linux-stable/tools/perf/builtin-probe.c
Masami Hiramatsu f41ebe9def perf probe: Do not show the skipped events
When a probe point is expanded to several places (like inlined) and if
some of them are skipped because of blacklisted or __init function,
those trace_events has no event name. It must be skipped while showing
results.

Without this fix, you can see "(null):(null)" on the list,

  # ./perf probe request_resource
  reserve_setup is out of .text, skip it.
  Added new events:
    (null):(null)        (on request_resource)
    probe:request_resource (on request_resource)

  You can now use it in all perf tools, such as:

  	perf record -e probe:request_resource -aR sleep 1

  #

With this fix, it is ignored:

  # ./perf probe request_resource
  reserve_setup is out of .text, skip it.
  Added new events:
    probe:request_resource (on request_resource)

  You can now use it in all perf tools, such as:

  	perf record -e probe:request_resource -aR sleep 1

  #

Fixes: 5a51fcd1f3 ("perf probe: Skip kernel symbols which is out of .text")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: stable@vger.kernel.org
Link: http://lore.kernel.org/lkml/158763968263.30755.12800484151476026340.stgit@devnote2
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2020-05-28 10:03:24 -03:00

738 lines
18 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* builtin-probe.c
*
* Builtin probe command: Set up probe events by C expression
*
* Written by Masami Hiramatsu <mhiramat@redhat.com>
*/
#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 "builtin.h"
#include "namespaces.h"
#include "util/build-id.h"
#include "util/strlist.h"
#include "util/strfilter.h"
#include "util/symbol_conf.h"
#include "util/debug.h"
#include <subcmd/parse-options.h>
#include "util/probe-finder.h"
#include "util/probe-event.h"
#include "util/probe-file.h"
#include <linux/string.h>
#include <linux/zalloc.h>
#define DEFAULT_VAR_FILTER "!__k???tab_* & !__crc_*"
#define DEFAULT_FUNC_FILTER "!_*"
#define DEFAULT_LIST_FILTER "*"
/* Session management structure */
static struct {
int command; /* Command short_name */
bool list_events;
bool uprobes;
bool quiet;
bool target_used;
int nevents;
struct perf_probe_event events[MAX_PROBES];
struct line_range line_range;
char *target;
struct strfilter *filter;
struct nsinfo *nsi;
} params;
/* Parse an event definition. Note that any error must die. */
static int parse_probe_event(const char *str)
{
struct perf_probe_event *pev = &params.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;
if (params.target) {
pev->target = strdup(params.target);
if (!pev->target)
return -ENOMEM;
params.target_used = true;
}
pev->nsi = nsinfo__get(params.nsi);
/* 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 params_add_filter(const char *str)
{
const char *err = NULL;
int ret = 0;
pr_debug2("Add filter: %s\n", str);
if (!params.filter) {
params.filter = strfilter__new(str, &err);
if (!params.filter)
ret = err ? -EINVAL : -ENOMEM;
} else
ret = strfilter__or(params.filter, str, &err);
if (ret == -EINVAL) {
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 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;
params.target_used = false;
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]);
}
ret = parse_probe_event(buf);
free(buf);
return ret;
}
static int opt_set_target(const struct option *opt, const char *str,
int unset __maybe_unused)
{
int ret = -ENOENT;
char *tmp;
if (str) {
if (!strcmp(opt->long_name, "exec"))
params.uprobes = true;
else if (!strcmp(opt->long_name, "module"))
params.uprobes = false;
else
return ret;
/* Expand given path to absolute path, except for modulename */
if (params.uprobes || strchr(str, '/')) {
tmp = nsinfo__realpath(str, params.nsi);
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;
}
free(params.target);
params.target = tmp;
params.target_used = false;
ret = 0;
}
