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Linux/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c

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  1 // SPDX-License-Identifier: GPL-2.0-only
  2 /*
  3  * intel_pt_decoder.c: Intel Processor Trace support
  4  * Copyright (c) 2013-2014, Intel Corporation.
  5  */
  6 
  7 #ifndef _GNU_SOURCE
  8 #define _GNU_SOURCE
  9 #endif
 10 #include <stdlib.h>
 11 #include <stdbool.h>
 12 #include <string.h>
 13 #include <errno.h>
 14 #include <stdint.h>
 15 #include <inttypes.h>
 16 #include <linux/compiler.h>
 17 #include <linux/string.h>
 18 #include <linux/zalloc.h>
 19 
 20 #include "../auxtrace.h"
 21 
 22 #include "intel-pt-insn-decoder.h"
 23 #include "intel-pt-pkt-decoder.h"
 24 #include "intel-pt-decoder.h"
 25 #include "intel-pt-log.h"
 26 
 27 #define BITULL(x) (1ULL << (x))
 28 
 29 /* IA32_RTIT_CTL MSR bits */
 30 #define INTEL_PT_CYC_ENABLE             BITULL(1)
 31 #define INTEL_PT_CYC_THRESHOLD          (BITULL(22) | BITULL(21) | BITULL(20) | BITULL(19))
 32 #define INTEL_PT_CYC_THRESHOLD_SHIFT    19
 33 
 34 #define INTEL_PT_BLK_SIZE 1024
 35 
 36 #define BIT63 (((uint64_t)1 << 63))
 37 
 38 #define SEVEN_BYTES 0xffffffffffffffULL
 39 
 40 #define NO_VMCS 0xffffffffffULL
 41 
 42 #define INTEL_PT_RETURN 1
 43 
 44 /*
 45  * Default maximum number of loops with no packets consumed i.e. stuck in a
 46  * loop.
 47  */
 48 #define INTEL_PT_MAX_LOOPS 100000
 49 
 50 struct intel_pt_blk {
 51         struct intel_pt_blk *prev;
 52         uint64_t ip[INTEL_PT_BLK_SIZE];
 53 };
 54 
 55 struct intel_pt_stack {
 56         struct intel_pt_blk *blk;
 57         struct intel_pt_blk *spare;
 58         int pos;
 59 };
 60 
 61 enum intel_pt_p_once {
 62         INTEL_PT_PRT_ONCE_UNK_VMCS,
 63         INTEL_PT_PRT_ONCE_ERANGE,
 64 };
 65 
 66 enum intel_pt_pkt_state {
 67         INTEL_PT_STATE_NO_PSB,
 68         INTEL_PT_STATE_NO_IP,
 69         INTEL_PT_STATE_ERR_RESYNC,
 70         INTEL_PT_STATE_IN_SYNC,
 71         INTEL_PT_STATE_TNT_CONT,
 72         INTEL_PT_STATE_TNT,
 73         INTEL_PT_STATE_TIP,
 74         INTEL_PT_STATE_TIP_PGD,
 75         INTEL_PT_STATE_FUP,
 76         INTEL_PT_STATE_FUP_NO_TIP,
 77         INTEL_PT_STATE_FUP_IN_PSB,
 78         INTEL_PT_STATE_RESAMPLE,
 79         INTEL_PT_STATE_VM_TIME_CORRELATION,
 80 };
 81 
 82 static inline bool intel_pt_sample_time(enum intel_pt_pkt_state pkt_state)
 83 {
 84         switch (pkt_state) {
 85         case INTEL_PT_STATE_NO_PSB:
 86         case INTEL_PT_STATE_NO_IP:
 87         case INTEL_PT_STATE_ERR_RESYNC:
 88         case INTEL_PT_STATE_IN_SYNC:
 89         case INTEL_PT_STATE_TNT_CONT:
 90         case INTEL_PT_STATE_RESAMPLE:
 91         case INTEL_PT_STATE_VM_TIME_CORRELATION:
 92                 return true;
 93         case INTEL_PT_STATE_TNT:
 94         case INTEL_PT_STATE_TIP:
 95         case INTEL_PT_STATE_TIP_PGD:
 96         case INTEL_PT_STATE_FUP:
 97         case INTEL_PT_STATE_FUP_NO_TIP:
 98         case INTEL_PT_STATE_FUP_IN_PSB:
 99                 return false;
100         default:
101                 return true;
102         };
103 }
104 
105 #ifdef INTEL_PT_STRICT
106 #define INTEL_PT_STATE_ERR1     INTEL_PT_STATE_NO_PSB
107 #define INTEL_PT_STATE_ERR2     INTEL_PT_STATE_NO_PSB
108 #define INTEL_PT_STATE_ERR3     INTEL_PT_STATE_NO_PSB
109 #define INTEL_PT_STATE_ERR4     INTEL_PT_STATE_NO_PSB
110 #else
111 #define INTEL_PT_STATE_ERR1     (decoder->pkt_state)
112 #define INTEL_PT_STATE_ERR2     INTEL_PT_STATE_NO_IP
113 #define INTEL_PT_STATE_ERR3     INTEL_PT_STATE_ERR_RESYNC
114 #define INTEL_PT_STATE_ERR4     INTEL_PT_STATE_IN_SYNC
115 #endif
116 
117 struct intel_pt_decoder {
118         int (*get_trace)(struct intel_pt_buffer *buffer, void *data);
119         int (*walk_insn)(struct intel_pt_insn *intel_pt_insn,
120                          uint64_t *insn_cnt_ptr, uint64_t *ip, uint64_t to_ip,
121                          uint64_t max_insn_cnt, void *data);
122         bool (*pgd_ip)(uint64_t ip, void *data);
123         int (*lookahead)(void *data, intel_pt_lookahead_cb_t cb, void *cb_data);
124         struct intel_pt_vmcs_info *(*findnew_vmcs_info)(void *data, uint64_t vmcs);
125         void *data;
126         struct intel_pt_state state;
127         const unsigned char *buf;
128         size_t len;
129         bool return_compression;
130         bool branch_enable;
131         bool mtc_insn;
132         bool pge;
133         bool have_tma;
134         bool have_cyc;
135         bool fixup_last_mtc;
136         bool have_last_ip;
137         bool in_psb;
138         bool hop;
139         bool leap;
140         bool emulated_ptwrite;
141         bool vm_time_correlation;
142         bool vm_tm_corr_dry_run;
143         bool vm_tm_corr_reliable;
144         bool vm_tm_corr_same_buf;
145         bool vm_tm_corr_continuous;
146         bool nr;
147         bool next_nr;
148         bool iflag;
149         bool next_iflag;
150         enum intel_pt_param_flags flags;
151         uint64_t pos;
152         uint64_t last_ip;
153         uint64_t ip;
154         uint64_t pip_payload;
155         uint64_t timestamp;
156         uint64_t tsc_timestamp;
157         uint64_t ref_timestamp;
158         uint64_t buf_timestamp;
159         uint64_t sample_timestamp;
160         uint64_t ret_addr;
161         uint64_t ctc_timestamp;
162         uint64_t ctc_delta;
163         uint64_t cycle_cnt;
164         uint64_t cyc_ref_timestamp;
165         uint64_t first_timestamp;
166         uint64_t last_reliable_timestamp;
167         uint64_t vmcs;
168         uint64_t print_once;
169         uint64_t last_ctc;
170         uint32_t last_mtc;
171         uint32_t tsc_ctc_ratio_n;
172         uint32_t tsc_ctc_ratio_d;
173         uint32_t tsc_ctc_mult;
174         uint32_t tsc_slip;
175         uint32_t ctc_rem_mask;
176         int mtc_shift;
177         struct intel_pt_stack stack;
178         enum intel_pt_pkt_state pkt_state;
179         enum intel_pt_pkt_ctx pkt_ctx;
180         enum intel_pt_pkt_ctx prev_pkt_ctx;
181         enum intel_pt_blk_type blk_type;
182         int blk_type_pos;
183         struct intel_pt_pkt packet;
184         struct intel_pt_pkt tnt;
185         int pkt_step;
186         int pkt_len;
187         int last_packet_type;
188         unsigned int cbr;
189         unsigned int cbr_seen;
190         unsigned int max_non_turbo_ratio;
191         double max_non_turbo_ratio_fp;
192         double cbr_cyc_to_tsc;
193         double calc_cyc_to_tsc;
194         bool have_calc_cyc_to_tsc;
195         int exec_mode;
196         unsigned int insn_bytes;
197         uint64_t period;
198         enum intel_pt_period_type period_type;
199         uint64_t tot_insn_cnt;
200         uint64_t period_insn_cnt;
201         uint64_t period_mask;
202         uint64_t period_ticks;
203         uint64_t last_masked_timestamp;
204         uint64_t tot_cyc_cnt;
205         uint64_t sample_tot_cyc_cnt;
206         uint64_t base_cyc_cnt;
207         uint64_t cyc_cnt_timestamp;
208         uint64_t ctl;
209         uint64_t cyc_threshold;
210         double tsc_to_cyc;
211         bool continuous_period;
212         bool overflow;
213         bool set_fup_tx_flags;
214         bool set_fup_ptw;
215         bool set_fup_mwait;
216         bool set_fup_pwre;
217         bool set_fup_exstop;
218         bool set_fup_bep;
219         bool set_fup_cfe_ip;
220         bool set_fup_cfe;
221         bool set_fup_mode_exec;
222         bool sample_cyc;
223         unsigned int fup_tx_flags;
224         unsigned int tx_flags;
225         uint64_t fup_ptw_payload;
226         uint64_t fup_mwait_payload;
227         uint64_t fup_pwre_payload;
228         uint64_t cbr_payload;
229         uint64_t timestamp_insn_cnt;
230         uint64_t sample_insn_cnt;
231         uint64_t stuck_ip;
232         struct intel_pt_pkt fup_cfe_pkt;
233         int max_loops;
234         int no_progress;
235         int stuck_ip_prd;
236         int stuck_ip_cnt;
237         uint64_t psb_ip;
238         const unsigned char *next_buf;
239         size_t next_len;
240         unsigned char temp_buf[INTEL_PT_PKT_MAX_SZ];
241         int evd_cnt;
242         struct intel_pt_evd evd[INTEL_PT_MAX_EVDS];
243 };
244 
245 static uint64_t intel_pt_lower_power_of_2(uint64_t x)
246 {
247         int i;
248 
249         for (i = 0; x != 1; i++)
250                 x >>= 1;
251 
252         return x << i;
253 }
254 
255 __printf(1, 2)
256 static void p_log(const char *fmt, ...)
257 {
258         char buf[512];
259         va_list args;
260 
261         va_start(args, fmt);
262         vsnprintf(buf, sizeof(buf), fmt, args);
263         va_end(args);
264 
265         fprintf(stderr, "%s\n", buf);
266         intel_pt_log("%s\n", buf);
267 }
268 
269 static bool intel_pt_print_once(struct intel_pt_decoder *decoder,
270                                 enum intel_pt_p_once id)
271 {
272         uint64_t bit = 1ULL << id;
273 
274         if (decoder->print_once & bit)
275                 return false;
276         decoder->print_once |= bit;
277         return true;
278 }
279 
280 static uint64_t intel_pt_cyc_threshold(uint64_t ctl)
281 {
282         if (!(ctl & INTEL_PT_CYC_ENABLE))
283                 return 0;
284 
285         return (ctl & INTEL_PT_CYC_THRESHOLD) >> INTEL_PT_CYC_THRESHOLD_SHIFT;
286 }
287 
288 static void intel_pt_setup_period(struct intel_pt_decoder *decoder)
289 {
290         if (decoder->period_type == INTEL_PT_PERIOD_TICKS) {
291                 uint64_t period;
292 
293                 period = intel_pt_lower_power_of_2(decoder->period);
294                 decoder->period_mask  = ~(period - 1);
295                 decoder->period_ticks = period;
296         }
297 }
298 
299 static uint64_t multdiv(uint64_t t, uint32_t n, uint32_t d)
300 {
301         if (!d)
302                 return 0;
303         return (t / d) * n + ((t % d) * n) / d;
304 }
305 
306 struct intel_pt_decoder *intel_pt_decoder_new(struct intel_pt_params *params)
307 {
308         struct intel_pt_decoder *decoder;
309 
310         if (!params->get_trace || !params->walk_insn)
311                 return NULL;
312 
313         decoder = zalloc(sizeof(struct intel_pt_decoder));
314         if (!decoder)
315                 return NULL;
316 
317         decoder->get_trace          = params->get_trace;
318         decoder->walk_insn          = params->walk_insn;
319         decoder->pgd_ip             = params->pgd_ip;
320         decoder->lookahead          = params->lookahead;
321         decoder->findnew_vmcs_info  = params->findnew_vmcs_info;
322         decoder->data               = params->data;
323         decoder->return_compression = params->return_compression;
324         decoder->branch_enable      = params->branch_enable;
325         decoder->hop                = params->quick >= 1;
326         decoder->leap               = params->quick >= 2;
327         decoder->vm_time_correlation = params->vm_time_correlation;
328         decoder->vm_tm_corr_dry_run = params->vm_tm_corr_dry_run;
329         decoder->first_timestamp    = params->first_timestamp;
330         decoder->last_reliable_timestamp = params->first_timestamp;
331         decoder->max_loops          = params->max_loops ? params->max_loops : INTEL_PT_MAX_LOOPS;
332 
333         decoder->flags              = params->flags;
334 
335         decoder->ctl                = params->ctl;
336         decoder->period             = params->period;
337         decoder->period_type        = params->period_type;
338 
339         decoder->max_non_turbo_ratio    = params->max_non_turbo_ratio;
340         decoder->max_non_turbo_ratio_fp = params->max_non_turbo_ratio;
341 
342         decoder->cyc_threshold = intel_pt_cyc_threshold(decoder->ctl);
343 
344         intel_pt_setup_period(decoder);
345 
346         decoder->mtc_shift = params->mtc_period;
347         decoder->ctc_rem_mask = (1 << decoder->mtc_shift) - 1;
348 
349         decoder->tsc_ctc_ratio_n = params->tsc_ctc_ratio_n;
350         decoder->tsc_ctc_ratio_d = params->tsc_ctc_ratio_d;
351 
352         if (!decoder->tsc_ctc_ratio_n)
353                 decoder->tsc_ctc_ratio_d = 0;
354 
355         if (decoder->tsc_ctc_ratio_d) {
356                 if (!(decoder->tsc_ctc_ratio_n % decoder->tsc_ctc_ratio_d))
357                         decoder->tsc_ctc_mult = decoder->tsc_ctc_ratio_n /
358                                                 decoder->tsc_ctc_ratio_d;
359         }
360 
361         /*
362          * A TSC packet can slip past MTC packets so that the timestamp appears
363          * to go backwards. One estimate is that can be up to about 40 CPU
364          * cycles, which is certainly less than 0x1000 TSC ticks, but accept
365          * slippage an order of magnitude more to be on the safe side.
366          */
367         decoder->tsc_slip = 0x10000;
368 
369         intel_pt_log("timestamp: mtc_shift %u\n", decoder->mtc_shift);
370         intel_pt_log("timestamp: tsc_ctc_ratio_n %u\n", decoder->tsc_ctc_ratio_n);
371         intel_pt_log("timestamp: tsc_ctc_ratio_d %u\n", decoder->tsc_ctc_ratio_d);
372         intel_pt_log("timestamp: tsc_ctc_mult %u\n", decoder->tsc_ctc_mult);
373         intel_pt_log("timestamp: tsc_slip %#x\n", decoder->tsc_slip);
374 
375         if (decoder->hop)
376                 intel_pt_log("Hop mode: decoding FUP and TIPs, but not TNT\n");
377 
378         return decoder;
379 }
380 
381 void intel_pt_set_first_timestamp(struct intel_pt_decoder *decoder,
382                                   uint64_t first_timestamp)
383 {
384         decoder->first_timestamp = first_timestamp;
385 }
386 
387 static void intel_pt_pop_blk(struct intel_pt_stack *stack)
388 {
389         struct intel_pt_blk *blk = stack->blk;
390 
391         stack->blk = blk->prev;
392         if (!stack->spare)
393                 stack->spare = blk;
394         else
395                 free(blk);
396 }
397 
398 static uint64_t intel_pt_pop(struct intel_pt_stack *stack)
399 {
400         if (!stack->pos) {
401                 if (!stack->blk)
402                         return 0;
403                 intel_pt_pop_blk(stack);
404                 if (!stack->blk)
405                         return 0;
406                 stack->pos = INTEL_PT_BLK_SIZE;
407         }
408         return stack->blk->ip[--stack->pos];
409 }
410 
411 static int intel_pt_alloc_blk(struct intel_pt_stack *stack)
412 {
413         struct intel_pt_blk *blk;
414 
415         if (stack->spare) {
416                 blk = stack->spare;
417                 stack->spare = NULL;
418         } else {
419                 blk = malloc(sizeof(struct intel_pt_blk));
420                 if (!blk)
421                         return -ENOMEM;
422         }
423 
424         blk->prev = stack->blk;
425         stack->blk = blk;
426         stack->pos = 0;
427         return 0;
428 }
429 
430 static int intel_pt_push(struct intel_pt_stack *stack, uint64_t ip)
431 {
432         int err;
433 
434         if (!stack->blk || stack->pos == INTEL_PT_BLK_SIZE) {
435                 err = intel_pt_alloc_blk(stack);
436                 if (err)
437                         return err;
438         }
439 
440         stack->blk->ip[stack->pos++] = ip;
441         return 0;
442 }
443 
444 static void intel_pt_clear_stack(struct intel_pt_stack *stack)
445 {
446         while (stack->blk)
447                 intel_pt_pop_blk(stack);
448         stack->pos = 0;
449 }
450 
451 static void intel_pt_free_stack(struct intel_pt_stack *stack)
452 {
453         intel_pt_clear_stack(stack);
454         zfree(&stack->blk);
455         zfree(&stack->spare);
456 }
457 
458 void intel_pt_decoder_free(struct intel_pt_decoder *decoder)
459 {
460         intel_pt_free_stack(&decoder->stack);
461         free(decoder);
462 }
463 
464 static int intel_pt_ext_err(int code)
465 {
466         switch (code) {
467         case -ENOMEM:
468                 return INTEL_PT_ERR_NOMEM;
469         case -ENOSYS:
470                 return INTEL_PT_ERR_INTERN;
471         case -EBADMSG:
472                 return INTEL_PT_ERR_BADPKT;
473         case -ENODATA:
474                 return INTEL_PT_ERR_NODATA;
475         case -EILSEQ:
476                 return INTEL_PT_ERR_NOINSN;
477         case -ENOENT:
478                 return INTEL_PT_ERR_MISMAT;
479         case -EOVERFLOW:
480                 return INTEL_PT_ERR_OVR;
481         case -ENOSPC:
482                 return INTEL_PT_ERR_LOST;
483         case -ELOOP:
484                 return INTEL_PT_ERR_NELOOP;
485         case -ECONNRESET:
486                 return INTEL_PT_ERR_EPTW;
487         default:
488                 return INTEL_PT_ERR_UNK;
489         }
490 }
491 
492 static const char *intel_pt_err_msgs[] = {
493         [INTEL_PT_ERR_NOMEM]  = "Memory allocation failed",
494         [INTEL_PT_ERR_INTERN] = "Internal error",
495         [INTEL_PT_ERR_BADPKT] = "Bad packet",
496         [INTEL_PT_ERR_NODATA] = "No more data",
497         [INTEL_PT_ERR_NOINSN] = "Failed to get instruction",
498         [INTEL_PT_ERR_MISMAT] = "Trace doesn't match instruction",
499         [INTEL_PT_ERR_OVR]    = "Overflow packet",
500         [INTEL_PT_ERR_LOST]   = "Lost trace data",
501         [INTEL_PT_ERR_UNK]    = "Unknown error!",
502         [INTEL_PT_ERR_NELOOP] = "Never-ending loop (refer perf config intel-pt.max-loops)",
503         [INTEL_PT_ERR_EPTW]   = "Broken emulated ptwrite",
504 };
505 
506 int intel_pt__strerror(int code, char *buf, size_t buflen)
507 {
508         if (code < 1 || code >= INTEL_PT_ERR_MAX)
509                 code = INTEL_PT_ERR_UNK;
510         strlcpy(buf, intel_pt_err_msgs[code], buflen);
511         return 0;
512 }
513 
514 static uint64_t intel_pt_calc_ip(const struct intel_pt_pkt *packet,
515                                  uint64_t last_ip)
516 {
517         uint64_t ip;
518 
519         switch (packet->count) {
520         case 1:
521                 ip = (last_ip & (uint64_t)0xffffffffffff0000ULL) |
522                      packet->payload;
523                 break;
524         case 2:
525                 ip = (last_ip & (uint64_t)0xffffffff00000000ULL) |
526                      packet->payload;
527                 break;
528         case 3:
529                 ip = packet->payload;
530                 /* Sign-extend 6-byte ip */
531                 if (ip & (uint64_t)0x800000000000ULL)
532                         ip |= (uint64_t)0xffff000000000000ULL;
533                 break;
534         case 4:
535                 ip = (last_ip & (uint64_t)0xffff000000000000ULL) |
536                      packet->payload;
537                 break;
538         case 6:
539                 ip = packet->payload;
540                 break;
541         default:
542                 return 0;
543         }
544 
545         return ip;
546 }
547 
548 static inline void intel_pt_set_last_ip(struct intel_pt_decoder *decoder)
549 {
550         decoder->last_ip = intel_pt_calc_ip(&decoder->packet, decoder->last_ip);
551         decoder->have_last_ip = true;
552 }
553 
554 static inline void intel_pt_set_ip(struct intel_pt_decoder *decoder)
555 {
556         intel_pt_set_last_ip(decoder);
557         decoder->ip = decoder->last_ip;
558 }
559 
560 static void intel_pt_decoder_log_packet(struct intel_pt_decoder *decoder)
561 {
562         intel_pt_log_packet(&decoder->packet, decoder->pkt_len, decoder->pos,
563                             decoder->buf);
564 }
565 
566 static int intel_pt_bug(struct intel_pt_decoder *decoder)
567 {
568         intel_pt_log("ERROR: Internal error\n");
569         decoder->pkt_state = INTEL_PT_STATE_NO_PSB;
570         return -ENOSYS;
571 }
572 
573 static inline void intel_pt_clear_tx_flags(struct intel_pt_decoder *decoder)
574 {
575         decoder->tx_flags = 0;
576 }
577 
578 static inline void intel_pt_update_in_tx(struct intel_pt_decoder *decoder)
579 {
580         decoder->tx_flags = decoder->packet.payload & INTEL_PT_IN_TX;
581 }
582 
583 static inline void intel_pt_update_pip(struct intel_pt_decoder *decoder)
584 {
585         decoder->pip_payload = decoder->packet.payload;
586 }
587 
588 static inline void intel_pt_update_nr(struct intel_pt_decoder *decoder)
589 {
590         decoder->next_nr = decoder->pip_payload & 1;
591 }
592 
593 static inline void intel_pt_set_nr(struct intel_pt_decoder *decoder)
