| 1 | /* |
| 2 | * |
| 3 | * Function graph tracer. |
| 4 | * Copyright (c) 2008-2009 Frederic Weisbecker <fweisbec@gmail.com> |
| 5 | * Mostly borrowed from function tracer which |
| 6 | * is Copyright (c) Steven Rostedt <srostedt@redhat.com> |
| 7 | * |
| 8 | */ |
| 9 | #include <linux/debugfs.h> |
| 10 | #include <linux/uaccess.h> |
| 11 | #include <linux/ftrace.h> |
| 12 | #include <linux/slab.h> |
| 13 | #include <linux/fs.h> |
| 14 | |
| 15 | #include "trace.h" |
| 16 | #include "trace_output.h" |
| 17 | |
| 18 | /* When set, irq functions will be ignored */ |
| 19 | static int ftrace_graph_skip_irqs; |
| 20 | |
| 21 | struct fgraph_cpu_data { |
| 22 | pid_t last_pid; |
| 23 | int depth; |
| 24 | int depth_irq; |
| 25 | int ignore; |
| 26 | unsigned long enter_funcs[FTRACE_RETFUNC_DEPTH]; |
| 27 | }; |
| 28 | |
| 29 | struct fgraph_data { |
| 30 | struct fgraph_cpu_data __percpu *cpu_data; |
| 31 | |
| 32 | /* Place to preserve last processed entry. */ |
| 33 | struct ftrace_graph_ent_entry ent; |
| 34 | struct ftrace_graph_ret_entry ret; |
| 35 | int failed; |
| 36 | int cpu; |
| 37 | }; |
| 38 | |
| 39 | #define TRACE_GRAPH_INDENT 2 |
| 40 | |
| 41 | /* Flag options */ |
| 42 | #define TRACE_GRAPH_PRINT_OVERRUN 0x1 |
| 43 | #define TRACE_GRAPH_PRINT_CPU 0x2 |
| 44 | #define TRACE_GRAPH_PRINT_OVERHEAD 0x4 |
| 45 | #define TRACE_GRAPH_PRINT_PROC 0x8 |
| 46 | #define TRACE_GRAPH_PRINT_DURATION 0x10 |
| 47 | #define TRACE_GRAPH_PRINT_ABS_TIME 0x20 |
| 48 | #define TRACE_GRAPH_PRINT_IRQS 0x40 |
| 49 | |
| 50 | static struct tracer_opt trace_opts[] = { |
| 51 | /* Display overruns? (for self-debug purpose) */ |
| 52 | { TRACER_OPT(funcgraph-overrun, TRACE_GRAPH_PRINT_OVERRUN) }, |
| 53 | /* Display CPU ? */ |
| 54 | { TRACER_OPT(funcgraph-cpu, TRACE_GRAPH_PRINT_CPU) }, |
| 55 | /* Display Overhead ? */ |
| 56 | { TRACER_OPT(funcgraph-overhead, TRACE_GRAPH_PRINT_OVERHEAD) }, |
| 57 | /* Display proc name/pid */ |
| 58 | { TRACER_OPT(funcgraph-proc, TRACE_GRAPH_PRINT_PROC) }, |
| 59 | /* Display duration of execution */ |
| 60 | { TRACER_OPT(funcgraph-duration, TRACE_GRAPH_PRINT_DURATION) }, |
| 61 | /* Display absolute time of an entry */ |
| 62 | { TRACER_OPT(funcgraph-abstime, TRACE_GRAPH_PRINT_ABS_TIME) }, |
| 63 | /* Display interrupts */ |
| 64 | { TRACER_OPT(funcgraph-irqs, TRACE_GRAPH_PRINT_IRQS) }, |
| 65 | { } /* Empty entry */ |
| 66 | }; |
| 67 | |
| 68 | static struct tracer_flags tracer_flags = { |
| 69 | /* Don't display overruns and proc by default */ |
| 70 | .val = TRACE_GRAPH_PRINT_CPU | TRACE_GRAPH_PRINT_OVERHEAD | |
| 71 | TRACE_GRAPH_PRINT_DURATION | TRACE_GRAPH_PRINT_IRQS, |
| 72 | .opts = trace_opts |
| 73 | }; |
| 74 | |
| 75 | static struct trace_array *graph_array; |
| 76 | |
| 77 | /* |
| 78 | * DURATION column is being also used to display IRQ signs, |
| 79 | * following values are used by print_graph_irq and others |
| 80 | * to fill in space into DURATION column. |
| 81 | */ |
| 82 | enum { |
| 83 | DURATION_FILL_FULL = -1, |
| 84 | DURATION_FILL_START = -2, |
| 85 | DURATION_FILL_END = -3, |
| 86 | }; |
| 87 | |
| 88 | static enum print_line_t |
| 89 | print_graph_duration(unsigned long long duration, struct trace_seq *s, |
| 90 | u32 flags); |
| 91 | |
| 92 | /* Add a function return address to the trace stack on thread info.*/ |
| 93 | int |
| 94 | ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth, |
| 95 | unsigned long frame_pointer) |
| 96 | { |
| 97 | unsigned long long calltime; |
| 98 | int index; |
| 99 | |
| 100 | if (!current->ret_stack) |
| 101 | return -EBUSY; |
| 102 | |
| 103 | /* |
| 104 | * We must make sure the ret_stack is tested before we read |
| 105 | * anything else. |
| 106 | */ |
| 107 | smp_rmb(); |
| 108 | |
| 109 | /* The return trace stack is full */ |
| 110 | if (current->curr_ret_stack == FTRACE_RETFUNC_DEPTH - 1) { |
| 111 | atomic_inc(¤t->trace_overrun); |
| 112 | return -EBUSY; |
| 113 | } |
| 114 | |
| 115 | calltime = trace_clock_local(); |
| 116 | |
| 117 | index = ++current->curr_ret_stack; |
| 118 | barrier(); |
| 119 | current->ret_stack[index].ret = ret; |
| 120 | current->ret_stack[index].func = func; |
| 121 | current->ret_stack[index].calltime = calltime; |
| 122 | current->ret_stack[index].subtime = 0; |
| 123 | current->ret_stack[index].fp = frame_pointer; |
| 124 | *depth = index; |
| 125 | |
| 126 | return 0; |
| 127 | } |
| 128 | |
| 129 | /* Retrieve a function return address to the trace stack on thread info.*/ |
| 130 | static void |
| 131 | ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret, |
| 132 | unsigned long frame_pointer) |
| 133 | { |
| 134 | int index; |
| 135 | |
| 136 | index = current->curr_ret_stack; |
| 137 | |
| 138 | if (unlikely(index < 0)) { |
| 139 | ftrace_graph_stop(); |
| 140 | WARN_ON(1); |
| 141 | /* Might as well panic, otherwise we have no where to go */ |
| 142 | *ret = (unsigned long)panic; |
| 143 | return; |
| 144 | } |
| 145 | |
| 146 | #ifdef CONFIG_HAVE_FUNCTION_GRAPH_FP_TEST |
| 147 | /* |
| 148 | * The arch may choose to record the frame pointer used |
| 149 | * and check it here to make sure that it is what we expect it |
| 150 | * to be. If gcc does not set the place holder of the return |
| 151 | * address in the frame pointer, and does a copy instead, then |
| 152 | * the function graph trace will fail. This test detects this |
| 153 | * case. |
| 154 | * |
| 155 | * Currently, x86_32 with optimize for size (-Os) makes the latest |
| 156 | * gcc do the above. |
| 157 | */ |
| 158 | if (unlikely(current->ret_stack[index].fp != frame_pointer)) { |
| 159 | ftrace_graph_stop(); |
| 160 | WARN(1, "Bad frame pointer: expected %lx, received %lx\n" |
| 161 | " from func %ps return to %lx\n", |
| 162 | current->ret_stack[index].fp, |
| 163 | frame_pointer, |
| 164 | (void *)current->ret_stack[index].func, |
| 165 | current->ret_stack[index].ret); |
| 166 | *ret = (unsigned long)panic; |
| 167 | return; |
| 168 | } |
| 169 | #endif |
| 170 | |
| 171 | *ret = current->ret_stack[index].ret; |
| 172 | trace->func = current->ret_stack[index].func; |
