diff options
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/perf/util/intel-pt-decoder/Build | 2 | ||||
| -rw-r--r-- | tools/perf/util/intel-pt-decoder/intel-pt-decoder.c | 1816 | ||||
| -rw-r--r-- | tools/perf/util/intel-pt-decoder/intel-pt-decoder.h | 104 |
3 files changed, 1921 insertions, 1 deletions
diff --git a/tools/perf/util/intel-pt-decoder/Build b/tools/perf/util/intel-pt-decoder/Build index 3c717b4..240730d 100644 --- a/tools/perf/util/intel-pt-decoder/Build +++ b/tools/perf/util/intel-pt-decoder/Build @@ -1,4 +1,4 @@ -libperf-$(CONFIG_AUXTRACE) += intel-pt-pkt-decoder.o intel-pt-insn-decoder.o intel-pt-log.o +libperf-$(CONFIG_AUXTRACE) += intel-pt-pkt-decoder.o intel-pt-insn-decoder.o intel-pt-log.o intel-pt-decoder.o inat_tables_script = util/intel-pt-decoder/gen-insn-attr-x86.awk inat_tables_maps = util/intel-pt-decoder/x86-opcode-map.txt diff --git a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c new file mode 100644 index 0000000..f8ac462 --- /dev/null +++ b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c @@ -0,0 +1,1816 @@ +/* + * intel_pt_decoder.c: Intel Processor Trace support + * Copyright (c) 2013-2014, Intel Corporation. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + */ + +#ifndef _GNU_SOURCE +#define _GNU_SOURCE +#endif +#include <stdlib.h> +#include <stdbool.h> +#include <string.h> +#include <errno.h> +#include <stdint.h> +#include <inttypes.h> + +#include "../cache.h" +#include "../util.h" + +#include "intel-pt-insn-decoder.h" +#include "intel-pt-pkt-decoder.h" +#include "intel-pt-decoder.h" +#include "intel-pt-log.h" + +#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, + INTEL_PT_STATE_TIP, + INTEL_PT_STATE_TIP_PGD, + INTEL_PT_STATE_FUP, + INTEL_PT_STATE_FUP_NO_TIP, +}; + +#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); + void *data; + struct intel_pt_state state; + const unsigned char *buf; + size_t len; + bool return_compression; + bool pge; + uint64_t pos; + uint64_t last_ip; + uint64_t ip; + uint64_t cr3; + uint64_t timestamp; + uint64_t tsc_timestamp; + uint64_t ref_timestamp; + uint64_t ret_addr; + struct intel_pt_stack stack; + enum intel_pt_pkt_state pkt_state; + struct intel_pt_pkt packet; + struct intel_pt_pkt tnt; + int pkt_step; + int pkt_len; + unsigned int cbr; + unsigned int max_non_turbo_ratio; + int exec_mode; + unsigned int insn_bytes; + uint64_t sign_bit; + uint64_t sign_bits; + uint64_t period; + enum intel_pt_period_type period_type; + uint64_t period_insn_cnt; + uint64_t period_mask; + uint64_t period_ticks; + uint64_t last_masked_timestamp; + bool continuous_period; + bool overflow; + bool set_fup_tx_flags; + unsigned int fup_tx_flags; + unsigned int tx_flags; + uint64_t timestamp_insn_cnt; + uint64_t stuck_ip; + int no_progress; + int stuck_ip_prd; + int stuck_ip_cnt; + 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 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; + } +} + +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->data = params->data; + decoder->return_compression = params->return_compression; + + decoder->sign_bit = (uint64_t)1 << 47; + decoder->sign_bits = ~(((uint64_t)1 << 48) - 1); + + decoder->period = params->period; + decoder->period_type = params->period_type; + + decoder->max_non_turbo_ratio = params->max_non_turbo_ratio; + + intel_pt_setup_period(decoder); + + 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(struct intel_pt_decoder *decoder, + const struct intel_pt_pkt *packet, + uint64_t last_ip) +{ + uint64_t ip; + + switch (packet->count) { + case 2: + ip = (last_ip & (uint64_t)0xffffffffffff0000ULL) | + packet->payload; + break; + case 4: + ip = (last_ip & (uint64_t)0xffffffff00000000ULL) | + packet->payload; + break; + case 6: + ip = packet->payload; + break; + default: + return 0; + } + + if (ip & decoder->sign_bit) + return ip | decoder->sign_bits; + + return ip; +} + +static inline void intel_pt_set_last_ip(struct intel_pt_decoder *decoder) +{ + decoder->last_ip = intel_pt_calc_ip(decoder, &decoder->packet, + decoder->last_ip); +} + +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 int intel_pt_bad_packet(struct intel_pt_decoder *decoder) +{ + intel_pt_clear_tx_flags(decoder); + 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 int intel_pt_get_data(struct intel_pt_decoder *decoder) +{ + 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; + } + if (!buffer.consecutive) { + decoder->ip = 0; + decoder->pkt_state = INTEL_PT_STATE_NO_PSB; + decoder->ref_timestamp = buffer.ref_timestamp; + decoder->timestamp = 0; + 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) +{ + if (!decoder->next_buf) + return intel_pt_get_data(decoder); + + 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); + 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; + + ret = intel_pt_get_packet(buf, len, &decoder->packet); + 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; +} + +static int intel_pt_get_next_packet(struct intel_pt_decoder *decoder) +{ + int ret; + + 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); + if (ret) + return ret; + } + + ret = intel_pt_get_packet(decoder->buf, decoder->len, + &decoder->packet); + if (ret == INTEL_PT_NEED_MORE_BYTES && + 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; + } + } + 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: + 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; + decoder->last_masked_timestamp = masked_timestamp; + break; + case INTEL_PT_PERIOD_NONE: + 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; + + 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->timestamp_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; + + if (decoder->tx_flags & INTEL_PT_IN_TX) + decoder->state.flags |= INTEL_PT_IN_TX; + + return err; +} + +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) { + 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 0; + } + return err; + } + 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) + return 0; + if (err) + return err; + + 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; + decoder->state.to_ip = 0; + if (decoder->packet.count != 0) + decoder->ip = decoder->last_ip; + } 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) { + 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_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; + 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_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->ip += intel_pt_insn.length; + if (!decoder->tnt.count) + 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 void intel_pt_calc_tsc_timestamp(struct intel_pt_decoder *decoder) +{ + uint64_t timestamp; + + if (decoder->ref_timestamp) { + timestamp = decoder->packet.payload | + (decoder->ref_timestamp & (0xffULL << 56)); + if (timestamp < decoder->ref_timestamp) { + if (decoder->ref_timestamp - timestamp > (1ULL << 55)) + timestamp += (1ULL << 56); + } else { + if (timestamp - decoder->ref_timestamp > (1ULL << 55)) + timestamp -= (1ULL << 56); + } + 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)); + if (timestamp < decoder->timestamp && + decoder->timestamp - timestamp < 0x100) { + intel_pt_log_to("ERROR: Suppressing backwards timestamp", + timestamp); + timestamp = decoder->timestamp; + } + while (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; + } + + 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); + decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC; + decoder->overflow = true; + return -EOVERFLOW; +} + +/* Walk PSB+ packets when already in sync. */ +static int intel_pt_walk_psbend(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_PSBEND: + return 0; + + case INTEL_PT_TIP_PGD: + case INTEL_PT_TIP_PGE: + case INTEL_PT_TIP: + case INTEL_PT_TNT: + case INTEL_PT_BAD: + case INTEL_PT_PSB: + intel_pt_log("ERROR: Unexpected packet\n"); + return -EAGAIN; + + case INTEL_PT_OVF: + return intel_pt_overflow(decoder); + + case INTEL_PT_TSC: + intel_pt_calc_tsc_timestamp(decoder); + break; + + case INTEL_PT_CBR: + decoder->cbr = decoder->packet.payload; + break; + + case INTEL_PT_MODE_EXEC: + decoder->exec_mode = decoder->packet.payload; + break; + + case INTEL_PT_PIP: + decoder->cr3 = decoder->packet.payload; + break; + + case INTEL_PT_FUP: + decoder->pge = true; + intel_pt_set_last_ip(decoder); + break; + + case INTEL_PT_MODE_TSX: + intel_pt_update_in_tx(decoder); + break; + + case INTEL_PT_PAD: + default: + break; + } + } +} + +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_PSB: + case INTEL_PT_TSC: + case INTEL_PT_CBR: + case INTEL_PT_MODE_TSX: + case INTEL_PT_BAD: + case INTEL_PT_PSBEND: + intel_pt_log("ERROR: Missing TIP after FUP\n"); + decoder->pkt_state = INTEL_PT_STATE_ERR3; + return -ENOENT; + + case INTEL_PT_OVF: + return intel_pt_overflow(decoder); + + case INTEL_PT_TIP_PGD: + decoder->state.from_ip = decoder->ip; + decoder->state.to_ip = 0; + if (decoder->packet.count != 0) { + intel_pt_set_ip(decoder); + intel_pt_log("Omitting PGD ip " x64_fmt "\n", + decoder->ip); + } + decoder->pge = false; + decoder->continuous_period = false; + 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; + } + 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; + } + return 0; + + case INTEL_PT_PIP: + decoder->cr3 = decoder->packet.payload; + break; + + case INTEL_PT_MODE_EXEC: + decoder->exec_mode = decoder->packet.payload; + break; + + case INTEL_PT_PAD: + break; + + default: + return intel_pt_bug(decoder); + } + } +} + +static int intel_pt_walk_trace(struct intel_pt_decoder *decoder) +{ + bool no_tip = false; + int err; + + while (1) { + err = intel_pt_get_next_packet(decoder); + if (err) + return err; +next: + 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; + 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; + 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); + err = intel_pt_walk_fup(decoder); + if (err != -EAGAIN) { + if (err) + return err; + if (no_tip) + decoder->pkt_state = + INTEL_PT_STATE_FUP_NO_TIP; + else + decoder->pkt_state = INTEL_PT_STATE_FUP; + return 0; + } + if (no_tip) { + no_tip = false; + break; + } + return intel_pt_walk_fup_tip(decoder); + + case INTEL_PT_PSB: + intel_pt_clear_stack(&decoder->stack); + err = intel_pt_walk_psbend(decoder); + if (err == -EAGAIN) + goto next; + if (err) + return err; + break; + + case INTEL_PT_PIP: + decoder->cr3 = decoder->packet.payload; + break; + + case INTEL_PT_TSC: + intel_pt_calc_tsc_timestamp(decoder); + break; + + case INTEL_PT_CBR: + decoder->cbr = decoder->packet.payload; + 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) { + 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_PAD: + break; + + default: + return intel_pt_bug(decoder); + } + } +} + +/* Walk PSB+ packets to get in sync. */ +static int intel_pt_walk_psb(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; + case INTEL_PT_TIP_PGE: + case INTEL_PT_TIP: + intel_pt_log("ERROR: Unexpected packet\n"); + return -ENOENT; + + case INTEL_PT_FUP: + decoder->pge = true; + if (decoder->last_ip || decoder->packet.count == 6 || + decoder->packet.count == 0) { + uint64_t current_ip = decoder->ip; + + intel_pt_set_ip(decoder); + if (current_ip) + intel_pt_log_to("Setting IP", + decoder->ip); + } + break; + + case INTEL_PT_TSC: + intel_pt_calc_tsc_timestamp(decoder); + break; + + case INTEL_PT_CBR: + decoder->cbr = decoder->packet.payload; + break; + + case INTEL_PT_PIP: + decoder->cr3 = decoder->packet.payload; + 