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 decoder->state.insn_op = INTEL_PT_OP_OTHER;
1323 decoder->state.insn_len = 0;
1324
1325 if (decoder->set_fup_cfe_ip || decoder->set_fup_cfe) {
1326 bool ip = decoder->set_fup_cfe_ip;
1327
1328 decoder->set_fup_cfe_ip = false;
1329 decoder->set_fup_cfe = false;
1330 decoder->state.type |= INTEL_PT_EVT;
1331 if (!ip && decoder->pge)
1332 decoder->state.type |= INTEL_PT_BRANCH;
1333 decoder->state.cfe_type = decoder->fup_cfe_pkt.count;
1334 decoder->state.cfe_vector = decoder->fup_cfe_pkt.payload;
1335 decoder->state.evd_cnt = decoder->evd_cnt;
1336 decoder->state.evd = decoder->evd;
1337 decoder->evd_cnt = 0;
1338 if (ip || decoder->pge)
1339 decoder->state.flags |= INTEL_PT_FUP_IP;
1340 ret = true;
1341 }
1342 if (decoder->set_fup_mode_exec) {
1343 decoder->set_fup_mode_exec = false;
1344 intel_pt_sample_iflag(decoder);
1345 sample_fup_insn = no_tip;
1346 ret = true;
1347 }
1348 if (decoder->set_fup_tx_flags) {
1349 decoder->set_fup_tx_flags = false;
1350 decoder->tx_flags = decoder->fup_tx_flags;
1351 decoder->state.type |= INTEL_PT_TRANSACTION;
1352 if (decoder->fup_tx_flags & INTEL_PT_ABORT_TX)
1353 decoder->state.type |= INTEL_PT_BRANCH;
1354 decoder->state.flags = decoder->fup_tx_flags;
1355 ret = true;
1356 }
1357 if (decoder->set_fup_ptw) {
1358 decoder->set_fup_ptw = false;
1359 decoder->state.type |= INTEL_PT_PTW;
1360 decoder->state.flags |= INTEL_PT_FUP_IP;
1361 decoder->state.ptw_payload = decoder->fup_ptw_payload;
1362 ret = true;
1363 }
1364 if (decoder->set_fup_mwait) {
1365 decoder->set_fup_mwait = false;
1366 decoder->state.type |= INTEL_PT_MWAIT_OP;
1367 decoder->state.mwait_payload = decoder->fup_mwait_payload;
1368 ret = true;
1369 }
1370 if (decoder->set_fup_pwre) {
1371 decoder->set_fup_pwre = false;
1372 decoder->state.type |= INTEL_PT_PWR_ENTRY;
1373 decoder->state.pwre_payload = decoder->fup_pwre_payload;
1374 ret = true;
1375 }
1376 if (decoder->set_fup_exstop) {
1377 decoder->set_fup_exstop = false;
1378 decoder->state.type |= INTEL_PT_EX_STOP;
1379 decoder->state.flags |= INTEL_PT_FUP_IP;
1380 ret = true;
1381 }
1382 if (decoder->set_fup_bep) {
1383 decoder->set_fup_bep = false;
1384 decoder->state.type |= INTEL_PT_BLK_ITEMS;
1385 ret = true;
1386 }
1387 if (decoder->overflow) {
1388 decoder->overflow = false;
1389 if (!ret && !decoder->pge) {
1390 if (decoder->hop) {
1391 decoder->state.type = 0;
1392 decoder->pkt_state = INTEL_PT_STATE_RESAMPLE;
1393 }
1394 decoder->pge = true;
1395 decoder->state.type |= INTEL_PT_BRANCH | INTEL_PT_TRACE_BEGIN;
1396 decoder->state.from_ip = 0;
1397 decoder->state.to_ip = decoder->ip;
1398 return true;
1399 }
1400 }
1401 if (ret) {
1402 decoder->state.from_ip = decoder->ip;
1403 decoder->state.to_ip = 0;
1404 if (sample_fup_insn)
1405 intel_pt_sample_fup_insn(decoder);
1406 } else {
1407 decoder->state.type = type;
1408 }
1409 return ret;
1410 }
1411
intel_pt_fup_with_nlip(struct intel_pt_decoder * decoder,struct intel_pt_insn * intel_pt_insn,uint64_t ip,int err)1412 static inline bool intel_pt_fup_with_nlip(struct intel_pt_decoder *decoder,
1413 struct intel_pt_insn *intel_pt_insn,
1414 uint64_t ip, int err)
1415 {
1416 return decoder->flags & INTEL_PT_FUP_WITH_NLIP && !err &&
1417 intel_pt_insn->branch == INTEL_PT_BR_INDIRECT &&
1418 ip == decoder->ip + intel_pt_insn->length;
1419 }
1420
intel_pt_walk_fup(struct intel_pt_decoder * decoder)1421 static int intel_pt_walk_fup(struct intel_pt_decoder *decoder)
1422 {
1423 struct intel_pt_insn intel_pt_insn;
1424 uint64_t ip;
1425 int err;
1426
1427 ip = decoder->last_ip;
1428
1429 while (1) {
1430 err = intel_pt_walk_insn(decoder, &intel_pt_insn, ip);
1431 if (err == INTEL_PT_RETURN)
1432 return 0;
1433 if (err == -EAGAIN ||
1434 intel_pt_fup_with_nlip(decoder, &intel_pt_insn, ip, err)) {
1435 bool no_tip = decoder->pkt_state != INTEL_PT_STATE_FUP;
1436
1437 decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1438 if (intel_pt_fup_event(decoder, no_tip) && no_tip)
1439 return 0;
1440 return -EAGAIN;
1441 }
1442 decoder->set_fup_tx_flags = false;
1443 if (err)
1444 return err;
1445
1446 if (intel_pt_insn.branch == INTEL_PT_BR_INDIRECT) {
1447 intel_pt_log_at("ERROR: Unexpected indirect branch",
1448 decoder->ip);
1449 decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
1450 return -ENOENT;
1451 }
1452
1453 if (intel_pt_insn.branch == INTEL_PT_BR_CONDITIONAL) {
1454 intel_pt_log_at("ERROR: Unexpected conditional branch",
1455 decoder->ip);
1456 decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
1457 return -ENOENT;
1458 }
1459
1460 intel_pt_bug(decoder);
1461 }
1462 }
1463
intel_pt_walk_tip(struct intel_pt_decoder * decoder)1464 static int intel_pt_walk_tip(struct intel_pt_decoder *decoder)
1465 {
1466 struct intel_pt_insn intel_pt_insn;
1467 int err;
1468
1469 err = intel_pt_walk_insn(decoder, &intel_pt_insn, 0);
1470 if (err == INTEL_PT_RETURN &&
1471 decoder->pgd_ip &&
1472 decoder->pkt_state == INTEL_PT_STATE_TIP_PGD &&
1473 (decoder->state.type & INTEL_PT_BRANCH) &&
1474 decoder->pgd_ip(decoder->state.to_ip, decoder->data)) {
1475 /* Unconditional branch leaving filter region */
1476 decoder->no_progress = 0;
1477 decoder->pge = false;
1478 decoder->continuous_period = false;
1479 decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1480 decoder->state.type |= INTEL_PT_TRACE_END;
1481 intel_pt_update_nr(decoder);
1482 return 0;
1483 }
1484 if (err == INTEL_PT_RETURN)
1485 return 0;
1486 if (err)
1487 return err;
1488
1489 intel_pt_update_nr(decoder);
1490 intel_pt_sample_iflag_chg(decoder);
1491
1492 if (intel_pt_insn.branch == INTEL_PT_BR_INDIRECT) {
1493 if (decoder->pkt_state == INTEL_PT_STATE_TIP_PGD) {
1494 decoder->pge = false;
1495 decoder->continuous_period = false;
1496 decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1497 decoder->state.from_ip = decoder->ip;
1498 if (decoder->packet.count == 0) {
1499 decoder->state.to_ip = 0;
1500 } else {
1501 decoder->state.to_ip = decoder->last_ip;
1502 decoder->ip = decoder->last_ip;
1503 }
1504 decoder->state.type |= INTEL_PT_TRACE_END;
1505 } else {
1506 decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1507 decoder->state.from_ip = decoder->ip;
1508 if (decoder->packet.count == 0) {
1509 decoder->state.to_ip = 0;
1510 } else {
1511 decoder->state.to_ip = decoder->last_ip;
1512 decoder->ip = decoder->last_ip;
1513 }
1514 }
1515 return 0;
1516 }
1517
1518 if (intel_pt_insn.branch == INTEL_PT_BR_CONDITIONAL) {
1519 uint64_t to_ip = decoder->ip + intel_pt_insn.length +
1520 intel_pt_insn.rel;
1521
1522 if (decoder->pgd_ip &&
1523 decoder->pkt_state == INTEL_PT_STATE_TIP_PGD &&
1524 decoder->pgd_ip(to_ip, decoder->data)) {
1525 /* Conditional branch leaving filter region */
1526 decoder->pge = false;
1527 decoder->continuous_period = false;
1528 decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1529 decoder->ip = to_ip;
1530 decoder->state.from_ip = decoder->ip;
1531 decoder->state.to_ip = to_ip;
1532 decoder->state.type |= INTEL_PT_TRACE_END;
1533 return 0;
1534 }
1535 intel_pt_log_at("ERROR: Conditional branch when expecting indirect branch",
1536 decoder->ip);
1537 decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
1538 return -ENOENT;
1539 }
1540
1541 return intel_pt_bug(decoder);
1542 }
1543
1544 struct eptw_data {
1545 int bit_countdown;
1546 uint64_t payload;
1547 };
1548
intel_pt_eptw_lookahead_cb(struct intel_pt_pkt_info * pkt_info)1549 static int intel_pt_eptw_lookahead_cb(struct intel_pt_pkt_info *pkt_info)
1550 {
1551 struct eptw_data *data = pkt_info->data;
1552 int nr_bits;
1553
1554 switch (pkt_info->packet.type) {
1555 case INTEL_PT_PAD:
1556 case INTEL_PT_MNT:
1557 case INTEL_PT_MODE_EXEC:
1558 case INTEL_PT_MODE_TSX:
1559 case INTEL_PT_MTC:
1560 case INTEL_PT_FUP:
1561 case INTEL_PT_CYC:
1562 case INTEL_PT_CBR:
1563 case INTEL_PT_TSC:
1564 case INTEL_PT_TMA:
1565 case INTEL_PT_PIP:
1566 case INTEL_PT_VMCS:
1567 case INTEL_PT_PSB:
1568 case INTEL_PT_PSBEND:
1569 case INTEL_PT_PTWRITE:
1570 case INTEL_PT_PTWRITE_IP:
1571 case INTEL_PT_EXSTOP:
1572 case INTEL_PT_EXSTOP_IP:
1573 case INTEL_PT_MWAIT:
1574 case INTEL_PT_PWRE:
1575 case INTEL_PT_PWRX:
1576 case INTEL_PT_BBP:
1577 case INTEL_PT_BIP:
1578 case INTEL_PT_BEP:
1579 case INTEL_PT_BEP_IP:
1580 case INTEL_PT_CFE:
1581 case INTEL_PT_CFE_IP:
1582 case INTEL_PT_EVD:
1583 break;
1584
1585 case INTEL_PT_TNT:
1586 nr_bits = data->bit_countdown;
1587 if (nr_bits > pkt_info->packet.count)
1588 nr_bits = pkt_info->packet.count;
1589 data->payload <<= nr_bits;
1590 data->payload |= pkt_info->packet.payload >> (64 - nr_bits);
1591 data->bit_countdown -= nr_bits;
1592 return !data->bit_countdown;
1593
1594 case INTEL_PT_TIP_PGE:
1595 case INTEL_PT_TIP_PGD:
1596 case INTEL_PT_TIP:
1597 case INTEL_PT_BAD:
1598 case INTEL_PT_OVF:
1599 case INTEL_PT_TRACESTOP:
1600 default:
1601 return 1;
1602 }
1603
1604 return 0;
1605 }
1606
intel_pt_emulated_ptwrite(struct intel_pt_decoder * decoder)1607 static int intel_pt_emulated_ptwrite(struct intel_pt_decoder *decoder)
1608 {
1609 int n = 64 - decoder->tnt.count;
1610 struct eptw_data data = {
1611 .bit_countdown = n,
1612 .payload = decoder->tnt.payload >> n,
1613 };
1614
1615 decoder->emulated_ptwrite = false;
1616 intel_pt_log("Emulated ptwrite detected\n");
1617
1618 intel_pt_pkt_lookahead(decoder, intel_pt_eptw_lookahead_cb, &data);
1619 if (data.bit_countdown)
1620 return -ECONNRESET;
1621
1622 decoder->state.type = INTEL_PT_PTW;
1623 decoder->state.from_ip = decoder->ip;
1624 decoder->state.to_ip = 0;
1625 decoder->state.ptw_payload = data.payload;
1626 return 0;
1627 }
1628
intel_pt_walk_tnt(struct intel_pt_decoder * decoder)1629 static int intel_pt_walk_tnt(struct intel_pt_decoder *decoder)
1630 {
1631 struct intel_pt_insn intel_pt_insn;
1632 int err;
1633
1634 while (1) {
1635 if (decoder->emulated_ptwrite)
1636 return intel_pt_emulated_ptwrite(decoder);
1637 err = intel_pt_walk_insn(decoder, &intel_pt_insn, 0);
1638 if (err == INTEL_PT_RETURN) {
1639 decoder->emulated_ptwrite = intel_pt_insn.emulated_ptwrite;
1640 return 0;
1641 }
1642 if (err) {
1643 decoder->emulated_ptwrite = false;
1644 return err;
1645 }
1646
1647 if (intel_pt_insn.op == INTEL_PT_OP_RET) {
1648 if (!decoder->return_compression) {
1649 intel_pt_log_at("ERROR: RET when expecting conditional branch",
1650 decoder->ip);
1651 decoder->pkt_state = INTEL_PT_STATE_ERR3;
1652 return -ENOENT;
1653 }
1654 if (!decoder->ret_addr) {
1655 intel_pt_log_at("ERROR: Bad RET compression (stack empty)",
1656 decoder->ip);
1657 decoder->pkt_state = INTEL_PT_STATE_ERR3;
1658 return -ENOENT;
1659 }
1660 if (!(decoder->tnt.payload & BIT63)) {
1661 intel_pt_log_at("ERROR: Bad RET compression (TNT=N)",
1662 decoder->ip);
1663 decoder->pkt_state = INTEL_PT_STATE_ERR3;
1664 return -ENOENT;
1665 }
1666 decoder->tnt.count -= 1;
1667 if (decoder->tnt.count)
1668 decoder->pkt_state = INTEL_PT_STATE_TNT_CONT;
1669 else
1670 decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1671 decoder->tnt.payload <<= 1;
1672 decoder->state.from_ip = decoder->ip;
1673 decoder->ip = decoder->ret_addr;
1674 decoder->state.to_ip = decoder->ip;
1675 return 0;
1676 }
1677
1678 if (intel_pt_insn.branch == INTEL_PT_BR_INDIRECT) {
1679 /* Handle deferred TIPs */
1680 err = intel_pt_get_next_packet(decoder);
1681 if (err)
1682 return err;
1683 if (decoder->packet.type != INTEL_PT_TIP ||
1684 decoder->packet.count == 0) {
1685 intel_pt_log_at("ERROR: Missing deferred TIP for indirect branch",
1686 decoder->ip);
1687 decoder->pkt_state = INTEL_PT_STATE_ERR3;
1688 decoder->pkt_step = 0;
1689 return -ENOENT;
1690 }
