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
intel_pt_sample_time(enum intel_pt_pkt_state pkt_state)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
intel_pt_lower_power_of_2(uint64_t x)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)
p_log(const char * fmt,...)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
intel_pt_print_once(struct intel_pt_decoder * decoder,enum intel_pt_p_once id)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
intel_pt_cyc_threshold(uint64_t ctl)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
intel_pt_setup_period(struct intel_pt_decoder * decoder)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
multdiv(uint64_t t,uint32_t n,uint32_t d)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
intel_pt_decoder_new(struct intel_pt_params * params)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
intel_pt_set_first_timestamp(struct intel_pt_decoder * decoder,uint64_t first_timestamp)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
intel_pt_pop_blk(struct intel_pt_stack * stack)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
intel_pt_pop(struct intel_pt_stack * stack)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
intel_pt_alloc_blk(struct intel_pt_stack * stack)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
intel_pt_push(struct intel_pt_stack * stack,uint64_t ip)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
intel_pt_clear_stack(struct intel_pt_stack * stack)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
intel_pt_free_stack(struct intel_pt_stack * stack)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
intel_pt_decoder_free(struct intel_pt_decoder * decoder)458 void intel_pt_decoder_free(struct intel_pt_decoder *decoder)
459 {
460 intel_pt_free_stack(&decoder->stack);
461 free(decoder);
462 }
463
intel_pt_ext_err(int code)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
intel_pt__strerror(int code,char * buf,size_t buflen)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
intel_pt_calc_ip(const struct intel_pt_pkt * packet,uint64_t last_ip)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
intel_pt_set_last_ip(struct intel_pt_decoder * decoder)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
intel_pt_set_ip(struct intel_pt_decoder * decoder)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
intel_pt_decoder_log_packet(struct intel_pt_decoder * decoder)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
intel_pt_bug(struct intel_pt_decoder * decoder)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
intel_pt_clear_tx_flags(struct intel_pt_decoder * decoder)573 static inline void intel_pt_clear_tx_flags(struct intel_pt_decoder *decoder)
574 {
575 decoder->tx_flags = 0;
576 }
577
intel_pt_update_in_tx(struct intel_pt_decoder * decoder)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
intel_pt_update_pip(struct intel_pt_decoder * decoder)583 static inline void intel_pt_update_pip(struct intel_pt_decoder *decoder)
584 {
585 decoder->pip_payload = decoder->packet.payload;
586 }
587
intel_pt_update_nr(struct intel_pt_decoder * decoder)588 static inline void intel_pt_update_nr(struct intel_pt_decoder *decoder)
589 {
590 decoder->next_nr = decoder->pip_payload & 1;
591 }
592
intel_pt_set_nr(struct intel_pt_decoder * decoder)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
intel_pt_set_pip(struct intel_pt_decoder * decoder)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
intel_pt_bad_packet(struct intel_pt_decoder * decoder)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
intel_pt_update_sample_time(struct intel_pt_decoder * decoder)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
intel_pt_reposition(struct intel_pt_decoder * decoder)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
intel_pt_get_data(struct intel_pt_decoder * decoder,bool reposition)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
intel_pt_get_next_data(struct intel_pt_decoder * decoder,bool reposition)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
intel_pt_get_split_packet(struct intel_pt_decoder * decoder)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 */
intel_pt_pkt_lookahead(struct intel_pt_decoder * decoder,intel_pt_pkt_cb_t cb,void * data)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 */
intel_pt_fixup_last_mtc(uint32_t mtc,int mtc_shift,uint32_t * last_mtc)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
intel_pt_calc_cyc_cb(struct intel_pt_pkt_info * pkt_info)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
intel_pt_calc_cyc_to_tsc(struct intel_pt_decoder * decoder,bool from_mtc)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
intel_pt_get_next_packet(struct intel_pt_decoder * decoder)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
intel_pt_next_period(struct intel_pt_decoder * decoder)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
intel_pt_next_sample(struct intel_pt_decoder * decoder)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
intel_pt_sample_insn(struct intel_pt_decoder * decoder)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 */
intel_pt_sample_fup_insn(struct intel_pt_decoder * decoder)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
intel_pt_walk_insn(struct intel_pt_decoder * decoder,struct intel_pt_insn * intel_pt_insn,uint64_t ip)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
intel_pt_mode_exec_status(struct intel_pt_decoder * decoder)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
intel_pt_mode_exec(struct intel_pt_decoder * decoder)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
intel_pt_sample_iflag(struct intel_pt_decoder * decoder)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
intel_pt_sample_iflag_chg(struct intel_pt_decoder * decoder)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
intel_pt_clear_fup_event(struct intel_pt_decoder * decoder)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
intel_pt_fup_event(struct intel_pt_decoder * decoder,bool no_tip)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
1323 if (decoder->set_fup_cfe_ip || decoder->set_fup_cfe) {
1324 bool ip = decoder->set_fup_cfe_ip;
1325
1326 decoder->set_fup_cfe_ip = false;
1327 decoder->set_fup_cfe = false;
1328 decoder->state.type |= INTEL_PT_EVT;
1329 if (!ip && decoder->pge)
1330 decoder->state.type |= INTEL_PT_BRANCH;
1331 decoder->state.cfe_type = decoder->fup_cfe_pkt.count;
1332 decoder->state.cfe_vector = decoder->fup_cfe_pkt.payload;
1333 decoder->state.evd_cnt = decoder->evd_cnt;
1334 decoder->state.evd = decoder->evd;
1335 decoder->evd_cnt = 0;
1336 if (ip || decoder->pge)
1337 decoder->state.flags |= INTEL_PT_FUP_IP;
1338 ret = true;
1339 }
1340 if (decoder->set_fup_mode_exec) {
1341 decoder->set_fup_mode_exec = false;
1342 intel_pt_sample_iflag(decoder);
1343 sample_fup_insn = no_tip;
1344 ret = true;
1345 }
1346 if (decoder->set_fup_tx_flags) {
1347 decoder->set_fup_tx_flags = false;
1348 decoder->tx_flags = decoder->fup_tx_flags;
1349 decoder->state.type |= INTEL_PT_TRANSACTION;
1350 if (decoder->fup_tx_flags & INTEL_PT_ABORT_TX)
1351 decoder->state.type |= INTEL_PT_BRANCH;
1352 decoder->state.flags = decoder->fup_tx_flags;
1353 ret = true;
1354 }
1355 if (decoder->set_fup_ptw) {
1356 decoder->set_fup_ptw = false;
1357 decoder->state.type |= INTEL_PT_PTW;
1358 decoder->state.flags |= INTEL_PT_FUP_IP;
1359 decoder->state.ptw_payload = decoder->fup_ptw_payload;
1360 ret = true;
1361 }
1362 if (decoder->set_fup_mwait) {
1363 decoder->set_fup_mwait = false;
1364 decoder->state.type |= INTEL_PT_MWAIT_OP;
1365 decoder->state.mwait_payload = decoder->fup_mwait_payload;
1366 ret = true;
1367 }
1368 if (decoder->set_fup_pwre) {
1369 decoder->set_fup_pwre = false;
1370 decoder->state.type |= INTEL_PT_PWR_ENTRY;
1371 decoder->state.pwre_payload = decoder->fup_pwre_payload;
1372 ret = true;
1373 }
1374 if (decoder->set_fup_exstop) {
1375 decoder->set_fup_exstop = false;
1376 decoder->state.type |= INTEL_PT_EX_STOP;
1377 decoder->state.flags |= INTEL_PT_FUP_IP;
1378 ret = true;
1379 }
1380 if (decoder->set_fup_bep) {
1381 decoder->set_fup_bep = false;
1382 decoder->state.type |= INTEL_PT_BLK_ITEMS;
1383 ret = true;
1384 }
1385 if (decoder->overflow) {
1386 decoder->overflow = false;
1387 if (!ret && !decoder->pge) {
1388 if (decoder->hop) {
1389 decoder->state.type = 0;
1390 decoder->pkt_state = INTEL_PT_STATE_RESAMPLE;
1391 }
1392 decoder->pge = true;
1393 decoder->state.type |= INTEL_PT_BRANCH | INTEL_PT_TRACE_BEGIN;
1394 decoder->state.from_ip = 0;
1395 decoder->state.to_ip = decoder->ip;
1396 return true;
1397 }
1398 }
1399 if (ret) {
1400 decoder->state.from_ip = decoder->ip;
1401 decoder->state.to_ip = 0;
1402 if (sample_fup_insn)
1403 intel_pt_sample_fup_insn(decoder);
1404 } else {
1405 decoder->state.type = type;
1406 }
1407 return ret;
1408 }
1409
intel_pt_fup_with_nlip(struct intel_pt_decoder * decoder,struct intel_pt_insn * intel_pt_insn,uint64_t ip,int err)1410 static inline bool intel_pt_fup_with_nlip(struct intel_pt_decoder *decoder,
1411 struct intel_pt_insn *intel_pt_insn,
1412 uint64_t ip, int err)
1413 {
1414 return decoder->flags & INTEL_PT_FUP_WITH_NLIP && !err &&
1415 intel_pt_insn->branch == INTEL_PT_BR_INDIRECT &&
1416 ip == decoder->ip + intel_pt_insn->length;
1417 }
1418
intel_pt_walk_fup(struct intel_pt_decoder * decoder)1419 static int intel_pt_walk_fup(struct intel_pt_decoder *decoder)
1420 {
1421 struct intel_pt_insn intel_pt_insn;
1422 uint64_t ip;
1423 int err;
1424
1425 ip = decoder->last_ip;
1426
1427 while (1) {
1428 err = intel_pt_walk_insn(decoder, &intel_pt_insn, ip);
1429 if (err == INTEL_PT_RETURN)
1430 return 0;
1431 if (err == -EAGAIN ||
1432 intel_pt_fup_with_nlip(decoder, &intel_pt_insn, ip, err)) {
1433 bool no_tip = decoder->pkt_state != INTEL_PT_STATE_FUP;
1434
1435 decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1436 if (intel_pt_fup_event(decoder, no_tip) && no_tip)
1437 return 0;
1438 return -EAGAIN;
1439 }
1440 decoder->set_fup_tx_flags = false;
1441 if (err)
1442 return err;
1443
1444 if (intel_pt_insn.branch == INTEL_PT_BR_INDIRECT) {
1445 intel_pt_log_at("ERROR: Unexpected indirect branch",
1446 decoder->ip);
1447 decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
1448 return -ENOENT;
1449 }
1450
1451 if (intel_pt_insn.branch == INTEL_PT_BR_CONDITIONAL) {
1452 intel_pt_log_at("ERROR: Unexpected conditional branch",
1453 decoder->ip);
1454 decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
1455 return -ENOENT;
1456 }
1457
1458 intel_pt_bug(decoder);
1459 }
1460 }
1461
intel_pt_walk_tip(struct intel_pt_decoder * decoder)1462 static int intel_pt_walk_tip(struct intel_pt_decoder *decoder)
1463 {
1464 struct intel_pt_insn intel_pt_insn;
1465 int err;
1466
1467 err = intel_pt_walk_insn(decoder, &intel_pt_insn, 0);
1468 if (err == INTEL_PT_RETURN &&
1469 decoder->pgd_ip &&
1470 decoder->pkt_state == INTEL_PT_STATE_TIP_PGD &&
1471 (decoder->state.type & INTEL_PT_BRANCH) &&
1472 decoder->pgd_ip(decoder->state.to_ip, decoder->data)) {
1473 /* Unconditional branch leaving filter region */
1474 decoder->no_progress = 0;
1475 decoder->pge = false;
1476 decoder->continuous_period = false;
1477 decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1478 decoder->state.type |= INTEL_PT_TRACE_END;
1479 intel_pt_update_nr(decoder);
1480 return 0;
1481 }
1482 if (err == INTEL_PT_RETURN)
1483 return 0;
1484 if (err)
1485 return err;
1486
1487 intel_pt_update_nr(decoder);
1488 intel_pt_sample_iflag_chg(decoder);
1489
1490 if (intel_pt_insn.branch == INTEL_PT_BR_INDIRECT) {
1491 if (decoder->pkt_state == INTEL_PT_STATE_TIP_PGD) {
1492 decoder->pge = false;
1493 decoder->continuous_period = false;
1494 decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1495 decoder->state.from_ip = decoder->ip;
1496 if (decoder->packet.count == 0) {
1497 decoder->state.to_ip = 0;
1498 } else {
1499 decoder->state.to_ip = decoder->last_ip;
1500 decoder->ip = decoder->last_ip;
1501 }
1502 decoder->state.type |= INTEL_PT_TRACE_END;
1503 } else {
1504 decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1505 decoder->state.from_ip = decoder->ip;
1506 if (decoder->packet.count == 0) {
1507 decoder->state.to_ip = 0;
1508 } else {
1509 decoder->state.to_ip = decoder->last_ip;
1510 decoder->ip = decoder->last_ip;
1511 }
1512 }
1513 return 0;
1514 }
1515
1516 if (intel_pt_insn.branch == INTEL_PT_BR_CONDITIONAL) {
1517 uint64_t to_ip = decoder->ip + intel_pt_insn.length +
1518 intel_pt_insn.rel;
1519
1520 if (decoder->pgd_ip &&
1521 decoder->pkt_state == INTEL_PT_STATE_TIP_PGD &&
1522 decoder->pgd_ip(to_ip, decoder->data)) {
1523 /* Conditional branch leaving filter region */
1524 decoder->pge = false;
1525 decoder->continuous_period = false;
1526 decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1527 decoder->ip = to_ip;
1528 decoder->state.from_ip = decoder->ip;
1529 decoder->state.to_ip = to_ip;
1530 decoder->state.type |= INTEL_PT_TRACE_END;
1531 return 0;
1532 }
1533 intel_pt_log_at("ERROR: Conditional branch when expecting indirect branch",
1534 decoder->ip);
1535 decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
1536 return -ENOENT;
1537 }
1538
1539 return intel_pt_bug(decoder);
1540 }
1541
1542 struct eptw_data {
1543 int bit_countdown;
1544 uint64_t payload;
1545 };
1546
intel_pt_eptw_lookahead_cb(struct intel_pt_pkt_info * pkt_info)1547 static int intel_pt_eptw_lookahead_cb(struct intel_pt_pkt_info *pkt_info)
1548 {
1549 struct eptw_data *data = pkt_info->data;
1550 int nr_bits;
1551
1552 switch (pkt_info->packet.type) {
1553 case INTEL_PT_PAD:
1554 case INTEL_PT_MNT:
1555 case INTEL_PT_MODE_EXEC:
