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