1691 intel_pt_set_last_ip(decoder);
1692 decoder->state.from_ip = decoder->ip;
1693 decoder->state.to_ip = decoder->last_ip;
1694 decoder->ip = decoder->last_ip;
1695 intel_pt_update_nr(decoder);
1696 intel_pt_sample_iflag_chg(decoder);
1697 return 0;
1698 }
1699
1700 if (intel_pt_insn.branch == INTEL_PT_BR_CONDITIONAL) {
1701 decoder->tnt.count -= 1;
1702 if (decoder->tnt.count)
1703 decoder->pkt_state = INTEL_PT_STATE_TNT_CONT;
1704 else
1705 decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1706 if (decoder->tnt.payload & BIT63) {
1707 decoder->tnt.payload <<= 1;
1708 decoder->state.from_ip = decoder->ip;
1709 decoder->ip += intel_pt_insn.length +
1710 intel_pt_insn.rel;
1711 decoder->state.to_ip = decoder->ip;
1712 return 0;
1713 }
1714 /* Instruction sample for a non-taken branch */
1715 if (decoder->state.type & INTEL_PT_INSTRUCTION) {
1716 decoder->tnt.payload <<= 1;
1717 decoder->state.type = INTEL_PT_INSTRUCTION;
1718 decoder->state.from_ip = decoder->ip;
1719 decoder->state.to_ip = 0;
1720 decoder->ip += intel_pt_insn.length;
1721 return 0;
1722 }
1723 decoder->sample_cyc = false;
1724 decoder->ip += intel_pt_insn.length;
1725 if (!decoder->tnt.count) {
1726 intel_pt_update_sample_time(decoder);
1727 return -EAGAIN;
1728 }
1729 decoder->tnt.payload <<= 1;
1730 continue;
1731 }
1732
1733 return intel_pt_bug(decoder);
1734 }
1735 }
1736
intel_pt_mode_tsx(struct intel_pt_decoder * decoder,bool * no_tip)1737 static int intel_pt_mode_tsx(struct intel_pt_decoder *decoder, bool *no_tip)
1738 {
1739 unsigned int fup_tx_flags;
1740 int err;
1741
1742 fup_tx_flags = decoder->packet.payload &
1743 (INTEL_PT_IN_TX | INTEL_PT_ABORT_TX);
1744 err = intel_pt_get_next_packet(decoder);
1745 if (err)
1746 return err;
1747 if (decoder->packet.type == INTEL_PT_FUP) {
1748 decoder->fup_tx_flags = fup_tx_flags;
1749 decoder->set_fup_tx_flags = true;
1750 if (!(decoder->fup_tx_flags & INTEL_PT_ABORT_TX))
1751 *no_tip = true;
1752 } else {
1753 intel_pt_log_at("ERROR: Missing FUP after MODE.TSX",
1754 decoder->pos);
1755 intel_pt_update_in_tx(decoder);
1756 }
1757 return 0;
1758 }
1759
intel_pt_evd(struct intel_pt_decoder * decoder)1760 static int intel_pt_evd(struct intel_pt_decoder *decoder)
1761 {
1762 if (decoder->evd_cnt >= INTEL_PT_MAX_EVDS) {
1763 intel_pt_log_at("ERROR: Too many EVD packets", decoder->pos);
1764 return -ENOSYS;
1765 }
1766 decoder->evd[decoder->evd_cnt++] = (struct intel_pt_evd){
1767 .type = decoder->packet.count,
1768 .payload = decoder->packet.payload,
1769 };
1770 return 0;
1771 }
1772
intel_pt_8b_tsc(uint64_t timestamp,uint64_t ref_timestamp)1773 static uint64_t intel_pt_8b_tsc(uint64_t timestamp, uint64_t ref_timestamp)
1774 {
1775 timestamp |= (ref_timestamp & (0xffULL << 56));
1776
1777 if (timestamp < ref_timestamp) {
1778 if (ref_timestamp - timestamp > (1ULL << 55))
1779 timestamp += (1ULL << 56);
1780 } else {
1781 if (timestamp - ref_timestamp > (1ULL << 55))
1782 timestamp -= (1ULL << 56);
1783 }
1784
1785 return timestamp;
1786 }
1787
1788 /* For use only when decoder->vm_time_correlation is true */
intel_pt_time_in_range(struct intel_pt_decoder * decoder,uint64_t timestamp)1789 static bool intel_pt_time_in_range(struct intel_pt_decoder *decoder,
1790 uint64_t timestamp)
1791 {
1792 uint64_t max_timestamp = decoder->buf_timestamp;
1793
1794 if (!max_timestamp) {
1795 max_timestamp = decoder->last_reliable_timestamp +
1796 0x400000000ULL;
1797 }
1798 return timestamp >= decoder->last_reliable_timestamp &&
1799 timestamp < decoder->buf_timestamp;
1800 }
1801
intel_pt_calc_tsc_timestamp(struct intel_pt_decoder * decoder)1802 static void intel_pt_calc_tsc_timestamp(struct intel_pt_decoder *decoder)
1803 {
1804 uint64_t timestamp;
1805 bool bad = false;
1806
1807 decoder->have_tma = false;
1808
1809 if (decoder->ref_timestamp) {
1810 timestamp = intel_pt_8b_tsc(decoder->packet.payload,
1811 decoder->ref_timestamp);
1812 decoder->tsc_timestamp = timestamp;
1813 decoder->timestamp = timestamp;
1814 decoder->ref_timestamp = 0;
1815 decoder->timestamp_insn_cnt = 0;
1816 } else if (decoder->timestamp) {
1817 timestamp = decoder->packet.payload |
1818 (decoder->timestamp & (0xffULL << 56));
1819 decoder->tsc_timestamp = timestamp;
1820 if (timestamp < decoder->timestamp &&
1821 decoder->timestamp - timestamp < decoder->tsc_slip) {
1822 intel_pt_log_to("Suppressing backwards timestamp",
1823 timestamp);
1824 timestamp = decoder->timestamp;
1825 }
1826 if (timestamp < decoder->timestamp) {
1827 if (!decoder->buf_timestamp ||
1828 (timestamp + (1ULL << 56) < decoder->buf_timestamp)) {
1829 intel_pt_log_to("Wraparound timestamp", timestamp);
1830 timestamp += (1ULL << 56);
1831 decoder->tsc_timestamp = timestamp;
1832 } else {
1833 intel_pt_log_to("Suppressing bad timestamp", timestamp);
1834 timestamp = decoder->timestamp;
1835 bad = true;
1836 }
1837 }
1838 if (decoder->vm_time_correlation &&
1839 (bad || !intel_pt_time_in_range(decoder, timestamp)) &&
1840 intel_pt_print_once(decoder, INTEL_PT_PRT_ONCE_ERANGE))
1841 p_log("Timestamp out of range");
1842 decoder->timestamp = timestamp;
1843 decoder->timestamp_insn_cnt = 0;
1844 }
1845
1846 if (decoder->last_packet_type == INTEL_PT_CYC) {
1847 decoder->cyc_ref_timestamp = decoder->timestamp;
1848 decoder->cycle_cnt = 0;
1849 decoder->have_calc_cyc_to_tsc = false;
1850 intel_pt_calc_cyc_to_tsc(decoder, false);
1851 }
1852
1853 intel_pt_log_to("Setting timestamp", decoder->timestamp);
1854 }
1855
intel_pt_overflow(struct intel_pt_decoder * decoder)1856 static int intel_pt_overflow(struct intel_pt_decoder *decoder)
1857 {
1858 intel_pt_log("ERROR: Buffer overflow\n");
1859 intel_pt_clear_tx_flags(decoder);
1860 intel_pt_set_nr(decoder);
1861 decoder->timestamp_insn_cnt = 0;
1862 decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1863 decoder->state.from_ip = decoder->ip;
1864 decoder->ip = 0;
1865 decoder->pge = false;
1866 intel_pt_clear_fup_event(decoder);
1867 decoder->overflow = true;
1868 return -EOVERFLOW;
1869 }
1870
intel_pt_mtc_cyc_cnt_pge(struct intel_pt_decoder * decoder)1871 static inline void intel_pt_mtc_cyc_cnt_pge(struct intel_pt_decoder *decoder)
1872 {
1873 if (decoder->have_cyc)
1874 return;
1875
1876 decoder->cyc_cnt_timestamp = decoder->timestamp;
1877 decoder->base_cyc_cnt = decoder->tot_cyc_cnt;
1878 }
1879
intel_pt_mtc_cyc_cnt_cbr(struct intel_pt_decoder * decoder)1880 static inline void intel_pt_mtc_cyc_cnt_cbr(struct intel_pt_decoder *decoder)
1881 {
1882 decoder->tsc_to_cyc = decoder->cbr / decoder->max_non_turbo_ratio_fp;
1883
1884 if (decoder->pge)
1885 intel_pt_mtc_cyc_cnt_pge(decoder);
1886 }
1887
intel_pt_mtc_cyc_cnt_upd(struct intel_pt_decoder * decoder)1888 static inline void intel_pt_mtc_cyc_cnt_upd(struct intel_pt_decoder *decoder)
1889 {
1890 uint64_t tot_cyc_cnt, tsc_delta;
1891
1892 if (decoder->have_cyc)
1893 return;
1894
1895 decoder->sample_cyc = true;
1896
1897 if (!decoder->pge || decoder->timestamp <= decoder->cyc_cnt_timestamp)
1898 return;
1899
1900 tsc_delta = decoder->timestamp - decoder->cyc_cnt_timestamp;
1901 tot_cyc_cnt = tsc_delta * decoder->tsc_to_cyc + decoder->base_cyc_cnt;
1902
1903 if (tot_cyc_cnt > decoder->tot_cyc_cnt)
1904 decoder->tot_cyc_cnt = tot_cyc_cnt;
1905 }
1906
intel_pt_calc_tma(struct intel_pt_decoder * decoder)1907 static void intel_pt_calc_tma(struct intel_pt_decoder *decoder)
1908 {
1909 uint32_t ctc = decoder->packet.payload;
1910 uint32_t fc = decoder->packet.count;
1911 uint32_t ctc_rem = ctc & decoder->ctc_rem_mask;
1912
1913 if (!decoder->tsc_ctc_ratio_d)
1914 return;
1915
1916 if (decoder->pge && !decoder->in_psb)
1917 intel_pt_mtc_cyc_cnt_pge(decoder);
1918 else
1919 intel_pt_mtc_cyc_cnt_upd(decoder);
1920
1921 decoder->last_mtc = (ctc >> decoder->mtc_shift) & 0xff;
1922 decoder->last_ctc = ctc - ctc_rem;
1923 decoder->ctc_timestamp = decoder->tsc_timestamp - fc;
1924 if (decoder->tsc_ctc_mult) {
1925 decoder->ctc_timestamp -= ctc_rem * decoder->tsc_ctc_mult;
1926 } else {
1927 decoder->ctc_timestamp -= multdiv(ctc_rem,
1928 decoder->tsc_ctc_ratio_n,
1929 decoder->tsc_ctc_ratio_d);
1930 }
1931 decoder->ctc_delta = 0;
1932 decoder->have_tma = true;
1933 decoder->fixup_last_mtc = true;
1934 intel_pt_log("CTC timestamp " x64_fmt " last MTC %#x CTC rem %#x\n",
1935 decoder->ctc_timestamp, decoder->last_mtc, ctc_rem);
1936 }
1937
intel_pt_calc_mtc_timestamp(struct intel_pt_decoder * decoder)1938 static void intel_pt_calc_mtc_timestamp(struct intel_pt_decoder *decoder)
1939 {
1940 uint64_t timestamp;
1941 uint32_t mtc, mtc_delta;
1942
1943 if (!decoder->have_tma)
1944 return;
1945
1946 mtc = decoder->packet.payload;
1947
1948 if (decoder->mtc_shift > 8 && decoder->fixup_last_mtc) {
1949 decoder->fixup_last_mtc = false;
1950 intel_pt_fixup_last_mtc(mtc, decoder->mtc_shift,
1951 &decoder->last_mtc);
1952 }
1953
1954 if (mtc > decoder->last_mtc)
1955 mtc_delta = mtc - decoder->last_mtc;
1956 else
1957 mtc_delta = mtc + 256 - decoder->last_mtc;
1958
1959 decoder->ctc_delta += mtc_delta << decoder->mtc_shift;
1960
1961 if (decoder->tsc_ctc_mult) {
1962 timestamp = decoder->ctc_timestamp +
1963 decoder->ctc_delta * decoder->tsc_ctc_mult;
1964 } else {
1965 timestamp = decoder->ctc_timestamp +
1966 multdiv(decoder->ctc_delta,
1967 decoder->tsc_ctc_ratio_n,
1968 decoder->tsc_ctc_ratio_d);
1969 }
1970
1971 if (timestamp < decoder->timestamp)
1972 intel_pt_log("Suppressing MTC timestamp " x64_fmt " less than current timestamp " x64_fmt "\n",
1973 timestamp, decoder->timestamp);
1974 else
1975 decoder->timestamp = timestamp;
1976
1977 intel_pt_mtc_cyc_cnt_upd(decoder);
1978
1979 decoder->timestamp_insn_cnt = 0;
1980 decoder->last_mtc = mtc;
1981
1982 if (decoder->last_packet_type == INTEL_PT_CYC) {
1983 decoder->cyc_ref_timestamp = decoder->timestamp;
1984 decoder->cycle_cnt = 0;
1985 decoder->have_calc_cyc_to_tsc = false;
1986 intel_pt_calc_cyc_to_tsc(decoder, true);
1987 }
1988
1989 intel_pt_log_to("Setting timestamp", decoder->timestamp);
1990 }
1991
intel_pt_calc_cbr(struct intel_pt_decoder * decoder)1992 static void intel_pt_calc_cbr(struct intel_pt_decoder *decoder)
1993 {
1994 unsigned int cbr = decoder->packet.payload & 0xff;
1995
1996 decoder->cbr_payload = decoder->packet.payload;
1997
1998 if (decoder->cbr == cbr)
1999 return;
2000
2001 decoder->cbr = cbr;
2002 decoder->cbr_cyc_to_tsc = decoder->max_non_turbo_ratio_fp / cbr;
2003 decoder->cyc_ref_timestamp = decoder->timestamp;
2004 decoder->cycle_cnt = 0;
2005
2006 intel_pt_mtc_cyc_cnt_cbr(decoder);
2007 }
2008
intel_pt_calc_cyc_timestamp(struct intel_pt_decoder * decoder)2009 static void intel_pt_calc_cyc_timestamp(struct intel_pt_decoder *decoder)
2010 {
2011 uint64_t timestamp = decoder->cyc_ref_timestamp;
2012
2013 decoder->have_cyc = true;
2014
2015 decoder->cycle_cnt += decoder->packet.payload;
2016 if (decoder->pge)
2017 decoder->tot_cyc_cnt += decoder->packet.payload;
2018 decoder->sample_cyc = true;
2019
2020 if (!decoder->cyc_ref_timestamp)
2021 return;
2022
2023 if (decoder->have_calc_cyc_to_tsc)
2024 timestamp += decoder->cycle_cnt * decoder->calc_cyc_to_tsc;
2025 else if (decoder->cbr)
2026 timestamp += decoder->cycle_cnt * decoder->cbr_cyc_to_tsc;
2027 else
2028 return;
2029
2030 if (timestamp < decoder->timestamp)
2031 intel_pt_log("Suppressing CYC timestamp " x64_fmt " less than current timestamp " x64_fmt "\n",
2032 timestamp, decoder->timestamp);
2033 else
2034 decoder->timestamp = timestamp;
2035
2036 decoder->timestamp_insn_cnt = 0;
2037
2038 intel_pt_log_to("Setting timestamp", decoder->timestamp);
2039 }
2040
intel_pt_bbp(struct intel_pt_decoder * decoder)2041 static void intel_pt_bbp(struct intel_pt_decoder *decoder)