| 173 | trace->calltime = current->ret_stack[index].calltime; |
| 174 | trace->overrun = atomic_read(¤t->trace_overrun); |
| 175 | trace->depth = index; |
| 176 | } |
| 177 | |
| 178 | /* |
| 179 | * Send the trace to the ring-buffer. |
| 180 | * @return the original return address. |
| 181 | */ |
| 182 | unsigned long ftrace_return_to_handler(unsigned long frame_pointer) |
| 183 | { |
| 184 | struct ftrace_graph_ret trace; |
| 185 | unsigned long ret; |
| 186 | |
| 187 | ftrace_pop_return_trace(&trace, &ret, frame_pointer); |
| 188 | trace.rettime = trace_clock_local(); |
| 189 | ftrace_graph_return(&trace); |
| 190 | barrier(); |
| 191 | current->curr_ret_stack--; |
| 192 | |
| 193 | if (unlikely(!ret)) { |
| 194 | ftrace_graph_stop(); |
| 195 | WARN_ON(1); |
| 196 | /* Might as well panic. What else to do? */ |
| 197 | ret = (unsigned long)panic; |
| 198 | } |
| 199 | |
| 200 | return ret; |
| 201 | } |
| 202 | |
| 203 | int __trace_graph_entry(struct trace_array *tr, |
| 204 | struct ftrace_graph_ent *trace, |
| 205 | unsigned long flags, |
| 206 | int pc) |
| 207 | { |
| 208 | struct ftrace_event_call *call = &event_funcgraph_entry; |
| 209 | struct ring_buffer_event *event; |
| 210 | struct ring_buffer *buffer = tr->buffer; |
| 211 | struct ftrace_graph_ent_entry *entry; |
| 212 | |
| 213 | if (unlikely(__this_cpu_read(ftrace_cpu_disabled))) |
| 214 | return 0; |
| 215 | |
| 216 | event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_ENT, |
| 217 | sizeof(*entry), flags, pc); |
| 218 | if (!event) |
| 219 | return 0; |
| 220 | entry = ring_buffer_event_data(event); |
| 221 | entry->graph_ent = *trace; |
| 222 | if (!filter_current_check_discard(buffer, call, entry, event)) |
| 223 | ring_buffer_unlock_commit(buffer, event); |
| 224 | |
| 225 | return 1; |
| 226 | } |
| 227 | |
| 228 | static inline int ftrace_graph_ignore_irqs(void) |
| 229 | { |
| 230 | if (!ftrace_graph_skip_irqs || trace_recursion_test(TRACE_IRQ_BIT)) |
| 231 | return 0; |
| 232 | |
| 233 | return in_irq(); |
| 234 | } |
| 235 | |
| 236 | int trace_graph_entry(struct ftrace_graph_ent *trace) |
| 237 | { |
| 238 | struct trace_array *tr = graph_array; |
| 239 | struct trace_array_cpu *data; |
| 240 | unsigned long flags; |
| 241 | long disabled; |
| 242 | int ret; |
| 243 | int cpu; |
| 244 | int pc; |
| 245 | |
| 246 | if (!ftrace_trace_task(current)) |
| 247 | return 0; |
| 248 | |
| 249 | /* trace it when it is-nested-in or is a function enabled. */ |
| 250 | if (!(trace->depth || ftrace_graph_addr(trace->func)) || |
| 251 | ftrace_graph_ignore_irqs()) |
| 252 | return 0; |
| 253 | |
| 254 | local_irq_save(flags); |
| 255 | cpu = raw_smp_processor_id(); |
| 256 | data = tr->data[cpu]; |
| 257 | disabled = atomic_inc_return(&data->disabled); |
| 258 | if (likely(disabled == 1)) { |
| 259 | pc = preempt_count(); |
| 260 | ret = __trace_graph_entry(tr, trace, flags, pc); |
| 261 | } else { |
| 262 | ret = 0; |
| 263 | } |
| 264 | |
| 265 | atomic_dec(&data->disabled); |
| 266 | local_irq_restore(flags); |
| 267 | |
| 268 | return ret; |
| 269 | } |
| 270 | |
| 271 | int trace_graph_thresh_entry(struct ftrace_graph_ent *trace) |
| 272 | { |
| 273 | if (tracing_thresh) |
| 274 | return 1; |
| 275 | else |
| 276 | return trace_graph_entry(trace); |
| 277 | } |
| 278 | |
| 279 | static void |
| 280 | __trace_graph_function(struct trace_array *tr, |
| 281 | unsigned long ip, unsigned long flags, int pc) |
| 282 | { |
| 283 | u64 time = trace_clock_local(); |
| 284 | struct ftrace_graph_ent ent = { |
| 285 | .func = ip, |
| 286 | .depth = 0, |
| 287 | }; |
| 288 | struct ftrace_graph_ret ret = { |
| 289 | .func = ip, |
| 290 | .depth = 0, |
| 291 | .calltime = time, |
| 292 | .rettime = time, |
| 293 | }; |
| 294 | |
| 295 | __trace_graph_entry(tr, &ent, flags, pc); |
| 296 | __trace_graph_return(tr, &ret, flags, pc); |
| 297 | } |
| 298 | |
| 299 | void |
| 300 | trace_graph_function(struct trace_array *tr, |
| 301 | unsigned long ip, unsigned long parent_ip, |
| 302 | unsigned long flags, int pc) |
| 303 | { |
| 304 | __trace_graph_function(tr, ip, flags, pc); |
| 305 | } |
| 306 | |
| 307 | void __trace_graph_return(struct trace_array *tr, |
| 308 | struct ftrace_graph_ret *trace, |
| 309 | unsigned long flags, |
| 310 | int pc) |
| 311 | { |
| 312 | struct ftrace_event_call *call = &event_funcgraph_exit; |
| 313 | struct ring_buffer_event *event; |
| 314 | struct ring_buffer *buffer = tr->buffer; |
| 315 | struct ftrace_graph_ret_entry *entry; |
| 316 | |
| 317 | if (unlikely(__this_cpu_read(ftrace_cpu_disabled))) |
| 318 | return; |
| 319 | |
| 320 | event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_RET, |
| 321 | sizeof(*entry), flags, pc); |
| 322 | if (!event) |
| 323 | return; |
| 324 | entry = ring_buffer_event_data(event); |
| 325 | entry->ret = *trace; |
| 326 | if (!filter_current_check_discard(buffer, call, entry, event)) |
| 327 | ring_buffer_unlock_commit(buffer, event); |
| 328 | } |
| 329 | |
| 330 | void trace_graph_return(struct ftrace_graph_ret *trace) |
| 331 | { |
| 332 | struct trace_array *tr = graph_array; |
| 333 | struct trace_array_cpu *data; |
| 334 | unsigned long flags; |
| 335 | long disabled; |
| 336 | int cpu; |
| 337 | int pc; |
| 338 | |
| 339 | local_irq_save(flags); |
| 340 | cpu = raw_smp_processor_id(); |
| 341 | data = tr->data[cpu]; |
| 342 | disabled = atomic_inc_return(&data->disabled); |
| 343 | if (likely(disabled == 1)) { |
| 344 | pc = preempt_count(); |
| 345 | __trace_graph_return(tr, trace, flags, pc); |
| 346 | } |
| 347 | atomic_dec(&data->disabled); |
| 348 | local_irq_restore(flags); |
| 349 | } |
| 350 | |
| 351 | void set_graph_array(struct trace_array *tr) |
| 352 | { |
| 353 | graph_array = tr; |
| 354 | |
| 355 | /* Make graph_array visible before we start tracing */ |
| 356 | |
| 357 | smp_mb(); |
| 358 | } |
| 359 | |
| 360 | void trace_graph_thresh_return(struct ftrace_graph_ret *trace) |
| 361 | { |
| 362 | if (tracing_thresh && |
| 363 | (trace->rettime - trace->calltime < tracing_thresh)) |
