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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/*
2 * linux/kernel/power/user.c
3 *
4 * This file provides the user space interface for software suspend/resume.
5 *
6 * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
7 *
8 * This file is released under the GPLv2.
9 *
10 */
11
12#include <linux/suspend.h>
13#include <linux/syscalls.h>
14#include <linux/reboot.h>
15#include <linux/string.h>
16#include <linux/device.h>
17#include <linux/miscdevice.h>
18#include <linux/mm.h>
19#include <linux/swap.h>
20#include <linux/swapops.h>
21#include <linux/pm.h>
22#include <linux/fs.h>
23#include <linux/compat.h>
24#include <linux/console.h>
25#include <linux/cpu.h>
26#include <linux/freezer.h>
27
28#include <asm/uaccess.h>
29
30#include "power.h"
31
32
33#define SNAPSHOT_MINOR 231
34
35static struct snapshot_data {
36 struct snapshot_handle handle;
37 int swap;
38 int mode;
39 bool frozen;
40 bool ready;
41 bool platform_support;
42 bool free_bitmaps;
43} snapshot_state;
44
45atomic_t snapshot_device_available = ATOMIC_INIT(1);
46
47static int snapshot_open(struct inode *inode, struct file *filp)
48{
49 struct snapshot_data *data;
50 int error;
51
52 if (!hibernation_available())
53 return -EPERM;
54
55 lock_system_sleep();
56
57 if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
58 error = -EBUSY;
59 goto Unlock;
60 }
61
62 if ((filp->f_flags & O_ACCMODE) == O_RDWR) {
63 atomic_inc(&snapshot_device_available);
64 error = -ENOSYS;
65 goto Unlock;
66 }
67 nonseekable_open(inode, filp);
68 data = &snapshot_state;
69 filp->private_data = data;
70 memset(&data->handle, 0, sizeof(struct snapshot_handle));
71 if ((filp->f_flags & O_ACCMODE) == O_RDONLY) {
72 /* Hibernating. The image device should be accessible. */
73 data->swap = swsusp_resume_device ?
74 swap_type_of(swsusp_resume_device, 0, NULL) : -1;
75 data->mode = O_RDONLY;
76 data->free_bitmaps = false;
77 error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
78 if (error)
79 pm_notifier_call_chain(PM_POST_HIBERNATION);
80 } else {
81 /*
82 * Resuming. We may need to wait for the image device to
83 * appear.
84 */
85 wait_for_device_probe();
86
87 data->swap = -1;
88 data->mode = O_WRONLY;
89 error = pm_notifier_call_chain(PM_RESTORE_PREPARE);
90 if (!error) {
91 error = create_basic_memory_bitmaps();
92 data->free_bitmaps = !error;
93 }
94 if (error)
95 pm_notifier_call_chain(PM_POST_RESTORE);
96 }
97 if (error)
98 atomic_inc(&snapshot_device_available);
99
100 data->frozen = false;
101 data->ready = false;
102 data->platform_support = false;
103
104 Unlock:
105 unlock_system_sleep();
106
107 return error;
108}
109
110static int snapshot_release(struct inode *inode, struct file *filp)
111{
112 struct snapshot_data *data;
113
114 lock_system_sleep();
115
116 swsusp_free();
117 data = filp->private_data;
118 free_all_swap_pages(data->swap);
119 if (data->frozen) {
120 pm_restore_gfp_mask();
121 free_basic_memory_bitmaps();
122 thaw_processes();
123 } else if (data->free_bitmaps) {
124 free_basic_memory_bitmaps();
125 }
126 pm_notifier_call_chain(data->mode == O_RDONLY ?
