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 8 #define _GNU_SOURCE 9 10 #include <fcntl.h> 11 #include <pthread.h> 12 #include <semaphore.h> 13 #include <stdint.h> 14 #include <stdlib.h> 15 #include <unistd.h> 16 #include <sys/wait.h> 17 18 #include <test_util.h> 19 20 #include "kvm_util.h" 21 22 #define VCPU_NUM 4 23 #define SLEEPING_THREAD_NUM (1 << 4) 24 #define FORK_NUM (1ULL << 9) 25 #define DELAY_US_MAX 2000 26 #define GUEST_CODE_PIO_PORT 4 27 28 sem_t *sem; 29 30 /* Arguments for the pthreads */ 31 struct payload { 32 struct kvm_vm *vm; 33 uint32_t index; 34 }; 35 36 static void guest_code(void) 37 { 38 for (;;) 39 ; /* Some busy work */ 40 printf("Should not be reached.\n"); 41 } 42 43 static void *run_vcpu(void *arg) 44 { 45 struct payload *payload = (struct payload *)arg; 46 struct kvm_run *state = vcpu_state(payload->vm, payload->index); 47 48 vcpu_run(payload->vm, payload->index); 49 50 TEST_ASSERT(false, "%s: exited with reason %d: %s\n", 51 __func__, state->exit_reason, 52 exit_reason_str(state->exit_reason)); 53 pthread_exit(NULL); 54 } 55 56 static void *sleeping_thread(void *arg) 57 { 58 int fd; 59 60 while (true) { 61 fd = open("/dev/null", O_RDWR); 62 close(fd); 63 } 64 TEST_ASSERT(false, "%s: exited\n", __func__); 65 pthread_exit(NULL); 66 } 67 68 static inline void check_create_thread(pthread_t *thread, pthread_attr_t *attr, 69 void *(*f)(void *), void *arg) 70 { 71 int r; 72 73 r = pthread_create(thread, attr, f, arg); 74 TEST_ASSERT(r == 0, "%s: failed to create thread", __func__); 75 } 76 77 static inline void check_set_affinity(pthread_t thread, cpu_set_t *cpu_set) 78 { 79 int r; 80 81 r = pthread_setaffinity_np(thread, sizeof(cpu_set_t), cpu_set); 82 TEST_ASSERT(r == 0, "%s: failed set affinity", __func__); 83 } 84 85 static inline void check_join(pthread_t thread, void **retval) 86 { 87 int r; 88 89 r = pthread_join(thread, retval); 90 TEST_ASSERT(r == 0, "%s: failed to join thread", __func__); 91 } 92 93 static void run_test(uint32_t run) 94 { 95 struct kvm_vm *vm; 96 cpu_set_t cpu_set; 97 pthread_t threads[VCPU_NUM]; 98 pthread_t throw_away; 99 struct payload payloads[VCPU_NUM]; 100 void *b; 101 uint32_t i, j; 102 103 CPU_ZERO(&cpu_set); 104 for (i = 0; i < VCPU_NUM; i++) 105 CPU_SET(i, &cpu_set); 106 107 vm = vm_create(VM_MODE_DEFAULT, DEFAULT_GUEST_PHY_PAGES, O_RDWR); 108 kvm_vm_elf_load(vm, program_invocation_name); 109 vm_create_irqchip(vm); 110 111 pr_debug("%s: [%d] start vcpus\n", __func__, run); 112 for (i = 0; i < VCPU_NUM; ++i) { 113 vm_vcpu_add_default(vm, i, guest_code); 114 payloads[i].vm = vm; 115 payloads[i].index = i; 116 117 check_create_thread(&threads[i], NULL, run_vcpu, 118 (void *)&payloads[i]); 119 check_set_affinity(threads[i], &cpu_set); 120 121 for (j = 0; j < SLEEPING_THREAD_NUM; ++j) { 122 check_create_thread(&throw_away, NULL, sleeping_thread, 123 (void *)NULL); 124 check_set_affinity(throw_away, &cpu_set); 125 } 126 } 127 pr_debug("%s: [%d] all threads launched\n", __func__, run); 128 sem_post(sem); 129 for (i = 0; i < VCPU_NUM; ++i) 130 check_join(threads[i], &b); 131 /* Should not be reached */ 132 TEST_ASSERT(false, "%s: [%d] child escaped the ninja\n", __func__, run); 133 } 134 135 void wait_for_child_setup(pid_t pid) 136 { 137 /* 138 * Wait for the child to post to the semaphore, but wake up periodically 139 * to check if the child exited prematurely. 140 */ 141 for (;;) { 142 const struct timespec wait_period = { .tv_sec = 1 }; 143 int status; 144 145 if (!sem_timedwait(sem, &wait_period)) 146 return; 147 148 /* Child is still running, keep waiting. */ 149 if (pid != waitpid(pid, &status, WNOHANG)) 150 continue; 151 152 /* 153 * Child is no longer running, which is not expected. 154 * 155 * If it exited with a non-zero status, we explicitly forward 156 * the child's status in case it exited with KSFT_SKIP. 157 */ 158 if (WIFEXITED(status)) 159 exit(WEXITSTATUS(status)); 160 else 161 TEST_ASSERT(false, "Child exited unexpectedly"); 162 } 163 } 164 165 int main(int argc, char **argv) 166 { 167 uint32_t i; 168 int s, r; 169 pid_t pid; 170 171 sem = sem_open("vm_sem", O_CREAT | O_EXCL, 0644, 0); 172 sem_unlink("vm_sem"); 173 174 for (i = 0; i < FORK_NUM; ++i) { 175 pid = fork(); 176 TEST_ASSERT(pid >= 0, "%s: unable to fork", __func__); 177 if (pid == 0) 178 run_test(i); /* This function always exits */ 179 180 pr_debug("%s: [%d] waiting semaphore\n", __func__, i); 181 wait_for_child_setup(pid); 182 r = (rand() % DELAY_US_MAX) + 1; 183 pr_debug("%s: [%d] waiting %dus\n", __func__, i, r); 184 usleep(r); 185 r = waitpid(pid, &s, WNOHANG); 186 TEST_ASSERT(r != pid, 187 "%s: [%d] child exited unexpectedly status: [%d]", 188 __func__, i, s); 189 pr_debug("%s: [%d] killing child\n", __func__, i); 190 kill(pid, SIGKILL); 191 } 192 193 sem_destroy(sem); 194 exit(0); 195 } 196