root/tools/perf/arch/x86/util/intel-pt.c

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DEFINITIONS

This source file includes following definitions.
  1. intel_pt_parse_terms_with_default
  2. intel_pt_parse_terms
  3. intel_pt_masked_bits
  4. intel_pt_read_config
  5. intel_pt_psb_period
  6. intel_pt_pick_bit
  7. intel_pt_default_config
  8. intel_pt_parse_snapshot_options
  9. intel_pt_pmu_default_config
  10. intel_pt_find_filter
  11. intel_pt_filter_bytes
  12. intel_pt_info_priv_size
  13. intel_pt_tsc_ctc_ratio
  14. intel_pt_info_fill
  15. intel_pt_track_switches
  16. intel_pt_valid_str
  17. intel_pt_val_config_term
  18. intel_pt_validate_config
  19. intel_pt_too_many_aux_output
  20. intel_pt_recording_options
  21. intel_pt_snapshot_start
  22. intel_pt_snapshot_finish
  23. intel_pt_alloc_snapshot_refs
  24. intel_pt_free_snapshot_refs
  25. intel_pt_recording_free
  26. intel_pt_alloc_snapshot_ref
  27. intel_pt_snapshot_ref_buf_size
  28. intel_pt_snapshot_init
  29. intel_pt_compare_buffers
  30. intel_pt_compare_ref
  31. intel_pt_copy_ref
  32. intel_pt_wrapped
  33. intel_pt_first_wrap
  34. intel_pt_find_snapshot
  35. intel_pt_reference
  36. intel_pt_read_finish
  37. intel_pt_recording_init

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * intel_pt.c: Intel Processor Trace support
   4  * Copyright (c) 2013-2015, Intel Corporation.
   5  */
   6 
   7 #include <errno.h>
   8 #include <stdbool.h>
   9 #include <linux/kernel.h>
  10 #include <linux/types.h>
  11 #include <linux/bitops.h>
  12 #include <linux/log2.h>
  13 #include <linux/zalloc.h>
  14 #include <cpuid.h>
  15 
  16 #include "../../util/session.h"
  17 #include "../../util/event.h"
  18 #include "../../util/evlist.h"
  19 #include "../../util/evsel.h"
  20 #include "../../util/cpumap.h"
  21 #include "../../util/mmap.h"
  22 #include <subcmd/parse-options.h>
  23 #include "../../util/parse-events.h"
  24 #include "../../util/pmu.h"
  25 #include "../../util/debug.h"
  26 #include "../../util/auxtrace.h"
  27 #include "../../util/record.h"
  28 #include "../../util/target.h"
  29 #include "../../util/tsc.h"
  30 #include <internal/lib.h> // page_size
  31 #include "../../util/intel-pt.h"
  32 
  33 #define KiB(x) ((x) * 1024)
  34 #define MiB(x) ((x) * 1024 * 1024)
  35 #define KiB_MASK(x) (KiB(x) - 1)
  36 #define MiB_MASK(x) (MiB(x) - 1)
  37 
  38 #define INTEL_PT_PSB_PERIOD_NEAR        256
  39 
  40 struct intel_pt_snapshot_ref {
  41         void *ref_buf;
  42         size_t ref_offset;
  43         bool wrapped;
  44 };
  45 
  46 struct intel_pt_recording {
  47         struct auxtrace_record          itr;
  48         struct perf_pmu                 *intel_pt_pmu;
  49         int                             have_sched_switch;
  50         struct evlist           *evlist;
  51         bool                            snapshot_mode;
  52         bool                            snapshot_init_done;
  53         size_t                          snapshot_size;
  54         size_t                          snapshot_ref_buf_size;
  55         int                             snapshot_ref_cnt;
  56         struct intel_pt_snapshot_ref    *snapshot_refs;
  57         size_t                          priv_size;
  58 };
  59 
  60 static int intel_pt_parse_terms_with_default(struct list_head *formats,
  61                                              const char *str,
  62                                              u64 *config)
  63 {
  64         struct list_head *terms;
  65         struct perf_event_attr attr = { .size = 0, };
  66         int err;
  67 
  68         terms = malloc(sizeof(struct list_head));
  69         if (!terms)
  70                 return -ENOMEM;
  71 
  72         INIT_LIST_HEAD(terms);
  73 
  74         err = parse_events_terms(terms, str);
  75         if (err)
  76                 goto out_free;
  77 
  78         attr.config = *config;
  79         err = perf_pmu__config_terms(formats, &attr, terms, true, NULL);
  80         if (err)
  81                 goto out_free;
  82 
  83         *config = attr.config;
  84 out_free:
  85         parse_events_terms__delete(terms);
  86         return err;
  87 }
  88 
  89 static int intel_pt_parse_terms(struct list_head *formats, const char *str,
  90                                 u64 *config)
  91 {
  92         *config = 0;
  93         return intel_pt_parse_terms_with_default(formats, str, config);
  94 }
  95 
  96 static u64 intel_pt_masked_bits(u64 mask, u64 bits)
  97 {
  98         const u64 top_bit = 1ULL << 63;
  99         u64 res = 0;
 100         int i;
 101 
 102         for (i = 0; i < 64; i++) {
 103                 if (mask & top_bit) {
 104                         res <<= 1;
 105                         if (bits & top_bit)
 106                                 res |= 1;
 107                 }
 108                 mask <<= 1;
 109                 bits <<= 1;
 110         }
 111 
 112         return res;
 113 }
 114 
 115 static int intel_pt_read_config(struct perf_pmu *intel_pt_pmu, const char *str,
 116                                 struct evlist *evlist, u64 *res)
 117 {
 118         struct evsel *evsel;
 119         u64 mask;
 120 
 121         *res = 0;
 122 
 123         mask = perf_pmu__format_bits(&intel_pt_pmu->format, str);
 124         if (!mask)
 125                 return -EINVAL;
 126 
 127         evlist__for_each_entry(evlist, evsel) {
 128                 if (evsel->core.attr.type == intel_pt_pmu->type) {
 129                         *res = intel_pt_masked_bits(mask, evsel->core.attr.config);
 130                         return 0;
 131                 }
 132         }
 133 
 134         return -EINVAL;
 135 }
 136 
 137 static size_t intel_pt_psb_period(struct perf_pmu *intel_pt_pmu,
 138                                   struct evlist *evlist)
 139 {
 140         u64 val;
 141         int err, topa_multiple_entries;
 142         size_t psb_period;
 143 
 144         if (perf_pmu__scan_file(intel_pt_pmu, "caps/topa_multiple_entries",
 145                                 "%d", &topa_multiple_entries) != 1)
 146                 topa_multiple_entries = 0;
 147 
 148         /*
 149          * Use caps/topa_multiple_entries to indicate early hardware that had
 150          * extra frequent PSBs.
