granicus.if.org Git - strace/blob - perf.c

   1 /*
   2  * Copyright (c) 2013 Ben Noordhuis <info@bnoordhuis.nl>
   3  * Copyright (c) 2013-2015 Dmitry V. Levin <ldv@altlinux.org>
   4  * Copyright (c) 2016 Eugene Syromyatnikov <evgsyr@gmail.com>
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. The name of the author may not be used to endorse or promote products
  16  *    derived from this software without specific prior written permission.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  21  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  23  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  28  */
  29
  30 #include "defs.h"
  31
  32 #include "perf_event_struct.h"
  33
  34 #include "xlat/clocknames.h"
  35 #include "xlat/hw_breakpoint_len.h"
  36 #include "xlat/hw_breakpoint_type.h"
  37 #include "xlat/perf_attr_size.h"
  38 #include "xlat/perf_branch_sample_type.h"
  39 #include "xlat/perf_event_open_flags.h"
  40 #include "xlat/perf_event_read_format.h"
  41 #include "xlat/perf_event_sample_format.h"
  42 #include "xlat/perf_hw_cache_id.h"
  43 #include "xlat/perf_hw_cache_op_id.h"
  44 #include "xlat/perf_hw_cache_op_result_id.h"
  45 #include "xlat/perf_hw_id.h"
  46 #include "xlat/perf_sw_ids.h"
  47 #include "xlat/perf_type_id.h"
  48
  49 struct pea_desc {
  50         struct perf_event_attr *attr;
  51         uint32_t size;
  52 };
  53
  54 static void
  55 free_pea_desc(void *pea_desc_ptr)
  56 {
  57         struct pea_desc *desc = pea_desc_ptr;
  58
  59         free(desc->attr);
  60         free(desc);
  61 }
  62
  63 static int
  64 fetch_perf_event_attr(struct tcb *const tcp, const kernel_ulong_t addr)
  65 {
  66         struct pea_desc *desc;
  67         struct perf_event_attr *attr;
  68         uint32_t size;
  69
  70         if (umove(tcp, addr + offsetof(struct perf_event_attr, size), &size)) {
  71                 printaddr(addr);
  72                 return 1;
  73         }
  74
  75         if (size > sizeof(*attr))
  76                 size = sizeof(*attr);
  77
  78         if (!size)
  79                 size = PERF_ATTR_SIZE_VER0;
  80
  81         /*
  82          * Kernel (rightfully) deems invalid attribute structures with size less
  83          * than first published format size, and we do the same.
  84          */
  85         if (size < PERF_ATTR_SIZE_VER0) {
  86                 printaddr(addr);
  87                 return 1;
  88         }
  89
  90         if (abbrev(tcp))
  91                 size = offsetofend(struct perf_event_attr, config);
  92
  93         /* Size should be multiple of 8, but kernel doesn't check for it */
  94         /* size &= ~7; */
  95
  96         attr = xcalloc(1, sizeof(*attr));
  97
  98         if (umoven_or_printaddr(tcp, addr, size, attr)) {
  99                 free(attr);
 100
 101                 return 1;
 102         }
 103
 104         desc = xmalloc(sizeof(*desc));
 105
 106         desc->attr = attr;
 107         desc->size = size;
 108
 109         set_tcb_priv_data(tcp, desc, free_pea_desc);
 110
 111         return 0;
 112 }
 113
 114 #define PRINT_XLAT(prefix, xlat, x, dflt) \
 115         do { \
 116                 tprints(prefix); \
 117                 printxval_search(xlat, x, dflt); \
 118         } while (0)
 119
 120 static void
 121 print_perf_event_attr(struct tcb *const tcp, const kernel_ulong_t addr)
 122 {
 123         static const char *precise_ip_desc[] = {
 124                 "arbitrary skid",
 125                 "constant skid",
 126                 "requested to have 0 skid",
 127                 "must have 0 skid",
 128         };
 129
 130         struct pea_desc *desc;
 131         struct perf_event_attr *attr;
 132         uint32_t size;
 133         uint32_t new_size;
 134         int use_new_size = 0;
 135
 136         /*
 137          * Amusingly, kernel accepts structures with only part of the field
 138          * present, so we making check like this (instead of checking
 139          * offsetofend against size) in order to print fields as kernel sees
 140          * them. This also should work great on big endian architectures.
