summaryrefslogtreecommitdiffstats
path: root/lib/libpmc/pmclog.c
blob: e5dd2fc2da16eea6b3993e0bdfe2572dca1b6ac0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
/*-
 * Copyright (c) 2005 Joseph Koshy
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#include <sys/param.h>
#include <sys/pmc.h>
#include <sys/pmclog.h>

#include <assert.h>
#include <errno.h>
#include <pmc.h>
#include <pmclog.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>
#include <unistd.h>

#include <machine/pmc_mdep.h>

#define	PMCLOG_BUFFER_SIZE			4096

/*
 * API NOTES
 *
 * The pmclog(3) API is oriented towards parsing an event stream in
 * "realtime", i.e., from an data source that may or may not preserve
 * record boundaries -- for example when the data source is elsewhere
 * on a network.  The API allows data to be fed into the parser zero
 * or more bytes at a time.
 *
 * The state for a log file parser is maintained in a 'struct
 * pmclog_parse_state'.  Parser invocations are done by calling
 * 'pmclog_read()'; this function will inform the caller when a
 * complete event is parsed.
 *
 * The parser first assembles a complete log file event in an internal
 * work area (see "ps_saved" below).  Once a complete log file event
 * is read, the parser then parses it and converts it to an event
 * descriptor usable by the client.  We could possibly avoid this two
 * step process by directly parsing the input log to set fields in the
 * event record.  However the parser's state machine would get
 * insanely complicated, and this code is unlikely to be used in
 * performance critical paths.
 */

enum pmclog_parser_state {
	PL_STATE_NEW_RECORD,		/* in-between records */
	PL_STATE_EXPECTING_HEADER,	/* header being read */
	PL_STATE_PARTIAL_RECORD,	/* header present but not the record */
	PL_STATE_ERROR			/* parsing error encountered */
};

struct pmclog_parse_state {
	enum pmclog_parser_state ps_state;
	enum pmc_cputype	ps_arch;	/* log file architecture */
	uint32_t		ps_version;	/* hwpmc version */
	int			ps_initialized;	/* whether initialized */
	int			ps_count;	/* count of records processed */
	off_t			ps_offset;	/* stream byte offset */
	union pmclog_entry	ps_saved;	/* saved partial log entry */
	int			ps_svcount;	/* #bytes saved */
	int			ps_fd;		/* active fd or -1 */
	char			*ps_buffer;	/* scratch buffer if fd != -1 */
	char			*ps_data;	/* current parse pointer */
	size_t			ps_len;		/* length of buffered data */
};

#define	PMCLOG_HEADER_FROM_SAVED_STATE(PS)				\
	(* ((uint32_t *) &(PS)->ps_saved))

#define	PMCLOG_INITIALIZE_READER(LE,A)	LE = (uint32_t *) &(A)
#define	PMCLOG_READ32(LE,V) 		do {				\
		(V)  = *(LE)++;						\
	} while (0)
#define	PMCLOG_READ64(LE,V)		do {				\
		uint64_t _v;						\
		_v  = (uint64_t) *(LE)++;				\
		_v |= ((uint64_t) *(LE)++) << 32;			\
		(V) = _v;						\
	} while (0)

#define	PMCLOG_READSTRING(LE,DST,LEN)	strlcpy((DST), (char *) (LE), (LEN))

/*
 * Assemble a log record from '*len' octets starting from address '*data'.
 * Update 'data' and 'len' to reflect the number of bytes consumed.
 *
 * '*data' is potentially an unaligned address and '*len' octets may
 * not be enough to complete a event record.
 */

static enum pmclog_parser_state
pmclog_get_record(struct pmclog_parse_state *ps, char **data, ssize_t *len)
{
	int avail, copylen, recordsize, used;
	uint32_t h;
	const int HEADERSIZE = sizeof(uint32_t);
	char *src, *dst;

	if ((avail = *len) <= 0)
		return (ps->ps_state = PL_STATE_ERROR);

	src = *data;
	h = used = 0;

	if (ps->ps_state == PL_STATE_NEW_RECORD)
		ps->ps_svcount = 0;

	dst = (char *) &ps->ps_saved + ps->ps_svcount;

	switch (ps->ps_state) {
	case PL_STATE_NEW_RECORD:

		/*
		 * Transitions:
		 *
		 * Case A: avail < headersize
		 *	-> 'expecting header'
		 *
		 * Case B: avail >= headersize
		 *    B.1: avail < recordsize
		 *	   -> 'partial record'
		 *    B.2: avail >= recordsize
		 *         -> 'new record'
		 */

		copylen = avail < HEADERSIZE ? avail : HEADERSIZE;
		bcopy(src, dst, copylen);
		ps->ps_svcount = used = copylen;

		if (copylen < HEADERSIZE) {
			ps->ps_state = PL_STATE_EXPECTING_HEADER;
			goto done;
		}

		src += copylen;
		dst += copylen;

		h = PMCLOG_HEADER_FROM_SAVED_STATE(ps);
		recordsize = PMCLOG_HEADER_TO_LENGTH(h);

		if (recordsize <= 0)
			goto error;

		if (recordsize <= avail) { /* full record available */
			bcopy(src, dst, recordsize - copylen);
			ps->ps_svcount = used = recordsize;
			goto done;
		}

		/* header + a partial record is available */
		bcopy(src, dst, avail - copylen);
		ps->ps_svcount = used = avail;
		ps->ps_state = PL_STATE_PARTIAL_RECORD;

		break;

	case PL_STATE_EXPECTING_HEADER:

		/*
		 * Transitions:
		 *
		 * Case C: avail+saved < headersize
		 * 	-> 'expecting header'
		 *
		 * Case D: avail+saved >= headersize
		 *    D.1: avail+saved < recordsize
		 *    	-> 'partial record'
		 *    D.2: avail+saved >= recordsize
		 *    	-> 'new record'
		 *    (see PARTIAL_RECORD handling below)
		 */

		if (avail + ps->ps_svcount < HEADERSIZE) {
			bcopy(src, dst, avail);
			ps->ps_svcount += avail;
			used = avail;
			break;
		}

		used = copylen = HEADERSIZE - ps->ps_svcount;
		bcopy(src, dst, copylen);
		src += copylen;
		dst += copylen;
		avail -= copylen;
		ps->ps_svcount += copylen;

		/*FALLTHROUGH*/

	case PL_STATE_PARTIAL_RECORD:

		/*
		 * Transitions:
		 *
		 * Case E: avail+saved < recordsize
		 * 	-> 'partial record'
		 *
		 * Case F: avail+saved >= recordsize
		 * 	-> 'new record'
		 */

		h = PMCLOG_HEADER_FROM_SAVED_STATE(ps);
		recordsize = PMCLOG_HEADER_TO_LENGTH(h);

		if (recordsize <= 0)
			goto error;

		if (avail + ps->ps_svcount < recordsize) {
			copylen = avail;
			ps->ps_state = PL_STATE_PARTIAL_RECORD;
		} else {
			copylen = recordsize - ps->ps_svcount;
			ps->ps_state = PL_STATE_NEW_RECORD;
		}

		bcopy(src, dst, copylen);
		ps->ps_svcount += copylen;
		used += copylen;
		break;

	default:
		goto error;
	}

 done:
	*data += used;
	*len  -= used;
	return ps->ps_state;

 error:
	ps->ps_state = PL_STATE_ERROR;
	return ps->ps_state;
}

/*
 * Get an event from the stream pointed to by '*data'.  '*len'
 * indicates the number of bytes available to parse.  Arguments
 * '*data' and '*len' are updated to indicate the number of bytes
 * consumed.
 */

static int
pmclog_get_event(void *cookie, char **data, ssize_t *len,
    struct pmclog_ev *ev)
{
	int evlen, pathlen;
	uint32_t h, *le;
	enum pmclog_parser_state e;
	struct pmclog_parse_state *ps;

	ps = (struct pmclog_parse_state *) cookie;

	assert(ps->ps_state != PL_STATE_ERROR);

	if ((e = pmclog_get_record(ps,data,len)) == PL_STATE_ERROR) {
		ev->pl_state = PMCLOG_ERROR;
		return -1;
	}

	if (e != PL_STATE_NEW_RECORD) {
		ev->pl_state = PMCLOG_REQUIRE_DATA;
		return -1;
	}

	PMCLOG_INITIALIZE_READER(le, ps->ps_saved);

	PMCLOG_READ32(le,h);

	if (!PMCLOG_HEADER_CHECK_MAGIC(h)) {
		ps->ps_state = PL_STATE_ERROR;
		ev->pl_state = PMCLOG_ERROR;
		return -1;
	}

	/* copy out the time stamp */
	PMCLOG_READ32(le,ev->pl_ts.tv_sec);
	PMCLOG_READ32(le,ev->pl_ts.tv_nsec);

	evlen = PMCLOG_HEADER_TO_LENGTH(h);

