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1 /*-
2  * Copyright (c) 2005-2007 Joseph Koshy
3  * Copyright (c) 2007 The FreeBSD Foundation
4  * All rights reserved.
5  *
6  * Portions of this software were developed by A. Joseph Koshy under
7  * sponsorship from the FreeBSD Foundation and Google, Inc.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
33
34 #include <sys/param.h>
35 #include <sys/pmc.h>
36 #include <sys/pmclog.h>
37
38 #include <assert.h>
39 #include <errno.h>
40 #include <pmc.h>
41 #include <pmclog.h>
42 #include <stddef.h>
43 #include <stdlib.h>
44 #include <string.h>
45 #include <strings.h>
46 #include <unistd.h>
47
48 #include <machine/pmc_mdep.h>
49
50 #include "libpmcinternal.h"
51
52 #define PMCLOG_BUFFER_SIZE                      4096
53
54 /*
55  * API NOTES
56  *
57  * The pmclog(3) API is oriented towards parsing an event stream in
58  * "realtime", i.e., from an data source that may or may not preserve
59  * record boundaries -- for example when the data source is elsewhere
60  * on a network.  The API allows data to be fed into the parser zero
61  * or more bytes at a time.
62  *
63  * The state for a log file parser is maintained in a 'struct
64  * pmclog_parse_state'.  Parser invocations are done by calling
65  * 'pmclog_read()'; this function will inform the caller when a
66  * complete event is parsed.
67  *
68  * The parser first assembles a complete log file event in an internal
69  * work area (see "ps_saved" below).  Once a complete log file event
70  * is read, the parser then parses it and converts it to an event
71  * descriptor usable by the client.  We could possibly avoid this two
72  * step process by directly parsing the input log to set fields in the
73  * event record.  However the parser's state machine would get
74  * insanely complicated, and this code is unlikely to be used in
75  * performance critical paths.
76  */
77
78 enum pmclog_parser_state {
79         PL_STATE_NEW_RECORD,            /* in-between records */
80         PL_STATE_EXPECTING_HEADER,      /* header being read */
81         PL_STATE_PARTIAL_RECORD,        /* header present but not the record */
82         PL_STATE_ERROR                  /* parsing error encountered */
83 };
84
85 struct pmclog_parse_state {
86         enum pmclog_parser_state ps_state;
87         enum pmc_cputype        ps_arch;        /* log file architecture */
88         uint32_t                ps_version;     /* hwpmc version */
89         int                     ps_initialized; /* whether initialized */
90         int                     ps_count;       /* count of records processed */
91         off_t                   ps_offset;      /* stream byte offset */
92         union pmclog_entry      ps_saved;       /* saved partial log entry */
93         int                     ps_svcount;     /* #bytes saved */
94         int                     ps_fd;          /* active fd or -1 */
95         char                    *ps_buffer;     /* scratch buffer if fd != -1 */
96         char                    *ps_data;       /* current parse pointer */
97         size_t                  ps_len;         /* length of buffered data */
98 };
99
100 #define PMCLOG_HEADER_FROM_SAVED_STATE(PS)                              \
101         (* ((uint32_t *) &(PS)->ps_saved))
102
103 #define PMCLOG_INITIALIZE_READER(LE,A)  LE = (uint32_t *) &(A)
104 #define PMCLOG_READ32(LE,V)             do {                            \
105                 (V)  = *(LE)++;                                         \
106         } while (0)
107 #define PMCLOG_READ64(LE,V)             do {                            \
108                 uint64_t _v;                                            \
109                 _v  = (uint64_t) *(LE)++;                               \
110                 _v |= ((uint64_t) *(LE)++) << 32;                       \
111                 (V) = _v;                                               \
112         } while (0)
113
114 #define PMCLOG_READSTRING(LE,DST,LEN)   strlcpy((DST), (char *) (LE), (LEN))
115
116 /*
117  * Assemble a log record from '*len' octets starting from address '*data'.
118  * Update 'data' and 'len' to reflect the number of bytes consumed.
119  *
120  * '*data' is potentially an unaligned address and '*len' octets may
121  * not be enough to complete a event record.
