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mmc: bcm2835: Fix DMA channel leak on probe error
[linux/fpc-iii.git] / tools / perf / util / intel-pt-decoder / intel-pt-decoder.c
blobd404bed7003aacee1079af492ba3f20334edc06e
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 #include <linux/compiler.h>
26
27 #include "../cache.h"
28 #include "../util.h"
29
30 #include "intel-pt-insn-decoder.h"
31 #include "intel-pt-pkt-decoder.h"
32 #include "intel-pt-decoder.h"
33 #include "intel-pt-log.h"
34
35 #define INTEL_PT_BLK_SIZE 1024
36
37 #define BIT63 (((uint64_t)1 << 63))
38
39 #define INTEL_PT_RETURN 1
40
41 /* Maximum number of loops with no packets consumed i.e. stuck in a loop */
42 #define INTEL_PT_MAX_LOOPS 10000
43
44 struct intel_pt_blk {
45 struct intel_pt_blk *prev;
46 uint64_t ip[INTEL_PT_BLK_SIZE];
47 };
48
49 struct intel_pt_stack {
50 struct intel_pt_blk *blk;
51 struct intel_pt_blk *spare;
52 int pos;
53 };
54
55 enum intel_pt_pkt_state {
56 INTEL_PT_STATE_NO_PSB,
57 INTEL_PT_STATE_NO_IP,
58 INTEL_PT_STATE_ERR_RESYNC,
59 INTEL_PT_STATE_IN_SYNC,
60 INTEL_PT_STATE_TNT,
61 INTEL_PT_STATE_TIP,
62 INTEL_PT_STATE_TIP_PGD,
63 INTEL_PT_STATE_FUP,
64 INTEL_PT_STATE_FUP_NO_TIP,
65 };
66
67 static inline bool intel_pt_sample_time(enum intel_pt_pkt_state pkt_state)
68 {
69 switch (pkt_state) {
70 case INTEL_PT_STATE_NO_PSB:
71 case INTEL_PT_STATE_NO_IP:
72 case INTEL_PT_STATE_ERR_RESYNC:
73 case INTEL_PT_STATE_IN_SYNC:
74 case INTEL_PT_STATE_TNT:
75 return true;
76 case INTEL_PT_STATE_TIP:
77 case INTEL_PT_STATE_TIP_PGD:
78 case INTEL_PT_STATE_FUP:
79 case INTEL_PT_STATE_FUP_NO_TIP:
80 return false;
81 default:
82 return true;
83 };
84 }
85
86 #ifdef INTEL_PT_STRICT
87 #define INTEL_PT_STATE_ERR1 INTEL_PT_STATE_NO_PSB
88 #define INTEL_PT_STATE_ERR2 INTEL_PT_STATE_NO_PSB
89 #define INTEL_PT_STATE_ERR3 INTEL_PT_STATE_NO_PSB
90 #define INTEL_PT_STATE_ERR4 INTEL_PT_STATE_NO_PSB
91 #else
92 #define INTEL_PT_STATE_ERR1 (decoder->pkt_state)
93 #define INTEL_PT_STATE_ERR2 INTEL_PT_STATE_NO_IP
94 #define INTEL_PT_STATE_ERR3 INTEL_PT_STATE_ERR_RESYNC
95 #define INTEL_PT_STATE_ERR4 INTEL_PT_STATE_IN_SYNC
96 #endif
97
98 struct intel_pt_decoder {
99 int (*get_trace)(struct intel_pt_buffer *buffer, void *data);
100 int (*walk_insn)(struct intel_pt_insn *intel_pt_insn,
101 uint64_t *insn_cnt_ptr, uint64_t *ip, uint64_t to_ip,
102 uint64_t max_insn_cnt, void *data);
103 bool (*pgd_ip)(uint64_t ip, void *data);
104 void *data;
105 struct intel_pt_state state;
106 const unsigned char *buf;
107 size_t len;
108 bool return_compression;
109 bool branch_enable;
110 bool mtc_insn;
111 bool pge;
112 bool have_tma;
113 bool have_cyc;
114 bool fixup_last_mtc;
115 bool have_last_ip;
116 enum intel_pt_param_flags flags;
117 uint64_t pos;
118 uint64_t last_ip;
119 uint64_t ip;
120 uint64_t cr3;
121 uint64_t timestamp;
122 uint64_t tsc_timestamp;
123 uint64_t ref_timestamp;
124 uint64_t sample_timestamp;
125 uint64_t ret_addr;
126 uint64_t ctc_timestamp;
127 uint64_t ctc_delta;
128 uint64_t cycle_cnt;
129 uint64_t cyc_ref_timestamp;
130 uint32_t last_mtc;
131 uint32_t tsc_ctc_ratio_n;
132 uint32_t tsc_ctc_ratio_d;
133 uint32_t tsc_ctc_mult;
134 uint32_t tsc_slip;
135 uint32_t ctc_rem_mask;
136 int mtc_shift;
137 struct intel_pt_stack stack;
138 enum intel_pt_pkt_state pkt_state;
139 struct intel_pt_pkt packet;
140 struct intel_pt_pkt tnt;
141 int pkt_step;
142 int pkt_len;
143 int last_packet_type;
144 unsigned int cbr;
145 unsigned int cbr_seen;
146 unsigned int max_non_turbo_ratio;
147 double max_non_turbo_ratio_fp;
148 double cbr_cyc_to_tsc;
149 double calc_cyc_to_tsc;
150 bool have_calc_cyc_to_tsc;
151 int exec_mode;
152 unsigned int insn_bytes;
153 uint64_t period;
154 enum intel_pt_period_type period_type;
155 uint64_t tot_insn_cnt;
156 uint64_t period_insn_cnt;
157 uint64_t period_mask;
158 uint64_t period_ticks;
159 uint64_t last_masked_timestamp;
160 bool continuous_period;
161 bool overflow;
162 bool set_fup_tx_flags;
163 bool set_fup_ptw;
164 bool set_fup_mwait;
165 bool set_fup_pwre;
166 bool set_fup_exstop;
167 unsigned int fup_tx_flags;
168 unsigned int tx_flags;
169 uint64_t fup_ptw_payload;
170 uint64_t fup_mwait_payload;
171 uint64_t fup_pwre_payload;
172 uint64_t cbr_payload;
173 uint64_t timestamp_insn_cnt;
174 uint64_t sample_insn_cnt;
175 uint64_t stuck_ip;
176 int no_progress;
177 int stuck_ip_prd;
178 int stuck_ip_cnt;
179 const unsigned char *next_buf;
180 size_t next_len;
181 unsigned char temp_buf[INTEL_PT_PKT_MAX_SZ];
182 };
183
184 static uint64_t intel_pt_lower_power_of_2(uint64_t x)
185 {
186 int i;
187
188 for (i = 0; x != 1; i++)
189 x >>= 1;
190
191 return x << i;
192 }
193
194 static void intel_pt_setup_period(struct intel_pt_decoder *decoder)
195 {
196 if (decoder->period_type == INTEL_PT_PERIOD_TICKS) {
197 uint64_t period;
198
199 period = intel_pt_lower_power_of_2(decoder->period);
200 decoder->period_mask = ~(period - 1);
201 decoder->period_ticks = period;
202 }
203 }
204
205 static uint64_t multdiv(uint64_t t, uint32_t n, uint32_t d)
206 {
207 if (!d)
208 return 0;
209 return (t / d) * n + ((t % d) * n) / d;
210 }
211
212 struct intel_pt_decoder *intel_pt_decoder_new(struct intel_pt_params *params)
213 {
214 struct intel_pt_decoder *decoder;
215
216 if (!params->get_trace || !params->walk_insn)
217 return NULL;
218
219 decoder = zalloc(sizeof(struct intel_pt_decoder));
220 if (!decoder)
221 return NULL;
222
223 decoder->get_trace = params->get_trace;
224 decoder->walk_insn = params->walk_insn;
225 decoder->pgd_ip = params->pgd_ip;
226 decoder->data = params->data;
227 decoder->return_compression = params->return_compression;
228 decoder->branch_enable = params->branch_enable;
229
230 decoder->flags = params->flags;
231
232 decoder->period = params->period;
233 decoder->period_type = params->period_type;
234
235 decoder->max_non_turbo_ratio = params->max_non_turbo_ratio;
236 decoder->max_non_turbo_ratio_fp = params->max_non_turbo_ratio;
237
238 intel_pt_setup_period(decoder);
239
240 decoder->mtc_shift = params->mtc_period;
241 decoder->ctc_rem_mask = (1 << decoder->mtc_shift) - 1;
242
243 decoder->tsc_ctc_ratio_n = params->tsc_ctc_ratio_n;
244 decoder->tsc_ctc_ratio_d = params->tsc_ctc_ratio_d;
245
246 if (!decoder->tsc_ctc_ratio_n)
247 decoder->tsc_ctc_ratio_d = 0;
248
249 if (decoder->tsc_ctc_ratio_d) {
250 if (!(decoder->tsc_ctc_ratio_n % decoder->tsc_ctc_ratio_d))
251 decoder->tsc_ctc_mult = decoder->tsc_ctc_ratio_n /
252 decoder->tsc_ctc_ratio_d;
253
254 /*
255 * Allow for timestamps appearing to backwards because a TSC
256 * packet has slipped past a MTC packet, so allow 2 MTC ticks
257 * or ...
