1
2#include <linux/compiler.h>
3#include <sys/types.h>
4#include <stdio.h>
5#include <string.h>
6#include <stdlib.h>
7#include <err.h>
8#include <jvmti.h>
9#include <jvmticmlr.h>
10#include <limits.h>
11
12#include "jvmti_agent.h"
13
14static int has_line_numbers;
15void *jvmti_agent;
16
17static void print_error(jvmtiEnv *jvmti, const char *msg, jvmtiError ret)
18{
19 char *err_msg = NULL;
20 jvmtiError err;
21 err = (*jvmti)->GetErrorName(jvmti, ret, &err_msg);
22 if (err == JVMTI_ERROR_NONE) {
23 warnx("%s failed with %s", msg, err_msg);
24 (*jvmti)->Deallocate(jvmti, (unsigned char *)err_msg);
25 } else {
26 warnx("%s failed with an unknown error %d", msg, ret);
27 }
28}
29
30static jvmtiError
31do_get_line_numbers(jvmtiEnv *jvmti, void *pc, jmethodID m, jint bci,
32 jvmti_line_info_t *tab, jint *nr)
33{
34 jint i, lines = 0;
35 jint nr_lines = 0;
36 jvmtiLineNumberEntry *loc_tab = NULL;
37 jvmtiError ret;
38
39 ret = (*jvmti)->GetLineNumberTable(jvmti, m, &nr_lines, &loc_tab);
40 if (ret != JVMTI_ERROR_NONE) {
41 print_error(jvmti, "GetLineNumberTable", ret);
42 return ret;
43 }
44
45 for (i = 0; i < nr_lines; i++) {
46 if (loc_tab[i].start_location < bci) {
47 tab[lines].pc = (unsigned long)pc;
48 tab[lines].line_number = loc_tab[i].line_number;
49 tab[lines].discrim = 0;
50 tab[lines].methodID = m;
51 lines++;
52 } else {
53 break;
54 }
55 }
56 (*jvmti)->Deallocate(jvmti, (unsigned char *)loc_tab);
57 *nr = lines;
58 return JVMTI_ERROR_NONE;
59}
60
61static jvmtiError
62get_line_numbers(jvmtiEnv *jvmti, const void *compile_info, jvmti_line_info_t **tab, int *nr_lines)
63{
64 const jvmtiCompiledMethodLoadRecordHeader *hdr;
65 jvmtiCompiledMethodLoadInlineRecord *rec;
66 jvmtiLineNumberEntry *lne = NULL;
67 PCStackInfo *c;
68 jint nr, ret;
69 int nr_total = 0;
70 int i, lines_total = 0;
71
72 if (!(tab && nr_lines))
73 return JVMTI_ERROR_NULL_POINTER;
74
75
76
77
78 for (hdr = compile_info; hdr != NULL; hdr = hdr->next) {
79 if (hdr->kind == JVMTI_CMLR_INLINE_INFO) {
80 rec = (jvmtiCompiledMethodLoadInlineRecord *)hdr;
81 for (i = 0; i < rec->numpcs; i++) {
82 c = rec->pcinfo + i;
83 nr = 0;
84
85
86
87 ret = (*jvmti)->GetLineNumberTable(jvmti, c->methods[0], &nr, &lne);
88 if (ret == JVMTI_ERROR_NONE) {
89
90 (*jvmti)->Deallocate(jvmti, (unsigned char *)lne);
91 nr_total += (int)nr;
92 } else {
93 print_error(jvmti, "GetLineNumberTable", ret);
94 }
95 }
96 }
97 }
98
99 if (nr_total == 0)
100 return JVMTI_ERROR_NOT_FOUND;
101
102
103
104
105 *tab = malloc(nr_total * sizeof(**tab));
106 if (!*tab)
107 return JVMTI_ERROR_OUT_OF_MEMORY;
108
109 for (hdr = compile_info; hdr != NULL; hdr = hdr->next) {
110 if (hdr->kind == JVMTI_CMLR_INLINE_INFO) {
111 rec = (jvmtiCompiledMethodLoadInlineRecord *)hdr;
112 for (i = 0; i < rec->numpcs; i++) {
113 c = rec->pcinfo + i;
