1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * 4 * Function graph tracer. 5 * Copyright (c) 2008-2009 Frederic Weisbecker <fweisbec@gmail.com> 6 * Mostly borrowed from function tracer which 7 * is Copyright (c) Steven Rostedt <srostedt@redhat.com> 8 * 9 */ 10 #include <linux/uaccess.h> 11 #include <linux/ftrace.h> 12 #include <linux/interrupt.h> 13 #include <linux/slab.h> 14 #include <linux/fs.h> 15 16 #include "trace.h" 17 #include "trace_output.h" 18 19 /* When set, irq functions will be ignored */ 20 static int ftrace_graph_skip_irqs; 21 22 struct fgraph_cpu_data { 23 pid_t last_pid; 24 int depth; 25 int depth_irq; 26 int ignore; 27 unsigned long enter_funcs[FTRACE_RETFUNC_DEPTH]; 28 }; 29 30 struct fgraph_data { 31 struct fgraph_cpu_data __percpu *cpu_data; 32 33 /* Place to preserve last processed entry. */ 34 union { 35 struct ftrace_graph_ent_entry ent; 36 struct fgraph_retaddr_ent_entry rent; 37 } ent; 38 struct ftrace_graph_ret_entry ret; 39 int failed; 40 int cpu; 41 }; 42 43 #define TRACE_GRAPH_INDENT 2 44 45 unsigned int fgraph_max_depth; 46 47 static struct tracer_opt trace_opts[] = { 48 /* Display overruns? (for self-debug purpose) */ 49 { TRACER_OPT(funcgraph-overrun, TRACE_GRAPH_PRINT_OVERRUN) }, 50 /* Display CPU ? */ 51 { TRACER_OPT(funcgraph-cpu, TRACE_GRAPH_PRINT_CPU) }, 52 /* Display Overhead ? */ 53 { TRACER_OPT(funcgraph-overhead, TRACE_GRAPH_PRINT_OVERHEAD) }, 54 /* Display proc name/pid */ 55 { TRACER_OPT(funcgraph-proc, TRACE_GRAPH_PRINT_PROC) }, 56 /* Display duration of execution */ 57 { TRACER_OPT(funcgraph-duration, TRACE_GRAPH_PRINT_DURATION) }, 58 /* Display absolute time of an entry */ 59 { TRACER_OPT(funcgraph-abstime, TRACE_GRAPH_PRINT_ABS_TIME) }, 60 /* Display interrupts */ 61 { TRACER_OPT(funcgraph-irqs, TRACE_GRAPH_PRINT_IRQS) }, 62 /* Display function name after trailing } */ 63 { TRACER_OPT(funcgraph-tail, TRACE_GRAPH_PRINT_TAIL) }, 64 #ifdef CONFIG_FUNCTION_GRAPH_RETVAL 65 /* Display function return value ? */ 66 { TRACER_OPT(funcgraph-retval, TRACE_GRAPH_PRINT_RETVAL) }, 67 /* Display function return value in hexadecimal format ? */ 68 { TRACER_OPT(funcgraph-retval-hex, TRACE_GRAPH_PRINT_RETVAL_HEX) }, 69 #endif 70 #ifdef CONFIG_FUNCTION_GRAPH_RETADDR 71 /* Display function return address ? */ 72 { TRACER_OPT(funcgraph-retaddr, TRACE_GRAPH_PRINT_RETADDR) }, 73 #endif 74 /* Include sleep time (scheduled out) between entry and return */ 75 { TRACER_OPT(sleep-time, TRACE_GRAPH_SLEEP_TIME) }, 76 77 #ifdef CONFIG_FUNCTION_PROFILER 78 /* Include time within nested functions */ 79 { TRACER_OPT(graph-time, TRACE_GRAPH_GRAPH_TIME) }, 80 #endif 81 82 { } /* Empty entry */ 83 }; 84 85 static struct tracer_flags tracer_flags = { 86 /* Don't display overruns, proc, or tail by default */ 87 .val = TRACE_GRAPH_PRINT_CPU | TRACE_GRAPH_PRINT_OVERHEAD | 88 TRACE_GRAPH_PRINT_DURATION | TRACE_GRAPH_PRINT_IRQS | 89 TRACE_GRAPH_SLEEP_TIME | TRACE_GRAPH_GRAPH_TIME, 90 .opts = trace_opts 91 }; 92 93 static bool tracer_flags_is_set(u32 flags) 94 { 95 return (tracer_flags.val & flags) == flags; 96 } 97 98 /* 99 * DURATION column is being also used to display IRQ signs, 100 * following values are used by print_graph_irq and others 101 * to fill in space into DURATION column. 102 */ 103 enum { 104 FLAGS_FILL_FULL = 1 << TRACE_GRAPH_PRINT_FILL_SHIFT, 105 FLAGS_FILL_START = 2 << TRACE_GRAPH_PRINT_FILL_SHIFT, 106 FLAGS_FILL_END = 3 << TRACE_GRAPH_PRINT_FILL_SHIFT, 107 }; 108 109 static void 110 print_graph_duration(struct trace_array *tr, unsigned long long duration, 111 struct trace_seq *s, u32 flags); 112 113 int __trace_graph_entry(struct trace_array *tr, 114 struct ftrace_graph_ent *trace, 115 unsigned int trace_ctx) 116 { 117 struct ring_buffer_event *event; 118 struct trace_buffer *buffer = tr->array_buffer.buffer; 119 struct ftrace_graph_ent_entry *entry; 120 121 event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_ENT, 122 sizeof(*entry), trace_ctx); 123 if (!event) 124 return 0; 125 entry = ring_buffer_event_data(event); 126 entry->graph_ent = *trace; 127 trace_buffer_unlock_commit_nostack(buffer, event); 128 129 return 1; 130 } 131 132 #ifdef CONFIG_FUNCTION_GRAPH_RETADDR 133 int __trace_graph_retaddr_entry(struct trace_array *tr, 134 struct ftrace_graph_ent *trace, 135 unsigned int trace_ctx, 136 unsigned long retaddr) 137 { 138 struct ring_buffer_event *event; 139 struct trace_buffer *buffer = tr->array_buffer.buffer; 140 struct fgraph_retaddr_ent_entry *entry; 141 142 event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_RETADDR_ENT, 143 sizeof(*entry), trace_ctx); 144 if (!event) 145 return 0; 146 entry = ring_buffer_event_data(event); 147 entry->graph_ent.func = trace->func; 148 entry->graph_ent.depth = trace->depth; 149 entry->graph_ent.retaddr = retaddr; 150 trace_buffer_unlock_commit_nostack(buffer, event); 151 152 return 1; 153 } 154 #else 155 int __trace_graph_retaddr_entry(struct trace_array *tr, 156 struct ftrace_graph_ent *trace, 157 unsigned int trace_ctx, 158 unsigned long retaddr) 159 { 160 return 1; 161 } 162 #endif 163 164 static inline int ftrace_graph_ignore_irqs(void) 165 { 166 if (!ftrace_graph_skip_irqs || trace_recursion_test(TRACE_IRQ_BIT)) 167 return 0; 168 169 return in_hardirq(); 170 } 171 172 struct fgraph_times { 173 unsigned long long calltime; 174 unsigned long long sleeptime; /* may be optional! */ 175 }; 176 177 int trace_graph_entry(struct ftrace_graph_ent *trace, 178 struct fgraph_ops *gops) 179 { 180 unsigned long *task_var = fgraph_get_task_var(gops); 181 struct trace_array *tr = gops->private; 182 struct trace_array_cpu *data; 183 struct fgraph_times *ftimes; 184 unsigned long flags; 185 unsigned int trace_ctx; 186 long disabled; 187 int ret; 188 int cpu; 189 190 if (*task_var & TRACE_GRAPH_NOTRACE) 191 return 0; 192 193 /* 194 * Do not trace a function if it's filtered by set_graph_notrace. 