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1// SPDX-License-Identifier: GPL-2.0-only
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>
8 */
9
10#include <linux/suspend.h>
11#include <linux/reboot.h>
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>
20#include <linux/compat.h>
21#include <linux/console.h>
22#include <linux/cpu.h>
23#include <linux/freezer.h>
24
25#include <linux/uaccess.h>
26
27#include "power.h"
28
29
30static struct snapshot_data {
31 struct snapshot_handle handle;
32 int swap;
33 int mode;
34 bool frozen;
35 bool ready;
36 bool platform_support;
37 bool free_bitmaps;
38 struct inode *bd_inode;
39} snapshot_state;
40
41int is_hibernate_resume_dev(const struct inode *bd_inode)
42{
43 return hibernation_available() && snapshot_state.bd_inode == bd_inode;
44}
45
46static int snapshot_open(struct inode *inode, struct file *filp)
47{
48 struct snapshot_data *data;
49 int error, nr_calls = 0;
50
51 if (!hibernation_available())
52 return -EPERM;
53
54 lock_system_sleep();
55
56 if (!hibernate_acquire()) {
57 error = -EBUSY;
58 goto Unlock;
59 }
60
61 if ((filp->f_flags & O_ACCMODE) == O_RDWR) {
62 hibernate_release();
63 error = -ENOSYS;
64 goto Unlock;
65 }
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) {
71 /* Hibernating. The image device should be accessible. */
72 data->swap = swsusp_resume_device ?
73 swap_type_of(swsusp_resume_device, 0, NULL) : -1;
74 data->mode = O_RDONLY;
75 data->free_bitmaps = false;
76 error = __pm_notifier_call_chain(PM_HIBERNATION_PREPARE, -1, &nr_calls);
77 if (error)
78 __pm_notifier_call_chain(PM_POST_HIBERNATION, --nr_calls, NULL);
79 } else {
80 /*
81 * Resuming. We may need to wait for the image device to
82 * appear.
83 */
84 wait_for_device_probe();
85
86 data->swap = -1;
87 data->mode = O_WRONLY;
88 error = __pm_notifier_call_chain(PM_RESTORE_PREPARE, -1, &nr_calls);
89 if (!error) {
90 error = create_basic_memory_bitmaps();
91 data->free_bitmaps = !error;
92 } else
93 nr_calls--;
94
95 if (error)
96 __pm_notifier_call_chain(PM_POST_RESTORE, nr_calls, NULL);
97 }
98 if (error)
99 hibernate_release();
100
101 data->frozen = false;
102 data->ready = false;
103 data->platform_support = false;
104 data->bd_inode = NULL;
105
106 Unlock:
107 unlock_system_sleep();
108
109 return error;
110}
111
112static int snapshot_release(struct inode *inode, struct file *filp)
113{
114 struct snapshot_data *data;
115
116 lock_system_sleep();
117
118 swsusp_free();
119 data = filp->private_data;
120 data->bd_inode = NULL;
121 free_all_swap_pages(data->swap);
122 if (data->frozen) {
123 pm_restore_gfp_mask();
124 free_basic_memory_bitmaps();
125 thaw_processes();
126 } else if (data->free_bitmaps) {
127 free_basic_memory_bitmaps();
128 }
129 pm_notifier_call_chain(data->mode == O_RDONLY ?
