/*
* builtin-probe.c
*
* Builtin probe command: Set up probe events by C expression
*
* Written by Masami Hiramatsu <mhiramat@redhat.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
*/
#define _GNU_SOURCE
#include <sys/utsname.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#undef _GNU_SOURCE
#include "perf.h"
#include "builtin.h"
#include "util/util.h"
#include "util/strlist.h"
#include "util/event.h"
#include "util/debug.h"
#include "util/debugfs.h"
#include "util/symbol.h"
#include "util/thread.h"
#include "util/session.h"
#include "util/parse-options.h"
#include "util/parse-events.h" /* For debugfs_path */
#include "util/probe-finder.h"
#include "util/probe-event.h"
#define MAX_PATH_LEN 256
#define MAX_PROBES 128
/* Session management structure */
static struct {
bool need_dwarf;
bool list_events;
bool force_add;
int nr_probe;
struct probe_point probes[MAX_PROBES];
struct strlist *dellist;
struct perf_session *psession;
struct map *kmap;
} session;
/* Parse an event definition. Note that any error must die. */
static void parse_probe_event(const char *str)
{
struct probe_point *pp = &session.probes[session.nr_probe];
pr_debug("probe-definition(%d): %s\n", session.nr_probe, str);
if (++session.nr_probe == MAX_PROBES)
die("Too many probes (> %d) are specified.", MAX_PROBES);
/* Parse perf-probe event into probe_point */
parse_perf_probe_event(str, pp, &session.need_dwarf);
pr_debug("%d arguments\n", pp->nr_args);
}
static void parse_probe_event_argv(int argc, const char **argv)
{
int i, len;
char *buf;
/* Bind up rest arguments */
len = 0;
for (i = 0; i < argc; i++)
len += strlen(argv[i]) + 1;
buf = zalloc(len + 1);
if (!buf)
die("Failed to allocate memory for binding arguments.");
len = 0;
for (i = 0; i < argc; i++)
len += sprintf(&buf[len], "%s ", argv[i]);
parse_probe_event(buf);
free(buf);
}
static int opt_add_probe_event(const struct option *opt __used,
const char *str, int unset __used)
{
if (str)
parse_probe_event(str);
return 0;
}
static int opt_del_probe_event(const struct option *opt __used,
const char *str, int unset __used)
{
if (str) {
if (!session.dellist)
session.dellist = strlist__new(true, NULL);
strlist__add(session.dellist, str);
}
return 0;
}
/* Currently just checking function name from symbol map */
static void evaluate_probe_point(struct probe_point *pp)
{
struct symbol *sym;
sym = map__find_symbol_by_name(session.kmap, pp->function,
session.psession, NULL);
if (!sym)
die("Kernel symbol \'%s\' not found - probe not added.",
pp->function);
}
#ifndef NO_LIBDWARF
static int open_vmlinux(void)
{
if (map__load(session.kmap, session.psession, NULL) < 0) {
pr_debug("Failed to load kernel map.\n");
return -EINVAL;
}
pr_debug("Try to open %s\n", session.kmap->dso->long_name);
return open(session.kmap->dso->long_name, O_RDONLY);
}
#endif
static const char * const probe_usage[] = {
"perf probe [<options>] 'PROBEDEF' ['PROBEDEF' ...]",
"perf probe [<options>] --add 'PROBEDEF' [--add 'PROBEDEF' ...]",
"perf probe [<options>] --del '[GROUP:]EVENT' ...",
"perf probe --list",
NULL
};
static const struct option options[] = {
OPT_BOOLEAN('v', "verbose", &verbose,
"be more verbose (show parsed arguments, etc)"),
#ifndef NO_LIBDWARF
OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name,
"file", "vmlinux pathname"),
#endif
OPT_BOOLEAN('l', "list", &session.list_events,
"list up current probe events"),
OPT_CALLBACK('d', "del", NULL, "[GROUP:]EVENT", "delete a probe event.",
opt_del_probe_event),
OPT_CALLBACK('a', "add", NULL,
#ifdef NO_LIBDWARF
"[EVENT=]FUNC[+OFFS|%return] [ARG ...]",
#else
"[EVENT=]FUNC[+OFFS|%return|:RLN][@SRC]|SRC:ALN [ARG ...]",
#endif