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_TNT: + 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; + return -ENOENT; + + case INTEL_PT_BAD: /* Does not happen */ + return intel_pt_bug(decoder); + + case INTEL_PT_OVF: + return intel_pt_overflow(decoder); + + case INTEL_PT_PSBEND: + return 0; + + case INTEL_PT_PSB: + case INTEL_PT_PAD: + default: + break; + } + } +} + +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; + case INTEL_PT_TIP_PGE: + case INTEL_PT_TIP: + decoder->pge = decoder->packet.type != INTEL_PT_TIP_PGD; + if (decoder->last_ip || decoder->packet.count == 6 || + decoder->packet.count == 0) + intel_pt_set_ip(decoder); + if (decoder->ip) + return 0; + break; + + case INTEL_PT_FUP: + if (decoder->overflow) { + if (decoder->last_ip || + decoder->packet.count == 6 || + decoder->packet.count == 0) + intel_pt_set_ip(decoder); + if (decoder->ip) + return 0; + } + if (decoder->packet.count) + intel_pt_set_last_ip(decoder); + break; + + case INTEL_PT_TSC: + intel_pt_calc_tsc_timestamp(decoder); + break; + + case INTEL_PT_CBR: + decoder->cbr = decoder->packet.payload; + break; + + case INTEL_PT_PIP: + decoder->cr3 = decoder->packet.payload; + 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_PSB: + err = intel_pt_walk_psb(decoder); + if (err) + return err; + if (decoder->ip) { + /* Do not have a sample */ + decoder->state.type = 0; + return 0; + } + break; + + case INTEL_PT_TNT: + case INTEL_PT_PSBEND: + case INTEL_PT_PAD: + default: + break; + } + } +} + +static int intel_pt_sync_ip(struct intel_pt_decoder *decoder) +{ + int err; + + intel_pt_log("Scanning for full IP\n"); + err = intel_pt_walk_to_ip(decoder); + if (err) + return err; + + 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); + 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); + 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->last_ip = 0; + decoder->ip = 0; + intel_pt_clear_stack(&decoder->stack); + + err = intel_pt_scan_for_psb(decoder); + if (err) + return err; + + decoder->pkt_state = INTEL_PT_STATE_NO_IP; + + err = intel_pt_walk_psb(decoder); + if (err) + return err; + + if (decoder->ip) { + decoder->state.type = 0; /* Do not have a sample */ + decoder->pkt_state = INTEL_PT_STATE_IN_SYNC; + } else { + return intel_pt_sync_ip(decoder); + } + + return 0; +} + +static uint64_t intel_pt_est_timestamp(struct intel_pt_decoder *decoder) +{ + uint64_t est = decoder->timestamp_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->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->last_ip = 0; + /* Fall through */ + 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: + 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: + decoder->pkt_state = INTEL_PT_STATE_IN_SYNC; + err = intel_pt_walk_fup(decoder); + if (err == -EAGAIN) + err = intel_pt_walk_fup_tip(decoder); + else if (!err) + decoder->pkt_state = INTEL_PT_STATE_FUP; + break; + case INTEL_PT_STATE_FUP_NO_TIP: + decoder->pkt_state = INTEL_PT_STATE_IN_SYNC; + err = intel_pt_walk_fup(decoder); + if (err == -EAGAIN) + err = intel_pt_walk_trace(decoder); + break; + default: + err = intel_pt_bug(decoder); + break; + } + } while (err == -ENOLINK); + + decoder->state.err = err ? intel_pt_ext_err(err) : 0; + decoder->state.timestamp = decoder->timestamp; + decoder->state.est_timestamp = intel_pt_est_timestamp(decoder); + decoder->state.cr3 = decoder->cr3; + + if (err) + decoder->state.from_ip = decoder->ip; + + return &decoder->state; +} + +static bool intel_pt_at_psb(unsigned char *buf, size_t len) +{ + if (len < INTEL_PT_PSB_LEN) + return false; + return memmem(buf, INTEL_PT_PSB_LEN, INTEL_PT_PSB_STR, + INTEL_PT_PSB_LEN); +} + +/** + * 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 + * + * 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) +{ + struct intel_pt_pkt packet; + int ret; + + while (len) { + ret = intel_pt_get_packet(buf, len, &packet); + if (ret <= 0) + return false; + if (packet.type == INTEL_PT_TSC) { + *tsc = packet.payload; + 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; + } +} + +/** + * 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 + * + * 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) +{ + uint64_t tsc_a, tsc_b; + unsigned char *p; + size_t len; + + 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)) { + /* 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)) + 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) && + intel_pt_tsc_cmp(tsc_a, tsc_b) < 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 + * + * 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) +{ + 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); + 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 */ + if (len_b > len_a) { + /* The leftover buffer 'b' must start at a PSB */ + while (!intel_pt_at_psb(buf_b + len_a, len_b - len_a)) { + if (!intel_pt_step_psb(&buf_a, &len_a)) + return buf_b; /* No overlap */ + } + } + + while (1) { + /* Potential overlap so check the bytes */ + found = memmem(buf_a, len_a, buf_b, len_a); + if (found) + return buf_b + len_a; + + /* Try again at next PSB in buffer 'a' */ + if (!intel_pt_step_psb(&buf_a, &len_a)) + return buf_b; /* No overlap */ + + /* The leftover buffer 'b' must start at a PSB */ + while (!intel_pt_at_psb(buf_b + len_a, len_b - len_a)) { + if (!intel_pt_step_psb(&buf_a, &len_a)) + return buf_b; /* No overlap */ + } + } +} diff --git a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.h b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.h new file mode 100644 index 0000000..4c488023 --- /dev/null +++ b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.h @@ -0,0 +1,104 @@ +/* + * intel_pt_decoder.h: Intel Processor Trace support + * Copyright (c) 2013-2014, Intel Corporation. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + */ + +#ifndef INCLUDE__INTEL_PT_DECODER_H__ +#define INCLUDE__INTEL_PT_DECODER_H__ + +#include <stdint.h> +#include <stddef.h> +#include <stdbool.h> + +#include "intel-pt-insn-decoder.h" + +#define INTEL_PT_IN_TX (1 << 0) +#define INTEL_PT_ABORT_TX (1 << 1) +#define INTEL_PT_ASYNC (1 << 2) + +enum intel_pt_sample_type { + INTEL_PT_BRANCH = 1 << 0, + INTEL_PT_INSTRUCTION = 1 << 1, + INTEL_PT_TRANSACTION = 1 << 2, +}; + +enum intel_pt_period_type { + INTEL_PT_PERIOD_NONE, + INTEL_PT_PERIOD_INSTRUCTIONS, + INTEL_PT_PERIOD_TICKS, +}; + +enum { + INTEL_PT_ERR_NOMEM = 1, + INTEL_PT_ERR_INTERN, + INTEL_PT_ERR_BADPKT, + INTEL_PT_ERR_NODATA, + INTEL_PT_ERR_NOINSN, + INTEL_PT_ERR_MISMAT, + INTEL_PT_ERR_OVR, + INTEL_PT_ERR_LOST, + INTEL_PT_ERR_UNK, + INTEL_PT_ERR_NELOOP, + INTEL_PT_ERR_MAX, +}; + +struct intel_pt_state { + enum intel_pt_sample_type type; + int err; + uint64_t from_ip; + uint64_t to_ip; + uint64_t cr3; + uint64_t timestamp; + uint64_t est_timestamp; + uint64_t trace_nr; + uint32_t flags; + enum intel_pt_insn_op insn_op; + int insn_len; +}; + +struct intel_pt_insn; + +struct intel_pt_buffer { + const unsigned char *buf; + size_t len; + bool consecutive; + uint64_t ref_timestamp; + uint64_t trace_nr; +}; + +struct intel_pt_params { + 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); + void *data; + bool return_compression; + uint64_t period; + enum intel_pt_period_type period_type; + unsigned max_non_turbo_ratio; +}; + +struct intel_pt_decoder; + +struct intel_pt_decoder *intel_pt_decoder_new(struct intel_pt_params *params); +void intel_pt_decoder_free(struct intel_pt_decoder *decoder); + +const struct intel_pt_state *intel_pt_decode(struct intel_pt_decoder *decoder); + +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); + +int intel_pt__strerror(int code, char *buf, size_t buflen); + +#endif |
