1 /*
2  * efi_selftest_watchdog
3  *
4  * Copyright (c) 2017 Heinrich Schuchardt <xypron.glpk@gmx.de>
5  *
6  * SPDX-License-Identifier:     GPL-2.0+
7  *
8  * The 'watchdog timer' unit test checks that the watchdog timer
9  * will not cause a system restart during the timeout period after
10  * a timer reset.
11  *
12  * The 'watchdog reboot' unit test checks that the watchdog timer
13  * actually reboots the system after a timeout. The test is only
14  * executed on explicit request. Use the following commands:
15  *
16  *	setenv efi_selftest watchdog reboot
17  *	bootefi selftest
18  */
19 
20 #include <efi_selftest.h>
21 
22 /*
23  * This is the communication structure for the notification function.
24  */
25 struct notify_context {
26 	/* Status code returned when resetting watchdog */
27 	efi_status_t status;
28 	/* Number of invocations of the notification function */
29 	unsigned int timer_ticks;
30 };
31 
32 static struct efi_event *event_notify;
33 static struct efi_event *event_wait;
34 static struct efi_boot_services *boottime;
35 static struct notify_context notification_context;
36 static bool watchdog_reset;
37 
38 /*
39  * Notification function, increments the notfication count if parameter
40  * context is provided.
41  *
42  * @event	notified event
43  * @context	pointer to the timeout
44  */
45 static void EFIAPI notify(struct efi_event *event, void *context)
46 {
47 	struct notify_context *notify_context = context;
48 	efi_status_t ret = EFI_SUCCESS;
49 
50 	if (!notify_context)
51 		return;
52 
53 	/* Reset watchdog timer to one second */
54 	ret = boottime->set_watchdog_timer(1, 0, 0, NULL);
55 	if (ret != EFI_SUCCESS)
56 		notify_context->status = ret;
57 	/* Count number of calls */
58 	notify_context->timer_ticks++;
59 }
60 
61 /*
62  * Setup unit test.
63  *
64  * Create two timer events.
65  * One with EVT_NOTIFY_SIGNAL, the other with EVT_NOTIFY_WAIT.
66  *
67  * @handle:	handle of the loaded image
68  * @systable:	system table
69  * @return:	EFI_ST_SUCCESS for success
70  */
71 static int setup(const efi_handle_t handle,
72 		 const struct efi_system_table *systable)
73 {
74 	efi_status_t ret;
75 
76 	boottime = systable->boottime;
77 
78 	notification_context.status = EFI_SUCCESS;
79 	notification_context.timer_ticks = 0;
80 	ret = boottime->create_event(EVT_TIMER | EVT_NOTIFY_SIGNAL,
81 				     TPL_CALLBACK, notify,
82 				     (void *)&notification_context,
83 				     &event_notify);
84 	if (ret != EFI_SUCCESS) {
85 		efi_st_error("could not create event\n");
86 		return EFI_ST_FAILURE;
87 	}
88 	ret = boottime->create_event(EVT_TIMER | EVT_NOTIFY_WAIT,
89 				     TPL_CALLBACK, notify, NULL, &event_wait);
90 	if (ret != EFI_SUCCESS) {
91 		efi_st_error("could not create event\n");
92 		return EFI_ST_FAILURE;
93 	}
94 	return EFI_ST_SUCCESS;
95 }
96 
97 /*
98  * Execute the test resetting the watchdog in a timely manner. No reboot occurs.
99  *
100  * @handle:	handle of the loaded image
101  * @systable:	system table
102  * @return:	EFI_ST_SUCCESS for success
103  */
104 static int setup_timer(const efi_handle_t handle,
105 		       const struct efi_system_table *systable)
106 {
107 	watchdog_reset = true;
108 	return setup(handle, systable);
109 }
110 
111 /*
112  * Execute the test without resetting the watchdog. A system reboot occurs.
113  *
114  * @handle:	handle of the loaded image
115  * @systable:	system table
116  * @return:	EFI_ST_SUCCESS for success
117  */
118 static int setup_reboot(const efi_handle_t handle,
119 			const struct efi_system_table *systable)
120 {
121 	watchdog_reset = false;
122 	return setup(handle, systable);
123 }
124 
125 /*
126  * Tear down unit test.
