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PM / Hibernate: Fix memory corruption related to swap
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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>
3592695c 14#include <linux/reboot.h>
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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>
97c7801c 23#include <linux/console.h>
e3920fb4 24#include <linux/cpu.h>
7dfb7103 25#include <linux/freezer.h>
c7510859 26#include <scsi/scsi_scan.h>
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27
28#include <asm/uaccess.h>
29
30#include "power.h"
31
eb57c1cf 32/*
96f73749
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33 * NOTE: The SNAPSHOT_SET_SWAP_FILE and SNAPSHOT_PMOPS ioctls are obsolete and
34 * will be removed in the future. They are only preserved here for
35 * compatibility with existing userland utilities.
eb57c1cf 36 */
96f73749 37#define SNAPSHOT_SET_SWAP_FILE _IOW(SNAPSHOT_IOC_MAGIC, 10, unsigned int)
eb57c1cf
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38#define SNAPSHOT_PMOPS _IOW(SNAPSHOT_IOC_MAGIC, 12, unsigned int)
39
40#define PMOPS_PREPARE 1
41#define PMOPS_ENTER 2
42#define PMOPS_FINISH 3
43
cc5d207c
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44/*
45 * NOTE: The following ioctl definitions are wrong and have been replaced with
46 * correct ones. They are only preserved here for compatibility with existing
47 * userland utilities and will be removed in the future.
48 */
49#define SNAPSHOT_ATOMIC_SNAPSHOT _IOW(SNAPSHOT_IOC_MAGIC, 3, void *)
50#define SNAPSHOT_SET_IMAGE_SIZE _IOW(SNAPSHOT_IOC_MAGIC, 6, unsigned long)
51#define SNAPSHOT_AVAIL_SWAP _IOR(SNAPSHOT_IOC_MAGIC, 7, void *)
52#define SNAPSHOT_GET_SWAP_PAGE _IOR(SNAPSHOT_IOC_MAGIC, 8, void *)
53
eb57c1cf 54
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55#define SNAPSHOT_MINOR 231
56
57static struct snapshot_data {
58 struct snapshot_handle handle;
59 int swap;
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60 int mode;
61 char frozen;
62 char ready;
eb57c1cf 63 char platform_support;
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64} snapshot_state;
65
0709db60 66atomic_t snapshot_device_available = ATOMIC_INIT(1);
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67
68static int snapshot_open(struct inode *inode, struct file *filp)
69{
70 struct snapshot_data *data;
c3e94d89 71 int error;
6e1819d6 72
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73 mutex_lock(&pm_mutex);
74
75 if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
76 error = -EBUSY;
77 goto Unlock;
78 }
6e1819d6 79
1525a2ad 80 if ((filp->f_flags & O_ACCMODE) == O_RDWR) {
0709db60 81 atomic_inc(&snapshot_device_available);
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82 error = -ENOSYS;
83 goto Unlock;
1525a2ad
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84 }
85 if(create_basic_memory_bitmaps()) {
0709db60 86 atomic_inc(&snapshot_device_available);
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87 error = -ENOMEM;
88 goto Unlock;
1525a2ad 89 }
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90 nonseekable_open(inode, filp);
91 data = &snapshot_state;
92 filp->private_data = data;
93 memset(&data->handle, 0, sizeof(struct snapshot_handle));
94 if ((filp->f_flags & O_ACCMODE) == O_RDONLY) {
c7510859 95 /* Hibernating. The image device should be accessible. */
915bae9e 96 data->swap = swsusp_resume_device ?
7bf23687 97 swap_type_of(swsusp_resume_device, 0, NULL) : -1;
6e1819d6 98 data->mode = O_RDONLY;
ebae2604 99 error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
c3e94d89 100 if (error)
ebae2604 101 pm_notifier_call_chain(PM_POST_HIBERNATION);
6e1819d6 102 } else {
c7510859
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103 /*
104 * Resuming. We may need to wait for the image device to
105 * appear.
