(trace, struct ftrace_profile_stat, stat); |
| 311 | |
| 312 | if (!stat || !stat->start) |
| 313 | return NULL; |
| 314 | |
| 315 | return function_stat_next(&stat->start->records[0], 0); |
| 316 | } |
| 317 | |
| 318 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
| 319 | /* function graph compares on total time */ |
| 320 | static int function_stat_cmp(void *p1, void *p2) |
| 321 | { |
| 322 | struct ftrace_profile *a = p1; |
| 323 | struct ftrace_profile *b = p2; |
| 324 | |
| 325 | if (a->time < b->time) |
| 326 | return -1; |
| 327 | if (a->time > b->time) |
| 328 | return 1; |
| 329 | else |
| 330 | return 0; |
| 331 | } |
| 332 | #else |
| 333 | /* not function graph compares against hits */ |
| 334 | static int function_stat_cmp(void *p1, void *p2) |
| 335 | { |
| 336 | struct ftrace_profile *a = p1; |
| 337 | struct ftrace_profile *b = p2; |
| 338 | |
| 339 | if (a->counter < b->counter) |
| 340 | return -1; |
| 341 | if (a->counter > b->counter) |
| 342 | return 1; |
| 343 | else |
| 344 | return 0; |
| 345 | } |
| 346 | #endif |
| 347 | |
| 348 | static int function_stat_headers(struct seq_file *m) |
| 349 | { |
| 350 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
| 351 | seq_printf(m, " Function " |
| 352 | "Hit Time Avg\n" |
| 353 | " -------- " |
| 354 | "--- ---- ---\n"); |
| 355 | #else |
| 356 | seq_printf(m, " Function Hit\n" |
| 357 | " -------- ---\n"); |
| 358 | #endif |
| 359 | return 0; |
| 360 | } |
| 361 | |
| 362 | static int function_stat_show(struct seq_file *m, void *v) |
| 363 | { |
| 364 | struct ftrace_profile *rec = v; |
| 365 | char str[KSYM_SYMBOL_LEN]; |
| 366 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
| 367 | static DEFINE_MUTEX(mutex); |
| 368 | static struct trace_seq s; |
| 369 | unsigned long long avg; |
| 370 | #endif |
| 371 | |
| 372 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); |
| 373 | seq_printf(m, " %-30.30s %10lu", str, rec->counter); |
| 374 | |
| 375 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
| 376 | seq_printf(m, " "); |
| 377 | avg = rec->time; |
| 378 | do_div(avg, rec->counter); |
| 379 | |
| 380 | mutex_lock(&mutex); |
| 381 | trace_seq_init(&s); |
| 382 | trace_print_graph_duration(rec->time, &s); |
| 383 | trace_seq_puts(&s, " "); |
| 384 | trace_print_graph_duration(avg, &s); |
| 385 | trace_print_seq(m, &s); |
| 386 | mutex_unlock(&mutex); |
| 387 | #endif |
| 388 | seq_putc(m, '\n'); |
| 389 | |
| 390 | return 0; |
| 391 | } |
| 392 | |
| 393 | static void ftrace_profile_reset(struct ftrace_profile_stat *stat) |
| 394 | { |
| 395 | struct ftrace_profile_page *pg; |
| 396 | |
| 397 | pg = stat->pages = stat->start; |
| 398 | |
| 399 | while (pg) { |
| 400 | memset(pg->records, 0, PROFILE_RECORDS_SIZE); |
| 401 | pg->index = 0; |
| 402 | pg = pg->next; |
| 403 | } |
| 404 | |
| 405 | memset(stat->hash, 0, |
| 406 | FTRACE_PROFILE_HASH_SIZE * sizeof(struct hlist_head)); |
| 407 | } |
| 408 | |
| 409 | int ftrace_profile_pages_init(struct ftrace_profile_stat *stat) |
| 410 | { |
| 411 | struct ftrace_profile_page *pg; |
| 412 | int functions; |
| 413 | int pages; |
| 414 | int i; |
| 415 | |
| 416 | /* If we already allocated, do nothing */ |
| 417 | if (stat->pages) |
| 418 | return 0; |
| 419 | |
| 420 | stat->pages = (void *)get_zeroed_page(GFP_KERNEL); |
| 421 | if (!stat->pages) |
| 422 | return -ENOMEM; |
| 423 | |
| 424 | #ifdef CONFIG_DYNAMIC_FTRACE |
| 425 | functions = ftrace_update_tot_cnt; |
| 426 | #else |
| 427 | /* |
| 428 | * We do not know the number of functions that exist because |
| 429 | * dynamic tracing is what counts them. With past experience |
| 430 | * we have around 20K functions. That should be more than enough. |
| 431 | * It is highly unlikely we will execute every function in |
| 432 | * the kernel. |
| 433 | */ |
| 434 | functions = 20000; |
| 435 | #endif |
| 436 | |
| 437 | pg = stat->start = stat->pages; |
| 438 | |
| 439 | pages = DIV_ROUND_UP(functions, PROFILES_PER_PAGE); |
| 440 | |
| 441 | for (i = 0; i < pages; i++) { |
| 442 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); |
| 443 | if (!pg->next) |
| 444 | goto out_free; |
| 445 | pg = pg->next; |
| 446 | } |
| 447 | |
| 448 | return 0; |
| 449 | |
| 450 | out_free: |
| 451 | pg = stat->start; |
| 452 | while (pg) { |
| 453 | unsigned long tmp = (unsigned long)pg; |
| 454 | |
| 455 | pg = pg->next; |
| 456 | free_page(tmp); |
| 457 | } |
| 458 | |
| 459 | free_page((unsigned long)stat->pages); |
| 460 | stat->pages = NULL; |
| 461 | stat->start = NULL; |
| 462 | |
| 463 | return -ENOMEM; |
| 464 | } |
| 465 | |
| 466 | static int ftrace_profile_init_cpu(int cpu) |
| 467 | { |
| 468 | struct ftrace_profile_stat *stat; |
| 469 | int size; |
| 470 | |
| 471 | stat = &per_cpu(ftrace_profile_stats, cpu); |
| 472 | |
| 473 | if (stat->hash) { |
| 474 | /* If the profile is already created, simply reset it */ |
| 475 | ftrace_profile_reset(stat); |
| 476 | return 0; |
| 477 | } |
| 478 | |
| 479 | /* |
| 480 | * We are profiling all functions, but usually only a few thousand |
| 481 | * functions are hit. We'll make a hash of 1024 items. |
| 482 | */ |
| 483 | size = FTRACE_PROFILE_HASH_SIZE; |
| 484 | |
| 485 | stat->hash = kzalloc(sizeof(struct hlist_head) * size, GFP_KERNEL); |
| 486 | |
| 487 | if (!stat->hash) |
| 488 | return -ENOMEM; |
| 489 | |
| 490 | if (!ftrace_profile_bits) { |
| 491 | size--; |
| 492 | |
| 493 | for (; size; size >>= 1) |
| 494 | ftrace_profile_bits++; |
| 495 | } |
| 496 | |
| 497 | /* Preallocate the function profiling pages */ |
| 498 | if (ftrace_profile_pages_init(stat) < 0) { |
| 499 | kfree(stat->hash); |
| 500 | stat->hash = NULL; |
| 501 | return -ENOMEM; |
| 502 | } |
| 503 | |
| 504 | return 0; |
| 505 | } |
| 506 | |
| 507 | static int ftrace_profile_init(void) |
| 508 | { |
| 509 | int cpu; |
| 510 | int ret = 0; |
| 511 | |
| 512 | for_each_online_cpu(cpu) { |
| 513 | ret = ftrace_profile_init_cpu(cpu); |
| 514 | if (ret) |
| 515 | break; |
| 516 | } |
| 517 | |
| 518 | return ret; |
| 519 | } |
| 520 | |
| 521 | /* interrupts must be disabled */ |
| 522 | static struct ftrace_profile * |
| 523 | ftrace_find_profiled_func(struct ftrace_profile_stat *stat, unsigned long ip) |
| 524 | { |
| 525 | struct ftrace_profile *rec; |
| 526 | struct hlist_head *hhd; |
| 527 | struct hlist_node *n; |
| 528 | unsigned long key; |
| 529 | |
| 530 | key = hash_long(ip, ftrace_profile_bits); |
| 531 | hhd = &stat->hash[key]; |
| 532 | |
| 533 | if (hlist_empty(hhd)) |
| 534 | return NULL; |
| 535 | |
| 536 | hlist_for_each_entry_rcu(rec, n, hhd, node) { |
| 537 | if (rec->ip == ip) |
| 538 | return rec; |
| 539 | } |
| 540 | |
| 541 | return NULL; |
| 542 | } |
| 543 | |
| 544 | static void ftrace_add_profile(struct ftrace_profile_stat *stat, |
| 545 | struct ftrace_profile *rec) |
| 546 | { |
| 547 | unsigned long key; |
| 548 | |
| 549 | key = hash_long(rec->ip, ftrace_profile_bits); |
| 550 | hlist_add_head_rcu(&rec->node, &stat->hash[key]); |
| 551 | } |
| 552 | |
| 553 | /* |
| 554 | * The memory is already allocated, this simply finds a new record to use. |
| 555 | */ |
| 556 | static struct ftrace_profile * |
| 557 | ftrace_profile_alloc(struct ftrace_profile_stat *stat, unsigned long ip) |
| 558 | { |
| 559 | struct ftrace_profile *rec = NULL; |
| 560 | |
| 561 | /* prevent recursion (from NMIs) */ |
| 562 | if (atomic_inc_return(&stat->disabled) != 1) |
| 563 | goto out; |
| 564 | |
| 565 | /* |
| 566 | * Try to find the function again since an NMI |
| 567 | * could have added it |
| 568 | */ |
| 569 | rec = ftrace_find_profiled_func(stat, ip); |
| 570 | if (rec) |
| 571 | goto out; |
| 572 | |
| 573 | if (stat->pages->index == PROFILES_PER_PAGE) { |
| 574 | if (!stat->pages->next) |
| 575 | goto out; |
| 576 | stat->pages = stat->pages->next; |
| 577 | } |
| 578 | |
| 579 | rec = &stat->pages->records[stat->pages->index++]; |
| 580 | rec->ip = ip; |
| 581 | ftrace_add_profile(stat, rec); |
| 582 | |
| 583 | out: |
| 584 | atomic_dec(&stat->disabled); |
| 585 | |
| 586 | return rec; |
| 587 | } |
| 588 | |
| 589 | static void |
| 590 | function_profile_call(unsigned long ip, unsigned long parent_ip) |
| 591 | { |
| 592 | struct ftrace_profile_stat *stat; |
| 593 | struct ftrace_profile *rec; |
| 594 | unsigned long flags; |
| 595 | |
| 596 | if (!ftrace_profile_enabled) |
| 597 | return; |
| 598 | |
| 599 | local_irq_save(flags); |
| 600 | |
| 601 | stat = &__get_cpu_var(ftrace_profile_stats); |
| 602 | if (!stat->hash || !ftrace_profile_enabled) |
| 603 | goto out; |
| 604 | |
| 605 | rec = ftrace_find_profiled_func(stat, ip); |
| 606 | if (!rec) { |
| 607 | rec = ftrace_profile_alloc(stat, ip); |
| 608 | if (!rec) |
| 609 | goto out; |
| 610 | } |
| 611 | |
| 612 | rec->counter++; |
| 613 | out: |
| 614 | local_irq_restore(flags); |
| 615 | } |
| 616 | |
| 617 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
| 618 | static int profile_graph_entry(struct ftrace_graph_ent *trace) |
| 619 | { |
| 620 | function_profile_call(trace->func, 0); |
| 621 | return 1; |
| 622 | } |
| 623 | |
| 624 | static void profile_graph_return(struct ftrace_graph_ret *trace) |
| 625 | { |
| 626 | struct ftrace_profile_stat *stat; |
| 627 | unsigned long long calltime; |
| 628 | struct ftrace_profile *rec; |
| 629 | unsigned long flags; |
| 630 | |
| 631 | local_irq_save(flags); |
| 632 | stat = &__get_cpu_var(ftrace_profile_stats); |
| 633 | if (!stat->hash || !ftrace_profile_enabled) |
| 634 | goto out; |
| 635 | |
| 636 | calltime = trace->rettime - trace->calltime; |
| 637 | |
| 638 | if (!(trace_flags & TRACE_ITER_GRAPH_TIME)) { |
| 639 | int index; |
| 640 | |
| 641 | index = trace->depth; |
| 642 | |
| 643 | /* Append this call time to the parent time to subtract */ |
| 644 | if (index) |
| 645 | current->ret_stack[index - 1].subtime += calltime; |
| 646 | |
| 647 | if (current->ret_stack[index].subtime < calltime) |
| 648 | calltime -= current->ret_stack[index].subtime; |
| 649 | else |
| 650 | calltime = 0; |
| 651 | } |
| 652 | |
| 653 | rec = ftrace_find_profiled_func(stat, trace->func); |
| 654 | if (rec) |
| 655 | rec->time += calltime; |
| 656 | |
| 657 | out: |
| 658 | local_irq_restore(flags); |
| 659 | } |
| 660 | |
| 661 | static int register_ftrace_profiler(void) |
| 662 | { |
| 663 | return register_ftrace_graph(&profile_graph_return, |
| 664 | &profile_graph_entry); |
| 665 | } |
| 666 | |
| 667 | static void unregister_ftrace_profiler(void) |
| 668 | { |
| 669 | unregister_ftrace_graph(); |
| 670 | } |
| 671 | #else |
| 672 | static struct ftrace_ops ftrace_profile_ops __read_mostly = |
| 673 | { |
| 674 | .func = function_profile_call, |
| 675 | }; |
| 676 | |
| 677 | static int register_ftrace_profiler(void) |
| 678 | { |
| 679 | return register_ftrace_function(&ftrace_profile_ops); |
| 680 | } |
| 681 | |
| 682 | static void unregister_ftrace_profiler(void) |
| 683 | { |
| 684 | unregister_ftrace_function(&ftrace_profile_ops); |
| 685 | } |
| 686 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
| 687 | |
| 688 | static ssize_t |
| 689 | ftrace_profile_write(struct file *filp, const char __user *ubuf, |
| 690 | size_t cnt, loff_t *ppos) |
| 691 | { |
| 692 | unsigned long val; |
| 693 | char buf[64]; /* big enough to hold a number */ |
| 694 | int ret; |
| 695 | |
| 696 | if (cnt >= sizeof(buf)) |
| 697 | return -EINVAL; |
| 698 | |
| 699 | if (copy_from_user(&buf, ubuf, cnt)) |
| 700 | return -EFAULT; |
| 701 | |
| 702 | buf[cnt] = 0; |
| 703 | |
| 704 | ret = strict_strtoul(buf, 10, &val); |
| 705 | if (ret < 0) |
| 706 | return ret; |
| 707 | |
| 708 | val = !!val; |
| 709 | |
| 710 | mutex_lock(&ftrace_profile_lock); |
| 711 | if (ftrace_profile_enabled ^ val) { |
| 712 | if (val) { |
| 713 | ret = ftrace_profile_init(); |