 151          */
 152         if (!topa_multiple_entries) {
 153                 psb_period = 256;
 154                 goto out;
 155         }
 156 
 157         err = intel_pt_read_config(intel_pt_pmu, "psb_period", evlist, &val);
 158         if (err)
 159                 val = 0;
 160 
 161         psb_period = 1 << (val + 11);
 162 out:
 163         pr_debug2("%s psb_period %zu\n", intel_pt_pmu->name, psb_period);
 164         return psb_period;
 165 }
 166 
 167 static int intel_pt_pick_bit(int bits, int target)
 168 {
 169         int pos, pick = -1;
 170 
 171         for (pos = 0; bits; bits >>= 1, pos++) {
 172                 if (bits & 1) {
 173                         if (pos <= target || pick < 0)
 174                                 pick = pos;
 175                         if (pos >= target)
 176                                 break;
 177                 }
 178         }
 179 
 180         return pick;
 181 }
 182 
 183 static u64 intel_pt_default_config(struct perf_pmu *intel_pt_pmu)
 184 {
 185         char buf[256];
 186         int mtc, mtc_periods = 0, mtc_period;
 187         int psb_cyc, psb_periods, psb_period;
 188         int pos = 0;
 189         u64 config;
 190         char c;
 191 
 192         pos += scnprintf(buf + pos, sizeof(buf) - pos, "tsc");
 193 
 194         if (perf_pmu__scan_file(intel_pt_pmu, "caps/mtc", "%d",
 195                                 &mtc) != 1)
 196                 mtc = 1;
 197 
 198         if (mtc) {
 199                 if (perf_pmu__scan_file(intel_pt_pmu, "caps/mtc_periods", "%x",
 200                                         &mtc_periods) != 1)
 201                         mtc_periods = 0;
 202                 if (mtc_periods) {
 203                         mtc_period = intel_pt_pick_bit(mtc_periods, 3);
 204                         pos += scnprintf(buf + pos, sizeof(buf) - pos,
 205                                          ",mtc,mtc_period=%d", mtc_period);
 206                 }
 207         }
 208 
 209         if (perf_pmu__scan_file(intel_pt_pmu, "caps/psb_cyc", "%d",
 210                                 &psb_cyc) != 1)
 211                 psb_cyc = 1;
 212 
 213         if (psb_cyc && mtc_periods) {
 214                 if (perf_pmu__scan_file(intel_pt_pmu, "caps/psb_periods", "%x",
 215                                         &psb_periods) != 1)
 216                         psb_periods = 0;
 217                 if (psb_periods) {
 218                         psb_period = intel_pt_pick_bit(psb_periods, 3);
 219                         pos += scnprintf(buf + pos, sizeof(buf) - pos,
 220                                          ",psb_period=%d", psb_period);
 221                 }
 222         }
 223 
 224         if (perf_pmu__scan_file(intel_pt_pmu, "format/pt", "%c", &c) == 1 &&
 225             perf_pmu__scan_file(intel_pt_pmu, "format/branch", "%c", &c) == 1)
 226                 pos += scnprintf(buf + pos, sizeof(buf) - pos, ",pt,branch");
 227 
 228         pr_debug2("%s default config: %s\n", intel_pt_pmu->name, buf);
 229 
 230         intel_pt_parse_terms(&intel_pt_pmu->format, buf, &config);
 231 
 232         return config;
 233 }
 234 
 235 static int intel_pt_parse_snapshot_options(struct auxtrace_record *itr,
 236                                            struct record_opts *opts,
 237                                            const char *str)
 238 {
 239         struct intel_pt_recording *ptr =
 240                         container_of(itr, struct intel_pt_recording, itr);
 241         unsigned long long snapshot_size = 0;
 242         char *endptr;
 243 
 244         if (str) {
 245                 snapshot_size = strtoull(str, &endptr, 0);
 246                 if (*endptr || snapshot_size > SIZE_MAX)
 247                         return -1;
 248         }
 249 
 250         opts->auxtrace_snapshot_mode = true;
 251         opts->auxtrace_snapshot_size = snapshot_size;
 252 
 253         ptr->snapshot_size = snapshot_size;
 254 
 255         return 0;
 256 }
 257 
 258 struct perf_event_attr *
 259 intel_pt_pmu_default_config(struct perf_pmu *intel_pt_pmu)
 260 {
 261         struct perf_event_attr *attr;
 262 
 263         attr = zalloc(sizeof(struct perf_event_attr));
 264         if (!attr)
 265                 return NULL;
 266 
 267         attr->config = intel_pt_default_config(intel_pt_pmu);
 268 
 269         intel_pt_pmu->selectable = true;
 270 
 271         return attr;
 272 }
 273 
 274 static const char *intel_pt_find_filter(struct evlist *evlist,
 275                                         struct perf_pmu *intel_pt_pmu)
 276 {
 277         struct evsel *evsel;
 278 
 279         evlist__for_each_entry(evlist, evsel) {
 280                 if (evsel->core.attr.type == intel_pt_pmu->type)
 281                         return evsel->filter;
 282         }
 283 
 284         return NULL;
 285 }
 286 
 287 static size_t intel_pt_filter_bytes(const char *filter)
 288 {
 289         size_t len = filter ? strlen(filter) : 0;
 290 
 291         return len ? roundup(len + 1, 8) : 0;
 292 }
 293 
 294 static size_t
 295 intel_pt_info_priv_size(struct auxtrace_record *itr, struct evlist *evlist)
 296 {
 297         struct intel_pt_recording *ptr =
 298                         container_of(itr, struct intel_pt_recording, itr);