130 PM_POST_HIBERNATION : PM_POST_RESTORE);
131 hibernate_release();
132
133 unlock_system_sleep();
134
135 return 0;
136}
137
138static ssize_t snapshot_read(struct file *filp, char __user *buf,
139 size_t count, loff_t *offp)
140{
141 struct snapshot_data *data;
142 ssize_t res;
143 loff_t pg_offp = *offp & ~PAGE_MASK;
144
145 lock_system_sleep();
146
147 data = filp->private_data;
148 if (!data->ready) {
149 res = -ENODATA;
150 goto Unlock;
151 }
152 if (!pg_offp) { /* on page boundary? */
153 res = snapshot_read_next(&data->handle);
154 if (res <= 0)
155 goto Unlock;
156 } else {
157 res = PAGE_SIZE - pg_offp;
158 }
159
160 res = simple_read_from_buffer(buf, count, &pg_offp,
161 data_of(data->handle), res);
162 if (res > 0)
163 *offp += res;
164
165 Unlock:
166 unlock_system_sleep();
167
168 return res;
169}
170
171static ssize_t snapshot_write(struct file *filp, const char __user *buf,
172 size_t count, loff_t *offp)
173{
174 struct snapshot_data *data;
175 ssize_t res;
176 loff_t pg_offp = *offp & ~PAGE_MASK;
177
178 lock_system_sleep();
179
180 data = filp->private_data;
181
182 if (!pg_offp) {
183 res = snapshot_write_next(&data->handle);
184 if (res <= 0)
185 goto unlock;
186 } else {
187 res = PAGE_SIZE - pg_offp;
188 }
189
190 if (!data_of(data->handle)) {
191 res = -EINVAL;
192 goto unlock;
193 }
194
195 res = simple_write_to_buffer(data_of(data->handle), res, &pg_offp,
196 buf, count);
197 if (res > 0)
198 *offp += res;
199unlock:
200 unlock_system_sleep();
201
202 return res;
203}
204
205struct compat_resume_swap_area {
206 compat_loff_t offset;
207 u32 dev;
208} __packed;
209
210static int snapshot_set_swap_area(struct snapshot_data *data,
211 void __user *argp)
212{
213 struct block_device *bdev;
214 sector_t offset;
215 dev_t swdev;
216
217 if (swsusp_swap_in_use())
218 return -EPERM;
219
220 if (in_compat_syscall()) {
221 struct compat_resume_swap_area swap_area;
222
223 if (copy_from_user(&swap_area, argp, sizeof(swap_area)))
224 return -EFAULT;
225 swdev = new_decode_dev(swap_area.dev);
226 offset = swap_area.offset;
227 } else {
228 struct resume_swap_area swap_area;
229
230 if (copy_from_user(&swap_area, argp, sizeof(swap_area)))
231 return -EFAULT;
232 swdev = new_decode_dev(swap_area.dev);
233 offset = swap_area.offset;
234 }
235
236 /*
237 * User space encodes device types as two-byte values,
238 * so we need to recode them
239 */
240 if (!swdev) {
241 data->swap = -1;
242 return -EINVAL;
243 }
244 data->swap = swap_type_of(swdev, offset, &bdev);
245 if (data->swap < 0)
246 return -ENODEV;
247
248 data->bd_inode = bdev->bd_inode;
249 bdput(bdev);
250 return 0;
251}
252
253static long snapshot_ioctl(struct file *filp, unsigned int cmd,
254 unsigned long arg)
255{
256 int error = 0;
257 struct snapshot_data *data;
258 loff_t size;
259 sector_t offset;
260
261 if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC)
262 return -ENOTTY;
263 if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR)
264 return -ENOTTY;
265 if (!capable(CAP_SYS_ADMIN))
266 return -EPERM;
267
268 if (!mutex_trylock(&system_transition_mutex))
269 return -EBUSY;
270
271 lock_device_hotplug();
272 data = filp->private_data;
273
274 switch (cmd) {
275
276 case SNAPSHOT_FREEZE:
277 if (data->frozen)
278 break;
279
280 ksys_sync_helper();
281
282 error = freeze_processes();
283 if (error)
284 break;
285
286 error = create_basic_memory_bitmaps();
287 if (error)
288 thaw_processes();
289 else
290 data->frozen = true;
291
292 break;
293
294 case SNAPSHOT_UNFREEZE:
295 if (!data->frozen || data->ready)
296 break;
297 pm_restore_gfp_mask();
298 free_basic_memory_bitmaps();
299 data->free_bitmaps = false;
300 thaw_processes();
301 data->frozen = false;
302 break;
303
304 case SNAPSHOT_CREATE_IMAGE:
305 if (data->mode != O_RDONLY || !data->frozen || data->ready) {
306 error = -EPERM;
307 break;
308 }
309 pm_restore_gfp_mask();
310 error = hibernation_snapshot(data->platform_support);
311 if (!error) {
312 error = put_user(in_suspend, (int __user *)arg);
313 data->ready = !freezer_test_done && !error;
314 freezer_test_done = false;
315 }
316 break;
317
318 case SNAPSHOT_ATOMIC_RESTORE:
319 snapshot_write_finalize(&data->handle);
320 if (data->mode != O_WRONLY || !data->frozen ||
321 !snapshot_image_loaded(&data->handle)) {
322 error = -EPERM;
323 break;
324 }
325 error = hibernation_restore(data->platform_support);
326 break;
327
328 case SNAPSHOT_FREE:
329 swsusp_free();
330 memset(&data->handle, 0, sizeof(struct snapshot_handle));
331 data->ready = false;
332 /*
333 * It is necessary to thaw kernel threads here, because
334 * SNAPSHOT_CREATE_IMAGE may be invoked directly after
335 * SNAPSHOT_FREE. In that case, if kernel threads were not
336 * thawed, the preallocation of memory carried out by
337 * hibernation_snapshot() might run into problems (i.e. it
338 * might fail or even deadlock).