| 364 | return; |
| 365 | else |
| 366 | trace_graph_return(trace); |
| 367 | } |
| 368 | |
| 369 | static int graph_trace_init(struct trace_array *tr) |
| 370 | { |
| 371 | int ret; |
| 372 | |
| 373 | set_graph_array(tr); |
| 374 | if (tracing_thresh) |
| 375 | ret = register_ftrace_graph(&trace_graph_thresh_return, |
| 376 | &trace_graph_thresh_entry); |
| 377 | else |
| 378 | ret = register_ftrace_graph(&trace_graph_return, |
| 379 | &trace_graph_entry); |
| 380 | if (ret) |
| 381 | return ret; |
| 382 | tracing_start_cmdline_record(); |
| 383 | |
| 384 | return 0; |
| 385 | } |
| 386 | |
| 387 | static void graph_trace_reset(struct trace_array *tr) |
| 388 | { |
| 389 | tracing_stop_cmdline_record(); |
| 390 | unregister_ftrace_graph(); |
| 391 | } |
| 392 | |
| 393 | static int max_bytes_for_cpu; |
| 394 | |
| 395 | static enum print_line_t |
| 396 | print_graph_cpu(struct trace_seq *s, int cpu) |
| 397 | { |
| 398 | int ret; |
| 399 | |
| 400 | /* |
| 401 | * Start with a space character - to make it stand out |
| 402 | * to the right a bit when trace output is pasted into |
| 403 | * email: |
| 404 | */ |
| 405 | ret = trace_seq_printf(s, " %*d) ", max_bytes_for_cpu, cpu); |
| 406 | if (!ret) |
| 407 | return TRACE_TYPE_PARTIAL_LINE; |
| 408 | |
| 409 | return TRACE_TYPE_HANDLED; |
| 410 | } |
| 411 | |
| 412 | #define TRACE_GRAPH_PROCINFO_LENGTH 14 |
| 413 | |
| 414 | static enum print_line_t |
| 415 | print_graph_proc(struct trace_seq *s, pid_t pid) |
| 416 | { |
| 417 | char comm[TASK_COMM_LEN]; |
| 418 | /* sign + log10(MAX_INT) + '\0' */ |
| 419 | char pid_str[11]; |
| 420 | int spaces = 0; |
| 421 | int ret; |
| 422 | int len; |
| 423 | int i; |
| 424 | |
| 425 | trace_find_cmdline(pid, comm); |
| 426 | comm[7] = '\0'; |
| 427 | sprintf(pid_str, "%d", pid); |
| 428 | |
| 429 | /* 1 stands for the "-" character */ |
| 430 | len = strlen(comm) + strlen(pid_str) + 1; |
| 431 | |
| 432 | if (len < TRACE_GRAPH_PROCINFO_LENGTH) |
| 433 | spaces = TRACE_GRAPH_PROCINFO_LENGTH - len; |
| 434 | |
| 435 | /* First spaces to align center */ |
| 436 | for (i = 0; i < spaces / 2; i++) { |
| 437 | ret = trace_seq_printf(s, " "); |
| 438 | if (!ret) |
| 439 | return TRACE_TYPE_PARTIAL_LINE; |
| 440 | } |
| 441 | |
| 442 | ret = trace_seq_printf(s, "%s-%s", comm, pid_str); |
| 443 | if (!ret) |
| 444 | return TRACE_TYPE_PARTIAL_LINE; |
| 445 | |
| 446 | /* Last spaces to align center */ |
| 447 | for (i = 0; i < spaces - (spaces / 2); i++) { |
| 448 | ret = trace_seq_printf(s, " "); |
| 449 | if (!ret) |
| 450 | return TRACE_TYPE_PARTIAL_LINE; |
| 451 | } |
| 452 | return TRACE_TYPE_HANDLED; |
| 453 | } |
| 454 | |
| 455 | |
| 456 | static enum print_line_t |
| 457 | print_graph_lat_fmt(struct trace_seq *s, struct trace_entry *entry) |
| 458 | { |
| 459 | if (!trace_seq_putc(s, ' ')) |
| 460 | return 0; |
| 461 | |
| 462 | return trace_print_lat_fmt(s, entry); |
| 463 | } |
| 464 | |
| 465 | /* If the pid changed since the last trace, output this event */ |
| 466 | static enum print_line_t |
| 467 | verif_pid(struct trace_seq *s, pid_t pid, int cpu, struct fgraph_data *data) |
| 468 | { |
| 469 | pid_t prev_pid; |
| 470 | pid_t *last_pid; |
| 471 | int ret; |
| 472 | |
| 473 | if (!data) |
| 474 | return TRACE_TYPE_HANDLED; |
| 475 | |
| 476 | last_pid = &(per_cpu_ptr(data->cpu_data, cpu)->last_pid); |
| 477 | |
| 478 | if (*last_pid == pid) |
| 479 | return TRACE_TYPE_HANDLED; |
| 480 | |
| 481 | prev_pid = *last_pid; |
| 482 | *last_pid = pid; |
| 483 | |
| 484 | if (prev_pid == -1) |
| 485 | return TRACE_TYPE_HANDLED; |
| 486 | /* |
| 487 | * Context-switch trace line: |
| 488 | |
| 489 | ------------------------------------------ |
| 490 | | 1) migration/0--1 => sshd-1755 |
| 491 | ------------------------------------------ |
| 492 | |
| 493 | */ |
| 494 | ret = trace_seq_printf(s, |
| 495 | " ------------------------------------------\n"); |
| 496 | if (!ret) |
| 497 | return TRACE_TYPE_PARTIAL_LINE; |
| 498 | |
| 499 | ret = print_graph_cpu(s, cpu); |
| 500 | if (ret == TRACE_TYPE_PARTIAL_LINE) |
| 501 | return TRACE_TYPE_PARTIAL_LINE; |
| 502 | |
| 503 | ret = print_graph_proc(s, prev_pid); |
| 504 | if (ret == TRACE_TYPE_PARTIAL_LINE) |
| 505 | return TRACE_TYPE_PARTIAL_LINE; |
| 506 | |
| 507 | ret = trace_seq_printf(s, " => "); |
| 508 | if (!ret) |
| 509 | return TRACE_TYPE_PARTIAL_LINE; |
| 510 | |
| 511 | ret = print_graph_proc(s, pid); |
| 512 | if (ret == TRACE_TYPE_PARTIAL_LINE) |
| 513 | return TRACE_TYPE_PARTIAL_LINE; |
| 514 | |
| 515 | ret = trace_seq_printf(s, |
| 516 | "\n ------------------------------------------\n\n"); |
| 517 | if (!ret) |
| 518 | return TRACE_TYPE_PARTIAL_LINE; |
| 519 | |
| 520 | return TRACE_TYPE_HANDLED; |
| 521 | } |
| 522 | |
| 523 | static struct ftrace_graph_ret_entry * |
| 524 | get_return_for_leaf(struct trace_iterator *iter, |
| 525 | struct ftrace_graph_ent_entry *curr) |
| 526 | { |
| 527 | struct fgraph_data *data = iter->private; |
| 528 | struct ring_buffer_iter *ring_iter = NULL; |
| 529 | struct ring_buffer_event *event; |
| 530 | struct ftrace_graph_ret_entry *next; |
| 531 | |
| 532 | /* |
| 533 | * If the previous output failed to write to the seq buffer, |
| 534 | * then we just reuse the data from before. |
| 535 | */ |
| 536 | if (data && data->failed) { |
| 537 | curr = &data->ent; |
| 538 | next = &data->ret; |
| 539 | } else { |
| 540 | |
| 541 | ring_iter = trace_buffer_iter(iter, iter->cpu); |
| 542 | |
| 543 | /* First peek to compare current entry and the next one */ |
| 544 | if (ring_iter) |
| 545 | event = ring_buffer_iter_peek(ring_iter, NULL); |
| 546 | else { |
| 547 | /* |
| 548 | * We need to consume the current entry to see |
| 549 | * the next one. |
| 550 | */ |
| 551 | ring_buffer_consume(iter->tr->buffer, iter->cpu, |
| 552 | NULL, NULL); |
| 553 | event = ring_buffer_peek(iter->tr->buffer, iter->cpu, |
| 554 | NULL, NULL); |
| 555 | } |
| 556 | |
| 557 | if (!event) |
| 558 | return NULL; |
| 559 | |
| 560 | next = ring_buffer_event_data(event); |
| 561 | |
| 562 | if (data) { |
