| 1 | /* |
| 2 | * ring buffer based function tracer |
| 3 | * |
| 4 | * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com> |
| 5 | * Copyright (C) 2008 Ingo Molnar <mingo@redhat.com> |
| 6 | * |
| 7 | * Originally taken from the RT patch by: |
| 8 | * Arnaldo Carvalho de Melo <acme@redhat.com> |
| 9 | * |
| 10 | * Based on code from the latency_tracer, that is: |
| 11 | * Copyright (C) 2004-2006 Ingo Molnar |
| 12 | * Copyright (C) 2004 William Lee Irwin III |
| 13 | */ |
| 14 | #include <linux/utsrelease.h> |
| 15 | #include <linux/kallsyms.h> |
| 16 | #include <linux/seq_file.h> |
| 17 | #include <linux/debugfs.h> |
| 18 | #include <linux/pagemap.h> |
| 19 | #include <linux/hardirq.h> |
| 20 | #include <linux/linkage.h> |
| 21 | #include <linux/uaccess.h> |
| 22 | #include <linux/ftrace.h> |
| 23 | #include <linux/module.h> |
| 24 | #include <linux/percpu.h> |
| 25 | #include <linux/ctype.h> |
| 26 | #include <linux/init.h> |
| 27 | #include <linux/poll.h> |
| 28 | #include <linux/gfp.h> |
| 29 | #include <linux/fs.h> |
| 30 | |
| 31 | #include <linux/stacktrace.h> |
| 32 | |
| 33 | #include "trace.h" |
| 34 | |
| 35 | unsigned long __read_mostly tracing_max_latency = (cycle_t)ULONG_MAX; |
| 36 | unsigned long __read_mostly tracing_thresh; |
| 37 | |
| 38 | static int tracing_disabled = 1; |
| 39 | |
| 40 | static long |
| 41 | ns2usecs(cycle_t nsec) |
| 42 | { |
| 43 | nsec += 500; |
| 44 | do_div(nsec, 1000); |
| 45 | return nsec; |
| 46 | } |
| 47 | |
| 48 | cycle_t ftrace_now(int cpu) |
| 49 | { |
| 50 | return cpu_clock(cpu); |
| 51 | } |
| 52 | |
| 53 | static struct trace_array global_trace; |
| 54 | |
| 55 | static DEFINE_PER_CPU(struct trace_array_cpu, global_trace_cpu); |
| 56 | |
| 57 | static struct trace_array max_tr; |
| 58 | |
| 59 | static DEFINE_PER_CPU(struct trace_array_cpu, max_data); |
| 60 | |
| 61 | static int tracer_enabled = 1; |
| 62 | static unsigned long trace_nr_entries = 65536UL; |
| 63 | |
| 64 | static struct tracer *trace_types __read_mostly; |
| 65 | static struct tracer *current_trace __read_mostly; |
| 66 | static int max_tracer_type_len; |
| 67 | |
| 68 | static DEFINE_MUTEX(trace_types_lock); |
| 69 | static DECLARE_WAIT_QUEUE_HEAD (trace_wait); |
| 70 | |
| 71 | #define ENTRIES_PER_PAGE (PAGE_SIZE / sizeof(struct trace_entry)) |
| 72 | |
| 73 | static int __init set_nr_entries(char *str) |
| 74 | { |
| 75 | if (!str) |
| 76 | return 0; |
| 77 | trace_nr_entries = simple_strtoul(str, &str, 0); |
| 78 | return 1; |
| 79 | } |
| 80 | __setup("trace_entries=", set_nr_entries); |
| 81 | |
| 82 | unsigned long nsecs_to_usecs(unsigned long nsecs) |
| 83 | { |
| 84 | return nsecs / 1000; |
| 85 | } |
| 86 | |
| 87 | enum trace_type { |
| 88 | __TRACE_FIRST_TYPE = 0, |
| 89 | |
| 90 | TRACE_FN, |
| 91 | TRACE_CTX, |
| 92 | TRACE_WAKE, |
| 93 | TRACE_STACK, |
| 94 | TRACE_SPECIAL, |
| 95 | |
| 96 | __TRACE_LAST_TYPE |
| 97 | }; |
| 98 | |
| 99 | enum trace_flag_type { |
| 100 | TRACE_FLAG_IRQS_OFF = 0x01, |
| 101 | TRACE_FLAG_NEED_RESCHED = 0x02, |
| 102 | TRACE_FLAG_HARDIRQ = 0x04, |
| 103 | TRACE_FLAG_SOFTIRQ = 0x08, |
| 104 | }; |
| 105 | |
| 106 | enum trace_iterator_flags { |
| 107 | TRACE_ITER_PRINT_PARENT = 0x01, |
| 108 | TRACE_ITER_SYM_OFFSET = 0x02, |
| 109 | TRACE_ITER_SYM_ADDR = 0x04, |
| 110 | TRACE_ITER_VERBOSE = 0x08, |
| 111 | TRACE_ITER_RAW = 0x10, |
| 112 | TRACE_ITER_HEX = 0x20, |
| 113 | TRACE_ITER_BIN = 0x40, |
| 114 | TRACE_ITER_BLOCK = 0x80, |
| 115 | TRACE_ITER_STACKTRACE = 0x100, |
| 116 | }; |
| 117 | |
| 118 | #define TRACE_ITER_SYM_MASK \ |
| 119 | (TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR) |
| 120 | |
| 121 | /* These must match the bit postions above */ |
| 122 | static const char *trace_options[] = { |
| 123 | "print-parent", |
| 124 | "sym-offset", |
| 125 | "sym-addr", |
| 126 | "verbose", |
| 127 | "raw", |
| 128 | "hex", |
| 129 | "bin", |
| 130 | "block", |
| 131 | "stacktrace", |
| 132 | NULL |
| 133 | }; |
| 134 | |
| 135 | static unsigned trace_flags = TRACE_ITER_PRINT_PARENT | TRACE_ITER_STACKTRACE; |
| 136 | |
| 137 | static DEFINE_SPINLOCK(ftrace_max_lock); |
| 138 | |
| 139 | /* |
| 140 | * Copy the new maximum trace into the separate maximum-trace |
| 141 | * structure. (this way the maximum trace is permanently saved, |
| 142 | * for later retrieval via /debugfs/tracing/latency_trace) |
| 143 | */ |
| 144 | static void |
| 145 | __update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) |
| 146 | { |
| 147 | struct trace_array_cpu *data = tr->data[cpu]; |
| 148 | |
| 149 | max_tr.cpu = cpu; |
| 150 | max_tr.time_start = data->preempt_timestamp; |
| 151 | |
| 152 | data = max_tr.data[cpu]; |
| 153 | data->saved_latency = tracing_max_latency; |
| 154 | |
| 155 | memcpy(data->comm, tsk->comm, TASK_COMM_LEN); |
| 156 | data->pid = tsk->pid; |
| 157 | data->uid = tsk->uid; |
| 158 | data->nice = tsk->static_prio - 20 - MAX_RT_PRIO; |
| 159 | data->policy = tsk->policy; |
| 160 | data->rt_priority = tsk->rt_priority; |
| 161 | |
| 162 | /* record this tasks comm */ |
| 163 | tracing_record_cmdline(current); |
| 164 | } |
| 165 | |
| 166 | void check_pages(struct trace_array_cpu *data) |
| 167 | { |
| 168 | struct page *page, *tmp; |
| 169 | |
| 170 | BUG_ON(data->trace_pages.next->prev != &data->trace_pages); |
| 171 | BUG_ON(data->trace_pages.prev->next != &data->trace_pages); |
| 172 | |
| 173 | list_for_each_entry_safe(page, tmp, &data->trace_pages, lru) { |
| 174 | BUG_ON(page->lru.next->prev != &page->lru); |
| 175 | BUG_ON(page->lru.prev->next != &page->lru); |
| 176 | } |
| 177 | } |
| 178 | |
| 179 | void *head_page(struct trace_array_cpu *data) |
| 180 | { |
| 181 | struct page *page; |
| 182 | |
| 183 | check_pages(data); |
| 184 | if (list_empty(&data->trace_pages)) |
| 185 | return NULL; |
| 186 | |
| 187 | page = list_entry(data->trace_pages.next, struct page, lru); |
| 188 | BUG_ON(&page->lru == &data->trace_pages); |
| 189 | |
| 190 | return page_address(page); |
| 191 | } |
| 192 | |
| 193 | static int |
| 194 | trace_seq_printf(struct trace_seq *s, const char *fmt, ...) |
| 195 | { |
| 196 | int len = (PAGE_SIZE - 1) - s->len; |
| 197 | va_list ap; |
| 198 | int ret; |
| 199 | |
| 200 | if (!len) |
| 201 | return 0; |
| 202 | |
| 203 | va_start(ap, fmt); |
| 204 | ret = vsnprintf(s->buffer + s->len, len, fmt, ap); |
| 205 | va_end(ap); |
| 206 | |
| 207 | /* If we can't write it all, don't bother writing anything */ |
| 208 | if (ret > len) |
| 209 | return 0; |
| 210 | |
| 211 | s->len += ret; |
| 212 | |
| 213 | return len; |
| 214 | } |
| 215 | |
| 216 | static int |
| 217 | trace_seq_puts(struct trace_seq *s, const char *str) |
| 218 | { |
| 219 | int len = strlen(str); |
| 220 | |
| 221 | if (len > ((PAGE_SIZE - 1) - s->len)) |
| 222 | return 0; |
| 223 | |
| 224 | memcpy(s->buffer + s->len, str, len); |
| 225 | s->len += len; |
| 226 | |
| 227 | return len; |
| 228 | } |
| 229 | |
| 230 | static int |
| 231 | trace_seq_putc(struct trace_seq *s, unsigned char c) |
| 232 | { |
| 233 | if (s->len >= (PAGE_SIZE - 1)) |
| 234 | return 0; |
| 235 | |
| 236 | s->buffer[s->len++] = c; |
| 237 | |
| 238 | return 1; |
| 239 | } |
| 240 | |
| 241 | static int |
| 242 | trace_seq_putmem(struct trace_seq *s, void *mem, size_t len) |
| 243 | { |
| 244 | if (len > ((PAGE_SIZE - 1) - s->len)) |
| 245 | return 0; |
| 246 | |
| 247 | memcpy(s->buffer + s->len, mem, len); |
| 248 | s->len += len; |
| 249 | |
| 250 | return len; |
| 251 | } |
| 252 | |
| 253 | #define HEX_CHARS 17 |
| 254 | |
| 255 | static int |
| 256 | trace_seq_putmem_hex(struct trace_seq *s, void *mem, size_t len) |
| 257 | { |
| 258 | unsigned char hex[HEX_CHARS]; |
| 259 | unsigned char *data; |
| 260 | unsigned char byte; |
| 261 | int i, j; |
| 262 | |
| 263 | BUG_ON(len >= HEX_CHARS); |
| 264 | |
| 265 | data = mem; |
| 266 | |
| 267 | #ifdef __BIG_ENDIAN |
| 268 | for (i = 0, j = 0; i < len; i++) { |
| 269 | #else |
| 270 | for (i = len-1, j = 0; i >= 0; i--) { |
| 271 | #endif |
| 272 | byte = data[i]; |
| 273 | |
| 274 | hex[j] = byte & 0x0f; |
| 275 | if (hex[j] >= 10) |
| 276 | hex[j] += 'a' - 10; |
| 277 | else |
| 278 | hex[j] += '0'; |
| 279 | j++; |
| 280 | |
| 281 | hex[j] = byte >> 4; |
| 282 | if (hex[j] >= 10) |
| 283 | hex[j] += 'a' - 10; |
| 284 | else |
| 285 | hex[j] += '0'; |
| 286 | j++; |
| 287 | } |
| 288 | hex[j] = ' '; |
| 289 | j++; |
| 290 | |
| 291 | return trace_seq_putmem(s, hex, j); |
| 292 | } |
| 293 | |
| 294 | static void |
| 295 | trace_seq_reset(struct trace_seq *s) |
| 296 | { |
| 297 | s->len = 0; |
| 298 | } |
| 299 | |
| 300 | static void |
| 301 | trace_print_seq(struct seq_file *m, struct trace_seq *s) |
| 302 | { |
| 303 | int len = s->len >= PAGE_SIZE ? PAGE_SIZE - 1 : s->len; |
| 304 | |
| 305 | s->buffer[len] = 0; |
| 306 | seq_puts(m, s->buffer); |
| 307 | |
| 308 | trace_seq_reset(s); |
| 309 | } |
| 310 | |
| 311 | static void |
| 312 | flip_trace(struct trace_array_cpu *tr1, struct trace_array_cpu *tr2) |
| 313 | { |
| 314 | struct list_head flip_pages; |
| 315 | |
| 316 | INIT_LIST_HEAD(&flip_pages); |
| 317 | |
| 318 | memcpy(&tr1->trace_head_idx, &tr2->trace_head_idx, |
| 319 | sizeof(struct trace_array_cpu) - |
| 320 | offsetof(struct trace_array_cpu, trace_head_idx)); |
| 321 | |
| 322 | check_pages(tr1); |
| 323 | check_pages(tr2); |
| 324 | list_splice_init(&tr1->trace_pages, &flip_pages); |
| 325 | list_splice_init(&tr2->trace_pages, &tr1->trace_pages); |
| 326 | list_splice_init(&flip_pages, &tr2->trace_pages); |
| 327 | BUG_ON(!list_empty(&flip_pages)); |
| 328 | check_pages(tr1); |
| 329 | check_pages(tr2); |
| 330 | } |
| 331 | |
| 332 | void |
| 333 | update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) |
| 334 | { |
| 335 | struct trace_array_cpu *data; |
| 336 | int i; |
| 337 | |
| 338 | WARN_ON_ONCE(!irqs_disabled()); |
| 339 | spin_lock(&ftrace_max_lock); |
| 340 | /* clear out all the previous traces */ |
| 341 | for_each_possible_cpu(i) { |
| 342 | data = tr->data[i]; |
| 343 | flip_trace(max_tr.data[i], data); |