594 {
595         decoder->nr = decoder->pip_payload & 1;
596         decoder->next_nr = decoder->nr;
597 }
598 
599 static inline void intel_pt_set_pip(struct intel_pt_decoder *decoder)
600 {
601         intel_pt_update_pip(decoder);
602         intel_pt_set_nr(decoder);
603 }
604 
605 static int intel_pt_bad_packet(struct intel_pt_decoder *decoder)
606 {
607         intel_pt_clear_tx_flags(decoder);
608         decoder->have_tma = false;
609         decoder->pkt_len = 1;
610         decoder->pkt_step = 1;
611         intel_pt_decoder_log_packet(decoder);
612         if (decoder->pkt_state != INTEL_PT_STATE_NO_PSB) {
613                 intel_pt_log("ERROR: Bad packet\n");
614                 decoder->pkt_state = INTEL_PT_STATE_ERR1;
615         }
616         return -EBADMSG;
617 }
618 
619 static inline void intel_pt_update_sample_time(struct intel_pt_decoder *decoder)
620 {
621         decoder->sample_timestamp = decoder->timestamp;
622         decoder->sample_insn_cnt = decoder->timestamp_insn_cnt;
623         decoder->state.cycles = decoder->tot_cyc_cnt;
624 }
625 
626 static void intel_pt_reposition(struct intel_pt_decoder *decoder)
627 {
628         decoder->ip = 0;
629         decoder->pkt_state = INTEL_PT_STATE_NO_PSB;
630         decoder->timestamp = 0;
631         decoder->have_tma = false;
632 }
633 
634 static int intel_pt_get_data(struct intel_pt_decoder *decoder, bool reposition)
635 {
636         struct intel_pt_buffer buffer = { .buf = 0, };
637         int ret;
638 
639         decoder->pkt_step = 0;
640 
641         intel_pt_log("Getting more data\n");
642         ret = decoder->get_trace(&buffer, decoder->data);
643         if (ret)
644                 return ret;
645         decoder->buf = buffer.buf;
646         decoder->len = buffer.len;
647         if (!decoder->len) {
648                 intel_pt_log("No more data\n");
649                 return -ENODATA;
650         }
651         decoder->buf_timestamp = buffer.ref_timestamp;
652         if (!buffer.consecutive || reposition) {
653                 intel_pt_reposition(decoder);
654                 decoder->ref_timestamp = buffer.ref_timestamp;
655                 decoder->state.trace_nr = buffer.trace_nr;
656                 decoder->vm_tm_corr_same_buf = false;
657                 intel_pt_log("Reference timestamp 0x%" PRIx64 "\n",
658                              decoder->ref_timestamp);
659                 return -ENOLINK;
660         }
661 
662         return 0;
663 }
664 
665 static int intel_pt_get_next_data(struct intel_pt_decoder *decoder,
666                                   bool reposition)
667 {
668         if (!decoder->next_buf)
669                 return intel_pt_get_data(decoder, reposition);
670 
671         decoder->buf = decoder->next_buf;
672         decoder->len = decoder->next_len;
673         decoder->next_buf = 0;
674         decoder->next_len = 0;
675         return 0;
676 }
677 
678 static int intel_pt_get_split_packet(struct intel_pt_decoder *decoder)
679 {
680         unsigned char *buf = decoder->temp_buf;
681         size_t old_len, len, n;
682         int ret;
683 
684         old_len = decoder->len;
685         len = decoder->len;
686         memcpy(buf, decoder->buf, len);
687 
688         ret = intel_pt_get_data(decoder, false);
689         if (ret) {
690                 decoder->pos += old_len;
691                 return ret < 0 ? ret : -EINVAL;
692         }
693 
694         n = INTEL_PT_PKT_MAX_SZ - len;
695         if (n > decoder->len)
696                 n = decoder->len;
697         memcpy(buf + len, decoder->buf, n);
698         len += n;
699 
700         decoder->prev_pkt_ctx = decoder->pkt_ctx;
701         ret = intel_pt_get_packet(buf, len, &decoder->packet, &decoder->pkt_ctx);
702         if (ret < (int)old_len) {
703                 decoder->next_buf = decoder->buf;
704                 decoder->next_len = decoder->len;
705                 decoder->buf = buf;
706                 decoder->len = old_len;
707                 return intel_pt_bad_packet(decoder);
708         }
709 
710         decoder->next_buf = decoder->buf + (ret - old_len);
711         decoder->next_len = decoder->len - (ret - old_len);
712 
713         decoder->buf = buf;
714         decoder->len = ret;
715 
716         return ret;
717 }
718 
719 struct intel_pt_pkt_info {
720         struct intel_pt_decoder   *decoder;
721         struct intel_pt_pkt       packet;
722         uint64_t                  pos;
723         int                       pkt_len;
724         int                       last_packet_type;
725         void                      *data;
726 };
727 
728 typedef int (*intel_pt_pkt_cb_t)(struct intel_pt_pkt_info *pkt_info);
729 
730 /* Lookahead packets in current buffer */
731 static int intel_pt_pkt_lookahead(struct intel_pt_decoder *decoder,
732                                   intel_pt_pkt_cb_t cb, void *data)
733 {
734         struct intel_pt_pkt_info pkt_info;
735         const unsigned char *buf = decoder->buf;
736         enum intel_pt_pkt_ctx pkt_ctx = decoder->pkt_ctx;
737         size_t len = decoder->len;
738         int ret;
739 
740         pkt_info.decoder          = decoder;
741         pkt_info.pos              = decoder->pos;
742         pkt_info.pkt_len          = decoder->pkt_step;
743         pkt_info.last_packet_type = decoder->last_packet_type;
744         pkt_info.data             = data;
745 
746         while (1) {
747                 do {
748                         pkt_info.pos += pkt_info.pkt_len;
749                         buf          += pkt_info.pkt_len;
750                         len          -= pkt_info.pkt_len;
751 
752                         if (!len)
753                                 return INTEL_PT_NEED_MORE_BYTES;
754 
755                         ret = intel_pt_get_packet(buf, len, &pkt_info.packet,
756                                                   &pkt_ctx);
757                         if (!ret)
758                                 return INTEL_PT_NEED_MORE_BYTES;
759                         if (ret < 0)
760                                 return ret;
761 
762                         pkt_info.pkt_len = ret;
763                 } while (pkt_info.packet.type == INTEL_PT_PAD);
764 
765                 ret = cb(&pkt_info);
766                 if (ret)
767                         return 0;
768 
769                 pkt_info.last_packet_type = pkt_info.packet.type;
770         }
771 }
772 
773 struct intel_pt_calc_cyc_to_tsc_info {
774         uint64_t        cycle_cnt;
775         unsigned int    cbr;
776         uint32_t        last_mtc;
777         uint64_t        ctc_timestamp;
778         uint64_t        ctc_delta;
779         uint64_t        tsc_timestamp;
780         uint64_t        timestamp;
781         bool            have_tma;
782         bool            fixup_last_mtc;
783         bool            from_mtc;
784         double          cbr_cyc_to_tsc;
785 };
786 
787 /*
788  * MTC provides a 8-bit slice of CTC but the TMA packet only provides the lower
789  * 16 bits of CTC. If mtc_shift > 8 then some of the MTC bits are not in the CTC
790  * provided by the TMA packet. Fix-up the last_mtc calculated from the TMA
791  * packet by copying the missing bits from the current MTC assuming the least
792  * difference between the two, and that the current MTC comes after last_mtc.
793  */
794 static void intel_pt_fixup_last_mtc(uint32_t mtc, int mtc_shift,
795                                     uint32_t *last_mtc)
796 {
797         uint32_t first_missing_bit = 1U << (16 - mtc_shift);
798         uint32_t mask = ~(first_missing_bit - 1);
799 
800         *last_mtc |= mtc & mask;
801         if (*last_mtc >= mtc) {
802                 *last_mtc -= first_missing_bit;
803                 *last_mtc &= 0xff;
804         }
805 }
806 
807 static int intel_pt_calc_cyc_cb(struct intel_pt_pkt_info *pkt_info)
808 {
809         struct intel_pt_decoder *decoder = pkt_info->decoder;
810         struct intel_pt_calc_cyc_to_tsc_info *data = pkt_info->data;
811         uint64_t timestamp;
812         double cyc_to_tsc;
813         unsigned int cbr;
814         uint32_t mtc, mtc_delta, ctc, fc, ctc_rem;
815 
816         switch (pkt_info->packet.type) {
817         case INTEL_PT_TNT:
818         case INTEL_PT_TIP_PGE:
819         case INTEL_PT_TIP:
820         case INTEL_PT_FUP:
821         case INTEL_PT_PSB:
822         case INTEL_PT_PIP:
823         case INTEL_PT_MODE_EXEC:
824         case INTEL_PT_MODE_TSX:
825         case INTEL_PT_PSBEND:
826         case INTEL_PT_PAD:
827         case INTEL_PT_VMCS:
828         case INTEL_PT_MNT:
829         case INTEL_PT_PTWRITE:
830         case INTEL_PT_PTWRITE_IP:
831         case INTEL_PT_BBP:
832         case INTEL_PT_BIP:
833         case INTEL_PT_BEP:
834         case INTEL_PT_BEP_IP:
835         case INTEL_PT_CFE:
836         case INTEL_PT_CFE_IP:
837         case INTEL_PT_EVD:
838                 return 0;
839 
840         case INTEL_PT_MTC:
841                 if (!data->have_tma)
842                         return 0;
843 
844                 mtc = pkt_info->packet.payload;
845                 if (decoder->mtc_shift > 8 && data->fixup_last_mtc) {
846                         data->fixup_last_mtc = false;
847                         intel_pt_fixup_last_mtc(mtc, decoder->mtc_shift,
848                                                 &data->last_mtc);
849                 }
850                 if (mtc > data->last_mtc)
851                         mtc_delta = mtc - data->last_mtc;
852                 else
853                         mtc_delta = mtc + 256 - data->last_mtc;
854                 data->ctc_delta += mtc_delta << decoder->mtc_shift;
855                 data->last_mtc = mtc;
856 
857                 if (decoder->tsc_ctc_mult) {
858                         timestamp = data->ctc_timestamp +
859                                 data->ctc_delta * decoder->tsc_ctc_mult;
860                 } else {
861                         timestamp = data->ctc_timestamp +
862                                 multdiv(data->ctc_delta,
863                                         decoder->tsc_ctc_ratio_n,
864                                         decoder->tsc_ctc_ratio_d);
865                 }
866 
867                 if (timestamp < data->timestamp)
868                         return 1;
869 
870                 if (pkt_info->last_packet_type != INTEL_PT_CYC) {
871                         data->timestamp = timestamp;
872                         return 0;
873                 }
874 
875                 break;
876 
877         case INTEL_PT_TSC:
878                 /*
879                  * For now, do not support using TSC packets - refer
880                  * intel_pt_calc_cyc_to_tsc().
881                  */
882                 if (data->from_mtc)
883                         return 1;
884                 timestamp = pkt_info->packet.payload |
885                             (data->timestamp & (0xffULL << 56));
886                 if (data->from_mtc && timestamp < data->timestamp &&
887                     data->timestamp - timestamp < decoder->tsc_slip)
888                         return 1;
889                 if (timestamp < data->timestamp)
890                         timestamp += (1ULL << 56);
891                 if (pkt_info->last_packet_type != INTEL_PT_CYC) {
892                         if (data->from_mtc)
893                                 return 1;
894                         data->tsc_timestamp = timestamp;
895                         data->timestamp = timestamp;
896                         return 0;
897                 }
898                 break;
899 
900         case INTEL_PT_TMA:
901                 if (data->from_mtc)
902                         return 1;
903 
904                 if (!decoder->tsc_ctc_ratio_d)
905                         return 0;
906 
907                 ctc = pkt_info->packet.payload;
908                 fc = pkt_info->packet.count;
909                 ctc_rem = ctc & decoder->ctc_rem_mask;
910 
911                 data->last_mtc = (ctc >> decoder->mtc_shift) & 0xff;
912 
913                 data->ctc_timestamp = data->tsc_timestamp - fc;
914                 if (decoder->tsc_ctc_mult) {
915                         data->ctc_timestamp -= ctc_rem * decoder->tsc_ctc_mult;
916                 } else {
917                         data->ctc_timestamp -=
918                                 multdiv(ctc_rem, decoder->tsc_ctc_ratio_n,
919                                         decoder->tsc_ctc_ratio_d);
920                 }
921 
922                 data->ctc_delta = 0;
923                 data->have_tma = true;
924                 data->fixup_last_mtc = true;
925 
926                 return 0;
927 
928         case INTEL_PT_CYC:
929                 data->cycle_cnt += pkt_info->packet.payload;
930                 return 0;
931 
932         case INTEL_PT_CBR:
933                 cbr = pkt_info->packet.payload;
934                 if (data->cbr && data->cbr != cbr)
935                         return 1;
936                 data->cbr = cbr;
937                 data->cbr_cyc_to_tsc = decoder->max_non_turbo_ratio_fp / cbr;
938                 return 0;
939 
940         case INTEL_PT_TIP_PGD:
941         case INTEL_PT_TRACESTOP:
942         case INTEL_PT_EXSTOP:
943         case INTEL_PT_EXSTOP_IP:
944         case INTEL_PT_MWAIT:
945         case INTEL_PT_PWRE:
946         case INTEL_PT_PWRX:
947         case INTEL_PT_OVF:
948         case INTEL_PT_BAD: /* Does not happen */
949         default:
950                 return 1;
951         }
952 
953         if (!data->cbr && decoder->cbr) {
954                 data->cbr = decoder->cbr;
955                 data->cbr_cyc_to_tsc = decoder->cbr_cyc_to_tsc;
956         }
957 
958         if (!data->cycle_cnt)
959                 return 1;
960 
961         cyc_to_tsc = (double)(timestamp - decoder->timestamp) / data->cycle_cnt;
962 
963         if (data->cbr && cyc_to_tsc > data->cbr_cyc_to_tsc &&
964             cyc_to_tsc / data->cbr_cyc_to_tsc > 1.25) {
965                 intel_pt_log("Timestamp: calculated %g TSC ticks per cycle too big (c.f. CBR-based value %g), pos " x64_fmt "\n",
966                              cyc_to_tsc, data->cbr_cyc_to_tsc, pkt_info->pos);
967                 return 1;
968         }
969 
970         decoder->calc_cyc_to_tsc = cyc_to_tsc;
971         decoder->have_calc_cyc_to_tsc = true;
972 
973         if (data->cbr) {
974                 intel_pt_log("Timestamp: calculated %g TSC ticks per cycle c.f. CBR-based value %g, pos " x64_fmt "\n",
975                              cyc_to_tsc, data->cbr_cyc_to_tsc, pkt_info->pos);
976         } else {
977                 intel_pt_log("Timestamp: calculated %g TSC ticks per cycle c.f. unknown CBR-based value, pos " x64_fmt "\n",
978                              cyc_to_tsc, pkt_info->pos);
979         }
980 
981         return 1;
982 }
983 
984 static void intel_pt_calc_cyc_to_tsc(struct intel_pt_decoder *decoder,
985                                      bool from_mtc)
986 {
987         struct intel_pt_calc_cyc_to_tsc_info data = {
988                 .cycle_cnt      = 0,
989                 .cbr            = 0,
990                 .last_mtc       = decoder->last_mtc,
991                 .ctc_timestamp  = decoder->ctc_timestamp,
992                 .ctc_delta      = decoder->ctc_delta,
993                 .tsc_timestamp  = decoder->tsc_timestamp,
994                 .timestamp      = decoder->timestamp,
995                 .have_tma       = decoder->have_tma,
996                 .fixup_last_mtc = decoder->fixup_last_mtc,
997                 .from_mtc       = from_mtc,
998                 .cbr_cyc_to_tsc = 0,
999         };
1000 
1001         /*
1002          * For now, do not support using TSC packets for at least the reasons:
1003          * 1) timing might have stopped
1004          * 2) TSC packets within PSB+ can slip against CYC packets
1005          */
1006         if (!from_mtc)
1007                 return;
1008 
1009         intel_pt_pkt_lookahead(decoder, intel_pt_calc_cyc_cb, &data);
1010 }
1011 
1012 static int intel_pt_get_next_packet(struct intel_pt_decoder *decoder)
1013 {
1014         int ret;
1015 
1016         decoder->last_packet_type = decoder->packet.type;
1017 
1018         do {
1019                 decoder->pos += decoder->pkt_step;
1020                 decoder->buf += decoder->pkt_step;
1021                 decoder->len -= decoder->pkt_step;
1022 
1023                 if (!decoder->len) {
1024                         ret = intel_pt_get_next_data(decoder, false);
1025                         if (ret)
1026                                 return ret;
1027                 }
1028 
1029                 decoder->prev_pkt_ctx = decoder->pkt_ctx;
1030                 ret = intel_pt_get_packet(decoder->buf, decoder->len,
1031                                           &decoder->packet, &decoder->pkt_ctx);
1032                 if (ret == INTEL_PT_NEED_MORE_BYTES && BITS_PER_LONG == 32 &&
1033                     decoder->len < INTEL_PT_PKT_MAX_SZ && !decoder->next_buf) {
1034                         ret = intel_pt_get_split_packet(decoder);
1035                         if (ret < 0)
1036                                 return ret;
1037                 }
1038                 if (ret <= 0)
1039                         return intel_pt_bad_packet(decoder);
1040 
1041                 decoder->pkt_len = ret;
1042                 decoder->pkt_step = ret;
1043                 intel_pt_decoder_log_packet(decoder);
1044         } while (decoder->packet.type == INTEL_PT_PAD);
1045 
1046         return 0;
1047 }
1048 
1049 static uint64_t intel_pt_next_period(struct intel_pt_decoder *decoder)
1050 {
1051         uint64_t timestamp, masked_timestamp;
1052 
1053         timestamp = decoder->timestamp + decoder->timestamp_insn_cnt;
1054         masked_timestamp = timestamp & decoder->period_mask;
1055         if (decoder->continuous_period) {
1056                 if (masked_timestamp > decoder->last_masked_timestamp)
1057                         return 1;
1058         } else {
1059                 timestamp += 1;
1060                 masked_timestamp = timestamp & decoder->period_mask;
1061                 if (masked_timestamp > decoder->last_masked_timestamp) {
1062                         decoder->last_masked_timestamp = masked_timestamp;
1063                         decoder->continuous_period = true;
1064                 }
1065         }
1066 
1067         if (masked_timestamp < decoder->last_masked_timestamp)
1068                 return decoder->period_ticks;
1069 
1070         return decoder->period_ticks - (timestamp - masked_timestamp);
1071 }
1072 
1073 static uint64_t intel_pt_next_sample(struct intel_pt_decoder *decoder)
1074 {
1075         switch (decoder->period_type) {
1076         case INTEL_PT_PERIOD_INSTRUCTIONS:
1077                 return decoder->period - decoder->period_insn_cnt;
1078         case INTEL_PT_PERIOD_TICKS:
1079                 return intel_pt_next_period(decoder);
1080         case INTEL_PT_PERIOD_NONE:
1081         case INTEL_PT_PERIOD_MTC:
1082         default:
1083                 return 0;
1084         }
1085 }
1086 
1087 static void intel_pt_sample_insn(struct intel_pt_decoder *decoder)
1088 {
1089         uint64_t timestamp, masked_timestamp;
1090 
1091         switch (decoder->period_type) {
1092         case INTEL_PT_PERIOD_INSTRUCTIONS:
1093                 decoder->period_insn_cnt = 0;
1094                 break;
1095         case INTEL_PT_PERIOD_TICKS:
1096                 timestamp = decoder->timestamp + decoder->timestamp_insn_cnt;
1097                 masked_timestamp = timestamp & decoder->period_mask;
1098                 if (masked_timestamp > decoder->last_masked_timestamp)
1099                         decoder->last_masked_timestamp = masked_timestamp;
1100                 else
1101                         decoder->last_masked_timestamp += decoder->period_ticks;
1102                 break;
1103         case INTEL_PT_PERIOD_NONE:
1104         case INTEL_PT_PERIOD_MTC:
1105         default:
1106                 break;
1107         }
1108 
1109         decoder->state.type |= INTEL_PT_INSTRUCTION;
1110 }
1111 
1112 /*
1113  * Sample FUP instruction at the same time as reporting the FUP event, so the
1114  * instruction sample gets the same flags as the FUP event.