127  *
128  * Close the events created in setup.
129  *
130  * @return:	EFI_ST_SUCCESS for success
131  */
132 static int teardown(void)
133 {
134 	efi_status_t ret;
135 
136 	/* Set the watchdog timer to the five minute default value */
137 	ret = boottime->set_watchdog_timer(300, 0, 0, NULL);
138 	if (ret != EFI_SUCCESS) {
139 		efi_st_error("Setting watchdog timer failed\n");
140 		return EFI_ST_FAILURE;
141 	}
142 	if (event_notify) {
143 		ret = boottime->close_event(event_notify);
144 		event_notify = NULL;
145 		if (ret != EFI_SUCCESS) {
146 			efi_st_error("Could not close event\n");
147 			return EFI_ST_FAILURE;
148 		}
149 	}
150 	if (event_wait) {
151 		ret = boottime->close_event(event_wait);
152 		event_wait = NULL;
153 		if (ret != EFI_SUCCESS) {
154 			efi_st_error("Could not close event\n");
155 			return EFI_ST_FAILURE;
156 		}
157 	}
158 	return EFI_ST_SUCCESS;
159 }
160 
161 /*
162  * Execute unit test.
163  *
164  * Run a 600 ms periodic timer that resets the watchdog to one second
165  * on every timer tick.
166  *
167  * Run a 1350 ms single shot timer and check that the 600ms timer has
168  * been called 2 times.
169  *
170  * @return:	EFI_ST_SUCCESS for success
171  */
172 static int execute(void)
173 {
174 	size_t index;
175 	efi_status_t ret;
176 
177 	/* Set the watchdog timeout to one second */
178 	ret = boottime->set_watchdog_timer(1, 0, 0, NULL);
179 	if (ret != EFI_SUCCESS) {
180 		efi_st_error("Setting watchdog timer failed\n");
181 		return EFI_ST_FAILURE;
182 	}
183 	if (watchdog_reset) {
184 		/* Set 600 ms timer */
185 		ret = boottime->set_timer(event_notify, EFI_TIMER_PERIODIC,
186 					  6000000);
187 		if (ret != EFI_SUCCESS) {
188 			efi_st_error("Could not set timer\n");
189 			return EFI_ST_FAILURE;
190 		}
191 	}
192 	/* Set 1350 ms timer */
193 	ret = boottime->set_timer(event_wait, EFI_TIMER_RELATIVE, 13500000);
194 	if (ret != EFI_SUCCESS) {
195 		efi_st_error("Could not set timer\n");
196 		return EFI_ST_FAILURE;
197 	}
198 
199 	ret = boottime->wait_for_event(1, &event_wait, &index);
200 	if (ret != EFI_SUCCESS) {
201 		efi_st_error("Could not wait for event\n");
202 		return EFI_ST_FAILURE;
203 	}
204 	if (notification_context.status != EFI_SUCCESS) {
205 		efi_st_error("Setting watchdog timer failed\n");
206 		return EFI_ST_FAILURE;
207 	}
208 	if (notification_context.timer_ticks != 2) {
209 		efi_st_error("The timer was called %u times, expected 2.\n",
210 			     notification_context.timer_ticks);
211 		return EFI_ST_FAILURE;
212 	}
213 	return EFI_ST_SUCCESS;
214 }
215 
216 EFI_UNIT_TEST(watchdog1) = {
217 	.name = "watchdog timer",
218 	.phase = EFI_EXECUTE_BEFORE_BOOTTIME_EXIT,
219 	.setup = setup_timer,
220 	.execute = execute,
221 	.teardown = teardown,
222 };
223 
224 EFI_UNIT_TEST(watchdog2) = {
225 	.name = "watchdog reboot",
226 	.phase = EFI_EXECUTE_BEFORE_BOOTTIME_EXIT,
227 	.setup = setup_reboot,
228 	.execute = execute,
229 	.teardown = teardown,
230 	.on_request = true,
231 };
232