tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
28sem_t *sem;
29
30/* Arguments for the pthreads */
31struct payload {
32 struct kvm_vm *vm;
33 uint32_t index;
34};
35
36static void guest_code(void)
37{
38 for (;;)
39 ; /* Some busy work */
40 printf("Should not be reached.\n");
41}
42
43static 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
56static 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
68static 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
77static 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
85static 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
93static 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, 0, 0);
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
135int main(int argc, char **argv)
136{
137 uint32_t i;
138 int s, r;
139 pid_t pid;
140
141 sem = sem_open("vm_sem", O_CREAT | O_EXCL, 0644, 0);
142 sem_unlink("vm_sem");
143
144 for (i = 0; i < FORK_NUM; ++i) {
145 pid = fork();
146 TEST_ASSERT(pid >= 0, "%s: unable to fork", __func__);
147 if (pid == 0)
148 run_test(i); /* This function always exits */
149
150 pr_debug("%s: [%d] waiting semaphore\n", __func__, i);
151 sem_wait(sem);
152 r = (rand() % DELAY_US_MAX) + 1;
153 pr_debug("%s: [%d] waiting %dus\n", __func__, i, r);
154 usleep(r);
155 r = waitpid(pid, &s, WNOHANG);
156 TEST_ASSERT(r != pid,
157 "%s: [%d] child exited unexpectedly status: [%d]",
158 __func__, i, s);
159 pr_debug("%s: [%d] killing child\n", __func__, i);
160 kill(pid, SIGKILL);
161 }
162
163 sem_destroy(sem);
164 exit(0);
165}