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Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/evalenti/linux...
[linux/fpc-iii.git] / tools / perf / util / intel-pt-decoder / intel-pt-decoder.c
blob9409d014b46c713de02df828cf9ad7ff726881e8
1 /*
2 * intel_pt_decoder.c: Intel Processor Trace support
3 * Copyright (c) 2013-2014, Intel Corporation.
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms and conditions of the GNU General Public License,
7 * version 2, as published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
12 * more details.
13 *
14 */
15
16 #ifndef _GNU_SOURCE
17 #define _GNU_SOURCE
18 #endif
19 #include <stdlib.h>
20 #include <stdbool.h>
21 #include <string.h>
22 #include <errno.h>
23 #include <stdint.h>
24 #include <inttypes.h>
25
26 #include "../cache.h"
27 #include "../util.h"
28
29 #include "intel-pt-insn-decoder.h"
30 #include "intel-pt-pkt-decoder.h"
31 #include "intel-pt-decoder.h"
32 #include "intel-pt-log.h"
33
34 #define INTEL_PT_BLK_SIZE 1024
35
36 #define BIT63 (((uint64_t)1 << 63))
37
38 #define INTEL_PT_RETURN 1
39
40 /* Maximum number of loops with no packets consumed i.e. stuck in a loop */
41 #define INTEL_PT_MAX_LOOPS 10000
42
43 struct intel_pt_blk {
44 struct intel_pt_blk *prev;
45 uint64_t ip[INTEL_PT_BLK_SIZE];
46 };
47
48 struct intel_pt_stack {
49 struct intel_pt_blk *blk;
50 struct intel_pt_blk *spare;
51 int pos;
52 };
53
54 enum intel_pt_pkt_state {
55 INTEL_PT_STATE_NO_PSB,
56 INTEL_PT_STATE_NO_IP,
57 INTEL_PT_STATE_ERR_RESYNC,
58 INTEL_PT_STATE_IN_SYNC,
59 INTEL_PT_STATE_TNT,
60 INTEL_PT_STATE_TIP,
61 INTEL_PT_STATE_TIP_PGD,
62 INTEL_PT_STATE_FUP,
63 INTEL_PT_STATE_FUP_NO_TIP,
64 };
65
66 #ifdef INTEL_PT_STRICT
67 #define INTEL_PT_STATE_ERR1 INTEL_PT_STATE_NO_PSB
68 #define INTEL_PT_STATE_ERR2 INTEL_PT_STATE_NO_PSB
69 #define INTEL_PT_STATE_ERR3 INTEL_PT_STATE_NO_PSB
70 #define INTEL_PT_STATE_ERR4 INTEL_PT_STATE_NO_PSB
71 #else
72 #define INTEL_PT_STATE_ERR1 (decoder->pkt_state)
73 #define INTEL_PT_STATE_ERR2 INTEL_PT_STATE_NO_IP
74 #define INTEL_PT_STATE_ERR3 INTEL_PT_STATE_ERR_RESYNC
75 #define INTEL_PT_STATE_ERR4 INTEL_PT_STATE_IN_SYNC
76 #endif
77
78 struct intel_pt_decoder {
79 int (*get_trace)(struct intel_pt_buffer *buffer, void *data);
80 int (*walk_insn)(struct intel_pt_insn *intel_pt_insn,
81 uint64_t *insn_cnt_ptr, uint64_t *ip, uint64_t to_ip,
82 uint64_t max_insn_cnt, void *data);
83 void *data;
84 struct intel_pt_state state;
85 const unsigned char *buf;
86 size_t len;
87 bool return_compression;
88 bool mtc_insn;
89 bool pge;
90 bool have_tma;
91 bool have_cyc;
92 uint64_t pos;
93 uint64_t last_ip;
94 uint64_t ip;
95 uint64_t cr3;
96 uint64_t timestamp;
97 uint64_t tsc_timestamp;
98 uint64_t ref_timestamp;
99 uint64_t ret_addr;
100 uint64_t ctc_timestamp;
101 uint64_t ctc_delta;
102 uint64_t cycle_cnt;
103 uint64_t cyc_ref_timestamp;
104 uint32_t last_mtc;
105 uint32_t tsc_ctc_ratio_n;
106 uint32_t tsc_ctc_ratio_d;
107 uint32_t tsc_ctc_mult;
108 uint32_t tsc_slip;
109 uint32_t ctc_rem_mask;
110 int mtc_shift;
111 struct intel_pt_stack stack;
112 enum intel_pt_pkt_state pkt_state;
113 struct intel_pt_pkt packet;
114 struct intel_pt_pkt tnt;
115 int pkt_step;
116 int pkt_len;
117 int last_packet_type;
118 unsigned int cbr;
119 unsigned int max_non_turbo_ratio;
120 double max_non_turbo_ratio_fp;
121 double cbr_cyc_to_tsc;
122 double calc_cyc_to_tsc;
123 bool have_calc_cyc_to_tsc;
124 int exec_mode;
125 unsigned int insn_bytes;
126 uint64_t sign_bit;
127 uint64_t sign_bits;
128 uint64_t period;
129 enum intel_pt_period_type period_type;
130 uint64_t tot_insn_cnt;
131 uint64_t period_insn_cnt;
132 uint64_t period_mask;
133 uint64_t period_ticks;
134 uint64_t last_masked_timestamp;
135 bool continuous_period;
136 bool overflow;
137 bool set_fup_tx_flags;
138 unsigned int fup_tx_flags;
139 unsigned int tx_flags;
140 uint64_t timestamp_insn_cnt;
141 uint64_t stuck_ip;
142 int no_progress;
143 int stuck_ip_prd;
144 int stuck_ip_cnt;
145 const unsigned char *next_buf;
146 size_t next_len;
147 unsigned char temp_buf[INTEL_PT_PKT_MAX_SZ];
148 };
149
150 static uint64_t intel_pt_lower_power_of_2(uint64_t x)
151 {
152 int i;
153
154 for (i = 0; x != 1; i++)
155 x >>= 1;
156
157 return x << i;
158 }
159
160 static void intel_pt_setup_period(struct intel_pt_decoder *decoder)
161 {
162 if (decoder->period_type == INTEL_PT_PERIOD_TICKS) {
163 uint64_t period;
164
165 period = intel_pt_lower_power_of_2(decoder->period);
166 decoder->period_mask = ~(period - 1);
167 decoder->period_ticks = period;
168 }
169 }
170
171 static uint64_t multdiv(uint64_t t, uint32_t n, uint32_t d)
172 {
173 if (!d)
174 return 0;
175 return (t / d) * n + ((t % d) * n) / d;
176 }
177
178 struct intel_pt_decoder *intel_pt_decoder_new(struct intel_pt_params *params)
179 {
180 struct intel_pt_decoder *decoder;
181
182 if (!params->get_trace || !params->walk_insn)
183 return NULL;
184
185 decoder = zalloc(sizeof(struct intel_pt_decoder));
186 if (!decoder)
187 return NULL;
188
189 decoder->get_trace = params->get_trace;
190 decoder->walk_insn = params->walk_insn;
191 decoder->data = params->data;
192 decoder->return_compression = params->return_compression;
193
194 decoder->sign_bit = (uint64_t)1 << 47;
195 decoder->sign_bits = ~(((uint64_t)1 << 48) - 1);
196
197 decoder->period = params->period;
198 decoder->period_type = params->period_type;
199
200 decoder->max_non_turbo_ratio = params->max_non_turbo_ratio;
201 decoder->max_non_turbo_ratio_fp = params->max_non_turbo_ratio;
202
203 intel_pt_setup_period(decoder);
204
205 decoder->mtc_shift = params->mtc_period;
206 decoder->ctc_rem_mask = (1 << decoder->mtc_shift) - 1;
207
208 decoder->tsc_ctc_ratio_n = params->tsc_ctc_ratio_n;
209 decoder->tsc_ctc_ratio_d = params->tsc_ctc_ratio_d;
210
211 if (!decoder->tsc_ctc_ratio_n)
212 decoder->tsc_ctc_ratio_d = 0;
213
214 if (decoder->tsc_ctc_ratio_d) {
215 if (!(decoder->tsc_ctc_ratio_n % decoder->tsc_ctc_ratio_d))
216 decoder->tsc_ctc_mult = decoder->tsc_ctc_ratio_n /
217 decoder->tsc_ctc_ratio_d;
218
219 /*
220 * Allow for timestamps appearing to backwards because a TSC
221 * packet has slipped past a MTC packet, so allow 2 MTC ticks
222 * or ...