1556 case INTEL_PT_MODE_TSX:
1557 case INTEL_PT_MTC:
1558 case INTEL_PT_FUP:
1559 case INTEL_PT_CYC:
1560 case INTEL_PT_CBR:
1561 case INTEL_PT_TSC:
1562 case INTEL_PT_TMA:
1563 case INTEL_PT_PIP:
1564 case INTEL_PT_VMCS:
1565 case INTEL_PT_PSB:
1566 case INTEL_PT_PSBEND:
1567 case INTEL_PT_PTWRITE:
1568 case INTEL_PT_PTWRITE_IP:
1569 case INTEL_PT_EXSTOP:
1570 case INTEL_PT_EXSTOP_IP:
1571 case INTEL_PT_MWAIT:
1572 case INTEL_PT_PWRE:
1573 case INTEL_PT_PWRX:
1574 case INTEL_PT_BBP:
1575 case INTEL_PT_BIP:
1576 case INTEL_PT_BEP:
1577 case INTEL_PT_BEP_IP:
1578 case INTEL_PT_CFE:
1579 case INTEL_PT_CFE_IP:
1580 case INTEL_PT_EVD:
1581 break;
1582
1583 case INTEL_PT_TNT:
1584 nr_bits = data->bit_countdown;
1585 if (nr_bits > pkt_info->packet.count)
1586 nr_bits = pkt_info->packet.count;
1587 data->payload <<= nr_bits;
1588 data->payload |= pkt_info->packet.payload >> (64 - nr_bits);
1589 data->bit_countdown -= nr_bits;
1590 return !data->bit_countdown;
1591
1592 case INTEL_PT_TIP_PGE:
1593 case INTEL_PT_TIP_PGD:
1594 case INTEL_PT_TIP:
1595 case INTEL_PT_BAD:
1596 case INTEL_PT_OVF:
1597 case INTEL_PT_TRACESTOP:
1598 default:
1599 return 1;
1600 }
1601
1602 return 0;
1603 }
1604
intel_pt_emulated_ptwrite(struct intel_pt_decoder * decoder)1605 static int intel_pt_emulated_ptwrite(struct intel_pt_decoder *decoder)
1606 {
1607 int n = 64 - decoder->tnt.count;
1608 struct eptw_data data = {
1609 .bit_countdown = n,
1610 .payload = decoder->tnt.payload >> n,
1611 };
1612
1613 decoder->emulated_ptwrite = false;
1614 intel_pt_log("Emulated ptwrite detected\n");
1615
1616 intel_pt_pkt_lookahead(decoder, intel_pt_eptw_lookahead_cb, &data);
1617 if (data.bit_countdown)
1618 return -ECONNRESET;
1619
1620 decoder->state.type = INTEL_PT_PTW;
1621 decoder->state.from_ip = decoder->ip;
1622 decoder->state.to_ip = 0;
1623 decoder->state.ptw_payload = data.payload;
1624 return 0;
1625 }
1626
intel_pt_walk_tnt(struct intel_pt_decoder * decoder)1627 static int intel_pt_walk_tnt(struct intel_pt_decoder *decoder)
1628 {
1629 struct intel_pt_insn intel_pt_insn;
1630 int err;
1631
1632 while (1) {
1633 if (decoder->emulated_ptwrite)
1634 return intel_pt_emulated_ptwrite(decoder);
1635 err = intel_pt_walk_insn(decoder, &intel_pt_insn, 0);
1636 if (err == INTEL_PT_RETURN) {
1637 decoder->emulated_ptwrite = intel_pt_insn.emulated_ptwrite;
1638 return 0;
1639 }
1640 if (err) {
1641 decoder->emulated_ptwrite = false;
1642 return err;
1643 }
1644
1645 if (intel_pt_insn.op == INTEL_PT_OP_RET) {
1646 if (!decoder->return_compression) {
1647 intel_pt_log_at("ERROR: RET when expecting conditional branch",
1648 decoder->ip);
1649 decoder->pkt_state = INTEL_PT_STATE_ERR3;
1650 return -ENOENT;
1651 }
1652 if (!decoder->ret_addr) {
1653 intel_pt_log_at("ERROR: Bad RET compression (stack empty)",
1654 decoder->ip);
1655 decoder->pkt_state = INTEL_PT_STATE_ERR3;
1656 return -ENOENT;
1657 }
1658 if (!(decoder->tnt.payload & BIT63)) {
1659 intel_pt_log_at("ERROR: Bad RET compression (TNT=N)",
1660 decoder->ip);
1661 decoder->pkt_state = INTEL_PT_STATE_ERR3;
1662 return -ENOENT;
1663 }
1664 decoder->tnt.count -= 1;
1665 if (decoder->tnt.count)
1666 decoder->pkt_state = INTEL_PT_STATE_TNT_CONT;
1667 else
1668 decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1669 decoder->tnt.payload <<= 1;
1670 decoder->state.from_ip = decoder->ip;
1671 decoder->ip = decoder->ret_addr;
1672 decoder->state.to_ip = decoder->ip;
1673 return 0;
1674 }
1675
1676 if (intel_pt_insn.branch == INTEL_PT_BR_INDIRECT) {
1677 /* Handle deferred TIPs */
1678 err = intel_pt_get_next_packet(decoder);
1679 if (err)
1680 return err;
1681 if (decoder->packet.type != INTEL_PT_TIP ||
1682 decoder->packet.count == 0) {
1683 intel_pt_log_at("ERROR: Missing deferred TIP for indirect branch",
1684 decoder->ip);
1685 decoder->pkt_state = INTEL_PT_STATE_ERR3;
1686 decoder->pkt_step = 0;
1687 return -ENOENT;
1688 }
1689 intel_pt_set_last_ip(decoder);
1690 decoder->state.from_ip = decoder->ip;
1691 decoder->state.to_ip = decoder->last_ip;
1692 decoder->ip = decoder->last_ip;
1693 intel_pt_update_nr(decoder);
1694 intel_pt_sample_iflag_chg(decoder);
1695 return 0;
1696 }
1697
1698 if (intel_pt_insn.branch == INTEL_PT_BR_CONDITIONAL) {
1699 decoder->tnt.count -= 1;
1700 if (decoder->tnt.count)
1701 decoder->pkt_state = INTEL_PT_STATE_TNT_CONT;
1702 else
1703 decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1704 if (decoder->tnt.payload & BIT63) {
1705 decoder->tnt.payload <<= 1;
1706 decoder->state.from_ip = decoder->ip;
1707 decoder->ip += intel_pt_insn.length +
1708 intel_pt_insn.rel;
1709 decoder->state.to_ip = decoder->ip;
1710 return 0;
1711 }
1712 /* Instruction sample for a non-taken branch */
1713 if (decoder->state.type & INTEL_PT_INSTRUCTION) {
1714 decoder->tnt.payload <<= 1;
1715 decoder->state.type = INTEL_PT_INSTRUCTION;
1716 decoder->state.from_ip = decoder->ip;
1717 decoder->state.to_ip = 0;
1718 decoder->ip += intel_pt_insn.length;
1719 return 0;
1720 }
1721 decoder->sample_cyc = false;
1722 decoder->ip += intel_pt_insn.length;
1723 if (!decoder->tnt.count) {
1724 intel_pt_update_sample_time(decoder);
1725 return -EAGAIN;
1726 }
1727 decoder->tnt.payload <<= 1;
1728 continue;
1729 }
1730
1731 return intel_pt_bug(decoder);
1732 }
1733 }
1734
intel_pt_mode_tsx(struct intel_pt_decoder * decoder,bool * no_tip)1735 static int intel_pt_mode_tsx(struct intel_pt_decoder *decoder, bool *no_tip)
1736 {
1737 unsigned int fup_tx_flags;
1738 int err;
1739
1740 fup_tx_flags = decoder->packet.payload &
1741 (INTEL_PT_IN_TX | INTEL_PT_ABORT_TX);
1742 err = intel_pt_get_next_packet(decoder);
1743 if (err)
1744 return err;
1745 if (decoder->packet.type == INTEL_PT_FUP) {
1746 decoder->fup_tx_flags = fup_tx_flags;
1747 decoder->set_fup_tx_flags = true;
1748 if (!(decoder->fup_tx_flags & INTEL_PT_ABORT_TX))
1749 *no_tip = true;
1750 } else {
1751 intel_pt_log_at("ERROR: Missing FUP after MODE.TSX",
1752 decoder->pos);
1753 intel_pt_update_in_tx(decoder);
1754 }
1755 return 0;
1756 }
1757
intel_pt_evd(struct intel_pt_decoder * decoder)1758 static int intel_pt_evd(struct intel_pt_decoder *decoder)
1759 {
1760 if (decoder->evd_cnt >= INTEL_PT_MAX_EVDS) {
1761 intel_pt_log_at("ERROR: Too many EVD packets", decoder->pos);
1762 return -ENOSYS;
1763 }
1764 decoder->evd[decoder->evd_cnt++] = (struct intel_pt_evd){
1765 .type = decoder->packet.count,
1766 .payload = decoder->packet.payload,
1767 };
1768 return 0;
1769 }
1770
intel_pt_8b_tsc(uint64_t timestamp,uint64_t ref_timestamp)1771 static uint64_t intel_pt_8b_tsc(uint64_t timestamp, uint64_t ref_timestamp)
1772 {
1773 timestamp |= (ref_timestamp & (0xffULL << 56));
1774
1775 if (timestamp < ref_timestamp) {
1776 if (ref_timestamp - timestamp > (1ULL << 55))
1777 timestamp += (1ULL << 56);
1778 } else {
1779 if (timestamp - ref_timestamp > (1ULL << 55))
1780 timestamp -= (1ULL << 56);
1781 }
1782
1783 return timestamp;
1784 }
1785
1786 /* For use only when decoder->vm_time_correlation is true */
intel_pt_time_in_range(struct intel_pt_decoder * decoder,uint64_t timestamp)1787 static bool intel_pt_time_in_range(struct intel_pt_decoder *decoder,
1788 uint64_t timestamp)
1789 {
1790 uint64_t max_timestamp = decoder->buf_timestamp;
1791
1792 if (!max_timestamp) {
1793 max_timestamp = decoder->last_reliable_timestamp +
1794 0x400000000ULL;
1795 }
1796 return timestamp >= decoder->last_reliable_timestamp &&
1797 timestamp < decoder->buf_timestamp;
1798 }
1799
intel_pt_calc_tsc_timestamp(struct intel_pt_decoder * decoder)1800 static void intel_pt_calc_tsc_timestamp(struct intel_pt_decoder *decoder)
1801 {
1802 uint64_t timestamp;
1803 bool bad = false;
1804
1805 decoder->have_tma = false;
1806
1807 if (decoder->ref_timestamp) {
1808 timestamp = intel_pt_8b_tsc(decoder->packet.payload,
1809 decoder->ref_timestamp);
1810 decoder->tsc_timestamp = timestamp;
1811 decoder->timestamp = timestamp;
1812 decoder->ref_timestamp = 0;
1813 decoder->timestamp_insn_cnt = 0;
1814 } else if (decoder->timestamp) {
1815 timestamp = decoder->packet.payload |
1816 (decoder->timestamp & (0xffULL << 56));
1817 decoder->tsc_timestamp = timestamp;
1818 if (timestamp < decoder->timestamp &&
1819 decoder->timestamp - timestamp < decoder->tsc_slip) {
1820 intel_pt_log_to("Suppressing backwards timestamp",
1821 timestamp);
1822 timestamp = decoder->timestamp;
1823 }
1824 if (timestamp < decoder->timestamp) {
1825 if (!decoder->buf_timestamp ||
1826 (timestamp + (1ULL << 56) < decoder->buf_timestamp)) {
1827 intel_pt_log_to("Wraparound timestamp", timestamp);
1828 timestamp += (1ULL << 56);
1829 decoder->tsc_timestamp = timestamp;
1830 } else {
1831 intel_pt_log_to("Suppressing bad timestamp", timestamp);
1832 timestamp = decoder->timestamp;
1833 bad = true;
1834 }
1835 }
1836 if (decoder->vm_time_correlation &&
1837 (bad || !intel_pt_time_in_range(decoder, timestamp)) &&
1838 intel_pt_print_once(decoder, INTEL_PT_PRT_ONCE_ERANGE))
1839 p_log("Timestamp out of range");
1840 decoder->timestamp = timestamp;
1841 decoder->timestamp_insn_cnt = 0;
1842 }
1843
1844 if (decoder->last_packet_type == INTEL_PT_CYC) {
1845 decoder->cyc_ref_timestamp = decoder->timestamp;
1846 decoder->cycle_cnt = 0;
1847 decoder->have_calc_cyc_to_tsc = false;
1848 intel_pt_calc_cyc_to_tsc(decoder, false);
1849 }
1850
1851 intel_pt_log_to("Setting timestamp", decoder->timestamp);
1852 }
1853
intel_pt_overflow(struct intel_pt_decoder * decoder)1854 static int intel_pt_overflow(struct intel_pt_decoder *decoder)
1855 {
1856 intel_pt_log("ERROR: Buffer overflow\n");
1857 intel_pt_clear_tx_flags(decoder);
1858 intel_pt_set_nr(decoder);
1859 decoder->timestamp_insn_cnt = 0;
1860 decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1861 decoder->state.from_ip = decoder->ip;
1862 decoder->ip = 0;
1863 decoder->pge = false;
1864 intel_pt_clear_fup_event(decoder);
1865 decoder->overflow = true;
1866 return -EOVERFLOW;
1867 }
1868
intel_pt_mtc_cyc_cnt_pge(struct intel_pt_decoder * decoder)1869 static inline void intel_pt_mtc_cyc_cnt_pge(struct intel_pt_decoder *decoder)
1870 {
1871 if (decoder->have_cyc)
1872 return;
1873
1874 decoder->cyc_cnt_timestamp = decoder->timestamp;
1875 decoder->base_cyc_cnt = decoder->tot_cyc_cnt;
1876 }
1877
intel_pt_mtc_cyc_cnt_cbr(struct intel_pt_decoder * decoder)1878 static inline void intel_pt_mtc_cyc_cnt_cbr(struct intel_pt_decoder *decoder)
1879 {
1880 decoder->tsc_to_cyc = decoder->cbr / decoder->max_non_turbo_ratio_fp;
1881
1882 if (decoder->pge)
1883 intel_pt_mtc_cyc_cnt_pge(decoder);
1884 }
1885
intel_pt_mtc_cyc_cnt_upd(struct intel_pt_decoder * decoder)1886 static inline void intel_pt_mtc_cyc_cnt_upd(struct intel_pt_decoder *decoder)
1887 {
1888 uint64_t tot_cyc_cnt, tsc_delta;
1889
1890 if (decoder->have_cyc)
1891 return;
1892
1893 decoder->sample_cyc = true;
1894
1895 if (!decoder->pge || decoder->timestamp <= decoder->cyc_cnt_timestamp)
1896 return;
1897
1898 tsc_delta = decoder->timestamp - decoder->cyc_cnt_timestamp;
1899 tot_cyc_cnt = tsc_delta * decoder->tsc_to_cyc + decoder->base_cyc_cnt;
1900
1901 if (tot_cyc_cnt > decoder->tot_cyc_cnt)
1902 decoder->tot_cyc_cnt = tot_cyc_cnt;
1903 }
1904
intel_pt_calc_tma(struct intel_pt_decoder * decoder)1905 static void intel_pt_calc_tma(struct intel_pt_decoder *decoder)
1906 {
1907 uint32_t ctc = decoder->packet.payload;
1908 uint32_t fc = decoder->packet.count;
1909 uint32_t ctc_rem = ctc & decoder->ctc_rem_mask;
1910
1911 if (!decoder->tsc_ctc_ratio_d)
1912 return;
1913
1914 if (decoder->pge && !decoder->in_psb)
1915 intel_pt_mtc_cyc_cnt_pge(decoder);
1916 else
1917 intel_pt_mtc_cyc_cnt_upd(decoder);
1918
1919 decoder->last_mtc = (ctc >> decoder->mtc_shift) & 0xff;
1920 decoder->last_ctc = ctc - ctc_rem;
1921 decoder->ctc_timestamp = decoder->tsc_timestamp - fc;
1922 if (decoder->tsc_ctc_mult) {
1923 decoder->ctc_timestamp -= ctc_rem * decoder->tsc_ctc_mult;
1924 } else {
1925 decoder->ctc_timestamp -= multdiv(ctc_rem,
1926 decoder->tsc_ctc_ratio_n,
1927 decoder->tsc_ctc_ratio_d);
1928 }
1929 decoder->ctc_delta = 0;
1930 decoder->have_tma = true;
1931 decoder->fixup_last_mtc = true;
1932 intel_pt_log("CTC timestamp " x64_fmt " last MTC %#x CTC rem %#x\n",
1933 decoder->ctc_timestamp, decoder->last_mtc, ctc_rem);
1934 }
1935
intel_pt_calc_mtc_timestamp(struct intel_pt_decoder * decoder)1936 static void intel_pt_calc_mtc_timestamp(struct intel_pt_decoder *decoder)
1937 {
1938 uint64_t timestamp;
1939 uint32_t mtc, mtc_delta;
1940
1941 if (!decoder->have_tma)
1942 return;
1943
1944 mtc = decoder->packet.payload;
1945
1946 if (decoder->mtc_shift > 8 && decoder->fixup_last_mtc) {
1947 decoder->fixup_last_mtc = false;
1948 intel_pt_fixup_last_mtc(mtc, decoder->mtc_shift,
1949 &decoder->last_mtc);
1950 }
1951
1952 if (mtc > decoder->last_mtc)
1953 mtc_delta = mtc - decoder->last_mtc;
1954 else
1955 mtc_delta = mtc + 256 - decoder->last_mtc;
1956
1957 decoder->ctc_delta += mtc_delta << decoder->mtc_shift;
1958
1959 if (decoder->tsc_ctc_mult) {
1960 timestamp = decoder->ctc_timestamp +
1961 decoder->ctc_delta * decoder->tsc_ctc_mult;
1962 } else {
1963 timestamp = decoder->ctc_timestamp +
1964 multdiv(decoder->ctc_delta,
1965 decoder->tsc_ctc_ratio_n,
1966 decoder->tsc_ctc_ratio_d);
1967 }
1968
1969 if (timestamp < decoder->timestamp)
1970 intel_pt_log("Suppressing MTC timestamp " x64_fmt " less than current timestamp " x64_fmt "\n",
1971 timestamp, decoder->timestamp);
1972 else
1973 decoder->timestamp = timestamp;
1974
1975 intel_pt_mtc_cyc_cnt_upd(decoder);
1976
1977 decoder->timestamp_insn_cnt = 0;
1978 decoder->last_mtc = mtc;
1979
1980 if (decoder->last_packet_type == INTEL_PT_CYC) {