1115  */
1116 static void intel_pt_sample_fup_insn(struct intel_pt_decoder *decoder)
1117 {
1118         struct intel_pt_insn intel_pt_insn;
1119         uint64_t max_insn_cnt, insn_cnt = 0;
1120         int err;
1121 
1122         decoder->state.insn_op = INTEL_PT_OP_OTHER;
1123         decoder->state.insn_len = 0;
1124 
1125         if (!decoder->branch_enable || !decoder->pge || decoder->hop ||
1126             decoder->ip != decoder->last_ip)
1127                 return;
1128 
1129         if (!decoder->mtc_insn)
1130                 decoder->mtc_insn = true;
1131 
1132         max_insn_cnt = intel_pt_next_sample(decoder);
1133         if (max_insn_cnt != 1)
1134                 return;
1135 
1136         err = decoder->walk_insn(&intel_pt_insn, &insn_cnt, &decoder->ip,
1137                                  0, max_insn_cnt, decoder->data);
1138         /* Ignore error, it will be reported next walk anyway */
1139         if (err)
1140                 return;
1141 
1142         if (intel_pt_insn.branch != INTEL_PT_BR_NO_BRANCH) {
1143                 intel_pt_log_at("ERROR: Unexpected branch at FUP instruction", decoder->ip);
1144                 return;
1145         }
1146 
1147         decoder->tot_insn_cnt += insn_cnt;
1148         decoder->timestamp_insn_cnt += insn_cnt;
1149         decoder->sample_insn_cnt += insn_cnt;
1150         decoder->period_insn_cnt += insn_cnt;
1151 
1152         intel_pt_sample_insn(decoder);
1153 
1154         decoder->state.type |= INTEL_PT_INSTRUCTION;
1155         decoder->ip += intel_pt_insn.length;
1156 }
1157 
1158 static int intel_pt_walk_insn(struct intel_pt_decoder *decoder,
1159                               struct intel_pt_insn *intel_pt_insn, uint64_t ip)
1160 {
1161         uint64_t max_insn_cnt, insn_cnt = 0;
1162         int err;
1163 
1164         if (!decoder->mtc_insn)
1165                 decoder->mtc_insn = true;
1166 
1167         max_insn_cnt = intel_pt_next_sample(decoder);
1168 
1169         err = decoder->walk_insn(intel_pt_insn, &insn_cnt, &decoder->ip, ip,
1170                                  max_insn_cnt, decoder->data);
1171 
1172         decoder->tot_insn_cnt += insn_cnt;
1173         decoder->timestamp_insn_cnt += insn_cnt;
1174         decoder->sample_insn_cnt += insn_cnt;
1175         decoder->period_insn_cnt += insn_cnt;
1176 
1177         if (err) {
1178                 decoder->no_progress = 0;
1179                 decoder->pkt_state = INTEL_PT_STATE_ERR2;
1180                 intel_pt_log_at("ERROR: Failed to get instruction",
1181                                 decoder->ip);
1182                 if (err == -ENOENT)
1183                         return -ENOLINK;
1184                 return -EILSEQ;
1185         }
1186 
1187         if (ip && decoder->ip == ip) {
1188                 err = -EAGAIN;
1189                 goto out;
1190         }
1191 
1192         if (max_insn_cnt && insn_cnt >= max_insn_cnt)
1193                 intel_pt_sample_insn(decoder);
1194 
1195         if (intel_pt_insn->branch == INTEL_PT_BR_NO_BRANCH) {
1196                 decoder->state.type = INTEL_PT_INSTRUCTION;
1197                 decoder->state.from_ip = decoder->ip;
1198                 decoder->state.to_ip = 0;
1199                 decoder->ip += intel_pt_insn->length;
1200                 err = INTEL_PT_RETURN;
1201                 goto out;
1202         }
1203 
1204         if (intel_pt_insn->op == INTEL_PT_OP_CALL) {
1205                 /* Zero-length calls are excluded */
1206                 if (intel_pt_insn->branch != INTEL_PT_BR_UNCONDITIONAL ||
1207                     intel_pt_insn->rel) {
1208                         err = intel_pt_push(&decoder->stack, decoder->ip +
1209                                             intel_pt_insn->length);
1210                         if (err)
1211                                 goto out;
1212                 }
1213         } else if (intel_pt_insn->op == INTEL_PT_OP_RET) {
1214                 decoder->ret_addr = intel_pt_pop(&decoder->stack);
1215         }
1216 
1217         if (intel_pt_insn->branch == INTEL_PT_BR_UNCONDITIONAL) {
1218                 int cnt = decoder->no_progress++;
1219 
1220                 decoder->state.from_ip = decoder->ip;
1221                 decoder->ip += intel_pt_insn->length +
1222                                 intel_pt_insn->rel;
1223                 decoder->state.to_ip = decoder->ip;
1224                 err = INTEL_PT_RETURN;
1225 
1226                 /*
1227                  * Check for being stuck in a loop.  This can happen if a
1228                  * decoder error results in the decoder erroneously setting the
1229                  * ip to an address that is itself in an infinite loop that
1230                  * consumes no packets.  When that happens, there must be an
1231                  * unconditional branch.
1232                  */
1233                 if (cnt) {
1234                         if (cnt == 1) {
1235                                 decoder->stuck_ip = decoder->state.to_ip;
1236                                 decoder->stuck_ip_prd = 1;
1237                                 decoder->stuck_ip_cnt = 1;
1238                         } else if (cnt > decoder->max_loops ||
1239                                    decoder->state.to_ip == decoder->stuck_ip) {
1240                                 intel_pt_log_at("ERROR: Never-ending loop",
1241                                                 decoder->state.to_ip);
1242                                 decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
1243                                 err = -ELOOP;
1244                                 goto out;
1245                         } else if (!--decoder->stuck_ip_cnt) {
1246                                 decoder->stuck_ip_prd += 1;
1247                                 decoder->stuck_ip_cnt = decoder->stuck_ip_prd;
1248                                 decoder->stuck_ip = decoder->state.to_ip;
1249                         }
1250                 }
1251                 goto out_no_progress;
1252         }
1253 out:
1254         decoder->no_progress = 0;
1255 out_no_progress:
1256         decoder->state.insn_op = intel_pt_insn->op;
1257         decoder->state.insn_len = intel_pt_insn->length;
1258         memcpy(decoder->state.insn, intel_pt_insn->buf,
1259                INTEL_PT_INSN_BUF_SZ);
1260 
1261         if (decoder->tx_flags & INTEL_PT_IN_TX)
1262                 decoder->state.flags |= INTEL_PT_IN_TX;
1263 
1264         return err;
1265 }
1266 
1267 static void intel_pt_mode_exec_status(struct intel_pt_decoder *decoder)
1268 {
1269         bool iflag = decoder->packet.count & INTEL_PT_IFLAG;
1270 
1271         decoder->exec_mode = decoder->packet.payload;
1272         decoder->iflag = iflag;
1273         decoder->next_iflag = iflag;
1274         decoder->state.from_iflag = iflag;
1275         decoder->state.to_iflag = iflag;
1276 }
1277 
1278 static void intel_pt_mode_exec(struct intel_pt_decoder *decoder)
1279 {
1280         bool iflag = decoder->packet.count & INTEL_PT_IFLAG;
1281 
1282         decoder->exec_mode = decoder->packet.payload;
1283         decoder->next_iflag = iflag;
1284 }
1285 
1286 static void intel_pt_sample_iflag(struct intel_pt_decoder *decoder)
1287 {
1288         decoder->state.type |= INTEL_PT_IFLAG_CHG;
1289         decoder->state.from_iflag = decoder->iflag;
1290         decoder->state.to_iflag = decoder->next_iflag;
1291         decoder->iflag = decoder->next_iflag;
1292 }
1293 
1294 static void intel_pt_sample_iflag_chg(struct intel_pt_decoder *decoder)
1295 {
1296         if (decoder->iflag != decoder->next_iflag)
1297                 intel_pt_sample_iflag(decoder);
1298 }
1299 
1300 static void intel_pt_clear_fup_event(struct intel_pt_decoder *decoder)
1301 {
1302         decoder->set_fup_tx_flags = false;
1303         decoder->set_fup_ptw = false;
1304         decoder->set_fup_mwait = false;
1305         decoder->set_fup_pwre = false;
1306         decoder->set_fup_exstop = false;
1307         decoder->set_fup_bep = false;
1308         decoder->set_fup_cfe_ip = false;
1309         decoder->set_fup_cfe = false;
1310         decoder->evd_cnt = 0;
1311         decoder->set_fup_mode_exec = false;
1312         decoder->iflag = decoder->next_iflag;
1313 }
1314 
1315 static bool intel_pt_fup_event(struct intel_pt_decoder *decoder, bool no_tip)
1316 {
1317         enum intel_pt_sample_type type = decoder->state.type;
1318         bool sample_fup_insn = false;
1319         bool ret = false;
1320 
1321         decoder->state.type &= ~INTEL_PT_BRANCH;
1322         decoder->state.insn_op = INTEL_PT_OP_OTHER;
1323         decoder->state.insn_len = 0;
1324 
1325         if (decoder->set_fup_cfe_ip || decoder->set_fup_cfe) {
1326                 bool ip = decoder->set_fup_cfe_ip;
1327 
1328                 decoder->set_fup_cfe_ip = false;
1329                 decoder->set_fup_cfe = false;
1330                 decoder->state.type |= INTEL_PT_EVT;
1331                 if (!ip && decoder->pge)
1332                         decoder->state.type |= INTEL_PT_BRANCH;
1333                 decoder->state.cfe_type = decoder->fup_cfe_pkt.count;
1334                 decoder->state.cfe_vector = decoder->fup_cfe_pkt.payload;
1335                 decoder->state.evd_cnt = decoder->evd_cnt;
1336                 decoder->state.evd = decoder->evd;
1337                 decoder->evd_cnt = 0;
1338                 if (ip || decoder->pge)
1339                         decoder->state.flags |= INTEL_PT_FUP_IP;
1340                 ret = true;
1341         }
1342         if (decoder->set_fup_mode_exec) {
1343                 decoder->set_fup_mode_exec = false;
1344                 intel_pt_sample_iflag(decoder);
1345                 sample_fup_insn = no_tip;
1346                 ret = true;
1347         }
1348         if (decoder->set_fup_tx_flags) {
1349                 decoder->set_fup_tx_flags = false;
1350                 decoder->tx_flags = decoder->fup_tx_flags;
1351                 decoder->state.type |= INTEL_PT_TRANSACTION;
1352                 if (decoder->fup_tx_flags & INTEL_PT_ABORT_TX)
1353                         decoder->state.type |= INTEL_PT_BRANCH;
1354                 decoder->state.flags = decoder->fup_tx_flags;
1355                 ret = true;
1356         }
1357         if (decoder->set_fup_ptw) {
1358                 decoder->set_fup_ptw = false;
1359                 decoder->state.type |= INTEL_PT_PTW;
1360                 decoder->state.flags |= INTEL_PT_FUP_IP;
1361                 decoder->state.ptw_payload = decoder->fup_ptw_payload;
1362                 ret = true;
1363         }
1364         if (decoder->set_fup_mwait) {
1365                 decoder->set_fup_mwait = false;
1366                 decoder->state.type |= INTEL_PT_MWAIT_OP;
1367                 decoder->state.mwait_payload = decoder->fup_mwait_payload;
1368                 ret = true;
1369         }
1370         if (decoder->set_fup_pwre) {
1371                 decoder->set_fup_pwre = false;
1372                 decoder->state.type |= INTEL_PT_PWR_ENTRY;
1373                 decoder->state.pwre_payload = decoder->fup_pwre_payload;
1374                 ret = true;
1375         }
1376         if (decoder->set_fup_exstop) {
1377                 decoder->set_fup_exstop = false;
1378                 decoder->state.type |= INTEL_PT_EX_STOP;
1379                 decoder->state.flags |= INTEL_PT_FUP_IP;
1380                 ret = true;
1381         }
1382         if (decoder->set_fup_bep) {
1383                 decoder->set_fup_bep = false;
1384                 decoder->state.type |= INTEL_PT_BLK_ITEMS;
1385                 ret = true;
1386         }
1387         if (decoder->overflow) {
1388                 decoder->overflow = false;
1389                 if (!ret && !decoder->pge) {
1390                         if (decoder->hop) {
1391                                 decoder->state.type = 0;
1392                                 decoder->pkt_state = INTEL_PT_STATE_RESAMPLE;
1393                         }
1394                         decoder->pge = true;
1395                         decoder->state.type |= INTEL_PT_BRANCH | INTEL_PT_TRACE_BEGIN;
1396                         decoder->state.from_ip = 0;
1397                         decoder->state.to_ip = decoder->ip;
1398                         return true;
1399                 }
1400         }
1401         if (ret) {
1402                 decoder->state.from_ip = decoder->ip;
1403                 decoder->state.to_ip = 0;
1404                 if (sample_fup_insn)
1405                         intel_pt_sample_fup_insn(decoder);
1406         } else {
1407                 decoder->state.type = type;
1408         }
1409         return ret;
1410 }
1411 
1412 static inline bool intel_pt_fup_with_nlip(struct intel_pt_decoder *decoder,
1413                                           struct intel_pt_insn *intel_pt_insn,
1414                                           uint64_t ip, int err)
1415 {
1416         return decoder->flags & INTEL_PT_FUP_WITH_NLIP && !err &&
1417                intel_pt_insn->branch == INTEL_PT_BR_INDIRECT &&
1418                ip == decoder->ip + intel_pt_insn->length;
1419 }
1420 
1421 static int intel_pt_walk_fup(struct intel_pt_decoder *decoder)
1422 {
1423         struct intel_pt_insn intel_pt_insn;
1424         uint64_t ip;
1425         int err;
1426 
1427         ip = decoder->last_ip;
1428 
1429         while (1) {
1430                 err = intel_pt_walk_insn(decoder, &intel_pt_insn, ip);
1431                 if (err == INTEL_PT_RETURN)
1432                         return 0;
1433                 if (err == -EAGAIN ||
1434                     intel_pt_fup_with_nlip(decoder, &intel_pt_insn, ip, err)) {
1435                         bool no_tip = decoder->pkt_state != INTEL_PT_STATE_FUP;
1436 
1437                         decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1438                         if (intel_pt_fup_event(decoder, no_tip) && no_tip)
1439                                 return 0;
1440                         return -EAGAIN;
1441                 }
1442                 decoder->set_fup_tx_flags = false;
1443                 if (err)
1444                         return err;
1445 
1446                 if (intel_pt_insn.branch == INTEL_PT_BR_INDIRECT) {
1447                         intel_pt_log_at("ERROR: Unexpected indirect branch",
1448                                         decoder->ip);
1449                         decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
1450                         return -ENOENT;
1451                 }
1452 
1453                 if (intel_pt_insn.branch == INTEL_PT_BR_CONDITIONAL) {
1454                         intel_pt_log_at("ERROR: Unexpected conditional branch",
1455                                         decoder->ip);
1456                         decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
1457                         return -ENOENT;
1458                 }
1459 
1460                 intel_pt_bug(decoder);
1461         }
1462 }
1463 
1464 static int intel_pt_walk_tip(struct intel_pt_decoder *decoder)
1465 {
1466         struct intel_pt_insn intel_pt_insn;
1467         int err;
1468 
1469         err = intel_pt_walk_insn(decoder, &intel_pt_insn, 0);
1470         if (err == INTEL_PT_RETURN &&
1471             decoder->pgd_ip &&
1472             decoder->pkt_state == INTEL_PT_STATE_TIP_PGD &&
1473             (decoder->state.type & INTEL_PT_BRANCH) &&
1474             decoder->pgd_ip(decoder->state.to_ip, decoder->data)) {
1475                 /* Unconditional branch leaving filter region */
1476                 decoder->no_progress = 0;
1477                 decoder->pge = false;
1478                 decoder->continuous_period = false;
1479                 decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1480                 decoder->state.type |= INTEL_PT_TRACE_END;
1481                 intel_pt_update_nr(decoder);
1482                 return 0;
1483         }
1484         if (err == INTEL_PT_RETURN)
1485                 return 0;
1486         if (err)
1487                 return err;
1488 
1489         intel_pt_update_nr(decoder);
1490         intel_pt_sample_iflag_chg(decoder);
1491 
1492         if (intel_pt_insn.branch == INTEL_PT_BR_INDIRECT) {
1493                 if (decoder->pkt_state == INTEL_PT_STATE_TIP_PGD) {
1494                         decoder->pge = false;
1495                         decoder->continuous_period = false;
1496                         decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1497                         decoder->state.from_ip = decoder->ip;
1498                         if (decoder->packet.count == 0) {
1499                                 decoder->state.to_ip = 0;
1500                         } else {
1501                                 decoder->state.to_ip = decoder->last_ip;
1502                                 decoder->ip = decoder->last_ip;
1503                         }
1504                         decoder->state.type |= INTEL_PT_TRACE_END;
1505                 } else {
1506                         decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1507                         decoder->state.from_ip = decoder->ip;
1508                         if (decoder->packet.count == 0) {
1509                                 decoder->state.to_ip = 0;
1510                         } else {
1511                                 decoder->state.to_ip = decoder->last_ip;
1512                                 decoder->ip = decoder->last_ip;
1513                         }
1514                 }
1515                 return 0;
1516         }
1517 
1518         if (intel_pt_insn.branch == INTEL_PT_BR_CONDITIONAL) {
1519                 uint64_t to_ip = decoder->ip + intel_pt_insn.length +
1520                                  intel_pt_insn.rel;
1521 
1522                 if (decoder->pgd_ip &&
1523                     decoder->pkt_state == INTEL_PT_STATE_TIP_PGD &&
1524                     decoder->pgd_ip(to_ip, decoder->data)) {
1525                         /* Conditional branch leaving filter region */
1526                         decoder->pge = false;
1527                         decoder->continuous_period = false;
1528                         decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1529                         decoder->ip = to_ip;
1530                         decoder->state.from_ip = decoder->ip;
1531                         decoder->state.to_ip = to_ip;
1532                         decoder->state.type |= INTEL_PT_TRACE_END;
1533                         return 0;
1534                 }
1535                 intel_pt_log_at("ERROR: Conditional branch when expecting indirect branch",
1536                                 decoder->ip);
1537                 decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
1538                 return -ENOENT;
1539         }
1540 
1541         return intel_pt_bug(decoder);
1542 }
1543 
1544 struct eptw_data {
1545         int bit_countdown;
1546         uint64_t payload;
1547 };
1548 
1549 static int intel_pt_eptw_lookahead_cb(struct intel_pt_pkt_info *pkt_info)
1550 {
1551         struct eptw_data *data = pkt_info->data;
1552         int nr_bits;
1553 
1554         switch (pkt_info->packet.type) {
1555         case INTEL_PT_PAD:
1556         case INTEL_PT_MNT:
1557         case INTEL_PT_MODE_EXEC:
1558         case INTEL_PT_MODE_TSX:
1559         case INTEL_PT_MTC:
1560         case INTEL_PT_FUP:
1561         case INTEL_PT_CYC:
1562         case INTEL_PT_CBR:
1563         case INTEL_PT_TSC:
1564         case INTEL_PT_TMA:
1565         case INTEL_PT_PIP:
1566         case INTEL_PT_VMCS:
1567         case INTEL_PT_PSB:
1568         case INTEL_PT_PSBEND:
1569         case INTEL_PT_PTWRITE:
1570         case INTEL_PT_PTWRITE_IP:
1571         case INTEL_PT_EXSTOP:
1572         case INTEL_PT_EXSTOP_IP:
1573         case INTEL_PT_MWAIT:
1574         case INTEL_PT_PWRE:
1575         case INTEL_PT_PWRX:
1576         case INTEL_PT_BBP:
1577         case INTEL_PT_BIP:
1578         case INTEL_PT_BEP:
1579         case INTEL_PT_BEP_IP:
1580         case INTEL_PT_CFE:
1581         case INTEL_PT_CFE_IP:
1582         case INTEL_PT_EVD:
1583                 break;
1584 
1585         case INTEL_PT_TNT:
1586                 nr_bits = data->bit_countdown;
1587                 if (nr_bits > pkt_info->packet.count)
1588                         nr_bits = pkt_info->packet.count;
1589                 data->payload <<= nr_bits;
1590                 data->payload |= pkt_info->packet.payload >> (64 - nr_bits);
1591                 data->bit_countdown -= nr_bits;
1592                 return !data->bit_countdown;
1593 
1594         case INTEL_PT_TIP_PGE:
1595         case INTEL_PT_TIP_PGD:
1596         case INTEL_PT_TIP:
1597         case INTEL_PT_BAD:
1598         case INTEL_PT_OVF:
1599         case INTEL_PT_TRACESTOP:
1600         default:
1601                 return 1;
1602         }
1603 
1604         return 0;
1605 }
1606 
1607 static int intel_pt_emulated_ptwrite(struct intel_pt_decoder *decoder)
1608 {
1609         int n = 64 - decoder->tnt.count;
1610         struct eptw_data data = {
1611                 .bit_countdown = n,
1612                 .payload = decoder->tnt.payload >> n,
1613         };
1614 
1615         decoder->emulated_ptwrite = false;
1616         intel_pt_log("Emulated ptwrite detected\n");
1617 
1618         intel_pt_pkt_lookahead(decoder, intel_pt_eptw_lookahead_cb, &data);
1619         if (data.bit_countdown)
1620                 return -ECONNRESET;
1621 
1622         decoder->state.type = INTEL_PT_PTW;
1623         decoder->state.from_ip = decoder->ip;
1624         decoder->state.to_ip = 0;
1625         decoder->state.ptw_payload = data.payload;
1626         return 0;
1627 }
1628 
1629 static int intel_pt_walk_tnt(struct intel_pt_decoder *decoder)
1630 {
1631         struct intel_pt_insn intel_pt_insn;
1632         int err;
1633 
1634         while (1) {
1635                 if (decoder->emulated_ptwrite)
1636                         return intel_pt_emulated_ptwrite(decoder);
1637                 err = intel_pt_walk_insn(decoder, &intel_pt_insn, 0);
1638                 if (err == INTEL_PT_RETURN) {
1639                         decoder->emulated_ptwrite = intel_pt_insn.emulated_ptwrite;
1640                         return 0;
1641                 }
1642                 if (err) {
1643                         decoder->emulated_ptwrite = false;
1644                         return err;
1645                 }
1646 
1647                 if (intel_pt_insn.op == INTEL_PT_OP_RET) {
1648                         if (!decoder->return_compression) {