195 * Make the index of ret stack negative to indicate that it should 196 * ignore further functions. But it needs its own ret stack entry 197 * to recover the original index in order to continue tracing after 198 * returning from the function. 199 */ 200 if (ftrace_graph_notrace_addr(trace->func)) { 201 *task_var |= TRACE_GRAPH_NOTRACE_BIT; 202 /* 203 * Need to return 1 to have the return called 204 * that will clear the NOTRACE bit. 205 */ 206 return 1; 207 } 208 209 if (!ftrace_trace_task(tr)) 210 return 0; 211 212 if (ftrace_graph_ignore_func(gops, trace)) 213 return 0; 214 215 if (ftrace_graph_ignore_irqs()) 216 return 0; 217 218 if (fgraph_sleep_time) { 219 /* Only need to record the calltime */ 220 ftimes = fgraph_reserve_data(gops->idx, sizeof(ftimes->calltime)); 221 } else { 222 ftimes = fgraph_reserve_data(gops->idx, sizeof(*ftimes)); 223 if (ftimes) 224 ftimes->sleeptime = current->ftrace_sleeptime; 225 } 226 if (!ftimes) 227 return 0; 228 229 ftimes->calltime = trace_clock_local(); 230 231 /* 232 * Stop here if tracing_threshold is set. We only write function return 233 * events to the ring buffer. 234 */ 235 if (tracing_thresh) 236 return 1; 237 238 local_irq_save(flags); 239 cpu = raw_smp_processor_id(); 240 data = per_cpu_ptr(tr->array_buffer.data, cpu); 241 disabled = atomic_inc_return(&data->disabled); 242 if (likely(disabled == 1)) { 243 trace_ctx = tracing_gen_ctx_flags(flags); 244 if (unlikely(IS_ENABLED(CONFIG_FUNCTION_GRAPH_RETADDR) && 245 tracer_flags_is_set(TRACE_GRAPH_PRINT_RETADDR))) { 246 unsigned long retaddr = ftrace_graph_top_ret_addr(current); 247 248 ret = __trace_graph_retaddr_entry(tr, trace, trace_ctx, retaddr); 249 } else 250 ret = __trace_graph_entry(tr, trace, trace_ctx); 251 } else { 252 ret = 0; 253 } 254 255 atomic_dec(&data->disabled); 256 local_irq_restore(flags); 257 258 return ret; 259 } 260 261 static void 262 __trace_graph_function(struct trace_array *tr, 263 unsigned long ip, unsigned int trace_ctx) 264 { 265 u64 time = trace_clock_local(); 266 struct ftrace_graph_ent ent = { 267 .func = ip, 268 .depth = 0, 269 }; 270 struct ftrace_graph_ret ret = { 271 .func = ip, 272 .depth = 0, 273 .calltime = time, 274 .rettime = time, 275 }; 276 277 __trace_graph_entry(tr, &ent, trace_ctx); 278 __trace_graph_return(tr, &ret, trace_ctx); 279 } 280 281 void 282 trace_graph_function(struct trace_array *tr, 283 unsigned long ip, unsigned long parent_ip, 284 unsigned int trace_ctx) 285 { 286 __trace_graph_function(tr, ip, trace_ctx); 287 } 288 289 void __trace_graph_return(struct trace_array *tr, 290 struct ftrace_graph_ret *trace, 291 unsigned int trace_ctx) 292 { 293 struct ring_buffer_event *event; 294 struct trace_buffer *buffer = tr->array_buffer.buffer; 295 struct ftrace_graph_ret_entry *entry; 296 297 event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_RET, 298 sizeof(*entry), trace_ctx); 299 if (!event) 300 return; 301 entry = ring_buffer_event_data(event); 302 entry->ret = *trace; 303 trace_buffer_unlock_commit_nostack(buffer, event); 304 } 305 306 static void handle_nosleeptime(struct ftrace_graph_ret *trace, 307 struct fgraph_times *ftimes, 308 int size) 309 { 310 if (fgraph_sleep_time || size < sizeof(*ftimes)) 311 return; 312 313 ftimes->calltime += current->ftrace_sleeptime - ftimes->sleeptime; 314 } 315 316 void trace_graph_return(struct ftrace_graph_ret *trace, 317 struct fgraph_ops *gops) 318 { 319 unsigned long *task_var = fgraph_get_task_var(gops); 320 struct trace_array *tr = gops->private; 321 struct trace_array_cpu *data; 322 struct fgraph_times *ftimes; 323 unsigned long flags; 324 unsigned int trace_ctx; 325 long disabled; 326 int size; 327 int cpu; 328 329 ftrace_graph_addr_finish(gops, trace); 330 331 if (*task_var & TRACE_GRAPH_NOTRACE) { 332 *task_var &= ~TRACE_GRAPH_NOTRACE; 333 return; 334 } 335 336 ftimes = fgraph_retrieve_data(gops->idx, &size); 337 if (!ftimes) 338 return; 339 340 handle_nosleeptime(trace, ftimes, size); 341 342 trace->calltime = ftimes->calltime; 343 344 local_irq_save(flags); 345 cpu = raw_smp_processor_id(); 346 data = per_cpu_ptr(tr->array_buffer.data, cpu); 347 disabled = atomic_inc_return(&data->disabled); 348 if (likely(disabled == 1)) { 349 trace_ctx = tracing_gen_ctx_flags(flags); 350 __trace_graph_return(tr, trace, trace_ctx); 351 } 352 atomic_dec(&data->disabled); 353 local_irq_restore(flags); 354 } 355 356 static void trace_graph_thresh_return(struct ftrace_graph_ret *trace, 357 struct fgraph_ops *gops) 358 { 359 struct fgraph_times *ftimes; 360 int size; 361 362 ftrace_graph_addr_finish(gops, trace); 363 364 if (trace_recursion_test(TRACE_GRAPH_NOTRACE_BIT)) { 365 trace_recursion_clear(TRACE_GRAPH_NOTRACE_BIT); 366 return; 367 } 368 369 ftimes = fgraph_retrieve_data(gops->idx, &size); 370 if (!ftimes) 371 return; 372 373 handle_nosleeptime(trace, ftimes, size); 374 375 trace->calltime = ftimes->calltime; 376 377 if (tracing_thresh && 378 (trace->rettime - ftimes->calltime < tracing_thresh)) 379 return; 380 else 381 trace_graph_return(trace, gops); 382 } 383 384 static struct fgraph_ops funcgraph_ops = { 385 .entryfunc = &trace_graph_entry, 386 .retfunc = &trace_graph_return, 387 }; 388 389 int allocate_fgraph_ops(struct trace_array *tr, struct ftrace_ops *ops) 390 { 391 struct fgraph_ops *gops; 392 393 gops = kzalloc(sizeof(*gops), GFP_KERNEL); 394 if (!gops) 395 return -ENOMEM; 396 397 gops->entryfunc = &trace_graph_entry; 398 gops->retfunc = &trace_graph_return; 399 400 tr->gops = gops; 401 gops->private = tr; 402 403 fgraph_init_ops(&gops->ops, ops); 404 405 return 0; 406 } 407 408 void free_fgraph_ops(struct trace_array *tr) 409 { 410 kfree(tr->gops); 411 } 412 413 __init void init_array_fgraph_ops(struct trace_array *tr, struct ftrace_ops *ops) 414 { 415 tr->gops = &funcgraph_ops; 416 funcgraph_ops.private = tr; 417 fgraph_init_ops(&tr->gops->ops, ops); 418 } 419 420 static int graph_trace_init(struct trace_array *tr) 421 { 422 int ret; 423 424 tr->gops->entryfunc = trace_graph_entry; 425 426 if (tracing_thresh) 427 tr->gops->retfunc = trace_graph_thresh_return; 428 else 429 tr->gops->retfunc = trace_graph_return; 430 431 /* Make gops functions are visible before we start tracing */ 432 smp_mb(); 433 434 ret = register_ftrace_graph(tr->gops); 435 if (ret) 436 return ret; 437 tracing_start_cmdline_record(); 438 439 return 0; 440 } 441 442 static void graph_trace_reset(struct trace_array *tr) 443 { 444 tracing_stop_cmdline_record(); 445 unregister_ftrace_graph(tr->gops); 446 } 447 448 static int graph_trace_update_thresh(struct trace_array *tr) 449 { 450 graph_trace_reset(tr); 451 return graph_trace_init(tr); 452 } 453 454 static int max_bytes_for_cpu; 455 456 static void print_graph_cpu(struct trace_seq *s, int cpu) 457 { 458 /* 459 * Start with a space character - to make it stand out 460 * to the right a bit when trace output is pasted into 461 * email: 462 */ 463 trace_seq_printf(s, " %*d) ", max_bytes_for_cpu, cpu); 464 } 465 466 #define TRACE_GRAPH_PROCINFO_LENGTH 14 467 468 static void print_graph_proc(struct trace_seq *s, pid_t pid) 469 { 470 char comm[TASK_COMM_LEN]; 471 /* sign + log10(MAX_INT) + '\0' */ 472 char pid_str[11]; 473 int spaces = 0; 474 int len; 475 int i; 476 477 trace_find_cmdline(pid, comm); 478 comm[7] = '\0'; 479 sprintf(pid_str, "%d", pid); 480 481 /* 1 stands for the "-" character */ 482 len = strlen(comm) + strlen(pid_str) + 1; 483 484 if (len < TRACE_GRAPH_PROCINFO_LENGTH) 485 spaces = TRACE_GRAPH_PROCINFO_LENGTH - len; 486 487 /* First spaces to align center */ 488 for (i = 0; i < spaces / 2; i++) 489 trace_seq_putc(s, ' '); 490 491 trace_seq_printf(s, "%s-%s", comm, pid_str); 492 493 /* Last spaces to align center */ 494 for (i = 0; i < spaces - (spaces / 2); i++) 495 trace_seq_putc(s, ' '); 496 } 497 498 499 static void print_graph_lat_fmt(struct trace_seq *s, struct trace_entry *entry) 500 { 501 trace_seq_putc(s, ' '); 502 trace_print_lat_fmt(s, entry); 503 trace_seq_puts(s, " | "); 504 } 505 506 /* If the pid changed since the last trace, output this event */ 507 static void 508 verif_pid(struct trace_seq *s, pid_t pid, int cpu, struct fgraph_data *data) 509 { 510 pid_t prev_pid; 511 pid_t *last_pid; 512 513 if (!data) 514 return; 515 516 last_pid = &(per_cpu_ptr(data->cpu_data, cpu)->last_pid); 517 518 if (*last_pid == pid) 519 return; 520 521 prev_pid = *last_pid; 522 *last_pid = pid; 523 524 if (prev_pid == -1) 525 return; 526 /* 527 * Context-switch trace line: 528 529 ------------------------------------------ 530 | 1) migration/0--1 => sshd-1755 531 ------------------------------------------ 532 533 */ 534 trace_seq_puts(s, " ------------------------------------------\n"); 535 print_graph_cpu(s, cpu); 536 print_graph_proc(s, prev_pid); 537 trace_seq_puts(s, " => "); 538 print_graph_proc(s, pid); 539 trace_seq_puts(s, "\n ------------------------------------------\n\n"); 540 } 541 542 static struct ftrace_graph_ret_entry * 543 get_return_for_leaf(struct trace_iterator *iter, 544 struct ftrace_graph_ent_entry *curr) 545 { 546 struct fgraph_data *data = iter->private; 547 struct ring_buffer_iter *ring_iter = NULL; 548 struct ring_buffer_event *event; 549 struct ftrace_graph_ret_entry *next; 550 551 /* 552 * If the previous output failed to write to the seq buffer, 553 * then we just reuse the data from before. 554 */ 555 if (data && data->failed) { 556 curr = &data->ent.ent; 557 next = &data->ret; 558 } else { 559 560 ring_iter = trace_buffer_iter(iter, iter->cpu); 561 562 /* First peek to compare current entry and the next one */ 563 if (ring_iter) 564 event = ring_buffer_iter_peek(ring_iter, NULL); 565 else { 566 /* 567 * We need to consume the current entry to see 568 * the next one. 569 */ 570 ring_buffer_consume(iter->array_buffer->buffer, iter->cpu, 571 NULL, NULL); 572 event = ring_buffer_peek(iter->array_buffer->buffer, iter->cpu, 573 NULL, NULL); 574 } 575 576 if (!event) 577 return NULL; 578 579 next = ring_buffer_event_data(event); 580 581 if (data) { 582 /* 583 * Save current and next entries for later reference 584 * if the output fails. 585 */ 586 if (unlikely(curr->ent.type == TRACE_GRAPH_RETADDR_ENT)) 587 data->ent.rent = *(struct fgraph_retaddr_ent_entry *)curr; 588 else 589 data->ent.ent = *curr; 590 /* 591 * If the next event is not a return type, then 592 * we only care about what type it is. Otherwise we can 593 * safely copy the entire event. 594 */ 595 if (next->ent.type == TRACE_GRAPH_RET) 596 data->ret = *next; 597 else 598 data->ret.ent.type = next->ent.type; 599 } 600 } 601 602 if (next->ent.type != TRACE_GRAPH_RET) 603 return NULL; 604 605 if (curr->ent.pid != next->ent.pid || 606 curr->graph_ent.func != next->ret.func) 607 return NULL; 608 609 /* this is a leaf, now advance the iterator */ 610 if (ring_iter) 611 ring_buffer_iter_advance(ring_iter); 612 613 return next; 614 } 615 616 static void print_graph_abs_time(u64 t, struct trace_seq *s) 617 { 618 unsigned long usecs_rem; 619 620 usecs_rem = do_div(t, NSEC_PER_SEC); 621 usecs_rem /= 1000; 622 623 trace_seq_printf(s, "%5lu.