1981 decoder->cyc_ref_timestamp = decoder->timestamp;
1982 decoder->cycle_cnt = 0;
1983 decoder->have_calc_cyc_to_tsc = false;
1984 intel_pt_calc_cyc_to_tsc(decoder, true);
1985 }
1986
1987 intel_pt_log_to("Setting timestamp", decoder->timestamp);
1988 }
1989
intel_pt_calc_cbr(struct intel_pt_decoder * decoder)1990 static void intel_pt_calc_cbr(struct intel_pt_decoder *decoder)
1991 {
1992 unsigned int cbr = decoder->packet.payload & 0xff;
1993
1994 decoder->cbr_payload = decoder->packet.payload;
1995
1996 if (decoder->cbr == cbr)
1997 return;
1998
1999 decoder->cbr = cbr;
2000 decoder->cbr_cyc_to_tsc = decoder->max_non_turbo_ratio_fp / cbr;
2001 decoder->cyc_ref_timestamp = decoder->timestamp;
2002 decoder->cycle_cnt = 0;
2003
2004 intel_pt_mtc_cyc_cnt_cbr(decoder);
2005 }
2006
intel_pt_calc_cyc_timestamp(struct intel_pt_decoder * decoder)2007 static void intel_pt_calc_cyc_timestamp(struct intel_pt_decoder *decoder)
2008 {
2009 uint64_t timestamp = decoder->cyc_ref_timestamp;
2010
2011 decoder->have_cyc = true;
2012
2013 decoder->cycle_cnt += decoder->packet.payload;
2014 if (decoder->pge)
2015 decoder->tot_cyc_cnt += decoder->packet.payload;
2016 decoder->sample_cyc = true;
2017
2018 if (!decoder->cyc_ref_timestamp)
2019 return;
2020
2021 if (decoder->have_calc_cyc_to_tsc)
2022 timestamp += decoder->cycle_cnt * decoder->calc_cyc_to_tsc;
2023 else if (decoder->cbr)
2024 timestamp += decoder->cycle_cnt * decoder->cbr_cyc_to_tsc;
2025 else
2026 return;
2027
2028 if (timestamp < decoder->timestamp)
2029 intel_pt_log("Suppressing CYC timestamp " x64_fmt " less than current timestamp " x64_fmt "\n",
2030 timestamp, decoder->timestamp);
2031 else
2032 decoder->timestamp = timestamp;
2033
2034 decoder->timestamp_insn_cnt = 0;
2035
2036 intel_pt_log_to("Setting timestamp", decoder->timestamp);
2037 }
2038
intel_pt_bbp(struct intel_pt_decoder * decoder)2039 static void intel_pt_bbp(struct intel_pt_decoder *decoder)
2040 {
2041 if (decoder->prev_pkt_ctx == INTEL_PT_NO_CTX) {
2042 memset(decoder->state.items.mask, 0, sizeof(decoder->state.items.mask));
2043 decoder->state.items.is_32_bit = false;
2044 }
2045 decoder->blk_type = decoder->packet.payload;
2046 decoder->blk_type_pos = intel_pt_blk_type_pos(decoder->blk_type);
2047 if (decoder->blk_type == INTEL_PT_GP_REGS)
2048 decoder->state.items.is_32_bit = decoder->packet.count;
2049 if (decoder->blk_type_pos < 0) {
2050 intel_pt_log("WARNING: Unknown block type %u\n",
2051 decoder->blk_type);
2052 } else if (decoder->state.items.mask[decoder->blk_type_pos]) {
2053 intel_pt_log("WARNING: Duplicate block type %u\n",
2054 decoder->blk_type);
2055 }
2056 }
2057
intel_pt_bip(struct intel_pt_decoder * decoder)2058 static void intel_pt_bip(struct intel_pt_decoder *decoder)
2059 {
2060 uint32_t id = decoder->packet.count;
2061 uint32_t bit = 1 << id;
2062 int pos = decoder->blk_type_pos;
2063
2064 if (pos < 0 || id >= INTEL_PT_BLK_ITEM_ID_CNT) {
2065 intel_pt_log("WARNING: Unknown block item %u type %d\n",
2066 id, decoder->blk_type);
2067 return;
2068 }
2069
2070 if (decoder->state.items.mask[pos] & bit) {
2071 intel_pt_log("WARNING: Duplicate block item %u type %d\n",
2072 id, decoder->blk_type);
2073 }
2074
2075 decoder->state.items.mask[pos] |= bit;
2076 decoder->state.items.val[pos][id] = decoder->packet.payload;
2077 }
2078
2079 /* Walk PSB+ packets when already in sync. */
intel_pt_walk_psbend(struct intel_pt_decoder * decoder)2080 static int intel_pt_walk_psbend(struct intel_pt_decoder *decoder)
2081 {
2082 int err;
2083
2084 decoder->in_psb = true;
2085
2086 while (1) {
2087 err = intel_pt_get_next_packet(decoder);
2088 if (err)
2089 goto out;
2090
2091 switch (decoder->packet.type) {
2092 case INTEL_PT_PSBEND:
2093 err = 0;
2094 goto out;
2095
2096 case INTEL_PT_TIP_PGD:
2097 case INTEL_PT_TIP_PGE:
2098 case INTEL_PT_TIP:
2099 case INTEL_PT_TNT:
2100 case INTEL_PT_TRACESTOP:
2101 case INTEL_PT_BAD:
2102 case INTEL_PT_PSB:
2103 case INTEL_PT_PTWRITE:
2104 case INTEL_PT_PTWRITE_IP:
2105 case INTEL_PT_EXSTOP:
2106 case INTEL_PT_EXSTOP_IP:
2107 case INTEL_PT_MWAIT:
2108 case INTEL_PT_PWRE:
2109 case INTEL_PT_PWRX:
2110 case INTEL_PT_BBP:
2111 case INTEL_PT_BIP:
2112 case INTEL_PT_BEP:
2113 case INTEL_PT_BEP_IP:
2114 case INTEL_PT_CFE:
2115 case INTEL_PT_CFE_IP:
2116 case INTEL_PT_EVD:
2117 decoder->have_tma = false;
2118 intel_pt_log("ERROR: Unexpected packet\n");
2119 err = -EAGAIN;
2120 goto out;
2121
2122 case INTEL_PT_OVF:
2123 err = intel_pt_overflow(decoder);
2124 goto out;
2125
2126 case INTEL_PT_TSC:
2127 intel_pt_calc_tsc_timestamp(decoder);
2128 break;
2129
2130 case INTEL_PT_TMA:
2131 intel_pt_calc_tma(decoder);
2132 break;
2133
2134 case INTEL_PT_CBR:
2135 intel_pt_calc_cbr(decoder);
2136 break;
2137
2138 case INTEL_PT_MODE_EXEC:
2139 intel_pt_mode_exec_status(decoder);
2140 break;
2141
2142 case INTEL_PT_PIP:
2143 intel_pt_set_pip(decoder);
2144 break;
2145
2146 case INTEL_PT_FUP:
2147 decoder->pge = true;
2148 if (decoder->packet.count) {
2149 intel_pt_set_last_ip(decoder);
2150 decoder->psb_ip = decoder->last_ip;
2151 }
2152 break;
2153
2154 case INTEL_PT_MODE_TSX:
2155 intel_pt_update_in_tx(decoder);
2156 break;
2157
2158 case INTEL_PT_MTC:
2159 intel_pt_calc_mtc_timestamp(decoder);
2160 if (decoder->period_type == INTEL_PT_PERIOD_MTC)
2161 decoder->state.type |= INTEL_PT_INSTRUCTION;
2162 break;
2163
2164 case INTEL_PT_CYC:
2165 intel_pt_calc_cyc_timestamp(decoder);
2166 break;
2167
2168 case INTEL_PT_VMCS:
2169 case INTEL_PT_MNT:
2170 case INTEL_PT_PAD:
2171 default:
2172 break;
2173 }
2174 }
2175 out:
2176 decoder->in_psb = false;
2177
2178 return err;
2179 }
2180
intel_pt_walk_fup_tip(struct intel_pt_decoder * decoder)2181 static int intel_pt_walk_fup_tip(struct intel_pt_decoder *decoder)
2182 {
2183 int err;
2184
2185 if (decoder->tx_flags & INTEL_PT_ABORT_TX) {
2186 decoder->tx_flags = 0;
2187 decoder->state.flags &= ~INTEL_PT_IN_TX;
2188 decoder->state.flags |= INTEL_PT_ABORT_TX;
2189 } else {
2190 decoder->state.flags |= INTEL_PT_ASYNC;
2191 }
2192
2193 while (1) {
2194 err = intel_pt_get_next_packet(decoder);
2195 if (err)
2196 return err;
2197
2198 switch (decoder->packet.type) {
2199 case INTEL_PT_TNT:
2200 case INTEL_PT_FUP:
2201 case INTEL_PT_TRACESTOP:
2202 case INTEL_PT_PSB:
2203 case INTEL_PT_TSC:
2204 case INTEL_PT_TMA:
2205 case INTEL_PT_MODE_TSX:
2206 case INTEL_PT_BAD:
2207 case INTEL_PT_PSBEND:
2208 case INTEL_PT_PTWRITE:
2209 case INTEL_PT_PTWRITE_IP:
2210 case INTEL_PT_EXSTOP:
2211 case INTEL_PT_EXSTOP_IP:
2212 case INTEL_PT_MWAIT:
2213 case INTEL_PT_PWRE:
2214 case INTEL_PT_PWRX:
2215 case INTEL_PT_BBP:
2216 case INTEL_PT_BIP:
2217 case INTEL_PT_BEP:
2218 case INTEL_PT_BEP_IP:
2219 case INTEL_PT_CFE:
2220 case INTEL_PT_CFE_IP:
2221 case INTEL_PT_EVD:
2222 intel_pt_log("ERROR: Missing TIP after FUP\n");
2223 decoder->pkt_state = INTEL_PT_STATE_ERR3;
2224 decoder->pkt_step = 0;
2225 return -ENOENT;
2226
2227 case INTEL_PT_CBR:
2228 intel_pt_calc_cbr(decoder);
2229 break;
2230
2231 case INTEL_PT_OVF:
2232 return intel_pt_overflow(decoder);
2233
2234 case INTEL_PT_TIP_PGD:
2235 decoder->state.from_ip = decoder->ip;
2236 if (decoder->packet.count == 0) {
2237 decoder->state.to_ip = 0;
2238 } else {
2239 intel_pt_set_ip(decoder);
2240 decoder->state.to_ip = decoder->ip;
2241 }
2242 decoder->pge = false;
2243 decoder->continuous_period = false;
2244 decoder->state.type |= INTEL_PT_TRACE_END;
2245 intel_pt_update_nr(decoder);
2246 return 0;
2247
2248 case INTEL_PT_TIP_PGE:
2249 decoder->pge = true;
2250 intel_pt_log("Omitting PGE ip " x64_fmt "\n",
2251 decoder->ip);
2252 decoder->state.from_ip = 0;
2253 if (decoder->packet.count == 0) {
2254 decoder->state.to_ip = 0;
2255 } else {
2256 intel_pt_set_ip(decoder);
2257 decoder->state.to_ip = decoder->ip;
2258 }
2259 decoder->state.type |= INTEL_PT_TRACE_BEGIN;
2260 intel_pt_mtc_cyc_cnt_pge(decoder);
2261 intel_pt_set_nr(decoder);
2262 return 0;
2263
2264 case INTEL_PT_TIP:
2265 decoder->state.from_ip = decoder->ip;
2266 if (decoder->packet.count == 0) {
2267 decoder->state.to_ip = 0;
2268 } else {
2269 intel_pt_set_ip(decoder);
2270 decoder->state.to_ip = decoder->ip;
2271 }
2272 intel_pt_update_nr(decoder);
2273 intel_pt_sample_iflag_chg(decoder);
2274 return 0;
2275
2276 case INTEL_PT_PIP:
2277 intel_pt_update_pip(decoder);
2278 break;
2279
2280 case INTEL_PT_MTC:
2281 intel_pt_calc_mtc_timestamp(decoder);
2282 if (decoder->period_type == INTEL_PT_PERIOD_MTC)
2283 decoder->state.type |= INTEL_PT_INSTRUCTION;
2284 break;
2285
2286 case INTEL_PT_CYC:
2287 intel_pt_calc_cyc_timestamp(decoder);
2288 break;
2289
2290 case INTEL_PT_MODE_EXEC:
2291 intel_pt_mode_exec(decoder);
2292 break;
2293
2294 case INTEL_PT_VMCS:
2295 case INTEL_PT_MNT:
2296 case INTEL_PT_PAD:
2297 break;
2298
2299 default:
2300 return intel_pt_bug(decoder);
2301 }
2302 }
2303 }
2304
intel_pt_resample(struct intel_pt_decoder * decoder)2305 static int intel_pt_resample(struct intel_pt_decoder *decoder)
2306 {
2307 decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
2308 decoder->state.type = INTEL_PT_INSTRUCTION;
2309 decoder->state.from_ip = decoder->ip;
2310 decoder->state.to_ip = 0;
2311 return 0;
2312 }
2313
2314 struct intel_pt_vm_tsc_info {
2315 struct intel_pt_pkt pip_packet;
2316 struct intel_pt_pkt vmcs_packet;
2317 struct intel_pt_pkt tma_packet;
2318 bool tsc, pip, vmcs, tma, psbend;
2319 uint64_t ctc_delta;
2320 uint64_t last_ctc;
2321 int max_lookahead;
2322 };
2323
2324 /* Lookahead and get the PIP, VMCS and TMA packets from PSB+ */
intel_pt_vm_psb_lookahead_cb(struct intel_pt_pkt_info * pkt_info)2325 static int intel_pt_vm_psb_lookahead_cb(struct intel_pt_pkt_info *pkt_info)
2326 {
2327 struct intel_pt_vm_tsc_info *data = pkt_info->data;
2328
2329 switch (pkt_info->packet.type) {
2330 case INTEL_PT_PAD:
2331 case INTEL_PT_MNT:
2332 case INTEL_PT_MODE_EXEC:
2333 case INTEL_PT_MODE_TSX:
2334 case INTEL_PT_MTC:
2335 case INTEL_PT_FUP:
2336 case INTEL_PT_CYC:
2337 case INTEL_PT_CBR:
2338 break;
2339
2340 case INTEL_PT_TSC:
2341 data->tsc = true;
2342 break;
2343
2344 case INTEL_PT_TMA:
2345 data->tma_packet = pkt_info->packet;
2346 data->tma = true;
2347 break;
2348
2349 case INTEL_PT_PIP:
2350 data->pip_packet = pkt_info->packet;
2351 data->pip = true;
2352 break;
2353
2354 case INTEL_PT_VMCS:
2355 data->vmcs_packet = pkt_info->packet;
2356 data->vmcs = true;
2357 break;
2358
2359 case INTEL_PT_PSBEND:
2360 data->psbend = true;
2361 return 1;
2362
2363 case INTEL_PT_TIP_PGE:
2364 case INTEL_PT_PTWRITE:
2365 case INTEL_PT_PTWRITE_IP:
2366 case INTEL_PT_EXSTOP:
2367 case INTEL_PT_EXSTOP_IP:
2368 case INTEL_PT_MWAIT:
2369 case INTEL_PT_PWRE:
2370 case INTEL_PT_PWRX:
2371 case INTEL_PT_BBP:
2372 case INTEL_PT_BIP:
2373 case INTEL_PT_BEP:
2374 case INTEL_PT_BEP_IP:
2375 case INTEL_PT_OVF:
2376 case INTEL_PT_BAD:
2377 case INTEL_PT_TNT:
2378 case INTEL_PT_TIP_PGD:
2379 case INTEL_PT_TIP:
2380 case INTEL_PT_PSB:
2381 case INTEL_PT_TRACESTOP:
2382 case INTEL_PT_CFE:
2383 case INTEL_PT_CFE_IP:
2384 case INTEL_PT_EVD:
2385 default:
2386 return 1;
2387 }
2388
2389 return 0;
2390 }
2391
2392 struct intel_pt_ovf_fup_info {
2393 int max_lookahead;
2394 bool found;
2395 };
2396
2397 /* Lookahead to detect a FUP packet after OVF */
intel_pt_ovf_fup_lookahead_cb(struct intel_pt_pkt_info * pkt_info)2398 static int intel_pt_ovf_fup_lookahead_cb(struct intel_pt_pkt_info *pkt_info)
2399 {
2400 struct intel_pt_ovf_fup_info *data = pkt_info->data;
2401
2402 if (pkt_info->packet.type == INTEL_PT_CYC ||
2403 pkt_info->packet.type == INTEL_PT_MTC ||
2404 pkt_info->packet.type == INTEL_PT_TSC)
2405 return !--(data->max_lookahead);
2406 data->found = pkt_info->packet.type == INTEL_PT_FUP;
2407 return 1;
2408 }
2409
intel_pt_ovf_fup_lookahead(struct intel_pt_decoder * decoder)2410 static bool intel_pt_ovf_fup_lookahead(struct intel_pt_decoder *decoder)
2411 {
2412 struct intel_pt_ovf_fup_info data = {
2413 .max_lookahead = 16,
2414 .found = false,
2415 };
2416
2417 intel_pt_pkt_lookahead(decoder, intel_pt_ovf_fup_lookahead_cb, &data);
2418 return data.found;
2419 }
2420
2421 /* Lookahead and get the TMA packet after TSC */
intel_pt_tma_lookahead_cb(struct intel_pt_pkt_info * pkt_info)2422 static int intel_pt_tma_lookahead_cb(struct intel_pt_pkt_info *pkt_info)
2423 {
2424 struct intel_pt_vm_tsc_info *data = pkt_info->data;
2425
2426 if (pkt_info->packet.type == INTEL_PT_CYC ||
2427 pkt_info->packet.type == INTEL_PT_MTC)
2428 return !--(data->max_lookahead);
2429
2430 if (pkt_info->packet.type == INTEL_PT_TMA) {
2431 data->tma_packet = pkt_info->packet;
2432 data->tma = true;
2433 }
2434 return 1;
2435 }
2436
intel_pt_ctc_to_tsc(struct intel_pt_decoder * decoder,uint64_t ctc)2437 static uint64_t intel_pt_ctc_to_tsc(struct intel_pt_decoder *decoder, uint64_t ctc)
2438 {
2439 if (decoder->tsc_ctc_mult)
2440 return ctc * decoder->tsc_ctc_mult;
2441 else
2442 return multdiv(ctc, decoder->tsc_ctc_ratio_n, decoder->tsc_ctc_ratio_d);
2443 }
2444
intel_pt_calc_expected_tsc(struct intel_pt_decoder * decoder,uint32_t ctc,uint32_t fc,uint64_t last_ctc_timestamp,uint64_t ctc_delta,uint32_t last_ctc)2445 static uint64_t intel_pt_calc_expected_tsc(struct intel_pt_decoder *decoder,
2446 uint32_t ctc,
2447 uint32_t fc,
2448 uint64_t last_ctc_timestamp,
2449 uint64_t ctc_delta,
2450 uint32_t last_ctc)
2451 {
2452 /* Number of CTC ticks from last_ctc_timestamp to last_mtc */
2453 uint64_t last_mtc_ctc = last_ctc + ctc_delta;
2454 /*
2455 * Number of CTC ticks from there until current TMA packet. We would
2456 * expect last_mtc_ctc to be before ctc, but the TSC packet can slip
2457 * past an MTC, so a sign-extended value is used.
