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55716d26 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
6e1819d6 RW |
2 | /* |
3 | * linux/kernel/power/user.c | |
4 | * | |
5 | * This file provides the user space interface for software suspend/resume. | |
6 | * | |
7 | * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl> | |
6e1819d6 RW |
8 | */ |
9 | ||
10 | #include <linux/suspend.h> | |
3592695c | 11 | #include <linux/reboot.h> |
6e1819d6 RW |
12 | #include <linux/string.h> |
13 | #include <linux/device.h> | |
14 | #include <linux/miscdevice.h> | |
15 | #include <linux/mm.h> | |
16 | #include <linux/swap.h> | |
17 | #include <linux/swapops.h> | |
18 | #include <linux/pm.h> | |
19 | #include <linux/fs.h> | |
c336078b | 20 | #include <linux/compat.h> |
97c7801c | 21 | #include <linux/console.h> |
e3920fb4 | 22 | #include <linux/cpu.h> |
7dfb7103 | 23 | #include <linux/freezer.h> |
6e1819d6 | 24 | |
7c0f6ba6 | 25 | #include <linux/uaccess.h> |
6e1819d6 RW |
26 | |
27 | #include "power.h" | |
28 | ||
eb57c1cf | 29 | |
6e1819d6 RW |
30 | static struct snapshot_data { |
31 | struct snapshot_handle handle; | |
32 | int swap; | |
6e1819d6 | 33 | int mode; |
7bc9b1cf RW |
34 | bool frozen; |
35 | bool ready; | |
36 | bool platform_support; | |
aab17289 | 37 | bool free_bitmaps; |
bb3247a3 | 38 | dev_t dev; |
6e1819d6 RW |
39 | } snapshot_state; |
40 | ||
bb3247a3 | 41 | int is_hibernate_resume_dev(dev_t dev) |
ad1e4f74 | 42 | { |
bb3247a3 | 43 | return hibernation_available() && snapshot_state.dev == dev; |
ad1e4f74 DA |
44 | } |
45 | ||
6e1819d6 RW |
46 | static int snapshot_open(struct inode *inode, struct file *filp) |
47 | { | |
48 | struct snapshot_data *data; | |
70d93298 | 49 | int error; |
6e1819d6 | 50 | |
a6e15a39 KC |
51 | if (!hibernation_available()) |
52 | return -EPERM; | |
53 | ||
bcda53fa | 54 | lock_system_sleep(); |
25f2f3da | 55 | |
ab7e9b06 | 56 | if (!hibernate_acquire()) { |
25f2f3da RW |
57 | error = -EBUSY; |
58 | goto Unlock; | |
59 | } | |
6e1819d6 | 60 | |
1525a2ad | 61 | if ((filp->f_flags & O_ACCMODE) == O_RDWR) { |
ab7e9b06 | 62 | hibernate_release(); |
25f2f3da RW |
63 | error = -ENOSYS; |
64 | goto Unlock; | |
1525a2ad | 65 | } |
6e1819d6 RW |
66 | nonseekable_open(inode, filp); |
67 | data = &snapshot_state; | |
68 | filp->private_data = data; | |
69 | memset(&data->handle, 0, sizeof(struct snapshot_handle)); | |
70 | if ((filp->f_flags & O_ACCMODE) == O_RDONLY) { | |
c7510859 | 71 | /* Hibernating. The image device should be accessible. */ |
21bd9005 | 72 | data->swap = swap_type_of(swsusp_resume_device, 0); |
6e1819d6 | 73 | data->mode = O_RDONLY; |
6a0c7cd3 | 74 | data->free_bitmaps = false; |
70d93298 | 75 | error = pm_notifier_call_chain_robust(PM_HIBERNATION_PREPARE, PM_POST_HIBERNATION); |
6e1819d6 | 76 | } else { |
c7510859 RW |
77 | /* |
78 | * Resuming. We may need to wait for the image device to | |
79 | * appear. | |
80 | */ | |
81 | wait_for_device_probe(); | |
c7510859 | 82 | |
6e1819d6 RW |
83 | data->swap = -1; |
84 | data->mode = O_WRONLY; | |