"probe point definition, where\n"
"\t\tGROUP:\tGroup name (optional)\n"
"\t\tEVENT:\tEvent name\n"
"\t\tFUNC:\tFunction name\n"
"\t\tOFFS:\tOffset from function entry (in byte)\n"
"\t\t%return:\tPut the probe at function return\n"
#ifdef NO_LIBDWARF
"\t\tARG:\tProbe argument (only \n"
#else
"\t\tSRC:\tSource code path\n"
"\t\tRLN:\tRelative line number from function entry.\n"
"\t\tALN:\tAbsolute line number in file.\n"
"\t\tARG:\tProbe argument (local variable name or\n"
#endif
"\t\t\tkprobe-tracer argument format.)\n",
opt_add_probe_event),
OPT_BOOLEAN('f', "force", &session.force_add, "forcibly add events"
" with existing name"),
OPT_END()
};
int cmd_probe(int argc, const char **argv, const char *prefix __used)
{
int i, ret;
#ifndef NO_LIBDWARF
int fd;
#endif
struct probe_point *pp;
argc = parse_options(argc, argv, options, probe_usage,
PARSE_OPT_STOP_AT_NON_OPTION);
if (argc > 0) {
if (strcmp(argv[0], "-") == 0) {
pr_warning(" Error: '-' is not supported.\n");
usage_with_options(probe_usage, options);
}
parse_probe_event_argv(argc, argv);
}
if ((!session.nr_probe && !session.dellist && !session.list_events))
usage_with_options(probe_usage, options);
if (debugfs_valid_mountpoint(debugfs_path) < 0)
die("Failed to find debugfs path.");
if (session.list_events) {
if (session.nr_probe != 0 || session.dellist) {
pr_warning(" Error: Don't use --list with"
" --add/--del.\n");
usage_with_options(probe_usage, options);
}
show_perf_probe_events();
return 0;
}
if (session.dellist) {
del_trace_kprobe_events(session.dellist);
strlist__delete(session.dellist);
if (session.nr_probe == 0)
return 0;
}
/* Initialize symbol maps for vmlinux */
symbol_conf.sort_by_name = true;
if (symbol_conf.vmlinux_name == NULL)
symbol_conf.try_vmlinux_path = true;
if (symbol__init() < 0)
die("Failed to init symbol map.");
session.psession = perf_session__new(NULL, O_WRONLY, false);
if (session.psession == NULL)
die("Failed to init perf_session.");
session.kmap = map_groups__find_by_name(&session.psession->kmaps,
MAP__FUNCTION,
"[kernel.kallsyms]");
if (!session.kmap)
die("Could not find kernel map.\n");
if (session.need_dwarf)
#ifdef NO_LIBDWARF
die("Debuginfo-analysis is not supported");
#else /* !NO_LIBDWARF */
pr_debug("Some probes require debuginfo.\n");
fd = open_vmlinux();
if (fd < 0) {
if (session.need_dwarf)
die("Could not open debuginfo file.");
pr_debug("Could not open vmlinux/module file."
" Try to use symbols.\n");
goto end_dwarf;
}
/* Searching probe points */
for (i = 0; i < session.nr_probe; i++) {
pp = &session.probes[i];
if (pp->found)
continue;
lseek(fd, SEEK_SET, 0);
ret = find_probepoint(fd, pp);
if (ret > 0)
continue;
if (ret == 0) { /* No error but failed to find probe point. */
synthesize_perf_probe_point(pp);
die("Probe point '%s' not found. - probe not added.",
pp->probes[0]);
}
/* Error path */
if (session.need_dwarf) {
if (ret == -ENOENT)
pr_warning("No dwarf info found in the vmlinux - please rebuild with CONFIG_DEBUG_INFO=y.\n");
die("Could not analyze debuginfo.");
}
pr_debug("An error occurred in debuginfo analysis."
" Try to use symbols.\n");
break;
}
close(fd);
end_dwarf:
#endif /* !NO_LIBDWARF */
/* Synthesize probes without dwarf */
for (i = 0; i < session.nr_probe; i++) {
pp = &session.probes[i];
if (pp->found) /* This probe is already found. */
continue;
evaluate_probe_point(pp);
ret = synthesize_trace_kprobe_event(pp);
if (ret == -E2BIG)
die("probe point definition becomes too long.");
else if (ret < 0)
die("Failed to synthesize a probe point.");
}
/* Settng up probe points */
add_trace_kprobe_events(session.probes, session.nr_probe,
session.force_add);
return 0;
}