| 344 | tracing_reset(data); |
| 345 | } |
| 346 | |
| 347 | __update_max_tr(tr, tsk, cpu); |
| 348 | spin_unlock(&ftrace_max_lock); |
| 349 | } |
| 350 | |
| 351 | /** |
| 352 | * update_max_tr_single - only copy one trace over, and reset the rest |
| 353 | * @tr - tracer |
| 354 | * @tsk - task with the latency |
| 355 | * @cpu - the cpu of the buffer to copy. |
| 356 | */ |
| 357 | void |
| 358 | update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu) |
| 359 | { |
| 360 | struct trace_array_cpu *data = tr->data[cpu]; |
| 361 | int i; |
| 362 | |
| 363 | WARN_ON_ONCE(!irqs_disabled()); |
| 364 | spin_lock(&ftrace_max_lock); |
| 365 | for_each_possible_cpu(i) |
| 366 | tracing_reset(max_tr.data[i]); |
| 367 | |
| 368 | flip_trace(max_tr.data[cpu], data); |
| 369 | tracing_reset(data); |
| 370 | |
| 371 | __update_max_tr(tr, tsk, cpu); |
| 372 | spin_unlock(&ftrace_max_lock); |
| 373 | } |
| 374 | |
| 375 | int register_tracer(struct tracer *type) |
| 376 | { |
| 377 | struct tracer *t; |
| 378 | int len; |
| 379 | int ret = 0; |
| 380 | |
| 381 | if (!type->name) { |
| 382 | pr_info("Tracer must have a name\n"); |
| 383 | return -1; |
| 384 | } |
| 385 | |
| 386 | mutex_lock(&trace_types_lock); |
| 387 | for (t = trace_types; t; t = t->next) { |
| 388 | if (strcmp(type->name, t->name) == 0) { |
| 389 | /* already found */ |
| 390 | pr_info("Trace %s already registered\n", |
| 391 | type->name); |
| 392 | ret = -1; |
| 393 | goto out; |
| 394 | } |
| 395 | } |
| 396 | |
| 397 | #ifdef CONFIG_FTRACE_STARTUP_TEST |
| 398 | if (type->selftest) { |
| 399 | struct tracer *saved_tracer = current_trace; |
| 400 | struct trace_array_cpu *data; |
| 401 | struct trace_array *tr = &global_trace; |
| 402 | int saved_ctrl = tr->ctrl; |
| 403 | int i; |
| 404 | /* |
| 405 | * Run a selftest on this tracer. |
| 406 | * Here we reset the trace buffer, and set the current |
| 407 | * tracer to be this tracer. The tracer can then run some |
| 408 | * internal tracing to verify that everything is in order. |
| 409 | * If we fail, we do not register this tracer. |
| 410 | */ |
| 411 | for_each_possible_cpu(i) { |
| 412 | data = tr->data[i]; |
| 413 | if (!head_page(data)) |
| 414 | continue; |
| 415 | tracing_reset(data); |
| 416 | } |
| 417 | current_trace = type; |
| 418 | tr->ctrl = 0; |
| 419 | /* the test is responsible for initializing and enabling */ |
| 420 | pr_info("Testing tracer %s: ", type->name); |
| 421 | ret = type->selftest(type, tr); |
| 422 | /* the test is responsible for resetting too */ |
| 423 | current_trace = saved_tracer; |
| 424 | tr->ctrl = saved_ctrl; |
| 425 | if (ret) { |
| 426 | printk(KERN_CONT "FAILED!\n"); |
| 427 | goto out; |
| 428 | } |
| 429 | /* Only reset on passing, to avoid touching corrupted buffers */ |
| 430 | for_each_possible_cpu(i) { |
| 431 | data = tr->data[i]; |
| 432 | if (!head_page(data)) |
| 433 | continue; |
| 434 | tracing_reset(data); |
| 435 | } |
| 436 | printk(KERN_CONT "PASSED\n"); |
| 437 | } |
| 438 | #endif |
| 439 | |
| 440 | type->next = trace_types; |
| 441 | trace_types = type; |
| 442 | len = strlen(type->name); |
| 443 | if (len > max_tracer_type_len) |
| 444 | max_tracer_type_len = len; |
| 445 | |
| 446 | out: |
| 447 | mutex_unlock(&trace_types_lock); |
| 448 | |
| 449 | return ret; |
| 450 | } |
| 451 | |
| 452 | void unregister_tracer(struct tracer *type) |
| 453 | { |
| 454 | struct tracer **t; |
| 455 | int len; |
| 456 | |
| 457 | mutex_lock(&trace_types_lock); |
| 458 | for (t = &trace_types; *t; t = &(*t)->next) { |
| 459 | if (*t == type) |
| 460 | goto found; |
| 461 | } |
| 462 | pr_info("Trace %s not registered\n", type->name); |
| 463 | goto out; |
| 464 | |
| 465 | found: |
| 466 | *t = (*t)->next; |
| 467 | if (strlen(type->name) != max_tracer_type_len) |
| 468 | goto out; |
| 469 | |
| 470 | max_tracer_type_len = 0; |
| 471 | for (t = &trace_types; *t; t = &(*t)->next) { |
| 472 | len = strlen((*t)->name); |
| 473 | if (len > max_tracer_type_len) |
| 474 | max_tracer_type_len = len; |
| 475 | } |
| 476 | out: |
| 477 | mutex_unlock(&trace_types_lock); |
| 478 | } |
| 479 | |
| 480 | void tracing_reset(struct trace_array_cpu *data) |
| 481 | { |
| 482 | data->trace_idx = 0; |
| 483 | data->trace_head = data->trace_tail = head_page(data); |
| 484 | data->trace_head_idx = 0; |
| 485 | data->trace_tail_idx = 0; |
| 486 | } |
| 487 | |
| 488 | #define SAVED_CMDLINES 128 |
| 489 | static unsigned map_pid_to_cmdline[PID_MAX_DEFAULT+1]; |
| 490 | static unsigned map_cmdline_to_pid[SAVED_CMDLINES]; |
| 491 | static char saved_cmdlines[SAVED_CMDLINES][TASK_COMM_LEN]; |
| 492 | static int cmdline_idx; |
| 493 | static DEFINE_SPINLOCK(trace_cmdline_lock); |
| 494 | atomic_t trace_record_cmdline_disabled; |
| 495 | |
| 496 | static void trace_init_cmdlines(void) |
| 497 | { |
| 498 | memset(&map_pid_to_cmdline, -1, sizeof(map_pid_to_cmdline)); |
| 499 | memset(&map_cmdline_to_pid, -1, sizeof(map_cmdline_to_pid)); |
| 500 | cmdline_idx = 0; |
| 501 | } |
| 502 | |
| 503 | void trace_stop_cmdline_recording(void); |
| 504 | |
| 505 | static void trace_save_cmdline(struct task_struct *tsk) |
| 506 | { |
| 507 | unsigned map; |
| 508 | unsigned idx; |
| 509 | |
| 510 | if (!tsk->pid || unlikely(tsk->pid > PID_MAX_DEFAULT)) |
| 511 | return; |
| 512 | |
| 513 | /* |
| 514 | * It's not the end of the world if we don't get |
| 515 | * the lock, but we also don't want to spin |
| 516 | * nor do we want to disable interrupts, |
| 517 | * so if we miss here, then better luck next time. |
| 518 | */ |
| 519 | if (!spin_trylock(&trace_cmdline_lock)) |
| 520 | return; |
| 521 | |
| 522 | idx = map_pid_to_cmdline[tsk->pid]; |
| 523 | if (idx >= SAVED_CMDLINES) { |
| 524 | idx = (cmdline_idx + 1) % SAVED_CMDLINES; |
| 525 | |
| 526 | map = map_cmdline_to_pid[idx]; |
| 527 | if (map <= PID_MAX_DEFAULT) |
| 528 | map_pid_to_cmdline[map] = (unsigned)-1; |
| 529 | |
| 530 | map_pid_to_cmdline[tsk->pid] = idx; |
| 531 | |
| 532 | cmdline_idx = idx; |
| 533 | } |
| 534 | |
| 535 | memcpy(&saved_cmdlines[idx], tsk->comm, TASK_COMM_LEN); |
| 536 | |
| 537 | spin_unlock(&trace_cmdline_lock); |
| 538 | } |
| 539 | |
| 540 | static char *trace_find_cmdline(int pid) |
| 541 | { |
| 542 | char *cmdline = "<...>"; |
| 543 | unsigned map; |
| 544 | |
| 545 | if (!pid) |
| 546 | return "<idle>"; |
| 547 | |
| 548 | if (pid > PID_MAX_DEFAULT) |
| 549 | goto out; |
| 550 | |
| 551 | map = map_pid_to_cmdline[pid]; |
| 552 | if (map >= SAVED_CMDLINES) |
| 553 | goto out; |
| 554 | |
| 555 | cmdline = saved_cmdlines[map]; |
| 556 | |
| 557 | out: |
| 558 | return cmdline; |
| 559 | } |
| 560 | |
| 561 | void tracing_record_cmdline(struct task_struct *tsk) |
| 562 | { |
| 563 | if (atomic_read(&trace_record_cmdline_disabled)) |
| 564 | return; |
| 565 | |
| 566 | trace_save_cmdline(tsk); |
| 567 | } |
| 568 | |
| 569 | static inline struct list_head * |
| 570 | trace_next_list(struct trace_array_cpu *data, struct list_head *next) |
| 571 | { |
| 572 | /* |
| 573 | * Roundrobin - but skip the head (which is not a real page): |
| 574 | */ |
| 575 | next = next->next; |
| 576 | if (unlikely(next == &data->trace_pages)) |
| 577 | next = next->next; |
| 578 | BUG_ON(next == &data->trace_pages); |
| 579 | |
| 580 | return next; |
| 581 | } |
| 582 | |
| 583 | static inline void * |
| 584 | trace_next_page(struct trace_array_cpu *data, void *addr) |
| 585 | { |
| 586 | struct list_head *next; |
| 587 | struct page *page; |
| 588 | |
| 589 | page = virt_to_page(addr); |
| 590 | |
| 591 | next = trace_next_list(data, &page->lru); |
| 592 | page = list_entry(next, struct page, lru); |
| 593 | |
| 594 | return page_address(page); |
| 595 | } |
| 596 | |
| 597 | static inline struct trace_entry * |
| 598 | tracing_get_trace_entry(struct trace_array *tr, struct trace_array_cpu *data) |
| 599 | { |
| 600 | unsigned long idx, idx_next; |
| 601 | struct trace_entry *entry; |
| 602 | |
| 603 | data->trace_idx++; |
| 604 | idx = data->trace_head_idx; |
| 605 | idx_next = idx + 1; |
| 606 | |
| 607 | BUG_ON(idx * TRACE_ENTRY_SIZE >= PAGE_SIZE); |
| 608 | |
| 609 | entry = data->trace_head + idx * TRACE_ENTRY_SIZE; |
| 610 | |
| 611 | if (unlikely(idx_next >= ENTRIES_PER_PAGE)) { |
| 612 | data->trace_head = trace_next_page(data, data->trace_head); |
| 613 | idx_next = 0; |
| 614 | } |
| 615 | |
| 616 | if (data->trace_head == data->trace_tail && |
| 617 | idx_next == data->trace_tail_idx) { |
| 618 | /* overrun */ |
| 619 | data->trace_tail_idx++; |
| 620 | if (data->trace_tail_idx >= ENTRIES_PER_PAGE) { |
| 621 | data->trace_tail = |
| 622 | trace_next_page(data, data->trace_tail); |
| 623 | data->trace_tail_idx = 0; |
| 624 | } |
| 625 | } |
| 626 | |
| 627 | data->trace_head_idx = idx_next; |
| 628 | |
| 629 | return entry; |
| 630 | } |
| 631 | |
| 632 | static inline void |
| 633 | tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags) |
| 634 | { |
| 635 | struct task_struct *tsk = current; |
| 636 | unsigned long pc; |
| 637 | |
| 638 | pc = preempt_count(); |
| 639 | |
| 640 | entry->preempt_count = pc & 0xff; |
| 641 | entry->pid = tsk->pid; |
| 642 | entry->t = ftrace_now(raw_smp_processor_id()); |
| 643 | entry->flags = (irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) | |
| 644 | ((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) | |
| 645 | ((pc & SOFTIRQ_MASK) ? TRACE_FLAG_SOFTIRQ : 0) | |
| 646 | (need_resched() ? TRACE_FLAG_NEED_RESCHED : 0); |
| 647 | } |
| 648 | |
| 649 | void |
| 650 | trace_function(struct trace_array *tr, struct trace_array_cpu *data, |
| 651 | unsigned long ip, unsigned long parent_ip, unsigned long flags) |
| 652 | { |
| 653 | struct trace_entry *entry; |
| 654 | unsigned long irq_flags; |
| 655 | |
| 656 | spin_lock_irqsave(&data->lock, irq_flags); |
| 657 | entry = tracing_get_trace_entry(tr, data); |
| 658 | tracing_generic_entry_update(entry, flags); |
| 659 | entry->type = TRACE_FN; |
| 660 | entry->fn.ip = ip; |
| 661 | entry->fn.parent_ip = parent_ip; |
| 662 | spin_unlock_irqrestore(&data->lock, irq_flags); |
