// SPDX-License-Identifier: GPL-2.0-only /* * intel_pt_decoder.c: Intel Processor Trace support * Copyright (c) 2013-2014, Intel Corporation. */ #ifndef _GNU_SOURCE #define _GNU_SOURCE #endif #include #include #include #include #include #include #include #include #include #include "../auxtrace.h" #include "intel-pt-insn-decoder.h" #include "intel-pt-pkt-decoder.h" #include "intel-pt-decoder.h" #include "intel-pt-log.h" #define BITULL(x) (1ULL << (x)) /* IA32_RTIT_CTL MSR bits */ #define INTEL_PT_CYC_ENABLE BITULL(1) #define INTEL_PT_CYC_THRESHOLD (BITULL(22) | BITULL(21) | BITULL(20) | BITULL(19)) #define INTEL_PT_CYC_THRESHOLD_SHIFT 19 #define INTEL_PT_BLK_SIZE 1024 #define BIT63 (((uint64_t)1 << 63)) #define INTEL_PT_RETURN 1 /* Maximum number of loops with no packets consumed i.e. stuck in a loop */ #define INTEL_PT_MAX_LOOPS 10000 struct intel_pt_blk { struct intel_pt_blk *prev; uint64_t ip[INTEL_PT_BLK_SIZE]; }; struct intel_pt_stack { struct intel_pt_blk *blk; struct intel_pt_blk *spare; int pos; }; enum intel_pt_pkt_state { INTEL_PT_STATE_NO_PSB, INTEL_PT_STATE_NO_IP, INTEL_PT_STATE_ERR_RESYNC, INTEL_PT_STATE_IN_SYNC, INTEL_PT_STATE_TNT_CONT, INTEL_PT_STATE_TNT, INTEL_PT_STATE_TIP, INTEL_PT_STATE_TIP_PGD, INTEL_PT_STATE_FUP, INTEL_PT_STATE_FUP_NO_TIP, INTEL_PT_STATE_FUP_IN_PSB, INTEL_PT_STATE_RESAMPLE, }; static inline bool intel_pt_sample_time(enum intel_pt_pkt_state pkt_state) { switch (pkt_state) { case INTEL_PT_STATE_NO_PSB: case INTEL_PT_STATE_NO_IP: case INTEL_PT_STATE_ERR_RESYNC: case INTEL_PT_STATE_IN_SYNC: case INTEL_PT_STATE_TNT_CONT: case INTEL_PT_STATE_RESAMPLE: return true; case INTEL_PT_STATE_TNT: case INTEL_PT_STATE_TIP: case INTEL_PT_STATE_TIP_PGD: case INTEL_PT_STATE_FUP: case INTEL_PT_STATE_FUP_NO_TIP: case INTEL_PT_STATE_FUP_IN_PSB: return false; default: return true; }; } #ifdef INTEL_PT_STRICT #define INTEL_PT_STATE_ERR1 INTEL_PT_STATE_NO_PSB #define INTEL_PT_STATE_ERR2 INTEL_PT_STATE_NO_PSB #define INTEL_PT_STATE_ERR3 INTEL_PT_STATE_NO_PSB #define INTEL_PT_STATE_ERR4 INTEL_PT_STATE_NO_PSB #else #define INTEL_PT_STATE_ERR1 (decoder->pkt_state) #define INTEL_PT_STATE_ERR2 INTEL_PT_STATE_NO_IP #define INTEL_PT_STATE_ERR3 INTEL_PT_STATE_ERR_RESYNC #define INTEL_PT_STATE_ERR4 INTEL_PT_STATE_IN_SYNC #endif struct intel_pt_decoder { int (*get_trace)(struct intel_pt_buffer *buffer, void *data); int (*walk_insn)(struct intel_pt_insn *intel_pt_insn, uint64_t *insn_cnt_ptr, uint64_t *ip, uint64_t to_ip, uint64_t max_insn_cnt, void *data); bool (*pgd_ip)(uint64_t ip, void *data); int (*lookahead)(void *data, intel_pt_lookahead_cb_t cb, void *cb_data); void *data; struct intel_pt_state state; const unsigned char *buf; size_t len; bool return_compression; bool branch_enable; bool mtc_insn; bool pge; bool have_tma; bool have_cyc; bool fixup_last_mtc; bool have_last_ip; bool in_psb; bool hop; bool leap; bool nr; bool next_nr; enum intel_pt_param_flags flags; uint64_t pos; uint64_t last_ip; uint64_t ip; uint64_t pip_payload; uint64_t timestamp; uint64_t tsc_timestamp; uint64_t ref_timestamp; uint64_t buf_timestamp; uint64_t sample_timestamp; uint64_t ret_addr; uint64_t ctc_timestamp; uint64_t ctc_delta; uint64_t cycle_cnt; uint64_t cyc_ref_timestamp; uint32_t last_mtc; uint32_t tsc_ctc_ratio_n; uint32_t tsc_ctc_ratio_d; uint32_t tsc_ctc_mult; uint32_t tsc_slip; uint32_t ctc_rem_mask; int mtc_shift; struct intel_pt_stack stack; enum intel_pt_pkt_state pkt_state; enum intel_pt_pkt_ctx pkt_ctx; enum intel_pt_pkt_ctx prev_pkt_ctx; enum intel_pt_blk_type blk_type; int blk_type_pos; struct intel_pt_pkt packet; struct intel_pt_pkt tnt; int pkt_step; int pkt_len; int last_packet_type; unsigned int cbr; unsigned int cbr_seen; unsigned int max_non_turbo_ratio; double max_non_turbo_ratio_fp; double cbr_cyc_to_tsc; double calc_cyc_to_tsc; bool have_calc_cyc_to_tsc; int exec_mode; unsigned int insn_bytes; uint64_t period; enum intel_pt_period_type period_type; uint64_t tot_insn_cnt; uint64_t period_insn_cnt; uint64_t period_mask; uint64_t period_ticks; uint64_t last_masked_timestamp; uint64_t tot_cyc_cnt; uint64_t sample_tot_cyc_cnt; uint64_t base_cyc_cnt; uint64_t cyc_cnt_timestamp; uint64_t ctl; uint64_t cyc_threshold; double tsc_to_cyc; bool continuous_period; bool overflow; bool set_fup_tx_flags; bool set_fup_ptw; bool set_fup_mwait; bool set_fup_pwre; bool set_fup_exstop; bool set_fup_bep; bool sample_cyc; unsigned int fup_tx_flags; unsigned int tx_flags; uint64_t fup_ptw_payload; uint64_t fup_mwait_payload; uint64_t fup_pwre_payload; uint64_t cbr_payload; uint64_t timestamp_insn_cnt; uint64_t sample_insn_cnt; uint64_t stuck_ip; int no_progress; int stuck_ip_prd; int stuck_ip_cnt; uint64_t psb_ip; const unsigned char *next_buf; size_t next_len; unsigned char temp_buf[INTEL_PT_PKT_MAX_SZ]; }; static uint64_t intel_pt_lower_power_of_2(uint64_t x) { int i; for (i = 0; x != 1; i++) x >>= 1; return x << i; } static uint64_t intel_pt_cyc_threshold(uint64_t ctl) { if (!(ctl & INTEL_PT_CYC_ENABLE)) return 0; return (ctl & INTEL_PT_CYC_THRESHOLD) >> INTEL_PT_CYC_THRESHOLD_SHIFT; } static void intel_pt_setup_period(struct intel_pt_decoder *decoder) { if (decoder->period_type == INTEL_PT_PERIOD_TICKS) { uint64_t period; period = intel_pt_lower_power_of_2(decoder->period); decoder->period_mask = ~(period - 1); decoder->period_ticks = period; } } static uint64_t multdiv(uint64_t t, uint32_t n, uint32_t d) { if (!d) return 0; return (t / d) * n + ((t % d) * n) / d; } struct intel_pt_decoder *intel_pt_decoder_new(struct intel_pt_params *params) { struct intel_pt_decoder *decoder; if (!params->get_trace || !params->walk_insn) return NULL; decoder = zalloc(sizeof(struct intel_pt_decoder)); if (!decoder) return NULL; decoder->get_trace = params->get_trace; decoder->walk_insn = params->walk_insn; decoder->pgd_ip = params->pgd_ip; decoder->lookahead = params->lookahead; decoder->data = params->data; decoder->return_compression = params->return_compression; decoder->branch_enable = params->branch_enable; decoder->hop = params->quick >= 1; decoder->leap = params->quick >= 2; decoder->flags = params->flags; decoder->ctl = params->ctl; decoder->period = params->period; decoder->period_type = params->period_type; decoder->max_non_turbo_ratio = params->max_non_turbo_ratio; decoder->max_non_turbo_ratio_fp = params->max_non_turbo_ratio; decoder->cyc_threshold = intel_pt_cyc_threshold(decoder->ctl); intel_pt_setup_period(decoder); decoder->mtc_shift = params->mtc_period; decoder->ctc_rem_mask = (1 << decoder->mtc_shift) - 1; decoder->tsc_ctc_ratio_n = params->tsc_ctc_ratio_n; decoder->tsc_ctc_ratio_d = params->tsc_ctc_ratio_d; if (!decoder->tsc_ctc_ratio_n) decoder->tsc_ctc_ratio_d = 0; if (decoder->tsc_ctc_ratio_d) { if (!(decoder->tsc_ctc_ratio_n % decoder->tsc_ctc_ratio_d)) decoder->tsc_ctc_mult = decoder->tsc_ctc_ratio_n / decoder->tsc_ctc_ratio_d; } /* * A TSC packet can slip past MTC packets so that the timestamp appears * to go backwards. One estimate is that can be up to about 40 CPU * cycles, which is certainly less than 0x1000 TSC ticks, but accept * slippage an order of magnitude more to be on the safe side. */ decoder->tsc_slip = 0x10000; intel_pt_log("timestamp: mtc_shift %u\n", decoder->mtc_shift); intel_pt_log("timestamp: tsc_ctc_ratio_n %u\n", decoder->tsc_ctc_ratio_n); intel_pt_log("timestamp: tsc_ctc_ratio_d %u\n", decoder->tsc_ctc_ratio_d); intel_pt_log("timestamp: tsc_ctc_mult %u\n", decoder->tsc_ctc_mult); intel_pt_log("timestamp: tsc_slip %#x\n", decoder->tsc_slip); if (decoder->hop) intel_pt_log("Hop mode: decoding FUP and TIPs, but not TNT\n"); return decoder; } static void intel_pt_pop_blk(struct intel_pt_stack *stack) { struct intel_pt_blk *blk = stack->blk; stack->blk = blk->prev; if (!stack->spare) stack->spare = blk; else free(blk); } static uint64_t intel_pt_pop(struct intel_pt_stack *stack) { if (!stack->pos) { if (!stack->blk) return 0; intel_pt_pop_blk(stack); if (!stack->blk) return 0; stack->pos = INTEL_PT_BLK_SIZE; } return stack->blk->ip[--stack->pos]; } static int intel_pt_alloc_blk(struct intel_pt_stack *stack) { struct intel_pt_blk *blk; if (stack->spare) { blk = stack->spare; stack->spare = NULL; } else { blk = malloc(sizeof(struct intel_pt_blk)); if (!blk) return -ENOMEM; } blk->prev = stack->blk; stack->blk = blk; stack->pos = 0; return 0; } static int intel_pt_push(struct intel_pt_stack *stack, uint64_t ip) { int err; if (!stack->blk || stack->pos == INTEL_PT_BLK_SIZE) { err = intel_pt_alloc_blk(stack); if (err) return err; } stack->blk->ip[stack->pos++] = ip; return 0; } static void intel_pt_clear_stack(struct intel_pt_stack *stack) { while (stack->blk) intel_pt_pop_blk(stack); stack->pos = 0; } static void intel_pt_free_stack(struct intel_pt_stack *stack) { intel_pt_clear_stack(stack); zfree(&stack->blk); zfree(&stack->spare); } void intel_pt_decoder_free(struct intel_pt_decoder *decoder) { intel_pt_free_stack(&decoder->stack); free(decoder); } static int intel_pt_ext_err(int code) { switch (code) { case -ENOMEM: return INTEL_PT_ERR_NOMEM; case -ENOSYS: return INTEL_PT_ERR_INTERN; case -EBADMSG: return INTEL_PT_ERR_BADPKT; case -ENODATA: return INTEL_PT_ERR_NODATA; case -EILSEQ: return INTEL_PT_ERR_NOINSN; case -ENOENT: return INTEL_PT_ERR_MISMAT; case -EOVERFLOW: return INTEL_PT_ERR_OVR; case -ENOSPC: return INTEL_PT_ERR_LOST; case -ELOOP: return INTEL_PT_ERR_NELOOP; default: return INTEL_PT_ERR_UNK; } } static const char *intel_pt_err_msgs[] = { [INTEL_PT_ERR_NOMEM] = "Memory allocation failed", [INTEL_PT_ERR_INTERN] = "Internal error", [INTEL_PT_ERR_BADPKT] = "Bad packet", [INTEL_PT_ERR_NODATA] = "No more data", [INTEL_PT_ERR_NOINSN] = "Failed to get instruction", [INTEL_PT_ERR_MISMAT] = "Trace doesn't match instruction", [INTEL_PT_ERR_OVR] = "Overflow packet", [INTEL_PT_ERR_LOST] = "Lost trace data", [INTEL_PT_ERR_UNK] = "Unknown error!", [INTEL_PT_ERR_NELOOP] = "Never-ending loop", }; int intel_pt__strerror(int code, char *buf, size_t buflen) { if (code < 1 || code >= INTEL_PT_ERR_MAX) code = INTEL_PT_ERR_UNK; strlcpy(buf, intel_pt_err_msgs[code], buflen); return 0; } static uint64_t intel_pt_calc_ip(const struct intel_pt_pkt *packet, uint64_t last_ip) { uint64_t ip; switch (packet->count) { case 1: ip = (last_ip & (uint64_t)0xffffffffffff0000ULL) | packet->payload; break; case 2: ip = (last_ip & (uint64_t)0xffffffff00000000ULL) | packet->payload; break; case 3: ip = packet->payload; /* Sign-extend 6-byte ip */ if (ip & (uint64_t)0x800000000000ULL) ip |= (uint64_t)0xffff000000000000ULL; break; case 4: ip = (last_ip & (uint64_t)0xffff000000000000ULL) | packet->payload; break; case 6: ip = packet->payload; break; default: return 0; } return ip; } static inline void intel_pt_set_last_ip(struct intel_pt_decoder *decoder) { decoder->last_ip = intel_pt_calc_ip(&decoder->packet, decoder->last_ip); decoder->have_last_ip = true; } static inline void intel_pt_set_ip(struct intel_pt_decoder *decoder) { intel_pt_set_last_ip(decoder); decoder->ip = decoder->last_ip; } static void intel_pt_decoder_log_packet(struct intel_pt_decoder *decoder) { intel_pt_log_packet(&decoder->packet, decoder->pkt_len, decoder->pos, decoder->buf); } static int intel_pt_bug(struct intel_pt_decoder *decoder) { intel_pt_log("ERROR: Internal error\n"); decoder->pkt_state = INTEL_PT_STATE_NO_PSB; return -ENOSYS; } static inline void intel_pt_clear_tx_flags(struct intel_pt_decoder *decoder) { decoder->tx_flags = 0; } static inline void intel_pt_update_in_tx(struct intel_pt_decoder *decoder) { decoder->tx_flags = decoder->packet.payload & INTEL_PT_IN_TX; } static inline void intel_pt_update_pip(struct intel_pt_decoder *decoder) { decoder->pip_payload = decoder->packet.payload; } static inline void intel_pt_update_nr(struct intel_pt_decoder *decoder) { decoder->next_nr = decoder->pip_payload & 1; } static inline void intel_pt_set_nr(struct intel_pt_decoder *decoder) { decoder->nr = decoder->pip_payload & 1; decoder->next_nr = decoder->nr; } static inline void intel_pt_set_pip(struct intel_pt_decoder *decoder) { intel_pt_update_pip(decoder); intel_pt_set_nr(decoder); } static int intel_pt_bad_packet(struct intel_pt_decoder *decoder) { intel_pt_clear_tx_flags(decoder); decoder->have_tma = false; decoder->pkt_len = 1; decoder->pkt_step = 1; intel_pt_decoder_log_packet(decoder); if (decoder->pkt_state != INTEL_PT_STATE_NO_PSB) { intel_pt_log("ERROR: Bad packet\n"); decoder->pkt_state = INTEL_PT_STATE_ERR1; } return -EBADMSG; } static inline void intel_pt_update_sample_time(struct intel_pt_decoder *decoder) { decoder->sample_timestamp = decoder->timestamp; decoder->sample_insn_cnt = decoder->timestamp_insn_cnt; } static void intel_pt_reposition(struct intel_pt_decoder *decoder) { decoder->ip = 0; decoder->pkt_state = INTEL_PT_STATE_NO_PSB; decoder->timestamp = 0; decoder->have_tma = false; } static int intel_pt_get_data(struct intel_pt_decoder *decoder, bool reposition) { struct intel_pt_buffer buffer = { .buf = 0, }; int ret; decoder->pkt_step = 0; intel_pt_log("Getting more data\n"); ret = decoder->get_trace(&buffer, decoder->data); if (ret) return ret; decoder->buf = buffer.buf; decoder->len = buffer.len; if (!decoder->len) { intel_pt_log("No more data\n"); return -ENODATA; } decoder->buf_timestamp = buffer.ref_timestamp; if (!buffer.consecutive || reposition) { intel_pt_reposition(decoder); decoder->ref_timestamp = buffer.ref_timestamp; decoder->state.trace_nr = buffer.trace_nr; intel_pt_log("Reference timestamp 0x%" PRIx64 "\n", decoder->ref_timestamp); return -ENOLINK; } return 0; } static int intel_pt_get_next_data(struct intel_pt_decoder *decoder, bool reposition) { if (!decoder->next_buf) return intel_pt_get_data(decoder, reposition); decoder->buf = decoder->next_buf; decoder->len = decoder->next_len; decoder->next_buf = 0; decoder->next_len = 0; return 0; } static int intel_pt_get_split_packet(struct intel_pt_decoder *decoder) { unsigned char *buf = decoder->temp_buf; size_t old_len, len, n; int ret; old_len = decoder->len; len = decoder->len; memcpy(buf, decoder->buf, len); ret = intel_pt_get_data(decoder, false); if (ret) { decoder->pos += old_len; return ret < 0 ? ret : -EINVAL; } n = INTEL_PT_PKT_MAX_SZ - len; if (n > decoder->len) n = decoder->len; memcpy(buf + len, decoder->buf, n); len += n; decoder->prev_pkt_ctx = decoder->pkt_ctx; ret = intel_pt_get_packet(buf, len, &decoder->packet, &decoder->pkt_ctx); if (ret < (int)old_len) { decoder->next_buf = decoder->buf; decoder->next_len = decoder->len; decoder->buf = buf; decoder->len = old_len; return intel_pt_bad_packet(decoder); } decoder->next_buf = decoder->buf + (ret - old_len); decoder->next_len = decoder->len - (ret - old_len); decoder->buf = buf; decoder->len = ret; return ret; } struct intel_pt_pkt_info { struct intel_pt_decoder *decoder; struct intel_pt_pkt packet; uint64_t pos; int pkt_len; int last_packet_type; void *data; }; typedef int (*intel_pt_pkt_cb_t)(struct intel_pt_pkt_info *pkt_info); /* Lookahead packets in current buffer */ static int intel_pt_pkt_lookahead(struct intel_pt_decoder *decoder, intel_pt_pkt_cb_t cb, void *data) { struct intel_pt_pkt_info pkt_info; const unsigned char *buf = decoder->buf; enum intel_pt_pkt_ctx pkt_ctx = decoder->pkt_ctx; size_t len = decoder->len; int ret; pkt_info.decoder = decoder; pkt_info.pos = decoder->pos; pkt_info.pkt_len = decoder->pkt_step; pkt_info.last_packet_type = decoder->last_packet_type; pkt_info.data = data; while (1) { do { pkt_info.pos += pkt_info.pkt_len; buf += pkt_info.pkt_len; len -= pkt_info.pkt_len; if (!len) return INTEL_PT_NEED_MORE_BYTES; ret = intel_pt_get_packet(buf, len, &pkt_info.packet, &pkt_ctx); if (!ret) return INTEL_PT_NEED_MORE_BYTES; if (ret < 0) return ret; pkt_info.pkt_len = ret; } while (pkt_info.packet.type == INTEL_PT_PAD); ret = cb(&pkt_info); if (ret) return 0; pkt_info.last_packet_type = pkt_info.packet.type; } } struct intel_pt_calc_cyc_to_tsc_info { uint64_t cycle_cnt; unsigned int cbr; uint32_t last_mtc; uint64_t ctc_timestamp; uint64_t ctc_delta; uint64_t tsc_timestamp; uint64_t timestamp; bool have_tma; bool fixup_last_mtc; bool from_mtc; double cbr_cyc_to_tsc; }; /* * MTC provides a 8-bit slice of CTC but the TMA packet only provides the lower * 16 bits of CTC. If mtc_shift > 8 then some of the MTC bits are not in the CTC * provided by the TMA packet. Fix-up the last_mtc calculated from the TMA * packet by copying the missing bits from the current MTC assuming the least * difference between the two, and that the current MTC comes after last_mtc. */ static void intel_pt_fixup_last_mtc(uint32_t mtc, int mtc_shift, uint32_t *last_mtc) { uint32_t first_missing_bit = 1U << (16 - mtc_shift); uint32_t mask = ~(first_missing_bit - 1); *last_mtc |= mtc & mask; if (*last_mtc >= mtc) { *last_mtc -= first_missing_bit; *last_mtc &= 0xff; } } static int intel_pt_calc_cyc_cb(struct intel_pt_pkt_info *pkt_info) { struct intel_pt_decoder *decoder = pkt_info->decoder; struct intel_pt_calc_cyc_to_tsc_info *data = pkt_info->data; uint64_t timestamp; double cyc_to_tsc; unsigned int cbr; uint32_t mtc, mtc_delta, ctc, fc, ctc_rem; switch (pkt_info->packet.type) { case INTEL_PT_TNT: case INTEL_PT_TIP_PGE: case INTEL_PT_TIP: case INTEL_PT_FUP: case INTEL_PT_PSB: case INTEL_PT_PIP: case INTEL_PT_MODE_EXEC: case INTEL_PT_MODE_TSX: case INTEL_PT_PSBEND: case INTEL_PT_PAD: case INTEL_PT_VMCS: case INTEL_PT_MNT: case INTEL_PT_PTWRITE: case INTEL_PT_PTWRITE_IP: case INTEL_PT_BBP: case INTEL_PT_BIP: case INTEL_PT_BEP: case INTEL_PT_BEP_IP: return 0; case INTEL_PT_MTC: if (!data->have_tma) return 0; mtc = pkt_info->packet.payload; if (decoder->mtc_shift > 8 && data->fixup_last_mtc) { data->fixup_last_mtc = false; intel_pt_fixup_last_mtc(mtc, decoder->mtc_shift, &data->last_mtc); } if (mtc > data->last_mtc) mtc_delta = mtc - data->last_mtc; else mtc_delta = mtc + 256 - data->last_mtc; data->ctc_delta += mtc_delta << decoder->mtc_shift; data->last_mtc = mtc; if (decoder->tsc_ctc_mult) { timestamp = data->ctc_timestamp + data->ctc_delta * decoder->tsc_ctc_mult; } else { timestamp = data->ctc_timestamp + multdiv(data->ctc_delta, decoder->tsc_ctc_ratio_n, decoder->tsc_ctc_ratio_d); } if (timestamp < data->timestamp) return 1; if (pkt_info->last_packet_type != INTEL_PT_CYC) { data->timestamp = timestamp; return 0; } break; case INTEL_PT_TSC: /* * For now, do not support using TSC packets - refer * intel_pt_calc_cyc_to_tsc(). */ if (data->from_mtc) return 1; timestamp = pkt_info->packet.payload | (data->timestamp & (0xffULL << 56)); if (data->from_mtc && timestamp < data->timestamp && data->timestamp - timestamp < decoder->tsc_slip) return 1; if (timestamp < data->timestamp) timestamp += (1ULL << 56); if (pkt_info->last_packet_type != INTEL_PT_CYC) { if (data->from_mtc) return 1; data->tsc_timestamp = timestamp; data->timestamp = timestamp; return 0; } break; case INTEL_PT_TMA: if (data->from_mtc) return 1; if (!decoder->tsc_ctc_ratio_d) return 0; ctc = pkt_info->packet.payload; fc = pkt_info->packet.count; ctc_rem = ctc & decoder->ctc_rem_mask; data->last_mtc = (ctc >> decoder->mtc_shift) & 0xff; data->ctc_timestamp = data->tsc_timestamp - fc; if (decoder->tsc_ctc_mult) { data->ctc_timestamp -= ctc_rem * decoder->tsc_ctc_mult; } else { data->ctc_timestamp -= multdiv(ctc_rem, decoder->tsc_ctc_ratio_n, decoder->tsc_ctc_ratio_d); } data->ctc_delta = 0; data->have_tma = true; data->fixup_last_mtc = true; return 0; case INTEL_PT_CYC: data->cycle_cnt += pkt_info->packet.payload; return 0; case INTEL_PT_CBR: cbr = pkt_info->packet.payload; if (data->cbr && data->cbr != cbr) return 1; data->cbr = cbr; data->cbr_cyc_to_tsc = decoder->max_non_turbo_ratio_fp / cbr; return 0; case INTEL_PT_TIP_PGD: case INTEL_PT_TRACESTOP: case INTEL_PT_EXSTOP: case INTEL_PT_EXSTOP_IP: case INTEL_PT_MWAIT: case INTEL_PT_PWRE: case INTEL_PT_PWRX: case INTEL_PT_OVF: case INTEL_PT_BAD: /* Does not happen */ default: return 1; } if (!data->cbr && decoder->cbr) { data->cbr = decoder->cbr; data->cbr_cyc_to_tsc = decoder->cbr_cyc_to_tsc; } if (!data->cycle_cnt) return 1; cyc_to_tsc = (double)(timestamp - decoder->timestamp) / data->cycle_cnt; if (data->cbr && cyc_to_tsc > data->cbr_cyc_to_tsc && cyc_to_tsc / data->cbr_cyc_to_tsc > 1.25) { intel_pt_log("Timestamp: calculated %g TSC ticks per cycle too big (c.f. CBR-based value %g), pos " x64_fmt "\n", cyc_to_tsc, data->cbr_cyc_to_tsc, pkt_info->pos); return 1; } decoder->calc_cyc_to_tsc = cyc_to_tsc; decoder->have_calc_cyc_to_tsc = true; if (data->cbr) { intel_pt_log("Timestamp: calculated %g TSC ticks per cycle c.f. CBR-based value %g, pos " x64_fmt "\n", cyc_to_tsc, data->cbr_cyc_to_tsc, pkt_info->pos); } else { intel_pt_log("Timestamp: calculated %g TSC ticks per cycle c.f. unknown CBR-based value, pos " x64_fmt "\n", cyc_to_tsc, pkt_info->pos); } return 1; } static void intel_pt_calc_cyc_to_tsc(struct intel_pt_decoder *decoder, bool from_mtc) { struct intel_pt_calc_cyc_to_tsc_info data = { .cycle_cnt = 0, .cbr = 0, .last_mtc = decoder->last_mtc, .ctc_timestamp = decoder->ctc_timestamp, .ctc_delta = decoder->ctc_delta, .tsc_timestamp = decoder->tsc_timestamp, .timestamp = decoder->timestamp, .have_tma = decoder->have_tma, .fixup_last_mtc = decoder->fixup_last_mtc, .from_mtc = from_mtc, .cbr_cyc_to_tsc = 0, }; /* * For now, do not support using TSC packets for at least the reasons: * 1) timing might have stopped * 2) TSC packets within PSB+ can slip against CYC packets */ if (!from_mtc) return; intel_pt_pkt_lookahead(decoder, intel_pt_calc_cyc_cb, &data); } static int intel_pt_get_next_packet(struct intel_pt_decoder *decoder) { int ret; decoder->last_packet_type = decoder->packet.type; do { decoder->pos += decoder->pkt_step; decoder->buf += decoder->pkt_step; decoder->len -= decoder->pkt_step; if (!decoder->len) { ret = intel_pt_get_next_data(decoder, false); if (ret) return ret; } decoder->prev_pkt_ctx = decoder->pkt_ctx; ret = intel_pt_get_packet(decoder->buf, decoder->len, &decoder->packet, &decoder->pkt_ctx); if (ret == INTEL_PT_NEED_MORE_BYTES && BITS_PER_LONG == 32 && decoder->len < INTEL_PT_PKT_MAX_SZ && !decoder->next_buf) { ret = intel_pt_get_split_packet(decoder); if (ret < 0) return ret; } if (ret <= 0) return intel_pt_bad_packet(decoder); decoder->pkt_len = ret; decoder->pkt_step = ret; intel_pt_decoder_log_packet(decoder); } while (decoder->packet.type == INTEL_PT_PAD); return 0; } static uint64_t intel_pt_next_period(struct intel_pt_decoder *decoder) { uint64_t timestamp, masked_timestamp; timestamp = decoder->timestamp + decoder->timestamp_insn_cnt; masked_timestamp = timestamp & decoder->period_mask; if (decoder->continuous_period) { if (masked_timestamp > decoder->last_masked_timestamp) return 1; } else { timestamp += 1; masked_timestamp = timestamp & decoder->period_mask; if (masked_timestamp > decoder->last_masked_timestamp) { decoder->last_masked_timestamp = masked_timestamp; decoder->continuous_period = true; } } if (masked_timestamp < decoder->last_masked_timestamp) return decoder->period_ticks; return decoder->period_ticks - (timestamp - masked_timestamp); } static uint64_t intel_pt_next_sample(struct intel_pt_decoder *decoder) { switch (decoder->period_type) { case INTEL_PT_PERIOD_INSTRUCTIONS: return decoder->period - decoder->period_insn_cnt; case INTEL_PT_PERIOD_TICKS: return intel_pt_next_period(decoder); case INTEL_PT_PERIOD_NONE: case INTEL_PT_PERIOD_MTC: default: return 0; } } static void intel_pt_sample_insn(struct intel_pt_decoder *decoder) { uint64_t timestamp, masked_timestamp; switch (decoder->period_type) { case INTEL_PT_PERIOD_INSTRUCTIONS: decoder->period_insn_cnt = 0; break; case INTEL_PT_PERIOD_TICKS: timestamp = decoder->timestamp + decoder->timestamp_insn_cnt; masked_timestamp = timestamp & decoder->period_mask; if (masked_timestamp > decoder->last_masked_timestamp) decoder->last_masked_timestamp = masked_timestamp; else decoder->last_masked_timestamp += decoder->period_ticks; break; case INTEL_PT_PERIOD_NONE: case INTEL_PT_PERIOD_MTC: default: break; } decoder->state.type |= INTEL_PT_INSTRUCTION; } static int intel_pt_walk_insn(struct intel_pt_decoder *decoder, struct intel_pt_insn *intel_pt_insn, uint64_t ip) { uint64_t max_insn_cnt, insn_cnt = 0; int err; if (!decoder->mtc_insn) decoder->mtc_insn = true; max_insn_cnt = intel_pt_next_sample(decoder); err = decoder->walk_insn(intel_pt_insn, &insn_cnt, &decoder->ip, ip, max_insn_cnt, decoder->data); decoder->tot_insn_cnt += insn_cnt; decoder->timestamp_insn_cnt += insn_cnt; decoder->sample_insn_cnt += insn_cnt; decoder->period_insn_cnt += insn_cnt; if (err) { decoder->no_progress = 0; decoder->pkt_state = INTEL_PT_STATE_ERR2; intel_pt_log_at("ERROR: Failed to get instruction", decoder->ip); if (err == -ENOENT) return -ENOLINK; return -EILSEQ; } if (ip && decoder->ip == ip) { err = -EAGAIN; goto out; } if (max_insn_cnt && insn_cnt >= max_insn_cnt) intel_pt_sample_insn(decoder); if (intel_pt_insn->branch == INTEL_PT_BR_NO_BRANCH) { decoder->state.type = INTEL_PT_INSTRUCTION; decoder->state.from_ip = decoder->ip; decoder->state.to_ip = 0; decoder->ip += intel_pt_insn->length; err = INTEL_PT_RETURN; goto out; } if (intel_pt_insn->op == INTEL_PT_OP_CALL) { /* Zero-length calls are excluded */ if (intel_pt_insn->branch != INTEL_PT_BR_UNCONDITIONAL || intel_pt_insn->rel) { err = intel_pt_push(&decoder->stack, decoder->ip + intel_pt_insn->length); if (err) goto out; } } else if (intel_pt_insn->op == INTEL_PT_OP_RET) { decoder->ret_addr = intel_pt_pop(&decoder->stack); } if (intel_pt_insn->branch == INTEL_PT_BR_UNCONDITIONAL) { int cnt = decoder->no_progress++; decoder->state.from_ip = decoder->ip; decoder->ip += intel_pt_insn->length + intel_pt_insn->rel; decoder->state.to_ip = decoder->ip; err = INTEL_PT_RETURN; /* * Check for being stuck in a loop. This can happen if a * decoder error results in the decoder erroneously setting the * ip to an address that is itself in an infinite loop that * consumes no packets. When that happens, there must be an * unconditional branch. */ if (cnt) { if (cnt == 1) { decoder->stuck_ip = decoder->state.to_ip; decoder->stuck_ip_prd = 1; decoder->stuck_ip_cnt = 1; } else if (cnt > INTEL_PT_MAX_LOOPS || decoder->state.to_ip == decoder->stuck_ip) { intel_pt_log_at("ERROR: Never-ending loop", decoder->state.to_ip); decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC; err = -ELOOP; goto out; } else if (!--decoder->stuck_ip_cnt) { decoder->stuck_ip_prd += 1; decoder->stuck_ip_cnt = decoder->stuck_ip_prd; decoder->stuck_ip = decoder->state.to_ip; } } goto out_no_progress; } out: decoder->no_progress = 0; out_no_progress: decoder->state.insn_op = intel_pt_insn->op; decoder->state.insn_len = intel_pt_insn->length; memcpy(decoder->state.insn, intel_pt_insn->buf, INTEL_PT_INSN_BUF_SZ); if (decoder->tx_flags & INTEL_PT_IN_TX) decoder->state.flags |= INTEL_PT_IN_TX; return err; } static bool intel_pt_fup_event(struct intel_pt_decoder *decoder) { bool ret = false; if (decoder->set_fup_tx_flags) { decoder->set_fup_tx_flags = false; decoder->tx_flags = decoder->fup_tx_flags; decoder->state.type = INTEL_PT_TRANSACTION; decoder->state.from_ip = decoder->ip; decoder->state.to_ip = 0; decoder->state.flags = decoder->fup_tx_flags; return true; } if (decoder->set_fup_ptw) { decoder->set_fup_ptw = false; decoder->state.type = INTEL_PT_PTW; decoder->state.flags |= INTEL_PT_FUP_IP; decoder->state.from_ip = decoder->ip; decoder->state.to_ip = 0; decoder->state.ptw_payload = decoder->fup_ptw_payload; return true; } if (decoder->set_fup_mwait) { decoder->set_fup_mwait = false; decoder->state.type = INTEL_PT_MWAIT_OP; decoder->state.from_ip = decoder->ip; decoder->state.to_ip = 0; decoder->state.mwait_payload = decoder->fup_mwait_payload; ret = true; } if (decoder->set_fup_pwre) { decoder->set_fup_pwre = false; decoder->state.type |= INTEL_PT_PWR_ENTRY; decoder->state.type &= ~INTEL_PT_BRANCH; decoder->state.from_ip = decoder->ip; decoder->state.to_ip = 0; decoder->state.pwre_payload = decoder->fup_pwre_payload; ret = true; } if (decoder->set_fup_exstop) { decoder->set_fup_exstop = false; decoder->state.type |= INTEL_PT_EX_STOP; decoder->state.type &= ~INTEL_PT_BRANCH; decoder->state.flags |= INTEL_PT_FUP_IP; decoder->state.from_ip = decoder->ip; decoder->state.to_ip = 0; ret = true; } if (decoder->set_fup_bep) { decoder->set_fup_bep = false; decoder->state.type |= INTEL_PT_BLK_ITEMS; decoder->state.type &= ~INTEL_PT_BRANCH; decoder->state.from_ip = decoder->ip; decoder->state.to_ip = 0; ret = true; } return ret; } static inline bool intel_pt_fup_with_nlip(struct intel_pt_decoder *decoder, struct intel_pt_insn *intel_pt_insn, uint64_t ip, int err) { return decoder->flags & INTEL_PT_FUP_WITH_NLIP && !err && intel_pt_insn->branch == INTEL_PT_BR_INDIRECT && ip == decoder->ip + intel_pt_insn->length; } static int intel_pt_walk_fup(struct intel_pt_decoder *decoder) { struct intel_pt_insn intel_pt_insn; uint64_t ip; int err; ip = decoder->last_ip; while (1) { err = intel_pt_walk_insn(decoder, &intel_pt_insn, ip); if (err == INTEL_PT_RETURN) return 0; if (err == -EAGAIN || intel_pt_fup_with_nlip(decoder, &intel_pt_insn, ip, err)) { decoder->pkt_state = INTEL_PT_STATE_IN_SYNC; if (intel_pt_fup_event(decoder)) return 0; return -EAGAIN; } decoder->set_fup_tx_flags = false; if (err) return err; if (intel_pt_insn.branch == INTEL_PT_BR_INDIRECT) { intel_pt_log_at("ERROR: Unexpected indirect branch", decoder->ip); decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC; return -ENOENT; } if (intel_pt_insn.branch == INTEL_PT_BR_CONDITIONAL) { intel_pt_log_at("ERROR: Unexpected conditional branch", decoder->ip); decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC; return -ENOENT; } intel_pt_bug(decoder); } } static int intel_pt_walk_tip(struct intel_pt_decoder *decoder) { struct intel_pt_insn intel_pt_insn; int err; err = intel_pt_walk_insn(decoder, &intel_pt_insn, 0); if (err == INTEL_PT_RETURN && decoder->pgd_ip && decoder->pkt_state == INTEL_PT_STATE_TIP_PGD && (decoder->state.type & INTEL_PT_BRANCH) && decoder->pgd_ip(decoder->state.to_ip, decoder->data)) { /* Unconditional branch leaving filter region */ decoder->no_progress = 0; decoder->pge = false; decoder->continuous_period = false; decoder->pkt_state = INTEL_PT_STATE_IN_SYNC; decoder->state.type |= INTEL_PT_TRACE_END; intel_pt_update_nr(decoder); return 0; } if (err == INTEL_PT_RETURN) return 0; if (err) return err; intel_pt_update_nr(decoder); if (intel_pt_insn.branch == INTEL_PT_BR_INDIRECT) { if (decoder->pkt_state == INTEL_PT_STATE_TIP_PGD) { decoder->pge = false; decoder->continuous_period = false; decoder->pkt_state = INTEL_PT_STATE_IN_SYNC; decoder->state.from_ip = decoder->ip; if (decoder->packet.count == 0) { decoder->state.to_ip = 0; } else { decoder->state.to_ip = decoder->last_ip; decoder->ip = decoder->last_ip; } decoder->state.type |= INTEL_PT_TRACE_END; } else { decoder->pkt_state = INTEL_PT_STATE_IN_SYNC; decoder->state.from_ip = decoder->ip; if (decoder->packet.count == 0) { decoder->state.to_ip = 0; } else { decoder->state.to_ip = decoder->last_ip; decoder->ip = decoder->last_ip; } } return 0; } if (intel_pt_insn.branch == INTEL_PT_BR_CONDITIONAL) { uint64_t to_ip = decoder->ip + intel_pt_insn.length + intel_pt_insn.rel; if (decoder->pgd_ip && decoder->pkt_state == INTEL_PT_STATE_TIP_PGD && decoder->pgd_ip(to_ip, decoder->data)) { /* Conditional branch leaving filter region */ decoder->pge = false; decoder->continuous_period = false; decoder->pkt_state = INTEL_PT_STATE_IN_SYNC; decoder->ip = to_ip; decoder->state.from_ip = decoder->ip; decoder->state.to_ip = to_ip; decoder->state.type |= INTEL_PT_TRACE_END; return 0; } intel_pt_log_at("ERROR: Conditional branch when expecting indirect branch", decoder->ip); decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC; return -ENOENT; } return intel_pt_bug(decoder); } static int intel_pt_walk_tnt(struct intel_pt_decoder *decoder) { struct intel_pt_insn intel_pt_insn; int err; while (1) { err = intel_pt_walk_insn(decoder, &intel_pt_insn, 0); if (err == INTEL_PT_RETURN) return 0; if (err) return err; if (intel_pt_insn.op == INTEL_PT_OP_RET) { if (!decoder->return_compression) { intel_pt_log_at("ERROR: RET when expecting conditional branch", decoder->ip); decoder->pkt_state = INTEL_PT_STATE_ERR3; return -ENOENT; } if (!decoder->ret_addr) { intel_pt_log_at("ERROR: Bad RET compression (stack empty)", decoder->ip); decoder->pkt_state = INTEL_PT_STATE_ERR3; return -ENOENT; } if (!(decoder->tnt.payload & BIT63)) { intel_pt_log_at("ERROR: Bad RET compression (TNT=N)", decoder->ip); decoder->pkt_state = INTEL_PT_STATE_ERR3; return -ENOENT; } decoder->tnt.count -= 1; if (decoder->tnt.count) decoder->pkt_state = INTEL_PT_STATE_TNT_CONT; else decoder->pkt_state = INTEL_PT_STATE_IN_SYNC; decoder->tnt.payload <<= 1; decoder->state.from_ip = decoder->ip; decoder->ip = decoder->ret_addr; decoder->state.to_ip = decoder->ip; return 0; } if (intel_pt_insn.branch == INTEL_PT_BR_INDIRECT) { /* Handle deferred TIPs */ err = intel_pt_get_next_packet(decoder); if (err) return err; if (decoder->packet.type != INTEL_PT_TIP || decoder->packet.count == 0) { intel_pt_log_at("ERROR: Missing deferred TIP for indirect branch", decoder->ip); decoder->pkt_state = INTEL_PT_STATE_ERR3; decoder->pkt_step = 0; return -ENOENT; } intel_pt_set_last_ip(decoder); decoder->state.from_ip = decoder->ip; decoder->state.to_ip = decoder->last_ip; decoder->ip = decoder->last_ip; intel_pt_update_nr(decoder); return 0; } if (intel_pt_insn.branch == INTEL_PT_BR_CONDITIONAL) { decoder->tnt.count -= 1; if (decoder->tnt.count) decoder->pkt_state = INTEL_PT_STATE_TNT_CONT; else decoder->pkt_state = INTEL_PT_STATE_IN_SYNC; if (decoder->tnt.payload & BIT63) { decoder->tnt.payload <<= 1; decoder->state.from_ip = decoder->ip; decoder->ip += intel_pt_insn.length + intel_pt_insn.rel; decoder->state.to_ip = decoder->ip; return 0; } /* Instruction sample for a non-taken branch */ if (decoder->state.type & INTEL_PT_INSTRUCTION) { decoder->tnt.payload <<= 1; decoder->state.type = INTEL_PT_INSTRUCTION; decoder->state.from_ip = decoder->ip; decoder->state.to_ip = 0; decoder->ip += intel_pt_insn.length; return 0; } decoder->sample_cyc = false; decoder->ip += intel_pt_insn.length; if (!decoder->tnt.count) { intel_pt_update_sample_time(decoder); return -EAGAIN; } decoder->tnt.payload <<= 1; continue; } return intel_pt_bug(decoder); } } static int intel_pt_mode_tsx(struct intel_pt_decoder *decoder, bool *no_tip) { unsigned int fup_tx_flags; int err; fup_tx_flags = decoder->packet.payload & (INTEL_PT_IN_TX | INTEL_PT_ABORT_TX); err = intel_pt_get_next_packet(decoder); if (err) return err; if (decoder->packet.type == INTEL_PT_FUP) { decoder->fup_tx_flags = fup_tx_flags; decoder->set_fup_tx_flags = true; if (!(decoder->fup_tx_flags & INTEL_PT_ABORT_TX)) *no_tip = true; } else { intel_pt_log_at("ERROR: Missing FUP after MODE.TSX", decoder->pos); intel_pt_update_in_tx(decoder); } return 0; } static uint64_t intel_pt_8b_tsc(uint64_t timestamp, uint64_t ref_timestamp) { timestamp |= (ref_timestamp & (0xffULL << 56)); if (timestamp < ref_timestamp) { if (ref_timestamp - timestamp > (1ULL << 55)) timestamp += (1ULL << 56); } else { if (timestamp - ref_timestamp > (1ULL << 55)) timestamp -= (1ULL << 56); } return timestamp; } static void intel_pt_calc_tsc_timestamp(struct intel_pt_decoder *decoder) { uint64_t timestamp; decoder->have_tma = false; if (decoder->ref_timestamp) { timestamp = intel_pt_8b_tsc(decoder->packet.payload, decoder->ref_timestamp); decoder->tsc_timestamp = timestamp; decoder->timestamp = timestamp; decoder->ref_timestamp = 0; decoder->timestamp_insn_cnt = 0; } else if (decoder->timestamp) { timestamp = decoder->packet.payload | (decoder->timestamp & (0xffULL << 56)); decoder->tsc_timestamp = timestamp; if (timestamp < decoder->timestamp && decoder->timestamp - timestamp < decoder->tsc_slip) { intel_pt_log_to("Suppressing backwards timestamp", timestamp); timestamp = decoder->timestamp; } if (timestamp < decoder->timestamp) { intel_pt_log_to("Wraparound timestamp", timestamp); timestamp += (1ULL << 56); decoder->tsc_timestamp = timestamp; } decoder->timestamp = timestamp; decoder->timestamp_insn_cnt = 0; } if (decoder->last_packet_type == INTEL_PT_CYC) { decoder->cyc_ref_timestamp = decoder->timestamp; decoder->cycle_cnt = 0; decoder->have_calc_cyc_to_tsc = false; intel_pt_calc_cyc_to_tsc(decoder, false); } intel_pt_log_to("Setting timestamp", decoder->timestamp); } static int intel_pt_overflow(struct intel_pt_decoder *decoder) { intel_pt_log("ERROR: Buffer overflow\n"); intel_pt_clear_tx_flags(decoder); intel_pt_set_nr(decoder); decoder->timestamp_insn_cnt = 0; decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC; decoder->overflow = true; return -EOVERFLOW; } static inline void intel_pt_mtc_cyc_cnt_pge(struct intel_pt_decoder *decoder) { if (decoder->have_cyc) return; decoder->cyc_cnt_timestamp = decoder->timestamp; decoder->base_cyc_cnt = decoder->tot_cyc_cnt; } static inline void intel_pt_mtc_cyc_cnt_cbr(struct intel_pt_decoder *decoder) { decoder->tsc_to_cyc = decoder->cbr / decoder->max_non_turbo_ratio_fp; if (decoder->pge) intel_pt_mtc_cyc_cnt_pge(decoder); } static inline void intel_pt_mtc_cyc_cnt_upd(struct intel_pt_decoder *decoder) { uint64_t tot_cyc_cnt, tsc_delta; if (decoder->have_cyc) return; decoder->sample_cyc = true; if (!decoder->pge || decoder->timestamp <= decoder->cyc_cnt_timestamp) return; tsc_delta = decoder->timestamp - decoder->cyc_cnt_timestamp; tot_cyc_cnt = tsc_delta * decoder->tsc_to_cyc + decoder->base_cyc_cnt; if (tot_cyc_cnt > decoder->tot_cyc_cnt) decoder->tot_cyc_cnt = tot_cyc_cnt; } static void intel_pt_calc_tma(struct intel_pt_decoder *decoder) { uint32_t ctc = decoder->packet.payload; uint32_t fc = decoder->packet.count; uint32_t ctc_rem = ctc & decoder->ctc_rem_mask; if (!decoder->tsc_ctc_ratio_d) return; if (decoder->pge && !decoder->in_psb) intel_pt_mtc_cyc_cnt_pge(decoder); else intel_pt_mtc_cyc_cnt_upd(decoder); decoder->last_mtc = (ctc >> decoder->mtc_shift) & 0xff; decoder->ctc_timestamp = decoder->tsc_timestamp - fc; if (decoder->tsc_ctc_mult) { decoder->ctc_timestamp -= ctc_rem * decoder->tsc_ctc_mult; } else { decoder->ctc_timestamp -= multdiv(ctc_rem, decoder->tsc_ctc_ratio_n, decoder->tsc_ctc_ratio_d); } decoder->ctc_delta = 0; decoder->have_tma = true; decoder->fixup_last_mtc = true; intel_pt_log("CTC timestamp " x64_fmt " last MTC %#x CTC rem %#x\n", decoder->ctc_timestamp, decoder->last_mtc, ctc_rem); } static void intel_pt_calc_mtc_timestamp(struct intel_pt_decoder *decoder) { uint64_t timestamp; uint32_t mtc, mtc_delta; if (!decoder->have_tma) return; mtc = decoder->packet.payload; if (decoder->mtc_shift > 8 && decoder->fixup_last_mtc) { decoder->fixup_last_mtc = false; intel_pt_fixup_last_mtc(mtc, decoder->mtc_shift, &decoder->last_mtc); } if (mtc > decoder->last_mtc) mtc_delta = mtc - decoder->last_mtc; else mtc_delta = mtc + 256 - decoder->last_mtc; decoder->ctc_delta += mtc_delta << decoder->mtc_shift; if (decoder->tsc_ctc_mult) { timestamp = decoder->ctc_timestamp + decoder->ctc_delta * decoder->tsc_ctc_mult; } else { timestamp = decoder->ctc_timestamp + multdiv(decoder->ctc_delta, decoder->tsc_ctc_ratio_n, decoder->tsc_ctc_ratio_d); } if (timestamp < decoder->timestamp) intel_pt_log("Suppressing MTC timestamp " x64_fmt " less than current timestamp " x64_fmt "\n", timestamp, decoder->timestamp); else decoder->timestamp = timestamp; intel_pt_mtc_cyc_cnt_upd(decoder); decoder->timestamp_insn_cnt = 0; decoder->last_mtc = mtc; if (decoder->last_packet_type == INTEL_PT_CYC) { decoder->cyc_ref_timestamp = decoder->timestamp; decoder->cycle_cnt = 0; decoder->have_calc_cyc_to_tsc = false; intel_pt_calc_cyc_to_tsc(decoder, true); } intel_pt_log_to("Setting timestamp", decoder->timestamp); } static void intel_pt_calc_cbr(struct intel_pt_decoder *decoder) { unsigned int cbr = decoder->packet.payload & 0xff; decoder->cbr_payload = decoder->packet.payload; if (decoder->cbr == cbr) return; decoder->cbr = cbr; decoder->cbr_cyc_to_tsc = decoder->max_non_turbo_ratio_fp / cbr; intel_pt_mtc_cyc_cnt_cbr(decoder); } static void intel_pt_calc_cyc_timestamp(struct intel_pt_decoder *decoder) { uint64_t timestamp = decoder->cyc_ref_timestamp; decoder->have_cyc = true; decoder->cycle_cnt += decoder->packet.payload; if (decoder->pge) decoder->tot_cyc_cnt += decoder->packet.payload; decoder->sample_cyc = true; if (!decoder->cyc_ref_timestamp) return; if (decoder->have_calc_cyc_to_tsc) timestamp += decoder->cycle_cnt * decoder->calc_cyc_to_tsc; else if (decoder->cbr) timestamp += decoder->cycle_cnt * decoder->cbr_cyc_to_tsc; else return; if (timestamp < decoder->timestamp) intel_pt_log("Suppressing CYC timestamp " x64_fmt " less than current timestamp " x64_fmt "\n", timestamp, decoder->timestamp); else decoder->timestamp = timestamp; decoder->timestamp_insn_cnt = 0; intel_pt_log_to("Setting timestamp", decoder->timestamp); } static void intel_pt_bbp(struct intel_pt_decoder *decoder) { if (decoder->prev_pkt_ctx == INTEL_PT_NO_CTX) { memset(decoder->state.items.mask, 0, sizeof(decoder->state.items.mask)); decoder->state.items.is_32_bit = false; } decoder->blk_type = decoder->packet.payload; decoder->blk_type_pos = intel_pt_blk_type_pos(decoder->blk_type); if (decoder->blk_type == INTEL_PT_GP_REGS) decoder->state.items.is_32_bit = decoder->packet.count; if (decoder->blk_type_pos < 0) { intel_pt_log("WARNING: Unknown block type %u\n", decoder->blk_type); } else if (decoder->state.items.mask[decoder->blk_type_pos]) { intel_pt_log("WARNING: Duplicate block type %u\n", decoder->blk_type); } } static void intel_pt_bip(struct intel_pt_decoder *decoder) { uint32_t id = decoder->packet.count; uint32_t bit = 1 << id; int pos = decoder->blk_type_pos; if (pos < 0 || id >= INTEL_PT_BLK_ITEM_ID_CNT) { intel_pt_log("WARNING: Unknown block item %u type %d\n", id, decoder->blk_type); return; } if (decoder->state.items.mask[pos] & bit) { intel_pt_log("WARNING: Duplicate block item %u type %d\n", id, decoder->blk_type); } decoder->state.items.mask[pos] |= bit; decoder->state.items.val[pos][id] = decoder->packet.payload; } /* Walk PSB+ packets when already in sync. */ static int intel_pt_walk_psbend(struct intel_pt_decoder *decoder) { int err; decoder->in_psb = true; while (1) { err = intel_pt_get_next_packet(decoder); if (err) goto out; switch (decoder->packet.type) { case INTEL_PT_PSBEND: err = 0; goto out; case INTEL_PT_TIP_PGD: case INTEL_PT_TIP_PGE: case INTEL_PT_TIP: case INTEL_PT_TNT: case INTEL_PT_TRACESTOP: case INTEL_PT_BAD: case INTEL_PT_PSB: case INTEL_PT_PTWRITE: case INTEL_PT_PTWRITE_IP: case INTEL_PT_EXSTOP: case INTEL_PT_EXSTOP_IP: case INTEL_PT_MWAIT: case INTEL_PT_PWRE: case INTEL_PT_PWRX: case INTEL_PT_BBP: case INTEL_PT_BIP: case INTEL_PT_BEP: case INTEL_PT_BEP_IP: decoder->have_tma = false; intel_pt_log("ERROR: Unexpected packet\n"); err = -EAGAIN; goto out; case INTEL_PT_OVF: err = intel_pt_overflow(decoder); goto out; case INTEL_PT_TSC: intel_pt_calc_tsc_timestamp(decoder); break; case INTEL_PT_TMA: intel_pt_calc_tma(decoder); break; case INTEL_PT_CBR: intel_pt_calc_cbr(decoder); break; case INTEL_PT_MODE_EXEC: decoder->exec_mode = decoder->packet.payload; break; case INTEL_PT_PIP: intel_pt_set_pip(decoder); break; case INTEL_PT_FUP: decoder->pge = true; if (decoder->packet.count) { intel_pt_set_last_ip(decoder); decoder->psb_ip = decoder->last_ip; } break; case INTEL_PT_MODE_TSX: intel_pt_update_in_tx(decoder); break; case INTEL_PT_MTC: intel_pt_calc_mtc_timestamp(decoder); if (decoder->period_type == INTEL_PT_PERIOD_MTC) decoder->state.type |= INTEL_PT_INSTRUCTION; break; case INTEL_PT_CYC: intel_pt_calc_cyc_timestamp(decoder); break; case INTEL_PT_VMCS: case INTEL_PT_MNT: case INTEL_PT_PAD: default: break; } } out: decoder->in_psb = false; return err; } static int intel_pt_walk_fup_tip(struct intel_pt_decoder *decoder) { int err; if (decoder->tx_flags & INTEL_PT_ABORT_TX) { decoder->tx_flags = 0; decoder->state.flags &= ~INTEL_PT_IN_TX; decoder->state.flags |= INTEL_PT_ABORT_TX; } else { decoder->state.flags |= INTEL_PT_ASYNC; } while (1) { err = intel_pt_get_next_packet(decoder); if (err) return err; switch (decoder->packet.type) { case INTEL_PT_TNT: case INTEL_PT_FUP: case INTEL_PT_TRACESTOP: case INTEL_PT_PSB: case INTEL_PT_TSC: case INTEL_PT_TMA: case INTEL_PT_MODE_TSX: case INTEL_PT_BAD: case INTEL_PT_PSBEND: case INTEL_PT_PTWRITE: case INTEL_PT_PTWRITE_IP: case INTEL_PT_EXSTOP: case INTEL_PT_EXSTOP_IP: case INTEL_PT_MWAIT: case INTEL_PT_PWRE: case INTEL_PT_PWRX: case INTEL_PT_BBP: case INTEL_PT_BIP: case INTEL_PT_BEP: case INTEL_PT_BEP_IP: intel_pt_log("ERROR: Missing TIP after FUP\n"); decoder->pkt_state = INTEL_PT_STATE_ERR3; decoder->pkt_step = 0; return -ENOENT; case INTEL_PT_CBR: intel_pt_calc_cbr(decoder); break; case INTEL_PT_OVF: return intel_pt_overflow(decoder); case INTEL_PT_TIP_PGD: decoder->state.from_ip = decoder->ip; if (decoder->packet.count == 0) { decoder->state.to_ip = 0; } else { intel_pt_set_ip(decoder); decoder->state.to_ip = decoder->ip; } decoder->pge = false; decoder->continuous_period = false; decoder->state.type |= INTEL_PT_TRACE_END; intel_pt_update_nr(decoder); return 0; case INTEL_PT_TIP_PGE: decoder->pge = true; intel_pt_log("Omitting PGE ip " x64_fmt "\n", decoder->ip); decoder->state.from_ip = 0; if (decoder->packet.count == 0) { decoder->state.to_ip = 0; } else { intel_pt_set_ip(decoder); decoder->state.to_ip = decoder->ip; } decoder->state.type |= INTEL_PT_TRACE_BEGIN; intel_pt_mtc_cyc_cnt_pge(decoder); intel_pt_set_nr(decoder); return 0; case INTEL_PT_TIP: decoder->state.from_ip = decoder->ip; if (decoder->packet.count == 0) { decoder->state.to_ip = 0; } else { intel_pt_set_ip(decoder); decoder->state.to_ip = decoder->ip; } intel_pt_update_nr(decoder); return 0; case INTEL_PT_PIP: intel_pt_update_pip(decoder); break; case INTEL_PT_MTC: intel_pt_calc_mtc_timestamp(decoder); if (decoder->period_type == INTEL_PT_PERIOD_MTC) decoder->state.type |= INTEL_PT_INSTRUCTION; break; case INTEL_PT_CYC: intel_pt_calc_cyc_timestamp(decoder); break; case INTEL_PT_MODE_EXEC: decoder->exec_mode = decoder->packet.payload; break; case INTEL_PT_VMCS: case INTEL_PT_MNT: case INTEL_PT_PAD: break; default: return intel_pt_bug(decoder); } } } static int intel_pt_resample(struct intel_pt_decoder *decoder) { decoder->pkt_state = INTEL_PT_STATE_IN_SYNC; decoder->state.type = INTEL_PT_INSTRUCTION; decoder->state.from_ip = decoder->ip; decoder->state.to_ip = 0; return 0; } #define HOP_PROCESS 0 #define HOP_IGNORE 1 #define HOP_RETURN 2 #define HOP_AGAIN 3 static int intel_pt_scan_for_psb(struct intel_pt_decoder *decoder); /* Hop mode: Ignore TNT, do not walk code, but get ip from FUPs and TIPs */ static int intel_pt_hop_trace(struct intel_pt_decoder *decoder, bool *no_tip, int *err) { /* Leap from PSB to PSB, getting ip from FUP within PSB+ */ if (decoder->leap && !decoder->in_psb && decoder->packet.type != INTEL_PT_PSB) { *err = intel_pt_scan_for_psb(decoder); if (*err) return HOP_RETURN; } switch (decoder->packet.type) { case INTEL_PT_TNT: return HOP_IGNORE; case INTEL_PT_TIP_PGD: if (!decoder->packet.count) { intel_pt_set_nr(decoder); return HOP_IGNORE; } intel_pt_set_ip(decoder); decoder->state.type |= INTEL_PT_TRACE_END; decoder->state.from_ip = 0; decoder->state.to_ip = decoder->ip; intel_pt_update_nr(decoder); return HOP_RETURN; case INTEL_PT_TIP: if (!decoder->packet.count) { intel_pt_set_nr(decoder); return HOP_IGNORE; } intel_pt_set_ip(decoder); decoder->state.type = INTEL_PT_INSTRUCTION; decoder->state.from_ip = decoder->ip; decoder->state.to_ip = 0; intel_pt_update_nr(decoder); return HOP_RETURN; case INTEL_PT_FUP: if (!decoder->packet.count) return HOP_IGNORE; intel_pt_set_ip(decoder); if (intel_pt_fup_event(decoder)) return HOP_RETURN; if (!decoder->branch_enable) *no_tip = true; if (*no_tip) { decoder->state.type = INTEL_PT_INSTRUCTION; decoder->state.from_ip = decoder->ip; decoder->state.to_ip = 0; return HOP_RETURN; } *err = intel_pt_walk_fup_tip(decoder); if (!*err) decoder->pkt_state = INTEL_PT_STATE_RESAMPLE; return HOP_RETURN; case INTEL_PT_PSB: decoder->state.psb_offset = decoder->pos; decoder->psb_ip = 0; decoder->last_ip = 0; decoder->have_last_ip = true; *err = intel_pt_walk_psbend(decoder); if (*err == -EAGAIN) return HOP_AGAIN; if (*err) return HOP_RETURN; decoder->state.type = INTEL_PT_PSB_EVT; if (decoder->psb_ip) { decoder->state.type |= INTEL_PT_INSTRUCTION; decoder->ip = decoder->psb_ip; } decoder->state.from_ip = decoder->psb_ip; decoder->state.to_ip = 0; return HOP_RETURN; case INTEL_PT_BAD: case INTEL_PT_PAD: case INTEL_PT_TIP_PGE: case INTEL_PT_TSC: case INTEL_PT_TMA: case INTEL_PT_MODE_EXEC: case INTEL_PT_MODE_TSX: case INTEL_PT_MTC: case INTEL_PT_CYC: case INTEL_PT_VMCS: case INTEL_PT_PSBEND: case INTEL_PT_CBR: case INTEL_PT_TRACESTOP: case INTEL_PT_PIP: case INTEL_PT_OVF: case INTEL_PT_MNT: case INTEL_PT_PTWRITE: case INTEL_PT_PTWRITE_IP: case INTEL_PT_EXSTOP: case INTEL_PT_EXSTOP_IP: case INTEL_PT_MWAIT: case INTEL_PT_PWRE: case INTEL_PT_PWRX: case INTEL_PT_BBP: case INTEL_PT_BIP: case INTEL_PT_BEP: case INTEL_PT_BEP_IP: default: return HOP_PROCESS; } } struct intel_pt_psb_info { struct intel_pt_pkt fup_packet; bool fup; int after_psbend; }; /* Lookahead and get the FUP packet from PSB+ */ static int intel_pt_psb_lookahead_cb(struct intel_pt_pkt_info *pkt_info) { struct intel_pt_psb_info *data = pkt_info->data; switch (pkt_info->packet.type) { case INTEL_PT_PAD: case INTEL_PT_MNT: case INTEL_PT_TSC: case INTEL_PT_TMA: case INTEL_PT_MODE_EXEC: case INTEL_PT_MODE_TSX: case INTEL_PT_MTC: case INTEL_PT_CYC: case INTEL_PT_VMCS: case INTEL_PT_CBR: case INTEL_PT_PIP: if (data->after_psbend) { data->after_psbend -= 1; if (!data->after_psbend) return 1; } break; case INTEL_PT_FUP: if (data->after_psbend) return 1; if (data->fup || pkt_info->packet.count == 0) return 1; data->fup_packet = pkt_info->packet; data->fup = true; break; case INTEL_PT_PSBEND: if (!data->fup) return 1; /* Keep going to check for a TIP.PGE */ data->after_psbend = 6; break; case INTEL_PT_TIP_PGE: /* Ignore FUP in PSB+ if followed by TIP.PGE */ if (data->after_psbend) data->fup = false; return 1; case INTEL_PT_PTWRITE: case INTEL_PT_PTWRITE_IP: case INTEL_PT_EXSTOP: case INTEL_PT_EXSTOP_IP: case INTEL_PT_MWAIT: case INTEL_PT_PWRE: case INTEL_PT_PWRX: case INTEL_PT_BBP: case INTEL_PT_BIP: case INTEL_PT_BEP: case INTEL_PT_BEP_IP: if (data->after_psbend) { data->after_psbend -= 1; if (!data->after_psbend) return 1; break; } return 1; case INTEL_PT_OVF: case INTEL_PT_BAD: case INTEL_PT_TNT: case INTEL_PT_TIP_PGD: case INTEL_PT_TIP: case INTEL_PT_PSB: case INTEL_PT_TRACESTOP: default: return 1; } return 0; } static int intel_pt_psb(struct intel_pt_decoder *decoder) { int err; decoder->last_ip = 0; decoder->psb_ip = 0; decoder->have_last_ip = true; intel_pt_clear_stack(&decoder->stack); err = intel_pt_walk_psbend(decoder); if (err) return err; decoder->state.type = INTEL_PT_PSB_EVT; decoder->state.from_ip = decoder->psb_ip; decoder->state.to_ip = 0; return 0; } static int intel_pt_fup_in_psb(struct intel_pt_decoder *decoder) { int err; if (decoder->ip != decoder->last_ip) { err = intel_pt_walk_fup(decoder); if (!err || err != -EAGAIN) return err; } decoder->pkt_state = INTEL_PT_STATE_IN_SYNC; err = intel_pt_psb(decoder); if (err) { decoder->pkt_state = INTEL_PT_STATE_ERR3; return -ENOENT; } return 0; } static bool intel_pt_psb_with_fup(struct intel_pt_decoder *decoder, int *err) { struct intel_pt_psb_info data = { .fup = false }; if (!decoder->branch_enable || !decoder->pge) return false; intel_pt_pkt_lookahead(decoder, intel_pt_psb_lookahead_cb, &data); if (!data.fup) return false; decoder->packet = data.fup_packet; intel_pt_set_last_ip(decoder); decoder->pkt_state = INTEL_PT_STATE_FUP_IN_PSB; *err = intel_pt_fup_in_psb(decoder); return true; } static int intel_pt_walk_trace(struct intel_pt_decoder *decoder) { int last_packet_type = INTEL_PT_PAD; bool no_tip = false; int err; while (1) { err = intel_pt_get_next_packet(decoder); if (err) return err; next: if (decoder->cyc_threshold) { if (decoder->sample_cyc && last_packet_type != INTEL_PT_CYC) decoder->sample_cyc = false; last_packet_type = decoder->packet.type; } if (decoder->hop) { switch (intel_pt_hop_trace(decoder, &no_tip, &err)) { case HOP_IGNORE: continue; case HOP_RETURN: return err; case HOP_AGAIN: goto next; default: break; } } switch (decoder->packet.type) { case INTEL_PT_TNT: if (!decoder->packet.count) break; decoder->tnt = decoder->packet; decoder->pkt_state = INTEL_PT_STATE_TNT; err = intel_pt_walk_tnt(decoder); if (err == -EAGAIN) break; return err; case INTEL_PT_TIP_PGD: if (decoder->packet.count != 0) intel_pt_set_last_ip(decoder); decoder->pkt_state = INTEL_PT_STATE_TIP_PGD; return intel_pt_walk_tip(decoder); case INTEL_PT_TIP_PGE: { decoder->pge = true; intel_pt_mtc_cyc_cnt_pge(decoder); intel_pt_set_nr(decoder); if (decoder->packet.count == 0) { intel_pt_log_at("Skipping zero TIP.PGE", decoder->pos); break; } intel_pt_set_ip(decoder); decoder->state.from_ip = 0; decoder->state.to_ip = decoder->ip; decoder->state.type |= INTEL_PT_TRACE_BEGIN; /* * In hop mode, resample to get the to_ip as an * "instruction" sample. */ if (decoder->hop) decoder->pkt_state = INTEL_PT_STATE_RESAMPLE; return 0; } case INTEL_PT_OVF: return intel_pt_overflow(decoder); case INTEL_PT_TIP: if (decoder->packet.count != 0) intel_pt_set_last_ip(decoder); decoder->pkt_state = INTEL_PT_STATE_TIP; return intel_pt_walk_tip(decoder); case INTEL_PT_FUP: if (decoder->packet.count == 0) { intel_pt_log_at("Skipping zero FUP", decoder->pos); no_tip = false; break; } intel_pt_set_last_ip(decoder); if (!decoder->branch_enable) { decoder->ip = decoder->last_ip; if (intel_pt_fup_event(decoder)) return 0; no_tip = false; break; } if (decoder->set_fup_mwait) no_tip = true; if (no_tip) decoder->pkt_state = INTEL_PT_STATE_FUP_NO_TIP; else decoder->pkt_state = INTEL_PT_STATE_FUP; err = intel_pt_walk_fup(decoder); if (err != -EAGAIN) return err; if (no_tip) { no_tip = false; break; } return intel_pt_walk_fup_tip(decoder); case INTEL_PT_TRACESTOP: decoder->pge = false; decoder->continuous_period = false; intel_pt_clear_tx_flags(decoder); decoder->have_tma = false; break; case INTEL_PT_PSB: decoder->state.psb_offset = decoder->pos; decoder->psb_ip = 0; if (intel_pt_psb_with_fup(decoder, &err)) return err; err = intel_pt_psb(decoder); if (err == -EAGAIN) goto next; return err; case INTEL_PT_PIP: intel_pt_update_pip(decoder); break; case INTEL_PT_MTC: intel_pt_calc_mtc_timestamp(decoder); if (decoder->period_type != INTEL_PT_PERIOD_MTC) break; /* * Ensure that there has been an instruction since the * last MTC. */ if (!decoder->mtc_insn) break; decoder->mtc_insn = false; /* Ensure that there is a timestamp */ if (!decoder->timestamp) break; decoder->state.type = INTEL_PT_INSTRUCTION; decoder->state.from_ip = decoder->ip; decoder->state.to_ip = 0; decoder->mtc_insn = false; return 0; case INTEL_PT_TSC: intel_pt_calc_tsc_timestamp(decoder); break; case INTEL_PT_TMA: intel_pt_calc_tma(decoder); break; case INTEL_PT_CYC: intel_pt_calc_cyc_timestamp(decoder); break; case INTEL_PT_CBR: intel_pt_calc_cbr(decoder); if (decoder->cbr != decoder->cbr_seen) { decoder->state.type = 0; return 0; } break; case INTEL_PT_MODE_EXEC: decoder->exec_mode = decoder->packet.payload; break; case INTEL_PT_MODE_TSX: /* MODE_TSX need not be followed by FUP */ if (!decoder->pge || decoder->in_psb) { intel_pt_update_in_tx(decoder); break; } err = intel_pt_mode_tsx(decoder, &no_tip); if (err) return err; goto next; case INTEL_PT_BAD: /* Does not happen */ return intel_pt_bug(decoder); case INTEL_PT_PSBEND: case INTEL_PT_VMCS: case INTEL_PT_MNT: case INTEL_PT_PAD: break; case INTEL_PT_PTWRITE_IP: decoder->fup_ptw_payload = decoder->packet.payload; err = intel_pt_get_next_packet(decoder); if (err) return err; if (decoder->packet.type == INTEL_PT_FUP) { decoder->set_fup_ptw = true; no_tip = true; } else { intel_pt_log_at("ERROR: Missing FUP after PTWRITE", decoder->pos); } goto next; case INTEL_PT_PTWRITE: decoder->state.type = INTEL_PT_PTW; decoder->state.from_ip = decoder->ip; decoder->state.to_ip = 0; decoder->state.ptw_payload = decoder->packet.payload; return 0; case INTEL_PT_MWAIT: decoder->fup_mwait_payload = decoder->packet.payload; decoder->set_fup_mwait = true; break; case INTEL_PT_PWRE: if (decoder->set_fup_mwait) { decoder->fup_pwre_payload = decoder->packet.payload; decoder->set_fup_pwre = true; break; } decoder->state.type = INTEL_PT_PWR_ENTRY; decoder->state.from_ip = decoder->ip; decoder->state.to_ip = 0; decoder->state.pwrx_payload = decoder->packet.payload; return 0; case INTEL_PT_EXSTOP_IP: err = intel_pt_get_next_packet(decoder); if (err) return err; if (decoder->packet.type == INTEL_PT_FUP) { decoder->set_fup_exstop = true; no_tip = true; } else { intel_pt_log_at("ERROR: Missing FUP after EXSTOP", decoder->pos); } goto next; case INTEL_PT_EXSTOP: decoder->state.type = INTEL_PT_EX_STOP; decoder->state.from_ip = decoder->ip; decoder->state.to_ip = 0; return 0; case INTEL_PT_PWRX: decoder->state.type = INTEL_PT_PWR_EXIT; decoder->state.from_ip = decoder->ip; decoder->state.to_ip = 0; decoder->state.pwrx_payload = decoder->packet.payload; return 0; case INTEL_PT_BBP: intel_pt_bbp(decoder); break; case INTEL_PT_BIP: intel_pt_bip(decoder); break; case INTEL_PT_BEP: decoder->state.type = INTEL_PT_BLK_ITEMS; decoder->state.from_ip = decoder->ip; decoder->state.to_ip = 0; return 0; case INTEL_PT_BEP_IP: err = intel_pt_get_next_packet(decoder); if (err) return err; if (decoder->packet.type == INTEL_PT_FUP) { decoder->set_fup_bep = true; no_tip = true; } else { intel_pt_log_at("ERROR: Missing FUP after BEP", decoder->pos); } goto next; default: return intel_pt_bug(decoder); } } } static inline bool intel_pt_have_ip(struct intel_pt_decoder *decoder) { return decoder->packet.count && (decoder->have_last_ip || decoder->packet.count == 3 || decoder->packet.count == 6); } /* Walk PSB+ packets to get in sync. */ static int intel_pt_walk_psb(struct intel_pt_decoder *decoder) { int err; decoder->in_psb = true; while (1) { err = intel_pt_get_next_packet(decoder); if (err) goto out; switch (decoder->packet.type) { case INTEL_PT_TIP_PGD: decoder->continuous_period = false; __fallthrough; case INTEL_PT_TIP_PGE: case INTEL_PT_TIP: case INTEL_PT_PTWRITE: case INTEL_PT_PTWRITE_IP: case INTEL_PT_EXSTOP: case INTEL_PT_EXSTOP_IP: case INTEL_PT_MWAIT: case INTEL_PT_PWRE: case INTEL_PT_PWRX: case INTEL_PT_BBP: case INTEL_PT_BIP: case INTEL_PT_BEP: case INTEL_PT_BEP_IP: intel_pt_log("ERROR: Unexpected packet\n"); err = -ENOENT; goto out; case INTEL_PT_FUP: decoder->pge = true; if (intel_pt_have_ip(decoder)) { uint64_t current_ip = decoder->ip; intel_pt_set_ip(decoder); decoder->psb_ip = decoder->ip; if (current_ip) intel_pt_log_to("Setting IP", decoder->ip); } break; case INTEL_PT_MTC: intel_pt_calc_mtc_timestamp(decoder); break; case INTEL_PT_TSC: intel_pt_calc_tsc_timestamp(decoder); break; case INTEL_PT_TMA: intel_pt_calc_tma(decoder); break; case INTEL_PT_CYC: intel_pt_calc_cyc_timestamp(decoder); break; case INTEL_PT_CBR: intel_pt_calc_cbr(decoder); break; case INTEL_PT_PIP: intel_pt_set_pip(decoder); break; case INTEL_PT_MODE_EXEC: decoder->exec_mode = decoder->packet.payload; break; case INTEL_PT_MODE_TSX: intel_pt_update_in_tx(decoder); break; case INTEL_PT_TRACESTOP: decoder->pge = false; decoder->continuous_period = false; intel_pt_clear_tx_flags(decoder); __fallthrough; case INTEL_PT_TNT: decoder->have_tma = false; intel_pt_log("ERROR: Unexpected packet\n"); if (decoder->ip) decoder->pkt_state = INTEL_PT_STATE_ERR4; else decoder->pkt_state = INTEL_PT_STATE_ERR3; err = -ENOENT; goto out; case