| 714 | if (ret < 0) { |
| 715 | cnt = ret; |
| 716 | goto out; |
| 717 | } |
| 718 | |
| 719 | ret = register_ftrace_profiler(); |
| 720 | if (ret < 0) { |
| 721 | cnt = ret; |
| 722 | goto out; |
| 723 | } |
| 724 | ftrace_profile_enabled = 1; |
| 725 | } else { |
| 726 | ftrace_profile_enabled = 0; |
| 727 | /* |
| 728 | * unregister_ftrace_profiler calls stop_machine |
| 729 | * so this acts like an synchronize_sched. |
| 730 | */ |
| 731 | unregister_ftrace_profiler(); |
| 732 | } |
| 733 | } |
| 734 | out: |
| 735 | mutex_unlock(&ftrace_profile_lock); |
| 736 | |
| 737 | filp->f_pos += cnt; |
| 738 | |
| 739 | return cnt; |
| 740 | } |
| 741 | |
| 742 | static ssize_t |
| 743 | ftrace_profile_read(struct file *filp, char __user *ubuf, |
| 744 | size_t cnt, loff_t *ppos) |
| 745 | { |
| 746 | char buf[64]; /* big enough to hold a number */ |
| 747 | int r; |
| 748 | |
| 749 | r = sprintf(buf, "%u\n", ftrace_profile_enabled); |
| 750 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); |
| 751 | } |
| 752 | |
| 753 | static const struct file_operations ftrace_profile_fops = { |
| 754 | .open = tracing_open_generic, |
| 755 | .read = ftrace_profile_read, |
| 756 | .write = ftrace_profile_write, |
| 757 | }; |
| 758 | |
| 759 | /* used to initialize the real stat files */ |
| 760 | static struct tracer_stat function_stats __initdata = { |
| 761 | .name = "functions", |
| 762 | .stat_start = function_stat_start, |
| 763 | .stat_next = function_stat_next, |
| 764 | .stat_cmp = function_stat_cmp, |
| 765 | .stat_headers = function_stat_headers, |
| 766 | .stat_show = function_stat_show |
| 767 | }; |
| 768 | |
| 769 | static void ftrace_profile_debugfs(struct dentry *d_tracer) |
| 770 | { |
| 771 | struct ftrace_profile_stat *stat; |
| 772 | struct dentry *entry; |
| 773 | char *name; |
| 774 | int ret; |
| 775 | int cpu; |
| 776 | |
| 777 | for_each_possible_cpu(cpu) { |
| 778 | stat = &per_cpu(ftrace_profile_stats, cpu); |
| 779 | |
| 780 | /* allocate enough for function name + cpu number */ |
| 781 | name = kmalloc(32, GFP_KERNEL); |
| 782 | if (!name) { |
| 783 | /* |
| 784 | * The files created are permanent, if something happens |
| 785 | * we still do not free memory. |
| 786 | */ |
| 787 | kfree(stat); |
| 788 | WARN(1, |
| 789 | "Could not allocate stat file for cpu %d\n", |
| 790 | cpu); |
| 791 | return; |
| 792 | } |
| 793 | stat->stat = function_stats; |
| 794 | snprintf(name, 32, "function%d", cpu); |
| 795 | stat->stat.name = name; |
| 796 | ret = register_stat_tracer(&stat->stat); |
| 797 | if (ret) { |
| 798 | WARN(1, |
| 799 | "Could not register function stat for cpu %d\n", |
| 800 | cpu); |
| 801 | kfree(name); |
| 802 | return; |
| 803 | } |
| 804 | } |
| 805 | |
| 806 | entry = debugfs_create_file("function_profile_enabled", 0644, |
| 807 | d_tracer, NULL, &ftrace_profile_fops); |
| 808 | if (!entry) |
| 809 | pr_warning("Could not create debugfs " |
| 810 | "'function_profile_enabled' entry\n"); |
| 811 | } |
| 812 | |
| 813 | #else /* CONFIG_FUNCTION_PROFILER */ |
| 814 | static void ftrace_profile_debugfs(struct dentry *d_tracer) |
| 815 | { |
| 816 | } |
| 817 | #endif /* CONFIG_FUNCTION_PROFILER */ |
| 818 | |
| 819 | /* set when tracing only a pid */ |
| 820 | struct pid *ftrace_pid_trace; |
| 821 | static struct pid * const ftrace_swapper_pid = &init_struct_pid; |
| 822 | |
| 823 | #ifdef CONFIG_DYNAMIC_FTRACE |
| 824 | |
| 825 | #ifndef CONFIG_FTRACE_MCOUNT_RECORD |
| 826 | # error Dynamic ftrace depends on MCOUNT_RECORD |
| 827 | #endif |
| 828 | |
| 829 | static struct hlist_head ftrace_func_hash[FTRACE_FUNC_HASHSIZE] __read_mostly; |
| 830 | |
| 831 | struct ftrace_func_probe { |
| 832 | struct hlist_node node; |
| 833 | struct ftrace_probe_ops *ops; |
| 834 | unsigned long flags; |
| 835 | unsigned long ip; |
| 836 | void *data; |
| 837 | struct rcu_head rcu; |
| 838 | }; |
| 839 | |
| 840 | enum { |
| 841 | FTRACE_ENABLE_CALLS = (1 << 0), |
| 842 | FTRACE_DISABLE_CALLS = (1 << 1), |
| 843 | FTRACE_UPDATE_TRACE_FUNC = (1 << 2), |
| 844 | FTRACE_ENABLE_MCOUNT = (1 << 3), |
| 845 | FTRACE_DISABLE_MCOUNT = (1 << 4), |
| 846 | FTRACE_START_FUNC_RET = (1 << 5), |
| 847 | FTRACE_STOP_FUNC_RET = (1 << 6), |
| 848 | }; |
| 849 | |
| 850 | static int ftrace_filtered; |
| 851 | |
| 852 | static struct dyn_ftrace *ftrace_new_addrs; |
| 853 | |
| 854 | static DEFINE_MUTEX(ftrace_regex_lock); |
| 855 | |
| 856 | struct ftrace_page { |
| 857 | struct ftrace_page *next; |
| 858 | int index; |
| 859 | struct dyn_ftrace records[]; |
| 860 | }; |
| 861 | |
| 862 | #define ENTRIES_PER_PAGE \ |
| 863 | ((PAGE_SIZE - sizeof(struct ftrace_page)) / sizeof(struct dyn_ftrace)) |
| 864 | |
| 865 | /* estimate from running different kernels */ |
| 866 | #define NR_TO_INIT 10000 |
| 867 | |
| 868 | static struct ftrace_page *ftrace_pages_start; |
| 869 | static struct ftrace_page *ftrace_pages; |
| 870 | |
| 871 | static struct dyn_ftrace *ftrace_free_records; |
| 872 | |
| 873 | /* |
| 874 | * This is a double for. Do not use 'break' to break out of the loop, |
| 875 | * you must use a goto. |
| 876 | */ |
| 877 | #define do_for_each_ftrace_rec(pg, rec) \ |
| 878 | for (pg = ftrace_pages_start; pg; pg = pg->next) { \ |
| 879 | int _____i; \ |
| 880 | for (_____i = 0; _____i < pg->index; _____i++) { \ |
| 881 | rec = &pg->records[_____i]; |
| 882 | |
| 883 | #define while_for_each_ftrace_rec() \ |
| 884 | } \ |
| 885 | } |
| 886 | |
| 887 | #ifdef CONFIG_KPROBES |
| 888 | |
| 889 | static int frozen_record_count; |
| 890 | |
| 891 | static inline void freeze_record(struct dyn_ftrace *rec) |
| 892 | { |
| 893 | if (!(rec->flags & FTRACE_FL_FROZEN)) { |
| 894 | rec->flags |= FTRACE_FL_FROZEN; |
| 895 | frozen_record_count++; |
| 896 | } |
| 897 | } |
| 898 | |
| 899 | static inline void unfreeze_record(struct dyn_ftrace *rec) |
| 900 | { |
| 901 | if (rec->flags & FTRACE_FL_FROZEN) { |
| 902 | rec->flags &= ~FTRACE_FL_FROZEN; |
| 903 | frozen_record_count--; |
| 904 | } |
| 905 | } |
| 906 | |
| 907 | static inline int record_frozen(struct dyn_ftrace *rec) |
| 908 | { |
| 909 | return rec->flags & FTRACE_FL_FROZEN; |
| 910 | } |
| 911 | #else |
| 912 | # define freeze_record(rec) ({ 0; }) |
| 913 | # define unfreeze_record(rec) ({ 0; }) |
| 914 | # define record_frozen(rec) ({ 0; }) |
| 915 | #endif /* CONFIG_KPROBES */ |
| 916 | |
| 917 | static void ftrace_free_rec(struct dyn_ftrace *rec) |
| 918 | { |
| 919 | rec->freelist = ftrace_free_records; |
| 920 | ftrace_free_records = rec; |
| 921 | rec->flags |= FTRACE_FL_FREE; |
| 922 | } |
| 923 | |
| 924 | static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip) |
| 925 | { |
| 926 | struct dyn_ftrace *rec; |
| 927 | |
| 928 | /* First check for freed records */ |
| 929 | if (ftrace_free_records) { |
| 930 | rec = ftrace_free_records; |
| 931 | |
| 932 | if (unlikely(!(rec->flags & FTRACE_FL_FREE))) { |
| 933 | FTRACE_WARN_ON_ONCE(1); |
| 934 | ftrace_free_records = NULL; |
| 935 | return NULL; |
| 936 | } |
| 937 | |
| 938 | ftrace_free_records = rec->freelist; |
| 939 | memset(rec, 0, sizeof(*rec)); |
| 940 | return rec; |
| 941 | } |
| 942 | |
| 943 | if (ftrace_pages->index == ENTRIES_PER_PAGE) { |
| 944 | if (!ftrace_pages->next) { |
| 945 | /* allocate another page */ |
| 946 | ftrace_pages->next = |
| 947 | (void *)get_zeroed_page(GFP_KERNEL); |
| 948 | if (!ftrace_pages->next) |
| 949 | return NULL; |
| 950 | } |
| 951 | ftrace_pages = ftrace_pages->next; |
| 952 | } |
| 953 | |
| 954 | return &ftrace_pages->records[ftrace_pages->index++]; |
| 955 | } |
| 956 | |
| 957 | static struct dyn_ftrace * |
| 958 | ftrace_record_ip(unsigned long ip) |
| 959 | { |
| 960 | struct dyn_ftrace *rec; |
| 961 | |
| 962 | if (ftrace_disabled) |
| 963 | return NULL; |
| 964 | |
| 965 | rec = ftrace_alloc_dyn_node(ip); |
| 966 | if (!rec) |
| 967 | return NULL; |
| 968 | |
| 969 | rec->ip = ip; |
| 970 | rec->newlist = ftrace_new_addrs; |
| 971 | ftrace_new_addrs = rec; |
| 972 | |
| 973 | return rec; |
| 974 | } |
| 975 | |
| 976 | static void print_ip_ins(const char *fmt, unsigned char *p) |
| 977 | { |
| 978 | int i; |
| 979 | |
| 980 | printk(KERN_CONT "%s", fmt); |
| 981 | |
| 982 | for (i = 0; i < MCOUNT_INSN_SIZE; i++) |
| 983 | printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]); |
| 984 | } |
| 985 | |
| 986 | static void ftrace_bug(int failed, unsigned long ip) |
| 987 | { |
| 988 | switch (failed) { |
| 989 | case -EFAULT: |
| 990 | FTRACE_WARN_ON_ONCE(1); |
| 991 | pr_info("ftrace faulted on modifying "); |
| 992 | print_ip_sym(ip); |
| 993 | break; |
| 994 | case -EINVAL: |
| 995 | FTRACE_WARN_ON_ONCE(1); |
| 996 | pr_info("ftrace failed to modify "); |
| 997 | print_ip_sym(ip); |
| 998 | print_ip_ins(" actual: ", (unsigned char *)ip); |
| 999 | printk(KERN_CONT "\n"); |
| 1000 | break; |
| 1001 | case -EPERM: |
| 1002 | FTRACE_WARN_ON_ONCE(1); |
| 1003 | pr_info("ftrace faulted on writing "); |
| 1004 | print_ip_sym(ip); |
| 1005 | break; |
| 1006 | default: |
| 1007 | FTRACE_WARN_ON_ONCE(1); |
| 1008 | pr_info("ftrace faulted on unknown error "); |
| 1009 | print_ip_sym(ip); |
| 1010 | } |
| 1011 | } |
| 1012 | |
| 1013 | |
| 1014 | static int |
| 1015 | __ftrace_replace_code(struct dyn_ftrace *rec, int enable) |
| 1016 | { |
| 1017 | unsigned long ftrace_addr; |
| 1018 | unsigned long ip, fl; |
| 1019 | |
| 1020 | ftrace_addr = (unsigned long)FTRACE_ADDR; |
| 1021 | |
| 1022 | ip = rec->ip; |
| 1023 | |
| 1024 | /* |
| 1025 | * If this record is not to be traced and |
| 1026 | * it is not enabled then do nothing. |
| 1027 | * |
| 1028 | * If this record is not to be traced and |
| 1029 | * it is enabled then disable it. |
| 1030 | * |
| 1031 | */ |
| 1032 | if (rec->flags & FTRACE_FL_NOTRACE) { |
| 1033 | if (rec->flags & FTRACE_FL_ENABLED) |
| 1034 | rec->flags &= ~FTRACE_FL_ENABLED; |
| 1035 | else |
| 1036 | return 0; |
| 1037 | |
| 1038 | } else if (ftrace_filtered && enable) { |
| 1039 | /* |
| 1040 | * Filtering is on: |
| 1041 | */ |
| 1042 | |
| 1043 | fl = rec->flags & (FTRACE_FL_FILTER | FTRACE_FL_ENABLED); |
| 1044 | |
| 1045 | /* Record is filtered and enabled, do nothing */ |
| 1046 | if (fl == (FTRACE_FL_FILTER | FTRACE_FL_ENABLED)) |
| 1047 | return 0; |
| 1048 | |
| 1049 | /* Record is not filtered or enabled, do nothing */ |
| 1050 | if (!fl) |
| 1051 | return 0; |
| 1052 | |
| 1053 | /* Record is not filtered but enabled, disable it */ |
| 1054 | if (fl == FTRACE_FL_ENABLED) |
| 1055 | rec->flags &= ~FTRACE_FL_ENABLED; |
| 1056 | else |
| 1057 | /* Otherwise record is filtered but not enabled, enable it */ |
| 1058 | rec->flags |= FTRACE_FL_ENABLED; |
| 1059 | } else { |
| 1060 | /* Disable or not filtered */ |
| 1061 | |
| 1062 | if (enable) { |
| 1063 | /* if record is enabled, do nothing */ |
| 1064 | if (rec->flags & FTRACE_FL_ENABLED) |
| 1065 | return 0; |
| 1066 | |
| 1067 | rec->flags |= FTRACE_FL_ENABLED; |
| 1068 | |
| 1069 | } else { |
| 1070 | |
| 1071 | /* if record is not enabled, do nothing */ |
| 1072 | if (!(rec->flags & FTRACE_FL_ENABLED)) |
| 1073 | return 0; |
| 1074 | |
| 1075 | rec->flags &= ~FTRACE_FL_ENABLED; |
| 1076 | } |
| 1077 | } |
| 1078 | |
| 1079 | if (rec->flags & FTRACE_FL_ENABLED) |
| 1080 | return ftrace_make_call(rec, ftrace_addr); |
| 1081 | else |
| 1082 | return ftrace_make_nop(NULL, rec, ftrace_addr); |
| 1083 | } |
| 1084 | |
| 1085 | static void ftrace_replace_code(int enable) |
| 1086 | { |
| 1087 | struct dyn_ftrace *rec; |
| 1088 | struct ftrace_page *pg; |
| 1089 | int failed; |
| 1090 | |
| 1091 | do_for_each_ftrace_rec(pg, rec) { |
| 1092 | /* |
| 1093 | * Skip over free records, records that have |
| 1094 | * failed and not converted. |
| 1095 | */ |
| 1096 | if (rec->flags & FTRACE_FL_FREE || |