| 663 | |
| 664 | if (!(trace_flags & TRACE_ITER_BLOCK)) |
| 665 | wake_up(&trace_wait); |
| 666 | } |
| 667 | |
| 668 | void |
| 669 | ftrace(struct trace_array *tr, struct trace_array_cpu *data, |
| 670 | unsigned long ip, unsigned long parent_ip, unsigned long flags) |
| 671 | { |
| 672 | if (likely(!atomic_read(&data->disabled))) |
| 673 | trace_function(tr, data, ip, parent_ip, flags); |
| 674 | } |
| 675 | |
| 676 | void |
| 677 | trace_special(struct trace_array *tr, struct trace_array_cpu *data, |
| 678 | unsigned long arg1, unsigned long arg2, unsigned long arg3) |
| 679 | { |
| 680 | struct trace_entry *entry; |
| 681 | unsigned long irq_flags; |
| 682 | |
| 683 | spin_lock_irqsave(&data->lock, irq_flags); |
| 684 | entry = tracing_get_trace_entry(tr, data); |
| 685 | tracing_generic_entry_update(entry, 0); |
| 686 | entry->type = TRACE_SPECIAL; |
| 687 | entry->special.arg1 = arg1; |
| 688 | entry->special.arg2 = arg2; |
| 689 | entry->special.arg3 = arg3; |
| 690 | spin_unlock_irqrestore(&data->lock, irq_flags); |
| 691 | |
| 692 | if (!(trace_flags & TRACE_ITER_BLOCK)) |
| 693 | wake_up(&trace_wait); |
| 694 | } |
| 695 | |
| 696 | void __trace_stack(struct trace_array *tr, |
| 697 | struct trace_array_cpu *data, |
| 698 | unsigned long flags, |
| 699 | int skip) |
| 700 | { |
| 701 | struct trace_entry *entry; |
| 702 | struct stack_trace trace; |
| 703 | |
| 704 | if (!(trace_flags & TRACE_ITER_STACKTRACE)) |
| 705 | return; |
| 706 | |
| 707 | entry = tracing_get_trace_entry(tr, data); |
| 708 | tracing_generic_entry_update(entry, flags); |
| 709 | entry->type = TRACE_STACK; |
| 710 | |
| 711 | memset(&entry->stack, 0, sizeof(entry->stack)); |
| 712 | |
| 713 | trace.nr_entries = 0; |
| 714 | trace.max_entries = FTRACE_STACK_ENTRIES; |
| 715 | trace.skip = skip; |
| 716 | trace.entries = entry->stack.caller; |
| 717 | |
| 718 | save_stack_trace(&trace); |
| 719 | } |
| 720 | |
| 721 | void |
| 722 | tracing_sched_switch_trace(struct trace_array *tr, |
| 723 | struct trace_array_cpu *data, |
| 724 | struct task_struct *prev, |
| 725 | struct task_struct *next, |
| 726 | unsigned long flags) |
| 727 | { |
| 728 | struct trace_entry *entry; |
| 729 | unsigned long irq_flags; |
| 730 | |
| 731 | spin_lock_irqsave(&data->lock, irq_flags); |
| 732 | entry = tracing_get_trace_entry(tr, data); |
| 733 | tracing_generic_entry_update(entry, flags); |
| 734 | entry->type = TRACE_CTX; |
| 735 | entry->ctx.prev_pid = prev->pid; |
| 736 | entry->ctx.prev_prio = prev->prio; |
| 737 | entry->ctx.prev_state = prev->state; |
| 738 | entry->ctx.next_pid = next->pid; |
| 739 | entry->ctx.next_prio = next->prio; |
| 740 | __trace_stack(tr, data, flags, 4); |
| 741 | spin_unlock_irqrestore(&data->lock, irq_flags); |
| 742 | |
| 743 | if (!(trace_flags & TRACE_ITER_BLOCK)) |
| 744 | wake_up(&trace_wait); |
| 745 | } |
| 746 | |
| 747 | void |
| 748 | tracing_sched_wakeup_trace(struct trace_array *tr, |
| 749 | struct trace_array_cpu *data, |
| 750 | struct task_struct *wakee, |
| 751 | struct task_struct *curr, |
| 752 | unsigned long flags) |
| 753 | { |
| 754 | struct trace_entry *entry; |
| 755 | unsigned long irq_flags; |
| 756 | |
| 757 | spin_lock_irqsave(&data->lock, irq_flags); |
| 758 | entry = tracing_get_trace_entry(tr, data); |
| 759 | tracing_generic_entry_update(entry, flags); |
| 760 | entry->type = TRACE_WAKE; |
| 761 | entry->ctx.prev_pid = curr->pid; |
| 762 | entry->ctx.prev_prio = curr->prio; |
| 763 | entry->ctx.prev_state = curr->state; |
| 764 | entry->ctx.next_pid = wakee->pid; |
| 765 | entry->ctx.next_prio = wakee->prio; |
| 766 | __trace_stack(tr, data, flags, 5); |
| 767 | spin_unlock_irqrestore(&data->lock, irq_flags); |
| 768 | |
| 769 | if (!(trace_flags & TRACE_ITER_BLOCK)) |
| 770 | wake_up(&trace_wait); |
| 771 | } |
| 772 | |
| 773 | #ifdef CONFIG_FTRACE |
| 774 | static void |
| 775 | function_trace_call(unsigned long ip, unsigned long parent_ip) |
| 776 | { |
| 777 | struct trace_array *tr = &global_trace; |
| 778 | struct trace_array_cpu *data; |
| 779 | unsigned long flags; |
| 780 | long disabled; |
| 781 | int cpu; |
| 782 | |
| 783 | if (unlikely(!tracer_enabled)) |
| 784 | return; |
| 785 | |
| 786 | local_irq_save(flags); |
| 787 | cpu = raw_smp_processor_id(); |
| 788 | data = tr->data[cpu]; |
| 789 | disabled = atomic_inc_return(&data->disabled); |
| 790 | |
| 791 | if (likely(disabled == 1)) |
| 792 | trace_function(tr, data, ip, parent_ip, flags); |
| 793 | |
| 794 | atomic_dec(&data->disabled); |
| 795 | local_irq_restore(flags); |
| 796 | } |
| 797 | |
| 798 | static struct ftrace_ops trace_ops __read_mostly = |
| 799 | { |
| 800 | .func = function_trace_call, |
| 801 | }; |
| 802 | |
| 803 | void tracing_start_function_trace(void) |
| 804 | { |
| 805 | register_ftrace_function(&trace_ops); |
| 806 | } |
| 807 | |
| 808 | void tracing_stop_function_trace(void) |
| 809 | { |
| 810 | unregister_ftrace_function(&trace_ops); |
| 811 | } |
| 812 | #endif |
| 813 | |
| 814 | enum trace_file_type { |
| 815 | TRACE_FILE_LAT_FMT = 1, |
| 816 | }; |
| 817 | |
| 818 | static struct trace_entry * |
| 819 | trace_entry_idx(struct trace_array *tr, struct trace_array_cpu *data, |
| 820 | struct trace_iterator *iter, int cpu) |
| 821 | { |
| 822 | struct page *page; |
| 823 | struct trace_entry *array; |
| 824 | |
| 825 | if (iter->next_idx[cpu] >= tr->entries || |
| 826 | iter->next_idx[cpu] >= data->trace_idx || |
| 827 | (data->trace_head == data->trace_tail && |
| 828 | data->trace_head_idx == data->trace_tail_idx)) |
| 829 | return NULL; |
| 830 | |
| 831 | if (!iter->next_page[cpu]) { |
| 832 | /* Initialize the iterator for this cpu trace buffer */ |
| 833 | WARN_ON(!data->trace_tail); |
| 834 | page = virt_to_page(data->trace_tail); |
| 835 | iter->next_page[cpu] = &page->lru; |
| 836 | iter->next_page_idx[cpu] = data->trace_tail_idx; |
| 837 | } |
| 838 | |
| 839 | page = list_entry(iter->next_page[cpu], struct page, lru); |
| 840 | BUG_ON(&data->trace_pages == &page->lru); |
| 841 | |
| 842 | array = page_address(page); |
| 843 | |
| 844 | WARN_ON(iter->next_page_idx[cpu] >= ENTRIES_PER_PAGE); |
| 845 | return &array[iter->next_page_idx[cpu]]; |
| 846 | } |
| 847 | |
| 848 | static struct trace_entry * |
| 849 | find_next_entry(struct trace_iterator *iter, int *ent_cpu) |
| 850 | { |
| 851 | struct trace_array *tr = iter->tr; |
| 852 | struct trace_entry *ent, *next = NULL; |
| 853 | int next_cpu = -1; |
| 854 | int cpu; |
| 855 | |
| 856 | for_each_possible_cpu(cpu) { |
| 857 | if (!head_page(tr->data[cpu])) |
| 858 | continue; |
| 859 | ent = trace_entry_idx(tr, tr->data[cpu], iter, cpu); |
| 860 | /* |
| 861 | * Pick the entry with the smallest timestamp: |
| 862 | */ |
| 863 | if (ent && (!next || ent->t < next->t)) { |
| 864 | next = ent; |
| 865 | next_cpu = cpu; |
| 866 | } |
| 867 | } |
| 868 | |
| 869 | if (ent_cpu) |
| 870 | *ent_cpu = next_cpu; |
| 871 | |
| 872 | return next; |
| 873 | } |
| 874 | |
| 875 | static void trace_iterator_increment(struct trace_iterator *iter) |
| 876 | { |
| 877 | iter->idx++; |
| 878 | iter->next_idx[iter->cpu]++; |
| 879 | iter->next_page_idx[iter->cpu]++; |
| 880 | |
| 881 | if (iter->next_page_idx[iter->cpu] >= ENTRIES_PER_PAGE) { |
| 882 | struct trace_array_cpu *data = iter->tr->data[iter->cpu]; |
| 883 | |
| 884 | iter->next_page_idx[iter->cpu] = 0; |
| 885 | iter->next_page[iter->cpu] = |
| 886 | trace_next_list(data, iter->next_page[iter->cpu]); |
| 887 | } |
| 888 | } |
| 889 | |
| 890 | static void trace_consume(struct trace_iterator *iter) |
| 891 | { |
| 892 | struct trace_array_cpu *data = iter->tr->data[iter->cpu]; |
| 893 | |
| 894 | data->trace_tail_idx++; |
| 895 | if (data->trace_tail_idx >= ENTRIES_PER_PAGE) { |
| 896 | data->trace_tail = trace_next_page(data, data->trace_tail); |
| 897 | data->trace_tail_idx = 0; |
| 898 | } |
| 899 | |
| 900 | /* Check if we empty it, then reset the index */ |
| 901 | if (data->trace_head == data->trace_tail && |
| 902 | data->trace_head_idx == data->trace_tail_idx) |
| 903 | data->trace_idx = 0; |
| 904 | } |
| 905 | |
| 906 | static void *find_next_entry_inc(struct trace_iterator *iter) |
| 907 | { |
| 908 | struct trace_entry *next; |
| 909 | int next_cpu = -1; |
| 910 | |
| 911 | next = find_next_entry(iter, &next_cpu); |
| 912 | |
| 913 | iter->prev_ent = iter->ent; |
| 914 | iter->prev_cpu = iter->cpu; |
| 915 | |
| 916 | iter->ent = next; |
| 917 | iter->cpu = next_cpu; |
| 918 | |
| 919 | if (next) |
| 920 | trace_iterator_increment(iter); |
| 921 | |
| 922 | return next ? iter : NULL; |
| 923 | } |
| 924 | |
| 925 | static void *s_next(struct seq_file *m, void *v, loff_t *pos) |
| 926 | { |
| 927 | struct trace_iterator *iter = m->private; |
| 928 | void *last_ent = iter->ent; |
| 929 | int i = (int)*pos; |
| 930 | void *ent; |
| 931 | |
| 932 | (*pos)++; |
| 933 | |
| 934 | /* can't go backwards */ |
| 935 | if (iter->idx > i) |
| 936 | return NULL; |
| 937 | |
| 938 | if (iter->idx < 0) |
| 939 | ent = find_next_entry_inc(iter); |
| 940 | else |
| 941 | ent = iter; |
| 942 | |
| 943 | while (ent && iter->idx < i) |
| 944 | ent = find_next_entry_inc(iter); |
| 945 | |
| 946 | iter->pos = *pos; |
| 947 | |
| 948 | if (last_ent && !ent) |
| 949 | seq_puts(m, "\n\nvim:ft=help\n"); |
| 950 | |
| 951 | return ent; |
| 952 | } |
| 953 | |
| 954 | static void *s_start(struct seq_file *m, loff_t *pos) |
| 955 | { |
| 956 | struct trace_iterator *iter = m->private; |
| 957 | void *p = NULL; |
| 958 | loff_t l = 0; |
| 959 | int i; |
| 960 | |
| 961 | mutex_lock(&trace_types_lock); |
| 962 | |
| 963 | if (!current_trace || current_trace != iter->trace) |
| 964 | return NULL; |
| 965 | |
| 966 | atomic_inc(&trace_record_cmdline_disabled); |
| 967 | |
| 968 | /* let the tracer grab locks here if needed */ |
| 969 | if (current_trace->start) |
| 970 | current_trace->start(iter); |
| 971 | |
| 972 | if (*pos != iter->pos) { |
| 973 | iter->ent = NULL; |
| 974 | iter->cpu = 0; |
| 975 | iter->idx = -1; |
| 976 | iter->prev_ent = NULL; |