2458 */
2459 uint64_t delta = (int16_t)((uint16_t)ctc - (uint16_t)last_mtc_ctc);
2460 /* Total CTC ticks from last_ctc_timestamp to current TMA packet */
2461 uint64_t new_ctc_delta = ctc_delta + delta;
2462 uint64_t expected_tsc;
2463
2464 /*
2465 * Convert CTC ticks to TSC ticks, add the starting point
2466 * (last_ctc_timestamp) and the fast counter from the TMA packet.
2467 */
2468 expected_tsc = last_ctc_timestamp + intel_pt_ctc_to_tsc(decoder, new_ctc_delta) + fc;
2469
2470 if (intel_pt_enable_logging) {
2471 intel_pt_log_x64(last_mtc_ctc);
2472 intel_pt_log_x32(last_ctc);
2473 intel_pt_log_x64(ctc_delta);
2474 intel_pt_log_x64(delta);
2475 intel_pt_log_x32(ctc);
2476 intel_pt_log_x64(new_ctc_delta);
2477 intel_pt_log_x64(last_ctc_timestamp);
2478 intel_pt_log_x32(fc);
2479 intel_pt_log_x64(intel_pt_ctc_to_tsc(decoder, new_ctc_delta));
2480 intel_pt_log_x64(expected_tsc);
2481 }
2482
2483 return expected_tsc;
2484 }
2485
intel_pt_expected_tsc(struct intel_pt_decoder * decoder,struct intel_pt_vm_tsc_info * data)2486 static uint64_t intel_pt_expected_tsc(struct intel_pt_decoder *decoder,
2487 struct intel_pt_vm_tsc_info *data)
2488 {
2489 uint32_t ctc = data->tma_packet.payload;
2490 uint32_t fc = data->tma_packet.count;
2491
2492 return intel_pt_calc_expected_tsc(decoder, ctc, fc,
2493 decoder->ctc_timestamp,
2494 data->ctc_delta, data->last_ctc);
2495 }
2496
intel_pt_translate_vm_tsc(struct intel_pt_decoder * decoder,struct intel_pt_vmcs_info * vmcs_info)2497 static void intel_pt_translate_vm_tsc(struct intel_pt_decoder *decoder,
2498 struct intel_pt_vmcs_info *vmcs_info)
2499 {
2500 uint64_t payload = decoder->packet.payload;
2501
2502 /* VMX adds the TSC Offset, so subtract to get host TSC */
2503 decoder->packet.payload -= vmcs_info->tsc_offset;
2504 /* TSC packet has only 7 bytes */
2505 decoder->packet.payload &= SEVEN_BYTES;
2506
2507 /*
2508 * The buffer is mmapped from the data file, so this also updates the
2509 * data file.
2510 */
2511 if (!decoder->vm_tm_corr_dry_run)
2512 memcpy((void *)decoder->buf + 1, &decoder->packet.payload, 7);
2513
2514 intel_pt_log("Translated VM TSC %#" PRIx64 " -> %#" PRIx64
2515 " VMCS %#" PRIx64 " TSC Offset %#" PRIx64 "\n",
2516 payload, decoder->packet.payload, vmcs_info->vmcs,
2517 vmcs_info->tsc_offset);
2518 }
2519
intel_pt_translate_vm_tsc_offset(struct intel_pt_decoder * decoder,uint64_t tsc_offset)2520 static void intel_pt_translate_vm_tsc_offset(struct intel_pt_decoder *decoder,
2521 uint64_t tsc_offset)
2522 {
2523 struct intel_pt_vmcs_info vmcs_info = {
2524 .vmcs = NO_VMCS,
2525 .tsc_offset = tsc_offset
2526 };
2527
2528 intel_pt_translate_vm_tsc(decoder, &vmcs_info);
2529 }
2530
in_vm(uint64_t pip_payload)2531 static inline bool in_vm(uint64_t pip_payload)
2532 {
2533 return pip_payload & 1;
2534 }
2535
pip_in_vm(struct intel_pt_pkt * pip_packet)2536 static inline bool pip_in_vm(struct intel_pt_pkt *pip_packet)
2537 {
2538 return pip_packet->payload & 1;
2539 }
2540
intel_pt_print_vmcs_info(struct intel_pt_vmcs_info * vmcs_info)2541 static void intel_pt_print_vmcs_info(struct intel_pt_vmcs_info *vmcs_info)
2542 {
2543 p_log("VMCS: %#" PRIx64 " TSC Offset %#" PRIx64,
2544 vmcs_info->vmcs, vmcs_info->tsc_offset);
2545 }
2546
intel_pt_vm_tm_corr_psb(struct intel_pt_decoder * decoder,struct intel_pt_vm_tsc_info * data)2547 static void intel_pt_vm_tm_corr_psb(struct intel_pt_decoder *decoder,
2548 struct intel_pt_vm_tsc_info *data)
2549 {
2550 memset(data, 0, sizeof(*data));
2551 data->ctc_delta = decoder->ctc_delta;
2552 data->last_ctc = decoder->last_ctc;
2553 intel_pt_pkt_lookahead(decoder, intel_pt_vm_psb_lookahead_cb, data);
2554 if (data->tsc && !data->psbend)
2555 p_log("ERROR: PSB without PSBEND");
2556 decoder->in_psb = data->psbend;
2557 }
2558
intel_pt_vm_tm_corr_first_tsc(struct intel_pt_decoder * decoder,struct intel_pt_vm_tsc_info * data,struct intel_pt_vmcs_info * vmcs_info,uint64_t host_tsc)2559 static void intel_pt_vm_tm_corr_first_tsc(struct intel_pt_decoder *decoder,
2560 struct intel_pt_vm_tsc_info *data,
2561 struct intel_pt_vmcs_info *vmcs_info,
2562 uint64_t host_tsc)
2563 {
2564 if (!decoder->in_psb) {
2565 /* Can't happen */
2566 p_log("ERROR: First TSC is not in PSB+");
2567 }
2568
2569 if (data->pip) {
2570 if (pip_in_vm(&data->pip_packet)) { /* Guest */
2571 if (vmcs_info && vmcs_info->tsc_offset) {
2572 intel_pt_translate_vm_tsc(decoder, vmcs_info);
2573 decoder->vm_tm_corr_reliable = true;
2574 } else {
2575 p_log("ERROR: First TSC, unknown TSC Offset");
2576 }
2577 } else { /* Host */
2578 decoder->vm_tm_corr_reliable = true;
2579 }
2580 } else { /* Host or Guest */
2581 decoder->vm_tm_corr_reliable = false;
2582 if (intel_pt_time_in_range(decoder, host_tsc)) {
2583 /* Assume Host */
2584 } else {
2585 /* Assume Guest */
2586 if (vmcs_info && vmcs_info->tsc_offset)
2587 intel_pt_translate_vm_tsc(decoder, vmcs_info);
2588 else
2589 p_log("ERROR: First TSC, no PIP, unknown TSC Offset");
2590 }
2591 }
2592 }
2593
intel_pt_vm_tm_corr_tsc(struct intel_pt_decoder * decoder,struct intel_pt_vm_tsc_info * data)2594 static void intel_pt_vm_tm_corr_tsc(struct intel_pt_decoder *decoder,
2595 struct intel_pt_vm_tsc_info *data)
2596 {
2597 struct intel_pt_vmcs_info *vmcs_info;
2598 uint64_t tsc_offset = 0;
2599 uint64_t vmcs;
2600 bool reliable = true;
2601 uint64_t expected_tsc;
2602 uint64_t host_tsc;
2603 uint64_t ref_timestamp;
2604
2605 bool assign = false;
2606 bool assign_reliable = false;
2607
2608 /* Already have 'data' for the in_psb case */
2609 if (!decoder->in_psb) {
2610 memset(data, 0, sizeof(*data));
2611 data->ctc_delta = decoder->ctc_delta;
2612 data->last_ctc = decoder->last_ctc;
2613 data->max_lookahead = 16;
2614 intel_pt_pkt_lookahead(decoder, intel_pt_tma_lookahead_cb, data);
2615 if (decoder->pge) {
2616 data->pip = true;
2617 data->pip_packet.payload = decoder->pip_payload;
2618 }
2619 }
2620
2621 /* Calculations depend on having TMA packets */
2622 if (!data->tma) {
2623 p_log("ERROR: TSC without TMA");
2624 return;
2625 }
2626
2627 vmcs = data->vmcs ? data->vmcs_packet.payload : decoder->vmcs;
2628 if (vmcs == NO_VMCS)
2629 vmcs = 0;
2630
2631 vmcs_info = decoder->findnew_vmcs_info(decoder->data, vmcs);
2632
2633 ref_timestamp = decoder->timestamp ? decoder->timestamp : decoder->buf_timestamp;
2634 host_tsc = intel_pt_8b_tsc(decoder->packet.payload, ref_timestamp);
2635
2636 if (!decoder->ctc_timestamp) {
2637 intel_pt_vm_tm_corr_first_tsc(decoder, data, vmcs_info, host_tsc);
2638 return;
2639 }
2640
2641 expected_tsc = intel_pt_expected_tsc(decoder, data);
2642
2643 tsc_offset = host_tsc - expected_tsc;
2644
2645 /* Determine if TSC is from Host or Guest */
2646 if (data->pip) {
2647 if (pip_in_vm(&data->pip_packet)) { /* Guest */
2648 if (!vmcs_info) {
2649 /* PIP NR=1 without VMCS cannot happen */
2650 p_log("ERROR: Missing VMCS");
2651 intel_pt_translate_vm_tsc_offset(decoder, tsc_offset);
2652 decoder->vm_tm_corr_reliable = false;
2653 return;
2654 }
2655 } else { /* Host */
2656 decoder->last_reliable_timestamp = host_tsc;
2657 decoder->vm_tm_corr_reliable = true;
2658 return;
2659 }
2660 } else { /* Host or Guest */
2661 reliable = false; /* Host/Guest is a guess, so not reliable */
2662 if (decoder->in_psb) {
2663 if (!tsc_offset)
2664 return; /* Zero TSC Offset, assume Host */
2665 /*
2666 * TSC packet has only 7 bytes of TSC. We have no
2667 * information about the Guest's 8th byte, but it
2668 * doesn't matter because we only need 7 bytes.
2669 * Here, since the 8th byte is unreliable and
2670 * irrelevant, compare only 7 byes.
2671 */
2672 if (vmcs_info &&
2673 (tsc_offset & SEVEN_BYTES) ==
2674 (vmcs_info->tsc_offset & SEVEN_BYTES)) {
2675 /* Same TSC Offset as last VMCS, assume Guest */
2676 goto guest;
2677 }
2678 }
2679 /*
2680 * Check if the host_tsc is within the expected range.
2681 * Note, we could narrow the range more by looking ahead for
2682 * the next host TSC in the same buffer, but we don't bother to
2683 * do that because this is probably good enough.
2684 */
2685 if (host_tsc >= expected_tsc && intel_pt_time_in_range(decoder, host_tsc)) {
2686 /* Within expected range for Host TSC, assume Host */
2687 decoder->vm_tm_corr_reliable = false;
2688 return;
2689 }
2690 }
2691
2692 guest: /* Assuming Guest */
2693
2694 /* Determine whether to assign TSC Offset */
2695 if (vmcs_info && vmcs_info->vmcs) {
2696 if (vmcs_info->tsc_offset && vmcs_info->reliable) {
2697 assign = false;
2698 } else if (decoder->in_psb && data->pip && decoder->vm_tm_corr_reliable &&
2699 decoder->vm_tm_corr_continuous && decoder->vm_tm_corr_same_buf) {
2700 /* Continuous tracing, TSC in a PSB is not a time loss */
2701 assign = true;
2702 assign_reliable = true;
2703 } else if (decoder->in_psb && data->pip && decoder->vm_tm_corr_same_buf) {
2704 /*
2705 * Unlikely to be a time loss TSC in a PSB which is not
2706 * at the start of a buffer.