| 1097 | rec->flags & FTRACE_FL_FAILED || |
| 1098 | !(rec->flags & FTRACE_FL_CONVERTED)) |
| 1099 | continue; |
| 1100 | |
| 1101 | /* ignore updates to this record's mcount site */ |
| 1102 | if (get_kprobe((void *)rec->ip)) { |
| 1103 | freeze_record(rec); |
| 1104 | continue; |
| 1105 | } else { |
| 1106 | unfreeze_record(rec); |
| 1107 | } |
| 1108 | |
| 1109 | failed = __ftrace_replace_code(rec, enable); |
| 1110 | if (failed) { |
| 1111 | rec->flags |= FTRACE_FL_FAILED; |
| 1112 | if ((system_state == SYSTEM_BOOTING) || |
| 1113 | !core_kernel_text(rec->ip)) { |
| 1114 | ftrace_free_rec(rec); |
| 1115 | } else { |
| 1116 | ftrace_bug(failed, rec->ip); |
| 1117 | /* Stop processing */ |
| 1118 | return; |
| 1119 | } |
| 1120 | } |
| 1121 | } while_for_each_ftrace_rec(); |
| 1122 | } |
| 1123 | |
| 1124 | static int |
| 1125 | ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec) |
| 1126 | { |
| 1127 | unsigned long ip; |
| 1128 | int ret; |
| 1129 | |
| 1130 | ip = rec->ip; |
| 1131 | |
| 1132 | ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR); |
| 1133 | if (ret) { |
| 1134 | ftrace_bug(ret, ip); |
| 1135 | rec->flags |= FTRACE_FL_FAILED; |
| 1136 | return 0; |
| 1137 | } |
| 1138 | return 1; |
| 1139 | } |
| 1140 | |
| 1141 | /* |
| 1142 | * archs can override this function if they must do something |
| 1143 | * before the modifying code is performed. |
| 1144 | */ |
| 1145 | int __weak ftrace_arch_code_modify_prepare(void) |
| 1146 | { |
| 1147 | return 0; |
| 1148 | } |
| 1149 | |
| 1150 | /* |
| 1151 | * archs can override this function if they must do something |
| 1152 | * after the modifying code is performed. |
| 1153 | */ |
| 1154 | int __weak ftrace_arch_code_modify_post_process(void) |
| 1155 | { |
| 1156 | return 0; |
| 1157 | } |
| 1158 | |
| 1159 | static int __ftrace_modify_code(void *data) |
| 1160 | { |
| 1161 | int *command = data; |
| 1162 | |
| 1163 | if (*command & FTRACE_ENABLE_CALLS) |
| 1164 | ftrace_replace_code(1); |
| 1165 | else if (*command & FTRACE_DISABLE_CALLS) |
| 1166 | ftrace_replace_code(0); |
| 1167 | |
| 1168 | if (*command & FTRACE_UPDATE_TRACE_FUNC) |
| 1169 | ftrace_update_ftrace_func(ftrace_trace_function); |
| 1170 | |
| 1171 | if (*command & FTRACE_START_FUNC_RET) |
| 1172 | ftrace_enable_ftrace_graph_caller(); |
| 1173 | else if (*command & FTRACE_STOP_FUNC_RET) |
| 1174 | ftrace_disable_ftrace_graph_caller(); |
| 1175 | |
| 1176 | return 0; |
| 1177 | } |
| 1178 | |
| 1179 | static void ftrace_run_update_code(int command) |
| 1180 | { |
| 1181 | int ret; |
| 1182 | |
| 1183 | ret = ftrace_arch_code_modify_prepare(); |
| 1184 | FTRACE_WARN_ON(ret); |
| 1185 | if (ret) |
| 1186 | return; |
| 1187 | |
| 1188 | stop_machine(__ftrace_modify_code, &command, NULL); |
| 1189 | |
| 1190 | ret = ftrace_arch_code_modify_post_process(); |
| 1191 | FTRACE_WARN_ON(ret); |
| 1192 | } |
| 1193 | |
| 1194 | static ftrace_func_t saved_ftrace_func; |
| 1195 | static int ftrace_start_up; |
| 1196 | |
| 1197 | static void ftrace_startup_enable(int command) |
| 1198 | { |
| 1199 | if (saved_ftrace_func != ftrace_trace_function) { |
| 1200 | saved_ftrace_func = ftrace_trace_function; |
| 1201 | command |= FTRACE_UPDATE_TRACE_FUNC; |
| 1202 | } |
| 1203 | |
| 1204 | if (!command || !ftrace_enabled) |
| 1205 | return; |
| 1206 | |
| 1207 | ftrace_run_update_code(command); |
| 1208 | } |
| 1209 | |
| 1210 | static void ftrace_startup(int command) |
| 1211 | { |
| 1212 | if (unlikely(ftrace_disabled)) |
| 1213 | return; |
| 1214 | |
| 1215 | ftrace_start_up++; |
| 1216 | command |= FTRACE_ENABLE_CALLS; |
| 1217 | |
| 1218 | ftrace_startup_enable(command); |
| 1219 | } |
| 1220 | |
| 1221 | static void ftrace_shutdown(int command) |
| 1222 | { |
| 1223 | if (unlikely(ftrace_disabled)) |
| 1224 | return; |
| 1225 | |
| 1226 | ftrace_start_up--; |
| 1227 | /* |
| 1228 | * Just warn in case of unbalance, no need to kill ftrace, it's not |
| 1229 | * critical but the ftrace_call callers may be never nopped again after |
| 1230 | * further ftrace uses. |
| 1231 | */ |
| 1232 | WARN_ON_ONCE(ftrace_start_up < 0); |
| 1233 | |
| 1234 | if (!ftrace_start_up) |
| 1235 | command |= FTRACE_DISABLE_CALLS; |
| 1236 | |
| 1237 | if (saved_ftrace_func != ftrace_trace_function) { |
| 1238 | saved_ftrace_func = ftrace_trace_function; |
| 1239 | command |= FTRACE_UPDATE_TRACE_FUNC; |
| 1240 | } |
| 1241 | |
| 1242 | if (!command || !ftrace_enabled) |
| 1243 | return; |
| 1244 | |
| 1245 | ftrace_run_update_code(command); |
| 1246 | } |
| 1247 | |
| 1248 | static void ftrace_startup_sysctl(void) |
| 1249 | { |
| 1250 | int command = FTRACE_ENABLE_MCOUNT; |
| 1251 | |
| 1252 | if (unlikely(ftrace_disabled)) |
| 1253 | return; |
| 1254 | |
| 1255 | /* Force update next time */ |
| 1256 | saved_ftrace_func = NULL; |
| 1257 | /* ftrace_start_up is true if we want ftrace running */ |
| 1258 | if (ftrace_start_up) |
| 1259 | command |= FTRACE_ENABLE_CALLS; |
| 1260 | |
| 1261 | ftrace_run_update_code(command); |
| 1262 | } |
| 1263 | |
| 1264 | static void ftrace_shutdown_sysctl(void) |
| 1265 | { |
| 1266 | int command = FTRACE_DISABLE_MCOUNT; |
| 1267 | |
| 1268 | if (unlikely(ftrace_disabled)) |
| 1269 | return; |
| 1270 | |
| 1271 | /* ftrace_start_up is true if ftrace is running */ |
| 1272 | if (ftrace_start_up) |
| 1273 | command |= FTRACE_DISABLE_CALLS; |
| 1274 | |
| 1275 | ftrace_run_update_code(command); |
| 1276 | } |
| 1277 | |
| 1278 | static cycle_t ftrace_update_time; |
| 1279 | static unsigned long ftrace_update_cnt; |
| 1280 | unsigned long ftrace_update_tot_cnt; |
| 1281 | |
| 1282 | static int ftrace_update_code(struct module *mod) |
| 1283 | { |
| 1284 | struct dyn_ftrace *p; |
| 1285 | cycle_t start, stop; |
| 1286 | |
| 1287 | start = ftrace_now(raw_smp_processor_id()); |
| 1288 | ftrace_update_cnt = 0; |
| 1289 | |
| 1290 | while (ftrace_new_addrs) { |
| 1291 | |
| 1292 | /* If something went wrong, bail without enabling anything */ |
| 1293 | if (unlikely(ftrace_disabled)) |
| 1294 | return -1; |
| 1295 | |
| 1296 | p = ftrace_new_addrs; |
| 1297 | ftrace_new_addrs = p->newlist; |
| 1298 | p->flags = 0L; |
| 1299 | |
| 1300 | /* convert record (i.e, patch mcount-call with NOP) */ |
| 1301 | if (ftrace_code_disable(mod, p)) { |
| 1302 | p->flags |= FTRACE_FL_CONVERTED; |
| 1303 | ftrace_update_cnt++; |
| 1304 | } else |
| 1305 | ftrace_free_rec(p); |
| 1306 | } |
| 1307 | |
| 1308 | stop = ftrace_now(raw_smp_processor_id()); |
| 1309 | ftrace_update_time = stop - start; |
| 1310 | ftrace_update_tot_cnt += ftrace_update_cnt; |
| 1311 | |
| 1312 | return 0; |
| 1313 | } |
| 1314 | |
| 1315 | static int __init ftrace_dyn_table_alloc(unsigned long num_to_init) |
| 1316 | { |
| 1317 | struct ftrace_page *pg; |
| 1318 | int cnt; |
| 1319 | int i; |
| 1320 | |
| 1321 | /* allocate a few pages */ |
| 1322 | ftrace_pages_start = (void *)get_zeroed_page(GFP_KERNEL); |
| 1323 | if (!ftrace_pages_start) |
| 1324 | return -1; |
| 1325 | |
| 1326 | /* |
| 1327 | * Allocate a few more pages. |
| 1328 | * |
| 1329 | * TODO: have some parser search vmlinux before |
| 1330 | * final linking to find all calls to ftrace. |
| 1331 | * Then we can: |
| 1332 | * a) know how many pages to allocate. |
| 1333 | * and/or |
| 1334 | * b) set up the table then. |
| 1335 | * |
| 1336 | * The dynamic code is still necessary for |
| 1337 | * modules. |
| 1338 | */ |
| 1339 | |
| 1340 | pg = ftrace_pages = ftrace_pages_start; |
| 1341 | |
| 1342 | cnt = num_to_init / ENTRIES_PER_PAGE; |
| 1343 | pr_info("ftrace: allocating %ld entries in %d pages\n", |
| 1344 | num_to_init, cnt + 1); |
| 1345 | |
| 1346 | for (i = 0; i < cnt; i++) { |
| 1347 | pg->next = (void *)get_zeroed_page(GFP_KERNEL); |
| 1348 | |
| 1349 | /* If we fail, we'll try later anyway */ |
| 1350 | if (!pg->next) |
| 1351 | break; |
| 1352 | |
| 1353 | pg = pg->next; |
| 1354 | } |
| 1355 | |
| 1356 | return 0; |
| 1357 | } |
| 1358 | |
| 1359 | enum { |
| 1360 | FTRACE_ITER_FILTER = (1 << 0), |
| 1361 | FTRACE_ITER_CONT = (1 << 1), |
| 1362 | FTRACE_ITER_NOTRACE = (1 << 2), |
| 1363 | FTRACE_ITER_FAILURES = (1 << 3), |
| 1364 | FTRACE_ITER_PRINTALL = (1 << 4), |
| 1365 | FTRACE_ITER_HASH = (1 << 5), |
| 1366 | }; |
| 1367 | |
| 1368 | #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */ |
| 1369 | |
| 1370 | struct ftrace_iterator { |
| 1371 | struct ftrace_page *pg; |
| 1372 | int hidx; |
| 1373 | int idx; |
| 1374 | unsigned flags; |
| 1375 | unsigned char buffer[FTRACE_BUFF_MAX+1]; |
| 1376 | unsigned buffer_idx; |
| 1377 | unsigned filtered; |
| 1378 | }; |
| 1379 | |
| 1380 | static void * |
| 1381 | t_hash_next(struct seq_file *m, void *v, loff_t *pos) |
| 1382 | { |
| 1383 | struct ftrace_iterator *iter = m->private; |
| 1384 | struct hlist_node *hnd = v; |
| 1385 | struct hlist_head *hhd; |
| 1386 | |
| 1387 | WARN_ON(!(iter->flags & FTRACE_ITER_HASH)); |
| 1388 | |
| 1389 | (*pos)++; |
| 1390 | |
| 1391 | retry: |
| 1392 | if (iter->hidx >= FTRACE_FUNC_HASHSIZE) |
| 1393 | return NULL; |
| 1394 | |
| 1395 | hhd = &ftrace_func_hash[iter->hidx]; |
| 1396 | |
| 1397 | if (hlist_empty(hhd)) { |
| 1398 | iter->hidx++; |
| 1399 | hnd = NULL; |
| 1400 | goto retry; |
| 1401 | } |
| 1402 | |
| 1403 | if (!hnd) |
| 1404 | hnd = hhd->first; |
| 1405 | else { |
| 1406 | hnd = hnd->next; |
| 1407 | if (!hnd) { |
| 1408 | iter->hidx++; |
| 1409 | goto retry; |
| 1410 | } |
| 1411 | } |
| 1412 | |
| 1413 | return hnd; |
| 1414 | } |
| 1415 | |
| 1416 | static void *t_hash_start(struct seq_file *m, loff_t *pos) |
| 1417 | { |
| 1418 | struct ftrace_iterator *iter = m->private; |
| 1419 | void *p = NULL; |
| 1420 | |
| 1421 | iter->flags |= FTRACE_ITER_HASH; |
| 1422 | |
| 1423 | return t_hash_next(m, p, pos); |
| 1424 | } |
| 1425 | |
| 1426 | static int t_hash_show(struct seq_file *m, void *v) |
| 1427 | { |
| 1428 | struct ftrace_func_probe *rec; |
| 1429 | struct hlist_node *hnd = v; |
| 1430 | char str[KSYM_SYMBOL_LEN]; |
| 1431 | |
| 1432 | rec = hlist_entry(hnd, struct ftrace_func_probe, node); |
| 1433 | |
| 1434 | if (rec->ops->print) |
| 1435 | return rec->ops->print(m, rec->ip, rec->ops, rec->data); |
| 1436 | |
| 1437 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); |
| 1438 | seq_printf(m, "%s:", str); |
| 1439 | |
| 1440 | kallsyms_lookup((unsigned long)rec->ops->func, NULL, NULL, NULL, str); |
| 1441 | seq_printf(m, "%s", str); |
| 1442 | |
| 1443 | if (rec->data) |
| 1444 | seq_printf(m, ":%p", rec->data); |
| 1445 | seq_putc(m, '\n'); |
| 1446 | |
| 1447 | return 0; |
| 1448 | } |
| 1449 | |
| 1450 | static void * |
| 1451 | t_next(struct seq_file *m, void *v, loff_t *pos) |
| 1452 | { |
| 1453 | struct ftrace_iterator *iter = m->private; |
| 1454 | struct dyn_ftrace *rec = NULL; |
| 1455 | |
| 1456 | if (iter->flags & FTRACE_ITER_HASH) |
| 1457 | return t_hash_next(m, v, pos); |
| 1458 | |
| 1459 | (*pos)++; |
| 1460 | |
| 1461 | if (iter->flags & FTRACE_ITER_PRINTALL) |
| 1462 | return NULL; |
| 1463 | |
| 1464 | retry: |
| 1465 | if (iter->idx >= iter->pg->index) { |
| 1466 | if (iter->pg->next) { |
| 1467 | iter->pg = iter->pg->next; |
| 1468 | iter->idx = 0; |
| 1469 | goto retry; |
| 1470 | } |
| 1471 | } else { |
| 1472 | rec = &iter->pg->records[iter->idx++]; |
| 1473 | if ((rec->flags & FTRACE_FL_FREE) || |
| 1474 | |
| 1475 | (!(iter->flags & FTRACE_ITER_FAILURES) && |
| 1476 | (rec->flags & FTRACE_FL_FAILED)) || |
| 1477 | |
| 1478 | ((iter->flags & FTRACE_ITER_FAILURES) && |
| 1479 | !(rec->flags & FTRACE_FL_FAILED)) || |
| 1480 | |
| 1481 | ((iter->flags & FTRACE_ITER_FILTER) && |
| 1482 | !(rec->flags & FTRACE_FL_FILTER)) || |
| 1483 | |
| 1484 | ((iter->flags & FTRACE_ITER_NOTRACE) && |
| 1485 | !(rec->flags & FTRACE_FL_NOTRACE))) { |
| 1486 | rec = NULL; |
| 1487 | goto retry; |