| 977 | iter->prev_cpu = -1; |
| 978 | |
| 979 | for_each_possible_cpu(i) { |
| 980 | iter->next_idx[i] = 0; |
| 981 | iter->next_page[i] = NULL; |
| 982 | } |
| 983 | |
| 984 | for (p = iter; p && l < *pos; p = s_next(m, p, &l)) |
| 985 | ; |
| 986 | |
| 987 | } else { |
| 988 | l = *pos - 1; |
| 989 | p = s_next(m, p, &l); |
| 990 | } |
| 991 | |
| 992 | return p; |
| 993 | } |
| 994 | |
| 995 | static void s_stop(struct seq_file *m, void *p) |
| 996 | { |
| 997 | struct trace_iterator *iter = m->private; |
| 998 | |
| 999 | atomic_dec(&trace_record_cmdline_disabled); |
| 1000 | |
| 1001 | /* let the tracer release locks here if needed */ |
| 1002 | if (current_trace && current_trace == iter->trace && iter->trace->stop) |
| 1003 | iter->trace->stop(iter); |
| 1004 | |
| 1005 | mutex_unlock(&trace_types_lock); |
| 1006 | } |
| 1007 | |
| 1008 | static int |
| 1009 | seq_print_sym_short(struct trace_seq *s, const char *fmt, unsigned long address) |
| 1010 | { |
| 1011 | #ifdef CONFIG_KALLSYMS |
| 1012 | char str[KSYM_SYMBOL_LEN]; |
| 1013 | |
| 1014 | kallsyms_lookup(address, NULL, NULL, NULL, str); |
| 1015 | |
| 1016 | return trace_seq_printf(s, fmt, str); |
| 1017 | #endif |
| 1018 | return 1; |
| 1019 | } |
| 1020 | |
| 1021 | static int |
| 1022 | seq_print_sym_offset(struct trace_seq *s, const char *fmt, |
| 1023 | unsigned long address) |
| 1024 | { |
| 1025 | #ifdef CONFIG_KALLSYMS |
| 1026 | char str[KSYM_SYMBOL_LEN]; |
| 1027 | |
| 1028 | sprint_symbol(str, address); |
| 1029 | return trace_seq_printf(s, fmt, str); |
| 1030 | #endif |
| 1031 | return 1; |
| 1032 | } |
| 1033 | |
| 1034 | #ifndef CONFIG_64BIT |
| 1035 | # define IP_FMT "%08lx" |
| 1036 | #else |
| 1037 | # define IP_FMT "%016lx" |
| 1038 | #endif |
| 1039 | |
| 1040 | static int |
| 1041 | seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags) |
| 1042 | { |
| 1043 | int ret; |
| 1044 | |
| 1045 | if (!ip) |
| 1046 | return trace_seq_printf(s, "0"); |
| 1047 | |
| 1048 | if (sym_flags & TRACE_ITER_SYM_OFFSET) |
| 1049 | ret = seq_print_sym_offset(s, "%s", ip); |
| 1050 | else |
| 1051 | ret = seq_print_sym_short(s, "%s", ip); |
| 1052 | |
| 1053 | if (!ret) |
| 1054 | return 0; |
| 1055 | |
| 1056 | if (sym_flags & TRACE_ITER_SYM_ADDR) |
| 1057 | ret = trace_seq_printf(s, " <" IP_FMT ">", ip); |
| 1058 | return ret; |
| 1059 | } |
| 1060 | |
| 1061 | static void print_lat_help_header(struct seq_file *m) |
| 1062 | { |
| 1063 | seq_puts(m, "# _------=> CPU# \n"); |
| 1064 | seq_puts(m, "# / _-----=> irqs-off \n"); |
| 1065 | seq_puts(m, "# | / _----=> need-resched \n"); |
| 1066 | seq_puts(m, "# || / _---=> hardirq/softirq \n"); |
| 1067 | seq_puts(m, "# ||| / _--=> preempt-depth \n"); |
| 1068 | seq_puts(m, "# |||| / \n"); |
| 1069 | seq_puts(m, "# ||||| delay \n"); |
| 1070 | seq_puts(m, "# cmd pid ||||| time | caller \n"); |
| 1071 | seq_puts(m, "# \\ / ||||| \\ | / \n"); |
| 1072 | } |
| 1073 | |
| 1074 | static void print_func_help_header(struct seq_file *m) |
| 1075 | { |
| 1076 | seq_puts(m, "# TASK-PID CPU# TIMESTAMP FUNCTION\n"); |
| 1077 | seq_puts(m, "# | | | | |\n"); |
| 1078 | } |
| 1079 | |
| 1080 | |
| 1081 | static void |
| 1082 | print_trace_header(struct seq_file *m, struct trace_iterator *iter) |
| 1083 | { |
| 1084 | unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK); |
| 1085 | struct trace_array *tr = iter->tr; |
| 1086 | struct trace_array_cpu *data = tr->data[tr->cpu]; |
| 1087 | struct tracer *type = current_trace; |
| 1088 | unsigned long total = 0; |
| 1089 | unsigned long entries = 0; |
| 1090 | int cpu; |
| 1091 | const char *name = "preemption"; |
| 1092 | |
| 1093 | if (type) |
| 1094 | name = type->name; |
| 1095 | |
| 1096 | for_each_possible_cpu(cpu) { |
| 1097 | if (head_page(tr->data[cpu])) { |
| 1098 | total += tr->data[cpu]->trace_idx; |
| 1099 | if (tr->data[cpu]->trace_idx > tr->entries) |
| 1100 | entries += tr->entries; |
| 1101 | else |
| 1102 | entries += tr->data[cpu]->trace_idx; |
| 1103 | } |
| 1104 | } |
| 1105 | |
| 1106 | seq_printf(m, "%s latency trace v1.1.5 on %s\n", |
| 1107 | name, UTS_RELEASE); |
| 1108 | seq_puts(m, "-----------------------------------" |
| 1109 | "---------------------------------\n"); |
| 1110 | seq_printf(m, " latency: %lu us, #%lu/%lu, CPU#%d |" |
| 1111 | " (M:%s VP:%d, KP:%d, SP:%d HP:%d", |
| 1112 | nsecs_to_usecs(data->saved_latency), |
| 1113 | entries, |
| 1114 | total, |
| 1115 | tr->cpu, |
| 1116 | #if defined(CONFIG_PREEMPT_NONE) |
| 1117 | "server", |
| 1118 | #elif defined(CONFIG_PREEMPT_VOLUNTARY) |
| 1119 | "desktop", |
| 1120 | #elif defined(CONFIG_PREEMPT_DESKTOP) |
| 1121 | "preempt", |
| 1122 | #else |
| 1123 | "unknown", |
| 1124 | #endif |
| 1125 | /* These are reserved for later use */ |
| 1126 | 0, 0, 0, 0); |
| 1127 | #ifdef CONFIG_SMP |
| 1128 | seq_printf(m, " #P:%d)\n", num_online_cpus()); |
| 1129 | #else |
| 1130 | seq_puts(m, ")\n"); |
| 1131 | #endif |
| 1132 | seq_puts(m, " -----------------\n"); |
| 1133 | seq_printf(m, " | task: %.16s-%d " |
| 1134 | "(uid:%d nice:%ld policy:%ld rt_prio:%ld)\n", |
| 1135 | data->comm, data->pid, data->uid, data->nice, |
| 1136 | data->policy, data->rt_priority); |
| 1137 | seq_puts(m, " -----------------\n"); |
| 1138 | |
| 1139 | if (data->critical_start) { |
| 1140 | seq_puts(m, " => started at: "); |
| 1141 | seq_print_ip_sym(&iter->seq, data->critical_start, sym_flags); |
| 1142 | trace_print_seq(m, &iter->seq); |
| 1143 | seq_puts(m, "\n => ended at: "); |
| 1144 | seq_print_ip_sym(&iter->seq, data->critical_end, sym_flags); |
| 1145 | trace_print_seq(m, &iter->seq); |
| 1146 | seq_puts(m, "\n"); |
| 1147 | } |
| 1148 | |
| 1149 | seq_puts(m, "\n"); |
| 1150 | } |
| 1151 | |
| 1152 | static void |
| 1153 | lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu) |
| 1154 | { |
| 1155 | int hardirq, softirq; |
| 1156 | char *comm; |
| 1157 | |
| 1158 | comm = trace_find_cmdline(entry->pid); |
| 1159 | |
| 1160 | trace_seq_printf(s, "%8.8s-%-5d ", comm, entry->pid); |
| 1161 | trace_seq_printf(s, "%d", cpu); |
| 1162 | trace_seq_printf(s, "%c%c", |
| 1163 | (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' : '.', |
| 1164 | ((entry->flags & TRACE_FLAG_NEED_RESCHED) ? 'N' : '.')); |
| 1165 | |
| 1166 | hardirq = entry->flags & TRACE_FLAG_HARDIRQ; |
| 1167 | softirq = entry->flags & TRACE_FLAG_SOFTIRQ; |
| 1168 | if (hardirq && softirq) |
| 1169 | trace_seq_putc(s, 'H'); |
| 1170 | else { |
| 1171 | if (hardirq) |
| 1172 | trace_seq_putc(s, 'h'); |
| 1173 | else { |
| 1174 | if (softirq) |
| 1175 | trace_seq_putc(s, 's'); |
| 1176 | else |
| 1177 | trace_seq_putc(s, '.'); |
| 1178 | } |
| 1179 | } |
| 1180 | |
| 1181 | if (entry->preempt_count) |
| 1182 | trace_seq_printf(s, "%x", entry->preempt_count); |
| 1183 | else |
| 1184 | trace_seq_puts(s, "."); |
| 1185 | } |
| 1186 | |
| 1187 | unsigned long preempt_mark_thresh = 100; |
| 1188 | |
| 1189 | static void |
| 1190 | lat_print_timestamp(struct trace_seq *s, unsigned long long abs_usecs, |
| 1191 | unsigned long rel_usecs) |
| 1192 | { |
| 1193 | trace_seq_printf(s, " %4lldus", abs_usecs); |
| 1194 | if (rel_usecs > preempt_mark_thresh) |
| 1195 | trace_seq_puts(s, "!: "); |
| 1196 | else if (rel_usecs > 1) |
| 1197 | trace_seq_puts(s, "+: "); |
| 1198 | else |
| 1199 | trace_seq_puts(s, " : "); |
| 1200 | } |
| 1201 | |
| 1202 | static const char state_to_char[] = TASK_STATE_TO_CHAR_STR; |
| 1203 | |
| 1204 | static int |
| 1205 | print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu) |
| 1206 | { |
| 1207 | struct trace_seq *s = &iter->seq; |
| 1208 | unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK); |
| 1209 | struct trace_entry *next_entry = find_next_entry(iter, NULL); |
| 1210 | unsigned long verbose = (trace_flags & TRACE_ITER_VERBOSE); |
| 1211 | struct trace_entry *entry = iter->ent; |
| 1212 | unsigned long abs_usecs; |
| 1213 | unsigned long rel_usecs; |
| 1214 | char *comm; |
| 1215 | int S; |
| 1216 | int i; |
| 1217 | |
| 1218 | if (!next_entry) |
| 1219 | next_entry = entry; |
| 1220 | rel_usecs = ns2usecs(next_entry->t - entry->t); |
| 1221 | abs_usecs = ns2usecs(entry->t - iter->tr->time_start); |
| 1222 | |
| 1223 | if (verbose) { |
| 1224 | comm = trace_find_cmdline(entry->pid); |
| 1225 | trace_seq_printf(s, "%16s %5d %d %d %08x %08x [%08lx]" |
| 1226 | " %ld.%03ldms (+%ld.%03ldms): ", |
| 1227 | comm, |
| 1228 | entry->pid, cpu, entry->flags, |
| 1229 | entry->preempt_count, trace_idx, |
| 1230 | ns2usecs(entry->t), |
| 1231 | abs_usecs/1000, |
| 1232 | abs_usecs % 1000, rel_usecs/1000, |
| 1233 | rel_usecs % 1000); |
| 1234 | } else { |
| 1235 | if (entry->type != TRACE_STACK) { |
| 1236 | lat_print_generic(s, entry, cpu); |
| 1237 | lat_print_timestamp(s, abs_usecs, rel_usecs); |
| 1238 | } |
| 1239 | } |
| 1240 | switch (entry->type) { |
| 1241 | case TRACE_FN: |
| 1242 | seq_print_ip_sym(s, entry->fn.ip, sym_flags); |
| 1243 | trace_seq_puts(s, " ("); |
| 1244 | seq_print_ip_sym(s, entry->fn.parent_ip, sym_flags); |
| 1245 | trace_seq_puts(s, ")\n"); |
| 1246 | break; |
| 1247 | case TRACE_CTX: |
| 1248 | case TRACE_WAKE: |
| 1249 | S = entry->ctx.prev_state < sizeof(state_to_char) ? |
| 1250 | state_to_char[entry->ctx.prev_state] : 'X'; |
| 1251 | comm = trace_find_cmdline(entry->ctx.next_pid); |
| 1252 | trace_seq_printf(s, " %5d:%3d:%c %s %5d:%3d %s\n", |
| 1253 | entry->ctx.prev_pid, |
| 1254 | entry->ctx.prev_prio, |
| 1255 | S, entry->type == TRACE_CTX ? "==>" : " +", |
| 1256 | entry->ctx.next_pid, |
| 1257 | entry->ctx.next_prio, |
| 1258 | comm); |
| 1259 | break; |
| 1260 | case TRACE_SPECIAL: |
| 1261 | trace_seq_printf(s, " %lx %lx %lx\n", |
| 1262 | entry->special.arg1, |
| 1263 | entry->special.arg2, |
| 1264 | entry->special.arg3); |
| 1265 | break; |
| 1266 | case TRACE_STACK: |
| 1267 | for (i = 0; i < FTRACE_STACK_ENTRIES; i++) { |
| 1268 | if (i) |
| 1269 | trace_seq_puts(s, " <= "); |
| 1270 | seq_print_ip_sym(s, entry->stack.caller[i], sym_flags); |
| 1271 | } |
| 1272 | trace_seq_puts(s, "\n"); |
| 1273 | break; |