 299         const char *filter = intel_pt_find_filter(evlist, ptr->intel_pt_pmu);
 300 
 301         ptr->priv_size = (INTEL_PT_AUXTRACE_PRIV_MAX * sizeof(u64)) +
 302                          intel_pt_filter_bytes(filter);
 303 
 304         return ptr->priv_size;
 305 }
 306 
 307 static void intel_pt_tsc_ctc_ratio(u32 *n, u32 *d)
 308 {
 309         unsigned int eax = 0, ebx = 0, ecx = 0, edx = 0;
 310 
 311         __get_cpuid(0x15, &eax, &ebx, &ecx, &edx);
 312         *n = ebx;
 313         *d = eax;
 314 }
 315 
 316 static int intel_pt_info_fill(struct auxtrace_record *itr,
 317                               struct perf_session *session,
 318                               struct perf_record_auxtrace_info *auxtrace_info,
 319                               size_t priv_size)
 320 {
 321         struct intel_pt_recording *ptr =
 322                         container_of(itr, struct intel_pt_recording, itr);
 323         struct perf_pmu *intel_pt_pmu = ptr->intel_pt_pmu;
 324         struct perf_event_mmap_page *pc;
 325         struct perf_tsc_conversion tc = { .time_mult = 0, };
 326         bool cap_user_time_zero = false, per_cpu_mmaps;
 327         u64 tsc_bit, mtc_bit, mtc_freq_bits, cyc_bit, noretcomp_bit;
 328         u32 tsc_ctc_ratio_n, tsc_ctc_ratio_d;
 329         unsigned long max_non_turbo_ratio;
 330         size_t filter_str_len;
 331         const char *filter;
 332         __u64 *info;
 333         int err;
 334 
 335         if (priv_size != ptr->priv_size)
 336                 return -EINVAL;
 337 
 338         intel_pt_parse_terms(&intel_pt_pmu->format, "tsc", &tsc_bit);
 339         intel_pt_parse_terms(&intel_pt_pmu->format, "noretcomp",
 340                              &noretcomp_bit);
 341         intel_pt_parse_terms(&intel_pt_pmu->format, "mtc", &mtc_bit);
 342         mtc_freq_bits = perf_pmu__format_bits(&intel_pt_pmu->format,
 343                                               "mtc_period");
 344         intel_pt_parse_terms(&intel_pt_pmu->format, "cyc", &cyc_bit);
 345 
 346         intel_pt_tsc_ctc_ratio(&tsc_ctc_ratio_n, &tsc_ctc_ratio_d);
 347 
 348         if (perf_pmu__scan_file(intel_pt_pmu, "max_nonturbo_ratio",
 349                                 "%lu", &max_non_turbo_ratio) != 1)
 350                 max_non_turbo_ratio = 0;
 351 
 352         filter = intel_pt_find_filter(session->evlist, ptr->intel_pt_pmu);
 353         filter_str_len = filter ? strlen(filter) : 0;
 354 
 355         if (!session->evlist->core.nr_mmaps)
 356                 return -EINVAL;
 357 
 358         pc = session->evlist->mmap[0].core.base;
 359         if (pc) {
 360                 err = perf_read_tsc_conversion(pc, &tc);
 361                 if (err) {
 362                         if (err != -EOPNOTSUPP)
 363                                 return err;
 364                 } else {
 365                         cap_user_time_zero = tc.time_mult != 0;
 366                 }
 367                 if (!cap_user_time_zero)
 368                         ui__warning("Intel Processor Trace: TSC not available\n");
 369         }
 370 
 371         per_cpu_mmaps = !perf_cpu_map__empty(session->evlist->core.cpus);
 372 
 373         auxtrace_info->type = PERF_AUXTRACE_INTEL_PT;
 374         auxtrace_info->priv[INTEL_PT_PMU_TYPE] = intel_pt_pmu->type;
 375         auxtrace_info->priv[INTEL_PT_TIME_SHIFT] = tc.time_shift;
 376         auxtrace_info->priv[INTEL_PT_TIME_MULT] = tc.time_mult;
 377         auxtrace_info->priv[INTEL_PT_TIME_ZERO] = tc.time_zero;
 378         auxtrace_info->priv[INTEL_PT_CAP_USER_TIME_ZERO] = cap_user_time_zero;
 379         auxtrace_info->priv[INTEL_PT_TSC_BIT] = tsc_bit;
 380         auxtrace_info->priv[INTEL_PT_NORETCOMP_BIT] = noretcomp_bit;
 381         auxtrace_info->priv[INTEL_PT_HAVE_SCHED_SWITCH] = ptr->have_sched_switch;
 382         auxtrace_info->priv[INTEL_PT_SNAPSHOT_MODE] = ptr->snapshot_mode;
 383         auxtrace_info->priv[INTEL_PT_PER_CPU_MMAPS] = per_cpu_mmaps;
 384         auxtrace_info->priv[INTEL_PT_MTC_BIT] = mtc_bit;
 385         auxtrace_info->priv[INTEL_PT_MTC_FREQ_BITS] = mtc_freq_bits;
 386         auxtrace_info->priv[INTEL_PT_TSC_CTC_N] = tsc_ctc_ratio_n;
 387         auxtrace_info->priv[INTEL_PT_TSC_CTC_D] = tsc_ctc_ratio_d;
 388         auxtrace_info->priv[INTEL_PT_CYC_BIT] = cyc_bit;
 389         auxtrace_info->priv[INTEL_PT_MAX_NONTURBO_RATIO] = max_non_turbo_ratio;
 390         auxtrace_info->priv[INTEL_PT_FILTER_STR_LEN] = filter_str_len;
 391 
 392         info = &auxtrace_info->priv[INTEL_PT_FILTER_STR_LEN] + 1;
 393 
 394         if (filter_str_len) {
 395                 size_t len = intel_pt_filter_bytes(filter);
 396 
 397                 strncpy((char *)info, filter, len);
 398                 info += len >> 3;
 399         }
 400 
 401         return 0;
 402 }
 403 
 404 static int intel_pt_track_switches(struct evlist *evlist)
 405 {
 406         const char *sched_switch = "sched:sched_switch";
 407         struct evsel *evsel;
 408         int err;
 409 
 410         if (!perf_evlist__can_select_event(evlist, sched_switch))
 411                 return -EPERM;
 412 
 413         err = parse_events(evlist, sched_switch, NULL);
 414         if (err) {
 415                 pr_debug2("%s: failed to parse %s, error %d\n",