| 1488 | } |
| 1489 | } |
| 1490 | |
| 1491 | return rec; |
| 1492 | } |
| 1493 | |
| 1494 | static void *t_start(struct seq_file *m, loff_t *pos) |
| 1495 | { |
| 1496 | struct ftrace_iterator *iter = m->private; |
| 1497 | void *p = NULL; |
| 1498 | loff_t l; |
| 1499 | |
| 1500 | mutex_lock(&ftrace_lock); |
| 1501 | /* |
| 1502 | * For set_ftrace_filter reading, if we have the filter |
| 1503 | * off, we can short cut and just print out that all |
| 1504 | * functions are enabled. |
| 1505 | */ |
| 1506 | if (iter->flags & FTRACE_ITER_FILTER && !ftrace_filtered) { |
| 1507 | if (*pos > 0) |
| 1508 | return t_hash_start(m, pos); |
| 1509 | iter->flags |= FTRACE_ITER_PRINTALL; |
| 1510 | return iter; |
| 1511 | } |
| 1512 | |
| 1513 | if (iter->flags & FTRACE_ITER_HASH) |
| 1514 | return t_hash_start(m, pos); |
| 1515 | |
| 1516 | iter->pg = ftrace_pages_start; |
| 1517 | iter->idx = 0; |
| 1518 | for (l = 0; l <= *pos; ) { |
| 1519 | p = t_next(m, p, &l); |
| 1520 | if (!p) |
| 1521 | break; |
| 1522 | } |
| 1523 | |
| 1524 | if (!p && iter->flags & FTRACE_ITER_FILTER) |
| 1525 | return t_hash_start(m, pos); |
| 1526 | |
| 1527 | return p; |
| 1528 | } |
| 1529 | |
| 1530 | static void t_stop(struct seq_file *m, void *p) |
| 1531 | { |
| 1532 | mutex_unlock(&ftrace_lock); |
| 1533 | } |
| 1534 | |
| 1535 | static int t_show(struct seq_file *m, void *v) |
| 1536 | { |
| 1537 | struct ftrace_iterator *iter = m->private; |
| 1538 | struct dyn_ftrace *rec = v; |
| 1539 | char str[KSYM_SYMBOL_LEN]; |
| 1540 | |
| 1541 | if (iter->flags & FTRACE_ITER_HASH) |
| 1542 | return t_hash_show(m, v); |
| 1543 | |
| 1544 | if (iter->flags & FTRACE_ITER_PRINTALL) { |
| 1545 | seq_printf(m, "#### all functions enabled ####\n"); |
| 1546 | return 0; |
| 1547 | } |
| 1548 | |
| 1549 | if (!rec) |
| 1550 | return 0; |
| 1551 | |
| 1552 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); |
| 1553 | |
| 1554 | seq_printf(m, "%s\n", str); |
| 1555 | |
| 1556 | return 0; |
| 1557 | } |
| 1558 | |
| 1559 | static struct seq_operations show_ftrace_seq_ops = { |
| 1560 | .start = t_start, |
| 1561 | .next = t_next, |
| 1562 | .stop = t_stop, |
| 1563 | .show = t_show, |
| 1564 | }; |
| 1565 | |
| 1566 | static int |
| 1567 | ftrace_avail_open(struct inode *inode, struct file *file) |
| 1568 | { |
| 1569 | struct ftrace_iterator *iter; |
| 1570 | int ret; |
| 1571 | |
| 1572 | if (unlikely(ftrace_disabled)) |
| 1573 | return -ENODEV; |
| 1574 | |
| 1575 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
| 1576 | if (!iter) |
| 1577 | return -ENOMEM; |
| 1578 | |
| 1579 | iter->pg = ftrace_pages_start; |
| 1580 | |
| 1581 | ret = seq_open(file, &show_ftrace_seq_ops); |
| 1582 | if (!ret) { |
| 1583 | struct seq_file *m = file->private_data; |
| 1584 | |
| 1585 | m->private = iter; |
| 1586 | } else { |
| 1587 | kfree(iter); |
| 1588 | } |
| 1589 | |
| 1590 | return ret; |
| 1591 | } |
| 1592 | |
| 1593 | int ftrace_avail_release(struct inode *inode, struct file *file) |
| 1594 | { |
| 1595 | struct seq_file *m = (struct seq_file *)file->private_data; |
| 1596 | struct ftrace_iterator *iter = m->private; |
| 1597 | |
| 1598 | seq_release(inode, file); |
| 1599 | kfree(iter); |
| 1600 | |
| 1601 | return 0; |
| 1602 | } |
| 1603 | |
| 1604 | static int |
| 1605 | ftrace_failures_open(struct inode *inode, struct file *file) |
| 1606 | { |
| 1607 | int ret; |
| 1608 | struct seq_file *m; |
| 1609 | struct ftrace_iterator *iter; |
| 1610 | |
| 1611 | ret = ftrace_avail_open(inode, file); |
| 1612 | if (!ret) { |
| 1613 | m = (struct seq_file *)file->private_data; |
| 1614 | iter = (struct ftrace_iterator *)m->private; |
| 1615 | iter->flags = FTRACE_ITER_FAILURES; |
| 1616 | } |
| 1617 | |
| 1618 | return ret; |
| 1619 | } |
| 1620 | |
| 1621 | |
| 1622 | static void ftrace_filter_reset(int enable) |
| 1623 | { |
| 1624 | struct ftrace_page *pg; |
| 1625 | struct dyn_ftrace *rec; |
| 1626 | unsigned long type = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
| 1627 | |
| 1628 | mutex_lock(&ftrace_lock); |
| 1629 | if (enable) |
| 1630 | ftrace_filtered = 0; |
| 1631 | do_for_each_ftrace_rec(pg, rec) { |
| 1632 | if (rec->flags & FTRACE_FL_FAILED) |
| 1633 | continue; |
| 1634 | rec->flags &= ~type; |
| 1635 | } while_for_each_ftrace_rec(); |
| 1636 | mutex_unlock(&ftrace_lock); |
| 1637 | } |
| 1638 | |
| 1639 | static int |
| 1640 | ftrace_regex_open(struct inode *inode, struct file *file, int enable) |
| 1641 | { |
| 1642 | struct ftrace_iterator *iter; |
| 1643 | int ret = 0; |
| 1644 | |
| 1645 | if (unlikely(ftrace_disabled)) |
| 1646 | return -ENODEV; |
| 1647 | |
| 1648 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
| 1649 | if (!iter) |
| 1650 | return -ENOMEM; |
| 1651 | |
| 1652 | mutex_lock(&ftrace_regex_lock); |
| 1653 | if ((file->f_mode & FMODE_WRITE) && |
| 1654 | !(file->f_flags & O_APPEND)) |
| 1655 | ftrace_filter_reset(enable); |
| 1656 | |
| 1657 | if (file->f_mode & FMODE_READ) { |
| 1658 | iter->pg = ftrace_pages_start; |
| 1659 | iter->flags = enable ? FTRACE_ITER_FILTER : |
| 1660 | FTRACE_ITER_NOTRACE; |
| 1661 | |
| 1662 | ret = seq_open(file, &show_ftrace_seq_ops); |
| 1663 | if (!ret) { |
| 1664 | struct seq_file *m = file->private_data; |
| 1665 | m->private = iter; |
| 1666 | } else |
| 1667 | kfree(iter); |
| 1668 | } else |
| 1669 | file->private_data = iter; |
| 1670 | mutex_unlock(&ftrace_regex_lock); |
| 1671 | |
| 1672 | return ret; |
| 1673 | } |
| 1674 | |
| 1675 | static int |
| 1676 | ftrace_filter_open(struct inode *inode, struct file *file) |
| 1677 | { |
| 1678 | return ftrace_regex_open(inode, file, 1); |
| 1679 | } |
| 1680 | |
| 1681 | static int |
| 1682 | ftrace_notrace_open(struct inode *inode, struct file *file) |
| 1683 | { |
| 1684 | return ftrace_regex_open(inode, file, 0); |
| 1685 | } |
| 1686 | |
| 1687 | static loff_t |
| 1688 | ftrace_regex_lseek(struct file *file, loff_t offset, int origin) |
| 1689 | { |
| 1690 | loff_t ret; |
| 1691 | |
| 1692 | if (file->f_mode & FMODE_READ) |
| 1693 | ret = seq_lseek(file, offset, origin); |
| 1694 | else |
| 1695 | file->f_pos = ret = 1; |
| 1696 | |
| 1697 | return ret; |
| 1698 | } |
| 1699 | |
| 1700 | enum { |
| 1701 | MATCH_FULL, |
| 1702 | MATCH_FRONT_ONLY, |
| 1703 | MATCH_MIDDLE_ONLY, |
| 1704 | MATCH_END_ONLY, |
| 1705 | }; |
| 1706 | |
| 1707 | /* |
| 1708 | * (static function - no need for kernel doc) |
| 1709 | * |
| 1710 | * Pass in a buffer containing a glob and this function will |
| 1711 | * set search to point to the search part of the buffer and |
| 1712 | * return the type of search it is (see enum above). |
| 1713 | * This does modify buff. |
| 1714 | * |
| 1715 | * Returns enum type. |
| 1716 | * search returns the pointer to use for comparison. |
| 1717 | * not returns 1 if buff started with a '!' |
| 1718 | * 0 otherwise. |
| 1719 | */ |
| 1720 | static int |
| 1721 | ftrace_setup_glob(char *buff, int len, char **search, int *not) |
| 1722 | { |
| 1723 | int type = MATCH_FULL; |
| 1724 | int i; |
| 1725 | |
| 1726 | if (buff[0] == '!') { |
| 1727 | *not = 1; |
| 1728 | buff++; |
| 1729 | len--; |
| 1730 | } else |
| 1731 | *not = 0; |
| 1732 | |
| 1733 | *search = buff; |
| 1734 | |
| 1735 | for (i = 0; i < len; i++) { |
| 1736 | if (buff[i] == '*') { |
| 1737 | if (!i) { |
| 1738 | *search = buff + 1; |
| 1739 | type = MATCH_END_ONLY; |
| 1740 | } else { |
| 1741 | if (type == MATCH_END_ONLY) |
| 1742 | type = MATCH_MIDDLE_ONLY; |
| 1743 | else |
| 1744 | type = MATCH_FRONT_ONLY; |
| 1745 | buff[i] = 0; |
| 1746 | break; |
| 1747 | } |
| 1748 | } |
| 1749 | } |
| 1750 | |
| 1751 | return type; |
| 1752 | } |
| 1753 | |
| 1754 | static int ftrace_match(char *str, char *regex, int len, int type) |
| 1755 | { |
| 1756 | int matched = 0; |
| 1757 | char *ptr; |
| 1758 | |
| 1759 | switch (type) { |
| 1760 | case MATCH_FULL: |
| 1761 | if (strcmp(str, regex) == 0) |
| 1762 | matched = 1; |
| 1763 | break; |
| 1764 | case MATCH_FRONT_ONLY: |
| 1765 | if (strncmp(str, regex, len) == 0) |
| 1766 | matched = 1; |
| 1767 | break; |
| 1768 | case MATCH_MIDDLE_ONLY: |
| 1769 | if (strstr(str, regex)) |
| 1770 | matched = 1; |
| 1771 | break; |
| 1772 | case MATCH_END_ONLY: |
| 1773 | ptr = strstr(str, regex); |
| 1774 | if (ptr && (ptr[len] == 0)) |
| 1775 | matched = 1; |
| 1776 | break; |
| 1777 | } |
| 1778 | |
| 1779 | return matched; |
| 1780 | } |
| 1781 | |
| 1782 | static int |
| 1783 | ftrace_match_record(struct dyn_ftrace *rec, char *regex, int len, int type) |
| 1784 | { |
| 1785 | char str[KSYM_SYMBOL_LEN]; |
| 1786 | |
| 1787 | kallsyms_lookup(rec->ip, NULL, NULL, NULL, str); |
| 1788 | return ftrace_match(str, regex, len, type); |
| 1789 | } |
| 1790 | |
| 1791 | static void ftrace_match_records(char *buff, int len, int enable) |
| 1792 | { |
| 1793 | unsigned int search_len; |
| 1794 | struct ftrace_page *pg; |
| 1795 | struct dyn_ftrace *rec; |
| 1796 | unsigned long flag; |
| 1797 | char *search; |
| 1798 | int type; |
| 1799 | int not; |
| 1800 | |
| 1801 | flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
| 1802 | type = ftrace_setup_glob(buff, len, &search, ¬); |
| 1803 | |
| 1804 | search_len = strlen(search); |
| 1805 | |
| 1806 | mutex_lock(&ftrace_lock); |
| 1807 | do_for_each_ftrace_rec(pg, rec) { |
| 1808 | |
| 1809 | if (rec->flags & FTRACE_FL_FAILED) |
| 1810 | continue; |
| 1811 | |
| 1812 | if (ftrace_match_record(rec, search, search_len, type)) { |
| 1813 | if (not) |
| 1814 | rec->flags &= ~flag; |
| 1815 | else |
| 1816 | rec->flags |= flag; |
| 1817 | } |
| 1818 | /* |
| 1819 | * Only enable filtering if we have a function that |
| 1820 | * is filtered on. |
| 1821 | */ |
| 1822 | if (enable && (rec->flags & FTRACE_FL_FILTER)) |
| 1823 | ftrace_filtered = 1; |
| 1824 | } while_for_each_ftrace_rec(); |
| 1825 | mutex_unlock(&ftrace_lock); |
| 1826 | } |
| 1827 | |
| 1828 | static int |
| 1829 | ftrace_match_module_record(struct dyn_ftrace *rec, char *mod, |
| 1830 | char *regex, int len, int type) |
| 1831 | { |
| 1832 | char str[KSYM_SYMBOL_LEN]; |
| 1833 | char *modname; |
| 1834 | |
| 1835 | kallsyms_lookup(rec->ip, NULL, NULL, &modname, str); |
| 1836 | |
| 1837 | if (!modname || strcmp(modname, mod)) |
| 1838 | return 0; |
| 1839 | |
| 1840 | /* blank search means to match all funcs in the mod */ |
| 1841 | if (len) |
| 1842 | return ftrace_match(str, regex, len, type); |
| 1843 | else |
| 1844 | return 1; |
| 1845 | } |
| 1846 | |
| 1847 | static void ftrace_match_module_records(char *buff, char *mod, int enable) |
| 1848 | { |
| 1849 | unsigned search_len = 0; |
| 1850 | struct ftrace_page *pg; |
| 1851 | struct dyn_ftrace *rec; |
| 1852 | int type = MATCH_FULL; |
| 1853 | char *search = buff; |
| 1854 | unsigned long flag; |
| 1855 | int not = 0; |
| 1856 | |
| 1857 | flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; |
| 1858 | |
| 1859 | /* blank or '*' mean the same */ |
| 1860 | if (strcmp(buff, "*") == 0) |
| 1861 | buff[0] = 0; |
| 1862 | |
| 1863 | /* handle the case of 'dont filter this module' */ |
| 1864 | if (strcmp(buff, "!") == 0 || strcmp(buff, "!*") == 0) { |
| 1865 | buff[0] = 0; |
| 1866 | not = 1; |
| 1867 | } |
| 1868 | |
| 1869 | if (strlen(buff)) { |
| 1870 | type = ftrace_setup_glob(buff, strlen(buff), &search, ¬); |
| 1871 | search_len = strlen(search); |
| 1872 | } |
| 1873 | |
| 1874 | mutex_lock(&ftrace_lock); |
| 1875 | do_for_each_ftrace_rec(pg, rec) { |
| 1876 | |
| 1877 | if (rec->flags & FTRACE_FL_FAILED) |
| 1878 | continue; |
| 1879 | |
| 1880 | if (ftrace_match_module_record(rec, mod, |
| 1881 | search, search_len, type)) { |
| 1882 | if (not) |
| 1883 | rec->flags &= ~flag; |
| 1884 | else |
| 1885 | rec->flags |= flag; |
| 1886 | } |
| 1887 | if (enable && (rec->flags & FTRACE_FL_FILTER)) |