| 1274 | default: |
| 1275 | trace_seq_printf(s, "Unknown type %d\n", entry->type); |
| 1276 | } |
| 1277 | return 1; |
| 1278 | } |
| 1279 | |
| 1280 | static int print_trace_fmt(struct trace_iterator *iter) |
| 1281 | { |
| 1282 | struct trace_seq *s = &iter->seq; |
| 1283 | unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK); |
| 1284 | struct trace_entry *entry; |
| 1285 | unsigned long usec_rem; |
| 1286 | unsigned long long t; |
| 1287 | unsigned long secs; |
| 1288 | char *comm; |
| 1289 | int ret; |
| 1290 | int S; |
| 1291 | int i; |
| 1292 | |
| 1293 | entry = iter->ent; |
| 1294 | |
| 1295 | comm = trace_find_cmdline(iter->ent->pid); |
| 1296 | |
| 1297 | t = ns2usecs(entry->t); |
| 1298 | usec_rem = do_div(t, 1000000ULL); |
| 1299 | secs = (unsigned long)t; |
| 1300 | |
| 1301 | if (entry->type != TRACE_STACK) { |
| 1302 | ret = trace_seq_printf(s, "%16s-%-5d ", comm, entry->pid); |
| 1303 | if (!ret) |
| 1304 | return 0; |
| 1305 | ret = trace_seq_printf(s, "[%02d] ", iter->cpu); |
| 1306 | if (!ret) |
| 1307 | return 0; |
| 1308 | ret = trace_seq_printf(s, "%5lu.%06lu: ", secs, usec_rem); |
| 1309 | if (!ret) |
| 1310 | return 0; |
| 1311 | } |
| 1312 | |
| 1313 | switch (entry->type) { |
| 1314 | case TRACE_FN: |
| 1315 | ret = seq_print_ip_sym(s, entry->fn.ip, sym_flags); |
| 1316 | if (!ret) |
| 1317 | return 0; |
| 1318 | if ((sym_flags & TRACE_ITER_PRINT_PARENT) && |
| 1319 | entry->fn.parent_ip) { |
| 1320 | ret = trace_seq_printf(s, " <-"); |
| 1321 | if (!ret) |
| 1322 | return 0; |
| 1323 | ret = seq_print_ip_sym(s, entry->fn.parent_ip, |
| 1324 | sym_flags); |
| 1325 | if (!ret) |
| 1326 | return 0; |
| 1327 | } |
| 1328 | ret = trace_seq_printf(s, "\n"); |
| 1329 | if (!ret) |
| 1330 | return 0; |
| 1331 | break; |
| 1332 | case TRACE_CTX: |
| 1333 | case TRACE_WAKE: |
| 1334 | S = entry->ctx.prev_state < sizeof(state_to_char) ? |
| 1335 | state_to_char[entry->ctx.prev_state] : 'X'; |
| 1336 | ret = trace_seq_printf(s, " %5d:%3d:%c %s %5d:%3d\n", |
| 1337 | entry->ctx.prev_pid, |
| 1338 | entry->ctx.prev_prio, |
| 1339 | S, |
| 1340 | entry->type == TRACE_CTX ? "==>" : " +", |
| 1341 | entry->ctx.next_pid, |
| 1342 | entry->ctx.next_prio); |
| 1343 | if (!ret) |
| 1344 | return 0; |
| 1345 | break; |
| 1346 | case TRACE_SPECIAL: |
| 1347 | ret = trace_seq_printf(s, " %lx %lx %lx\n", |
| 1348 | entry->special.arg1, |
| 1349 | entry->special.arg2, |
| 1350 | entry->special.arg3); |
| 1351 | if (!ret) |
| 1352 | return 0; |
| 1353 | break; |
| 1354 | case TRACE_STACK: |
| 1355 | for (i = 0; i < FTRACE_STACK_ENTRIES; i++) { |
| 1356 | if (i) { |
| 1357 | ret = trace_seq_puts(s, " <= "); |
| 1358 | if (!ret) |
| 1359 | return 0; |
| 1360 | } |
| 1361 | ret = seq_print_ip_sym(s, entry->stack.caller[i], |
| 1362 | sym_flags); |
| 1363 | if (!ret) |
| 1364 | return 0; |
| 1365 | } |
| 1366 | ret = trace_seq_puts(s, "\n"); |
| 1367 | if (!ret) |
| 1368 | return 0; |
| 1369 | break; |
| 1370 | } |
| 1371 | return 1; |
| 1372 | } |
| 1373 | |
| 1374 | static int print_raw_fmt(struct trace_iterator *iter) |
| 1375 | { |
| 1376 | struct trace_seq *s = &iter->seq; |
| 1377 | struct trace_entry *entry; |
| 1378 | int ret; |
| 1379 | int S; |
| 1380 | |
| 1381 | entry = iter->ent; |
| 1382 | |
| 1383 | ret = trace_seq_printf(s, "%d %d %llu ", |
| 1384 | entry->pid, iter->cpu, entry->t); |
| 1385 | if (!ret) |
| 1386 | return 0; |
| 1387 | |
| 1388 | switch (entry->type) { |
| 1389 | case TRACE_FN: |
| 1390 | ret = trace_seq_printf(s, "%x %x\n", |
| 1391 | entry->fn.ip, entry->fn.parent_ip); |
| 1392 | if (!ret) |
| 1393 | return 0; |
| 1394 | break; |
| 1395 | case TRACE_CTX: |
| 1396 | case TRACE_WAKE: |
| 1397 | S = entry->ctx.prev_state < sizeof(state_to_char) ? |
| 1398 | state_to_char[entry->ctx.prev_state] : 'X'; |
| 1399 | if (entry->type == TRACE_WAKE) |
| 1400 | S = '+'; |
| 1401 | ret = trace_seq_printf(s, "%d %d %c %d %d\n", |
| 1402 | entry->ctx.prev_pid, |
| 1403 | entry->ctx.prev_prio, |
| 1404 | S, |
| 1405 | entry->ctx.next_pid, |
| 1406 | entry->ctx.next_prio); |
| 1407 | if (!ret) |
| 1408 | return 0; |
| 1409 | break; |
| 1410 | case TRACE_SPECIAL: |
| 1411 | case TRACE_STACK: |
| 1412 | ret = trace_seq_printf(s, " %lx %lx %lx\n", |
| 1413 | entry->special.arg1, |
| 1414 | entry->special.arg2, |
| 1415 | entry->special.arg3); |
| 1416 | if (!ret) |
| 1417 | return 0; |
| 1418 | break; |
| 1419 | } |
| 1420 | return 1; |
| 1421 | } |
| 1422 | |
| 1423 | #define SEQ_PUT_FIELD_RET(s, x) \ |
| 1424 | do { \ |
| 1425 | if (!trace_seq_putmem(s, &(x), sizeof(x))) \ |
| 1426 | return 0; \ |
| 1427 | } while (0) |
| 1428 | |
| 1429 | #define SEQ_PUT_HEX_FIELD_RET(s, x) \ |
| 1430 | do { \ |
| 1431 | if (!trace_seq_putmem_hex(s, &(x), sizeof(x))) \ |
| 1432 | return 0; \ |
| 1433 | } while (0) |
| 1434 | |
| 1435 | static int print_hex_fmt(struct trace_iterator *iter) |
| 1436 | { |
| 1437 | struct trace_seq *s = &iter->seq; |
| 1438 | unsigned char newline = '\n'; |
| 1439 | struct trace_entry *entry; |
| 1440 | int S; |
| 1441 | |
| 1442 | entry = iter->ent; |
| 1443 | |
| 1444 | SEQ_PUT_HEX_FIELD_RET(s, entry->pid); |
| 1445 | SEQ_PUT_HEX_FIELD_RET(s, iter->cpu); |
| 1446 | SEQ_PUT_HEX_FIELD_RET(s, entry->t); |
| 1447 | |
| 1448 | switch (entry->type) { |
| 1449 | case TRACE_FN: |
| 1450 | SEQ_PUT_HEX_FIELD_RET(s, entry->fn.ip); |
| 1451 | SEQ_PUT_HEX_FIELD_RET(s, entry->fn.parent_ip); |
| 1452 | break; |
| 1453 | case TRACE_CTX: |
| 1454 | case TRACE_WAKE: |
| 1455 | S = entry->ctx.prev_state < sizeof(state_to_char) ? |
| 1456 | state_to_char[entry->ctx.prev_state] : 'X'; |
| 1457 | if (entry->type == TRACE_WAKE) |
| 1458 | S = '+'; |
| 1459 | SEQ_PUT_HEX_FIELD_RET(s, entry->ctx.prev_pid); |
| 1460 | SEQ_PUT_HEX_FIELD_RET(s, entry->ctx.prev_prio); |
| 1461 | SEQ_PUT_HEX_FIELD_RET(s, S); |
| 1462 | SEQ_PUT_HEX_FIELD_RET(s, entry->ctx.next_pid); |
| 1463 | SEQ_PUT_HEX_FIELD_RET(s, entry->ctx.next_prio); |
| 1464 | SEQ_PUT_HEX_FIELD_RET(s, entry->fn.parent_ip); |
| 1465 | break; |
| 1466 | case TRACE_SPECIAL: |
| 1467 | case TRACE_STACK: |
| 1468 | SEQ_PUT_HEX_FIELD_RET(s, entry->special.arg1); |
| 1469 | SEQ_PUT_HEX_FIELD_RET(s, entry->special.arg2); |
| 1470 | SEQ_PUT_HEX_FIELD_RET(s, entry->special.arg3); |
| 1471 | break; |
| 1472 | } |
| 1473 | SEQ_PUT_FIELD_RET(s, newline); |
| 1474 | |
| 1475 | return 1; |
| 1476 | } |
| 1477 | |
| 1478 | static int print_bin_fmt(struct trace_iterator *iter) |
| 1479 | { |
| 1480 | struct trace_seq *s = &iter->seq; |
| 1481 | struct trace_entry *entry; |
| 1482 | |
| 1483 | entry = iter->ent; |
| 1484 | |
| 1485 | SEQ_PUT_FIELD_RET(s, entry->pid); |
| 1486 | SEQ_PUT_FIELD_RET(s, entry->cpu); |
| 1487 | SEQ_PUT_FIELD_RET(s, entry->t); |
| 1488 | |
| 1489 | switch (entry->type) { |
| 1490 | case TRACE_FN: |
| 1491 | SEQ_PUT_FIELD_RET(s, entry->fn.ip); |
| 1492 | SEQ_PUT_FIELD_RET(s, entry->fn.parent_ip); |
| 1493 | break; |
| 1494 | case TRACE_CTX: |
| 1495 | SEQ_PUT_FIELD_RET(s, entry->ctx.prev_pid); |
| 1496 | SEQ_PUT_FIELD_RET(s, entry->ctx.prev_prio); |
| 1497 | SEQ_PUT_FIELD_RET(s, entry->ctx.prev_state); |
| 1498 | SEQ_PUT_FIELD_RET(s, entry->ctx.next_pid); |
| 1499 | SEQ_PUT_FIELD_RET(s, entry->ctx.next_prio); |
| 1500 | break; |
| 1501 | case TRACE_SPECIAL: |
| 1502 | case TRACE_STACK: |
| 1503 | SEQ_PUT_FIELD_RET(s, entry->special.arg1); |
| 1504 | SEQ_PUT_FIELD_RET(s, entry->special.arg2); |
| 1505 | SEQ_PUT_FIELD_RET(s, entry->special.arg3); |
| 1506 | break; |
| 1507 | } |
| 1508 | return 1; |
| 1509 | } |
| 1510 | |
| 1511 | static int trace_empty(struct trace_iterator *iter) |
| 1512 | { |
| 1513 | struct trace_array_cpu *data; |
| 1514 | int cpu; |
| 1515 | |
| 1516 | for_each_possible_cpu(cpu) { |
| 1517 | data = iter->tr->data[cpu]; |
| 1518 | |
| 1519 | if (head_page(data) && data->trace_idx && |
| 1520 | (data->trace_tail != data->trace_head || |
| 1521 | data->trace_tail_idx != data->trace_head_idx)) |
| 1522 | return 0; |
| 1523 | } |
| 1524 | return 1; |
| 1525 | } |
| 1526 | |
| 1527 | static int print_trace_line(struct trace_iterator *iter) |
| 1528 | { |
| 1529 | if (trace_flags & TRACE_ITER_BIN) |
| 1530 | return print_bin_fmt(iter); |
| 1531 | |
| 1532 | if (trace_flags & TRACE_ITER_HEX) |
| 1533 | return print_hex_fmt(iter); |
| 1534 | |
| 1535 | if (trace_flags & TRACE_ITER_RAW) |
| 1536 | return print_raw_fmt(iter); |
| 1537 | |
| 1538 | if (iter->iter_flags & TRACE_FILE_LAT_FMT) |
| 1539 | return print_lat_fmt(iter, iter->idx, iter->cpu); |
| 1540 | |
| 1541 | return print_trace_fmt(iter); |
| 1542 | } |
| 1543 | |
| 1544 | static int s_show(struct seq_file *m, void *v) |
| 1545 | { |
| 1546 | struct trace_iterator *iter = v; |
| 1547 | |
| 1548 | if (iter->ent == NULL) { |
| 1549 | if (iter->tr) { |
| 1550 | seq_printf(m, "# tracer: %s\n", iter->trace->name); |
| 1551 | seq_puts(m, "#\n"); |
| 1552 | } |
| 1553 | if (iter->iter_flags & TRACE_FILE_LAT_FMT) { |
| 1554 | /* print nothing if the buffers are empty */ |
| 1555 | if (trace_empty(iter)) |
| 1556 | return 0; |
| 1557 | print_trace_header(m, iter); |
| 1558 | if (!(trace_flags & TRACE_ITER_VERBOSE)) |
| 1559 | print_lat_help_header(m); |
| 1560 | } else { |
| 1561 | if (!(trace_flags & TRACE_ITER_VERBOSE)) |
| 1562 | print_func_help_header(m); |
| 1563 | } |
| 1564 | } else { |
| 1565 | print_trace_line(iter); |
| 1566 | trace_print_seq(m, &iter->seq); |
| 1567 | } |
| 1568 | |
| 1569 | return 0; |
| 1570 | } |
| 1571 | |
| 1572 | static struct seq_operations tracer_seq_ops = { |
| 1573 | .start = s_start, |
| 1574 | .next = s_next, |
| 1575 | .stop = s_stop, |
| 1576 | .show = s_show, |
| 1577 | }; |
| 1578 | |
| 1579 | static struct trace_iterator * |
| 1580 | __tracing_open(struct inode *inode, struct file *file, int *ret) |
| 1581 | { |
| 1582 | struct trace_iterator *iter; |
| 1583 | |
| 1584 | if (tracing_disabled) { |
| 1585 | *ret = -ENODEV; |
| 1586 | return NULL; |
| 1587 | } |
| 1588 | |
| 1589 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
| 1590 | if (!iter) { |
| 1591 | *ret = -ENOMEM; |
