lib/libpmc/pmclog.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
   3  *
   4  * Copyright (c) 2005-2007 Joseph Koshy
   5  * Copyright (c) 2007 The FreeBSD Foundation
   6  * All rights reserved.
   7  *
   8  * Portions of this software were developed by A. Joseph Koshy under
   9  * sponsorship from the FreeBSD Foundation and Google, Inc.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions and the following disclaimer.
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in the
  18  *    documentation and/or other materials provided with the distribution.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  */
  32
  33 #include <sys/cdefs.h>
  34 __FBSDID("$FreeBSD$");
  35
  36 #include <sys/param.h>
  37 #include <sys/pmc.h>
  38 #include <sys/pmclog.h>
  39
  40 #include <assert.h>
  41 #include <errno.h>
  42 #include <pmc.h>
  43 #include <pmclog.h>
  44 #include <stddef.h>
  45 #include <stdlib.h>
  46 #include <string.h>
  47 #include <strings.h>
  48 #include <unistd.h>
  49 #include <stdio.h>
  50
  51 #include <machine/pmc_mdep.h>
  52
  53 #include "libpmcinternal.h"
  54
  55 #define PMCLOG_BUFFER_SIZE                      4096
  56
  57 /*
  58  * API NOTES
  59  *
  60  * The pmclog(3) API is oriented towards parsing an event stream in
  61  * "realtime", i.e., from an data source that may or may not preserve
  62  * record boundaries -- for example when the data source is elsewhere
  63  * on a network.  The API allows data to be fed into the parser zero
  64  * or more bytes at a time.
  65  *
  66  * The state for a log file parser is maintained in a 'struct
  67  * pmclog_parse_state'.  Parser invocations are done by calling
  68  * 'pmclog_read()'; this function will inform the caller when a
  69  * complete event is parsed.
  70  *
  71  * The parser first assembles a complete log file event in an internal
  72  * work area (see "ps_saved" below).  Once a complete log file event
  73  * is read, the parser then parses it and converts it to an event
  74  * descriptor usable by the client.  We could possibly avoid this two
  75  * step process by directly parsing the input log to set fields in the
  76  * event record.  However the parser's state machine would get
  77  * insanely complicated, and this code is unlikely to be used in
  78  * performance critical paths.
  79  */
  80
  81 #define PMCLOG_HEADER_FROM_SAVED_STATE(PS)                              \
  82         (* ((uint32_t *) &(PS)->ps_saved))
  83
  84 #define PMCLOG_INITIALIZE_READER(LE,A)  LE = (uint32_t *) &(A)
  85 #define PMCLOG_READ32(LE,V)             do {                            \
  86                 (V)  = *(LE)++;                                         \
  87         } while (0)
  88 #define PMCLOG_READ64(LE,V)             do {                            \
  89                 uint64_t _v;                                            \
  90                 _v  = (uint64_t) *(LE)++;                               \
  91                 _v |= ((uint64_t) *(LE)++) << 32;                       \
  92                 (V) = _v;                                               \
  93         } while (0)
  94
  95 #define PMCLOG_READSTRING(LE,DST,LEN)   strlcpy((DST), (char *) (LE), (LEN))
  96
  97 /*
  98  * Assemble a log record from '*len' octets starting from address '*data'.
  99  * Update 'data' and 'len' to reflect the number of bytes consumed.
 100  *
 101  * '*data' is potentially an unaligned address and '*len' octets may
 102  * not be enough to complete a event record.