| 1888 | ftrace_filtered = 1; |
| 1889 | |
| 1890 | } while_for_each_ftrace_rec(); |
| 1891 | mutex_unlock(&ftrace_lock); |
| 1892 | } |
| 1893 | |
| 1894 | /* |
| 1895 | * We register the module command as a template to show others how |
| 1896 | * to register the a command as well. |
| 1897 | */ |
| 1898 | |
| 1899 | static int |
| 1900 | ftrace_mod_callback(char *func, char *cmd, char *param, int enable) |
| 1901 | { |
| 1902 | char *mod; |
| 1903 | |
| 1904 | /* |
| 1905 | * cmd == 'mod' because we only registered this func |
| 1906 | * for the 'mod' ftrace_func_command. |
| 1907 | * But if you register one func with multiple commands, |
| 1908 | * you can tell which command was used by the cmd |
| 1909 | * parameter. |
| 1910 | */ |
| 1911 | |
| 1912 | /* we must have a module name */ |
| 1913 | if (!param) |
| 1914 | return -EINVAL; |
| 1915 | |
| 1916 | mod = strsep(¶m, ":"); |
| 1917 | if (!strlen(mod)) |
| 1918 | return -EINVAL; |
| 1919 | |
| 1920 | ftrace_match_module_records(func, mod, enable); |
| 1921 | return 0; |
| 1922 | } |
| 1923 | |
| 1924 | static struct ftrace_func_command ftrace_mod_cmd = { |
| 1925 | .name = "mod", |
| 1926 | .func = ftrace_mod_callback, |
| 1927 | }; |
| 1928 | |
| 1929 | static int __init ftrace_mod_cmd_init(void) |
| 1930 | { |
| 1931 | return register_ftrace_command(&ftrace_mod_cmd); |
| 1932 | } |
| 1933 | device_initcall(ftrace_mod_cmd_init); |
| 1934 | |
| 1935 | static void |
| 1936 | function_trace_probe_call(unsigned long ip, unsigned long parent_ip) |
| 1937 | { |
| 1938 | struct ftrace_func_probe *entry; |
| 1939 | struct hlist_head *hhd; |
| 1940 | struct hlist_node *n; |
| 1941 | unsigned long key; |
| 1942 | int resched; |
| 1943 | |
| 1944 | key = hash_long(ip, FTRACE_HASH_BITS); |
| 1945 | |
| 1946 | hhd = &ftrace_func_hash[key]; |
| 1947 | |
| 1948 | if (hlist_empty(hhd)) |
| 1949 | return; |
| 1950 | |
| 1951 | /* |
| 1952 | * Disable preemption for these calls to prevent a RCU grace |
| 1953 | * period. This syncs the hash iteration and freeing of items |
| 1954 | * on the hash. rcu_read_lock is too dangerous here. |
| 1955 | */ |
| 1956 | resched = ftrace_preempt_disable(); |
| 1957 | hlist_for_each_entry_rcu(entry, n, hhd, node) { |
| 1958 | if (entry->ip == ip) |
| 1959 | entry->ops->func(ip, parent_ip, &entry->data); |
| 1960 | } |
| 1961 | ftrace_preempt_enable(resched); |
| 1962 | } |
| 1963 | |
| 1964 | static struct ftrace_ops trace_probe_ops __read_mostly = |
| 1965 | { |
| 1966 | .func = function_trace_probe_call, |
| 1967 | }; |
| 1968 | |
| 1969 | static int ftrace_probe_registered; |
| 1970 | |
| 1971 | static void __enable_ftrace_function_probe(void) |
| 1972 | { |
| 1973 | int i; |
| 1974 | |
| 1975 | if (ftrace_probe_registered) |
| 1976 | return; |
| 1977 | |
| 1978 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { |
| 1979 | struct hlist_head *hhd = &ftrace_func_hash[i]; |
| 1980 | if (hhd->first) |
| 1981 | break; |
| 1982 | } |
| 1983 | /* Nothing registered? */ |
| 1984 | if (i == FTRACE_FUNC_HASHSIZE) |
| 1985 | return; |
| 1986 | |
| 1987 | __register_ftrace_function(&trace_probe_ops); |
| 1988 | ftrace_startup(0); |
| 1989 | ftrace_probe_registered = 1; |
| 1990 | } |
| 1991 | |
| 1992 | static void __disable_ftrace_function_probe(void) |
| 1993 | { |
| 1994 | int i; |
| 1995 | |
| 1996 | if (!ftrace_probe_registered) |
| 1997 | return; |
| 1998 | |
| 1999 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { |
| 2000 | struct hlist_head *hhd = &ftrace_func_hash[i]; |
| 2001 | if (hhd->first) |
| 2002 | return; |
| 2003 | } |
| 2004 | |
| 2005 | /* no more funcs left */ |
| 2006 | __unregister_ftrace_function(&trace_probe_ops); |
| 2007 | ftrace_shutdown(0); |
| 2008 | ftrace_probe_registered = 0; |
| 2009 | } |
| 2010 | |
| 2011 | |
| 2012 | static void ftrace_free_entry_rcu(struct rcu_head *rhp) |
| 2013 | { |
| 2014 | struct ftrace_func_probe *entry = |
| 2015 | container_of(rhp, struct ftrace_func_probe, rcu); |
| 2016 | |
| 2017 | if (entry->ops->free) |
| 2018 | entry->ops->free(&entry->data); |
| 2019 | kfree(entry); |
| 2020 | } |
| 2021 | |
| 2022 | |
| 2023 | int |
| 2024 | register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
| 2025 | void *data) |
| 2026 | { |
| 2027 | struct ftrace_func_probe *entry; |
| 2028 | struct ftrace_page *pg; |
| 2029 | struct dyn_ftrace *rec; |
| 2030 | int type, len, not; |
| 2031 | unsigned long key; |
| 2032 | int count = 0; |
| 2033 | char *search; |
| 2034 | |
| 2035 | type = ftrace_setup_glob(glob, strlen(glob), &search, ¬); |
| 2036 | len = strlen(search); |
| 2037 | |
| 2038 | /* we do not support '!' for function probes */ |
| 2039 | if (WARN_ON(not)) |
| 2040 | return -EINVAL; |
| 2041 | |
| 2042 | mutex_lock(&ftrace_lock); |
| 2043 | do_for_each_ftrace_rec(pg, rec) { |
| 2044 | |
| 2045 | if (rec->flags & FTRACE_FL_FAILED) |
| 2046 | continue; |
| 2047 | |
| 2048 | if (!ftrace_match_record(rec, search, len, type)) |
| 2049 | continue; |
| 2050 | |
| 2051 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); |
| 2052 | if (!entry) { |
| 2053 | /* If we did not process any, then return error */ |
| 2054 | if (!count) |
| 2055 | count = -ENOMEM; |
| 2056 | goto out_unlock; |
| 2057 | } |
| 2058 | |
| 2059 | count++; |
| 2060 | |
| 2061 | entry->data = data; |
| 2062 | |
| 2063 | /* |
| 2064 | * The caller might want to do something special |
| 2065 | * for each function we find. We call the callback |
| 2066 | * to give the caller an opportunity to do so. |
| 2067 | */ |
| 2068 | if (ops->callback) { |
| 2069 | if (ops->callback(rec->ip, &entry->data) < 0) { |
| 2070 | /* caller does not like this func */ |
| 2071 | kfree(entry); |
| 2072 | continue; |
| 2073 | } |
| 2074 | } |
| 2075 | |
| 2076 | entry->ops = ops; |
| 2077 | entry->ip = rec->ip; |
| 2078 | |
| 2079 | key = hash_long(entry->ip, FTRACE_HASH_BITS); |
| 2080 | hlist_add_head_rcu(&entry->node, &ftrace_func_hash[key]); |
| 2081 | |
| 2082 | } while_for_each_ftrace_rec(); |
| 2083 | __enable_ftrace_function_probe(); |
| 2084 | |
| 2085 | out_unlock: |
| 2086 | mutex_unlock(&ftrace_lock); |
| 2087 | |
| 2088 | return count; |
| 2089 | } |
| 2090 | |
| 2091 | enum { |
| 2092 | PROBE_TEST_FUNC = 1, |
| 2093 | PROBE_TEST_DATA = 2 |
| 2094 | }; |
| 2095 | |
| 2096 | static void |
| 2097 | __unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
| 2098 | void *data, int flags) |
| 2099 | { |
| 2100 | struct ftrace_func_probe *entry; |
| 2101 | struct hlist_node *n, *tmp; |
| 2102 | char str[KSYM_SYMBOL_LEN]; |
| 2103 | int type = MATCH_FULL; |
| 2104 | int i, len = 0; |
| 2105 | char *search; |
| 2106 | |
| 2107 | if (glob && (strcmp(glob, "*") || !strlen(glob))) |
| 2108 | glob = NULL; |
| 2109 | else { |
| 2110 | int not; |
| 2111 | |
| 2112 | type = ftrace_setup_glob(glob, strlen(glob), &search, ¬); |
| 2113 | len = strlen(search); |
| 2114 | |
| 2115 | /* we do not support '!' for function probes */ |
| 2116 | if (WARN_ON(not)) |
| 2117 | return; |
| 2118 | } |
| 2119 | |
| 2120 | mutex_lock(&ftrace_lock); |
| 2121 | for (i = 0; i < FTRACE_FUNC_HASHSIZE; i++) { |
| 2122 | struct hlist_head *hhd = &ftrace_func_hash[i]; |
| 2123 | |
| 2124 | hlist_for_each_entry_safe(entry, n, tmp, hhd, node) { |
| 2125 | |
| 2126 | /* break up if statements for readability */ |
| 2127 | if ((flags & PROBE_TEST_FUNC) && entry->ops != ops) |
| 2128 | continue; |
| 2129 | |
| 2130 | if ((flags & PROBE_TEST_DATA) && entry->data != data) |
| 2131 | continue; |
| 2132 | |
| 2133 | /* do this last, since it is the most expensive */ |
| 2134 | if (glob) { |
| 2135 | kallsyms_lookup(entry->ip, NULL, NULL, |
| 2136 | NULL, str); |
| 2137 | if (!ftrace_match(str, glob, len, type)) |
| 2138 | continue; |
| 2139 | } |
| 2140 | |
| 2141 | hlist_del(&entry->node); |
| 2142 | call_rcu(&entry->rcu, ftrace_free_entry_rcu); |
| 2143 | } |
| 2144 | } |
| 2145 | __disable_ftrace_function_probe(); |
| 2146 | mutex_unlock(&ftrace_lock); |
| 2147 | } |
| 2148 | |
| 2149 | void |
| 2150 | unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops, |
| 2151 | void *data) |
| 2152 | { |
| 2153 | __unregister_ftrace_function_probe(glob, ops, data, |
| 2154 | PROBE_TEST_FUNC | PROBE_TEST_DATA); |
| 2155 | } |
| 2156 | |
| 2157 | void |
| 2158 | unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops) |
| 2159 | { |
| 2160 | __unregister_ftrace_function_probe(glob, ops, NULL, PROBE_TEST_FUNC); |
| 2161 | } |
| 2162 | |
| 2163 | void unregister_ftrace_function_probe_all(char *glob) |
| 2164 | { |
| 2165 | __unregister_ftrace_function_probe(glob, NULL, NULL, 0); |
| 2166 | } |
| 2167 | |
| 2168 | static LIST_HEAD(ftrace_commands); |
| 2169 | static DEFINE_MUTEX(ftrace_cmd_mutex); |
| 2170 | |
| 2171 | int register_ftrace_command(struct ftrace_func_command *cmd) |
| 2172 | { |
| 2173 | struct ftrace_func_command *p; |
| 2174 | int ret = 0; |
| 2175 | |
| 2176 | mutex_lock(&ftrace_cmd_mutex); |
| 2177 | list_for_each_entry(p, &ftrace_commands, list) { |
| 2178 | if (strcmp(cmd->name, p->name) == 0) { |
| 2179 | ret = -EBUSY; |
| 2180 | goto out_unlock; |
| 2181 | } |
| 2182 | } |
| 2183 | list_add(&cmd->list, &ftrace_commands); |
| 2184 | out_unlock: |
| 2185 | mutex_unlock(&ftrace_cmd_mutex); |
| 2186 | |
| 2187 | return ret; |
| 2188 | } |
| 2189 | |
| 2190 | int unregister_ftrace_command(struct ftrace_func_command *cmd) |
| 2191 | { |
| 2192 | struct ftrace_func_command *p, *n; |
| 2193 | int ret = -ENODEV; |
| 2194 | |
| 2195 | mutex_lock(&ftrace_cmd_mutex); |
| 2196 | list_for_each_entry_safe(p, n, &ftrace_commands, list) { |
| 2197 | if (strcmp(cmd->name, p->name) == 0) { |
| 2198 | ret = 0; |
| 2199 | list_del_init(&p->list); |
| 2200 | goto out_unlock; |
| 2201 | } |
| 2202 | } |
| 2203 | out_unlock: |
| 2204 | mutex_unlock(&ftrace_cmd_mutex); |
| 2205 | |
| 2206 | return ret; |
| 2207 | } |
| 2208 | |
| 2209 | static int ftrace_process_regex(char *buff, int len, int enable) |
| 2210 | { |
| 2211 | char *func, *command, *next = buff; |
| 2212 | struct ftrace_func_command *p; |
| 2213 | int ret = -EINVAL; |
| 2214 | |
| 2215 | func = strsep(&next, ":"); |
| 2216 | |
| 2217 | if (!next) { |
| 2218 | ftrace_match_records(func, len, enable); |
| 2219 | return 0; |
| 2220 | } |
| 2221 | |
| 2222 | /* command found */ |
| 2223 | |
| 2224 | command = strsep(&next, ":"); |
| 2225 | |
| 2226 | mutex_lock(&ftrace_cmd_mutex); |
| 2227 | list_for_each_entry(p, &ftrace_commands, list) { |
| 2228 | if (strcmp(p->name, command) == 0) { |
| 2229 | ret = p->func(func, command, next, enable); |
| 2230 | goto out_unlock; |
| 2231 | } |
| 2232 | } |
| 2233 | out_unlock: |
| 2234 | mutex_unlock(&ftrace_cmd_mutex); |
| 2235 | |
| 2236 | return ret; |
| 2237 | } |
| 2238 | |
| 2239 | static ssize_t |
| 2240 | ftrace_regex_write(struct file *file, const char __user *ubuf, |
| 2241 | size_t cnt, loff_t *ppos, int enable) |
| 2242 | { |
| 2243 | struct ftrace_iterator *iter; |
| 2244 | char ch; |
| 2245 | size_t read = 0; |
| 2246 | ssize_t ret; |
| 2247 | |
| 2248 | if (!cnt || cnt < 0) |
| 2249 | return 0; |
| 2250 | |
| 2251 | mutex_lock(&ftrace_regex_lock); |
| 2252 | |
| 2253 | if (file->f_mode & FMODE_READ) { |
| 2254 | struct seq_file *m = file->private_data; |
| 2255 | iter = m->private; |
| 2256 | } else |
| 2257 | iter = file->private_data; |
| 2258 | |
| 2259 | if (!*ppos) { |
| 2260 | iter->flags &= ~FTRACE_ITER_CONT; |
| 2261 | iter->buffer_idx = 0; |
| 2262 | } |
| 2263 | |
| 2264 | ret = get_user(ch, ubuf++); |
| 2265 | if (ret) |
| 2266 | goto out; |
| 2267 | read++; |
| 2268 | cnt--; |
| 2269 | |
| 2270 | if (!(iter->flags & ~FTRACE_ITER_CONT)) { |
| 2271 | /* skip white space */ |
| 2272 | while (cnt && isspace(ch)) { |
| 2273 | ret = get_user(ch, ubuf++); |
| 2274 | if (ret) |
