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v4.6
  1/*
  2 * jvmti_agent.c: JVMTI agent interface
  3 *
  4 * Adapted from the Oprofile code in opagent.c:
  5 * This library is free software; you can redistribute it and/or
  6 * modify it under the terms of the GNU Lesser General Public
  7 * License as published by the Free Software Foundation; either
  8 * version 2.1 of the License, or (at your option) any later version.
  9 *
 10 * This library is distributed in the hope that it will be useful,
 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 13 * Lesser General Public License for more details.
 14 *
 15 * You should have received a copy of the GNU Lesser General Public
 16 * License along with this library; if not, write to the Free Software
 17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 18 *
 19 * Copyright 2007 OProfile authors
 20 * Jens Wilke
 21 * Daniel Hansel
 22 * Copyright IBM Corporation 2007
 23 */
 24#include <sys/types.h>
 25#include <sys/stat.h> /* for mkdir() */
 26#include <stdio.h>
 27#include <errno.h>
 28#include <string.h>
 29#include <stdlib.h>
 30#include <stdint.h>
 31#include <limits.h>
 32#include <fcntl.h>
 33#include <unistd.h>
 34#include <time.h>
 35#include <sys/mman.h>
 36#include <syscall.h> /* for gettid() */
 37#include <err.h>
 38
 39#include "jvmti_agent.h"
 40#include "../util/jitdump.h"
 41
 42#define JIT_LANG "java"
 43
 44static char jit_path[PATH_MAX];
 45static void *marker_addr;
 46
 47/*
 48 * padding buffer
 49 */
 50static const char pad_bytes[7];
 51
 52static inline pid_t gettid(void)
 53{
 54	return (pid_t)syscall(__NR_gettid);
 55}
 56
 57static int get_e_machine(struct jitheader *hdr)
 58{
 59	ssize_t sret;
 60	char id[16];
 61	int fd, ret = -1;
 62	int m = -1;
 63	struct {
 64		uint16_t e_type;
 65		uint16_t e_machine;
 66	} info;
 67
 68	fd = open("/proc/self/exe", O_RDONLY);
 69	if (fd == -1)
 70		return -1;
 71
 72	sret = read(fd, id, sizeof(id));
 73	if (sret != sizeof(id))
 74		goto error;
 75
 76	/* check ELF signature */
 77	if (id[0] != 0x7f || id[1] != 'E' || id[2] != 'L' || id[3] != 'F')
 78		goto error;
 79
 80	sret = read(fd, &info, sizeof(info));
 81	if (sret != sizeof(info))
 82		goto error;
 83
 84	m = info.e_machine;
 85	if (m < 0)
 86		m = 0; /* ELF EM_NONE */
 87
 88	hdr->elf_mach = m;
 89	ret = 0;
 90error:
 91	close(fd);
 92	return ret;
 93}
 94
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 95#define NSEC_PER_SEC	1000000000
 96static int perf_clk_id = CLOCK_MONOTONIC;
 97
 98static inline uint64_t
 99timespec_to_ns(const struct timespec *ts)
100{
101        return ((uint64_t) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
102}
103
104static inline uint64_t
105perf_get_timestamp(void)
106{
107	struct timespec ts;
108	int ret;
109
 
 
 