| 563 | /* |
| 564 | * Save current and next entries for later reference |
| 565 | * if the output fails. |
| 566 | */ |
| 567 | data->ent = *curr; |
| 568 | /* |
| 569 | * If the next event is not a return type, then |
| 570 | * we only care about what type it is. Otherwise we can |
| 571 | * safely copy the entire event. |
| 572 | */ |
| 573 | if (next->ent.type == TRACE_GRAPH_RET) |
| 574 | data->ret = *next; |
| 575 | else |
| 576 | data->ret.ent.type = next->ent.type; |
| 577 | } |
| 578 | } |
| 579 | |
| 580 | if (next->ent.type != TRACE_GRAPH_RET) |
| 581 | return NULL; |
| 582 | |
| 583 | if (curr->ent.pid != next->ent.pid || |
| 584 | curr->graph_ent.func != next->ret.func) |
| 585 | return NULL; |
| 586 | |
| 587 | /* this is a leaf, now advance the iterator */ |
| 588 | if (ring_iter) |
| 589 | ring_buffer_read(ring_iter, NULL); |
| 590 | |
| 591 | return next; |
| 592 | } |
| 593 | |
| 594 | static int print_graph_abs_time(u64 t, struct trace_seq *s) |
| 595 | { |
| 596 | unsigned long usecs_rem; |
| 597 | |
| 598 | usecs_rem = do_div(t, NSEC_PER_SEC); |
| 599 | usecs_rem /= 1000; |
| 600 | |
| 601 | return trace_seq_printf(s, "%5lu.%06lu | ", |
| 602 | (unsigned long)t, usecs_rem); |
| 603 | } |
| 604 | |
| 605 | static enum print_line_t |
| 606 | print_graph_irq(struct trace_iterator *iter, unsigned long addr, |
| 607 | enum trace_type type, int cpu, pid_t pid, u32 flags) |
| 608 | { |
| 609 | int ret; |
| 610 | struct trace_seq *s = &iter->seq; |
| 611 | |
| 612 | if (addr < (unsigned long)__irqentry_text_start || |
| 613 | addr >= (unsigned long)__irqentry_text_end) |
| 614 | return TRACE_TYPE_UNHANDLED; |
| 615 | |
| 616 | if (trace_flags & TRACE_ITER_CONTEXT_INFO) { |
| 617 | /* Absolute time */ |
| 618 | if (flags & TRACE_GRAPH_PRINT_ABS_TIME) { |
| 619 | ret = print_graph_abs_time(iter->ts, s); |
| 620 | if (!ret) |
| 621 | return TRACE_TYPE_PARTIAL_LINE; |
| 622 | } |
| 623 | |
| 624 | /* Cpu */ |
| 625 | if (flags & TRACE_GRAPH_PRINT_CPU) { |
| 626 | ret = print_graph_cpu(s, cpu); |
| 627 | if (ret == TRACE_TYPE_PARTIAL_LINE) |
| 628 | return TRACE_TYPE_PARTIAL_LINE; |
| 629 | } |
| 630 | |
| 631 | /* Proc */ |
| 632 | if (flags & TRACE_GRAPH_PRINT_PROC) { |
| 633 | ret = print_graph_proc(s, pid); |
| 634 | if (ret == TRACE_TYPE_PARTIAL_LINE) |
| 635 | return TRACE_TYPE_PARTIAL_LINE; |
| 636 | ret = trace_seq_printf(s, " | "); |
| 637 | if (!ret) |
| 638 | return TRACE_TYPE_PARTIAL_LINE; |
| 639 | } |
| 640 | } |
| 641 | |
| 642 | /* No overhead */ |
| 643 | ret = print_graph_duration(DURATION_FILL_START, s, flags); |
| 644 | if (ret != TRACE_TYPE_HANDLED) |
| 645 | return ret; |
| 646 | |
| 647 | if (type == TRACE_GRAPH_ENT) |
| 648 | ret = trace_seq_printf(s, "==========>"); |
| 649 | else |
| 650 | ret = trace_seq_printf(s, "<=========="); |
| 651 | |
| 652 | if (!ret) |
| 653 | return TRACE_TYPE_PARTIAL_LINE; |
| 654 | |
| 655 | ret = print_graph_duration(DURATION_FILL_END, s, flags); |
| 656 | if (ret != TRACE_TYPE_HANDLED) |
| 657 | return ret; |
| 658 | |
| 659 | ret = trace_seq_printf(s, "\n"); |
| 660 | |
| 661 | if (!ret) |
| 662 | return TRACE_TYPE_PARTIAL_LINE; |
| 663 | return TRACE_TYPE_HANDLED; |
| 664 | } |
| 665 | |
| 666 | enum print_line_t |
| 667 | trace_print_graph_duration(unsigned long long duration, struct trace_seq *s) |
| 668 | { |
| 669 | unsigned long nsecs_rem = do_div(duration, 1000); |
| 670 | /* log10(ULONG_MAX) + '\0' */ |
| 671 | char msecs_str[21]; |
| 672 | char nsecs_str[5]; |
| 673 | int ret, len; |
| 674 | int i; |
| 675 | |
| 676 | sprintf(msecs_str, "%lu", (unsigned long) duration); |
| 677 | |
| 678 | /* Print msecs */ |
| 679 | ret = trace_seq_printf(s, "%s", msecs_str); |
| 680 | if (!ret) |
| 681 | return TRACE_TYPE_PARTIAL_LINE; |
| 682 | |
| 683 | len = strlen(msecs_str); |
| 684 | |
| 685 | /* Print nsecs (we don't want to exceed 7 numbers) */ |
| 686 | if (len < 7) { |
| 687 | size_t slen = min_t(size_t, sizeof(nsecs_str), 8UL - len); |
| 688 | |
| 689 | snprintf(nsecs_str, slen, "%03lu", nsecs_rem); |
| 690 | ret = trace_seq_printf(s, ".%s", nsecs_str); |
| 691 | if (!ret) |
| 692 | return TRACE_TYPE_PARTIAL_LINE; |
| 693 | len += strlen(nsecs_str); |
| 694 | } |
| 695 | |
| 696 | ret = trace_seq_printf(s, " us "); |
| 697 | if (!ret) |
| 698 | return TRACE_TYPE_PARTIAL_LINE; |
| 699 | |
| 700 | /* Print remaining spaces to fit the row's width */ |
| 701 | for (i = len; i < 7; i++) { |
| 702 | ret = trace_seq_printf(s, " "); |
| 703 | if (!ret) |
| 704 | return TRACE_TYPE_PARTIAL_LINE; |
| 705 | } |
| 706 | return TRACE_TYPE_HANDLED; |
| 707 | } |
| 708 | |
| 709 | static enum print_line_t |
| 710 | print_graph_duration(unsigned long long duration, struct trace_seq *s, |
| 711 | u32 flags) |
| 712 | { |
| 713 | int ret = -1; |
| 714 | |
| 715 | if (!(flags & TRACE_GRAPH_PRINT_DURATION) || |
| 716 | !(trace_flags & TRACE_ITER_CONTEXT_INFO)) |
| 717 | return TRACE_TYPE_HANDLED; |
| 718 | |
| 719 | /* No real adata, just filling the column with spaces */ |
| 720 | switch (duration) { |
| 721 | case DURATION_FILL_FULL: |
| 722 | ret = trace_seq_printf(s, " | "); |
| 723 | return ret ? TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE; |
| 724 | case DURATION_FILL_START: |
| 725 | ret = trace_seq_printf(s, " "); |
| 726 | return ret ? TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE; |
| 727 | case DURATION_FILL_END: |
| 728 | ret = trace_seq_printf(s, " |"); |
| 729 | return ret ? TRACE_TYPE_HANDLED : TRACE_TYPE_PARTIAL_LINE; |
| 730 | } |
| 731 | |
| 732 | /* Signal a overhead of time execution to the output */ |
| 733 | if (flags & TRACE_GRAPH_PRINT_OVERHEAD) { |
| 734 | /* Duration exceeded 100 msecs */ |
| 735 | if (duration > 100000ULL) |
| 736 | ret = trace_seq_printf(s, "! "); |
| 737 | /* Duration exceeded 10 msecs */ |
| 738 | else if (duration > 10000ULL) |
| 739 | ret = trace_seq_printf(s, "+ "); |
| 740 | } |
| 741 | |
| 742 | /* |
| 743 | * The -1 means we either did not exceed the duration tresholds |
| 744 | * or we dont want to print out the overhead. Either way we need |
