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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#include <linux/security.h>
28
29#include <asm/uaccess.h>
30
31#include "power.h"
32
33
34#define SNAPSHOT_MINOR 231
35
36static struct snapshot_data {
37 struct snapshot_handle handle;
38 int swap;
39 int mode;
40 char frozen;
41 char ready;
42 char platform_support;
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 (get_securelevel() > 0)
53 return -EPERM;
54
55 if (!hibernation_available())
56 return -EPERM;
57
58 lock_system_sleep();
59
60 if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
61 error = -EBUSY;
62 goto Unlock;
63 }
64
65 if ((filp->f_flags & O_ACCMODE) == O_RDWR) {
66 atomic_inc(&snapshot_device_available);
67 error = -ENOSYS;
68 goto Unlock;
69 }
70 nonseekable_open(inode, filp);
71 data = &snapshot_state;
72 filp->private_data = data;
73 memset(&data->handle, 0, sizeof(struct snapshot_handle));
74 if ((filp->f_flags & O_ACCMODE) == O_RDONLY) {
75
76 data->swap = swsusp_resume_device ?
77 swap_type_of(swsusp_resume_device, 0, NULL) : -1;
78 data->mode = O_RDONLY;
79 error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
80 if (error)
81 pm_notifier_call_chain(PM_POST_HIBERNATION);
82 } else {
83
84
85
86
87 wait_for_device_probe();
88
89 data->swap = -1;
90 data->mode = O_WRONLY;
91 error = pm_notifier_call_chain(PM_RESTORE_PREPARE);
92 if (error)
93 pm_notifier_call_chain(PM_POST_RESTORE);
94 }
95 if (error)
96 atomic_inc(&snapshot_device_available);
97
98 data->frozen = 0;
99 data->ready = 0;
100 data->platform_support = 0;
101
102 Unlock:
103 unlock_system_sleep();
104
105 return error;
106}
107
108static int snapshot_release(struct inode *inode, struct file *filp)
109{
110 struct snapshot_data *data;
111
112 lock_system_sleep();
113
114 swsusp_free();
115 data = filp->private_data;
116 free_all_swap_pages(data->swap);
117 if (data->frozen) {
118 pm_restore_gfp_mask();
119 free_basic_memory_bitmaps();
120 thaw_processes();
121 }
122 pm_notifier_call_chain(data->mode == O_RDONLY ?
123 PM_POST_HIBERNATION : PM_POST_RESTORE);
124 atomic_inc(&snapshot_device_available);
125
126 unlock_system_sleep();
127
128 return 0;
129}
130
131static ssize_t snapshot_read(struct file *filp, char __user *buf,
132 size_t count, loff_t *offp)
133{
134 struct snapshot_data *data;
135 ssize_t res;
136 loff_t pg_offp = *offp & ~PAGE_MASK;
137
138 lock_system_sleep();
139
140 data = filp->private_data;
141 if (!data->ready) {
142 res = -ENODATA;
143 goto Unlock;
144 }
145 if (!pg_offp) {
146 res = snapshot_read_next(&data->handle);
147 if (res <= 0)
148 goto Unlock;
149 } else {
150 res = PAGE_SIZE - pg_offp;
151 }
152
153 res = simple_read_from_buffer(buf, count, &pg_offp,
154 data_of(data->handle), res);
155 if (res > 0)
156 *offp += res;
157
158 Unlock:
159 unlock_system_sleep();
160
161 return res;
162}
163
164static ssize_t snapshot_write(struct file *filp, const char __user *buf,
165 size_t count, loff_t *offp)
166{
167 struct snapshot_data *data;
168 ssize_t res;
169 loff_t pg_offp = *offp & ~PAGE_MASK;
170
171 lock_system_sleep();
172
173 data = filp->private_data;
174
175 if (!pg_offp) {
176 res = snapshot_write_next(&data->handle);
