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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
50 #include <machine/pmc_mdep.h>
51
52 #include "libpmcinternal.h"
53
54 #define PMCLOG_BUFFER_SIZE                      4096
55
56 /*
57  * API NOTES
58  *
59  * The pmclog(3) API is oriented towards parsing an event stream in
60  * "realtime", i.e., from an data source that may or may not preserve
61  * record boundaries -- for example when the data source is elsewhere
62  * on a network.  The API allows data to be fed into the parser zero
63  * or more bytes at a time.
64  *
65  * The state for a log file parser is maintained in a 'struct
66  * pmclog_parse_state'.  Parser invocations are done by calling
67  * 'pmclog_read()'; this function will inform the caller when a
68  * complete event is parsed.
69  *
70  * The parser first assembles a complete log file event in an internal
71  * work area (see "ps_saved" below).  Once a complete log file event
72  * is read, the parser then parses it and converts it to an event
73  * descriptor usable by the client.  We could possibly avoid this two
74  * step process by directly parsing the input log to set fields in the
75  * event record.  However the parser's state machine would get
76  * insanely complicated, and this code is unlikely to be used in
77  * performance critical paths.
78  */
79
80 enum pmclog_parser_state {
81         PL_STATE_NEW_RECORD,            /* in-between records */
82         PL_STATE_EXPECTING_HEADER,      /* header being read */
83         PL_STATE_PARTIAL_RECORD,        /* header present but not the record */
84         PL_STATE_ERROR                  /* parsing error encountered */
85 };
86
87 struct pmclog_parse_state {
88         enum pmclog_parser_state ps_state;
89         enum pmc_cputype        ps_arch;        /* log file architecture */
90         uint32_t                ps_version;     /* hwpmc version */
91         int                     ps_initialized; /* whether initialized */
92         int                     ps_count;       /* count of records processed */
93         off_t                   ps_offset;      /* stream byte offset */
94         union pmclog_entry      ps_saved;       /* saved partial log entry */
95         int                     ps_svcount;     /* #bytes saved */
96         int                     ps_fd;          /* active fd or -1 */
97         char                    *ps_buffer;     /* scratch buffer if fd != -1 */
98         char                    *ps_data;       /* current parse pointer */
99         size_t                  ps_len;         /* length of buffered data */
100 };
101
102 #define PMCLOG_HEADER_FROM_SAVED_STATE(PS)                              \
103         (* ((uint32_t *) &(PS)->ps_saved))
104
105 #define PMCLOG_INITIALIZE_READER(LE,A)  LE = (uint32_t *) &(A)
106 #define PMCLOG_READ32(LE,V)             do {                            \
107                 (V)  = *(LE)++;                                         \
108         } while (0)
109 #define PMCLOG_READ64(LE,V)             do {                            \
110                 uint64_t _v;                                            \
111                 _v  = (uint64_t) *(LE)++;                               \
112                 _v |= ((uint64_t) *(LE)++) << 32;                       \
113                 (V) = _v;                                               \
114         } while (0)
115
116 #define PMCLOG_READSTRING(LE,DST,LEN)   strlcpy((DST), (char *) (LE), (LEN))
117
118 /*
119  * Assemble a log record from '*len' octets starting from address '*data'.
120  * Update 'data' and 'len' to reflect the number of bytes consumed.
121  *
122  * '*data' is potentially an unaligned address and '*len' octets may
123  * not be enough to complete a event record.
