1 files changed, 496 insertions, 0 deletions
diff --git a/tools/perf/jvmti/jvmti_agent.c b/tools/perf/jvmti/jvmti_agent.c
new file mode 100644
index 000000000..526dcaf9f
--- /dev/null
+++ b/tools/perf/jvmti/jvmti_agent.c
@@ -0,0 +1,496 @@
+/*
+ * jvmti_agent.c: JVMTI agent interface
+ *
+ * Adapted from the Oprofile code in opagent.c:
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ * Copyright 2007 OProfile authors
+ * Jens Wilke
+ * Daniel Hansel
+ * Copyright IBM Corporation 2007
+ */
+#include <sys/types.h>
+#include <sys/stat.h> /* for mkdir() */
+#include <stdio.h>
+#include <errno.h>
+#include <string.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <limits.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <time.h>
+#include <sys/mman.h>
+#include <syscall.h> /* for gettid() */
+#include <err.h>
+#include <linux/kernel.h>
+
+#include "jvmti_agent.h"
+#include "../util/jitdump.h"
+
+#define JIT_LANG "java"
+
+static char jit_path[PATH_MAX];
+static void *marker_addr;
+
+#ifndef HAVE_GETTID
+static inline pid_t gettid(void)
+{
+	return (pid_t)syscall(__NR_gettid);
+}
+#endif
+
+static int get_e_machine(struct jitheader *hdr)
+{
+	ssize_t sret;
+	char id[16];
+	int fd, ret = -1;
+	struct {
+		uint16_t e_type;
+		uint16_t e_machine;
+	} info;
+
+	fd = open("/proc/self/exe", O_RDONLY);
+	if (fd == -1)
+		return -1;
+
+	sret = read(fd, id, sizeof(id));
+	if (sret != sizeof(id))
+		goto error;
+
+	/* check ELF signature */
+	if (id[0] != 0x7f || id[1] != 'E' || id[2] != 'L' || id[3] != 'F')
+		goto error;
+
+	sret = read(fd, &info, sizeof(info));
+	if (sret != sizeof(info))
+		goto error;
+
+	hdr->elf_mach = info.e_machine;
+	ret = 0;
+error:
+	close(fd);
+	return ret;
+}
+
+static int use_arch_timestamp;
+
+static inline uint64_t
+get_arch_timestamp(void)
+{
+#if defined(__i386__) || defined(__x86_64__)
+	unsigned int low, high;
+
+	asm volatile("rdtsc" : "=a" (low), "=d" (high));
+
+	return low | ((uint64_t)high) << 32;
+#else
+	return 0;
+#endif
+}
+
+#define NSEC_PER_SEC	1000000000
+static int perf_clk_id = CLOCK_MONOTONIC;
+
+static inline uint64_t
+timespec_to_ns(const struct timespec *ts)
+{
+        return ((uint64_t) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
+}
+
+static inline uint64_t
+perf_get_timestamp(void)
+{
+	struct timespec ts;
+	int ret;
+
+	if (use_arch_timestamp)
+		return get_arch_timestamp();
+
+	ret = clock_gettime(perf_clk_id, &ts);
+	if (ret)
+		return 0;
+
+	return timespec_to_ns(&ts);
+}
+
+static int
+create_jit_cache_dir(void)
+{
+	char str[32];
+	char *base, *p;
+	struct tm tm;
+	time_t t;
+	int ret;
+
+	time(&t);
+	localtime_r(&t, &tm);
+
+	base = getenv("JITDUMPDIR");
+	if (!base)
+		base = getenv("HOME");
+	if (!base)
+		base = ".";
+
+	strftime(str, sizeof(str), JIT_LANG"-jit-%Y%m%d", &tm);
+
+	ret = snprintf(jit_path, PATH_MAX, "%s/.debug/", base);
+	if (ret >= PATH_MAX) {
+		warnx("jvmti: cannot generate jit cache dir because %s/.debug/"
+			" is too long, please check the cwd, JITDUMPDIR, and"
+			" HOME variables", base);
+		return -1;
+	}
+	ret = mkdir(jit_path, 0755);
+	if (ret == -1) {
+		if (errno != EEXIST) {
+			warn("jvmti: cannot create jit cache dir %s", jit_path);
+			return -1;
+		}
+	}
+
+	ret = snprintf(jit_path, PATH_MAX, "%s/.debug/jit", base);
+	if (ret >= PATH_MAX) {
+		warnx("jvmti: cannot generate jit cache dir because"
+			" %s/.debug/jit is too long, please check the cwd,"
+			" JITDUMPDIR, and HOME variables", base);
+		return -1;
+	}
+	ret = mkdir(jit_path, 0755);
+	if (ret == -1) {
+		if (errno != EEXIST) {
+			warn("jvmti: cannot create jit cache dir %s", jit_path);
+			return -1;
+		}
+	}
+
+	ret = snprintf(jit_path, PATH_MAX, "%s/.debug/jit/%s.XXXXXXXX", base, str);
+	if (ret >= PATH_MAX) {
+		warnx("jvmti: cannot generate jit cache dir because"
+			" %s/.debug/jit/%s.XXXXXXXX is too long, please check"
+			" the cwd, JITDUMPDIR, and HOME variables",
+			base, str);
+		return -1;
+	}
+	p = mkdtemp(jit_path);
+	if (p != jit_path) {
+		warn("jvmti: cannot create jit cache dir %s", jit_path);
+		return -1;
+	}
+
+	return 0;
+}
+
+static int
+perf_open_marker_file(int fd)
+{
+	long pgsz;
+
+	pgsz = sysconf(_SC_PAGESIZE);
+	if (pgsz == -1)
+		return -1;
+
+	/*
+	 * we mmap the jitdump to create an MMAP RECORD in perf.data file.