return ret;
}
static int opt_set_target_ns(const struct option *opt __maybe_unused,
const char *str, int unset __maybe_unused)
{
int ret = -ENOENT;
pid_t ns_pid;
struct nsinfo *nsip;
if (str) {
errno = 0;
ns_pid = (pid_t)strtol(str, NULL, 10);
if (errno != 0) {
ret = -errno;
pr_warning("Failed to parse %s as a pid: %s\n", str,
strerror(errno));
return ret;
}
nsip = nsinfo__new(ns_pid);
if (nsip && nsip->need_setns)
params.nsi = nsinfo__get(nsip);
nsinfo__put(nsip);
ret = 0;
}
return ret;
}
/* Command option callbacks */
#ifdef HAVE_DWARF_SUPPORT
static int opt_show_lines(const struct option *opt,
const char *str, int unset __maybe_unused)
{
int ret = 0;
if (!str)
return 0;
if (params.command == 'L') {
pr_warning("Warning: more than one --line options are"
" detected. Only the first one is valid.\n");
return 0;
}
params.command = opt->short_name;
ret = parse_line_range_desc(str, &params.line_range);
return ret;
}
static int opt_show_vars(const struct option *opt,
const char *str, int unset __maybe_unused)
{
struct perf_probe_event *pev = &params.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.command = opt->short_name;
return ret;
}
#else
# define opt_show_lines NULL
# define opt_show_vars NULL
#endif
static int opt_add_probe_event(const struct option *opt,
const char *str, int unset __maybe_unused)
{
if (str) {
params.command = opt->short_name;
return parse_probe_event(str);
}
return 0;
}
static int opt_set_filter_with_command(const struct option *opt,
const char *str, int unset)
{
if (!unset)
params.command = opt->short_name;
if (str)
return params_add_filter(str);
return 0;
}
static int opt_set_filter(const struct option *opt __maybe_unused,
const char *str, int unset __maybe_unused)
{
if (str)
return params_add_filter(str);
return 0;
}
static int init_params(void)
{
return line_range__init(&params.line_range);
}
static void cleanup_params(void)
{
int i;
for (i = 0; i < params.nevents; i++)
clear_perf_probe_event(params.events + i);
line_range__clear(&params.line_range);
free(params.target);
strfilter__delete(params.filter);
nsinfo__put(params.nsi);
memset(&params, 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)",
str_error_r(-err, sbuf, sizeof(sbuf)), err);
pr_err("\n");
}
static int perf_add_probe_events(struct perf_probe_event *pevs, int npevs)
{
int ret;
int i, k;
const char *event = NULL, *group = NULL;
ret = init_probe_symbol_maps(pevs->uprobes);
if (ret < 0)
return ret;
ret = convert_perf_probe_events(pevs, npevs);
if (ret < 0)
goto out_cleanup;
if (params.command == 'D') { /* it shows definition */
ret = show_probe_trace_events(pevs, npevs);
goto out_cleanup;
}
ret = apply_perf_probe_events(pevs, npevs);
if (ret < 0)
goto out_cleanup;
for (i = k = 0; i < npevs; i++)
k += pevs[i].ntevs;
pr_info("Added new event%s\n", (k > 1) ? "s:" : ":");
for (i = 0; i < npevs; i++) {
struct perf_probe_event *pev = &pevs[i];
for (k = 0; k < pev->ntevs; k++) {
struct probe_trace_event *tev = &pev->tevs[k];
/* Skipped events have no event name */
if (!tev->event)
continue;
/* We use tev's name for showing new events */
show_perf_probe_event(tev->group, tev->event, pev,
tev->point.module, false);
/* Save the last valid name */
event = tev->event;
group = tev->group;
}
}
/* Note that it is possible to skip all events because of blacklist */
if (event) {
/* Show how to use the event. */
pr_info("\nYou can now use it in all perf tools, such as:\n\n");
pr_info("\tperf record -e %s:%s -aR sleep 1\n\n", group, event);
}
out_cleanup:
cleanup_perf_probe_events(pevs, npevs);
exit_probe_symbol_maps();
return ret;
}
static int del_perf_probe_caches(struct strfilter *filter)
{
struct probe_cache *cache;
struct strlist *bidlist;
struct str_node *nd;
int ret;
bidlist = build_id_cache__list_all(false);
if (!bidlist) {
ret = -errno;
pr_debug("Failed to get buildids: %d\n", ret);
return ret ?: -ENOMEM;
}
strlist__for_each_entry(nd, bidlist) {
