mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-12 05:48:40 +00:00
2b394bc446
Do not access kallsyms to show available variables and show source lines
in user binaries.
This behavior always requires the root privilege when sysctl sets
kernel.kptr_restrict=1, but we don't need it just for analyzing user
binaries.
Without this patch (by normal user, kptr_restrict=1):
----
$ perf probe -x ./perf -V add_cmdname
Failed to init vmlinux path.
Error: Failed to show vars.
$ perf probe -x ./perf -L add_cmdname
Failed to init vmlinux path.
Error: Failed to show lines.
----
With this patch:
----
$ perf probe -x ./perf -V add_cmdname
Available variables at add_cmdname
@<perf_unknown_cmd_config+144>
(No matched variables)
@<list_commands_in_dir+160>
(No matched variables)
@<add_cmdname+0>
char* name
size_t len
struct cmdnames* cmds
$ perf probe -x ./perf -L add_cmdname
<add_cmdname@/home/fedora/ksrc/linux-3/tools/perf/util/help.c:0>
0 void add_cmdname(struct cmdnames *cmds, const char *name, size_t len)
1 {
2 struct cmdname *ent = malloc(sizeof(*ent) + len + 1);
4 ent->len = len;
5 memcpy(ent->name, name, len);
6 ent->name[len] = 0;
...
----
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: david lerner <dlernerdroid@gmail.com>
Cc: linux-perf-user@vger.kernel.org
Cc: yrl.pp-manager.tt@hitachi.com
Link: http://lkml.kernel.org/r/20140917084054.3722.73975.stgit@kbuild-f20.novalocal
[ Added missing 'bool user' argument to the !DWARF show_line_range() stub ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
536 lines
14 KiB
C
536 lines
14 KiB
C
/*
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* builtin-probe.c
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*
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* Builtin probe command: Set up probe events by C expression
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*
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* Written by Masami Hiramatsu <mhiramat@redhat.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*
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*/
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#include <sys/utsname.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <fcntl.h>
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#include <errno.h>
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#include <stdio.h>
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#include <unistd.h>
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#include <stdlib.h>
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#include <string.h>
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#include "perf.h"
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#include "builtin.h"
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#include "util/util.h"
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#include "util/strlist.h"
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#include "util/strfilter.h"
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#include "util/symbol.h"
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#include "util/debug.h"
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#include <api/fs/debugfs.h>
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#include "util/parse-options.h"
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#include "util/probe-finder.h"
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#include "util/probe-event.h"
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#define DEFAULT_VAR_FILTER "!__k???tab_* & !__crc_*"
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#define DEFAULT_FUNC_FILTER "!_*"
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/* Session management structure */
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static struct {
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bool list_events;
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bool force_add;
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bool show_lines;
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bool show_vars;
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bool show_ext_vars;
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bool show_funcs;
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bool mod_events;
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bool uprobes;
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int nevents;
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struct perf_probe_event events[MAX_PROBES];
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struct strlist *dellist;
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struct line_range line_range;
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char *target;
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int max_probe_points;
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struct strfilter *filter;
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} params;
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/* Parse an event definition. Note that any error must die. */
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static int parse_probe_event(const char *str)
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{
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struct perf_probe_event *pev = ¶ms.events[params.nevents];
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int ret;
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pr_debug("probe-definition(%d): %s\n", params.nevents, str);
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if (++params.nevents == MAX_PROBES) {
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pr_err("Too many probes (> %d) were specified.", MAX_PROBES);
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return -1;
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}
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pev->uprobes = params.uprobes;
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/* Parse a perf-probe command into event */
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ret = parse_perf_probe_command(str, pev);
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pr_debug("%d arguments\n", pev->nargs);
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return ret;
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}
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static int set_target(const char *ptr)
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{
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int found = 0;
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const char *buf;
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/*
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* The first argument after options can be an absolute path
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* to an executable / library or kernel module.
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*
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* TODO: Support relative path, and $PATH, $LD_LIBRARY_PATH,
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* short module name.