2707 */
2708 assign = true;
2709 assign_reliable = false;
2710 }
2711 }
2712
2713 /* Record VMCS TSC Offset */
2714 if (assign && (vmcs_info->tsc_offset != tsc_offset ||
2715 vmcs_info->reliable != assign_reliable)) {
2716 bool print = vmcs_info->tsc_offset != tsc_offset;
2717
2718 vmcs_info->tsc_offset = tsc_offset;
2719 vmcs_info->reliable = assign_reliable;
2720 if (print)
2721 intel_pt_print_vmcs_info(vmcs_info);
2722 }
2723
2724 /* Determine what TSC Offset to use */
2725 if (vmcs_info && vmcs_info->tsc_offset) {
2726 if (!vmcs_info->reliable)
2727 reliable = false;
2728 intel_pt_translate_vm_tsc(decoder, vmcs_info);
2729 } else {
2730 reliable = false;
2731 if (vmcs_info) {
2732 if (!vmcs_info->error_printed) {
2733 p_log("ERROR: Unknown TSC Offset for VMCS %#" PRIx64,
2734 vmcs_info->vmcs);
2735 vmcs_info->error_printed = true;
2736 }
2737 } else {
2738 if (intel_pt_print_once(decoder, INTEL_PT_PRT_ONCE_UNK_VMCS))
2739 p_log("ERROR: Unknown VMCS");
2740 }
2741 intel_pt_translate_vm_tsc_offset(decoder, tsc_offset);
2742 }
2743
2744 decoder->vm_tm_corr_reliable = reliable;
2745 }
2746
intel_pt_vm_tm_corr_pebs_tsc(struct intel_pt_decoder * decoder)2747 static void intel_pt_vm_tm_corr_pebs_tsc(struct intel_pt_decoder *decoder)
2748 {
2749 uint64_t host_tsc = decoder->packet.payload;
2750 uint64_t guest_tsc = decoder->packet.payload;
2751 struct intel_pt_vmcs_info *vmcs_info;
2752 uint64_t vmcs;
2753
2754 vmcs = decoder->vmcs;
2755 if (vmcs == NO_VMCS)
2756 vmcs = 0;
2757
2758 vmcs_info = decoder->findnew_vmcs_info(decoder->data, vmcs);
2759
2760 if (decoder->pge) {
2761 if (in_vm(decoder->pip_payload)) { /* Guest */
2762 if (!vmcs_info) {
2763 /* PIP NR=1 without VMCS cannot happen */
2764 p_log("ERROR: Missing VMCS");
2765 }
2766 } else { /* Host */
2767 return;
2768 }
2769 } else { /* Host or Guest */
2770 if (intel_pt_time_in_range(decoder, host_tsc)) {
2771 /* Within expected range for Host TSC, assume Host */
2772 return;
2773 }
2774 }
2775
2776 if (vmcs_info) {
2777 /* Translate Guest TSC to Host TSC */
2778 host_tsc = ((guest_tsc & SEVEN_BYTES) - vmcs_info->tsc_offset) & SEVEN_BYTES;
2779 host_tsc = intel_pt_8b_tsc(host_tsc, decoder->timestamp);
2780 intel_pt_log("Translated VM TSC %#" PRIx64 " -> %#" PRIx64
2781 " VMCS %#" PRIx64 " TSC Offset %#" PRIx64 "\n",
2782 guest_tsc, host_tsc, vmcs_info->vmcs,
2783 vmcs_info->tsc_offset);
2784 if (!intel_pt_time_in_range(decoder, host_tsc) &&
2785 intel_pt_print_once(decoder, INTEL_PT_PRT_ONCE_ERANGE))
2786 p_log("Timestamp out of range");
2787 } else {
2788 if (intel_pt_print_once(decoder, INTEL_PT_PRT_ONCE_UNK_VMCS))
2789 p_log("ERROR: Unknown VMCS");
2790 host_tsc = decoder->timestamp;
2791 }
2792
2793 decoder->packet.payload = host_tsc;
2794
2795 if (!decoder->vm_tm_corr_dry_run)
2796 memcpy((void *)decoder->buf + 1, &host_tsc, 8);
2797 }
2798
intel_pt_vm_time_correlation(struct intel_pt_decoder * decoder)2799 static int intel_pt_vm_time_correlation(struct intel_pt_decoder *decoder)
2800 {
2801 struct intel_pt_vm_tsc_info data = { .psbend = false };
2802 bool pge;
2803 int err;
2804
2805 if (decoder->in_psb)
2806 intel_pt_vm_tm_corr_psb(decoder, &data);
2807
2808 while (1) {
2809 err = intel_pt_get_next_packet(decoder);
2810 if (err == -ENOLINK)
2811 continue;
2812 if (err)
2813 break;
2814
2815 switch (decoder->packet.type) {
2816 case INTEL_PT_TIP_PGD:
2817 decoder->pge = false;
2818 decoder->vm_tm_corr_continuous = false;
2819 break;
2820
2821 case INTEL_PT_TNT:
2822 case INTEL_PT_TIP:
2823 case INTEL_PT_TIP_PGE:
2824 decoder->pge = true;
2825 break;
2826
2827 case INTEL_PT_OVF:
2828 decoder->in_psb = false;
2829 pge = decoder->pge;
2830 decoder->pge = intel_pt_ovf_fup_lookahead(decoder);
2831 if (pge != decoder->pge)
2832 intel_pt_log("Surprising PGE change in OVF!");
2833 if (!decoder->pge)
2834 decoder->vm_tm_corr_continuous = false;
2835 break;
2836
2837 case INTEL_PT_FUP:
2838 if (decoder->in_psb)
2839 decoder->pge = true;
2840 break;
2841
2842 case INTEL_PT_TRACESTOP:
2843 decoder->pge = false;
2844 decoder->vm_tm_corr_continuous = false;
2845 decoder->have_tma = false;
2846 break;
2847
2848 case INTEL_PT_PSB:
2849 intel_pt_vm_tm_corr_psb(decoder, &data);
2850 break;
2851
2852 case INTEL_PT_PIP:
2853 decoder->pip_payload = decoder->packet.payload;
2854 break;
2855
2856 case INTEL_PT_MTC:
2857 intel_pt_calc_mtc_timestamp(decoder);
2858 break;
2859
2860 case INTEL_PT_TSC:
2861 intel_pt_vm_tm_corr_tsc(decoder, &data);
2862 intel_pt_calc_tsc_timestamp(decoder);
2863 decoder->vm_tm_corr_same_buf = true;
2864 decoder->vm_tm_corr_continuous = decoder->pge;
2865 break;
2866
2867 case INTEL_PT_TMA:
2868 intel_pt_calc_tma(decoder);
2869 break;
2870
2871 case INTEL_PT_CYC:
2872 intel_pt_calc_cyc_timestamp(decoder);
2873 break;
2874
2875 case INTEL_PT_CBR:
2876 intel_pt_calc_cbr(decoder);
2877 break;
2878
2879 case INTEL_PT_PSBEND:
2880 decoder->in_psb = false;
2881 data.psbend = false;
2882 break;
2883
2884 case INTEL_PT_VMCS:
2885 if (decoder->packet.payload != NO_VMCS)
2886 decoder->vmcs = decoder->packet.payload;
2887 break;
2888
2889 case INTEL_PT_BBP:
2890 decoder->blk_type = decoder->packet.payload;
2891 break;
2892
2893 case INTEL_PT_BIP:
2894 if (decoder->blk_type == INTEL_PT_PEBS_BASIC &&
2895 decoder->packet.count == 2)
2896 intel_pt_vm_tm_corr_pebs_tsc(decoder);
2897 break;
2898
2899 case INTEL_PT_BEP:
2900 case INTEL_PT_BEP_IP:
2901 decoder->blk_type = 0;
2902 break;
2903
2904 case INTEL_PT_CFE:
2905 case INTEL_PT_CFE_IP:
2906 case INTEL_PT_EVD:
2907 case INTEL_PT_MODE_EXEC:
2908 case INTEL_PT_MODE_TSX:
2909 case INTEL_PT_MNT:
2910 case INTEL_PT_PAD:
2911 case INTEL_PT_PTWRITE_IP:
2912 case INTEL_PT_PTWRITE:
2913 case INTEL_PT_MWAIT:
2914 case INTEL_PT_PWRE:
2915 case INTEL_PT_EXSTOP_IP:
2916 case INTEL_PT_EXSTOP:
2917 case INTEL_PT_PWRX:
2918 case INTEL_PT_BAD: /* Does not happen */
2919 default:
2920 break;
2921 }
2922 }
2923
2924 return err;
2925 }
2926
2927 #define HOP_PROCESS 0
2928 #define HOP_IGNORE 1
2929 #define HOP_RETURN 2
2930 #define HOP_AGAIN 3
2931
2932 static int intel_pt_scan_for_psb(struct intel_pt_decoder *decoder);
2933
2934 /* Hop mode: Ignore TNT, do not walk code, but get ip from FUPs and TIPs */
intel_pt_hop_trace(struct intel_pt_decoder * decoder,bool * no_tip,int * err)2935 static int intel_pt_hop_trace(struct intel_pt_decoder *decoder, bool *no_tip, int *err)
2936 {
2937 *err = 0;
2938
2939 /* Leap from PSB to PSB, getting ip from FUP within PSB+ */
2940 if (decoder->leap && !decoder->in_psb && decoder->packet.type != INTEL_PT_PSB) {
2941 *err = intel_pt_scan_for_psb(decoder);
2942 if (*err)
2943 return HOP_RETURN;
2944 }
2945
2946 switch (decoder->packet.type) {
2947 case INTEL_PT_TNT:
2948 return HOP_IGNORE;
2949
2950 case INTEL_PT_TIP_PGD:
2951 decoder->pge = false;
2952 if (!decoder->packet.count) {
2953 intel_pt_set_nr(decoder);
2954 return HOP_IGNORE;
2955 }
2956 intel_pt_set_ip(decoder);
2957 decoder->state.type |= INTEL_PT_TRACE_END;
2958 decoder->state.from_ip = 0;
2959 decoder->state.to_ip = decoder->ip;
2960 intel_pt_update_nr(decoder);
2961 return HOP_RETURN;
2962
2963 case INTEL_PT_TIP:
2964 if (!decoder->packet.count) {
2965 intel_pt_set_nr(decoder);
2966 return HOP_IGNORE;
2967 }
2968 intel_pt_set_ip(decoder);
2969 decoder->state.type = INTEL_PT_INSTRUCTION;
2970 decoder->state.from_ip = decoder->ip;
2971 decoder->state.to_ip = 0;
2972 intel_pt_update_nr(decoder);
2973 intel_pt_sample_iflag_chg(decoder);
2974 return HOP_RETURN;
2975
2976 case INTEL_PT_FUP:
2977 if (!decoder->packet.count)
2978 return HOP_IGNORE;
2979 intel_pt_set_ip(decoder);
2980 if (decoder->set_fup_mwait || decoder->set_fup_pwre)
2981 *no_tip = true;
2982 if (!decoder->branch_enable || !decoder->pge)
2983 *no_tip = true;
2984 if (*no_tip) {
2985 decoder->state.type = INTEL_PT_INSTRUCTION;
2986 decoder->state.from_ip = decoder->ip;
2987 decoder->state.to_ip = 0;
2988 intel_pt_fup_event(decoder, *no_tip);
2989 return HOP_RETURN;
2990 }
2991 intel_pt_fup_event(decoder, *no_tip);
2992 decoder->state.type |= INTEL_PT_INSTRUCTION | INTEL_PT_BRANCH;
2993 *err = intel_pt_walk_fup_tip(decoder);
2994 if (!*err && decoder->state.to_ip)
2995 decoder->pkt_state = INTEL_PT_STATE_RESAMPLE;
2996 return HOP_RETURN;
2997
2998 case INTEL_PT_PSB:
2999 decoder->state.psb_offset = decoder->pos;
3000 decoder->psb_ip = 0;
3001 decoder->last_ip = 0;
3002 decoder->have_last_ip = true;
3003 *err = intel_pt_walk_psbend(decoder);
3004 if (*err == -EAGAIN)
3005 return HOP_AGAIN;
3006 if (*err)
3007 return HOP_RETURN;
3008 decoder->state.type = INTEL_PT_PSB_EVT;
3009 if (decoder->psb_ip) {
3010 decoder->state.type |= INTEL_PT_INSTRUCTION;
3011 decoder->ip = decoder->psb_ip;
3012 }
3013 decoder->state.from_ip = decoder->psb_ip;
3014 decoder->state.to_ip = 0;
3015 return HOP_RETURN;
3016
3017 case INTEL_PT_BAD:
3018 case INTEL_PT_PAD:
3019 case INTEL_PT_TIP_PGE:
3020 case INTEL_PT_TSC:
3021 case INTEL_PT_TMA:
3022 case INTEL_PT_MODE_EXEC:
3023 case INTEL_PT_MODE_TSX:
3024 case INTEL_PT_MTC:
3025 case INTEL_PT_CYC:
3026 case INTEL_PT_VMCS:
3027 case INTEL_PT_PSBEND:
3028 case INTEL_PT_CBR:
3029 case INTEL_PT_TRACESTOP:
3030 case INTEL_PT_PIP:
3031 case INTEL_PT_OVF:
3032 case INTEL_PT_MNT:
3033 case INTEL_PT_PTWRITE:
3034 case INTEL_PT_PTWRITE_IP:
3035 case INTEL_PT_EXSTOP:
3036 case INTEL_PT_EXSTOP_IP:
3037 case INTEL_PT_MWAIT:
3038 case INTEL_PT_PWRE:
3039 case INTEL_PT_PWRX:
3040 case INTEL_PT_BBP:
3041 case INTEL_PT_BIP:
3042 case INTEL_PT_BEP:
3043 case INTEL_PT_BEP_IP:
3044 case INTEL_PT_CFE:
3045 case INTEL_PT_CFE_IP:
3046 case INTEL_PT_EVD:
3047 default:
3048 return HOP_PROCESS;
3049 }
3050 }
3051
3052 struct intel_pt_psb_info {
3053 struct intel_pt_pkt fup_packet;
3054 bool fup;
3055 int after_psbend;
3056 };
3057
3058 /* Lookahead and get the FUP packet from PSB+ */
intel_pt_psb_lookahead_cb(struct intel_pt_pkt_info * pkt_info)3059 static int intel_pt_psb_lookahead_cb(struct intel_pt_pkt_info *pkt_info)
3060 {
3061 struct intel_pt_psb_info *data = pkt_info->data;
3062
3063 switch (pkt_info->packet.type) {
3064 case INTEL_PT_PAD:
3065 case INTEL_PT_MNT:
3066 case INTEL_PT_TSC:
3067 case INTEL_PT_TMA:
3068 case INTEL_PT_MODE_EXEC:
3069 case INTEL_PT_MODE_TSX:
3070 case INTEL_PT_MTC:
3071 case INTEL_PT_CYC:
3072 case INTEL_PT_VMCS:
3073 case INTEL_PT_CBR:
3074 case INTEL_PT_PIP:
3075 if (data->after_psbend) {
3076 data->after_psbend -= 1;
3077 if (!data->after_psbend)
3078 return 1;
3079 }
3080 break;
3081
3082 case INTEL_PT_FUP:
3083 if (data->after_psbend)
3084 return 1;
3085 if (data->fup || pkt_info->packet.count == 0)
3086 return 1;
3087 data->fup_packet = pkt_info->packet;
3088 data->fup = true;
3089 break;
3090
3091 case INTEL_PT_PSBEND:
3092 if (!data->fup)
3093 return 1;
3094 /* Keep going to check for a TIP.PGE */
3095 data->after_psbend = 6;
3096 break;
3097
3098 case INTEL_PT_TIP_PGE:
3099 /* Ignore FUP in PSB+ if followed by TIP.PGE */
3100 if (data->after_psbend)
3101 data->fup = false;
3102 return 1;
3103
3104 case INTEL_PT_PTWRITE:
3105 case INTEL_PT_PTWRITE_IP:
3106 case INTEL_PT_EXSTOP:
3107 case INTEL_PT_EXSTOP_IP:
3108 case INTEL_PT_MWAIT:
3109 case INTEL_PT_PWRE:
3110 case INTEL_PT_PWRX:
3111 case INTEL_PT_BBP:
3112 case INTEL_PT_BIP:
3113 case INTEL_PT_BEP:
3114 case INTEL_PT_BEP_IP:
3115 case INTEL_PT_CFE:
3116 case INTEL_PT_CFE_IP:
3117 case INTEL_PT_EVD:
3118 if (data->after_psbend) {
3119 data->after_psbend -= 1;
3120 if (!data->after_psbend)
3121 return 1;
3122 break;
3123 }
3124 return 1;
3125
3126 case INTEL_PT_OVF:
3127 case INTEL_PT_BAD:
3128 case INTEL_PT_TNT:
3129 case INTEL_PT_TIP_PGD:
3130 case INTEL_PT_TIP:
3131 case INTEL_PT_PSB:
3132 case INTEL_PT_TRACESTOP:
3133 default:
3134 return 1;
3135 }
3136
3137 return 0;
3138 }
3139
intel_pt_psb(struct intel_pt_decoder * decoder)3140 static int intel_pt_psb(struct intel_pt_decoder *decoder)
3141 {
3142 int err;
3143
3144 decoder->last_ip = 0;
3145 decoder->psb_ip = 0;
3146 decoder->have_last_ip = true;
3147 intel_pt_clear_stack(&decoder->stack);
3148 err = intel_pt_walk_psbend(decoder);
3149 if (err)
3150 return err;
3151 decoder->state.type = INTEL_PT_PSB_EVT;
3152 decoder->state.from_ip = decoder->psb_ip;
3153 decoder->state.to_ip = 0;
3154 return 0;
3155 }
3156
intel_pt_fup_in_psb(struct intel_pt_decoder * decoder)3157 static int intel_pt_fup_in_psb(struct intel_pt_decoder *decoder)
3158 {
3159 int err;
3160
3161 if (decoder->ip != decoder->last_ip) {
3162 err = intel_pt_walk_fup(decoder);
3163 if (!err || err != -EAGAIN)
3164 return err;
3165 }
3166
3167 decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
3168 err = intel_pt_psb(decoder);
3169 if (err) {
3170 decoder->pkt_state = INTEL_PT_STATE_ERR3;
3171 return -ENOENT;
3172 }
3173
3174 return 0;
3175 }
3176
intel_pt_psb_with_fup(struct intel_pt_decoder * decoder,int * err)3177 static bool intel_pt_psb_with_fup(struct intel_pt_decoder *decoder, int *err)
3178 {
3179 struct intel_pt_psb_info data = { .fup = false };
3180
3181 if (!decoder->branch_enable)
3182 return false;
3183
3184 intel_pt_pkt_lookahead(decoder, intel_pt_psb_lookahead_cb, &data);
3185 if (!data.fup)
3186 return false;
3187
3188 decoder->packet = data.fup_packet;
3189 intel_pt_set_last_ip(decoder);
3190 decoder->pkt_state = INTEL_PT_STATE_FUP_IN_PSB;
3191
3192 *err = intel_pt_fup_in_psb(decoder);
3193
3194 return true;
3195 }
3196
intel_pt_walk_trace(struct intel_pt_decoder * decoder)3197 static int intel_pt_walk_trace(struct intel_pt_decoder *decoder)
3198 {
3199 int last_packet_type = INTEL_PT_PAD;
3200 bool no_tip = false;
3201 int err;
3202
3203 while (1) {
3204 err = intel_pt_get_next_packet(decoder);
3205 if (err)
3206 return err;
3207 next:
3208 err = 0;
3209 if (decoder->cyc_threshold) {
3210 if (decoder->sample_cyc && last_packet_type != INTEL_PT_CYC)
3211 decoder->sample_cyc = false;
3212 last_packet_type = decoder->packet.type;
3213 }
3214
3215 if (decoder->hop) {
3216 switch (intel_pt_hop_trace(decoder, &no_tip, &err)) {
3217 case HOP_IGNORE:
3218 continue;
3219 case HOP_RETURN:
3220 return err;
3221 case HOP_AGAIN:
3222 goto next;
3223 default:
3224 break;
3225 }
3226 }
3227
3228 switch (decoder->packet.type) {
3229 case INTEL_PT_TNT:
3230 if (!decoder->packet.count)
3231 break;
3232 decoder->tnt = decoder->packet;
3233 decoder->pkt_state = INTEL_PT_STATE_TNT;
3234 err = intel_pt_walk_tnt(decoder);
3235 if (err == -EAGAIN)
3236 break;
3237 return err;
3238
3239 case INTEL_PT_TIP_PGD:
3240 if (decoder->packet.count != 0)
3241 intel_pt_set_last_ip(decoder);
3242 decoder->pkt_state = INTEL_PT_STATE_TIP_PGD;
3243 return intel_pt_walk_tip(decoder);
3244
3245 case INTEL_PT_TIP_PGE: {
3246 decoder->pge = true;
3247 decoder->overflow = false;
3248 intel_pt_mtc_cyc_cnt_pge(decoder);
3249 intel_pt_set_nr(decoder);
3250 if (decoder->packet.count == 0) {
3251 intel_pt_log_at("Skipping zero TIP.PGE",
3252 decoder->pos);
3253 break;
3254 }
3255 intel_pt_sample_iflag_chg(decoder);
3256 intel_pt_set_ip(decoder);
3257 decoder->state.from_ip = 0;
3258 decoder->state.to_ip = decoder->ip;
3259 decoder->state.type |= INTEL_PT_TRACE_BEGIN;
3260 /*
3261 * In hop mode, resample to get the to_ip as an
3262 * "instruction" sample.
