1
2
3
4
5
6
7
8
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
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
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);
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) {
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
280
281
282
283
284
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
338
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
369
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
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);
479
