1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * This test is intended to reproduce a crash that happens when
4 * kvm_arch_hardware_disable is called and it attempts to unregister the user
5 * return notifiers.
6 */
7 #include <fcntl.h>
8 #include <pthread.h>
9 #include <semaphore.h>
10 #include <stdint.h>
11 #include <stdlib.h>
12 #include <unistd.h>
13 #include <sys/wait.h>
14
15 #include <test_util.h>
16
17 #include "kvm_util.h"
18
19 #define VCPU_NUM 4
20 #define SLEEPING_THREAD_NUM (1 << 4)
21 #define FORK_NUM (1ULL << 9)
22 #define DELAY_US_MAX 2000
23 #define GUEST_CODE_PIO_PORT 4
24
25 sem_t *sem;
26
guest_code(void)27 static void guest_code(void)
28 {
29 for (;;)
30 ; /* Some busy work */
31 printf("Should not be reached.\n");
32 }
33
run_vcpu(void * arg)34 static void *run_vcpu(void *arg)
35 {
36 struct kvm_vcpu *vcpu = arg;
37 struct kvm_run *run = vcpu->run;
38
39 vcpu_run(vcpu);
40
41 TEST_ASSERT(false, "%s: exited with reason %d: %s",
42 __func__, run->exit_reason,
43 exit_reason_str(run->exit_reason));
44 pthread_exit(NULL);
45 }
46
sleeping_thread(void * arg)47 static void *sleeping_thread(void *arg)
48 {
49 int fd;
50
51 while (true) {
52 fd = open("/dev/null", O_RDWR);
53 close(fd);
54 }
55 TEST_ASSERT(false, "%s: exited", __func__);
56 pthread_exit(NULL);
57 }
58
check_create_thread(pthread_t * thread,pthread_attr_t * attr,void * (* f)(void *),void * arg)59 static inline void check_create_thread(pthread_t *thread, pthread_attr_t *attr,
60 void *(*f)(void *), void *arg)
61 {
62 int r;
63
64 r = pthread_create(thread, attr, f, arg);
65 TEST_ASSERT(r == 0, "%s: failed to create thread", __func__);
66 }
67
check_set_affinity(pthread_t thread,cpu_set_t * cpu_set)68 static inline void check_set_affinity(pthread_t thread, cpu_set_t *cpu_set)
69 {
70 int r;
71
72 r = pthread_setaffinity_np(thread, sizeof(cpu_set_t), cpu_set);
73 TEST_ASSERT(r == 0, "%s: failed set affinity", __func__);
74 }
75
check_join(pthread_t thread,void ** retval)76 static inline void check_join(pthread_t thread, void **retval)
77 {
78 int r;
79
80 r = pthread_join(thread, retval);
81 TEST_ASSERT(r == 0, "%s: failed to join thread", __func__);
82 }
83
run_test(uint32_t run)84 static void run_test(uint32_t run)
85 {
86 struct kvm_vcpu *vcpu;
87 struct kvm_vm *vm;
88 cpu_set_t cpu_set;
89 pthread_t threads[VCPU_NUM];
90 pthread_t throw_away;
91 void *b;
92 uint32_t i, j;
93
94 CPU_ZERO(&cpu_set);
95 for (i = 0; i < VCPU_NUM; i++)
96 CPU_SET(i, &cpu_set);
97
98 vm = vm_create(VCPU_NUM);
99
100 pr_debug("%s: [%d] start vcpus\n", __func__, run);
101 for (i = 0; i < VCPU_NUM; ++i) {
102 vcpu = vm_vcpu_add(vm, i, guest_code);
103
104 check_create_thread(&threads[i], NULL, run_vcpu, vcpu);
105 check_set_affinity(threads[i], &cpu_set);
106
107 for (j = 0; j < SLEEPING_THREAD_NUM; ++j) {
108 check_create_thread(&throw_away, NULL, sleeping_thread,
109 (void *)NULL);
110 check_set_affinity(throw_away, &cpu_set);
111 }
112 }
113 pr_debug("%s: [%d] all threads launched\n", __func__, run);
114 sem_post(sem);
115 for (i = 0; i < VCPU_NUM; ++i)
116 check_join(threads[i], &b);
117 /* Should not be reached */
118 TEST_ASSERT(false, "%s: [%d] child escaped the ninja", __func__, run);
119 }
120
wait_for_child_setup(pid_t pid)121 void wait_for_child_setup(pid_t pid)
122 {
123 /*
124 * Wait for the child to post to the semaphore, but wake up periodically
125 * to check if the child exited prematurely.
126 */
127 for (;;) {
128 const struct timespec wait_period = { .tv_sec = 1 };
129 int status;
130
131 if (!sem_timedwait(sem, &wait_period))
132 return;
133
134 /* Child is still running, keep waiting. */
135 if (pid != waitpid(pid, &status, WNOHANG))
136 continue;
137
138 /*
139 * Child is no longer running, which is not expected.
140 *
141 * If it exited with a non-zero status, we explicitly forward
142 * the child's status in case it exited with KSFT_SKIP.
143 */
144 if (WIFEXITED(status))
145 exit(WEXITSTATUS(status));
146 else
147 TEST_ASSERT(false, "Child exited unexpectedly");
148 }
149 }
150
main(int argc,char ** argv)151 int main(int argc, char **argv)
152 {
153 uint32_t i;
154 int s, r;
155 pid_t pid;
156
157 sem = sem_open("vm_sem", O_CREAT | O_EXCL, 0644, 0);
158 sem_unlink("vm_sem");
159
160 for (i = 0; i < FORK_NUM; ++i) {
161 pid = fork();
162 TEST_ASSERT(pid >= 0, "%s: unable to fork", __func__);
163 if (pid == 0)
164 run_test(i); /* This function always exits */
165
166 pr_debug("%s: [%d] waiting semaphore\n", __func__, i);
167 wait_for_child_setup(pid);
168 r = (rand() % DELAY_US_MAX) + 1;
169 pr_debug("%s: [%d] waiting %dus\n", __func__, i, r);
170 usleep(r);
171 r = waitpid(pid, &s, WNOHANG);
172 TEST_ASSERT(r != pid,
173 "%s: [%d] child exited unexpectedly status: [%d]",
174 __func__, i, s);
175 pr_debug("%s: [%d] killing child\n", __func__, i);
176 kill(pid, SIGKILL);
177 }
178
179 sem_destroy(sem);
180 exit(0);
181 }
182