223 */
224 decoder->tsc_slip = multdiv(2 << decoder->mtc_shift,
225 decoder->tsc_ctc_ratio_n,
226 decoder->tsc_ctc_ratio_d);
227 }
228 /* ... or 0x100 paranoia */
229 if (decoder->tsc_slip < 0x100)
230 decoder->tsc_slip = 0x100;
231
232 intel_pt_log("timestamp: mtc_shift %u\n", decoder->mtc_shift);
233 intel_pt_log("timestamp: tsc_ctc_ratio_n %u\n", decoder->tsc_ctc_ratio_n);
234 intel_pt_log("timestamp: tsc_ctc_ratio_d %u\n", decoder->tsc_ctc_ratio_d);
235 intel_pt_log("timestamp: tsc_ctc_mult %u\n", decoder->tsc_ctc_mult);
236 intel_pt_log("timestamp: tsc_slip %#x\n", decoder->tsc_slip);
237
238 return decoder;
239 }
240
241 static void intel_pt_pop_blk(struct intel_pt_stack *stack)
242 {
243 struct intel_pt_blk *blk = stack->blk;
244
245 stack->blk = blk->prev;
246 if (!stack->spare)
247 stack->spare = blk;
248 else
249 free(blk);
250 }
251
252 static uint64_t intel_pt_pop(struct intel_pt_stack *stack)
253 {
254 if (!stack->pos) {
255 if (!stack->blk)
256 return 0;
257 intel_pt_pop_blk(stack);
258 if (!stack->blk)
259 return 0;
260 stack->pos = INTEL_PT_BLK_SIZE;
261 }
262 return stack->blk->ip[--stack->pos];
263 }
264
265 static int intel_pt_alloc_blk(struct intel_pt_stack *stack)
266 {
267 struct intel_pt_blk *blk;
268
269 if (stack->spare) {
270 blk = stack->spare;
271 stack->spare = NULL;
272 } else {
273 blk = malloc(sizeof(struct intel_pt_blk));
274 if (!blk)
275 return -ENOMEM;
276 }
277
278 blk->prev = stack->blk;
279 stack->blk = blk;
280 stack->pos = 0;
281 return 0;
282 }
283
284 static int intel_pt_push(struct intel_pt_stack *stack, uint64_t ip)
285 {
286 int err;
287
288 if (!stack->blk || stack->pos == INTEL_PT_BLK_SIZE) {
289 err = intel_pt_alloc_blk(stack);
290 if (err)
291 return err;
292 }
293
294 stack->blk->ip[stack->pos++] = ip;
295 return 0;
296 }
297
298 static void intel_pt_clear_stack(struct intel_pt_stack *stack)
299 {
300 while (stack->blk)
301 intel_pt_pop_blk(stack);
302 stack->pos = 0;
303 }
304
305 static void intel_pt_free_stack(struct intel_pt_stack *stack)
306 {
307 intel_pt_clear_stack(stack);
308 zfree(&stack->blk);
309 zfree(&stack->spare);
310 }
311
312 void intel_pt_decoder_free(struct intel_pt_decoder *decoder)
313 {
314 intel_pt_free_stack(&decoder->stack);
315 free(decoder);
316 }
317
318 static int intel_pt_ext_err(int code)
319 {
320 switch (code) {
321 case -ENOMEM:
322 return INTEL_PT_ERR_NOMEM;
323 case -ENOSYS:
324 return INTEL_PT_ERR_INTERN;
325 case -EBADMSG:
326 return INTEL_PT_ERR_BADPKT;
327 case -ENODATA:
328 return INTEL_PT_ERR_NODATA;
329 case -EILSEQ:
330 return INTEL_PT_ERR_NOINSN;
331 case -ENOENT:
332 return INTEL_PT_ERR_MISMAT;
333 case -EOVERFLOW:
334 return INTEL_PT_ERR_OVR;
335 case -ENOSPC:
336 return INTEL_PT_ERR_LOST;
337 case -ELOOP:
338 return INTEL_PT_ERR_NELOOP;
339 default:
340 return INTEL_PT_ERR_UNK;
341 }
342 }
343
344 static const char *intel_pt_err_msgs[] = {
345 [INTEL_PT_ERR_NOMEM] = "Memory allocation failed",
346 [INTEL_PT_ERR_INTERN] = "Internal error",
347 [INTEL_PT_ERR_BADPKT] = "Bad packet",
348 [INTEL_PT_ERR_NODATA] = "No more data",
349 [INTEL_PT_ERR_NOINSN] = "Failed to get instruction",
350 [INTEL_PT_ERR_MISMAT] = "Trace doesn't match instruction",
351 [INTEL_PT_ERR_OVR] = "Overflow packet",
352 [INTEL_PT_ERR_LOST] = "Lost trace data",
353 [INTEL_PT_ERR_UNK] = "Unknown error!",
354 [INTEL_PT_ERR_NELOOP] = "Never-ending loop",
355 };
356
357 int intel_pt__strerror(int code, char *buf, size_t buflen)
358 {
359 if (code < 1 || code > INTEL_PT_ERR_MAX)
360 code = INTEL_PT_ERR_UNK;
361 strlcpy(buf, intel_pt_err_msgs[code], buflen);
362 return 0;
363 }
364
365 static uint64_t intel_pt_calc_ip(struct intel_pt_decoder *decoder,
366 const struct intel_pt_pkt *packet,
367 uint64_t last_ip)
368 {
369 uint64_t ip;
370
371 switch (packet->count) {
372 case 2:
373 ip = (last_ip & (uint64_t)0xffffffffffff0000ULL) |
374 packet->payload;
375 break;
376 case 4:
377 ip = (last_ip & (uint64_t)0xffffffff00000000ULL) |
378 packet->payload;
379 break;
380 case 6:
381 ip = packet->payload;
382 break;
383 default:
384 return 0;
385 }
386
387 if (ip & decoder->sign_bit)
388 return ip | decoder->sign_bits;
389
390 return ip;
391 }
392
393 static inline void intel_pt_set_last_ip(struct intel_pt_decoder *decoder)
394 {
395 decoder->last_ip = intel_pt_calc_ip(decoder, &decoder->packet,
396 decoder->last_ip);
397 }
398
399 static inline void intel_pt_set_ip(struct intel_pt_decoder *decoder)
400 {
401 intel_pt_set_last_ip(decoder);
402 decoder->ip = decoder->last_ip;
403 }
404
405 static void intel_pt_decoder_log_packet(struct intel_pt_decoder *decoder)
406 {
407 intel_pt_log_packet(&decoder->packet, decoder->pkt_len, decoder->pos,
408 decoder->buf);
409 }
410
411 static int intel_pt_bug(struct intel_pt_decoder *decoder)
412 {
413 intel_pt_log("ERROR: Internal error\n");
414 decoder->pkt_state = INTEL_PT_STATE_NO_PSB;
415 return -ENOSYS;
416 }
417
418 static inline void intel_pt_clear_tx_flags(struct intel_pt_decoder *decoder)
419 {
420 decoder->tx_flags = 0;
421 }
422
423 static inline void intel_pt_update_in_tx(struct intel_pt_decoder *decoder)
424 {
425 decoder->tx_flags = decoder->packet.payload & INTEL_PT_IN_TX;
426 }
427
428 static int intel_pt_bad_packet(struct intel_pt_decoder *decoder)
429 {
430 intel_pt_clear_tx_flags(decoder);
431 decoder->have_tma = false;
432 decoder->pkt_len = 1;
433 decoder->pkt_step = 1;
434 intel_pt_decoder_log_packet(decoder);
435 if (decoder->pkt_state != INTEL_PT_STATE_NO_PSB) {
436 intel_pt_log("ERROR: Bad packet\n");
437 decoder->pkt_state = INTEL_PT_STATE_ERR1;
438 }
439 return -EBADMSG;
440 }
441
442 static int intel_pt_get_data(struct intel_pt_decoder *decoder)
443 {
444 struct intel_pt_buffer buffer = { .buf = 0, };
445 int ret;
446
447 decoder->pkt_step = 0;
448
449 intel_pt_log("Getting more data\n");
450 ret = decoder->get_trace(&buffer, decoder->data);
451 if (ret)
452 return ret;
453 decoder->buf = buffer.buf;
454 decoder->len = buffer.len;
455 if (!decoder->len) {
456 intel_pt_log("No more data\n");
457 return -ENODATA;
458 }
459 if (!buffer.consecutive) {
460 decoder->ip = 0;
461 decoder->pkt_state = INTEL_PT_STATE_NO_PSB;
462 decoder->ref_timestamp = buffer.ref_timestamp;
463 decoder->timestamp = 0;
464 decoder->have_tma = false;
465 decoder->state.trace_nr = buffer.trace_nr;
466 intel_pt_log("Reference timestamp 0x%" PRIx64 "\n",
467 decoder->ref_timestamp);
468 return -ENOLINK;
469 }
470
471 return 0;
472 }
473
474 static int intel_pt_get_next_data(struct intel_pt_decoder *decoder)
475 {
476 if (!decoder->next_buf)
477 return intel_pt_get_data(decoder);
478
479 decoder->buf = decoder->next_buf;
480 decoder->len = decoder->next_len;
481 decoder->next_buf = 0;
482 decoder->next_len = 0;
483 return 0;
484 }
485
486 static int intel_pt_get_split_packet(struct intel_pt_decoder *decoder)
487 {
488 unsigned char *buf = decoder->temp_buf;
489 size_t old_len, len, n;
490 int ret;
491
492 old_len = decoder->len;
493 len = decoder->len;
494 memcpy(buf, decoder->buf, len);
495
496 ret = intel_pt_get_data(decoder);
497 if (ret) {
498 decoder->pos += old_len;
499 return ret < 0 ? ret : -EINVAL;
500 }
501
502 n = INTEL_PT_PKT_MAX_SZ - len;
503 if (n > decoder->len)
504 n = decoder->len;
505 memcpy(buf + len, decoder->buf, n);
506 len += n;
507
508 ret = intel_pt_get_packet(buf, len, &decoder->packet);
509 if (ret < (int)old_len) {
510 decoder->next_buf = decoder->buf;
511 decoder->next_len = decoder->len;
512 decoder->buf = buf;
513 decoder->len = old_len;
514 return intel_pt_bad_packet(decoder);
515 }
516
517 decoder->next_buf = decoder->buf + (ret - old_len);
518 decoder->next_len = decoder->len - (ret - old_len);
519
520 decoder->buf = buf;
521 decoder->len = ret;
522
523 return ret;
524 }
525
526 struct intel_pt_pkt_info {
527 struct intel_pt_decoder *decoder;
528 struct intel_pt_pkt packet;
529 uint64_t pos;
530 int pkt_len;
531 int last_packet_type;
532 void *data;
533 };
534
535 typedef int (*intel_pt_pkt_cb_t)(struct intel_pt_pkt_info *pkt_info);
536
537 /* Lookahead packets in current buffer */
538 static int intel_pt_pkt_lookahead(struct intel_pt_decoder *decoder,
539 intel_pt_pkt_cb_t cb, void *data)
540 {
541 struct intel_pt_pkt_info pkt_info;
542 const unsigned char *buf = decoder->buf;
543 size_t len = decoder->len;
544 int ret;
545
546 pkt_info.decoder = decoder;
547 pkt_info.pos = decoder->pos;
548 pkt_info.pkt_len = decoder->pkt_step;
549 pkt_info.last_packet_type = decoder->last_packet_type;
550 pkt_info.data = data;
551
552 while (1) {
553 do {
554 pkt_info.pos += pkt_info.pkt_len;
555 buf += pkt_info.pkt_len;
556 len -= pkt_info.pkt_len;
557
558 if (!len)
559 return INTEL_PT_NEED_MORE_BYTES;
560
561 ret = intel_pt_get_packet(buf, len, &pkt_info.packet);
562 if (!ret)
563 return INTEL_PT_NEED_MORE_BYTES;
564 if (ret < 0)
565 return ret;
566
567 pkt_info.pkt_len = ret;
568 } while (pkt_info.packet.type == INTEL_PT_PAD);
569
570 ret = cb(&pkt_info);
571 if (ret)
572 return 0;
573
574 pkt_info.last_packet_type = pkt_info.packet.type;
575 }
576 }
577
578 struct intel_pt_calc_cyc_to_tsc_info {
579 uint64_t cycle_cnt;
580 unsigned int cbr;
581 uint32_t last_mtc;
582 uint64_t ctc_timestamp;
583 uint64_t ctc_delta;
584 uint64_t tsc_timestamp;
585 uint64_t timestamp;
586 bool have_tma;
587 bool from_mtc;
588 double cbr_cyc_to_tsc;
589 };
590
591 static int intel_pt_calc_cyc_cb(struct intel_pt_pkt_info *pkt_info)