%06lu | ", 624 (unsigned long)t, usecs_rem); 625 } 626 627 static void 628 print_graph_rel_time(struct trace_iterator *iter, struct trace_seq *s) 629 { 630 unsigned long long usecs; 631 632 usecs = iter->ts - iter->array_buffer->time_start; 633 do_div(usecs, NSEC_PER_USEC); 634 635 trace_seq_printf(s, "%9llu us | ", usecs); 636 } 637 638 static void 639 print_graph_irq(struct trace_iterator *iter, unsigned long addr, 640 enum trace_type type, int cpu, pid_t pid, u32 flags) 641 { 642 struct trace_array *tr = iter->tr; 643 struct trace_seq *s = &iter->seq; 644 struct trace_entry *ent = iter->ent; 645 646 addr += iter->tr->text_delta; 647 648 if (addr < (unsigned long)__irqentry_text_start || 649 addr >= (unsigned long)__irqentry_text_end) 650 return; 651 652 if (tr->trace_flags & TRACE_ITER_CONTEXT_INFO) { 653 /* Absolute time */ 654 if (flags & TRACE_GRAPH_PRINT_ABS_TIME) 655 print_graph_abs_time(iter->ts, s); 656 657 /* Relative time */ 658 if (flags & TRACE_GRAPH_PRINT_REL_TIME) 659 print_graph_rel_time(iter, s); 660 661 /* Cpu */ 662 if (flags & TRACE_GRAPH_PRINT_CPU) 663 print_graph_cpu(s, cpu); 664 665 /* Proc */ 666 if (flags & TRACE_GRAPH_PRINT_PROC) { 667 print_graph_proc(s, pid); 668 trace_seq_puts(s, " | "); 669 } 670 671 /* Latency format */ 672 if (tr->trace_flags & TRACE_ITER_LATENCY_FMT) 673 print_graph_lat_fmt(s, ent); 674 } 675 676 /* No overhead */ 677 print_graph_duration(tr, 0, s, flags | FLAGS_FILL_START); 678 679 if (type == TRACE_GRAPH_ENT) 680 trace_seq_puts(s, "==========>"); 681 else 682 trace_seq_puts(s, "<=========="); 683 684 print_graph_duration(tr, 0, s, flags | FLAGS_FILL_END); 685 trace_seq_putc(s, '\n'); 686 } 687 688 void 689 trace_print_graph_duration(unsigned long long duration, struct trace_seq *s) 690 { 691 unsigned long nsecs_rem = do_div(duration, 1000); 692 /* log10(ULONG_MAX) + '\0' */ 693 char usecs_str[21]; 694 char nsecs_str[5]; 695 int len; 696 int i; 697 698 sprintf(usecs_str, "%lu", (unsigned long) duration); 699 700 /* Print msecs */ 701 trace_seq_printf(s, "%s", usecs_str); 702 703 len = strlen(usecs_str); 704 705 /* Print nsecs (we don't want to exceed 7 numbers) */ 706 if (len < 7) { 707 size_t slen = min_t(size_t, sizeof(nsecs_str), 8UL - len); 708 709 snprintf(nsecs_str, slen, "%03lu", nsecs_rem); 710 trace_seq_printf(s, ".%s", nsecs_str); 711 len += strlen(nsecs_str) + 1; 712 } 713 714 trace_seq_puts(s, " us "); 715 716 /* Print remaining spaces to fit the row's width */ 717 for (i = len; i < 8; i++) 718 trace_seq_putc(s, ' '); 719 } 720 721 static void 722 print_graph_duration(struct trace_array *tr, unsigned long long duration, 723 struct trace_seq *s, u32 flags) 724 { 725 if (!(flags & TRACE_GRAPH_PRINT_DURATION) || 726 !(tr->trace_flags & TRACE_ITER_CONTEXT_INFO)) 727 return; 728 729 /* No real adata, just filling the column with spaces */ 730 switch (flags & TRACE_GRAPH_PRINT_FILL_MASK) { 731 case FLAGS_FILL_FULL: 732 trace_seq_puts(s, " | "); 733 return; 734 case FLAGS_FILL_START: 735 trace_seq_puts(s, " "); 736 return; 737 case FLAGS_FILL_END: 738 trace_seq_puts(s, " |"); 739 return; 740 } 741 742 /* Signal a overhead of time execution to the output */ 743 if (flags & TRACE_GRAPH_PRINT_OVERHEAD) 744 trace_seq_printf(s, "%c ", trace_find_mark(duration)); 745 else 746 trace_seq_puts(s, " "); 747 748 trace_print_graph_duration(duration, s); 749 trace_seq_puts(s, "| "); 750 } 751 752 #ifdef CONFIG_FUNCTION_GRAPH_RETVAL 753 #define __TRACE_GRAPH_PRINT_RETVAL TRACE_GRAPH_PRINT_RETVAL 754 #else 755 #define __TRACE_GRAPH_PRINT_RETVAL 0 756 #endif 757 758 #ifdef CONFIG_FUNCTION_GRAPH_RETADDR 759 #define __TRACE_GRAPH_PRINT_RETADDR TRACE_GRAPH_PRINT_RETADDR 760 static void print_graph_retaddr(struct trace_seq *s, struct fgraph_retaddr_ent_entry *entry, 761 u32 trace_flags, bool comment) 762 { 763 if (comment) 764 trace_seq_puts(s, " /*"); 765 766 trace_seq_puts(s, " <-"); 767 seq_print_ip_sym(s, entry->graph_ent.retaddr, trace_flags | TRACE_ITER_SYM_OFFSET); 768 769 if (comment) 770 trace_seq_puts(s, " */"); 771 } 772 #else 773 #define __TRACE_GRAPH_PRINT_RETADDR 0 774 #define print_graph_retaddr(_seq, _entry, _tflags, _comment) do { } while (0) 775 #endif 776 777 #if defined(CONFIG_FUNCTION_GRAPH_RETVAL) || defined(CONFIG_FUNCTION_GRAPH_RETADDR) 778 779 static void print_graph_retval(struct trace_seq *s, struct ftrace_graph_ent_entry *entry, 780 struct ftrace_graph_ret *graph_ret, void *func, 781 u32 opt_flags, u32 trace_flags) 782 { 783 unsigned long err_code = 0; 784 unsigned long retval = 0; 785 bool print_retaddr = false; 786 bool print_retval = false; 787 bool hex_format = !!(opt_flags & TRACE_GRAPH_PRINT_RETVAL_HEX); 788 789 #ifdef CONFIG_FUNCTION_GRAPH_RETVAL 790 retval = graph_ret->retval; 791 print_retval = !!(opt_flags & TRACE_GRAPH_PRINT_RETVAL); 792 #endif 793 794 #ifdef CONFIG_FUNCTION_GRAPH_RETADDR 795 print_retaddr = !!(opt_flags & TRACE_GRAPH_PRINT_RETADDR); 796 #endif 797 798 if (print_retval && retval && !hex_format) { 799 /* Check if the return value matches the negative format */ 800 if (IS_ENABLED(CONFIG_64BIT) && (retval & BIT(31)) && 801 (((u64)retval) >> 32) == 0) { 802 err_code = sign_extend64(retval, 31); 803 } else { 804 err_code = retval; 805 } 806 807 if (!IS_ERR_VALUE(err_code)) 808 err_code = 0; 809 } 810 811 if (entry) { 812 if (entry->ent.type != TRACE_GRAPH_RETADDR_ENT) 813 print_retaddr = false; 814 815 trace_seq_printf(s, "%ps();", func); 816 if (print_retval || print_retaddr) 817 trace_seq_puts(s, " /*"); 818 else 819 trace_seq_putc(s, '\n'); 820 } else { 821 print_retaddr = false; 822 trace_seq_printf(s, "} /* %ps", func); 823 } 824 825 if (print_retaddr) 826 print_graph_retaddr(s, (struct fgraph_retaddr_ent_entry *)entry, 827 trace_flags, false); 828 829 if (print_retval) { 830 if (hex_format || (err_code == 0)) 831 trace_seq_printf(s, " ret=0x%lx", retval); 832 else 833 trace_seq_printf(s, " ret=%ld", err_code); 834 } 835 836 if (!entry || print_retval || print_retaddr) 837 trace_seq_puts(s, " */\n"); 838 } 839 840 #else 841 842 #define print_graph_retval(_seq, _ent, _ret, _func, _opt_flags, _trace_flags) do {} while (0) 843 844 #endif 845 846 /* Case of a leaf function on its call entry */ 847 static enum print_line_t 848 print_graph_entry_leaf(struct trace_iterator *iter, 849 struct ftrace_graph_ent_entry *entry, 850 struct ftrace_graph_ret_entry *ret_entry, 851 struct trace_seq *s, u32 flags) 852 { 853 struct fgraph_data *data = iter->private; 854 struct trace_array *tr = iter->tr; 855 struct ftrace_graph_ret *graph_ret; 856 struct ftrace_graph_ent *call; 857 unsigned long long duration; 858 unsigned long func; 859 int cpu = iter->cpu; 860 int i; 861 862 graph_ret = &ret_entry->ret; 863 call = &entry->graph_ent; 864 duration = graph_ret->rettime - graph_ret->calltime; 865 866 func = call->func + iter->tr->text_delta; 867 868 if (data) { 869 struct fgraph_cpu_data *cpu_data; 870 871 cpu_data = per_cpu_ptr(data->cpu_data, cpu); 872 873 /* 874 * Comments display at + 1 to depth. Since 875 * this is a leaf function, keep the comments 876 * equal to this depth. 877 */ 878 cpu_data->depth = call->depth - 1; 879 880 /* No need to keep this function around for this depth */ 881 if (call->depth < FTRACE_RETFUNC_DEPTH && 882 !WARN_ON_ONCE(call->depth < 0)) 883 cpu_data->enter_funcs[call->depth] = 0; 884 } 885 886 /* Overhead and duration */ 887 print_graph_duration(tr, duration, s, flags); 888 889 /* Function */ 890 for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) 891 trace_seq_putc(s, ' '); 892 893 /* 894 * Write out the function return value or return address 895 */ 896 if (flags & (__TRACE_GRAPH_PRINT_RETVAL | __TRACE_GRAPH_PRINT_RETADDR)) { 897 print_graph_retval(s, entry, graph_ret, 898 (void *)graph_ret->func + iter->tr->text_delta, 899 flags, tr->trace_flags); 900 } else { 901 trace_seq_printf(s, "%ps();\n", (void *)func); 902 } 903 904 print_graph_irq(iter, graph_ret->func, TRACE_GRAPH_RET, 905 cpu, iter->ent->pid, flags); 906 907 return trace_handle_return(s); 908 } 909 910 static enum print_line_t 911 print_graph_entry_nested(struct trace_iterator *iter, 912 struct ftrace_graph_ent_entry *entry, 913 struct trace_seq *s, int cpu, u32 flags) 914 { 915 struct ftrace_graph_ent *call = &entry->graph_ent; 916 struct fgraph_data *data = iter->private; 917 struct trace_array *tr = iter->tr; 918 unsigned long func; 919 int i; 920 921 if (data) { 922 struct fgraph_cpu_data *cpu_data; 923 int cpu = iter->cpu; 924 925 cpu_data = per_cpu_ptr(data->cpu_data, cpu); 926 cpu_data->depth = call->depth; 927 928 /* Save this function pointer to see if the exit matches */ 929 if (call->depth < FTRACE_RETFUNC_DEPTH && 930 !WARN_ON_ONCE(call->depth < 0)) 931 cpu_data->enter_funcs[call->depth] = call->func; 932 } 933 934 /* No time */ 935 print_graph_duration(tr, 0, s, flags | FLAGS_FILL_FULL); 936 937 /* Function */ 938 for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) 939 trace_seq_putc(s, ' '); 940 941 func = call->func + iter->tr->text_delta; 942 943 trace_seq_printf(s, "%ps() {", (void *)func); 944 if (flags & __TRACE_GRAPH_PRINT_RETADDR && 945 entry->ent.type == TRACE_GRAPH_RETADDR_ENT) 946 print_graph_retaddr(s, (struct fgraph_retaddr_ent_entry *)entry, 947 tr->trace_flags, true); 948 trace_seq_putc(s, '\n'); 949 950 if (trace_seq_has_overflowed(s)) 951 return TRACE_TYPE_PARTIAL_LINE; 952 953 /* 954 * we already consumed the current entry to check the next one 955 * and see if this is a leaf. 956 */ 957 return TRACE_TYPE_NO_CONSUME; 958 } 959 960 static void 961 print_graph_prologue(struct trace_iterator *iter, struct trace_seq *s, 962 int type, unsigned long addr, u32 flags) 963 { 964 struct fgraph_data *data = iter->private; 965 struct trace_entry *ent = iter->ent; 966 struct trace_array *tr = iter->tr; 967 int cpu = iter->cpu; 968 969 /* Pid */ 970 verif_pid(s, ent->pid, cpu, data); 971 972 if (type) 973 /* Interrupt */ 974 print_graph_irq(iter, addr, type, cpu, ent->pid, flags); 975 976 if (!(tr->trace_flags & TRACE_ITER_CONTEXT_INFO)) 977 return; 978 979 /* Absolute time */ 980 if (flags & TRACE_GRAPH_PRINT_ABS_TIME) 981 print_graph_abs_time(iter->ts, s); 982 983 /* Relative time */ 984 if (flags & TRACE_GRAPH_PRINT_REL_TIME) 985 print_graph_rel_time(iter, s); 986 987 /* Cpu */ 988 if (flags & TRACE_GRAPH_PRINT_CPU) 989 print_graph_cpu(s, cpu); 990 991 /* Proc */ 992 if (flags & TRACE_GRAPH_PRINT_PROC) { 993 print_graph_proc(s, ent->pid); 994 trace_seq_puts(s, " | "); 995 } 996 997 /* Latency format */ 998 if (tr->trace_flags & TRACE_ITER_LATENCY_FMT) 999 print_graph_lat_fmt(s, ent); 1000 1001 return; 1002 } 1003 1004 /* 1005 * Entry check for irq code 1006 * 1007 * returns 1 if 1008 * - we are inside irq code 1009 * - we just entered irq code 1010 * 1011 * returns 0 if 1012 * - funcgraph-interrupts option is set 1013 * - we are not inside irq code 1014 */ 1015 static int 1016 check_irq_entry(struct trace_iterator *iter, u32 flags, 1017 unsigned long addr, int depth) 1018 { 1019 int cpu = iter->cpu; 1020 int *depth_irq; 1021 struct fgraph_data *data = iter->private; 1022 1023 addr += iter->tr->text_delta; 1024 1025 /* 1026 * If we are either displaying irqs, or we got called as 1027 * a graph event and private data does not exist, 1028 * then we bypass the irq check. 