2042 {
2043 if (decoder->prev_pkt_ctx == INTEL_PT_NO_CTX) {
2044 memset(decoder->state.items.mask, 0, sizeof(decoder->state.items.mask));
2045 decoder->state.items.is_32_bit = false;
2046 }
2047 decoder->blk_type = decoder->packet.payload;
2048 decoder->blk_type_pos = intel_pt_blk_type_pos(decoder->blk_type);
2049 if (decoder->blk_type == INTEL_PT_GP_REGS)
2050 decoder->state.items.is_32_bit = decoder->packet.count;
2051 if (decoder->blk_type_pos < 0) {
2052 intel_pt_log("WARNING: Unknown block type %u\n",
2053 decoder->blk_type);
2054 } else if (decoder->state.items.mask[decoder->blk_type_pos]) {
2055 intel_pt_log("WARNING: Duplicate block type %u\n",
2056 decoder->blk_type);
2057 }
2058 }
2059
intel_pt_bip(struct intel_pt_decoder * decoder)2060 static void intel_pt_bip(struct intel_pt_decoder *decoder)
2061 {
2062 uint32_t id = decoder->packet.count;
2063 uint32_t bit = 1 << id;
2064 int pos = decoder->blk_type_pos;
2065
2066 if (pos < 0 || id >= INTEL_PT_BLK_ITEM_ID_CNT) {
2067 intel_pt_log("WARNING: Unknown block item %u type %d\n",
2068 id, decoder->blk_type);
2069 return;
2070 }
2071
2072 if (decoder->state.items.mask[pos] & bit) {
2073 intel_pt_log("WARNING: Duplicate block item %u type %d\n",
2074 id, decoder->blk_type);
2075 }
2076
2077 decoder->state.items.mask[pos] |= bit;
2078 decoder->state.items.val[pos][id] = decoder->packet.payload;
2079 }
2080
2081 /* Walk PSB+ packets when already in sync. */
intel_pt_walk_psbend(struct intel_pt_decoder * decoder)2082 static int intel_pt_walk_psbend(struct intel_pt_decoder *decoder)
2083 {
2084 int err;
2085
2086 decoder->in_psb = true;
2087
2088 while (1) {
2089 err = intel_pt_get_next_packet(decoder);
2090 if (err)
2091 goto out;
2092
2093 switch (decoder->packet.type) {
2094 case INTEL_PT_PSBEND:
2095 err = 0;
2096 goto out;
2097
2098 case INTEL_PT_TIP_PGD:
2099 case INTEL_PT_TIP_PGE:
2100 case INTEL_PT_TIP:
2101 case INTEL_PT_TNT:
2102 case INTEL_PT_TRACESTOP:
2103 case INTEL_PT_BAD:
2104 case INTEL_PT_PSB:
2105 case INTEL_PT_PTWRITE:
2106 case INTEL_PT_PTWRITE_IP:
2107 case INTEL_PT_EXSTOP:
2108 case INTEL_PT_EXSTOP_IP:
2109 case INTEL_PT_MWAIT:
2110 case INTEL_PT_PWRE:
2111 case INTEL_PT_PWRX:
2112 case INTEL_PT_BBP:
2113 case INTEL_PT_BIP:
2114 case INTEL_PT_BEP:
2115 case INTEL_PT_BEP_IP:
2116 case INTEL_PT_CFE:
2117 case INTEL_PT_CFE_IP:
2118 case INTEL_PT_EVD:
2119 decoder->have_tma = false;
2120 intel_pt_log("ERROR: Unexpected packet\n");
2121 err = -EAGAIN;
2122 goto out;
2123
2124 case INTEL_PT_OVF:
2125 err = intel_pt_overflow(decoder);
2126 goto out;
2127
2128 case INTEL_PT_TSC:
2129 intel_pt_calc_tsc_timestamp(decoder);
2130 break;
2131
2132 case INTEL_PT_TMA:
2133 intel_pt_calc_tma(decoder);
2134 break;
2135
2136 case INTEL_PT_CBR:
2137 intel_pt_calc_cbr(decoder);
2138 break;
2139
2140 case INTEL_PT_MODE_EXEC:
2141 intel_pt_mode_exec_status(decoder);
2142 break;
2143
2144 case INTEL_PT_PIP:
2145 intel_pt_set_pip(decoder);
2146 break;
2147
2148 case INTEL_PT_FUP:
2149 decoder->pge = true;
2150 if (decoder->packet.count) {
2151 intel_pt_set_last_ip(decoder);
2152 decoder->psb_ip = decoder->last_ip;
2153 }
2154 break;
2155
2156 case INTEL_PT_MODE_TSX:
2157 intel_pt_update_in_tx(decoder);
2158 break;
2159
2160 case INTEL_PT_MTC:
2161 intel_pt_calc_mtc_timestamp(decoder);
2162 if (decoder->period_type == INTEL_PT_PERIOD_MTC)
2163 decoder->state.type |= INTEL_PT_INSTRUCTION;
2164 break;
2165
2166 case INTEL_PT_CYC:
2167 intel_pt_calc_cyc_timestamp(decoder);
2168 break;
2169
2170 case INTEL_PT_VMCS:
2171 case INTEL_PT_MNT:
2172 case INTEL_PT_PAD:
2173 default:
2174 break;
2175 }
2176 }
2177 out:
2178 decoder->in_psb = false;
2179
2180 return err;
2181 }
2182
intel_pt_walk_fup_tip(struct intel_pt_decoder * decoder)2183 static int intel_pt_walk_fup_tip(struct intel_pt_decoder *decoder)
2184 {
2185 int err;
2186
2187 if (decoder->tx_flags & INTEL_PT_ABORT_TX) {
2188 decoder->tx_flags = 0;
2189 decoder->state.flags &= ~INTEL_PT_IN_TX;
2190 decoder->state.flags |= INTEL_PT_ABORT_TX;
2191 } else {
2192 decoder->state.flags |= INTEL_PT_ASYNC;
2193 }
2194
2195 while (1) {
2196 err = intel_pt_get_next_packet(decoder);
2197 if (err)
2198 return err;
2199
2200 switch (decoder->packet.type) {
2201 case INTEL_PT_TNT:
2202 case INTEL_PT_FUP:
2203 case INTEL_PT_TRACESTOP:
2204 case INTEL_PT_PSB:
2205 case INTEL_PT_TSC:
2206 case INTEL_PT_TMA:
2207 case INTEL_PT_MODE_TSX:
2208 case INTEL_PT_BAD:
2209 case INTEL_PT_PSBEND:
2210 case INTEL_PT_PTWRITE:
2211 case INTEL_PT_PTWRITE_IP:
2212 case INTEL_PT_EXSTOP:
2213 case INTEL_PT_EXSTOP_IP:
2214 case INTEL_PT_MWAIT:
2215 case INTEL_PT_PWRE:
2216 case INTEL_PT_PWRX:
2217 case INTEL_PT_BBP:
2218 case INTEL_PT_BIP:
2219 case INTEL_PT_BEP:
2220 case INTEL_PT_BEP_IP:
2221 case INTEL_PT_CFE:
2222 case INTEL_PT_CFE_IP:
2223 case INTEL_PT_EVD:
2224 intel_pt_log("ERROR: Missing TIP after FUP\n");
2225 decoder->pkt_state = INTEL_PT_STATE_ERR3;
2226 decoder->pkt_step = 0;
2227 return -ENOENT;
2228
2229 case INTEL_PT_CBR:
2230 intel_pt_calc_cbr(decoder);
2231 break;
2232
2233 case INTEL_PT_OVF:
2234 return intel_pt_overflow(decoder);
2235
2236 case INTEL_PT_TIP_PGD:
2237 decoder->state.from_ip = decoder->ip;
2238 if (decoder->packet.count == 0) {
2239 decoder->state.to_ip = 0;
2240 } else {
2241 intel_pt_set_ip(decoder);
2242 decoder->state.to_ip = decoder->ip;
2243 }
2244 decoder->pge = false;
2245 decoder->continuous_period = false;
2246 decoder->state.type |= INTEL_PT_TRACE_END;
2247 intel_pt_update_nr(decoder);
2248 return 0;
2249
2250 case INTEL_PT_TIP_PGE:
2251 decoder->pge = true;
2252 intel_pt_log("Omitting PGE ip " x64_fmt "\n",
2253 decoder->ip);
2254 decoder->state.from_ip = 0;
2255 if (decoder->packet.count == 0) {
2256 decoder->state.to_ip = 0;
2257 } else {
2258 intel_pt_set_ip(decoder);
2259 decoder->state.to_ip = decoder->ip;
2260 }
2261 decoder->state.type |= INTEL_PT_TRACE_BEGIN;
2262 intel_pt_mtc_cyc_cnt_pge(decoder);
2263 intel_pt_set_nr(decoder);
2264 return 0;
2265
2266 case INTEL_PT_TIP:
2267 decoder->state.from_ip = decoder->ip;
2268 if (decoder->packet.count == 0) {
2269 decoder->state.to_ip = 0;
2270 } else {
2271 intel_pt_set_ip(decoder);
2272 decoder->state.to_ip = decoder->ip;
2273 }
2274 intel_pt_update_nr(decoder);
2275 intel_pt_sample_iflag_chg(decoder);
2276 return 0;
2277
2278 case INTEL_PT_PIP:
2279 intel_pt_update_pip(decoder);
2280 break;
2281
2282 case INTEL_PT_MTC:
2283 intel_pt_calc_mtc_timestamp(decoder);
2284 if (decoder->period_type == INTEL_PT_PERIOD_MTC)
2285 decoder->state.type |= INTEL_PT_INSTRUCTION;
2286 break;
2287
2288 case INTEL_PT_CYC:
2289 intel_pt_calc_cyc_timestamp(decoder);
2290 break;
2291
2292 case INTEL_PT_MODE_EXEC:
2293 intel_pt_mode_exec(decoder);
2294 break;
2295
2296 case INTEL_PT_VMCS:
2297 case INTEL_PT_MNT:
2298 case INTEL_PT_PAD:
2299 break;
2300
2301 default:
2302 return intel_pt_bug(decoder);
2303 }
2304 }
2305 }
2306
intel_pt_resample(struct intel_pt_decoder * decoder)2307 static int intel_pt_resample(struct intel_pt_decoder *decoder)
2308 {
2309 decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
2310 decoder->state.type = INTEL_PT_INSTRUCTION;
2311 decoder->state.from_ip = decoder->ip;
2312 decoder->state.to_ip = 0;
2313 return 0;
2314 }
2315
2316 struct intel_pt_vm_tsc_info {
2317 struct intel_pt_pkt pip_packet;
2318 struct intel_pt_pkt vmcs_packet;
2319 struct intel_pt_pkt tma_packet;
2320 bool tsc, pip, vmcs, tma, psbend;
2321 uint64_t ctc_delta;
2322 uint64_t last_ctc;
2323 int max_lookahead;
2324 };
2325
2326 /* Lookahead and get the PIP, VMCS and TMA packets from PSB+ */
intel_pt_vm_psb_lookahead_cb(struct intel_pt_pkt_info * pkt_info)2327 static int intel_pt_vm_psb_lookahead_cb(struct intel_pt_pkt_info *pkt_info)
2328 {
2329 struct intel_pt_vm_tsc_info *data = pkt_info->data;
2330
2331 switch (pkt_info->packet.type) {
2332 case INTEL_PT_PAD:
2333 case INTEL_PT_MNT:
2334 case INTEL_PT_MODE_EXEC:
2335 case INTEL_PT_MODE_TSX:
2336 case INTEL_PT_MTC:
2337 case INTEL_PT_FUP:
2338 case INTEL_PT_CYC:
2339 case INTEL_PT_CBR:
2340 break;
2341
2342 case INTEL_PT_TSC:
2343 data->tsc = true;
2344 break;
2345
2346 case INTEL_PT_TMA:
2347 data->tma_packet = pkt_info->packet;
2348 data->tma = true;
2349 break;
2350
2351 case INTEL_PT_PIP:
2352 data->pip_packet = pkt_info->packet;
2353 data->pip = true;
2354 break;
2355
2356 case INTEL_PT_VMCS:
2357 data->vmcs_packet = pkt_info->packet;
2358 data->vmcs = true;
2359 break;
2360
2361 case INTEL_PT_PSBEND:
2362 data->psbend = true;
2363 return 1;
2364
2365 case INTEL_PT_TIP_PGE:
2366 case INTEL_PT_PTWRITE:
2367 case INTEL_PT_PTWRITE_IP:
2368 case INTEL_PT_EXSTOP:
2369 case INTEL_PT_EXSTOP_IP:
2370 case INTEL_PT_MWAIT:
2371 case INTEL_PT_PWRE:
2372 case INTEL_PT_PWRX:
2373 case INTEL_PT_BBP:
2374 case INTEL_PT_BIP:
2375 case INTEL_PT_BEP:
2376 case INTEL_PT_BEP_IP:
2377 case INTEL_PT_OVF:
2378 case INTEL_PT_BAD:
2379 case INTEL_PT_TNT:
2380 case INTEL_PT_TIP_PGD:
2381 case INTEL_PT_TIP:
2382 case INTEL_PT_PSB:
2383 case INTEL_PT_TRACESTOP:
2384 case INTEL_PT_CFE:
2385 case INTEL_PT_CFE_IP:
2386 case INTEL_PT_EVD:
2387 default:
2388 return 1;
2389 }
2390
2391 return 0;
2392 }
2393
2394 struct intel_pt_ovf_fup_info {
2395 int max_lookahead;
2396 bool found;
2397 };
2398
2399 /* Lookahead to detect a FUP packet after OVF */
intel_pt_ovf_fup_lookahead_cb(struct intel_pt_pkt_info * pkt_info)2400 static int intel_pt_ovf_fup_lookahead_cb(struct intel_pt_pkt_info *pkt_info)
2401 {
2402 struct intel_pt_ovf_fup_info *data = pkt_info->data;
2403
2404 if (pkt_info->packet.type == INTEL_PT_CYC ||
2405 pkt_info->packet.type == INTEL_PT_MTC ||
2406 pkt_info->packet.type == INTEL_PT_TSC)
2407 return !--(data->max_lookahead);
2408 data->found = pkt_info->packet.type == INTEL_PT_FUP;
2409 return 1;
2410 }
2411
intel_pt_ovf_fup_lookahead(struct intel_pt_decoder * decoder)2412 static bool intel_pt_ovf_fup_lookahead(struct intel_pt_decoder *decoder)
2413 {
2414 struct intel_pt_ovf_fup_info data = {
2415 .max_lookahead = 16,
2416 .found = false,
2417 };
2418
2419 intel_pt_pkt_lookahead(decoder, intel_pt_ovf_fup_lookahead_cb, &data);
2420 return data.found;
2421 }
2422
2423 /* Lookahead and get the TMA packet after TSC */
intel_pt_tma_lookahead_cb(struct intel_pt_pkt_info * pkt_info)2424 static int intel_pt_tma_lookahead_cb(struct intel_pt_pkt_info *pkt_info)
2425 {
2426 struct intel_pt_vm_tsc_info *data = pkt_info->data;
2427
2428 if (pkt_info->packet.type == INTEL_PT_CYC ||
2429 pkt_info->packet.type == INTEL_PT_MTC)
2430 return !--(data->max_lookahead);
2431
2432 if (pkt_info->packet.type == INTEL_PT_TMA) {
2433 data->tma_packet = pkt_info->packet;
2434 data->tma = true;
2435 }
2436 return 1;
2437 }
2438
intel_pt_ctc_to_tsc(struct intel_pt_decoder * decoder,uint64_t ctc)2439 static uint64_t intel_pt_ctc_to_tsc(struct intel_pt_decoder *decoder, uint64_t ctc)
2440 {
2441 if (decoder->tsc_ctc_mult)
2442 return ctc * decoder->tsc_ctc_mult;
2443 else
2444 return multdiv(ctc, decoder->tsc_ctc_ratio_n, decoder->tsc_ctc_ratio_d);
2445 }
2446
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)2447 static uint64_t intel_pt_calc_expected_tsc(struct intel_pt_decoder *decoder,
2448 uint32_t ctc,
2449 uint32_t fc,
2450 uint64_t last_ctc_timestamp,
2451 uint64_t ctc_delta,
2452 uint32_t last_ctc)
2453 {
2454 /* Number of CTC ticks from last_ctc_timestamp to last_mtc */
2455 uint64_t last_mtc_ctc = last_ctc + ctc_delta;
2456 /*
2457 * Number of CTC ticks from there until current TMA packet. We would
2458 * expect last_mtc_ctc to be before ctc, but the TSC packet can slip
2459 * past an MTC, so a sign-extended value is used.