70d93298 | 85 | error = pm_notifier_call_chain_robust(PM_RESTORE_PREPARE, PM_POST_RESTORE); |
aab17289 RW |
86 | if (!error) { |
87 | error = create_basic_memory_bitmaps(); | |
88 | data->free_bitmaps = !error; | |
70d93298 | 89 | } |
c3e94d89 | 90 | } |
8fd37a4c | 91 | if (error) |
ab7e9b06 | 92 | hibernate_release(); |
8fd37a4c | 93 | |
7bc9b1cf RW |
94 | data->frozen = false; |
95 | data->ready = false; | |
96 | data->platform_support = false; | |
bb3247a3 | 97 | data->dev = 0; |
6e1819d6 | 98 | |
25f2f3da | 99 | Unlock: |
bcda53fa | 100 | unlock_system_sleep(); |
25f2f3da RW |
101 | |
102 | return error; | |
6e1819d6 RW |
103 | } |
104 | ||
105 | static int snapshot_release(struct inode *inode, struct file *filp) | |
106 | { | |
107 | struct snapshot_data *data; | |
108 | ||
bcda53fa | 109 | lock_system_sleep(); |
25f2f3da | 110 | |
6e1819d6 RW |
111 | swsusp_free(); |
112 | data = filp->private_data; | |
bb3247a3 | 113 | data->dev = 0; |
d1d241cc | 114 | free_all_swap_pages(data->swap); |
9744997a RW |
115 | if (data->frozen) { |
116 | pm_restore_gfp_mask(); | |
8fd37a4c | 117 | free_basic_memory_bitmaps(); |
6e1819d6 | 118 | thaw_processes(); |
aab17289 RW |
119 | } else if (data->free_bitmaps) { |
120 | free_basic_memory_bitmaps(); | |
9744997a | 121 | } |
1497dd1d | 122 | pm_notifier_call_chain(data->mode == O_RDONLY ? |
c3e94d89 | 123 | PM_POST_HIBERNATION : PM_POST_RESTORE); |
ab7e9b06 | 124 | hibernate_release(); |
25f2f3da | 125 | |
bcda53fa | 126 | unlock_system_sleep(); |
25f2f3da | 127 | |
6e1819d6 RW |
128 | return 0; |
129 | } | |
130 | ||
131 | static ssize_t snapshot_read(struct file *filp, char __user *buf, | |
132 | size_t count, loff_t *offp) | |
133 | { | |
134 | struct snapshot_data *data; | |
135 | ssize_t res; | |
d3c1b24c | 136 | loff_t pg_offp = *offp & ~PAGE_MASK; |
6e1819d6 | 137 | |
bcda53fa | 138 | lock_system_sleep(); |
25f2f3da | 139 | |
6e1819d6 | 140 | data = filp->private_data; |
25f2f3da RW |
141 | if (!data->ready) { |
142 | res = -ENODATA; | |
143 | goto Unlock; | |
144 | } | |
d3c1b24c JS |
145 | if (!pg_offp) { /* on page boundary? */ |
146 | res = snapshot_read_next(&data->handle); | |
147 | if (res <= 0) | |
148 | goto Unlock; | |
149 | } else { | |
150 | res = PAGE_SIZE - pg_offp; | |
6e1819d6 | 151 | } |
25f2f3da | 152 | |
d3c1b24c JS |
153 | res = simple_read_from_buffer(buf, count, &pg_offp, |
154 | data_of(data->handle), res); | |
155 | if (res > 0) | |
156 | *offp += res; | |
157 | ||
25f2f3da | 158 | Unlock: |
bcda53fa | 159 | unlock_system_sleep(); |
25f2f3da | 160 | |
6e1819d6 RW |
161 | return res; |
162 | } | |
163 | ||
164 | static ssize_t snapshot_write(struct file *filp, const char __user *buf, | |
165 | size_t count, loff_t *offp) | |
166 | { | |
167 | struct snapshot_data *data; | |
168 | ssize_t res; | |
d3c1b24c | 169 | loff_t pg_offp = *offp & ~PAGE_MASK; |
6e1819d6 | 170 | |
bcda53fa | 171 | lock_system_sleep(); |
25f2f3da | 172 | |
6e1819d6 | 173 | data = filp->private_data; |
d3c1b24c JS |
174 | |
175 | if (!pg_offp) { | |
176 | res = snapshot_write_next(&data->handle); | |