258 */
259 decoder->tsc_slip = multdiv(2 << decoder->mtc_shift,
260 decoder->tsc_ctc_ratio_n,
261 decoder->tsc_ctc_ratio_d);
262 }
263 /* ... or 0x100 paranoia */
264 if (decoder->tsc_slip < 0x100)
265 decoder->tsc_slip = 0x100;
266
267 intel_pt_log("timestamp: mtc_shift %u\n", decoder->mtc_shift);
268 intel_pt_log("timestamp: tsc_ctc_ratio_n %u\n", decoder->tsc_ctc_ratio_n);
269 intel_pt_log("timestamp: tsc_ctc_ratio_d %u\n", decoder->tsc_ctc_ratio_d);
270 intel_pt_log("timestamp: tsc_ctc_mult %u\n", decoder->tsc_ctc_mult);
271 intel_pt_log("timestamp: tsc_slip %#x\n", decoder->tsc_slip);
272
273 return decoder;
274 }
275
276 static void intel_pt_pop_blk(struct intel_pt_stack *stack)
277 {
278 struct intel_pt_blk *blk = stack->blk;
279
280 stack->blk = blk->prev;
281 if (!stack->spare)
282 stack->spare = blk;
283 else
284 free(blk);
285 }
286
287 static uint64_t intel_pt_pop(struct intel_pt_stack *stack)
288 {
289 if (!stack->pos) {
290 if (!stack->blk)
291 return 0;
292 intel_pt_pop_blk(stack);
293 if (!stack->blk)
294 return 0;
295 stack->pos = INTEL_PT_BLK_SIZE;
296 }
297 return stack->blk->ip[--stack->pos];
298 }
299
300 static int intel_pt_alloc_blk(struct intel_pt_stack *stack)
301 {
302 struct intel_pt_blk *blk;
303
304 if (stack->spare) {
305 blk = stack->spare;
306 stack->spare = NULL;
307 } else {
308 blk = malloc(sizeof(struct intel_pt_blk));
309 if (!blk)
310 return -ENOMEM;
311 }
312
313 blk->prev = stack->blk;
314 stack->blk = blk;
315 stack->pos = 0;
316 return 0;
317 }
318
319 static int intel_pt_push(struct intel_pt_stack *stack, uint64_t ip)
320 {
321 int err;
322
323 if (!stack->blk || stack->pos == INTEL_PT_BLK_SIZE) {
324 err = intel_pt_alloc_blk(stack);
325 if (err)
326 return err;
327 }
328
329 stack->blk->ip[stack->pos++] = ip;
330 return 0;
331 }
332
333 static void intel_pt_clear_stack(struct intel_pt_stack *stack)
334 {
335 while (stack->blk)
336 intel_pt_pop_blk(stack);
337 stack->pos = 0;
338 }
339
340 static void intel_pt_free_stack(struct intel_pt_stack *stack)
341 {
342 intel_pt_clear_stack(stack);
343 zfree(&stack->blk);
344 zfree(&stack->spare);
345 }
346
347 void intel_pt_decoder_free(struct intel_pt_decoder *decoder)
348 {
349 intel_pt_free_stack(&decoder->stack);
350 free(decoder);
351 }
352
353 static int intel_pt_ext_err(int code)
354 {
355 switch (code) {
356 case -ENOMEM:
357 return INTEL_PT_ERR_NOMEM;
358 case -ENOSYS:
359 return INTEL_PT_ERR_INTERN;
360 case -EBADMSG:
361 return INTEL_PT_ERR_BADPKT;
362 case -ENODATA:
363 return INTEL_PT_ERR_NODATA;
364 case -EILSEQ:
365 return INTEL_PT_ERR_NOINSN;
366 case -ENOENT:
367 return INTEL_PT_ERR_MISMAT;
368 case -EOVERFLOW:
369 return INTEL_PT_ERR_OVR;
370 case -ENOSPC:
371 return INTEL_PT_ERR_LOST;
372 case -ELOOP:
373 return INTEL_PT_ERR_NELOOP;
374 default:
375 return INTEL_PT_ERR_UNK;
376 }
377 }
378
379 static const char *intel_pt_err_msgs[] = {
380 [INTEL_PT_ERR_NOMEM] = "Memory allocation failed",
381 [INTEL_PT_ERR_INTERN] = "Internal error",
382 [INTEL_PT_ERR_BADPKT] = "Bad packet",
383 [INTEL_PT_ERR_NODATA] = "No more data",
384 [INTEL_PT_ERR_NOINSN] = "Failed to get instruction",
385 [INTEL_PT_ERR_MISMAT] = "Trace doesn't match instruction",
386 [INTEL_PT_ERR_OVR] = "Overflow packet",
387 [INTEL_PT_ERR_LOST] = "Lost trace data",
388 [INTEL_PT_ERR_UNK] = "Unknown error!",
389 [INTEL_PT_ERR_NELOOP] = "Never-ending loop",
390 };
391
392 int intel_pt__strerror(int code, char *buf, size_t buflen)
393 {
394 if (code < 1 || code >= INTEL_PT_ERR_MAX)
395 code = INTEL_PT_ERR_UNK;
396 strlcpy(buf, intel_pt_err_msgs[code], buflen);
397 return 0;
398 }
399
400 static uint64_t intel_pt_calc_ip(const struct intel_pt_pkt *packet,
401 uint64_t last_ip)
402 {
403 uint64_t ip;
404
405 switch (packet->count) {
406 case 1:
407 ip = (last_ip & (uint64_t)0xffffffffffff0000ULL) |
408 packet->payload;
409 break;
410 case 2:
411 ip = (last_ip & (uint64_t)0xffffffff00000000ULL) |
412 packet->payload;
413 break;
414 case 3:
415 ip = packet->payload;
416 /* Sign-extend 6-byte ip */
417 if (ip & (uint64_t)0x800000000000ULL)
418 ip |= (uint64_t)0xffff000000000000ULL;
419 break;
420 case 4:
421 ip = (last_ip & (uint64_t)0xffff000000000000ULL) |
422 packet->payload;
423 break;
424 case 6:
425 ip = packet->payload;
426 break;
427 default:
428 return 0;
429 }
430
431 return ip;
432 }
433
434 static inline void intel_pt_set_last_ip(struct intel_pt_decoder *decoder)
435 {
436 decoder->last_ip = intel_pt_calc_ip(&decoder->packet, decoder->last_ip);
437 decoder->have_last_ip = true;
438 }
439
440 static inline void intel_pt_set_ip(struct intel_pt_decoder *decoder)
441 {
442 intel_pt_set_last_ip(decoder);
443 decoder->ip = decoder->last_ip;
444 }
445
446 static void intel_pt_decoder_log_packet(struct intel_pt_decoder *decoder)
447 {
448 intel_pt_log_packet(&decoder->packet, decoder->pkt_len, decoder->pos,
449 decoder->buf);
450 }
451
452 static int intel_pt_bug(struct intel_pt_decoder *decoder)
453 {
454 intel_pt_log("ERROR: Internal error\n");
455 decoder->pkt_state = INTEL_PT_STATE_NO_PSB;
456 return -ENOSYS;
457 }
458
459 static inline void intel_pt_clear_tx_flags(struct intel_pt_decoder *decoder)
460 {
461 decoder->tx_flags = 0;
462 }
463
464 static inline void intel_pt_update_in_tx(struct intel_pt_decoder *decoder)
465 {
466 decoder->tx_flags = decoder->packet.payload & INTEL_PT_IN_TX;
467 }
468
469 static int intel_pt_bad_packet(struct intel_pt_decoder *decoder)
470 {
471 intel_pt_clear_tx_flags(decoder);
472 decoder->have_tma = false;
473 decoder->pkt_len = 1;
474 decoder->pkt_step = 1;
475 intel_pt_decoder_log_packet(decoder);
476 if (decoder->pkt_state != INTEL_PT_STATE_NO_PSB) {
477 intel_pt_log("ERROR: Bad packet\n");
478 decoder->pkt_state = INTEL_PT_STATE_ERR1;
479 }
480 return -EBADMSG;
481 }
482
483 static int intel_pt_get_data(struct intel_pt_decoder *decoder)
484 {
485 struct intel_pt_buffer buffer = { .buf = 0, };
486 int ret;
487
488 decoder->pkt_step = 0;
489
490 intel_pt_log("Getting more data\n");
491 ret = decoder->get_trace(&buffer, decoder->data);
492 if (ret)
493 return ret;
494 decoder->buf = buffer.buf;
495 decoder->len = buffer.len;
496 if (!decoder->len) {
497 intel_pt_log("No more data\n");
498 return -ENODATA;
499 }
500 if (!buffer.consecutive) {
501 decoder->ip = 0;
502 decoder->pkt_state = INTEL_PT_STATE_NO_PSB;
503 decoder->ref_timestamp = buffer.ref_timestamp;
504 decoder->timestamp = 0;
505 decoder->have_tma = false;
506 decoder->state.trace_nr = buffer.trace_nr;
507 intel_pt_log("Reference timestamp 0x%" PRIx64 "\n",
508 decoder->ref_timestamp);
509 return -ENOLINK;
510 }
511
512 return 0;
513 }
514
515 static int intel_pt_get_next_data(struct intel_pt_decoder *decoder)
516 {
517 if (!decoder->next_buf)
518 return intel_pt_get_data(decoder);
519
520 decoder->buf = decoder->next_buf;
521 decoder->len = decoder->next_len;
522 decoder->next_buf = 0;
523 decoder->next_len = 0;
524 return 0;
525 }
526
527 static int intel_pt_get_split_packet(struct intel_pt_decoder *decoder)
528 {
529 unsigned char *buf = decoder->temp_buf;
530 size_t old_len, len, n;
531 int ret;
532
533 old_len = decoder->len;
534 len = decoder->len;
535 memcpy(buf, decoder->buf, len);
536
537 ret = intel_pt_get_data(decoder);
538 if (ret) {
539 decoder->pos += old_len;
540 return ret < 0 ? ret : -EINVAL;
541 }
542
543 n = INTEL_PT_PKT_MAX_SZ - len;
544 if (n > decoder->len)
545 n = decoder->len;
546 memcpy(buf + len, decoder->buf, n);
547 len += n;
548
549 ret = intel_pt_get_packet(buf, len, &decoder->packet);
550 if (ret < (int)old_len) {
551 decoder->next_buf = decoder->buf;
552 decoder->next_len = decoder->len;
553 decoder->buf = buf;
554 decoder->len = old_len;
555 return intel_pt_bad_packet(decoder);
556 }
557
558 decoder->next_buf = decoder->buf + (ret - old_len);
559 decoder->next_len = decoder->len - (ret - old_len);
560
561 decoder->buf = buf;
562 decoder->len = ret;
563
564 return ret;
565 }
566
567 struct intel_pt_pkt_info {
568 struct intel_pt_decoder *decoder;
569 struct intel_pt_pkt packet;
570 uint64_t pos;
571 int pkt_len;
572 int last_packet_type;
573 void *data;
574 };
575
576 typedef int (*intel_pt_pkt_cb_t)(struct intel_pt_pkt_info *pkt_info);
577
578 /* Lookahead packets in current buffer */
579 static int intel_pt_pkt_lookahead(struct intel_pt_decoder *decoder,
580 intel_pt_pkt_cb_t cb, void *data)
581 {
582 struct intel_pt_pkt_info pkt_info;
583 const unsigned char *buf = decoder->buf;
584 size_t len = decoder->len;
585 int ret;
586
587 pkt_info.decoder = decoder;
588 pkt_info.pos = decoder->pos;
589 pkt_info.pkt_len = decoder->pkt_step;
590 pkt_info.last_packet_type = decoder->last_packet_type;
591 pkt_info.data = data;
592
593 while (1) {
594 do {
595 pkt_info.pos += pkt_info.pkt_len;
596 buf += pkt_info.pkt_len;
597 len -= pkt_info.pkt_len;
598
599 if (!len)
600 return INTEL_PT_NEED_MORE_BYTES;
601
602 ret = intel_pt_get_packet(buf, len, &pkt_info.packet);
603 if (!ret)
604 return INTEL_PT_NEED_MORE_BYTES;
605 if (ret < 0)
606 return ret;
607
608 pkt_info.pkt_len = ret;
609 } while (pkt_info.packet.type == INTEL_PT_PAD);
610
611 ret = cb(&pkt_info);
612 if (ret)
613 return 0;
614
615 pkt_info.last_packet_type = pkt_info.packet.type;
616 }
617 }
618
619 struct intel_pt_calc_cyc_to_tsc_info {
620 uint64_t cycle_cnt;
621 unsigned int cbr;
622 uint32_t last_mtc;
623 uint64_t ctc_timestamp;
624 uint64_t ctc_delta;
625 uint64_t tsc_timestamp;
626 uint64_t timestamp;
627 bool have_tma;
628 bool fixup_last_mtc;
629 bool from_mtc;
630 double cbr_cyc_to_tsc;
631 };
632
633 /*
634 * MTC provides a 8-bit slice of CTC but the TMA packet only provides the lower
635 * 16 bits of CTC. If mtc_shift > 8 then some of the MTC bits are not in the CTC
636 * provided by the TMA packet. Fix-up the last_mtc calculated from the TMA
637 * packet by copying the missing bits from the current MTC assuming the least
638 * difference between the two, and that the current MTC comes after last_mtc.
639 */
640 static void intel_pt_fixup_last_mtc(uint32_t mtc, int mtc_shift,
641 uint32_t *last_mtc)
642 {
643 uint32_t first_missing_bit = 1U << (16 - mtc_shift);
644 uint32_t mask = ~(first_missing_bit - 1);
645
646 *last_mtc |= mtc & mask;
647 if (*last_mtc >= mtc) {
648 *last_mtc -= first_missing_bit;
649 *last_mtc &= 0xff;
650 }
651 }
652
653 static int intel_pt_calc_cyc_cb(struct intel_pt_pkt_info *pkt_info)
654 {
655 struct intel_pt_decoder *decoder = pkt_info->decoder;
656 struct intel_pt_calc_cyc_to_tsc_info *data = pkt_info->data;
657 uint64_t timestamp;
658 double cyc_to_tsc;
659 unsigned int cbr;
660 uint32_t mtc, mtc_delta, ctc, fc, ctc_rem;
661
662 switch (pkt_info->packet.type) {
663 case INTEL_PT_TNT:
664 case INTEL_PT_TIP_PGE:
665 case INTEL_PT_TIP:
666 case INTEL_PT_FUP:
667 case INTEL_PT_PSB:
668 case INTEL_PT_PIP:
669 case INTEL_PT_MODE_EXEC:
670 case INTEL_PT_MODE_TSX:
671 case INTEL_PT_PSBEND:
672 case INTEL_PT_PAD:
673 case INTEL_PT_VMCS:
674 case INTEL_PT_MNT:
675 case INTEL_PT_PTWRITE:
676 case INTEL_PT_PTWRITE_IP:
677 return 0;
678
679 case INTEL_PT_MTC:
680 if (!data->have_tma)
681 return 0;
682
683 mtc = pkt_info->packet.payload;
684 if (decoder->mtc_shift > 8 && data->fixup_last_mtc) {
685 data->fixup_last_mtc = false;
686 intel_pt_fixup_last_mtc(mtc, decoder->mtc_shift,
687 &data->last_mtc);
688 }
689 if (mtc > data->last_mtc)
690 mtc_delta = mtc - data->last_mtc;
691 else
692 mtc_delta = mtc + 256 - data->last_mtc;
693 data->ctc_delta += mtc_delta << decoder->mtc_shift;
694 data->last_mtc = mtc;
695
696 if (decoder->tsc_ctc_mult) {
697 timestamp = data->ctc_timestamp +
698 data->ctc_delta * decoder->tsc_ctc_mult;
699 } else {
700 timestamp = data->ctc_timestamp +
701 multdiv(data->ctc_delta,
702 decoder->tsc_ctc_ratio_n,
703 decoder->tsc_ctc_ratio_d);
704 }
705
706 if (timestamp < data->timestamp)
707 return 1;
708
709 if (pkt_info->last_packet_type != INTEL_PT_CYC) {
710 data->timestamp = timestamp;
711 return 0;
712 }
713
714 break;
715
716 case INTEL_PT_TSC:
717 /*
718 * For now, do not support using TSC packets - refer
719 * intel_pt_calc_cyc_to_tsc().