2460 */
2461 uint64_t delta = (int16_t)((uint16_t)ctc - (uint16_t)last_mtc_ctc);
2462 /* Total CTC ticks from last_ctc_timestamp to current TMA packet */
2463 uint64_t new_ctc_delta = ctc_delta + delta;
2464 uint64_t expected_tsc;
2465
2466 /*
2467 * Convert CTC ticks to TSC ticks, add the starting point
2468 * (last_ctc_timestamp) and the fast counter from the TMA packet.
2469 */
2470 expected_tsc = last_ctc_timestamp + intel_pt_ctc_to_tsc(decoder, new_ctc_delta) + fc;
2471
2472 if (intel_pt_enable_logging) {
2473 intel_pt_log_x64(last_mtc_ctc);
2474 intel_pt_log_x32(last_ctc);
2475 intel_pt_log_x64(ctc_delta);
2476 intel_pt_log_x64(delta);
2477 intel_pt_log_x32(ctc);
2478 intel_pt_log_x64(new_ctc_delta);
2479 intel_pt_log_x64(last_ctc_timestamp);
2480 intel_pt_log_x32(fc);
2481 intel_pt_log_x64(intel_pt_ctc_to_tsc(decoder, new_ctc_delta));
2482 intel_pt_log_x64(expected_tsc);
2483 }
2484
2485 return expected_tsc;
2486 }
2487
intel_pt_expected_tsc(struct intel_pt_decoder * decoder,struct intel_pt_vm_tsc_info * data)2488 static uint64_t intel_pt_expected_tsc(struct intel_pt_decoder *decoder,
2489 struct intel_pt_vm_tsc_info *data)
2490 {
2491 uint32_t ctc = data->tma_packet.payload;
2492 uint32_t fc = data->tma_packet.count;
2493
2494 return intel_pt_calc_expected_tsc(decoder, ctc, fc,
2495 decoder->ctc_timestamp,
2496 data->ctc_delta, data->last_ctc);
2497 }
2498
intel_pt_translate_vm_tsc(struct intel_pt_decoder * decoder,struct intel_pt_vmcs_info * vmcs_info)2499 static void intel_pt_translate_vm_tsc(struct intel_pt_decoder *decoder,
2500 struct intel_pt_vmcs_info *vmcs_info)
2501 {
2502 uint64_t payload = decoder->packet.payload;
2503
2504 /* VMX adds the TSC Offset, so subtract to get host TSC */
2505 decoder->packet.payload -= vmcs_info->tsc_offset;
2506 /* TSC packet has only 7 bytes */
2507 decoder->packet.payload &= SEVEN_BYTES;
2508
2509 /*
2510 * The buffer is mmapped from the data file, so this also updates the
2511 * data file.
2512 */
2513 if (!decoder->vm_tm_corr_dry_run)
2514 memcpy((void *)decoder->buf + 1, &decoder->packet.payload, 7);
2515
2516 intel_pt_log("Translated VM TSC %#" PRIx64 " -> %#" PRIx64
2517 " VMCS %#" PRIx64 " TSC Offset %#" PRIx64 "\n",
2518 payload, decoder->packet.payload, vmcs_info->vmcs,
2519 vmcs_info->tsc_offset);
2520 }
2521
intel_pt_translate_vm_tsc_offset(struct intel_pt_decoder * decoder,uint64_t tsc_offset)2522 static void intel_pt_translate_vm_tsc_offset(struct intel_pt_decoder *decoder,
2523 uint64_t tsc_offset)
2524 {
2525 struct intel_pt_vmcs_info vmcs_info = {
2526 .vmcs = NO_VMCS,
2527 .tsc_offset = tsc_offset
2528 };
2529
2530 intel_pt_translate_vm_tsc(decoder, &vmcs_info);
2531 }
2532
in_vm(uint64_t pip_payload)2533 static inline bool in_vm(uint64_t pip_payload)
2534 {
2535 return pip_payload & 1;
2536 }
2537
pip_in_vm(struct intel_pt_pkt * pip_packet)2538 static inline bool pip_in_vm(struct intel_pt_pkt *pip_packet)
2539 {
2540 return pip_packet->payload & 1;
2541 }
2542
intel_pt_print_vmcs_info(struct intel_pt_vmcs_info * vmcs_info)2543 static void intel_pt_print_vmcs_info(struct intel_pt_vmcs_info *vmcs_info)
2544 {
2545 p_log("VMCS: %#" PRIx64 " TSC Offset %#" PRIx64,
2546 vmcs_info->vmcs, vmcs_info->tsc_offset);
2547 }
2548
intel_pt_vm_tm_corr_psb(struct intel_pt_decoder * decoder,struct intel_pt_vm_tsc_info * data)2549 static void intel_pt_vm_tm_corr_psb(struct intel_pt_decoder *decoder,
2550 struct intel_pt_vm_tsc_info *data)
2551 {
2552 memset(data, 0, sizeof(*data));
2553 data->ctc_delta = decoder->ctc_delta;
2554 data->last_ctc = decoder->last_ctc;
2555 intel_pt_pkt_lookahead(decoder, intel_pt_vm_psb_lookahead_cb, data);
2556 if (data->tsc && !data->psbend)
2557 p_log("ERROR: PSB without PSBEND");
2558 decoder->in_psb = data->psbend;
2559 }
2560
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)2561 static void intel_pt_vm_tm_corr_first_tsc(struct intel_pt_decoder *decoder,
2562 struct intel_pt_vm_tsc_info *data,
2563 struct intel_pt_vmcs_info *vmcs_info,
2564 uint64_t host_tsc)
2565 {
2566 if (!decoder->in_psb) {
2567 /* Can't happen */
2568 p_log("ERROR: First TSC is not in PSB+");
2569 }
2570
2571 if (data->pip) {
2572 if (pip_in_vm(&data->pip_packet)) { /* Guest */
2573 if (vmcs_info && vmcs_info->tsc_offset) {
2574 intel_pt_translate_vm_tsc(decoder, vmcs_info);
2575 decoder->vm_tm_corr_reliable = true;
2576 } else {
2577 p_log("ERROR: First TSC, unknown TSC Offset");
2578 }
2579 } else { /* Host */
2580 decoder->vm_tm_corr_reliable = true;
2581 }
2582 } else { /* Host or Guest */
2583 decoder->vm_tm_corr_reliable = false;
2584 if (intel_pt_time_in_range(decoder, host_tsc)) {
2585 /* Assume Host */
2586 } else {
2587 /* Assume Guest */
2588 if (vmcs_info && vmcs_info->tsc_offset)
2589 intel_pt_translate_vm_tsc(decoder, vmcs_info);
2590 else
2591 p_log("ERROR: First TSC, no PIP, unknown TSC Offset");
2592 }
2593 }
2594 }
2595
intel_pt_vm_tm_corr_tsc(struct intel_pt_decoder * decoder,struct intel_pt_vm_tsc_info * data)2596 static void intel_pt_vm_tm_corr_tsc(struct intel_pt_decoder *decoder,
2597 struct intel_pt_vm_tsc_info *data)
2598 {
2599 struct intel_pt_vmcs_info *vmcs_info;
2600 uint64_t tsc_offset = 0;
2601 uint64_t vmcs;
2602 bool reliable = true;
2603 uint64_t expected_tsc;
2604 uint64_t host_tsc;
2605 uint64_t ref_timestamp;
2606
2607 bool assign = false;
2608 bool assign_reliable = false;
2609
2610 /* Already have 'data' for the in_psb case */
2611 if (!decoder->in_psb) {
2612 memset(data, 0, sizeof(*data));
2613 data->ctc_delta = decoder->ctc_delta;
2614 data->last_ctc = decoder->last_ctc;
2615 data->max_lookahead = 16;
2616 intel_pt_pkt_lookahead(decoder, intel_pt_tma_lookahead_cb, data);
2617 if (decoder->pge) {
2618 data->pip = true;
2619 data->pip_packet.payload = decoder->pip_payload;
2620 }
2621 }
2622
2623 /* Calculations depend on having TMA packets */
2624 if (!data->tma) {
2625 p_log("ERROR: TSC without TMA");
2626 return;
2627 }
2628
2629 vmcs = data->vmcs ? data->vmcs_packet.payload : decoder->vmcs;
2630 if (vmcs == NO_VMCS)
2631 vmcs = 0;
2632
2633 vmcs_info = decoder->findnew_vmcs_info(decoder->data, vmcs);
2634
2635 ref_timestamp = decoder->timestamp ? decoder->timestamp : decoder->buf_timestamp;
2636 host_tsc = intel_pt_8b_tsc(decoder->packet.payload, ref_timestamp);
2637
2638 if (!decoder->ctc_timestamp) {
2639 intel_pt_vm_tm_corr_first_tsc(decoder, data, vmcs_info, host_tsc);
2640 return;
2641 }
2642
2643 expected_tsc = intel_pt_expected_tsc(decoder, data);
2644
2645 tsc_offset = host_tsc - expected_tsc;
2646
2647 /* Determine if TSC is from Host or Guest */
2648 if (data->pip) {
2649 if (pip_in_vm(&data->pip_packet)) { /* Guest */
2650 if (!vmcs_info) {
2651 /* PIP NR=1 without VMCS cannot happen */
2652 p_log("ERROR: Missing VMCS");
2653 intel_pt_translate_vm_tsc_offset(decoder, tsc_offset);
2654 decoder->vm_tm_corr_reliable = false;
2655 return;
2656 }
2657 } else { /* Host */
2658 decoder->last_reliable_timestamp = host_tsc;
2659 decoder->vm_tm_corr_reliable = true;
2660 return;
2661 }
2662 } else { /* Host or Guest */
2663 reliable = false; /* Host/Guest is a guess, so not reliable */
2664 if (decoder->in_psb) {
2665 if (!tsc_offset)
2666 return; /* Zero TSC Offset, assume Host */
2667 /*
2668 * TSC packet has only 7 bytes of TSC. We have no
2669 * information about the Guest's 8th byte, but it
2670 * doesn't matter because we only need 7 bytes.
2671 * Here, since the 8th byte is unreliable and
2672 * irrelevant, compare only 7 byes.
2673 */
2674 if (vmcs_info &&
2675 (tsc_offset & SEVEN_BYTES) ==
2676 (vmcs_info->tsc_offset & SEVEN_BYTES)) {
2677 /* Same TSC Offset as last VMCS, assume Guest */
2678 goto guest;
2679 }
2680 }
2681 /*
2682 * Check if the host_tsc is within the expected range.
2683 * Note, we could narrow the range more by looking ahead for
2684 * the next host TSC in the same buffer, but we don't bother to
2685 * do that because this is probably good enough.
2686 */
2687 if (host_tsc >= expected_tsc && intel_pt_time_in_range(decoder, host_tsc)) {
2688 /* Within expected range for Host TSC, assume Host */
2689 decoder->vm_tm_corr_reliable = false;
2690 return;
2691 }
2692 }
2693
2694 guest: /* Assuming Guest */
2695
2696 /* Determine whether to assign TSC Offset */
2697 if (vmcs_info && vmcs_info->vmcs) {
2698 if (vmcs_info->tsc_offset && vmcs_info->reliable) {
2699 assign = false;
2700 } else if (decoder->in_psb && data->pip && decoder->vm_tm_corr_reliable &&
2701 decoder->vm_tm_corr_continuous && decoder->vm_tm_corr_same_buf) {
2702 /* Continuous tracing, TSC in a PSB is not a time loss */
2703 assign = true;
2704 assign_reliable = true;
2705 } else if (decoder->in_psb && data->pip && decoder->vm_tm_corr_same_buf) {
2706 /*
2707 * Unlikely to be a time loss TSC in a PSB which is not
2708 * at the start of a buffer.