1649                                 intel_pt_log_at("ERROR: RET when expecting conditional branch",
1650                                                 decoder->ip);
1651                                 decoder->pkt_state = INTEL_PT_STATE_ERR3;
1652                                 return -ENOENT;
1653                         }
1654                         if (!decoder->ret_addr) {
1655                                 intel_pt_log_at("ERROR: Bad RET compression (stack empty)",
1656                                                 decoder->ip);
1657                                 decoder->pkt_state = INTEL_PT_STATE_ERR3;
1658                                 return -ENOENT;
1659                         }
1660                         if (!(decoder->tnt.payload & BIT63)) {
1661                                 intel_pt_log_at("ERROR: Bad RET compression (TNT=N)",
1662                                                 decoder->ip);
1663                                 decoder->pkt_state = INTEL_PT_STATE_ERR3;
1664                                 return -ENOENT;
1665                         }
1666                         decoder->tnt.count -= 1;
1667                         if (decoder->tnt.count)
1668                                 decoder->pkt_state = INTEL_PT_STATE_TNT_CONT;
1669                         else
1670                                 decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1671                         decoder->tnt.payload <<= 1;
1672                         decoder->state.from_ip = decoder->ip;
1673                         decoder->ip = decoder->ret_addr;
1674                         decoder->state.to_ip = decoder->ip;
1675                         return 0;
1676                 }
1677 
1678                 if (intel_pt_insn.branch == INTEL_PT_BR_INDIRECT) {
1679                         /* Handle deferred TIPs */
1680                         err = intel_pt_get_next_packet(decoder);
1681                         if (err)
1682                                 return err;
1683                         if (decoder->packet.type != INTEL_PT_TIP ||
1684                             decoder->packet.count == 0) {
1685                                 intel_pt_log_at("ERROR: Missing deferred TIP for indirect branch",
1686                                                 decoder->ip);
1687                                 decoder->pkt_state = INTEL_PT_STATE_ERR3;
1688                                 decoder->pkt_step = 0;
1689                                 return -ENOENT;
1690                         }
1691                         intel_pt_set_last_ip(decoder);
1692                         decoder->state.from_ip = decoder->ip;
1693                         decoder->state.to_ip = decoder->last_ip;
1694                         decoder->ip = decoder->last_ip;
1695                         intel_pt_update_nr(decoder);
1696                         intel_pt_sample_iflag_chg(decoder);
1697                         return 0;
1698                 }
1699 
1700                 if (intel_pt_insn.branch == INTEL_PT_BR_CONDITIONAL) {
1701                         decoder->tnt.count -= 1;
1702                         if (decoder->tnt.count)
1703                                 decoder->pkt_state = INTEL_PT_STATE_TNT_CONT;
1704                         else
1705                                 decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1706                         if (decoder->tnt.payload & BIT63) {
1707                                 decoder->tnt.payload <<= 1;
1708                                 decoder->state.from_ip = decoder->ip;
1709                                 decoder->ip += intel_pt_insn.length +
1710                                                intel_pt_insn.rel;
1711                                 decoder->state.to_ip = decoder->ip;
1712                                 return 0;
1713                         }
1714                         /* Instruction sample for a non-taken branch */
1715                         if (decoder->state.type & INTEL_PT_INSTRUCTION) {
1716                                 decoder->tnt.payload <<= 1;
1717                                 decoder->state.type = INTEL_PT_INSTRUCTION;
1718                                 decoder->state.from_ip = decoder->ip;
1719                                 decoder->state.to_ip = 0;
1720                                 decoder->ip += intel_pt_insn.length;
1721                                 return 0;
1722                         }
1723                         decoder->sample_cyc = false;
1724                         decoder->ip += intel_pt_insn.length;
1725                         if (!decoder->tnt.count) {
1726                                 intel_pt_update_sample_time(decoder);
1727                                 return -EAGAIN;
1728                         }
1729                         decoder->tnt.payload <<= 1;
1730                         continue;
1731                 }
1732 
1733                 return intel_pt_bug(decoder);
1734         }
1735 }
1736 
1737 static int intel_pt_mode_tsx(struct intel_pt_decoder *decoder, bool *no_tip)
1738 {
1739         unsigned int fup_tx_flags;
1740         int err;
1741 
1742         fup_tx_flags = decoder->packet.payload &
1743                        (INTEL_PT_IN_TX | INTEL_PT_ABORT_TX);
1744         err = intel_pt_get_next_packet(decoder);
1745         if (err)
1746                 return err;
1747         if (decoder->packet.type == INTEL_PT_FUP) {
1748                 decoder->fup_tx_flags = fup_tx_flags;
1749                 decoder->set_fup_tx_flags = true;
1750                 if (!(decoder->fup_tx_flags & INTEL_PT_ABORT_TX))
1751                         *no_tip = true;
1752         } else {
1753                 intel_pt_log_at("ERROR: Missing FUP after MODE.TSX",
1754                                 decoder->pos);
1755                 intel_pt_update_in_tx(decoder);
1756         }
1757         return 0;
1758 }
1759 
1760 static int intel_pt_evd(struct intel_pt_decoder *decoder)
1761 {
1762         if (decoder->evd_cnt >= INTEL_PT_MAX_EVDS) {
1763                 intel_pt_log_at("ERROR: Too many EVD packets", decoder->pos);
1764                 return -ENOSYS;
1765         }
1766         decoder->evd[decoder->evd_cnt++] = (struct intel_pt_evd){
1767                 .type = decoder->packet.count,
1768                 .payload = decoder->packet.payload,
1769         };
1770         return 0;
1771 }
1772 
1773 static uint64_t intel_pt_8b_tsc(uint64_t timestamp, uint64_t ref_timestamp)
1774 {
1775         timestamp |= (ref_timestamp & (0xffULL << 56));
1776 
1777         if (timestamp < ref_timestamp) {
1778                 if (ref_timestamp - timestamp > (1ULL << 55))
1779                         timestamp += (1ULL << 56);
1780         } else {
1781                 if (timestamp - ref_timestamp > (1ULL << 55))
1782                         timestamp -= (1ULL << 56);
1783         }
1784 
1785         return timestamp;
1786 }
1787 
1788 /* For use only when decoder->vm_time_correlation is true */
1789 static bool intel_pt_time_in_range(struct intel_pt_decoder *decoder,
1790                                    uint64_t timestamp)
1791 {
1792         uint64_t max_timestamp = decoder->buf_timestamp;
1793 
1794         if (!max_timestamp) {
1795                 max_timestamp = decoder->last_reliable_timestamp +
1796                                 0x400000000ULL;
1797         }
1798         return timestamp >= decoder->last_reliable_timestamp &&
1799                timestamp < decoder->buf_timestamp;
1800 }
1801 
1802 static void intel_pt_calc_tsc_timestamp(struct intel_pt_decoder *decoder)
1803 {
1804         uint64_t timestamp;
1805         bool bad = false;
1806 
1807         decoder->have_tma = false;
1808 
1809         if (decoder->ref_timestamp) {
1810                 timestamp = intel_pt_8b_tsc(decoder->packet.payload,
1811                                             decoder->ref_timestamp);
1812                 decoder->tsc_timestamp = timestamp;
1813                 decoder->timestamp = timestamp;
1814                 decoder->ref_timestamp = 0;
1815                 decoder->timestamp_insn_cnt = 0;
1816         } else if (decoder->timestamp) {
1817                 timestamp = decoder->packet.payload |
1818                             (decoder->timestamp & (0xffULL << 56));
1819                 decoder->tsc_timestamp = timestamp;
1820                 if (timestamp < decoder->timestamp &&
1821                     decoder->timestamp - timestamp < decoder->tsc_slip) {
1822                         intel_pt_log_to("Suppressing backwards timestamp",
1823                                         timestamp);
1824                         timestamp = decoder->timestamp;
1825                 }
1826                 if (timestamp < decoder->timestamp) {
1827                         if (!decoder->buf_timestamp ||
1828                             (timestamp + (1ULL << 56) < decoder->buf_timestamp)) {
1829                                 intel_pt_log_to("Wraparound timestamp", timestamp);
1830                                 timestamp += (1ULL << 56);
1831                                 decoder->tsc_timestamp = timestamp;
1832                         } else {
1833                                 intel_pt_log_to("Suppressing bad timestamp", timestamp);
1834                                 timestamp = decoder->timestamp;
1835                                 bad = true;
1836                         }
1837                 }
1838                 if (decoder->vm_time_correlation &&
1839                     (bad || !intel_pt_time_in_range(decoder, timestamp)) &&
1840                     intel_pt_print_once(decoder, INTEL_PT_PRT_ONCE_ERANGE))
1841                         p_log("Timestamp out of range");
1842                 decoder->timestamp = timestamp;
1843                 decoder->timestamp_insn_cnt = 0;
1844         }
1845 
1846         if (decoder->last_packet_type == INTEL_PT_CYC) {
1847                 decoder->cyc_ref_timestamp = decoder->timestamp;
1848                 decoder->cycle_cnt = 0;
1849                 decoder->have_calc_cyc_to_tsc = false;
1850                 intel_pt_calc_cyc_to_tsc(decoder, false);
1851         }
1852 
1853         intel_pt_log_to("Setting timestamp", decoder->timestamp);
1854 }
1855 
1856 static int intel_pt_overflow(struct intel_pt_decoder *decoder)
1857 {
1858         intel_pt_log("ERROR: Buffer overflow\n");
1859         intel_pt_clear_tx_flags(decoder);
1860         intel_pt_set_nr(decoder);
1861         decoder->timestamp_insn_cnt = 0;
1862         decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1863         decoder->state.from_ip = decoder->ip;
1864         decoder->ip = 0;
1865         decoder->pge = false;
1866         intel_pt_clear_fup_event(decoder);
1867         decoder->overflow = true;
1868         return -EOVERFLOW;
1869 }
1870 
1871 static inline void intel_pt_mtc_cyc_cnt_pge(struct intel_pt_decoder *decoder)
1872 {
1873         if (decoder->have_cyc)
1874                 return;
1875 
1876         decoder->cyc_cnt_timestamp = decoder->timestamp;
1877         decoder->base_cyc_cnt = decoder->tot_cyc_cnt;
1878 }
1879 
1880 static inline void intel_pt_mtc_cyc_cnt_cbr(struct intel_pt_decoder *decoder)
1881 {
1882         decoder->tsc_to_cyc = decoder->cbr / decoder->max_non_turbo_ratio_fp;
1883 
1884         if (decoder->pge)
1885                 intel_pt_mtc_cyc_cnt_pge(decoder);
1886 }
1887 
1888 static inline void intel_pt_mtc_cyc_cnt_upd(struct intel_pt_decoder *decoder)
1889 {
1890         uint64_t tot_cyc_cnt, tsc_delta;
1891 
1892         if (decoder->have_cyc)
1893                 return;
1894 
1895         decoder->sample_cyc = true;
1896 
1897         if (!decoder->pge || decoder->timestamp <= decoder->cyc_cnt_timestamp)
1898                 return;
1899 
1900         tsc_delta = decoder->timestamp - decoder->cyc_cnt_timestamp;
1901         tot_cyc_cnt = tsc_delta * decoder->tsc_to_cyc + decoder->base_cyc_cnt;
1902 
1903         if (tot_cyc_cnt > decoder->tot_cyc_cnt)
1904                 decoder->tot_cyc_cnt = tot_cyc_cnt;
1905 }
1906 
1907 static void intel_pt_calc_tma(struct intel_pt_decoder *decoder)
1908 {
1909         uint32_t ctc = decoder->packet.payload;
1910         uint32_t fc = decoder->packet.count;
1911         uint32_t ctc_rem = ctc & decoder->ctc_rem_mask;
1912 
1913         if (!decoder->tsc_ctc_ratio_d)
1914                 return;
1915 
1916         if (decoder->pge && !decoder->in_psb)
1917                 intel_pt_mtc_cyc_cnt_pge(decoder);
1918         else
1919                 intel_pt_mtc_cyc_cnt_upd(decoder);
1920 
1921         decoder->last_mtc = (ctc >> decoder->mtc_shift) & 0xff;
1922         decoder->last_ctc = ctc - ctc_rem;
1923         decoder->ctc_timestamp = decoder->tsc_timestamp - fc;
1924         if (decoder->tsc_ctc_mult) {
1925                 decoder->ctc_timestamp -= ctc_rem * decoder->tsc_ctc_mult;
1926         } else {
1927                 decoder->ctc_timestamp -= multdiv(ctc_rem,
1928                                                   decoder->tsc_ctc_ratio_n,
1929                                                   decoder->tsc_ctc_ratio_d);
1930         }
1931         decoder->ctc_delta = 0;
1932         decoder->have_tma = true;
1933         decoder->fixup_last_mtc = true;
1934         intel_pt_log("CTC timestamp " x64_fmt " last MTC %#x  CTC rem %#x\n",
1935                      decoder->ctc_timestamp, decoder->last_mtc, ctc_rem);
1936 }
1937 
1938 static void intel_pt_calc_mtc_timestamp(struct intel_pt_decoder *decoder)
1939 {
1940         uint64_t timestamp;
1941         uint32_t mtc, mtc_delta;
1942 
1943         if (!decoder->have_tma)
1944                 return;
1945 
1946         mtc = decoder->packet.payload;
1947 
1948         if (decoder->mtc_shift > 8 && decoder->fixup_last_mtc) {
1949                 decoder->fixup_last_mtc = false;
1950                 intel_pt_fixup_last_mtc(mtc, decoder->mtc_shift,
1951                                         &decoder->last_mtc);
1952         }
1953 
1954         if (mtc > decoder->last_mtc)
1955                 mtc_delta = mtc - decoder->last_mtc;
1956         else
1957                 mtc_delta = mtc + 256 - decoder->last_mtc;
1958 
1959         decoder->ctc_delta += mtc_delta << decoder->mtc_shift;
1960 
1961         if (decoder->tsc_ctc_mult) {
1962                 timestamp = decoder->ctc_timestamp +
1963                             decoder->ctc_delta * decoder->tsc_ctc_mult;
1964         } else {
1965                 timestamp = decoder->ctc_timestamp +
1966                             multdiv(decoder->ctc_delta,
1967                                     decoder->tsc_ctc_ratio_n,
1968                                     decoder->tsc_ctc_ratio_d);
1969         }
1970 
1971         if (timestamp < decoder->timestamp)
1972                 intel_pt_log("Suppressing MTC timestamp " x64_fmt " less than current timestamp " x64_fmt "\n",
1973                              timestamp, decoder->timestamp);
1974         else
1975                 decoder->timestamp = timestamp;
1976 
1977         intel_pt_mtc_cyc_cnt_upd(decoder);
1978 
1979         decoder->timestamp_insn_cnt = 0;
1980         decoder->last_mtc = mtc;
1981 
1982         if (decoder->last_packet_type == INTEL_PT_CYC) {
1983                 decoder->cyc_ref_timestamp = decoder->timestamp;
1984                 decoder->cycle_cnt = 0;
1985                 decoder->have_calc_cyc_to_tsc = false;
1986                 intel_pt_calc_cyc_to_tsc(decoder, true);
1987         }
1988 
1989         intel_pt_log_to("Setting timestamp", decoder->timestamp);
1990 }
1991 
1992 static void intel_pt_calc_cbr(struct intel_pt_decoder *decoder)
1993 {
1994         unsigned int cbr = decoder->packet.payload & 0xff;
1995 
1996         decoder->cbr_payload = decoder->packet.payload;
1997 
1998         if (decoder->cbr == cbr)
1999                 return;
2000 
2001         decoder->cbr = cbr;
2002         decoder->cbr_cyc_to_tsc = decoder->max_non_turbo_ratio_fp / cbr;
2003         decoder->cyc_ref_timestamp = decoder->timestamp;
2004         decoder->cycle_cnt = 0;
2005 
2006         intel_pt_mtc_cyc_cnt_cbr(decoder);
2007 }
2008 
2009 static void intel_pt_calc_cyc_timestamp(struct intel_pt_decoder *decoder)
2010 {
2011         uint64_t timestamp = decoder->cyc_ref_timestamp;
2012 
2013         decoder->have_cyc = true;
2014 
2015         decoder->cycle_cnt += decoder->packet.payload;
2016         if (decoder->pge)
2017                 decoder->tot_cyc_cnt += decoder->packet.payload;
2018         decoder->sample_cyc = true;
2019 
2020         if (!decoder->cyc_ref_timestamp)
2021                 return;
2022 
2023         if (decoder->have_calc_cyc_to_tsc)
2024                 timestamp += decoder->cycle_cnt * decoder->calc_cyc_to_tsc;
2025         else if (decoder->cbr)
2026                 timestamp += decoder->cycle_cnt * decoder->cbr_cyc_to_tsc;
2027         else
2028                 return;
2029 
2030         if (timestamp < decoder->timestamp)
2031                 intel_pt_log("Suppressing CYC timestamp " x64_fmt " less than current timestamp " x64_fmt "\n",
2032                              timestamp, decoder->timestamp);
2033         else
2034                 decoder->timestamp = timestamp;
2035 
2036         decoder->timestamp_insn_cnt = 0;
2037 
2038         intel_pt_log_to("Setting timestamp", decoder->timestamp);
2039 }
2040 
2041 static void intel_pt_bbp(struct intel_pt_decoder *decoder)
2042 {
2043         if (decoder->prev_pkt_ctx == INTEL_PT_NO_CTX) {
2044                 memset(decoder->state.items.mask, 0, sizeof(decoder->state.items.mask));
2045                 decoder->state.items.is_32_bit = false;
2046         }
2047         decoder->blk_type = decoder->packet.payload;
2048         decoder->blk_type_pos = intel_pt_blk_type_pos(decoder->blk_type);
2049         if (decoder->blk_type == INTEL_PT_GP_REGS)
2050                 decoder->state.items.is_32_bit = decoder->packet.count;
2051         if (decoder->blk_type_pos < 0) {
2052                 intel_pt_log("WARNING: Unknown block type %u\n",
2053                              decoder->blk_type);
2054         } else if (decoder->state.items.mask[decoder->blk_type_pos]) {
2055                 intel_pt_log("WARNING: Duplicate block type %u\n",
2056                              decoder->blk_type);
2057         }
2058 }
2059 
2060 static void intel_pt_bip(struct intel_pt_decoder *decoder)
2061 {
2062         uint32_t id = decoder->packet.count;
2063         uint32_t bit = 1 << id;
2064         int pos = decoder->blk_type_pos;
2065 
2066         if (pos < 0 || id >= INTEL_PT_BLK_ITEM_ID_CNT) {
2067                 intel_pt_log("WARNING: Unknown block item %u type %d\n",
2068                              id, decoder->blk_type);
2069                 return;
2070         }
2071 
2072         if (decoder->state.items.mask[pos] & bit) {
2073                 intel_pt_log("WARNING: Duplicate block item %u type %d\n",
2074                              id, decoder->blk_type);
2075         }
2076 
2077         decoder->state.items.mask[pos] |= bit;
2078         decoder->state.items.val[pos][id] = decoder->packet.payload;
2079 }
2080 
2081 /* Walk PSB+ packets when already in sync. */
2082 static int intel_pt_walk_psbend(struct intel_pt_decoder *decoder)
2083 {
2084         int err;
2085 
2086         decoder->in_psb = true;
2087 
2088         while (1) {
2089                 err = intel_pt_get_next_packet(decoder);
2090                 if (err)
2091                         goto out;
2092 
2093                 switch (decoder->packet.type) {
2094                 case INTEL_PT_PSBEND:
2095                         err = 0;
2096                         goto out;
2097 
2098                 case INTEL_PT_TIP_PGD:
2099                 case INTEL_PT_TIP_PGE:
2100                 case INTEL_PT_TIP:
2101                 case INTEL_PT_TNT:
2102                 case INTEL_PT_TRACESTOP:
2103                 case INTEL_PT_BAD:
2104                 case INTEL_PT_PSB:
2105                 case INTEL_PT_PTWRITE:
2106                 case INTEL_PT_PTWRITE_IP:
2107                 case INTEL_PT_EXSTOP:
2108                 case INTEL_PT_EXSTOP_IP:
2109                 case INTEL_PT_MWAIT:
2110                 case INTEL_PT_PWRE:
2111                 case INTEL_PT_PWRX:
2112                 case INTEL_PT_BBP:
2113                 case INTEL_PT_BIP:
2114                 case INTEL_PT_BEP:
2115                 case INTEL_PT_BEP_IP:
2116                 case INTEL_PT_CFE:
2117                 case INTEL_PT_CFE_IP:
2118                 case INTEL_PT_EVD:
2119                         decoder->have_tma = false;
2120                         intel_pt_log("ERROR: Unexpected packet\n");
2121                         err = -EAGAIN;
2122                         goto out;
2123 
2124                 case INTEL_PT_OVF:
2125                         err = intel_pt_overflow(decoder);
2126                         goto out;
2127 
2128                 case INTEL_PT_TSC:
2129                         intel_pt_calc_tsc_timestamp(decoder);
2130                         break;
2131 
2132                 case INTEL_PT_TMA:
2133                         intel_pt_calc_tma(decoder);
2134                         break;
2135 
2136                 case INTEL_PT_CBR:
2137                         intel_pt_calc_cbr(decoder);
2138                         break;
2139 
2140                 case INTEL_PT_MODE_EXEC:
2141                         intel_pt_mode_exec_status(decoder);
2142                         break;
2143 
2144                 case INTEL_PT_PIP:
2145                         intel_pt_set_pip(decoder);
2146                         break;
2147 
2148                 case INTEL_PT_FUP:
2149                         decoder->pge = true;
2150                         if (decoder->packet.count) {
2151                                 intel_pt_set_last_ip(decoder);
2152                                 decoder->psb_ip = decoder->last_ip;
2153                         }
2154                         break;
2155 
2156                 case INTEL_PT_MODE_TSX:
2157                         intel_pt_update_in_tx(decoder);
2158                         break;
2159 
2160                 case INTEL_PT_MTC:
2161                         intel_pt_calc_mtc_timestamp(decoder);
2162                         if (decoder->period_type == INTEL_PT_PERIOD_MTC)
2163                                 decoder->state.type |= INTEL_PT_INSTRUCTION;
2164                         break;
2165 
2166                 case INTEL_PT_CYC:
2167                         intel_pt_calc_cyc_timestamp(decoder);
