1/*-
2 * Copyright (c) 2010 Giovanni Trematerra <giovanni.trematerra@gmail.com>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27/*
28 * PURPOSE:
29 *
30 * This kernel module helped to identify a deadlock in kthread
31 * interface, also pointed out a race in kthread_exit function.
32 *
33 */
34
35#include <sys/cdefs.h>
| 1/*-
2 * Copyright (c) 2010 Giovanni Trematerra <giovanni.trematerra@gmail.com>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27/*
28 * PURPOSE:
29 *
30 * This kernel module helped to identify a deadlock in kthread
31 * interface, also pointed out a race in kthread_exit function.
32 *
33 */
34
35#include <sys/cdefs.h>
|
37
38#include <sys/param.h>
39#include <sys/kernel.h>
40#include <sys/kthread.h>
41#include <sys/lock.h>
42#include <sys/module.h>
43#include <sys/mutex.h>
44#include <sys/systm.h>
45#include <sys/time.h>
46
47#ifdef TESTPAUSE_DEBUG
48#define DPRINTF(x) do { \
49 printf (x); \
50} while (0)
51#else
52#define DPRINTF(x)
53#endif
54
55static struct mtx test_global_lock;
56static int global_condvar;
57static int test_thrcnt;
58volatile int QUIT;
59
60static void
61thr_suspender(void *arg)
62{
63 struct thread *td = (struct thread *) arg;
64 int error;
65
66 for (;;) {
67 if (QUIT == 1)
68 break;
69 error = kthread_suspend(td, 10*hz);
70 if (error != 0 && QUIT == 0) {
71 if (error == EWOULDBLOCK)
72 panic("Ooops: kthread deadlock\n");
73 else
74 panic("kthread_suspend error: %d\n", error);
75 break;
76 }
77 }
78
79 mtx_lock(&test_global_lock);
80 test_thrcnt--;
81 wakeup(&global_condvar);
82 mtx_unlock(&test_global_lock);
83
84 kthread_exit();
85}
86
87static void
88thr_resumer(void *arg)
89{
90 struct thread *td = (struct thread *) arg;
91 int error;
92
93 for (;;) {
94 /* must be the last thread to exit */
95 if (QUIT == 1 && test_thrcnt == 1)
96 break;
97 error = kthread_resume(td);
98 if (error != 0)
99 panic("%s: error on kthread_resume. error: %d\n",
100 __func__, error);
101 }
102
103 mtx_lock(&test_global_lock);
104 test_thrcnt--;
105 wakeup(&global_condvar);
106 mtx_unlock(&test_global_lock);
107
108 kthread_exit();
109}
110
111static void
112thr_getsuspended(void *arg)
113{
114 for (;;) {
115 if (QUIT == 1)
116 break;
117 kthread_suspend_check();
118 }
119
120 mtx_lock(&test_global_lock);
121 test_thrcnt--;
122 wakeup(&global_condvar);
123 mtx_unlock(&test_global_lock);
124
125 kthread_exit();
126}
127
128static void
129kthrdlk_init(void)
130{
131 struct proc *testproc;
132 struct thread *newthr;
133 int error;
134
135 QUIT = 0;
136 test_thrcnt = 3;
137 mtx_init(&test_global_lock, "kthrdlk_lock", NULL, MTX_DEF);
138 testproc = NULL;
139 error = kproc_kthread_add(thr_getsuspended, NULL, &testproc, &newthr,
140 0, 0, "kthrdlk", "thr_getsuspended");
141 if (error != 0)
142 panic("cannot start thr_getsuspended error: %d\n", error);
143
144 error = kproc_kthread_add(thr_resumer, newthr, &testproc, NULL, 0, 0,
145 "kthrdlk", "thr_resumer");
146 if (error != 0)
147 panic("cannot start thr_resumer error: %d\n", error);
148
149 error = kproc_kthread_add(thr_suspender, newthr, &testproc, NULL, 0, 0,
150 "kthrdlk", "thr_suspender");
151 if (error != 0)
152 panic("cannot start thr_suspender error: %d\n", error);
153}
154
155static void
156kthrdlk_done(void)
157{
158 int ret;
159 DPRINTF(("sending QUIT signal to the thrdlk threads\n"));
160
161 /* wait kernel threads end */
162 mtx_lock(&test_global_lock);
163 QUIT = 1;
164 while (test_thrcnt != 0) {
165 ret = mtx_sleep(&global_condvar, &test_global_lock, 0, "waiting thrs end", 30 * hz);
166 if (ret == EWOULDBLOCK) {
167 panic("some threads not die! remaining: %d", test_thrcnt);
168 break;
169 }
170 }
171 if (test_thrcnt == 0)
172 DPRINTF(("All test_pause threads die\n"));
173
174 mtx_destroy(&test_global_lock);
175}
176
177static int
178kthrdlk_handler(module_t mod, int /*modeventtype_t*/ what,