124  */
125
126 static enum pmclog_parser_state
127 pmclog_get_record(struct pmclog_parse_state *ps, char **data, ssize_t *len)
128 {
129         int avail, copylen, recordsize, used;
130         uint32_t h;
131         const int HEADERSIZE = sizeof(uint32_t);
132         char *src, *dst;
133
134         if ((avail = *len) <= 0)
135                 return (ps->ps_state = PL_STATE_ERROR);
136
137         src = *data;
138         h = used = 0;
139
140         if (ps->ps_state == PL_STATE_NEW_RECORD)
141                 ps->ps_svcount = 0;
142
143         dst = (char *) &ps->ps_saved + ps->ps_svcount;
144
145         switch (ps->ps_state) {
146         case PL_STATE_NEW_RECORD:
147
148                 /*
149                  * Transitions:
150                  *
151                  * Case A: avail < headersize
152                  *      -> 'expecting header'
153                  *
154                  * Case B: avail >= headersize
155                  *    B.1: avail < recordsize
156                  *         -> 'partial record'
157                  *    B.2: avail >= recordsize
158                  *         -> 'new record'
159                  */
160
161                 copylen = avail < HEADERSIZE ? avail : HEADERSIZE;
162                 bcopy(src, dst, copylen);
163                 ps->ps_svcount = used = copylen;
164
165                 if (copylen < HEADERSIZE) {
166                         ps->ps_state = PL_STATE_EXPECTING_HEADER;
167                         goto done;
168                 }
169
170                 src += copylen;
171                 dst += copylen;
172
173                 h = PMCLOG_HEADER_FROM_SAVED_STATE(ps);
174                 recordsize = PMCLOG_HEADER_TO_LENGTH(h);
175
176                 if (recordsize <= 0)
177                         goto error;
178
179                 if (recordsize <= avail) { /* full record available */
180                         bcopy(src, dst, recordsize - copylen);
181                         ps->ps_svcount = used = recordsize;
182                         goto done;
183                 }
184
185                 /* header + a partial record is available */
186                 bcopy(src, dst, avail - copylen);
187                 ps->ps_svcount = used = avail;
188                 ps->ps_state = PL_STATE_PARTIAL_RECORD;
189
190                 break;
191
192         case PL_STATE_EXPECTING_HEADER:
193
194                 /*
195                  * Transitions:
196                  *
197                  * Case C: avail+saved < headersize
198                  *      -> 'expecting header'
199                  *
200                  * Case D: avail+saved >= headersize
201                  *    D.1: avail+saved < recordsize
202                  *      -> 'partial record'
203                  *    D.2: avail+saved >= recordsize
204                  *      -> 'new record'
205                  *    (see PARTIAL_RECORD handling below)
206                  */
207
208                 if (avail + ps->ps_svcount < HEADERSIZE) {
209                         bcopy(src, dst, avail);
210                         ps->ps_svcount += avail;
211                         used = avail;
212                         break;
213                 }
214
215                 used = copylen = HEADERSIZE - ps->ps_svcount;
216                 bcopy(src, dst, copylen);
217                 src += copylen;
218                 dst += copylen;
219                 avail -= copylen;
220                 ps->ps_svcount += copylen;
221
222                 /*FALLTHROUGH*/
223
224         case PL_STATE_PARTIAL_RECORD:
225
226                 /*
227                  * Transitions:
228                  *
229                  * Case E: avail+saved < recordsize
230                  *      -> 'partial record'
231                  *
232                  * Case F: avail+saved >= recordsize
233                  *      -> 'new record'
234                  */
235
236                 h = PMCLOG_HEADER_FROM_SAVED_STATE(ps);
237                 recordsize = PMCLOG_HEADER_TO_LENGTH(h);
238
239                 if (recordsize <= 0)
240                         goto error;
241
242                 if (avail + ps->ps_svcount < recordsize) {
243                         copylen = avail;
244                         ps->ps_state = PL_STATE_PARTIAL_RECORD;
245                 } else {
246                         copylen = recordsize - ps->ps_svcount;
247                         ps->ps_state = PL_STATE_NEW_RECORD;
248                 }
249
250                 bcopy(src, dst, copylen);
251                 ps->ps_svcount += copylen;
252                 used += copylen;
253                 break;
254
255         default:
256                 goto error;
257         }
258
259  done:
260         *data += used;
261         *len  -= used;
262         return ps->ps_state;
263
264  error:
265         ps->ps_state = PL_STATE_ERROR;
266         return ps->ps_state;
267 }
268
269 /*
270  * Get an event from the stream pointed to by '*data'.  '*len'
271  * indicates the number of bytes available to parse.  Arguments
272  * '*data' and '*len' are updated to indicate the number of bytes
273  * consumed.