2168                         break;
2169 
2170                 case INTEL_PT_VMCS:
2171                 case INTEL_PT_MNT:
2172                 case INTEL_PT_PAD:
2173                 default:
2174                         break;
2175                 }
2176         }
2177 out:
2178         decoder->in_psb = false;
2179 
2180         return err;
2181 }
2182 
2183 static int intel_pt_walk_fup_tip(struct intel_pt_decoder *decoder)
2184 {
2185         int err;
2186 
2187         if (decoder->tx_flags & INTEL_PT_ABORT_TX) {
2188                 decoder->tx_flags = 0;
2189                 decoder->state.flags &= ~INTEL_PT_IN_TX;
2190                 decoder->state.flags |= INTEL_PT_ABORT_TX;
2191         } else {
2192                 decoder->state.flags |= INTEL_PT_ASYNC;
2193         }
2194 
2195         while (1) {
2196                 err = intel_pt_get_next_packet(decoder);
2197                 if (err)
2198                         return err;
2199 
2200                 switch (decoder->packet.type) {
2201                 case INTEL_PT_TNT:
2202                 case INTEL_PT_FUP:
2203                 case INTEL_PT_TRACESTOP:
2204                 case INTEL_PT_PSB:
2205                 case INTEL_PT_TSC:
2206                 case INTEL_PT_TMA:
2207                 case INTEL_PT_MODE_TSX:
2208                 case INTEL_PT_BAD:
2209                 case INTEL_PT_PSBEND:
2210                 case INTEL_PT_PTWRITE:
2211                 case INTEL_PT_PTWRITE_IP:
2212                 case INTEL_PT_EXSTOP:
2213                 case INTEL_PT_EXSTOP_IP:
2214                 case INTEL_PT_MWAIT:
2215                 case INTEL_PT_PWRE:
2216                 case INTEL_PT_PWRX:
2217                 case INTEL_PT_BBP:
2218                 case INTEL_PT_BIP:
2219                 case INTEL_PT_BEP:
2220                 case INTEL_PT_BEP_IP:
2221                 case INTEL_PT_CFE:
2222                 case INTEL_PT_CFE_IP:
2223                 case INTEL_PT_EVD:
2224                         intel_pt_log("ERROR: Missing TIP after FUP\n");
2225                         decoder->pkt_state = INTEL_PT_STATE_ERR3;
2226                         decoder->pkt_step = 0;
2227                         return -ENOENT;
2228 
2229                 case INTEL_PT_CBR:
2230                         intel_pt_calc_cbr(decoder);
2231                         break;
2232 
2233                 case INTEL_PT_OVF:
2234                         return intel_pt_overflow(decoder);
2235 
2236                 case INTEL_PT_TIP_PGD:
2237                         decoder->state.from_ip = decoder->ip;
2238                         if (decoder->packet.count == 0) {
2239                                 decoder->state.to_ip = 0;
2240                         } else {
2241                                 intel_pt_set_ip(decoder);
2242                                 decoder->state.to_ip = decoder->ip;
2243                         }
2244                         decoder->pge = false;
2245                         decoder->continuous_period = false;
2246                         decoder->state.type |= INTEL_PT_TRACE_END;
2247                         intel_pt_update_nr(decoder);
2248                         return 0;
2249 
2250                 case INTEL_PT_TIP_PGE:
2251                         decoder->pge = true;
2252                         intel_pt_log("Omitting PGE ip " x64_fmt "\n",
2253                                      decoder->ip);
2254                         decoder->state.from_ip = 0;
2255                         if (decoder->packet.count == 0) {
2256                                 decoder->state.to_ip = 0;
2257                         } else {
2258                                 intel_pt_set_ip(decoder);
2259                                 decoder->state.to_ip = decoder->ip;
2260                         }
2261                         decoder->state.type |= INTEL_PT_TRACE_BEGIN;
2262                         intel_pt_mtc_cyc_cnt_pge(decoder);
2263                         intel_pt_set_nr(decoder);
2264                         return 0;
2265 
2266                 case INTEL_PT_TIP:
2267                         decoder->state.from_ip = decoder->ip;
2268                         if (decoder->packet.count == 0) {
2269                                 decoder->state.to_ip = 0;
2270                         } else {
2271                                 intel_pt_set_ip(decoder);
2272                                 decoder->state.to_ip = decoder->ip;
2273                         }
2274                         intel_pt_update_nr(decoder);
2275                         intel_pt_sample_iflag_chg(decoder);
2276                         return 0;
2277 
2278                 case INTEL_PT_PIP:
2279                         intel_pt_update_pip(decoder);
2280                         break;
2281 
2282                 case INTEL_PT_MTC:
2283                         intel_pt_calc_mtc_timestamp(decoder);
2284                         if (decoder->period_type == INTEL_PT_PERIOD_MTC)
2285                                 decoder->state.type |= INTEL_PT_INSTRUCTION;
2286                         break;
2287 
2288                 case INTEL_PT_CYC:
2289                         intel_pt_calc_cyc_timestamp(decoder);
2290                         break;
2291 
2292                 case INTEL_PT_MODE_EXEC:
2293                         intel_pt_mode_exec(decoder);
2294                         break;
2295 
2296                 case INTEL_PT_VMCS:
2297                 case INTEL_PT_MNT:
2298                 case INTEL_PT_PAD:
2299                         break;
2300 
2301                 default:
2302                         return intel_pt_bug(decoder);
2303                 }
2304         }
2305 }
2306 
2307 static int intel_pt_resample(struct intel_pt_decoder *decoder)
2308 {
2309         decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
2310         decoder->state.type = INTEL_PT_INSTRUCTION;
2311         decoder->state.from_ip = decoder->ip;
2312         decoder->state.to_ip = 0;
2313         return 0;
2314 }
2315 
2316 struct intel_pt_vm_tsc_info {
2317         struct intel_pt_pkt pip_packet;
2318         struct intel_pt_pkt vmcs_packet;
2319         struct intel_pt_pkt tma_packet;
2320         bool tsc, pip, vmcs, tma, psbend;
2321         uint64_t ctc_delta;
2322         uint64_t last_ctc;
2323         int max_lookahead;
2324 };
2325 
2326 /* Lookahead and get the PIP, VMCS and TMA packets from PSB+ */
2327 static int intel_pt_vm_psb_lookahead_cb(struct intel_pt_pkt_info *pkt_info)
2328 {
2329         struct intel_pt_vm_tsc_info *data = pkt_info->data;
2330 
2331         switch (pkt_info->packet.type) {
2332         case INTEL_PT_PAD:
2333         case INTEL_PT_MNT:
2334         case INTEL_PT_MODE_EXEC:
2335         case INTEL_PT_MODE_TSX:
2336         case INTEL_PT_MTC:
2337         case INTEL_PT_FUP:
2338         case INTEL_PT_CYC:
2339         case INTEL_PT_CBR:
2340                 break;
2341 
2342         case INTEL_PT_TSC:
2343                 data->tsc = true;
2344                 break;
2345 
2346         case INTEL_PT_TMA:
2347                 data->tma_packet = pkt_info->packet;
2348                 data->tma = true;
2349                 break;
2350 
2351         case INTEL_PT_PIP:
2352                 data->pip_packet = pkt_info->packet;
2353                 data->pip = true;
2354                 break;
2355 
2356         case INTEL_PT_VMCS:
2357                 data->vmcs_packet = pkt_info->packet;
2358                 data->vmcs = true;
2359                 break;
2360 
2361         case INTEL_PT_PSBEND:
2362                 data->psbend = true;
2363                 return 1;
2364 
2365         case INTEL_PT_TIP_PGE:
2366         case INTEL_PT_PTWRITE:
2367         case INTEL_PT_PTWRITE_IP:
2368         case INTEL_PT_EXSTOP:
2369         case INTEL_PT_EXSTOP_IP:
2370         case INTEL_PT_MWAIT:
2371         case INTEL_PT_PWRE:
2372         case INTEL_PT_PWRX:
2373         case INTEL_PT_BBP:
2374         case INTEL_PT_BIP:
2375         case INTEL_PT_BEP:
2376         case INTEL_PT_BEP_IP:
2377         case INTEL_PT_OVF:
2378         case INTEL_PT_BAD:
2379         case INTEL_PT_TNT:
2380         case INTEL_PT_TIP_PGD:
2381         case INTEL_PT_TIP:
2382         case INTEL_PT_PSB:
2383         case INTEL_PT_TRACESTOP:
2384         case INTEL_PT_CFE:
2385         case INTEL_PT_CFE_IP:
2386         case INTEL_PT_EVD:
2387         default:
2388                 return 1;
2389         }
2390 
2391         return 0;
2392 }
2393 
2394 struct intel_pt_ovf_fup_info {
2395         int max_lookahead;
2396         bool found;
2397 };
2398 
2399 /* Lookahead to detect a FUP packet after OVF */
2400 static int intel_pt_ovf_fup_lookahead_cb(struct intel_pt_pkt_info *pkt_info)
2401 {
2402         struct intel_pt_ovf_fup_info *data = pkt_info->data;
2403 
2404         if (pkt_info->packet.type == INTEL_PT_CYC ||
2405             pkt_info->packet.type == INTEL_PT_MTC ||
2406             pkt_info->packet.type == INTEL_PT_TSC)
2407                 return !--(data->max_lookahead);
2408         data->found = pkt_info->packet.type == INTEL_PT_FUP;
2409         return 1;
2410 }
2411 
2412 static bool intel_pt_ovf_fup_lookahead(struct intel_pt_decoder *decoder)
2413 {
2414         struct intel_pt_ovf_fup_info data = {
2415                 .max_lookahead = 16,
2416                 .found = false,
2417         };
2418 
2419         intel_pt_pkt_lookahead(decoder, intel_pt_ovf_fup_lookahead_cb, &data);
2420         return data.found;
2421 }
2422 
2423 /* Lookahead and get the TMA packet after TSC */
2424 static int intel_pt_tma_lookahead_cb(struct intel_pt_pkt_info *pkt_info)
2425 {
2426         struct intel_pt_vm_tsc_info *data = pkt_info->data;
2427 
2428         if (pkt_info->packet.type == INTEL_PT_CYC ||
2429             pkt_info->packet.type == INTEL_PT_MTC)
2430                 return !--(data->max_lookahead);
2431 
2432         if (pkt_info->packet.type == INTEL_PT_TMA) {
2433                 data->tma_packet = pkt_info->packet;
2434                 data->tma = true;
2435         }
2436         return 1;
2437 }
2438 
2439 static uint64_t intel_pt_ctc_to_tsc(struct intel_pt_decoder *decoder, uint64_t ctc)
2440 {
2441         if (decoder->tsc_ctc_mult)
2442                 return ctc * decoder->tsc_ctc_mult;
2443         else
2444                 return multdiv(ctc, decoder->tsc_ctc_ratio_n, decoder->tsc_ctc_ratio_d);
2445 }
2446 
2447 static uint64_t intel_pt_calc_expected_tsc(struct intel_pt_decoder *decoder,
2448                                            uint32_t ctc,
2449                                            uint32_t fc,
2450                                            uint64_t last_ctc_timestamp,
2451                                            uint64_t ctc_delta,
2452                                            uint32_t last_ctc)
2453 {
2454         /* Number of CTC ticks from last_ctc_timestamp to last_mtc */
2455         uint64_t last_mtc_ctc = last_ctc + ctc_delta;
2456         /*
2457          * Number of CTC ticks from there until current TMA packet. We would
2458          * expect last_mtc_ctc to be before ctc, but the TSC packet can slip
2459          * past an MTC, so a sign-extended value is used.
2460          */
2461         uint64_t delta = (int16_t)((uint16_t)ctc - (uint16_t)last_mtc_ctc);
2462         /* Total CTC ticks from last_ctc_timestamp to current TMA packet */
2463         uint64_t new_ctc_delta = ctc_delta + delta;
2464         uint64_t expected_tsc;
2465 
2466         /*
2467          * Convert CTC ticks to TSC ticks, add the starting point
2468          * (last_ctc_timestamp) and the fast counter from the TMA packet.
2469          */
2470         expected_tsc = last_ctc_timestamp + intel_pt_ctc_to_tsc(decoder, new_ctc_delta) + fc;
2471 
2472         if (intel_pt_enable_logging) {
2473                 intel_pt_log_x64(last_mtc_ctc);
2474                 intel_pt_log_x32(last_ctc);
2475                 intel_pt_log_x64(ctc_delta);
2476                 intel_pt_log_x64(delta);
2477                 intel_pt_log_x32(ctc);
2478                 intel_pt_log_x64(new_ctc_delta);
2479                 intel_pt_log_x64(last_ctc_timestamp);
2480                 intel_pt_log_x32(fc);
2481                 intel_pt_log_x64(intel_pt_ctc_to_tsc(decoder, new_ctc_delta));
2482                 intel_pt_log_x64(expected_tsc);
2483         }
2484 
2485         return expected_tsc;
2486 }
2487 
2488 static uint64_t intel_pt_expected_tsc(struct intel_pt_decoder *decoder,
2489                                       struct intel_pt_vm_tsc_info *data)
2490 {
2491         uint32_t ctc = data->tma_packet.payload;
2492         uint32_t fc = data->tma_packet.count;
2493 
2494         return intel_pt_calc_expected_tsc(decoder, ctc, fc,
2495                                           decoder->ctc_timestamp,
2496                                           data->ctc_delta, data->last_ctc);
2497 }
2498 
2499 static void intel_pt_translate_vm_tsc(struct intel_pt_decoder *decoder,
2500                                       struct intel_pt_vmcs_info *vmcs_info)
2501 {
2502         uint64_t payload = decoder->packet.payload;
2503 
2504         /* VMX adds the TSC Offset, so subtract to get host TSC */
2505         decoder->packet.payload -= vmcs_info->tsc_offset;
2506         /* TSC packet has only 7 bytes */
2507         decoder->packet.payload &= SEVEN_BYTES;
2508 
2509         /*
2510          * The buffer is mmapped from the data file, so this also updates the
2511          * data file.
2512          */
2513         if (!decoder->vm_tm_corr_dry_run)
2514                 memcpy((void *)decoder->buf + 1, &decoder->packet.payload, 7);
2515 
2516         intel_pt_log("Translated VM TSC %#" PRIx64 " -> %#" PRIx64
2517                      "    VMCS %#" PRIx64 "    TSC Offset %#" PRIx64 "\n",
2518                      payload, decoder->packet.payload, vmcs_info->vmcs,
2519                      vmcs_info->tsc_offset);
2520 }
2521 
2522 static void intel_pt_translate_vm_tsc_offset(struct intel_pt_decoder *decoder,
2523                                              uint64_t tsc_offset)
2524 {
2525         struct intel_pt_vmcs_info vmcs_info = {
2526                 .vmcs = NO_VMCS,
2527                 .tsc_offset = tsc_offset
2528         };
2529 
2530         intel_pt_translate_vm_tsc(decoder, &vmcs_info);
2531 }
2532 
2533 static inline bool in_vm(uint64_t pip_payload)
2534 {
2535         return pip_payload & 1;
2536 }
2537 
2538 static inline bool pip_in_vm(struct intel_pt_pkt *pip_packet)
2539 {
2540         return pip_packet->payload & 1;
2541 }
2542 
2543 static void intel_pt_print_vmcs_info(struct intel_pt_vmcs_info *vmcs_info)
2544 {
2545         p_log("VMCS: %#" PRIx64 "  TSC Offset %#" PRIx64,
2546               vmcs_info->vmcs, vmcs_info->tsc_offset);
2547 }
2548 
2549 static void intel_pt_vm_tm_corr_psb(struct intel_pt_decoder *decoder,
2550                                     struct intel_pt_vm_tsc_info *data)
2551 {
2552         memset(data, 0, sizeof(*data));
2553         data->ctc_delta = decoder->ctc_delta;
2554         data->last_ctc = decoder->last_ctc;
2555         intel_pt_pkt_lookahead(decoder, intel_pt_vm_psb_lookahead_cb, data);
2556         if (data->tsc && !data->psbend)
2557                 p_log("ERROR: PSB without PSBEND");
2558         decoder->in_psb = data->psbend;
2559 }
2560 
2561 static void intel_pt_vm_tm_corr_first_tsc(struct intel_pt_decoder *decoder,
2562                                           struct intel_pt_vm_tsc_info *data,
2563                                           struct intel_pt_vmcs_info *vmcs_info,
2564                                           uint64_t host_tsc)
2565 {
2566         if (!decoder->in_psb) {
2567                 /* Can't happen */
2568                 p_log("ERROR: First TSC is not in PSB+");
2569         }
2570 
2571         if (data->pip) {
2572                 if (pip_in_vm(&data->pip_packet)) { /* Guest */
2573                         if (vmcs_info && vmcs_info->tsc_offset) {
2574                                 intel_pt_translate_vm_tsc(decoder, vmcs_info);
2575                                 decoder->vm_tm_corr_reliable = true;
2576                         } else {
2577                                 p_log("ERROR: First TSC, unknown TSC Offset");
2578                         }
2579                 } else { /* Host */
2580                         decoder->vm_tm_corr_reliable = true;
2581                 }
2582         } else { /* Host or Guest */
2583                 decoder->vm_tm_corr_reliable = false;
2584                 if (intel_pt_time_in_range(decoder, host_tsc)) {
2585                         /* Assume Host */
2586                 } else {
2587                         /* Assume Guest */
2588                         if (vmcs_info && vmcs_info->tsc_offset)
2589                                 intel_pt_translate_vm_tsc(decoder, vmcs_info);
2590                         else
2591                                 p_log("ERROR: First TSC, no PIP, unknown TSC Offset");
2592                 }
2593         }
2594 }
2595 
2596 static void intel_pt_vm_tm_corr_tsc(struct intel_pt_decoder *decoder,
2597                                     struct intel_pt_vm_tsc_info *data)
2598 {
2599         struct intel_pt_vmcs_info *vmcs_info;
2600         uint64_t tsc_offset = 0;
2601         uint64_t vmcs;
2602         bool reliable = true;
2603         uint64_t expected_tsc;
2604         uint64_t host_tsc;
2605         uint64_t ref_timestamp;
2606 
2607         bool assign = false;
2608         bool assign_reliable = false;
2609 
2610         /* Already have 'data' for the in_psb case */
2611         if (!decoder->in_psb) {
2612                 memset(data, 0, sizeof(*data));
2613                 data->ctc_delta = decoder->ctc_delta;
2614                 data->last_ctc = decoder->last_ctc;
2615                 data->max_lookahead = 16;
2616                 intel_pt_pkt_lookahead(decoder, intel_pt_tma_lookahead_cb, data);
2617                 if (decoder->pge) {
2618                         data->pip = true;
2619                         data->pip_packet.payload = decoder->pip_payload;
2620                 }
2621         }
2622 
2623         /* Calculations depend on having TMA packets */
2624         if (!data->tma) {
2625                 p_log("ERROR: TSC without TMA");
2626                 return;
2627         }
2628 
2629         vmcs = data->vmcs ? data->vmcs_packet.payload : decoder->vmcs;
2630         if (vmcs == NO_VMCS)
2631                 vmcs = 0;
2632 
2633         vmcs_info = decoder->findnew_vmcs_info(decoder->data, vmcs);
2634 
2635         ref_timestamp = decoder->timestamp ? decoder->timestamp : decoder->buf_timestamp;
2636         host_tsc = intel_pt_8b_tsc(decoder->packet.payload, ref_timestamp);
2637 
2638         if (!decoder->ctc_timestamp) {
2639                 intel_pt_vm_tm_corr_first_tsc(decoder, data, vmcs_info, host_tsc);
2640                 return;
2641         }
2642 
2643         expected_tsc = intel_pt_expected_tsc(decoder, data);
2644 
2645         tsc_offset = host_tsc - expected_tsc;
2646 
2647         /* Determine if TSC is from Host or Guest */
2648         if (data->pip) {
2649                 if (pip_in_vm(&data->pip_packet)) { /* Guest */
2650                         if (!vmcs_info) {
2651                                 /* PIP NR=1 without VMCS cannot happen */
2652                                 p_log("ERROR: Missing VMCS");
2653                                 intel_pt_translate_vm_tsc_offset(decoder, tsc_offset);
2654                                 decoder->vm_tm_corr_reliable = false;
2655                                 return;
2656                         }
2657                 } else { /* Host */
2658                         decoder->last_reliable_timestamp = host_tsc;
2659                         decoder->vm_tm_corr_reliable = true;
2660                         return;
2661                 }
2662         } else { /* Host or Guest */
2663                 reliable = false; /* Host/Guest is a guess, so not reliable */
2664                 if (decoder->in_psb) {
2665                         if (!tsc_offset)
2666                                 return; /* Zero TSC Offset, assume Host */
2667                         /*
2668                          * TSC packet has only 7 bytes of TSC. We have no
2669                          * information about the Guest's 8th byte, but it
2670                          * doesn't matter because we only need 7 bytes.
2671                          * Here, since the 8th byte is unreliable and
2672                          * irrelevant, compare only 7 byes.
2673                          */
2674                         if (vmcs_info &&
2675                             (tsc_offset & SEVEN_BYTES) ==
2676                             (vmcs_info->tsc_offset & SEVEN_BYTES)) {
2677                                 /* Same TSC Offset as last VMCS, assume Guest */
2678                                 goto guest;
2679                         }
2680                 }
2681                 /*
2682                  * Check if the host_tsc is within the expected range.
2683                  * Note, we could narrow the range more by looking ahead for
2684                  * the next host TSC in the same buffer, but we don't bother to
2685                  * do that because this is probably good enough.
2686                  */
2687                 if (host_tsc >= expected_tsc && intel_pt_time_in_range(decoder, host_tsc)) {
2688                         /* Within expected range for Host TSC, assume Host */
2689                         decoder->vm_tm_corr_reliable = false;
2690                         return;
2691                 }
2692         }
2693 
2694 guest: /* Assuming Guest */
2695 
2696         /* Determine whether to assign TSC Offset */
2697         if (vmcs_info && vmcs_info->vmcs) {
2698                 if (vmcs_info->tsc_offset && vmcs_info->reliable) {
2699                         assign = false;
2700                 } else if (decoder->in_psb && data->pip && decoder->vm_tm_corr_reliable &&
2701                            decoder->vm_tm_corr_continuous && decoder->vm_tm_corr_same_buf) {
2702                         /* Continuous tracing, TSC in a PSB is not a time loss */
2703                         assign = true;
2704                         assign_reliable = true;
2705                 } else if (decoder->in_psb && data->pip && decoder->vm_tm_corr_same_buf) {
2706                         /*
2707                          * Unlikely to be a time loss TSC in a PSB which is not
2708                          * at the start of a buffer.
