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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
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
83
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) {
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 if (!data_of(data->handle)) {
190 res = -EINVAL;
191 goto unlock;
192 }
193
194 res = simple_write_to_buffer(data_of(data->handle), res, &pg_offp,
195 buf, count);
196 if (res > 0)
197 *offp += res;
198unlock:
199 unlock_system_sleep();
200
201 return res;
202}
203
204static long snapshot_ioctl(struct file *filp, unsigned int cmd,
205 unsigned long arg)
206{
207 int error = 0;
208 struct snapshot_data *data;
209 loff_t size;
210 sector_t offset;
211
212 if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC)
213 return -ENOTTY;
214 if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR)
215 return -ENOTTY;
216 if (!capable(CAP_SYS_ADMIN))
217 return -EPERM;
218
219 if (!mutex_trylock(&system_transition_mutex))
220 return -EBUSY;
221
222 lock_device_hotplug();
223 data = filp->private_data;
224
225 switch (cmd) {
226
227 case SNAPSHOT_FREEZE:
228 if (data->frozen)
229 break;
230
231 printk("Syncing filesystems ... ");
232 ksys_sync();
233 printk("done.\n");
234
235 error = freeze_processes();
236 if (error)
237 break;
238
239 error = create_basic_memory_bitmaps();
240 if (error)
241 thaw_processes();
242 else
243 data->frozen = true;
244
245 break;
246
247 case SNAPSHOT_UNFREEZE:
248 if (!data->frozen || data->ready)
249 break;
250 pm_restore_gfp_mask();
251 free_basic_memory_bitmaps();
252 data->free_bitmaps = false;
253 thaw_processes();
254 data->frozen = false;
255 break;
256
257 case SNAPSHOT_CREATE_IMAGE:
258 if (data->mode != O_RDONLY || !data->frozen || data->ready) {
259 error = -EPERM;
260 break;
261 }
262 pm_restore_gfp_mask();
263 error = hibernation_snapshot(data->platform_support);
264 if (!error) {
265 error = put_user(in_suspend, (int __user *)arg);
266 data->ready = !freezer_test_done && !error;
267 freezer_test_done = false;
268 }
269 break;
270
271 case SNAPSHOT_ATOMIC_RESTORE:
272 snapshot_write_finalize(&data->handle);
273 if (data->mode != O_WRONLY || !data->frozen ||
274 !snapshot_image_loaded(&data->handle)) {
275 error = -EPERM;
276 break;
277 }
278 error = hibernation_restore(data->platform_support);
279 break;
280
281 case SNAPSHOT_FREE:
282 swsusp_free();
283 memset(&data->handle, 0, sizeof(struct snapshot_handle));
284 data->ready = false;
285
286
287
288
289
290
291
292
293 thaw_kernel_threads();
294 break;
295
296 case SNAPSHOT_PREF_IMAGE_SIZE:
297 image_size = arg;
298 break;
299
300 case SNAPSHOT_GET_IMAGE_SIZE:
301 if (!data->ready) {
302 error = -ENODATA;
303 break;
304 }
305 size = snapshot_get_image_size();
306 size <<= PAGE_SHIFT;
307 error = put_user(size, (loff_t __user *)arg);
308 break;
309
310 case SNAPSHOT_AVAIL_SWAP_SIZE:
311 size = count_swap_pages(data->swap, 1);
312 size <<= PAGE_SHIFT;
313 error = put_user(size, (loff_t __user *)arg);
314 break;
315
316 case SNAPSHOT_ALLOC_SWAP_PAGE:
317 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
318 error = -ENODEV;
319 break;
320 }
321 offset = alloc_swapdev_block(data->swap);
322 if (offset) {
323 offset <<= PAGE_SHIFT;
324 error = put_user(offset, (loff_t __user *)arg);