274  */
275
276 static int
277 pmclog_get_event(void *cookie, char **data, ssize_t *len,
278     struct pmclog_ev *ev)
279 {
280         int evlen, pathlen;
281         uint32_t h, *le, npc;
282         enum pmclog_parser_state e;
283         struct pmclog_parse_state *ps;
284
285         ps = (struct pmclog_parse_state *) cookie;
286
287         assert(ps->ps_state != PL_STATE_ERROR);
288
289         if ((e = pmclog_get_record(ps,data,len)) == PL_STATE_ERROR) {
290                 ev->pl_state = PMCLOG_ERROR;
291                 return -1;
292         }
293
294         if (e != PL_STATE_NEW_RECORD) {
295                 ev->pl_state = PMCLOG_REQUIRE_DATA;
296                 return -1;
297         }
298
299         PMCLOG_INITIALIZE_READER(le, ps->ps_saved);
300
301         PMCLOG_READ32(le,h);
302
303         if (!PMCLOG_HEADER_CHECK_MAGIC(h)) {
304                 ps->ps_state = PL_STATE_ERROR;
305                 ev->pl_state = PMCLOG_ERROR;
306                 return -1;
307         }
308
309         /* copy out the time stamp */
310         PMCLOG_READ32(le,ev->pl_ts.tv_sec);
311         PMCLOG_READ32(le,ev->pl_ts.tv_nsec);
312
313         evlen = PMCLOG_HEADER_TO_LENGTH(h);
314
315 #define PMCLOG_GET_PATHLEN(P,E,TYPE) do {                               \
316                 (P) = (E) - offsetof(struct TYPE, pl_pathname);         \
317                 if ((P) > PATH_MAX || (P) < 0)                          \
318                         goto error;                                     \
319         } while (0)
320
321 #define PMCLOG_GET_CALLCHAIN_SIZE(SZ,E) do {                            \
322                 (SZ) = ((E) - offsetof(struct pmclog_callchain, pl_pc)) \
323                         / sizeof(uintfptr_t);                           \
324         } while (0);
325
326         switch (ev->pl_type = PMCLOG_HEADER_TO_TYPE(h)) {
327         case PMCLOG_TYPE_CALLCHAIN:
328                 PMCLOG_READ32(le,ev->pl_u.pl_cc.pl_pid);
329                 PMCLOG_READ32(le,ev->pl_u.pl_cc.pl_pmcid);
330                 PMCLOG_READ32(le,ev->pl_u.pl_cc.pl_cpuflags);
331                 PMCLOG_GET_CALLCHAIN_SIZE(ev->pl_u.pl_cc.pl_npc,evlen);
332                 for (npc = 0; npc < ev->pl_u.pl_cc.pl_npc; npc++)
333                         PMCLOG_READADDR(le,ev->pl_u.pl_cc.pl_pc[npc]);
334                 for (;npc < PMC_CALLCHAIN_DEPTH_MAX; npc++)
335                         ev->pl_u.pl_cc.pl_pc[npc] = (uintfptr_t) 0;
336                 break;
337         case PMCLOG_TYPE_CLOSELOG:
338                 ev->pl_state = PMCLOG_EOF;
339                 return (-1);
340         case PMCLOG_TYPE_DROPNOTIFY:
341                 /* nothing to do */
342                 break;
343         case PMCLOG_TYPE_INITIALIZE:
344                 PMCLOG_READ32(le,ev->pl_u.pl_i.pl_version);
345                 PMCLOG_READ32(le,ev->pl_u.pl_i.pl_arch);
346                 ps->ps_version = ev->pl_u.pl_i.pl_version;
347                 ps->ps_arch = ev->pl_u.pl_i.pl_arch;
348                 ps->ps_initialized = 1;
349                 break;
350         case PMCLOG_TYPE_MAP_IN:
351                 PMCLOG_GET_PATHLEN(pathlen,evlen,pmclog_map_in);
352                 PMCLOG_READ32(le,ev->pl_u.pl_mi.pl_pid);
353                 PMCLOG_READADDR(le,ev->pl_u.pl_mi.pl_start);
354                 PMCLOG_READSTRING(le, ev->pl_u.pl_mi.pl_pathname, pathlen);
355                 break;
356         case PMCLOG_TYPE_MAP_OUT:
357                 PMCLOG_READ32(le,ev->pl_u.pl_mo.pl_pid);
358                 PMCLOG_READADDR(le,ev->pl_u.pl_mo.pl_start);
359                 PMCLOG_READADDR(le,ev->pl_u.pl_mo.pl_end);
360                 break;
361         case PMCLOG_TYPE_PCSAMPLE:
362                 PMCLOG_READ32(le,ev->pl_u.pl_s.pl_pid);