cache = probe_cache__new(nd->s, NULL);
if (!cache)
continue;
if (probe_cache__filter_purge(cache, filter) < 0 ||
probe_cache__commit(cache) < 0)
pr_warning("Failed to remove entries for %s\n", nd->s);
probe_cache__delete(cache);
}
return 0;
}
static int perf_del_probe_events(struct strfilter *filter)
{
int ret, ret2, ufd = -1, kfd = -1;
char *str = strfilter__string(filter);
struct strlist *klist = NULL, *ulist = NULL;
struct str_node *ent;
if (!str)
return -EINVAL;
pr_debug("Delete filter: \'%s\'\n", str);
if (probe_conf.cache)
return del_perf_probe_caches(filter);
/* Get current event names */
ret = probe_file__open_both(&kfd, &ufd, PF_FL_RW);
if (ret < 0)
goto out;
klist = strlist__new(NULL, NULL);
ulist = strlist__new(NULL, NULL);
if (!klist || !ulist) {
ret = -ENOMEM;
goto out;
}
ret = probe_file__get_events(kfd, filter, klist);
if (ret == 0) {
strlist__for_each_entry(ent, klist)
pr_info("Removed event: %s\n", ent->s);
ret = probe_file__del_strlist(kfd, klist);
if (ret < 0)
goto error;
} else if (ret == -ENOMEM)
goto error;
ret2 = probe_file__get_events(ufd, filter, ulist);
if (ret2 == 0) {
strlist__for_each_entry(ent, ulist)
pr_info("Removed event: %s\n", ent->s);
ret2 = probe_file__del_strlist(ufd, ulist);
if (ret2 < 0)
goto error;
} else if (ret2 == -ENOMEM)
goto error;
if (ret == -ENOENT && ret2 == -ENOENT)
pr_warning("\"%s\" does not hit any event.\n", str);
else
ret = 0;
error:
if (kfd >= 0)
close(kfd);
if (ufd >= 0)
close(ufd);
out:
strlist__delete(klist);
strlist__delete(ulist);
free(str);
return ret;
}
#ifdef HAVE_DWARF_SUPPORT
#define PROBEDEF_STR \
"[EVENT=]FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT [[NAME=]ARG ...]"
#else
#define PROBEDEF_STR "[EVENT=]FUNC[+OFF|%return] [[NAME=]ARG ...]"
#endif
static int
__cmd_probe(int argc, const char **argv)
{
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 [GROUP:]EVENT ...",
#ifdef HAVE_DWARF_SUPPORT
"perf probe [<options>] --line 'LINEDESC'",
"perf probe [<options>] --vars 'PROBEPOINT'",
#endif
"perf probe [<options>] --funcs",
NULL
};
struct option options[] = {
OPT_INCR('v', "verbose", &verbose,
"be more verbose (show parsed arguments, etc)"),
OPT_BOOLEAN('q', "quiet", &params.quiet,
"be quiet (do not show any messages)"),
OPT_CALLBACK_DEFAULT('l', "list", NULL, "[GROUP:]EVENT",
"list up probe events",
opt_set_filter_with_command, DEFAULT_LIST_FILTER),
OPT_CALLBACK('d', "del", NULL, "[GROUP:]EVENT", "delete a probe event.",
opt_set_filter_with_command),
OPT_CALLBACK('a', "add", NULL, PROBEDEF_STR,
"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_CALLBACK('D', "definition", NULL, PROBEDEF_STR,
"Show trace event definition of given traceevent for k/uprobe_events.",
opt_add_probe_event),
OPT_BOOLEAN('f', "force", &probe_conf.force_add, "forcibly add events"
" with existing name"),
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", &probe_conf.show_ext_vars,
"Show external variables too (with --vars only)"),
OPT_BOOLEAN('\0', "range", &probe_conf.show_location_range,
"Show variables location range in scope (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_BOOLEAN('\0', "no-inlines", &probe_conf.no_inlines,
"Don't search inlined functions"),
OPT__DRY_RUN(&probe_event_dry_run),
OPT_INTEGER('\0', "max-probes", &probe_conf.max_probes,
"Set how many probe points can be found for a probe."),
OPT_CALLBACK_DEFAULT('F', "funcs", NULL, "[FILTER]",
"Show potential probe-able functions.",
opt_set_filter_with_command, DEFAULT_FUNC_FILTER),
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_CALLBACK('m', "module", NULL, "modname|path",
"target module name (for online) or path (for offline)",
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_BOOLEAN(0, "cache", &probe_conf.cache, "Manipulate probe cache"),
OPT_STRING(0, "symfs", &symbol_conf.symfs, "directory",
"Look for files with symbols relative to this directory"),