+	 * The mmap is captured either live (perf record running when we mmap)
+	 * or  in deferred mode, via /proc/PID/maps
+	 * the MMAP record is used as a marker of a jitdump file for more meta
+	 * data info about the jitted code. Perf report/annotate detect this
+	 * special filename and process the jitdump file.
+	 *
+	 * mapping must be PROT_EXEC to ensure it is captured by perf record
+	 * even when not using -d option
+	 */
+	marker_addr = mmap(NULL, pgsz, PROT_READ|PROT_EXEC, MAP_PRIVATE, fd, 0);
+	return (marker_addr == MAP_FAILED) ? -1 : 0;
+}
+
+static void
+perf_close_marker_file(void)
+{
+	long pgsz;
+
+	if (!marker_addr)
+		return;
+
+	pgsz = sysconf(_SC_PAGESIZE);
+	if (pgsz == -1)
+		return;
+
+	munmap(marker_addr, pgsz);
+}
+
+static void
+init_arch_timestamp(void)
+{
+	char *str = getenv("JITDUMP_USE_ARCH_TIMESTAMP");
+
+	if (!str || !*str || !strcmp(str, "0"))
+		return;
+
+	use_arch_timestamp = 1;
+}
+
+void *jvmti_open(void)
+{
+	char dump_path[PATH_MAX];
+	struct jitheader header;
+	int fd, ret;
+	FILE *fp;
+
+	init_arch_timestamp();
+
+	/*
+	 * check if clockid is supported
+	 */
+	if (!perf_get_timestamp()) {
+		if (use_arch_timestamp)
+			warnx("jvmti: arch timestamp not supported");
+		else
+			warnx("jvmti: kernel does not support %d clock id", perf_clk_id);
+	}
+
+	memset(&header, 0, sizeof(header));
+
+	/*
+	 * jitdump file dir
+	 */
+	if (create_jit_cache_dir() < 0)
+		return NULL;
+
+	/*
+	 * jitdump file name
+	 */
+	ret = snprintf(dump_path, PATH_MAX, "%s/jit-%i.dump", jit_path, getpid());
+	if (ret >= PATH_MAX) {
+		warnx("jvmti: cannot generate jitdump file full path because"
+			" %s/jit-%i.dump is too long, please check the cwd,"
+			" JITDUMPDIR, and HOME variables", jit_path, getpid());
+		return NULL;
+	}
+
+	fd = open(dump_path, O_CREAT|O_TRUNC|O_RDWR, 0666);
+	if (fd == -1)
+		return NULL;
+
+	/*
+	 * create perf.data maker for the jitdump file
+	 */
+	if (perf_open_marker_file(fd)) {
+		warnx("jvmti: failed to create marker file");
+		return NULL;
+	}
+
+	fp = fdopen(fd, "w+");
+	if (!fp) {
+		warn("jvmti: cannot create %s", dump_path);
+		close(fd);
+		goto error;
+	}
+
+	warnx("jvmti: jitdump in %s", dump_path);
+
+	if (get_e_machine(&header)) {
+		warn("get_e_machine failed\n");
+		goto error;
+	}
+
+	header.magic      = JITHEADER_MAGIC;
+	header.version    = JITHEADER_VERSION;
+	header.total_size = sizeof(header);
+	header.pid        = getpid();
+
+	header.timestamp = perf_get_timestamp();
+
+	if (use_arch_timestamp)
+		header.flags |= JITDUMP_FLAGS_ARCH_TIMESTAMP;
+
+	if (!fwrite(&header, sizeof(header), 1, fp)) {
+		warn("jvmti: cannot write dumpfile header");
+		goto error;
+	}
+	return fp;
+error:
+	fclose(fp);
+	return NULL;
+}
+
+int
+jvmti_close(void *agent)
+{
+	struct jr_code_close rec;
+	FILE *fp = agent;
+
+	if (!fp) {
+		warnx("jvmti: invalid fd in close_agent");
+		return -1;
+	}
+
+	rec.p.id = JIT_CODE_CLOSE;
+	rec.p.total_size = sizeof(rec);
+
+	rec.p.timestamp = perf_get_timestamp();
+
+	if (!fwrite(&rec, sizeof(rec), 1, fp))
+		return -1;
+