3263 */
3264 if (decoder->hop)
3265 decoder->pkt_state = INTEL_PT_STATE_RESAMPLE;
3266 return 0;
3267 }
3268
3269 case INTEL_PT_OVF:
3270 return intel_pt_overflow(decoder);
3271
3272 case INTEL_PT_TIP:
3273 if (decoder->packet.count != 0)
3274 intel_pt_set_last_ip(decoder);
3275 decoder->pkt_state = INTEL_PT_STATE_TIP;
3276 return intel_pt_walk_tip(decoder);
3277
3278 case INTEL_PT_FUP:
3279 if (decoder->packet.count == 0) {
3280 intel_pt_log_at("Skipping zero FUP",
3281 decoder->pos);
3282 no_tip = false;
3283 break;
3284 }
3285 intel_pt_set_last_ip(decoder);
3286 if (!decoder->branch_enable || !decoder->pge) {
3287 decoder->ip = decoder->last_ip;
3288 if (intel_pt_fup_event(decoder, no_tip))
3289 return 0;
3290 no_tip = false;
3291 break;
3292 }
3293 if (decoder->set_fup_mwait)
3294 no_tip = true;
3295 if (no_tip)
3296 decoder->pkt_state = INTEL_PT_STATE_FUP_NO_TIP;
3297 else
3298 decoder->pkt_state = INTEL_PT_STATE_FUP;
3299 err = intel_pt_walk_fup(decoder);
3300 if (err != -EAGAIN)
3301 return err;
3302 if (no_tip) {
3303 no_tip = false;
3304 break;
3305 }
3306 return intel_pt_walk_fup_tip(decoder);
3307
3308 case INTEL_PT_TRACESTOP:
3309 decoder->pge = false;
3310 decoder->continuous_period = false;
3311 intel_pt_clear_tx_flags(decoder);
3312 decoder->have_tma = false;
3313 break;
3314
3315 case INTEL_PT_PSB:
3316 decoder->state.psb_offset = decoder->pos;
3317 decoder->psb_ip = 0;
3318 if (intel_pt_psb_with_fup(decoder, &err))
3319 return err;
3320 err = intel_pt_psb(decoder);
3321 if (err == -EAGAIN)
3322 goto next;
3323 return err;
3324
3325 case INTEL_PT_PIP:
3326 intel_pt_update_pip(decoder);
3327 break;
3328
3329 case INTEL_PT_MTC:
3330 intel_pt_calc_mtc_timestamp(decoder);
3331 if (decoder->period_type != INTEL_PT_PERIOD_MTC)
3332 break;
3333 /*
3334 * Ensure that there has been an instruction since the
3335 * last MTC.
3336 */
3337 if (!decoder->mtc_insn)
3338 break;
3339 decoder->mtc_insn = false;
3340 /* Ensure that there is a timestamp */
3341 if (!decoder->timestamp)
3342 break;
3343 decoder->state.type = INTEL_PT_INSTRUCTION;
3344 decoder->state.from_ip = decoder->ip;
3345 decoder->state.to_ip = 0;
3346 decoder->mtc_insn = false;
3347 return 0;
3348
3349 case INTEL_PT_TSC:
3350 intel_pt_calc_tsc_timestamp(decoder);
3351 break;
3352
3353 case INTEL_PT_TMA:
3354 intel_pt_calc_tma(decoder);
3355 break;
3356
3357 case INTEL_PT_CYC:
3358 intel_pt_calc_cyc_timestamp(decoder);
3359 break;
3360
3361 case INTEL_PT_CBR:
3362 intel_pt_calc_cbr(decoder);
3363 if (decoder->cbr != decoder->cbr_seen) {
3364 decoder->state.type = 0;
3365 return 0;
3366 }
3367 break;
3368
3369 case INTEL_PT_MODE_EXEC:
3370 intel_pt_mode_exec(decoder);
3371 err = intel_pt_get_next_packet(decoder);
3372 if (err)
3373 return err;
3374 if (decoder->packet.type == INTEL_PT_FUP) {
3375 decoder->set_fup_mode_exec = true;
3376 no_tip = true;
3377 }
3378 goto next;
3379
3380 case INTEL_PT_MODE_TSX:
3381 /* MODE_TSX need not be followed by FUP */
3382 if (!decoder->pge || decoder->in_psb) {
3383 intel_pt_update_in_tx(decoder);
3384 break;
3385 }
3386 err = intel_pt_mode_tsx(decoder, &no_tip);
3387 if (err)
3388 return err;
3389 goto next;
3390
3391 case INTEL_PT_BAD: /* Does not happen */
3392 return intel_pt_bug(decoder);
3393
3394 case INTEL_PT_PSBEND:
3395 case INTEL_PT_VMCS:
3396 case INTEL_PT_MNT:
3397 case INTEL_PT_PAD:
3398 break;
3399
3400 case INTEL_PT_PTWRITE_IP:
3401 decoder->fup_ptw_payload = decoder->packet.payload;
3402 err = intel_pt_get_next_packet(decoder);
3403 if (err)
3404 return err;
3405 if (decoder->packet.type == INTEL_PT_FUP) {
3406 decoder->set_fup_ptw = true;
3407 no_tip = true;
3408 } else {
3409 intel_pt_log_at("ERROR: Missing FUP after PTWRITE",
3410 decoder->pos);
3411 }
3412 goto next;
3413
3414 case INTEL_PT_PTWRITE:
3415 decoder->state.type = INTEL_PT_PTW;
3416 decoder->state.from_ip = decoder->ip;
3417 decoder->state.to_ip = 0;
3418 decoder->state.ptw_payload = decoder->packet.payload;
3419 return 0;
3420
3421 case INTEL_PT_MWAIT:
3422 decoder->fup_mwait_payload = decoder->packet.payload;
3423 decoder->set_fup_mwait = true;
3424 break;
3425
3426 case INTEL_PT_PWRE:
3427 if (decoder->set_fup_mwait) {
3428 decoder->fup_pwre_payload =
3429 decoder->packet.payload;
3430 decoder->set_fup_pwre = true;
3431 break;
3432 }
3433 decoder->state.type = INTEL_PT_PWR_ENTRY;
3434 decoder->state.from_ip = decoder->ip;
3435 decoder->state.to_ip = 0;
3436 decoder->state.pwrx_payload = decoder->packet.payload;
3437 return 0;
3438
3439 case INTEL_PT_EXSTOP_IP:
3440 err = intel_pt_get_next_packet(decoder);
3441 if (err)
3442 return err;
3443 if (decoder->packet.type == INTEL_PT_FUP) {
3444 decoder->set_fup_exstop = true;
3445 no_tip = true;
3446 } else {
3447 intel_pt_log_at("ERROR: Missing FUP after EXSTOP",
3448 decoder->pos);
3449 }
3450 goto next;
3451
3452 case INTEL_PT_EXSTOP:
3453 decoder->state.type = INTEL_PT_EX_STOP;
3454 decoder->state.from_ip = decoder->ip;
3455 decoder->state.to_ip = 0;
3456 return 0;
3457
3458 case INTEL_PT_PWRX:
3459 decoder->state.type = INTEL_PT_PWR_EXIT;
3460 decoder->state.from_ip = decoder->ip;
3461 decoder->state.to_ip = 0;
3462 decoder->state.pwrx_payload = decoder->packet.payload;
3463 return 0;
3464
3465 case INTEL_PT_BBP:
3466 intel_pt_bbp(decoder);
3467 break;
3468
3469 case INTEL_PT_BIP:
3470 intel_pt_bip(decoder);
3471 break;
3472
3473 case INTEL_PT_BEP:
3474 decoder->state.type = INTEL_PT_BLK_ITEMS;
3475 decoder->state.from_ip = decoder->ip;
3476 decoder->state.to_ip = 0;
3477 return 0;
3478
3479 case INTEL_PT_BEP_IP:
3480 err = intel_pt_get_next_packet(decoder);
3481 if (err)
3482 return err;
3483 if (decoder->packet.type == INTEL_PT_FUP) {
3484 decoder->set_fup_bep = true;
3485 no_tip = true;
3486 } else {
3487 intel_pt_log_at("ERROR: Missing FUP after BEP",
3488 decoder->pos);
3489 }
3490 goto next;
3491
3492 case INTEL_PT_CFE:
3493 decoder->fup_cfe_pkt = decoder->packet;
3494 decoder->set_fup_cfe = true;
3495 if (!decoder->pge) {
3496 intel_pt_fup_event(decoder, true);
3497 return 0;
3498 }
3499 break;
3500
3501 case INTEL_PT_CFE_IP:
3502 decoder->fup_cfe_pkt = decoder->packet;
3503 err = intel_pt_get_next_packet(decoder);
3504 if (err)
3505 return err;
3506 if (decoder->packet.type == INTEL_PT_FUP) {
3507 decoder->set_fup_cfe_ip = true;
3508 no_tip = true;
3509 } else {
3510 intel_pt_log_at("ERROR: Missing FUP after CFE",
3511 decoder->pos);
3512 }
3513 goto next;
3514
3515 case INTEL_PT_EVD:
3516 err = intel_pt_evd(decoder);
3517 if (err)
3518 return err;
3519 break;
3520
3521 default:
3522 return intel_pt_bug(decoder);
3523 }
3524 }
3525 }
3526
intel_pt_have_ip(struct intel_pt_decoder * decoder)3527 static inline bool intel_pt_have_ip(struct intel_pt_decoder *decoder)
3528 {
3529 return decoder->packet.count &&
3530 (decoder->have_last_ip || decoder->packet.count == 3 ||
3531 decoder->packet.count == 6);
3532 }
3533
3534 /* Walk PSB+ packets to get in sync. */
intel_pt_walk_psb(struct intel_pt_decoder * decoder)3535 static int intel_pt_walk_psb(struct intel_pt_decoder *decoder)
3536 {
3537 int err;
3538
3539 decoder->in_psb = true;
3540
3541 while (1) {
3542 err = intel_pt_get_next_packet(decoder);
3543 if (err)
3544 goto out;
3545
3546 switch (decoder->packet.type) {
3547 case INTEL_PT_TIP_PGD:
3548 decoder->continuous_period = false;
3549 fallthrough;
3550 case INTEL_PT_TIP_PGE:
3551 case INTEL_PT_TIP:
3552 case INTEL_PT_PTWRITE:
3553 case INTEL_PT_PTWRITE_IP:
3554 case INTEL_PT_EXSTOP:
3555 case INTEL_PT_EXSTOP_IP:
3556 case INTEL_PT_MWAIT:
3557 case INTEL_PT_PWRE:
3558 case INTEL_PT_PWRX:
3559 case INTEL_PT_BBP:
3560 case INTEL_PT_BIP:
3561 case INTEL_PT_BEP:
3562 case INTEL_PT_BEP_IP:
3563 case INTEL_PT_CFE:
3564 case INTEL_PT_CFE_IP:
3565 case INTEL_PT_EVD:
3566 intel_pt_log("ERROR: Unexpected packet\n");
3567 err = -ENOENT;
3568 goto out;
3569
3570 case INTEL_PT_FUP:
3571 decoder->pge = true;
3572 if (intel_pt_have_ip(decoder)) {
3573 uint64_t current_ip = decoder->ip;
3574
3575 intel_pt_set_ip(decoder);
3576 decoder->psb_ip = decoder->ip;
3577 if (current_ip)
3578 intel_pt_log_to("Setting IP",
3579 decoder->ip);
3580 }
3581 break;
3582
3583 case INTEL_PT_MTC:
3584 intel_pt_calc_mtc_timestamp(decoder);
3585 break;
3586
3587 case INTEL_PT_TSC:
3588 intel_pt_calc_tsc_timestamp(decoder);
3589 break;
3590
3591 case INTEL_PT_TMA:
3592 intel_pt_calc_tma(decoder);
3593 break;
3594
3595 case INTEL_PT_CYC:
3596 intel_pt_calc_cyc_timestamp(decoder);
3597 break;
3598
3599 case INTEL_PT_CBR:
3600 intel_pt_calc_cbr(decoder);
3601 break;
3602
3603 case INTEL_PT_PIP:
3604 intel_pt_set_pip(decoder);
3605 break;
3606
3607 case INTEL_PT_MODE_EXEC:
3608 intel_pt_mode_exec_status(decoder);
3609 break;
3610
3611 case INTEL_PT_MODE_TSX:
3612 intel_pt_update_in_tx(decoder);
3613 break;
3614
3615 case INTEL_PT_TRACESTOP:
3616 decoder->pge = false;
3617 decoder->continuous_period = false;
3618 intel_pt_clear_tx_flags(decoder);
3619 fallthrough;
3620
3621 case INTEL_PT_TNT:
3622 decoder->have_tma = false;
3623 intel_pt_log("ERROR: Unexpected packet\n");
3624 if (decoder->ip)
3625 decoder->pkt_state = INTEL_PT_STATE_ERR4;
3626 else
3627 decoder->pkt_state = INTEL_PT_STATE_ERR3;
3628 err = -ENOENT;
3629 goto out;
3630
3631 case INTEL_PT_BAD: /* Does not happen */
3632 err = intel_pt_bug(decoder);
3633 goto out;
3634
3635 case INTEL_PT_OVF:
3636 err = intel_pt_overflow(decoder);
3637 goto out;
3638
3639 case INTEL_PT_PSBEND:
3640 err = 0;
3641 goto out;
3642
3643 case INTEL_PT_PSB:
3644 case INTEL_PT_VMCS:
3645 case INTEL_PT_MNT:
3646 case INTEL_PT_PAD:
3647 default:
3648 break;
3649 }
3650 }
3651 out:
3652 decoder->in_psb = false;
3653
3654 return err;
3655 }
3656
intel_pt_walk_to_ip(struct intel_pt_decoder * decoder)3657 static int intel_pt_walk_to_ip(struct intel_pt_decoder *decoder)
3658 {
3659 int err;
3660
3661 while (1) {
3662 err = intel_pt_get_next_packet(decoder);
3663 if (err)
3664 return err;
3665
3666 switch (decoder->packet.type) {
3667 case INTEL_PT_TIP_PGD:
3668 decoder->continuous_period = false;
3669 decoder->pge = false;
3670 if (intel_pt_have_ip(decoder))
3671 intel_pt_set_ip(decoder);
3672 if (!decoder->ip)
3673 break;
3674 decoder->state.type |= INTEL_PT_TRACE_END;
3675 return 0;
3676
3677 case INTEL_PT_TIP_PGE:
3678 decoder->pge = true;
3679 intel_pt_mtc_cyc_cnt_pge(decoder);
3680 if (intel_pt_have_ip(decoder))
3681 intel_pt_set_ip(decoder);
3682 if (!decoder->ip)
3683 break;
3684 decoder->state.type |= INTEL_PT_TRACE_BEGIN;
3685 return 0;
3686
3687 case INTEL_PT_TIP:
3688 decoder->pge = true;
3689 if (intel_pt_have_ip(decoder))
3690 intel_pt_set_ip(decoder);
3691 if (!decoder->ip)
3692 break;
3693 return 0;
3694
3695 case INTEL_PT_FUP:
3696 if (intel_pt_have_ip(decoder))
3697 intel_pt_set_ip(decoder);
3698 if (decoder->ip)
3699 return 0;
3700 break;
3701
3702 case INTEL_PT_MTC:
3703 intel_pt_calc_mtc_timestamp(decoder);
3704 break;
3705
3706 case INTEL_PT_TSC:
3707 intel_pt_calc_tsc_timestamp(decoder);
3708 break;
3709
3710 case INTEL_PT_TMA:
3711 intel_pt_calc_tma(decoder);
3712 break;
3713
3714 case INTEL_PT_CYC:
3715 intel_pt_calc_cyc_timestamp(decoder);