OPT_CALLBACK(0, "target-ns", NULL, "pid",
"target pid for namespace contexts", opt_set_target_ns),
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, 'D', "definition", 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);
#else
# define set_nobuild(s, l, c) set_option_nobuild(options, s, l, "NO_DWARF=1", c)
set_nobuild('L', "line", false);
set_nobuild('V', "vars", false);
set_nobuild('\0', "externs", false);
set_nobuild('\0', "range", false);
set_nobuild('k', "vmlinux", true);
set_nobuild('s', "source", true);
set_nobuild('\0', "no-inlines", true);
# undef set_nobuild
#endif
set_option_flag(options, 'F', "funcs", PARSE_OPT_EXCLUSIVE);
argc = parse_options(argc, argv, options, probe_usage,
PARSE_OPT_STOP_AT_NON_OPTION);
if (argc > 0) {
if (strcmp(argv[0], "-") == 0) {
usage_with_options_msg(probe_usage, options,
"'-' is not supported.\n");
}
if (params.command && params.command != 'a') {
usage_with_options_msg(probe_usage, options,
"another command except --add is set.\n");
}
ret = parse_probe_event_argv(argc, argv);
if (ret < 0) {
pr_err_with_code(" Error: Command Parse Error.", ret);
return ret;
}
params.command = 'a';
}
if (params.quiet) {
if (verbose != 0) {
pr_err(" Error: -v and -q are exclusive.\n");
return -EINVAL;
}
verbose = -1;
}
if (probe_conf.max_probes == 0)
probe_conf.max_probes = MAX_PROBES;
/*
* Only consider the user's kernel image path if given.
*/
symbol_conf.try_vmlinux_path = (symbol_conf.vmlinux_name == NULL);
/*
* Except for --list, --del and --add, other command doesn't depend
* nor change running kernel. So if user gives offline vmlinux,
* ignore its buildid.
*/
if (!strchr("lda", params.command) && symbol_conf.vmlinux_name)
symbol_conf.ignore_vmlinux_buildid = true;
switch (params.command) {
case 'l':
if (params.uprobes) {
pr_err(" Error: Don't use --list with --exec.\n");
parse_options_usage(probe_usage, options, "l", true);
parse_options_usage(NULL, options, "x", true);
return -EINVAL;
}
ret = show_perf_probe_events(params.filter);
if (ret < 0)
pr_err_with_code(" Error: Failed to show event list.", ret);
return ret;
case 'F':
ret = show_available_funcs(params.target, params.nsi,
params.filter, params.uprobes);
if (ret < 0)
pr_err_with_code(" Error: Failed to show functions.", ret);
return ret;
#ifdef HAVE_DWARF_SUPPORT
case 'L':
ret = show_line_range(&params.line_range, params.target,
params.nsi, params.uprobes);
if (ret < 0)
pr_err_with_code(" Error: Failed to show lines.", ret);
return ret;
case 'V':
if (!params.filter)
params.filter = strfilter__new(DEFAULT_VAR_FILTER,
NULL);
ret = show_available_vars(params.events, params.nevents,
params.filter);
if (ret < 0)
pr_err_with_code(" Error: Failed to show vars.", ret);
return ret;
#endif
case 'd':
ret = perf_del_probe_events(params.filter);
if (ret < 0) {
pr_err_with_code(" Error: Failed to delete events.", ret);
return ret;
}
break;
case 'D':
case 'a':
/* Ensure the last given target is used */
if (params.target && !params.target_used) {
pr_err(" Error: -x/-m must follow the probe definitions.\n");
parse_options_usage(probe_usage, options, "m", true);
parse_options_usage(NULL, options, "x", true);
return -EINVAL;
}
ret = perf_add_probe_events(params.events, params.nevents);
if (ret < 0) {
/*
* When perf_add_probe_events() fails it calls
* cleanup_perf_probe_events(pevs, npevs), i.e.
* cleanup_perf_probe_events(params.events, params.nevents), which
* will call clear_perf_probe_event(), so set nevents to zero
* to avoid cleanup_params() to call clear_perf_probe_event() again
* on the same pevs.
*/
params.nevents = 0;
pr_err_with_code(" Error: Failed to add events.", ret);
return ret;
}
break;
default:
usage_with_options(probe_usage, options);
}
return 0;
}
int cmd_probe(int argc, const char **argv)
{
int ret;
ret = init_params();
if (!ret) {
ret = __cmd_probe(argc, argv);
cleanup_params();
}
return ret < 0 ? ret : 0;
}