| 1592 | goto out; |
| 1593 | } |
| 1594 | |
| 1595 | mutex_lock(&trace_types_lock); |
| 1596 | if (current_trace && current_trace->print_max) |
| 1597 | iter->tr = &max_tr; |
| 1598 | else |
| 1599 | iter->tr = inode->i_private; |
| 1600 | iter->trace = current_trace; |
| 1601 | iter->pos = -1; |
| 1602 | |
| 1603 | /* TODO stop tracer */ |
| 1604 | *ret = seq_open(file, &tracer_seq_ops); |
| 1605 | if (!*ret) { |
| 1606 | struct seq_file *m = file->private_data; |
| 1607 | m->private = iter; |
| 1608 | |
| 1609 | /* stop the trace while dumping */ |
| 1610 | if (iter->tr->ctrl) |
| 1611 | tracer_enabled = 0; |
| 1612 | |
| 1613 | if (iter->trace && iter->trace->open) |
| 1614 | iter->trace->open(iter); |
| 1615 | } else { |
| 1616 | kfree(iter); |
| 1617 | iter = NULL; |
| 1618 | } |
| 1619 | mutex_unlock(&trace_types_lock); |
| 1620 | |
| 1621 | out: |
| 1622 | return iter; |
| 1623 | } |
| 1624 | |
| 1625 | int tracing_open_generic(struct inode *inode, struct file *filp) |
| 1626 | { |
| 1627 | if (tracing_disabled) |
| 1628 | return -ENODEV; |
| 1629 | |
| 1630 | filp->private_data = inode->i_private; |
| 1631 | return 0; |
| 1632 | } |
| 1633 | |
| 1634 | int tracing_release(struct inode *inode, struct file *file) |
| 1635 | { |
| 1636 | struct seq_file *m = (struct seq_file *)file->private_data; |
| 1637 | struct trace_iterator *iter = m->private; |
| 1638 | |
| 1639 | mutex_lock(&trace_types_lock); |
| 1640 | if (iter->trace && iter->trace->close) |
| 1641 | iter->trace->close(iter); |
| 1642 | |
| 1643 | /* reenable tracing if it was previously enabled */ |
| 1644 | if (iter->tr->ctrl) |
| 1645 | tracer_enabled = 1; |
| 1646 | mutex_unlock(&trace_types_lock); |
| 1647 | |
| 1648 | seq_release(inode, file); |
| 1649 | kfree(iter); |
| 1650 | return 0; |
| 1651 | } |
| 1652 | |
| 1653 | static int tracing_open(struct inode *inode, struct file *file) |
| 1654 | { |
| 1655 | int ret; |
| 1656 | |
| 1657 | __tracing_open(inode, file, &ret); |
| 1658 | |
| 1659 | return ret; |
| 1660 | } |
| 1661 | |
| 1662 | static int tracing_lt_open(struct inode *inode, struct file *file) |
| 1663 | { |
| 1664 | struct trace_iterator *iter; |
| 1665 | int ret; |
| 1666 | |
| 1667 | iter = __tracing_open(inode, file, &ret); |
| 1668 | |
| 1669 | if (!ret) |
| 1670 | iter->iter_flags |= TRACE_FILE_LAT_FMT; |
| 1671 | |
| 1672 | return ret; |
| 1673 | } |
| 1674 | |
| 1675 | |
| 1676 | static void * |
| 1677 | t_next(struct seq_file *m, void *v, loff_t *pos) |
| 1678 | { |
| 1679 | struct tracer *t = m->private; |
| 1680 | |
| 1681 | (*pos)++; |
| 1682 | |
| 1683 | if (t) |
| 1684 | t = t->next; |
| 1685 | |
| 1686 | m->private = t; |
| 1687 | |
| 1688 | return t; |
| 1689 | } |
| 1690 | |
| 1691 | static void *t_start(struct seq_file *m, loff_t *pos) |
| 1692 | { |
| 1693 | struct tracer *t = m->private; |
| 1694 | loff_t l = 0; |
| 1695 | |
| 1696 | mutex_lock(&trace_types_lock); |
| 1697 | for (; t && l < *pos; t = t_next(m, t, &l)) |
| 1698 | ; |
| 1699 | |
| 1700 | return t; |
| 1701 | } |
| 1702 | |
| 1703 | static void t_stop(struct seq_file *m, void *p) |
| 1704 | { |
| 1705 | mutex_unlock(&trace_types_lock); |
| 1706 | } |
| 1707 | |
| 1708 | static int t_show(struct seq_file *m, void *v) |
| 1709 | { |
| 1710 | struct tracer *t = v; |
| 1711 | |
| 1712 | if (!t) |
| 1713 | return 0; |
| 1714 | |
| 1715 | seq_printf(m, "%s", t->name); |
| 1716 | if (t->next) |
| 1717 | seq_putc(m, ' '); |
| 1718 | else |
| 1719 | seq_putc(m, '\n'); |
| 1720 | |
| 1721 | return 0; |
| 1722 | } |
| 1723 | |
| 1724 | static struct seq_operations show_traces_seq_ops = { |
| 1725 | .start = t_start, |
| 1726 | .next = t_next, |
| 1727 | .stop = t_stop, |
| 1728 | .show = t_show, |
| 1729 | }; |
| 1730 | |
| 1731 | static int show_traces_open(struct inode *inode, struct file *file) |
| 1732 | { |
| 1733 | int ret; |
| 1734 | |
| 1735 | if (tracing_disabled) |
| 1736 | return -ENODEV; |
| 1737 | |
| 1738 | ret = seq_open(file, &show_traces_seq_ops); |
| 1739 | if (!ret) { |
| 1740 | struct seq_file *m = file->private_data; |
| 1741 | m->private = trace_types; |
| 1742 | } |
| 1743 | |
| 1744 | return ret; |
| 1745 | } |
| 1746 | |
| 1747 | static struct file_operations tracing_fops = { |
| 1748 | .open = tracing_open, |
| 1749 | .read = seq_read, |
| 1750 | .llseek = seq_lseek, |
| 1751 | .release = tracing_release, |
| 1752 | }; |
| 1753 | |
| 1754 | static struct file_operations tracing_lt_fops = { |
| 1755 | .open = tracing_lt_open, |
| 1756 | .read = seq_read, |
| 1757 | .llseek = seq_lseek, |
| 1758 | .release = tracing_release, |
| 1759 | }; |
| 1760 | |
| 1761 | static struct file_operations show_traces_fops = { |
| 1762 | .open = show_traces_open, |
| 1763 | .read = seq_read, |
| 1764 | .release = seq_release, |
| 1765 | }; |
| 1766 | |
| 1767 | static ssize_t |
| 1768 | tracing_iter_ctrl_read(struct file *filp, char __user *ubuf, |
| 1769 | size_t cnt, loff_t *ppos) |
| 1770 | { |
| 1771 | char *buf; |
| 1772 | int r = 0; |
| 1773 | int len = 0; |
| 1774 | int i; |
| 1775 | |
| 1776 | /* calulate max size */ |
| 1777 | for (i = 0; trace_options[i]; i++) { |
| 1778 | len += strlen(trace_options[i]); |
| 1779 | len += 3; /* "no" and space */ |
| 1780 | } |
| 1781 | |
| 1782 | /* +2 for \n and \0 */ |
| 1783 | buf = kmalloc(len + 2, GFP_KERNEL); |
| 1784 | if (!buf) |
| 1785 | return -ENOMEM; |
| 1786 | |
| 1787 | for (i = 0; trace_options[i]; i++) { |
| 1788 | if (trace_flags & (1 << i)) |
| 1789 | r += sprintf(buf + r, "%s ", trace_options[i]); |
| 1790 | else |
| 1791 | r += sprintf(buf + r, "no%s ", trace_options[i]); |
| 1792 | } |
| 1793 | |
| 1794 | r += sprintf(buf + r, "\n"); |
| 1795 | WARN_ON(r >= len + 2); |
| 1796 | |
| 1797 | r = simple_read_from_buffer(ubuf, cnt, ppos, |
| 1798 | buf, r); |
| 1799 | |
| 1800 | kfree(buf); |
| 1801 | |
| 1802 | return r; |
| 1803 | } |
| 1804 | |
| 1805 | static ssize_t |
| 1806 | tracing_iter_ctrl_write(struct file *filp, const char __user *ubuf, |
| 1807 | size_t cnt, loff_t *ppos) |
| 1808 | { |
| 1809 | char buf[64]; |
| 1810 | char *cmp = buf; |
| 1811 | int neg = 0; |
| 1812 | int i; |
| 1813 | |
| 1814 | if (cnt > 63) |
| 1815 | cnt = 63; |
| 1816 | |
| 1817 | if (copy_from_user(&buf, ubuf, cnt)) |
| 1818 | return -EFAULT; |
| 1819 | |
| 1820 | buf[cnt] = 0; |
| 1821 | |
| 1822 | if (strncmp(buf, "no", 2) == 0) { |
| 1823 | neg = 1; |
| 1824 | cmp += 2; |
| 1825 | } |
| 1826 | |
| 1827 | for (i = 0; trace_options[i]; i++) { |
| 1828 | int len = strlen(trace_options[i]); |
| 1829 | |
| 1830 | if (strncmp(cmp, trace_options[i], len) == 0) { |
| 1831 | if (neg) |
| 1832 | trace_flags &= ~(1 << i); |
| 1833 | else |
| 1834 | trace_flags |= (1 << i); |
| 1835 | break; |
| 1836 | } |
| 1837 | } |
| 1838 | |
| 1839 | filp->f_pos += cnt; |
| 1840 | |
| 1841 | return cnt; |
| 1842 | } |
| 1843 | |
| 1844 | static struct file_operations tracing_iter_fops = { |
| 1845 | .open = tracing_open_generic, |
| 1846 | .read = tracing_iter_ctrl_read, |
| 1847 | .write = tracing_iter_ctrl_write, |
| 1848 | }; |
| 1849 | |
| 1850 | static const char readme_msg[] = |
| 1851 | "tracing mini-HOWTO:\n\n" |
| 1852 | "# mkdir /debug\n" |
| 1853 | "# mount -t debugfs nodev /debug\n\n" |
| 1854 | "# cat /debug/tracing/available_tracers\n" |
| 1855 | "wakeup preemptirqsoff preemptoff irqsoff ftrace sched_switch none\n\n" |
| 1856 | "# cat /debug/tracing/current_tracer\n" |
| 1857 | "none\n" |
| 1858 | "# echo sched_switch > /debug/tracing/current_tracer\n" |
| 1859 | "# cat /debug/tracing/current_tracer\n" |
| 1860 | "sched_switch\n" |
| 1861 | "# cat /debug/tracing/iter_ctrl\n" |
| 1862 | "noprint-parent nosym-offset nosym-addr noverbose\n" |
| 1863 | "# echo print-parent > /debug/tracing/iter_ctrl\n" |
| 1864 | "# echo 1 > /debug/tracing/tracing_enabled\n" |
| 1865 | "# cat /debug/tracing/trace > /tmp/trace.txt\n" |
| 1866 | "echo 0 > /debug/tracing/tracing_enabled\n" |
| 1867 | ; |
| 1868 | |
| 1869 | static ssize_t |
| 1870 | tracing_readme_read(struct file *filp, char __user *ubuf, |
| 1871 | size_t cnt, loff_t *ppos) |
| 1872 | { |
| 1873 | return simple_read_from_buffer(ubuf, cnt, ppos, |
| 1874 | readme_msg, strlen(readme_msg)); |
| 1875 | } |
| 1876 | |
| 1877 | static struct file_operations tracing_readme_fops = { |
| 1878 | .open = tracing_open_generic, |
| 1879 | .read = tracing_readme_read, |
| 1880 | }; |
| 1881 | |
| 1882 | static ssize_t |
| 1883 | tracing_ctrl_read(struct file *filp, char __user *ubuf, |
| 1884 | size_t cnt, loff_t *ppos) |
| 1885 | { |
| 1886 | struct trace_array *tr = filp->private_data; |
| 1887 | char buf[64]; |
| 1888 | int r; |
| 1889 | |
| 1890 | r = sprintf(buf, "%ld\n", tr->ctrl); |
| 1891 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); |
| 1892 | } |
| 1893 | |
| 1894 | static ssize_t |
| 1895 | tracing_ctrl_write(struct file *filp, const char __user *ubuf, |
| 1896 | size_t cnt, loff_t *ppos) |
| 1897 | { |
| 1898 | struct trace_array *tr = filp->private_data; |
| 1899 | long val; |
| 1900 | char buf[64]; |
| 1901 | |
| 1902 | if (cnt > 63) |
| 1903 | cnt = 63; |
| 1904 | |
| 1905 | if (copy_from_user(&buf, ubuf, cnt)) |
| 1906 | return -EFAULT; |
| 1907 | |
| 1908 | buf[cnt] = 0; |
| 1909 | |
| 1910 | val = simple_strtoul(buf, NULL, 10); |
| 1911 | |
| 1912 | val = !!val; |
| 1913 | |
| 1914 | mutex_lock(&trace_types_lock); |
| 1915 | if (tr->ctrl ^ val) { |
| 1916 | if (val) |
| 1917 | tracer_enabled = 1; |
| 1918 | else |
| 1919 | tracer_enabled = 0; |
| 1920 | |
| 1921 | tr->ctrl = val; |
| 1922 | |
| 1923 | if (current_trace && current_trace->ctrl_update) |
| 1924 | current_trace->ctrl_update(tr); |
| 1925 | } |
| 1926 | mutex_unlock(&trace_types_lock); |
| 1927 | |
| 1928 | filp->f_pos += cnt; |
| 1929 | |
| 1930 | return cnt; |
| 1931 | } |
| 1932 | |
| 1933 | static ssize_t |
| 1934 | tracing_set_trace_read(struct file *filp, char __user *ubuf, |
| 1935 | size_t cnt, loff_t *ppos) |
| 1936 | { |
| 1937 | char buf[max_tracer_type_len+2]; |
| 1938 | int r; |
| 1939 | |
| 1940 | mutex_lock(&trace_types_lock); |