179 void *arg)
180{
181 switch (what) {
182 case MOD_LOAD:
183 kthrdlk_init();
184 uprintf("kthrdlk loaded!\n");
185 return (0);
186 case MOD_UNLOAD:
187 kthrdlk_done();
188 uprintf("Bye Bye! kthrdlk unloaded!\n");
189 return (0);
190 }
191
192 return (EOPNOTSUPP);
193}
194
195static moduledata_t mod_data= {
| 37
38#include <sys/param.h>
39#include <sys/kernel.h>
40#include <sys/kthread.h>
41#include <sys/lock.h>
42#include <sys/module.h>
43#include <sys/mutex.h>
44#include <sys/systm.h>
45#include <sys/time.h>
46
47#ifdef TESTPAUSE_DEBUG
48#define DPRINTF(x) do { \
49 printf (x); \
50} while (0)
51#else
52#define DPRINTF(x)
53#endif
54
55static struct mtx test_global_lock;
56static int global_condvar;
57static int test_thrcnt;
58volatile int QUIT;
59
60static void
61thr_suspender(void *arg)
62{
63 struct thread *td = (struct thread *) arg;
64 int error;
65
66 for (;;) {
67 if (QUIT == 1)
68 break;
69 error = kthread_suspend(td, 10*hz);
70 if (error != 0 && QUIT == 0) {
71 if (error == EWOULDBLOCK)
72 panic("Ooops: kthread deadlock\n");
73 else
74 panic("kthread_suspend error: %d\n", error);
75 break;
76 }
77 }
78
79 mtx_lock(&test_global_lock);
80 test_thrcnt--;
81 wakeup(&global_condvar);
82 mtx_unlock(&test_global_lock);
83
84 kthread_exit();
85}
86
87static void
88thr_resumer(void *arg)
89{
90 struct thread *td = (struct thread *) arg;
91 int error;
92
93 for (;;) {
94 /* must be the last thread to exit */
95 if (QUIT == 1 && test_thrcnt == 1)
96 break;
97 error = kthread_resume(td);
98 if (error != 0)
99 panic("%s: error on kthread_resume. error: %d\n",
100 __func__, error);
101 }
102
103 mtx_lock(&test_global_lock);
104 test_thrcnt--;
105 wakeup(&global_condvar);
106 mtx_unlock(&test_global_lock);
107
108 kthread_exit();
109}
110
111static void
112thr_getsuspended(void *arg)
113{
114 for (;;) {
115 if (QUIT == 1)
116 break;
117 kthread_suspend_check();
118 }
119
120 mtx_lock(&test_global_lock);
121 test_thrcnt--;
122 wakeup(&global_condvar);
123 mtx_unlock(&test_global_lock);
124
125 kthread_exit();
126}
127
128static void
129kthrdlk_init(void)
130{
131 struct proc *testproc;
132 struct thread *newthr;
133 int error;
134
135 QUIT = 0;
136 test_thrcnt = 3;
137 mtx_init(&test_global_lock, "kthrdlk_lock", NULL, MTX_DEF);
138 testproc = NULL;
139 error = kproc_kthread_add(thr_getsuspended, NULL, &testproc, &newthr,
140 0, 0, "kthrdlk", "thr_getsuspended");
141 if (error != 0)
142 panic("cannot start thr_getsuspended error: %d\n", error);
143
144 error = kproc_kthread_add(thr_resumer, newthr, &testproc, NULL, 0, 0,
145 "kthrdlk", "thr_resumer");
146 if (error != 0)
147 panic("cannot start thr_resumer error: %d\n", error);
148
149 error = kproc_kthread_add(thr_suspender, newthr, &testproc, NULL, 0, 0,
150 "kthrdlk", "thr_suspender");
151 if (error != 0)
152 panic("cannot start thr_suspender error: %d\n", error);
153}
154
155static void
156kthrdlk_done(void)
157{
158 int ret;
159 DPRINTF(("sending QUIT signal to the thrdlk threads\n"));
160
161 /* wait kernel threads end */
162 mtx_lock(&test_global_lock);
163 QUIT = 1;
164 while (test_thrcnt != 0) {
165 ret = mtx_sleep(&global_condvar, &test_global_lock, 0, "waiting thrs end", 30 * hz);
166 if (ret == EWOULDBLOCK) {
167 panic("some threads not die! remaining: %d", test_thrcnt);
168 break;
169 }
170 }
171 if (test_thrcnt == 0)
172 DPRINTF(("All test_pause threads die\n"));
173
174 mtx_destroy(&test_global_lock);
175}
176
177static int
178kthrdlk_handler(module_t mod, int /*modeventtype_t*/ what,
179 void *arg)
180{
181 switch (what) {
182 case MOD_LOAD:
183 kthrdlk_init();
184 uprintf("kthrdlk loaded!\n");
185 return (0);
186 case MOD_UNLOAD:
187 kthrdlk_done();
188 uprintf("Bye Bye! kthrdlk unloaded!\n");
189 return (0);
190 }
191
192 return (EOPNOTSUPP);
193}
194
195static moduledata_t mod_data= {
|