1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * intel_pt_log.c: Intel Processor Trace support
4 * 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 256
24
25 #define DFLT_BUF_SZ (16 * 1024)
26
27 struct log_buf {
28 char *buf;
29 size_t buf_sz;
30 size_t head;
31 bool wrapped;
32 FILE *backend;
33 };
34
35 static FILE *f;
36 static char log_name[MAX_LOG_NAME];
37 bool intel_pt_enable_logging;
38 static bool intel_pt_dump_log_on_error;
39 static unsigned int intel_pt_log_on_error_size;
40 static struct log_buf log_buf;
41
42 void *intel_pt_log_fp(void)
43 {
44 return f;
45 }
46
47 void 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
54 void intel_pt_log_disable(void)
55 {
56 if (f)
57 fflush(f);
58 intel_pt_enable_logging = false;
59 }
60
61 void 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
67 static 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
83 static 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
96 static 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
120 static int log_buf__close(void *cookie)
121 {
122 struct log_buf *b = cookie;
123
124 zfree(&b->buf);
125 return 0;
126 }
127
128 static 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
146 static 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
158 static 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
165 static 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
185 void intel_pt_log_dump_buf(void)
186 {
187 log_buf__dump(&log_buf);
188 }
189
190 static 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 else
201 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
212 void __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
225 void __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 else
239 fprintf(f, "Bad instruction!\n");
240 }
241
242 void __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 else
254 fprintf(f, "Bad instruction!\n");
255 }
256
257 void __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
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