177 | if (res <= 0) | |
178 | goto unlock; | |
179 | } else { | |
180 | res = PAGE_SIZE - pg_offp; | |
6e1819d6 | 181 | } |
25f2f3da | 182 | |
fc14eebf TH |
183 | if (!data_of(data->handle)) { |
184 | res = -EINVAL; | |
185 | goto unlock; | |
186 | } | |
187 | ||
d3c1b24c JS |
188 | res = simple_write_to_buffer(data_of(data->handle), res, &pg_offp, |
189 | buf, count); | |
190 | if (res > 0) | |
191 | *offp += res; | |
192 | unlock: | |
bcda53fa | 193 | unlock_system_sleep(); |
25f2f3da | 194 | |
6e1819d6 RW |
195 | return res; |
196 | } | |
197 | ||
0f5c4c6e CH |
198 | struct compat_resume_swap_area { |
199 | compat_loff_t offset; | |
200 | u32 dev; | |
201 | } __packed; | |
202 | ||
88a77559 CH |
203 | static int snapshot_set_swap_area(struct snapshot_data *data, |
204 | void __user *argp) | |
205 | { | |
88a77559 CH |
206 | sector_t offset; |
207 | dev_t swdev; | |
208 | ||
209 | if (swsusp_swap_in_use()) | |
210 | return -EPERM; | |
0f5c4c6e CH |
211 | |
212 | if (in_compat_syscall()) { | |
213 | struct compat_resume_swap_area swap_area; | |
214 | ||
215 | if (copy_from_user(&swap_area, argp, sizeof(swap_area))) | |
216 | return -EFAULT; | |
217 | swdev = new_decode_dev(swap_area.dev); | |
218 | offset = swap_area.offset; | |
219 | } else { | |
220 | struct resume_swap_area swap_area; | |
221 | ||
222 | if (copy_from_user(&swap_area, argp, sizeof(swap_area))) | |
223 | return -EFAULT; | |
224 | swdev = new_decode_dev(swap_area.dev); | |
225 | offset = swap_area.offset; | |
226 | } | |
88a77559 CH |
227 | |
228 | /* | |
229 | * User space encodes device types as two-byte values, | |
230 | * so we need to recode them | |
231 | */ | |
21bd9005 | 232 | data->swap = swap_type_of(swdev, offset); |
88a77559 | 233 | if (data->swap < 0) |
21bd9005 CH |
234 | return swdev ? -ENODEV : -EINVAL; |
235 | data->dev = swdev; | |
88a77559 CH |
236 | return 0; |
237 | } | |
238 | ||
52d11025 AC |
239 | static long snapshot_ioctl(struct file *filp, unsigned int cmd, |
240 | unsigned long arg) | |
6e1819d6 RW |
241 | { |
242 | int error = 0; | |
243 | struct snapshot_data *data; | |
af508b34 | 244 | loff_t size; |
3aef83e0 | 245 | sector_t offset; |
6e1819d6 RW |
246 | |
247 | if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC) | |
248 | return -ENOTTY; | |
249 | if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR) | |
250 | return -ENOTTY; | |
251 | if (!capable(CAP_SYS_ADMIN)) | |
252 | return -EPERM; | |
253 | ||
55f2503c | 254 | if (!mutex_trylock(&system_transition_mutex)) |
25f2f3da | 255 | return -EBUSY; |
6e1819d6 | 256 | |
942f4015 | 257 | lock_device_hotplug(); |
25f2f3da | 258 | data = filp->private_data; |
52d11025 | 259 | |
6e1819d6 RW |
260 | switch (cmd) { |
261 | ||
262 | case SNAPSHOT_FREEZE: | |
263 | if (data->frozen) | |
264 | break; | |
1bfcf130 | 265 | |
b5dee313 | 266 | ksys_sync_helper(); |
c3e94d89 | 267 | |
1bfcf130 | 268 | error = freeze_processes(); |
8fd37a4c RW |
269 | if (error) |
270 | break; | |
271 | ||
272 | error = create_basic_memory_bitmaps(); | |
273 | if (error) | |