720 */
721 if (data->from_mtc)
722 return 1;
723 timestamp = pkt_info->packet.payload |
724 (data->timestamp & (0xffULL << 56));
725 if (data->from_mtc && timestamp < data->timestamp &&
726 data->timestamp - timestamp < decoder->tsc_slip)
727 return 1;
728 if (timestamp < data->timestamp)
729 timestamp += (1ULL << 56);
730 if (pkt_info->last_packet_type != INTEL_PT_CYC) {
731 if (data->from_mtc)
732 return 1;
733 data->tsc_timestamp = timestamp;
734 data->timestamp = timestamp;
735 return 0;
736 }
737 break;
738
739 case INTEL_PT_TMA:
740 if (data->from_mtc)
741 return 1;
742
743 if (!decoder->tsc_ctc_ratio_d)
744 return 0;
745
746 ctc = pkt_info->packet.payload;
747 fc = pkt_info->packet.count;
748 ctc_rem = ctc & decoder->ctc_rem_mask;
749
750 data->last_mtc = (ctc >> decoder->mtc_shift) & 0xff;
751
752 data->ctc_timestamp = data->tsc_timestamp - fc;
753 if (decoder->tsc_ctc_mult) {
754 data->ctc_timestamp -= ctc_rem * decoder->tsc_ctc_mult;
755 } else {
756 data->ctc_timestamp -=
757 multdiv(ctc_rem, decoder->tsc_ctc_ratio_n,
758 decoder->tsc_ctc_ratio_d);
759 }
760
761 data->ctc_delta = 0;
762 data->have_tma = true;
763 data->fixup_last_mtc = true;
764
765 return 0;
766
767 case INTEL_PT_CYC:
768 data->cycle_cnt += pkt_info->packet.payload;
769 return 0;
770
771 case INTEL_PT_CBR:
772 cbr = pkt_info->packet.payload;
773 if (data->cbr && data->cbr != cbr)
774 return 1;
775 data->cbr = cbr;
776 data->cbr_cyc_to_tsc = decoder->max_non_turbo_ratio_fp / cbr;
777 return 0;
778
779 case INTEL_PT_TIP_PGD:
780 case INTEL_PT_TRACESTOP:
781 case INTEL_PT_EXSTOP:
782 case INTEL_PT_EXSTOP_IP:
783 case INTEL_PT_MWAIT:
784 case INTEL_PT_PWRE:
785 case INTEL_PT_PWRX:
786 case INTEL_PT_OVF:
787 case INTEL_PT_BAD: /* Does not happen */
788 default:
789 return 1;
790 }
791
792 if (!data->cbr && decoder->cbr) {
793 data->cbr = decoder->cbr;
794 data->cbr_cyc_to_tsc = decoder->cbr_cyc_to_tsc;
795 }
796
797 if (!data->cycle_cnt)
798 return 1;
799
800 cyc_to_tsc = (double)(timestamp - decoder->timestamp) / data->cycle_cnt;
801
802 if (data->cbr && cyc_to_tsc > data->cbr_cyc_to_tsc &&
803 cyc_to_tsc / data->cbr_cyc_to_tsc > 1.25) {
804 intel_pt_log("Timestamp: calculated %g TSC ticks per cycle too big (c.f. CBR-based value %g), pos " x64_fmt "\n",
805 cyc_to_tsc, data->cbr_cyc_to_tsc, pkt_info->pos);
806 return 1;
807 }
808
809 decoder->calc_cyc_to_tsc = cyc_to_tsc;
810 decoder->have_calc_cyc_to_tsc = true;
811
812 if (data->cbr) {
813 intel_pt_log("Timestamp: calculated %g TSC ticks per cycle c.f. CBR-based value %g, pos " x64_fmt "\n",
814 cyc_to_tsc, data->cbr_cyc_to_tsc, pkt_info->pos);
815 } else {
816 intel_pt_log("Timestamp: calculated %g TSC ticks per cycle c.f. unknown CBR-based value, pos " x64_fmt "\n",
817 cyc_to_tsc, pkt_info->pos);
818 }
819
820 return 1;
821 }
822
823 static void intel_pt_calc_cyc_to_tsc(struct intel_pt_decoder *decoder,
824 bool from_mtc)
825 {
826 struct intel_pt_calc_cyc_to_tsc_info data = {
827 .cycle_cnt = 0,
828 .cbr = 0,
829 .last_mtc = decoder->last_mtc,
830 .ctc_timestamp = decoder->ctc_timestamp,
831 .ctc_delta = decoder->ctc_delta,
832 .tsc_timestamp = decoder->tsc_timestamp,
833 .timestamp = decoder->timestamp,
834 .have_tma = decoder->have_tma,
835 .fixup_last_mtc = decoder->fixup_last_mtc,
836 .from_mtc = from_mtc,
837 .cbr_cyc_to_tsc = 0,
838 };
839
840 /*
841 * For now, do not support using TSC packets for at least the reasons:
842 * 1) timing might have stopped
843 * 2) TSC packets within PSB+ can slip against CYC packets
844 */
845 if (!from_mtc)
846 return;
847
848 intel_pt_pkt_lookahead(decoder, intel_pt_calc_cyc_cb, &data);
849 }
850
851 static int intel_pt_get_next_packet(struct intel_pt_decoder *decoder)
852 {
853 int ret;
854
855 decoder->last_packet_type = decoder->packet.type;
856
857 do {
858 decoder->pos += decoder->pkt_step;
859 decoder->buf += decoder->pkt_step;
860 decoder->len -= decoder->pkt_step;
861
862 if (!decoder->len) {
863 ret = intel_pt_get_next_data(decoder);
864 if (ret)
865 return ret;
866 }
867
868 ret = intel_pt_get_packet(decoder->buf, decoder->len,
869 &decoder->packet);
870 if (ret == INTEL_PT_NEED_MORE_BYTES &&
871 decoder->len < INTEL_PT_PKT_MAX_SZ && !decoder->next_buf) {
872 ret = intel_pt_get_split_packet(decoder);
873 if (ret < 0)
874 return ret;
875 }
876 if (ret <= 0)
877 return intel_pt_bad_packet(decoder);
878
879 decoder->pkt_len = ret;
880 decoder->pkt_step = ret;
881 intel_pt_decoder_log_packet(decoder);
882 } while (decoder->packet.type == INTEL_PT_PAD);
883
884 return 0;
885 }
886
887 static uint64_t intel_pt_next_period(struct intel_pt_decoder *decoder)
888 {
889 uint64_t timestamp, masked_timestamp;
890
891 timestamp = decoder->timestamp + decoder->timestamp_insn_cnt;
892 masked_timestamp = timestamp & decoder->period_mask;
893 if (decoder->continuous_period) {
894 if (masked_timestamp != decoder->last_masked_timestamp)
895 return 1;
896 } else {
897 timestamp += 1;
898 masked_timestamp = timestamp & decoder->period_mask;
899 if (masked_timestamp != decoder->last_masked_timestamp) {
900 decoder->last_masked_timestamp = masked_timestamp;
901 decoder->continuous_period = true;
902 }
903 }
904 return decoder->period_ticks - (timestamp - masked_timestamp);
905 }
906
907 static uint64_t intel_pt_next_sample(struct intel_pt_decoder *decoder)
908 {
909 switch (decoder->period_type) {
910 case INTEL_PT_PERIOD_INSTRUCTIONS:
911 return decoder->period - decoder->period_insn_cnt;
912 case INTEL_PT_PERIOD_TICKS:
913 return intel_pt_next_period(decoder);
914 case INTEL_PT_PERIOD_NONE:
915 case INTEL_PT_PERIOD_MTC:
916 default:
917 return 0;
918 }
919 }
920
921 static void intel_pt_sample_insn(struct intel_pt_decoder *decoder)
922 {
923 uint64_t timestamp, masked_timestamp;
924
925 switch (decoder->period_type) {
926 case INTEL_PT_PERIOD_INSTRUCTIONS:
927 decoder->period_insn_cnt = 0;
928 break;
929 case INTEL_PT_PERIOD_TICKS:
930 timestamp = decoder->timestamp + decoder->timestamp_insn_cnt;
931 masked_timestamp = timestamp & decoder->period_mask;
932 decoder->last_masked_timestamp = masked_timestamp;
933 break;
934 case INTEL_PT_PERIOD_NONE:
935 case INTEL_PT_PERIOD_MTC:
936 default:
937 break;
938 }
939
940 decoder->state.type |= INTEL_PT_INSTRUCTION;
941 }
942
943 static int intel_pt_walk_insn(struct intel_pt_decoder *decoder,
944 struct intel_pt_insn *intel_pt_insn, uint64_t ip)
945 {
946 uint64_t max_insn_cnt, insn_cnt = 0;
947 int err;
948
949 if (!decoder->mtc_insn)
950 decoder->mtc_insn = true;
951
952 max_insn_cnt = intel_pt_next_sample(decoder);
953
954 err = decoder->walk_insn(intel_pt_insn, &insn_cnt, &decoder->ip, ip,
955 max_insn_cnt, decoder->data);
956
957 decoder->tot_insn_cnt += insn_cnt;
958 decoder->timestamp_insn_cnt += insn_cnt;
959 decoder->sample_insn_cnt += insn_cnt;
960 decoder->period_insn_cnt += insn_cnt;
961
962 if (err) {
963 decoder->no_progress = 0;
964 decoder->pkt_state = INTEL_PT_STATE_ERR2;
965 intel_pt_log_at("ERROR: Failed to get instruction",
966 decoder->ip);
967 if (err == -ENOENT)
968 return -ENOLINK;
969 return -EILSEQ;
970 }
971
972 if (ip && decoder->ip == ip) {
973 err = -EAGAIN;
974 goto out;
975 }
976
977 if (max_insn_cnt && insn_cnt >= max_insn_cnt)
978 intel_pt_sample_insn(decoder);
979
980 if (intel_pt_insn->branch == INTEL_PT_BR_NO_BRANCH) {
981 decoder->state.type = INTEL_PT_INSTRUCTION;
982 decoder->state.from_ip = decoder->ip;
983 decoder->state.to_ip = 0;
984 decoder->ip += intel_pt_insn->length;
985 err = INTEL_PT_RETURN;
986 goto out;
987 }
988
989 if (intel_pt_insn->op == INTEL_PT_OP_CALL) {
990 /* Zero-length calls are excluded */
991 if (intel_pt_insn->branch != INTEL_PT_BR_UNCONDITIONAL ||
992 intel_pt_insn->rel) {
993 err = intel_pt_push(&decoder->stack, decoder->ip +
994 intel_pt_insn->length);
995 if (err)
996 goto out;
997 }
998 } else if (intel_pt_insn->op == INTEL_PT_OP_RET) {
999 decoder->ret_addr = intel_pt_pop(&decoder->stack);
1000 }
1001
1002 if (intel_pt_insn->branch == INTEL_PT_BR_UNCONDITIONAL) {
1003 int cnt = decoder->no_progress++;
1004
1005 decoder->state.from_ip = decoder->ip;
1006 decoder->ip += intel_pt_insn->length +
1007 intel_pt_insn->rel;
1008 decoder->state.to_ip = decoder->ip;
1009 err = INTEL_PT_RETURN;
1010
1011 /*
1012 * Check for being stuck in a loop. This can happen if a
1013 * decoder error results in the decoder erroneously setting the
1014 * ip to an address that is itself in an infinite loop that
1015 * consumes no packets. When that happens, there must be an
1016 * unconditional branch.