 416                           __func__, sched_switch, err);
 417                 return err;
 418         }
 419 
 420         evsel = evlist__last(evlist);
 421 
 422         perf_evsel__set_sample_bit(evsel, CPU);
 423         perf_evsel__set_sample_bit(evsel, TIME);
 424 
 425         evsel->core.system_wide = true;
 426         evsel->no_aux_samples = true;
 427         evsel->immediate = true;
 428 
 429         return 0;
 430 }
 431 
 432 static void intel_pt_valid_str(char *str, size_t len, u64 valid)
 433 {
 434         unsigned int val, last = 0, state = 1;
 435         int p = 0;
 436 
 437         str[0] = '\0';
 438 
 439         for (val = 0; val <= 64; val++, valid >>= 1) {
 440                 if (valid & 1) {
 441                         last = val;
 442                         switch (state) {
 443                         case 0:
 444                                 p += scnprintf(str + p, len - p, ",");
 445                                 /* Fall through */
 446                         case 1:
 447                                 p += scnprintf(str + p, len - p, "%u", val);
 448                                 state = 2;
 449                                 break;
 450                         case 2:
 451                                 state = 3;
 452                                 break;
 453                         case 3:
 454                                 state = 4;
 455                                 break;
 456                         default:
 457                                 break;
 458                         }
 459                 } else {
 460                         switch (state) {
 461                         case 3:
 462                                 p += scnprintf(str + p, len - p, ",%u", last);
 463                                 state = 0;
 464                                 break;
 465                         case 4:
 466                                 p += scnprintf(str + p, len - p, "-%u", last);
 467                                 state = 0;
 468                                 break;
 469                         default:
 470                                 break;
 471                         }
 472                         if (state != 1)
 473                                 state = 0;
 474                 }
 475         }
 476 }
 477 
 478 static int intel_pt_val_config_term(struct perf_pmu *intel_pt_pmu,
 479                                     const char *caps, const char *name,
 480                                     const char *supported, u64 config)
 481 {
 482         char valid_str[256];
 483         unsigned int shift;
 484         unsigned long long valid;
 485         u64 bits;
 486         int ok;
 487 
 488         if (perf_pmu__scan_file(intel_pt_pmu, caps, "%llx", &valid) != 1)
 489                 valid = 0;
 490 
 491         if (supported &&
 492             perf_pmu__scan_file(intel_pt_pmu, supported, "%d", &ok) == 1 && !ok)
 493                 valid = 0;
 494 
 495         valid |= 1;
 496 
 497         bits = perf_pmu__format_bits(&intel_pt_pmu->format, name);
 498 
 499         config &= bits;
 500 
 501         for (shift = 0; bits && !(bits & 1); shift++)
 502                 bits >>= 1;
 503 
 504         config >>= shift;
 505 
 506         if (config > 63)
 507                 goto out_err;
 508 
 509         if (valid & (1 << config))
 510                 return 0;
 511 out_err:
 512         intel_pt_valid_str(valid_str, sizeof(valid_str), valid);
 513         pr_err("Invalid %s for %s. Valid values are: %s\n",
 514                name, INTEL_PT_PMU_NAME, valid_str);
 515         return -EINVAL;
 516 }
 517 
 518 static int intel_pt_validate_config(struct perf_pmu *intel_pt_pmu,
 519                                     struct evsel *evsel)
 520 {
 521         int err;
 522         char c;
 523 
 524         if (!evsel)
 525                 return 0;
 526 
 527         /*
 528          * If supported, force pass-through config term (pt=1) even if user
 529          * sets pt=0, which avoids senseless kernel errors.
 530          */
 531         if (perf_pmu__scan_file(intel_pt_pmu, "format/pt", "%c", &c) == 1 &&
 532             !(evsel->core.attr.config & 1)) {
 533                 pr_warning("pt=0 doesn't make sense, forcing pt=1\n");
 534                 evsel->core.attr.config |= 1;
 535         }
 536 
 537         err = intel_pt_val_config_term(intel_pt_pmu, "caps/cycle_thresholds",
 538                                        "cyc_thresh", "caps/psb_cyc",
 539                                        evsel->core.attr.config);
 540         if (err)
 541                 return err;
 542 
 543         err = intel_pt_val_config_term(intel_pt_pmu, "caps/mtc_periods",
 544                                        "mtc_period", "caps/mtc",
 545                                        evsel->core.attr.config);
 546         if (err)
 547                 return err;
 548 
 549         return intel_pt_val_config_term(intel_pt_pmu, "caps/psb_periods",
 550                                         "psb_period", "caps/psb_cyc",
 551                                         evsel->core.attr.config);
 552 }
 553 
 554 /*
 555  * Currently, there is not enough information to disambiguate different PEBS
 556  * events, so only allow one.
