linux/tools/perf/jvmti/jvmti_agent.c
Ben Gainey ca58d7e64b perf jvmti: Generate correct debug information for inlined code
tools/perf/jvmti is broken in so far as it generates incorrect debug
information. Specifically it attributes all debug lines to the original
method being output even in the case that some code is being inlined
from elsewhere.  This patch fixes the issue.

To test (from within linux/tools/perf):

export JDIR=/usr/lib/jvm/java-8-openjdk-amd64/
make
cat << __EOF > Test.java
public class Test
{
    private StringBuilder b = new StringBuilder();

    private void loop(int i, String... args)
    {
        for (String a : args)
            b.append(a);

        long hc = b.hashCode() * System.nanoTime();

        b = new StringBuilder();
        b.append(hc);

        System.out.printf("Iteration %d = %d\n", i, hc);
    }

    public void run(String... args)
    {
        for (int i = 0; i < 10000; ++i)
        {
            loop(i, args);
        }
    }

    public static void main(String... args)
    {
        Test t = new Test();
        t.run(args);
    }
}
__EOF
$JDIR/bin/javac Test.java
./perf record -F 10000 -g -k mono $JDIR/bin/java -agentpath:`pwd`/libperf-jvmti.so Test
./perf inject --jit -i perf.data -o perf.data.jitted
./perf annotate -i perf.data.jitted --stdio | grep Test\.java: | sort -u

Before this patch, Test.java line numbers get reported that are greater
than the number of lines in the Test.java file.  They come from the
source file of the inlined function, e.g. java/lang/String.java:1085.
For further validation one can examine those lines in the JDK source
distribution and confirm that they map to inlined functions called by
Test.java.

After this patch, the filename of the inlined function is output
rather than the incorrect original source filename.

Signed-off-by: Ben Gainey <ben.gainey@arm.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Tested-by: Stephane Eranian <eranian@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ben Gainey <ben.gainey@arm.com>
Cc: Colin King <colin.king@canonical.com>
Cc: Darren Hart <dvhart@infradead.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 598b7c6919 ("perf jit: add source line info support")
Link: http://lkml.kernel.org/r/20171122182541.d25599a3eb1ada3480d142fa@arm.com
Signed-off-by: Kim Phillips <kim.phillips@arm.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-12-18 11:54:08 -03:00

467 lines
9.2 KiB
C

/*
* 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 "jvmti_agent.h"
#include "../util/jitdump.h"
#define JIT_LANG "java"
static char jit_path[PATH_MAX];
static void *marker_addr;
static inline pid_t gettid(void)
{
return (pid_t)syscall(__NR_gettid);
}
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
debug_cache_init(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);
snprintf(jit_path, PATH_MAX - 1, "%s/.debug/", base);
ret = mkdir(jit_path, 0755);
if (ret == -1) {
if (errno != EEXIST) {
warn("jvmti: cannot create jit cache dir %s", jit_path);
return -1;
}
}
snprintf(jit_path, PATH_MAX - 1, "%s/.debug/jit", base);
ret = mkdir(jit_path, 0755);
if (ret == -1) {
if (errno != EEXIST) {
warn("cannot create jit cache dir %s", jit_path);
return -1;
}
}
snprintf(jit_path, PATH_MAX - 1, "%s/.debug/jit/%s.XXXXXXXX", base, str);
p = mkdtemp(jit_path);
if (p != jit_path) {
warn("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;
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));
debug_cache_init();
/*
* jitdump file name
*/
snprintf(dump_path, PATH_MAX, "%s/jit-%i.dump", jit_path, getpid());
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;
}