| 1941 | if (current_trace) |
| 1942 | r = sprintf(buf, "%s\n", current_trace->name); |
| 1943 | else |
| 1944 | r = sprintf(buf, "\n"); |
| 1945 | mutex_unlock(&trace_types_lock); |
| 1946 | |
| 1947 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); |
| 1948 | } |
| 1949 | |
| 1950 | static ssize_t |
| 1951 | tracing_set_trace_write(struct file *filp, const char __user *ubuf, |
| 1952 | size_t cnt, loff_t *ppos) |
| 1953 | { |
| 1954 | struct trace_array *tr = &global_trace; |
| 1955 | struct tracer *t; |
| 1956 | char buf[max_tracer_type_len+1]; |
| 1957 | int i; |
| 1958 | |
| 1959 | if (cnt > max_tracer_type_len) |
| 1960 | cnt = max_tracer_type_len; |
| 1961 | |
| 1962 | if (copy_from_user(&buf, ubuf, cnt)) |
| 1963 | return -EFAULT; |
| 1964 | |
| 1965 | buf[cnt] = 0; |
| 1966 | |
| 1967 | /* strip ending whitespace. */ |
| 1968 | for (i = cnt - 1; i > 0 && isspace(buf[i]); i--) |
| 1969 | buf[i] = 0; |
| 1970 | |
| 1971 | mutex_lock(&trace_types_lock); |
| 1972 | for (t = trace_types; t; t = t->next) { |
| 1973 | if (strcmp(t->name, buf) == 0) |
| 1974 | break; |
| 1975 | } |
| 1976 | if (!t || t == current_trace) |
| 1977 | goto out; |
| 1978 | |
| 1979 | if (current_trace && current_trace->reset) |
| 1980 | current_trace->reset(tr); |
| 1981 | |
| 1982 | current_trace = t; |
| 1983 | if (t->init) |
| 1984 | t->init(tr); |
| 1985 | |
| 1986 | out: |
| 1987 | mutex_unlock(&trace_types_lock); |
| 1988 | |
| 1989 | filp->f_pos += cnt; |
| 1990 | |
| 1991 | return cnt; |
| 1992 | } |
| 1993 | |
| 1994 | static ssize_t |
| 1995 | tracing_max_lat_read(struct file *filp, char __user *ubuf, |
| 1996 | size_t cnt, loff_t *ppos) |
| 1997 | { |
| 1998 | unsigned long *ptr = filp->private_data; |
| 1999 | char buf[64]; |
| 2000 | int r; |
| 2001 | |
| 2002 | r = snprintf(buf, 64, "%ld\n", |
| 2003 | *ptr == (unsigned long)-1 ? -1 : nsecs_to_usecs(*ptr)); |
| 2004 | if (r > 64) |
| 2005 | r = 64; |
| 2006 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); |
| 2007 | } |
| 2008 | |
| 2009 | static ssize_t |
| 2010 | tracing_max_lat_write(struct file *filp, const char __user *ubuf, |
| 2011 | size_t cnt, loff_t *ppos) |
| 2012 | { |
| 2013 | long *ptr = filp->private_data; |
| 2014 | long val; |
| 2015 | char buf[64]; |
| 2016 | |
| 2017 | if (cnt > 63) |
| 2018 | cnt = 63; |
| 2019 | |
| 2020 | if (copy_from_user(&buf, ubuf, cnt)) |
| 2021 | return -EFAULT; |
| 2022 | |
| 2023 | buf[cnt] = 0; |
| 2024 | |
| 2025 | val = simple_strtoul(buf, NULL, 10); |
| 2026 | |
| 2027 | *ptr = val * 1000; |
| 2028 | |
| 2029 | return cnt; |
| 2030 | } |
| 2031 | |
| 2032 | static atomic_t tracing_reader; |
| 2033 | |
| 2034 | static int tracing_open_pipe(struct inode *inode, struct file *filp) |
| 2035 | { |
| 2036 | struct trace_iterator *iter; |
| 2037 | |
| 2038 | if (tracing_disabled) |
| 2039 | return -ENODEV; |
| 2040 | |
| 2041 | /* We only allow for reader of the pipe */ |
| 2042 | if (atomic_inc_return(&tracing_reader) != 1) { |
| 2043 | atomic_dec(&tracing_reader); |
| 2044 | return -EBUSY; |
| 2045 | } |
| 2046 | |
| 2047 | /* create a buffer to store the information to pass to userspace */ |
| 2048 | iter = kzalloc(sizeof(*iter), GFP_KERNEL); |
| 2049 | if (!iter) |
| 2050 | return -ENOMEM; |
| 2051 | |
| 2052 | iter->tr = &global_trace; |
| 2053 | |
| 2054 | filp->private_data = iter; |
| 2055 | |
| 2056 | return 0; |
| 2057 | } |
| 2058 | |
| 2059 | static int tracing_release_pipe(struct inode *inode, struct file *file) |
| 2060 | { |
| 2061 | struct trace_iterator *iter = file->private_data; |
| 2062 | |
| 2063 | kfree(iter); |
| 2064 | atomic_dec(&tracing_reader); |
| 2065 | |
| 2066 | return 0; |
| 2067 | } |
| 2068 | |
| 2069 | static unsigned int |
| 2070 | tracing_poll_pipe(struct file *filp, poll_table *poll_table) |
| 2071 | { |
| 2072 | struct trace_iterator *iter = filp->private_data; |
| 2073 | |
| 2074 | if (trace_flags & TRACE_ITER_BLOCK) { |
| 2075 | /* |
| 2076 | * Always select as readable when in blocking mode |
| 2077 | */ |
| 2078 | return POLLIN | POLLRDNORM; |
| 2079 | } |
| 2080 | else { |
| 2081 | if (!trace_empty(iter)) |
| 2082 | return POLLIN | POLLRDNORM; |
| 2083 | poll_wait(filp, &trace_wait, poll_table); |
| 2084 | if (!trace_empty(iter)) |
| 2085 | return POLLIN | POLLRDNORM; |
| 2086 | |
| 2087 | return 0; |
| 2088 | } |
| 2089 | } |
| 2090 | |
| 2091 | /* |
| 2092 | * Consumer reader. |
| 2093 | */ |
| 2094 | static ssize_t |
| 2095 | tracing_read_pipe(struct file *filp, char __user *ubuf, |
| 2096 | size_t cnt, loff_t *ppos) |
| 2097 | { |
| 2098 | struct trace_iterator *iter = filp->private_data; |
| 2099 | struct trace_array_cpu *data; |
| 2100 | static cpumask_t mask; |
| 2101 | static int start; |
| 2102 | unsigned long flags; |
| 2103 | #ifdef CONFIG_FTRACE |
| 2104 | int ftrace_save; |
| 2105 | #endif |
| 2106 | int read = 0; |
| 2107 | int cpu; |
| 2108 | int len; |
| 2109 | int ret; |
| 2110 | |
| 2111 | /* return any leftover data */ |
| 2112 | if (iter->seq.len > start) { |
| 2113 | len = iter->seq.len - start; |
| 2114 | if (cnt > len) |
| 2115 | cnt = len; |
| 2116 | ret = copy_to_user(ubuf, iter->seq.buffer + start, cnt); |
| 2117 | if (ret) |
| 2118 | cnt = -EFAULT; |
| 2119 | |
| 2120 | start += len; |
| 2121 | |
| 2122 | return cnt; |
| 2123 | } |
| 2124 | |
| 2125 | trace_seq_reset(&iter->seq); |
| 2126 | start = 0; |
| 2127 | |
| 2128 | while (trace_empty(iter)) { |
| 2129 | if (!(trace_flags & TRACE_ITER_BLOCK)) |
| 2130 | return -EWOULDBLOCK; |
| 2131 | /* |
| 2132 | * This is a make-shift waitqueue. The reason we don't use |
| 2133 | * an actual wait queue is because: |
| 2134 | * 1) we only ever have one waiter |
| 2135 | * 2) the tracing, traces all functions, we don't want |
| 2136 | * the overhead of calling wake_up and friends |
| 2137 | * (and tracing them too) |
| 2138 | * Anyway, this is really very primitive wakeup. |
| 2139 | */ |
| 2140 | set_current_state(TASK_INTERRUPTIBLE); |
| 2141 | iter->tr->waiter = current; |
| 2142 | |
| 2143 | /* sleep for one second, and try again. */ |
| 2144 | schedule_timeout(HZ); |
| 2145 | |
| 2146 | iter->tr->waiter = NULL; |
| 2147 | |
| 2148 | if (signal_pending(current)) |
| 2149 | return -EINTR; |
| 2150 | |
| 2151 | /* |
| 2152 | * We block until we read something and tracing is disabled. |
| 2153 | * We still block if tracing is disabled, but we have never |
| 2154 | * read anything. This allows a user to cat this file, and |
| 2155 | * then enable tracing. But after we have read something, |
| 2156 | * we give an EOF when tracing is again disabled. |
| 2157 | * |
| 2158 | * iter->pos will be 0 if we haven't read anything. |
| 2159 | */ |
| 2160 | if (!tracer_enabled && iter->pos) |
| 2161 | break; |
| 2162 | |
| 2163 | continue; |
| 2164 | } |
| 2165 | |
| 2166 | /* stop when tracing is finished */ |
| 2167 | if (trace_empty(iter)) |
| 2168 | return 0; |
| 2169 | |
| 2170 | if (cnt >= PAGE_SIZE) |
| 2171 | cnt = PAGE_SIZE - 1; |
| 2172 | |
| 2173 | memset(iter, 0, sizeof(*iter)); |
| 2174 | iter->tr = &global_trace; |
| 2175 | iter->pos = -1; |
| 2176 | |
| 2177 | /* |
| 2178 | * We need to stop all tracing on all CPUS to read the |
| 2179 | * the next buffer. This is a bit expensive, but is |
| 2180 | * not done often. We fill all what we can read, |
| 2181 | * and then release the locks again. |
| 2182 | */ |
| 2183 | |
| 2184 | cpus_clear(mask); |
| 2185 | local_irq_save(flags); |
| 2186 | #ifdef CONFIG_FTRACE |
| 2187 | ftrace_save = ftrace_enabled; |
| 2188 | ftrace_enabled = 0; |
| 2189 | #endif |
| 2190 | smp_wmb(); |
| 2191 | for_each_possible_cpu(cpu) { |
| 2192 | data = iter->tr->data[cpu]; |
| 2193 | |
| 2194 | if (!head_page(data) || !data->trace_idx) |
| 2195 | continue; |
| 2196 | |
| 2197 | atomic_inc(&data->disabled); |
| 2198 | cpu_set(cpu, mask); |
| 2199 | } |
| 2200 | |
| 2201 | for_each_cpu_mask(cpu, mask) { |
| 2202 | data = iter->tr->data[cpu]; |
| 2203 | spin_lock(&data->lock); |
| 2204 | } |
| 2205 | |
| 2206 | while (find_next_entry_inc(iter) != NULL) { |
| 2207 | int len = iter->seq.len; |
| 2208 | |
| 2209 | ret = print_trace_line(iter); |
| 2210 | if (!ret) { |
| 2211 | /* don't print partial lines */ |
| 2212 | iter->seq.len = len; |
| 2213 | break; |
| 2214 | } |
| 2215 | |
| 2216 | trace_consume(iter); |
| 2217 | |
| 2218 | if (iter->seq.len >= cnt) |
| 2219 | break; |
| 2220 | } |
| 2221 | |
| 2222 | for_each_cpu_mask(cpu, mask) { |
| 2223 | data = iter->tr->data[cpu]; |
| 2224 | spin_unlock(&data->lock); |
| 2225 | } |
| 2226 | |
| 2227 | for_each_cpu_mask(cpu, mask) { |
| 2228 | data = iter->tr->data[cpu]; |
| 2229 | atomic_dec(&data->disabled); |
| 2230 | } |
| 2231 | #ifdef CONFIG_FTRACE |
| 2232 | ftrace_enabled = ftrace_save; |
| 2233 | #endif |
| 2234 | local_irq_restore(flags); |
| 2235 | |
| 2236 | /* Now copy what we have to the user */ |
| 2237 | read = iter->seq.len; |
| 2238 | if (read > cnt) |
| 2239 | read = cnt; |
| 2240 | |
| 2241 | ret = copy_to_user(ubuf, iter->seq.buffer, read); |
| 2242 | |
| 2243 | if (read < iter->seq.len) |
| 2244 | start = read; |
| 2245 | else |
| 2246 | trace_seq_reset(&iter->seq); |
| 2247 | |
| 2248 | if (ret) |
| 2249 | read = -EFAULT; |
| 2250 | |
| 2251 | return read; |
| 2252 | } |
| 2253 | |
| 2254 | static struct file_operations tracing_max_lat_fops = { |
| 2255 | .open = tracing_open_generic, |
| 2256 | .read = tracing_max_lat_read, |
| 2257 | .write = tracing_max_lat_write, |
| 2258 | }; |
| 2259 | |
| 2260 | static struct file_operations tracing_ctrl_fops = { |
| 2261 | .open = tracing_open_generic, |
| 2262 | .read = tracing_ctrl_read, |
| 2263 | .write = tracing_ctrl_write, |
| 2264 | }; |
| 2265 | |
| 2266 | static struct file_operations set_tracer_fops = { |
| 2267 | .open = tracing_open_generic, |
| 2268 | .read = tracing_set_trace_read, |
| 2269 | .write = tracing_set_trace_write, |
| 2270 | }; |
| 2271 | |
| 2272 | static struct file_operations tracing_pipe_fops = { |
| 2273 | .open = tracing_open_pipe, |
| 2274 | .poll = tracing_poll_pipe, |
| 2275 | .read = tracing_read_pipe, |