1029 */ 1030 if ((flags & TRACE_GRAPH_PRINT_IRQS) || 1031 (!data)) 1032 return 0; 1033 1034 depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq); 1035 1036 /* 1037 * We are inside the irq code 1038 */ 1039 if (*depth_irq >= 0) 1040 return 1; 1041 1042 if ((addr < (unsigned long)__irqentry_text_start) || 1043 (addr >= (unsigned long)__irqentry_text_end)) 1044 return 0; 1045 1046 /* 1047 * We are entering irq code. 1048 */ 1049 *depth_irq = depth; 1050 return 1; 1051 } 1052 1053 /* 1054 * Return check for irq code 1055 * 1056 * returns 1 if 1057 * - we are inside irq code 1058 * - we just left irq code 1059 * 1060 * returns 0 if 1061 * - funcgraph-interrupts option is set 1062 * - we are not inside irq code 1063 */ 1064 static int 1065 check_irq_return(struct trace_iterator *iter, u32 flags, int depth) 1066 { 1067 int cpu = iter->cpu; 1068 int *depth_irq; 1069 struct fgraph_data *data = iter->private; 1070 1071 /* 1072 * If we are either displaying irqs, or we got called as 1073 * a graph event and private data does not exist, 1074 * then we bypass the irq check. 1075 */ 1076 if ((flags & TRACE_GRAPH_PRINT_IRQS) || 1077 (!data)) 1078 return 0; 1079 1080 depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq); 1081 1082 /* 1083 * We are not inside the irq code. 1084 */ 1085 if (*depth_irq == -1) 1086 return 0; 1087 1088 /* 1089 * We are inside the irq code, and this is returning entry. 1090 * Let's not trace it and clear the entry depth, since 1091 * we are out of irq code. 1092 * 1093 * This condition ensures that we 'leave the irq code' once 1094 * we are out of the entry depth. Thus protecting us from 1095 * the RETURN entry loss. 1096 */ 1097 if (*depth_irq >= depth) { 1098 *depth_irq = -1; 1099 return 1; 1100 } 1101 1102 /* 1103 * We are inside the irq code, and this is not the entry. 1104 */ 1105 return 1; 1106 } 1107 1108 static enum print_line_t 1109 print_graph_entry(struct ftrace_graph_ent_entry *field, struct trace_seq *s, 1110 struct trace_iterator *iter, u32 flags) 1111 { 1112 struct fgraph_data *data = iter->private; 1113 struct ftrace_graph_ent *call = &field->graph_ent; 1114 struct ftrace_graph_ret_entry *leaf_ret; 1115 static enum print_line_t ret; 1116 int cpu = iter->cpu; 1117 1118 if (check_irq_entry(iter, flags, call->func, call->depth)) 1119 return TRACE_TYPE_HANDLED; 1120 1121 print_graph_prologue(iter, s, TRACE_GRAPH_ENT, call->func, flags); 1122 1123 leaf_ret = get_return_for_leaf(iter, field); 1124 if (leaf_ret) 1125 ret = print_graph_entry_leaf(iter, field, leaf_ret, s, flags); 1126 else 1127 ret = print_graph_entry_nested(iter, field, s, cpu, flags); 1128 1129 if (data) { 1130 /* 1131 * If we failed to write our output, then we need to make 1132 * note of it. Because we already consumed our entry. 1133 */ 1134 if (s->full) { 1135 data->failed = 1; 1136 data->cpu = cpu; 1137 } else 1138 data->failed = 0; 1139 } 1140 1141 return ret; 1142 } 1143 1144 static enum print_line_t 1145 print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s, 1146 struct trace_entry *ent, struct trace_iterator *iter, 1147 u32 flags) 1148 { 1149 unsigned long long duration = trace->rettime - trace->calltime; 1150 struct fgraph_data *data = iter->private; 1151 struct trace_array *tr = iter->tr; 1152 unsigned long func; 1153 pid_t pid = ent->pid; 1154 int cpu = iter->cpu; 1155 int func_match = 1; 1156 int i; 1157 1158 func = trace->func + iter->tr->text_delta; 1159 1160 if (check_irq_return(iter, flags, trace->depth)) 1161 return TRACE_TYPE_HANDLED; 1162 1163 if (data) { 1164 struct fgraph_cpu_data *cpu_data; 1165 int cpu = iter->cpu; 1166 1167 cpu_data = per_cpu_ptr(data->cpu_data, cpu); 1168 1169 /* 1170 * Comments display at + 1 to depth. This is the 1171 * return from a function, we now want the comments 1172 * to display at the same level of the bracket. 1173 */ 1174 cpu_data->depth = trace->depth - 1; 1175 1176 if (trace->depth < FTRACE_RETFUNC_DEPTH && 1177 !WARN_ON_ONCE(trace->depth < 0)) { 1178 if (cpu_data->enter_funcs[trace->depth] != trace->func) 1179 func_match = 0; 1180 cpu_data->enter_funcs[trace->depth] = 0; 1181 } 1182 } 1183 1184 print_graph_prologue(iter, s, 0, 0, flags); 1185 1186 /* Overhead and duration */ 1187 print_graph_duration(tr, duration, s, flags); 1188 1189 /* Closing brace */ 1190 for (i = 0; i < trace->depth * TRACE_GRAPH_INDENT; i++) 1191 trace_seq_putc(s, ' '); 1192 1193 /* 1194 * Always write out the function name and its return value if the 1195 * funcgraph-retval option is enabled. 1196 */ 1197 if (flags & __TRACE_GRAPH_PRINT_RETVAL) { 1198 print_graph_retval(s, NULL, trace, (void *)func, flags, tr->trace_flags); 1199 } else { 1200 /* 1201 * If the return function does not have a matching entry, 1202 * then the entry was lost. Instead of just printing 1203 * the '}' and letting the user guess what function this 1204 * belongs to, write out the function name. Always do 1205 * that if the funcgraph-tail option is enabled. 1206 */ 1207 if (func_match && !(flags & TRACE_GRAPH_PRINT_TAIL)) 1208 trace_seq_puts(s, "}\n"); 1209 else 1210 trace_seq_printf(s, "} /* %ps */\n", (void *)func); 1211 } 1212 1213 /* Overrun */ 1214 if (flags & TRACE_GRAPH_PRINT_OVERRUN) 1215 trace_seq_printf(s, " (Overruns: %u)\n", 1216 trace->overrun); 1217 1218 print_graph_irq(iter, trace->func, TRACE_GRAPH_RET, 1219 cpu, pid, flags); 1220 1221 return trace_handle_return(s); 1222 } 1223 1224 static enum print_line_t 1225 print_graph_comment(struct trace_seq *s, struct trace_entry *ent, 1226 struct trace_iterator *iter, u32 flags) 1227 { 1228 struct trace_array *tr = iter->tr; 1229 unsigned long sym_flags = (tr->trace_flags & TRACE_ITER_SYM_MASK); 1230 struct fgraph_data *data = iter->private; 1231 struct trace_event *event; 1232 int depth = 0; 1233 int ret; 1234 int i; 1235 1236 if (data) 1237 depth = per_cpu_ptr(data->cpu_data, iter->cpu)->depth; 1238 