592 {
593 struct intel_pt_decoder *decoder = pkt_info->decoder;
594 struct intel_pt_calc_cyc_to_tsc_info *data = pkt_info->data;
595 uint64_t timestamp;
596 double cyc_to_tsc;
597 unsigned int cbr;
598 uint32_t mtc, mtc_delta, ctc, fc, ctc_rem;
599
600 switch (pkt_info->packet.type) {
601 case INTEL_PT_TNT:
602 case INTEL_PT_TIP_PGE:
603 case INTEL_PT_TIP:
604 case INTEL_PT_FUP:
605 case INTEL_PT_PSB:
606 case INTEL_PT_PIP:
607 case INTEL_PT_MODE_EXEC:
608 case INTEL_PT_MODE_TSX:
609 case INTEL_PT_PSBEND:
610 case INTEL_PT_PAD:
611 case INTEL_PT_VMCS:
612 case INTEL_PT_MNT:
613 return 0;
614
615 case INTEL_PT_MTC:
616 if (!data->have_tma)
617 return 0;
618
619 mtc = pkt_info->packet.payload;
620 if (mtc > data->last_mtc)
621 mtc_delta = mtc - data->last_mtc;
622 else
623 mtc_delta = mtc + 256 - data->last_mtc;
624 data->ctc_delta += mtc_delta << decoder->mtc_shift;
625 data->last_mtc = mtc;
626
627 if (decoder->tsc_ctc_mult) {
628 timestamp = data->ctc_timestamp +
629 data->ctc_delta * decoder->tsc_ctc_mult;
630 } else {
631 timestamp = data->ctc_timestamp +
632 multdiv(data->ctc_delta,
633 decoder->tsc_ctc_ratio_n,
634 decoder->tsc_ctc_ratio_d);
635 }
636
637 if (timestamp < data->timestamp)
638 return 1;
639
640 if (pkt_info->last_packet_type != INTEL_PT_CYC) {
641 data->timestamp = timestamp;
642 return 0;
643 }
644
645 break;
646
647 case INTEL_PT_TSC:
648 timestamp = pkt_info->packet.payload |
649 (data->timestamp & (0xffULL << 56));
650 if (data->from_mtc && timestamp < data->timestamp &&
651 data->timestamp - timestamp < decoder->tsc_slip)
652 return 1;
653 if (timestamp < data->timestamp)
654 timestamp += (1ULL << 56);
655 if (pkt_info->last_packet_type != INTEL_PT_CYC) {
656 if (data->from_mtc)
657 return 1;
658 data->tsc_timestamp = timestamp;
659 data->timestamp = timestamp;
660 return 0;
661 }
662 break;
663
664 case INTEL_PT_TMA:
665 if (data->from_mtc)
666 return 1;
667
668 if (!decoder->tsc_ctc_ratio_d)
669 return 0;
670
671 ctc = pkt_info->packet.payload;
672 fc = pkt_info->packet.count;
673 ctc_rem = ctc & decoder->ctc_rem_mask;
674
675 data->last_mtc = (ctc >> decoder->mtc_shift) & 0xff;
676
677 data->ctc_timestamp = data->tsc_timestamp - fc;
678 if (decoder->tsc_ctc_mult) {
679 data->ctc_timestamp -= ctc_rem * decoder->tsc_ctc_mult;
680 } else {
681 data->ctc_timestamp -=
682 multdiv(ctc_rem, decoder->tsc_ctc_ratio_n,
683 decoder->tsc_ctc_ratio_d);
684 }
685
686 data->ctc_delta = 0;
687 data->have_tma = true;
688
689 return 0;
690
691 case INTEL_PT_CYC:
692 data->cycle_cnt += pkt_info->packet.payload;
693 return 0;
694
695 case INTEL_PT_CBR:
696 cbr = pkt_info->packet.payload;
697 if (data->cbr && data->cbr != cbr)
698 return 1;
699 data->cbr = cbr;
700 data->cbr_cyc_to_tsc = decoder->max_non_turbo_ratio_fp / cbr;
701 return 0;
702
703 case INTEL_PT_TIP_PGD:
704 case INTEL_PT_TRACESTOP:
705 case INTEL_PT_OVF:
706 case INTEL_PT_BAD: /* Does not happen */
707 default:
708 return 1;
709 }
710
711 if (!data->cbr && decoder->cbr) {
712 data->cbr = decoder->cbr;
713 data->cbr_cyc_to_tsc = decoder->cbr_cyc_to_tsc;
714 }
715
716 if (!data->cycle_cnt)
717 return 1;
718
719 cyc_to_tsc = (double)(timestamp - decoder->timestamp) / data->cycle_cnt;
720
721 if (data->cbr && cyc_to_tsc > data->cbr_cyc_to_tsc &&
722 cyc_to_tsc / data->cbr_cyc_to_tsc > 1.25) {
723 intel_pt_log("Timestamp: calculated %g TSC ticks per cycle too big (c.f. CBR-based value %g), pos " x64_fmt "\n",
724 cyc_to_tsc, data->cbr_cyc_to_tsc, pkt_info->pos);
725 return 1;
726 }
727
728 decoder->calc_cyc_to_tsc = cyc_to_tsc;
729 decoder->have_calc_cyc_to_tsc = true;
730
731 if (data->cbr) {
732 intel_pt_log("Timestamp: calculated %g TSC ticks per cycle c.f. CBR-based value %g, pos " x64_fmt "\n",
733 cyc_to_tsc, data->cbr_cyc_to_tsc, pkt_info->pos);
734 } else {
735 intel_pt_log("Timestamp: calculated %g TSC ticks per cycle c.f. unknown CBR-based value, pos " x64_fmt "\n",
736 cyc_to_tsc, pkt_info->pos);
737 }
738
739 return 1;
740 }
741
742 static void intel_pt_calc_cyc_to_tsc(struct intel_pt_decoder *decoder,
743 bool from_mtc)
744 {
745 struct intel_pt_calc_cyc_to_tsc_info data = {
746 .cycle_cnt = 0,
747 .cbr = 0,
748 .last_mtc = decoder->last_mtc,
749 .ctc_timestamp = decoder->ctc_timestamp,
750 .ctc_delta = decoder->ctc_delta,
751 .tsc_timestamp = decoder->tsc_timestamp,
752 .timestamp = decoder->timestamp,
753 .have_tma = decoder->have_tma,
754 .from_mtc = from_mtc,
755 .cbr_cyc_to_tsc = 0,
756 };
757
758 intel_pt_pkt_lookahead(decoder, intel_pt_calc_cyc_cb, &data);
759 }
760
761 static int intel_pt_get_next_packet(struct intel_pt_decoder *decoder)
762 {
763 int ret;
764
765 decoder->last_packet_type = decoder->packet.type;
766
767 do {
768 decoder->pos += decoder->pkt_step;
769 decoder->buf += decoder->pkt_step;
770 decoder->len -= decoder->pkt_step;
771
772 if (!decoder->len) {
773 ret = intel_pt_get_next_data(decoder);
774 if (ret)
775 return ret;
776 }
777
778 ret = intel_pt_get_packet(decoder->buf, decoder->len,
779 &decoder->packet);
780 if (ret == INTEL_PT_NEED_MORE_BYTES &&
781 decoder->len < INTEL_PT_PKT_MAX_SZ && !decoder->next_buf) {
782 ret = intel_pt_get_split_packet(decoder);
783 if (ret < 0)
784 return ret;
785 }
786 if (ret <= 0)
787 return intel_pt_bad_packet(decoder);
788
789 decoder->pkt_len = ret;
790 decoder->pkt_step = ret;
791 intel_pt_decoder_log_packet(decoder);
792 } while (decoder->packet.type == INTEL_PT_PAD);
793
794 return 0;
795 }
796
797 static uint64_t intel_pt_next_period(struct intel_pt_decoder *decoder)
798 {
799 uint64_t timestamp, masked_timestamp;
800
801 timestamp = decoder->timestamp + decoder->timestamp_insn_cnt;
802 masked_timestamp = timestamp & decoder->period_mask;
803 if (decoder->continuous_period) {
804 if (masked_timestamp != decoder->last_masked_timestamp)
805 return 1;
806 } else {
807 timestamp += 1;
808 masked_timestamp = timestamp & decoder->period_mask;
809 if (masked_timestamp != decoder->last_masked_timestamp) {
810 decoder->last_masked_timestamp = masked_timestamp;
811 decoder->continuous_period = true;
812 }
813 }
814 return decoder->period_ticks - (timestamp - masked_timestamp);
815 }
816
817 static uint64_t intel_pt_next_sample(struct intel_pt_decoder *decoder)
818 {
819 switch (decoder->period_type) {
820 case INTEL_PT_PERIOD_INSTRUCTIONS:
821 return decoder->period - decoder->period_insn_cnt;
822 case INTEL_PT_PERIOD_TICKS:
823 return intel_pt_next_period(decoder);
824 case INTEL_PT_PERIOD_NONE:
825 case INTEL_PT_PERIOD_MTC:
826 default:
827 return 0;
828 }
829 }
830
831 static void intel_pt_sample_insn(struct intel_pt_decoder *decoder)
832 {
833 uint64_t timestamp, masked_timestamp;
834
835 switch (decoder->period_type) {
836 case INTEL_PT_PERIOD_INSTRUCTIONS:
837 decoder->period_insn_cnt = 0;
838 break;
839 case INTEL_PT_PERIOD_TICKS:
840 timestamp = decoder->timestamp + decoder->timestamp_insn_cnt;
841 masked_timestamp = timestamp & decoder->period_mask;
842 decoder->last_masked_timestamp = masked_timestamp;
843 break;
844 case INTEL_PT_PERIOD_NONE:
845 case INTEL_PT_PERIOD_MTC:
846 default:
847 break;
848 }
849
850 decoder->state.type |= INTEL_PT_INSTRUCTION;
851 }
852
853 static int intel_pt_walk_insn(struct intel_pt_decoder *decoder,
854 struct intel_pt_insn *intel_pt_insn, uint64_t ip)
855 {
856 uint64_t max_insn_cnt, insn_cnt = 0;
857 int err;
858
859 if (!decoder->mtc_insn)
860 decoder->mtc_insn = true;
861
862 max_insn_cnt = intel_pt_next_sample(decoder);
863
864 err = decoder->walk_insn(intel_pt_insn, &insn_cnt, &decoder->ip, ip,
865 max_insn_cnt, decoder->data);
866
867 decoder->tot_insn_cnt += insn_cnt;
868 decoder->timestamp_insn_cnt += insn_cnt;
869 decoder->period_insn_cnt += insn_cnt;
870
871 if (err) {
872 decoder->no_progress = 0;
873 decoder->pkt_state = INTEL_PT_STATE_ERR2;
874 intel_pt_log_at("ERROR: Failed to get instruction",
875 decoder->ip);
876 if (err == -ENOENT)
877 return -ENOLINK;
878 return -EILSEQ;
879 }
880
881 if (ip && decoder->ip == ip) {
882 err = -EAGAIN;
883 goto out;
884 }
885
886 if (max_insn_cnt && insn_cnt >= max_insn_cnt)
887 intel_pt_sample_insn(decoder);
888
889 if (intel_pt_insn->branch == INTEL_PT_BR_NO_BRANCH) {
890 decoder->state.type = INTEL_PT_INSTRUCTION;
891 decoder->state.from_ip = decoder->ip;
892 decoder->state.to_ip = 0;
893 decoder->ip += intel_pt_insn->length;
894 err = INTEL_PT_RETURN;
895 goto out;
896 }
897
898 if (intel_pt_insn->op == INTEL_PT_OP_CALL) {
899 /* Zero-length calls are excluded */
900 if (intel_pt_insn->branch != INTEL_PT_BR_UNCONDITIONAL ||
901 intel_pt_insn->rel) {
902 err = intel_pt_push(&decoder->stack, decoder->ip +
903 intel_pt_insn->length);
904 if (err)
905 goto out;
906 }
907 } else if (intel_pt_insn->op == INTEL_PT_OP_RET) {
908 decoder->ret_addr = intel_pt_pop(&decoder->stack);
909 }
910
911 if (intel_pt_insn->branch == INTEL_PT_BR_UNCONDITIONAL) {
912 int cnt = decoder->no_progress++;
913
914 decoder->state.from_ip = decoder->ip;
915 decoder->ip += intel_pt_insn->length +
916 intel_pt_insn->rel;
917 decoder->state.to_ip = decoder->ip;
918 err = INTEL_PT_RETURN;
919
920 /*
921 * Check for being stuck in a loop. This can happen if a
922 * decoder error results in the decoder erroneously setting the
923 * ip to an address that is itself in an infinite loop that
924 * consumes no packets. When that happens, there must be an
925 * unconditional branch.