1017 */
1018 if (cnt) {
1019 if (cnt == 1) {
1020 decoder->stuck_ip = decoder->state.to_ip;
1021 decoder->stuck_ip_prd = 1;
1022 decoder->stuck_ip_cnt = 1;
1023 } else if (cnt > INTEL_PT_MAX_LOOPS ||
1024 decoder->state.to_ip == decoder->stuck_ip) {
1025 intel_pt_log_at("ERROR: Never-ending loop",
1026 decoder->state.to_ip);
1027 decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
1028 err = -ELOOP;
1029 goto out;
1030 } else if (!--decoder->stuck_ip_cnt) {
1031 decoder->stuck_ip_prd += 1;
1032 decoder->stuck_ip_cnt = decoder->stuck_ip_prd;
1033 decoder->stuck_ip = decoder->state.to_ip;
1034 }
1035 }
1036 goto out_no_progress;
1037 }
1038 out:
1039 decoder->no_progress = 0;
1040 out_no_progress:
1041 decoder->state.insn_op = intel_pt_insn->op;
1042 decoder->state.insn_len = intel_pt_insn->length;
1043 memcpy(decoder->state.insn, intel_pt_insn->buf,
1044 INTEL_PT_INSN_BUF_SZ);
1045
1046 if (decoder->tx_flags & INTEL_PT_IN_TX)
1047 decoder->state.flags |= INTEL_PT_IN_TX;
1048
1049 return err;
1050 }
1051
1052 static bool intel_pt_fup_event(struct intel_pt_decoder *decoder)
1053 {
1054 bool ret = false;
1055
1056 if (decoder->set_fup_tx_flags) {
1057 decoder->set_fup_tx_flags = false;
1058 decoder->tx_flags = decoder->fup_tx_flags;
1059 decoder->state.type = INTEL_PT_TRANSACTION;
1060 decoder->state.from_ip = decoder->ip;
1061 decoder->state.to_ip = 0;
1062 decoder->state.flags = decoder->fup_tx_flags;
1063 return true;
1064 }
1065 if (decoder->set_fup_ptw) {
1066 decoder->set_fup_ptw = false;
1067 decoder->state.type = INTEL_PT_PTW;
1068 decoder->state.flags |= INTEL_PT_FUP_IP;
1069 decoder->state.from_ip = decoder->ip;
1070 decoder->state.to_ip = 0;
1071 decoder->state.ptw_payload = decoder->fup_ptw_payload;
1072 return true;
1073 }
1074 if (decoder->set_fup_mwait) {
1075 decoder->set_fup_mwait = false;
1076 decoder->state.type = INTEL_PT_MWAIT_OP;
1077 decoder->state.from_ip = decoder->ip;
1078 decoder->state.to_ip = 0;
1079 decoder->state.mwait_payload = decoder->fup_mwait_payload;
1080 ret = true;
1081 }
1082 if (decoder->set_fup_pwre) {
1083 decoder->set_fup_pwre = false;
1084 decoder->state.type |= INTEL_PT_PWR_ENTRY;
1085 decoder->state.type &= ~INTEL_PT_BRANCH;
1086 decoder->state.from_ip = decoder->ip;
1087 decoder->state.to_ip = 0;
1088 decoder->state.pwre_payload = decoder->fup_pwre_payload;
1089 ret = true;
1090 }
1091 if (decoder->set_fup_exstop) {
1092 decoder->set_fup_exstop = false;
1093 decoder->state.type |= INTEL_PT_EX_STOP;
1094 decoder->state.type &= ~INTEL_PT_BRANCH;
1095 decoder->state.flags |= INTEL_PT_FUP_IP;
1096 decoder->state.from_ip = decoder->ip;
1097 decoder->state.to_ip = 0;
1098 ret = true;
1099 }
1100 return ret;
1101 }
1102
1103 static inline bool intel_pt_fup_with_nlip(struct intel_pt_decoder *decoder,
1104 struct intel_pt_insn *intel_pt_insn,
1105 uint64_t ip, int err)
1106 {
1107 return decoder->flags & INTEL_PT_FUP_WITH_NLIP && !err &&
1108 intel_pt_insn->branch == INTEL_PT_BR_INDIRECT &&
1109 ip == decoder->ip + intel_pt_insn->length;
1110 }
1111
1112 static int intel_pt_walk_fup(struct intel_pt_decoder *decoder)
1113 {
1114 struct intel_pt_insn intel_pt_insn;
1115 uint64_t ip;
1116 int err;
1117
1118 ip = decoder->last_ip;
1119
1120 while (1) {
1121 err = intel_pt_walk_insn(decoder, &intel_pt_insn, ip);
1122 if (err == INTEL_PT_RETURN)
1123 return 0;
1124 if (err == -EAGAIN ||
1125 intel_pt_fup_with_nlip(decoder, &intel_pt_insn, ip, err)) {
1126 if (intel_pt_fup_event(decoder))
1127 return 0;
1128 return -EAGAIN;
1129 }
1130 decoder->set_fup_tx_flags = false;
1131 if (err)
1132 return err;
1133
1134 if (intel_pt_insn.branch == INTEL_PT_BR_INDIRECT) {
1135 intel_pt_log_at("ERROR: Unexpected indirect branch",
1136 decoder->ip);
1137 decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
1138 return -ENOENT;
1139 }
1140
1141 if (intel_pt_insn.branch == INTEL_PT_BR_CONDITIONAL) {
1142 intel_pt_log_at("ERROR: Unexpected conditional branch",
1143 decoder->ip);
1144 decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
1145 return -ENOENT;
1146 }
1147
1148 intel_pt_bug(decoder);
1149 }
1150 }
1151
1152 static int intel_pt_walk_tip(struct intel_pt_decoder *decoder)
1153 {
1154 struct intel_pt_insn intel_pt_insn;
1155 int err;
1156
1157 err = intel_pt_walk_insn(decoder, &intel_pt_insn, 0);
1158 if (err == INTEL_PT_RETURN &&
1159 decoder->pgd_ip &&
1160 decoder->pkt_state == INTEL_PT_STATE_TIP_PGD &&
1161 (decoder->state.type & INTEL_PT_BRANCH) &&
1162 decoder->pgd_ip(decoder->state.to_ip, decoder->data)) {
1163 /* Unconditional branch leaving filter region */
1164 decoder->no_progress = 0;
1165 decoder->pge = false;
1166 decoder->continuous_period = false;
1167 decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1168 decoder->state.to_ip = 0;
1169 return 0;
1170 }
1171 if (err == INTEL_PT_RETURN)
1172 return 0;
1173 if (err)
1174 return err;
1175
1176 if (intel_pt_insn.branch == INTEL_PT_BR_INDIRECT) {
1177 if (decoder->pkt_state == INTEL_PT_STATE_TIP_PGD) {
1178 decoder->pge = false;
1179 decoder->continuous_period = false;
1180 decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1181 decoder->state.from_ip = decoder->ip;
1182 decoder->state.to_ip = 0;
1183 if (decoder->packet.count != 0)
1184 decoder->ip = decoder->last_ip;
1185 } else {
1186 decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1187 decoder->state.from_ip = decoder->ip;
1188 if (decoder->packet.count == 0) {
1189 decoder->state.to_ip = 0;
1190 } else {
1191 decoder->state.to_ip = decoder->last_ip;
1192 decoder->ip = decoder->last_ip;
1193 }
1194 }
1195 return 0;
1196 }
1197
1198 if (intel_pt_insn.branch == INTEL_PT_BR_CONDITIONAL) {
1199 uint64_t to_ip = decoder->ip + intel_pt_insn.length +
1200 intel_pt_insn.rel;
1201
1202 if (decoder->pgd_ip &&
1203 decoder->pkt_state == INTEL_PT_STATE_TIP_PGD &&
1204 decoder->pgd_ip(to_ip, decoder->data)) {
1205 /* Conditional branch leaving filter region */
1206 decoder->pge = false;
1207 decoder->continuous_period = false;
1208 decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1209 decoder->ip = to_ip;
1210 decoder->state.from_ip = decoder->ip;
1211 decoder->state.to_ip = 0;
1212 return 0;
1213 }
1214 intel_pt_log_at("ERROR: Conditional branch when expecting indirect branch",
1215 decoder->ip);
1216 decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
1217 return -ENOENT;
1218 }
1219
1220 return intel_pt_bug(decoder);
1221 }
1222
1223 static int intel_pt_walk_tnt(struct intel_pt_decoder *decoder)
1224 {
1225 struct intel_pt_insn intel_pt_insn;
1226 int err;
1227
1228 while (1) {
1229 err = intel_pt_walk_insn(decoder, &intel_pt_insn, 0);
1230 if (err == INTEL_PT_RETURN)
1231 return 0;
1232 if (err)
1233 return err;
1234
1235 if (intel_pt_insn.op == INTEL_PT_OP_RET) {
1236 if (!decoder->return_compression) {
1237 intel_pt_log_at("ERROR: RET when expecting conditional branch",
1238 decoder->ip);
1239 decoder->pkt_state = INTEL_PT_STATE_ERR3;
1240 return -ENOENT;
1241 }
1242 if (!decoder->ret_addr) {
1243 intel_pt_log_at("ERROR: Bad RET compression (stack empty)",
1244 decoder->ip);
1245 decoder->pkt_state = INTEL_PT_STATE_ERR3;
1246 return -ENOENT;
1247 }
1248 if (!(decoder->tnt.payload & BIT63)) {
1249 intel_pt_log_at("ERROR: Bad RET compression (TNT=N)",
1250 decoder->ip);
1251 decoder->pkt_state = INTEL_PT_STATE_ERR3;
1252 return -ENOENT;
1253 }
1254 decoder->tnt.count -= 1;
1255 if (!decoder->tnt.count)
1256 decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1257 decoder->tnt.payload <<= 1;
1258 decoder->state.from_ip = decoder->ip;
1259 decoder->ip = decoder->ret_addr;
1260 decoder->state.to_ip = decoder->ip;
1261 return 0;
1262 }
1263
1264 if (intel_pt_insn.branch == INTEL_PT_BR_INDIRECT) {
1265 /* Handle deferred TIPs */
1266 err = intel_pt_get_next_packet(decoder);
1267 if (err)
1268 return err;
1269 if (decoder->packet.type != INTEL_PT_TIP ||
1270 decoder->packet.count == 0) {
1271 intel_pt_log_at("ERROR: Missing deferred TIP for indirect branch",
1272 decoder->ip);
1273 decoder->pkt_state = INTEL_PT_STATE_ERR3;
1274 decoder->pkt_step = 0;
1275 return -ENOENT;
1276 }
1277 intel_pt_set_last_ip(decoder);
1278 decoder->state.from_ip = decoder->ip;
1279 decoder->state.to_ip = decoder->last_ip;
1280 decoder->ip = decoder->last_ip;
1281 return 0;
1282 }
1283
1284 if (intel_pt_insn.branch == INTEL_PT_BR_CONDITIONAL) {
1285 decoder->tnt.count -= 1;
1286 if (!decoder->tnt.count)
1287 decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1288 if (decoder->tnt.payload & BIT63) {
1289 decoder->tnt.payload <<= 1;
1290 decoder->state.from_ip = decoder->ip;
1291 decoder->ip += intel_pt_insn.length +
1292 intel_pt_insn.rel;
1293 decoder->state.to_ip = decoder->ip;
1294 return 0;
1295 }
1296 /* Instruction sample for a non-taken branch */
1297 if (decoder->state.type & INTEL_PT_INSTRUCTION) {
1298 decoder->tnt.payload <<= 1;
1299 decoder->state.type = INTEL_PT_INSTRUCTION;
1300 decoder->state.from_ip = decoder->ip;
1301 decoder->state.to_ip = 0;
1302 decoder->ip += intel_pt_insn.length;
1303 return 0;
1304 }
1305 decoder->ip += intel_pt_insn.length;
1306 if (!decoder->tnt.count)
1307 return -EAGAIN;
1308 decoder->tnt.payload <<= 1;
1309 continue;
1310 }
1311
1312 return intel_pt_bug(decoder);
1313 }
1314 }
1315
1316 static int intel_pt_mode_tsx(struct intel_pt_decoder *decoder, bool *no_tip)
1317 {
1318 unsigned int fup_tx_flags;
1319 int err;
1320
1321 fup_tx_flags = decoder->packet.payload &
1322 (INTEL_PT_IN_TX | INTEL_PT_ABORT_TX);