 557  */
 558 static bool intel_pt_too_many_aux_output(struct evlist *evlist)
 559 {
 560         struct evsel *evsel;
 561         int aux_output_cnt = 0;
 562 
 563         evlist__for_each_entry(evlist, evsel)
 564                 aux_output_cnt += !!evsel->core.attr.aux_output;
 565 
 566         if (aux_output_cnt > 1) {
 567                 pr_err(INTEL_PT_PMU_NAME " supports at most one event with aux-output\n");
 568                 return true;
 569         }
 570 
 571         return false;
 572 }
 573 
 574 static int intel_pt_recording_options(struct auxtrace_record *itr,
 575                                       struct evlist *evlist,
 576                                       struct record_opts *opts)
 577 {
 578         struct intel_pt_recording *ptr =
 579                         container_of(itr, struct intel_pt_recording, itr);
 580         struct perf_pmu *intel_pt_pmu = ptr->intel_pt_pmu;
 581         bool have_timing_info, need_immediate = false;
 582         struct evsel *evsel, *intel_pt_evsel = NULL;
 583         const struct perf_cpu_map *cpus = evlist->core.cpus;
 584         bool privileged = perf_event_paranoid_check(-1);
 585         u64 tsc_bit;
 586         int err;
 587 
 588         ptr->evlist = evlist;
 589         ptr->snapshot_mode = opts->auxtrace_snapshot_mode;
 590 
 591         evlist__for_each_entry(evlist, evsel) {
 592                 if (evsel->core.attr.type == intel_pt_pmu->type) {
 593                         if (intel_pt_evsel) {
 594                                 pr_err("There may be only one " INTEL_PT_PMU_NAME " event\n");
 595                                 return -EINVAL;
 596                         }
 597                         evsel->core.attr.freq = 0;
 598                         evsel->core.attr.sample_period = 1;
 599                         intel_pt_evsel = evsel;
 600                         opts->full_auxtrace = true;
 601                 }
 602         }
 603 
 604         if (opts->auxtrace_snapshot_mode && !opts->full_auxtrace) {
 605                 pr_err("Snapshot mode (-S option) requires " INTEL_PT_PMU_NAME " PMU event (-e " INTEL_PT_PMU_NAME ")\n");
 606                 return -EINVAL;
 607         }
 608 
 609         if (opts->use_clockid) {
 610                 pr_err("Cannot use clockid (-k option) with " INTEL_PT_PMU_NAME "\n");
 611                 return -EINVAL;
 612         }
 613 
 614         if (intel_pt_too_many_aux_output(evlist))
 615                 return -EINVAL;
 616 
 617         if (!opts->full_auxtrace)
 618                 return 0;
 619 
 620         err = intel_pt_validate_config(intel_pt_pmu, intel_pt_evsel);
 621         if (err)
 622                 return err;
 623 
 624         /* Set default sizes for snapshot mode */
 625         if (opts->auxtrace_snapshot_mode) {
 626                 size_t psb_period = intel_pt_psb_period(intel_pt_pmu, evlist);
 627 
 628                 if (!opts->auxtrace_snapshot_size && !opts->auxtrace_mmap_pages) {
 629                         if (privileged) {
 630                                 opts->auxtrace_mmap_pages = MiB(4) / page_size;
 631                         } else {
 632                                 opts->auxtrace_mmap_pages = KiB(128) / page_size;
 633                                 if (opts->mmap_pages == UINT_MAX)
 634                                         opts->mmap_pages = KiB(256) / page_size;
 635                         }
 636                 } else if (!opts->auxtrace_mmap_pages && !privileged &&
 637                            opts->mmap_pages == UINT_MAX) {
 638                         opts->mmap_pages = KiB(256) / page_size;
 639                 }
 640                 if (!opts->auxtrace_snapshot_size)
 641                         opts->auxtrace_snapshot_size =
 642                                 opts->auxtrace_mmap_pages * (size_t)page_size;
 643                 if (!opts->auxtrace_mmap_pages) {
 644                         size_t sz = opts->auxtrace_snapshot_size;
 645 
 646                         sz = round_up(sz, page_size) / page_size;
 647                         opts->auxtrace_mmap_pages = roundup_pow_of_two(sz);
 648                 }
 649                 if (opts->auxtrace_snapshot_size >
 650                                 opts->auxtrace_mmap_pages * (size_t)page_size) {
 651                         pr_err("Snapshot size %zu must not be greater than AUX area tracing mmap size %zu\n",
 652                                opts->auxtrace_snapshot_size,
 653                                opts->auxtrace_mmap_pages * (size_t)page_size);
 654                         return -EINVAL;
 655                 }
 656                 if (!opts->auxtrace_snapshot_size || !opts->auxtrace_mmap_pages) {
 657                         pr_err("Failed to calculate default snapshot size and/or AUX area tracing mmap pages\n");
 658                         return -EINVAL;
 659                 }
 660                 pr_debug2("Intel PT snapshot size: %zu\n",
 661                           opts->auxtrace_snapshot_size);
 662                 if (psb_period &&
 663                     opts->auxtrace_snapshot_size <= psb_period +
 664                                                   INTEL_PT_PSB_PERIOD_NEAR)
 665                         ui__warning("Intel PT snapshot size (%zu) may be too small for PSB period (%zu)\n",
 666                                     opts->auxtrace_snapshot_size, psb_period);
 667         }
 668 
 669         /* Set default sizes for full trace mode */
 670         if (opts->full_auxtrace && !opts->auxtrace_mmap_pages) {
 671                 if (privileged) {
 672                         opts->auxtrace_mmap_pages = MiB(4) / page_size;
 673                 } else {
 674                         opts->auxtrace_mmap_pages = KiB(128) / page_size;
 675                         if (opts->mmap_pages == UINT_MAX)
 676                                 opts->mmap_pages = KiB(256) / page_size;
 677                 }
 678         }
 679 
 680         /* Validate auxtrace_mmap_pages */
 681         if (opts->auxtrace_mmap_pages) {
 682                 size_t sz = opts->auxtrace_mmap_pages * (size_t)page_size;
 683                 size_t min_sz;
 684 
 685                 if (opts->auxtrace_snapshot_mode)
 686                         min_sz = KiB(4);
 687                 else
 688                         min_sz = KiB(8);
 689 
 690                 if (sz < min_sz || !is_power_of_2(sz)) {
 691                         pr_err("Invalid mmap size for Intel Processor Trace: must be at least %zuKiB and a power of 2\n",
 692                                min_sz / 1024);
 693                         return -EINVAL;
 694                 }
 695         }
 696 
 697         intel_pt_parse_terms(&intel_pt_pmu->format, "tsc", &tsc_bit);
 698 
 699         if (opts->full_auxtrace && (intel_pt_evsel->core.attr.config & tsc_bit))
 700                 have_timing_info = true;
 701         else
 702                 have_timing_info = false;
 703 
 704         /*
 705          * Per-cpu recording needs sched_switch events to distinguish different
 706          * threads.