122  */
123
124 static enum pmclog_parser_state
125 pmclog_get_record(struct pmclog_parse_state *ps, char **data, ssize_t *len)
126 {
127         int avail, copylen, recordsize, used;
128         uint32_t h;
129         const int HEADERSIZE = sizeof(uint32_t);
130         char *src, *dst;
131
132         if ((avail = *len) <= 0)
133                 return (ps->ps_state = PL_STATE_ERROR);
134
135         src = *data;
136         h = used = 0;
137
138         if (ps->ps_state == PL_STATE_NEW_RECORD)
139                 ps->ps_svcount = 0;
140
141         dst = (char *) &ps->ps_saved + ps->ps_svcount;
142
143         switch (ps->ps_state) {
144         case PL_STATE_NEW_RECORD:
145
146                 /*
147                  * Transitions:
148                  *
149                  * Case A: avail < headersize
150                  *      -> 'expecting header'
151                  *
152                  * Case B: avail >= headersize
153                  *    B.1: avail < recordsize
154                  *         -> 'partial record'
155                  *    B.2: avail >= recordsize
156                  *         -> 'new record'
157                  */
158
159                 copylen = avail < HEADERSIZE ? avail : HEADERSIZE;
160                 bcopy(src, dst, copylen);
161                 ps->ps_svcount = used = copylen;
162
163                 if (copylen < HEADERSIZE) {
164                         ps->ps_state = PL_STATE_EXPECTING_HEADER;
165                         goto done;
166                 }
167
168                 src += copylen;
169                 dst += copylen;
170
171                 h = PMCLOG_HEADER_FROM_SAVED_STATE(ps);
172                 recordsize = PMCLOG_HEADER_TO_LENGTH(h);
173
174                 if (recordsize <= 0)
175                         goto error;
176
177                 if (recordsize <= avail) { /* full record available */
178                         bcopy(src, dst, recordsize - copylen);
179                         ps->ps_svcount = used = recordsize;
180                         goto done;
181                 }
182
183                 /* header + a partial record is available */
184                 bcopy(src, dst, avail - copylen);
185                 ps->ps_svcount = used = avail;
186                 ps->ps_state = PL_STATE_PARTIAL_RECORD;
187
188                 break;
189
190         case PL_STATE_EXPECTING_HEADER:
191
192                 /*
193                  * Transitions:
194                  *
195                  * Case C: avail+saved < headersize
196                  *      -> 'expecting header'
197                  *
198                  * Case D: avail+saved >= headersize
199                  *    D.1: avail+saved < recordsize
200                  *      -> 'partial record'
201                  *    D.2: avail+saved >= recordsize
202                  *      -> 'new record'
203                  *    (see PARTIAL_RECORD handling below)
204                  */
205
206                 if (avail + ps->ps_svcount < HEADERSIZE) {
207                         bcopy(src, dst, avail);
208                         ps->ps_svcount += avail;
209                         used = avail;
210                         break;
211                 }
212
213                 used = copylen = HEADERSIZE - ps->ps_svcount;
214                 bcopy(src, dst, copylen);
215                 src += copylen;
216                 dst += copylen;
217                 avail -= copylen;
218                 ps->ps_svcount += copylen;
219
220                 /*FALLTHROUGH*/
221
222         case PL_STATE_PARTIAL_RECORD:
223
224                 /*
225                  * Transitions:
226                  *
227                  * Case E: avail+saved < recordsize
228                  *      -> 'partial record'
229                  *
230                  * Case F: avail+saved >= recordsize
231                  *      -> 'new record'
232                  */
233
234                 h = PMCLOG_HEADER_FROM_SAVED_STATE(ps);
235                 recordsize = PMCLOG_HEADER_TO_LENGTH(h);
236
237                 if (recordsize <= 0)
238                         goto error;
239
240                 if (avail + ps->ps_svcount < recordsize) {
241                         copylen = avail;
242                         ps->ps_state = PL_STATE_PARTIAL_RECORD;
243                 } else {
244                         copylen = recordsize - ps->ps_svcount;
245                         ps->ps_state = PL_STATE_NEW_RECORD;
246                 }
247
248                 bcopy(src, dst, copylen);
249                 ps->ps_svcount += copylen;
250                 used += copylen;
251                 break;
252
253         default:
254                 goto error;
255         }
256
257  done:
258         *data += used;
259         *len  -= used;
260         return ps->ps_state;
261
262  error:
263         ps->ps_state = PL_STATE_ERROR;
264         return ps->ps_state;
265 }
266
267 /*
268  * Get an event from the stream pointed to by '*data'.  '*len'
269  * indicates the number of bytes available to parse.  Arguments
270  * '*data' and '*len' are updated to indicate the number of bytes
271  * consumed.