1323 err = intel_pt_get_next_packet(decoder);
1324 if (err)
1325 return err;
1326 if (decoder->packet.type == INTEL_PT_FUP) {
1327 decoder->fup_tx_flags = fup_tx_flags;
1328 decoder->set_fup_tx_flags = true;
1329 if (!(decoder->fup_tx_flags & INTEL_PT_ABORT_TX))
1330 *no_tip = true;
1331 } else {
1332 intel_pt_log_at("ERROR: Missing FUP after MODE.TSX",
1333 decoder->pos);
1334 intel_pt_update_in_tx(decoder);
1335 }
1336 return 0;
1337 }
1338
1339 static void intel_pt_calc_tsc_timestamp(struct intel_pt_decoder *decoder)
1340 {
1341 uint64_t timestamp;
1342
1343 decoder->have_tma = false;
1344
1345 if (decoder->ref_timestamp) {
1346 timestamp = decoder->packet.payload |
1347 (decoder->ref_timestamp & (0xffULL << 56));
1348 if (timestamp < decoder->ref_timestamp) {
1349 if (decoder->ref_timestamp - timestamp > (1ULL << 55))
1350 timestamp += (1ULL << 56);
1351 } else {
1352 if (timestamp - decoder->ref_timestamp > (1ULL << 55))
1353 timestamp -= (1ULL << 56);
1354 }
1355 decoder->tsc_timestamp = timestamp;
1356 decoder->timestamp = timestamp;
1357 decoder->ref_timestamp = 0;
1358 decoder->timestamp_insn_cnt = 0;
1359 } else if (decoder->timestamp) {
1360 timestamp = decoder->packet.payload |
1361 (decoder->timestamp & (0xffULL << 56));
1362 decoder->tsc_timestamp = timestamp;
1363 if (timestamp < decoder->timestamp &&
1364 decoder->timestamp - timestamp < decoder->tsc_slip) {
1365 intel_pt_log_to("Suppressing backwards timestamp",
1366 timestamp);
1367 timestamp = decoder->timestamp;
1368 }
1369 if (timestamp < decoder->timestamp) {
1370 intel_pt_log_to("Wraparound timestamp", timestamp);
1371 timestamp += (1ULL << 56);
1372 decoder->tsc_timestamp = timestamp;
1373 }
1374 decoder->timestamp = timestamp;
1375 decoder->timestamp_insn_cnt = 0;
1376 }
1377
1378 if (decoder->last_packet_type == INTEL_PT_CYC) {
1379 decoder->cyc_ref_timestamp = decoder->timestamp;
1380 decoder->cycle_cnt = 0;
1381 decoder->have_calc_cyc_to_tsc = false;
1382 intel_pt_calc_cyc_to_tsc(decoder, false);
1383 }
1384
1385 intel_pt_log_to("Setting timestamp", decoder->timestamp);
1386 }
1387
1388 static int intel_pt_overflow(struct intel_pt_decoder *decoder)
1389 {
1390 intel_pt_log("ERROR: Buffer overflow\n");
1391 intel_pt_clear_tx_flags(decoder);
1392 decoder->cbr = 0;
1393 decoder->timestamp_insn_cnt = 0;
1394 decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
1395 decoder->overflow = true;
1396 return -EOVERFLOW;
1397 }
1398
1399 static void intel_pt_calc_tma(struct intel_pt_decoder *decoder)
1400 {
1401 uint32_t ctc = decoder->packet.payload;
1402 uint32_t fc = decoder->packet.count;
1403 uint32_t ctc_rem = ctc & decoder->ctc_rem_mask;
1404
1405 if (!decoder->tsc_ctc_ratio_d)
1406 return;
1407
1408 decoder->last_mtc = (ctc >> decoder->mtc_shift) & 0xff;
1409 decoder->ctc_timestamp = decoder->tsc_timestamp - fc;
1410 if (decoder->tsc_ctc_mult) {
1411 decoder->ctc_timestamp -= ctc_rem * decoder->tsc_ctc_mult;
1412 } else {
1413 decoder->ctc_timestamp -= multdiv(ctc_rem,
1414 decoder->tsc_ctc_ratio_n,
1415 decoder->tsc_ctc_ratio_d);
1416 }
1417 decoder->ctc_delta = 0;
1418 decoder->have_tma = true;
1419 decoder->fixup_last_mtc = true;
1420 intel_pt_log("CTC timestamp " x64_fmt " last MTC %#x CTC rem %#x\n",
1421 decoder->ctc_timestamp, decoder->last_mtc, ctc_rem);
1422 }
1423
1424 static void intel_pt_calc_mtc_timestamp(struct intel_pt_decoder *decoder)
1425 {
1426 uint64_t timestamp;
1427 uint32_t mtc, mtc_delta;
1428
1429 if (!decoder->have_tma)
1430 return;
1431
1432 mtc = decoder->packet.payload;
1433
1434 if (decoder->mtc_shift > 8 && decoder->fixup_last_mtc) {
1435 decoder->fixup_last_mtc = false;
1436 intel_pt_fixup_last_mtc(mtc, decoder->mtc_shift,
1437 &decoder->last_mtc);
1438 }
1439
1440 if (mtc > decoder->last_mtc)
1441 mtc_delta = mtc - decoder->last_mtc;
1442 else
1443 mtc_delta = mtc + 256 - decoder->last_mtc;
1444
1445 decoder->ctc_delta += mtc_delta << decoder->mtc_shift;
1446
1447 if (decoder->tsc_ctc_mult) {
1448 timestamp = decoder->ctc_timestamp +
1449 decoder->ctc_delta * decoder->tsc_ctc_mult;
1450 } else {
1451 timestamp = decoder->ctc_timestamp +
1452 multdiv(decoder->ctc_delta,
1453 decoder->tsc_ctc_ratio_n,
1454 decoder->tsc_ctc_ratio_d);
1455 }
1456
1457 if (timestamp < decoder->timestamp)
1458 intel_pt_log("Suppressing MTC timestamp " x64_fmt " less than current timestamp " x64_fmt "\n",
1459 timestamp, decoder->timestamp);
1460 else
1461 decoder->timestamp = timestamp;
1462
1463 decoder->timestamp_insn_cnt = 0;
1464 decoder->last_mtc = mtc;
1465
1466 if (decoder->last_packet_type == INTEL_PT_CYC) {
1467 decoder->cyc_ref_timestamp = decoder->timestamp;
1468 decoder->cycle_cnt = 0;
1469 decoder->have_calc_cyc_to_tsc = false;
1470 intel_pt_calc_cyc_to_tsc(decoder, true);
1471 }
1472 }
1473
1474 static void intel_pt_calc_cbr(struct intel_pt_decoder *decoder)
1475 {
1476 unsigned int cbr = decoder->packet.payload & 0xff;
1477
1478 decoder->cbr_payload = decoder->packet.payload;
1479
1480 if (decoder->cbr == cbr)
1481 return;
1482
1483 decoder->cbr = cbr;
1484 decoder->cbr_cyc_to_tsc = decoder->max_non_turbo_ratio_fp / cbr;
1485 }
1486
1487 static void intel_pt_calc_cyc_timestamp(struct intel_pt_decoder *decoder)
1488 {
1489 uint64_t timestamp = decoder->cyc_ref_timestamp;
1490
1491 decoder->have_cyc = true;
1492
1493 decoder->cycle_cnt += decoder->packet.payload;
1494
1495 if (!decoder->cyc_ref_timestamp)
1496 return;
1497
1498 if (decoder->have_calc_cyc_to_tsc)
1499 timestamp += decoder->cycle_cnt * decoder->calc_cyc_to_tsc;
1500 else if (decoder->cbr)
1501 timestamp += decoder->cycle_cnt * decoder->cbr_cyc_to_tsc;
1502 else
1503 return;
1504
1505 if (timestamp < decoder->timestamp)
1506 intel_pt_log("Suppressing CYC timestamp " x64_fmt " less than current timestamp " x64_fmt "\n",
1507 timestamp, decoder->timestamp);
1508 else
1509 decoder->timestamp = timestamp;
1510
1511 decoder->timestamp_insn_cnt = 0;
1512 }
1513
1514 /* Walk PSB+ packets when already in sync. */
1515 static int intel_pt_walk_psbend(struct intel_pt_decoder *decoder)
1516 {
1517 int err;
1518
1519 while (1) {
1520 err = intel_pt_get_next_packet(decoder);
1521 if (err)
1522 return err;
1523
1524 switch (decoder->packet.type) {
1525 case INTEL_PT_PSBEND:
1526 return 0;
1527
1528 case INTEL_PT_TIP_PGD:
1529 case INTEL_PT_TIP_PGE:
1530 case INTEL_PT_TIP:
1531 case INTEL_PT_TNT:
1532 case INTEL_PT_TRACESTOP:
1533 case INTEL_PT_BAD:
1534 case INTEL_PT_PSB:
1535 case INTEL_PT_PTWRITE:
1536 case INTEL_PT_PTWRITE_IP:
1537 case INTEL_PT_EXSTOP:
1538 case INTEL_PT_EXSTOP_IP:
1539 case INTEL_PT_MWAIT:
1540 case INTEL_PT_PWRE:
1541 case INTEL_PT_PWRX:
1542 decoder->have_tma = false;
1543 intel_pt_log("ERROR: Unexpected packet\n");
1544 return -EAGAIN;
1545
1546 case INTEL_PT_OVF:
1547 return intel_pt_overflow(decoder);
1548
1549 case INTEL_PT_TSC:
1550 intel_pt_calc_tsc_timestamp(decoder);
1551 break;
1552
1553 case INTEL_PT_TMA:
1554 intel_pt_calc_tma(decoder);
1555 break;
1556
1557 case INTEL_PT_CBR:
1558 intel_pt_calc_cbr(decoder);
1559 break;
1560
1561 case INTEL_PT_MODE_EXEC:
1562 decoder->exec_mode = decoder->packet.payload;
1563 break;
1564
1565 case INTEL_PT_PIP:
1566 decoder->cr3 = decoder->packet.payload & (BIT63 - 1);
1567 break;
1568
1569 case INTEL_PT_FUP:
1570 decoder->pge = true;
1571 if (decoder->packet.count)
1572 intel_pt_set_last_ip(decoder);
1573 break;
1574
1575 case INTEL_PT_MODE_TSX:
1576 intel_pt_update_in_tx(decoder);
1577 break;
1578
1579 case INTEL_PT_MTC:
1580 intel_pt_calc_mtc_timestamp(decoder);
1581 if (decoder->period_type == INTEL_PT_PERIOD_MTC)
1582 decoder->state.type |= INTEL_PT_INSTRUCTION;
1583 break;
1584
1585 case INTEL_PT_CYC:
1586 case INTEL_PT_VMCS:
1587 case INTEL_PT_MNT:
1588 case INTEL_PT_PAD:
1589 default:
1590 break;
1591 }
1592 }
1593 }
1594
1595 static int intel_pt_walk_fup_tip(struct intel_pt_decoder *decoder)
1596 {
1597 int err;
1598
1599 if (decoder->tx_flags & INTEL_PT_ABORT_TX) {
1600 decoder->tx_flags = 0;
1601 decoder->state.flags &= ~INTEL_PT_IN_TX;
1602 decoder->state.flags |= INTEL_PT_ABORT_TX;
1603 } else {
1604 decoder->state.flags |= INTEL_PT_ASYNC;
1605 }
1606
1607 while (1) {
1608 err = intel_pt_get_next_packet(decoder);
1609 if (err)
1610 return err;
1611
1612 switch (decoder->packet.type) {
1613 case INTEL_PT_TNT:
1614 case INTEL_PT_FUP:
1615 case INTEL_PT_TRACESTOP:
1616 case INTEL_PT_PSB:
1617 case INTEL_PT_TSC:
1618 case INTEL_PT_TMA:
1619 case INTEL_PT_MODE_TSX:
1620 case INTEL_PT_BAD:
1621 case INTEL_PT_PSBEND:
1622 case INTEL_PT_PTWRITE:
1623 case INTEL_PT_PTWRITE_IP:
1624 case INTEL_PT_EXSTOP:
1625 case INTEL_PT_EXSTOP_IP:
1626 case INTEL_PT_MWAIT:
1627 case INTEL_PT_PWRE:
1628 case INTEL_PT_PWRX:
1629 intel_pt_log("ERROR: Missing TIP after FUP\n");
1630 decoder->pkt_state = INTEL_PT_STATE_ERR3;
1631 decoder->pkt_step = 0;
1632 return -ENOENT;
1633
1634 case INTEL_PT_CBR:
1635 intel_pt_calc_cbr(decoder);
1636 break;
1637
1638 case INTEL_PT_OVF:
1639 return intel_pt_overflow(decoder);
1640
1641 case INTEL_PT_TIP_PGD:
1642 decoder->state.from_ip = decoder->ip;
1643 decoder->state.to_ip = 0;
1644 if (decoder->packet.count != 0) {
1645 intel_pt_set_ip(decoder);
1646 intel_pt_log("Omitting PGD ip " x64_fmt "\n",
1647 decoder->ip);
1648 }
1649 decoder->pge = false;
1650 decoder->continuous_period = false;
1651 return 0;
1652
1653 case INTEL_PT_TIP_PGE:
1654 decoder->pge = true;
1655 intel_pt_log("Omitting PGE ip " x64_fmt "\n",
1656 decoder->ip);
1657 decoder->state.from_ip = 0;
1658 if (decoder->packet.count == 0) {