 141          */
 142         #define _PERF_CHECK_FIELD(_field) \
 143                 do { \
 144                         if (offsetof(struct perf_event_attr, _field) >= size) \
 145                                 goto print_perf_event_attr_out; \
 146                 } while (0)
 147
 148         desc = get_tcb_priv_data(tcp);
 149
 150         attr = desc->attr;
 151         size = desc->size;
 152
 153         /* The only error which expected to change size field currently */
 154         if (tcp->u_error == E2BIG) {
 155                 if (umove(tcp, addr + offsetof(struct perf_event_attr, size),
 156                     &new_size))
 157                         use_new_size = -1;
 158                 else
 159                         use_new_size = 1;
 160         }
 161
 162         PRINT_XLAT("{type=", perf_type_id, attr->type, "PERF_TYPE_???");
 163         tprintf(", size=");
 164         printxval(perf_attr_size, attr->size, "PERF_ATTR_SIZE_???");
 165
 166         if (use_new_size) {
 167                 tprints(" => ");
 168
 169                 if (use_new_size > 0)
 170                         printxval(perf_attr_size, new_size,
 171                                   "PERF_ATTR_SIZE_???");
 172                 else
 173                         tprints("???");
 174         }
 175
 176         switch (attr->type) {
 177         case PERF_TYPE_HARDWARE:
 178                 PRINT_XLAT(", config=", perf_hw_id, attr->config,
 179                            "PERF_COUNT_HW_???");
 180                 break;
 181         case PERF_TYPE_SOFTWARE:
 182                 PRINT_XLAT(", config=", perf_sw_ids, attr->config,
 183                            "PERF_COUNT_SW_???");
 184                 break;
 185         case PERF_TYPE_TRACEPOINT:
 186                 /*
 187                  * "The value to use in config can be obtained from under
 188                  * debugfs tracing/events/../../id if ftrace is enabled in the
 189                  * kernel."
 190                  */
 191                 tprintf(", config=%" PRIu64, attr->config);
 192                 break;
 193         case PERF_TYPE_HW_CACHE:
 194                 /*
 195                  * (perf_hw_cache_id) | (perf_hw_cache_op_id << 8) |
 196                  * (perf_hw_cache_op_result_id << 16)
 197                  */
 198                 PRINT_XLAT(", config=", perf_hw_cache_id, attr->config & 0xFF,
 199                            "PERF_COUNT_HW_CACHE_???");
 200                 PRINT_XLAT("|", perf_hw_cache_op_id, (attr->config >> 8) & 0xFF,
 201                            "PERF_COUNT_HW_CACHE_OP_???");
 202                 /*
 203                  * Current code (see set_ext_hw_attr in arch/x86/events/core.c,
 204                  * tile_map_cache_event in arch/tile/kernel/perf_event.c,
 205                  * arc_pmu_cache_event in arch/arc/kernel/perf_event.c,
 206                  * hw_perf_cache_event in arch/blackfin/kernel/perf_event.c,
 207                  * _hw_perf_cache_event in arch/metag/kernel/perf/perf_event.c,
 208                  * mipspmu_map_cache_event in arch/mips/kernel/perf_event_mipsxx.c,
 209                  * hw_perf_cache_event in arch/powerpc/perf/core-book3s.c,
 210                  * hw_perf_cache_event in arch/powerpc/perf/core-fsl-emb.c,
 211                  * hw_perf_cache_event in arch/sh/kernel/perf_event.c,
 212                  * sparc_map_cache_event in arch/sparc/kernel/perf_event.c,
 213                  * xtensa_pmu_cache_event in arch/xtensa/kernel/perf_event.c,
 214                  * armpmu_map_cache_event in drivers/perf/arm_pmu.c) assumes
 215                  * that cache result is 8 bits in size.
 216                  */
 217                 PRINT_XLAT("<<8|", perf_hw_cache_op_result_id,
 218                            (attr->config >> 16) & 0xFF,
 219                            "PERF_COUNT_HW_CACHE_RESULT_???");
 220                 tprintf("<<16");
 221                 if (attr->config >> 24)
 222                         tprintf("|%#" PRIx64 "<<24 "
 223                                 "/* PERF_COUNT_HW_CACHE_??? */",
 224                                 attr->config >> 24);
 225                 break;
 226         case PERF_TYPE_RAW:
 227                 /*
 228                  * "If type is PERF_TYPE_RAW, then a custom "raw" config
 229                  * value is needed. Most CPUs support events that are not
 230                  * covered by the "generalized" events. These are
 231                  * implementation defined; see your CPU manual (for example the
 232                  * Intel Volume 3B documentation or the AMD BIOS and Kernel
 233                  * Developer Guide). The libpfm4 library can be used to
 234                  * translate from the name in the architectural manuals
 235                  * to the raw hex value perf_event_open() expects in this
 236                  * field."
