--- /dev/null
+/*
+ * 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 */
+ }
+ }
+}
projects / karo-tx-linux.git / commitdiff