110	ret = clock_gettime(perf_clk_id, &ts);
111	if (ret)
112		return 0;
113
114	return timespec_to_ns(&ts);
115}
116
117static int
118debug_cache_init(void)
119{
120	char str[32];
121	char *base, *p;
122	struct tm tm;
123	time_t t;
124	int ret;
125
126	time(&t);
127	localtime_r(&t, &tm);
128
129	base = getenv("JITDUMPDIR");
130	if (!base)
131		base = getenv("HOME");
132	if (!base)
133		base = ".";
134
135	strftime(str, sizeof(str), JIT_LANG"-jit-%Y%m%d", &tm);
136
137	snprintf(jit_path, PATH_MAX - 1, "%s/.debug/", base);
138
139	ret = mkdir(jit_path, 0755);
140	if (ret == -1) {
141		if (errno != EEXIST) {
142			warn("jvmti: cannot create jit cache dir %s", jit_path);
143			return -1;
144		}
145	}
146
147	snprintf(jit_path, PATH_MAX - 1, "%s/.debug/jit", base);
148	ret = mkdir(jit_path, 0755);
149	if (ret == -1) {
150		if (errno != EEXIST) {
151			warn("cannot create jit cache dir %s", jit_path);
152			return -1;
153		}
154	}
155
156	snprintf(jit_path, PATH_MAX - 1, "%s/.debug/jit/%s.XXXXXXXX", base, str);
157
158	p = mkdtemp(jit_path);
159	if (p != jit_path) {
160		warn("cannot create jit cache dir %s", jit_path);
161		return -1;
162	}
163
164	return 0;
165}
166
167static int
168perf_open_marker_file(int fd)
169{
170	long pgsz;
171
172	pgsz = sysconf(_SC_PAGESIZE);
173	if (pgsz == -1)
174		return -1;
175
176	/*
177	 * we mmap the jitdump to create an MMAP RECORD in perf.data file.
178	 * The mmap is captured either live (perf record running when we mmap)
179	 * or  in deferred mode, via /proc/PID/maps
180	 * the MMAP record is used as a marker of a jitdump file for more meta
181	 * data info about the jitted code. Perf report/annotate detect this
182	 * special filename and process the jitdump file.
183	 *
184	 * mapping must be PROT_EXEC to ensure it is captured by perf record
185	 * even when not using -d option
186	 */
187	marker_addr = mmap(NULL, pgsz, PROT_READ|PROT_EXEC, MAP_PRIVATE, fd, 0);
188	return (marker_addr == MAP_FAILED) ? -1 : 0;
189}
190
191static void
192perf_close_marker_file(void)
193{
194	long pgsz;
195
196	if (!marker_addr)
197		return;
198
199	pgsz = sysconf(_SC_PAGESIZE);
200	if (pgsz == -1)
201		return;
202
203	munmap(marker_addr, pgsz);
204}
205
 
 
 
 
 
 
 
 
 
 
 
206void *jvmti_open(void)
207{
208	int pad_cnt;
209	char dump_path[PATH_MAX];
210	struct jitheader header;
211	int fd;
212	FILE *fp;
213
 
 
214	/*
215	 * check if clockid is supported
216	 */
217	if (!perf_get_timestamp())
218		warnx("jvmti: kernel does not support %d clock id", perf_clk_id);
 
 
 
 
219
220	memset(&header, 0, sizeof(header));
221
222	debug_cache_init();
223
224	/*
225	 * jitdump file name
226	 */
227	snprintf(dump_path, PATH_MAX, "%s/jit-%i.dump", jit_path, getpid());
228
229	fd = open(dump_path, O_CREAT|O_TRUNC|O_RDWR, 0666);
230	if (fd == -1)
231		return NULL;
232
233	/*
234	 * create perf.data maker for the jitdump file
235	 */
236	if (perf_open_marker_file(fd)) {
237		warnx("jvmti: failed to create marker file");
238		return NULL;
239	}
240
241	fp = fdopen(fd, "w+");
242	if (!fp) {
243		warn("jvmti: cannot create %s", dump_path);
244		close(fd);
245		goto error;
246	}
247
248	warnx("jvmti: jitdump in %s", dump_path);
249
250	if (get_e_machine(&header)) {
251		warn("get_e_machine failed\n");
252		goto error;
253	}
254
255	header.magic      = JITHEADER_MAGIC;
256	header.version    = JITHEADER_VERSION;
257	header.total_size = sizeof(header);
258	header.pid        = getpid();
259
260	/* calculate amount of padding '\0' */
261	pad_cnt = PADDING_8ALIGNED(header.total_size);
262	header.total_size += pad_cnt;
263
264	header.timestamp = perf_get_timestamp();
265
 
