swh:1:snp:c3bf2749e3476071fa748f67b0ffa2fdc5fe49d9
Tip revision: 97bf6af1f928216fd6c5a66e8a57bfa95a659672 authored by Linus Torvalds on 21 December 2014, 01:08:50 UTC
Linux 3.19-rc1
Linux 3.19-rc1
Tip revision: 97bf6af
builtin-probe.c
/*
* 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.
*
*/
#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>
#include "perf.h"
#include "builtin.h"
#include "util/util.h"
#include "util/strlist.h"
#include "util/strfilter.h"
#include "util/symbol.h"
#include "util/debug.h"
#include <api/fs/debugfs.h>
#include "util/parse-options.h"
#include "util/probe-finder.h"
#include "util/probe-event.h"
#define DEFAULT_VAR_FILTER "!__k???tab_* & !__crc_*"
#define DEFAULT_FUNC_FILTER "!_*"
/* Session management structure */
static struct {
bool list_events;
bool force_add;
bool show_lines;
bool show_vars;
bool show_ext_vars;
bool show_funcs;
bool mod_events;
bool uprobes;
bool quiet;
int nevents;
struct perf_probe_event events[MAX_PROBES];
struct strlist *dellist;
struct line_range line_range;
char *target;
int max_probe_points;
struct strfilter *filter;
} params;
/* Parse an event definition. Note that any error must die. */
static int parse_probe_event(const char *str)
{
struct perf_probe_event *pev = ¶ms.events[params.nevents];
int ret;
pr_debug("probe-definition(%d): %s\n", params.nevents, str);
if (++params.nevents == MAX_PROBES) {
pr_err("Too many probes (> %d) were specified.", MAX_PROBES);
return -1;
}
pev->uprobes = params.uprobes;
/* Parse a perf-probe command into event */
ret = parse_perf_probe_command(str, pev);
pr_debug("%d arguments\n", pev->nargs);
return ret;
}
static int set_target(const char *ptr)
{
int found = 0;
const char *buf;
/*
* The first argument after options can be an absolute path
* to an executable / library or kernel module.
*
* TODO: Support relative path, and $PATH, $LD_LIBRARY_PATH,
* short module name.
*/
if (!params.target && ptr && *ptr == '/') {
params.target = strdup(ptr);
if (!params.target)
return -ENOMEM;
found = 1;
buf = ptr + (strlen(ptr) - 3);
if (strcmp(buf, ".ko"))
params.uprobes = true;
}
return found;
}
static int parse_probe_event_argv(int argc, const char **argv)
{
int i, len, ret, found_target;
char *buf;
found_target = set_target(argv[0]);
if (found_target < 0)
return found_target;
if (found_target && argc == 1)
return 0;
/* Bind up rest arguments */
len = 0;
for (i = 0; i < argc; i++) {
if (i == 0 && found_target)
continue;
len += strlen(argv[i]) + 1;
}
buf = zalloc(len + 1);
if (buf == NULL)
return -ENOMEM;
len = 0;
for (i = 0; i < argc; i++) {
if (i == 0 && found_target)
continue;
len += sprintf(&buf[len], "%s ", argv[i]);
}
params.mod_events = true;
ret = parse_probe_event(buf);
free(buf);
return ret;
}
static int opt_add_probe_event(const struct option *opt __maybe_unused,
const char *str, int unset __maybe_unused)
{
if (str) {
params.mod_events = true;
return parse_probe_event(str);
} else
return 0;
}
static int opt_del_probe_event(const struct option *opt __maybe_unused,
const char *str, int unset __maybe_unused)
{
if (str) {
params.mod_events = true;
if (!params.dellist)
params.dellist = strlist__new(true, NULL);
strlist__add(params.dellist, str);
}
return 0;
}
static int opt_set_target(const struct option *opt, const char *str,
int unset __maybe_unused)
{
int ret = -ENOENT;
char *tmp;
if (str && !params.target) {
if (!strcmp(opt->long_name, "exec"))
params.uprobes = true;
#ifdef HAVE_DWARF_SUPPORT
else if (!strcmp(opt->long_name, "module"))
params.uprobes = false;
#endif
else
return ret;
/* Expand given path to absolute path, except for modulename */
if (params.uprobes || strchr(str, '/')) {
tmp = realpath(str, NULL);
if (!tmp) {
pr_warning("Failed to get the absolute path of %s: %m\n", str);
return ret;
}
