linux/tools/perf/util/probe-file.c
Wang Nan 421fd0845e perf probe: Verify parameters in two functions
On kernel with only one out of CONFIG_KPROBE_EVENTS and
CONFIG_UPROBE_EVENTS enabled, 'perf probe -d' causes a segfault because
perf_del_probe_events() calls probe_file__get_events() with a negative
fd.

This patch fixes it by adding parameter validation at the entry of
probe_file__get_events() and probe_file__get_rawlist(). Since they are
both non-static public functions (in .h file), parameter verifying is
required.

v1 -> v2: Verify fd at the head of probe_file__get_rawlist() instead of
          checking at call site (suggested by Masami and Arnaldo at [1,2]).

[1] http://lkml.kernel.org/r/50399556C9727B4D88A595C8584AAB37526048E3@GSjpTKYDCembx32.service.hitachi.net
[2] http://lkml.kernel.org/r/20151105155830.GV13236@kernel.org

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1446803415-83382-1-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-11-11 18:41:32 -03:00

328 lines
6.9 KiB
C

/*
* probe-file.c : operate ftrace k/uprobe events files
*
* Written by Masami Hiramatsu <masami.hiramatsu.pt@hitachi.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.
*
*/
#include "util.h"
#include "event.h"
#include "strlist.h"
#include "debug.h"
#include "cache.h"
#include "color.h"
#include "symbol.h"
#include "thread.h"
#include <api/fs/tracing_path.h>
#include "probe-event.h"
#include "probe-file.h"
#include "session.h"
#define MAX_CMDLEN 256
static void print_open_warning(int err, bool uprobe)
{
char sbuf[STRERR_BUFSIZE];
if (err == -ENOENT) {
const char *config;
if (uprobe)
config = "CONFIG_UPROBE_EVENTS";
else
config = "CONFIG_KPROBE_EVENTS";
pr_warning("%cprobe_events file does not exist"
" - please rebuild kernel with %s.\n",
uprobe ? 'u' : 'k', config);
} else if (err == -ENOTSUP)
pr_warning("Tracefs or debugfs is not mounted.\n");
else
pr_warning("Failed to open %cprobe_events: %s\n",
uprobe ? 'u' : 'k',
strerror_r(-err, sbuf, sizeof(sbuf)));
}
static void print_both_open_warning(int kerr, int uerr)
{
/* Both kprobes and uprobes are disabled, warn it. */
if (kerr == -ENOTSUP && uerr == -ENOTSUP)
pr_warning("Tracefs or debugfs is not mounted.\n");
else if (kerr == -ENOENT && uerr == -ENOENT)
pr_warning("Please rebuild kernel with CONFIG_KPROBE_EVENTS "
"or/and CONFIG_UPROBE_EVENTS.\n");
else {
char sbuf[STRERR_BUFSIZE];
pr_warning("Failed to open kprobe events: %s.\n",
strerror_r(-kerr, sbuf, sizeof(sbuf)));
pr_warning("Failed to open uprobe events: %s.\n",
strerror_r(-uerr, sbuf, sizeof(sbuf)));
}
}
static int open_probe_events(const char *trace_file, bool readwrite)
{
char buf[PATH_MAX];
const char *tracing_dir = "";
int ret;
ret = e_snprintf(buf, PATH_MAX, "%s/%s%s",
tracing_path, tracing_dir, trace_file);
if (ret >= 0) {
pr_debug("Opening %s write=%d\n", buf, readwrite);
if (readwrite && !probe_event_dry_run)
ret = open(buf, O_RDWR | O_APPEND, 0);
else
ret = open(buf, O_RDONLY, 0);
if (ret < 0)
ret = -errno;
}
return ret;
}
static int open_kprobe_events(bool readwrite)
{
return open_probe_events("kprobe_events", readwrite);
}
static int open_uprobe_events(bool readwrite)
{
return open_probe_events("uprobe_events", readwrite);
}
int probe_file__open(int flag)
{
int fd;
if (flag & PF_FL_UPROBE)
fd = open_uprobe_events(flag & PF_FL_RW);
else
fd = open_kprobe_events(flag & PF_FL_RW);
if (fd < 0)
print_open_warning(fd, flag & PF_FL_UPROBE);
return fd;
}
int probe_file__open_both(int *kfd, int *ufd, int flag)
{
if (!kfd || !ufd)
return -EINVAL;
*kfd = open_kprobe_events(flag & PF_FL_RW);
*ufd = open_uprobe_events(flag & PF_FL_RW);