 
 
266	if (!fwrite(&header, sizeof(header), 1, fp)) {
267		warn("jvmti: cannot write dumpfile header");
268		goto error;
269	}
270
271	/* write padding '\0' if necessary */
272	if (pad_cnt && !fwrite(pad_bytes, pad_cnt, 1, fp)) {
273		warn("jvmti: cannot write dumpfile header padding");
274		goto error;
275	}
276
277	return fp;
278error:
279	fclose(fp);
280	return NULL;
281}
282
283int
284jvmti_close(void *agent)
285{
286	struct jr_code_close rec;
287	FILE *fp = agent;
288
289	if (!fp) {
290		warnx("jvmti: incalid fd in close_agent");
291		return -1;
292	}
293
294	rec.p.id = JIT_CODE_CLOSE;
295	rec.p.total_size = sizeof(rec);
296
297	rec.p.timestamp = perf_get_timestamp();
298
299	if (!fwrite(&rec, sizeof(rec), 1, fp))
300		return -1;
301
302	fclose(fp);
303
304	fp = NULL;
305
306	perf_close_marker_file();
307
308	return 0;
309}
310
311int
312jvmti_write_code(void *agent, char const *sym,
313	uint64_t vma, void const *code, unsigned int const size)
314{
315	static int code_generation = 1;
316	struct jr_code_load rec;
317	size_t sym_len;
318	size_t padding_count;
319	FILE *fp = agent;
320	int ret = -1;
321
322	/* don't care about 0 length function, no samples */
323	if (size == 0)
324		return 0;
325
326	if (!fp) {
327		warnx("jvmti: invalid fd in write_native_code");
328		return -1;
329	}
330
331	sym_len = strlen(sym) + 1;
332
333	rec.p.id           = JIT_CODE_LOAD;
334	rec.p.total_size   = sizeof(rec) + sym_len;
335	padding_count      = PADDING_8ALIGNED(rec.p.total_size);
336	rec.p. total_size += padding_count;
337	rec.p.timestamp    = perf_get_timestamp();
338
339	rec.code_size  = size;
340	rec.vma        = vma;
341	rec.code_addr  = vma;
342	rec.pid	       = getpid();
343	rec.tid	       = gettid();
344
345	if (code)
346		rec.p.total_size += size;
347
348	/*
349	 * If JVM is multi-threaded, nultiple concurrent calls to agent
350	 * may be possible, so protect file writes
351	 */
352	flockfile(fp);
353
354	/*
355	 * get code index inside lock to avoid race condition
356	 */
357	rec.code_index = code_generation++;
358
359	ret = fwrite_unlocked(&rec, sizeof(rec), 1, fp);
360	fwrite_unlocked(sym, sym_len, 1, fp);
361
362	if (padding_count)
363		fwrite_unlocked(pad_bytes, padding_count, 1, fp);
364
365	if (code)
366		fwrite_unlocked(code, size, 1, fp);
367
368	funlockfile(fp);
369
370	ret = 0;
371
372	return ret;
373}
374
375int
376jvmti_write_debug_info(void *agent, uint64_t code, const char *file,
377		       jvmti_line_info_t *li, int nr_lines)
 
378{
379	struct jr_code_debug_info rec;
380	size_t sret, len, size, flen;
381	size_t padding_count;
382	uint64_t addr;
383	const char *fn = file;
384	FILE *fp = agent;
385	int i;
386
387	/*
388	 * no entry to write
389	 */
390	if (!nr_lines)
391		return 0;
392
393	if (!fp) {
394		warnx("jvmti: invalid fd in write_debug_info");
395		return -1;
396	}
397
398	flen = strlen(file) + 1;
 