INTEL_PT_BAD: /* Does not happen */ err = intel_pt_bug(decoder); goto out; case INTEL_PT_OVF: err = intel_pt_overflow(decoder); goto out; case INTEL_PT_PSBEND: err = 0; goto out; case INTEL_PT_PSB: case INTEL_PT_VMCS: case INTEL_PT_MNT: case INTEL_PT_PAD: default: break; } } out: decoder->in_psb = false; return err; } static int intel_pt_walk_to_ip(struct intel_pt_decoder *decoder) { int err; while (1) { err = intel_pt_get_next_packet(decoder); if (err) return err; switch (decoder->packet.type) { case INTEL_PT_TIP_PGD: decoder->continuous_period = false; decoder->pge = false; if (intel_pt_have_ip(decoder)) intel_pt_set_ip(decoder); if (!decoder->ip) break; decoder->state.type |= INTEL_PT_TRACE_END; return 0; case INTEL_PT_TIP_PGE: decoder->pge = true; intel_pt_mtc_cyc_cnt_pge(decoder); if (intel_pt_have_ip(decoder)) intel_pt_set_ip(decoder); if (!decoder->ip) break; decoder->state.type |= INTEL_PT_TRACE_BEGIN; return 0; case INTEL_PT_TIP: decoder->pge = true; if (intel_pt_have_ip(decoder)) intel_pt_set_ip(decoder); if (!decoder->ip) break; return 0; case INTEL_PT_FUP: if (intel_pt_have_ip(decoder)) intel_pt_set_ip(decoder); if (decoder->ip) return 0; break; case INTEL_PT_MTC: intel_pt_calc_mtc_timestamp(decoder); break; case INTEL_PT_TSC: intel_pt_calc_tsc_timestamp(decoder); break; case INTEL_PT_TMA: intel_pt_calc_tma(decoder); break; case INTEL_PT_CYC: intel_pt_calc_cyc_timestamp(decoder); break; case INTEL_PT_CBR: intel_pt_calc_cbr(decoder); break; case INTEL_PT_PIP: intel_pt_set_pip(decoder); break; case INTEL_PT_MODE_EXEC: decoder->exec_mode = decoder->packet.payload; break; case INTEL_PT_MODE_TSX: intel_pt_update_in_tx(decoder); break; case INTEL_PT_OVF: return intel_pt_overflow(decoder); case INTEL_PT_BAD: /* Does not happen */ return intel_pt_bug(decoder); case INTEL_PT_TRACESTOP: decoder->pge = false; decoder->continuous_period = false; intel_pt_clear_tx_flags(decoder); decoder->have_tma = false; break; case INTEL_PT_PSB: decoder->state.psb_offset = decoder->pos; decoder->psb_ip = 0; decoder->last_ip = 0; decoder->have_last_ip = true; intel_pt_clear_stack(&decoder->stack); err = intel_pt_walk_psb(decoder); if (err) return err; decoder->state.type = INTEL_PT_PSB_EVT; decoder->state.from_ip = decoder->psb_ip; decoder->state.to_ip = 0; return 0; case INTEL_PT_TNT: case INTEL_PT_PSBEND: case INTEL_PT_VMCS: case INTEL_PT_MNT: case INTEL_PT_PAD: case INTEL_PT_PTWRITE: case INTEL_PT_PTWRITE_IP: case INTEL_PT_EXSTOP: case INTEL_PT_EXSTOP_IP: case INTEL_PT_MWAIT: case INTEL_PT_PWRE: case INTEL_PT_PWRX: case INTEL_PT_BBP: case INTEL_PT_BIP: case INTEL_PT_BEP: case INTEL_PT_BEP_IP: default: break; } } } static int intel_pt_sync_ip(struct intel_pt_decoder *decoder) { int err; decoder->set_fup_tx_flags = false; decoder->set_fup_ptw = false; decoder->set_fup_mwait = false; decoder->set_fup_pwre = false; decoder->set_fup_exstop = false; decoder->set_fup_bep = false; if (!decoder->branch_enable) { decoder->pkt_state = INTEL_PT_STATE_IN_SYNC; decoder->overflow = false; decoder->state.type = 0; /* Do not have a sample */ return 0; } intel_pt_log("Scanning for full IP\n"); err = intel_pt_walk_to_ip(decoder); if (err || ((decoder->state.type & INTEL_PT_PSB_EVT) && !decoder->ip)) return err; /* In hop mode, resample to get the to_ip as an "instruction" sample */ if (decoder->hop) decoder->pkt_state = INTEL_PT_STATE_RESAMPLE; else decoder->pkt_state = INTEL_PT_STATE_IN_SYNC; decoder->overflow = false; decoder->state.from_ip = 0; decoder->state.to_ip = decoder->ip; intel_pt_log_to("Setting IP", decoder->ip); return 0; } static int intel_pt_part_psb(struct intel_pt_decoder *decoder) { const unsigned char *end = decoder->buf + decoder->len; size_t i; for (i = INTEL_PT_PSB_LEN - 1; i; i--) { if (i > decoder->len) continue; if (!memcmp(end - i, INTEL_PT_PSB_STR, i)) return i; } return 0; } static int intel_pt_rest_psb(struct intel_pt_decoder *decoder, int part_psb) { size_t rest_psb = INTEL_PT_PSB_LEN - part_psb; const char *psb = INTEL_PT_PSB_STR; if (rest_psb > decoder->len || memcmp(decoder->buf, psb + part_psb, rest_psb)) return 0; return rest_psb; } static int intel_pt_get_split_psb(struct intel_pt_decoder *decoder, int part_psb) { int rest_psb, ret; decoder->pos += decoder->len; decoder->len = 0; ret = intel_pt_get_next_data(decoder, false); if (ret) return ret; rest_psb = intel_pt_rest_psb(decoder, part_psb); if (!rest_psb) return 0; decoder->pos -= part_psb; decoder->next_buf = decoder->buf + rest_psb; decoder->next_len = decoder->len - rest_psb; memcpy(decoder->temp_buf, INTEL_PT_PSB_STR, INTEL_PT_PSB_LEN); decoder->buf = decoder->temp_buf; decoder->len = INTEL_PT_PSB_LEN; return 0; } static int intel_pt_scan_for_psb(struct intel_pt_decoder *decoder) { unsigned char *next; int ret; intel_pt_log("Scanning for PSB\n"); while (1) { if (!decoder->len) { ret = intel_pt_get_next_data(decoder, false); if (ret) return ret; } next = memmem(decoder->buf, decoder->len, INTEL_PT_PSB_STR, INTEL_PT_PSB_LEN); if (!next) { int part_psb; part_psb = intel_pt_part_psb(decoder); if (part_psb) { ret = intel_pt_get_split_psb(decoder, part_psb); if (ret) return ret; } else { decoder->pos += decoder->len; decoder->len = 0; } continue; } decoder->pkt_step = next - decoder->buf; return intel_pt_get_next_packet(decoder); } } static int intel_pt_sync(struct intel_pt_decoder *decoder) { int err; decoder->pge = false; decoder->continuous_period = false; decoder->have_last_ip = false; decoder->last_ip = 0; decoder->psb_ip = 0; decoder->ip = 0; intel_pt_clear_stack(&decoder->stack); err = intel_pt_scan_for_psb(decoder); if (err) return err; decoder->have_last_ip = true; decoder->pkt_state = INTEL_PT_STATE_NO_IP; err = intel_pt_walk_psb(decoder); if (err) return err; decoder->state.type = INTEL_PT_PSB_EVT; /* Only PSB sample */ decoder->state.from_ip = decoder->psb_ip; decoder->state.to_ip = 0; if (decoder->ip) { /* * In hop mode, resample to get the PSB FUP ip as an * "instruction" sample. */ if (decoder->hop) decoder->pkt_state = INTEL_PT_STATE_RESAMPLE; else decoder->pkt_state = INTEL_PT_STATE_IN_SYNC; } return 0; } static uint64_t intel_pt_est_timestamp(struct intel_pt_decoder *decoder) { uint64_t est = decoder->sample_insn_cnt << 1; if (!decoder->cbr || !decoder->max_non_turbo_ratio) goto out; est *= decoder->max_non_turbo_ratio; est /= decoder->cbr; out: return decoder->sample_timestamp + est; } const struct intel_pt_state *intel_pt_decode(struct intel_pt_decoder *decoder) { int err; do { decoder->state.type = INTEL_PT_BRANCH; decoder->state.flags = 0; switch (decoder->pkt_state) { case INTEL_PT_STATE_NO_PSB: err = intel_pt_sync(decoder); break; case INTEL_PT_STATE_NO_IP: decoder->have_last_ip = false; decoder->last_ip = 0; decoder->ip = 0; __fallthrough; case INTEL_PT_STATE_ERR_RESYNC: err = intel_pt_sync_ip(decoder); break; case INTEL_PT_STATE_IN_SYNC: err = intel_pt_walk_trace(decoder); break; case INTEL_PT_STATE_TNT: case INTEL_PT_STATE_TNT_CONT: err = intel_pt_walk_tnt(decoder); if (err == -EAGAIN) err = intel_pt_walk_trace(decoder); break; case INTEL_PT_STATE_TIP: case INTEL_PT_STATE_TIP_PGD: err = intel_pt_walk_tip(decoder); break; case INTEL_PT_STATE_FUP: err = intel_pt_walk_fup(decoder); if (err == -EAGAIN) err = intel_pt_walk_fup_tip(decoder); break; case INTEL_PT_STATE_FUP_NO_TIP: err = intel_pt_walk_fup(decoder); if (err == -EAGAIN) err = intel_pt_walk_trace(decoder); break; case INTEL_PT_STATE_FUP_IN_PSB: err = intel_pt_fup_in_psb(decoder); break; case INTEL_PT_STATE_RESAMPLE: err = intel_pt_resample(decoder); break; default: err = intel_pt_bug(decoder); break; } } while (err == -ENOLINK); if (err) { decoder->state.err = intel_pt_ext_err(err); decoder->state.from_ip = decoder->ip; intel_pt_update_sample_time(decoder); decoder->sample_tot_cyc_cnt = decoder->tot_cyc_cnt; intel_pt_set_nr(decoder); } else { decoder->state.err = 0; if (decoder->cbr != decoder->cbr_seen) { decoder->cbr_seen = decoder->cbr; if (!decoder->state.type) { decoder->state.from_ip = decoder->ip; decoder->state.to_ip = 0; } decoder->state.type |= INTEL_PT_CBR_CHG; decoder->state.cbr_payload = decoder->cbr_payload; decoder->state.cbr = decoder->cbr; } if (intel_pt_sample_time(decoder->pkt_state)) { intel_pt_update_sample_time(decoder); if (decoder->sample_cyc) { decoder->sample_tot_cyc_cnt = decoder->tot_cyc_cnt; decoder->state.flags |= INTEL_PT_SAMPLE_IPC; decoder->sample_cyc = false; } } /* * When using only TSC/MTC to compute cycles, IPC can be * sampled as soon as the cycle count changes. */ if (!decoder->have_cyc) decoder->state.flags |= INTEL_PT_SAMPLE_IPC; } /* Let PSB event always have TSC timestamp */ if ((decoder->state.type & INTEL_PT_PSB_EVT) && decoder->tsc_timestamp) decoder->sample_timestamp = decoder->tsc_timestamp; decoder->state.from_nr = decoder->nr; decoder->state.to_nr = decoder->next_nr; decoder->nr = decoder->next_nr; decoder->state.timestamp = decoder->sample_timestamp; decoder->state.est_timestamp = intel_pt_est_timestamp(decoder); decoder->state.tot_insn_cnt = decoder->tot_insn_cnt; decoder->state.tot_cyc_cnt = decoder->sample_tot_cyc_cnt; return &decoder->state; } /** * intel_pt_next_psb - move buffer pointer to the start of the next PSB packet. * @buf: pointer to buffer pointer * @len: size of buffer * * Updates the buffer pointer to point to the start of the next PSB packet if * there is one, otherwise the buffer pointer is unchanged. If @buf is updated, * @len is adjusted accordingly. * * Return: %true if a PSB packet is found, %false otherwise. */ static bool intel_pt_next_psb(unsigned char **buf, size_t *len) { unsigned char *next; next = memmem(*buf, *len, INTEL_PT_PSB_STR, INTEL_PT_PSB_LEN); if (next) { *len -= next - *buf; *buf = next; return true; } return false; } /** * intel_pt_step_psb - move buffer pointer to the start of the following PSB * packet. * @buf: pointer to buffer pointer * @len: size of buffer * * Updates the buffer pointer to point to the start of the following PSB packet * (skipping the PSB at @buf itself) if there is one, otherwise the buffer * pointer is unchanged. If @buf is updated, @len is adjusted accordingly. * * Return: %true if a PSB packet is found, %false otherwise. */ static bool intel_pt_step_psb(unsigned char **buf, size_t *len) { unsigned char *next; if (!