3716 break;
3717
3718 case INTEL_PT_CBR:
3719 intel_pt_calc_cbr(decoder);
3720 break;
3721
3722 case INTEL_PT_PIP:
3723 intel_pt_set_pip(decoder);
3724 break;
3725
3726 case INTEL_PT_MODE_EXEC:
3727 intel_pt_mode_exec_status(decoder);
3728 break;
3729
3730 case INTEL_PT_MODE_TSX:
3731 intel_pt_update_in_tx(decoder);
3732 break;
3733
3734 case INTEL_PT_OVF:
3735 return intel_pt_overflow(decoder);
3736
3737 case INTEL_PT_BAD: /* Does not happen */
3738 return intel_pt_bug(decoder);
3739
3740 case INTEL_PT_TRACESTOP:
3741 decoder->pge = false;
3742 decoder->continuous_period = false;
3743 intel_pt_clear_tx_flags(decoder);
3744 decoder->have_tma = false;
3745 break;
3746
3747 case INTEL_PT_PSB:
3748 decoder->state.psb_offset = decoder->pos;
3749 decoder->psb_ip = 0;
3750 decoder->last_ip = 0;
3751 decoder->have_last_ip = true;
3752 intel_pt_clear_stack(&decoder->stack);
3753 err = intel_pt_walk_psb(decoder);
3754 if (err)
3755 return err;
3756 decoder->state.type = INTEL_PT_PSB_EVT;
3757 decoder->state.from_ip = decoder->psb_ip;
3758 decoder->state.to_ip = 0;
3759 return 0;
3760
3761 case INTEL_PT_TNT:
3762 case INTEL_PT_PSBEND:
3763 case INTEL_PT_VMCS:
3764 case INTEL_PT_MNT:
3765 case INTEL_PT_PAD:
3766 case INTEL_PT_PTWRITE:
3767 case INTEL_PT_PTWRITE_IP:
3768 case INTEL_PT_EXSTOP:
3769 case INTEL_PT_EXSTOP_IP:
3770 case INTEL_PT_MWAIT:
3771 case INTEL_PT_PWRE:
3772 case INTEL_PT_PWRX:
3773 case INTEL_PT_BBP:
3774 case INTEL_PT_BIP:
3775 case INTEL_PT_BEP:
3776 case INTEL_PT_BEP_IP:
3777 case INTEL_PT_CFE:
3778 case INTEL_PT_CFE_IP:
3779 case INTEL_PT_EVD:
3780 default:
3781 break;
3782 }
3783 }
3784 }
3785
intel_pt_sync_ip(struct intel_pt_decoder * decoder)3786 static int intel_pt_sync_ip(struct intel_pt_decoder *decoder)
3787 {
3788 int err;
3789
3790 intel_pt_clear_fup_event(decoder);
3791 decoder->overflow = false;
3792
3793 if (!decoder->branch_enable) {
3794 decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
3795 decoder->state.type = 0; /* Do not have a sample */
3796 return 0;
3797 }
3798
3799 intel_pt_log("Scanning for full IP\n");
3800 err = intel_pt_walk_to_ip(decoder);
3801 if (err || ((decoder->state.type & INTEL_PT_PSB_EVT) && !decoder->ip))
3802 return err;
3803
3804 /* In hop mode, resample to get the to_ip as an "instruction" sample */
3805 if (decoder->hop)
3806 decoder->pkt_state = INTEL_PT_STATE_RESAMPLE;
3807 else
3808 decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
3809
3810 decoder->state.from_ip = 0;
3811 decoder->state.to_ip = decoder->ip;
3812 intel_pt_log_to("Setting IP", decoder->ip);
3813
3814 return 0;
3815 }
3816
intel_pt_part_psb(struct intel_pt_decoder * decoder)3817 static int intel_pt_part_psb(struct intel_pt_decoder *decoder)
3818 {
3819 const unsigned char *end = decoder->buf + decoder->len;
3820 size_t i;
3821
3822 for (i = INTEL_PT_PSB_LEN - 1; i; i--) {
3823 if (i > decoder->len)
3824 continue;
3825 if (!memcmp(end - i, INTEL_PT_PSB_STR, i))
3826 return i;
3827 }
3828 return 0;
3829 }
3830
intel_pt_rest_psb(struct intel_pt_decoder * decoder,int part_psb)3831 static int intel_pt_rest_psb(struct intel_pt_decoder *decoder, int part_psb)
3832 {
3833 size_t rest_psb = INTEL_PT_PSB_LEN - part_psb;
3834 const char *psb = INTEL_PT_PSB_STR;
3835
3836 if (rest_psb > decoder->len ||
3837 memcmp(decoder->buf, psb + part_psb, rest_psb))
3838 return 0;
3839
3840 return rest_psb;
3841 }
3842
intel_pt_get_split_psb(struct intel_pt_decoder * decoder,int part_psb)3843 static int intel_pt_get_split_psb(struct intel_pt_decoder *decoder,
3844 int part_psb)
3845 {
3846 int rest_psb, ret;
3847
3848 decoder->pos += decoder->len;
3849 decoder->len = 0;
3850
3851 ret = intel_pt_get_next_data(decoder, false);
3852 if (ret)
3853 return ret;
3854
3855 rest_psb = intel_pt_rest_psb(decoder, part_psb);
3856 if (!rest_psb)
3857 return 0;
3858
3859 decoder->pos -= part_psb;
3860 decoder->next_buf = decoder->buf + rest_psb;
3861 decoder->next_len = decoder->len - rest_psb;
3862 memcpy(decoder->temp_buf, INTEL_PT_PSB_STR, INTEL_PT_PSB_LEN);
3863 decoder->buf = decoder->temp_buf;
3864 decoder->len = INTEL_PT_PSB_LEN;
3865
3866 return 0;
3867 }
3868
intel_pt_scan_for_psb(struct intel_pt_decoder * decoder)3869 static int intel_pt_scan_for_psb(struct intel_pt_decoder *decoder)
3870 {
3871 unsigned char *next;
3872 int ret;
3873
3874 intel_pt_log("Scanning for PSB\n");
3875 while (1) {
3876 if (!decoder->len) {
3877 ret = intel_pt_get_next_data(decoder, false);
3878 if (ret)
3879 return ret;
3880 }
3881
3882 next = memmem(decoder->buf, decoder->len, INTEL_PT_PSB_STR,
3883 INTEL_PT_PSB_LEN);
3884 if (!next) {
3885 int part_psb;
3886
3887 part_psb = intel_pt_part_psb(decoder);
3888 if (part_psb) {
3889 ret = intel_pt_get_split_psb(decoder, part_psb);
3890 if (ret)
3891 return ret;
3892 } else {
3893 decoder->pos += decoder->len;
3894 decoder->len = 0;
3895 }
3896 continue;
3897 }
3898
3899 decoder->pkt_step = next - decoder->buf;
3900 return intel_pt_get_next_packet(decoder);
3901 }
3902 }
3903
intel_pt_sync(struct intel_pt_decoder * decoder)3904 static int intel_pt_sync(struct intel_pt_decoder *decoder)
3905 {
3906 int err;
3907
3908 decoder->pge = false;
3909 decoder->continuous_period = false;
3910 decoder->have_last_ip = false;
3911 decoder->last_ip = 0;
3912 decoder->psb_ip = 0;
3913 decoder->ip = 0;
3914 intel_pt_clear_stack(&decoder->stack);
3915
3916 err = intel_pt_scan_for_psb(decoder);
3917 if (err)
3918 return err;
3919
3920 if (decoder->vm_time_correlation) {
3921 decoder->in_psb = true;
3922 if (!decoder->timestamp)
3923 decoder->timestamp = 1;
3924 decoder->state.type = 0;
3925 decoder->pkt_state = INTEL_PT_STATE_VM_TIME_CORRELATION;
3926 return 0;
3927 }
3928
3929 decoder->have_last_ip = true;
3930 decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
3931
3932 err = intel_pt_walk_psb(decoder);
3933 if (err)
3934 return err;
3935
3936 decoder->state.type = INTEL_PT_PSB_EVT; /* Only PSB sample */
3937 decoder->state.from_ip = decoder->psb_ip;
3938 decoder->state.to_ip = 0;
3939
3940 if (decoder->ip) {
3941 /*
3942 * In hop mode, resample to get the PSB FUP ip as an
3943 * "instruction" sample.
3944 */
3945 if (decoder->hop)
3946 decoder->pkt_state = INTEL_PT_STATE_RESAMPLE;
3947 else
3948 decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
3949 }
3950
3951 return 0;
3952 }
3953
intel_pt_est_timestamp(struct intel_pt_decoder * decoder)3954 static uint64_t intel_pt_est_timestamp(struct intel_pt_decoder *decoder)
3955 {
3956 uint64_t est = decoder->sample_insn_cnt << 1;
3957
3958 if (!decoder->cbr || !decoder->max_non_turbo_ratio)
3959 goto out;
3960
3961 est *= decoder->max_non_turbo_ratio;
3962 est /= decoder->cbr;
3963 out:
3964 return decoder->sample_timestamp + est;
3965 }
3966
intel_pt_decode(struct intel_pt_decoder * decoder)3967 const struct intel_pt_state *intel_pt_decode(struct intel_pt_decoder *decoder)
3968 {
3969 int err;
3970
3971 do {
3972 decoder->state.type = INTEL_PT_BRANCH;
3973 decoder->state.flags = 0;
3974
3975 switch (decoder->pkt_state) {
3976 case INTEL_PT_STATE_NO_PSB:
3977 err = intel_pt_sync(decoder);
3978 break;
3979 case INTEL_PT_STATE_NO_IP:
3980 decoder->have_last_ip = false;
3981 decoder->last_ip = 0;
3982 decoder->ip = 0;
3983 fallthrough;
3984 case INTEL_PT_STATE_ERR_RESYNC:
3985 err = intel_pt_sync_ip(decoder);
3986 break;
3987 case INTEL_PT_STATE_IN_SYNC:
3988 err = intel_pt_walk_trace(decoder);
3989 break;
3990 case INTEL_PT_STATE_TNT:
3991 case INTEL_PT_STATE_TNT_CONT:
3992 err = intel_pt_walk_tnt(decoder);
3993 if (err == -EAGAIN)
3994 err = intel_pt_walk_trace(decoder);
3995 break;
3996 case INTEL_PT_STATE_TIP:
3997 case INTEL_PT_STATE_TIP_PGD:
3998 err = intel_pt_walk_tip(decoder);
3999 break;
4000 case INTEL_PT_STATE_FUP:
4001 err = intel_pt_walk_fup(decoder);
4002 if (err == -EAGAIN)
4003 err = intel_pt_walk_fup_tip(decoder);
4004 break;
4005 case INTEL_PT_STATE_FUP_NO_TIP:
4006 err = intel_pt_walk_fup(decoder);
4007 if (err == -EAGAIN)
4008 err = intel_pt_walk_trace(decoder);
4009 break;
4010 case INTEL_PT_STATE_FUP_IN_PSB:
4011 err = intel_pt_fup_in_psb(decoder);
4012 break;
4013 case INTEL_PT_STATE_RESAMPLE:
4014 err = intel_pt_resample(decoder);
4015 break;
4016 case INTEL_PT_STATE_VM_TIME_CORRELATION:
4017 err = intel_pt_vm_time_correlation(decoder);
4018 break;
4019 default:
4020 err = intel_pt_bug(decoder);
4021 break;
4022 }
4023 } while (err == -ENOLINK);
4024
4025 if (err) {
4026 decoder->state.err = intel_pt_ext_err(err);
4027 if (err != -EOVERFLOW)
4028 decoder->state.from_ip = decoder->ip;
4029 intel_pt_update_sample_time(decoder);
4030 decoder->sample_tot_cyc_cnt = decoder->tot_cyc_cnt;
4031 intel_pt_set_nr(decoder);
4032 } else {
4033 decoder->state.err = 0;
4034 if (decoder->cbr != decoder->cbr_seen) {
4035 decoder->cbr_seen = decoder->cbr;
4036 if (!decoder->state.type) {
4037 decoder->state.from_ip = decoder->ip;
4038 decoder->state.to_ip = 0;
4039 }
4040 decoder->state.type |= INTEL_PT_CBR_CHG;
4041 decoder->state.cbr_payload = decoder->cbr_payload;
4042 decoder->state.cbr = decoder->cbr;
4043 }
4044 if (intel_pt_sample_time(decoder->pkt_state)) {
4045 intel_pt_update_sample_time(decoder);
4046 if (decoder->sample_cyc) {
4047 decoder->sample_tot_cyc_cnt = decoder->tot_cyc_cnt;
4048 decoder->state.flags |= INTEL_PT_SAMPLE_IPC;
4049 decoder->sample_cyc = false;
4050 }
4051 }
4052 /*
4053 * When using only TSC/MTC to compute cycles, IPC can be
4054 * sampled as soon as the cycle count changes.
4055 */
4056 if (!decoder->have_cyc)
4057 decoder->state.flags |= INTEL_PT_SAMPLE_IPC;
4058 }
4059
4060 /* Let PSB event always have TSC timestamp */
4061 if ((decoder->state.type & INTEL_PT_PSB_EVT) && decoder->tsc_timestamp)
4062 decoder->sample_timestamp = decoder->tsc_timestamp;
4063
4064 decoder->state.from_nr = decoder->nr;
4065 decoder->state.to_nr = decoder->next_nr;
4066 decoder->nr = decoder->next_nr;
4067
4068 decoder->state.timestamp = decoder->sample_timestamp;
4069 decoder->state.est_timestamp = intel_pt_est_timestamp(decoder);
4070 decoder->state.tot_insn_cnt = decoder->tot_insn_cnt;
4071 decoder->state.tot_cyc_cnt = decoder->sample_tot_cyc_cnt;
4072
4073 return &decoder->state;
4074 }
4075
4076 /**
4077 * intel_pt_next_psb - move buffer pointer to the start of the next PSB packet.
4078 * @buf: pointer to buffer pointer
4079 * @len: size of buffer
4080 *
4081 * Updates the buffer pointer to point to the start of the next PSB packet if
4082 * there is one, otherwise the buffer pointer is unchanged. If @buf is updated,
4083 * @len is adjusted accordingly.
4084 *
4085 * Return: %true if a PSB packet is found, %false otherwise.
4086 */
intel_pt_next_psb(unsigned char ** buf,size_t * len)4087 static bool intel_pt_next_psb(unsigned char **buf, size_t *len)
4088 {
4089 unsigned char *next;
4090
4091 next = memmem(*buf, *len, INTEL_PT_PSB_STR, INTEL_PT_PSB_LEN);
4092 if (next) {
4093 *len -= next - *buf;
4094 *buf = next;
4095 return true;
4096 }
4097 return false;
4098 }
4099
4100 /**
4101 * intel_pt_step_psb - move buffer pointer to the start of the following PSB
4102 * packet.