 
399
400	rec.p.id        = JIT_CODE_DEBUG_INFO;
401	size            = sizeof(rec);
402	rec.p.timestamp = perf_get_timestamp();
403	rec.code_addr   = (uint64_t)(uintptr_t)code;
404	rec.nr_entry    = nr_lines;
405
406	/*
407	 * on disk source line info layout:
408	 * uint64_t : addr
409	 * int      : line number
410	 * int      : column discriminator
411	 * file[]   : source file name
412	 * padding  : pad to multiple of 8 bytes
413	 */
414	size += nr_lines * sizeof(struct debug_entry);
415	size += flen * nr_lines;
416	/*
417	 * pad to 8 bytes
418	 */
419	padding_count = PADDING_8ALIGNED(size);
420
421	rec.p.total_size = size + padding_count;
422
423	/*
424	 * If JVM is multi-threaded, nultiple concurrent calls to agent
425	 * may be possible, so protect file writes
426	 */
427	flockfile(fp);
428
429	sret = fwrite_unlocked(&rec, sizeof(rec), 1, fp);
430	if (sret != 1)
431		goto error;
432
433	for (i = 0; i < nr_lines; i++) {
434
435		addr = (uint64_t)li[i].pc;
436		len  = sizeof(addr);
437		sret = fwrite_unlocked(&addr, len, 1, fp);
438		if (sret != 1)
439			goto error;
440
441		len  = sizeof(li[0].line_number);
442		sret = fwrite_unlocked(&li[i].line_number, len, 1, fp);
443		if (sret != 1)
444			goto error;
445
446		len  = sizeof(li[0].discrim);
447		sret = fwrite_unlocked(&li[i].discrim, len, 1, fp);
448		if (sret != 1)
449			goto error;
450
451		sret = fwrite_unlocked(fn, flen, 1, fp);
452		if (sret != 1)
453			goto error;
454	}
455	if (padding_count)
456		sret = fwrite_unlocked(pad_bytes, padding_count, 1, fp);
457		if (sret != 1)
458			goto error;
459
460	funlockfile(fp);
461	return 0;
462error:
463	funlockfile(fp);
464	return -1;
465}
v4.17
  1/*
  2 * jvmti_agent.c: JVMTI agent interface
  3 *
  4 * Adapted from the Oprofile code in opagent.c:
  5 * This library is free software; you can redistribute it and/or
  6 * modify it under the terms of the GNU Lesser General Public
  7 * License as published by the Free Software Foundation; either
  8 * version 2.1 of the License, or (at your option) any later version.
  9 *
 10 * This library is distributed in the hope that it will be useful,
 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 13 * Lesser General Public License for more details.
 14 *
 15 * You should have received a copy of the GNU Lesser General Public
 16 * License along with this library; if not, write to the Free Software
 17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 18 *
 19 * Copyright 2007 OProfile authors
 20 * Jens Wilke
 21 * Daniel Hansel
 22 * Copyright IBM Corporation 2007
 23 */
 24#include <sys/types.h>
 25#include <sys/stat.h> /* for mkdir() */
 26#include <stdio.h>
 27#include <errno.h>
 28#include <string.h>
 29#include <stdlib.h>
 30#include <stdint.h>
 31#include <limits.h>
 32#include <fcntl.h>
 33#include <unistd.h>
 34#include <time.h>
 35#include <sys/mman.h>
 36#include <syscall.h> /* for gettid() */
 37#include <err.h>
 38
 39#include "jvmti_agent.h"
 40#include "../util/jitdump.h"
 41
 42#define JIT_LANG "java"
 43
 44static char jit_path[PATH_MAX];
 45static void *marker_addr;
 46
 
 
 
 
 
 47static inline pid_t gettid(void)
 48{
 49	return (pid_t)syscall(__NR_gettid);
 50}
 51
 52static int get_e_machine(struct jitheader *hdr)
 53{
 54	ssize_t sret;
 55	char id[16];
 56	int fd, ret = -1;
 