+	fclose(fp);
+
+	fp = NULL;
+
+	perf_close_marker_file();
+
+	return 0;
+}
+
+int
+jvmti_write_code(void *agent, char const *sym,
+	uint64_t vma, void const *code, unsigned int const size)
+{
+	static int code_generation = 1;
+	struct jr_code_load rec;
+	size_t sym_len;
+	FILE *fp = agent;
+	int ret = -1;
+
+	/* don't care about 0 length function, no samples */
+	if (size == 0)
+		return 0;
+
+	if (!fp) {
+		warnx("jvmti: invalid fd in write_native_code");
+		return -1;
+	}
+
+	sym_len = strlen(sym) + 1;
+
+	rec.p.id           = JIT_CODE_LOAD;
+	rec.p.total_size   = sizeof(rec) + sym_len;
+	rec.p.timestamp    = perf_get_timestamp();
+
+	rec.code_size  = size;
+	rec.vma        = vma;
+	rec.code_addr  = vma;
+	rec.pid	       = getpid();
+	rec.tid	       = gettid();
+
+	if (code)
+		rec.p.total_size += size;
+
+	/*
+	 * If JVM is multi-threaded, multiple concurrent calls to agent
+	 * may be possible, so protect file writes
+	 */
+	flockfile(fp);
+
+	/*
+	 * get code index inside lock to avoid race condition
+	 */
+	rec.code_index = code_generation++;
+
+	ret = fwrite_unlocked(&rec, sizeof(rec), 1, fp);
+	fwrite_unlocked(sym, sym_len, 1, fp);
+
+	if (code)
+		fwrite_unlocked(code, size, 1, fp);
+
+	funlockfile(fp);
+
+	ret = 0;
+
+	return ret;
+}
+
+int
+jvmti_write_debug_info(void *agent, uint64_t code,
+    int nr_lines, jvmti_line_info_t *li,
+    const char * const * file_names)
+{
+	struct jr_code_debug_info rec;
+	size_t sret, len, size, flen = 0;
+	uint64_t addr;
+	FILE *fp = agent;
+	int i;
+
+	/*
+	 * no entry to write
+	 */
+	if (!nr_lines)
+		return 0;
+
+	if (!fp) {
+		warnx("jvmti: invalid fd in write_debug_info");
+		return -1;
+	}
+
+	for (i = 0; i < nr_lines; ++i) {
+	    flen += strlen(file_names[i]) + 1;
+	}
+
+	rec.p.id        = JIT_CODE_DEBUG_INFO;
+	size            = sizeof(rec);
+	rec.p.timestamp = perf_get_timestamp();
+	rec.code_addr   = (uint64_t)(uintptr_t)code;
+	rec.nr_entry    = nr_lines;
+
+	/*
+	 * on disk source line info layout:
+	 * uint64_t : addr
+	 * int      : line number
+	 * int      : column discriminator
+	 * file[]   : source file name
+	 */
+	size += nr_lines * sizeof(struct debug_entry);
+	size += flen;
+	rec.p.total_size = size;
+
+	/*
+	 * If JVM is multi-threaded, multiple concurrent calls to agent
+	 * may be possible, so protect file writes
+	 */
+	flockfile(fp);
+
+	sret = fwrite_unlocked(&rec, sizeof(rec), 1, fp);
+	if (sret != 1)
+		goto error;
+
+	for (i = 0; i < nr_lines; i++) {
+
+		addr = (uint64_t)li[i].pc;
+		len  = sizeof(addr);
+		sret = fwrite_unlocked(&addr, len, 1, fp);
+		if (sret != 1)
+			goto error;
+
+		len  = sizeof(li[0].line_number);
+		sret = fwrite_unlocked(&li[i].line_number, len, 1, fp);
+		if (sret != 1)
+			goto error;
+
+		len  = sizeof(li[0].discrim);
+		sret = fwrite_unlocked(&li[i].discrim, len, 1, fp);
+		if (sret != 1)
+			goto error;
+
+		sret = fwrite_unlocked(file_names[i], strlen(file_names[i]) + 1, 1, fp);
+		if (sret != 1)
+			goto error;
+	}
+	funlockfile(fp);
+	return 0;
+error:
+	funlockfile(fp);
+	return -1;
+}