} else {
tmp = strdup(str);
if (!tmp)
return -ENOMEM;
}
params.target = tmp;
ret = 0;
}
return ret;
}
#ifdef HAVE_DWARF_SUPPORT
static int opt_show_lines(const struct option *opt __maybe_unused,
const char *str, int unset __maybe_unused)
{
int ret = 0;
if (!str)
return 0;
if (params.show_lines) {
pr_warning("Warning: more than one --line options are"
" detected. Only the first one is valid.\n");
return 0;
}
params.show_lines = true;
ret = parse_line_range_desc(str, ¶ms.line_range);
return ret;
}
static int opt_show_vars(const struct option *opt __maybe_unused,
const char *str, int unset __maybe_unused)
{
struct perf_probe_event *pev = ¶ms.events[params.nevents];
int ret;
if (!str)
return 0;
ret = parse_probe_event(str);
if (!ret && pev->nargs != 0) {
pr_err(" Error: '--vars' doesn't accept arguments.\n");
return -EINVAL;
}
params.show_vars = true;
return ret;
}
#endif
static int opt_set_filter(const struct option *opt __maybe_unused,
const char *str, int unset __maybe_unused)
{
const char *err;
if (str) {
pr_debug2("Set filter: %s\n", str);
if (params.filter)
strfilter__delete(params.filter);
params.filter = strfilter__new(str, &err);
if (!params.filter) {
pr_err("Filter parse error at %td.\n", err - str + 1);
pr_err("Source: \"%s\"\n", str);
pr_err(" %*c\n", (int)(err - str + 1), '^');
return -EINVAL;
}
}
return 0;
}
static int init_params(void)
{
return line_range__init(¶ms.line_range);
}
static void cleanup_params(void)
{
int i;
for (i = 0; i < params.nevents; i++)
clear_perf_probe_event(params.events + i);
if (params.dellist)
strlist__delete(params.dellist);
line_range__clear(¶ms.line_range);
free(params.target);
if (params.filter)
strfilter__delete(params.filter);
memset(¶ms, 0, sizeof(params));
}
static void pr_err_with_code(const char *msg, int err)
{
char sbuf[STRERR_BUFSIZE];
pr_err("%s", msg);
pr_debug(" Reason: %s (Code: %d)",
strerror_r(-err, sbuf, sizeof(sbuf)), err);
pr_err("\n");
}
static int
__cmd_probe(int argc, const char **argv, const char *prefix __maybe_unused)
{
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",
#ifdef HAVE_DWARF_SUPPORT
"perf probe [<options>] --line 'LINEDESC'",
"perf probe [<options>] --vars 'PROBEPOINT'",
#endif
NULL
};
struct option options[] = {
OPT_INCR('v', "verbose", &verbose,
"be more verbose (show parsed arguments, etc)"),
OPT_BOOLEAN('q', "quiet", ¶ms.quiet,
"be quiet (do not show any mesages)"),
OPT_BOOLEAN('l', "list", ¶ms.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 HAVE_DWARF_SUPPORT
"[EVENT=]FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT"
" [[NAME=]ARG ...]",
#else
"[EVENT=]FUNC[+OFF|%return] [[NAME=]ARG ...]",
#endif
"probe point definition, where\n"
"\t\tGROUP:\tGroup name (optional)\n"
"\t\tEVENT:\tEvent name\n"
"\t\tFUNC:\tFunction name\n"
"\t\tOFF:\tOffset from function entry (in byte)\n"
"\t\t%return:\tPut the probe at function return\n"
#ifdef HAVE_DWARF_SUPPORT
"\t\tSRC:\tSource code path\n"
"\t\tRL:\tRelative line number from function entry.\n"
"\t\tAL:\tAbsolute line number in file.\n"
"\t\tPT:\tLazy expression of line code.\n"
"\t\tARG:\tProbe argument (local variable name or\n"
"\t\t\tkprobe-tracer argument format.)\n",
#else
"\t\tARG:\tProbe argument (kprobe-tracer argument format.)\n",
#endif
opt_add_probe_event),
OPT_BOOLEAN('f', "force", ¶ms.force_add, "forcibly add events"
" with existing name"),
#ifdef HAVE_DWARF_SUPPORT
OPT_CALLBACK('L', "line", NULL,
"FUNC[:RLN[+NUM|-RLN2]]|SRC:ALN[+NUM|-ALN2]",
"Show source code lines.", opt_show_lines),
OPT_CALLBACK('V', "vars", NULL,
"FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT",
"Show accessible variables on PROBEDEF", opt_show_vars),
OPT_BOOLEAN('\0', "externs", ¶ms.show_ext_vars,
"Show external variables too (with --vars only)"),
OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name,
"file", "vmlinux pathname"),
OPT_STRING('s', "source", &symbol_conf.source_prefix,
"directory", "path to kernel source"),
OPT_CALLBACK('m', "module", NULL, "modname|path",
"target module name (for online) or path (for offline)",
opt_set_target),
#endif
OPT__DRY_RUN(&probe_event_dry_run),
OPT_INTEGER('\0', "max-probes", ¶ms.max_probe_points,
"Set how many probe points can be found for a probe."),
OPT_BOOLEAN('F', "funcs", ¶ms.show_funcs,
"Show potential probe-able functions."),
OPT_CALLBACK('\0', "filter", NULL,
"[!]FILTER", "Set a filter (with --vars/funcs only)\n"
"\t\t\t(default: \"" DEFAULT_VAR_FILTER "\" for --vars,\n"
"\t\t\t \"" DEFAULT_FUNC_FILTER "\" for --funcs)",
opt_set_filter),
OPT_CALLBACK('x', "exec", NULL, "executable|path",
"target executable name or path", opt_set_target),
OPT_BOOLEAN(0, "demangle", &symbol_conf.demangle,
"Enable symbol demangling"),
OPT_BOOLEAN(0, "demangle-kernel", &symbol_conf.demangle_kernel,
"Enable kernel symbol demangling"),
OPT_END()
};
int ret;
set_option_flag(options, 'a', "add", PARSE_OPT_EXCLUSIVE);
set_option_flag(options, 'd', "del", PARSE_OPT_EXCLUSIVE);
set_option_flag(options, 'l', "list", PARSE_OPT_EXCLUSIVE);
#ifdef HAVE_DWARF_SUPPORT
set_option_flag(options, 'L', "line", PARSE_OPT_EXCLUSIVE);
set_option_flag(options, 'V', "vars", PARSE_OPT_EXCLUSIVE);
#endif
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);
}
ret = parse_probe_event_argv(argc, argv);
if (ret < 0) {
pr_err_with_code(" Error: Command Parse Error.", ret);
return ret;
}
}
if (params.quiet) {
if (verbose != 0) {
pr_err(" Error: -v and -q are exclusive.\n");
return -EINVAL;
}
verbose = -1;
}
if (params.max_probe_points == 0)
params.max_probe_points = MAX_PROBES;
if ((!params.nevents && !params.dellist && !params.list_events &&
!params.show_lines && !params.show_funcs))
usage_with_options(probe_usage, options);
/*
* Only consider the user's kernel image path if given.
*/
symbol_conf.try_vmlinux_path = (symbol_conf.vmlinux_name == NULL);
if (params.list_events) {
if (params.uprobes) {
pr_warning(" Error: Don't use --list with --exec.\n");
usage_with_options(probe_usage, options);
}
ret = show_perf_probe_events();
if (ret < 0)
pr_err_with_code(" Error: Failed to show event list.", ret);
return ret;
}
if (params.show_funcs) {
if (!params.filter)
params.filter = strfilter__new(DEFAULT_FUNC_FILTER,
NULL);
ret = show_available_funcs(params.target, params.filter,
params.uprobes);
strfilter__delete(params.filter);
params.filter = NULL;
if (ret < 0)
pr_err_with_code(" Error: Failed to show functions.", ret);
return ret;
}
#ifdef HAVE_DWARF_SUPPORT
if (params.show_lines) {
ret = show_line_range(¶ms.line_range, params.target,
params.uprobes);
if (ret < 0)
pr_err_with_code(" Error: Failed to show lines.", ret);
return ret;
}
if (params.show_vars) {
if (!params.filter)
params.filter = strfilter__new(DEFAULT_VAR_FILTER,
NULL);
ret = show_available_vars(params.events, params.nevents,
params.max_probe_points,
params.target,
params.filter,
params.show_ext_vars);
strfilter__delete(params.filter);
params.filter = NULL;
if (ret < 0)
pr_err_with_code(" Error: Failed to show vars.", ret);
return ret;
}
#endif
if (params.dellist) {
ret = del_perf_probe_events(params.dellist);
if (ret < 0) {
pr_err_with_code(" Error: Failed to delete events.", ret);
return ret;
}
}
if (params.nevents) {
ret = add_perf_probe_events(params.events, params.nevents,
params.max_probe_points,
params.target,
params.force_add);
if (ret < 0) {
pr_err_with_code(" Error: Failed to add events.", ret);
return ret;
}
}
return 0;
}
int cmd_probe(int argc, const char **argv, const char *prefix)
{
int ret;
ret = init_params();
if (!ret) {
ret = __cmd_probe(argc, argv, prefix);
cleanup_params();
}
return ret;
}