 103  */
 104
 105 static enum pmclog_parser_state
 106 pmclog_get_record(struct pmclog_parse_state *ps, char **data, ssize_t *len)
 107 {
 108         int avail, copylen, recordsize, used;
 109         uint32_t h;
 110         const int HEADERSIZE = sizeof(uint32_t);
 111         char *src, *dst;
 112
 113         if ((avail = *len) <= 0)
 114                 return (ps->ps_state = PL_STATE_ERROR);
 115
 116         src = *data;
 117         used = 0;
 118
 119         if (ps->ps_state == PL_STATE_NEW_RECORD)
 120                 ps->ps_svcount = 0;
 121
 122         dst = (char *) &ps->ps_saved + ps->ps_svcount;
 123
 124         switch (ps->ps_state) {
 125         case PL_STATE_NEW_RECORD:
 126
 127                 /*
 128                  * Transitions:
 129                  *
 130                  * Case A: avail < headersize
 131                  *      -> 'expecting header'
 132                  *
 133                  * Case B: avail >= headersize
 134                  *    B.1: avail < recordsize
 135                  *         -> 'partial record'
 136                  *    B.2: avail >= recordsize
 137                  *         -> 'new record'
 138                  */
 139
 140                 copylen = avail < HEADERSIZE ? avail : HEADERSIZE;
 141                 bcopy(src, dst, copylen);
 142                 ps->ps_svcount = used = copylen;
 143
 144                 if (copylen < HEADERSIZE) {
 145                         ps->ps_state = PL_STATE_EXPECTING_HEADER;
 146                         goto done;
 147                 }
 148
 149                 src += copylen;
 150                 dst += copylen;
 151
 152                 h = PMCLOG_HEADER_FROM_SAVED_STATE(ps);
 153                 recordsize = PMCLOG_HEADER_TO_LENGTH(h);
 154
 155                 if (recordsize <= 0)
 156                         goto error;
 157
 158                 if (recordsize <= avail) { /* full record available */
 159                         bcopy(src, dst, recordsize - copylen);
 160                         ps->ps_svcount = used = recordsize;
 161                         goto done;
 162                 }
 163
 164                 /* header + a partial record is available */
 165                 bcopy(src, dst, avail - copylen);
 166                 ps->ps_svcount = used = avail;
 167                 ps->ps_state = PL_STATE_PARTIAL_RECORD;
 168
 169                 break;
 170
 171         case PL_STATE_EXPECTING_HEADER:
 172
 173                 /*
 174                  * Transitions:
 175                  *
 176                  * Case C: avail+saved < headersize
 177                  *      -> 'expecting header'
 178                  *
 179                  * Case D: avail+saved >= headersize
 180                  *    D.1: avail+saved < recordsize
 181                  *      -> 'partial record'
 182                  *    D.2: avail+saved >= recordsize
 183                  *      -> 'new record'
 184                  *    (see PARTIAL_RECORD handling below)
 185                  */
 186
 187                 if (avail + ps->ps_svcount < HEADERSIZE) {
 188                         bcopy(src, dst, avail);
 189                         ps->ps_svcount += avail;
 190                         used = avail;
 191                         break;
 192                 }
 193
 194                 used = copylen = HEADERSIZE - ps->ps_svcount;
 195                 bcopy(src, dst, copylen);
 196                 src += copylen;
 197                 dst += copylen;
 198                 avail -= copylen;
 199                 ps->ps_svcount += copylen;
 200
 201                 /*FALLTHROUGH*/
 202
 203         case PL_STATE_PARTIAL_RECORD:
 204
 205                 /*
 206                  * Transitions:
 207                  *
 208                  * Case E: avail+saved < recordsize
 209                  *      -> 'partial record'
 210                  *
 211                  * Case F: avail+saved >= recordsize
 212                  *      -> 'new record'
 213                  */
 214
 215                 h = PMCLOG_HEADER_FROM_SAVED_STATE(ps);
 216                 recordsize = PMCLOG_HEADER_TO_LENGTH(h);
 217
 218                 if (recordsize <= 0)
 219                         goto error;
 220
 221                 if (avail + ps->ps_svcount < recordsize) {
 222                         copylen = avail;
 223                         ps->ps_state = PL_STATE_PARTIAL_RECORD;
 224                 } else {
 225                         copylen = recordsize - ps->ps_svcount;
 226                         ps->ps_state = PL_STATE_NEW_RECORD;
 227                 }
 228
 229                 bcopy(src, dst, copylen);
 230                 ps->ps_svcount += copylen;
 231                 used += copylen;
 232                 break;
 233
 234         default:
 235                 goto error;
 236         }
 237
 238  done:
 239         *data += used;
 240         *len  -= used;
 241         return ps->ps_state;
 242
 243  error:
 244         ps->ps_state = PL_STATE_ERROR;
 245         return ps->ps_state;
 246 }
 247
 248 /*
 249  * Get an event from the stream pointed to by '*data'.  '*len'
 250  * indicates the number of bytes available to parse.  Arguments
 251  * '*data' and '*len' are updated to indicate the number of bytes
 252  * consumed.
