| /* |
| * Copyright (c) 2017 Fujitsu Ltd. |
| * Ported: Guangwen Feng <fenggw-fnst@cn.fujitsu.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, see <http://www.gnu.org/licenses/>. |
| */ |
| |
| /* |
| * This is a regression test about the race in autogroup, this test |
| * can crash the buggy kernel, and the bug has been fixed in: |
| * |
| * commit 18f649ef344127ef6de23a5a4272dbe2fdb73dde |
| * Author: Oleg Nesterov <oleg@redhat.com> |
| * Date: Mon Nov 14 19:46:09 2016 +0100 |
| * |
| * sched/autogroup: Fix autogroup_move_group() to never skip sched_move_task() |
| */ |
| |
| #include <sys/types.h> |
| #include <unistd.h> |
| #include <stdlib.h> |
| #include "tst_test.h" |
| |
| #define LOOPS 1000 |
| #define PATH_AUTOGROUP "/proc/sys/kernel/sched_autogroup_enabled" |
| |
| static int orig_autogroup = -1; |
| |
| static void do_test(void) |
| { |
| int i; |
| |
| if (!SAFE_FORK()) { |
| SAFE_FILE_PRINTF(PATH_AUTOGROUP, "%d", 1); |
| SAFE_SETSID(); |
| |
| if (SAFE_FORK()) |
| pause(); |
| |
| SAFE_KILL(getppid(), SIGKILL); |
| usleep(1000); |
| |
| // The child has gone, the grandchild runs with kref == 1 |
| SAFE_FILE_PRINTF(PATH_AUTOGROUP, "%d", 0); |
| SAFE_SETSID(); |
| |
| // runs with the freed ag/tg |
| for (i = 0; i < LOOPS; i++) |
| usleep(10); |
| |
| TST_CHECKPOINT_WAKE(0); |
| |
| exit(0); |
| } |
| |
| SAFE_WAIT(NULL); // destroy the child's ag/tg |
| |
| TST_CHECKPOINT_WAIT(0); |
| |
| tst_res(TPASS, "Bug not reproduced"); |
| } |
| |
| static void setup(void) |
| { |
| if (access(PATH_AUTOGROUP, F_OK)) |
| tst_brk(TCONF, "autogroup not supported"); |
| |
| SAFE_FILE_SCANF(PATH_AUTOGROUP, "%d", &orig_autogroup); |
| } |
| |
| static void cleanup(void) |
| { |
| if (orig_autogroup != -1) |
| SAFE_FILE_PRINTF(PATH_AUTOGROUP, "%d", orig_autogroup); |
| } |
| |
| static struct tst_test test = { |
| .forks_child = 1, |
| .needs_root = 1, |
| .needs_checkpoints = 1, |
| .setup = setup, |
| .cleanup = cleanup, |
| .test_all = do_test, |
| }; |