1659 decoder->state.to_ip = 0;
1660 } else {
1661 intel_pt_set_ip(decoder);
1662 decoder->state.to_ip = decoder->ip;
1663 }
1664 return 0;
1665
1666 case INTEL_PT_TIP:
1667 decoder->state.from_ip = decoder->ip;
1668 if (decoder->packet.count == 0) {
1669 decoder->state.to_ip = 0;
1670 } else {
1671 intel_pt_set_ip(decoder);
1672 decoder->state.to_ip = decoder->ip;
1673 }
1674 return 0;
1675
1676 case INTEL_PT_PIP:
1677 decoder->cr3 = decoder->packet.payload & (BIT63 - 1);
1678 break;
1679
1680 case INTEL_PT_MTC:
1681 intel_pt_calc_mtc_timestamp(decoder);
1682 if (decoder->period_type == INTEL_PT_PERIOD_MTC)
1683 decoder->state.type |= INTEL_PT_INSTRUCTION;
1684 break;
1685
1686 case INTEL_PT_CYC:
1687 intel_pt_calc_cyc_timestamp(decoder);
1688 break;
1689
1690 case INTEL_PT_MODE_EXEC:
1691 decoder->exec_mode = decoder->packet.payload;
1692 break;
1693
1694 case INTEL_PT_VMCS:
1695 case INTEL_PT_MNT:
1696 case INTEL_PT_PAD:
1697 break;
1698
1699 default:
1700 return intel_pt_bug(decoder);
1701 }
1702 }
1703 }
1704
1705 static int intel_pt_walk_trace(struct intel_pt_decoder *decoder)
1706 {
1707 bool no_tip = false;
1708 int err;
1709
1710 while (1) {
1711 err = intel_pt_get_next_packet(decoder);
1712 if (err)
1713 return err;
1714 next:
1715 switch (decoder->packet.type) {
1716 case INTEL_PT_TNT:
1717 if (!decoder->packet.count)
1718 break;
1719 decoder->tnt = decoder->packet;
1720 decoder->pkt_state = INTEL_PT_STATE_TNT;
1721 err = intel_pt_walk_tnt(decoder);
1722 if (err == -EAGAIN)
1723 break;
1724 return err;
1725
1726 case INTEL_PT_TIP_PGD:
1727 if (decoder->packet.count != 0)
1728 intel_pt_set_last_ip(decoder);
1729 decoder->pkt_state = INTEL_PT_STATE_TIP_PGD;
1730 return intel_pt_walk_tip(decoder);
1731
1732 case INTEL_PT_TIP_PGE: {
1733 decoder->pge = true;
1734 if (decoder->packet.count == 0) {
1735 intel_pt_log_at("Skipping zero TIP.PGE",
1736 decoder->pos);
1737 break;
1738 }
1739 intel_pt_set_ip(decoder);
1740 decoder->state.from_ip = 0;
1741 decoder->state.to_ip = decoder->ip;
1742 return 0;
1743 }
1744
1745 case INTEL_PT_OVF:
1746 return intel_pt_overflow(decoder);
1747
1748 case INTEL_PT_TIP:
1749 if (decoder->packet.count != 0)
1750 intel_pt_set_last_ip(decoder);
1751 decoder->pkt_state = INTEL_PT_STATE_TIP;
1752 return intel_pt_walk_tip(decoder);
1753
1754 case INTEL_PT_FUP:
1755 if (decoder->packet.count == 0) {
1756 intel_pt_log_at("Skipping zero FUP",
1757 decoder->pos);
1758 no_tip = false;
1759 break;
1760 }
1761 intel_pt_set_last_ip(decoder);
1762 if (!decoder->branch_enable) {
1763 decoder->ip = decoder->last_ip;
1764 if (intel_pt_fup_event(decoder))
1765 return 0;
1766 no_tip = false;
1767 break;
1768 }
1769 if (decoder->set_fup_mwait)
1770 no_tip = true;
1771 err = intel_pt_walk_fup(decoder);
1772 if (err != -EAGAIN) {
1773 if (err)
1774 return err;
1775 if (no_tip)
1776 decoder->pkt_state =
1777 INTEL_PT_STATE_FUP_NO_TIP;
1778 else
1779 decoder->pkt_state = INTEL_PT_STATE_FUP;
1780 return 0;
1781 }
1782 if (no_tip) {
1783 no_tip = false;
1784 break;
1785 }
1786 return intel_pt_walk_fup_tip(decoder);
1787
1788 case INTEL_PT_TRACESTOP:
1789 decoder->pge = false;
1790 decoder->continuous_period = false;
1791 intel_pt_clear_tx_flags(decoder);
1792 decoder->have_tma = false;
1793 break;
1794
1795 case INTEL_PT_PSB:
1796 decoder->last_ip = 0;
1797 decoder->have_last_ip = true;
1798 intel_pt_clear_stack(&decoder->stack);
1799 err = intel_pt_walk_psbend(decoder);
1800 if (err == -EAGAIN)
1801 goto next;
1802 if (err)
1803 return err;
1804 break;
1805
1806 case INTEL_PT_PIP:
1807 decoder->cr3 = decoder->packet.payload & (BIT63 - 1);
1808 break;
1809
1810 case INTEL_PT_MTC:
1811 intel_pt_calc_mtc_timestamp(decoder);
1812 if (decoder->period_type != INTEL_PT_PERIOD_MTC)
1813 break;
1814 /*
1815 * Ensure that there has been an instruction since the
1816 * last MTC.
1817 */
1818 if (!decoder->mtc_insn)
1819 break;
1820 decoder->mtc_insn = false;
1821 /* Ensure that there is a timestamp */
1822 if (!decoder->timestamp)
1823 break;
1824 decoder->state.type = INTEL_PT_INSTRUCTION;
1825 decoder->state.from_ip = decoder->ip;
1826 decoder->state.to_ip = 0;
1827 decoder->mtc_insn = false;
1828 return 0;
1829
1830 case INTEL_PT_TSC:
1831 intel_pt_calc_tsc_timestamp(decoder);
1832 break;
1833
1834 case INTEL_PT_TMA:
1835 intel_pt_calc_tma(decoder);
1836 break;
1837
1838 case INTEL_PT_CYC:
1839 intel_pt_calc_cyc_timestamp(decoder);
1840 break;
1841
1842 case INTEL_PT_CBR:
1843 intel_pt_calc_cbr(decoder);
1844 if (!decoder->branch_enable &&
1845 decoder->cbr != decoder->cbr_seen) {
1846 decoder->cbr_seen = decoder->cbr;
1847 decoder->state.type = INTEL_PT_CBR_CHG;
1848 decoder->state.from_ip = decoder->ip;
1849 decoder->state.to_ip = 0;
1850 decoder->state.cbr_payload =
1851 decoder->packet.payload;
1852 return 0;
1853 }
1854 break;
1855
1856 case INTEL_PT_MODE_EXEC:
1857 decoder->exec_mode = decoder->packet.payload;
1858 break;
1859
1860 case INTEL_PT_MODE_TSX:
1861 /* MODE_TSX need not be followed by FUP */
1862 if (!decoder->pge) {
1863 intel_pt_update_in_tx(decoder);
1864 break;
1865 }
1866 err = intel_pt_mode_tsx(decoder, &no_tip);
1867 if (err)
1868 return err;
1869 goto next;
1870
1871 case INTEL_PT_BAD: /* Does not happen */
1872 return intel_pt_bug(decoder);
1873
1874 case INTEL_PT_PSBEND:
1875 case INTEL_PT_VMCS:
1876 case INTEL_PT_MNT:
1877 case INTEL_PT_PAD:
1878 break;
1879
1880 case INTEL_PT_PTWRITE_IP:
1881 decoder->fup_ptw_payload = decoder->packet.payload;
1882 err = intel_pt_get_next_packet(decoder);
1883 if (err)
1884 return err;
1885 if (decoder->packet.type == INTEL_PT_FUP) {
1886 decoder->set_fup_ptw = true;
1887 no_tip = true;
1888 } else {
1889 intel_pt_log_at("ERROR: Missing FUP after PTWRITE",
1890 decoder->pos);
1891 }
1892 goto next;
1893
1894 case INTEL_PT_PTWRITE:
1895 decoder->state.type = INTEL_PT_PTW;
1896 decoder->state.from_ip = decoder->ip;
1897 decoder->state.to_ip = 0;
1898 decoder->state.ptw_payload = decoder->packet.payload;
1899 return 0;
1900
1901 case INTEL_PT_MWAIT:
1902 decoder->fup_mwait_payload = decoder->packet.payload;
1903 decoder->set_fup_mwait = true;
1904 break;
1905
1906 case INTEL_PT_PWRE:
1907 if (decoder->set_fup_mwait) {
1908 decoder->fup_pwre_payload =
1909 decoder->packet.payload;
1910 decoder->set_fup_pwre = true;
1911 break;
1912 }
1913 decoder->state.type = INTEL_PT_PWR_ENTRY;
1914 decoder->state.from_ip = decoder->ip;
1915 decoder->state.to_ip = 0;
1916 decoder->state.pwrx_payload = decoder->packet.payload;
1917 return 0;
1918
1919 case INTEL_PT_EXSTOP_IP:
1920 err = intel_pt_get_next_packet(decoder);
1921 if (err)
1922 return err;
1923 if (decoder->packet.type == INTEL_PT_FUP) {
1924 decoder->set_fup_exstop = true;
1925 no_tip = true;
1926 } else {
1927 intel_pt_log_at("ERROR: Missing FUP after EXSTOP",
1928 decoder->pos);
1929 }
1930 goto next;
1931
1932 case INTEL_PT_EXSTOP:
1933 decoder->state.type = INTEL_PT_EX_STOP;
1934 decoder->state.from_ip = decoder->ip;
1935 decoder->state.to_ip = 0;
1936 return 0;
1937
1938 case INTEL_PT_PWRX:
1939 decoder->state.type = INTEL_PT_PWR_EXIT;
1940 decoder->state.from_ip = decoder->ip;
1941 decoder->state.to_ip = 0;
1942 decoder->state.pwrx_payload = decoder->packet.payload;
1943 return 0;
1944
1945 default:
1946 return intel_pt_bug(decoder);
1947 }
1948 }
1949 }
1950
1951 static inline bool intel_pt_have_ip(struct intel_pt_decoder *decoder)
1952 {
1953 return decoder->packet.count &&
1954 (decoder->have_last_ip || decoder->packet.count == 3 ||
1955 decoder->packet.count == 6);
1956 }
1957
1958 /* Walk PSB+ packets to get in sync. */
1959 static int intel_pt_walk_psb(struct intel_pt_decoder *decoder)
1960 {
1961 int err;
1962
1963 while (1) {
1964 err = intel_pt_get_next_packet(decoder);
1965 if (err)
1966 return err;
1967
1968 switch (decoder->packet.type) {
1969 case INTEL_PT_TIP_PGD:
1970 decoder->continuous_period = false;
1971 __fallthrough;
1972 case INTEL_PT_TIP_PGE:
1973 case INTEL_PT_TIP:
1974 case INTEL_PT_PTWRITE:
1975 case INTEL_PT_PTWRITE_IP:
1976 case INTEL_PT_EXSTOP:
1977 case INTEL_PT_EXSTOP_IP:
1978 case INTEL_PT_MWAIT:
1979 case INTEL_PT_PWRE:
1980 case INTEL_PT_PWRX:
1981 intel_pt_log("ERROR: Unexpected packet\n");
1982 return -ENOENT;
1983
1984 case INTEL_PT_FUP:
1985 decoder->pge = true;
1986 if (intel_pt_have_ip(decoder)) {
1987 uint64_t current_ip = decoder->ip;
1988
1989 intel_pt_set_ip(decoder);
1990 if (current_ip)
1991 intel_pt_log_to("Setting IP",
1992 decoder->ip);
1993 }
1994 break;
1995
1996 case INTEL_PT_MTC:
1997 intel_pt_calc_mtc_timestamp(decoder);
1998 break;
1999
2000 case INTEL_PT_TSC:
2001 intel_pt_calc_tsc_timestamp(decoder);
2002 break;
2003
2004 case INTEL_PT_TMA:
2005 intel_pt_calc_tma(decoder);
2006 break;
2007
2008 case INTEL_PT_CYC:
2009 intel_pt_calc_cyc_timestamp(decoder);
2010 break;
2011
2012 case INTEL_PT_CBR:
2013 intel_pt_calc_cbr(decoder);
2014 break;
2015
2016 case INTEL_PT_PIP:
2017 decoder->cr3 = decoder->packet.payload & (BIT63 - 1);
2018 break;
2019
2020 case INTEL_PT_MODE_EXEC:
2021 decoder->exec_mode = decoder->packet.payload;
2022 break;
2023
2024 case INTEL_PT_MODE_TSX:
2025 intel_pt_update_in_tx(decoder);
2026 break;
2027
2028 case INTEL_PT_TRACESTOP:
2029 decoder->pge = false;
2030 decoder->continuous_period = false;
2031 intel_pt_clear_tx_flags(decoder);
2032 __fallthrough;
2033
2034 case INTEL_PT_TNT:
2035 decoder->have_tma = false;
2036 intel_pt_log("ERROR: Unexpected packet\n");
2037 if (decoder->ip)
2038 decoder->pkt_state = INTEL_PT_STATE_ERR4;