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*/
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if (!params.target && ptr && *ptr == '/') {
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params.target = strdup(ptr);
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if (!params.target)
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return -ENOMEM;
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found = 1;
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buf = ptr + (strlen(ptr) - 3);
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if (strcmp(buf, ".ko"))
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params.uprobes = true;
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}
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return found;
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}
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static int parse_probe_event_argv(int argc, const char **argv)
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{
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int i, len, ret, found_target;
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char *buf;
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found_target = set_target(argv[0]);
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if (found_target < 0)
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return found_target;
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if (found_target && argc == 1)
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return 0;
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/* Bind up rest arguments */
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len = 0;
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for (i = 0; i < argc; i++) {
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if (i == 0 && found_target)
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continue;
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len += strlen(argv[i]) + 1;
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}
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buf = zalloc(len + 1);
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if (buf == NULL)
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return -ENOMEM;
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len = 0;
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for (i = 0; i < argc; i++) {
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if (i == 0 && found_target)
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continue;
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len += sprintf(&buf[len], "%s ", argv[i]);
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}
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params.mod_events = true;
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ret = parse_probe_event(buf);
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free(buf);
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return ret;
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}
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static int opt_add_probe_event(const struct option *opt __maybe_unused,
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const char *str, int unset __maybe_unused)
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{
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if (str) {
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params.mod_events = true;
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return parse_probe_event(str);
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} else
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return 0;
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}
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static int opt_del_probe_event(const struct option *opt __maybe_unused,
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const char *str, int unset __maybe_unused)
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{
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if (str) {
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params.mod_events = true;
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if (!params.dellist)
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params.dellist = strlist__new(true, NULL);
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strlist__add(params.dellist, str);
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}
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return 0;
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}
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static int opt_set_target(const struct option *opt, const char *str,
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int unset __maybe_unused)
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{
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int ret = -ENOENT;
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char *tmp;
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if (str && !params.target) {
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if (!strcmp(opt->long_name, "exec"))
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params.uprobes = true;
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#ifdef HAVE_DWARF_SUPPORT
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else if (!strcmp(opt->long_name, "module"))
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params.uprobes = false;
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#endif
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else
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return ret;
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/* Expand given path to absolute path, except for modulename */
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if (params.uprobes || strchr(str, '/')) {
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tmp = realpath(str, NULL);
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if (!tmp) {
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pr_warning("Failed to get the absolute path of %s: %m\n", str);
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return ret;
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}
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} else {
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tmp = strdup(str);
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if (!tmp)
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return -ENOMEM;
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}
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params.target = tmp;
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ret = 0;
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}
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return ret;
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}
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#ifdef HAVE_DWARF_SUPPORT
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static int opt_show_lines(const struct option *opt __maybe_unused,
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const char *str, int unset __maybe_unused)
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{
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int ret = 0;
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if (!str)
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return 0;
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if (params.show_lines) {
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pr_warning("Warning: more than one --line options are"
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" detected. Only the first one is valid.\n");
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return 0;
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}
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params.show_lines = true;
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ret = parse_line_range_desc(str, ¶ms.line_range);
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return ret;
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}
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static int opt_show_vars(const struct option *opt __maybe_unused,
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const char *str, int unset __maybe_unused)
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{
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struct perf_probe_event *pev = ¶ms.events[params.nevents];
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int ret;
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if (!str)
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return 0;
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ret = parse_probe_event(str);
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if (!ret && pev->nargs != 0) {
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pr_err(" Error: '--vars' doesn't accept arguments.\n");
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return -EINVAL;