325 } else {
326 error = -ENOSPC;
327 }
328 break;
329
330 case SNAPSHOT_FREE_SWAP_PAGES:
331 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
332 error = -ENODEV;
333 break;
334 }
335 free_all_swap_pages(data->swap);
336 break;
337
338 case SNAPSHOT_S2RAM:
339 if (!data->frozen) {
340 error = -EPERM;
341 break;
342 }
343
344
345
346
347 error = suspend_devices_and_enter(PM_SUSPEND_MEM);
348 data->ready = false;
349 break;
350
351 case SNAPSHOT_PLATFORM_SUPPORT:
352 data->platform_support = !!arg;
353 break;
354
355 case SNAPSHOT_POWER_OFF:
356 if (data->platform_support)
357 error = hibernation_platform_enter();
358 break;
359
360 case SNAPSHOT_SET_SWAP_AREA:
361 if (swsusp_swap_in_use()) {
362 error = -EPERM;
363 } else {
364 struct resume_swap_area swap_area;
365 dev_t swdev;
366
367 error = copy_from_user(&swap_area, (void __user *)arg,
368 sizeof(struct resume_swap_area));
369 if (error) {
370 error = -EFAULT;
371 break;
372 }
373
374
375
376
377
378 swdev = new_decode_dev(swap_area.dev);
379 if (swdev) {
380 offset = swap_area.offset;
381 data->swap = swap_type_of(swdev, offset, NULL);
382 if (data->swap < 0)
383 error = -ENODEV;
384 } else {
385 data->swap = -1;
386 error = -EINVAL;
387 }
388 }
389 break;
390
391 default:
392 error = -ENOTTY;
393
394 }
395
396 unlock_device_hotplug();
397 mutex_unlock(&system_transition_mutex);
398
399 return error;
400}
401
402#ifdef CONFIG_COMPAT
403
404struct compat_resume_swap_area {
405 compat_loff_t offset;
406 u32 dev;
407} __packed;
408
409static long
410snapshot_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:
417 case SNAPSHOT_ALLOC_SWAP_PAGE: {
418 compat_loff_t __user *uoffset = compat_ptr(arg);
419 loff_t offset;
420 mm_segment_t old_fs;
421 int err;
422
423 old_fs = get_fs();
424 set_fs(KERNEL_DS);
425 err = snapshot_ioctl(file, cmd, (unsigned long) &offset);
426 set_fs(old_fs);
427 if (!err && put_user(offset, uoffset))
428 err = -EFAULT;
429 return err;
430 }
431
432 case SNAPSHOT_CREATE_IMAGE:
433 return snapshot_ioctl(file, cmd,
434 (unsigned long) compat_ptr(arg));
435
436 case SNAPSHOT_SET_SWAP_AREA: {
437 struct compat_resume_swap_area __user *u_swap_area =
438 compat_ptr(arg);
439 struct resume_swap_area swap_area;
440 mm_segment_t old_fs;
441 int err;
442
443 err = get_user(swap_area.offset, &u_swap_area->offset);
444 err |= get_user(swap_area.dev, &u_swap_area->dev);
445 if (err)
446 return -EFAULT;
447 old_fs = get_fs();
448 set_fs(KERNEL_DS);
449 err = snapshot_ioctl(file, SNAPSHOT_SET_SWAP_AREA,
450 (unsigned long) &swap_area);
451 set_fs(old_fs);
452 return err;
453 }
454
455 default:
456 return snapshot_ioctl(file, cmd, arg);
457 }
458}
459
460#endif
461
462static const struct file_operations snapshot_fops = {
463 .open = snapshot_open,
464 .release = snapshot_release,
465 .read = snapshot_read,
466 .write = snapshot_write,
467 .llseek = no_llseek,
468 .unlocked_ioctl = snapshot_ioctl,
469#ifdef CONFIG_COMPAT
470 .compat_ioctl = snapshot_compat_ioctl,
471#endif
472};
473
474static struct miscdevice snapshot_device = {
475 .minor = SNAPSHOT_MINOR,
476 .name = "snapshot",
477 .fops = &snapshot_fops,
478};
479
480static int __init snapshot_device_init(void)
481{
482 return misc_register(&snapshot_device);
483};
484
485device_initcall(snapshot_device_init);
486