363                 PMCLOG_READADDR(le,ev->pl_u.pl_s.pl_pc);
364                 PMCLOG_READ32(le,ev->pl_u.pl_s.pl_pmcid);
365                 PMCLOG_READ32(le,ev->pl_u.pl_s.pl_usermode);
366                 break;
367         case PMCLOG_TYPE_PMCALLOCATE:
368                 PMCLOG_READ32(le,ev->pl_u.pl_a.pl_pmcid);
369                 PMCLOG_READ32(le,ev->pl_u.pl_a.pl_event);
370                 PMCLOG_READ32(le,ev->pl_u.pl_a.pl_flags);
371                 if ((ev->pl_u.pl_a.pl_evname =
372                     _pmc_name_of_event(ev->pl_u.pl_a.pl_event, ps->ps_arch))
373                     == NULL)
374                         goto error;
375                 break;
376         case PMCLOG_TYPE_PMCALLOCATEDYN:
377                 PMCLOG_READ32(le,ev->pl_u.pl_ad.pl_pmcid);
378                 PMCLOG_READ32(le,ev->pl_u.pl_ad.pl_event);
379                 PMCLOG_READ32(le,ev->pl_u.pl_ad.pl_flags);
380                 PMCLOG_READSTRING(le,ev->pl_u.pl_ad.pl_evname,PMC_NAME_MAX);
381                 break;
382         case PMCLOG_TYPE_PMCATTACH:
383                 PMCLOG_GET_PATHLEN(pathlen,evlen,pmclog_pmcattach);
384                 PMCLOG_READ32(le,ev->pl_u.pl_t.pl_pmcid);
385                 PMCLOG_READ32(le,ev->pl_u.pl_t.pl_pid);
386                 PMCLOG_READSTRING(le,ev->pl_u.pl_t.pl_pathname,pathlen);
387                 break;
388         case PMCLOG_TYPE_PMCDETACH:
389                 PMCLOG_READ32(le,ev->pl_u.pl_d.pl_pmcid);
390                 PMCLOG_READ32(le,ev->pl_u.pl_d.pl_pid);
391                 break;
392         case PMCLOG_TYPE_PROCCSW:
393                 PMCLOG_READ32(le,ev->pl_u.pl_c.pl_pmcid);
394                 PMCLOG_READ64(le,ev->pl_u.pl_c.pl_value);
395                 PMCLOG_READ32(le,ev->pl_u.pl_c.pl_pid);
396                 break;
397         case PMCLOG_TYPE_PROCEXEC:
398                 PMCLOG_GET_PATHLEN(pathlen,evlen,pmclog_procexec);
399                 PMCLOG_READ32(le,ev->pl_u.pl_x.pl_pid);
400                 PMCLOG_READADDR(le,ev->pl_u.pl_x.pl_entryaddr);
401                 PMCLOG_READ32(le,ev->pl_u.pl_x.pl_pmcid);
402                 PMCLOG_READSTRING(le,ev->pl_u.pl_x.pl_pathname,pathlen);
403                 break;
404         case PMCLOG_TYPE_PROCEXIT:
405                 PMCLOG_READ32(le,ev->pl_u.pl_e.pl_pmcid);
406                 PMCLOG_READ64(le,ev->pl_u.pl_e.pl_value);
407                 PMCLOG_READ32(le,ev->pl_u.pl_e.pl_pid);
408                 break;
409         case PMCLOG_TYPE_PROCFORK:
410                 PMCLOG_READ32(le,ev->pl_u.pl_f.pl_oldpid);
411                 PMCLOG_READ32(le,ev->pl_u.pl_f.pl_newpid);
412                 break;
413         case PMCLOG_TYPE_SYSEXIT:
414                 PMCLOG_READ32(le,ev->pl_u.pl_se.pl_pid);
415                 break;
416         case PMCLOG_TYPE_USERDATA:
417                 PMCLOG_READ32(le,ev->pl_u.pl_u.pl_userdata);
418                 break;
419         default:        /* unknown record type */
420                 ps->ps_state = PL_STATE_ERROR;
421                 ev->pl_state = PMCLOG_ERROR;
422                 return (-1);
423         }
424
425         ev->pl_offset = (ps->ps_offset += evlen);
426         ev->pl_count  = (ps->ps_count += 1);
427         ev->pl_state = PMCLOG_OK;
428         return 0;
429
430  error:
431         ev->pl_state = PMCLOG_ERROR;
432         ps->ps_state = PL_STATE_ERROR;
433         return -1;
434 }
435
436 /*
437  * Extract and return the next event from the byte stream.
438  *
439  * Returns 0 and sets the event's state to PMCLOG_OK in case an event
440  * was successfully parsed.  Otherwise this function returns -1 and
441  * sets the event's state to one of PMCLOG_REQUIRE_DATA (if more data
442  * is needed) or PMCLOG_EOF (if an EOF was seen) or PMCLOG_ERROR if
443  * a parse error was encountered.