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}
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params.show_vars = true;
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return ret;
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}
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#endif
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static int opt_set_filter(const struct option *opt __maybe_unused,
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const char *str, int unset __maybe_unused)
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{
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const char *err;
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if (str) {
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pr_debug2("Set filter: %s\n", str);
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if (params.filter)
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strfilter__delete(params.filter);
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params.filter = strfilter__new(str, &err);
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if (!params.filter) {
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pr_err("Filter parse error at %td.\n", err - str + 1);
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pr_err("Source: \"%s\"\n", str);
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pr_err(" %*c\n", (int)(err - str + 1), '^');
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return -EINVAL;
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}
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}
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return 0;
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}
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static int init_params(void)
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{
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return line_range__init(¶ms.line_range);
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}
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static void cleanup_params(void)
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{
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int i;
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for (i = 0; i < params.nevents; i++)
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clear_perf_probe_event(params.events + i);
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if (params.dellist)
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strlist__delete(params.dellist);
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line_range__clear(¶ms.line_range);
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free(params.target);
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if (params.filter)
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strfilter__delete(params.filter);
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memset(¶ms, 0, sizeof(params));
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}
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static void pr_err_with_code(const char *msg, int err)
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{
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char sbuf[STRERR_BUFSIZE];
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pr_err("%s", msg);
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pr_debug(" Reason: %s (Code: %d)",
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strerror_r(-err, sbuf, sizeof(sbuf)), err);
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pr_err("\n");
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}
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static int
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__cmd_probe(int argc, const char **argv, const char *prefix __maybe_unused)
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{
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const char * const probe_usage[] = {
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"perf probe [<options>] 'PROBEDEF' ['PROBEDEF' ...]",
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"perf probe [<options>] --add 'PROBEDEF' [--add 'PROBEDEF' ...]",
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"perf probe [<options>] --del '[GROUP:]EVENT' ...",
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"perf probe --list",
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#ifdef HAVE_DWARF_SUPPORT
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"perf probe [<options>] --line 'LINEDESC'",
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"perf probe [<options>] --vars 'PROBEPOINT'",
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#endif
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NULL
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};
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const struct option options[] = {
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OPT_INCR('v', "verbose", &verbose,
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"be more verbose (show parsed arguments, etc)"),
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OPT_BOOLEAN('l', "list", ¶ms.list_events,
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"list up current probe events"),
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OPT_CALLBACK('d', "del", NULL, "[GROUP:]EVENT", "delete a probe event.",
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opt_del_probe_event),
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OPT_CALLBACK('a', "add", NULL,
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#ifdef HAVE_DWARF_SUPPORT
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"[EVENT=]FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT"
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" [[NAME=]ARG ...]",
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#else
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"[EVENT=]FUNC[+OFF|%return] [[NAME=]ARG ...]",
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#endif
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"probe point definition, where\n"
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"\t\tGROUP:\tGroup name (optional)\n"
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"\t\tEVENT:\tEvent name\n"
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"\t\tFUNC:\tFunction name\n"
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"\t\tOFF:\tOffset from function entry (in byte)\n"
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"\t\t%return:\tPut the probe at function return\n"
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#ifdef HAVE_DWARF_SUPPORT
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"\t\tSRC:\tSource code path\n"
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"\t\tRL:\tRelative line number from function entry.\n"
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"\t\tAL:\tAbsolute line number in file.\n"
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"\t\tPT:\tLazy expression of line code.\n"
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"\t\tARG:\tProbe argument (local variable name or\n"
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"\t\t\tkprobe-tracer argument format.)\n",
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#else
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"\t\tARG:\tProbe argument (kprobe-tracer argument format.)\n",
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#endif
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opt_add_probe_event),
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OPT_BOOLEAN('f', "force", ¶ms.force_add, "forcibly add events"
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" with existing name"),
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#ifdef HAVE_DWARF_SUPPORT
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OPT_CALLBACK('L', "line", NULL,
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"FUNC[:RLN[+NUM|-RLN2]]|SRC:ALN[+NUM|-ALN2]",
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"Show source code lines.", opt_show_lines),
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OPT_CALLBACK('V', "vars", NULL,
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"FUNC[@SRC][+OFF|%return|:RL|;PT]|SRC:AL|SRC;PT",
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"Show accessible variables on PROBEDEF", opt_show_vars),
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OPT_BOOLEAN('\0', "externs", ¶ms.show_ext_vars,
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"Show external variables too (with --vars only)"),
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OPT_STRING('k', "vmlinux", &symbol_conf.vmlinux_name,
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"file", "vmlinux pathname"),
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OPT_STRING('s', "source", &symbol_conf.source_prefix,
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"directory", "path to kernel source"),
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OPT_CALLBACK('m', "module", NULL, "modname|path",