2709 */
2710 assign = true;
2711 assign_reliable = false;
2712 }
2713 }
2714
2715 /* Record VMCS TSC Offset */
2716 if (assign && (vmcs_info->tsc_offset != tsc_offset ||
2717 vmcs_info->reliable != assign_reliable)) {
2718 bool print = vmcs_info->tsc_offset != tsc_offset;
2719
2720 vmcs_info->tsc_offset = tsc_offset;
2721 vmcs_info->reliable = assign_reliable;
2722 if (print)
2723 intel_pt_print_vmcs_info(vmcs_info);
2724 }
2725
2726 /* Determine what TSC Offset to use */
2727 if (vmcs_info && vmcs_info->tsc_offset) {
2728 if (!vmcs_info->reliable)
2729 reliable = false;
2730 intel_pt_translate_vm_tsc(decoder, vmcs_info);
2731 } else {
2732 reliable = false;
2733 if (vmcs_info) {
2734 if (!vmcs_info->error_printed) {
2735 p_log("ERROR: Unknown TSC Offset for VMCS %#" PRIx64,
2736 vmcs_info->vmcs);
2737 vmcs_info->error_printed = true;
2738 }
2739 } else {
2740 if (intel_pt_print_once(decoder, INTEL_PT_PRT_ONCE_UNK_VMCS))
2741 p_log("ERROR: Unknown VMCS");
2742 }
2743 intel_pt_translate_vm_tsc_offset(decoder, tsc_offset);
2744 }
2745
2746 decoder->vm_tm_corr_reliable = reliable;
2747 }
2748
intel_pt_vm_tm_corr_pebs_tsc(struct intel_pt_decoder * decoder)2749 static void intel_pt_vm_tm_corr_pebs_tsc(struct intel_pt_decoder *decoder)
2750 {
2751 uint64_t host_tsc = decoder->packet.payload;
2752 uint64_t guest_tsc = decoder->packet.payload;
2753 struct intel_pt_vmcs_info *vmcs_info;
2754 uint64_t vmcs;
2755
2756 vmcs = decoder->vmcs;
2757 if (vmcs == NO_VMCS)
2758 vmcs = 0;
2759
2760 vmcs_info = decoder->findnew_vmcs_info(decoder->data, vmcs);
2761
2762 if (decoder->pge) {
2763 if (in_vm(decoder->pip_payload)) { /* Guest */
2764 if (!vmcs_info) {
2765 /* PIP NR=1 without VMCS cannot happen */
2766 p_log("ERROR: Missing VMCS");
2767 }
2768 } else { /* Host */
2769 return;
2770 }
2771 } else { /* Host or Guest */
2772 if (intel_pt_time_in_range(decoder, host_tsc)) {
2773 /* Within expected range for Host TSC, assume Host */
2774 return;
2775 }
2776 }
2777
2778 if (vmcs_info) {
2779 /* Translate Guest TSC to Host TSC */
2780 host_tsc = ((guest_tsc & SEVEN_BYTES) - vmcs_info->tsc_offset) & SEVEN_BYTES;
2781 host_tsc = intel_pt_8b_tsc(host_tsc, decoder->timestamp);
2782 intel_pt_log("Translated VM TSC %#" PRIx64 " -> %#" PRIx64
2783 " VMCS %#" PRIx64 " TSC Offset %#" PRIx64 "\n",
2784 guest_tsc, host_tsc, vmcs_info->vmcs,
2785 vmcs_info->tsc_offset);
2786 if (!intel_pt_time_in_range(decoder, host_tsc) &&
2787 intel_pt_print_once(decoder, INTEL_PT_PRT_ONCE_ERANGE))
2788 p_log("Timestamp out of range");
2789 } else {
2790 if (intel_pt_print_once(decoder, INTEL_PT_PRT_ONCE_UNK_VMCS))
2791 p_log("ERROR: Unknown VMCS");
2792 host_tsc = decoder->timestamp;
2793 }
2794
2795 decoder->packet.payload = host_tsc;
2796
2797 if (!decoder->vm_tm_corr_dry_run)
2798 memcpy((void *)decoder->buf + 1, &host_tsc, 8);
2799 }
2800
intel_pt_vm_time_correlation(struct intel_pt_decoder * decoder)2801 static int intel_pt_vm_time_correlation(struct intel_pt_decoder *decoder)
2802 {
2803 struct intel_pt_vm_tsc_info data = { .psbend = false };
2804 bool pge;
2805 int err;
2806
2807 if (decoder->in_psb)
2808 intel_pt_vm_tm_corr_psb(decoder, &data);
2809
2810 while (1) {
2811 err = intel_pt_get_next_packet(decoder);
2812 if (err == -ENOLINK)
2813 continue;
2814 if (err)
2815 break;
2816
2817 switch (decoder->packet.type) {
2818 case INTEL_PT_TIP_PGD:
2819 decoder->pge = false;
2820 decoder->vm_tm_corr_continuous = false;
2821 break;
2822
2823 case INTEL_PT_TNT:
2824 case INTEL_PT_TIP:
2825 case INTEL_PT_TIP_PGE:
2826 decoder->pge = true;
2827 break;
2828
2829 case INTEL_PT_OVF:
2830 decoder->in_psb = false;
2831 pge = decoder->pge;
2832 decoder->pge = intel_pt_ovf_fup_lookahead(decoder);
2833 if (pge != decoder->pge)
2834 intel_pt_log("Surprising PGE change in OVF!");
2835 if (!decoder->pge)
2836 decoder->vm_tm_corr_continuous = false;
2837 break;
2838
2839 case INTEL_PT_FUP:
2840 if (decoder->in_psb)
2841 decoder->pge = true;
2842 break;
2843
2844 case INTEL_PT_TRACESTOP:
2845 decoder->pge = false;
2846 decoder->vm_tm_corr_continuous = false;
2847 decoder->have_tma = false;
2848 break;
2849
2850 case INTEL_PT_PSB:
2851 intel_pt_vm_tm_corr_psb(decoder, &data);
2852 break;
2853
2854 case INTEL_PT_PIP:
2855 decoder->pip_payload = decoder->packet.payload;
2856 break;
2857
2858 case INTEL_PT_MTC:
2859 intel_pt_calc_mtc_timestamp(decoder);
2860 break;
2861
2862 case INTEL_PT_TSC:
2863 intel_pt_vm_tm_corr_tsc(decoder, &data);
2864 intel_pt_calc_tsc_timestamp(decoder);
2865 decoder->vm_tm_corr_same_buf = true;
2866 decoder->vm_tm_corr_continuous = decoder->pge;
2867 break;
2868
2869 case INTEL_PT_TMA:
2870 intel_pt_calc_tma(decoder);
2871 break;
2872
2873 case INTEL_PT_CYC:
2874 intel_pt_calc_cyc_timestamp(decoder);
2875 break;
2876
2877 case INTEL_PT_CBR:
2878 intel_pt_calc_cbr(decoder);
2879 break;
2880
2881 case INTEL_PT_PSBEND:
2882 decoder->in_psb = false;
2883 data.psbend = false;
2884 break;
2885
2886 case INTEL_PT_VMCS:
2887 if (decoder->packet.payload != NO_VMCS)
2888 decoder->vmcs = decoder->packet.payload;
2889 break;
2890
2891 case INTEL_PT_BBP:
2892 decoder->blk_type = decoder->packet.payload;
2893 break;
2894
2895 case INTEL_PT_BIP:
2896 if (decoder->blk_type == INTEL_PT_PEBS_BASIC &&
2897 decoder->packet.count == 2)
2898 intel_pt_vm_tm_corr_pebs_tsc(decoder);
2899 break;
2900
2901 case INTEL_PT_BEP:
2902 case INTEL_PT_BEP_IP:
2903 decoder->blk_type = 0;
2904 break;
2905
2906 case INTEL_PT_CFE:
2907 case INTEL_PT_CFE_IP:
2908 case INTEL_PT_EVD:
2909 case INTEL_PT_MODE_EXEC:
2910 case INTEL_PT_MODE_TSX:
2911 case INTEL_PT_MNT:
2912 case INTEL_PT_PAD:
2913 case INTEL_PT_PTWRITE_IP:
2914 case INTEL_PT_PTWRITE:
2915 case INTEL_PT_MWAIT:
2916 case INTEL_PT_PWRE:
2917 case INTEL_PT_EXSTOP_IP:
2918 case INTEL_PT_EXSTOP:
2919 case INTEL_PT_PWRX:
2920 case INTEL_PT_BAD: /* Does not happen */
2921 default:
2922 break;
2923 }
2924 }
2925
2926 return err;
2927 }
2928
2929 #define HOP_PROCESS 0
2930 #define HOP_IGNORE 1
2931 #define HOP_RETURN 2
2932 #define HOP_AGAIN 3
2933
2934 static int intel_pt_scan_for_psb(struct intel_pt_decoder *decoder);
2935
2936 /* Hop mode: Ignore TNT, do not walk code, but get ip from FUPs and TIPs */
intel_pt_hop_trace(struct intel_pt_decoder * decoder,bool * no_tip,int * err)2937 static int intel_pt_hop_trace(struct intel_pt_decoder *decoder, bool *no_tip, int *err)
2938 {
2939 *err = 0;
2940
2941 /* Leap from PSB to PSB, getting ip from FUP within PSB+ */
2942 if (decoder->leap && !decoder->in_psb && decoder->packet.type != INTEL_PT_PSB) {
2943 *err = intel_pt_scan_for_psb(decoder);
2944 if (*err)
2945 return HOP_RETURN;
2946 }
2947
2948 switch (decoder->packet.type) {
2949 case INTEL_PT_TNT:
2950 return HOP_IGNORE;
2951
2952 case INTEL_PT_TIP_PGD:
2953 decoder->pge = false;
2954 if (!decoder->packet.count) {
2955 intel_pt_set_nr(decoder);
2956 return HOP_IGNORE;
2957 }
2958 intel_pt_set_ip(decoder);
2959 decoder->state.type |= INTEL_PT_TRACE_END;
2960 decoder->state.from_ip = 0;
2961 decoder->state.to_ip = decoder->ip;
2962 intel_pt_update_nr(decoder);
2963 return HOP_RETURN;
2964
2965 case INTEL_PT_TIP:
2966 if (!decoder->packet.count) {
2967 intel_pt_set_nr(decoder);
2968 return HOP_IGNORE;
2969 }
2970 intel_pt_set_ip(decoder);
2971 decoder->state.type = INTEL_PT_INSTRUCTION;
2972 decoder->state.from_ip = decoder->ip;
2973 decoder->state.to_ip = 0;
2974 intel_pt_update_nr(decoder);
2975 intel_pt_sample_iflag_chg(decoder);
2976 return HOP_RETURN;
2977
2978 case INTEL_PT_FUP:
2979 if (!decoder->packet.count)
2980 return HOP_IGNORE;
2981 intel_pt_set_ip(decoder);
2982 if (decoder->set_fup_mwait || decoder->set_fup_pwre)
2983 *no_tip = true;
2984 if (!decoder->branch_enable || !decoder->pge)
2985 *no_tip = true;
2986 if (*no_tip) {
2987 decoder->state.type = INTEL_PT_INSTRUCTION;
2988 decoder->state.from_ip = decoder->ip;
2989 decoder->state.to_ip = 0;
2990 intel_pt_fup_event(decoder, *no_tip);
2991 return HOP_RETURN;
2992 }
2993 intel_pt_fup_event(decoder, *no_tip);
2994 decoder->state.type |= INTEL_PT_INSTRUCTION | INTEL_PT_BRANCH;
2995 *err = intel_pt_walk_fup_tip(decoder);
2996 if (!*err && decoder->state.to_ip)
2997 decoder->pkt_state = INTEL_PT_STATE_RESAMPLE;
2998 return HOP_RETURN;
2999
3000 case INTEL_PT_PSB:
3001 decoder->state.psb_offset = decoder->pos;
3002 decoder->psb_ip = 0;
3003 decoder->last_ip = 0;
3004 decoder->have_last_ip = true;
3005 *err = intel_pt_walk_psbend(decoder);
3006 if (*err == -EAGAIN)
3007 return HOP_AGAIN;
3008 if (*err)
3009 return HOP_RETURN;
3010 decoder->state.type = INTEL_PT_PSB_EVT;
3011 if (decoder->psb_ip) {
3012 decoder->state.type |= INTEL_PT_INSTRUCTION;
3013 decoder->ip = decoder->psb_ip;
3014 }
3015 decoder->state.from_ip = decoder->psb_ip;
3016 decoder->state.to_ip = 0;
3017 return HOP_RETURN;
3018
3019 case INTEL_PT_BAD:
3020 case INTEL_PT_PAD:
3021 case INTEL_PT_TIP_PGE:
3022 case INTEL_PT_TSC:
3023 case INTEL_PT_TMA:
3024 case INTEL_PT_MODE_EXEC:
3025 case INTEL_PT_MODE_TSX:
3026 case INTEL_PT_MTC:
3027 case INTEL_PT_CYC:
3028 case INTEL_PT_VMCS:
3029 case INTEL_PT_PSBEND:
3030 case INTEL_PT_CBR:
3031 case INTEL_PT_TRACESTOP:
3032 case INTEL_PT_PIP:
3033 case INTEL_PT_OVF:
3034 case INTEL_PT_MNT:
3035 case INTEL_PT_PTWRITE:
3036 case INTEL_PT_PTWRITE_IP:
3037 case INTEL_PT_EXSTOP:
3038 case INTEL_PT_EXSTOP_IP:
3039 case INTEL_PT_MWAIT:
3040 case INTEL_PT_PWRE:
3041 case INTEL_PT_PWRX:
3042 case INTEL_PT_BBP:
3043 case INTEL_PT_BIP:
3044 case INTEL_PT_BEP:
3045 case INTEL_PT_BEP_IP:
3046 case INTEL_PT_CFE:
3047 case INTEL_PT_CFE_IP:
3048 case INTEL_PT_EVD:
3049 default:
3050 return HOP_PROCESS;
3051 }
3052 }
3053
3054 struct intel_pt_psb_info {
3055 struct intel_pt_pkt fup_packet;
3056 bool fup;
3057 int after_psbend;
3058 };
3059
3060 /* Lookahead and get the FUP packet from PSB+ */
intel_pt_psb_lookahead_cb(struct intel_pt_pkt_info * pkt_info)3061 static int intel_pt_psb_lookahead_cb(struct intel_pt_pkt_info *pkt_info)
3062 {
3063 struct intel_pt_psb_info *data = pkt_info->data;
3064
3065 switch (pkt_info->packet.type) {
3066 case INTEL_PT_PAD:
3067 case INTEL_PT_MNT:
3068 case INTEL_PT_TSC:
3069 case INTEL_PT_TMA:
3070 case INTEL_PT_MODE_EXEC:
3071 case INTEL_PT_MODE_TSX:
3072 case INTEL_PT_MTC:
3073 case INTEL_PT_CYC:
3074 case INTEL_PT_VMCS:
3075 case INTEL_PT_CBR:
3076 case INTEL_PT_PIP:
3077 if (data->after_psbend) {
3078 data->after_psbend -= 1;
3079 if (!data->after_psbend)
3080 return 1;
3081 }
3082 break;
3083
3084 case INTEL_PT_FUP:
3085 if (data->after_psbend)
3086 return 1;
3087 if (data->fup || pkt_info->packet.count == 0)
3088 return 1;
3089 data->fup_packet = pkt_info->packet;
3090 data->fup = true;
3091 break;
3092
3093 case INTEL_PT_PSBEND:
3094 if (!data->fup)
3095 return 1;
3096 /* Keep going to check for a TIP.PGE */
3097 data->after_psbend = 6;
3098 break;
3099
3100 case INTEL_PT_TIP_PGE:
3101 /* Ignore FUP in PSB+ if followed by TIP.PGE */
3102 if (data->after_psbend)
3103 data->fup = false;
3104 return 1;
3105
3106 case INTEL_PT_PTWRITE:
3107 case INTEL_PT_PTWRITE_IP:
3108 case INTEL_PT_EXSTOP:
3109 case INTEL_PT_EXSTOP_IP:
3110 case INTEL_PT_MWAIT:
3111 case INTEL_PT_PWRE:
3112 case INTEL_PT_PWRX:
3113 case INTEL_PT_BBP:
3114 case INTEL_PT_BIP:
3115 case INTEL_PT_BEP:
3116 case INTEL_PT_BEP_IP:
3117 case INTEL_PT_CFE:
3118 case INTEL_PT_CFE_IP:
3119 case INTEL_PT_EVD:
3120 if (data->after_psbend) {
3121 data->after_psbend -= 1;
3122 if (!data->after_psbend)
3123 return 1;
3124 break;
3125 }
3126 return 1;
3127
3128 case INTEL_PT_OVF:
3129 case INTEL_PT_BAD:
3130 case INTEL_PT_TNT:
3131 case INTEL_PT_TIP_PGD:
3132 case INTEL_PT_TIP:
3133 case INTEL_PT_PSB:
3134 case INTEL_PT_TRACESTOP:
3135 default:
3136 return 1;
3137 }
3138
3139 return 0;
3140 }
3141
intel_pt_psb(struct intel_pt_decoder * decoder)3142 static int intel_pt_psb(struct intel_pt_decoder *decoder)
3143 {
3144 int err;
3145
3146 decoder->last_ip = 0;
3147 decoder->psb_ip = 0;
3148 decoder->have_last_ip = true;
3149 intel_pt_clear_stack(&decoder->stack);
3150 err = intel_pt_walk_psbend(decoder);
3151 if (err)
3152 return err;
3153 decoder->state.type = INTEL_PT_PSB_EVT;
3154 decoder->state.from_ip = decoder->psb_ip;
3155 decoder->state.to_ip = 0;
3156 return 0;
3157 }
3158
intel_pt_fup_in_psb(struct intel_pt_decoder * decoder)3159 static int intel_pt_fup_in_psb(struct intel_pt_decoder *decoder)
3160 {
3161 int err;
3162
3163 if (decoder->ip != decoder->last_ip) {
3164 err = intel_pt_walk_fup(decoder);
3165 if (!err || err != -EAGAIN)
3166 return err;
3167 }
3168
3169 decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
3170 err = intel_pt_psb(decoder);
3171 if (err) {
3172 decoder->pkt_state = INTEL_PT_STATE_ERR3;
3173 return -ENOENT;
3174 }
3175
3176 return 0;
3177 }
3178
intel_pt_psb_with_fup(struct intel_pt_decoder * decoder,int * err)3179 static bool intel_pt_psb_with_fup(struct intel_pt_decoder *decoder, int *err)
3180 {
3181 struct intel_pt_psb_info data = { .fup = false };
3182
3183 if (!decoder->branch_enable)
3184 return false;
3185
3186 intel_pt_pkt_lookahead(decoder, intel_pt_psb_lookahead_cb, &data);
3187 if (!data.fup)
3188 return false;
3189
3190 decoder->packet = data.fup_packet;
3191 intel_pt_set_last_ip(decoder);
3192 decoder->pkt_state = INTEL_PT_STATE_FUP_IN_PSB;
3193
3194 *err = intel_pt_fup_in_psb(decoder);
3195
3196 return true;
3197 }
3198
intel_pt_walk_trace(struct intel_pt_decoder * decoder)3199 static int intel_pt_walk_trace(struct intel_pt_decoder *decoder)
3200 {
3201 int last_packet_type = INTEL_PT_PAD;
3202 bool no_tip = false;
3203 int err;
3204
3205 while (1) {
3206 err = intel_pt_get_next_packet(decoder);
3207 if (err)
3208 return err;
3209 next:
3210 err = 0;
3211 if (decoder->cyc_threshold) {
3212 if (decoder->sample_cyc && last_packet_type != INTEL_PT_CYC)
3213 decoder->sample_cyc = false;
3214 last_packet_type = decoder->packet.type;
3215 }
3216
3217 if (decoder->hop) {
3218 switch (intel_pt_hop_trace(decoder, &no_tip, &err)) {
3219 case HOP_IGNORE:
3220 continue;
3221 case HOP_RETURN:
3222 return err;
3223 case HOP_AGAIN:
3224 goto next;
3225 default:
3226 break;
3227 }
3228 }
3229
3230 switch (decoder->packet.type) {
3231 case INTEL_PT_TNT:
3232 if (!decoder->packet.count)
3233 break;
3234 decoder->tnt = decoder->packet;
3235 decoder->pkt_state = INTEL_PT_STATE_TNT;
3236 err = intel_pt_walk_tnt(decoder);
3237 if (err == -EAGAIN)
3238 break;
3239 return err;
3240
3241 case INTEL_PT_TIP_PGD:
3242 if (decoder->packet.count != 0)
3243 intel_pt_set_last_ip(decoder);
3244 decoder->pkt_state = INTEL_PT_STATE_TIP_PGD;
3245 return intel_pt_walk_tip(decoder);
3246
3247 case INTEL_PT_TIP_PGE: {
3248 decoder->pge = true;
3249 decoder->overflow = false;
3250 intel_pt_mtc_cyc_cnt_pge(decoder);
3251 intel_pt_set_nr(decoder);
3252 if (decoder->packet.count == 0) {
3253 intel_pt_log_at("Skipping zero TIP.PGE",
3254 decoder->pos);
3255 break;
3256 }
3257 intel_pt_sample_iflag_chg(decoder);
3258 intel_pt_set_ip(decoder);
3259 decoder->state.from_ip = 0;
3260 decoder->state.to_ip = decoder->ip;
3261 decoder->state.type |= INTEL_PT_TRACE_BEGIN;
3262 /*
3263 * In hop mode, resample to get the to_ip as an
3264 * "instruction" sample.