 57	struct {
 58		uint16_t e_type;
 59		uint16_t e_machine;
 60	} info;
 61
 62	fd = open("/proc/self/exe", O_RDONLY);
 63	if (fd == -1)
 64		return -1;
 65
 66	sret = read(fd, id, sizeof(id));
 67	if (sret != sizeof(id))
 68		goto error;
 69
 70	/* check ELF signature */
 71	if (id[0] != 0x7f || id[1] != 'E' || id[2] != 'L' || id[3] != 'F')
 72		goto error;
 73
 74	sret = read(fd, &info, sizeof(info));
 75	if (sret != sizeof(info))
 76		goto error;
 77
 78	hdr->elf_mach = info.e_machine;
 
 
 
 
 79	ret = 0;
 80error:
 81	close(fd);
 82	return ret;
 83}
 84
 85static int use_arch_timestamp;
 86
 87static inline uint64_t
 88get_arch_timestamp(void)
 89{
 90#if defined(__i386__) || defined(__x86_64__)
 91	unsigned int low, high;
 92
 93	asm volatile("rdtsc" : "=a" (low), "=d" (high));
 94
 95	return low | ((uint64_t)high) << 32;
 96#else
 97	return 0;
 98#endif
 99}
100
101#define NSEC_PER_SEC	1000000000
102static int perf_clk_id = CLOCK_MONOTONIC;
103
104static inline uint64_t
105timespec_to_ns(const struct timespec *ts)
106{
107        return ((uint64_t) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
108}
109
110static inline uint64_t
111perf_get_timestamp(void)
112{
113	struct timespec ts;
114	int ret;
115
116	if (use_arch_timestamp)
117		return get_arch_timestamp();
118
119	ret = clock_gettime(perf_clk_id, &ts);
120	if (ret)
121		return 0;
122
123	return timespec_to_ns(&ts);
124}
125
126static int
127debug_cache_init(void)
128{
129	char str[32];
130	char *base, *p;
131	struct tm tm;
132	time_t t;
133	int ret;
134
135	time(&t);
136	localtime_r(&t, &tm);
137
138	base = getenv("JITDUMPDIR");
139	if (!base)
140		base = getenv("HOME");
141	if (!base)
142		base = ".";
143
144	strftime(str, sizeof(str), JIT_LANG"-jit-%Y%m%d", &tm);
145
146	snprintf(jit_path, PATH_MAX - 1, "%s/.debug/", base);
147
148	ret = mkdir(jit_path, 0755);
149	if (ret == -1) {
150		if (errno != EEXIST) {
151			warn("jvmti: cannot create jit cache dir %s", jit_path);
152			return -1;
153		}
154	}
155
156	snprintf(jit_path, PATH_MAX - 1, "%s/.debug/jit", base);
157	ret = mkdir(jit_path, 0755);
158	if (ret == -1) {
159		if (errno != EEXIST) {
160			warn("cannot create jit cache dir %s", jit_path);
161			return -1;
162		}
163	}
164
165	snprintf(jit_path, PATH_MAX - 1, "%s/.debug/jit/%s.XXXXXXXX", base, str);
166
167	p = mkdtemp(jit_path);
168	if (p != jit_path) {
169		warn("cannot create jit cache dir %s", jit_path);
170		return -1;
171	}
172
173	return 0;
174}
175
176static int
177perf_open_marker_file(int fd)
178{
179	long pgsz;
180
181	pgsz = sysconf(_SC_PAGESIZE);
182	if (pgsz == -1)
183		return -1;
184
185	/*
186	 * we mmap the jitdump to create an MMAP RECORD in perf.data file.
187	 * The mmap is captured either live (perf record running when we mmap)
188	 * or  in deferred mode, via /proc/PID/maps
189	 * the MMAP record is used as a marker of a jitdump file for more meta
190	 * data info about the jitted code. Perf report/annotate detect this
191	 * special filename and process the jitdump file.
192	 *
193	 * mapping must be PROT_EXEC to ensure it is captured by perf record
194	 * even when not using -d option
195	 */
196	marker_addr = mmap(NULL, pgsz, PROT_READ|PROT_EXEC, MAP_PRIVATE, fd, 0);
197	return (marker_addr == MAP_FAILED) ? -1 : 0;
198}
199
200static void
201perf_close_marker_file(void)
202{
203	long pgsz;
204
205	if (!marker_addr)
206		return;
207
208	pgsz = sysconf(_SC_PAGESIZE);
209	if (pgsz == -1)
210		return;
211
212	munmap(marker_addr, pgsz);
213}
214
215static void
216init_arch_timestamp(void)
217{
218	char *str = getenv("JITDUMP_USE_ARCH_TIMESTAMP");
219
220	if (!str || !*str || !strcmp(str, "0"))
221		return;
222
223	use_arch_timestamp = 1;
224}
225
226void *jvmti_open(void)
227{
 