926 */
927 if (cnt) {
928 if (cnt == 1) {
929 decoder->stuck_ip = decoder->state.to_ip;
930 decoder->stuck_ip_prd = 1;
931 decoder->stuck_ip_cnt = 1;
932 } else if (cnt > INTEL_PT_MAX_LOOPS ||
933 decoder->state.to_ip == decoder->stuck_ip) {
934 intel_pt_log_at("ERROR: Never-ending loop",
935 decoder->state.to_ip);
936 decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
937 err = -ELOOP;
938 goto out;
939 } else if (!--decoder->stuck_ip_cnt) {
940 decoder->stuck_ip_prd += 1;
941 decoder->stuck_ip_cnt = decoder->stuck_ip_prd;
942 decoder->stuck_ip = decoder->state.to_ip;
943 }
944 }
945 goto out_no_progress;
946 }
947 out:
948 decoder->no_progress = 0;
949 out_no_progress:
950 decoder->state.insn_op = intel_pt_insn->op;
951 decoder->state.insn_len = intel_pt_insn->length;
952
953 if (decoder->tx_flags & INTEL_PT_IN_TX)
954 decoder->state.flags |= INTEL_PT_IN_TX;
955
956 return err;
957 }
958
959 static int intel_pt_walk_fup(struct intel_pt_decoder *decoder)
960 {
961 struct intel_pt_insn intel_pt_insn;
962 uint64_t ip;
963 int err;
964
965 ip = decoder->last_ip;
966
967 while (1) {
968 err = intel_pt_walk_insn(decoder, &intel_pt_insn, ip);
969 if (err == INTEL_PT_RETURN)
970 return 0;
971 if (err == -EAGAIN) {
972 if (decoder->set_fup_tx_flags) {
973 decoder->set_fup_tx_flags = false;
974 decoder->tx_flags = decoder->fup_tx_flags;
975 decoder->state.type = INTEL_PT_TRANSACTION;
976 decoder->state.from_ip = decoder->ip;
977 decoder->state.to_ip = 0;
978 decoder->state.flags = decoder->fup_tx_flags;
979 return 0;
980 }
981 return err;
982 }
983 decoder->set_fup_tx_flags = false;
984 if (err)
985 return err;
986
987 if (intel_pt_insn.branch == INTEL_PT_BR_INDIRECT) {
988 intel_pt_log_at("ERROR: Unexpected indirect branch",
989 decoder->ip);
990 decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
991 return -ENOENT;
992 }
993
994 if (intel_pt_insn.branch == INTEL_PT_BR_CONDITIONAL) {
995 intel_pt_log_at("ERROR: Unexpected conditional branch",
996 decoder->ip);
997 decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
998 return -ENOENT;
999 }
1000
1001 intel_pt_bug(decoder);
1002 }
1003 }
1004
1005 static int intel_pt_walk_tip(struct intel_pt_decoder *decoder)
1006 {
1007 struct intel_pt_insn intel_pt_insn;
1008 int err;
1009
1010 err = intel_pt_walk_insn(decoder, &intel_pt_insn, 0);
1011 if (err == INTEL_PT_RETURN)
1012 return 0;
1013 if (err)
1014 return err;
1015
1016 if (intel_pt_insn.branch == INTEL_PT_BR_INDIRECT) {
1017 if (decoder->pkt_state == INTEL_PT_STATE_TIP_PGD) {
1018 decoder->pge = false;
1019 decoder->continuous_period = false;
1020 decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1021 decoder->state.from_ip = decoder->ip;
1022 decoder->state.to_ip = 0;
1023 if (decoder->packet.count != 0)
1024 decoder->ip = decoder->last_ip;
1025 } else {
1026 decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1027 decoder->state.from_ip = decoder->ip;
1028 if (decoder->packet.count == 0) {
1029 decoder->state.to_ip = 0;
1030 } else {
1031 decoder->state.to_ip = decoder->last_ip;
1032 decoder->ip = decoder->last_ip;
1033 }
1034 }
1035 return 0;
1036 }
1037
1038 if (intel_pt_insn.branch == INTEL_PT_BR_CONDITIONAL) {
1039 intel_pt_log_at("ERROR: Conditional branch when expecting indirect branch",
1040 decoder->ip);
1041 decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
1042 return -ENOENT;
1043 }
1044
1045 return intel_pt_bug(decoder);
1046 }
1047
1048 static int intel_pt_walk_tnt(struct intel_pt_decoder *decoder)
1049 {
1050 struct intel_pt_insn intel_pt_insn;
1051 int err;
1052
1053 while (1) {
1054 err = intel_pt_walk_insn(decoder, &intel_pt_insn, 0);
1055 if (err == INTEL_PT_RETURN)
1056 return 0;
1057 if (err)
1058 return err;
1059
1060 if (intel_pt_insn.op == INTEL_PT_OP_RET) {
1061 if (!decoder->return_compression) {
1062 intel_pt_log_at("ERROR: RET when expecting conditional branch",
1063 decoder->ip);
1064 decoder->pkt_state = INTEL_PT_STATE_ERR3;
1065 return -ENOENT;
1066 }
1067 if (!decoder->ret_addr) {
1068 intel_pt_log_at("ERROR: Bad RET compression (stack empty)",
1069 decoder->ip);
1070 decoder->pkt_state = INTEL_PT_STATE_ERR3;
1071 return -ENOENT;
1072 }
1073 if (!(decoder->tnt.payload & BIT63)) {
1074 intel_pt_log_at("ERROR: Bad RET compression (TNT=N)",
1075 decoder->ip);
1076 decoder->pkt_state = INTEL_PT_STATE_ERR3;
1077 return -ENOENT;
1078 }
1079 decoder->tnt.count -= 1;
1080 if (!decoder->tnt.count)
1081 decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1082 decoder->tnt.payload <<= 1;
1083 decoder->state.from_ip = decoder->ip;
1084 decoder->ip = decoder->ret_addr;
1085 decoder->state.to_ip = decoder->ip;
1086 return 0;
1087 }
1088
1089 if (intel_pt_insn.branch == INTEL_PT_BR_INDIRECT) {
1090 /* Handle deferred TIPs */
1091 err = intel_pt_get_next_packet(decoder);
1092 if (err)
1093 return err;
1094 if (decoder->packet.type != INTEL_PT_TIP ||
1095 decoder->packet.count == 0) {
1096 intel_pt_log_at("ERROR: Missing deferred TIP for indirect branch",
1097 decoder->ip);
1098 decoder->pkt_state = INTEL_PT_STATE_ERR3;
1099 decoder->pkt_step = 0;
1100 return -ENOENT;
1101 }
1102 intel_pt_set_last_ip(decoder);
1103 decoder->state.from_ip = decoder->ip;
1104 decoder->state.to_ip = decoder->last_ip;
1105 decoder->ip = decoder->last_ip;
1106 return 0;
1107 }
1108
1109 if (intel_pt_insn.branch == INTEL_PT_BR_CONDITIONAL) {
1110 decoder->tnt.count -= 1;
1111 if (!decoder->tnt.count)
1112 decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1113 if (decoder->tnt.payload & BIT63) {
1114 decoder->tnt.payload <<= 1;
1115 decoder->state.from_ip = decoder->ip;
1116 decoder->ip += intel_pt_insn.length +
1117 intel_pt_insn.rel;
1118 decoder->state.to_ip = decoder->ip;
1119 return 0;
1120 }
1121 /* Instruction sample for a non-taken branch */
1122 if (decoder->state.type & INTEL_PT_INSTRUCTION) {
1123 decoder->tnt.payload <<= 1;
1124 decoder->state.type = INTEL_PT_INSTRUCTION;
1125 decoder->state.from_ip = decoder->ip;
1126 decoder->state.to_ip = 0;
1127 decoder->ip += intel_pt_insn.length;
1128 return 0;
1129 }
1130 decoder->ip += intel_pt_insn.length;
1131 if (!decoder->tnt.count)
1132 return -EAGAIN;
1133 decoder->tnt.payload <<= 1;
1134 continue;
1135 }
1136
1137 return intel_pt_bug(decoder);
1138 }
1139 }
1140
1141 static int intel_pt_mode_tsx(struct intel_pt_decoder *decoder, bool *no_tip)
1142 {
1143 unsigned int fup_tx_flags;
1144 int err;
1145
1146 fup_tx_flags = decoder->packet.payload &
1147 (INTEL_PT_IN_TX | INTEL_PT_ABORT_TX);
1148 err = intel_pt_get_next_packet(decoder);
1149 if (err)
1150 return err;
1151 if (decoder->packet.type == INTEL_PT_FUP) {
1152 decoder->fup_tx_flags = fup_tx_flags;
1153 decoder->set_fup_tx_flags = true;
1154 if (!(decoder->fup_tx_flags & INTEL_PT_ABORT_TX))
1155 *no_tip = true;
1156 } else {
1157 intel_pt_log_at("ERROR: Missing FUP after MODE.TSX",
1158 decoder->pos);
1159 intel_pt_update_in_tx(decoder);
1160 }
1161 return 0;
1162 }
1163
1164 static void intel_pt_calc_tsc_timestamp(struct intel_pt_decoder *decoder)
1165 {
1166 uint64_t timestamp;
1167
1168 decoder->have_tma = false;
1169
1170 if (decoder->ref_timestamp) {
1171 timestamp = decoder->packet.payload |
1172 (decoder->ref_timestamp & (0xffULL << 56));
1173 if (timestamp < decoder->ref_timestamp) {
1174 if (decoder->ref_timestamp - timestamp > (1ULL << 55))
1175 timestamp += (1ULL << 56);
1176 } else {
1177 if (timestamp - decoder->ref_timestamp > (1ULL << 55))
1178 timestamp -= (1ULL << 56);
1179 }
1180 decoder->tsc_timestamp = timestamp;
1181 decoder->timestamp = timestamp;
1182 decoder->ref_timestamp = 0;