2709                          */
2710                         assign = true;
2711                         assign_reliable = false;
2712                 }
2713         }
2714 
2715         /* Record VMCS TSC Offset */
2716         if (assign && (vmcs_info->tsc_offset != tsc_offset ||
2717                        vmcs_info->reliable != assign_reliable)) {
2718                 bool print = vmcs_info->tsc_offset != tsc_offset;
2719 
2720                 vmcs_info->tsc_offset = tsc_offset;
2721                 vmcs_info->reliable = assign_reliable;
2722                 if (print)
2723                         intel_pt_print_vmcs_info(vmcs_info);
2724         }
2725 
2726         /* Determine what TSC Offset to use */
2727         if (vmcs_info && vmcs_info->tsc_offset) {
2728                 if (!vmcs_info->reliable)
2729                         reliable = false;
2730                 intel_pt_translate_vm_tsc(decoder, vmcs_info);
2731         } else {
2732                 reliable = false;
2733                 if (vmcs_info) {
2734                         if (!vmcs_info->error_printed) {
2735                                 p_log("ERROR: Unknown TSC Offset for VMCS %#" PRIx64,
2736                                       vmcs_info->vmcs);
2737                                 vmcs_info->error_printed = true;
2738                         }
2739                 } else {
2740                         if (intel_pt_print_once(decoder, INTEL_PT_PRT_ONCE_UNK_VMCS))
2741                                 p_log("ERROR: Unknown VMCS");
2742                 }
2743                 intel_pt_translate_vm_tsc_offset(decoder, tsc_offset);
2744         }
2745 
2746         decoder->vm_tm_corr_reliable = reliable;
2747 }
2748 
2749 static void intel_pt_vm_tm_corr_pebs_tsc(struct intel_pt_decoder *decoder)
2750 {
2751         uint64_t host_tsc = decoder->packet.payload;
2752         uint64_t guest_tsc = decoder->packet.payload;
2753         struct intel_pt_vmcs_info *vmcs_info;
2754         uint64_t vmcs;
2755 
2756         vmcs = decoder->vmcs;
2757         if (vmcs == NO_VMCS)
2758                 vmcs = 0;
2759 
2760         vmcs_info = decoder->findnew_vmcs_info(decoder->data, vmcs);
2761 
2762         if (decoder->pge) {
2763                 if (in_vm(decoder->pip_payload)) { /* Guest */
2764                         if (!vmcs_info) {
2765                                 /* PIP NR=1 without VMCS cannot happen */
2766                                 p_log("ERROR: Missing VMCS");
2767                         }
2768                 } else { /* Host */
2769                         return;
2770                 }
2771         } else { /* Host or Guest */
2772                 if (intel_pt_time_in_range(decoder, host_tsc)) {
2773                         /* Within expected range for Host TSC, assume Host */
2774                         return;
2775                 }
2776         }
2777 
2778         if (vmcs_info) {
2779                 /* Translate Guest TSC to Host TSC */
2780                 host_tsc = ((guest_tsc & SEVEN_BYTES) - vmcs_info->tsc_offset) & SEVEN_BYTES;
2781                 host_tsc = intel_pt_8b_tsc(host_tsc, decoder->timestamp);
2782                 intel_pt_log("Translated VM TSC %#" PRIx64 " -> %#" PRIx64
2783                              "    VMCS %#" PRIx64 "    TSC Offset %#" PRIx64 "\n",
2784                              guest_tsc, host_tsc, vmcs_info->vmcs,
2785                              vmcs_info->tsc_offset);
2786                 if (!intel_pt_time_in_range(decoder, host_tsc) &&
2787                     intel_pt_print_once(decoder, INTEL_PT_PRT_ONCE_ERANGE))
2788                         p_log("Timestamp out of range");
2789         } else {
2790                 if (intel_pt_print_once(decoder, INTEL_PT_PRT_ONCE_UNK_VMCS))
2791                         p_log("ERROR: Unknown VMCS");
2792                 host_tsc = decoder->timestamp;
2793         }
2794 
2795         decoder->packet.payload = host_tsc;
2796 
2797         if (!decoder->vm_tm_corr_dry_run)
2798                 memcpy((void *)decoder->buf + 1, &host_tsc, 8);
2799 }
2800 
2801 static int intel_pt_vm_time_correlation(struct intel_pt_decoder *decoder)
2802 {
2803         struct intel_pt_vm_tsc_info data = { .psbend = false };
2804         bool pge;
2805         int err;
2806 
2807         if (decoder->in_psb)
2808                 intel_pt_vm_tm_corr_psb(decoder, &data);
2809 
2810         while (1) {
2811                 err = intel_pt_get_next_packet(decoder);
2812                 if (err == -ENOLINK)
2813                         continue;
2814                 if (err)
2815                         break;
2816 
2817                 switch (decoder->packet.type) {
2818                 case INTEL_PT_TIP_PGD:
2819                         decoder->pge = false;
2820                         decoder->vm_tm_corr_continuous = false;
2821                         break;
2822 
2823                 case INTEL_PT_TNT:
2824                 case INTEL_PT_TIP:
2825                 case INTEL_PT_TIP_PGE:
2826                         decoder->pge = true;
2827                         break;
2828 
2829                 case INTEL_PT_OVF:
2830                         decoder->in_psb = false;
2831                         pge = decoder->pge;
2832                         decoder->pge = intel_pt_ovf_fup_lookahead(decoder);
2833                         if (pge != decoder->pge)
2834                                 intel_pt_log("Surprising PGE change in OVF!");
2835                         if (!decoder->pge)
2836                                 decoder->vm_tm_corr_continuous = false;
2837                         break;
2838 
2839                 case INTEL_PT_FUP:
2840                         if (decoder->in_psb)
2841                                 decoder->pge = true;
2842                         break;
2843 
2844                 case INTEL_PT_TRACESTOP:
2845                         decoder->pge = false;
2846                         decoder->vm_tm_corr_continuous = false;
2847                         decoder->have_tma = false;
2848                         break;
2849 
2850                 case INTEL_PT_PSB:
2851                         intel_pt_vm_tm_corr_psb(decoder, &data);
2852                         break;
2853 
2854                 case INTEL_PT_PIP:
2855                         decoder->pip_payload = decoder->packet.payload;
2856                         break;
2857 
2858                 case INTEL_PT_MTC:
2859                         intel_pt_calc_mtc_timestamp(decoder);
2860                         break;
2861 
2862                 case INTEL_PT_TSC:
2863                         intel_pt_vm_tm_corr_tsc(decoder, &data);
2864                         intel_pt_calc_tsc_timestamp(decoder);
2865                         decoder->vm_tm_corr_same_buf = true;
2866                         decoder->vm_tm_corr_continuous = decoder->pge;
2867                         break;
2868 
2869                 case INTEL_PT_TMA:
2870                         intel_pt_calc_tma(decoder);
2871                         break;
2872 
2873                 case INTEL_PT_CYC:
2874                         intel_pt_calc_cyc_timestamp(decoder);
2875                         break;
2876 
2877                 case INTEL_PT_CBR:
2878                         intel_pt_calc_cbr(decoder);
2879                         break;
2880 
2881                 case INTEL_PT_PSBEND:
2882                         decoder->in_psb = false;
2883                         data.psbend = false;
2884                         break;
2885 
2886                 case INTEL_PT_VMCS:
2887                         if (decoder->packet.payload != NO_VMCS)
2888                                 decoder->vmcs = decoder->packet.payload;
2889                         break;
2890 
2891                 case INTEL_PT_BBP:
2892                         decoder->blk_type = decoder->packet.payload;
2893                         break;
2894 
2895                 case INTEL_PT_BIP:
2896                         if (decoder->blk_type == INTEL_PT_PEBS_BASIC &&
2897                             decoder->packet.count == 2)
2898                                 intel_pt_vm_tm_corr_pebs_tsc(decoder);
2899                         break;
2900 
2901                 case INTEL_PT_BEP:
2902                 case INTEL_PT_BEP_IP:
2903                         decoder->blk_type = 0;
2904                         break;
2905 
2906                 case INTEL_PT_CFE:
2907                 case INTEL_PT_CFE_IP:
2908                 case INTEL_PT_EVD:
2909                 case INTEL_PT_MODE_EXEC:
2910                 case INTEL_PT_MODE_TSX:
2911                 case INTEL_PT_MNT:
2912                 case INTEL_PT_PAD:
2913                 case INTEL_PT_PTWRITE_IP:
2914                 case INTEL_PT_PTWRITE:
2915                 case INTEL_PT_MWAIT:
2916                 case INTEL_PT_PWRE:
2917                 case INTEL_PT_EXSTOP_IP:
2918                 case INTEL_PT_EXSTOP:
2919                 case INTEL_PT_PWRX:
2920                 case INTEL_PT_BAD: /* Does not happen */
2921                 default:
2922                         break;
2923                 }
2924         }
2925 
2926         return err;
2927 }
2928 
2929 #define HOP_PROCESS     0
2930 #define HOP_IGNORE      1
2931 #define HOP_RETURN      2
2932 #define HOP_AGAIN       3
2933 
2934 static int intel_pt_scan_for_psb(struct intel_pt_decoder *decoder);
2935 
2936 /* Hop mode: Ignore TNT, do not walk code, but get ip from FUPs and TIPs */
2937 static int intel_pt_hop_trace(struct intel_pt_decoder *decoder, bool *no_tip, int *err)
2938 {
2939         *err = 0;
2940 
2941         /* Leap from PSB to PSB, getting ip from FUP within PSB+ */
2942         if (decoder->leap && !decoder->in_psb && decoder->packet.type != INTEL_PT_PSB) {
2943                 *err = intel_pt_scan_for_psb(decoder);
2944                 if (*err)
2945                         return HOP_RETURN;
2946         }
2947 
2948         switch (decoder->packet.type) {
2949         case INTEL_PT_TNT:
2950                 return HOP_IGNORE;
2951 
2952         case INTEL_PT_TIP_PGD:
2953                 decoder->pge = false;
2954                 if (!decoder->packet.count) {
2955                         intel_pt_set_nr(decoder);
2956                         return HOP_IGNORE;
2957                 }
2958                 intel_pt_set_ip(decoder);
2959                 decoder->state.type |= INTEL_PT_TRACE_END;
2960                 decoder->state.from_ip = 0;
2961                 decoder->state.to_ip = decoder->ip;
2962                 intel_pt_update_nr(decoder);
2963                 return HOP_RETURN;
2964 
2965         case INTEL_PT_TIP:
2966                 if (!decoder->packet.count) {
2967                         intel_pt_set_nr(decoder);
2968                         return HOP_IGNORE;
2969                 }
2970                 intel_pt_set_ip(decoder);
2971                 decoder->state.type = INTEL_PT_INSTRUCTION;
2972                 decoder->state.from_ip = decoder->ip;
2973                 decoder->state.to_ip = 0;
2974                 intel_pt_update_nr(decoder);
2975                 intel_pt_sample_iflag_chg(decoder);
2976                 return HOP_RETURN;
2977 
2978         case INTEL_PT_FUP:
2979                 if (!decoder->packet.count)
2980                         return HOP_IGNORE;
2981                 intel_pt_set_ip(decoder);
2982                 if (decoder->set_fup_mwait || decoder->set_fup_pwre)
2983                         *no_tip = true;
2984                 if (!decoder->branch_enable || !decoder->pge)
2985                         *no_tip = true;
2986                 if (*no_tip) {
2987                         decoder->state.type = INTEL_PT_INSTRUCTION;
2988                         decoder->state.from_ip = decoder->ip;
2989                         decoder->state.to_ip = 0;
2990                         intel_pt_fup_event(decoder, *no_tip);
2991                         return HOP_RETURN;
2992                 }
2993                 intel_pt_fup_event(decoder, *no_tip);
2994                 decoder->state.type |= INTEL_PT_INSTRUCTION | INTEL_PT_BRANCH;
2995                 *err = intel_pt_walk_fup_tip(decoder);
2996                 if (!*err && decoder->state.to_ip)
2997                         decoder->pkt_state = INTEL_PT_STATE_RESAMPLE;
2998                 return HOP_RETURN;
2999 
3000         case INTEL_PT_PSB:
3001                 decoder->state.psb_offset = decoder->pos;
3002                 decoder->psb_ip = 0;
3003                 decoder->last_ip = 0;
3004                 decoder->have_last_ip = true;
3005                 *err = intel_pt_walk_psbend(decoder);
3006                 if (*err == -EAGAIN)
3007                         return HOP_AGAIN;
3008                 if (*err)
3009                         return HOP_RETURN;
3010                 decoder->state.type = INTEL_PT_PSB_EVT;
3011                 if (decoder->psb_ip) {
3012                         decoder->state.type |= INTEL_PT_INSTRUCTION;
3013                         decoder->ip = decoder->psb_ip;
3014                 }
3015                 decoder->state.from_ip = decoder->psb_ip;
3016                 decoder->state.to_ip = 0;
3017                 return HOP_RETURN;
3018 
3019         case INTEL_PT_BAD:
3020         case INTEL_PT_PAD:
3021         case INTEL_PT_TIP_PGE:
3022         case INTEL_PT_TSC:
3023         case INTEL_PT_TMA:
3024         case INTEL_PT_MODE_EXEC:
3025         case INTEL_PT_MODE_TSX:
3026         case INTEL_PT_MTC:
3027         case INTEL_PT_CYC:
3028         case INTEL_PT_VMCS:
3029         case INTEL_PT_PSBEND:
3030         case INTEL_PT_CBR:
3031         case INTEL_PT_TRACESTOP:
3032         case INTEL_PT_PIP:
3033         case INTEL_PT_OVF:
3034         case INTEL_PT_MNT:
3035         case INTEL_PT_PTWRITE:
3036         case INTEL_PT_PTWRITE_IP:
3037         case INTEL_PT_EXSTOP:
3038         case INTEL_PT_EXSTOP_IP:
3039         case INTEL_PT_MWAIT:
3040         case INTEL_PT_PWRE:
3041         case INTEL_PT_PWRX:
3042         case INTEL_PT_BBP:
3043         case INTEL_PT_BIP:
3044         case INTEL_PT_BEP:
3045         case INTEL_PT_BEP_IP:
3046         case INTEL_PT_CFE:
3047         case INTEL_PT_CFE_IP:
3048         case INTEL_PT_EVD:
3049         default:
3050                 return HOP_PROCESS;
3051         }
3052 }
3053 
3054 struct intel_pt_psb_info {
3055         struct intel_pt_pkt fup_packet;
3056         bool fup;
3057         int after_psbend;
3058 };
3059 
3060 /* Lookahead and get the FUP packet from PSB+ */
3061 static int intel_pt_psb_lookahead_cb(struct intel_pt_pkt_info *pkt_info)
3062 {
3063         struct intel_pt_psb_info *data = pkt_info->data;
3064 
3065         switch (pkt_info->packet.type) {
3066         case INTEL_PT_PAD:
3067         case INTEL_PT_MNT:
3068         case INTEL_PT_TSC:
3069         case INTEL_PT_TMA:
3070         case INTEL_PT_MODE_EXEC:
3071         case INTEL_PT_MODE_TSX:
3072         case INTEL_PT_MTC:
3073         case INTEL_PT_CYC:
3074         case INTEL_PT_VMCS:
3075         case INTEL_PT_CBR:
3076         case INTEL_PT_PIP:
3077                 if (data->after_psbend) {
3078                         data->after_psbend -= 1;
3079                         if (!data->after_psbend)
3080                                 return 1;
3081                 }
3082                 break;
3083 
3084         case INTEL_PT_FUP:
3085                 if (data->after_psbend)
3086                         return 1;
3087                 if (data->fup || pkt_info->packet.count == 0)
3088                         return 1;
3089                 data->fup_packet = pkt_info->packet;
3090                 data->fup = true;
3091                 break;
3092 
3093         case INTEL_PT_PSBEND:
3094                 if (!data->fup)
3095                         return 1;
3096                 /* Keep going to check for a TIP.PGE */
3097                 data->after_psbend = 6;
3098                 break;
3099 
3100         case INTEL_PT_TIP_PGE:
3101                 /* Ignore FUP in PSB+ if followed by TIP.PGE */
3102                 if (data->after_psbend)
3103                         data->fup = false;
3104                 return 1;
3105 
3106         case INTEL_PT_PTWRITE:
3107         case INTEL_PT_PTWRITE_IP:
3108         case INTEL_PT_EXSTOP:
3109         case INTEL_PT_EXSTOP_IP:
3110         case INTEL_PT_MWAIT:
3111         case INTEL_PT_PWRE:
3112         case INTEL_PT_PWRX:
3113         case INTEL_PT_BBP:
3114         case INTEL_PT_BIP:
3115         case INTEL_PT_BEP:
3116         case INTEL_PT_BEP_IP:
3117         case INTEL_PT_CFE:
3118         case INTEL_PT_CFE_IP:
3119         case INTEL_PT_EVD:
3120                 if (data->after_psbend) {
3121                         data->after_psbend -= 1;
3122                         if (!data->after_psbend)
3123                                 return 1;
3124                         break;
3125                 }
3126                 return 1;
3127 
3128         case INTEL_PT_OVF:
3129         case INTEL_PT_BAD:
3130         case INTEL_PT_TNT:
3131         case INTEL_PT_TIP_PGD:
3132         case INTEL_PT_TIP:
3133         case INTEL_PT_PSB:
3134         case INTEL_PT_TRACESTOP:
3135         default:
3136                 return 1;
3137         }
3138 
3139         return 0;
3140 }
3141 
3142 static int intel_pt_psb(struct intel_pt_decoder *decoder)
3143 {
3144         int err;
3145 
3146         decoder->last_ip = 0;
3147         decoder->psb_ip = 0;
3148         decoder->have_last_ip = true;
3149         intel_pt_clear_stack(&decoder->stack);
3150         err = intel_pt_walk_psbend(decoder);
3151         if (err)
3152                 return err;
3153         decoder->state.type = INTEL_PT_PSB_EVT;
3154         decoder->state.from_ip = decoder->psb_ip;
3155         decoder->state.to_ip = 0;
3156         return 0;
3157 }
3158 
3159 static int intel_pt_fup_in_psb(struct intel_pt_decoder *decoder)
3160 {
3161         int err;
3162 
3163         if (decoder->ip != decoder->last_ip) {
3164                 err = intel_pt_walk_fup(decoder);
3165                 if (!err || err != -EAGAIN)
3166                         return err;
3167         }
3168 
3169         decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
3170         err = intel_pt_psb(decoder);
3171         if (err) {
3172                 decoder->pkt_state = INTEL_PT_STATE_ERR3;
3173                 return -ENOENT;
3174         }
3175 
3176         return 0;
3177 }
3178 
3179 static bool intel_pt_psb_with_fup(struct intel_pt_decoder *decoder, int *err)
3180 {
3181         struct intel_pt_psb_info data = { .fup = false };
3182 
3183         if (!decoder->branch_enable)
3184                 return false;
3185 
3186         intel_pt_pkt_lookahead(decoder, intel_pt_psb_lookahead_cb, &data);
3187         if (!data.fup)
3188                 return false;
3189 
3190         decoder->packet = data.fup_packet;
3191         intel_pt_set_last_ip(decoder);
3192         decoder->pkt_state = INTEL_PT_STATE_FUP_IN_PSB;
3193 
3194         *err = intel_pt_fup_in_psb(decoder);
3195 
3196         return true;
3197 }
3198 
3199 static int intel_pt_walk_trace(struct intel_pt_decoder *decoder)
3200 {
3201         int last_packet_type = INTEL_PT_PAD;
3202         bool no_tip = false;
3203         int err;
3204 
3205         while (1) {
3206                 err = intel_pt_get_next_packet(decoder);
3207                 if (err)
3208                         return err;
3209 next:
3210                 err = 0;
3211                 if (decoder->cyc_threshold) {
3212                         if (decoder->sample_cyc && last_packet_type != INTEL_PT_CYC)
3213                                 decoder->sample_cyc = false;
3214                         last_packet_type = decoder->packet.type;
3215                 }
3216 
3217                 if (decoder->hop) {
3218                         switch (intel_pt_hop_trace(decoder, &no_tip, &err)) {
3219                         case HOP_IGNORE:
3220                                 continue;
3221                         case HOP_RETURN:
3222                                 return err;
3223                         case HOP_AGAIN:
3224                                 goto next;
3225                         default:
3226                                 break;
3227                         }
3228                 }
3229 
3230                 switch (decoder->packet.type) {
3231                 case INTEL_PT_TNT:
3232                         if (!decoder->packet.count)
3233                                 break;
3234                         decoder->tnt = decoder->packet;
3235                         decoder->pkt_state = INTEL_PT_STATE_TNT;
3236                         err = intel_pt_walk_tnt(decoder);
3237                         if (err == -EAGAIN)
3238                                 break;
3239                         return err;
3240 
3241                 case INTEL_PT_TIP_PGD:
3242                         if (decoder->packet.count != 0)
3243                                 intel_pt_set_last_ip(decoder);
3244                         decoder->pkt_state = INTEL_PT_STATE_TIP_PGD;
3245                         return intel_pt_walk_tip(decoder);
3246 
3247                 case INTEL_PT_TIP_PGE: {
3248                         decoder->pge = true;
3249                         decoder->overflow = false;
3250                         intel_pt_mtc_cyc_cnt_pge(decoder);
3251                         intel_pt_set_nr(decoder);
3252                         if (decoder->packet.count == 0) {
3253                                 intel_pt_log_at("Skipping zero TIP.PGE",
3254                                                 decoder->pos);
3255                                 break;
3256                         }
3257                         intel_pt_sample_iflag_chg(decoder);
3258                         intel_pt_set_ip(decoder);
3259                         decoder->state.from_ip = 0;
3260                         decoder->state.to_ip = decoder->ip;
3261                         decoder->state.type |= INTEL_PT_TRACE_BEGIN;
3262                         /*
3263                          * In hop mode, resample to get the to_ip as an
3264                          * "instruction" sample.
3265                          */
3266                         if (decoder->hop)
3267                                 decoder->pkt_state = INTEL_PT_STATE_RESAMPLE;
3268                         return 0;
3269                 }
3270 
3271                 case INTEL_PT_OVF:
3272                         return intel_pt_overflow(decoder);
3273 
3274                 case INTEL_PT_TIP:
3275                         if (decoder->packet.count != 0)
3276                                 intel_pt_set_last_ip(decoder);
3277                         decoder->pkt_state = INTEL_PT_STATE_TIP;
3278                         return intel_pt_walk_tip(decoder);
3279 
3280                 case INTEL_PT_FUP:
3281                         if (decoder->packet.count == 0) {
3282                                 intel_pt_log_at("Skipping zero FUP",
3283                                                 decoder->pos);
3284                                 no_tip = false;
3285                                 break;
3286                         }
3287                         intel_pt_set_last_ip(decoder);
3288                         if (!decoder->branch_enable || !decoder->pge) {
3289                                 decoder->ip = decoder->last_ip;
3290                                 if (intel_pt_fup_event(decoder, no_tip))
3291                                         return 0;
3292                                 no_tip = false;
3293                                 break;
3294                         }
3295                         if (decoder->set_fup_mwait)
3296                                 no_tip = true;
3297                         if (no_tip)
3298                                 decoder->pkt_state = INTEL_PT_STATE_FUP_NO_TIP;
3299                         else
3300                                 decoder->pkt_state = INTEL_PT_STATE_FUP;
3301                         err = intel_pt_walk_fup(decoder);
3302                         if (err != -EAGAIN)
3303                                 return err;
3304                         if (no_tip) {
3305                                 no_tip = false;
3306                                 break;
3307                         }
3308                         return intel_pt_walk_fup_tip(decoder);
3309 
3310                 case INTEL_PT_TRACESTOP:
3311                         decoder->pge = false;
3312                         decoder->continuous_period = false;
3313                         intel_pt_clear_tx_flags(decoder);
3314                         decoder->have_tma = false;
3315                         break;
3316 
3317                 case INTEL_PT_PSB:
3318                         decoder->state.psb_offset = decoder->pos;
3319                         decoder->psb_ip = 0;
3320                         if (intel_pt_psb_with_fup(decoder, &err))
3321                                 return err;
3322                         err = intel_pt_psb(decoder);
3323                         if (err == -EAGAIN)
3324                                 goto next;
3325                         return err;
3326 
3327                 case INTEL_PT_PIP:
3328                         intel_pt_update_pip(decoder);
3329                         break;
3330 
3331                 case INTEL_PT_MTC:
3332                         intel_pt_calc_mtc_timestamp(decoder);
3333                         if (decoder->period_type != INTEL_PT_PERIOD_MTC)
3334                                 break;
3335                         /*
3336                          * Ensure that there has been an instruction since the
3337                          * last MTC.