228	char dump_path[PATH_MAX];
229	struct jitheader header;
230	int fd;
231	FILE *fp;
232
233	init_arch_timestamp();
234
235	/*
236	 * check if clockid is supported
237	 */
238	if (!perf_get_timestamp()) {
239		if (use_arch_timestamp)
240			warnx("jvmti: arch timestamp not supported");
241		else
242			warnx("jvmti: kernel does not support %d clock id", perf_clk_id);
243	}
244
245	memset(&header, 0, sizeof(header));
246
247	debug_cache_init();
248
249	/*
250	 * jitdump file name
251	 */
252	snprintf(dump_path, PATH_MAX, "%s/jit-%i.dump", jit_path, getpid());
253
254	fd = open(dump_path, O_CREAT|O_TRUNC|O_RDWR, 0666);
255	if (fd == -1)
256		return NULL;
257
258	/*
259	 * create perf.data maker for the jitdump file
260	 */
261	if (perf_open_marker_file(fd)) {
262		warnx("jvmti: failed to create marker file");
263		return NULL;
264	}
265
266	fp = fdopen(fd, "w+");
267	if (!fp) {
268		warn("jvmti: cannot create %s", dump_path);
269		close(fd);
270		goto error;
271	}
272
273	warnx("jvmti: jitdump in %s", dump_path);
274
275	if (get_e_machine(&header)) {
276		warn("get_e_machine failed\n");
277		goto error;
278	}
279
280	header.magic      = JITHEADER_MAGIC;
281	header.version    = JITHEADER_VERSION;
282	header.total_size = sizeof(header);
283	header.pid        = getpid();
284
 
 
 
 
285	header.timestamp = perf_get_timestamp();
286
287	if (use_arch_timestamp)
288		header.flags |= JITDUMP_FLAGS_ARCH_TIMESTAMP;
289
290	if (!fwrite(&header, sizeof(header), 1, fp)) {
291		warn("jvmti: cannot write dumpfile header");
292		goto error;
293	}
 
 
 
 
 
 
 
294	return fp;
295error:
296	fclose(fp);
297	return NULL;
298}
299
300int
301jvmti_close(void *agent)
302{
303	struct jr_code_close rec;
304	FILE *fp = agent;
305
306	if (!fp) {
307		warnx("jvmti: invalid fd in close_agent");
308		return -1;
309	}
310
311	rec.p.id = JIT_CODE_CLOSE;
312	rec.p.total_size = sizeof(rec);
313
314	rec.p.timestamp = perf_get_timestamp();
315
316	if (!fwrite(&rec, sizeof(rec), 1, fp))
317		return -1;
318
319	fclose(fp);
320
321	fp = NULL;
322
323	perf_close_marker_file();
324
325	return 0;
326}
327
328int
329jvmti_write_code(void *agent, char const *sym,
330	uint64_t vma, void const *code, unsigned int const size)
331{
332	static int code_generation = 1;
333	struct jr_code_load rec;
334	size_t sym_len;
 