| 2275 | goto out; |
| 2276 | read++; |
| 2277 | cnt--; |
| 2278 | } |
| 2279 | |
| 2280 | if (isspace(ch)) { |
| 2281 | file->f_pos += read; |
| 2282 | ret = read; |
| 2283 | goto out; |
| 2284 | } |
| 2285 | |
| 2286 | iter->buffer_idx = 0; |
| 2287 | } |
| 2288 | |
| 2289 | while (cnt && !isspace(ch)) { |
| 2290 | if (iter->buffer_idx < FTRACE_BUFF_MAX) |
| 2291 | iter->buffer[iter->buffer_idx++] = ch; |
| 2292 | else { |
| 2293 | ret = -EINVAL; |
| 2294 | goto out; |
| 2295 | } |
| 2296 | ret = get_user(ch, ubuf++); |
| 2297 | if (ret) |
| 2298 | goto out; |
| 2299 | read++; |
| 2300 | cnt--; |
| 2301 | } |
| 2302 | |
| 2303 | if (isspace(ch)) { |
| 2304 | iter->filtered++; |
| 2305 | iter->buffer[iter->buffer_idx] = 0; |
| 2306 | ret = ftrace_process_regex(iter->buffer, |
| 2307 | iter->buffer_idx, enable); |
| 2308 | if (ret) |
| 2309 | goto out; |
| 2310 | iter->buffer_idx = 0; |
| 2311 | } else |
| 2312 | iter->flags |= FTRACE_ITER_CONT; |
| 2313 | |
| 2314 | |
| 2315 | file->f_pos += read; |
| 2316 | |
| 2317 | ret = read; |
| 2318 | out: |
| 2319 | mutex_unlock(&ftrace_regex_lock); |
| 2320 | |
| 2321 | return ret; |
| 2322 | } |
| 2323 | |
| 2324 | static ssize_t |
| 2325 | ftrace_filter_write(struct file *file, const char __user *ubuf, |
| 2326 | size_t cnt, loff_t *ppos) |
| 2327 | { |
| 2328 | return ftrace_regex_write(file, ubuf, cnt, ppos, 1); |
| 2329 | } |
| 2330 | |
| 2331 | static ssize_t |
| 2332 | ftrace_notrace_write(struct file *file, const char __user *ubuf, |
| 2333 | size_t cnt, loff_t *ppos) |
| 2334 | { |
| 2335 | return ftrace_regex_write(file, ubuf, cnt, ppos, 0); |
| 2336 | } |
| 2337 | |
| 2338 | static void |
| 2339 | ftrace_set_regex(unsigned char *buf, int len, int reset, int enable) |
| 2340 | { |
| 2341 | if (unlikely(ftrace_disabled)) |
| 2342 | return; |
| 2343 | |
| 2344 | mutex_lock(&ftrace_regex_lock); |
| 2345 | if (reset) |
| 2346 | ftrace_filter_reset(enable); |
| 2347 | if (buf) |
| 2348 | ftrace_match_records(buf, len, enable); |
| 2349 | mutex_unlock(&ftrace_regex_lock); |
| 2350 | } |
| 2351 | |
| 2352 | /** |
| 2353 | * ftrace_set_filter - set a function to filter on in ftrace |
| 2354 | * @buf - the string that holds the function filter text. |
| 2355 | * @len - the length of the string. |
| 2356 | * @reset - non zero to reset all filters before applying this filter. |
| 2357 | * |
| 2358 | * Filters denote which functions should be enabled when tracing is enabled. |
| 2359 | * If @buf is NULL and reset is set, all functions will be enabled for tracing. |
| 2360 | */ |
| 2361 | void ftrace_set_filter(unsigned char *buf, int len, int reset) |
| 2362 | { |
| 2363 | ftrace_set_regex(buf, len, reset, 1); |
| 2364 | } |
| 2365 | |
| 2366 | /** |
| 2367 | * ftrace_set_notrace - set a function to not trace in ftrace |
| 2368 | * @buf - the string that holds the function notrace text. |
| 2369 | * @len - the length of the string. |
| 2370 | * @reset - non zero to reset all filters before applying this filter. |
| 2371 | * |
| 2372 | * Notrace Filters denote which functions should not be enabled when tracing |
| 2373 | * is enabled. If @buf is NULL and reset is set, all functions will be enabled |
| 2374 | * for tracing. |
| 2375 | */ |
| 2376 | void ftrace_set_notrace(unsigned char *buf, int len, int reset) |
| 2377 | { |
| 2378 | ftrace_set_regex(buf, len, reset, 0); |
| 2379 | } |
| 2380 | |
| 2381 | /* |
| 2382 | * command line interface to allow users to set filters on boot up. |
| 2383 | */ |
| 2384 | #define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE |
| 2385 | static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata; |
| 2386 | static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata; |
| 2387 | |
| 2388 | static int __init set_ftrace_notrace(char *str) |
| 2389 | { |
| 2390 | strncpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE); |
| 2391 | return 1; |
| 2392 | } |
| 2393 | __setup("ftrace_notrace=", set_ftrace_notrace); |
| 2394 | |
| 2395 | static int __init set_ftrace_filter(char *str) |
| 2396 | { |
| 2397 | strncpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE); |
| 2398 | return 1; |
| 2399 | } |
| 2400 | __setup("ftrace_filter=", set_ftrace_filter); |
| 2401 | |
| 2402 | static void __init set_ftrace_early_filter(char *buf, int enable) |
| 2403 | { |
| 2404 | char *func; |
| 2405 | |
| 2406 | while (buf) { |
| 2407 | func = strsep(&buf, ","); |
| 2408 | ftrace_set_regex(func, strlen(func), 0, enable); |
| 2409 | } |
| 2410 | } |
| 2411 | |
| 2412 | static void __init set_ftrace_early_filters(void) |
| 2413 | { |
| 2414 | if (ftrace_filter_buf[0]) |
| 2415 | set_ftrace_early_filter(ftrace_filter_buf, 1); |
| 2416 | if (ftrace_notrace_buf[0]) |
| 2417 | set_ftrace_early_filter(ftrace_notrace_buf, 0); |
| 2418 | } |
| 2419 | |
| 2420 | static int |
| 2421 | ftrace_regex_release(struct inode *inode, struct file *file, int enable) |
| 2422 | { |
| 2423 | struct seq_file *m = (struct seq_file *)file->private_data; |
| 2424 | struct ftrace_iterator *iter; |
| 2425 | |
| 2426 | mutex_lock(&ftrace_regex_lock); |
| 2427 | if (file->f_mode & FMODE_READ) { |
| 2428 | iter = m->private; |
| 2429 | |
| 2430 | seq_release(inode, file); |
| 2431 | } else |
| 2432 | iter = file->private_data; |
| 2433 | |
| 2434 | if (iter->buffer_idx) { |
| 2435 | iter->filtered++; |
| 2436 | iter->buffer[iter->buffer_idx] = 0; |
| 2437 | ftrace_match_records(iter->buffer, iter->buffer_idx, enable); |
| 2438 | } |
| 2439 | |
| 2440 | mutex_lock(&ftrace_lock); |
| 2441 | if (ftrace_start_up && ftrace_enabled) |
| 2442 | ftrace_run_update_code(FTRACE_ENABLE_CALLS); |
| 2443 | mutex_unlock(&ftrace_lock); |
| 2444 | |
| 2445 | kfree(iter); |
| 2446 | mutex_unlock(&ftrace_regex_lock); |
| 2447 | return 0; |
| 2448 | } |
| 2449 | |
| 2450 | static int |
| 2451 | ftrace_filter_release(struct inode *inode, struct file *file) |
| 2452 | { |
| 2453 | return ftrace_regex_release(inode, file, 1); |
| 2454 | } |
| 2455 | |
| 2456 | static int |
| 2457 | ftrace_notrace_release(struct inode *inode, struct file *file) |
| 2458 | { |
| 2459 | return ftrace_regex_release(inode, file, 0); |
| 2460 | } |
| 2461 | |
| 2462 | static const struct file_operations ftrace_avail_fops = { |
| 2463 | .open = ftrace_avail_open, |
| 2464 | .read = seq_read, |
| 2465 | .llseek = seq_lseek, |
| 2466 | .release = ftrace_avail_release, |
| 2467 | }; |
| 2468 | |
| 2469 | static const struct file_operations ftrace_failures_fops = { |
| 2470 | .open = ftrace_failures_open, |
| 2471 | .read = seq_read, |
| 2472 | .llseek = seq_lseek, |
| 2473 | .release = ftrace_avail_release, |
| 2474 | }; |
| 2475 | |
| 2476 | static const struct file_operations ftrace_filter_fops = { |
| 2477 | .open = ftrace_filter_open, |
| 2478 | .read = seq_read, |
| 2479 | .write = ftrace_filter_write, |
| 2480 | .llseek = ftrace_regex_lseek, |
| 2481 | .release = ftrace_filter_release, |
| 2482 | }; |
| 2483 | |
| 2484 | static const struct file_operations ftrace_notrace_fops = { |
| 2485 | .open = ftrace_notrace_open, |
| 2486 | .read = seq_read, |
| 2487 | .write = ftrace_notrace_write, |
| 2488 | .llseek = ftrace_regex_lseek, |
| 2489 | .release = ftrace_notrace_release, |
| 2490 | }; |
| 2491 | |
| 2492 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
| 2493 | |
| 2494 | static DEFINE_MUTEX(graph_lock); |
| 2495 | |
| 2496 | int ftrace_graph_count; |
| 2497 | unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly; |
| 2498 | |
| 2499 | static void * |
| 2500 | __g_next(struct seq_file *m, loff_t *pos) |
| 2501 | { |
| 2502 | unsigned long *array = m->private; |
| 2503 | |
| 2504 | if (*pos >= ftrace_graph_count) |
| 2505 | return NULL; |
| 2506 | return &array[*pos]; |
| 2507 | } |
| 2508 | |
| 2509 | static void * |
| 2510 | g_next(struct seq_file *m, void *v, loff_t *pos) |
| 2511 | { |
| 2512 | (*pos)++; |
| 2513 | return __g_next(m, pos); |
| 2514 | } |
| 2515 | |
| 2516 | static void *g_start(struct seq_file *m, loff_t *pos) |
| 2517 | { |
| 2518 | mutex_lock(&graph_lock); |
| 2519 | |
| 2520 | /* Nothing, tell g_show to print all functions are enabled */ |
| 2521 | if (!ftrace_graph_count && !*pos) |
| 2522 | return (void *)1; |
| 2523 | |
| 2524 | return __g_next(m, pos); |
| 2525 | } |
| 2526 | |
| 2527 | static void g_stop(struct seq_file *m, void *p) |
| 2528 | { |
| 2529 | mutex_unlock(&graph_lock); |
| 2530 | } |
| 2531 | |
| 2532 | static int g_show(struct seq_file *m, void *v) |
| 2533 | { |
| 2534 | unsigned long *ptr = v; |
| 2535 | char str[KSYM_SYMBOL_LEN]; |
| 2536 | |
| 2537 | if (!ptr) |
| 2538 | return 0; |
| 2539 | |
| 2540 | if (ptr == (unsigned long *)1) { |
| 2541 | seq_printf(m, "#### all functions enabled ####\n"); |
| 2542 | return 0; |
| 2543 | } |
| 2544 | |
| 2545 | kallsyms_lookup(*ptr, NULL, NULL, NULL, str); |
| 2546 | |
| 2547 | seq_printf(m, "%s\n", str); |
| 2548 | |
| 2549 | return 0; |
| 2550 | } |
| 2551 | |
| 2552 | static struct seq_operations ftrace_graph_seq_ops = { |
| 2553 | .start = g_start, |
| 2554 | .next = g_next, |
| 2555 | .stop = g_stop, |
| 2556 | .show = g_show, |
| 2557 | }; |
| 2558 | |
| 2559 | static int |
| 2560 | ftrace_graph_open(struct inode *inode, struct file *file) |
| 2561 | { |
| 2562 | int ret = 0; |
| 2563 | |
| 2564 | if (unlikely(ftrace_disabled)) |
| 2565 | return -ENODEV; |
| 2566 | |
| 2567 | mutex_lock(&graph_lock); |
| 2568 | if ((file->f_mode & FMODE_WRITE) && |
| 2569 | !(file->f_flags & O_APPEND)) { |
| 2570 | ftrace_graph_count = 0; |
| 2571 | memset(ftrace_graph_funcs, 0, sizeof(ftrace_graph_funcs)); |
| 2572 | } |
| 2573 | |
| 2574 | if (file->f_mode & FMODE_READ) { |
| 2575 | ret = seq_open(file, &ftrace_graph_seq_ops); |
| 2576 | if (!ret) { |
| 2577 | struct seq_file *m = file->private_data; |
| 2578 | m->private = ftrace_graph_funcs; |
| 2579 | } |
| 2580 | } else |
| 2581 | file->private_data = ftrace_graph_funcs; |
| 2582 | mutex_unlock(&graph_lock); |
| 2583 | |
| 2584 | return ret; |
| 2585 | } |
| 2586 | |
| 2587 | static int |
| 2588 | ftrace_set_func(unsigned long *array, int *idx, char *buffer) |
| 2589 | { |
| 2590 | struct dyn_ftrace *rec; |
| 2591 | struct ftrace_page *pg; |
| 2592 | int search_len; |
| 2593 | int found = 0; |
| 2594 | int type, not; |
| 2595 | char *search; |
| 2596 | bool exists; |
| 2597 | int i; |
| 2598 | |
| 2599 | if (ftrace_disabled) |
| 2600 | return -ENODEV; |
| 2601 | |
| 2602 | /* decode regex */ |
| 2603 | type = ftrace_setup_glob(buffer, strlen(buffer), &search, ¬); |
| 2604 | if (not) |
| 2605 | return -EINVAL; |
| 2606 | |
| 2607 | search_len = strlen(search); |
| 2608 | |
| 2609 | mutex_lock(&ftrace_lock); |
| 2610 | do_for_each_ftrace_rec(pg, rec) { |
| 2611 | |
| 2612 | if (*idx >= FTRACE_GRAPH_MAX_FUNCS) |
| 2613 | break; |
| 2614 | |
| 2615 | if (rec->flags & (FTRACE_FL_FAILED | FTRACE_FL_FREE)) |
| 2616 | continue; |
| 2617 | |
| 2618 | if (ftrace_match_record(rec, search, search_len, type)) { |
| 2619 | /* ensure it is not already in the array */ |
| 2620 | exists = false; |
| 2621 | for (i = 0; i < *idx; i++) |
| 2622 | if (array[i] == rec->ip) { |
| 2623 | exists = true; |
| 2624 | break; |
| 2625 | } |
| 2626 | if (!exists) { |
| 2627 | array[(*idx)++] = rec->ip; |
| 2628 | found = 1; |
| 2629 | } |
| 2630 | } |
| 2631 | } while_for_each_ftrace_rec(); |
| 2632 | |
| 2633 | mutex_unlock(&ftrace_lock); |
| 2634 | |
| 2635 | return found ? 0 : -EINVAL; |
| 2636 | } |
| 2637 | |
| 2638 | static ssize_t |
| 2639 | ftrace_graph_write(struct file *file, const char __user *ubuf, |
| 2640 | size_t cnt, loff_t *ppos) |
| 2641 | { |
| 2642 | unsigned char buffer[FTRACE_BUFF_MAX+1]; |
| 2643 | unsigned long *array; |
| 2644 | size_t read = 0; |
| 2645 | ssize_t ret; |
| 2646 | int index = 0; |
| 2647 | char ch; |
| 2648 | |