1183 decoder->timestamp_insn_cnt = 0;
1184 } else if (decoder->timestamp) {
1185 timestamp = decoder->packet.payload |
1186 (decoder->timestamp & (0xffULL << 56));
1187 decoder->tsc_timestamp = timestamp;
1188 if (timestamp < decoder->timestamp &&
1189 decoder->timestamp - timestamp < decoder->tsc_slip) {
1190 intel_pt_log_to("Suppressing backwards timestamp",
1191 timestamp);
1192 timestamp = decoder->timestamp;
1193 }
1194 if (timestamp < decoder->timestamp) {
1195 intel_pt_log_to("Wraparound timestamp", timestamp);
1196 timestamp += (1ULL << 56);
1197 decoder->tsc_timestamp = timestamp;
1198 }
1199 decoder->timestamp = timestamp;
1200 decoder->timestamp_insn_cnt = 0;
1201 }
1202
1203 if (decoder->last_packet_type == INTEL_PT_CYC) {
1204 decoder->cyc_ref_timestamp = decoder->timestamp;
1205 decoder->cycle_cnt = 0;
1206 decoder->have_calc_cyc_to_tsc = false;
1207 intel_pt_calc_cyc_to_tsc(decoder, false);
1208 }
1209
1210 intel_pt_log_to("Setting timestamp", decoder->timestamp);
1211 }
1212
1213 static int intel_pt_overflow(struct intel_pt_decoder *decoder)
1214 {
1215 intel_pt_log("ERROR: Buffer overflow\n");
1216 intel_pt_clear_tx_flags(decoder);
1217 decoder->have_tma = false;
1218 decoder->cbr = 0;
1219 decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
1220 decoder->overflow = true;
1221 return -EOVERFLOW;
1222 }
1223
1224 static void intel_pt_calc_tma(struct intel_pt_decoder *decoder)
1225 {
1226 uint32_t ctc = decoder->packet.payload;
1227 uint32_t fc = decoder->packet.count;
1228 uint32_t ctc_rem = ctc & decoder->ctc_rem_mask;
1229
1230 if (!decoder->tsc_ctc_ratio_d)
1231 return;
1232
1233 decoder->last_mtc = (ctc >> decoder->mtc_shift) & 0xff;
1234 decoder->ctc_timestamp = decoder->tsc_timestamp - fc;
1235 if (decoder->tsc_ctc_mult) {
1236 decoder->ctc_timestamp -= ctc_rem * decoder->tsc_ctc_mult;
1237 } else {
1238 decoder->ctc_timestamp -= multdiv(ctc_rem,
1239 decoder->tsc_ctc_ratio_n,
1240 decoder->tsc_ctc_ratio_d);
1241 }
1242 decoder->ctc_delta = 0;
1243 decoder->have_tma = true;
1244 intel_pt_log("CTC timestamp " x64_fmt " last MTC %#x CTC rem %#x\n",
1245 decoder->ctc_timestamp, decoder->last_mtc, ctc_rem);
1246 }
1247
1248 static void intel_pt_calc_mtc_timestamp(struct intel_pt_decoder *decoder)
1249 {
1250 uint64_t timestamp;
1251 uint32_t mtc, mtc_delta;
1252
1253 if (!decoder->have_tma)
1254 return;
1255
1256 mtc = decoder->packet.payload;
1257
1258 if (mtc > decoder->last_mtc)
1259 mtc_delta = mtc - decoder->last_mtc;
1260 else
1261 mtc_delta = mtc + 256 - decoder->last_mtc;
1262
1263 decoder->ctc_delta += mtc_delta << decoder->mtc_shift;
1264
1265 if (decoder->tsc_ctc_mult) {
1266 timestamp = decoder->ctc_timestamp +
1267 decoder->ctc_delta * decoder->tsc_ctc_mult;
1268 } else {
1269 timestamp = decoder->ctc_timestamp +
1270 multdiv(decoder->ctc_delta,
1271 decoder->tsc_ctc_ratio_n,
1272 decoder->tsc_ctc_ratio_d);
1273 }
1274
1275 if (timestamp < decoder->timestamp)
1276 intel_pt_log("Suppressing MTC timestamp " x64_fmt " less than current timestamp " x64_fmt "\n",
1277 timestamp, decoder->timestamp);
1278 else
1279 decoder->timestamp = timestamp;
1280
1281 decoder->timestamp_insn_cnt = 0;
1282 decoder->last_mtc = mtc;
1283
1284 if (decoder->last_packet_type == INTEL_PT_CYC) {
1285 decoder->cyc_ref_timestamp = decoder->timestamp;
1286 decoder->cycle_cnt = 0;
1287 decoder->have_calc_cyc_to_tsc = false;
1288 intel_pt_calc_cyc_to_tsc(decoder, true);
1289 }
1290 }
1291
1292 static void intel_pt_calc_cbr(struct intel_pt_decoder *decoder)
1293 {
1294 unsigned int cbr = decoder->packet.payload;
1295
1296 if (decoder->cbr == cbr)
1297 return;
1298
1299 decoder->cbr = cbr;
1300 decoder->cbr_cyc_to_tsc = decoder->max_non_turbo_ratio_fp / cbr;
1301 }
1302
1303 static void intel_pt_calc_cyc_timestamp(struct intel_pt_decoder *decoder)
1304 {
1305 uint64_t timestamp = decoder->cyc_ref_timestamp;
1306
1307 decoder->have_cyc = true;
1308
1309 decoder->cycle_cnt += decoder->packet.payload;
1310
1311 if (!decoder->cyc_ref_timestamp)
1312 return;
1313
1314 if (decoder->have_calc_cyc_to_tsc)
1315 timestamp += decoder->cycle_cnt * decoder->calc_cyc_to_tsc;
1316 else if (decoder->cbr)
1317 timestamp += decoder->cycle_cnt * decoder->cbr_cyc_to_tsc;
1318 else
1319 return;
1320
1321 if (timestamp < decoder->timestamp)
1322 intel_pt_log("Suppressing CYC timestamp " x64_fmt " less than current timestamp " x64_fmt "\n",
1323 timestamp, decoder->timestamp);
1324 else
1325 decoder->timestamp = timestamp;
1326 }
1327
1328 /* Walk PSB+ packets when already in sync. */
1329 static int intel_pt_walk_psbend(struct intel_pt_decoder *decoder)
1330 {
1331 int err;
1332
1333 while (1) {
1334 err = intel_pt_get_next_packet(decoder);
1335 if (err)
1336 return err;
1337
1338 switch (decoder->packet.type) {
1339 case INTEL_PT_PSBEND:
1340 return 0;
1341
1342 case INTEL_PT_TIP_PGD:
1343 case INTEL_PT_TIP_PGE:
1344 case INTEL_PT_TIP:
1345 case INTEL_PT_TNT:
1346 case INTEL_PT_TRACESTOP:
1347 case INTEL_PT_BAD:
1348 case INTEL_PT_PSB:
1349 decoder->have_tma = false;
1350 intel_pt_log("ERROR: Unexpected packet\n");
1351 return -EAGAIN;
1352
1353 case INTEL_PT_OVF:
1354 return intel_pt_overflow(decoder);
1355
1356 case INTEL_PT_TSC:
1357 intel_pt_calc_tsc_timestamp(decoder);
1358 break;
1359
1360 case INTEL_PT_TMA:
1361 intel_pt_calc_tma(decoder);
1362 break;
1363
1364 case INTEL_PT_CBR:
1365 intel_pt_calc_cbr(decoder);
1366 break;
1367
1368 case INTEL_PT_MODE_EXEC:
1369 decoder->exec_mode = decoder->packet.payload;
1370 break;
1371
1372 case INTEL_PT_PIP:
1373 decoder->cr3 = decoder->packet.payload & (BIT63 - 1);
1374 break;
1375
1376 case INTEL_PT_FUP:
1377 decoder->pge = true;
1378 intel_pt_set_last_ip(decoder);
1379 break;
1380
1381 case INTEL_PT_MODE_TSX:
1382 intel_pt_update_in_tx(decoder);
1383 break;
1384
1385 case INTEL_PT_MTC:
1386 intel_pt_calc_mtc_timestamp(decoder);
1387 if (decoder->period_type == INTEL_PT_PERIOD_MTC)
1388 decoder->state.type |= INTEL_PT_INSTRUCTION;
1389 break;
1390
1391 case INTEL_PT_CYC:
1392 case INTEL_PT_VMCS:
1393 case INTEL_PT_MNT:
1394 case INTEL_PT_PAD:
1395 default:
1396 break;
1397 }
1398 }
1399 }
1400
1401 static int intel_pt_walk_fup_tip(struct intel_pt_decoder *decoder)
1402 {
1403 int err;
1404
1405 if (decoder->tx_flags & INTEL_PT_ABORT_TX) {
1406 decoder->tx_flags = 0;
1407 decoder->state.flags &= ~INTEL_PT_IN_TX;
1408 decoder->state.flags |= INTEL_PT_ABORT_TX;
1409 } else {
1410 decoder->state.flags |= INTEL_PT_ASYNC;
1411 }
1412
1413 while (1) {
1414 err = intel_pt_get_next_packet(decoder);
1415 if (err)
1416 return err;
1417
1418 switch (decoder->packet.type) {
1419 case INTEL_PT_TNT:
1420 case INTEL_PT_FUP:
1421 case INTEL_PT_TRACESTOP:
1422 case INTEL_PT_PSB:
1423 case INTEL_PT_TSC:
1424 case INTEL_PT_TMA:
1425 case INTEL_PT_CBR:
1426 case INTEL_PT_MODE_TSX:
1427 case INTEL_PT_BAD:
1428 case INTEL_PT_PSBEND:
1429 intel_pt_log("ERROR: Missing TIP after FUP\n");
1430 decoder->pkt_state = INTEL_PT_STATE_ERR3;
1431 return -ENOENT;
1432
1433 case INTEL_PT_OVF:
1434 return intel_pt_overflow(decoder);
1435
1436 case INTEL_PT_TIP_PGD:
1437 decoder->state.from_ip = decoder->ip;
1438 decoder->state.to_ip = 0;
1439 if (decoder->packet.count != 0) {
1440 intel_pt_set_ip(decoder);
1441 intel_pt_log("Omitting PGD ip " x64_fmt "\n",
1442 decoder->ip);
1443 }
1444 decoder->pge = false;
1445 decoder->continuous_period = false;
1446 return 0;
1447
1448 case INTEL_PT_TIP_PGE:
1449 decoder->pge = true;
1450 intel_pt_log("Omitting PGE ip " x64_fmt "\n",
1451 decoder->ip);
1452 decoder->state.from_ip = 0;
1453 if (decoder->packet.count == 0) {