3265 */
3266 if (decoder->hop)
3267 decoder->pkt_state = INTEL_PT_STATE_RESAMPLE;
3268 return 0;
3269 }
3270
3271 case INTEL_PT_OVF:
3272 return intel_pt_overflow(decoder);
3273
3274 case INTEL_PT_TIP:
3275 if (decoder->packet.count != 0)
3276 intel_pt_set_last_ip(decoder);
3277 decoder->pkt_state = INTEL_PT_STATE_TIP;
3278 return intel_pt_walk_tip(decoder);
3279
3280 case INTEL_PT_FUP:
3281 if (decoder->packet.count == 0) {
3282 intel_pt_log_at("Skipping zero FUP",
3283 decoder->pos);
3284 no_tip = false;
3285 break;
3286 }
3287 intel_pt_set_last_ip(decoder);
3288 if (!decoder->branch_enable || !decoder->pge) {
3289 decoder->ip = decoder->last_ip;
3290 if (intel_pt_fup_event(decoder, no_tip))
3291 return 0;
3292 no_tip = false;
3293 break;
3294 }
3295 if (decoder->set_fup_mwait)
3296 no_tip = true;
3297 if (no_tip)
3298 decoder->pkt_state = INTEL_PT_STATE_FUP_NO_TIP;
3299 else
3300 decoder->pkt_state = INTEL_PT_STATE_FUP;
3301 err = intel_pt_walk_fup(decoder);
3302 if (err != -EAGAIN)
3303 return err;
3304 if (no_tip) {
3305 no_tip = false;
3306 break;
3307 }
3308 return intel_pt_walk_fup_tip(decoder);
3309
3310 case INTEL_PT_TRACESTOP:
3311 decoder->pge = false;
3312 decoder->continuous_period = false;
3313 intel_pt_clear_tx_flags(decoder);
3314 decoder->have_tma = false;
3315 break;
3316
3317 case INTEL_PT_PSB:
3318 decoder->state.psb_offset = decoder->pos;
3319 decoder->psb_ip = 0;
3320 if (intel_pt_psb_with_fup(decoder, &err))
3321 return err;
3322 err = intel_pt_psb(decoder);
3323 if (err == -EAGAIN)
3324 goto next;
3325 return err;
3326
3327 case INTEL_PT_PIP:
3328 intel_pt_update_pip(decoder);
3329 break;
3330
3331 case INTEL_PT_MTC:
3332 intel_pt_calc_mtc_timestamp(decoder);
3333 if (decoder->period_type != INTEL_PT_PERIOD_MTC)
3334 break;
3335 /*
3336 * Ensure that there has been an instruction since the
3337 * last MTC.
3338 */
3339 if (!decoder->mtc_insn)
3340 break;
3341 decoder->mtc_insn = false;
3342 /* Ensure that there is a timestamp */
3343 if (!decoder->timestamp)
3344 break;
3345 decoder->state.type = INTEL_PT_INSTRUCTION;
3346 decoder->state.from_ip = decoder->ip;
3347 decoder->state.to_ip = 0;
3348 decoder->mtc_insn = false;
3349 return 0;
3350
3351 case INTEL_PT_TSC:
3352 intel_pt_calc_tsc_timestamp(decoder);
3353 break;
3354
3355 case INTEL_PT_TMA:
3356 intel_pt_calc_tma(decoder);
3357 break;
3358
3359 case INTEL_PT_CYC:
3360 intel_pt_calc_cyc_timestamp(decoder);
3361 break;
3362
3363 case INTEL_PT_CBR:
3364 intel_pt_calc_cbr(decoder);
3365 if (decoder->cbr != decoder->cbr_seen) {
3366 decoder->state.type = 0;
3367 return 0;
3368 }
3369 break;
3370
3371 case INTEL_PT_MODE_EXEC:
3372 intel_pt_mode_exec(decoder);
3373 err = intel_pt_get_next_packet(decoder);
3374 if (err)
3375 return err;
3376 if (decoder->packet.type == INTEL_PT_FUP) {
3377 decoder->set_fup_mode_exec = true;
3378 no_tip = true;
3379 }
3380 goto next;
3381
3382 case INTEL_PT_MODE_TSX:
3383 /* MODE_TSX need not be followed by FUP */
3384 if (!decoder->pge || decoder->in_psb) {
3385 intel_pt_update_in_tx(decoder);
3386 break;
3387 }
3388 err = intel_pt_mode_tsx(decoder, &no_tip);
3389 if (err)
3390 return err;
3391 goto next;
3392
3393 case INTEL_PT_BAD: /* Does not happen */
3394 return intel_pt_bug(decoder);
3395
3396 case INTEL_PT_PSBEND:
3397 case INTEL_PT_VMCS:
3398 case INTEL_PT_MNT:
3399 case INTEL_PT_PAD:
3400 break;
3401
3402 case INTEL_PT_PTWRITE_IP:
3403 decoder->fup_ptw_payload = decoder->packet.payload;
3404 err = intel_pt_get_next_packet(decoder);
3405 if (err)
3406 return err;
3407 if (decoder->packet.type == INTEL_PT_FUP) {
3408 decoder->set_fup_ptw = true;
3409 no_tip = true;
3410 } else {
3411 intel_pt_log_at("ERROR: Missing FUP after PTWRITE",
3412 decoder->pos);
3413 }
3414 goto next;
3415
3416 case INTEL_PT_PTWRITE:
3417 decoder->state.type = INTEL_PT_PTW;
3418 decoder->state.from_ip = decoder->ip;
3419 decoder->state.to_ip = 0;
3420 decoder->state.ptw_payload = decoder->packet.payload;
3421 return 0;
3422
3423 case INTEL_PT_MWAIT:
3424 decoder->fup_mwait_payload = decoder->packet.payload;
3425 decoder->set_fup_mwait = true;
3426 break;
3427
3428 case INTEL_PT_PWRE:
3429 if (decoder->set_fup_mwait) {
3430 decoder->fup_pwre_payload =
3431 decoder->packet.payload;
3432 decoder->set_fup_pwre = true;
3433 break;
3434 }
3435 decoder->state.type = INTEL_PT_PWR_ENTRY;
3436 decoder->state.from_ip = decoder->ip;
3437 decoder->state.to_ip = 0;
3438 decoder->state.pwrx_payload = decoder->packet.payload;
3439 return 0;
3440
3441 case INTEL_PT_EXSTOP_IP:
3442 err = intel_pt_get_next_packet(decoder);
3443 if (err)
3444 return err;
3445 if (decoder->packet.type == INTEL_PT_FUP) {
3446 decoder->set_fup_exstop = true;
3447 no_tip = true;
3448 } else {
3449 intel_pt_log_at("ERROR: Missing FUP after EXSTOP",
3450 decoder->pos);
3451 }
3452 goto next;
3453
3454 case INTEL_PT_EXSTOP:
3455 decoder->state.type = INTEL_PT_EX_STOP;
3456 decoder->state.from_ip = decoder->ip;
3457 decoder->state.to_ip = 0;
3458 return 0;
3459
3460 case INTEL_PT_PWRX:
3461 decoder->state.type = INTEL_PT_PWR_EXIT;
3462 decoder->state.from_ip = decoder->ip;
3463 decoder->state.to_ip = 0;
3464 decoder->state.pwrx_payload = decoder->packet.payload;
3465 return 0;
3466
3467 case INTEL_PT_BBP:
3468 intel_pt_bbp(decoder);
3469 break;
3470
3471 case INTEL_PT_BIP:
3472 intel_pt_bip(decoder);
3473 break;
3474
3475 case INTEL_PT_BEP:
3476 decoder->state.type = INTEL_PT_BLK_ITEMS;
3477 decoder->state.from_ip = decoder->ip;
3478 decoder->state.to_ip = 0;
3479 return 0;
3480
3481 case INTEL_PT_BEP_IP:
3482 err = intel_pt_get_next_packet(decoder);
3483 if (err)
3484 return err;
3485 if (decoder->packet.type == INTEL_PT_FUP) {
3486 decoder->set_fup_bep = true;
3487 no_tip = true;
3488 } else {
3489 intel_pt_log_at("ERROR: Missing FUP after BEP",
3490 decoder->pos);
3491 }
3492 goto next;
3493
3494 case INTEL_PT_CFE:
3495 decoder->fup_cfe_pkt = decoder->packet;
3496 decoder->set_fup_cfe = true;
3497 if (!decoder->pge) {
3498 intel_pt_fup_event(decoder, true);
3499 return 0;
3500 }
3501 break;
3502
3503 case INTEL_PT_CFE_IP:
3504 decoder->fup_cfe_pkt = decoder->packet;
3505 err = intel_pt_get_next_packet(decoder);
3506 if (err)
3507 return err;
3508 if (decoder->packet.type == INTEL_PT_FUP) {
3509 decoder->set_fup_cfe_ip = true;
3510 no_tip = true;
3511 } else {
3512 intel_pt_log_at("ERROR: Missing FUP after CFE",
3513 decoder->pos);
3514 }
3515 goto next;
3516
3517 case INTEL_PT_EVD:
3518 err = intel_pt_evd(decoder);
3519 if (err)
3520 return err;
3521 break;
3522
3523 default:
3524 return intel_pt_bug(decoder);
3525 }
3526 }
3527 }
3528
intel_pt_have_ip(struct intel_pt_decoder * decoder)3529 static inline bool intel_pt_have_ip(struct intel_pt_decoder *decoder)
3530 {
3531 return decoder->packet.count &&
3532 (decoder->have_last_ip || decoder->packet.count == 3 ||
3533 decoder->packet.count == 6);
3534 }
3535
3536 /* Walk PSB+ packets to get in sync. */
intel_pt_walk_psb(struct intel_pt_decoder * decoder)3537 static int intel_pt_walk_psb(struct intel_pt_decoder *decoder)
3538 {
3539 int err;
3540
3541 decoder->in_psb = true;
3542
3543 while (1) {
3544 err = intel_pt_get_next_packet(decoder);
3545 if (err)
3546 goto out;
3547
3548 switch (decoder->packet.type) {
3549 case INTEL_PT_TIP_PGD:
3550 decoder->continuous_period = false;
3551 fallthrough;
3552 case INTEL_PT_TIP_PGE:
3553 case INTEL_PT_TIP:
3554 case INTEL_PT_PTWRITE:
3555 case INTEL_PT_PTWRITE_IP:
3556 case INTEL_PT_EXSTOP:
3557 case INTEL_PT_EXSTOP_IP:
3558 case INTEL_PT_MWAIT:
3559 case INTEL_PT_PWRE:
3560 case INTEL_PT_PWRX:
3561 case INTEL_PT_BBP:
3562 case INTEL_PT_BIP:
3563 case INTEL_PT_BEP:
3564 case INTEL_PT_BEP_IP:
3565 case INTEL_PT_CFE:
3566 case INTEL_PT_CFE_IP:
3567 case INTEL_PT_EVD:
3568 intel_pt_log("ERROR: Unexpected packet\n");
3569 err = -ENOENT;
3570 goto out;
3571
3572 case INTEL_PT_FUP:
3573 decoder->pge = true;
3574 if (intel_pt_have_ip(decoder)) {
3575 uint64_t current_ip = decoder->ip;
3576
3577 intel_pt_set_ip(decoder);
3578 decoder->psb_ip = decoder->ip;
3579 if (current_ip)
3580 intel_pt_log_to("Setting IP",
3581 decoder->ip);
3582 }
3583 break;
3584
3585 case INTEL_PT_MTC:
3586 intel_pt_calc_mtc_timestamp(decoder);
3587 break;
3588
3589 case INTEL_PT_TSC:
3590 intel_pt_calc_tsc_timestamp(decoder);
3591 break;
3592
3593 case INTEL_PT_TMA:
3594 intel_pt_calc_tma(decoder);
3595 break;
3596
3597 case INTEL_PT_CYC:
3598 intel_pt_calc_cyc_timestamp(decoder);
3599 break;
3600
3601 case INTEL_PT_CBR:
3602 intel_pt_calc_cbr(decoder);
3603 break;
3604
3605 case INTEL_PT_PIP:
3606 intel_pt_set_pip(decoder);
3607 break;
3608
3609 case INTEL_PT_MODE_EXEC:
3610 intel_pt_mode_exec_status(decoder);
3611 break;
3612
3613 case INTEL_PT_MODE_TSX:
3614 intel_pt_update_in_tx(decoder);
3615 break;
3616
3617 case INTEL_PT_TRACESTOP:
3618 decoder->pge = false;
3619 decoder->continuous_period = false;
3620 intel_pt_clear_tx_flags(decoder);
3621 fallthrough;
3622
3623 case INTEL_PT_TNT:
3624 decoder->have_tma = false;
3625 intel_pt_log("ERROR: Unexpected packet\n");
3626 if (decoder->ip)
3627 decoder->pkt_state = INTEL_PT_STATE_ERR4;
3628 else
3629 decoder->pkt_state = INTEL_PT_STATE_ERR3;
3630 err = -ENOENT;
3631 goto out;
3632
3633 case INTEL_PT_BAD: /* Does not happen */
3634 err = intel_pt_bug(decoder);
3635 goto out;
3636
3637 case INTEL_PT_OVF:
3638 err = intel_pt_overflow(decoder);
3639 goto out;
3640
3641 case INTEL_PT_PSBEND:
3642 err = 0;
3643 goto out;
3644
3645 case INTEL_PT_PSB:
3646 case INTEL_PT_VMCS:
3647 case INTEL_PT_MNT:
3648 case INTEL_PT_PAD:
3649 default:
3650 break;
3651 }
3652 }
3653 out:
3654 decoder->in_psb = false;
3655
3656 return err;
3657 }
3658
intel_pt_walk_to_ip(struct intel_pt_decoder * decoder)3659 static int intel_pt_walk_to_ip(struct intel_pt_decoder *decoder)
3660 {
3661 int err;
3662
3663 while (1) {
3664 err = intel_pt_get_next_packet(decoder);
3665 if (err)
3666 return err;
3667
3668 switch (decoder->packet.type) {
3669 case INTEL_PT_TIP_PGD:
3670 decoder->continuous_period = false;
3671 decoder->pge = false;
3672 if (intel_pt_have_ip(decoder))
3673 intel_pt_set_ip(decoder);
3674 if (!decoder->ip)
3675 break;
3676 decoder->state.type |= INTEL_PT_TRACE_END;
3677 return 0;
3678
3679 case INTEL_PT_TIP_PGE:
3680 decoder->pge = true;
3681 intel_pt_mtc_cyc_cnt_pge(decoder);
3682 if (intel_pt_have_ip(decoder))
3683 intel_pt_set_ip(decoder);
3684 if (!decoder->ip)
3685 break;
3686 decoder->state.type |= INTEL_PT_TRACE_BEGIN;
3687 return 0;
3688
3689 case INTEL_PT_TIP:
3690 decoder->pge = true;
3691 if (intel_pt_have_ip(decoder))
3692 intel_pt_set_ip(decoder);
3693 if (!decoder->ip)
3694 break;
3695 return 0;
3696
3697 case INTEL_PT_FUP:
3698 if (intel_pt_have_ip(decoder))
3699 intel_pt_set_ip(decoder);
3700 if (decoder->ip)
3701 return 0;
3702 break;
3703
3704 case INTEL_PT_MTC:
3705 intel_pt_calc_mtc_timestamp(decoder);
3706 break;
3707
3708 case INTEL_PT_TSC:
3709 intel_pt_calc_tsc_timestamp(decoder);
3710 break;
3711
3712 case INTEL_PT_TMA:
3713 intel_pt_calc_tma(decoder);
3714 break;
3715
3716 case INTEL_PT_CYC:
3717 intel_pt_calc_cyc_timestamp(decoder);