339 */
340 thaw_kernel_threads();
341 break;
342
343 case SNAPSHOT_PREF_IMAGE_SIZE:
344 image_size = arg;
345 break;
346
347 case SNAPSHOT_GET_IMAGE_SIZE:
348 if (!data->ready) {
349 error = -ENODATA;
350 break;
351 }
352 size = snapshot_get_image_size();
353 size <<= PAGE_SHIFT;
354 error = put_user(size, (loff_t __user *)arg);
355 break;
356
357 case SNAPSHOT_AVAIL_SWAP_SIZE:
358 size = count_swap_pages(data->swap, 1);
359 size <<= PAGE_SHIFT;
360 error = put_user(size, (loff_t __user *)arg);
361 break;
362
363 case SNAPSHOT_ALLOC_SWAP_PAGE:
364 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
365 error = -ENODEV;
366 break;
367 }
368 offset = alloc_swapdev_block(data->swap);
369 if (offset) {
370 offset <<= PAGE_SHIFT;
371 error = put_user(offset, (loff_t __user *)arg);
372 } else {
373 error = -ENOSPC;
374 }
375 break;
376
377 case SNAPSHOT_FREE_SWAP_PAGES:
378 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
379 error = -ENODEV;
380 break;
381 }
382 free_all_swap_pages(data->swap);
383 break;
384
385 case SNAPSHOT_S2RAM:
386 if (!data->frozen) {
387 error = -EPERM;
388 break;
389 }
390 /*
391 * Tasks are frozen and the notifiers have been called with
392 * PM_HIBERNATION_PREPARE
393 */
394 error = suspend_devices_and_enter(PM_SUSPEND_MEM);
395 data->ready = false;
396 break;
397
398 case SNAPSHOT_PLATFORM_SUPPORT:
399 data->platform_support = !!arg;
400 break;
401
402 case SNAPSHOT_POWER_OFF:
403 if (data->platform_support)
404 error = hibernation_platform_enter();
405 break;
406
407 case SNAPSHOT_SET_SWAP_AREA:
408 error = snapshot_set_swap_area(data, (void __user *)arg);
409 break;
410
411 default:
412 error = -ENOTTY;
413
414 }
415
416 unlock_device_hotplug();
417 mutex_unlock(&system_transition_mutex);
418
419 return error;
420}
421
422#ifdef CONFIG_COMPAT
423static long
424snapshot_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
425{
426 BUILD_BUG_ON(sizeof(loff_t) != sizeof(compat_loff_t));
427
428 switch (cmd) {
429 case SNAPSHOT_GET_IMAGE_SIZE:
430 case SNAPSHOT_AVAIL_SWAP_SIZE:
431 case SNAPSHOT_ALLOC_SWAP_PAGE:
432 case SNAPSHOT_CREATE_IMAGE:
433 case SNAPSHOT_SET_SWAP_AREA:
434 return snapshot_ioctl(file, cmd,
435 (unsigned long) compat_ptr(arg));
436 default:
437 return snapshot_ioctl(file, cmd, arg);
438 }
439}
440#endif /* CONFIG_COMPAT */
441
442static const struct file_operations snapshot_fops = {
443 .open = snapshot_open,
444 .release = snapshot_release,
445 .read = snapshot_read,
446 .write = snapshot_write,
447 .llseek = no_llseek,
448 .unlocked_ioctl = snapshot_ioctl,
449#ifdef CONFIG_COMPAT
450 .compat_ioctl = snapshot_compat_ioctl,
451#endif
452};
453
454static struct miscdevice snapshot_device = {
455 .minor = SNAPSHOT_MINOR,
456 .name = "snapshot",
457 .fops = &snapshot_fops,
458};
459
460static int __init snapshot_device_init(void)
461{
462 return misc_register(&snapshot_device);
463};
464
465device_initcall(snapshot_device_init);
1// SPDX-License-Identifier: GPL-2.0-only
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>
8 */
9
10#include <linux/suspend.h>
11#include <linux/reboot.h>
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>
20#include <linux/compat.h>
21#include <linux/console.h>
22#include <linux/cpu.h>
23#include <linux/freezer.h>
24
25#include <linux/uaccess.h>
26
27#include "power.h"
28
29
30#define SNAPSHOT_MINOR 231
31
32static struct snapshot_data {
33 struct snapshot_handle handle;
34 int swap;
35 int mode;
36 bool frozen;
37 bool ready;
38 bool platform_support;
39 bool free_bitmaps;
40} snapshot_state;
41
42atomic_t snapshot_device_available = ATOMIC_INIT(1);
43
44static int snapshot_open(struct inode *inode, struct file *filp)
45{
46 struct snapshot_data *data;
47 int error, nr_calls = 0;
48
49 if (!hibernation_available())
50 return -EPERM;
51
52 lock_system_sleep();
53
54 if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
55 error = -EBUSY;
56 goto Unlock;
57 }
58
59 if ((filp->f_flags & O_ACCMODE) == O_RDWR) {
60 atomic_inc(&snapshot_device_available);
61 error = -ENOSYS;
62 goto Unlock;
63 }
64 nonseekable_open(inode, filp);
65 data = &snapshot_state;
66 filp->private_data = data;
67 memset(&data->handle, 0, sizeof(struct snapshot_handle));
68 if ((filp->f_flags & O_ACCMODE) == O_RDONLY) {
69 /* Hibernating. The image device should be accessible. */
70 data->swap = swsusp_resume_device ?