177 if (res <= 0)
178 goto unlock;
179 } else {
180 res = PAGE_SIZE - pg_offp;
181 }
182
183 res = simple_write_to_buffer(data_of(data->handle), res, &pg_offp,
184 buf, count);
185 if (res > 0)
186 *offp += res;
187unlock:
188 unlock_system_sleep();
189
190 return res;
191}
192
193static long snapshot_ioctl(struct file *filp, unsigned int cmd,
194 unsigned long arg)
195{
196 int error = 0;
197 struct snapshot_data *data;
198 loff_t size;
199 sector_t offset;
200
201 if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC)
202 return -ENOTTY;
203 if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR)
204 return -ENOTTY;
205 if (!capable(CAP_SYS_ADMIN))
206 return -EPERM;
207
208 if (!mutex_trylock(&pm_mutex))
209 return -EBUSY;
210
211 lock_device_hotplug();
212 data = filp->private_data;
213
214 switch (cmd) {
215
216 case SNAPSHOT_FREEZE:
217 if (data->frozen)
218 break;
219
220 printk("Syncing filesystems ... ");
221 sys_sync();
222 printk("done.\n");
223
224 error = freeze_processes();
225 if (error)
226 break;
227
228 error = create_basic_memory_bitmaps();
229 if (error)
230 thaw_processes();
231 else
232 data->frozen = 1;
233
234 break;
235
236 case SNAPSHOT_UNFREEZE:
237 if (!data->frozen || data->ready)
238 break;
239 pm_restore_gfp_mask();
240 free_basic_memory_bitmaps();
241 thaw_processes();
242 data->frozen = 0;
243 break;
244
245 case SNAPSHOT_CREATE_IMAGE:
246 if (data->mode != O_RDONLY || !data->frozen || data->ready) {
247 error = -EPERM;
248 break;
249 }
250 pm_restore_gfp_mask();
251 error = hibernation_snapshot(data->platform_support);
252 if (!error) {
253 error = put_user(in_suspend, (int __user *)arg);
254 data->ready = !freezer_test_done && !error;
255 freezer_test_done = false;
256 }
257 break;
258
259 case SNAPSHOT_ATOMIC_RESTORE:
260 snapshot_write_finalize(&data->handle);
261 if (data->mode != O_WRONLY || !data->frozen ||
262 !snapshot_image_loaded(&data->handle)) {
263 error = -EPERM;
264 break;
265 }
266 error = hibernation_restore(data->platform_support);
267 break;
268
269 case SNAPSHOT_FREE:
270 swsusp_free();
271 memset(&data->handle, 0, sizeof(struct snapshot_handle));
272 data->ready = 0;
273
274
275
276
277
278
279
280
281 thaw_kernel_threads();
282 break;
283
284 case SNAPSHOT_PREF_IMAGE_SIZE:
285 image_size = arg;
286 break;
287
288 case SNAPSHOT_GET_IMAGE_SIZE:
289 if (!data->ready) {
290 error = -ENODATA;
291 break;
292 }
293 size = snapshot_get_image_size();
294 size <<= PAGE_SHIFT;
295 error = put_user(size, (loff_t __user *)arg);
296 break;
297
298 case SNAPSHOT_AVAIL_SWAP_SIZE:
299 size = count_swap_pages(data->swap, 1);
300 size <<= PAGE_SHIFT;
301 error = put_user(size, (loff_t __user *)arg);
302 break;
303
304 case SNAPSHOT_ALLOC_SWAP_PAGE:
305 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
306 error = -ENODEV;
307 break;
308 }
309 offset = alloc_swapdev_block(data->swap);
310 if (offset) {
311 offset <<= PAGE_SHIFT;
312 error = put_user(offset, (loff_t __user *)arg);
313 } else {
314 error = -ENOSPC;
315 }
316 break;
317
318 case SNAPSHOT_FREE_SWAP_PAGES:
319 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
320 error = -ENODEV;
321 break;
322 }
323 free_all_swap_pages(data->swap);
