| /* |
| * Copyright (c) 2014 Fujitsu Ltd. |
| * Author: Xiaoguang Wang <wangxg.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. |
| */ |
| |
| /* |
| * Note: this test has already been in xfstests generic/028 test case, |
| * I just port it to LTP. |
| * |
| * Kernel commit '232d2d60aa5469bb097f55728f65146bd49c1d25' introduced a race |
| * condition that causes getcwd(2) to return "/" instead of correct path. |
| * 232d2d6 dcache: Translating dentry into pathname without |
| * taking rename_lock |
| * |
| * And these two kernel commits fixed the bug: |
| * ede4cebce16f5643c61aedd6d88d9070a1d23a68 |
| * prepend_path() needs to reinitialize dentry/vfsmount/mnt on restarts |
| * f6500801522c61782d4990fa1ad96154cb397cd4 |
| * f650080 __dentry_path() fixes |
| * |
| * This test is to check whether this bug exists in the running kernel, |
| * or whether this bug has been fixed. |
| */ |
| |
| #include <stdio.h> |
| #include <errno.h> |
| #include <fcntl.h> |
| #include <sys/types.h> |
| #include <unistd.h> |
| #include "tst_test.h" |
| |
| #define TIMEOUT 5 |
| |
| static void do_child(void); |
| static void sigproc(int sig); |
| static volatile sig_atomic_t end; |
| static char init_cwd[PATH_MAX]; |
| |
| static void verify_getcwd(void) |
| { |
| int status; |
| char cur_cwd[PATH_MAX]; |
| pid_t child; |
| |
| child = SAFE_FORK(); |
| if (child == 0) |
| do_child(); |
| |
| while (1) { |
| SAFE_GETCWD(cur_cwd, PATH_MAX); |
| if (strncmp(init_cwd, cur_cwd, PATH_MAX)) { |
| tst_res(TFAIL, "initial current work directory is " |
| "%s, now is %s. Bug is reproduced!", |
| init_cwd, cur_cwd); |
| break; |
| } |
| |
| if (end) { |
| tst_res(TPASS, "Bug is not reproduced!"); |
| break; |
| } |
| } |
| |
| SAFE_KILL(child, SIGKILL); |
| SAFE_WAITPID(child, &status, 0); |
| } |
| |
| static void setup(void) |
| { |
| if (tst_ncpus() == 1) |
| tst_brk(TCONF, "This test needs two cpus at least"); |
| |
| SAFE_SIGNAL(SIGALRM, sigproc); |
| |
| alarm(TIMEOUT); |
| |
| SAFE_GETCWD(init_cwd, PATH_MAX); |
| } |
| |
| static void sigproc(int sig) |
| { |
| end = sig; |
| } |
| |
| static void do_child(void) |
| { |
| unsigned int i = 0; |
| char c_name[PATH_MAX] = "testfile", n_name[PATH_MAX]; |
| |
| SAFE_TOUCH(c_name, 0644, NULL); |
| |
| while (1) { |
| snprintf(n_name, PATH_MAX, "testfile%u", i++); |
| SAFE_RENAME(c_name, n_name); |
| strncpy(c_name, n_name, PATH_MAX); |
| } |
| } |
| |
| static struct tst_test test = { |
| .tid = "getcwd04", |
| .setup = setup, |
| .test_all = verify_getcwd, |
| .needs_tmpdir = 1, |
| .forks_child = 1 |
| }; |