71 swap_type_of(swsusp_resume_device, 0, NULL) : -1;
72 data->mode = O_RDONLY;
73 data->free_bitmaps = false;
74 error = __pm_notifier_call_chain(PM_HIBERNATION_PREPARE, -1, &nr_calls);
75 if (error)
76 __pm_notifier_call_chain(PM_POST_HIBERNATION, --nr_calls, NULL);
77 } else {
78 /*
79 * Resuming. We may need to wait for the image device to
80 * appear.
81 */
82 wait_for_device_probe();
83
84 data->swap = -1;
85 data->mode = O_WRONLY;
86 error = __pm_notifier_call_chain(PM_RESTORE_PREPARE, -1, &nr_calls);
87 if (!error) {
88 error = create_basic_memory_bitmaps();
89 data->free_bitmaps = !error;
90 } else
91 nr_calls--;
92
93 if (error)
94 __pm_notifier_call_chain(PM_POST_RESTORE, nr_calls, NULL);
95 }
96 if (error)
97 atomic_inc(&snapshot_device_available);
98
99 data->frozen = false;
100 data->ready = false;
101 data->platform_support = false;
102
103 Unlock:
104 unlock_system_sleep();
105
106 return error;
107}
108
109static int snapshot_release(struct inode *inode, struct file *filp)
110{
111 struct snapshot_data *data;
112
113 lock_system_sleep();
114
115 swsusp_free();
116 data = filp->private_data;
117 free_all_swap_pages(data->swap);
118 if (data->frozen) {
119 pm_restore_gfp_mask();
120 free_basic_memory_bitmaps();
121 thaw_processes();
122 } else if (data->free_bitmaps) {
123 free_basic_memory_bitmaps();
124 }
125 pm_notifier_call_chain(data->mode == O_RDONLY ?
126 PM_POST_HIBERNATION : PM_POST_RESTORE);
127 atomic_inc(&snapshot_device_available);
128
129 unlock_system_sleep();
130
131 return 0;
132}
133
134static ssize_t snapshot_read(struct file *filp, char __user *buf,
135 size_t count, loff_t *offp)
136{
137 struct snapshot_data *data;
138 ssize_t res;
139 loff_t pg_offp = *offp & ~PAGE_MASK;
140
141 lock_system_sleep();
142
143 data = filp->private_data;
144 if (!data->ready) {
145 res = -ENODATA;
146 goto Unlock;
147 }
148 if (!pg_offp) { /* on page boundary? */
149 res = snapshot_read_next(&data->handle);
150 if (res <= 0)
151 goto Unlock;
152 } else {
153 res = PAGE_SIZE - pg_offp;
154 }
155
156 res = simple_read_from_buffer(buf, count, &pg_offp,
157 data_of(data->handle), res);
158 if (res > 0)
159 *offp += res;
160
161 Unlock:
162 unlock_system_sleep();
163
164 return res;
165}
166
167static ssize_t snapshot_write(struct file *filp, const char __user *buf,
168 size_t count, loff_t *offp)
169{
170 struct snapshot_data *data;
171 ssize_t res;
172 loff_t pg_offp = *offp & ~PAGE_MASK;
173
174 lock_system_sleep();
175
176 data = filp->private_data;
177
178 if (!pg_offp) {
179 res = snapshot_write_next(&data->handle);