106 */
107 wait_for_device_probe();
108 scsi_complete_async_scans();
109
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110 data->swap = -1;
111 data->mode = O_WRONLY;
ebae2604 112 error = pm_notifier_call_chain(PM_RESTORE_PREPARE);
c3e94d89 113 if (error)
ebae2604 114 pm_notifier_call_chain(PM_POST_RESTORE);
c3e94d89 115 }
25f2f3da 116 if (error)
c3e94d89 117 atomic_inc(&snapshot_device_available);
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118 data->frozen = 0;
119 data->ready = 0;
eb57c1cf 120 data->platform_support = 0;
6e1819d6 121
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122 Unlock:
123 mutex_unlock(&pm_mutex);
124
125 return error;
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126}
127
128static int snapshot_release(struct inode *inode, struct file *filp)
129{
130 struct snapshot_data *data;
131
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132 mutex_lock(&pm_mutex);
133
6e1819d6 134 swsusp_free();
74dfd666 135 free_basic_memory_bitmaps();
6e1819d6 136 data = filp->private_data;
d1d241cc 137 free_all_swap_pages(data->swap);
25f2f3da 138 if (data->frozen)
6e1819d6 139 thaw_processes();
c3e94d89
AS
140 pm_notifier_call_chain(data->mode == O_WRONLY ?
141 PM_POST_HIBERNATION : PM_POST_RESTORE);
0709db60 142 atomic_inc(&snapshot_device_available);
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143
144 mutex_unlock(&pm_mutex);
145
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146 return 0;
147}
148
149static ssize_t snapshot_read(struct file *filp, char __user *buf,
150 size_t count, loff_t *offp)
151{
152 struct snapshot_data *data;
153 ssize_t res;
d3c1b24c 154 loff_t pg_offp = *offp & ~PAGE_MASK;
6e1819d6 155
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156 mutex_lock(&pm_mutex);
157
6e1819d6 158 data = filp->private_data;
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159 if (!data->ready) {
160 res = -ENODATA;
161 goto Unlock;
162 }
d3c1b24c
JS
163 if (!pg_offp) { /* on page boundary? */
164 res = snapshot_read_next(&data->handle);
165 if (res <= 0)
166 goto Unlock;
167 } else {
168 res = PAGE_SIZE - pg_offp;
6e1819d6 169 }
25f2f3da 170
d3c1b24c
JS
171 res = simple_read_from_buffer(buf, count, &pg_offp,
172 data_of(data->handle), res);
173 if (res > 0)
174 *offp += res;
175
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176 Unlock:
177 mutex_unlock(&pm_mutex);
178
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179 return res;
180}
181
182static ssize_t snapshot_write(struct file *filp, const char __user *buf,
183 size_t count, loff_t *offp)
184{
185 struct snapshot_data *data;
186 ssize_t res;
d3c1b24c 187 loff_t pg_offp = *offp & ~PAGE_MASK;
6e1819d6 188
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189 mutex_lock(&pm_mutex);
190
6e1819d6 191 data = filp->private_data;
d3c1b24c
JS
192
193 if (!pg_offp) {
194 res = snapshot_write_next(&data->handle);
195 if (res <= 0)
196 goto unlock;
197 } else {
198 res = PAGE_SIZE - pg_offp;
6e1819d6 199 }
25f2f3da 200
d3c1b24c
JS
201 res = simple_write_to_buffer(data_of(data->handle), res, &pg_offp,
202 buf, count);
203 if (res > 0)
204 *offp += res;
205unlock:
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206 mutex_unlock(&pm_mutex);
207
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208 return res;
209}
210
b694e52e
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211static void snapshot_deprecated_ioctl(unsigned int cmd)
212{
213 if (printk_ratelimit())
214 printk(KERN_NOTICE "%pf: ioctl '%.8x' is deprecated and will "
215 "be removed soon, update your suspend-to-disk "
216 "utilities\n",
217 __builtin_return_address(0), cmd);
218}
219
52d11025
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220static long snapshot_ioctl(struct file *filp, unsigned int cmd,
221 unsigned long arg)
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222{
223 int error = 0;
224 struct snapshot_data *data;
af508b34 225 loff_t size;
3aef83e0 226 sector_t offset;
