summaryrefslogtreecommitdiffstats
path: root/tools/perf/jvmti/libjvmti.c
blob: ac12e4b91a9265fda46192f28a8854e755515c7f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
#include <sys/types.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <err.h>
#include <jvmti.h>
#include <jvmticmlr.h>
#include <limits.h>

#include "jvmti_agent.h"

static int has_line_numbers;
void *jvmti_agent;

static jvmtiError
do_get_line_numbers(jvmtiEnv *jvmti, void *pc, jmethodID m, jint bci,
		    jvmti_line_info_t *tab, jint *nr)
{
	jint i, lines = 0;
	jint nr_lines = 0;
	jvmtiLineNumberEntry *loc_tab = NULL;
	jvmtiError ret;

	ret = (*jvmti)->GetLineNumberTable(jvmti, m, &nr_lines, &loc_tab);
	if (ret != JVMTI_ERROR_NONE)
		return ret;

	for (i = 0; i < nr_lines; i++) {
		if (loc_tab[i].start_location < bci) {
			tab[lines].pc = (unsigned long)pc;
			tab[lines].line_number = loc_tab[i].line_number;
			tab[lines].discrim = 0; /* not yet used */
			lines++;
		} else {
			break;
		}
	}
	(*jvmti)->Deallocate(jvmti, (unsigned char *)loc_tab);
	*nr = lines;
	return JVMTI_ERROR_NONE;
}

static jvmtiError
get_line_numbers(jvmtiEnv *jvmti, const void *compile_info, jvmti_line_info_t **tab, int *nr_lines)
{
	const jvmtiCompiledMethodLoadRecordHeader *hdr;
	jvmtiCompiledMethodLoadInlineRecord *rec;
	jvmtiLineNumberEntry *lne = NULL;
	PCStackInfo *c;
	jint nr, ret;
	int nr_total = 0;
	int i, lines_total = 0;

	if (!(tab && nr_lines))
		return JVMTI_ERROR_NULL_POINTER;

	/*
	 * Phase 1 -- get the number of lines necessary
	 */
	for (hdr = compile_info; hdr != NULL; hdr = hdr->next) {
		if (hdr->kind == JVMTI_CMLR_INLINE_INFO) {
			rec = (jvmtiCompiledMethodLoadInlineRecord *)hdr;
			for (i = 0; i < rec->numpcs; i++) {
				c = rec->pcinfo + i;
				nr = 0;
				/*
				 * unfortunately, need a tab to get the number of lines!
				 */
				ret = (*jvmti)->GetLineNumberTable(jvmti, c->methods[0], &nr, &lne);
				if (ret == JVMTI_ERROR_NONE) {
					/* free what was allocated for nothing */
					(*jvmti)->Deallocate(jvmti, (unsigned char *)lne);
					nr_total += (int)nr;
				}
			}
		}
	}

	if (nr_total == 0)
		return JVMTI_ERROR_NOT_FOUND;

	/*
	 * Phase 2 -- allocate big enough line table
	 */
	*tab = malloc(nr_total * sizeof(**tab));
	if (!*tab)
		return JVMTI_ERROR_OUT_OF_MEMORY;

	for (hdr = compile_info; hdr != NULL; hdr = hdr->next) {
		if (hdr->kind == JVMTI_CMLR_INLINE_INFO) {
			rec = (jvmtiCompiledMethodLoadInlineRecord *)hdr;
			for (i = 0; i < rec->numpcs; i++) {
				c = rec->pcinfo + i;
				nr = 0;
				ret = do_get_line_numbers(jvmti, c->pc,
							  c->methods[0],
							  c->bcis[0],
							  *tab + lines_total,
							  &nr);
				if (ret == JVMTI_ERROR_NONE)
					lines_total += nr;
			}
		}
	}
	*nr_lines = lines_total;
	return JVMTI_ERROR_NONE;
}

static void JNICALL
compiled_method_load_cb(jvmtiEnv *jvmti,
			jmethodID method,
			jint code_size,
			void const *code_addr,
			jint map_length,
			jvmtiAddrLocationMap const *map,
			const void *compile_info)
{
	jvmti_line_info_t *line_tab = NULL;
	jclass decl_class;
	char *class_sign = NULL;
	char *func_name = NULL;
	char *func_sign = NULL;
	char *file_name= NULL;
	char fn[PATH_MAX];
	uint64_t addr = (uint64_t)(uintptr_t)code_addr;
	jvmtiError ret;
	int nr_lines = 0; /* in line_tab[] */
	size_t len;

	ret = (*jvmti)->GetMethodDeclaringClass(jvmti, method,
						&decl_class);
	if (ret != JVMTI_ERROR_NONE) {
		warnx("jvmti: cannot get declaring class");
		return;
	}

	if (has_line_numbers && map && map_length) {
		ret = get_line_numbers(jvmti, compile_info, &line_tab, &nr_lines);
		if (ret != JVMTI_ERROR_NONE) {
			warnx("jvmti: cannot get line table for method");
			nr_lines = 0;
		}
	}

	ret = (*jvmti)->GetSourceFileName(jvmti, decl_class, &file_name);
	if (ret != JVMTI_ERROR_NONE) {
		warnx("jvmti: cannot get source filename ret=%d", ret);
		goto error;
	}

	ret = (*jvmti)->GetClassSignature(jvmti, decl_class,
					  &class_sign, NULL);
	if (ret != JVMTI_ERROR_NONE) {
		warnx("jvmti: getclassignature failed");
		goto error;
	}

	ret = (*jvmti)->GetMethodName(jvmti, method, &func_name,
				      &func_sign, NULL);
	if (ret != JVMTI_ERROR_NONE) {
		warnx("jvmti: failed getmethodname");
		goto error;
	}