| 745 | * to fill out the space. |
| 746 | */ |
| 747 | if (ret == -1) |
| 748 | ret = trace_seq_printf(s, " "); |
| 749 | |
| 750 | /* Catching here any failure happenned above */ |
| 751 | if (!ret) |
| 752 | return TRACE_TYPE_PARTIAL_LINE; |
| 753 | |
| 754 | ret = trace_print_graph_duration(duration, s); |
| 755 | if (ret != TRACE_TYPE_HANDLED) |
| 756 | return ret; |
| 757 | |
| 758 | ret = trace_seq_printf(s, "| "); |
| 759 | if (!ret) |
| 760 | return TRACE_TYPE_PARTIAL_LINE; |
| 761 | |
| 762 | return TRACE_TYPE_HANDLED; |
| 763 | } |
| 764 | |
| 765 | /* Case of a leaf function on its call entry */ |
| 766 | static enum print_line_t |
| 767 | print_graph_entry_leaf(struct trace_iterator *iter, |
| 768 | struct ftrace_graph_ent_entry *entry, |
| 769 | struct ftrace_graph_ret_entry *ret_entry, |
| 770 | struct trace_seq *s, u32 flags) |
| 771 | { |
| 772 | struct fgraph_data *data = iter->private; |
| 773 | struct ftrace_graph_ret *graph_ret; |
| 774 | struct ftrace_graph_ent *call; |
| 775 | unsigned long long duration; |
| 776 | int ret; |
| 777 | int i; |
| 778 | |
| 779 | graph_ret = &ret_entry->ret; |
| 780 | call = &entry->graph_ent; |
| 781 | duration = graph_ret->rettime - graph_ret->calltime; |
| 782 | |
| 783 | if (data) { |
| 784 | struct fgraph_cpu_data *cpu_data; |
| 785 | int cpu = iter->cpu; |
| 786 | |
| 787 | cpu_data = per_cpu_ptr(data->cpu_data, cpu); |
| 788 | |
| 789 | /* |
| 790 | * Comments display at + 1 to depth. Since |
| 791 | * this is a leaf function, keep the comments |
| 792 | * equal to this depth. |
| 793 | */ |
| 794 | cpu_data->depth = call->depth - 1; |
| 795 | |
| 796 | /* No need to keep this function around for this depth */ |
| 797 | if (call->depth < FTRACE_RETFUNC_DEPTH) |
| 798 | cpu_data->enter_funcs[call->depth] = 0; |
| 799 | } |
| 800 | |
| 801 | /* Overhead and duration */ |
| 802 | ret = print_graph_duration(duration, s, flags); |
| 803 | if (ret == TRACE_TYPE_PARTIAL_LINE) |
| 804 | return TRACE_TYPE_PARTIAL_LINE; |
| 805 | |
| 806 | /* Function */ |
| 807 | for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) { |
| 808 | ret = trace_seq_printf(s, " "); |
| 809 | if (!ret) |
| 810 | return TRACE_TYPE_PARTIAL_LINE; |
| 811 | } |
| 812 | |
| 813 | ret = trace_seq_printf(s, "%ps();\n", (void *)call->func); |
| 814 | if (!ret) |
| 815 | return TRACE_TYPE_PARTIAL_LINE; |
| 816 | |
| 817 | return TRACE_TYPE_HANDLED; |
| 818 | } |
| 819 | |
| 820 | static enum print_line_t |
| 821 | print_graph_entry_nested(struct trace_iterator *iter, |
| 822 | struct ftrace_graph_ent_entry *entry, |
| 823 | struct trace_seq *s, int cpu, u32 flags) |
| 824 | { |
| 825 | struct ftrace_graph_ent *call = &entry->graph_ent; |
| 826 | struct fgraph_data *data = iter->private; |
| 827 | int ret; |
| 828 | int i; |
| 829 | |
| 830 | if (data) { |
| 831 | struct fgraph_cpu_data *cpu_data; |
| 832 | int cpu = iter->cpu; |
| 833 | |
| 834 | cpu_data = per_cpu_ptr(data->cpu_data, cpu); |
| 835 | cpu_data->depth = call->depth; |
| 836 | |
| 837 | /* Save this function pointer to see if the exit matches */ |
| 838 | if (call->depth < FTRACE_RETFUNC_DEPTH) |
| 839 | cpu_data->enter_funcs[call->depth] = call->func; |
| 840 | } |
| 841 | |
| 842 | /* No time */ |
| 843 | ret = print_graph_duration(DURATION_FILL_FULL, s, flags); |
| 844 | if (ret != TRACE_TYPE_HANDLED) |
| 845 | return ret; |
| 846 | |
| 847 | /* Function */ |
| 848 | for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) { |
| 849 | ret = trace_seq_printf(s, " "); |
| 850 | if (!ret) |
| 851 | return TRACE_TYPE_PARTIAL_LINE; |
| 852 | } |
| 853 | |
| 854 | ret = trace_seq_printf(s, "%ps() {\n", (void *)call->func); |
| 855 | if (!ret) |
| 856 | return TRACE_TYPE_PARTIAL_LINE; |
| 857 | |
| 858 | /* |
| 859 | * we already consumed the current entry to check the next one |
| 860 | * and see if this is a leaf. |
| 861 | */ |
| 862 | return TRACE_TYPE_NO_CONSUME; |
| 863 | } |
| 864 | |
| 865 | static enum print_line_t |
| 866 | print_graph_prologue(struct trace_iterator *iter, struct trace_seq *s, |
| 867 | int type, unsigned long addr, u32 flags) |
| 868 | { |
| 869 | struct fgraph_data *data = iter->private; |
| 870 | struct trace_entry *ent = iter->ent; |
| 871 | int cpu = iter->cpu; |
| 872 | int ret; |
| 873 | |
| 874 | /* Pid */ |
| 875 | if (verif_pid(s, ent->pid, cpu, data) == TRACE_TYPE_PARTIAL_LINE) |
| 876 | return TRACE_TYPE_PARTIAL_LINE; |
| 877 | |
| 878 | if (type) { |
| 879 | /* Interrupt */ |
| 880 | ret = print_graph_irq(iter, addr, type, cpu, ent->pid, flags); |
| 881 | if (ret == TRACE_TYPE_PARTIAL_LINE) |
| 882 | return TRACE_TYPE_PARTIAL_LINE; |
| 883 | } |
| 884 | |
| 885 | if (!(trace_flags & TRACE_ITER_CONTEXT_INFO)) |
| 886 | return 0; |
| 887 | |
| 888 | /* Absolute time */ |
| 889 | if (flags & TRACE_GRAPH_PRINT_ABS_TIME) { |
| 890 | ret = print_graph_abs_time(iter->ts, s); |
| 891 | if (!ret) |
| 892 | return TRACE_TYPE_PARTIAL_LINE; |
| 893 | } |
| 894 | |
| 895 | /* Cpu */ |
| 896 | if (flags & TRACE_GRAPH_PRINT_CPU) { |
| 897 | ret = print_graph_cpu(s, cpu); |
| 898 | if (ret == TRACE_TYPE_PARTIAL_LINE) |
| 899 | return TRACE_TYPE_PARTIAL_LINE; |
| 900 | } |
| 901 | |
| 902 | /* Proc */ |
| 903 | if (flags & TRACE_GRAPH_PRINT_PROC) { |
| 904 | ret = print_graph_proc(s, ent->pid); |
| 905 | if (ret == TRACE_TYPE_PARTIAL_LINE) |
| 906 | return TRACE_TYPE_PARTIAL_LINE; |
| 907 | |
| 908 | ret = trace_seq_printf(s, " | "); |
| 909 | if (!ret) |
| 910 | return TRACE_TYPE_PARTIAL_LINE; |
| 911 | } |
| 912 | |
| 913 | /* Latency format */ |
| 914 | if (trace_flags & TRACE_ITER_LATENCY_FMT) { |
| 915 | ret = print_graph_lat_fmt(s, ent); |
| 916 | if (ret == TRACE_TYPE_PARTIAL_LINE) |
| 917 | return TRACE_TYPE_PARTIAL_LINE; |
| 918 | } |
| 919 | |
| 920 | return 0; |
| 921 | } |
| 922 | |
| 923 | /* |
| 924 | * Entry check for irq code |
| 925 | * |
| 926 | * returns 1 if |
| 927 | * - we are inside irq code |
| 928 | * - we just entered irq code |
| 929 | * |
| 930 | * retunns 0 if |
| 931 | * - funcgraph-interrupts option is set |