1454 decoder->state.to_ip = 0;
1455 } else {
1456 intel_pt_set_ip(decoder);
1457 decoder->state.to_ip = decoder->ip;
1458 }
1459 return 0;
1460
1461 case INTEL_PT_TIP:
1462 decoder->state.from_ip = decoder->ip;
1463 if (decoder->packet.count == 0) {
1464 decoder->state.to_ip = 0;
1465 } else {
1466 intel_pt_set_ip(decoder);
1467 decoder->state.to_ip = decoder->ip;
1468 }
1469 return 0;
1470
1471 case INTEL_PT_PIP:
1472 decoder->cr3 = decoder->packet.payload & (BIT63 - 1);
1473 break;
1474
1475 case INTEL_PT_MTC:
1476 intel_pt_calc_mtc_timestamp(decoder);
1477 if (decoder->period_type == INTEL_PT_PERIOD_MTC)
1478 decoder->state.type |= INTEL_PT_INSTRUCTION;
1479 break;
1480
1481 case INTEL_PT_CYC:
1482 intel_pt_calc_cyc_timestamp(decoder);
1483 break;
1484
1485 case INTEL_PT_MODE_EXEC:
1486 decoder->exec_mode = decoder->packet.payload;
1487 break;
1488
1489 case INTEL_PT_VMCS:
1490 case INTEL_PT_MNT:
1491 case INTEL_PT_PAD:
1492 break;
1493
1494 default:
1495 return intel_pt_bug(decoder);
1496 }
1497 }
1498 }
1499
1500 static int intel_pt_walk_trace(struct intel_pt_decoder *decoder)
1501 {
1502 bool no_tip = false;
1503 int err;
1504
1505 while (1) {
1506 err = intel_pt_get_next_packet(decoder);
1507 if (err)
1508 return err;
1509 next:
1510 switch (decoder->packet.type) {
1511 case INTEL_PT_TNT:
1512 if (!decoder->packet.count)
1513 break;
1514 decoder->tnt = decoder->packet;
1515 decoder->pkt_state = INTEL_PT_STATE_TNT;
1516 err = intel_pt_walk_tnt(decoder);
1517 if (err == -EAGAIN)
1518 break;
1519 return err;
1520
1521 case INTEL_PT_TIP_PGD:
1522 if (decoder->packet.count != 0)
1523 intel_pt_set_last_ip(decoder);
1524 decoder->pkt_state = INTEL_PT_STATE_TIP_PGD;
1525 return intel_pt_walk_tip(decoder);
1526
1527 case INTEL_PT_TIP_PGE: {
1528 decoder->pge = true;
1529 if (decoder->packet.count == 0) {
1530 intel_pt_log_at("Skipping zero TIP.PGE",
1531 decoder->pos);
1532 break;
1533 }
1534 intel_pt_set_ip(decoder);
1535 decoder->state.from_ip = 0;
1536 decoder->state.to_ip = decoder->ip;
1537 return 0;
1538 }
1539
1540 case INTEL_PT_OVF:
1541 return intel_pt_overflow(decoder);
1542
1543 case INTEL_PT_TIP:
1544 if (decoder->packet.count != 0)
1545 intel_pt_set_last_ip(decoder);
1546 decoder->pkt_state = INTEL_PT_STATE_TIP;
1547 return intel_pt_walk_tip(decoder);
1548
1549 case INTEL_PT_FUP:
1550 if (decoder->packet.count == 0) {
1551 intel_pt_log_at("Skipping zero FUP",
1552 decoder->pos);
1553 no_tip = false;
1554 break;
1555 }
1556 intel_pt_set_last_ip(decoder);
1557 err = intel_pt_walk_fup(decoder);
1558 if (err != -EAGAIN) {
1559 if (err)
1560 return err;
1561 if (no_tip)
1562 decoder->pkt_state =
1563 INTEL_PT_STATE_FUP_NO_TIP;
1564 else
1565 decoder->pkt_state = INTEL_PT_STATE_FUP;
1566 return 0;
1567 }
1568 if (no_tip) {
1569 no_tip = false;
1570 break;
1571 }
1572 return intel_pt_walk_fup_tip(decoder);
1573
1574 case INTEL_PT_TRACESTOP:
1575 decoder->pge = false;
1576 decoder->continuous_period = false;
1577 intel_pt_clear_tx_flags(decoder);
1578 decoder->have_tma = false;
1579 break;
1580
1581 case INTEL_PT_PSB:
1582 intel_pt_clear_stack(&decoder->stack);
1583 err = intel_pt_walk_psbend(decoder);
1584 if (err == -EAGAIN)
1585 goto next;
1586 if (err)
1587 return err;
1588 break;
1589
1590 case INTEL_PT_PIP:
1591 decoder->cr3 = decoder->packet.payload & (BIT63 - 1);
1592 break;
1593
1594 case INTEL_PT_MTC:
1595 intel_pt_calc_mtc_timestamp(decoder);
1596 if (decoder->period_type != INTEL_PT_PERIOD_MTC)
1597 break;
1598 /*
1599 * Ensure that there has been an instruction since the
1600 * last MTC.
1601 */
1602 if (!decoder->mtc_insn)
1603 break;
1604 decoder->mtc_insn = false;
1605 /* Ensure that there is a timestamp */
1606 if (!decoder->timestamp)
1607 break;
1608 decoder->state.type = INTEL_PT_INSTRUCTION;
1609 decoder->state.from_ip = decoder->ip;
1610 decoder->state.to_ip = 0;
1611 decoder->mtc_insn = false;
1612 return 0;
1613
1614 case INTEL_PT_TSC:
1615 intel_pt_calc_tsc_timestamp(decoder);
1616 break;
1617
1618 case INTEL_PT_TMA:
1619 intel_pt_calc_tma(decoder);
1620 break;
1621
1622 case INTEL_PT_CYC:
1623 intel_pt_calc_cyc_timestamp(decoder);
1624 break;
1625
1626 case INTEL_PT_CBR:
1627 intel_pt_calc_cbr(decoder);
1628 break;
1629
1630 case INTEL_PT_MODE_EXEC:
1631 decoder->exec_mode = decoder->packet.payload;
1632 break;
1633
1634 case INTEL_PT_MODE_TSX:
1635 /* MODE_TSX need not be followed by FUP */
1636 if (!decoder->pge) {
1637 intel_pt_update_in_tx(decoder);
1638 break;
1639 }
1640 err = intel_pt_mode_tsx(decoder, &no_tip);
1641 if (err)
1642 return err;
1643 goto next;
1644
1645 case INTEL_PT_BAD: /* Does not happen */
1646 return intel_pt_bug(decoder);
1647
1648 case INTEL_PT_PSBEND:
1649 case INTEL_PT_VMCS:
1650 case INTEL_PT_MNT:
1651 case INTEL_PT_PAD:
1652 break;
1653
1654 default:
1655 return intel_pt_bug(decoder);
1656 }
1657 }
1658 }
1659
1660 /* Walk PSB+ packets to get in sync. */
1661 static int intel_pt_walk_psb(struct intel_pt_decoder *decoder)
1662 {
1663 int err;
1664
1665 while (1) {
1666 err = intel_pt_get_next_packet(decoder);
1667 if (err)
1668 return err;
1669
1670 switch (decoder->packet.type) {
1671 case INTEL_PT_TIP_PGD:
1672 decoder->continuous_period = false;
1673 case INTEL_PT_TIP_PGE:
1674 case INTEL_PT_TIP:
1675 intel_pt_log("ERROR: Unexpected packet\n");
1676 return -ENOENT;
1677
1678 case INTEL_PT_FUP:
1679 decoder->pge = true;
1680 if (decoder->last_ip || decoder->packet.count == 6 ||
1681 decoder->packet.count == 0) {
1682 uint64_t current_ip = decoder->ip;
1683
1684 intel_pt_set_ip(decoder);
1685 if (current_ip)
1686 intel_pt_log_to("Setting IP",
1687 decoder->ip);
1688 }
1689 break;
1690
1691 case INTEL_PT_MTC:
1692 intel_pt_calc_mtc_timestamp(decoder);
1693 break;
1694
1695 case INTEL_PT_TSC:
1696 intel_pt_calc_tsc_timestamp(decoder);
1697 break;
1698
1699 case INTEL_PT_TMA:
1700 intel_pt_calc_tma(decoder);
1701 break;
1702
1703 case INTEL_PT_CYC:
1704 intel_pt_calc_cyc_timestamp(decoder);
1705 break;
1706
1707 case INTEL_PT_CBR:
1708 intel_pt_calc_cbr(decoder);
1709 break;
1710
1711 case INTEL_PT_PIP:
1712 decoder->cr3 = decoder->packet.payload & (BIT63 - 1);
1713 break;
1714
1715 case INTEL_PT_MODE_EXEC:
1716 decoder->exec_mode = decoder->packet.payload;
1717 break;
1718
1719 case INTEL_PT_MODE_TSX:
1720 intel_pt_update_in_tx(decoder);
1721 break;
1722
1723 case INTEL_PT_TRACESTOP:
1724 decoder->pge = false;
1725 decoder->continuous_period = false;
1726 intel_pt_clear_tx_flags(decoder);
1727 case INTEL_PT_TNT:
1728 decoder->have_tma = false;
1729 intel_pt_log("ERROR: Unexpected packet\n");
1730 if (decoder->ip)
1731 decoder->pkt_state = INTEL_PT_STATE_ERR4;
1732 else
1733 decoder->pkt_state = INTEL_PT_STATE_ERR3;
1734 return -ENOENT;
1735
1736 case INTEL_PT_BAD: /* Does not happen */
1737 return intel_pt_bug(decoder);
1738
1739 case INTEL_PT_OVF:
1740 return intel_pt_overflow(decoder);
1741
1742 case INTEL_PT_PSBEND:
1743 return 0;
1744
1745 case INTEL_PT_PSB:
1746 case INTEL_PT_VMCS:
1747 case INTEL_PT_MNT:
1748 case INTEL_PT_PAD:
1749 default:
1750 break;
1751 }
1752 }
1753 }
1754
1755 static int intel_pt_walk_to_ip(struct intel_pt_decoder *decoder)
1756 {
1757 int err;
1758
1759 while (1) {
1760 err = intel_pt_get_next_packet(decoder);
1761 if (err)
1762 return err;
1763
1764 switch (decoder->packet.type) {
1765 case INTEL_PT_TIP_PGD:
1766 decoder->continuous_period = false;
1767 case INTEL_PT_TIP_PGE:
1768 case INTEL_PT_TIP:
1769 decoder->pge = decoder->packet.type != INTEL_PT_TIP_PGD;
1770 if (decoder->last_ip || decoder->packet.count == 6 ||
1771 decoder->packet.count == 0)