3718 break;
3719
3720 case INTEL_PT_CBR:
3721 intel_pt_calc_cbr(decoder);
3722 break;
3723
3724 case INTEL_PT_PIP:
3725 intel_pt_set_pip(decoder);
3726 break;
3727
3728 case INTEL_PT_MODE_EXEC:
3729 intel_pt_mode_exec_status(decoder);
3730 break;
3731
3732 case INTEL_PT_MODE_TSX:
3733 intel_pt_update_in_tx(decoder);
3734 break;
3735
3736 case INTEL_PT_OVF:
3737 return intel_pt_overflow(decoder);
3738
3739 case INTEL_PT_BAD: /* Does not happen */
3740 return intel_pt_bug(decoder);
3741
3742 case INTEL_PT_TRACESTOP:
3743 decoder->pge = false;
3744 decoder->continuous_period = false;
3745 intel_pt_clear_tx_flags(decoder);
3746 decoder->have_tma = false;
3747 break;
3748
3749 case INTEL_PT_PSB:
3750 decoder->state.psb_offset = decoder->pos;
3751 decoder->psb_ip = 0;
3752 decoder->last_ip = 0;
3753 decoder->have_last_ip = true;
3754 intel_pt_clear_stack(&decoder->stack);
3755 err = intel_pt_walk_psb(decoder);
3756 if (err)
3757 return err;
3758 decoder->state.type = INTEL_PT_PSB_EVT;
3759 decoder->state.from_ip = decoder->psb_ip;
3760 decoder->state.to_ip = 0;
3761 return 0;
3762
3763 case INTEL_PT_TNT:
3764 case INTEL_PT_PSBEND:
3765 case INTEL_PT_VMCS:
3766 case INTEL_PT_MNT:
3767 case INTEL_PT_PAD:
3768 case INTEL_PT_PTWRITE:
3769 case INTEL_PT_PTWRITE_IP:
3770 case INTEL_PT_EXSTOP:
3771 case INTEL_PT_EXSTOP_IP:
3772 case INTEL_PT_MWAIT:
3773 case INTEL_PT_PWRE:
3774 case INTEL_PT_PWRX:
3775 case INTEL_PT_BBP:
3776 case INTEL_PT_BIP:
3777 case INTEL_PT_BEP:
3778 case INTEL_PT_BEP_IP:
3779 case INTEL_PT_CFE:
3780 case INTEL_PT_CFE_IP:
3781 case INTEL_PT_EVD:
3782 default:
3783 break;
3784 }
3785 }
3786 }
3787
intel_pt_sync_ip(struct intel_pt_decoder * decoder)3788 static int intel_pt_sync_ip(struct intel_pt_decoder *decoder)
3789 {
3790 int err;
3791
3792 intel_pt_clear_fup_event(decoder);
3793 decoder->overflow = false;
3794
3795 if (!decoder->branch_enable) {
3796 decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
3797 decoder->state.type = 0; /* Do not have a sample */
3798 return 0;
3799 }
3800
3801 intel_pt_log("Scanning for full IP\n");
3802 err = intel_pt_walk_to_ip(decoder);
3803 if (err || ((decoder->state.type & INTEL_PT_PSB_EVT) && !decoder->ip))
3804 return err;
3805
3806 /* In hop mode, resample to get the to_ip as an "instruction" sample */
3807 if (decoder->hop)
3808 decoder->pkt_state = INTEL_PT_STATE_RESAMPLE;
3809 else
3810 decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
3811
3812 decoder->state.from_ip = 0;
3813 decoder->state.to_ip = decoder->ip;
3814 intel_pt_log_to("Setting IP", decoder->ip);
3815
3816 return 0;
3817 }
3818
intel_pt_part_psb(struct intel_pt_decoder * decoder)3819 static int intel_pt_part_psb(struct intel_pt_decoder *decoder)
3820 {
3821 const unsigned char *end = decoder->buf + decoder->len;
3822 size_t i;
3823
3824 for (i = INTEL_PT_PSB_LEN - 1; i; i--) {
3825 if (i > decoder->len)
3826 continue;
3827 if (!memcmp(end - i, INTEL_PT_PSB_STR, i))
3828 return i;
3829 }
3830 return 0;
3831 }
3832
intel_pt_rest_psb(struct intel_pt_decoder * decoder,int part_psb)3833 static int intel_pt_rest_psb(struct intel_pt_decoder *decoder, int part_psb)
3834 {
3835 size_t rest_psb = INTEL_PT_PSB_LEN - part_psb;
3836 const char *psb = INTEL_PT_PSB_STR;
3837
3838 if (rest_psb > decoder->len ||
3839 memcmp(decoder->buf, psb + part_psb, rest_psb))
3840 return 0;
3841
3842 return rest_psb;
3843 }
3844
intel_pt_get_split_psb(struct intel_pt_decoder * decoder,int part_psb)3845 static int intel_pt_get_split_psb(struct intel_pt_decoder *decoder,
3846 int part_psb)
3847 {
3848 int rest_psb, ret;
3849
3850 decoder->pos += decoder->len;
3851 decoder->len = 0;
3852
3853 ret = intel_pt_get_next_data(decoder, false);
3854 if (ret)
3855 return ret;
3856
3857 rest_psb = intel_pt_rest_psb(decoder, part_psb);
3858 if (!rest_psb)
3859 return 0;
3860
3861 decoder->pos -= part_psb;
3862 decoder->next_buf = decoder->buf + rest_psb;
3863 decoder->next_len = decoder->len - rest_psb;
3864 memcpy(decoder->temp_buf, INTEL_PT_PSB_STR, INTEL_PT_PSB_LEN);
3865 decoder->buf = decoder->temp_buf;
3866 decoder->len = INTEL_PT_PSB_LEN;
3867
3868 return 0;
3869 }
3870
intel_pt_scan_for_psb(struct intel_pt_decoder * decoder)3871 static int intel_pt_scan_for_psb(struct intel_pt_decoder *decoder)
3872 {
3873 unsigned char *next;
3874 int ret;
3875
3876 intel_pt_log("Scanning for PSB\n");
3877 while (1) {
3878 if (!decoder->len) {
3879 ret = intel_pt_get_next_data(decoder, false);
3880 if (ret)
3881 return ret;
3882 }
3883
3884 next = memmem(decoder->buf, decoder->len, INTEL_PT_PSB_STR,
3885 INTEL_PT_PSB_LEN);
3886 if (!next) {
3887 int part_psb;
3888
3889 part_psb = intel_pt_part_psb(decoder);
3890 if (part_psb) {
3891 ret = intel_pt_get_split_psb(decoder, part_psb);
3892 if (ret)
3893 return ret;
3894 } else {
3895 decoder->pos += decoder->len;
3896 decoder->len = 0;
3897 }
3898 continue;
3899 }
3900
3901 decoder->pkt_step = next - decoder->buf;
3902 return intel_pt_get_next_packet(decoder);
3903 }
3904 }
3905
intel_pt_sync(struct intel_pt_decoder * decoder)3906 static int intel_pt_sync(struct intel_pt_decoder *decoder)
3907 {
3908 int err;
3909
3910 decoder->pge = false;
3911 decoder->continuous_period = false;
3912 decoder->have_last_ip = false;
3913 decoder->last_ip = 0;
3914 decoder->psb_ip = 0;
3915 decoder->ip = 0;
3916 intel_pt_clear_stack(&decoder->stack);
3917
3918 err = intel_pt_scan_for_psb(decoder);
3919 if (err)
3920 return err;
3921
3922 if (decoder->vm_time_correlation) {
3923 decoder->in_psb = true;
3924 if (!decoder->timestamp)
3925 decoder->timestamp = 1;
3926 decoder->state.type = 0;
3927 decoder->pkt_state = INTEL_PT_STATE_VM_TIME_CORRELATION;
3928 return 0;
3929 }
3930
3931 decoder->have_last_ip = true;
3932 decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
3933
3934 err = intel_pt_walk_psb(decoder);
3935 if (err)
3936 return err;
3937
3938 decoder->state.type = INTEL_PT_PSB_EVT; /* Only PSB sample */
3939 decoder->state.from_ip = decoder->psb_ip;
3940 decoder->state.to_ip = 0;
3941
3942 if (decoder->ip) {
3943 /*
3944 * In hop mode, resample to get the PSB FUP ip as an
3945 * "instruction" sample.
3946 */
3947 if (decoder->hop)
3948 decoder->pkt_state = INTEL_PT_STATE_RESAMPLE;
3949 else
3950 decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
3951 }
3952
3953 return 0;
3954 }
3955
intel_pt_est_timestamp(struct intel_pt_decoder * decoder)3956 static uint64_t intel_pt_est_timestamp(struct intel_pt_decoder *decoder)
3957 {
3958 uint64_t est = decoder->sample_insn_cnt << 1;
3959
3960 if (!decoder->cbr || !decoder->max_non_turbo_ratio)
3961 goto out;
3962
3963 est *= decoder->max_non_turbo_ratio;
3964 est /= decoder->cbr;
3965 out:
3966 return decoder->sample_timestamp + est;
3967 }
3968
intel_pt_decode(struct intel_pt_decoder * decoder)3969 const struct intel_pt_state *intel_pt_decode(struct intel_pt_decoder *decoder)
3970 {
3971 int err;
3972
3973 do {
3974 decoder->state.type = INTEL_PT_BRANCH;
3975 decoder->state.flags = 0;
3976
3977 switch (decoder->pkt_state) {
3978 case INTEL_PT_STATE_NO_PSB:
3979 err = intel_pt_sync(decoder);
3980 break;
3981 case INTEL_PT_STATE_NO_IP:
3982 decoder->have_last_ip = false;
3983 decoder->last_ip = 0;
3984 decoder->ip = 0;
3985 fallthrough;
3986 case INTEL_PT_STATE_ERR_RESYNC:
3987 err = intel_pt_sync_ip(decoder);
3988 break;
3989 case INTEL_PT_STATE_IN_SYNC:
3990 err = intel_pt_walk_trace(decoder);
3991 break;
3992 case INTEL_PT_STATE_TNT:
3993 case INTEL_PT_STATE_TNT_CONT:
3994 err = intel_pt_walk_tnt(decoder);
3995 if (err == -EAGAIN)
3996 err = intel_pt_walk_trace(decoder);
3997 break;
3998 case INTEL_PT_STATE_TIP:
3999 case INTEL_PT_STATE_TIP_PGD:
4000 err = intel_pt_walk_tip(decoder);
4001 break;
4002 case INTEL_PT_STATE_FUP:
4003 err = intel_pt_walk_fup(decoder);
4004 if (err == -EAGAIN)
4005 err = intel_pt_walk_fup_tip(decoder);
4006 break;
4007 case INTEL_PT_STATE_FUP_NO_TIP:
4008 err = intel_pt_walk_fup(decoder);
4009 if (err == -EAGAIN)
4010 err = intel_pt_walk_trace(decoder);
4011 break;
4012 case INTEL_PT_STATE_FUP_IN_PSB:
4013 err = intel_pt_fup_in_psb(decoder);
4014 break;
4015 case INTEL_PT_STATE_RESAMPLE:
4016 err = intel_pt_resample(decoder);
4017 break;
4018 case INTEL_PT_STATE_VM_TIME_CORRELATION:
4019 err = intel_pt_vm_time_correlation(decoder);
4020 break;
4021 default:
4022 err = intel_pt_bug(decoder);
4023 break;
4024 }
4025 } while (err == -ENOLINK);
4026
4027 if (err) {
4028 decoder->state.err = intel_pt_ext_err(err);
4029 if (err != -EOVERFLOW)
4030 decoder->state.from_ip = decoder->ip;
4031 intel_pt_update_sample_time(decoder);
4032 decoder->sample_tot_cyc_cnt = decoder->tot_cyc_cnt;
4033 intel_pt_set_nr(decoder);
4034 } else {
4035 decoder->state.err = 0;
4036 if (decoder->cbr != decoder->cbr_seen) {
4037 decoder->cbr_seen = decoder->cbr;
4038 if (!decoder->state.type) {
4039 decoder->state.from_ip = decoder->ip;
4040 decoder->state.to_ip = 0;
4041 }
4042 decoder->state.type |= INTEL_PT_CBR_CHG;
4043 decoder->state.cbr_payload = decoder->cbr_payload;
4044 decoder->state.cbr = decoder->cbr;
4045 }
4046 if (intel_pt_sample_time(decoder->pkt_state)) {
4047 intel_pt_update_sample_time(decoder);
4048 if (decoder->sample_cyc) {
4049 decoder->sample_tot_cyc_cnt = decoder->tot_cyc_cnt;
4050 decoder->state.flags |= INTEL_PT_SAMPLE_IPC;
4051 decoder->sample_cyc = false;
4052 }
4053 }
4054 /*
4055 * When using only TSC/MTC to compute cycles, IPC can be
4056 * sampled as soon as the cycle count changes.
4057 */
4058 if (!decoder->have_cyc)
4059 decoder->state.flags |= INTEL_PT_SAMPLE_IPC;
4060 }
4061
4062 /* Let PSB event always have TSC timestamp */
4063 if ((decoder->state.type & INTEL_PT_PSB_EVT) && decoder->tsc_timestamp)
4064 decoder->sample_timestamp = decoder->tsc_timestamp;
4065
4066 decoder->state.from_nr = decoder->nr;
4067 decoder->state.to_nr = decoder->next_nr;
4068 decoder->nr = decoder->next_nr;
4069
4070 decoder->state.timestamp = decoder->sample_timestamp;
4071 decoder->state.est_timestamp = intel_pt_est_timestamp(decoder);
4072 decoder->state.tot_insn_cnt = decoder->tot_insn_cnt;
4073 decoder->state.tot_cyc_cnt = decoder->sample_tot_cyc_cnt;
4074
4075 return &decoder->state;
4076 }
4077
4078 /**
4079 * intel_pt_next_psb - move buffer pointer to the start of the next PSB packet.
4080 * @buf: pointer to buffer pointer
4081 * @len: size of buffer
4082 *
4083 * Updates the buffer pointer to point to the start of the next PSB packet if
4084 * there is one, otherwise the buffer pointer is unchanged. If @buf is updated,
4085 * @len is adjusted accordingly.
4086 *
4087 * Return: %true if a PSB packet is found, %false otherwise.
4088 */
intel_pt_next_psb(unsigned char ** buf,size_t * len)4089 static bool intel_pt_next_psb(unsigned char **buf, size_t *len)
4090 {
4091 unsigned char *next;
4092
4093 next = memmem(*buf, *len, INTEL_PT_PSB_STR, INTEL_PT_PSB_LEN);
4094 if (next) {
4095 *len -= next - *buf;
4096 *buf = next;
4097 return true;
4098 }
4099 return false;
4100 }
4101
4102 /**
4103 * intel_pt_step_psb - move buffer pointer to the start of the following PSB
4104 * packet.