#define	PMCLOG_GET_PATHLEN(P,E,TYPE) do {				\
		(P) = (E) - offsetof(struct TYPE, pl_pathname);		\
		if ((P) > PATH_MAX || (P) < 0)				\
			goto error;					\
	} while (0)

	switch (ev->pl_type = PMCLOG_HEADER_TO_TYPE(h)) {
	case PMCLOG_TYPE_CLOSELOG:
	case PMCLOG_TYPE_DROPNOTIFY:
		/* nothing to do */
		break;
	case PMCLOG_TYPE_INITIALIZE:
		PMCLOG_READ32(le,ev->pl_u.pl_i.pl_version);
		PMCLOG_READ32(le,ev->pl_u.pl_i.pl_arch);
		ps->ps_version = ev->pl_u.pl_i.pl_version;
		ps->ps_arch = ev->pl_u.pl_i.pl_arch;
		ps->ps_initialized = 1;
		break;
	case PMCLOG_TYPE_MAPPINGCHANGE:
		PMCLOG_GET_PATHLEN(pathlen,evlen,pmclog_mappingchange);
		PMCLOG_READ32(le,ev->pl_u.pl_m.pl_type);
		PMCLOG_READADDR(le,ev->pl_u.pl_m.pl_start);
		PMCLOG_READADDR(le,ev->pl_u.pl_m.pl_end);
		PMCLOG_READ32(le,ev->pl_u.pl_m.pl_pid);
		PMCLOG_READSTRING(le, ev->pl_u.pl_m.pl_pathname, pathlen);
		break;
	case PMCLOG_TYPE_PCSAMPLE:
		PMCLOG_READ32(le,ev->pl_u.pl_s.pl_pid);
		PMCLOG_READADDR(le,ev->pl_u.pl_s.pl_pc);
		PMCLOG_READ32(le,ev->pl_u.pl_s.pl_pmcid);
		PMCLOG_READ32(le,ev->pl_u.pl_s.pl_usermode);
		break;
	case PMCLOG_TYPE_PMCALLOCATE:
		PMCLOG_READ32(le,ev->pl_u.pl_a.pl_pmcid);
		PMCLOG_READ32(le,ev->pl_u.pl_a.pl_event);
		PMCLOG_READ32(le,ev->pl_u.pl_a.pl_flags);
		if ((ev->pl_u.pl_a.pl_evname =
		    pmc_name_of_event(ev->pl_u.pl_a.pl_event)) == NULL)
			goto error;
		break;
	case PMCLOG_TYPE_PMCATTACH:
		PMCLOG_GET_PATHLEN(pathlen,evlen,pmclog_pmcattach);
		PMCLOG_READ32(le,ev->pl_u.pl_t.pl_pmcid);
		PMCLOG_READ32(le,ev->pl_u.pl_t.pl_pid);
		PMCLOG_READSTRING(le,ev->pl_u.pl_t.pl_pathname,pathlen);
		break;
	case PMCLOG_TYPE_PMCDETACH:
		PMCLOG_READ32(le,ev->pl_u.pl_d.pl_pmcid);
		PMCLOG_READ32(le,ev->pl_u.pl_d.pl_pid);
		break;
	case PMCLOG_TYPE_PROCCSW:
		PMCLOG_READ32(le,ev->pl_u.pl_c.pl_pmcid);
		PMCLOG_READ64(le,ev->pl_u.pl_c.pl_value);
		PMCLOG_READ32(le,ev->pl_u.pl_c.pl_pid);
		break;
	case PMCLOG_TYPE_PROCEXEC:
		PMCLOG_GET_PATHLEN(pathlen,evlen,pmclog_procexec);
		PMCLOG_READ32(le,ev->pl_u.pl_x.pl_pid);
		PMCLOG_READADDR(le,ev->pl_u.pl_x.pl_entryaddr);
		PMCLOG_READ32(le,ev->pl_u.pl_x.pl_pmcid);
		PMCLOG_READSTRING(le,ev->pl_u.pl_x.pl_pathname,pathlen);
		break;
	case PMCLOG_TYPE_PROCEXIT:
		PMCLOG_READ32(le,ev->pl_u.pl_e.pl_pmcid);
		PMCLOG_READ64(le,ev->pl_u.pl_e.pl_value);
		PMCLOG_READ32(le,ev->pl_u.pl_e.pl_pid);
		break;
	case PMCLOG_TYPE_PROCFORK:
		PMCLOG_READ32(le,ev->pl_u.pl_f.pl_oldpid);
		PMCLOG_READ32(le,ev->pl_u.pl_f.pl_newpid);
		break;
	case PMCLOG_TYPE_SYSEXIT:
		PMCLOG_READ32(le,ev->pl_u.pl_se.pl_pid);
		break;
	case PMCLOG_TYPE_USERDATA:
		PMCLOG_READ32(le,ev->pl_u.pl_u.pl_userdata);
		break;
	default:	/* unknown record type */
		ps->ps_state = PL_STATE_ERROR;
		ev->pl_state = PMCLOG_ERROR;
		return -1;
	}

	ev->pl_offset = (ps->ps_offset += evlen);
	ev->pl_count  = (ps->ps_count += 1);
	ev->pl_state = PMCLOG_OK;
	return 0;

 error:
	ev->pl_state = PMCLOG_ERROR;
	ps->ps_state = PL_STATE_ERROR;
	return -1;
}