1239 print_graph_prologue(iter, s, 0, 0, flags); 1240 1241 /* No time */ 1242 print_graph_duration(tr, 0, s, flags | FLAGS_FILL_FULL); 1243 1244 /* Indentation */ 1245 if (depth > 0) 1246 for (i = 0; i < (depth + 1) * TRACE_GRAPH_INDENT; i++) 1247 trace_seq_putc(s, ' '); 1248 1249 /* The comment */ 1250 trace_seq_puts(s, "/* "); 1251 1252 switch (iter->ent->type) { 1253 case TRACE_BPUTS: 1254 ret = trace_print_bputs_msg_only(iter); 1255 if (ret != TRACE_TYPE_HANDLED) 1256 return ret; 1257 break; 1258 case TRACE_BPRINT: 1259 ret = trace_print_bprintk_msg_only(iter); 1260 if (ret != TRACE_TYPE_HANDLED) 1261 return ret; 1262 break; 1263 case TRACE_PRINT: 1264 ret = trace_print_printk_msg_only(iter); 1265 if (ret != TRACE_TYPE_HANDLED) 1266 return ret; 1267 break; 1268 default: 1269 event = ftrace_find_event(ent->type); 1270 if (!event) 1271 return TRACE_TYPE_UNHANDLED; 1272 1273 ret = event->funcs->trace(iter, sym_flags, event); 1274 if (ret != TRACE_TYPE_HANDLED) 1275 return ret; 1276 } 1277 1278 if (trace_seq_has_overflowed(s)) 1279 goto out; 1280 1281 /* Strip ending newline */ 1282 if (s->buffer[s->seq.len - 1] == '\n') { 1283 s->buffer[s->seq.len - 1] = '\0'; 1284 s->seq.len--; 1285 } 1286 1287 trace_seq_puts(s, " */\n"); 1288 out: 1289 return trace_handle_return(s); 1290 } 1291 1292 1293 enum print_line_t 1294 print_graph_function_flags(struct trace_iterator *iter, u32 flags) 1295 { 1296 struct ftrace_graph_ent_entry *field; 1297 struct fgraph_data *data = iter->private; 1298 struct trace_entry *entry = iter->ent; 1299 struct trace_seq *s = &iter->seq; 1300 int cpu = iter->cpu; 1301 int ret; 1302 1303 if (data && per_cpu_ptr(data->cpu_data, cpu)->ignore) { 1304 per_cpu_ptr(data->cpu_data, cpu)->ignore = 0; 1305 return TRACE_TYPE_HANDLED; 1306 } 1307 1308 /* 1309 * If the last output failed, there's a possibility we need 1310 * to print out the missing entry which would never go out. 1311 */ 1312 if (data && data->failed) { 1313 field = &data->ent.ent; 1314 iter->cpu = data->cpu; 1315 ret = print_graph_entry(field, s, iter, flags); 1316 if (ret == TRACE_TYPE_HANDLED && iter->cpu != cpu) { 1317 per_cpu_ptr(data->cpu_data, iter->cpu)->ignore = 1; 1318 ret = TRACE_TYPE_NO_CONSUME; 1319 } 1320 iter->cpu = cpu; 1321 return ret; 1322 } 1323 1324 switch (entry->type) { 1325 case TRACE_GRAPH_ENT: { 1326 /* 1327 * print_graph_entry() may consume the current event, 1328 * thus @field may become invalid, so we need to save it. 1329 * sizeof(struct ftrace_graph_ent_entry) is very small, 1330 * it can be safely saved at the stack. 1331 */ 1332 struct ftrace_graph_ent_entry saved; 1333 trace_assign_type(field, entry); 1334 saved = *field; 1335 return print_graph_entry(&saved, s, iter, flags); 1336 } 1337 #ifdef CONFIG_FUNCTION_GRAPH_RETADDR 1338 case TRACE_GRAPH_RETADDR_ENT: { 1339 struct fgraph_retaddr_ent_entry saved; 1340 struct fgraph_retaddr_ent_entry *rfield; 1341 1342 trace_assign_type(rfield, entry); 1343 saved = *rfield; 1344 return print_graph_entry((struct ftrace_graph_ent_entry *)&saved, s, iter, flags); 1345 } 1346 #endif 1347 case TRACE_GRAPH_RET: { 1348 struct ftrace_graph_ret_entry *field; 1349 trace_assign_type(field, entry); 1350 return print_graph_return(&field->ret, s, entry, iter, flags); 1351 } 1352 case TRACE_STACK: 1353 case TRACE_FN: 1354 /* dont trace stack and functions as comments */ 1355 return TRACE_TYPE_UNHANDLED; 1356 1357 default: 1358 return print_graph_comment(s, entry, iter, flags); 1359 } 1360 1361 return TRACE_TYPE_HANDLED; 1362 } 1363 1364 static enum print_line_t 1365 print_graph_function(struct trace_iterator *iter) 1366 { 1367 return print_graph_function_flags(iter, tracer_flags.val); 1368 } 1369 1370 static enum print_line_t 1371 print_graph_function_event(struct trace_iterator *iter, int flags, 1372 struct trace_event *event) 1373 { 1374 return print_graph_function(iter); 1375 } 1376 1377 static void print_lat_header(struct seq_file *s, u32 flags) 1378 { 1379 static const char spaces[] = " " /* 16 spaces */ 1380 " " /* 4 spaces */ 1381 " "; /* 17 spaces */ 1382 int size = 0; 1383 1384 if (flags & TRACE_GRAPH_PRINT_ABS_TIME) 1385 size += 16; 1386 if (flags & TRACE_GRAPH_PRINT_REL_TIME) 1387 size += 16; 1388 if (flags & TRACE_GRAPH_PRINT_CPU) 1389 size += 4; 1390 if (flags & TRACE_GRAPH_PRINT_PROC) 1391 size += 17; 1392 1393 seq_printf(s, "#%.*s _-----=> irqs-off \n", size, spaces); 1394 seq_printf(s, "#%.*s / _----=> need-resched \n", size, spaces); 1395 seq_printf(s, "#%.*s| / _---=> hardirq/softirq \n", size, spaces); 1396 seq_printf(s, "#%.*s|| / _--=> preempt-depth \n", size, spaces); 1397 seq_printf(s, "#%.*s||| / \n", size, spaces); 1398 } 1399 1400 static void __print_graph_headers_flags(struct trace_array *tr, 1401 struct seq_file *s, u32 flags) 1402 { 1403 int lat = tr->trace_flags & TRACE_ITER_LATENCY_FMT; 1404 1405 if (lat) 1406 print_lat_header(s, flags); 1407 1408 /* 1st line */ 1409 seq_putc(s, '#'); 1410 if (flags & TRACE_GRAPH_PRINT_ABS_TIME) 1411 seq_puts(s, " TIME "); 1412 if (flags & TRACE_GRAPH_PRINT_REL_TIME) 1413 seq_puts(s, " REL TIME "); 1414 if (flags & TRACE_GRAPH_PRINT_CPU) 1415 seq_puts(s, " CPU"); 1416 if (flags & TRACE_GRAPH_PRINT_PROC) 1417 seq_puts(s, " TASK/PID "); 1418 if (lat) 1419 seq_puts(s, "|||| "); 1420 if (flags & TRACE_GRAPH_PRINT_DURATION) 1421 seq_puts(s, " DURATION "); 1422 seq_puts(s, " FUNCTION CALLS\n"); 1423 1424 /* 2nd line */ 1425 seq_putc(s, '#'); 1426 if (flags & TRACE_GRAPH_PRINT_ABS_TIME) 1427 seq_puts(s, " | "); 1428 if (flags & TRACE_GRAPH_PRINT_REL_TIME) 1429 seq_puts(s, " | "); 1430 if (flags & TRACE_GRAPH_PRINT_CPU) 1431 seq_puts(s, " | "); 1432 if (flags & TRACE_GRAPH_PRINT_PROC) 1433 seq_puts(s, " | | "); 1434 if (lat) 1435 seq_puts(s, "|||| "); 1436 if (flags & TRACE_GRAPH_PRINT_DURATION) 1437 seq_puts(s, " | | "); 1438 seq_puts(s, " | | | |\n"); 1439 } 1440 1441 static void print_graph_headers(struct seq_file *s) 1442 { 1443 print_graph_headers_flags(s, tracer_flags.val); 1444 } 1445 1446 void print_graph_headers_flags(struct seq_file *s, u32 flags) 1447 { 1448 struct trace_iterator *iter = s->private; 1449 struct trace_array *tr = iter->tr; 1450 1451 if (!