1772 intel_pt_set_ip(decoder);
1773 if (decoder->ip)
1774 return 0;
1775 break;
1776
1777 case INTEL_PT_FUP:
1778 if (decoder->overflow) {
1779 if (decoder->last_ip ||
1780 decoder->packet.count == 6 ||
1781 decoder->packet.count == 0)
1782 intel_pt_set_ip(decoder);
1783 if (decoder->ip)
1784 return 0;
1785 }
1786 if (decoder->packet.count)
1787 intel_pt_set_last_ip(decoder);
1788 break;
1789
1790 case INTEL_PT_MTC:
1791 intel_pt_calc_mtc_timestamp(decoder);
1792 break;
1793
1794 case INTEL_PT_TSC:
1795 intel_pt_calc_tsc_timestamp(decoder);
1796 break;
1797
1798 case INTEL_PT_TMA:
1799 intel_pt_calc_tma(decoder);
1800 break;
1801
1802 case INTEL_PT_CYC:
1803 intel_pt_calc_cyc_timestamp(decoder);
1804 break;
1805
1806 case INTEL_PT_CBR:
1807 intel_pt_calc_cbr(decoder);
1808 break;
1809
1810 case INTEL_PT_PIP:
1811 decoder->cr3 = decoder->packet.payload & (BIT63 - 1);
1812 break;
1813
1814 case INTEL_PT_MODE_EXEC:
1815 decoder->exec_mode = decoder->packet.payload;
1816 break;
1817
1818 case INTEL_PT_MODE_TSX:
1819 intel_pt_update_in_tx(decoder);
1820 break;
1821
1822 case INTEL_PT_OVF:
1823 return intel_pt_overflow(decoder);
1824
1825 case INTEL_PT_BAD: /* Does not happen */
1826 return intel_pt_bug(decoder);
1827
1828 case INTEL_PT_TRACESTOP:
1829 decoder->pge = false;
1830 decoder->continuous_period = false;
1831 intel_pt_clear_tx_flags(decoder);
1832 decoder->have_tma = false;
1833 break;
1834
1835 case INTEL_PT_PSB:
1836 err = intel_pt_walk_psb(decoder);
1837 if (err)
1838 return err;
1839 if (decoder->ip) {
1840 /* Do not have a sample */
1841 decoder->state.type = 0;
1842 return 0;
1843 }
1844 break;
1845
1846 case INTEL_PT_TNT:
1847 case INTEL_PT_PSBEND:
1848 case INTEL_PT_VMCS:
1849 case INTEL_PT_MNT:
1850 case INTEL_PT_PAD:
1851 default:
1852 break;
1853 }
1854 }
1855 }
1856
1857 static int intel_pt_sync_ip(struct intel_pt_decoder *decoder)
1858 {
1859 int err;
1860
1861 intel_pt_log("Scanning for full IP\n");
1862 err = intel_pt_walk_to_ip(decoder);
1863 if (err)
1864 return err;
1865
1866 decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1867 decoder->overflow = false;
1868
1869 decoder->state.from_ip = 0;
1870 decoder->state.to_ip = decoder->ip;
1871 intel_pt_log_to("Setting IP", decoder->ip);
1872
1873 return 0;
1874 }
1875
1876 static int intel_pt_part_psb(struct intel_pt_decoder *decoder)
1877 {
1878 const unsigned char *end = decoder->buf + decoder->len;
1879 size_t i;
1880
1881 for (i = INTEL_PT_PSB_LEN - 1; i; i--) {
1882 if (i > decoder->len)
1883 continue;
1884 if (!memcmp(end - i, INTEL_PT_PSB_STR, i))
1885 return i;
1886 }
1887 return 0;
1888 }
1889
1890 static int intel_pt_rest_psb(struct intel_pt_decoder *decoder, int part_psb)
1891 {
1892 size_t rest_psb = INTEL_PT_PSB_LEN - part_psb;
1893 const char *psb = INTEL_PT_PSB_STR;
1894
1895 if (rest_psb > decoder->len ||
1896 memcmp(decoder->buf, psb + part_psb, rest_psb))
1897 return 0;
1898
1899 return rest_psb;
1900 }
1901
1902 static int intel_pt_get_split_psb(struct intel_pt_decoder *decoder,
1903 int part_psb)
1904 {
1905 int rest_psb, ret;
1906
1907 decoder->pos += decoder->len;
1908 decoder->len = 0;
1909
1910 ret = intel_pt_get_next_data(decoder);
1911 if (ret)
1912 return ret;
1913
1914 rest_psb = intel_pt_rest_psb(decoder, part_psb);
1915 if (!rest_psb)
1916 return 0;
1917
1918 decoder->pos -= part_psb;
1919 decoder->next_buf = decoder->buf + rest_psb;
1920 decoder->next_len = decoder->len - rest_psb;
1921 memcpy(decoder->temp_buf, INTEL_PT_PSB_STR, INTEL_PT_PSB_LEN);
1922 decoder->buf = decoder->temp_buf;
1923 decoder->len = INTEL_PT_PSB_LEN;
1924
1925 return 0;
1926 }
1927
1928 static int intel_pt_scan_for_psb(struct intel_pt_decoder *decoder)
1929 {
1930 unsigned char *next;
1931 int ret;
1932
1933 intel_pt_log("Scanning for PSB\n");
1934 while (1) {
1935 if (!decoder->len) {
1936 ret = intel_pt_get_next_data(decoder);
1937 if (ret)
1938 return ret;
1939 }
1940
1941 next = memmem(decoder->buf, decoder->len, INTEL_PT_PSB_STR,
1942 INTEL_PT_PSB_LEN);
1943 if (!next) {
1944 int part_psb;
1945
1946 part_psb = intel_pt_part_psb(decoder);
1947 if (part_psb) {
1948 ret = intel_pt_get_split_psb(decoder, part_psb);
1949 if (ret)
1950 return ret;
1951 } else {
1952 decoder->pos += decoder->len;
1953 decoder->len = 0;
1954 }
1955 continue;
1956 }
1957
1958 decoder->pkt_step = next - decoder->buf;
1959 return intel_pt_get_next_packet(decoder);
1960 }
1961 }
1962
1963 static int intel_pt_sync(struct intel_pt_decoder *decoder)
1964 {
1965 int err;
1966
1967 decoder->pge = false;
1968 decoder->continuous_period = false;
1969 decoder->last_ip = 0;
1970 decoder->ip = 0;
1971 intel_pt_clear_stack(&decoder->stack);
1972
1973 err = intel_pt_scan_for_psb(decoder);
1974 if (err)
1975 return err;
1976
1977 decoder->pkt_state = INTEL_PT_STATE_NO_IP;
1978
1979 err = intel_pt_walk_psb(decoder);
1980 if (err)
1981 return err;
1982
1983 if (decoder->ip) {
1984 decoder->state.type = 0; /* Do not have a sample */
1985 decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1986 } else {
1987 return intel_pt_sync_ip(decoder);
1988 }
1989
1990 return 0;
1991 }
1992
1993 static uint64_t intel_pt_est_timestamp(struct intel_pt_decoder *decoder)
1994 {
1995 uint64_t est = decoder->timestamp_insn_cnt << 1;
1996
1997 if (!decoder->cbr || !decoder->max_non_turbo_ratio)
1998 goto out;
1999
2000 est *= decoder->max_non_turbo_ratio;
2001 est /= decoder->cbr;
2002 out:
2003 return decoder->timestamp + est;
2004 }
2005
2006 const struct intel_pt_state *intel_pt_decode(struct intel_pt_decoder *decoder)
2007 {
2008 int err;
2009
2010 do {
2011 decoder->state.type = INTEL_PT_BRANCH;
2012 decoder->state.flags = 0;
2013
2014 switch (decoder->pkt_state) {
2015 case INTEL_PT_STATE_NO_PSB:
2016 err = intel_pt_sync(decoder);
2017 break;
2018 case INTEL_PT_STATE_NO_IP:
2019 decoder->last_ip = 0;
2020 /* Fall through */
2021 case INTEL_PT_STATE_ERR_RESYNC:
2022 err = intel_pt_sync_ip(decoder);
2023 break;
2024 case INTEL_PT_STATE_IN_SYNC:
2025 err = intel_pt_walk_trace(decoder);
2026 break;
2027 case INTEL_PT_STATE_TNT:
2028 err = intel_pt_walk_tnt(decoder);
2029 if (err == -EAGAIN)
2030 err = intel_pt_walk_trace(decoder);
2031 break;
2032 case INTEL_PT_STATE_TIP:
2033 case INTEL_PT_STATE_TIP_PGD:
2034 err = intel_pt_walk_tip(decoder);
2035 break;
2036 case INTEL_PT_STATE_FUP:
2037 decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
2038 err = intel_pt_walk_fup(decoder);
2039 if (err == -EAGAIN)
2040 err = intel_pt_walk_fup_tip(decoder);
2041 else if (!err)
2042 decoder->pkt_state = INTEL_PT_STATE_FUP;
2043 break;
2044 case INTEL_PT_STATE_FUP_NO_TIP:
2045 decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
2046 err = intel_pt_walk_fup(decoder);
2047 if (err == -EAGAIN)
2048 err = intel_pt_walk_trace(decoder);
2049 break;
2050 default:
2051 err = intel_pt_bug(decoder);
2052 break;
2053 }
2054 } while (err == -ENOLINK);
2055
2056 decoder->state.err = err ? intel_pt_ext_err(err) : 0;
2057 decoder->state.timestamp = decoder->timestamp;
2058 decoder->state.est_timestamp = intel_pt_est_timestamp(decoder);
2059 decoder->state.cr3 = decoder->cr3;
2060 decoder->state.tot_insn_cnt = decoder->tot_insn_cnt;
2061
2062 if (err)
2063 decoder->state.from_ip = decoder->ip;
2064
2065 return &decoder->state;
2066 }
2067
2068 static bool intel_pt_at_psb(unsigned char *buf, size_t len)
2069 {
2070 if (len < INTEL_PT_PSB_LEN)
2071 return false;
2072 return memmem(buf, INTEL_PT_PSB_LEN, INTEL_PT_PSB_STR,
2073 INTEL_PT_PSB_LEN);
2074 }
2075
2076 /**
2077 * intel_pt_next_psb - move buffer pointer to the start of the next PSB packet.