127 PM_POST_HIBERNATION : PM_POST_RESTORE);
128 atomic_inc(&snapshot_device_available);
129
130 unlock_system_sleep();
131
132 return 0;
133}
134
135static ssize_t snapshot_read(struct file *filp, char __user *buf,
136 size_t count, loff_t *offp)
137{
138 struct snapshot_data *data;
139 ssize_t res;
140 loff_t pg_offp = *offp & ~PAGE_MASK;
141
142 lock_system_sleep();
143
144 data = filp->private_data;
145 if (!data->ready) {
146 res = -ENODATA;
147 goto Unlock;
148 }
149 if (!pg_offp) { /* on page boundary? */
150 res = snapshot_read_next(&data->handle);
151 if (res <= 0)
152 goto Unlock;
153 } else {
154 res = PAGE_SIZE - pg_offp;
155 }
156
157 res = simple_read_from_buffer(buf, count, &pg_offp,
158 data_of(data->handle), res);
159 if (res > 0)
160 *offp += res;
161
162 Unlock:
163 unlock_system_sleep();
164
165 return res;
166}
167
168static ssize_t snapshot_write(struct file *filp, const char __user *buf,
169 size_t count, loff_t *offp)
170{
171 struct snapshot_data *data;
172 ssize_t res;
173 loff_t pg_offp = *offp & ~PAGE_MASK;
174
175 lock_system_sleep();
176
177 data = filp->private_data;
178
179 if (!pg_offp) {
180 res = snapshot_write_next(&data->handle);
181 if (res <= 0)
182 goto unlock;
183 } else {
184 res = PAGE_SIZE - pg_offp;
185 }
186
187 res = simple_write_to_buffer(data_of(data->handle), res, &pg_offp,
188 buf, count);
189 if (res > 0)
190 *offp += res;
191unlock:
192 unlock_system_sleep();
193
194 return res;
195}
196
197static long snapshot_ioctl(struct file *filp, unsigned int cmd,
198 unsigned long arg)
199{
200 int error = 0;
201 struct snapshot_data *data;
202 loff_t size;
203 sector_t offset;
204
205 if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC)
206 return -ENOTTY;
207 if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR)
208 return -ENOTTY;
209 if (!capable(CAP_SYS_ADMIN))
210 return -EPERM;
211
212 if (!mutex_trylock(&pm_mutex))
213 return -EBUSY;
214
215 lock_device_hotplug();
216 data = filp->private_data;
217
218 switch (cmd) {
219
220 case SNAPSHOT_FREEZE:
221 if (data->frozen)
222 break;
223
224 printk("Syncing filesystems ... ");
225 sys_sync();
226 printk("done.\n");
227
228 error = freeze_processes();
229 if (error)
230 break;
231
232 error = create_basic_memory_bitmaps();
233 if (error)
234 thaw_processes();
235 else
236 data->frozen = true;
237
238 break;
239
240 case SNAPSHOT_UNFREEZE:
241 if (!data->frozen || data->ready)
242 break;
243 pm_restore_gfp_mask();
244 free_basic_memory_bitmaps();
245 data->free_bitmaps = false;
246 thaw_processes();
247 data->frozen = false;
248 break;
249
250 case SNAPSHOT_CREATE_IMAGE:
251 if (data->mode != O_RDONLY || !data->frozen || data->ready) {
252 error = -EPERM;
253 break;
254 }
255 pm_restore_gfp_mask();
256 error = hibernation_snapshot(data->platform_support);
257 if (!error) {
258 error = put_user(in_suspend, (int __user *)arg);
259 data->ready = !freezer_test_done && !error;
260 freezer_test_done = false;
261 }
262 break;
263
264 case SNAPSHOT_ATOMIC_RESTORE:
265 snapshot_write_finalize(&data->handle);
266 if (data->mode != O_WRONLY || !data->frozen ||
267 !snapshot_image_loaded(&data->handle)) {
268 error = -EPERM;
269 break;
270 }
271 error = hibernation_restore(data->platform_support);
272 break;
273
274 case SNAPSHOT_FREE:
275 swsusp_free();
276 memset(&data->handle, 0, sizeof(struct snapshot_handle));
277 data->ready = false;
278 /*
279 * It is necessary to thaw kernel threads here, because
280 * SNAPSHOT_CREATE_IMAGE may be invoked directly after
281 * SNAPSHOT_FREE. In that case, if kernel threads were not
282 * thawed, the preallocation of memory carried out by
283 * hibernation_snapshot() might run into problems (i.e. it
284 * might fail or even deadlock).
