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 lines++;
51 } else {
52 break;
53 }
54 }
55 (*jvmti)->Deallocate(jvmti, (unsigned char *)loc_tab);
56 *nr = lines;
57 return JVMTI_ERROR_NONE;
58}
59
60static jvmtiError
61get_line_numbers(jvmtiEnv *jvmti, const void *compile_info, jvmti_line_info_t **tab, int *nr_lines)
62{
63 const jvmtiCompiledMethodLoadRecordHeader *hdr;
64 jvmtiCompiledMethodLoadInlineRecord *rec;
65 jvmtiLineNumberEntry *lne = NULL;
66 PCStackInfo *c;
67 jint nr, ret;
68 int nr_total = 0;
69 int i, lines_total = 0;
70
71 if (!(tab && nr_lines))
72 return JVMTI_ERROR_NULL_POINTER;
73
74
75
76
77 for (hdr = compile_info; hdr != NULL; hdr = hdr->next) {
78 if (hdr->kind == JVMTI_CMLR_INLINE_INFO) {
79 rec = (jvmtiCompiledMethodLoadInlineRecord *)hdr;
80 for (i = 0; i < rec->numpcs; i++) {
81 c = rec->pcinfo + i;
82 nr = 0;
83
84
85
86 ret = (*jvmti)->GetLineNumberTable(jvmti, c->methods[0], &nr, &lne);
87 if (ret == JVMTI_ERROR_NONE) {
88
89 (*jvmti)->Deallocate(jvmti, (unsigned char *)lne);
90 nr_total += (int)nr;
91 } else {
92 print_error(jvmti, "GetLineNumberTable", ret);
93 }
94 }
95 }
96 }
97
98 if (nr_total == 0)
99 return JVMTI_ERROR_NOT_FOUND;
100
101
102
103
104 *tab = malloc(nr_total * sizeof(**tab));
105 if (!*tab)
106 return JVMTI_ERROR_OUT_OF_MEMORY;
107
108 for (hdr = compile_info; hdr != NULL; hdr = hdr->next) {
109 if (hdr->kind == JVMTI_CMLR_INLINE_INFO) {
110 rec = (jvmtiCompiledMethodLoadInlineRecord *)hdr;
111 for (i = 0; i < rec->numpcs; i++) {
112 c = rec->pcinfo + i;
113 nr = 0;
114 ret = do_get_line_numbers(jvmti, c->pc,
115 c->methods[0],
116 c->bcis[0],
117 *tab + lines_total,
118 &nr);
119 if (ret == JVMTI_ERROR_NONE)
120 lines_total += nr;
121 }
122 }
123 }
124 *nr_lines = lines_total;
125 return JVMTI_ERROR_NONE;
126}
127
128static void JNICALL
129compiled_method_load_cb(jvmtiEnv *jvmti,
130 jmethodID method,
131 jint code_size,
132 void const *code_addr,
133 jint map_length,
134 jvmtiAddrLocationMap const *map,
135 const void *compile_info)
136{
137 jvmti_line_info_t *line_tab = NULL;
138 jclass decl_class;
139 char *class_sign = NULL;
140 char *func_name = NULL;
141 char *func_sign = NULL;
142 char *file_name= NULL;
143 char fn[PATH_MAX];
144 uint64_t addr = (uint64_t)(uintptr_t)code_addr;
145 jvmtiError ret;
146 int nr_lines = 0;
147 size_t len;
148
149 ret = (*jvmti)->GetMethodDeclaringClass(jvmti, method,
150 &decl_class);
151 if (ret != JVMTI_ERROR_NONE) {
152 print_error(jvmti, "GetMethodDeclaringClass", ret);
153 return;
154 }
155
156 if (has_line_numbers && map && map_length) {
157 ret = get_line_numbers(jvmti, compile_info, &line_tab, &nr_lines);
158 if (ret != JVMTI_ERROR_NONE) {
159 warnx("jvmti: cannot get line table for method");
160 nr_lines = 0;
161 }
162 }
163
164 ret = (*jvmti)->GetSourceFileName(jvmti, decl_class, &file_name);
165 if (ret != JVMTI_ERROR_NONE) {
166 print_error(jvmti, "GetSourceFileName", ret);
167 goto error;
168 }
169
170 ret = (*jvmti)->GetClassSignature(jvmti, decl_class,
171 &class_sign, NULL);
172 if (ret != JVMTI_ERROR_NONE) {
173 print_error(jvmti, "GetClassSignature", ret);
174 goto error;
175 }
176
177 ret = (*jvmti)->GetMethodName(jvmti, method, &func_name,
178 &func_sign, NULL);
179 if (ret != JVMTI_ERROR_NONE) {
180 print_error(jvmti, "GetMethodName", ret);
181 goto error;
182 }
183
184
185
186
187 if (*class_sign == 'L') {
188 int j, i = 0;
189 char *p = strrchr(class_sign, '/');
190 if (p) {
191
192 for (i = 0; i < (p - class_sign); i++)
193 fn[i] = class_sign[i+1];
194 }
195