114 nr = 0;
115 ret = do_get_line_numbers(jvmti, c->pc,
116 c->methods[0],
117 c->bcis[0],
118 *tab + lines_total,
119 &nr);
120 if (ret == JVMTI_ERROR_NONE)
121 lines_total += nr;
122 }
123 }
124 }
125 *nr_lines = lines_total;
126 return JVMTI_ERROR_NONE;
127}
128
129static void
130copy_class_filename(const char * class_sign, const char * file_name, char * result, size_t max_length)
131{
132
133
134
135 if (*class_sign == 'L') {
136 int j, i = 0;
137 char *p = strrchr(class_sign, '/');
138 if (p) {
139
140 for (i = 0; i < (p - class_sign); i++)
141 result[i] = class_sign[i+1];
142 }
143
144
145
146
147 for (j = 0; i < (max_length - 1) && file_name && j < strlen(file_name); j++, i++)
148 result[i] = file_name[j];
149
150 result[i] = '\0';
151 } else {
152
153 size_t file_name_len = strlen(file_name);
154 strncpy(result, file_name, file_name_len < max_length ? file_name_len : max_length);
155 }
156}
157
158static jvmtiError
159get_source_filename(jvmtiEnv *jvmti, jmethodID methodID, char ** buffer)
160{
161 jvmtiError ret;
162 jclass decl_class;
163 char *file_name = NULL;
164 char *class_sign = NULL;
165 char fn[PATH_MAX];
166 size_t len;
167
168 ret = (*jvmti)->GetMethodDeclaringClass(jvmti, methodID, &decl_class);
169 if (ret != JVMTI_ERROR_NONE) {
170 print_error(jvmti, "GetMethodDeclaringClass", ret);
171 return ret;
172 }
173
174 ret = (*jvmti)->GetSourceFileName(jvmti, decl_class, &file_name);
175 if (ret != JVMTI_ERROR_NONE) {
176 print_error(jvmti, "GetSourceFileName", ret);
177 return ret;
178 }
179
180 ret = (*jvmti)->GetClassSignature(jvmti, decl_class, &class_sign, NULL);
181 if (ret != JVMTI_ERROR_NONE) {
182 print_error(jvmti, "GetClassSignature", ret);
183 goto free_file_name_error;
184 }
185
186 copy_class_filename(class_sign, file_name, fn, PATH_MAX);
187 len = strlen(fn);
188 *buffer = malloc((len + 1) * sizeof(char));
189 if (!*buffer) {
190 print_error(jvmti, "GetClassSignature", ret);
191 ret = JVMTI_ERROR_OUT_OF_MEMORY;
192 goto free_class_sign_error;
193 }
194 strcpy(*buffer, fn);
195 ret = JVMTI_ERROR_NONE;
196
197free_class_sign_error:
198 (*jvmti)->Deallocate(jvmti, (unsigned char *)class_sign);
199free_file_name_error:
200 (*jvmti)->Deallocate(jvmti, (unsigned char *)file_name);
201
202 return ret;
203}
204
205static jvmtiError
206fill_source_filenames(jvmtiEnv *jvmti, int nr_lines,
207 const jvmti_line_info_t * line_tab,
208 char ** file_names)
209{
210 int index;
211 jvmtiError ret;
212
213 for (index = 0; index < nr_lines; ++index) {
214 ret = get_source_filename(jvmti, line_tab[index].methodID, &(file_names[index]));
215 if (ret != JVMTI_ERROR_NONE)
216 return ret;
217 }
218
219 return JVMTI_ERROR_NONE;
220}
221
222static void JNICALL
223compiled_method_load_cb(jvmtiEnv *jvmti,
224 jmethodID method,
225 jint code_size,