	/*
	 * Assume path name is class hierarchy, this is a common practice with Java programs
	 */
	if (*class_sign == 'L') {
		int j, i = 0;
		char *p = strrchr(class_sign, '/');
		if (p) {
			/* drop the 'L' prefix and copy up to the final '/' */
			for (i = 0; i < (p - class_sign); i++)
				fn[i] = class_sign[i+1];
		}
		/*
		 * append file name, we use loops and not string ops to avoid modifying
		 * class_sign which is used later for the symbol name
		 */
		for (j = 0; i < (PATH_MAX - 1) && file_name && j < strlen(file_name); j++, i++)
			fn[i] = file_name[j];
		fn[i] = '\0';
	} else {
		/* fallback case */
		strcpy(fn, file_name);
	}
	/*
	 * write source line info record if we have it
	 */
	if (jvmti_write_debug_info(jvmti_agent, addr, fn, line_tab, nr_lines))
		warnx("jvmti: write_debug_info() failed");

	len = strlen(func_name) + strlen(class_sign) + strlen(func_sign) + 2;
	{
		char str[len];
		snprintf(str, len, "%s%s%s", class_sign, func_name, func_sign);

		if (jvmti_write_code(jvmti_agent, str, addr, code_addr, code_size))
			warnx("jvmti: write_code() failed");
	}
error:
	(*jvmti)->Deallocate(jvmti, (unsigned char *)func_name);
	(*jvmti)->Deallocate(jvmti, (unsigned char *)func_sign);
	(*jvmti)->Deallocate(jvmti, (unsigned char *)class_sign);
	(*jvmti)->Deallocate(jvmti, (unsigned char *)file_name);
	free(line_tab);
}

static void JNICALL
code_generated_cb(jvmtiEnv *jvmti,
		  char const *name,
		  void const *code_addr,
		  jint code_size)
{
	uint64_t addr = (uint64_t)(unsigned long)code_addr;
	int ret;

	ret = jvmti_write_code(jvmti_agent, name, addr, code_addr, code_size);
	if (ret)
		warnx("jvmti: write_code() failed for code_generated");
}

JNIEXPORT jint JNICALL
Agent_OnLoad(JavaVM *jvm, char *options, void *reserved __unused)
{
	jvmtiEventCallbacks cb;
	jvmtiCapabilities caps1;
	jvmtiJlocationFormat format;
	jvmtiEnv *jvmti = NULL;
	jint ret;

	jvmti_agent = jvmti_open();
	if (!jvmti_agent) {
		warnx("jvmti: open_agent failed");
		return -1;
	}

	/*
	 * Request a JVMTI interface version 1 environment
	 */
	ret = (*jvm)->GetEnv(jvm, (void *)&jvmti, JVMTI_VERSION_1);
	if (ret != JNI_OK) {
		warnx("jvmti: jvmti version 1 not supported");
		return -1;
	}

	/*
	 * acquire method_load capability, we require it
	 * request line numbers (optional)
	 */
	memset(&caps1, 0, sizeof(caps1));
	caps1.can_generate_compiled_method_load_events = 1;

	ret = (*jvmti)->AddCapabilities(jvmti, &caps1);
	if (ret != JVMTI_ERROR_NONE) {
		warnx("jvmti: acquire compiled_method capability failed");
		return -1;
	}
	ret = (*jvmti)->GetJLocationFormat(jvmti, &format);
        if (ret == JVMTI_ERROR_NONE && format == JVMTI_JLOCATION_JVMBCI) {
                memset(&caps1, 0, sizeof(caps1));
                caps1.can_get_line_numbers = 1;
                caps1.can_get_source_file_name = 1;
		ret = (*jvmti)->AddCapabilities(jvmti, &caps1);
                if (ret == JVMTI_ERROR_NONE)
                        has_line_numbers = 1;
        }

	memset(&cb, 0, sizeof(cb));

	cb.CompiledMethodLoad   = compiled_method_load_cb;
	cb.DynamicCodeGenerated = code_generated_cb;

	ret = (*jvmti)->SetEventCallbacks(jvmti, &cb, sizeof(cb));
	if (ret != JVMTI_ERROR_NONE) {
		warnx("jvmti: cannot set event callbacks");
		return -1;
	}

	ret = (*jvmti)->SetEventNotificationMode(jvmti, JVMTI_ENABLE,
			JVMTI_EVENT_COMPILED_METHOD_LOAD, NULL);
	if (ret != JVMTI_ERROR_NONE) {
		warnx("jvmti: setnotification failed for method_load");
		return -1;
	}

	ret = (*jvmti)->SetEventNotificationMode(jvmti, JVMTI_ENABLE,
			JVMTI_EVENT_DYNAMIC_CODE_GENERATED, NULL);
	if (ret != JVMTI_ERROR_NONE) {
		warnx("jvmti: setnotification failed on code_generated");
		return -1;
	}
	return 0;
}

JNIEXPORT void JNICALL
Agent_OnUnload(JavaVM *jvm __unused)
{
	int ret;

	ret = jvmti_close(jvmti_agent);
	if (ret)
		errx(1, "Error: op_close_agent()");
}