272  */
273
274 static int
275 pmclog_get_event(void *cookie, char **data, ssize_t *len,
276     struct pmclog_ev *ev)
277 {
278         int evlen, pathlen;
279         uint32_t h, *le, npc;
280         enum pmclog_parser_state e;
281         struct pmclog_parse_state *ps;
282
283         ps = (struct pmclog_parse_state *) cookie;
284
285         assert(ps->ps_state != PL_STATE_ERROR);
286
287         if ((e = pmclog_get_record(ps,data,len)) == PL_STATE_ERROR) {
288                 ev->pl_state = PMCLOG_ERROR;
289                 return -1;
290         }
291
292         if (e != PL_STATE_NEW_RECORD) {
293                 ev->pl_state = PMCLOG_REQUIRE_DATA;
294                 return -1;
295         }
296
297         PMCLOG_INITIALIZE_READER(le, ps->ps_saved);
298
299         PMCLOG_READ32(le,h);
300
301         if (!PMCLOG_HEADER_CHECK_MAGIC(h)) {
302                 ps->ps_state = PL_STATE_ERROR;
303                 ev->pl_state = PMCLOG_ERROR;
304                 return -1;
305         }
306
307         /* copy out the time stamp */
308         PMCLOG_READ32(le,ev->pl_ts.tv_sec);
309         PMCLOG_READ32(le,ev->pl_ts.tv_nsec);
310
311         evlen = PMCLOG_HEADER_TO_LENGTH(h);
312
313 #define PMCLOG_GET_PATHLEN(P,E,TYPE) do {                               \
314                 (P) = (E) - offsetof(struct TYPE, pl_pathname);         \
315                 if ((P) > PATH_MAX || (P) < 0)                          \
316                         goto error;                                     \
317         } while (0)
318
319 #define PMCLOG_GET_CALLCHAIN_SIZE(SZ,E) do {                            \
320                 (SZ) = ((E) - offsetof(struct pmclog_callchain, pl_pc)) \
321                         / sizeof(uintfptr_t);                           \
322         } while (0);
323
324         switch (ev->pl_type = PMCLOG_HEADER_TO_TYPE(h)) {
325         case PMCLOG_TYPE_CALLCHAIN:
326                 PMCLOG_READ32(le,ev->pl_u.pl_cc.pl_pid);
327                 PMCLOG_READ32(le,ev->pl_u.pl_cc.pl_pmcid);
328                 PMCLOG_READ32(le,ev->pl_u.pl_cc.pl_cpuflags);
329                 PMCLOG_GET_CALLCHAIN_SIZE(ev->pl_u.pl_cc.pl_npc,evlen);
330                 for (npc = 0; npc < ev->pl_u.pl_cc.pl_npc; npc++)
331                         PMCLOG_READADDR(le,ev->pl_u.pl_cc.pl_pc[npc]);
332                 for (;npc < PMC_CALLCHAIN_DEPTH_MAX; npc++)
333                         ev->pl_u.pl_cc.pl_pc[npc] = (uintfptr_t) 0;
334                 break;
335         case PMCLOG_TYPE_CLOSELOG:
336         case PMCLOG_TYPE_DROPNOTIFY:
337                 /* nothing to do */
338                 break;
339         case PMCLOG_TYPE_INITIALIZE:
340                 PMCLOG_READ32(le,ev->pl_u.pl_i.pl_version);
341                 PMCLOG_READ32(le,ev->pl_u.pl_i.pl_arch);
342                 ps->ps_version = ev->pl_u.pl_i.pl_version;
343                 ps->ps_arch = ev->pl_u.pl_i.pl_arch;
344                 ps->ps_initialized = 1;
345                 break;
346         case PMCLOG_TYPE_MAP_IN:
347                 PMCLOG_GET_PATHLEN(pathlen,evlen,pmclog_map_in);
348                 PMCLOG_READ32(le,ev->pl_u.pl_mi.pl_pid);
349                 PMCLOG_READADDR(le,ev->pl_u.pl_mi.pl_start);
350                 PMCLOG_READSTRING(le, ev->pl_u.pl_mi.pl_pathname, pathlen);
351                 break;
352         case PMCLOG_TYPE_MAP_OUT:
353                 PMCLOG_READ32(le,ev->pl_u.pl_mo.pl_pid);
354                 PMCLOG_READADDR(le,ev->pl_u.pl_mo.pl_start);
355                 PMCLOG_READADDR(le,ev->pl_u.pl_mo.pl_end);
356                 break;