324 break;
325
326 case SNAPSHOT_S2RAM:
327 if (!data->frozen) {
328 error = -EPERM;
329 break;
330 }
331
332
333
334
335 error = suspend_devices_and_enter(PM_SUSPEND_MEM);
336 data->ready = 0;
337 break;
338
339 case SNAPSHOT_PLATFORM_SUPPORT:
340 data->platform_support = !!arg;
341 break;
342
343 case SNAPSHOT_POWER_OFF:
344 if (data->platform_support)
345 error = hibernation_platform_enter();
346 break;
347
348 case SNAPSHOT_SET_SWAP_AREA:
349 if (swsusp_swap_in_use()) {
350 error = -EPERM;
351 } else {
352 struct resume_swap_area swap_area;
353 dev_t swdev;
354
355 error = copy_from_user(&swap_area, (void __user *)arg,
356 sizeof(struct resume_swap_area));
357 if (error) {
358 error = -EFAULT;
359 break;
360 }
361
362
363
364
365
366 swdev = new_decode_dev(swap_area.dev);
367 if (swdev) {
368 offset = swap_area.offset;
369 data->swap = swap_type_of(swdev, offset, NULL);
370 if (data->swap < 0)
371 error = -ENODEV;
372 } else {
373 data->swap = -1;
374 error = -EINVAL;
375 }
376 }
377 break;
378
379 default:
380 error = -ENOTTY;
381
382 }
383
384 unlock_device_hotplug();
385 mutex_unlock(&pm_mutex);
386
387 return error;
388}
389
390#ifdef CONFIG_COMPAT
391
392struct compat_resume_swap_area {
393 compat_loff_t offset;
394 u32 dev;
395} __packed;
396
397static long
398snapshot_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
399{
400 BUILD_BUG_ON(sizeof(loff_t) != sizeof(compat_loff_t));
401
402 switch (cmd) {
403 case SNAPSHOT_GET_IMAGE_SIZE:
404 case SNAPSHOT_AVAIL_SWAP_SIZE:
405 case SNAPSHOT_ALLOC_SWAP_PAGE: {
406 compat_loff_t __user *uoffset = compat_ptr(arg);
407 loff_t offset;
408 mm_segment_t old_fs;
409 int err;
410
411 old_fs = get_fs();
412 set_fs(KERNEL_DS);
413 err = snapshot_ioctl(file, cmd, (unsigned long) &offset);
414 set_fs(old_fs);
415 if (!err && put_user(offset, uoffset))
416 err = -EFAULT;
417 return err;
418 }
419
420 case SNAPSHOT_CREATE_IMAGE:
421 return snapshot_ioctl(file, cmd,
422 (unsigned long) compat_ptr(arg));
423
424 case SNAPSHOT_SET_SWAP_AREA: {
425 struct compat_resume_swap_area __user *u_swap_area =
426 compat_ptr(arg);
427 struct resume_swap_area swap_area;
428 mm_segment_t old_fs;
429 int err;
430
431 err = get_user(swap_area.offset, &u_swap_area->offset);
432 err |= get_user(swap_area.dev, &u_swap_area->dev);
433 if (err)
434 return -EFAULT;
435 old_fs = get_fs();
436 set_fs(KERNEL_DS);
437 err = snapshot_ioctl(file, SNAPSHOT_SET_SWAP_AREA,
438 (unsigned long) &swap_area);
439 set_fs(old_fs);
440 return err;
441 }
442
443 default:
444 return snapshot_ioctl(file, cmd, arg);
445 }
446}
447
448#endif
449
450static const struct file_operations snapshot_fops = {
451 .open = snapshot_open,
452 .release = snapshot_release,
453 .read = snapshot_read,
454 .write = snapshot_write,
455 .llseek = no_llseek,
456 .unlocked_ioctl = snapshot_ioctl,
457#ifdef CONFIG_COMPAT
458 .compat_ioctl = snapshot_compat_ioctl,
459#endif
460};
461
462static struct miscdevice snapshot_device = {
463 .minor = SNAPSHOT_MINOR,
464 .name = "snapshot",
465 .fops = &snapshot_fops,
466};
467
468static int __init snapshot_device_init(void)
469{
470 return misc_register(&snapshot_device);
471};
472
473device_initcall(snapshot_device_init);
474