2039 else
2040 decoder->pkt_state = INTEL_PT_STATE_ERR3;
2041 return -ENOENT;
2042
2043 case INTEL_PT_BAD: /* Does not happen */
2044 return intel_pt_bug(decoder);
2045
2046 case INTEL_PT_OVF:
2047 return intel_pt_overflow(decoder);
2048
2049 case INTEL_PT_PSBEND:
2050 return 0;
2051
2052 case INTEL_PT_PSB:
2053 case INTEL_PT_VMCS:
2054 case INTEL_PT_MNT:
2055 case INTEL_PT_PAD:
2056 default:
2057 break;
2058 }
2059 }
2060 }
2061
2062 static int intel_pt_walk_to_ip(struct intel_pt_decoder *decoder)
2063 {
2064 int err;
2065
2066 while (1) {
2067 err = intel_pt_get_next_packet(decoder);
2068 if (err)
2069 return err;
2070
2071 switch (decoder->packet.type) {
2072 case INTEL_PT_TIP_PGD:
2073 decoder->continuous_period = false;
2074 __fallthrough;
2075 case INTEL_PT_TIP_PGE:
2076 case INTEL_PT_TIP:
2077 decoder->pge = decoder->packet.type != INTEL_PT_TIP_PGD;
2078 if (intel_pt_have_ip(decoder))
2079 intel_pt_set_ip(decoder);
2080 if (decoder->ip)
2081 return 0;
2082 break;
2083
2084 case INTEL_PT_FUP:
2085 if (intel_pt_have_ip(decoder))
2086 intel_pt_set_ip(decoder);
2087 if (decoder->ip)
2088 return 0;
2089 break;
2090
2091 case INTEL_PT_MTC:
2092 intel_pt_calc_mtc_timestamp(decoder);
2093 break;
2094
2095 case INTEL_PT_TSC:
2096 intel_pt_calc_tsc_timestamp(decoder);
2097 break;
2098
2099 case INTEL_PT_TMA:
2100 intel_pt_calc_tma(decoder);
2101 break;
2102
2103 case INTEL_PT_CYC:
2104 intel_pt_calc_cyc_timestamp(decoder);
2105 break;
2106
2107 case INTEL_PT_CBR:
2108 intel_pt_calc_cbr(decoder);
2109 break;
2110
2111 case INTEL_PT_PIP:
2112 decoder->cr3 = decoder->packet.payload & (BIT63 - 1);
2113 break;
2114
2115 case INTEL_PT_MODE_EXEC:
2116 decoder->exec_mode = decoder->packet.payload;
2117 break;
2118
2119 case INTEL_PT_MODE_TSX:
2120 intel_pt_update_in_tx(decoder);
2121 break;
2122
2123 case INTEL_PT_OVF:
2124 return intel_pt_overflow(decoder);
2125
2126 case INTEL_PT_BAD: /* Does not happen */
2127 return intel_pt_bug(decoder);
2128
2129 case INTEL_PT_TRACESTOP:
2130 decoder->pge = false;
2131 decoder->continuous_period = false;
2132 intel_pt_clear_tx_flags(decoder);
2133 decoder->have_tma = false;
2134 break;
2135
2136 case INTEL_PT_PSB:
2137 decoder->last_ip = 0;
2138 decoder->have_last_ip = true;
2139 intel_pt_clear_stack(&decoder->stack);
2140 err = intel_pt_walk_psb(decoder);
2141 if (err)
2142 return err;
2143 if (decoder->ip) {
2144 /* Do not have a sample */
2145 decoder->state.type = 0;
2146 return 0;
2147 }
2148 break;
2149
2150 case INTEL_PT_TNT:
2151 case INTEL_PT_PSBEND:
2152 case INTEL_PT_VMCS:
2153 case INTEL_PT_MNT:
2154 case INTEL_PT_PAD:
2155 case INTEL_PT_PTWRITE:
2156 case INTEL_PT_PTWRITE_IP:
2157 case INTEL_PT_EXSTOP:
2158 case INTEL_PT_EXSTOP_IP:
2159 case INTEL_PT_MWAIT:
2160 case INTEL_PT_PWRE:
2161 case INTEL_PT_PWRX:
2162 default:
2163 break;
2164 }
2165 }
2166 }
2167
2168 static int intel_pt_sync_ip(struct intel_pt_decoder *decoder)
2169 {
2170 int err;
2171
2172 decoder->set_fup_tx_flags = false;
2173 decoder->set_fup_ptw = false;
2174 decoder->set_fup_mwait = false;
2175 decoder->set_fup_pwre = false;
2176 decoder->set_fup_exstop = false;
2177
2178 if (!decoder->branch_enable) {
2179 decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
2180 decoder->overflow = false;
2181 decoder->state.type = 0; /* Do not have a sample */
2182 return 0;
2183 }
2184
2185 intel_pt_log("Scanning for full IP\n");
2186 err = intel_pt_walk_to_ip(decoder);
2187 if (err)
2188 return err;
2189
2190 decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
2191 decoder->overflow = false;
2192
2193 decoder->state.from_ip = 0;
2194 decoder->state.to_ip = decoder->ip;
2195 intel_pt_log_to("Setting IP", decoder->ip);
2196
2197 return 0;
2198 }
2199
2200 static int intel_pt_part_psb(struct intel_pt_decoder *decoder)
2201 {
2202 const unsigned char *end = decoder->buf + decoder->len;
2203 size_t i;
2204
2205 for (i = INTEL_PT_PSB_LEN - 1; i; i--) {
2206 if (i > decoder->len)
2207 continue;
2208 if (!memcmp(end - i, INTEL_PT_PSB_STR, i))
2209 return i;
2210 }
2211 return 0;
2212 }
2213
2214 static int intel_pt_rest_psb(struct intel_pt_decoder *decoder, int part_psb)
2215 {
2216 size_t rest_psb = INTEL_PT_PSB_LEN - part_psb;
2217 const char *psb = INTEL_PT_PSB_STR;
2218
2219 if (rest_psb > decoder->len ||
2220 memcmp(decoder->buf, psb + part_psb, rest_psb))
2221 return 0;
2222
2223 return rest_psb;
2224 }
2225
2226 static int intel_pt_get_split_psb(struct intel_pt_decoder *decoder,
2227 int part_psb)
2228 {
2229 int rest_psb, ret;
2230
2231 decoder->pos += decoder->len;
2232 decoder->len = 0;
2233
2234 ret = intel_pt_get_next_data(decoder);
2235 if (ret)
2236 return ret;
2237
2238 rest_psb = intel_pt_rest_psb(decoder, part_psb);
2239 if (!rest_psb)
2240 return 0;
2241
2242 decoder->pos -= part_psb;
2243 decoder->next_buf = decoder->buf + rest_psb;
2244 decoder->next_len = decoder->len - rest_psb;
2245 memcpy(decoder->temp_buf, INTEL_PT_PSB_STR, INTEL_PT_PSB_LEN);
2246 decoder->buf = decoder->temp_buf;
2247 decoder->len = INTEL_PT_PSB_LEN;
2248
2249 return 0;
2250 }
2251
2252 static int intel_pt_scan_for_psb(struct intel_pt_decoder *decoder)
2253 {
2254 unsigned char *next;
2255 int ret;
2256
2257 intel_pt_log("Scanning for PSB\n");
2258 while (1) {
2259 if (!decoder->len) {
2260 ret = intel_pt_get_next_data(decoder);
2261 if (ret)
2262 return ret;
2263 }
2264
2265 next = memmem(decoder->buf, decoder->len, INTEL_PT_PSB_STR,
2266 INTEL_PT_PSB_LEN);
2267 if (!next) {
2268 int part_psb;
2269
2270 part_psb = intel_pt_part_psb(decoder);
2271 if (part_psb) {
2272 ret = intel_pt_get_split_psb(decoder, part_psb);
2273 if (ret)
2274 return ret;
2275 } else {
2276 decoder->pos += decoder->len;
2277 decoder->len = 0;
2278 }
2279 continue;
2280 }
2281
2282 decoder->pkt_step = next - decoder->buf;
2283 return intel_pt_get_next_packet(decoder);
2284 }
2285 }
2286
2287 static int intel_pt_sync(struct intel_pt_decoder *decoder)
2288 {
2289 int err;
2290
2291 decoder->pge = false;
2292 decoder->continuous_period = false;
2293 decoder->have_last_ip = false;
2294 decoder->last_ip = 0;
2295 decoder->ip = 0;
2296 intel_pt_clear_stack(&decoder->stack);
2297
2298 err = intel_pt_scan_for_psb(decoder);
2299 if (err)
2300 return err;
2301
2302 decoder->have_last_ip = true;
2303 decoder->pkt_state = INTEL_PT_STATE_NO_IP;
2304
2305 err = intel_pt_walk_psb(decoder);
2306 if (err)
2307 return err;
2308
2309 if (decoder->ip) {
2310 decoder->state.type = 0; /* Do not have a sample */
2311 decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
2312 } else {
2313 return intel_pt_sync_ip(decoder);
2314 }
2315
2316 return 0;
2317 }
2318
2319 static uint64_t intel_pt_est_timestamp(struct intel_pt_decoder *decoder)
2320 {
2321 uint64_t est = decoder->sample_insn_cnt << 1;
2322
2323 if (!decoder->cbr || !decoder->max_non_turbo_ratio)
2324 goto out;
2325
2326 est *= decoder->max_non_turbo_ratio;
2327 est /= decoder->cbr;
2328 out:
2329 return decoder->sample_timestamp + est;
2330 }
2331
2332 const struct intel_pt_state *intel_pt_decode(struct intel_pt_decoder *decoder)
2333 {
2334 int err;
2335
2336 do {
2337 decoder->state.type = INTEL_PT_BRANCH;
2338 decoder->state.flags = 0;
2339
2340 switch (decoder->pkt_state) {
2341 case INTEL_PT_STATE_NO_PSB:
2342 err = intel_pt_sync(decoder);
2343 break;
2344 case INTEL_PT_STATE_NO_IP:
2345 decoder->have_last_ip = false;
2346 decoder->last_ip = 0;
2347 decoder->ip = 0;
2348 __fallthrough;
2349 case INTEL_PT_STATE_ERR_RESYNC:
2350 err = intel_pt_sync_ip(decoder);
2351 break;
2352 case INTEL_PT_STATE_IN_SYNC:
2353 err = intel_pt_walk_trace(decoder);
2354 break;
2355 case INTEL_PT_STATE_TNT:
2356 err = intel_pt_walk_tnt(decoder);
2357 if (err == -EAGAIN)
2358 err = intel_pt_walk_trace(decoder);
2359 break;
2360 case INTEL_PT_STATE_TIP:
2361 case INTEL_PT_STATE_TIP_PGD:
2362 err = intel_pt_walk_tip(decoder);
2363 break;
2364 case INTEL_PT_STATE_FUP:
2365 decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
2366 err = intel_pt_walk_fup(decoder);
2367 if (err == -EAGAIN)
2368 err = intel_pt_walk_fup_tip(decoder);
2369 else if (!err)
2370 decoder->pkt_state = INTEL_PT_STATE_FUP;
2371 break;
2372 case INTEL_PT_STATE_FUP_NO_TIP:
2373 decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
2374 err = intel_pt_walk_fup(decoder);
2375 if (err == -EAGAIN)
2376 err = intel_pt_walk_trace(decoder);
2377 break;
2378 default:
2379 err = intel_pt_bug(decoder);
2380 break;
2381 }
2382 } while (err == -ENOLINK);
2383
2384 if (err) {
2385 decoder->state.err = intel_pt_ext_err(err);
2386 decoder->state.from_ip = decoder->ip;
2387 decoder->sample_timestamp = decoder->timestamp;
2388 decoder->sample_insn_cnt = decoder->timestamp_insn_cnt;
2389 } else {
2390 decoder->state.err = 0;
2391 if (decoder->cbr != decoder->cbr_seen && decoder->state.type) {
2392 decoder->cbr_seen = decoder->cbr;
2393 decoder->state.type |= INTEL_PT_CBR_CHG;
2394 decoder->state.cbr_payload = decoder->cbr_payload;
2395 }
2396 if (intel_pt_sample_time(decoder->pkt_state)) {
2397 decoder->sample_timestamp = decoder->timestamp;
2398 decoder->sample_insn_cnt = decoder->timestamp_insn_cnt;
2399 }
2400 }
2401
2402 decoder->state.timestamp = decoder->sample_timestamp;
2403 decoder->state.est_timestamp = intel_pt_est_timestamp(decoder);
2404 decoder->state.cr3 = decoder->cr3;
2405 decoder->state.tot_insn_cnt = decoder->tot_insn_cnt;
2406
2407 return &decoder->state;
2408 }
2409
2410 /**
2411 * intel_pt_next_psb - move buffer pointer to the start of the next PSB packet.
