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Diffstat (limited to '')
| -rw-r--r-- | tools/perf/jvmti/jvmti_agent.c | 496 |
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..88108598d --- /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, nultiple 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, nultiple 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; +} |