4105 * @buf: pointer to buffer pointer
4106 * @len: size of buffer
4107 *
4108 * Updates the buffer pointer to point to the start of the following PSB packet
4109 * (skipping the PSB at @buf itself) if there is one, otherwise the buffer
4110 * pointer is unchanged. If @buf is updated, @len is adjusted accordingly.
4111 *
4112 * Return: %true if a PSB packet is found, %false otherwise.
4113 */
intel_pt_step_psb(unsigned char ** buf,size_t * len)4114 static bool intel_pt_step_psb(unsigned char **buf, size_t *len)
4115 {
4116 unsigned char *next;
4117
4118 if (!*len)
4119 return false;
4120
4121 next = memmem(*buf + 1, *len - 1, INTEL_PT_PSB_STR, INTEL_PT_PSB_LEN);
4122 if (next) {
4123 *len -= next - *buf;
4124 *buf = next;
4125 return true;
4126 }
4127 return false;
4128 }
4129
4130 /**
4131 * intel_pt_last_psb - find the last PSB packet in a buffer.
4132 * @buf: buffer
4133 * @len: size of buffer
4134 *
4135 * This function finds the last PSB in a buffer.
4136 *
4137 * Return: A pointer to the last PSB in @buf if found, %NULL otherwise.
4138 */
intel_pt_last_psb(unsigned char * buf,size_t len)4139 static unsigned char *intel_pt_last_psb(unsigned char *buf, size_t len)
4140 {
4141 const char *n = INTEL_PT_PSB_STR;
4142 unsigned char *p;
4143 size_t k;
4144
4145 if (len < INTEL_PT_PSB_LEN)
4146 return NULL;
4147
4148 k = len - INTEL_PT_PSB_LEN + 1;
4149 while (1) {
4150 p = memrchr(buf, n[0], k);
4151 if (!p)
4152 return NULL;
4153 if (!memcmp(p + 1, n + 1, INTEL_PT_PSB_LEN - 1))
4154 return p;
4155 k = p - buf;
4156 if (!k)
4157 return NULL;
4158 }
4159 }
4160
4161 /**
4162 * intel_pt_next_tsc - find and return next TSC.
4163 * @buf: buffer
4164 * @len: size of buffer
4165 * @tsc: TSC value returned
4166 * @rem: returns remaining size when TSC is found
4167 *
4168 * Find a TSC packet in @buf and return the TSC value. This function assumes
4169 * that @buf starts at a PSB and that PSB+ will contain TSC and so stops if a
4170 * PSBEND packet is found.
4171 *
4172 * Return: %true if TSC is found, false otherwise.
4173 */
intel_pt_next_tsc(unsigned char * buf,size_t len,uint64_t * tsc,size_t * rem)4174 static bool intel_pt_next_tsc(unsigned char *buf, size_t len, uint64_t *tsc,
4175 size_t *rem)
4176 {
4177 enum intel_pt_pkt_ctx ctx = INTEL_PT_NO_CTX;
4178 struct intel_pt_pkt packet;
4179 int ret;
4180
4181 while (len) {
4182 ret = intel_pt_get_packet(buf, len, &packet, &ctx);
4183 if (ret <= 0)
4184 return false;
4185 if (packet.type == INTEL_PT_TSC) {
4186 *tsc = packet.payload;
4187 *rem = len;
4188 return true;
4189 }
4190 if (packet.type == INTEL_PT_PSBEND)
4191 return false;
4192 buf += ret;
4193 len -= ret;
4194 }
4195 return false;
4196 }
4197
4198 /**
4199 * intel_pt_tsc_cmp - compare 7-byte TSCs.
4200 * @tsc1: first TSC to compare
4201 * @tsc2: second TSC to compare
4202 *
4203 * This function compares 7-byte TSC values allowing for the possibility that
4204 * TSC wrapped around. Generally it is not possible to know if TSC has wrapped
4205 * around so for that purpose this function assumes the absolute difference is
4206 * less than half the maximum difference.
4207 *
4208 * Return: %-1 if @tsc1 is before @tsc2, %0 if @tsc1 == @tsc2, %1 if @tsc1 is
4209 * after @tsc2.
4210 */
intel_pt_tsc_cmp(uint64_t tsc1,uint64_t tsc2)4211 static int intel_pt_tsc_cmp(uint64_t tsc1, uint64_t tsc2)
4212 {
4213 const uint64_t halfway = (1ULL << 55);
4214
4215 if (tsc1 == tsc2)
4216 return 0;
4217
4218 if (tsc1 < tsc2) {
4219 if (tsc2 - tsc1 < halfway)
4220 return -1;
4221 else
4222 return 1;
4223 } else {
4224 if (tsc1 - tsc2 < halfway)
4225 return 1;
4226 else
4227 return -1;
4228 }
4229 }
4230
4231 #define MAX_PADDING (PERF_AUXTRACE_RECORD_ALIGNMENT - 1)
4232
4233 /**
4234 * adj_for_padding - adjust overlap to account for padding.
4235 * @buf_b: second buffer
4236 * @buf_a: first buffer
4237 * @len_a: size of first buffer
4238 *
4239 * @buf_a might have up to 7 bytes of padding appended. Adjust the overlap
4240 * accordingly.
4241 *
4242 * Return: A pointer into @buf_b from where non-overlapped data starts
4243 */
adj_for_padding(unsigned char * buf_b,unsigned char * buf_a,size_t len_a)4244 static unsigned char *adj_for_padding(unsigned char *buf_b,
4245 unsigned char *buf_a, size_t len_a)
4246 {
4247 unsigned char *p = buf_b - MAX_PADDING;
4248 unsigned char *q = buf_a + len_a - MAX_PADDING;
4249 int i;
4250
4251 for (i = MAX_PADDING; i; i--, p++, q++) {
4252 if (*p != *q)
4253 break;
4254 }
4255
4256 return p;
4257 }
4258
4259 /**
4260 * intel_pt_find_overlap_tsc - determine start of non-overlapped trace data
4261 * using TSC.
4262 * @buf_a: first buffer
4263 * @len_a: size of first buffer
4264 * @buf_b: second buffer
4265 * @len_b: size of second buffer
4266 * @consecutive: returns true if there is data in buf_b that is consecutive
4267 * to buf_a
4268 * @ooo_tsc: out-of-order TSC due to VM TSC offset / scaling
4269 *
4270 * If the trace contains TSC we can look at the last TSC of @buf_a and the
4271 * first TSC of @buf_b in order to determine if the buffers overlap, and then
4272 * walk forward in @buf_b until a later TSC is found. A precondition is that
4273 * @buf_a and @buf_b are positioned at a PSB.
4274 *
4275 * Return: A pointer into @buf_b from where non-overlapped data starts, or
4276 * @buf_b + @len_b if there is no non-overlapped data.
4277 */
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)4278 static unsigned char *intel_pt_find_overlap_tsc(unsigned char *buf_a,
4279 size_t len_a,
4280 unsigned char *buf_b,
4281 size_t len_b, bool *consecutive,
4282 bool ooo_tsc)
4283 {
4284 uint64_t tsc_a, tsc_b;
4285 unsigned char *p;
4286 size_t len, rem_a, rem_b;
4287
4288 p = intel_pt_last_psb(buf_a, len_a);
4289 if (!p)
4290 return buf_b; /* No PSB in buf_a => no overlap */
4291
4292 len = len_a - (p - buf_a);
4293 if (!intel_pt_next_tsc(p, len, &tsc_a, &rem_a)) {
4294 /* The last PSB+ in buf_a is incomplete, so go back one more */
4295 len_a -= len;
4296 p = intel_pt_last_psb(buf_a, len_a);
4297 if (!p)
4298 return buf_b; /* No full PSB+ => assume no overlap */
4299 len = len_a - (p - buf_a);
4300 if (!intel_pt_next_tsc(p, len, &tsc_a, &rem_a))
4301 return buf_b; /* No TSC in buf_a => assume no overlap */
4302 }
4303
4304 while (1) {
4305 /* Ignore PSB+ with no TSC */
4306 if (intel_pt_next_tsc(buf_b, len_b, &tsc_b, &rem_b)) {
4307 int cmp = intel_pt_tsc_cmp(tsc_a, tsc_b);
4308
4309 /* Same TSC, so buffers are consecutive */
4310 if (!cmp && rem_b >= rem_a) {
4311 unsigned char *start;
4312
4313 *consecutive = true;
4314 start = buf_b + len_b - (rem_b - rem_a);
4315 return adj_for_padding(start, buf_a, len_a);
4316 }
4317 if (cmp < 0 && !ooo_tsc)
4318 return buf_b; /* tsc_a < tsc_b => no overlap */
4319 }
4320
4321 if (!intel_pt_step_psb(&buf_b, &len_b))
4322 return buf_b + len_b; /* No PSB in buf_b => no data */
4323 }
4324 }
4325
4326 /**
4327 * intel_pt_find_overlap - determine start of non-overlapped trace data.
4328 * @buf_a: first buffer
4329 * @len_a: size of first buffer
4330 * @buf_b: second buffer
4331 * @len_b: size of second buffer
4332 * @have_tsc: can use TSC packets to detect overlap
4333 * @consecutive: returns true if there is data in buf_b that is consecutive
4334 * to buf_a
4335 * @ooo_tsc: out-of-order TSC due to VM TSC offset / scaling
4336 *
4337 * When trace samples or snapshots are recorded there is the possibility that
4338 * the data overlaps. Note that, for the purposes of decoding, data is only
4339 * useful if it begins with a PSB packet.
4340 *
4341 * Return: A pointer into @buf_b from where non-overlapped data starts, or
4342 * @buf_b + @len_b if there is no non-overlapped data.
4343 */
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)4344 unsigned char *intel_pt_find_overlap(unsigned char *buf_a, size_t len_a,
4345 unsigned char *buf_b, size_t len_b,
4346 bool have_tsc, bool *consecutive,
4347 bool ooo_tsc)
4348 {
4349 unsigned char *found;
4350
4351 /* Buffer 'b' must start at PSB so throw away everything before that */
4352 if (!intel_pt_next_psb(&buf_b, &len_b))
4353 return buf_b + len_b; /* No PSB */
4354
4355 if (!intel_pt_next_psb(&buf_a, &len_a))
4356 return buf_b; /* No overlap */
4357
4358 if (have_tsc) {
4359 found = intel_pt_find_overlap_tsc(buf_a, len_a, buf_b, len_b,
4360 consecutive, ooo_tsc);
4361 if (found)
4362 return found;
4363 }
4364
4365 /*
4366 * Buffer 'b' cannot end within buffer 'a' so, for comparison purposes,
4367 * we can ignore the first part of buffer 'a'.
4368 */
4369 while (len_b < len_a) {
4370 if (!intel_pt_step_psb(&buf_a, &len_a))
4371 return buf_b; /* No overlap */
4372 }
4373
4374 /* Now len_b >= len_a */
4375 while (1) {
4376 /* Potential overlap so check the bytes */
4377 found = memmem(buf_a, len_a, buf_b, len_a);
4378 if (found) {
4379 *consecutive = true;
4380 return adj_for_padding(buf_b + len_a, buf_a, len_a);
4381 }
4382
4383 /* Try again at next PSB in buffer 'a' */
4384 if (!intel_pt_step_psb(&buf_a, &len_a))
4385 return buf_b; /* No overlap */
4386 }
4387 }
4388
4389 /**
4390 * struct fast_forward_data - data used by intel_pt_ff_cb().
4391 * @timestamp: timestamp to fast forward towards
4392 * @buf_timestamp: buffer timestamp of last buffer with trace data earlier than
4393 * the fast forward timestamp.
4394 */
4395 struct fast_forward_data {
4396 uint64_t timestamp;
4397 uint64_t buf_timestamp;
4398 };
4399
4400 /**
4401 * intel_pt_ff_cb - fast forward lookahead callback.
4402 * @buffer: Intel PT trace buffer
4403 * @data: opaque pointer to fast forward data (struct fast_forward_data)
4404 *
4405 * Determine if @buffer trace is past the fast forward timestamp.
4406 *
4407 * Return: 1 (stop lookahead) if @buffer trace is past the fast forward
4408 * timestamp, and 0 otherwise.
4409 */
intel_pt_ff_cb(struct intel_pt_buffer * buffer,void * data)4410 static int intel_pt_ff_cb(struct intel_pt_buffer *buffer, void *data)
4411 {
4412 struct fast_forward_data *d = data;
4413 unsigned char *buf;
4414 uint64_t tsc;
4415 size_t rem;
4416 size_t len;
4417
4418 buf = (unsigned char *)buffer->buf;
4419 len = buffer->len;
4420
4421 if (!intel_pt_next_psb(&buf, &len) ||
4422 !intel_pt_next_tsc(buf, len, &tsc, &rem))
4423 return 0;
4424
4425 tsc = intel_pt_8b_tsc(tsc, buffer->ref_timestamp);
4426
4427 intel_pt_log("Buffer 1st timestamp " x64_fmt " ref timestamp " x64_fmt "\n",
4428 tsc, buffer->ref_timestamp);
4429
4430 /*
4431 * If the buffer contains a timestamp earlier that the fast forward
4432 * timestamp, then record it, else stop.
4433 */
4434 if (tsc < d->timestamp)
4435 d->buf_timestamp = buffer->ref_timestamp;
4436 else
4437 return 1;
4438
4439 return 0;
4440 }
4441
4442 /**
4443 * intel_pt_fast_forward - reposition decoder forwards.
4444 * @decoder: Intel PT decoder
4445 * @timestamp: timestamp to fast forward towards
4446 *
4447 * Reposition decoder at the last PSB with a timestamp earlier than @timestamp.
4448 *
4449 * Return: 0 on success or negative error code on failure.
4450 */
intel_pt_fast_forward(struct intel_pt_decoder * decoder,uint64_t timestamp)4451 int intel_pt_fast_forward(struct intel_pt_decoder *decoder, uint64_t timestamp)
4452 {
4453 struct fast_forward_data d = { .timestamp = timestamp };
4454 unsigned char *buf;
4455 size_t len;
4456 int err;
4457
4458 intel_pt_log("Fast forward towards timestamp " x64_fmt "\n", timestamp);
4459
4460 /* Find buffer timestamp of buffer to fast forward to */
4461 err = decoder->lookahead(decoder->data, intel_pt_ff_cb, &d);
4462 if (err < 0)
4463 return err;
4464
4465 /* Walk to buffer with same buffer timestamp */
4466 if (d.buf_timestamp) {
4467 do {
4468 decoder->pos += decoder->len;
4469 decoder->len = 0;
4470 err = intel_pt_get_next_data(decoder, true);
4471 /* -ENOLINK means non-consecutive trace */
4472 if (err && err != -ENOLINK)
4473 return err;
4474 } while (decoder->buf_timestamp != d.buf_timestamp);
4475 }
4476
4477 if (!decoder->buf)
4478 return 0;
4479
4480 buf = (unsigned char *)decoder->buf;
4481 len = decoder->len;
4482
4483 if (!intel_pt_next_psb(&buf, &len))
4484 return 0;
4485
4486 /*
4487 * Walk PSBs while the PSB timestamp is less than the fast forward
4488 * timestamp.
4489 */
4490 do {
4491 uint64_t tsc;
4492 size_t rem;
4493
4494 if (!intel_pt_next_tsc(buf, len, &tsc, &rem))
4495 break;
4496 tsc = intel_pt_8b_tsc(tsc, decoder->buf_timestamp);
4497 /*
4498 * A TSC packet can slip past MTC packets but, after fast
4499 * forward, decoding starts at the TSC timestamp. That means
4500 * the timestamps may not be exactly the same as the timestamps
4501 * that would have been decoded without fast forward.
4502 */
4503 if (tsc < timestamp) {
4504 intel_pt_log("Fast forward to next PSB timestamp " x64_fmt "\n", tsc);
4505 decoder->pos += decoder->len - len;
4506 decoder->buf = buf;
4507 decoder->len = len;
4508 intel_pt_reposition(decoder);
4509 } else {
4510 break;
4511 }
4512 } while (intel_pt_step_psb(&buf, &len));
4513
4514 return 0;
4515 }
4516