| 932 | * - we are not inside irq code |
| 933 | */ |
| 934 | static int |
| 935 | check_irq_entry(struct trace_iterator *iter, u32 flags, |
| 936 | unsigned long addr, int depth) |
| 937 | { |
| 938 | int cpu = iter->cpu; |
| 939 | int *depth_irq; |
| 940 | struct fgraph_data *data = iter->private; |
| 941 | |
| 942 | /* |
| 943 | * If we are either displaying irqs, or we got called as |
| 944 | * a graph event and private data does not exist, |
| 945 | * then we bypass the irq check. |
| 946 | */ |
| 947 | if ((flags & TRACE_GRAPH_PRINT_IRQS) || |
| 948 | (!data)) |
| 949 | return 0; |
| 950 | |
| 951 | depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq); |
| 952 | |
| 953 | /* |
| 954 | * We are inside the irq code |
| 955 | */ |
| 956 | if (*depth_irq >= 0) |
| 957 | return 1; |
| 958 | |
| 959 | if ((addr < (unsigned long)__irqentry_text_start) || |
| 960 | (addr >= (unsigned long)__irqentry_text_end)) |
| 961 | return 0; |
| 962 | |
| 963 | /* |
| 964 | * We are entering irq code. |
| 965 | */ |
| 966 | *depth_irq = depth; |
| 967 | return 1; |
| 968 | } |
| 969 | |
| 970 | /* |
| 971 | * Return check for irq code |
| 972 | * |
| 973 | * returns 1 if |
| 974 | * - we are inside irq code |
| 975 | * - we just left irq code |
| 976 | * |
| 977 | * returns 0 if |
| 978 | * - funcgraph-interrupts option is set |
| 979 | * - we are not inside irq code |
| 980 | */ |
| 981 | static int |
| 982 | check_irq_return(struct trace_iterator *iter, u32 flags, int depth) |
| 983 | { |
| 984 | int cpu = iter->cpu; |
| 985 | int *depth_irq; |
| 986 | struct fgraph_data *data = iter->private; |
| 987 | |
| 988 | /* |
| 989 | * If we are either displaying irqs, or we got called as |
| 990 | * a graph event and private data does not exist, |
| 991 | * then we bypass the irq check. |
| 992 | */ |
| 993 | if ((flags & TRACE_GRAPH_PRINT_IRQS) || |
| 994 | (!data)) |
| 995 | return 0; |
| 996 | |
| 997 | depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq); |
| 998 | |
| 999 | /* |
| 1000 | * We are not inside the irq code. |
| 1001 | */ |
| 1002 | if (*depth_irq == -1) |
| 1003 | return 0; |
| 1004 | |
| 1005 | /* |
| 1006 | * We are inside the irq code, and this is returning entry. |
| 1007 | * Let's not trace it and clear the entry depth, since |
| 1008 | * we are out of irq code. |
| 1009 | * |
| 1010 | * This condition ensures that we 'leave the irq code' once |
| 1011 | * we are out of the entry depth. Thus protecting us from |
| 1012 | * the RETURN entry loss. |
| 1013 | */ |
| 1014 | if (*depth_irq >= depth) { |
| 1015 | *depth_irq = -1; |
| 1016 | return 1; |
| 1017 | } |
| 1018 | |
| 1019 | /* |
| 1020 | * We are inside the irq code, and this is not the entry. |
| 1021 | */ |
| 1022 | return 1; |
| 1023 | } |
| 1024 | |
| 1025 | static enum print_line_t |
| 1026 | print_graph_entry(struct ftrace_graph_ent_entry *field, struct trace_seq *s, |
| 1027 | struct trace_iterator *iter, u32 flags) |
| 1028 | { |
| 1029 | struct fgraph_data *data = iter->private; |
| 1030 | struct ftrace_graph_ent *call = &field->graph_ent; |
| 1031 | struct ftrace_graph_ret_entry *leaf_ret; |
| 1032 | static enum print_line_t ret; |
| 1033 | int cpu = iter->cpu; |
| 1034 | |
| 1035 | if (check_irq_entry(iter, flags, call->func, call->depth)) |
| 1036 | return TRACE_TYPE_HANDLED; |
| 1037 | |
| 1038 | if (print_graph_prologue(iter, s, TRACE_GRAPH_ENT, call->func, flags)) |
| 1039 | return TRACE_TYPE_PARTIAL_LINE; |
| 1040 | |
| 1041 | leaf_ret = get_return_for_leaf(iter, field); |
| 1042 | if (leaf_ret) |
| 1043 | ret = print_graph_entry_leaf(iter, field, leaf_ret, s, flags); |
| 1044 | else |
| 1045 | ret = print_graph_entry_nested(iter, field, s, cpu, flags); |
| 1046 | |
| 1047 | if (data) { |
| 1048 | /* |
| 1049 | * If we failed to write our output, then we need to make |
| 1050 | * note of it. Because we already consumed our entry. |
| 1051 | */ |
| 1052 | if (s->full) { |
| 1053 | data->failed = 1; |
| 1054 | data->cpu = cpu; |
| 1055 | } else |
| 1056 | data->failed = 0; |
| 1057 | } |
| 1058 | |
| 1059 | return ret; |
| 1060 | } |
| 1061 | |
| 1062 | static enum print_line_t |
| 1063 | print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s, |
| 1064 | struct trace_entry *ent, struct trace_iterator *iter, |
| 1065 | u32 flags) |
| 1066 | { |
| 1067 | unsigned long long duration = trace->rettime - trace->calltime; |
| 1068 | struct fgraph_data *data = iter->private; |
| 1069 | pid_t pid = ent->pid; |
| 1070 | int cpu = iter->cpu; |
| 1071 | int func_match = 1; |
| 1072 | int ret; |
| 1073 | int i; |
| 1074 | |
| 1075 | if (check_irq_return(iter, flags, trace->depth)) |
| 1076 | return TRACE_TYPE_HANDLED; |
| 1077 | |
| 1078 | if (data) { |
| 1079 | struct fgraph_cpu_data *cpu_data; |
| 1080 | int cpu = iter->cpu; |
| 1081 | |
| 1082 | cpu_data = per_cpu_ptr(data->cpu_data, cpu); |
| 1083 | |
| 1084 | /* |
| 1085 | * Comments display at + 1 to depth. This is the |
| 1086 | * return from a function, we now want the comments |
| 1087 | * to display at the same level of the bracket. |
| 1088 | */ |
| 1089 | cpu_data->depth = trace->depth - 1; |
| 1090 | |
| 1091 | if (trace->depth < FTRACE_RETFUNC_DEPTH) { |
| 1092 | if (cpu_data->enter_funcs[trace->depth] != trace->func) |
| 1093 | func_match = 0; |
| 1094 | cpu_data->enter_funcs[trace->depth] = 0; |
| 1095 | } |
| 1096 | } |
| 1097 | |
| 1098 | if (print_graph_prologue(iter, s, 0, 0, flags)) |
| 1099 | return TRACE_TYPE_PARTIAL_LINE; |
| 1100 | |
| 1101 | /* Overhead and duration */ |
| 1102 | ret = print_graph_duration(duration, s, flags); |
| 1103 | if (ret == TRACE_TYPE_PARTIAL_LINE) |
| 1104 | return TRACE_TYPE_PARTIAL_LINE; |
| 1105 | |
| 1106 | /* Closing brace */ |
| 1107 | for (i = 0; i < trace->depth * TRACE_GRAPH_INDENT; i++) { |
| 1108 | ret = trace_seq_printf(s, " "); |
| 1109 | if (!ret) |
| 1110 | return TRACE_TYPE_PARTIAL_LINE; |
| 1111 | } |
| 1112 | |
| 1113 | /* |
| 1114 | * If the return function does not have a matching entry, |
| 1115 | * then the entry was lost. Instead of just printing |