 253  */
 254
 255 static int
 256 pmclog_get_event(void *cookie, char **data, ssize_t *len,
 257     struct pmclog_ev *ev)
 258 {
 259         int evlen, pathlen;
 260         uint32_t h, *le, npc, noop;
 261         enum pmclog_parser_state e;
 262         struct pmclog_parse_state *ps;
 263
 264         ps = (struct pmclog_parse_state *) cookie;
 265
 266         assert(ps->ps_state != PL_STATE_ERROR);
 267
 268         if ((e = pmclog_get_record(ps,data,len)) == PL_STATE_ERROR) {
 269                 ev->pl_state = PMCLOG_ERROR;
 270                 printf("state error\n");
 271                 return -1;
 272         }
 273
 274         if (e != PL_STATE_NEW_RECORD) {
 275                 ev->pl_state = PMCLOG_REQUIRE_DATA;
 276                 return -1;
 277         }
 278
 279         PMCLOG_INITIALIZE_READER(le, ps->ps_saved);
 280         ev->pl_data = le;
 281         PMCLOG_READ32(le,h);
 282
 283         if (!PMCLOG_HEADER_CHECK_MAGIC(h)) {
 284                 printf("bad magic\n");
 285                 ps->ps_state = PL_STATE_ERROR;
 286                 ev->pl_state = PMCLOG_ERROR;
 287                 return -1;
 288         }
 289
 290         /* copy out the time stamp */
 291         PMCLOG_READ32(le,ev->pl_ts.tv_sec);
 292         PMCLOG_READ32(le,ev->pl_ts.tv_nsec);
 293
 294         evlen = PMCLOG_HEADER_TO_LENGTH(h);
 295
 296 #define PMCLOG_GET_PATHLEN(P,E,TYPE) do {                               \
 297                 (P) = (E) - offsetof(struct TYPE, pl_pathname);         \
 298                 if ((P) > PATH_MAX || (P) < 0)                          \
 299                         goto error;                                     \
 300         } while (0)
 301
 302 #define PMCLOG_GET_CALLCHAIN_SIZE(SZ,E) do {                            \
 303                 (SZ) = ((E) - offsetof(struct pmclog_callchain, pl_pc)) \
 304                         / sizeof(uintfptr_t);                           \
 305         } while (0);
 306
 307         switch (ev->pl_type = PMCLOG_HEADER_TO_TYPE(h)) {
 308         case PMCLOG_TYPE_CALLCHAIN:
 309                 PMCLOG_READ32(le,ev->pl_u.pl_cc.pl_pid);
 310                 PMCLOG_READ32(le,ev->pl_u.pl_cc.pl_tid);
 311                 PMCLOG_READ32(le,ev->pl_u.pl_cc.pl_pmcid);
 312                 PMCLOG_READ32(le,ev->pl_u.pl_cc.pl_cpuflags);
 313                 PMCLOG_READ32(le,ev->pl_u.pl_cc.pl_cpuflags2);
 314                 PMCLOG_GET_CALLCHAIN_SIZE(ev->pl_u.pl_cc.pl_npc,evlen);
 315                 for (npc = 0; npc < ev->pl_u.pl_cc.pl_npc; npc++)
 316                         PMCLOG_READADDR(le,ev->pl_u.pl_cc.pl_pc[npc]);
 317                 for (;npc < PMC_CALLCHAIN_DEPTH_MAX; npc++)
 318                         ev->pl_u.pl_cc.pl_pc[npc] = (uintfptr_t) 0;
 319                 break;
 320         case PMCLOG_TYPE_CLOSELOG:
 321                 ev->pl_state = PMCLOG_EOF;
 322                 return (-1);
 323         case PMCLOG_TYPE_DROPNOTIFY:
 324                 /* nothing to do */
 325                 break;
 326         case PMCLOG_TYPE_INITIALIZE:
 327                 PMCLOG_READ32(le,ev->pl_u.pl_i.pl_version);
 328                 PMCLOG_READ32(le,ev->pl_u.pl_i.pl_arch);
 329                 PMCLOG_READSTRING(le, ev->pl_u.pl_i.pl_cpuid, PMC_CPUID_LEN);
 330                 memcpy(ev->pl_u.pl_i.pl_cpuid, le, PMC_CPUID_LEN);
 331                 ps->ps_version = ev->pl_u.pl_i.pl_version;
 332                 ps->ps_arch = ev->pl_u.pl_i.pl_arch;
 333                 ps->ps_initialized = 1;
 334                 break;
 335         case PMCLOG_TYPE_MAP_IN:
 336                 PMCLOG_GET_PATHLEN(pathlen,evlen,pmclog_map_in);
 337                 PMCLOG_READ32(le,ev->pl_u.pl_mi.pl_pid);
 338                 PMCLOG_READADDR(le,ev->pl_u.pl_mi.pl_start);
 339                 PMCLOG_READSTRING(le, ev->pl_u.pl_mi.pl_pathname, pathlen);
 340                 break;
 341         case PMCLOG_TYPE_MAP_OUT:
 342                 PMCLOG_READ32(le,ev->pl_u.pl_mo.pl_pid);
 343                 PMCLOG_READADDR(le,ev->pl_u.pl_mo.pl_start);
 344                 PMCLOG_READADDR(le,ev->pl_u.pl_mo.pl_end);
 345                 break;
 346         case PMCLOG_TYPE_PMCALLOCATE:
 347                 PMCLOG_READ32(le,ev->pl_u.pl_a.pl_pmcid);
 348                 PMCLOG_READ32(le,ev->pl_u.pl_a.pl_event);
 349                 PMCLOG_READ32(le,ev->pl_u.pl_a.pl_flags);
 350                 PMCLOG_READ32(le,noop);
 351                 ev->pl_u.pl_a.pl_evname = pmc_pmu_event_get_by_idx(ev->pl_u.pl_a.pl_event);
 352                 if (ev->pl_u.pl_a.pl_evname != NULL)
 353                         break;
 354                 else if ((ev->pl_u.pl_a.pl_evname =
 355                     _pmc_name_of_event(ev->pl_u.pl_a.pl_event, ps->ps_arch))
 356                     == NULL) {
 357                         printf("unknown event\n");
 358                         goto error;
 359                 }
 360                 break;
 361         case PMCLOG_TYPE_PMCALLOCATEDYN:
 362                 PMCLOG_READ32(le,ev->pl_u.pl_ad.pl_pmcid);
 363                 PMCLOG_READ32(le,ev->pl_u.pl_ad.pl_event);
 364                 PMCLOG_READ32(le,ev->pl_u.pl_ad.pl_flags);
 365                 PMCLOG_READSTRING(le,ev->pl_u.pl_ad.pl_evname,PMC_NAME_MAX);
 366                 break;
 367         case PMCLOG_TYPE_PMCATTACH:
 368                 PMCLOG_GET_PATHLEN(pathlen,evlen,pmclog_pmcattach);
 369                 PMCLOG_READ32(le,ev->pl_u.pl_t.pl_pmcid);
 370                 PMCLOG_READ32(le,ev->pl_u.pl_t.pl_pid);
 371                 PMCLOG_READSTRING(le,ev->pl_u.pl_t.pl_pathname,pathlen);
 372                 break;
 373         case PMCLOG_TYPE_PMCDETACH:
 374                 PMCLOG_READ32(le,ev->pl_u.pl_d.pl_pmcid);
 375                 PMCLOG_READ32(le,ev->pl_u.pl_d.pl_pid);
 376                 break;
 377         case PMCLOG_TYPE_PROCCSW:
 378                 PMCLOG_READ32(le,ev->pl_u.pl_c.pl_pmcid);
 379                 PMCLOG_READ64(le,ev->pl_u.pl_c.pl_value);
 380                 PMCLOG_READ32(le,ev->pl_u.pl_c.pl_pid);
 381                 PMCLOG_READ32(le,ev->pl_u.pl_c.pl_tid);
 382                 break;
 383         case PMCLOG_TYPE_PROCEXEC:
 384                 PMCLOG_GET_PATHLEN(pathlen,evlen,pmclog_procexec);
 385                 PMCLOG_READ32(le,ev->pl_u.pl_x.pl_pid);
 386                 PMCLOG_READ32(le,ev->pl_u.pl_x.pl_pmcid);
 387                 PMCLOG_READ32(le,noop);
 388                 PMCLOG_READADDR(le,ev->pl_u.pl_x.pl_entryaddr);
 389                 PMCLOG_READSTRING(le,ev->pl_u.pl_x.pl_pathname,pathlen);
 390                 break;
 391         case PMCLOG_TYPE_PROCEXIT:
 392                 PMCLOG_READ32(le,ev->pl_u.pl_e.pl_pmcid);
 393                 PMCLOG_READ32(le,ev->pl_u.pl_e.pl_pid);
 394                 PMCLOG_READ32(le,noop);
 395                 PMCLOG_READ64(le,ev->pl_u.pl_e.pl_value);
 396                 break;
 397         case PMCLOG_TYPE_PROCFORK:
 398                 PMCLOG_READ32(le,ev->pl_u.pl_f.pl_oldpid);
 399                 PMCLOG_READ32(le,ev->pl_u.pl_f.pl_newpid);
 400                 break;
 401         case PMCLOG_TYPE_SYSEXIT:
 402                 PMCLOG_READ32(le,ev->pl_u.pl_se.pl_pid);
 403                 break;
 404         case PMCLOG_TYPE_USERDATA:
 405                 PMCLOG_READ32(le,ev->pl_u.pl_u.pl_userdata);
 406                 break;
 407         default:        /* unknown record type */
 408                 ps->ps_state = PL_STATE_ERROR;
 409                 ev->pl_state = PMCLOG_ERROR;
 410                 return (-1);
 411         }
 412
 413         ev->pl_offset = (ps->ps_offset += evlen);
 414         ev->pl_count  = (ps->ps_count += 1);
 415         ev->pl_len = evlen;
 416         ev->pl_state = PMCLOG_OK;
 417         return 0;
 418
 419  error:
 420         ev->pl_state = PMCLOG_ERROR;
 421         ps->ps_state = PL_STATE_ERROR;
 422         return -1;
 423 }
 424
 425 /*
 426  * Extract and return the next event from the byte stream.
 427  *
 428  * Returns 0 and sets the event's state to PMCLOG_OK in case an event
 429  * was successfully parsed.  Otherwise this function returns -1 and
 430  * sets the event's state to one of PMCLOG_REQUIRE_DATA (if more data
 431  * is needed) or PMCLOG_EOF (if an EOF was seen) or PMCLOG_ERROR if
 432  * a parse error was encountered.
 433  */
 434
 435 int
 436 pmclog_read(void *cookie, struct pmclog_ev *ev)
 437 {
 438         int retval;
 439         ssize_t nread;
 440         struct pmclog_parse_state *ps;
 441
 442         ps = (struct pmclog_parse_state *) cookie;
 443
 444         if (ps->ps_state == PL_STATE_ERROR) {
 445                 ev->pl_state = PMCLOG_ERROR;
 446                 return -1;
 447         }
 448
 449         /*
 450          * If there isn't enough data left for a new event try and get
 451          * more data.