 707          */
 708         if (have_timing_info && !perf_cpu_map__empty(cpus)) {
 709                 if (perf_can_record_switch_events()) {
 710                         bool cpu_wide = !target__none(&opts->target) &&
 711                                         !target__has_task(&opts->target);
 712 
 713                         if (!cpu_wide && perf_can_record_cpu_wide()) {
 714                                 struct evsel *switch_evsel;
 715 
 716                                 err = parse_events(evlist, "dummy:u", NULL);
 717                                 if (err)
 718                                         return err;
 719 
 720                                 switch_evsel = evlist__last(evlist);
 721 
 722                                 switch_evsel->core.attr.freq = 0;
 723                                 switch_evsel->core.attr.sample_period = 1;
 724                                 switch_evsel->core.attr.context_switch = 1;
 725 
 726                                 switch_evsel->core.system_wide = true;
 727                                 switch_evsel->no_aux_samples = true;
 728                                 switch_evsel->immediate = true;
 729 
 730                                 perf_evsel__set_sample_bit(switch_evsel, TID);
 731                                 perf_evsel__set_sample_bit(switch_evsel, TIME);
 732                                 perf_evsel__set_sample_bit(switch_evsel, CPU);
 733                                 perf_evsel__reset_sample_bit(switch_evsel, BRANCH_STACK);
 734 
 735                                 opts->record_switch_events = false;
 736                                 ptr->have_sched_switch = 3;
 737                         } else {
 738                                 opts->record_switch_events = true;
 739                                 need_immediate = true;
 740                                 if (cpu_wide)
 741                                         ptr->have_sched_switch = 3;
 742                                 else
 743                                         ptr->have_sched_switch = 2;
 744                         }
 745                 } else {
 746                         err = intel_pt_track_switches(evlist);
 747                         if (err == -EPERM)
 748                                 pr_debug2("Unable to select sched:sched_switch\n");
 749                         else if (err)
 750                                 return err;
 751                         else
 752                                 ptr->have_sched_switch = 1;
 753                 }
 754         }
 755 
 756         if (intel_pt_evsel) {
 757                 /*
 758                  * To obtain the auxtrace buffer file descriptor, the auxtrace
 759                  * event must come first.
 760                  */
 761                 perf_evlist__to_front(evlist, intel_pt_evsel);
 762                 /*
 763                  * In the case of per-cpu mmaps, we need the CPU on the
 764                  * AUX event.
 765                  */
 766                 if (!perf_cpu_map__empty(cpus))
 767                         perf_evsel__set_sample_bit(intel_pt_evsel, CPU);
 768         }
 769 
 770         /* Add dummy event to keep tracking */
 771         if (opts->full_auxtrace) {
 772                 struct evsel *tracking_evsel;
 773 
 774                 err = parse_events(evlist, "dummy:u", NULL);
 775                 if (err)
 776                         return err;
 777 
 778                 tracking_evsel = evlist__last(evlist);
 779 
 780                 perf_evlist__set_tracking_event(evlist, tracking_evsel);
 781 
 782                 tracking_evsel->core.attr.freq = 0;
 783                 tracking_evsel->core.attr.sample_period = 1;
 784 
 785                 tracking_evsel->no_aux_samples = true;
 786                 if (need_immediate)
 787                         tracking_evsel->immediate = true;
 788 
 789                 /* In per-cpu case, always need the time of mmap events etc */
 790                 if (!perf_cpu_map__empty(cpus)) {
 791                         perf_evsel__set_sample_bit(tracking_evsel, TIME);
 792                         /* And the CPU for switch events */
 793                         perf_evsel__set_sample_bit(tracking_evsel, CPU);
 794                 }
 795                 perf_evsel__reset_sample_bit(tracking_evsel, BRANCH_STACK);
 796         }
 797 
 798         /*
 799          * Warn the user when we do not have enough information to decode i.e.
 800          * per-cpu with no sched_switch (except workload-only).