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"target module name (for online) or path (for offline)",
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opt_set_target),
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#endif
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OPT__DRY_RUN(&probe_event_dry_run),
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OPT_INTEGER('\0', "max-probes", ¶ms.max_probe_points,
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"Set how many probe points can be found for a probe."),
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OPT_BOOLEAN('F', "funcs", ¶ms.show_funcs,
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"Show potential probe-able functions."),
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OPT_CALLBACK('\0', "filter", NULL,
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"[!]FILTER", "Set a filter (with --vars/funcs only)\n"
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"\t\t\t(default: \"" DEFAULT_VAR_FILTER "\" for --vars,\n"
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"\t\t\t \"" DEFAULT_FUNC_FILTER "\" for --funcs)",
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opt_set_filter),
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OPT_CALLBACK('x', "exec", NULL, "executable|path",
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"target executable name or path", opt_set_target),
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OPT_BOOLEAN(0, "demangle", &symbol_conf.demangle,
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"Disable symbol demangling"),
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OPT_BOOLEAN(0, "demangle-kernel", &symbol_conf.demangle_kernel,
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"Enable kernel symbol demangling"),
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OPT_END()
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};
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int ret;
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argc = parse_options(argc, argv, options, probe_usage,
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PARSE_OPT_STOP_AT_NON_OPTION);
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if (argc > 0) {
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if (strcmp(argv[0], "-") == 0) {
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pr_warning(" Error: '-' is not supported.\n");
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usage_with_options(probe_usage, options);
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}
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ret = parse_probe_event_argv(argc, argv);
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if (ret < 0) {
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pr_err_with_code(" Error: Command Parse Error.", ret);
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return ret;
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}
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}
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if (params.max_probe_points == 0)
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params.max_probe_points = MAX_PROBES;
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if ((!params.nevents && !params.dellist && !params.list_events &&
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!params.show_lines && !params.show_funcs))
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usage_with_options(probe_usage, options);
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/*
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* Only consider the user's kernel image path if given.
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*/
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symbol_conf.try_vmlinux_path = (symbol_conf.vmlinux_name == NULL);
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if (params.list_events) {
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if (params.mod_events) {
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pr_err(" Error: Don't use --list with --add/--del.\n");
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usage_with_options(probe_usage, options);
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}
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if (params.show_lines) {
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pr_err(" Error: Don't use --list with --line.\n");
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usage_with_options(probe_usage, options);
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}
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if (params.show_vars) {
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pr_err(" Error: Don't use --list with --vars.\n");
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usage_with_options(probe_usage, options);
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}
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if (params.show_funcs) {
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pr_err(" Error: Don't use --list with --funcs.\n");
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usage_with_options(probe_usage, options);
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}
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if (params.uprobes) {
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pr_warning(" Error: Don't use --list with --exec.\n");
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usage_with_options(probe_usage, options);
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}
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ret = show_perf_probe_events();
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if (ret < 0)
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pr_err_with_code(" Error: Failed to show event list.", ret);
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return ret;
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}
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if (params.show_funcs) {
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if (params.nevents != 0 || params.dellist) {
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pr_err(" Error: Don't use --funcs with"
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" --add/--del.\n");
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usage_with_options(probe_usage, options);
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}
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if (params.show_lines) {
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pr_err(" Error: Don't use --funcs with --line.\n");
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usage_with_options(probe_usage, options);
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}
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if (params.show_vars) {
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pr_err(" Error: Don't use --funcs with --vars.\n");
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usage_with_options(probe_usage, options);
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}
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if (!params.filter)
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params.filter = strfilter__new(DEFAULT_FUNC_FILTER,
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NULL);
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ret = show_available_funcs(params.target, params.filter,
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params.uprobes);
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strfilter__delete(params.filter);
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params.filter = NULL;
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if (ret < 0)
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pr_err_with_code(" Error: Failed to show functions.", ret);
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return ret;
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}
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#ifdef HAVE_DWARF_SUPPORT
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if (params.show_lines) {
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if (params.mod_events) {
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pr_err(" Error: Don't use --line with"
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" --add/--del.\n");
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usage_with_options(probe_usage, options);
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}
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if (params.show_vars) {
|
|
pr_err(" Error: Don't use --line with --vars.\n");
|
|
usage_with_options(probe_usage, options);
|
|
}
|
|
|
|
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.mod_events) {
|
|
pr_err(" Error: Don't use --vars with"
|
|
" --add/--del.\n");
|
|
usage_with_options(probe_usage, options);
|
|
}
|
|
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;
|
|
}
|