2412 * @buf: pointer to buffer pointer
2413 * @len: size of buffer
2414 *
2415 * Updates the buffer pointer to point to the start of the next PSB packet if
2416 * there is one, otherwise the buffer pointer is unchanged. If @buf is updated,
2417 * @len is adjusted accordingly.
2418 *
2419 * Return: %true if a PSB packet is found, %false otherwise.
2420 */
2421 static bool intel_pt_next_psb(unsigned char **buf, size_t *len)
2422 {
2423 unsigned char *next;
2424
2425 next = memmem(*buf, *len, INTEL_PT_PSB_STR, INTEL_PT_PSB_LEN);
2426 if (next) {
2427 *len -= next - *buf;
2428 *buf = next;
2429 return true;
2430 }
2431 return false;
2432 }
2433
2434 /**
2435 * intel_pt_step_psb - move buffer pointer to the start of the following PSB
2436 * packet.
2437 * @buf: pointer to buffer pointer
2438 * @len: size of buffer
2439 *
2440 * Updates the buffer pointer to point to the start of the following PSB packet
2441 * (skipping the PSB at @buf itself) if there is one, otherwise the buffer
2442 * pointer is unchanged. If @buf is updated, @len is adjusted accordingly.
2443 *
2444 * Return: %true if a PSB packet is found, %false otherwise.
2445 */
2446 static bool intel_pt_step_psb(unsigned char **buf, size_t *len)
2447 {
2448 unsigned char *next;
2449
2450 if (!*len)
2451 return false;
2452
2453 next = memmem(*buf + 1, *len - 1, INTEL_PT_PSB_STR, INTEL_PT_PSB_LEN);
2454 if (next) {
2455 *len -= next - *buf;
2456 *buf = next;
2457 return true;
2458 }
2459 return false;
2460 }
2461
2462 /**
2463 * intel_pt_last_psb - find the last PSB packet in a buffer.
2464 * @buf: buffer
2465 * @len: size of buffer
2466 *
2467 * This function finds the last PSB in a buffer.
2468 *
2469 * Return: A pointer to the last PSB in @buf if found, %NULL otherwise.
2470 */
2471 static unsigned char *intel_pt_last_psb(unsigned char *buf, size_t len)
2472 {
2473 const char *n = INTEL_PT_PSB_STR;
2474 unsigned char *p;
2475 size_t k;
2476
2477 if (len < INTEL_PT_PSB_LEN)
2478 return NULL;
2479
2480 k = len - INTEL_PT_PSB_LEN + 1;
2481 while (1) {
2482 p = memrchr(buf, n[0], k);
2483 if (!p)
2484 return NULL;
2485 if (!memcmp(p + 1, n + 1, INTEL_PT_PSB_LEN - 1))
2486 return p;
2487 k = p - buf;
2488 if (!k)
2489 return NULL;
2490 }
2491 }
2492
2493 /**
2494 * intel_pt_next_tsc - find and return next TSC.
2495 * @buf: buffer
2496 * @len: size of buffer
2497 * @tsc: TSC value returned
2498 * @rem: returns remaining size when TSC is found
2499 *
2500 * Find a TSC packet in @buf and return the TSC value. This function assumes
2501 * that @buf starts at a PSB and that PSB+ will contain TSC and so stops if a
2502 * PSBEND packet is found.
2503 *
2504 * Return: %true if TSC is found, false otherwise.
2505 */
2506 static bool intel_pt_next_tsc(unsigned char *buf, size_t len, uint64_t *tsc,
2507 size_t *rem)
2508 {
2509 struct intel_pt_pkt packet;
2510 int ret;
2511
2512 while (len) {
2513 ret = intel_pt_get_packet(buf, len, &packet);
2514 if (ret <= 0)
2515 return false;
2516 if (packet.type == INTEL_PT_TSC) {
2517 *tsc = packet.payload;
2518 *rem = len;
2519 return true;
2520 }
2521 if (packet.type == INTEL_PT_PSBEND)
2522 return false;
2523 buf += ret;
2524 len -= ret;
2525 }
2526 return false;
2527 }
2528
2529 /**
2530 * intel_pt_tsc_cmp - compare 7-byte TSCs.
2531 * @tsc1: first TSC to compare
2532 * @tsc2: second TSC to compare
2533 *
2534 * This function compares 7-byte TSC values allowing for the possibility that
2535 * TSC wrapped around. Generally it is not possible to know if TSC has wrapped
2536 * around so for that purpose this function assumes the absolute difference is
2537 * less than half the maximum difference.
2538 *
2539 * Return: %-1 if @tsc1 is before @tsc2, %0 if @tsc1 == @tsc2, %1 if @tsc1 is
2540 * after @tsc2.
2541 */
2542 static int intel_pt_tsc_cmp(uint64_t tsc1, uint64_t tsc2)
2543 {
2544 const uint64_t halfway = (1ULL << 55);
2545
2546 if (tsc1 == tsc2)
2547 return 0;
2548
2549 if (tsc1 < tsc2) {
2550 if (tsc2 - tsc1 < halfway)
2551 return -1;
2552 else
2553 return 1;
2554 } else {
2555 if (tsc1 - tsc2 < halfway)
2556 return 1;
2557 else
2558 return -1;
2559 }
2560 }
2561
2562 /**
2563 * intel_pt_find_overlap_tsc - determine start of non-overlapped trace data
2564 * using TSC.
2565 * @buf_a: first buffer
2566 * @len_a: size of first buffer
2567 * @buf_b: second buffer
2568 * @len_b: size of second buffer
2569 * @consecutive: returns true if there is data in buf_b that is consecutive
2570 * to buf_a
2571 *
2572 * If the trace contains TSC we can look at the last TSC of @buf_a and the
2573 * first TSC of @buf_b in order to determine if the buffers overlap, and then
2574 * walk forward in @buf_b until a later TSC is found. A precondition is that
2575 * @buf_a and @buf_b are positioned at a PSB.
2576 *
2577 * Return: A pointer into @buf_b from where non-overlapped data starts, or
2578 * @buf_b + @len_b if there is no non-overlapped data.
2579 */
2580 static unsigned char *intel_pt_find_overlap_tsc(unsigned char *buf_a,
2581 size_t len_a,
2582 unsigned char *buf_b,
2583 size_t len_b, bool *consecutive)
2584 {
2585 uint64_t tsc_a, tsc_b;
2586 unsigned char *p;
2587 size_t len, rem_a, rem_b;
2588
2589 p = intel_pt_last_psb(buf_a, len_a);
2590 if (!p)
2591 return buf_b; /* No PSB in buf_a => no overlap */
2592
2593 len = len_a - (p - buf_a);
2594 if (!intel_pt_next_tsc(p, len, &tsc_a, &rem_a)) {
2595 /* The last PSB+ in buf_a is incomplete, so go back one more */
2596 len_a -= len;
2597 p = intel_pt_last_psb(buf_a, len_a);
2598 if (!p)
2599 return buf_b; /* No full PSB+ => assume no overlap */
2600 len = len_a - (p - buf_a);
2601 if (!intel_pt_next_tsc(p, len, &tsc_a, &rem_a))
2602 return buf_b; /* No TSC in buf_a => assume no overlap */
2603 }
2604
2605 while (1) {
2606 /* Ignore PSB+ with no TSC */
2607 if (intel_pt_next_tsc(buf_b, len_b, &tsc_b, &rem_b)) {
2608 int cmp = intel_pt_tsc_cmp(tsc_a, tsc_b);
2609
2610 /* Same TSC, so buffers are consecutive */
2611 if (!cmp && rem_b >= rem_a) {
2612 *consecutive = true;
2613 return buf_b + len_b - (rem_b - rem_a);
2614 }
2615 if (cmp < 0)
2616 return buf_b; /* tsc_a < tsc_b => no overlap */
2617 }
2618
2619 if (!intel_pt_step_psb(&buf_b, &len_b))
2620 return buf_b + len_b; /* No PSB in buf_b => no data */
2621 }
2622 }
2623
2624 /**
2625 * intel_pt_find_overlap - determine start of non-overlapped trace data.
2626 * @buf_a: first buffer
2627 * @len_a: size of first buffer
2628 * @buf_b: second buffer
2629 * @len_b: size of second buffer
2630 * @have_tsc: can use TSC packets to detect overlap
2631 * @consecutive: returns true if there is data in buf_b that is consecutive
2632 * to buf_a
2633 *
2634 * When trace samples or snapshots are recorded there is the possibility that
2635 * the data overlaps. Note that, for the purposes of decoding, data is only
2636 * useful if it begins with a PSB packet.
2637 *
2638 * Return: A pointer into @buf_b from where non-overlapped data starts, or
2639 * @buf_b + @len_b if there is no non-overlapped data.
2640 */
2641 unsigned char *intel_pt_find_overlap(unsigned char *buf_a, size_t len_a,
2642 unsigned char *buf_b, size_t len_b,
2643 bool have_tsc, bool *consecutive)
2644 {
2645 unsigned char *found;
2646
2647 /* Buffer 'b' must start at PSB so throw away everything before that */
2648 if (!intel_pt_next_psb(&buf_b, &len_b))
2649 return buf_b + len_b; /* No PSB */
2650
2651 if (!intel_pt_next_psb(&buf_a, &len_a))
2652 return buf_b; /* No overlap */
2653
2654 if (have_tsc) {
2655 found = intel_pt_find_overlap_tsc(buf_a, len_a, buf_b, len_b,
2656 consecutive);
2657 if (found)
2658 return found;
2659 }
2660
2661 /*
2662 * Buffer 'b' cannot end within buffer 'a' so, for comparison purposes,
2663 * we can ignore the first part of buffer 'a'.
2664 */
2665 while (len_b < len_a) {
2666 if (!intel_pt_step_psb(&buf_a, &len_a))
2667 return buf_b; /* No overlap */
2668 }
2669
2670 /* Now len_b >= len_a */
2671 while (1) {
2672 /* Potential overlap so check the bytes */
2673 found = memmem(buf_a, len_a, buf_b, len_a);
2674 if (found) {
2675 *consecutive = true;
2676 return buf_b + len_a;
2677 }
2678
2679 /* Try again at next PSB in buffer 'a' */
2680 if (!intel_pt_step_psb(&buf_a, &len_a))
2681 return buf_b; /* No overlap */
2682 }
2683 }
Linux with added FPC-III support