 452          */
 453         if (ps->ps_len == 0) {
 454                 ev->pl_state = PMCLOG_REQUIRE_DATA;
 455
 456                 /*
 457                  * If we have a valid file descriptor to read from, attempt
 458                  * to read from that.  This read may return with an error,
 459                  * (which may be EAGAIN or other recoverable error), or
 460                  * can return EOF.
 461                  */
 462                 if (ps->ps_fd != PMCLOG_FD_NONE) {
 463                 refill:
 464                         nread = read(ps->ps_fd, ps->ps_buffer,
 465                             PMCLOG_BUFFER_SIZE);
 466
 467                         if (nread <= 0) {
 468                                 if (nread == 0)
 469                                         ev->pl_state = PMCLOG_EOF;
 470                                 else if (errno != EAGAIN) /* not restartable */
 471                                         ev->pl_state = PMCLOG_ERROR;
 472                                 return -1;
 473                         }
 474
 475                         ps->ps_len = nread;
 476                         ps->ps_data = ps->ps_buffer;
 477                 } else {
 478                         return -1;
 479                 }
 480         }
 481
 482         assert(ps->ps_len > 0);
 483
 484
 485          /* Retrieve one event from the byte stream. */
 486         retval = pmclog_get_event(ps, &ps->ps_data, &ps->ps_len, ev);
 487         /*
 488          * If we need more data and we have a configured fd, try read
 489          * from it.
 490          */
 491         if (retval < 0 && ev->pl_state == PMCLOG_REQUIRE_DATA &&
 492             ps->ps_fd != -1) {
 493                 assert(ps->ps_len == 0);
 494                 goto refill;
 495         }
 496
 497         return retval;
 498 }
 499
 500 /*
 501  * Feed data to a memory based parser.
 502  *
 503  * The memory area pointed to by 'data' needs to be valid till the
 504  * next error return from pmclog_next_event().
 505  */
 506
 507 int
 508 pmclog_feed(void *cookie, char *data, int len)
 509 {
 510         struct pmclog_parse_state *ps;
 511
 512         ps = (struct pmclog_parse_state *) cookie;
 513
 514         if (len < 0 ||          /* invalid length */
 515             ps->ps_buffer ||    /* called for a file parser */
 516             ps->ps_len != 0)    /* unnecessary call */
 517                 return -1;
 518
 519         ps->ps_data = data;
 520         ps->ps_len  = len;
 521
 522         return 0;
 523 }
 524
 525 /*
 526  * Allocate and initialize parser state.
 527  */
 528
 529 void *
 530 pmclog_open(int fd)
 531 {
 532         struct pmclog_parse_state *ps;
 533
 534         if ((ps = (struct pmclog_parse_state *) malloc(sizeof(*ps))) == NULL)
 535                 return NULL;
 536
 537         ps->ps_state = PL_STATE_NEW_RECORD;
 538         ps->ps_arch = -1;
 539         ps->ps_initialized = 0;
 540         ps->ps_count = 0;
 541         ps->ps_offset = (off_t) 0;
 542         bzero(&ps->ps_saved, sizeof(ps->ps_saved));
 543         ps->ps_svcount = 0;
 544         ps->ps_fd    = fd;
 545         ps->ps_data  = NULL;
 546         ps->ps_buffer = NULL;
 547         ps->ps_len   = 0;
 548
 549         /* allocate space for a work area */
 550         if (ps->ps_fd != PMCLOG_FD_NONE) {
 551                 if ((ps->ps_buffer = malloc(PMCLOG_BUFFER_SIZE)) == NULL) {
 552                         free(ps);
 553                         return NULL;
 554                 }
 555         }
 556
 557         return ps;
 558 }
 559
 560
 561 /*
 562  * Free up parser state.
 563  */
 564
 565 void
 566 pmclog_close(void *cookie)
 567 {
 568         struct pmclog_parse_state *ps;
 569
 570         ps = (struct pmclog_parse_state *) cookie;
 571
 572         if (ps->ps_buffer)
 573                 free(ps->ps_buffer);
 574
 575         free(ps);
 576 }