3338                          */
3339                         if (!decoder->mtc_insn)
3340                                 break;
3341                         decoder->mtc_insn = false;
3342                         /* Ensure that there is a timestamp */
3343                         if (!decoder->timestamp)
3344                                 break;
3345                         decoder->state.type = INTEL_PT_INSTRUCTION;
3346                         decoder->state.from_ip = decoder->ip;
3347                         decoder->state.to_ip = 0;
3348                         decoder->mtc_insn = false;
3349                         return 0;
3350 
3351                 case INTEL_PT_TSC:
3352                         intel_pt_calc_tsc_timestamp(decoder);
3353                         break;
3354 
3355                 case INTEL_PT_TMA:
3356                         intel_pt_calc_tma(decoder);
3357                         break;
3358 
3359                 case INTEL_PT_CYC:
3360                         intel_pt_calc_cyc_timestamp(decoder);
3361                         break;
3362 
3363                 case INTEL_PT_CBR:
3364                         intel_pt_calc_cbr(decoder);
3365                         if (decoder->cbr != decoder->cbr_seen) {
3366                                 decoder->state.type = 0;
3367                                 return 0;
3368                         }
3369                         break;
3370 
3371                 case INTEL_PT_MODE_EXEC:
3372                         intel_pt_mode_exec(decoder);
3373                         err = intel_pt_get_next_packet(decoder);
3374                         if (err)
3375                                 return err;
3376                         if (decoder->packet.type == INTEL_PT_FUP) {
3377                                 decoder->set_fup_mode_exec = true;
3378                                 no_tip = true;
3379                         }
3380                         goto next;
3381 
3382                 case INTEL_PT_MODE_TSX:
3383                         /* MODE_TSX need not be followed by FUP */
3384                         if (!decoder->pge || decoder->in_psb) {
3385                                 intel_pt_update_in_tx(decoder);
3386                                 break;
3387                         }
3388                         err = intel_pt_mode_tsx(decoder, &no_tip);
3389                         if (err)
3390                                 return err;
3391                         goto next;
3392 
3393                 case INTEL_PT_BAD: /* Does not happen */
3394                         return intel_pt_bug(decoder);
3395 
3396                 case INTEL_PT_PSBEND:
3397                 case INTEL_PT_VMCS:
3398                 case INTEL_PT_MNT:
3399                 case INTEL_PT_PAD:
3400                         break;
3401 
3402                 case INTEL_PT_PTWRITE_IP:
3403                         decoder->fup_ptw_payload = decoder->packet.payload;
3404                         err = intel_pt_get_next_packet(decoder);
3405                         if (err)
3406                                 return err;
3407                         if (decoder->packet.type == INTEL_PT_FUP) {
3408                                 decoder->set_fup_ptw = true;
3409                                 no_tip = true;
3410                         } else {
3411                                 intel_pt_log_at("ERROR: Missing FUP after PTWRITE",
3412                                                 decoder->pos);
3413                         }
3414                         goto next;
3415 
3416                 case INTEL_PT_PTWRITE:
3417                         decoder->state.type = INTEL_PT_PTW;
3418                         decoder->state.from_ip = decoder->ip;
3419                         decoder->state.to_ip = 0;
3420                         decoder->state.ptw_payload = decoder->packet.payload;
3421                         return 0;
3422 
3423                 case INTEL_PT_MWAIT:
3424                         decoder->fup_mwait_payload = decoder->packet.payload;
3425                         decoder->set_fup_mwait = true;
3426                         break;
3427 
3428                 case INTEL_PT_PWRE:
3429                         if (decoder->set_fup_mwait) {
3430                                 decoder->fup_pwre_payload =
3431                                                         decoder->packet.payload;
3432                                 decoder->set_fup_pwre = true;
3433                                 break;
3434                         }
3435                         decoder->state.type = INTEL_PT_PWR_ENTRY;
3436                         decoder->state.from_ip = decoder->ip;
3437                         decoder->state.to_ip = 0;
3438                         decoder->state.pwrx_payload = decoder->packet.payload;
3439                         return 0;
3440 
3441                 case INTEL_PT_EXSTOP_IP:
3442                         err = intel_pt_get_next_packet(decoder);
3443                         if (err)
3444                                 return err;
3445                         if (decoder->packet.type == INTEL_PT_FUP) {
3446                                 decoder->set_fup_exstop = true;
3447                                 no_tip = true;
3448                         } else {
3449                                 intel_pt_log_at("ERROR: Missing FUP after EXSTOP",
3450                                                 decoder->pos);
3451                         }
3452                         goto next;
3453 
3454                 case INTEL_PT_EXSTOP:
3455                         decoder->state.type = INTEL_PT_EX_STOP;
3456                         decoder->state.from_ip = decoder->ip;
3457                         decoder->state.to_ip = 0;
3458                         return 0;
3459 
3460                 case INTEL_PT_PWRX:
3461                         decoder->state.type = INTEL_PT_PWR_EXIT;
3462                         decoder->state.from_ip = decoder->ip;
3463                         decoder->state.to_ip = 0;
3464                         decoder->state.pwrx_payload = decoder->packet.payload;
3465                         return 0;
3466 
3467                 case INTEL_PT_BBP:
3468                         intel_pt_bbp(decoder);
3469                         break;
3470 
3471                 case INTEL_PT_BIP:
3472                         intel_pt_bip(decoder);
3473                         break;
3474 
3475                 case INTEL_PT_BEP:
3476                         decoder->state.type = INTEL_PT_BLK_ITEMS;
3477                         decoder->state.from_ip = decoder->ip;
3478                         decoder->state.to_ip = 0;
3479                         return 0;
3480 
3481                 case INTEL_PT_BEP_IP:
3482                         err = intel_pt_get_next_packet(decoder);
3483                         if (err)
3484                                 return err;
3485                         if (decoder->packet.type == INTEL_PT_FUP) {
3486                                 decoder->set_fup_bep = true;
3487                                 no_tip = true;
3488                         } else {
3489                                 intel_pt_log_at("ERROR: Missing FUP after BEP",
3490                                                 decoder->pos);
3491                         }
3492                         goto next;
3493 
3494                 case INTEL_PT_CFE:
3495                         decoder->fup_cfe_pkt = decoder->packet;
3496                         decoder->set_fup_cfe = true;
3497                         if (!decoder->pge) {
3498                                 intel_pt_fup_event(decoder, true);
3499                                 return 0;
3500                         }
3501                         break;
3502 
3503                 case INTEL_PT_CFE_IP:
3504                         decoder->fup_cfe_pkt = decoder->packet;
3505                         err = intel_pt_get_next_packet(decoder);
3506                         if (err)
3507                                 return err;
3508                         if (decoder->packet.type == INTEL_PT_FUP) {
3509                                 decoder->set_fup_cfe_ip = true;
3510                                 no_tip = true;
3511                         } else {
3512                                 intel_pt_log_at("ERROR: Missing FUP after CFE",
3513                                                 decoder->pos);
3514                         }
3515                         goto next;
3516 
3517                 case INTEL_PT_EVD:
3518                         err = intel_pt_evd(decoder);
3519                         if (err)
3520                                 return err;
3521                         break;
3522 
3523                 default:
3524                         return intel_pt_bug(decoder);
3525                 }
3526         }
3527 }
3528 
3529 static inline bool intel_pt_have_ip(struct intel_pt_decoder *decoder)
3530 {
3531         return decoder->packet.count &&
3532                (decoder->have_last_ip || decoder->packet.count == 3 ||
3533                 decoder->packet.count == 6);
3534 }
3535 
3536 /* Walk PSB+ packets to get in sync. */
3537 static int intel_pt_walk_psb(struct intel_pt_decoder *decoder)
3538 {
3539         int err;
3540 
3541         decoder->in_psb = true;
3542 
3543         while (1) {
3544                 err = intel_pt_get_next_packet(decoder);
3545                 if (err)
3546                         goto out;
3547 
3548                 switch (decoder->packet.type) {
3549                 case INTEL_PT_TIP_PGD:
3550                         decoder->continuous_period = false;
3551                         fallthrough;
3552                 case INTEL_PT_TIP_PGE:
3553                 case INTEL_PT_TIP:
3554                 case INTEL_PT_PTWRITE:
3555                 case INTEL_PT_PTWRITE_IP:
3556                 case INTEL_PT_EXSTOP:
3557                 case INTEL_PT_EXSTOP_IP:
3558                 case INTEL_PT_MWAIT:
3559                 case INTEL_PT_PWRE:
3560                 case INTEL_PT_PWRX:
3561                 case INTEL_PT_BBP:
3562                 case INTEL_PT_BIP:
3563                 case INTEL_PT_BEP:
3564                 case INTEL_PT_BEP_IP:
3565                 case INTEL_PT_CFE:
3566                 case INTEL_PT_CFE_IP:
3567                 case INTEL_PT_EVD:
3568                         intel_pt_log("ERROR: Unexpected packet\n");
3569                         err = -ENOENT;
3570                         goto out;
3571 
3572                 case INTEL_PT_FUP:
3573                         decoder->pge = true;
3574                         if (intel_pt_have_ip(decoder)) {
3575                                 uint64_t current_ip = decoder->ip;
3576 
3577                                 intel_pt_set_ip(decoder);
3578                                 decoder->psb_ip = decoder->ip;
3579                                 if (current_ip)
3580                                         intel_pt_log_to("Setting IP",
3581                                                         decoder->ip);
3582                         }
3583                         break;
3584 
3585                 case INTEL_PT_MTC:
3586                         intel_pt_calc_mtc_timestamp(decoder);
3587                         break;
3588 
3589                 case INTEL_PT_TSC:
3590                         intel_pt_calc_tsc_timestamp(decoder);
3591                         break;
3592 
3593                 case INTEL_PT_TMA:
3594                         intel_pt_calc_tma(decoder);
3595                         break;
3596 
3597                 case INTEL_PT_CYC:
3598                         intel_pt_calc_cyc_timestamp(decoder);
3599                         break;
3600 
3601                 case INTEL_PT_CBR:
3602                         intel_pt_calc_cbr(decoder);
3603                         break;
3604 
3605                 case INTEL_PT_PIP:
3606                         intel_pt_set_pip(decoder);
3607                         break;
3608 
3609                 case INTEL_PT_MODE_EXEC:
3610                         intel_pt_mode_exec_status(decoder);
3611                         break;
3612 
3613                 case INTEL_PT_MODE_TSX:
3614                         intel_pt_update_in_tx(decoder);
3615                         break;
3616 
3617                 case INTEL_PT_TRACESTOP:
3618                         decoder->pge = false;
3619                         decoder->continuous_period = false;
3620                         intel_pt_clear_tx_flags(decoder);
3621                         fallthrough;
3622 
3623                 case INTEL_PT_TNT:
3624                         decoder->have_tma = false;
3625                         intel_pt_log("ERROR: Unexpected packet\n");
3626                         if (decoder->ip)
3627                                 decoder->pkt_state = INTEL_PT_STATE_ERR4;
3628                         else
3629                                 decoder->pkt_state = INTEL_PT_STATE_ERR3;
3630                         err = -ENOENT;
3631                         goto out;
3632 
3633                 case INTEL_PT_BAD: /* Does not happen */
3634                         err = intel_pt_bug(decoder);
3635                         goto out;
3636 
3637                 case INTEL_PT_OVF:
3638                         err = intel_pt_overflow(decoder);
3639                         goto out;
3640 
3641                 case INTEL_PT_PSBEND:
3642                         err = 0;
3643                         goto out;
3644 
3645                 case INTEL_PT_PSB:
3646                 case INTEL_PT_VMCS:
3647                 case INTEL_PT_MNT:
3648                 case INTEL_PT_PAD:
3649                 default:
3650                         break;
3651                 }
3652         }
3653 out:
3654         decoder->in_psb = false;
3655 
3656         return err;
3657 }
3658 
3659 static int intel_pt_walk_to_ip(struct intel_pt_decoder *decoder)
3660 {
3661         int err;
3662 
3663         while (1) {
3664                 err = intel_pt_get_next_packet(decoder);
3665                 if (err)
3666                         return err;
3667 
3668                 switch (decoder->packet.type) {
3669                 case INTEL_PT_TIP_PGD:
3670                         decoder->continuous_period = false;
3671                         decoder->pge = false;
3672                         if (intel_pt_have_ip(decoder))
3673                                 intel_pt_set_ip(decoder);
3674                         if (!decoder->ip)
3675                                 break;
3676                         decoder->state.type |= INTEL_PT_TRACE_END;
3677                         return 0;
3678 
3679                 case INTEL_PT_TIP_PGE:
3680                         decoder->pge = true;
3681                         intel_pt_mtc_cyc_cnt_pge(decoder);
3682                         if (intel_pt_have_ip(decoder))
3683                                 intel_pt_set_ip(decoder);
3684                         if (!decoder->ip)
3685                                 break;
3686                         decoder->state.type |= INTEL_PT_TRACE_BEGIN;
3687                         return 0;
3688 
3689                 case INTEL_PT_TIP:
3690                         decoder->pge = true;
3691                         if (intel_pt_have_ip(decoder))
3692                                 intel_pt_set_ip(decoder);
3693                         if (!decoder->ip)
3694                                 break;
3695                         return 0;
3696 
3697                 case INTEL_PT_FUP:
3698                         if (intel_pt_have_ip(decoder))
3699                                 intel_pt_set_ip(decoder);
3700                         if (decoder->ip)
3701                                 return 0;
3702                         break;
3703 
3704                 case INTEL_PT_MTC:
3705                         intel_pt_calc_mtc_timestamp(decoder);
3706                         break;
3707 
3708                 case INTEL_PT_TSC:
3709                         intel_pt_calc_tsc_timestamp(decoder);
3710                         break;
3711 
3712                 case INTEL_PT_TMA:
3713                         intel_pt_calc_tma(decoder);
3714                         break;
3715 
3716                 case INTEL_PT_CYC:
3717                         intel_pt_calc_cyc_timestamp(decoder);
3718                         break;
3719 
3720                 case INTEL_PT_CBR:
3721                         intel_pt_calc_cbr(decoder);
3722                         break;
3723 
3724                 case INTEL_PT_PIP:
3725                         intel_pt_set_pip(decoder);
3726                         break;
3727 
3728                 case INTEL_PT_MODE_EXEC:
3729                         intel_pt_mode_exec_status(decoder);
3730                         break;
3731 
3732                 case INTEL_PT_MODE_TSX:
3733                         intel_pt_update_in_tx(decoder);
3734                         break;
3735 
3736                 case INTEL_PT_OVF:
3737                         return intel_pt_overflow(decoder);
3738 
3739                 case INTEL_PT_BAD: /* Does not happen */
3740                         return intel_pt_bug(decoder);
3741 
3742                 case INTEL_PT_TRACESTOP:
3743                         decoder->pge = false;
3744                         decoder->continuous_period = false;
3745                         intel_pt_clear_tx_flags(decoder);
3746                         decoder->have_tma = false;
3747                         break;
3748 
3749                 case INTEL_PT_PSB:
3750                         decoder->state.psb_offset = decoder->pos;
3751                         decoder->psb_ip = 0;
3752                         decoder->last_ip = 0;
3753                         decoder->have_last_ip = true;
3754                         intel_pt_clear_stack(&decoder->stack);
3755                         err = intel_pt_walk_psb(decoder);
3756                         if (err)
3757                                 return err;
3758                         decoder->state.type = INTEL_PT_PSB_EVT;
3759                         decoder->state.from_ip = decoder->psb_ip;
3760                         decoder->state.to_ip = 0;
3761                         return 0;
3762 
3763                 case INTEL_PT_TNT:
3764                 case INTEL_PT_PSBEND:
3765                 case INTEL_PT_VMCS:
3766                 case INTEL_PT_MNT:
3767                 case INTEL_PT_PAD:
3768                 case INTEL_PT_PTWRITE:
3769                 case INTEL_PT_PTWRITE_IP:
3770                 case INTEL_PT_EXSTOP:
3771                 case INTEL_PT_EXSTOP_IP:
3772                 case INTEL_PT_MWAIT:
3773                 case INTEL_PT_PWRE:
3774                 case INTEL_PT_PWRX:
3775                 case INTEL_PT_BBP:
3776                 case INTEL_PT_BIP:
3777                 case INTEL_PT_BEP:
3778                 case INTEL_PT_BEP_IP:
3779                 case INTEL_PT_CFE:
3780                 case INTEL_PT_CFE_IP:
3781                 case INTEL_PT_EVD:
3782                 default:
3783                         break;
3784                 }
3785         }
3786 }
3787 
3788 static int intel_pt_sync_ip(struct intel_pt_decoder *decoder)
3789 {
3790         int err;
3791 
3792         intel_pt_clear_fup_event(decoder);
3793         decoder->overflow = false;
3794 
3795         if (!decoder->branch_enable) {
3796                 decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
3797                 decoder->state.type = 0; /* Do not have a sample */
3798                 return 0;
3799         }
3800 
3801         intel_pt_log("Scanning for full IP\n");
3802         err = intel_pt_walk_to_ip(decoder);
3803         if (err || ((decoder->state.type & INTEL_PT_PSB_EVT) && !decoder->ip))
3804                 return err;
3805 
3806         /* In hop mode, resample to get the to_ip as an "instruction" sample */
3807         if (decoder->hop)
3808                 decoder->pkt_state = INTEL_PT_STATE_RESAMPLE;
3809         else
3810                 decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
3811 
3812         decoder->state.from_ip = 0;
3813         decoder->state.to_ip = decoder->ip;
3814         intel_pt_log_to("Setting IP", decoder->ip);
3815 
3816         return 0;
3817 }
3818 
3819 static int intel_pt_part_psb(struct intel_pt_decoder *decoder)
3820 {
3821         const unsigned char *end = decoder->buf + decoder->len;
3822         size_t i;
3823 
3824         for (i = INTEL_PT_PSB_LEN - 1; i; i--) {
3825                 if (i > decoder->len)
3826                         continue;
3827                 if (!memcmp(end - i, INTEL_PT_PSB_STR, i))
3828                         return i;
3829         }
3830         return 0;
3831 }
3832 
3833 static int intel_pt_rest_psb(struct intel_pt_decoder *decoder, int part_psb)
3834 {
3835         size_t rest_psb = INTEL_PT_PSB_LEN - part_psb;
3836         const char *psb = INTEL_PT_PSB_STR;
3837 
3838         if (rest_psb > decoder->len ||
3839             memcmp(decoder->buf, psb + part_psb, rest_psb))
3840                 return 0;
3841 
3842         return rest_psb;
3843 }
3844 
3845 static int intel_pt_get_split_psb(struct intel_pt_decoder *decoder,
3846                                   int part_psb)
3847 {
3848         int rest_psb, ret;
3849 
3850         decoder->pos += decoder->len;
3851         decoder->len = 0;
3852 
3853         ret = intel_pt_get_next_data(decoder, false);
3854         if (ret)
3855                 return ret;
3856 
3857         rest_psb = intel_pt_rest_psb(decoder, part_psb);
3858         if (!rest_psb)
3859                 return 0;
3860 
3861         decoder->pos -= part_psb;
3862         decoder->next_buf = decoder->buf + rest_psb;
3863         decoder->next_len = decoder->len - rest_psb;
3864         memcpy(decoder->temp_buf, INTEL_PT_PSB_STR, INTEL_PT_PSB_LEN);
3865         decoder->buf = decoder->temp_buf;
3866         decoder->len = INTEL_PT_PSB_LEN;
3867 
3868         return 0;
3869 }
3870 
3871 static int intel_pt_scan_for_psb(struct intel_pt_decoder *decoder)
3872 {
3873         unsigned char *next;
3874         int ret;
3875 
3876         intel_pt_log("Scanning for PSB\n");
3877         while (1) {
3878                 if (!decoder->len) {
3879                         ret = intel_pt_get_next_data(decoder, false);
3880                         if (ret)
3881                                 return ret;
3882                 }
3883 
3884                 next = memmem(decoder->buf, decoder->len, INTEL_PT_PSB_STR,
3885                               INTEL_PT_PSB_LEN);
3886                 if (!next) {
3887                         int part_psb;
3888 
3889                         part_psb = intel_pt_part_psb(decoder);
3890                         if (part_psb) {
3891                                 ret = intel_pt_get_split_psb(decoder, part_psb);
3892                                 if (ret)
3893                                         return ret;
3894                         } else {
3895                                 decoder->pos += decoder->len;
3896                                 decoder->len = 0;
3897                         }
3898                         continue;
3899                 }
3900 
3901                 decoder->pkt_step = next - decoder->buf;
3902                 return intel_pt_get_next_packet(decoder);
3903         }
3904 }
3905 
3906 static int intel_pt_sync(struct intel_pt_decoder *decoder)
3907 {
3908         int err;
3909 
3910         decoder->pge = false;
3911         decoder->continuous_period = false;
3912         decoder->have_last_ip = false;
3913         decoder->last_ip = 0;
3914         decoder->psb_ip = 0;
3915         decoder->ip = 0;
3916         intel_pt_clear_stack(&decoder->stack);
3917 
3918         err = intel_pt_scan_for_psb(decoder);
3919         if (err)
3920                 return err;
3921 
3922         if (decoder->vm_time_correlation) {
3923                 decoder->in_psb = true;
3924                 if (!decoder->timestamp)
3925                         decoder->timestamp = 1;
3926                 decoder->state.type = 0;
3927                 decoder->pkt_state = INTEL_PT_STATE_VM_TIME_CORRELATION;
3928                 return 0;
3929         }
3930 
3931         decoder->have_last_ip = true;
3932         decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
3933 
3934         err = intel_pt_walk_psb(decoder);
3935         if (err)
3936                 return err;
3937 
3938         decoder->state.type = INTEL_PT_PSB_EVT; /* Only PSB sample */
3939         decoder->state.from_ip = decoder->psb_ip;
3940         decoder->state.to_ip = 0;
3941 
3942         if (decoder->ip) {
3943                 /*
3944                  * In hop mode, resample to get the PSB FUP ip as an
3945                  * "instruction" sample.