 801          */
 802         if (!ptr->have_sched_switch && !perf_cpu_map__empty(cpus) &&
 803             !target__none(&opts->target))
 804                 ui__warning("Intel Processor Trace decoding will not be possible except for kernel tracing!\n");
 805 
 806         return 0;
 807 }
 808 
 809 static int intel_pt_snapshot_start(struct auxtrace_record *itr)
 810 {
 811         struct intel_pt_recording *ptr =
 812                         container_of(itr, struct intel_pt_recording, itr);
 813         struct evsel *evsel;
 814 
 815         evlist__for_each_entry(ptr->evlist, evsel) {
 816                 if (evsel->core.attr.type == ptr->intel_pt_pmu->type)
 817                         return evsel__disable(evsel);
 818         }
 819         return -EINVAL;
 820 }
 821 
 822 static int intel_pt_snapshot_finish(struct auxtrace_record *itr)
 823 {
 824         struct intel_pt_recording *ptr =
 825                         container_of(itr, struct intel_pt_recording, itr);
 826         struct evsel *evsel;
 827 
 828         evlist__for_each_entry(ptr->evlist, evsel) {
 829                 if (evsel->core.attr.type == ptr->intel_pt_pmu->type)
 830                         return evsel__enable(evsel);
 831         }
 832         return -EINVAL;
 833 }
 834 
 835 static int intel_pt_alloc_snapshot_refs(struct intel_pt_recording *ptr, int idx)
 836 {
 837         const size_t sz = sizeof(struct intel_pt_snapshot_ref);
 838         int cnt = ptr->snapshot_ref_cnt, new_cnt = cnt * 2;
 839         struct intel_pt_snapshot_ref *refs;
 840 
 841         if (!new_cnt)
 842                 new_cnt = 16;
 843 
 844         while (new_cnt <= idx)
 845                 new_cnt *= 2;
 846 
 847         refs = calloc(new_cnt, sz);
 848         if (!refs)
 849                 return -ENOMEM;
 850 
 851         memcpy(refs, ptr->snapshot_refs, cnt * sz);
 852 
 853         ptr->snapshot_refs = refs;
 854         ptr->snapshot_ref_cnt = new_cnt;
 855 
 856         return 0;
 857 }
 858 
 859 static void intel_pt_free_snapshot_refs(struct intel_pt_recording *ptr)
 860 {
 861         int i;
 862 
 863         for (i = 0; i < ptr->snapshot_ref_cnt; i++)
 864                 zfree(&ptr->snapshot_refs[i].ref_buf);
 865         zfree(&ptr->snapshot_refs);
 866 }
 867 
 868 static void intel_pt_recording_free(struct auxtrace_record *itr)
 869 {
 870         struct intel_pt_recording *ptr =
 871                         container_of(itr, struct intel_pt_recording, itr);
 872 
 873         intel_pt_free_snapshot_refs(ptr);
 874         free(ptr);
 875 }
 876 
 877 static int intel_pt_alloc_snapshot_ref(struct intel_pt_recording *ptr, int idx,
 878                                        size_t snapshot_buf_size)
 879 {
 880         size_t ref_buf_size = ptr->snapshot_ref_buf_size;
 881         void *ref_buf;
 882 
 883         ref_buf = zalloc(ref_buf_size);
 884         if (!ref_buf)
 885                 return -ENOMEM;
 886 
 887         ptr->snapshot_refs[idx].ref_buf = ref_buf;
 888         ptr->snapshot_refs[idx].ref_offset = snapshot_buf_size - ref_buf_size;
 889 
 890         return 0;
 891 }
 892 
 893 static size_t intel_pt_snapshot_ref_buf_size(struct intel_pt_recording *ptr,
 894                                              size_t snapshot_buf_size)
 895 {
 896         const size_t max_size = 256 * 1024;
 897         size_t buf_size = 0, psb_period;
 898 
 899         if (ptr->snapshot_size <= 64 * 1024)
 900                 return 0;
 901 
 902         psb_period = intel_pt_psb_period(ptr->intel_pt_pmu, ptr->evlist);
 903         if (psb_period)
 904                 buf_size = psb_period * 2;
 905 
 906         if (!buf_size || buf_size > max_size)
 907                 buf_size = max_size;
 908 
 909         if (buf_size >= snapshot_buf_size)
 910                 return 0;
 911 
 912         if (buf_size >= ptr->snapshot_size / 2)
 913                 return 0;
 914 
 915         return buf_size;
 916 }
 917 
 918 static int intel_pt_snapshot_init(struct intel_pt_recording *ptr,
 919                                   size_t snapshot_buf_size)
 920 {
 921         if (ptr->snapshot_init_done)
 922                 return 0;
 923 
 924         ptr->snapshot_init_done = true;
 925 
 926         ptr->snapshot_ref_buf_size = intel_pt_snapshot_ref_buf_size(ptr,
 927                                                         snapshot_buf_size);
 928 
 929         return 0;
 930 }
 931 
 932 /**
 933  * intel_pt_compare_buffers - compare bytes in a buffer to a circular buffer.
 934  * @buf1: first buffer
 935  * @compare_size: number of bytes to compare
 936  * @buf2: second buffer (a circular buffer)
 937  * @offs2: offset in second buffer
 938  * @buf2_size: size of second buffer
 939  *
 940  * The comparison allows for the possibility that the bytes to compare in the
 941  * circular buffer are not contiguous.  It is assumed that @compare_size <=
 942  * @buf2_size.  This function returns %false if the bytes are identical, %true
 943  * otherwise.
 944  */
 945 static bool intel_pt_compare_buffers(void *buf1, size_t compare_size,
 946                                      void *buf2, size_t offs2, size_t buf2_size)
 947 {
 948         size_t end2 = offs2 + compare_size, part_size;
 949 
 950         if (end2 <= buf2_size)
 951                 return memcmp(buf1, buf2 + offs2, compare_size);
 952 
 953         part_size = end2 - buf2_size;
 954         if (memcmp(buf1, buf2 + offs2, part_size))
 955                 return true;
 956 
 957         compare_size -= part_size;
 958 
 959         return memcmp(buf1 + part_size, buf2, compare_size);
 960 }
 961 
 962 static bool intel_pt_compare_ref(void *ref_buf, size_t ref_offset,
 963                                  size_t ref_size, size_t buf_size,
 964                                  void *data, size_t head)
 965 {
 966         size_t ref_end = ref_offset + ref_size;
 967 
 968         if (ref_end > buf_size) {
 969                 if (head > ref_offset || head < ref_end - buf_size)
 970                         return true;
 971         } else if (head > ref_offset && head < ref_end) {
 972                 return true;
 973         }
 974 
 975         return intel_pt_compare_buffers(ref_buf, ref_size, data, ref_offset,
 976                                         buf_size);
 977 }
 978 
 979 static void intel_pt_copy_ref(void *ref_buf, size_t ref_size, size_t buf_size,