| 2276 | .release = tracing_release_pipe, |
| 2277 | }; |
| 2278 | |
| 2279 | #ifdef CONFIG_DYNAMIC_FTRACE |
| 2280 | |
| 2281 | static ssize_t |
| 2282 | tracing_read_long(struct file *filp, char __user *ubuf, |
| 2283 | size_t cnt, loff_t *ppos) |
| 2284 | { |
| 2285 | unsigned long *p = filp->private_data; |
| 2286 | char buf[64]; |
| 2287 | int r; |
| 2288 | |
| 2289 | r = sprintf(buf, "%ld\n", *p); |
| 2290 | |
| 2291 | return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); |
| 2292 | } |
| 2293 | |
| 2294 | static struct file_operations tracing_read_long_fops = { |
| 2295 | .open = tracing_open_generic, |
| 2296 | .read = tracing_read_long, |
| 2297 | }; |
| 2298 | #endif |
| 2299 | |
| 2300 | static struct dentry *d_tracer; |
| 2301 | |
| 2302 | struct dentry *tracing_init_dentry(void) |
| 2303 | { |
| 2304 | static int once; |
| 2305 | |
| 2306 | if (d_tracer) |
| 2307 | return d_tracer; |
| 2308 | |
| 2309 | d_tracer = debugfs_create_dir("tracing", NULL); |
| 2310 | |
| 2311 | if (!d_tracer && !once) { |
| 2312 | once = 1; |
| 2313 | pr_warning("Could not create debugfs directory 'tracing'\n"); |
| 2314 | return NULL; |
| 2315 | } |
| 2316 | |
| 2317 | return d_tracer; |
| 2318 | } |
| 2319 | |
| 2320 | #ifdef CONFIG_FTRACE_SELFTEST |
| 2321 | /* Let selftest have access to static functions in this file */ |
| 2322 | #include "trace_selftest.c" |
| 2323 | #endif |
| 2324 | |
| 2325 | static __init void tracer_init_debugfs(void) |
| 2326 | { |
| 2327 | struct dentry *d_tracer; |
| 2328 | struct dentry *entry; |
| 2329 | |
| 2330 | d_tracer = tracing_init_dentry(); |
| 2331 | |
| 2332 | entry = debugfs_create_file("tracing_enabled", 0644, d_tracer, |
| 2333 | &global_trace, &tracing_ctrl_fops); |
| 2334 | if (!entry) |
| 2335 | pr_warning("Could not create debugfs 'tracing_enabled' entry\n"); |
| 2336 | |
| 2337 | entry = debugfs_create_file("iter_ctrl", 0644, d_tracer, |
| 2338 | NULL, &tracing_iter_fops); |
| 2339 | if (!entry) |
| 2340 | pr_warning("Could not create debugfs 'iter_ctrl' entry\n"); |
| 2341 | |
| 2342 | entry = debugfs_create_file("latency_trace", 0444, d_tracer, |
| 2343 | &global_trace, &tracing_lt_fops); |
| 2344 | if (!entry) |
| 2345 | pr_warning("Could not create debugfs 'latency_trace' entry\n"); |
| 2346 | |
| 2347 | entry = debugfs_create_file("trace", 0444, d_tracer, |
| 2348 | &global_trace, &tracing_fops); |
| 2349 | if (!entry) |
| 2350 | pr_warning("Could not create debugfs 'trace' entry\n"); |
| 2351 | |
| 2352 | entry = debugfs_create_file("available_tracers", 0444, d_tracer, |
| 2353 | &global_trace, &show_traces_fops); |
| 2354 | if (!entry) |
| 2355 | pr_warning("Could not create debugfs 'trace' entry\n"); |
| 2356 | |
| 2357 | entry = debugfs_create_file("current_tracer", 0444, d_tracer, |
| 2358 | &global_trace, &set_tracer_fops); |
| 2359 | if (!entry) |
| 2360 | pr_warning("Could not create debugfs 'trace' entry\n"); |
| 2361 | |
| 2362 | entry = debugfs_create_file("tracing_max_latency", 0644, d_tracer, |
| 2363 | &tracing_max_latency, |
| 2364 | &tracing_max_lat_fops); |
| 2365 | if (!entry) |
| 2366 | pr_warning("Could not create debugfs " |
| 2367 | "'tracing_max_latency' entry\n"); |
| 2368 | |
| 2369 | entry = debugfs_create_file("tracing_thresh", 0644, d_tracer, |
| 2370 | &tracing_thresh, &tracing_max_lat_fops); |
| 2371 | if (!entry) |
| 2372 | pr_warning("Could not create debugfs " |
| 2373 | "'tracing_threash' entry\n"); |
| 2374 | entry = debugfs_create_file("README", 0644, d_tracer, |
| 2375 | NULL, &tracing_readme_fops); |
| 2376 | if (!entry) |
| 2377 | pr_warning("Could not create debugfs 'README' entry\n"); |
| 2378 | |
| 2379 | entry = debugfs_create_file("trace_pipe", 0644, d_tracer, |
| 2380 | NULL, &tracing_pipe_fops); |
| 2381 | if (!entry) |
| 2382 | pr_warning("Could not create debugfs " |
| 2383 | "'tracing_threash' entry\n"); |
| 2384 | |
| 2385 | #ifdef CONFIG_DYNAMIC_FTRACE |
| 2386 | entry = debugfs_create_file("dyn_ftrace_total_info", 0444, d_tracer, |
| 2387 | &ftrace_update_tot_cnt, |
| 2388 | &tracing_read_long_fops); |
| 2389 | if (!entry) |
| 2390 | pr_warning("Could not create debugfs " |
| 2391 | "'dyn_ftrace_total_info' entry\n"); |
| 2392 | #endif |
| 2393 | } |
| 2394 | |
| 2395 | /* dummy trace to disable tracing */ |
| 2396 | static struct tracer no_tracer __read_mostly = |
| 2397 | { |
| 2398 | .name = "none", |
| 2399 | }; |
| 2400 | |
| 2401 | static int trace_alloc_page(void) |
| 2402 | { |
| 2403 | struct trace_array_cpu *data; |
| 2404 | struct page *page, *tmp; |
| 2405 | LIST_HEAD(pages); |
| 2406 | void *array; |
| 2407 | int i; |
| 2408 | |
| 2409 | /* first allocate a page for each CPU */ |
| 2410 | for_each_possible_cpu(i) { |
| 2411 | array = (void *)__get_free_page(GFP_KERNEL); |
| 2412 | if (array == NULL) { |
| 2413 | printk(KERN_ERR "tracer: failed to allocate page" |
| 2414 | "for trace buffer!\n"); |
| 2415 | goto free_pages; |
| 2416 | } |
| 2417 | |
| 2418 | page = virt_to_page(array); |
| 2419 | list_add(&page->lru, &pages); |
| 2420 | |
| 2421 | /* Only allocate if we are actually using the max trace */ |
| 2422 | #ifdef CONFIG_TRACER_MAX_TRACE |
| 2423 | array = (void *)__get_free_page(GFP_KERNEL); |
| 2424 | if (array == NULL) { |
| 2425 | printk(KERN_ERR "tracer: failed to allocate page" |
| 2426 | "for trace buffer!\n"); |
| 2427 | goto free_pages; |
| 2428 | } |
| 2429 | page = virt_to_page(array); |
| 2430 | list_add(&page->lru, &pages); |
| 2431 | #endif |
| 2432 | } |
| 2433 | |
| 2434 | /* Now that we successfully allocate a page per CPU, add them */ |
| 2435 | for_each_possible_cpu(i) { |
| 2436 | data = global_trace.data[i]; |
| 2437 | spin_lock_init(&data->lock); |
| 2438 | lockdep_set_class(&data->lock, &data->lock_key); |
| 2439 | page = list_entry(pages.next, struct page, lru); |
| 2440 | list_del_init(&page->lru); |
| 2441 | list_add_tail(&page->lru, &data->trace_pages); |
| 2442 | ClearPageLRU(page); |
| 2443 | |
| 2444 | #ifdef CONFIG_TRACER_MAX_TRACE |
| 2445 | data = max_tr.data[i]; |
| 2446 | spin_lock_init(&data->lock); |
| 2447 | lockdep_set_class(&data->lock, &data->lock_key); |
| 2448 | page = list_entry(pages.next, struct page, lru); |
| 2449 | list_del_init(&page->lru); |
| 2450 | list_add_tail(&page->lru, &data->trace_pages); |
| 2451 | SetPageLRU(page); |
| 2452 | #endif |
| 2453 | } |
| 2454 | global_trace.entries += ENTRIES_PER_PAGE; |
| 2455 | |
| 2456 | return 0; |
| 2457 | |
| 2458 | free_pages: |
| 2459 | list_for_each_entry_safe(page, tmp, &pages, lru) { |
| 2460 | list_del_init(&page->lru); |
| 2461 | __free_page(page); |
| 2462 | } |
| 2463 | return -ENOMEM; |
| 2464 | } |
| 2465 | |
| 2466 | __init static int tracer_alloc_buffers(void) |
| 2467 | { |
| 2468 | struct trace_array_cpu *data; |
| 2469 | void *array; |
| 2470 | struct page *page; |
| 2471 | int pages = 0; |
| 2472 | int ret = -ENOMEM; |
| 2473 | int i; |
| 2474 | |
| 2475 | global_trace.ctrl = tracer_enabled; |
| 2476 | |
| 2477 | /* Allocate the first page for all buffers */ |
| 2478 | for_each_possible_cpu(i) { |
| 2479 | data = global_trace.data[i] = &per_cpu(global_trace_cpu, i); |
| 2480 | max_tr.data[i] = &per_cpu(max_data, i); |
| 2481 | |
| 2482 | array = (void *)__get_free_page(GFP_KERNEL); |
| 2483 | if (array == NULL) { |
| 2484 | printk(KERN_ERR "tracer: failed to allocate page" |
| 2485 | "for trace buffer!\n"); |
| 2486 | goto free_buffers; |
| 2487 | } |
| 2488 | |
| 2489 | /* set the array to the list */ |
| 2490 | INIT_LIST_HEAD(&data->trace_pages); |
| 2491 | page = virt_to_page(array); |
| 2492 | list_add(&page->lru, &data->trace_pages); |
| 2493 | /* use the LRU flag to differentiate the two buffers */ |
| 2494 | ClearPageLRU(page); |
| 2495 | |
| 2496 | /* Only allocate if we are actually using the max trace */ |
| 2497 | #ifdef CONFIG_TRACER_MAX_TRACE |
| 2498 | array = (void *)__get_free_page(GFP_KERNEL); |
| 2499 | if (array == NULL) { |
| 2500 | printk(KERN_ERR "tracer: failed to allocate page" |
| 2501 | "for trace buffer!\n"); |
| 2502 | goto free_buffers; |
| 2503 | } |
| 2504 | |
| 2505 | INIT_LIST_HEAD(&max_tr.data[i]->trace_pages); |
| 2506 | page = virt_to_page(array); |
| 2507 | list_add(&page->lru, &max_tr.data[i]->trace_pages); |
| 2508 | SetPageLRU(page); |
| 2509 | #endif |
| 2510 | } |
| 2511 | |
| 2512 | /* |
| 2513 | * Since we allocate by orders of pages, we may be able to |
| 2514 | * round up a bit. |
| 2515 | */ |
| 2516 | global_trace.entries = ENTRIES_PER_PAGE; |
| 2517 | pages++; |
| 2518 | |
| 2519 | while (global_trace.entries < trace_nr_entries) { |
| 2520 | if (trace_alloc_page()) |
| 2521 | break; |
| 2522 | pages++; |
| 2523 | } |
| 2524 | max_tr.entries = global_trace.entries; |
| 2525 | |
| 2526 | pr_info("tracer: %d pages allocated for %ld", |
| 2527 | pages, trace_nr_entries); |
| 2528 | pr_info(" entries of %ld bytes\n", (long)TRACE_ENTRY_SIZE); |
| 2529 | pr_info(" actual entries %ld\n", global_trace.entries); |
| 2530 | |
| 2531 | tracer_init_debugfs(); |
| 2532 | |
| 2533 | trace_init_cmdlines(); |
| 2534 | |
| 2535 | register_tracer(&no_tracer); |
| 2536 | current_trace = &no_tracer; |
| 2537 | |
| 2538 | /* All seems OK, enable tracing */ |
| 2539 | tracing_disabled = 0; |
| 2540 | |
| 2541 | return 0; |
| 2542 | |
| 2543 | free_buffers: |
| 2544 | for (i-- ; i >= 0; i--) { |
| 2545 | struct page *page, *tmp; |
| 2546 | struct trace_array_cpu *data = global_trace.data[i]; |
| 2547 | |
| 2548 | if (data) { |
| 2549 | list_for_each_entry_safe(page, tmp, |
| 2550 | &data->trace_pages, lru) { |
| 2551 | list_del_init(&page->lru); |
| 2552 | __free_page(page); |
| 2553 | } |
| 2554 | } |
| 2555 | |
| 2556 | #ifdef CONFIG_TRACER_MAX_TRACE |
| 2557 | data = max_tr.data[i]; |
| 2558 | if (data) { |
| 2559 | list_for_each_entry_safe(page, tmp, |
| 2560 | &data->trace_pages, lru) { |
| 2561 | list_del_init(&page->lru); |
| 2562 | __free_page(page); |
| 2563 | } |
| 2564 | } |
| 2565 | #endif |
| 2566 | } |
| 2567 | return ret; |
| 2568 | } |
| 2569 | fs_initcall(tracer_alloc_buffers); |