3946                  */
3947                 if (decoder->hop)
3948                         decoder->pkt_state = INTEL_PT_STATE_RESAMPLE;
3949                 else
3950                         decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
3951         }
3952 
3953         return 0;
3954 }
3955 
3956 static uint64_t intel_pt_est_timestamp(struct intel_pt_decoder *decoder)
3957 {
3958         uint64_t est = decoder->sample_insn_cnt << 1;
3959 
3960         if (!decoder->cbr || !decoder->max_non_turbo_ratio)
3961                 goto out;
3962 
3963         est *= decoder->max_non_turbo_ratio;
3964         est /= decoder->cbr;
3965 out:
3966         return decoder->sample_timestamp + est;
3967 }
3968 
3969 const struct intel_pt_state *intel_pt_decode(struct intel_pt_decoder *decoder)
3970 {
3971         int err;
3972 
3973         do {
3974                 decoder->state.type = INTEL_PT_BRANCH;
3975                 decoder->state.flags = 0;
3976 
3977                 switch (decoder->pkt_state) {
3978                 case INTEL_PT_STATE_NO_PSB:
3979                         err = intel_pt_sync(decoder);
3980                         break;
3981                 case INTEL_PT_STATE_NO_IP:
3982                         decoder->have_last_ip = false;
3983                         decoder->last_ip = 0;
3984                         decoder->ip = 0;
3985                         fallthrough;
3986                 case INTEL_PT_STATE_ERR_RESYNC:
3987                         err = intel_pt_sync_ip(decoder);
3988                         break;
3989                 case INTEL_PT_STATE_IN_SYNC:
3990                         err = intel_pt_walk_trace(decoder);
3991                         break;
3992                 case INTEL_PT_STATE_TNT:
3993                 case INTEL_PT_STATE_TNT_CONT:
3994                         err = intel_pt_walk_tnt(decoder);
3995                         if (err == -EAGAIN)
3996                                 err = intel_pt_walk_trace(decoder);
3997                         break;
3998                 case INTEL_PT_STATE_TIP:
3999                 case INTEL_PT_STATE_TIP_PGD:
4000                         err = intel_pt_walk_tip(decoder);
4001                         break;
4002                 case INTEL_PT_STATE_FUP:
4003                         err = intel_pt_walk_fup(decoder);
4004                         if (err == -EAGAIN)
4005                                 err = intel_pt_walk_fup_tip(decoder);
4006                         break;
4007                 case INTEL_PT_STATE_FUP_NO_TIP:
4008                         err = intel_pt_walk_fup(decoder);
4009                         if (err == -EAGAIN)
4010                                 err = intel_pt_walk_trace(decoder);
4011                         break;
4012                 case INTEL_PT_STATE_FUP_IN_PSB:
4013                         err = intel_pt_fup_in_psb(decoder);
4014                         break;
4015                 case INTEL_PT_STATE_RESAMPLE:
4016                         err = intel_pt_resample(decoder);
4017                         break;
4018                 case INTEL_PT_STATE_VM_TIME_CORRELATION:
4019                         err = intel_pt_vm_time_correlation(decoder);
4020                         break;
4021                 default:
4022                         err = intel_pt_bug(decoder);
4023                         break;
4024                 }
4025         } while (err == -ENOLINK);
4026 
4027         if (err) {
4028                 decoder->state.err = intel_pt_ext_err(err);
4029                 if (err != -EOVERFLOW)
4030                         decoder->state.from_ip = decoder->ip;
4031                 intel_pt_update_sample_time(decoder);
4032                 decoder->sample_tot_cyc_cnt = decoder->tot_cyc_cnt;
4033                 intel_pt_set_nr(decoder);
4034         } else {
4035                 decoder->state.err = 0;
4036                 if (decoder->cbr != decoder->cbr_seen) {
4037                         decoder->cbr_seen = decoder->cbr;
4038                         if (!decoder->state.type) {
4039                                 decoder->state.from_ip = decoder->ip;
4040                                 decoder->state.to_ip = 0;
4041                         }
4042                         decoder->state.type |= INTEL_PT_CBR_CHG;
4043                         decoder->state.cbr_payload = decoder->cbr_payload;
4044                         decoder->state.cbr = decoder->cbr;
4045                 }
4046                 if (intel_pt_sample_time(decoder->pkt_state)) {
4047                         intel_pt_update_sample_time(decoder);
4048                         if (decoder->sample_cyc) {
4049                                 decoder->sample_tot_cyc_cnt = decoder->tot_cyc_cnt;
4050                                 decoder->state.flags |= INTEL_PT_SAMPLE_IPC;
4051                                 decoder->sample_cyc = false;
4052                         }
4053                 }
4054                 /*
4055                  * When using only TSC/MTC to compute cycles, IPC can be
4056                  * sampled as soon as the cycle count changes.
4057                  */
4058                 if (!decoder->have_cyc)
4059                         decoder->state.flags |= INTEL_PT_SAMPLE_IPC;
4060         }
4061 
4062          /* Let PSB event always have TSC timestamp */
4063         if ((decoder->state.type & INTEL_PT_PSB_EVT) && decoder->tsc_timestamp)
4064                 decoder->sample_timestamp = decoder->tsc_timestamp;
4065 
4066         decoder->state.from_nr = decoder->nr;
4067         decoder->state.to_nr = decoder->next_nr;
4068         decoder->nr = decoder->next_nr;
4069 
4070         decoder->state.timestamp = decoder->sample_timestamp;
4071         decoder->state.est_timestamp = intel_pt_est_timestamp(decoder);
4072         decoder->state.tot_insn_cnt = decoder->tot_insn_cnt;
4073         decoder->state.tot_cyc_cnt = decoder->sample_tot_cyc_cnt;
4074 
4075         return &decoder->state;
4076 }
4077 
4078 /**
4079  * intel_pt_next_psb - move buffer pointer to the start of the next PSB packet.
4080  * @buf: pointer to buffer pointer
4081  * @len: size of buffer
4082  *
4083  * Updates the buffer pointer to point to the start of the next PSB packet if
4084  * there is one, otherwise the buffer pointer is unchanged.  If @buf is updated,
4085  * @len is adjusted accordingly.
4086  *
4087  * Return: %true if a PSB packet is found, %false otherwise.
4088  */
4089 static bool intel_pt_next_psb(unsigned char **buf, size_t *len)
4090 {
4091         unsigned char *next;
4092 
4093         next = memmem(*buf, *len, INTEL_PT_PSB_STR, INTEL_PT_PSB_LEN);
4094         if (next) {
4095                 *len -= next - *buf;
4096                 *buf = next;
4097                 return true;
4098         }
4099         return false;
4100 }
4101 
4102 /**
4103  * intel_pt_step_psb - move buffer pointer to the start of the following PSB
4104  *                     packet.
4105  * @buf: pointer to buffer pointer
4106  * @len: size of buffer
4107  *
4108  * Updates the buffer pointer to point to the start of the following PSB packet
4109  * (skipping the PSB at @buf itself) if there is one, otherwise the buffer
4110  * pointer is unchanged.  If @buf is updated, @len is adjusted accordingly.
4111  *
4112  * Return: %true if a PSB packet is found, %false otherwise.
4113  */
4114 static bool intel_pt_step_psb(unsigned char **buf, size_t *len)
4115 {
4116         unsigned char *next;
4117 
4118         if (!*len)
4119                 return false;
4120 
4121         next = memmem(*buf + 1, *len - 1, INTEL_PT_PSB_STR, INTEL_PT_PSB_LEN);
4122         if (next) {
4123                 *len -= next - *buf;
4124                 *buf = next;
4125                 return true;
4126         }
4127         return false;
4128 }
4129 
4130 /**
4131  * intel_pt_last_psb - find the last PSB packet in a buffer.
4132  * @buf: buffer
4133  * @len: size of buffer
4134  *
4135  * This function finds the last PSB in a buffer.
4136  *
4137  * Return: A pointer to the last PSB in @buf if found, %NULL otherwise.
4138  */
4139 static unsigned char *intel_pt_last_psb(unsigned char *buf, size_t len)
4140 {
4141         const char *n = INTEL_PT_PSB_STR;
4142         unsigned char *p;
4143         size_t k;
4144 
4145         if (len < INTEL_PT_PSB_LEN)
4146                 return NULL;
4147 
4148         k = len - INTEL_PT_PSB_LEN + 1;
4149         while (1) {
4150                 p = memrchr(buf, n[0], k);
4151                 if (!p)
4152                         return NULL;
4153                 if (!memcmp(p + 1, n + 1, INTEL_PT_PSB_LEN - 1))
4154                         return p;
4155                 k = p - buf;
4156                 if (!k)
4157                         return NULL;
4158         }
4159 }
4160 
4161 /**
4162  * intel_pt_next_tsc - find and return next TSC.
4163  * @buf: buffer
4164  * @len: size of buffer
4165  * @tsc: TSC value returned
4166  * @rem: returns remaining size when TSC is found
4167  *
4168  * Find a TSC packet in @buf and return the TSC value.  This function assumes
4169  * that @buf starts at a PSB and that PSB+ will contain TSC and so stops if a
4170  * PSBEND packet is found.
4171  *
4172  * Return: %true if TSC is found, false otherwise.
4173  */
4174 static bool intel_pt_next_tsc(unsigned char *buf, size_t len, uint64_t *tsc,
4175                               size_t *rem)
4176 {
4177         enum intel_pt_pkt_ctx ctx = INTEL_PT_NO_CTX;
4178         struct intel_pt_pkt packet;
4179         int ret;
4180 
4181         while (len) {
4182                 ret = intel_pt_get_packet(buf, len, &packet, &ctx);
4183                 if (ret <= 0)
4184                         return false;
4185                 if (packet.type == INTEL_PT_TSC) {
4186                         *tsc = packet.payload;
4187                         *rem = len;
4188                         return true;
4189                 }
4190                 if (packet.type == INTEL_PT_PSBEND)
4191                         return false;
4192                 buf += ret;
4193                 len -= ret;
4194         }
4195         return false;
4196 }
4197 
4198 /**
4199  * intel_pt_tsc_cmp - compare 7-byte TSCs.
4200  * @tsc1: first TSC to compare
4201  * @tsc2: second TSC to compare
4202  *
4203  * This function compares 7-byte TSC values allowing for the possibility that
4204  * TSC wrapped around.  Generally it is not possible to know if TSC has wrapped
4205  * around so for that purpose this function assumes the absolute difference is
4206  * less than half the maximum difference.
4207  *
4208  * Return: %-1 if @tsc1 is before @tsc2, %0 if @tsc1 == @tsc2, %1 if @tsc1 is
4209  * after @tsc2.
4210  */
4211 static int intel_pt_tsc_cmp(uint64_t tsc1, uint64_t tsc2)
4212 {
4213         const uint64_t halfway = (1ULL << 55);
4214 
4215         if (tsc1 == tsc2)
4216                 return 0;
4217 
4218         if (tsc1 < tsc2) {
4219                 if (tsc2 - tsc1 < halfway)
4220                         return -1;
4221                 else
4222                         return 1;
4223         } else {
4224                 if (tsc1 - tsc2 < halfway)
4225                         return 1;
4226                 else
4227                         return -1;
4228         }
4229 }
4230 
4231 #define MAX_PADDING (PERF_AUXTRACE_RECORD_ALIGNMENT - 1)
4232 
4233 /**
4234  * adj_for_padding - adjust overlap to account for padding.
4235  * @buf_b: second buffer
4236  * @buf_a: first buffer
4237  * @len_a: size of first buffer
4238  *
4239  * @buf_a might have up to 7 bytes of padding appended. Adjust the overlap
4240  * accordingly.
4241  *
4242  * Return: A pointer into @buf_b from where non-overlapped data starts
4243  */
4244 static unsigned char *adj_for_padding(unsigned char *buf_b,
4245                                       unsigned char *buf_a, size_t len_a)
4246 {
4247         unsigned char *p = buf_b - MAX_PADDING;
4248         unsigned char *q = buf_a + len_a - MAX_PADDING;
4249         int i;
4250 
4251         for (i = MAX_PADDING; i; i--, p++, q++) {
4252                 if (*p != *q)
4253                         break;
4254         }
4255 
4256         return p;
4257 }
4258 
4259 /**
4260  * intel_pt_find_overlap_tsc - determine start of non-overlapped trace data
4261  *                             using TSC.
4262  * @buf_a: first buffer
4263  * @len_a: size of first buffer
4264  * @buf_b: second buffer
4265  * @len_b: size of second buffer
4266  * @consecutive: returns true if there is data in buf_b that is consecutive
4267  *               to buf_a
4268  * @ooo_tsc: out-of-order TSC due to VM TSC offset / scaling
4269  *
4270  * If the trace contains TSC we can look at the last TSC of @buf_a and the
4271  * first TSC of @buf_b in order to determine if the buffers overlap, and then
4272  * walk forward in @buf_b until a later TSC is found.  A precondition is that
4273  * @buf_a and @buf_b are positioned at a PSB.
4274  *
4275  * Return: A pointer into @buf_b from where non-overlapped data starts, or
4276  * @buf_b + @len_b if there is no non-overlapped data.
4277  */
4278 static unsigned char *intel_pt_find_overlap_tsc(unsigned char *buf_a,
4279                                                 size_t len_a,
4280                                                 unsigned char *buf_b,
4281                                                 size_t len_b, bool *consecutive,
4282                                                 bool ooo_tsc)
4283 {
4284         uint64_t tsc_a, tsc_b;
4285         unsigned char *p;
4286         size_t len, rem_a, rem_b;
4287 
4288         p = intel_pt_last_psb(buf_a, len_a);
4289         if (!p)
4290                 return buf_b; /* No PSB in buf_a => no overlap */
4291 
4292         len = len_a - (p - buf_a);
4293         if (!intel_pt_next_tsc(p, len, &tsc_a, &rem_a)) {
4294                 /* The last PSB+ in buf_a is incomplete, so go back one more */
4295                 len_a -= len;
4296                 p = intel_pt_last_psb(buf_a, len_a);
4297                 if (!p)
4298                         return buf_b; /* No full PSB+ => assume no overlap */
4299                 len = len_a - (p - buf_a);
4300                 if (!intel_pt_next_tsc(p, len, &tsc_a, &rem_a))
4301                         return buf_b; /* No TSC in buf_a => assume no overlap */
4302         }
4303 
4304         while (1) {
4305                 /* Ignore PSB+ with no TSC */
4306                 if (intel_pt_next_tsc(buf_b, len_b, &tsc_b, &rem_b)) {
4307                         int cmp = intel_pt_tsc_cmp(tsc_a, tsc_b);
4308 
4309                         /* Same TSC, so buffers are consecutive */
4310                         if (!cmp && rem_b >= rem_a) {
4311                                 unsigned char *start;
4312 
4313                                 *consecutive = true;
4314                                 start = buf_b + len_b - (rem_b - rem_a);
4315                                 return adj_for_padding(start, buf_a, len_a);
4316                         }
4317                         if (cmp < 0 && !ooo_tsc)
4318                                 return buf_b; /* tsc_a < tsc_b => no overlap */
4319                 }
4320 
4321                 if (!intel_pt_step_psb(&buf_b, &len_b))
4322                         return buf_b + len_b; /* No PSB in buf_b => no data */
4323         }
4324 }
4325 
4326 /**
4327  * intel_pt_find_overlap - determine start of non-overlapped trace data.
4328  * @buf_a: first buffer
4329  * @len_a: size of first buffer
4330  * @buf_b: second buffer
4331  * @len_b: size of second buffer
4332  * @have_tsc: can use TSC packets to detect overlap
4333  * @consecutive: returns true if there is data in buf_b that is consecutive
4334  *               to buf_a
4335  * @ooo_tsc: out-of-order TSC due to VM TSC offset / scaling
4336  *
4337  * When trace samples or snapshots are recorded there is the possibility that
4338  * the data overlaps.  Note that, for the purposes of decoding, data is only
4339  * useful if it begins with a PSB packet.
4340  *
4341  * Return: A pointer into @buf_b from where non-overlapped data starts, or
4342  * @buf_b + @len_b if there is no non-overlapped data.
4343  */
4344 unsigned char *intel_pt_find_overlap(unsigned char *buf_a, size_t len_a,
4345                                      unsigned char *buf_b, size_t len_b,
4346                                      bool have_tsc, bool *consecutive,
4347                                      bool ooo_tsc)
4348 {
4349         unsigned char *found;
4350 
4351         /* Buffer 'b' must start at PSB so throw away everything before that */
4352         if (!intel_pt_next_psb(&buf_b, &len_b))
4353                 return buf_b + len_b; /* No PSB */
4354 
4355         if (!intel_pt_next_psb(&buf_a, &len_a))
4356                 return buf_b; /* No overlap */
4357 
4358         if (have_tsc) {
4359                 found = intel_pt_find_overlap_tsc(buf_a, len_a, buf_b, len_b,
4360                                                   consecutive, ooo_tsc);
4361                 if (found)
4362                         return found;
4363         }
4364 
4365         /*
4366          * Buffer 'b' cannot end within buffer 'a' so, for comparison purposes,
4367          * we can ignore the first part of buffer 'a'.
4368          */
4369         while (len_b < len_a) {
4370                 if (!intel_pt_step_psb(&buf_a, &len_a))
4371                         return buf_b; /* No overlap */
4372         }
4373 
4374         /* Now len_b >= len_a */
4375         while (1) {
4376                 /* Potential overlap so check the bytes */
4377                 found = memmem(buf_a, len_a, buf_b, len_a);
4378                 if (found) {
4379                         *consecutive = true;
4380                         return adj_for_padding(buf_b + len_a, buf_a, len_a);
4381                 }
4382 
4383                 /* Try again at next PSB in buffer 'a' */
4384                 if (!intel_pt_step_psb(&buf_a, &len_a))
4385                         return buf_b; /* No overlap */
4386         }
4387 }
4388 
4389 /**
4390  * struct fast_forward_data - data used by intel_pt_ff_cb().
4391  * @timestamp: timestamp to fast forward towards
4392  * @buf_timestamp: buffer timestamp of last buffer with trace data earlier than
4393  *                 the fast forward timestamp.
4394  */
4395 struct fast_forward_data {
4396         uint64_t timestamp;
4397         uint64_t buf_timestamp;
4398 };
4399 
4400 /**
4401  * intel_pt_ff_cb - fast forward lookahead callback.
4402  * @buffer: Intel PT trace buffer
4403  * @data: opaque pointer to fast forward data (struct fast_forward_data)
4404  *
4405  * Determine if @buffer trace is past the fast forward timestamp.
4406  *
4407  * Return: 1 (stop lookahead) if @buffer trace is past the fast forward
4408  *         timestamp, and 0 otherwise.
4409  */
4410 static int intel_pt_ff_cb(struct intel_pt_buffer *buffer, void *data)
4411 {
4412         struct fast_forward_data *d = data;
4413         unsigned char *buf;
4414         uint64_t tsc;
4415         size_t rem;
4416         size_t len;
4417 
4418         buf = (unsigned char *)buffer->buf;
4419         len = buffer->len;
4420 
4421         if (!intel_pt_next_psb(&buf, &len) ||
4422             !intel_pt_next_tsc(buf, len, &tsc, &rem))
4423                 return 0;
4424 
4425         tsc = intel_pt_8b_tsc(tsc, buffer->ref_timestamp);
4426 
4427         intel_pt_log("Buffer 1st timestamp " x64_fmt " ref timestamp " x64_fmt "\n",
4428                      tsc, buffer->ref_timestamp);
4429 
4430         /*
4431          * If the buffer contains a timestamp earlier that the fast forward
4432          * timestamp, then record it, else stop.
4433          */
4434         if (tsc < d->timestamp)
4435                 d->buf_timestamp = buffer->ref_timestamp;
4436         else
4437                 return 1;
4438 
4439         return 0;
4440 }
4441 
4442 /**
4443  * intel_pt_fast_forward - reposition decoder forwards.
4444  * @decoder: Intel PT decoder
4445  * @timestamp: timestamp to fast forward towards
4446  *
4447  * Reposition decoder at the last PSB with a timestamp earlier than @timestamp.
4448  *
4449  * Return: 0 on success or negative error code on failure.
4450  */
4451 int intel_pt_fast_forward(struct intel_pt_decoder *decoder, uint64_t timestamp)
4452 {
4453         struct fast_forward_data d = { .timestamp = timestamp };
4454         unsigned char *buf;
4455         size_t len;
4456         int err;
4457 
4458         intel_pt_log("Fast forward towards timestamp " x64_fmt "\n", timestamp);
4459 
4460         /* Find buffer timestamp of buffer to fast forward to */
4461         err = decoder->lookahead(decoder->data, intel_pt_ff_cb, &d);
4462         if (err < 0)
4463                 return err;
4464 
4465         /* Walk to buffer with same buffer timestamp */
4466         if (d.buf_timestamp) {
4467                 do {
4468                         decoder->pos += decoder->len;
4469                         decoder->len = 0;
4470                         err = intel_pt_get_next_data(decoder, true);
4471                         /* -ENOLINK means non-consecutive trace */
4472                         if (err && err != -ENOLINK)
4473                                 return err;
4474                 } while (decoder->buf_timestamp != d.buf_timestamp);
4475         }
4476 
4477         if (!decoder->buf)
4478                 return 0;
4479 
4480         buf = (unsigned char *)decoder->buf;
4481         len = decoder->len;
4482 
4483         if (!intel_pt_next_psb(&buf, &len))
4484                 return 0;
4485 
4486         /*
4487          * Walk PSBs while the PSB timestamp is less than the fast forward
4488          * timestamp.
4489          */
4490         do {
4491                 uint64_t tsc;
4492                 size_t rem;
4493 
4494                 if (!intel_pt_next_tsc(buf, len, &tsc, &rem))
4495                         break;
4496                 tsc = intel_pt_8b_tsc(tsc, decoder->buf_timestamp);
4497                 /*
4498                  * A TSC packet can slip past MTC packets but, after fast
4499                  * forward, decoding starts at the TSC timestamp. That means
4500                  * the timestamps may not be exactly the same as the timestamps
4501                  * that would have been decoded without fast forward.
4502                  */
4503                 if (tsc < timestamp) {
4504                         intel_pt_log("Fast forward to next PSB timestamp " x64_fmt "\n", tsc);
4505                         decoder->pos += decoder->len - len;
4506                         decoder->buf = buf;
4507                         decoder->len = len;
4508                         intel_pt_reposition(decoder);
4509                 } else {
4510                         break;
4511                 }
4512         } while (intel_pt_step_psb(&buf, &len));
4513 
4514         return 0;
4515 }
4516 

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