| 1116 | * the '}' and letting the user guess what function this |
| 1117 | * belongs to, write out the function name. |
| 1118 | */ |
| 1119 | if (func_match) { |
| 1120 | ret = trace_seq_printf(s, "}\n"); |
| 1121 | if (!ret) |
| 1122 | return TRACE_TYPE_PARTIAL_LINE; |
| 1123 | } else { |
| 1124 | ret = trace_seq_printf(s, "} /* %ps */\n", (void *)trace->func); |
| 1125 | if (!ret) |
| 1126 | return TRACE_TYPE_PARTIAL_LINE; |
| 1127 | } |
| 1128 | |
| 1129 | /* Overrun */ |
| 1130 | if (flags & TRACE_GRAPH_PRINT_OVERRUN) { |
| 1131 | ret = trace_seq_printf(s, " (Overruns: %lu)\n", |
| 1132 | trace->overrun); |
| 1133 | if (!ret) |
| 1134 | return TRACE_TYPE_PARTIAL_LINE; |
| 1135 | } |
| 1136 | |
| 1137 | ret = print_graph_irq(iter, trace->func, TRACE_GRAPH_RET, |
| 1138 | cpu, pid, flags); |
| 1139 | if (ret == TRACE_TYPE_PARTIAL_LINE) |
| 1140 | return TRACE_TYPE_PARTIAL_LINE; |
| 1141 | |
| 1142 | return TRACE_TYPE_HANDLED; |
| 1143 | } |
| 1144 | |
| 1145 | static enum print_line_t |
| 1146 | print_graph_comment(struct trace_seq *s, struct trace_entry *ent, |
| 1147 | struct trace_iterator *iter, u32 flags) |
| 1148 | { |
| 1149 | unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK); |
| 1150 | struct fgraph_data *data = iter->private; |
| 1151 | struct trace_event *event; |
| 1152 | int depth = 0; |
| 1153 | int ret; |
| 1154 | int i; |
| 1155 | |
| 1156 | if (data) |
| 1157 | depth = per_cpu_ptr(data->cpu_data, iter->cpu)->depth; |
| 1158 | |
| 1159 | if (print_graph_prologue(iter, s, 0, 0, flags)) |
| 1160 | return TRACE_TYPE_PARTIAL_LINE; |
| 1161 | |
| 1162 | /* No time */ |
| 1163 | ret = print_graph_duration(DURATION_FILL_FULL, s, flags); |
| 1164 | if (ret != TRACE_TYPE_HANDLED) |
| 1165 | return ret; |
| 1166 | |
| 1167 | /* Indentation */ |
| 1168 | if (depth > 0) |
| 1169 | for (i = 0; i < (depth + 1) * TRACE_GRAPH_INDENT; i++) { |
| 1170 | ret = trace_seq_printf(s, " "); |
| 1171 | if (!ret) |
| 1172 | return TRACE_TYPE_PARTIAL_LINE; |
| 1173 | } |
| 1174 | |
| 1175 | /* The comment */ |
| 1176 | ret = trace_seq_printf(s, "/* "); |
| 1177 | if (!ret) |
| 1178 | return TRACE_TYPE_PARTIAL_LINE; |
| 1179 | |
| 1180 | switch (iter->ent->type) { |
| 1181 | case TRACE_BPRINT: |
| 1182 | ret = trace_print_bprintk_msg_only(iter); |
| 1183 | if (ret != TRACE_TYPE_HANDLED) |
| 1184 | return ret; |
| 1185 | break; |
| 1186 | case TRACE_PRINT: |
| 1187 | ret = trace_print_printk_msg_only(iter); |
| 1188 | if (ret != TRACE_TYPE_HANDLED) |
| 1189 | return ret; |
| 1190 | break; |
| 1191 | default: |
| 1192 | event = ftrace_find_event(ent->type); |
| 1193 | if (!event) |
| 1194 | return TRACE_TYPE_UNHANDLED; |
| 1195 | |
| 1196 | ret = event->funcs->trace(iter, sym_flags, event); |
| 1197 | if (ret != TRACE_TYPE_HANDLED) |
| 1198 | return ret; |
| 1199 | } |
| 1200 | |
| 1201 | /* Strip ending newline */ |
| 1202 | if (s->buffer[s->len - 1] == '\n') { |
| 1203 | s->buffer[s->len - 1] = '\0'; |
| 1204 | s->len--; |
| 1205 | } |
| 1206 | |
| 1207 | ret = trace_seq_printf(s, " */\n"); |
| 1208 | if (!ret) |
| 1209 | return TRACE_TYPE_PARTIAL_LINE; |
| 1210 | |
| 1211 | return TRACE_TYPE_HANDLED; |
| 1212 | } |
| 1213 | |
| 1214 | |
| 1215 | enum print_line_t |
| 1216 | print_graph_function_flags(struct trace_iterator *iter, u32 flags) |
| 1217 | { |
| 1218 | struct ftrace_graph_ent_entry *field; |
| 1219 | struct fgraph_data *data = iter->private; |
| 1220 | struct trace_entry *entry = iter->ent; |
| 1221 | struct trace_seq *s = &iter->seq; |
| 1222 | int cpu = iter->cpu; |
| 1223 | int ret; |
| 1224 | |
| 1225 | if (data && per_cpu_ptr(data->cpu_data, cpu)->ignore) { |
| 1226 | per_cpu_ptr(data->cpu_data, cpu)->ignore = 0; |
| 1227 | return TRACE_TYPE_HANDLED; |
| 1228 | } |
| 1229 | |
| 1230 | /* |
| 1231 | * If the last output failed, there's a possibility we need |
| 1232 | * to print out the missing entry which would never go out. |
| 1233 | */ |
| 1234 | if (data && data->failed) { |
| 1235 | field = &data->ent; |
| 1236 | iter->cpu = data->cpu; |
| 1237 | ret = print_graph_entry(field, s, iter, flags); |
| 1238 | if (ret == TRACE_TYPE_HANDLED && iter->cpu != cpu) { |
| 1239 | per_cpu_ptr(data->cpu_data, iter->cpu)->ignore = 1; |
| 1240 | ret = TRACE_TYPE_NO_CONSUME; |
| 1241 | } |
| 1242 | iter->cpu = cpu; |
| 1243 | return ret; |
| 1244 | } |
| 1245 | |
| 1246 | switch (entry->type) { |
| 1247 | case TRACE_GRAPH_ENT: { |
| 1248 | /* |
| 1249 | * print_graph_entry() may consume the current event, |
| 1250 | * thus @field may become invalid, so we need to save it. |
| 1251 | * sizeof(struct ftrace_graph_ent_entry) is very small, |
| 1252 | * it can be safely saved at the stack. |
| 1253 | */ |
| 1254 | struct ftrace_graph_ent_entry saved; |
| 1255 | trace_assign_type(field, entry); |
| 1256 | saved = *field; |
| 1257 | return print_graph_entry(&saved, s, iter, flags); |
| 1258 | } |
| 1259 | case TRACE_GRAPH_RET: { |
| 1260 | struct ftrace_graph_ret_entry *field; |
| 1261 | trace_assign_type(field, entry); |
| 1262 | return print_graph_return(&field->ret, s, entry, iter, flags); |
| 1263 | } |
| 1264 | case TRACE_STACK: |
| 1265 | case TRACE_FN: |
| 1266 | /* dont trace stack and functions as comments */ |
| 1267 | return TRACE_TYPE_UNHANDLED; |
| 1268 | |
| 1269 | default: |
| 1270 | return print_graph_comment(s, entry, iter, flags); |
| 1271 | } |
| 1272 | |
| 1273 | return TRACE_TYPE_HANDLED; |
| 1274 | } |
| 1275 | |
| 1276 | static enum print_line_t |
| 1277 | print_graph_function(struct trace_iterator *iter) |
| 1278 | { |
| 1279 | return print_graph_function_flags(iter, tracer_flags.val); |
| 1280 | } |
| 1281 | |
| 1282 | static enum print_line_t |
| 1283 | print_graph_function_event(struct trace_iterator *iter, int flags, |
| 1284 | struct trace_event *event) |
| 1285 | { |
| 1286 | return print_graph_function(iter); |
| 1287 | } |
| 1288 | |
| 1289 | static void print_lat_header(struct seq_file *s, u32 flags) |
| 1290 | { |
| 1291 | static const char spaces[] = " " /* 16 spaces */ |
| 1292 | " " /* 4 spaces */ |
| 1293 | " "; /* 17 spaces */ |