*len) return false; next = memmem(*buf + 1, *len - 1, INTEL_PT_PSB_STR, INTEL_PT_PSB_LEN); if (next) { *len -= next - *buf; *buf = next; return true; } return false; } /** * intel_pt_last_psb - find the last PSB packet in a buffer. * @buf: buffer * @len: size of buffer * * This function finds the last PSB in a buffer. * * Return: A pointer to the last PSB in @buf if found, %NULL otherwise. */ static unsigned char *intel_pt_last_psb(unsigned char *buf, size_t len) { const char *n = INTEL_PT_PSB_STR; unsigned char *p; size_t k; if (len < INTEL_PT_PSB_LEN) return NULL; k = len - INTEL_PT_PSB_LEN + 1; while (1) { p = memrchr(buf, n[0], k); if (!p) return NULL; if (!memcmp(p + 1, n + 1, INTEL_PT_PSB_LEN - 1)) return p; k = p - buf; if (!k) return NULL; } } /** * intel_pt_next_tsc - find and return next TSC. * @buf: buffer * @len: size of buffer * @tsc: TSC value returned * @rem: returns remaining size when TSC is found * * Find a TSC packet in @buf and return the TSC value. This function assumes * that @buf starts at a PSB and that PSB+ will contain TSC and so stops if a * PSBEND packet is found. * * Return: %true if TSC is found, false otherwise. */ static bool intel_pt_next_tsc(unsigned char *buf, size_t len, uint64_t *tsc, size_t *rem) { enum intel_pt_pkt_ctx ctx = INTEL_PT_NO_CTX; struct intel_pt_pkt packet; int ret; while (len) { ret = intel_pt_get_packet(buf, len, &packet, &ctx); if (ret <= 0) return false; if (packet.type == INTEL_PT_TSC) { *tsc = packet.payload; *rem = len; return true; } if (packet.type == INTEL_PT_PSBEND) return false; buf += ret; len -= ret; } return false; } /** * intel_pt_tsc_cmp - compare 7-byte TSCs. * @tsc1: first TSC to compare * @tsc2: second TSC to compare * * This function compares 7-byte TSC values allowing for the possibility that * TSC wrapped around. Generally it is not possible to know if TSC has wrapped * around so for that purpose this function assumes the absolute difference is * less than half the maximum difference. * * Return: %-1 if @tsc1 is before @tsc2, %0 if @tsc1 == @tsc2, %1 if @tsc1 is * after @tsc2. */ static int intel_pt_tsc_cmp(uint64_t tsc1, uint64_t tsc2) { const uint64_t halfway = (1ULL << 55); if (tsc1 == tsc2) return 0; if (tsc1 < tsc2) { if (tsc2 - tsc1 < halfway) return -1; else return 1; } else { if (tsc1 - tsc2 < halfway) return 1; else return -1; } } #define MAX_PADDING (PERF_AUXTRACE_RECORD_ALIGNMENT - 1) /** * adj_for_padding - adjust overlap to account for padding. * @buf_b: second buffer * @buf_a: first buffer * @len_a: size of first buffer * * @buf_a might have up to 7 bytes of padding appended. Adjust the overlap * accordingly. * * Return: A pointer into @buf_b from where non-overlapped data starts */ static unsigned char *adj_for_padding(unsigned char *buf_b, unsigned char *buf_a, size_t len_a) { unsigned char *p = buf_b - MAX_PADDING; unsigned char *q = buf_a + len_a - MAX_PADDING; int i; for (i = MAX_PADDING; i; i--, p++, q++) { if (*p != *q) break; } return p; } /** * intel_pt_find_overlap_tsc - determine start of non-overlapped trace data * using TSC. * @buf_a: first buffer * @len_a: size of first buffer * @buf_b: second buffer * @len_b: size of second buffer * @consecutive: returns true if there is data in buf_b that is consecutive * to buf_a * * If the trace contains TSC we can look at the last TSC of @buf_a and the * first TSC of @buf_b in order to determine if the buffers overlap, and then * walk forward in @buf_b until a later TSC is found. A precondition is that * @buf_a and @buf_b are positioned at a PSB. * * Return: A pointer into @buf_b from where non-overlapped data starts, or * @buf_b + @len_b if there is no non-overlapped data. */ static unsigned char *intel_pt_find_overlap_tsc(unsigned char *buf_a, size_t len_a, unsigned char *buf_b, size_t len_b, bool *consecutive) { uint64_t tsc_a, tsc_b; unsigned char *p; size_t len, rem_a, rem_b; p = intel_pt_last_psb(buf_a, len_a); if (!p) return buf_b; /* No PSB in buf_a => no overlap */ len = len_a - (p - buf_a); if (!intel_pt_next_tsc(p, len, &tsc_a, &rem_a)) { /* The last PSB+ in buf_a is incomplete, so go back one more */ len_a -= len; p = intel_pt_last_psb(buf_a, len_a); if (!p) return buf_b; /* No full PSB+ => assume no overlap */ len = len_a - (p - buf_a); if (!intel_pt_next_tsc(p, len, &tsc_a, &rem_a)) return buf_b; /* No TSC in buf_a => assume no overlap */ } while (1) { /* Ignore PSB+ with no TSC */ if (intel_pt_next_tsc(buf_b, len_b, &tsc_b, &rem_b)) { int cmp = intel_pt_tsc_cmp(tsc_a, tsc_b); /* Same TSC, so buffers are consecutive */ if (!cmp && rem_b >= rem_a) { unsigned char *start; *consecutive = true; start = buf_b + len_b - (rem_b - rem_a); return adj_for_padding(start, buf_a, len_a); } if (cmp < 0) return buf_b; /* tsc_a < tsc_b => no overlap */ } if (!intel_pt_step_psb(&buf_b, &len_b)) return buf_b + len_b; /* No PSB in buf_b => no data */ } } /** * intel_pt_find_overlap - determine start of non-overlapped trace data. * @buf_a: first buffer * @len_a: size of first buffer * @buf_b: second buffer * @len_b: size of second buffer * @have_tsc: can use TSC packets to detect overlap * @consecutive: returns true if there is data in buf_b that is consecutive * to buf_a * * When trace samples or snapshots are recorded there is the possibility that * the data overlaps. Note that, for the purposes of decoding, data is only * useful if it begins with a PSB packet. * * Return: A pointer into @buf_b from where non-overlapped data starts, or * @buf_b + @len_b if there is no non-overlapped data. */ unsigned char *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) { unsigned char *found; /* Buffer 'b' must start at PSB so throw away everything before that */ if (!intel_pt_next_psb(&buf_b, &len_b)) return buf_b + len_b; /* No PSB */ if (!intel_pt_next_psb(&buf_a, &len_a)) return buf_b; /* No overlap */ if (have_tsc) { found = intel_pt_find_overlap_tsc(buf_a, len_a, buf_b, len_b, consecutive); if (found) return found; } /* * Buffer 'b' cannot end within buffer 'a' so, for comparison purposes, * we can ignore the first part of buffer 'a'. */ while (len_b < len_a) { if (!intel_pt_step_psb(&buf_a, &len_a)) return buf_b; /* No overlap */ } /* Now len_b >= len_a */ while (1) { /* Potential overlap so check the bytes */ found = memmem(buf_a, len_a, buf_b, len_a); if (found) { *consecutive = true; return adj_for_padding(buf_b + len_a, buf_a, len_a); } /* Try again at next PSB in buffer 'a' */ if (!intel_pt_step_psb(&buf_a, &len_a)) return buf_b; /* No overlap */ } } /** * struct fast_forward_data - data used by intel_pt_ff_cb(). * @timestamp: timestamp to fast forward towards * @buf_timestamp: buffer timestamp of last buffer with trace data earlier than * the fast forward timestamp. */ struct fast_forward_data { uint64_t timestamp; uint64_t buf_timestamp; }; /** * intel_pt_ff_cb - fast forward lookahead callback. * @buffer: Intel PT trace buffer * @data: opaque pointer to fast forward data (struct fast_forward_data) * * Determine if @buffer trace is past the fast forward timestamp. * * Return: 1 (stop lookahead) if @buffer trace is past the fast forward * timestamp, and 0 otherwise. */ static int intel_pt_ff_cb(struct intel_pt_buffer *buffer, void *data) { struct fast_forward_data *d = data; unsigned char *buf; uint64_t tsc; size_t rem; size_t len; buf = (unsigned char *)buffer->buf; len = buffer->len; if (!intel_pt_next_psb(&buf, &len) || !intel_pt_next_tsc(buf, len, &tsc, &rem)) return 0; tsc = intel_pt_8b_tsc(tsc, buffer->ref_timestamp); intel_pt_log("Buffer 1st timestamp " x64_fmt " ref timestamp " x64_fmt "\n", tsc, buffer->ref_timestamp); /* * If the buffer contains a timestamp earlier that the fast forward * timestamp, then record it, else stop. */ if (tsc < d->timestamp) d->buf_timestamp = buffer->ref_timestamp; else return 1; return 0; } /** * intel_pt_fast_forward - reposition decoder forwards. * @decoder: Intel PT decoder * @timestamp: timestamp to fast forward towards * * Reposition decoder at the last PSB with a timestamp earlier than @timestamp. * * Return: 0 on success or negative error code on failure. */ int intel_pt_fast_forward(struct intel_pt_decoder *decoder, uint64_t timestamp) { struct fast_forward_data d = { .timestamp = timestamp }; unsigned char *buf; size_t len; int err; intel_pt_log("Fast forward towards timestamp " x64_fmt "\n", timestamp); /* Find buffer timestamp of buffer to fast forward to */ err = decoder->lookahead(decoder->data, intel_pt_ff_cb, &d); if (err < 0) return err; /* Walk to buffer with same buffer timestamp */ if (d.buf_timestamp) { do { decoder->pos += decoder->len; decoder->len = 0; err = intel_pt_get_next_data(decoder, true); /* -ENOLINK means non-consecutive trace */ if (err && err != -ENOLINK) return err; } while (decoder->buf_timestamp != d.buf_timestamp); } if (!decoder->buf) return 0; buf = (unsigned char *)decoder->buf; len = decoder->len; if (!intel_pt_next_psb(&buf, &len)) return 0; /* * Walk PSBs while the PSB timestamp is less than the fast forward * timestamp. */ do { uint64_t tsc; size_t rem; if (!intel_pt_next_tsc(buf, len, &tsc, &rem)) break; tsc = intel_pt_8b_tsc(tsc, decoder->buf_timestamp); /* * A TSC packet can slip past MTC packets but, after fast * forward, decoding starts at the TSC timestamp. That means * the timestamps may not be exactly the same as the timestamps * that would have been decoded without fast forward. */ if (tsc < timestamp) { intel_pt_log("Fast forward to next PSB timestamp " x64_fmt "\n", tsc); decoder->pos += decoder->len - len; decoder->buf = buf; decoder->len = len; intel_pt_reposition(decoder); } else { break; } } while (intel_pt_step_psb(&buf, &len)); return 0; }