357         case PMCLOG_TYPE_PCSAMPLE:
358                 PMCLOG_READ32(le,ev->pl_u.pl_s.pl_pid);
359                 PMCLOG_READADDR(le,ev->pl_u.pl_s.pl_pc);
360                 PMCLOG_READ32(le,ev->pl_u.pl_s.pl_pmcid);
361                 PMCLOG_READ32(le,ev->pl_u.pl_s.pl_usermode);
362                 break;
363         case PMCLOG_TYPE_PMCALLOCATE:
364                 PMCLOG_READ32(le,ev->pl_u.pl_a.pl_pmcid);
365                 PMCLOG_READ32(le,ev->pl_u.pl_a.pl_event);
366                 PMCLOG_READ32(le,ev->pl_u.pl_a.pl_flags);
367                 if ((ev->pl_u.pl_a.pl_evname =
368                     _pmc_name_of_event(ev->pl_u.pl_a.pl_event, ps->ps_arch))
369                     == NULL)
370                         goto error;
371                 break;
372         case PMCLOG_TYPE_PMCALLOCATEDYN:
373                 PMCLOG_READ32(le,ev->pl_u.pl_ad.pl_pmcid);
374                 PMCLOG_READ32(le,ev->pl_u.pl_ad.pl_event);
375                 PMCLOG_READ32(le,ev->pl_u.pl_ad.pl_flags);
376                 PMCLOG_READSTRING(le,ev->pl_u.pl_ad.pl_evname,PMC_NAME_MAX);
377                 break;
378         case PMCLOG_TYPE_PMCATTACH:
379                 PMCLOG_GET_PATHLEN(pathlen,evlen,pmclog_pmcattach);
380                 PMCLOG_READ32(le,ev->pl_u.pl_t.pl_pmcid);
381                 PMCLOG_READ32(le,ev->pl_u.pl_t.pl_pid);
382                 PMCLOG_READSTRING(le,ev->pl_u.pl_t.pl_pathname,pathlen);
383                 break;
384         case PMCLOG_TYPE_PMCDETACH:
385                 PMCLOG_READ32(le,ev->pl_u.pl_d.pl_pmcid);
386                 PMCLOG_READ32(le,ev->pl_u.pl_d.pl_pid);
387                 break;
388         case PMCLOG_TYPE_PROCCSW:
389                 PMCLOG_READ32(le,ev->pl_u.pl_c.pl_pmcid);
390                 PMCLOG_READ64(le,ev->pl_u.pl_c.pl_value);
391                 PMCLOG_READ32(le,ev->pl_u.pl_c.pl_pid);
392                 break;
393         case PMCLOG_TYPE_PROCEXEC:
394                 PMCLOG_GET_PATHLEN(pathlen,evlen,pmclog_procexec);
395                 PMCLOG_READ32(le,ev->pl_u.pl_x.pl_pid);
396                 PMCLOG_READADDR(le,ev->pl_u.pl_x.pl_entryaddr);
397                 PMCLOG_READ32(le,ev->pl_u.pl_x.pl_pmcid);
398                 PMCLOG_READSTRING(le,ev->pl_u.pl_x.pl_pathname,pathlen);
399                 break;
400         case PMCLOG_TYPE_PROCEXIT:
401                 PMCLOG_READ32(le,ev->pl_u.pl_e.pl_pmcid);
402                 PMCLOG_READ64(le,ev->pl_u.pl_e.pl_value);
403                 PMCLOG_READ32(le,ev->pl_u.pl_e.pl_pid);
404                 break;
405         case PMCLOG_TYPE_PROCFORK:
406                 PMCLOG_READ32(le,ev->pl_u.pl_f.pl_oldpid);
407                 PMCLOG_READ32(le,ev->pl_u.pl_f.pl_newpid);
408                 break;
409         case PMCLOG_TYPE_SYSEXIT:
410                 PMCLOG_READ32(le,ev->pl_u.pl_se.pl_pid);
411                 break;
412         case PMCLOG_TYPE_USERDATA:
413                 PMCLOG_READ32(le,ev->pl_u.pl_u.pl_userdata);
414                 break;
415         default:        /* unknown record type */
416                 ps->ps_state = PL_STATE_ERROR;
417                 ev->pl_state = PMCLOG_ERROR;
418                 return (-1);
419         }
420
421         ev->pl_offset = (ps->ps_offset += evlen);
422         ev->pl_count  = (ps->ps_count += 1);
423         ev->pl_state = PMCLOG_OK;
424         return 0;
425
426  error:
427         ev->pl_state = PMCLOG_ERROR;
428         ps->ps_state = PL_STATE_ERROR;
429         return -1;
430 }
431
432 /*
433  * Extract and return the next event from the byte stream.