226 void const *code_addr,
227 jint map_length,
228 jvmtiAddrLocationMap const *map,
229 const void *compile_info)
230{
231 jvmti_line_info_t *line_tab = NULL;
232 char ** line_file_names = NULL;
233 jclass decl_class;
234 char *class_sign = NULL;
235 char *func_name = NULL;
236 char *func_sign = NULL;
237 char *file_name = NULL;
238 char fn[PATH_MAX];
239 uint64_t addr = (uint64_t)(uintptr_t)code_addr;
240 jvmtiError ret;
241 int nr_lines = 0;
242 size_t len;
243 int output_debug_info = 0;
244
245 ret = (*jvmti)->GetMethodDeclaringClass(jvmti, method,
246 &decl_class);
247 if (ret != JVMTI_ERROR_NONE) {
248 print_error(jvmti, "GetMethodDeclaringClass", ret);
249 return;
250 }
251
252 if (has_line_numbers && map && map_length) {
253 ret = get_line_numbers(jvmti, compile_info, &line_tab, &nr_lines);
254 if (ret != JVMTI_ERROR_NONE) {
255 warnx("jvmti: cannot get line table for method");
256 nr_lines = 0;
257 } else if (nr_lines > 0) {
258 line_file_names = malloc(sizeof(char*) * nr_lines);
259 if (!line_file_names) {
260 warnx("jvmti: cannot allocate space for line table method names");
261 } else {
262 memset(line_file_names, 0, sizeof(char*) * nr_lines);
263 ret = fill_source_filenames(jvmti, nr_lines, line_tab, line_file_names);
264 if (ret != JVMTI_ERROR_NONE) {
265 warnx("jvmti: fill_source_filenames failed");
266 } else {
267 output_debug_info = 1;
268 }
269 }
270 }
271 }
272
273 ret = (*jvmti)->GetSourceFileName(jvmti, decl_class, &file_name);
274 if (ret != JVMTI_ERROR_NONE) {
275 print_error(jvmti, "GetSourceFileName", ret);
276 goto error;
277 }
278
279 ret = (*jvmti)->GetClassSignature(jvmti, decl_class,
280 &class_sign, NULL);
281 if (ret != JVMTI_ERROR_NONE) {
282 print_error(jvmti, "GetClassSignature", ret);
283 goto error;
284 }
285
286 ret = (*jvmti)->GetMethodName(jvmti, method, &func_name,
287 &func_sign, NULL);
288 if (ret != JVMTI_ERROR_NONE) {
289 print_error(jvmti, "GetMethodName", ret);
290 goto error;
291 }
292
293 copy_class_filename(class_sign, file_name, fn, PATH_MAX);
294
295
296
297
298 if (output_debug_info)
299 if (jvmti_write_debug_info(jvmti_agent, addr, nr_lines, line_tab, (const char * const *) line_file_names))
300 warnx("jvmti: write_debug_info() failed");
301
302 len = strlen(func_name) + strlen(class_sign) + strlen(func_sign) + 2;
303 {
304 char str[len];
305 snprintf(str, len, "%s%s%s", class_sign, func_name, func_sign);
306
307 if (jvmti_write_code(jvmti_agent, str, addr, code_addr, code_size))
308 warnx("jvmti: write_code() failed");
309 }
310error:
311 (*jvmti)->Deallocate(jvmti, (unsigned char *)func_name);
312 (*jvmti)->Deallocate(jvmti, (unsigned char *)func_sign);
313 (*jvmti)->Deallocate(jvmti, (unsigned char *)class_sign);
314 (*jvmti)->Deallocate(jvmti, (unsigned char *)file_name);
315 free(line_tab);