196
197
198
199 for (j = 0; i < (PATH_MAX - 1) && file_name && j < strlen(file_name); j++, i++)
200 fn[i] = file_name[j];
201 fn[i] = '\0';
202 } else {
203
204 strcpy(fn, file_name);
205 }
206
207
208
209 if (jvmti_write_debug_info(jvmti_agent, addr, fn, line_tab, nr_lines))
210 warnx("jvmti: write_debug_info() failed");
211
212 len = strlen(func_name) + strlen(class_sign) + strlen(func_sign) + 2;
213 {
214 char str[len];
215 snprintf(str, len, "%s%s%s", class_sign, func_name, func_sign);
216
217 if (jvmti_write_code(jvmti_agent, str, addr, code_addr, code_size))
218 warnx("jvmti: write_code() failed");
219 }
220error:
221 (*jvmti)->Deallocate(jvmti, (unsigned char *)func_name);
222 (*jvmti)->Deallocate(jvmti, (unsigned char *)func_sign);
223 (*jvmti)->Deallocate(jvmti, (unsigned char *)class_sign);
224 (*jvmti)->Deallocate(jvmti, (unsigned char *)file_name);
225 free(line_tab);
226}
227
228static void JNICALL
229code_generated_cb(jvmtiEnv *jvmti,
230 char const *name,
231 void const *code_addr,
232 jint code_size)
233{
234 uint64_t addr = (uint64_t)(unsigned long)code_addr;
235 int ret;
236
237 ret = jvmti_write_code(jvmti_agent, name, addr, code_addr, code_size);
238 if (ret)
239 warnx("jvmti: write_code() failed for code_generated");
240}
241
242JNIEXPORT jint JNICALL
243Agent_OnLoad(JavaVM *jvm, char *options, void *reserved __maybe_unused)
244{
245 jvmtiEventCallbacks cb;
246 jvmtiCapabilities caps1;
247 jvmtiJlocationFormat format;
248 jvmtiEnv *jvmti = NULL;
249 jint ret;
250
251 jvmti_agent = jvmti_open();
252 if (!jvmti_agent) {
253 warnx("jvmti: open_agent failed");
254 return -1;
255 }
256
257
258
259
260 ret = (*jvm)->GetEnv(jvm, (void *)&jvmti, JVMTI_VERSION_1);
261 if (ret != JNI_OK) {
262 warnx("jvmti: jvmti version 1 not supported");
263 return -1;
264 }
265
266
267
268
269
270 memset(&caps1, 0, sizeof(caps1));
271 caps1.can_generate_compiled_method_load_events = 1;
272
273 ret = (*jvmti)->AddCapabilities(jvmti, &caps1);
274 if (ret != JVMTI_ERROR_NONE) {
275 print_error(jvmti, "AddCapabilities", ret);
276 return -1;
277 }
278 ret = (*jvmti)->GetJLocationFormat(jvmti, &format);
279 if (ret == JVMTI_ERROR_NONE && format == JVMTI_JLOCATION_JVMBCI) {
280 memset(&caps1, 0, sizeof(caps1));
281 caps1.can_get_line_numbers = 1;
282 caps1.can_get_source_file_name = 1;
283 ret = (*jvmti)->AddCapabilities(jvmti, &caps1);
284 if (ret == JVMTI_ERROR_NONE)
285 has_line_numbers = 1;
286 } else if (ret != JVMTI_ERROR_NONE)
287 print_error(jvmti, "GetJLocationFormat", ret);
288
289
290 memset(&cb, 0, sizeof(cb));
291
292 cb.CompiledMethodLoad = compiled_method_load_cb;
293 cb.DynamicCodeGenerated = code_generated_cb;
294
295 ret = (*jvmti)->SetEventCallbacks(jvmti, &cb, sizeof(cb));
296 if (ret != JVMTI_ERROR_NONE) {
297 print_error(jvmti, "SetEventCallbacks", ret);
298 return -1;
299 }
300
301 ret = (*jvmti)->SetEventNotificationMode(jvmti, JVMTI_ENABLE,
302 JVMTI_EVENT_COMPILED_METHOD_LOAD, NULL);
303 if (ret != JVMTI_ERROR_NONE) {
304 print_error(jvmti, "SetEventNotificationMode(METHOD_LOAD)", ret);
305 return -1;
306 }
307
308 ret = (*jvmti)->SetEventNotificationMode(jvmti, JVMTI_ENABLE,
309 JVMTI_EVENT_DYNAMIC_CODE_GENERATED, NULL);
310 if (ret != JVMTI_ERROR_NONE) {
311 print_error(jvmti, "SetEventNotificationMode(CODE_GENERATED)", ret);
312 return -1;
313 }
314 return 0;
315}
316
317JNIEXPORT void JNICALL
318Agent_OnUnload(JavaVM *jvm __maybe_unused)
319{
320 int ret;
321
322 ret = jvmti_close(jvmti_agent);
323 if (ret)
324 errx(1, "Error: op_close_agent()");
325}
326