434  *
435  * Returns 0 and sets the event's state to PMCLOG_OK in case an event
436  * was successfully parsed.  Otherwise this function returns -1 and
437  * sets the event's state to one of PMCLOG_REQUIRE_DATA (if more data
438  * is needed) or PMCLOG_EOF (if an EOF was seen) or PMCLOG_ERROR if
439  * a parse error was encountered.
440  */
441
442 int
443 pmclog_read(void *cookie, struct pmclog_ev *ev)
444 {
445         int retval;
446         ssize_t nread;
447         struct pmclog_parse_state *ps;
448
449         ps = (struct pmclog_parse_state *) cookie;
450
451         if (ps->ps_state == PL_STATE_ERROR) {
452                 ev->pl_state = PMCLOG_ERROR;
453                 return -1;
454         }
455
456         /*
457          * If there isn't enough data left for a new event try and get
458          * more data.
459          */
460         if (ps->ps_len == 0) {
461                 ev->pl_state = PMCLOG_REQUIRE_DATA;
462
463                 /*
464                  * If we have a valid file descriptor to read from, attempt
465                  * to read from that.  This read may return with an error,
466                  * (which may be EAGAIN or other recoverable error), or
467                  * can return EOF.
468                  */
469                 if (ps->ps_fd != PMCLOG_FD_NONE) {
470                 refill:
471                         nread = read(ps->ps_fd, ps->ps_buffer,
472                             PMCLOG_BUFFER_SIZE);
473
474                         if (nread <= 0) {
475                                 if (nread == 0)
476                                         ev->pl_state = PMCLOG_EOF;
477                                 else if (errno != EAGAIN) /* not restartable */
478                                         ev->pl_state = PMCLOG_ERROR;
479                                 return -1;
480                         }
481
482                         ps->ps_len = nread;
483                         ps->ps_data = ps->ps_buffer;
484                 } else
485                         return -1;
486         }
487
488         assert(ps->ps_len > 0);
489
490
491          /* Retrieve one event from the byte stream. */
492         retval = pmclog_get_event(ps, &ps->ps_data, &ps->ps_len, ev);
493
494         /*
495          * If we need more data and we have a configured fd, try read
496          * from it.
497          */
498         if (retval < 0 && ev->pl_state == PMCLOG_REQUIRE_DATA &&
499             ps->ps_fd != -1) {
500                 assert(ps->ps_len == 0);
501                 goto refill;
502         }
503
504         return retval;
505 }
506
507 /*
508  * Feed data to a memory based parser.
509  *
510  * The memory area pointed to by 'data' needs to be valid till the
511  * next error return from pmclog_next_event().
512  */
513
514 int
515 pmclog_feed(void *cookie, char *data, int len)
516 {
517         struct pmclog_parse_state *ps;
518
519         ps = (struct pmclog_parse_state *) cookie;
520
521         if (len < 0 ||          /* invalid length */
522             ps->ps_buffer ||    /* called for a file parser */
523             ps->ps_len != 0)    /* unnecessary call */
524                 return -1;
525
526         ps->ps_data = data;
527         ps->ps_len  = len;
528
529         return 0;
530 }
531
532 /*
533  * Allocate and initialize parser state.
534  */
535
536 void *
537 pmclog_open(int fd)
538 {
539         struct pmclog_parse_state *ps;
540
541         if ((ps = (struct pmclog_parse_state *) malloc(sizeof(*ps))) == NULL)
542                 return NULL;
543
544         ps->ps_state = PL_STATE_NEW_RECORD;
545         ps->ps_arch = -1;
546         ps->ps_initialized = 0;
547         ps->ps_count = 0;
548         ps->ps_offset = (off_t) 0;
549         bzero(&ps->ps_saved, sizeof(ps->ps_saved));
550         ps->ps_svcount = 0;
551         ps->ps_fd    = fd;
552         ps->ps_data  = NULL;
553         ps->ps_buffer = NULL;
554         ps->ps_len   = 0;
555
556         /* allocate space for a work area */
557         if (ps->ps_fd != PMCLOG_FD_NONE) {
558                 if ((ps->ps_buffer = malloc(PMCLOG_BUFFER_SIZE)) == NULL) {
559                         free(ps);
560                         return NULL;
561                 }
562         }
563
564         return ps;
565 }
566
567
568 /*
569  * Free up parser state.
570  */
571
572 void
573 pmclog_close(void *cookie)
574 {
575         struct pmclog_parse_state *ps;
576
577         ps = (struct pmclog_parse_state *) cookie;
578
579         if (ps->ps_buffer)
580                 free(ps->ps_buffer);
581
582         free(ps);
583 }