274 | thaw_processes(); | |
275 | else | |
7bc9b1cf | 276 | data->frozen = true; |
8fd37a4c | 277 | |
6e1819d6 RW |
278 | break; |
279 | ||
280 | case SNAPSHOT_UNFREEZE: | |
2f41dddb | 281 | if (!data->frozen || data->ready) |
6e1819d6 | 282 | break; |
c9e664f1 | 283 | pm_restore_gfp_mask(); |
8fd37a4c | 284 | free_basic_memory_bitmaps(); |
aab17289 | 285 | data->free_bitmaps = false; |
6e1819d6 | 286 | thaw_processes(); |
7bc9b1cf | 287 | data->frozen = false; |
6e1819d6 RW |
288 | break; |
289 | ||
b694e52e | 290 | case SNAPSHOT_CREATE_IMAGE: |
6e1819d6 RW |
291 | if (data->mode != O_RDONLY || !data->frozen || data->ready) { |
292 | error = -EPERM; | |
293 | break; | |
294 | } | |
c9e664f1 | 295 | pm_restore_gfp_mask(); |
eb57c1cf | 296 | error = hibernation_snapshot(data->platform_support); |
51d6ff7a | 297 | if (!error) { |
cc5d207c | 298 | error = put_user(in_suspend, (int __user *)arg); |
a556d5b5 SB |
299 | data->ready = !freezer_test_done && !error; |
300 | freezer_test_done = false; | |
97819a26 | 301 | } |
6e1819d6 RW |
302 | break; |
303 | ||
304 | case SNAPSHOT_ATOMIC_RESTORE: | |
8357376d | 305 | snapshot_write_finalize(&data->handle); |
6e1819d6 RW |
306 | if (data->mode != O_WRONLY || !data->frozen || |
307 | !snapshot_image_loaded(&data->handle)) { | |
308 | error = -EPERM; | |
309 | break; | |
310 | } | |
eb57c1cf | 311 | error = hibernation_restore(data->platform_support); |
6e1819d6 RW |
312 | break; |
313 | ||
314 | case SNAPSHOT_FREE: | |
315 | swsusp_free(); | |
316 | memset(&data->handle, 0, sizeof(struct snapshot_handle)); | |
7bc9b1cf | 317 | data->ready = false; |
181e9bde RW |
318 | /* |
319 | * It is necessary to thaw kernel threads here, because | |
320 | * SNAPSHOT_CREATE_IMAGE may be invoked directly after | |
321 | * SNAPSHOT_FREE. In that case, if kernel threads were not | |
322 | * thawed, the preallocation of memory carried out by | |
323 | * hibernation_snapshot() might run into problems (i.e. it | |
324 | * might fail or even deadlock). | |
325 | */ | |
326 | thaw_kernel_threads(); | |
6e1819d6 RW |
327 | break; |
328 | ||
b694e52e | 329 | case SNAPSHOT_PREF_IMAGE_SIZE: |
6e1819d6 RW |
330 | image_size = arg; |
331 | break; | |
332 | ||
af508b34 RW |
333 | case SNAPSHOT_GET_IMAGE_SIZE: |
334 | if (!data->ready) { | |
335 | error = -ENODATA; | |
336 | break; | |
337 | } | |
338 | size = snapshot_get_image_size(); | |
339 | size <<= PAGE_SHIFT; | |
340 | error = put_user(size, (loff_t __user *)arg); | |
341 | break; | |
342 | ||
b694e52e | 343 | case SNAPSHOT_AVAIL_SWAP_SIZE: |
af508b34 RW |
344 | size = count_swap_pages(data->swap, 1); |
345 | size <<= PAGE_SHIFT; | |
346 | error = put_user(size, (loff_t __user *)arg); | |
6e1819d6 RW |
347 | break; |
348 | ||
b694e52e | 349 | case SNAPSHOT_ALLOC_SWAP_PAGE: |
6e1819d6 RW |
350 | if (data->swap < 0 || data->swap >= MAX_SWAPFILES) { |
351 | error = -ENODEV; | |
352 | break; | |
353 | } | |
d1d241cc | 354 | offset = alloc_swapdev_block(data->swap); |
6e1819d6 RW |
355 | if (offset) { |
356 | offset <<= PAGE_SHIFT; | |
