268 lines · c
1// SPDX-License-Identifier: GPL-2.0-only2/*3 * intel_pt_log.c: Intel Processor Trace support4 * Copyright (c) 2013-2014, Intel Corporation.5 */6 7#include <stdio.h>8#include <stdlib.h>9#include <stdint.h>10#include <inttypes.h>11#include <stdarg.h>12#include <stdbool.h>13#include <string.h>14 15#include <linux/zalloc.h>16#include <linux/kernel.h>17 18#include "intel-pt-log.h"19#include "intel-pt-insn-decoder.h"20 21#include "intel-pt-pkt-decoder.h"22 23#define MAX_LOG_NAME 25624 25#define DFLT_BUF_SZ (16 * 1024)26 27struct log_buf {28 char *buf;29 size_t buf_sz;30 size_t head;31 bool wrapped;32 FILE *backend;33};34 35static FILE *f;36static char log_name[MAX_LOG_NAME];37bool intel_pt_enable_logging;38static bool intel_pt_dump_log_on_error;39static unsigned int intel_pt_log_on_error_size;40static struct log_buf log_buf;41 42void *intel_pt_log_fp(void)43{44 return f;45}46 47void intel_pt_log_enable(bool dump_log_on_error, unsigned int log_on_error_size)48{49 intel_pt_enable_logging = true;50 intel_pt_dump_log_on_error = dump_log_on_error;51 intel_pt_log_on_error_size = log_on_error_size;52}53 54void intel_pt_log_disable(void)55{56 if (f)57 fflush(f);58 intel_pt_enable_logging = false;59}60 61void intel_pt_log_set_name(const char *name)62{63 strncpy(log_name, name, MAX_LOG_NAME - 5);64 strcat(log_name, ".log");65}66 67static void intel_pt_print_data(const unsigned char *buf, int len, uint64_t pos,68 int indent)69{70 int i;71 72 for (i = 0; i < indent; i++)73 fprintf(f, " ");74 75 fprintf(f, " %08" PRIx64 ": ", pos);76 for (i = 0; i < len; i++)77 fprintf(f, " %02x", buf[i]);78 for (; i < 16; i++)79 fprintf(f, " ");80 fprintf(f, " ");81}82 83static void intel_pt_print_no_data(uint64_t pos, int indent)84{85 int i;86 87 for (i = 0; i < indent; i++)88 fprintf(f, " ");89 90 fprintf(f, " %08" PRIx64 ": ", pos);91 for (i = 0; i < 16; i++)92 fprintf(f, " ");93 fprintf(f, " ");94}95 96static ssize_t log_buf__write(void *cookie, const char *buf, size_t size)97{98 struct log_buf *b = cookie;99 size_t sz = size;100 101 if (!b->buf)102 return size;103 104 while (sz) {105 size_t space = b->buf_sz - b->head;106 size_t n = min(space, sz);107 108 memcpy(b->buf + b->head, buf, n);109 sz -= n;110 buf += n;111 b->head += n;112 if (sz && b->head >= b->buf_sz) {113 b->head = 0;114 b->wrapped = true;115 }116 }117 return size;118}119 120static int log_buf__close(void *cookie)121{122 struct log_buf *b = cookie;123 124 zfree(&b->buf);125 return 0;126}127 128static FILE *log_buf__open(struct log_buf *b, FILE *backend, unsigned int sz)129{130 cookie_io_functions_t fns = {131 .write = log_buf__write,132 .close = log_buf__close,133 };134 FILE *file;135 136 memset(b, 0, sizeof(*b));137 b->buf_sz = sz;138 b->buf = malloc(b->buf_sz);139 b->backend = backend;140 file = fopencookie(b, "a", fns);141 if (!file)142 zfree(&b->buf);143 return file;144}145 146static bool remove_first_line(const char **p, size_t *n)147{148 for (; *n && **p != '\n'; ++*p, --*n)149 ;150 if (*n) {151 *p += 1;152 *n -= 1;153 return true;154 }155 return false;156}157 158static void write_lines(const char *p, size_t n, FILE *fp, bool *remove_first)159{160 if (*remove_first)161 *remove_first = !remove_first_line(&p, &n);162 fwrite(p, n, 1, fp);163}164 165static void log_buf__dump(struct log_buf *b)166{167 bool remove_first = false;168 169 if (!b->buf)170 return;171 172 fflush(f); /* Could update b->head and b->wrapped */173 fprintf(b->backend, "Dumping debug log buffer\n");174 if (b->wrapped) {175 remove_first = true;176 write_lines(b->buf + b->head, b->buf_sz - b->head, b->backend, &remove_first);177 }178 write_lines(b->buf, b->head, b->backend, &remove_first);179 fprintf(b->backend, "End of debug log buffer dump\n");180 181 b->head = 0;182 b->wrapped = false;183}184 185void intel_pt_log_dump_buf(void)186{187 log_buf__dump(&log_buf);188}189 190static int intel_pt_log_open(void)191{192 if (!intel_pt_enable_logging)193 return -1;194 195 if (f)196 return 0;197 198 if (log_name[0])199 f = fopen(log_name, "w+");200 else201 f = stdout;202 if (f && intel_pt_dump_log_on_error)203 f = log_buf__open(&log_buf, f, intel_pt_log_on_error_size);204 if (!f) {205 intel_pt_enable_logging = false;206 return -1;207 }208 209 return 0;210}211 212void __intel_pt_log_packet(const struct intel_pt_pkt *packet, int pkt_len,213 uint64_t pos, const unsigned char *buf)214{215 char desc[INTEL_PT_PKT_DESC_MAX];216 217 if (intel_pt_log_open())218 return;219 220 intel_pt_print_data(buf, pkt_len, pos, 0);221 intel_pt_pkt_desc(packet, desc, INTEL_PT_PKT_DESC_MAX);222 fprintf(f, "%s\n", desc);223}224 225void __intel_pt_log_insn(struct intel_pt_insn *intel_pt_insn, uint64_t ip)226{227 char desc[INTEL_PT_INSN_DESC_MAX];228 size_t len = intel_pt_insn->length;229 230 if (intel_pt_log_open())231 return;232 233 if (len > INTEL_PT_INSN_BUF_SZ)234 len = INTEL_PT_INSN_BUF_SZ;235 intel_pt_print_data(intel_pt_insn->buf, len, ip, 8);236 if (intel_pt_insn_desc(intel_pt_insn, desc, INTEL_PT_INSN_DESC_MAX) > 0)237 fprintf(f, "%s\n", desc);238 else239 fprintf(f, "Bad instruction!\n");240}241 242void __intel_pt_log_insn_no_data(struct intel_pt_insn *intel_pt_insn,243 uint64_t ip)244{245 char desc[INTEL_PT_INSN_DESC_MAX];246 247 if (intel_pt_log_open())248 return;249 250 intel_pt_print_no_data(ip, 8);251 if (intel_pt_insn_desc(intel_pt_insn, desc, INTEL_PT_INSN_DESC_MAX) > 0)252 fprintf(f, "%s\n", desc);253 else254 fprintf(f, "Bad instruction!\n");255}256 257void __intel_pt_log(const char *fmt, ...)258{259 va_list args;260 261 if (intel_pt_log_open())262 return;263 264 va_start(args, fmt);265 vfprintf(f, fmt, args);266 va_end(args);267}268