1 /*
2 * Copyright (c) 2015 SUSE Linux. All Rights Reserved.
3 *
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms of version 2 of the GNU General Public License as
6 * published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it would be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
11 *
12 * Further, this software is distributed without any warranty that it is
13 * free of the rightful claim of any third person regarding infringement
14 * or the like. Any license provided herein, whether implied or
15 * otherwise, applies only to this software file. Patent licenses, if
16 * any, provided herein do not apply to combinations of this program with
17 * other software, or any other product whatsoever.
18 *
19 * Started by Jan Kara <jack@suse.cz>
20 *
21 * DESCRIPTION
22 * Test for inotify mark destruction race.
23 *
24 * Kernels prior to 4.2 have a race when inode is being deleted while
25 * inotify group watching that inode is being torn down. When the race is
26 * hit, the kernel crashes or loops.
27 *
28 * The problem has been fixed by commit:
29 * 8f2f3eb59dff "fsnotify: fix oops in fsnotify_clear_marks_by_group_flags()".
30 */
31
32 #include "config.h"
33
34 #include <stdio.h>
35 #include <unistd.h>
36 #include <stdlib.h>
37 #include <fcntl.h>
38 #include <time.h>
39 #include <signal.h>
40 #include <sys/time.h>
41 #include <sys/wait.h>
42 #include <sys/syscall.h>
43
44 #include "test.h"
45 #include "linux_syscall_numbers.h"
46 #include "inotify.h"
47 #include "safe_macros.h"
48
49 char *TCID = "inotify06";
50 int TST_TOTAL = 1;
51
52 #if defined(HAVE_SYS_INOTIFY_H)
53 #include <sys/inotify.h>
54
55 /* Number of test loops to run the test for */
56 #define TEARDOWNS 400
57
58 /* Number of files to test (must be > 1) */
59 #define FILES 5
60
61 char names[FILES][PATH_MAX];
62
cleanup(void)63 static void cleanup(void)
64 {
65 tst_rmdir();
66 }
67
setup(void)68 static void setup(void)
69 {
70 int i;
71
72 tst_sig(FORK, DEF_HANDLER, cleanup);
73
74 TEST_PAUSE;
75
76 tst_tmpdir();
77
78 for (i = 0; i < FILES; i++)
79 sprintf(names[i], "fname_%d", i);
80 }
81
verify_inotify(void)82 static void verify_inotify(void)
83 {
84 int inotify_fd, fd;
85 pid_t pid;
86 int i, tests;
87
88 pid = tst_fork();
89 if (pid == 0) {
90 while (1) {
91 for (i = 0; i < FILES; i++) {
92 fd = SAFE_OPEN(NULL, names[i], O_CREAT | O_RDWR, 0600);
93 SAFE_CLOSE(NULL, fd);
94 }
95 for (i = 0; i < FILES; i++)
96 SAFE_UNLINK(NULL, names[i]);
97 }
98 } else if (pid == -1)
99 tst_brkm(TBROK | TERRNO, cleanup, "fork() failed");
100
101 for (tests = 0; tests < TEARDOWNS; tests++) {
102 inotify_fd = ltp_syscall(__NR_inotify_init1, O_NONBLOCK);
103 if (inotify_fd < 0)
104 tst_brkm(TBROK | TERRNO, cleanup, "inotify_init failed");
105
106 for (i = 0; i < FILES; i++) {
107 /*
108 * Both failure and success are fine since
109 * files are being deleted in parallel - this
110 * is what provokes the race we want to test
111 * for...
112 */
113 myinotify_add_watch(inotify_fd, names[i], IN_MODIFY);
114 }
115 SAFE_CLOSE(cleanup, inotify_fd);
116 }
117 /* We survived for given time - test succeeded */
118 tst_resm(TPASS, "kernel survived inotify beating");
119
120 /* Kill the child creating / deleting files and wait for it */
121 kill(pid, SIGKILL);
122 wait(NULL);
123 }
124
main(int ac,char ** av)125 int main(int ac, char **av)
126 {
127 int lc;
128
129 tst_parse_opts(ac, av, NULL, NULL);
130
131 setup();
132
133 for (lc = 0; TEST_LOOPING(lc); lc++)
134 verify_inotify();
135
136 cleanup();
137 tst_exit();
138 }
139
140 #else
141
main(void)142 int main(void)
143 {
144 tst_brkm(TCONF, NULL, "system doesn't have required inotify support");
145 }
146
147 #endif
148