316 while (line_file_names && (nr_lines > 0)) {
317 if (line_file_names[nr_lines - 1]) {
318 free(line_file_names[nr_lines - 1]);
319 }
320 nr_lines -= 1;
321 }
322 free(line_file_names);
323}
324
325static void JNICALL
326code_generated_cb(jvmtiEnv *jvmti,
327 char const *name,
328 void const *code_addr,
329 jint code_size)
330{
331 uint64_t addr = (uint64_t)(unsigned long)code_addr;
332 int ret;
333
334 ret = jvmti_write_code(jvmti_agent, name, addr, code_addr, code_size);
335 if (ret)
336 warnx("jvmti: write_code() failed for code_generated");
337}
338
339JNIEXPORT jint JNICALL
340Agent_OnLoad(JavaVM *jvm, char *options, void *reserved __maybe_unused)
341{
342 jvmtiEventCallbacks cb;
343 jvmtiCapabilities caps1;
344 jvmtiJlocationFormat format;
345 jvmtiEnv *jvmti = NULL;
346 jint ret;
347
348 jvmti_agent = jvmti_open();
349 if (!jvmti_agent) {
350 warnx("jvmti: open_agent failed");
351 return -1;
352 }
353
354
355
356
357 ret = (*jvm)->GetEnv(jvm, (void *)&jvmti, JVMTI_VERSION_1);
358 if (ret != JNI_OK) {
359 warnx("jvmti: jvmti version 1 not supported");
360 return -1;
361 }
362
363
364
365
366
367 memset(&caps1, 0, sizeof(caps1));
368 caps1.can_generate_compiled_method_load_events = 1;
369
370 ret = (*jvmti)->AddCapabilities(jvmti, &caps1);
371 if (ret != JVMTI_ERROR_NONE) {
372 print_error(jvmti, "AddCapabilities", ret);
373 return -1;
374 }
375 ret = (*jvmti)->GetJLocationFormat(jvmti, &format);
376 if (ret == JVMTI_ERROR_NONE && format == JVMTI_JLOCATION_JVMBCI) {
377 memset(&caps1, 0, sizeof(caps1));
378 caps1.can_get_line_numbers = 1;
379 caps1.can_get_source_file_name = 1;
380 ret = (*jvmti)->AddCapabilities(jvmti, &caps1);
381 if (ret == JVMTI_ERROR_NONE)
382 has_line_numbers = 1;
383 } else if (ret != JVMTI_ERROR_NONE)
384 print_error(jvmti, "GetJLocationFormat", ret);
385
386
387 memset(&cb, 0, sizeof(cb));
388
389 cb.CompiledMethodLoad = compiled_method_load_cb;
390 cb.DynamicCodeGenerated = code_generated_cb;
391
392 ret = (*jvmti)->SetEventCallbacks(jvmti, &cb, sizeof(cb));
393 if (ret != JVMTI_ERROR_NONE) {
394 print_error(jvmti, "SetEventCallbacks", ret);
395 return -1;
396 }
397
398 ret = (*jvmti)->SetEventNotificationMode(jvmti, JVMTI_ENABLE,
399 JVMTI_EVENT_COMPILED_METHOD_LOAD, NULL);
400 if (ret != JVMTI_ERROR_NONE) {
401 print_error(jvmti, "SetEventNotificationMode(METHOD_LOAD)", ret);
402 return -1;
403 }
404
405 ret = (*jvmti)->SetEventNotificationMode(jvmti, JVMTI_ENABLE,
406 JVMTI_EVENT_DYNAMIC_CODE_GENERATED, NULL);
407 if (ret != JVMTI_ERROR_NONE) {
408 print_error(jvmti, "SetEventNotificationMode(CODE_GENERATED)", ret);
409 return -1;
410 }
411 return 0;
412}
413
414JNIEXPORT void JNICALL
415Agent_OnUnload(JavaVM *jvm __maybe_unused)
416{
417 int ret;
418
419 ret = jvmti_close(jvmti_agent);
420 if (ret)
421 errx(1, "Error: op_close_agent()");
422}
423