2078 * @buf: pointer to buffer pointer
2079 * @len: size of buffer
2080 *
2081 * Updates the buffer pointer to point to the start of the next PSB packet if
2082 * there is one, otherwise the buffer pointer is unchanged. If @buf is updated,
2083 * @len is adjusted accordingly.
2084 *
2085 * Return: %true if a PSB packet is found, %false otherwise.
2086 */
2087 static bool intel_pt_next_psb(unsigned char **buf, size_t *len)
2088 {
2089 unsigned char *next;
2090
2091 next = memmem(*buf, *len, INTEL_PT_PSB_STR, INTEL_PT_PSB_LEN);
2092 if (next) {
2093 *len -= next - *buf;
2094 *buf = next;
2095 return true;
2096 }
2097 return false;
2098 }
2099
2100 /**
2101 * intel_pt_step_psb - move buffer pointer to the start of the following PSB
2102 * packet.
2103 * @buf: pointer to buffer pointer
2104 * @len: size of buffer
2105 *
2106 * Updates the buffer pointer to point to the start of the following PSB packet
2107 * (skipping the PSB at @buf itself) if there is one, otherwise the buffer
2108 * pointer is unchanged. If @buf is updated, @len is adjusted accordingly.
2109 *
2110 * Return: %true if a PSB packet is found, %false otherwise.
2111 */
2112 static bool intel_pt_step_psb(unsigned char **buf, size_t *len)
2113 {
2114 unsigned char *next;
2115
2116 if (!*len)
2117 return false;
2118
2119 next = memmem(*buf + 1, *len - 1, INTEL_PT_PSB_STR, INTEL_PT_PSB_LEN);
2120 if (next) {
2121 *len -= next - *buf;
2122 *buf = next;
2123 return true;
2124 }
2125 return false;
2126 }
2127
2128 /**
2129 * intel_pt_last_psb - find the last PSB packet in a buffer.
2130 * @buf: buffer
2131 * @len: size of buffer
2132 *
2133 * This function finds the last PSB in a buffer.
2134 *
2135 * Return: A pointer to the last PSB in @buf if found, %NULL otherwise.
2136 */
2137 static unsigned char *intel_pt_last_psb(unsigned char *buf, size_t len)
2138 {
2139 const char *n = INTEL_PT_PSB_STR;
2140 unsigned char *p;
2141 size_t k;
2142
2143 if (len < INTEL_PT_PSB_LEN)
2144 return NULL;
2145
2146 k = len - INTEL_PT_PSB_LEN + 1;
2147 while (1) {
2148 p = memrchr(buf, n[0], k);
2149 if (!p)
2150 return NULL;
2151 if (!memcmp(p + 1, n + 1, INTEL_PT_PSB_LEN - 1))
2152 return p;
2153 k = p - buf;
2154 if (!k)
2155 return NULL;
2156 }
2157 }
2158
2159 /**
2160 * intel_pt_next_tsc - find and return next TSC.
2161 * @buf: buffer
2162 * @len: size of buffer
2163 * @tsc: TSC value returned
2164 *
2165 * Find a TSC packet in @buf and return the TSC value. This function assumes
2166 * that @buf starts at a PSB and that PSB+ will contain TSC and so stops if a
2167 * PSBEND packet is found.
2168 *
2169 * Return: %true if TSC is found, false otherwise.
2170 */
2171 static bool intel_pt_next_tsc(unsigned char *buf, size_t len, uint64_t *tsc)
2172 {
2173 struct intel_pt_pkt packet;
2174 int ret;
2175
2176 while (len) {
2177 ret = intel_pt_get_packet(buf, len, &packet);
2178 if (ret <= 0)
2179 return false;
2180 if (packet.type == INTEL_PT_TSC) {
2181 *tsc = packet.payload;
2182 return true;
2183 }
2184 if (packet.type == INTEL_PT_PSBEND)
2185 return false;
2186 buf += ret;
2187 len -= ret;
2188 }
2189 return false;
2190 }
2191
2192 /**
2193 * intel_pt_tsc_cmp - compare 7-byte TSCs.
2194 * @tsc1: first TSC to compare
2195 * @tsc2: second TSC to compare
2196 *
2197 * This function compares 7-byte TSC values allowing for the possibility that
2198 * TSC wrapped around. Generally it is not possible to know if TSC has wrapped
2199 * around so for that purpose this function assumes the absolute difference is
2200 * less than half the maximum difference.
2201 *
2202 * Return: %-1 if @tsc1 is before @tsc2, %0 if @tsc1 == @tsc2, %1 if @tsc1 is
2203 * after @tsc2.
2204 */
2205 static int intel_pt_tsc_cmp(uint64_t tsc1, uint64_t tsc2)
2206 {
2207 const uint64_t halfway = (1ULL << 55);
2208
2209 if (tsc1 == tsc2)
2210 return 0;
2211
2212 if (tsc1 < tsc2) {
2213 if (tsc2 - tsc1 < halfway)
2214 return -1;
2215 else
2216 return 1;
2217 } else {
2218 if (tsc1 - tsc2 < halfway)
2219 return 1;
2220 else
2221 return -1;
2222 }
2223 }
2224
2225 /**
2226 * intel_pt_find_overlap_tsc - determine start of non-overlapped trace data
2227 * using TSC.
2228 * @buf_a: first buffer
2229 * @len_a: size of first buffer
2230 * @buf_b: second buffer
2231 * @len_b: size of second buffer
2232 *
2233 * If the trace contains TSC we can look at the last TSC of @buf_a and the
2234 * first TSC of @buf_b in order to determine if the buffers overlap, and then
2235 * walk forward in @buf_b until a later TSC is found. A precondition is that
2236 * @buf_a and @buf_b are positioned at a PSB.
2237 *
2238 * Return: A pointer into @buf_b from where non-overlapped data starts, or
2239 * @buf_b + @len_b if there is no non-overlapped data.
2240 */
2241 static unsigned char *intel_pt_find_overlap_tsc(unsigned char *buf_a,
2242 size_t len_a,
2243 unsigned char *buf_b,
2244 size_t len_b)
2245 {
2246 uint64_t tsc_a, tsc_b;
2247 unsigned char *p;
2248 size_t len;
2249
2250 p = intel_pt_last_psb(buf_a, len_a);
2251 if (!p)
2252 return buf_b; /* No PSB in buf_a => no overlap */
2253
2254 len = len_a - (p - buf_a);
2255 if (!intel_pt_next_tsc(p, len, &tsc_a)) {
2256 /* The last PSB+ in buf_a is incomplete, so go back one more */
2257 len_a -= len;
2258 p = intel_pt_last_psb(buf_a, len_a);
2259 if (!p)
2260 return buf_b; /* No full PSB+ => assume no overlap */
2261 len = len_a - (p - buf_a);
2262 if (!intel_pt_next_tsc(p, len, &tsc_a))
2263 return buf_b; /* No TSC in buf_a => assume no overlap */
2264 }
2265
2266 while (1) {
2267 /* Ignore PSB+ with no TSC */
2268 if (intel_pt_next_tsc(buf_b, len_b, &tsc_b) &&
2269 intel_pt_tsc_cmp(tsc_a, tsc_b) < 0)
2270 return buf_b; /* tsc_a < tsc_b => no overlap */
2271
2272 if (!intel_pt_step_psb(&buf_b, &len_b))
2273 return buf_b + len_b; /* No PSB in buf_b => no data */
2274 }
2275 }
2276
2277 /**
2278 * intel_pt_find_overlap - determine start of non-overlapped trace data.
2279 * @buf_a: first buffer
2280 * @len_a: size of first buffer
2281 * @buf_b: second buffer
2282 * @len_b: size of second buffer
2283 * @have_tsc: can use TSC packets to detect overlap
2284 *
2285 * When trace samples or snapshots are recorded there is the possibility that
2286 * the data overlaps. Note that, for the purposes of decoding, data is only
2287 * useful if it begins with a PSB packet.
2288 *
2289 * Return: A pointer into @buf_b from where non-overlapped data starts, or
2290 * @buf_b + @len_b if there is no non-overlapped data.
2291 */
2292 unsigned char *intel_pt_find_overlap(unsigned char *buf_a, size_t len_a,
2293 unsigned char *buf_b, size_t len_b,
2294 bool have_tsc)
2295 {
2296 unsigned char *found;
2297
2298 /* Buffer 'b' must start at PSB so throw away everything before that */
2299 if (!intel_pt_next_psb(&buf_b, &len_b))
2300 return buf_b + len_b; /* No PSB */
2301
2302 if (!intel_pt_next_psb(&buf_a, &len_a))
2303 return buf_b; /* No overlap */
2304
2305 if (have_tsc) {
2306 found = intel_pt_find_overlap_tsc(buf_a, len_a, buf_b, len_b);
2307 if (found)
2308 return found;
2309 }
2310
2311 /*
2312 * Buffer 'b' cannot end within buffer 'a' so, for comparison purposes,
2313 * we can ignore the first part of buffer 'a'.
2314 */
2315 while (len_b < len_a) {
2316 if (!intel_pt_step_psb(&buf_a, &len_a))
2317 return buf_b; /* No overlap */
2318 }
2319
2320 /* Now len_b >= len_a */
2321 if (len_b > len_a) {
2322 /* The leftover buffer 'b' must start at a PSB */
2323 while (!intel_pt_at_psb(buf_b + len_a, len_b - len_a)) {
2324 if (!intel_pt_step_psb(&buf_a, &len_a))
2325 return buf_b; /* No overlap */
2326 }
2327 }
2328
2329 while (1) {
2330 /* Potential overlap so check the bytes */
2331 found = memmem(buf_a, len_a, buf_b, len_a);
2332 if (found)
2333 return buf_b + len_a;
2334
2335 /* Try again at next PSB in buffer 'a' */
2336 if (!intel_pt_step_psb(&buf_a, &len_a))
2337 return buf_b; /* No overlap */
2338
2339 /* The leftover buffer 'b' must start at a PSB */
2340 while (!intel_pt_at_psb(buf_b + len_a, len_b - len_a)) {
2341 if (!intel_pt_step_psb(&buf_a, &len_a))
2342 return buf_b; /* No overlap */
2343 }
2344 }
2345 }
Linux with added FPC-III support