(tr->trace_flags & TRACE_ITER_CONTEXT_INFO)) 1452 return; 1453 1454 if (tr->trace_flags & TRACE_ITER_LATENCY_FMT) { 1455 /* print nothing if the buffers are empty */ 1456 if (trace_empty(iter)) 1457 return; 1458 1459 print_trace_header(s, iter); 1460 } 1461 1462 __print_graph_headers_flags(tr, s, flags); 1463 } 1464 1465 void graph_trace_open(struct trace_iterator *iter) 1466 { 1467 /* pid and depth on the last trace processed */ 1468 struct fgraph_data *data; 1469 gfp_t gfpflags; 1470 int cpu; 1471 1472 iter->private = NULL; 1473 1474 /* We can be called in atomic context via ftrace_dump() */ 1475 gfpflags = (in_atomic() || irqs_disabled()) ? GFP_ATOMIC : GFP_KERNEL; 1476 1477 data = kzalloc(sizeof(*data), gfpflags); 1478 if (!data) 1479 goto out_err; 1480 1481 data->cpu_data = alloc_percpu_gfp(struct fgraph_cpu_data, gfpflags); 1482 if (!data->cpu_data) 1483 goto out_err_free; 1484 1485 for_each_possible_cpu(cpu) { 1486 pid_t *pid = &(per_cpu_ptr(data->cpu_data, cpu)->last_pid); 1487 int *depth = &(per_cpu_ptr(data->cpu_data, cpu)->depth); 1488 int *ignore = &(per_cpu_ptr(data->cpu_data, cpu)->ignore); 1489 int *depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq); 1490 1491 *pid = -1; 1492 *depth = 0; 1493 *ignore = 0; 1494 *depth_irq = -1; 1495 } 1496 1497 iter->private = data; 1498 1499 return; 1500 1501 out_err_free: 1502 kfree(data); 1503 out_err: 1504 pr_warn("function graph tracer: not enough memory\n"); 1505 } 1506 1507 void graph_trace_close(struct trace_iterator *iter) 1508 { 1509 struct fgraph_data *data = iter->private; 1510 1511 if (data) { 1512 free_percpu(data->cpu_data); 1513 kfree(data); 1514 } 1515 } 1516 1517 static int 1518 func_graph_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set) 1519 { 1520 if (bit == TRACE_GRAPH_PRINT_IRQS) 1521 ftrace_graph_skip_irqs = !set; 1522 1523 if (bit == TRACE_GRAPH_SLEEP_TIME) 1524 ftrace_graph_sleep_time_control(set); 1525 1526 if (bit == TRACE_GRAPH_GRAPH_TIME) 1527 ftrace_graph_graph_time_control(set); 1528 1529 return 0; 1530 } 1531 1532 static struct trace_event_functions graph_functions = { 1533 .trace = print_graph_function_event, 1534 }; 1535 1536 static struct trace_event graph_trace_entry_event = { 1537 .type = TRACE_GRAPH_ENT, 1538 .funcs = &graph_functions, 1539 }; 1540 1541 #ifdef CONFIG_FUNCTION_GRAPH_RETADDR 1542 static struct trace_event graph_trace_retaddr_entry_event = { 1543 .type = TRACE_GRAPH_RETADDR_ENT, 1544 .funcs = &graph_functions, 1545 }; 1546 #endif 1547 1548 static struct trace_event graph_trace_ret_event = { 1549 .type = TRACE_GRAPH_RET, 1550 .funcs = &graph_functions 1551 }; 1552 1553 static struct tracer graph_trace __tracer_data = { 1554 .name = "function_graph", 1555 .update_thresh = graph_trace_update_thresh, 1556 .open = graph_trace_open, 1557 .pipe_open = graph_trace_open, 1558 .close = graph_trace_close, 1559 .pipe_close = graph_trace_close, 1560 .init = graph_trace_init, 1561 .reset = graph_trace_reset, 1562 .print_line = print_graph_function, 1563 .print_header = print_graph_headers, 1564 .flags = &tracer_flags, 1565 .set_flag = func_graph_set_flag, 1566 .allow_instances = true, 1567 #ifdef CONFIG_FTRACE_SELFTEST 1568 .selftest = trace_selftest_startup_function_graph, 1569 #endif 1570 }; 1571 1572 1573 static ssize_t 1574 graph_depth_write(struct file *filp, const char __user *ubuf, size_t cnt, 1575 loff_t *ppos) 1576 { 1577 unsigned long val; 1578 int ret; 1579 1580 ret = kstrtoul_from_user(ubuf, cnt, 10, &val); 1581 if (ret) 1582 return ret; 1583 1584 fgraph_max_depth = val; 1585 1586 *ppos += cnt; 1587 1588 return cnt; 1589 } 1590 1591 static ssize_t 1592 graph_depth_read(struct file *filp, char __user *ubuf, size_t cnt, 1593 loff_t *ppos) 1594 { 1595 char buf[15]; /* More than enough to hold UINT_MAX + "\n"*/ 1596 int n; 1597 1598 n = sprintf(buf, "%d\n", fgraph_max_depth); 1599 1600 return simple_read_from_buffer(ubuf, cnt, ppos, buf, n); 1601 } 1602 1603 static const struct file_operations graph_depth_fops = { 1604 .open = tracing_open_generic, 1605 .write = graph_depth_write, 1606 .read = graph_depth_read, 1607 .llseek = generic_file_llseek, 1608 }; 1609 1610 static __init int init_graph_tracefs(void) 1611 { 1612 int ret; 1613 1614 ret = tracing_init_dentry(); 1615 if (ret) 1616 return 0; 1617 1618 trace_create_file("max_graph_depth", TRACE_MODE_WRITE, NULL, 1619 NULL, &graph_depth_fops); 1620 1621 return 0; 1622 } 1623 fs_initcall(init_graph_tracefs); 1624 1625 static __init int init_graph_trace(void) 1626 { 1627 max_bytes_for_cpu = snprintf(NULL, 0, "%u", nr_cpu_ids - 1); 1628 1629 if (!register_trace_event(&graph_trace_entry_event)) { 1630 pr_warn("Warning: could not register graph trace events\n"); 1631 return 1; 1632 } 1633 1634 #ifdef CONFIG_FUNCTION_GRAPH_RETADDR 1635 if (!register_trace_event(&graph_trace_retaddr_entry_event)) { 1636 pr_warn("Warning: could not register graph trace retaddr events\n"); 1637 return 1; 1638 } 1639 #endif 1640 1641 if (!register_trace_event(&graph_trace_ret_event)) { 1642 pr_warn("Warning: could not register graph trace events\n"); 1643 return 1; 1644 } 1645 1646 return register_tracer(&graph_trace); 1647 } 1648 1649 core_initcall(init_graph_trace); 1650