335	FILE *fp = agent;
336	int ret = -1;
337
338	/* don't care about 0 length function, no samples */
339	if (size == 0)
340		return 0;
341
342	if (!fp) {
343		warnx("jvmti: invalid fd in write_native_code");
344		return -1;
345	}
346
347	sym_len = strlen(sym) + 1;
348
349	rec.p.id           = JIT_CODE_LOAD;
350	rec.p.total_size   = sizeof(rec) + sym_len;
 
 
351	rec.p.timestamp    = perf_get_timestamp();
352
353	rec.code_size  = size;
354	rec.vma        = vma;
355	rec.code_addr  = vma;
356	rec.pid	       = getpid();
357	rec.tid	       = gettid();
358
359	if (code)
360		rec.p.total_size += size;
361
362	/*
363	 * If JVM is multi-threaded, nultiple concurrent calls to agent
364	 * may be possible, so protect file writes
365	 */
366	flockfile(fp);
367
368	/*
369	 * get code index inside lock to avoid race condition
370	 */
371	rec.code_index = code_generation++;
372
373	ret = fwrite_unlocked(&rec, sizeof(rec), 1, fp);
374	fwrite_unlocked(sym, sym_len, 1, fp);
375
 
 
 
376	if (code)
377		fwrite_unlocked(code, size, 1, fp);
378
379	funlockfile(fp);
380
381	ret = 0;
382
383	return ret;
384}
385
386int
387jvmti_write_debug_info(void *agent, uint64_t code,
388    int nr_lines, jvmti_line_info_t *li,
389    const char * const * file_names)
390{
391	struct jr_code_debug_info rec;
392	size_t sret, len, size, flen = 0;
 
393	uint64_t addr;
 
394	FILE *fp = agent;
395	int i;
396
397	/*
398	 * no entry to write
399	 */
400	if (!nr_lines)
401		return 0;
402
403	if (!fp) {
404		warnx("jvmti: invalid fd in write_debug_info");
405		return -1;
406	}
407
408	for (i = 0; i < nr_lines; ++i) {
409	    flen += strlen(file_names[i]) + 1;
410	}
411
412	rec.p.id        = JIT_CODE_DEBUG_INFO;
413	size            = sizeof(rec);
414	rec.p.timestamp = perf_get_timestamp();
415	rec.code_addr   = (uint64_t)(uintptr_t)code;
416	rec.nr_entry    = nr_lines;
417
418	/*
419	 * on disk source line info layout:
420	 * uint64_t : addr
421	 * int      : line number
422	 * int      : column discriminator
423	 * file[]   : source file name
 
424	 */
425	size += nr_lines * sizeof(struct debug_entry);
426	size += flen;
427	rec.p.total_size = size;
 
 
 
 
 
428
429	/*
430	 * If JVM is multi-threaded, nultiple concurrent calls to agent
431	 * may be possible, so protect file writes
432	 */
433	flockfile(fp);
434
435	sret = fwrite_unlocked(&rec, sizeof(rec), 1, fp);
436	if (sret != 1)
437		goto error;
438
439	for (i = 0; i < nr_lines; i++) {
440
441		addr = (uint64_t)li[i].pc;
442		len  = sizeof(addr);
443		sret = fwrite_unlocked(&addr, len, 1, fp);
444		if (sret != 1)
445			goto error;
446
447		len  = sizeof(li[0].line_number);
448		sret = fwrite_unlocked(&li[i].line_number, len, 1, fp);
449		if (sret != 1)
450			goto error;
451
452		len  = sizeof(li[0].discrim);
453		sret = fwrite_unlocked(&li[i].discrim, len, 1, fp);
454		if (sret != 1)
455			goto error;
456
457		sret = fwrite_unlocked(file_names[i], strlen(file_names[i]) + 1, 1, fp);
458		if (sret != 1)
459			goto error;
460	}
 
 
 
 
 
461	funlockfile(fp);
462	return 0;
463error:
464	funlockfile(fp);
465	return -1;
466}