4103 * @buf: pointer to buffer pointer
4104 * @len: size of buffer
4105 *
4106 * Updates the buffer pointer to point to the start of the following PSB packet
4107 * (skipping the PSB at @buf itself) if there is one, otherwise the buffer
4108 * pointer is unchanged. If @buf is updated, @len is adjusted accordingly.
4109 *
4110 * Return: %true if a PSB packet is found, %false otherwise.
4111 */
intel_pt_step_psb(unsigned char ** buf,size_t * len)4112 static bool intel_pt_step_psb(unsigned char **buf, size_t *len)
4113 {
4114 unsigned char *next;
4115
4116 if (!*len)
4117 return false;
4118
4119 next = memmem(*buf + 1, *len - 1, INTEL_PT_PSB_STR, INTEL_PT_PSB_LEN);
4120 if (next) {
4121 *len -= next - *buf;
4122 *buf = next;
4123 return true;
4124 }
4125 return false;
4126 }
4127
4128 /**
4129 * intel_pt_last_psb - find the last PSB packet in a buffer.
4130 * @buf: buffer
4131 * @len: size of buffer
4132 *
4133 * This function finds the last PSB in a buffer.
4134 *
4135 * Return: A pointer to the last PSB in @buf if found, %NULL otherwise.
4136 */
intel_pt_last_psb(unsigned char * buf,size_t len)4137 static unsigned char *intel_pt_last_psb(unsigned char *buf, size_t len)
4138 {
4139 const char *n = INTEL_PT_PSB_STR;
4140 unsigned char *p;
4141 size_t k;
4142
4143 if (len < INTEL_PT_PSB_LEN)
4144 return NULL;
4145
4146 k = len - INTEL_PT_PSB_LEN + 1;
4147 while (1) {
4148 p = memrchr(buf, n[0], k);
4149 if (!p)
4150 return NULL;
4151 if (!memcmp(p + 1, n + 1, INTEL_PT_PSB_LEN - 1))
4152 return p;
4153 k = p - buf;
4154 if (!k)
4155 return NULL;
4156 }
4157 }
4158
4159 /**
4160 * intel_pt_next_tsc - find and return next TSC.
4161 * @buf: buffer
4162 * @len: size of buffer
4163 * @tsc: TSC value returned
4164 * @rem: returns remaining size when TSC is found
4165 *
4166 * Find a TSC packet in @buf and return the TSC value. This function assumes
4167 * that @buf starts at a PSB and that PSB+ will contain TSC and so stops if a
4168 * PSBEND packet is found.
4169 *
4170 * Return: %true if TSC is found, false otherwise.
4171 */
intel_pt_next_tsc(unsigned char * buf,size_t len,uint64_t * tsc,size_t * rem)4172 static bool intel_pt_next_tsc(unsigned char *buf, size_t len, uint64_t *tsc,
4173 size_t *rem)
4174 {
4175 enum intel_pt_pkt_ctx ctx = INTEL_PT_NO_CTX;
4176 struct intel_pt_pkt packet;
4177 int ret;
4178
4179 while (len) {
4180 ret = intel_pt_get_packet(buf, len, &packet, &ctx);
4181 if (ret <= 0)
4182 return false;
4183 if (packet.type == INTEL_PT_TSC) {
4184 *tsc = packet.payload;
4185 *rem = len;
4186 return true;
4187 }
4188 if (packet.type == INTEL_PT_PSBEND)
4189 return false;
4190 buf += ret;
4191 len -= ret;
4192 }
4193 return false;
4194 }
4195
4196 /**
4197 * intel_pt_tsc_cmp - compare 7-byte TSCs.
4198 * @tsc1: first TSC to compare
4199 * @tsc2: second TSC to compare
4200 *
4201 * This function compares 7-byte TSC values allowing for the possibility that
4202 * TSC wrapped around. Generally it is not possible to know if TSC has wrapped
4203 * around so for that purpose this function assumes the absolute difference is
4204 * less than half the maximum difference.
4205 *
4206 * Return: %-1 if @tsc1 is before @tsc2, %0 if @tsc1 == @tsc2, %1 if @tsc1 is
4207 * after @tsc2.
4208 */
intel_pt_tsc_cmp(uint64_t tsc1,uint64_t tsc2)4209 static int intel_pt_tsc_cmp(uint64_t tsc1, uint64_t tsc2)
4210 {
4211 const uint64_t halfway = (1ULL << 55);
4212
4213 if (tsc1 == tsc2)
4214 return 0;
4215
4216 if (tsc1 < tsc2) {
4217 if (tsc2 - tsc1 < halfway)
4218 return -1;
4219 else
4220 return 1;
4221 } else {
4222 if (tsc1 - tsc2 < halfway)
4223 return 1;
4224 else
4225 return -1;
4226 }
4227 }
4228
4229 #define MAX_PADDING (PERF_AUXTRACE_RECORD_ALIGNMENT - 1)
4230
4231 /**
4232 * adj_for_padding - adjust overlap to account for padding.
4233 * @buf_b: second buffer
4234 * @buf_a: first buffer
4235 * @len_a: size of first buffer
4236 *
4237 * @buf_a might have up to 7 bytes of padding appended. Adjust the overlap
4238 * accordingly.
4239 *
4240 * Return: A pointer into @buf_b from where non-overlapped data starts
4241 */
adj_for_padding(unsigned char * buf_b,unsigned char * buf_a,size_t len_a)4242 static unsigned char *adj_for_padding(unsigned char *buf_b,
4243 unsigned char *buf_a, size_t len_a)
4244 {
4245 unsigned char *p = buf_b - MAX_PADDING;
4246 unsigned char *q = buf_a + len_a - MAX_PADDING;
4247 int i;
4248
4249 for (i = MAX_PADDING; i; i--, p++, q++) {
4250 if (*p != *q)
4251 break;
4252 }
4253
4254 return p;
4255 }
4256
4257 /**
4258 * intel_pt_find_overlap_tsc - determine start of non-overlapped trace data
4259 * using TSC.
4260 * @buf_a: first buffer
4261 * @len_a: size of first buffer
4262 * @buf_b: second buffer
4263 * @len_b: size of second buffer
4264 * @consecutive: returns true if there is data in buf_b that is consecutive
4265 * to buf_a
4266 * @ooo_tsc: out-of-order TSC due to VM TSC offset / scaling
4267 *
4268 * If the trace contains TSC we can look at the last TSC of @buf_a and the
4269 * first TSC of @buf_b in order to determine if the buffers overlap, and then
4270 * walk forward in @buf_b until a later TSC is found. A precondition is that
4271 * @buf_a and @buf_b are positioned at a PSB.
4272 *
4273 * Return: A pointer into @buf_b from where non-overlapped data starts, or
4274 * @buf_b + @len_b if there is no non-overlapped data.
4275 */
intel_pt_find_overlap_tsc(unsigned char * buf_a,size_t len_a,unsigned char * buf_b,size_t len_b,bool * consecutive,bool ooo_tsc)4276 static unsigned char *intel_pt_find_overlap_tsc(unsigned char *buf_a,
4277 size_t len_a,
4278 unsigned char *buf_b,
4279 size_t len_b, bool *consecutive,
4280 bool ooo_tsc)
4281 {
4282 uint64_t tsc_a, tsc_b;
4283 unsigned char *p;
4284 size_t len, rem_a, rem_b;
4285
4286 p = intel_pt_last_psb(buf_a, len_a);
4287 if (!p)
4288 return buf_b; /* No PSB in buf_a => no overlap */
4289
4290 len = len_a - (p - buf_a);
4291 if (!intel_pt_next_tsc(p, len, &tsc_a, &rem_a)) {
4292 /* The last PSB+ in buf_a is incomplete, so go back one more */
4293 len_a -= len;
4294 p = intel_pt_last_psb(buf_a, len_a);
4295 if (!p)
4296 return buf_b; /* No full PSB+ => assume no overlap */
4297 len = len_a - (p - buf_a);
4298 if (!intel_pt_next_tsc(p, len, &tsc_a, &rem_a))
4299 return buf_b; /* No TSC in buf_a => assume no overlap */
4300 }
4301
4302 while (1) {
4303 /* Ignore PSB+ with no TSC */
4304 if (intel_pt_next_tsc(buf_b, len_b, &tsc_b, &rem_b)) {
4305 int cmp = intel_pt_tsc_cmp(tsc_a, tsc_b);
4306
4307 /* Same TSC, so buffers are consecutive */
4308 if (!cmp && rem_b >= rem_a) {
4309 unsigned char *start;
4310
4311 *consecutive = true;
4312 start = buf_b + len_b - (rem_b - rem_a);
4313 return adj_for_padding(start, buf_a, len_a);
4314 }
4315 if (cmp < 0 && !ooo_tsc)
4316 return buf_b; /* tsc_a < tsc_b => no overlap */
4317 }
4318
4319 if (!intel_pt_step_psb(&buf_b, &len_b))
4320 return buf_b + len_b; /* No PSB in buf_b => no data */
4321 }
4322 }
4323
4324 /**
4325 * intel_pt_find_overlap - determine start of non-overlapped trace data.
4326 * @buf_a: first buffer
4327 * @len_a: size of first buffer
4328 * @buf_b: second buffer
4329 * @len_b: size of second buffer
4330 * @have_tsc: can use TSC packets to detect overlap
4331 * @consecutive: returns true if there is data in buf_b that is consecutive
4332 * to buf_a
4333 * @ooo_tsc: out-of-order TSC due to VM TSC offset / scaling
4334 *
4335 * When trace samples or snapshots are recorded there is the possibility that
4336 * the data overlaps. Note that, for the purposes of decoding, data is only
4337 * useful if it begins with a PSB packet.
4338 *
4339 * Return: A pointer into @buf_b from where non-overlapped data starts, or
4340 * @buf_b + @len_b if there is no non-overlapped data.
4341 */
intel_pt_find_overlap(unsigned char * buf_a,size_t len_a,unsigned char * buf_b,size_t len_b,bool have_tsc,bool * consecutive,bool ooo_tsc)4342 unsigned char *intel_pt_find_overlap(unsigned char *buf_a, size_t len_a,
4343 unsigned char *buf_b, size_t len_b,
4344 bool have_tsc, bool *consecutive,
4345 bool ooo_tsc)
4346 {
4347 unsigned char *found;
4348
4349 /* Buffer 'b' must start at PSB so throw away everything before that */
4350 if (!intel_pt_next_psb(&buf_b, &len_b))
4351 return buf_b + len_b; /* No PSB */
4352
4353 if (!intel_pt_next_psb(&buf_a, &len_a))
4354 return buf_b; /* No overlap */
4355
4356 if (have_tsc) {
4357 found = intel_pt_find_overlap_tsc(buf_a, len_a, buf_b, len_b,
4358 consecutive, ooo_tsc);
4359 if (found)
4360 return found;
4361 }
4362
4363 /*
4364 * Buffer 'b' cannot end within buffer 'a' so, for comparison purposes,
4365 * we can ignore the first part of buffer 'a'.
4366 */
4367 while (len_b < len_a) {
4368 if (!intel_pt_step_psb(&buf_a, &len_a))
4369 return buf_b; /* No overlap */
4370 }
4371
4372 /* Now len_b >= len_a */
4373 while (1) {
4374 /* Potential overlap so check the bytes */
4375 found = memmem(buf_a, len_a, buf_b, len_a);
4376 if (found) {
4377 *consecutive = true;
4378 return adj_for_padding(buf_b + len_a, buf_a, len_a);
4379 }
4380
4381 /* Try again at next PSB in buffer 'a' */
4382 if (!intel_pt_step_psb(&buf_a, &len_a))
4383 return buf_b; /* No overlap */
4384 }
4385 }
4386
4387 /**
4388 * struct fast_forward_data - data used by intel_pt_ff_cb().
4389 * @timestamp: timestamp to fast forward towards
4390 * @buf_timestamp: buffer timestamp of last buffer with trace data earlier than
4391 * the fast forward timestamp.
4392 */
4393 struct fast_forward_data {
4394 uint64_t timestamp;
4395 uint64_t buf_timestamp;
4396 };
4397
4398 /**
4399 * intel_pt_ff_cb - fast forward lookahead callback.
4400 * @buffer: Intel PT trace buffer
4401 * @data: opaque pointer to fast forward data (struct fast_forward_data)
4402 *
4403 * Determine if @buffer trace is past the fast forward timestamp.
4404 *
4405 * Return: 1 (stop lookahead) if @buffer trace is past the fast forward
4406 * timestamp, and 0 otherwise.
4407 */
intel_pt_ff_cb(struct intel_pt_buffer * buffer,void * data)4408 static int intel_pt_ff_cb(struct intel_pt_buffer *buffer, void *data)
4409 {
4410 struct fast_forward_data *d = data;
4411 unsigned char *buf;
4412 uint64_t tsc;
4413 size_t rem;
4414 size_t len;
4415
4416 buf = (unsigned char *)buffer->buf;
4417 len = buffer->len;
4418
4419 if (!intel_pt_next_psb(&buf, &len) ||
4420 !intel_pt_next_tsc(buf, len, &tsc, &rem))
4421 return 0;
4422
4423 tsc = intel_pt_8b_tsc(tsc, buffer->ref_timestamp);
4424
4425 intel_pt_log("Buffer 1st timestamp " x64_fmt " ref timestamp " x64_fmt "\n",
4426 tsc, buffer->ref_timestamp);
4427
4428 /*
4429 * If the buffer contains a timestamp earlier that the fast forward
4430 * timestamp, then record it, else stop.
4431 */
4432 if (tsc < d->timestamp)
4433 d->buf_timestamp = buffer->ref_timestamp;
4434 else
4435 return 1;
4436
4437 return 0;
4438 }
4439
4440 /**
4441 * intel_pt_fast_forward - reposition decoder forwards.
4442 * @decoder: Intel PT decoder
4443 * @timestamp: timestamp to fast forward towards
4444 *
4445 * Reposition decoder at the last PSB with a timestamp earlier than @timestamp.
4446 *
4447 * Return: 0 on success or negative error code on failure.
4448 */
intel_pt_fast_forward(struct intel_pt_decoder * decoder,uint64_t timestamp)4449 int intel_pt_fast_forward(struct intel_pt_decoder *decoder, uint64_t timestamp)
4450 {
4451 struct fast_forward_data d = { .timestamp = timestamp };
4452 unsigned char *buf;
4453 size_t len;
4454 int err;
4455
4456 intel_pt_log("Fast forward towards timestamp " x64_fmt "\n", timestamp);
4457
4458 /* Find buffer timestamp of buffer to fast forward to */
4459 err = decoder->lookahead(decoder->data, intel_pt_ff_cb, &d);
4460 if (err < 0)
4461 return err;
4462
4463 /* Walk to buffer with same buffer timestamp */
4464 if (d.buf_timestamp) {
4465 do {
4466 decoder->pos += decoder->len;
4467 decoder->len = 0;
4468 err = intel_pt_get_next_data(decoder, true);
4469 /* -ENOLINK means non-consecutive trace */
4470 if (err && err != -ENOLINK)
4471 return err;
4472 } while (decoder->buf_timestamp != d.buf_timestamp);
4473 }
4474
4475 if (!decoder->buf)
4476 return 0;
4477
4478 buf = (unsigned char *)decoder->buf;
4479 len = decoder->len;
4480
4481 if (!intel_pt_next_psb(&buf, &len))
4482 return 0;
4483
4484 /*
4485 * Walk PSBs while the PSB timestamp is less than the fast forward
4486 * timestamp.
4487 */
4488 do {
4489 uint64_t tsc;
4490 size_t rem;
4491
4492 if (!intel_pt_next_tsc(buf, len, &tsc, &rem))
4493 break;
4494 tsc = intel_pt_8b_tsc(tsc, decoder->buf_timestamp);
4495 /*
4496 * A TSC packet can slip past MTC packets but, after fast
4497 * forward, decoding starts at the TSC timestamp. That means
4498 * the timestamps may not be exactly the same as the timestamps
4499 * that would have been decoded without fast forward.
4500 */
4501 if (tsc < timestamp) {
4502 intel_pt_log("Fast forward to next PSB timestamp " x64_fmt "\n", tsc);
4503 decoder->pos += decoder->len - len;
4504 decoder->buf = buf;
4505 decoder->len = len;
4506 intel_pt_reposition(decoder);
4507 } else {
4508 break;
4509 }
4510 } while (intel_pt_step_psb(&buf, &len));
4511
4512 return 0;
4513 }
4514