285 */
286 thaw_kernel_threads();
287 break;
288
289 case SNAPSHOT_PREF_IMAGE_SIZE:
290 image_size = arg;
291 break;
292
293 case SNAPSHOT_GET_IMAGE_SIZE:
294 if (!data->ready) {
295 error = -ENODATA;
296 break;
297 }
298 size = snapshot_get_image_size();
299 size <<= PAGE_SHIFT;
300 error = put_user(size, (loff_t __user *)arg);
301 break;
302
303 case SNAPSHOT_AVAIL_SWAP_SIZE:
304 size = count_swap_pages(data->swap, 1);
305 size <<= PAGE_SHIFT;
306 error = put_user(size, (loff_t __user *)arg);
307 break;
308
309 case SNAPSHOT_ALLOC_SWAP_PAGE:
310 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
311 error = -ENODEV;
312 break;
313 }
314 offset = alloc_swapdev_block(data->swap);
315 if (offset) {
316 offset <<= PAGE_SHIFT;
317 error = put_user(offset, (loff_t __user *)arg);
318 } else {
319 error = -ENOSPC;
320 }
321 break;
322
323 case SNAPSHOT_FREE_SWAP_PAGES:
324 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
325 error = -ENODEV;
326 break;
327 }
328 free_all_swap_pages(data->swap);
329 break;
330
331 case SNAPSHOT_S2RAM:
332 if (!data->frozen) {
333 error = -EPERM;
334 break;
335 }
336 /*
337 * Tasks are frozen and the notifiers have been called with
338 * PM_HIBERNATION_PREPARE
339 */
340 error = suspend_devices_and_enter(PM_SUSPEND_MEM);
341 data->ready = false;
342 break;
343
344 case SNAPSHOT_PLATFORM_SUPPORT:
345 data->platform_support = !!arg;
346 break;
347
348 case SNAPSHOT_POWER_OFF:
349 if (data->platform_support)
350 error = hibernation_platform_enter();
351 break;
352
353 case SNAPSHOT_SET_SWAP_AREA:
354 if (swsusp_swap_in_use()) {
355 error = -EPERM;
356 } else {
357 struct resume_swap_area swap_area;
358 dev_t swdev;
359
360 error = copy_from_user(&swap_area, (void __user *)arg,
361 sizeof(struct resume_swap_area));
362 if (error) {
363 error = -EFAULT;
364 break;
365 }
366
367 /*
368 * User space encodes device types as two-byte values,
369 * so we need to recode them
370 */
371 swdev = new_decode_dev(swap_area.dev);
372 if (swdev) {
373 offset = swap_area.offset;
374 data->swap = swap_type_of(swdev, offset, NULL);
375 if (data->swap < 0)
376 error = -ENODEV;
377 } else {
378 data->swap = -1;
379 error = -EINVAL;
380 }
381 }
382 break;
383
384 default:
385 error = -ENOTTY;
386
387 }
388
389 unlock_device_hotplug();
390 mutex_unlock(&pm_mutex);
391
392 return error;
393}
394
395#ifdef CONFIG_COMPAT
396
397struct compat_resume_swap_area {
398 compat_loff_t offset;
399 u32 dev;
400} __packed;
401
402static long
403snapshot_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
404{
405 BUILD_BUG_ON(sizeof(loff_t) != sizeof(compat_loff_t));
406
407 switch (cmd) {
408 case SNAPSHOT_GET_IMAGE_SIZE:
409 case SNAPSHOT_AVAIL_SWAP_SIZE:
410 case SNAPSHOT_ALLOC_SWAP_PAGE: {
411 compat_loff_t __user *uoffset = compat_ptr(arg);
412 loff_t offset;
413 mm_segment_t old_fs;
414 int err;
415
416 old_fs = get_fs();
417 set_fs(KERNEL_DS);
418 err = snapshot_ioctl(file, cmd, (unsigned long) &offset);
419 set_fs(old_fs);
420 if (!err && put_user(offset, uoffset))
421 err = -EFAULT;
422 return err;
423 }
424
425 case SNAPSHOT_CREATE_IMAGE:
426 return snapshot_ioctl(file, cmd,
427 (unsigned long) compat_ptr(arg));
428
429 case SNAPSHOT_SET_SWAP_AREA: {
430 struct compat_resume_swap_area __user *u_swap_area =
431 compat_ptr(arg);
432 struct resume_swap_area swap_area;
433 mm_segment_t old_fs;
434 int err;
435
436 err = get_user(swap_area.offset, &u_swap_area->offset);
437 err |= get_user(swap_area.dev, &u_swap_area->dev);
438 if (err)
439 return -EFAULT;
440 old_fs = get_fs();
441 set_fs(KERNEL_DS);
442 err = snapshot_ioctl(file, SNAPSHOT_SET_SWAP_AREA,
443 (unsigned long) &swap_area);
444 set_fs(old_fs);
445 return err;
446 }
447
448 default:
449 return snapshot_ioctl(file, cmd, arg);
450 }
451}
452
453#endif /* CONFIG_COMPAT */
454
455static const struct file_operations snapshot_fops = {
456 .open = snapshot_open,
457 .release = snapshot_release,
458 .read = snapshot_read,
459 .write = snapshot_write,
460 .llseek = no_llseek,
461 .unlocked_ioctl = snapshot_ioctl,
462#ifdef CONFIG_COMPAT
463 .compat_ioctl = snapshot_compat_ioctl,
464#endif
465};
466
467static struct miscdevice snapshot_device = {
468 .minor = SNAPSHOT_MINOR,
469 .name = "snapshot",
470 .fops = &snapshot_fops,
471};
472
473static int __init snapshot_device_init(void)
474{
475 return misc_register(&snapshot_device);
476};
477
478device_initcall(snapshot_device_init);