| 1294 | int size = 0; |
| 1295 | |
| 1296 | if (flags & TRACE_GRAPH_PRINT_ABS_TIME) |
| 1297 | size += 16; |
| 1298 | if (flags & TRACE_GRAPH_PRINT_CPU) |
| 1299 | size += 4; |
| 1300 | if (flags & TRACE_GRAPH_PRINT_PROC) |
| 1301 | size += 17; |
| 1302 | |
| 1303 | seq_printf(s, "#%.*s _-----=> irqs-off \n", size, spaces); |
| 1304 | seq_printf(s, "#%.*s / _----=> need-resched \n", size, spaces); |
| 1305 | seq_printf(s, "#%.*s| / _---=> hardirq/softirq \n", size, spaces); |
| 1306 | seq_printf(s, "#%.*s|| / _--=> preempt-depth \n", size, spaces); |
| 1307 | seq_printf(s, "#%.*s||| / \n", size, spaces); |
| 1308 | } |
| 1309 | |
| 1310 | static void __print_graph_headers_flags(struct seq_file *s, u32 flags) |
| 1311 | { |
| 1312 | int lat = trace_flags & TRACE_ITER_LATENCY_FMT; |
| 1313 | |
| 1314 | if (lat) |
| 1315 | print_lat_header(s, flags); |
| 1316 | |
| 1317 | /* 1st line */ |
| 1318 | seq_printf(s, "#"); |
| 1319 | if (flags & TRACE_GRAPH_PRINT_ABS_TIME) |
| 1320 | seq_printf(s, " TIME "); |
| 1321 | if (flags & TRACE_GRAPH_PRINT_CPU) |
| 1322 | seq_printf(s, " CPU"); |
| 1323 | if (flags & TRACE_GRAPH_PRINT_PROC) |
| 1324 | seq_printf(s, " TASK/PID "); |
| 1325 | if (lat) |
| 1326 | seq_printf(s, "||||"); |
| 1327 | if (flags & TRACE_GRAPH_PRINT_DURATION) |
| 1328 | seq_printf(s, " DURATION "); |
| 1329 | seq_printf(s, " FUNCTION CALLS\n"); |
| 1330 | |
| 1331 | /* 2nd line */ |
| 1332 | seq_printf(s, "#"); |
| 1333 | if (flags & TRACE_GRAPH_PRINT_ABS_TIME) |
| 1334 | seq_printf(s, " | "); |
| 1335 | if (flags & TRACE_GRAPH_PRINT_CPU) |
| 1336 | seq_printf(s, " | "); |
| 1337 | if (flags & TRACE_GRAPH_PRINT_PROC) |
| 1338 | seq_printf(s, " | | "); |
| 1339 | if (lat) |
| 1340 | seq_printf(s, "||||"); |
| 1341 | if (flags & TRACE_GRAPH_PRINT_DURATION) |
| 1342 | seq_printf(s, " | | "); |
| 1343 | seq_printf(s, " | | | |\n"); |
| 1344 | } |
| 1345 | |
| 1346 | void print_graph_headers(struct seq_file *s) |
| 1347 | { |
| 1348 | print_graph_headers_flags(s, tracer_flags.val); |
| 1349 | } |
| 1350 | |
| 1351 | void print_graph_headers_flags(struct seq_file *s, u32 flags) |
| 1352 | { |
| 1353 | struct trace_iterator *iter = s->private; |
| 1354 | |
| 1355 | if (!(trace_flags & TRACE_ITER_CONTEXT_INFO)) |
| 1356 | return; |
| 1357 | |
| 1358 | if (trace_flags & TRACE_ITER_LATENCY_FMT) { |
| 1359 | /* print nothing if the buffers are empty */ |
| 1360 | if (trace_empty(iter)) |
| 1361 | return; |
| 1362 | |
| 1363 | print_trace_header(s, iter); |
| 1364 | } |
| 1365 | |
| 1366 | __print_graph_headers_flags(s, flags); |
| 1367 | } |
| 1368 | |
| 1369 | void graph_trace_open(struct trace_iterator *iter) |
| 1370 | { |
| 1371 | /* pid and depth on the last trace processed */ |
| 1372 | struct fgraph_data *data; |
| 1373 | int cpu; |
| 1374 | |
| 1375 | iter->private = NULL; |
| 1376 | |
| 1377 | data = kzalloc(sizeof(*data), GFP_KERNEL); |
| 1378 | if (!data) |
| 1379 | goto out_err; |
| 1380 | |
| 1381 | data->cpu_data = alloc_percpu(struct fgraph_cpu_data); |
| 1382 | if (!data->cpu_data) |
| 1383 | goto out_err_free; |
| 1384 | |
| 1385 | for_each_possible_cpu(cpu) { |
| 1386 | pid_t *pid = &(per_cpu_ptr(data->cpu_data, cpu)->last_pid); |
| 1387 | int *depth = &(per_cpu_ptr(data->cpu_data, cpu)->depth); |
| 1388 | int *ignore = &(per_cpu_ptr(data->cpu_data, cpu)->ignore); |
| 1389 | int *depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq); |
| 1390 | |
| 1391 | *pid = -1; |
| 1392 | *depth = 0; |
| 1393 | *ignore = 0; |
| 1394 | *depth_irq = -1; |
| 1395 | } |
| 1396 | |
| 1397 | iter->private = data; |
| 1398 | |
| 1399 | return; |
| 1400 | |
| 1401 | out_err_free: |
| 1402 | kfree(data); |
| 1403 | out_err: |
| 1404 | pr_warning("function graph tracer: not enough memory\n"); |
| 1405 | } |
| 1406 | |
| 1407 | void graph_trace_close(struct trace_iterator *iter) |
| 1408 | { |
| 1409 | struct fgraph_data *data = iter->private; |
| 1410 | |
| 1411 | if (data) { |
| 1412 | free_percpu(data->cpu_data); |
| 1413 | kfree(data); |
| 1414 | } |
| 1415 | } |
| 1416 | |
| 1417 | static int func_graph_set_flag(u32 old_flags, u32 bit, int set) |
| 1418 | { |
| 1419 | if (bit == TRACE_GRAPH_PRINT_IRQS) |
| 1420 | ftrace_graph_skip_irqs = !set; |
| 1421 | |
| 1422 | return 0; |
| 1423 | } |
| 1424 | |
| 1425 | static struct trace_event_functions graph_functions = { |
| 1426 | .trace = print_graph_function_event, |
| 1427 | }; |
| 1428 | |
| 1429 | static struct trace_event graph_trace_entry_event = { |
| 1430 | .type = TRACE_GRAPH_ENT, |
| 1431 | .funcs = &graph_functions, |
| 1432 | }; |
| 1433 | |
| 1434 | static struct trace_event graph_trace_ret_event = { |
| 1435 | .type = TRACE_GRAPH_RET, |
| 1436 | .funcs = &graph_functions |
| 1437 | }; |
| 1438 | |
| 1439 | static struct tracer graph_trace __read_mostly = { |
| 1440 | .name = "function_graph", |
| 1441 | .open = graph_trace_open, |
| 1442 | .pipe_open = graph_trace_open, |
| 1443 | .close = graph_trace_close, |
| 1444 | .pipe_close = graph_trace_close, |
| 1445 | .wait_pipe = poll_wait_pipe, |
| 1446 | .init = graph_trace_init, |
| 1447 | .reset = graph_trace_reset, |
| 1448 | .print_line = print_graph_function, |
| 1449 | .print_header = print_graph_headers, |
| 1450 | .flags = &tracer_flags, |
| 1451 | .set_flag = func_graph_set_flag, |
| 1452 | #ifdef CONFIG_FTRACE_SELFTEST |
| 1453 | .selftest = trace_selftest_startup_function_graph, |
| 1454 | #endif |
| 1455 | }; |
| 1456 | |
| 1457 | static __init int init_graph_trace(void) |
| 1458 | { |
| 1459 | max_bytes_for_cpu = snprintf(NULL, 0, "%d", nr_cpu_ids - 1); |
| 1460 | |
| 1461 | if (!register_ftrace_event(&graph_trace_entry_event)) { |
| 1462 | pr_warning("Warning: could not register graph trace events\n"); |
| 1463 | return 1; |
| 1464 | } |
| 1465 | |
| 1466 | if (!register_ftrace_event(&graph_trace_ret_event)) { |
| 1467 | pr_warning("Warning: could not register graph trace events\n"); |
| 1468 | return 1; |
| 1469 | } |
| 1470 | |
| 1471 | return register_tracer(&graph_trace); |
| 1472 | } |
| 1473 | |
| 1474 | device_initcall(init_graph_trace); |