 237                  */
 238         case PERF_TYPE_BREAKPOINT:
 239                 /*
 240                  * "If type is PERF_TYPE_BREAKPOINT, then leave config set
 241                  * to zero. Its parameters are set in other places."
 242                  */
 243         default:
 244                 tprintf(", config=%#" PRIx64, attr->config);
 245                 break;
 246         }
 247
 248         if (abbrev(tcp))
 249                 goto print_perf_event_attr_out;
 250
 251         if (attr->freq)
 252                 tprintf(", sample_freq=%" PRIu64, attr->sample_freq);
 253         else
 254                 tprintf(", sample_period=%" PRIu64, attr->sample_period);
 255
 256         tprintf(", sample_type=");
 257         printflags64(perf_event_sample_format, attr->sample_type,
 258                 "PERF_SAMPLE_???");
 259
 260         tprintf(", read_format=");
 261         printflags64(perf_event_read_format, attr->read_format,
 262                 "PERF_FORMAT_???");
 263
 264         tprintf(", disabled=%u"
 265                 ", inherit=%u"
 266                 ", pinned=%u"
 267                 ", exclusive=%u"
 268                 ", exclusive_user=%u"
 269                 ", exclude_kernel=%u"
 270                 ", exclude_hv=%u"
 271                 ", exclude_idle=%u"
 272                 ", mmap=%u"
 273                 ", comm=%u"
 274                 ", freq=%u"
 275                 ", inherit_stat=%u"
 276                 ", enable_on_exec=%u"
 277                 ", task=%u"
 278                 ", watermark=%u"
 279                 ", precise_ip=%u /* %s */"
 280                 ", mmap_data=%u"
 281                 ", sample_id_all=%u"
 282                 ", exclude_host=%u"
 283                 ", exclude_guest=%u"
 284                 ", exclude_callchain_kernel=%u"
 285                 ", exclude_callchain_user=%u"
 286                 ", mmap2=%u"
 287                 ", comm_exec=%u"
 288                 ", use_clockid=%u"
 289                 ", context_switch=%u"
 290                 ", write_backward=%u",
 291                 attr->disabled,
 292                 attr->inherit,
 293                 attr->pinned,
 294                 attr->exclusive,
 295                 attr->exclude_user,
 296                 attr->exclude_kernel,
 297                 attr->exclude_hv,
 298                 attr->exclude_idle,
 299                 attr->mmap,
 300                 attr->comm,
 301                 attr->freq,
 302                 attr->inherit_stat,
 303                 attr->enable_on_exec,
 304                 attr->task,
 305                 attr->watermark,
 306                 attr->precise_ip, precise_ip_desc[attr->precise_ip],
 307                 attr->mmap_data,
 308                 attr->sample_id_all,
 309                 attr->exclude_host,
 310                 attr->exclude_guest,
 311                 attr->exclude_callchain_kernel,
 312                 attr->exclude_callchain_user,
 313                 attr->mmap2,
 314                 attr->comm_exec,
 315                 attr->use_clockid,
 316                 attr->context_switch,
 317                 attr->write_backward);
 318
 319         /*
 320          * Print it only in case it is non-zero, since it may contain flags we
 321          * are not aware about.
 322          */
 323         if (attr->__reserved_1)
 324                 tprintf(", __reserved_1=%#" PRIx64 " /* Bits 63..28 */",
 325                         (uint64_t) attr->__reserved_1);
 326
 327         if (attr->watermark)
 328                 tprintf(", wakeup_watermark=%u", attr->wakeup_watermark);
 329         else
 330                 tprintf(", wakeup_events=%u", attr->wakeup_events);
 331
 332         if (attr->type == PERF_TYPE_BREAKPOINT)
 333                 /* Any combination of R/W with X is deemed invalid */
 334                 PRINT_XLAT(", bp_type=", hw_breakpoint_type, attr->bp_type,
 335                            (attr->bp_type <=
 336                                    (HW_BREAKPOINT_X | HW_BREAKPOINT_RW)) ?