| 2649 | if (!cnt || cnt < 0) |
| 2650 | return 0; |
| 2651 | |
| 2652 | mutex_lock(&graph_lock); |
| 2653 | |
| 2654 | if (ftrace_graph_count >= FTRACE_GRAPH_MAX_FUNCS) { |
| 2655 | ret = -EBUSY; |
| 2656 | goto out; |
| 2657 | } |
| 2658 | |
| 2659 | if (file->f_mode & FMODE_READ) { |
| 2660 | struct seq_file *m = file->private_data; |
| 2661 | array = m->private; |
| 2662 | } else |
| 2663 | array = file->private_data; |
| 2664 | |
| 2665 | ret = get_user(ch, ubuf++); |
| 2666 | if (ret) |
| 2667 | goto out; |
| 2668 | read++; |
| 2669 | cnt--; |
| 2670 | |
| 2671 | /* skip white space */ |
| 2672 | while (cnt && isspace(ch)) { |
| 2673 | ret = get_user(ch, ubuf++); |
| 2674 | if (ret) |
| 2675 | goto out; |
| 2676 | read++; |
| 2677 | cnt--; |
| 2678 | } |
| 2679 | |
| 2680 | if (isspace(ch)) { |
| 2681 | *ppos += read; |
| 2682 | ret = read; |
| 2683 | goto out; |
| 2684 | } |
| 2685 | |
| 2686 | while (cnt && !isspace(ch)) { |
| 2687 | if (index < FTRACE_BUFF_MAX) |
| 2688 | buffer[index++] = ch; |
| 2689 | else { |
| 2690 | ret = -EINVAL; |
| 2691 | goto out; |
| 2692 | } |
| 2693 | ret = get_user(ch, ubuf++); |
| 2694 | if (ret) |
| 2695 | goto out; |
| 2696 | read++; |
| 2697 | cnt--; |
| 2698 | } |
| 2699 | buffer[index] = 0; |
| 2700 | |
| 2701 | /* we allow only one expression at a time */ |
| 2702 | ret = ftrace_set_func(array, &ftrace_graph_count, buffer); |
| 2703 | if (ret) |
| 2704 | goto out; |
| 2705 | |
| 2706 | file->f_pos += read; |
| 2707 | |
| 2708 | ret = read; |
| 2709 | out: |
| 2710 | mutex_unlock(&graph_lock); |
| 2711 | |
| 2712 | return ret; |
| 2713 | } |
| 2714 | |
| 2715 | static const struct file_operations ftrace_graph_fops = { |
| 2716 | .open = ftrace_graph_open, |
| 2717 | .read = seq_read, |
| 2718 | .write = ftrace_graph_write, |
| 2719 | }; |
| 2720 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
| 2721 | |
| 2722 | static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer) |
| 2723 | { |
| 2724 | |
| 2725 | trace_create_file("available_filter_functions", 0444, |
| 2726 | d_tracer, NULL, &ftrace_avail_fops); |
| 2727 | |
| 2728 | trace_create_file("failures", 0444, |
| 2729 | d_tracer, NULL, &ftrace_failures_fops); |
| 2730 | |
| 2731 | trace_create_file("set_ftrace_filter", 0644, d_tracer, |
| 2732 | NULL, &ftrace_filter_fops); |
| 2733 | |
| 2734 | trace_create_file("set_ftrace_notrace", 0644, d_tracer, |
| 2735 | NULL, &ftrace_notrace_fops); |
| 2736 | |
| 2737 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
| 2738 | trace_create_file("set_graph_function", 0444, d_tracer, |
| 2739 | NULL, |
| 2740 | &ftrace_graph_fops); |
| 2741 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |
| 2742 | |
| 2743 | return 0; |
| 2744 | } |
| 2745 | |
| 2746 | static int ftrace_convert_nops(struct module *mod, |
| 2747 | unsigned long *start, |
| 2748 | unsigned long *end) |
| 2749 | { |
| 2750 | unsigned long *p; |
| 2751 | unsigned long addr; |
| 2752 | unsigned long flags; |
| 2753 | |
| 2754 | mutex_lock(&ftrace_lock); |
| 2755 | p = start; |
| 2756 | while (p < end) { |
| 2757 | addr = ftrace_call_adjust(*p++); |
| 2758 | /* |
| 2759 | * Some architecture linkers will pad between |
| 2760 | * the different mcount_loc sections of different |
| 2761 | * object files to satisfy alignments. |
| 2762 | * Skip any NULL pointers. |
| 2763 | */ |
| 2764 | if (!addr) |
| 2765 | continue; |
| 2766 | ftrace_record_ip(addr); |
| 2767 | } |
| 2768 | |
| 2769 | /* disable interrupts to prevent kstop machine */ |
| 2770 | local_irq_save(flags); |
| 2771 | ftrace_update_code(mod); |
| 2772 | local_irq_restore(flags); |
| 2773 | mutex_unlock(&ftrace_lock); |
| 2774 | |
| 2775 | return 0; |
| 2776 | } |
| 2777 | |
| 2778 | #ifdef CONFIG_MODULES |
| 2779 | void ftrace_release(void *start, void *end) |
| 2780 | { |
| 2781 | struct dyn_ftrace *rec; |
| 2782 | struct ftrace_page *pg; |
| 2783 | unsigned long s = (unsigned long)start; |
| 2784 | unsigned long e = (unsigned long)end; |
| 2785 | |
| 2786 | if (ftrace_disabled || !start || start == end) |
| 2787 | return; |
| 2788 | |
| 2789 | mutex_lock(&ftrace_lock); |
| 2790 | do_for_each_ftrace_rec(pg, rec) { |
| 2791 | if ((rec->ip >= s) && (rec->ip < e)) { |
| 2792 | /* |
| 2793 | * rec->ip is changed in ftrace_free_rec() |
| 2794 | * It should not between s and e if record was freed. |
| 2795 | */ |
| 2796 | FTRACE_WARN_ON(rec->flags & FTRACE_FL_FREE); |
| 2797 | ftrace_free_rec(rec); |
| 2798 | } |
| 2799 | } while_for_each_ftrace_rec(); |
| 2800 | mutex_unlock(&ftrace_lock); |
| 2801 | } |
| 2802 | |
| 2803 | static void ftrace_init_module(struct module *mod, |
| 2804 | unsigned long *start, unsigned long *end) |
| 2805 | { |
| 2806 | if (ftrace_disabled || start == end) |
| 2807 | return; |
| 2808 | ftrace_convert_nops(mod, start, end); |
| 2809 | } |
| 2810 | |
| 2811 | static int ftrace_module_notify(struct notifier_block *self, |
| 2812 | unsigned long val, void *data) |
| 2813 | { |
| 2814 | struct module *mod = data; |
| 2815 | |
| 2816 | switch (val) { |
| 2817 | case MODULE_STATE_COMING: |
| 2818 | ftrace_init_module(mod, mod->ftrace_callsites, |
| 2819 | mod->ftrace_callsites + |
| 2820 | mod->num_ftrace_callsites); |
| 2821 | break; |
| 2822 | case MODULE_STATE_GOING: |
| 2823 | ftrace_release(mod->ftrace_callsites, |
| 2824 | mod->ftrace_callsites + |
| 2825 | mod->num_ftrace_callsites); |
| 2826 | break; |
| 2827 | } |
| 2828 | |
| 2829 | return 0; |
| 2830 | } |
| 2831 | #else |
| 2832 | static int ftrace_module_notify(struct notifier_block *self, |
| 2833 | unsigned long val, void *data) |
| 2834 | { |
| 2835 | return 0; |
| 2836 | } |
| 2837 | #endif /* CONFIG_MODULES */ |
| 2838 | |
| 2839 | struct notifier_block ftrace_module_nb = { |
| 2840 | .notifier_call = ftrace_module_notify, |
| 2841 | .priority = 0, |
| 2842 | }; |
| 2843 | |
| 2844 | extern unsigned long __start_mcount_loc[]; |
| 2845 | extern unsigned long __stop_mcount_loc[]; |
| 2846 | |
| 2847 | void __init ftrace_init(void) |
| 2848 | { |
| 2849 | unsigned long count, addr, flags; |
| 2850 | int ret; |
| 2851 | |
| 2852 | /* Keep the ftrace pointer to the stub */ |
| 2853 | addr = (unsigned long)ftrace_stub; |
| 2854 | |
| 2855 | local_irq_save(flags); |
| 2856 | ftrace_dyn_arch_init(&addr); |
| 2857 | local_irq_restore(flags); |
| 2858 | |
| 2859 | /* ftrace_dyn_arch_init places the return code in addr */ |
| 2860 | if (addr) |
| 2861 | goto failed; |
| 2862 | |
| 2863 | count = __stop_mcount_loc - __start_mcount_loc; |
| 2864 | |
| 2865 | ret = ftrace_dyn_table_alloc(count); |
| 2866 | if (ret) |
| 2867 | goto failed; |
| 2868 | |
| 2869 | last_ftrace_enabled = ftrace_enabled = 1; |
| 2870 | |
| 2871 | ret = ftrace_convert_nops(NULL, |
| 2872 | __start_mcount_loc, |
| 2873 | __stop_mcount_loc); |
| 2874 | |
| 2875 | ret = register_module_notifier(&ftrace_module_nb); |
| 2876 | if (ret) |
| 2877 | pr_warning("Failed to register trace ftrace module notifier\n"); |
| 2878 | |
| 2879 | set_ftrace_early_filters(); |
| 2880 | |
| 2881 | return; |
| 2882 | failed: |
| 2883 | ftrace_disabled = 1; |
| 2884 | } |
| 2885 | |
| 2886 | #else |
| 2887 | |
| 2888 | static int __init ftrace_nodyn_init(void) |
| 2889 | { |
| 2890 | ftrace_enabled = 1; |
| 2891 | return 0; |
| 2892 | } |
| 2893 | device_initcall(ftrace_nodyn_init); |
| 2894 | |
| 2895 | static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; } |
| 2896 | static inline void ftrace_startup_enable(int command) { } |
| 2897 | /* Keep as macros so we do not need to define the commands */ |
| 2898 | # define ftrace_startup(command) do { } while (0) |
| 2899 | # define ftrace_shutdown(command) do { } while (0) |
| 2900 | # define ftrace_startup_sysctl() do { } while (0) |
| 2901 | # define ftrace_shutdown_sysctl() do { } while (0) |
| 2902 | #endif /* CONFIG_DYNAMIC_FTRACE */ |
| 2903 | |
| 2904 | static ssize_t |
| 2905 | ftrace_pid_read(struct file *file, char __user *ubuf, |
| 2906 | size_t cnt, loff_t *ppos) |
| 2907 | { |
| 2908 | char buf[64]; |
| 2909 | int r; |
| 2910 | |
| 2911 | if (ftrace_pid_trace == ftrace_swapper_pid) |
| 2912 | r = sprintf(buf, "swapper tasks\n"); |
| 2913 | else if (ftrace_pid_trace) |
| 2914 | r = sprintf(buf, "%u\n", pid_vnr(ftrace_pid_trace)); |
| 2915 | else |
| 2916 | r = sprintf(buf, "no pid\n"); |
| 2917 | |
| 2918 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); |
| 2919 | } |
| 2920 | |
| 2921 | static void clear_ftrace_swapper(void) |
| 2922 | { |
| 2923 | struct task_struct *p; |
| 2924 | int cpu; |
| 2925 | |
| 2926 | get_online_cpus(); |
| 2927 | for_each_online_cpu(cpu) { |
| 2928 | p = idle_task(cpu); |
| 2929 | clear_tsk_trace_trace(p); |
| 2930 | } |
| 2931 | put_online_cpus(); |
| 2932 | } |
| 2933 | |
| 2934 | static void set_ftrace_swapper(void) |
| 2935 | { |
| 2936 | struct task_struct *p; |
| 2937 | int cpu; |
| 2938 | |
| 2939 | get_online_cpus(); |
| 2940 | for_each_online_cpu(cpu) { |
| 2941 | p = idle_task(cpu); |
| 2942 | set_tsk_trace_trace(p); |
| 2943 | } |
| 2944 | put_online_cpus(); |
| 2945 | } |
| 2946 | |
| 2947 | static void clear_ftrace_pid(struct pid *pid) |
| 2948 | { |
| 2949 | struct task_struct *p; |
| 2950 | |
| 2951 | rcu_read_lock(); |
| 2952 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
| 2953 | clear_tsk_trace_trace(p); |
| 2954 | } while_each_pid_task(pid, PIDTYPE_PID, p); |
| 2955 | rcu_read_unlock(); |
| 2956 | |
| 2957 | put_pid(pid); |
| 2958 | } |
| 2959 | |
| 2960 | static void set_ftrace_pid(struct pid *pid) |
| 2961 | { |
| 2962 | struct task_struct *p; |
| 2963 | |
| 2964 | rcu_read_lock(); |
| 2965 | do_each_pid_task(pid, PIDTYPE_PID, p) { |
| 2966 | set_tsk_trace_trace(p); |
| 2967 | } while_each_pid_task(pid, PIDTYPE_PID, p); |
| 2968 | rcu_read_unlock(); |
| 2969 | } |
| 2970 | |
| 2971 | static void clear_ftrace_pid_task(struct pid **pid) |
| 2972 | { |
| 2973 | if (*pid == ftrace_swapper_pid) |
| 2974 | clear_ftrace_swapper(); |
| 2975 | else |
| 2976 | clear_ftrace_pid(*pid); |
| 2977 | |
| 2978 | *pid = NULL; |
| 2979 | } |
| 2980 | |
| 2981 | static void set_ftrace_pid_task(struct pid *pid) |
| 2982 | { |
| 2983 | if (pid == ftrace_swapper_pid) |
| 2984 | set_ftrace_swapper(); |
| 2985 | else |
| 2986 | set_ftrace_pid(pid); |
| 2987 | } |
| 2988 | |
| 2989 | static ssize_t |
| 2990 | ftrace_pid_write(struct file *filp, const char __user *ubuf, |
| 2991 | size_t cnt, loff_t *ppos) |
| 2992 | { |
| 2993 | struct pid *pid; |
| 2994 | char buf[64]; |
| 2995 | long val; |
| 2996 | int ret; |
| 2997 | |
| 2998 | if (cnt >= sizeof(buf)) |
| 2999 | return -EINVAL; |
| 3000 | |
| 3001 | if (copy_from_user(&buf, ubuf, cnt)) |
| 3002 | return -EFAULT; |
| 3003 | |
| 3004 | buf[cnt] = 0; |
| 3005 | |
| 3006 | ret = strict_strtol(buf, 10, &val); |
| 3007 | if (ret < 0) |
| 3008 | return ret; |
| 3009 | |
| 3010 | mutex_lock(&ftrace_lock); |
| 3011 | if (val < 0) { |
| 3012 | /* disable pid tracing */ |
| 3013 | if (!ftrace_pid_trace) |
| 3014 | goto out; |
| 3015 | |
| 3016 | clear_ftrace_pid_task(&ftrace_pid_trace); |
| 3017 | |
| 3018 | } else { |
| 3019 | /* swapper task is special */ |
| 3020 | if (!val) { |
| 3021 | pid = ftrace_swapper_pid; |
| 3022 | if (pid == ftrace_pid_trace) |
| 3023 | goto out; |
| 3024 | } else { |
| 3025 | pid = find_get_pid(val); |
| 3026 | |
| 3027 | if (pid == ftrace_pid_trace) { |
| 3028 | put_pid(pid); |
| 3029 | goto out; |
| 3030 | } |
| 3031 | } |
| 3032 | |
| 3033 | if (ftrace_pid_trace) |
| 3034 | clear_ftrace_pid_task(&ftrace_pid_trace); |
| 3035 | |
| 3036 | if (!pid) |
| 3037 | goto out; |
| 3038 | |
| 3039 | ftrace_pid_trace = pid; |
| 3040 | |
| 3041 | set_ftrace_pid_task(ftrace_pid_trace); |
| 3042 | } |
| 3043 | |
| 3044 | /* update the function call */ |
| 3045 | ftrace_update_pid_func(); |
