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