if (*kfd < 0 && *ufd < 0) {
print_both_open_warning(*kfd, *ufd);
return *kfd;
}
return 0;
}
/* Get raw string list of current kprobe_events or uprobe_events */
struct strlist *probe_file__get_rawlist(int fd)
{
int ret, idx;
FILE *fp;
char buf[MAX_CMDLEN];
char *p;
struct strlist *sl;
if (fd < 0)
return NULL;
sl = strlist__new(NULL, NULL);
fp = fdopen(dup(fd), "r");
while (!feof(fp)) {
p = fgets(buf, MAX_CMDLEN, fp);
if (!p)
break;
idx = strlen(p) - 1;
if (p[idx] == '\n')
p[idx] = '\0';
ret = strlist__add(sl, buf);
if (ret < 0) {
pr_debug("strlist__add failed (%d)\n", ret);
strlist__delete(sl);
return NULL;
}
}
fclose(fp);
return sl;
}
static struct strlist *__probe_file__get_namelist(int fd, bool include_group)
{
char buf[128];
struct strlist *sl, *rawlist;
struct str_node *ent;
struct probe_trace_event tev;
int ret = 0;
memset(&tev, 0, sizeof(tev));
rawlist = probe_file__get_rawlist(fd);
if (!rawlist)
return NULL;
sl = strlist__new(NULL, NULL);
strlist__for_each(ent, rawlist) {
ret = parse_probe_trace_command(ent->s, &tev);
if (ret < 0)
break;
if (include_group) {
ret = e_snprintf(buf, 128, "%s:%s", tev.group,
tev.event);
if (ret >= 0)
ret = strlist__add(sl, buf);
} else
ret = strlist__add(sl, tev.event);
clear_probe_trace_event(&tev);
if (ret < 0)
break;
}
strlist__delete(rawlist);
if (ret < 0) {
strlist__delete(sl);
return NULL;
}
return sl;
}
/* Get current perf-probe event names */
struct strlist *probe_file__get_namelist(int fd)
{
return __probe_file__get_namelist(fd, false);
}
int probe_file__add_event(int fd, struct probe_trace_event *tev)
{
int ret = 0;
char *buf = synthesize_probe_trace_command(tev);
char sbuf[STRERR_BUFSIZE];
if (!buf) {
pr_debug("Failed to synthesize probe trace event.\n");
return -EINVAL;
}
pr_debug("Writing event: %s\n", buf);
if (!probe_event_dry_run) {
ret = write(fd, buf, strlen(buf));
if (ret <= 0) {
ret = -errno;
pr_warning("Failed to write event: %s\n",
strerror_r(errno, sbuf, sizeof(sbuf)));
}
}
free(buf);
return ret;
}
static int __del_trace_probe_event(int fd, struct str_node *ent)
{
char *p;
char buf[128];
int ret;
/* Convert from perf-probe event to trace-probe event */
ret = e_snprintf(buf, 128, "-:%s", ent->s);
if (ret < 0)
goto error;
p = strchr(buf + 2, ':');
if (!p) {
pr_debug("Internal error: %s should have ':' but not.\n",
ent->s);
ret = -ENOTSUP;
goto error;
}
*p = '/';
pr_debug("Writing event: %s\n", buf);
ret = write(fd, buf, strlen(buf));
if (ret < 0) {
ret = -errno;
goto error;
}
return 0;
error:
pr_warning("Failed to delete event: %s\n",
strerror_r(-ret, buf, sizeof(buf)));
return ret;
}
int probe_file__get_events(int fd, struct strfilter *filter,
struct strlist *plist)
{
struct strlist *namelist;
struct str_node *ent;
const char *p;
int ret = -ENOENT;
if (!plist)
return -EINVAL;
namelist = __probe_file__get_namelist(fd, true);
if (!namelist)
return -ENOENT;
strlist__for_each(ent, namelist) {
p = strchr(ent->s, ':');
if ((p && strfilter__compare(filter, p + 1)) ||
strfilter__compare(filter, ent->s)) {
strlist__add(plist, ent->s);
ret = 0;
}
}
strlist__delete(namelist);
return ret;
}
int probe_file__del_strlist(int fd, struct strlist *namelist)
{
int ret = 0;
struct str_node *ent;
strlist__for_each(ent, namelist) {
ret = __del_trace_probe_event(fd, ent);
if (ret < 0)
break;
}
return ret;
}
int probe_file__del_events(int fd, struct strfilter *filter)
{
struct strlist *namelist;
int ret;
namelist = strlist__new(NULL, NULL);
if (!namelist)
return -ENOMEM;
ret = probe_file__get_events(fd, filter, namelist);
if (ret < 0)
return ret;
ret = probe_file__del_strlist(fd, namelist);
strlist__delete(namelist);
return ret;
}