| 3046 | ftrace_startup_enable(0); |
| 3047 | |
| 3048 | out: |
| 3049 | mutex_unlock(&ftrace_lock); |
| 3050 | |
| 3051 | return cnt; |
| 3052 | } |
| 3053 | |
| 3054 | static const struct file_operations ftrace_pid_fops = { |
| 3055 | .read = ftrace_pid_read, |
| 3056 | .write = ftrace_pid_write, |
| 3057 | }; |
| 3058 | |
| 3059 | static __init int ftrace_init_debugfs(void) |
| 3060 | { |
| 3061 | struct dentry *d_tracer; |
| 3062 | |
| 3063 | d_tracer = tracing_init_dentry(); |
| 3064 | if (!d_tracer) |
| 3065 | return 0; |
| 3066 | |
| 3067 | ftrace_init_dyn_debugfs(d_tracer); |
| 3068 | |
| 3069 | trace_create_file("set_ftrace_pid", 0644, d_tracer, |
| 3070 | NULL, &ftrace_pid_fops); |
| 3071 | |
| 3072 | ftrace_profile_debugfs(d_tracer); |
| 3073 | |
| 3074 | return 0; |
| 3075 | } |
| 3076 | fs_initcall(ftrace_init_debugfs); |
| 3077 | |
| 3078 | /** |
| 3079 | * ftrace_kill - kill ftrace |
| 3080 | * |
| 3081 | * This function should be used by panic code. It stops ftrace |
| 3082 | * but in a not so nice way. If you need to simply kill ftrace |
| 3083 | * from a non-atomic section, use ftrace_kill. |
| 3084 | */ |
| 3085 | void ftrace_kill(void) |
| 3086 | { |
| 3087 | ftrace_disabled = 1; |
| 3088 | ftrace_enabled = 0; |
| 3089 | clear_ftrace_function(); |
| 3090 | } |
| 3091 | |
| 3092 | /** |
| 3093 | * register_ftrace_function - register a function for profiling |
| 3094 | * @ops - ops structure that holds the function for profiling. |
| 3095 | * |
| 3096 | * Register a function to be called by all functions in the |
| 3097 | * kernel. |
| 3098 | * |
| 3099 | * Note: @ops->func and all the functions it calls must be labeled |
| 3100 | * with "notrace", otherwise it will go into a |
| 3101 | * recursive loop. |
| 3102 | */ |
| 3103 | int register_ftrace_function(struct ftrace_ops *ops) |
| 3104 | { |
| 3105 | int ret; |
| 3106 | |
| 3107 | if (unlikely(ftrace_disabled)) |
| 3108 | return -1; |
| 3109 | |
| 3110 | mutex_lock(&ftrace_lock); |
| 3111 | |
| 3112 | ret = __register_ftrace_function(ops); |
| 3113 | ftrace_startup(0); |
| 3114 | |
| 3115 | mutex_unlock(&ftrace_lock); |
| 3116 | return ret; |
| 3117 | } |
| 3118 | |
| 3119 | /** |
| 3120 | * unregister_ftrace_function - unregister a function for profiling. |
| 3121 | * @ops - ops structure that holds the function to unregister |
| 3122 | * |
| 3123 | * Unregister a function that was added to be called by ftrace profiling. |
| 3124 | */ |
| 3125 | int unregister_ftrace_function(struct ftrace_ops *ops) |
| 3126 | { |
| 3127 | int ret; |
| 3128 | |
| 3129 | mutex_lock(&ftrace_lock); |
| 3130 | ret = __unregister_ftrace_function(ops); |
| 3131 | ftrace_shutdown(0); |
| 3132 | mutex_unlock(&ftrace_lock); |
| 3133 | |
| 3134 | return ret; |
| 3135 | } |
| 3136 | |
| 3137 | int |
| 3138 | ftrace_enable_sysctl(struct ctl_table *table, int write, |
| 3139 | struct file *file, void __user *buffer, size_t *lenp, |
| 3140 | loff_t *ppos) |
| 3141 | { |
| 3142 | int ret; |
| 3143 | |
| 3144 | if (unlikely(ftrace_disabled)) |
| 3145 | return -ENODEV; |
| 3146 | |
| 3147 | mutex_lock(&ftrace_lock); |
| 3148 | |
| 3149 | ret = proc_dointvec(table, write, file, buffer, lenp, ppos); |
| 3150 | |
| 3151 | if (ret || !write || (last_ftrace_enabled == ftrace_enabled)) |
| 3152 | goto out; |
| 3153 | |
| 3154 | last_ftrace_enabled = ftrace_enabled; |
| 3155 | |
| 3156 | if (ftrace_enabled) { |
| 3157 | |
| 3158 | ftrace_startup_sysctl(); |
| 3159 | |
| 3160 | /* we are starting ftrace again */ |
| 3161 | if (ftrace_list != &ftrace_list_end) { |
| 3162 | if (ftrace_list->next == &ftrace_list_end) |
| 3163 | ftrace_trace_function = ftrace_list->func; |
| 3164 | else |
| 3165 | ftrace_trace_function = ftrace_list_func; |
| 3166 | } |
| 3167 | |
| 3168 | } else { |
| 3169 | /* stopping ftrace calls (just send to ftrace_stub) */ |
| 3170 | ftrace_trace_function = ftrace_stub; |
| 3171 | |
| 3172 | ftrace_shutdown_sysctl(); |
| 3173 | } |
| 3174 | |
| 3175 | out: |
| 3176 | mutex_unlock(&ftrace_lock); |
| 3177 | return ret; |
| 3178 | } |
| 3179 | |
| 3180 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
| 3181 | |
| 3182 | static int ftrace_graph_active; |
| 3183 | static struct notifier_block ftrace_suspend_notifier; |
| 3184 | |
| 3185 | int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace) |
| 3186 | { |
| 3187 | return 0; |
| 3188 | } |
| 3189 | |
| 3190 | /* The callbacks that hook a function */ |
| 3191 | trace_func_graph_ret_t ftrace_graph_return = |
| 3192 | (trace_func_graph_ret_t)ftrace_stub; |
| 3193 | trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub; |
| 3194 | |
| 3195 | /* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */ |
| 3196 | static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list) |
| 3197 | { |
| 3198 | int i; |
| 3199 | int ret = 0; |
| 3200 | unsigned long flags; |
| 3201 | int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE; |
| 3202 | struct task_struct *g, *t; |
| 3203 | |
| 3204 | for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) { |
| 3205 | ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH |
| 3206 | * sizeof(struct ftrace_ret_stack), |
| 3207 | GFP_KERNEL); |
| 3208 | if (!ret_stack_list[i]) { |
| 3209 | start = 0; |
| 3210 | end = i; |
| 3211 | ret = -ENOMEM; |
| 3212 | goto free; |
| 3213 | } |
| 3214 | } |
| 3215 | |
| 3216 | read_lock_irqsave(&tasklist_lock, flags); |
| 3217 | do_each_thread(g, t) { |
| 3218 | if (start == end) { |
| 3219 | ret = -EAGAIN; |
| 3220 | goto unlock; |
| 3221 | } |
| 3222 | |
| 3223 | if (t->ret_stack == NULL) { |
| 3224 | atomic_set(&t->tracing_graph_pause, 0); |
| 3225 | atomic_set(&t->trace_overrun, 0); |
| 3226 | t->curr_ret_stack = -1; |
| 3227 | /* Make sure the tasks see the -1 first: */ |
| 3228 | smp_wmb(); |
| 3229 | t->ret_stack = ret_stack_list[start++]; |
| 3230 | } |
| 3231 | } while_each_thread(g, t); |
| 3232 | |
| 3233 | unlock: |
| 3234 | read_unlock_irqrestore(&tasklist_lock, flags); |
| 3235 | free: |
| 3236 | for (i = start; i < end; i++) |
| 3237 | kfree(ret_stack_list[i]); |
| 3238 | return ret; |
| 3239 | } |
| 3240 | |
| 3241 | static void |
| 3242 | ftrace_graph_probe_sched_switch(struct rq *__rq, struct task_struct *prev, |
| 3243 | struct task_struct *next) |
| 3244 | { |
| 3245 | unsigned long long timestamp; |
| 3246 | int index; |
| 3247 | |
| 3248 | /* |
| 3249 | * Does the user want to count the time a function was asleep. |
| 3250 | * If so, do not update the time stamps. |
| 3251 | */ |
| 3252 | if (trace_flags & TRACE_ITER_SLEEP_TIME) |
| 3253 | return; |
| 3254 | |
| 3255 | timestamp = trace_clock_local(); |
| 3256 | |
| 3257 | prev->ftrace_timestamp = timestamp; |
| 3258 | |
| 3259 | /* only process tasks that we timestamped */ |
| 3260 | if (!next->ftrace_timestamp) |
| 3261 | return; |
| 3262 | |
| 3263 | /* |
| 3264 | * Update all the counters in next to make up for the |
| 3265 | * time next was sleeping. |
| 3266 | */ |
| 3267 | timestamp -= next->ftrace_timestamp; |
| 3268 | |
| 3269 | for (index = next->curr_ret_stack; index >= 0; index--) |
| 3270 | next->ret_stack[index].calltime += timestamp; |
| 3271 | } |
| 3272 | |
| 3273 | /* Allocate a return stack for each task */ |
| 3274 | static int start_graph_tracing(void) |
| 3275 | { |
| 3276 | struct ftrace_ret_stack **ret_stack_list; |
| 3277 | int ret, cpu; |
| 3278 | |
| 3279 | ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE * |
| 3280 | sizeof(struct ftrace_ret_stack *), |
| 3281 | GFP_KERNEL); |
| 3282 | |
| 3283 | if (!ret_stack_list) |
| 3284 | return -ENOMEM; |
| 3285 | |
| 3286 | /* The cpu_boot init_task->ret_stack will never be freed */ |
| 3287 | for_each_online_cpu(cpu) { |
| 3288 | if (!idle_task(cpu)->ret_stack) |
| 3289 | ftrace_graph_init_task(idle_task(cpu)); |
| 3290 | } |
| 3291 | |
| 3292 | do { |
| 3293 | ret = alloc_retstack_tasklist(ret_stack_list); |
| 3294 | } while (ret == -EAGAIN); |
| 3295 | |
| 3296 | if (!ret) { |
| 3297 | ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch); |
| 3298 | if (ret) |
| 3299 | pr_info("ftrace_graph: Couldn't activate tracepoint" |
| 3300 | " probe to kernel_sched_switch\n"); |
| 3301 | } |
| 3302 | |
| 3303 | kfree(ret_stack_list); |
| 3304 | return ret; |
| 3305 | } |
| 3306 | |
| 3307 | /* |
| 3308 | * Hibernation protection. |
| 3309 | * The state of the current task is too much unstable during |
| 3310 | * suspend/restore to disk. We want to protect against that. |
| 3311 | */ |
| 3312 | static int |
| 3313 | ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state, |
| 3314 | void *unused) |
| 3315 | { |
| 3316 | switch (state) { |
| 3317 | case PM_HIBERNATION_PREPARE: |
| 3318 | pause_graph_tracing(); |
| 3319 | break; |
| 3320 | |
| 3321 | case PM_POST_HIBERNATION: |
| 3322 | unpause_graph_tracing(); |
| 3323 | break; |
| 3324 | } |
| 3325 | return NOTIFY_DONE; |
| 3326 | } |
| 3327 | |
| 3328 | int register_ftrace_graph(trace_func_graph_ret_t retfunc, |
| 3329 | trace_func_graph_ent_t entryfunc) |
| 3330 | { |
| 3331 | int ret = 0; |
| 3332 | |
| 3333 | mutex_lock(&ftrace_lock); |
| 3334 | |
| 3335 | /* we currently allow only one tracer registered at a time */ |
| 3336 | if (ftrace_graph_active) { |
| 3337 | ret = -EBUSY; |
| 3338 | goto out; |
| 3339 | } |
| 3340 | |
| 3341 | ftrace_suspend_notifier.notifier_call = ftrace_suspend_notifier_call; |
| 3342 | register_pm_notifier(&ftrace_suspend_notifier); |
| 3343 | |
| 3344 | ftrace_graph_active++; |
| 3345 | ret = start_graph_tracing(); |
| 3346 | if (ret) { |
| 3347 | ftrace_graph_active--; |
| 3348 | goto out; |
| 3349 | } |
| 3350 | |
| 3351 | ftrace_graph_return = retfunc; |
| 3352 | ftrace_graph_entry = entryfunc; |
| 3353 | |
| 3354 | ftrace_startup(FTRACE_START_FUNC_RET); |
| 3355 | |
| 3356 | out: |
| 3357 | mutex_unlock(&ftrace_lock); |
| 3358 | return ret; |
| 3359 | } |
| 3360 | |
| 3361 | void unregister_ftrace_graph(void) |
| 3362 | { |
| 3363 | mutex_lock(&ftrace_lock); |
| 3364 | |
| 3365 | if (unlikely(!ftrace_graph_active)) |
| 3366 | goto out; |
| 3367 | |
| 3368 | ftrace_graph_active--; |
| 3369 | unregister_trace_sched_switch(ftrace_graph_probe_sched_switch); |
| 3370 | ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub; |
| 3371 | ftrace_graph_entry = ftrace_graph_entry_stub; |
| 3372 | ftrace_shutdown(FTRACE_STOP_FUNC_RET); |
| 3373 | unregister_pm_notifier(&ftrace_suspend_notifier); |
| 3374 | |
| 3375 | out: |
| 3376 | mutex_unlock(&ftrace_lock); |
| 3377 | } |
| 3378 | |
| 3379 | /* Allocate a return stack for newly created task */ |
| 3380 | void ftrace_graph_init_task(struct task_struct *t) |
| 3381 | { |
| 3382 | /* Make sure we do not use the parent ret_stack */ |
| 3383 | t->ret_stack = NULL; |
| 3384 | |
| 3385 | if (ftrace_graph_active) { |
| 3386 | struct ftrace_ret_stack *ret_stack; |
| 3387 | |
| 3388 | ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH |
| 3389 | * sizeof(struct ftrace_ret_stack), |
| 3390 | GFP_KERNEL); |
| 3391 | if (!ret_stack) |
| 3392 | return; |
| 3393 | t->curr_ret_stack = -1; |
| 3394 | atomic_set(&t->tracing_graph_pause, 0); |
| 3395 | atomic_set(&t->trace_overrun, 0); |
| 3396 | t->ftrace_timestamp = 0; |
| 3397 | /* make curr_ret_stack visable before we add the ret_stack */ |
| 3398 | smp_wmb(); |
| 3399 | t->ret_stack = ret_stack; |
| 3400 | } |
| 3401 | } |
| 3402 | |
| 3403 | void ftrace_graph_exit_task(struct task_struct *t) |
| 3404 | { |
| 3405 | struct ftrace_ret_stack *ret_stack = t->ret_stack; |
| 3406 | |
| 3407 | t->ret_stack = NULL; |
| 3408 | /* NULL must become visible to IRQs before we free it: */ |
| 3409 | barrier(); |
| 3410 | |
| 3411 | kfree(ret_stack); |
| 3412 | } |
| 3413 | |
| 3414 | void ftrace_graph_stop(void) |
| 3415 | { |
| 3416 | ftrace_stop(); |
| 3417 | } |
| 3418 | #endif |
| 3419 | |