 980                               void *data, size_t head)
 981 {
 982         if (head >= ref_size) {
 983                 memcpy(ref_buf, data + head - ref_size, ref_size);
 984         } else {
 985                 memcpy(ref_buf, data, head);
 986                 ref_size -= head;
 987                 memcpy(ref_buf + head, data + buf_size - ref_size, ref_size);
 988         }
 989 }
 990 
 991 static bool intel_pt_wrapped(struct intel_pt_recording *ptr, int idx,
 992                              struct auxtrace_mmap *mm, unsigned char *data,
 993                              u64 head)
 994 {
 995         struct intel_pt_snapshot_ref *ref = &ptr->snapshot_refs[idx];
 996         bool wrapped;
 997 
 998         wrapped = intel_pt_compare_ref(ref->ref_buf, ref->ref_offset,
 999                                        ptr->snapshot_ref_buf_size, mm->len,
1000                                        data, head);
1001 
1002         intel_pt_copy_ref(ref->ref_buf, ptr->snapshot_ref_buf_size, mm->len,
1003                           data, head);
1004 
1005         return wrapped;
1006 }
1007 
1008 static bool intel_pt_first_wrap(u64 *data, size_t buf_size)
1009 {
1010         int i, a, b;
1011 
1012         b = buf_size >> 3;
1013         a = b - 512;
1014         if (a < 0)
1015                 a = 0;
1016 
1017         for (i = a; i < b; i++) {
1018                 if (data[i])
1019                         return true;
1020         }
1021 
1022         return false;
1023 }
1024 
1025 static int intel_pt_find_snapshot(struct auxtrace_record *itr, int idx,
1026                                   struct auxtrace_mmap *mm, unsigned char *data,
1027                                   u64 *head, u64 *old)
1028 {
1029         struct intel_pt_recording *ptr =
1030                         container_of(itr, struct intel_pt_recording, itr);
1031         bool wrapped;
1032         int err;
1033 
1034         pr_debug3("%s: mmap index %d old head %zu new head %zu\n",
1035                   __func__, idx, (size_t)*old, (size_t)*head);
1036 
1037         err = intel_pt_snapshot_init(ptr, mm->len);
1038         if (err)
1039                 goto out_err;
1040 
1041         if (idx >= ptr->snapshot_ref_cnt) {
1042                 err = intel_pt_alloc_snapshot_refs(ptr, idx);
1043                 if (err)
1044                         goto out_err;
1045         }
1046 
1047         if (ptr->snapshot_ref_buf_size) {
1048                 if (!ptr->snapshot_refs[idx].ref_buf) {
1049                         err = intel_pt_alloc_snapshot_ref(ptr, idx, mm->len);
1050                         if (err)
1051                                 goto out_err;
1052                 }
1053                 wrapped = intel_pt_wrapped(ptr, idx, mm, data, *head);
1054         } else {
1055                 wrapped = ptr->snapshot_refs[idx].wrapped;
1056                 if (!wrapped && intel_pt_first_wrap((u64 *)data, mm->len)) {
1057                         ptr->snapshot_refs[idx].wrapped = true;
1058                         wrapped = true;
1059                 }
1060         }
1061 
1062         /*
1063          * In full trace mode 'head' continually increases.  However in snapshot
1064          * mode 'head' is an offset within the buffer.  Here 'old' and 'head'
1065          * are adjusted to match the full trace case which expects that 'old' is
1066          * always less than 'head'.
1067          */
1068         if (wrapped) {
1069                 *old = *head;
1070                 *head += mm->len;
1071         } else {
1072                 if (mm->mask)
1073                         *old &= mm->mask;
1074                 else
1075                         *old %= mm->len;
1076                 if (*old > *head)
1077                         *head += mm->len;
1078         }
1079 
1080         pr_debug3("%s: wrap-around %sdetected, adjusted old head %zu adjusted new head %zu\n",
1081                   __func__, wrapped ? "" : "not ", (size_t)*old, (size_t)*head);
1082 
1083         return 0;
1084 
1085 out_err:
1086         pr_err("%s: failed, error %d\n", __func__, err);
1087         return err;
1088 }
1089 
1090 static u64 intel_pt_reference(struct auxtrace_record *itr __maybe_unused)
1091 {
1092         return rdtsc();
1093 }
1094 
1095 static int intel_pt_read_finish(struct auxtrace_record *itr, int idx)
1096 {
1097         struct intel_pt_recording *ptr =
1098                         container_of(itr, struct intel_pt_recording, itr);
1099         struct evsel *evsel;
1100 
1101         evlist__for_each_entry(ptr->evlist, evsel) {
1102                 if (evsel->core.attr.type == ptr->intel_pt_pmu->type) {
1103                         if (evsel->disabled)
1104                                 return 0;
1105                         return perf_evlist__enable_event_idx(ptr->evlist, evsel,
1106                                                              idx);
1107                 }
1108         }
1109         return -EINVAL;
1110 }
1111 
1112 struct auxtrace_record *intel_pt_recording_init(int *err)
1113 {
1114         struct perf_pmu *intel_pt_pmu = perf_pmu__find(INTEL_PT_PMU_NAME);
1115         struct intel_pt_recording *ptr;
1116 
1117         if (!intel_pt_pmu)
1118                 return NULL;
1119 
1120         if (setenv("JITDUMP_USE_ARCH_TIMESTAMP", "1", 1)) {
1121                 *err = -errno;
1122                 return NULL;
1123         }
1124 
1125         ptr = zalloc(sizeof(struct intel_pt_recording));
1126         if (!ptr) {
1127                 *err = -ENOMEM;
1128                 return NULL;
1129         }
1130 
1131         ptr->intel_pt_pmu = intel_pt_pmu;
1132         ptr->itr.recording_options = intel_pt_recording_options;
1133         ptr->itr.info_priv_size = intel_pt_info_priv_size;
1134         ptr->itr.info_fill = intel_pt_info_fill;
1135         ptr->itr.free = intel_pt_recording_free;
1136         ptr->itr.snapshot_start = intel_pt_snapshot_start;
1137         ptr->itr.snapshot_finish = intel_pt_snapshot_finish;
1138         ptr->itr.find_snapshot = intel_pt_find_snapshot;
1139         ptr->itr.parse_snapshot_options = intel_pt_parse_snapshot_options;
1140         ptr->itr.reference = intel_pt_reference;
1141         ptr->itr.read_finish = intel_pt_read_finish;
1142         return &ptr->itr;
1143 }

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