/*
 * Extract and return the next event from the byte stream.
 *
 * Returns 0 and sets the event's state to PMCLOG_OK in case an event
 * was successfully parsed.  Otherwise this function returns -1 and
 * sets the event's state to one of PMCLOG_REQUIRE_DATA (if more data
 * is needed) or PMCLOG_EOF (if an EOF was seen) or PMCLOG_ERROR if
 * a parse error was encountered.
 */

int
pmclog_read(void *cookie, struct pmclog_ev *ev)
{
	int retval;
	ssize_t nread;
	struct pmclog_parse_state *ps;

	ps = (struct pmclog_parse_state *) cookie;

	if (ps->ps_state == PL_STATE_ERROR) {
		ev->pl_state = PMCLOG_ERROR;
		return -1;
	}

	/*
	 * If there isn't enough data left for a new event try and get
	 * more data.
	 */
	if (ps->ps_len == 0) {
		ev->pl_state = PMCLOG_REQUIRE_DATA;

		/*
		 * If we have a valid file descriptor to read from, attempt
		 * to read from that.  This read may return with an error,
		 * (which may be EAGAIN or other recoverable error), or
		 * can return EOF.
		 */
		if (ps->ps_fd != PMCLOG_FD_NONE) {
		refill:
			nread = read(ps->ps_fd, ps->ps_buffer,
			    PMCLOG_BUFFER_SIZE);

			if (nread <= 0) {
				if (nread == 0)
					ev->pl_state = PMCLOG_EOF;
				else if (errno != EAGAIN) /* not restartable */
					ev->pl_state = PMCLOG_ERROR;
				return -1;
			}

			ps->ps_len = nread;
			ps->ps_data = ps->ps_buffer;
		} else
			return -1;
	}

	assert(ps->ps_len > 0);


	 /* Retrieve one event from the byte stream. */
	retval = pmclog_get_event(ps, &ps->ps_data, &ps->ps_len, ev);

	/*
	 * If we need more data and we have a configured fd, try read
	 * from it.
	 */
	if (retval < 0 && ev->pl_state == PMCLOG_REQUIRE_DATA &&
	    ps->ps_fd != -1) {
		assert(ps->ps_len == 0);
		goto refill;
	}

	return retval;
}

/*
 * Feed data to a memory based parser.
 *
 * The memory area pointed to by 'data' needs to be valid till the
 * next error return from pmclog_next_event().
 */

int
pmclog_feed(void *cookie, char *data, int len)
{
	struct pmclog_parse_state *ps;

	ps = (struct pmclog_parse_state *) cookie;

	if (len < 0 ||		/* invalid length */
	    ps->ps_buffer ||	/* called for a file parser */
	    ps->ps_len != 0)	/* unnecessary call */
		return -1;

	ps->ps_data = data;
	ps->ps_len  = len;

	return 0;
}

/*
 * Allocate and initialize parser state.
 */

void *
pmclog_open(int fd)
{
	struct pmclog_parse_state *ps;

	if ((ps = (struct pmclog_parse_state *) malloc(sizeof(*ps))) == NULL)
		return NULL;

	ps->ps_state = PL_STATE_NEW_RECORD;
	ps->ps_arch = -1;
	ps->ps_initialized = 0;
	ps->ps_count = 0;
	ps->ps_offset = (off_t) 0;
	bzero(&ps->ps_saved, sizeof(ps->ps_saved));
	ps->ps_svcount = 0;
	ps->ps_fd    = fd;
	ps->ps_data  = NULL;
	ps->ps_buffer = NULL;
	ps->ps_len   = 0;

	/* allocate space for a work area */
	if (ps->ps_fd != PMCLOG_FD_NONE) {
		if ((ps->ps_buffer = malloc(PMCLOG_BUFFER_SIZE)) == NULL)
			return NULL;
	}

	return ps;
}


/*
 * Free up parser state.
 */

void
pmclog_close(void *cookie)
{
	struct pmclog_parse_state *ps;

	ps = (struct pmclog_parse_state *) cookie;

	if (ps->ps_buffer)
		free(ps->ps_buffer);

	free(ps);
}
OpenPOWER on IntegriCloud