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227
228 if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC)
229 return -ENOTTY;
230 if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR)
231 return -ENOTTY;
232 if (!capable(CAP_SYS_ADMIN))
233 return -EPERM;
234
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235 if (!mutex_trylock(&pm_mutex))
236 return -EBUSY;
6e1819d6 237
25f2f3da 238 data = filp->private_data;
52d11025 239
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240 switch (cmd) {
241
242 case SNAPSHOT_FREEZE:
243 if (data->frozen)
244 break;
1bfcf130 245
c3e94d89
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246 printk("Syncing filesystems ... ");
247 sys_sync();
248 printk("done.\n");
249
1bfcf130 250 error = usermodehelper_disable();
b10d9117 251 if (error)
1bfcf130
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252 break;
253
254 error = freeze_processes();
255 if (error) {
c3e94d89 256 thaw_processes();
1bfcf130
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257 usermodehelper_enable();
258 }
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259 if (!error)
260 data->frozen = 1;
261 break;
262
263 case SNAPSHOT_UNFREEZE:
2f41dddb 264 if (!data->frozen || data->ready)
6e1819d6 265 break;
c9e664f1 266 pm_restore_gfp_mask();
6e1819d6 267 thaw_processes();
1bfcf130 268 usermodehelper_enable();
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269 data->frozen = 0;
270 break;
271
272 case SNAPSHOT_ATOMIC_SNAPSHOT:
b694e52e
JS
273 snapshot_deprecated_ioctl(cmd);
274 case SNAPSHOT_CREATE_IMAGE:
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275 if (data->mode != O_RDONLY || !data->frozen || data->ready) {
276 error = -EPERM;
277 break;
278 }
c9e664f1 279 pm_restore_gfp_mask();
eb57c1cf 280 error = hibernation_snapshot(data->platform_support);
6e1819d6 281 if (!error)
cc5d207c 282 error = put_user(in_suspend, (int __user *)arg);
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283 if (!error)
284 data->ready = 1;
285 break;
286
287 case SNAPSHOT_ATOMIC_RESTORE:
8357376d 288 snapshot_write_finalize(&data->handle);
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289 if (data->mode != O_WRONLY || !data->frozen ||
290 !snapshot_image_loaded(&data->handle)) {
291 error = -EPERM;
292 break;
293 }
eb57c1cf 294 error = hibernation_restore(data->platform_support);
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295 break;
296
297 case SNAPSHOT_FREE:
298 swsusp_free();
299 memset(&data->handle, 0, sizeof(struct snapshot_handle));
300 data->ready = 0;
301 break;
302
303 case SNAPSHOT_SET_IMAGE_SIZE:
b694e52e
JS
304 snapshot_deprecated_ioctl(cmd);
305 case SNAPSHOT_PREF_IMAGE_SIZE:
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306 image_size = arg;
307 break;
308
af508b34
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309 case SNAPSHOT_GET_IMAGE_SIZE:
310 if (!data->ready) {
311 error = -ENODATA;
312 break;
313 }
314 size = snapshot_get_image_size();
315 size <<= PAGE_SHIFT;
316 error = put_user(size, (loff_t __user *)arg);
317 break;
318
6e1819d6 319 case SNAPSHOT_AVAIL_SWAP:
b694e52e
JS
320 snapshot_deprecated_ioctl(cmd);
321 case SNAPSHOT_AVAIL_SWAP_SIZE:
af508b34
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322 size = count_swap_pages(data->swap, 1);
323 size <<= PAGE_SHIFT;
324 error = put_user(size, (loff_t __user *)arg);
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325 break;
326
327 case SNAPSHOT_GET_SWAP_PAGE:
b694e52e
JS
328 snapshot_deprecated_ioctl(cmd);
329 case SNAPSHOT_ALLOC_SWAP_PAGE:
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330 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
331 error = -ENODEV;
332 break;
333 }
d1d241cc 334 offset = alloc_swapdev_block(data->swap);
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335 if (offset) {
336 offset <<= PAGE_SHIFT;
cc5d207c 337 error = put_user(offset, (loff_t __user *)arg);
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338 } else {
339 error = -ENOSPC;