 337                                            "HW_BREAKPOINT_INVALID" :
 338                                            "HW_BREAKPOINT_???");
 339
 340         if (attr->type == PERF_TYPE_BREAKPOINT)
 341                 tprintf(", bp_addr=%#" PRIx64, attr->bp_addr);
 342         else
 343                 tprintf(", config1=%#" PRIx64, attr->config1);
 344
 345         /*
 346          * Fields after bp_addr/config1 are optional and may not present; check
 347          * against size is needed.
 348          */
 349
 350         _PERF_CHECK_FIELD(bp_len);
 351         if (attr->type == PERF_TYPE_BREAKPOINT)
 352                 tprintf(", bp_len=%" PRIu64, attr->bp_len);
 353         else
 354                 tprintf(", config2=%#" PRIx64, attr->config2);
 355
 356         _PERF_CHECK_FIELD(branch_sample_type);
 357         if (attr->sample_type & PERF_SAMPLE_BRANCH_STACK) {
 358                 tprintf(", branch_sample_type=");
 359                 printflags64(perf_branch_sample_type, attr->branch_sample_type,
 360                              "PERF_SAMPLE_BRANCH_???");
 361         }
 362
 363         _PERF_CHECK_FIELD(sample_regs_user);
 364         /*
 365          * "This bit mask defines the set of user CPU registers to dump on
 366          * samples. The layout of the register mask is architecture-specific and
 367          * described in the kernel header
 368          * arch/ARCH/include/uapi/asm/perf_regs.h."
 369          */
 370         tprintf(", sample_regs_user=%#" PRIx64, attr->sample_regs_user);
 371
 372         _PERF_CHECK_FIELD(sample_stack_user);
 373         /*
 374          * "size of the user stack to dump if PERF_SAMPLE_STACK_USER is
 375          * specified."
 376          */
 377         if (attr->sample_type & PERF_SAMPLE_STACK_USER)
 378                 tprintf(", sample_stack_user=%#" PRIx32,
 379                         attr->sample_stack_user);
 380
 381         if (attr->use_clockid) {
 382                 _PERF_CHECK_FIELD(clockid);
 383                 tprintf(", clockid=");
 384                 printxval(clocknames, attr->clockid, "CLOCK_???");
 385         }
 386
 387         _PERF_CHECK_FIELD(sample_regs_intr);
 388         tprintf(", sample_regs_intr=%#" PRIx64, attr->sample_regs_intr);
 389
 390         _PERF_CHECK_FIELD(aux_watermark);
 391         tprintf(", aux_watermark=%" PRIu32, attr->aux_watermark);
 392
 393         _PERF_CHECK_FIELD(sample_max_stack);
 394         tprintf(", sample_max_stack=%" PRIu16, attr->sample_max_stack);
 395
 396         /* _PERF_CHECK_FIELD(__reserved_2);
 397         tprintf(", __reserved2=%" PRIu16, attr->__reserved_2); */
 398
 399 print_perf_event_attr_out:
 400         if ((attr->size && (attr->size > size)) ||
 401             (!attr->size && (size < PERF_ATTR_SIZE_VER0)))
 402                 tprintf(", ...");
 403
 404         tprintf("}");
 405 }
 406
 407 SYS_FUNC(perf_event_open)
 408 {
 409         /*
 410          * We try to copy out the whole structure on entering in order to check
 411          * size value on exiting. We do not check the rest of the fields because
 412          * they shouldn't be changed, but copy the whole structure instead
 413          * of just size field because they could.
 414          */
 415         if (entering(tcp)) {
 416                 if (!fetch_perf_event_attr(tcp, tcp->u_arg[0]))
 417                         return 0;
 418         } else {
 419                 print_perf_event_attr(tcp, tcp->u_arg[0]);
 420         }
 421
 422         tprintf(", %d, %d, %d, ",
 423                 (int) tcp->u_arg[1],
 424                 (int) tcp->u_arg[2],
 425                 (int) tcp->u_arg[3]);
 426         printflags64(perf_event_open_flags, tcp->u_arg[4], "PERF_FLAG_???");
 427
 428         return RVAL_DECODED | RVAL_FD;
 429 }