cc5d207c | 357 | error = put_user(offset, (loff_t __user *)arg); |
6e1819d6 RW |
358 | } else { |
359 | error = -ENOSPC; | |
360 | } | |
361 | break; | |
362 | ||
363 | case SNAPSHOT_FREE_SWAP_PAGES: | |
364 | if (data->swap < 0 || data->swap >= MAX_SWAPFILES) { | |
365 | error = -ENODEV; | |
366 | break; | |
367 | } | |
d1d241cc | 368 | free_all_swap_pages(data->swap); |
6e1819d6 RW |
369 | break; |
370 | ||
9b238205 LT |
371 | case SNAPSHOT_S2RAM: |
372 | if (!data->frozen) { | |
373 | error = -EPERM; | |
374 | break; | |
375 | } | |
6c961dfb RW |
376 | /* |
377 | * Tasks are frozen and the notifiers have been called with | |
378 | * PM_HIBERNATION_PREPARE | |
379 | */ | |
380 | error = suspend_devices_and_enter(PM_SUSPEND_MEM); | |
7bc9b1cf | 381 | data->ready = false; |
9b238205 LT |
382 | break; |
383 | ||
eb57c1cf RW |
384 | case SNAPSHOT_PLATFORM_SUPPORT: |
385 | data->platform_support = !!arg; | |
386 | break; | |
387 | ||
388 | case SNAPSHOT_POWER_OFF: | |
389 | if (data->platform_support) | |
390 | error = hibernation_platform_enter(); | |
391 | break; | |
392 | ||
37b2ba12 | 393 | case SNAPSHOT_SET_SWAP_AREA: |
88a77559 | 394 | error = snapshot_set_swap_area(data, (void __user *)arg); |
37b2ba12 RW |
395 | break; |
396 | ||
6e1819d6 RW |
397 | default: |
398 | error = -ENOTTY; | |
399 | ||
400 | } | |
25f2f3da | 401 | |
942f4015 | 402 | unlock_device_hotplug(); |
55f2503c | 403 | mutex_unlock(&system_transition_mutex); |
25f2f3da | 404 | |
6e1819d6 RW |
405 | return error; |
406 | } | |
407 | ||
c336078b | 408 | #ifdef CONFIG_COMPAT |
c336078b BH |
409 | static long |
410 | snapshot_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) | |
411 | { | |
412 | BUILD_BUG_ON(sizeof(loff_t) != sizeof(compat_loff_t)); | |
413 | ||
414 | switch (cmd) { | |
415 | case SNAPSHOT_GET_IMAGE_SIZE: | |
416 | case SNAPSHOT_AVAIL_SWAP_SIZE: | |
fba616a4 | 417 | case SNAPSHOT_ALLOC_SWAP_PAGE: |
c336078b | 418 | case SNAPSHOT_CREATE_IMAGE: |
0f5c4c6e | 419 | case SNAPSHOT_SET_SWAP_AREA: |
c336078b BH |
420 | return snapshot_ioctl(file, cmd, |
421 | (unsigned long) compat_ptr(arg)); | |
c336078b BH |
422 | default: |
423 | return snapshot_ioctl(file, cmd, arg); | |
424 | } | |
425 | } | |
c336078b BH |
426 | #endif /* CONFIG_COMPAT */ |
427 | ||
15ad7cdc | 428 | static const struct file_operations snapshot_fops = { |
6e1819d6 RW |
429 | .open = snapshot_open, |
430 | .release = snapshot_release, | |
431 | .read = snapshot_read, | |
432 | .write = snapshot_write, | |
433 | .llseek = no_llseek, | |
52d11025 | 434 | .unlocked_ioctl = snapshot_ioctl, |
c336078b BH |
435 | #ifdef CONFIG_COMPAT |
436 | .compat_ioctl = snapshot_compat_ioctl, | |
437 | #endif | |
6e1819d6 RW |
438 | }; |
439 | ||
440 | static struct miscdevice snapshot_device = { | |
441 | .minor = SNAPSHOT_MINOR, | |
442 | .name = "snapshot", | |
443 | .fops = &snapshot_fops, | |
444 | }; | |
445 | ||
446 | static int __init snapshot_device_init(void) | |
447 | { | |
448 | return misc_register(&snapshot_device); | |
449 | }; | |
450 | ||
451 | device_initcall(snapshot_device_init); |