340 }
341 break;
342
343 case SNAPSHOT_FREE_SWAP_PAGES:
344 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
345 error = -ENODEV;
346 break;
347 }
d1d241cc 348 free_all_swap_pages(data->swap);
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349 break;
350
96f73749 351 case SNAPSHOT_SET_SWAP_FILE: /* This ioctl is deprecated */
b694e52e 352 snapshot_deprecated_ioctl(cmd);
d1d241cc 353 if (!swsusp_swap_in_use()) {
6e1819d6
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354 /*
355 * User space encodes device types as two-byte values,
356 * so we need to recode them
357 */
358 if (old_decode_dev(arg)) {
7bf23687
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359 data->swap = swap_type_of(old_decode_dev(arg),
360 0, NULL);
6e1819d6
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361 if (data->swap < 0)
362 error = -ENODEV;
363 } else {
364 data->swap = -1;
365 error = -EINVAL;
366 }
367 } else {
368 error = -EPERM;
369 }
370 break;
371
9b238205
LT
372 case SNAPSHOT_S2RAM:
373 if (!data->frozen) {
374 error = -EPERM;
375 break;
376 }
6c961dfb
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377 /*
378 * Tasks are frozen and the notifiers have been called with
379 * PM_HIBERNATION_PREPARE
380 */
381 error = suspend_devices_and_enter(PM_SUSPEND_MEM);
9b238205
LT
382 break;
383
eb57c1cf
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384 case SNAPSHOT_PLATFORM_SUPPORT:
385 data->platform_support = !!arg;
386 break;
387
388 case SNAPSHOT_POWER_OFF:
389 if (data->platform_support)
390 error = hibernation_platform_enter();
391 break;
392
393 case SNAPSHOT_PMOPS: /* This ioctl is deprecated */
b694e52e 394 snapshot_deprecated_ioctl(cmd);
2b5b09b3
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395 error = -EINVAL;
396
3592695c
SS
397 switch (arg) {
398
399 case PMOPS_PREPARE:
eb57c1cf 400 data->platform_support = 1;
7777fab9 401 error = 0;
3592695c
SS
402 break;
403
404 case PMOPS_ENTER:
eb57c1cf 405 if (data->platform_support)
7777fab9 406 error = hibernation_platform_enter();
3592695c
SS
407 break;
408
409 case PMOPS_FINISH:
eb57c1cf 410 if (data->platform_support)
2b5b09b3 411 error = 0;
3592695c
SS
412 break;
413
414 default:
415 printk(KERN_ERR "SNAPSHOT_PMOPS: invalid argument %ld\n", arg);
3592695c
SS
416
417 }
418 break;
419
37b2ba12 420 case SNAPSHOT_SET_SWAP_AREA:
d1d241cc 421 if (swsusp_swap_in_use()) {
37b2ba12
RW
422 error = -EPERM;
423 } else {
424 struct resume_swap_area swap_area;
425 dev_t swdev;
426
427 error = copy_from_user(&swap_area, (void __user *)arg,
428 sizeof(struct resume_swap_area));
429 if (error) {
430 error = -EFAULT;
431 break;
432 }
433
434 /*
435 * User space encodes device types as two-byte values,
436 * so we need to recode them
437 */
d88d4050 438 swdev = new_decode_dev(swap_area.dev);
37b2ba12
RW
439 if (swdev) {
440 offset = swap_area.offset;
7bf23687 441 data->swap = swap_type_of(swdev, offset, NULL);
37b2ba12
RW
442 if (data->swap < 0)
443 error = -ENODEV;
444 } else {
445 data->swap = -1;
446 error = -EINVAL;
447 }
448 }
449 break;
450
6e1819d6
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451 default:
452 error = -ENOTTY;
453
454 }
25f2f3da
RW
455
456 mutex_unlock(&pm_mutex);
457
6e1819d6
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458 return error;
459}
460
15ad7cdc 461static const struct file_operations snapshot_fops = {
6e1819d6
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462 .open = snapshot_open,
463 .release = snapshot_release,
464 .read = snapshot_read,
465 .write = snapshot_write,
466 .llseek = no_llseek,
52d11025 467 .unlocked_ioctl = snapshot_ioctl,
6e1819d6
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468};
469
470static struct miscdevice snapshot_device = {
471 .minor = SNAPSHOT_MINOR,
472 .name = "snapshot",
473 .fops = &snapshot_fops,
474};
475
476static int __init snapshot_device_init(void)
477{
478 return misc_register(&snapshot_device);
479};
480
481device_initcall(snapshot_device_init);