180 if (res <= 0)
181 goto unlock;
182 } else {
183 res = PAGE_SIZE - pg_offp;
184 }
185
186 if (!data_of(data->handle)) {
187 res = -EINVAL;
188 goto unlock;
189 }
190
191 res = simple_write_to_buffer(data_of(data->handle), res, &pg_offp,
192 buf, count);
193 if (res > 0)
194 *offp += res;
195unlock:
196 unlock_system_sleep();
197
198 return res;
199}
200
201static long snapshot_ioctl(struct file *filp, unsigned int cmd,
202 unsigned long arg)
203{
204 int error = 0;
205 struct snapshot_data *data;
206 loff_t size;
207 sector_t offset;
208
209 if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC)
210 return -ENOTTY;
211 if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR)
212 return -ENOTTY;
213 if (!capable(CAP_SYS_ADMIN))
214 return -EPERM;
215
216 if (!mutex_trylock(&system_transition_mutex))
217 return -EBUSY;
218
219 lock_device_hotplug();
220 data = filp->private_data;
221
222 switch (cmd) {
223
224 case SNAPSHOT_FREEZE:
225 if (data->frozen)
226 break;
227
228 ksys_sync_helper();
229
230 error = freeze_processes();
231 if (error)
232 break;
233
234 error = create_basic_memory_bitmaps();
235 if (error)
236 thaw_processes();
237 else
238 data->frozen = true;
239
240 break;
241
242 case SNAPSHOT_UNFREEZE:
243 if (!data->frozen || data->ready)
244 break;
245 pm_restore_gfp_mask();
246 free_basic_memory_bitmaps();
247 data->free_bitmaps = false;
248 thaw_processes();
249 data->frozen = false;
250 break;
251
252 case SNAPSHOT_CREATE_IMAGE:
253 if (data->mode != O_RDONLY || !data->frozen || data->ready) {
254 error = -EPERM;
255 break;
256 }
257 pm_restore_gfp_mask();
258 error = hibernation_snapshot(data->platform_support);
259 if (!error) {
260 error = put_user(in_suspend, (int __user *)arg);
261 data->ready = !freezer_test_done && !error;
262 freezer_test_done = false;
263 }
264 break;
265
266 case SNAPSHOT_ATOMIC_RESTORE:
267 snapshot_write_finalize(&data->handle);
268 if (data->mode != O_WRONLY || !data->frozen ||
269 !snapshot_image_loaded(&data->handle)) {
270 error = -EPERM;
271 break;
272 }
273 error = hibernation_restore(data->platform_support);
274 break;
275
276 case SNAPSHOT_FREE:
277 swsusp_free();
278 memset(&data->handle, 0, sizeof(struct snapshot_handle));
279 data->ready = false;
280 /*
281 * It is necessary to thaw kernel threads here, because
282 * SNAPSHOT_CREATE_IMAGE may be invoked directly after
283 * SNAPSHOT_FREE. In that case, if kernel threads were not
284 * thawed, the preallocation of memory carried out by
285 * hibernation_snapshot() might run into problems (i.e. it
286 * might fail or even deadlock).