444  */
445
446 int
447 pmclog_read(void *cookie, struct pmclog_ev *ev)
448 {
449         int retval;
450         ssize_t nread;
451         struct pmclog_parse_state *ps;
452
453         ps = (struct pmclog_parse_state *) cookie;
454
455         if (ps->ps_state == PL_STATE_ERROR) {
456                 ev->pl_state = PMCLOG_ERROR;
457                 return -1;
458         }
459
460         /*
461          * If there isn't enough data left for a new event try and get
462          * more data.
463          */
464         if (ps->ps_len == 0) {
465                 ev->pl_state = PMCLOG_REQUIRE_DATA;
466
467                 /*
468                  * If we have a valid file descriptor to read from, attempt
469                  * to read from that.  This read may return with an error,
470                  * (which may be EAGAIN or other recoverable error), or
471                  * can return EOF.
472                  */
473                 if (ps->ps_fd != PMCLOG_FD_NONE) {
474                 refill:
475                         nread = read(ps->ps_fd, ps->ps_buffer,
476                             PMCLOG_BUFFER_SIZE);
477
478                         if (nread <= 0) {
479                                 if (nread == 0)
480                                         ev->pl_state = PMCLOG_EOF;
481                                 else if (errno != EAGAIN) /* not restartable */
482                                         ev->pl_state = PMCLOG_ERROR;
483                                 return -1;
484                         }
485
486                         ps->ps_len = nread;
487                         ps->ps_data = ps->ps_buffer;
488                 } else
489                         return -1;
490         }
491
492         assert(ps->ps_len > 0);
493
494
495          /* Retrieve one event from the byte stream. */
496         retval = pmclog_get_event(ps, &ps->ps_data, &ps->ps_len, ev);
497
498         /*
499          * If we need more data and we have a configured fd, try read
500          * from it.
501          */
502         if (retval < 0 && ev->pl_state == PMCLOG_REQUIRE_DATA &&
503             ps->ps_fd != -1) {
504                 assert(ps->ps_len == 0);
505                 goto refill;
506         }
507
508         return retval;
509 }
510
511 /*
512  * Feed data to a memory based parser.
513  *
514  * The memory area pointed to by 'data' needs to be valid till the
515  * next error return from pmclog_next_event().
516  */
517
518 int
519 pmclog_feed(void *cookie, char *data, int len)
520 {
521         struct pmclog_parse_state *ps;
522
523         ps = (struct pmclog_parse_state *) cookie;
524
525         if (len < 0 ||          /* invalid length */
526             ps->ps_buffer ||    /* called for a file parser */
527             ps->ps_len != 0)    /* unnecessary call */
528                 return -1;
529
530         ps->ps_data = data;
531         ps->ps_len  = len;
532
533         return 0;
534 }
535
536 /*
537  * Allocate and initialize parser state.
538  */
539
540 void *
541 pmclog_open(int fd)
542 {
543         struct pmclog_parse_state *ps;
544
545         if ((ps = (struct pmclog_parse_state *) malloc(sizeof(*ps))) == NULL)
546                 return NULL;
547
548         ps->ps_state = PL_STATE_NEW_RECORD;
549         ps->ps_arch = -1;
550         ps->ps_initialized = 0;
551         ps->ps_count = 0;
552         ps->ps_offset = (off_t) 0;
553         bzero(&ps->ps_saved, sizeof(ps->ps_saved));
554         ps->ps_svcount = 0;
555         ps->ps_fd    = fd;
556         ps->ps_data  = NULL;
557         ps->ps_buffer = NULL;
558         ps->ps_len   = 0;
559
560         /* allocate space for a work area */
561         if (ps->ps_fd != PMCLOG_FD_NONE) {
562                 if ((ps->ps_buffer = malloc(PMCLOG_BUFFER_SIZE)) == NULL) {
563                         free(ps);
564                         return NULL;
565                 }
566         }
567
568         return ps;
569 }
570
571
572 /*
573  * Free up parser state.
574  */
575
576 void
577 pmclog_close(void *cookie)
578 {
579         struct pmclog_parse_state *ps;
580
581         ps = (struct pmclog_parse_state *) cookie;
582
583         if (ps->ps_buffer)
584                 free(ps->ps_buffer);
585
586         free(ps);
587 }