287 */
288 thaw_kernel_threads();
289 break;
290
291 case SNAPSHOT_PREF_IMAGE_SIZE:
292 image_size = arg;
293 break;
294
295 case SNAPSHOT_GET_IMAGE_SIZE:
296 if (!data->ready) {
297 error = -ENODATA;
298 break;
299 }
300 size = snapshot_get_image_size();
301 size <<= PAGE_SHIFT;
302 error = put_user(size, (loff_t __user *)arg);
303 break;
304
305 case SNAPSHOT_AVAIL_SWAP_SIZE:
306 size = count_swap_pages(data->swap, 1);
307 size <<= PAGE_SHIFT;
308 error = put_user(size, (loff_t __user *)arg);
309 break;
310
311 case SNAPSHOT_ALLOC_SWAP_PAGE:
312 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
313 error = -ENODEV;
314 break;
315 }
316 offset = alloc_swapdev_block(data->swap);
317 if (offset) {
318 offset <<= PAGE_SHIFT;
319 error = put_user(offset, (loff_t __user *)arg);
320 } else {
321 error = -ENOSPC;
322 }
323 break;
324
325 case SNAPSHOT_FREE_SWAP_PAGES:
326 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
327 error = -ENODEV;
328 break;
329 }
330 free_all_swap_pages(data->swap);
331 break;
332
333 case SNAPSHOT_S2RAM:
334 if (!data->frozen) {
335 error = -EPERM;
336 break;
337 }
338 /*
339 * Tasks are frozen and the notifiers have been called with
340 * PM_HIBERNATION_PREPARE
341 */
342 error = suspend_devices_and_enter(PM_SUSPEND_MEM);
343 data->ready = false;
344 break;
345
346 case SNAPSHOT_PLATFORM_SUPPORT:
347 data->platform_support = !!arg;
348 break;
349
350 case SNAPSHOT_POWER_OFF:
351 if (data->platform_support)
352 error = hibernation_platform_enter();
353 break;
354
355 case SNAPSHOT_SET_SWAP_AREA:
356 if (swsusp_swap_in_use()) {
357 error = -EPERM;
358 } else {
359 struct resume_swap_area swap_area;
360 dev_t swdev;
361
362 error = copy_from_user(&swap_area, (void __user *)arg,
363 sizeof(struct resume_swap_area));
364 if (error) {
365 error = -EFAULT;
366 break;
367 }
368
369 /*
370 * User space encodes device types as two-byte values,
371 * so we need to recode them
372 */
373 swdev = new_decode_dev(swap_area.dev);
374 if (swdev) {
375 offset = swap_area.offset;
376 data->swap = swap_type_of(swdev, offset, NULL);
377 if (data->swap < 0)
378 error = -ENODEV;
379 } else {
380 data->swap = -1;
381 error = -EINVAL;
382 }
383 }
384 break;
385
386 default:
387 error = -ENOTTY;
388
389 }
390
391 unlock_device_hotplug();
392 mutex_unlock(&system_transition_mutex);
393
394 return error;
395}
396
397#ifdef CONFIG_COMPAT
398
399struct compat_resume_swap_area {
400 compat_loff_t offset;
401 u32 dev;
402} __packed;
403
404static long
405snapshot_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
406{
407 BUILD_BUG_ON(sizeof(loff_t) != sizeof(compat_loff_t));
408
409 switch (cmd) {
410 case SNAPSHOT_GET_IMAGE_SIZE:
411 case SNAPSHOT_AVAIL_SWAP_SIZE:
412 case SNAPSHOT_ALLOC_SWAP_PAGE: {
413 compat_loff_t __user *uoffset = compat_ptr(arg);
414 loff_t offset;
415 mm_segment_t old_fs;
416 int err;
417
418 old_fs = get_fs();
419 set_fs(KERNEL_DS);
420 err = snapshot_ioctl(file, cmd, (unsigned long) &offset);
421 set_fs(old_fs);
422 if (!err && put_user(offset, uoffset))
423 err = -EFAULT;
424 return err;
425 }
426
427 case SNAPSHOT_CREATE_IMAGE:
428 return snapshot_ioctl(file, cmd,
429 (unsigned long) compat_ptr(arg));
430
431 case SNAPSHOT_SET_SWAP_AREA: {
432 struct compat_resume_swap_area __user *u_swap_area =
433 compat_ptr(arg);
434 struct resume_swap_area swap_area;
435 mm_segment_t old_fs;
436 int err;
437
438 err = get_user(swap_area.offset, &u_swap_area->offset);
439 err |= get_user(swap_area.dev, &u_swap_area->dev);
440 if (err)
441 return -EFAULT;
442 old_fs = get_fs();
443 set_fs(KERNEL_DS);
444 err = snapshot_ioctl(file, SNAPSHOT_SET_SWAP_AREA,
445 (unsigned long) &swap_area);
446 set_fs(old_fs);
447 return err;
448 }
449
450 default:
451 return snapshot_ioctl(file, cmd, arg);
452 }
453}
454
455#endif /* CONFIG_COMPAT */
456
457static const struct file_operations snapshot_fops = {
458 .open = snapshot_open,
459 .release = snapshot_release,
460 .read = snapshot_read,
461 .write = snapshot_write,
462 .llseek = no_llseek,
463 .unlocked_ioctl = snapshot_ioctl,
464#ifdef CONFIG_COMPAT
465 .compat_ioctl = snapshot_compat_ioctl,
466#endif
467};
468
469static struct miscdevice snapshot_device = {
470 .minor = SNAPSHOT_MINOR,
471 .name = "snapshot",
472 .fops = &snapshot_fops,
473};
474
475static int __init snapshot_device_init(void)
476{
477 return misc_register(&snapshot_device);
478};
479
480device_initcall(snapshot_device_init);