~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/kernel/power/user.c

Version: ~ [ linux-5.8-rc5 ] ~ [ linux-5.7.8 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.51 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.132 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.188 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.230 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.230 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.85 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  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 
 35 static 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 
 45 atomic_t snapshot_device_available = ATOMIC_INIT(1);
 46 
 47 static int snapshot_open(struct inode *inode, struct file *filp)
 48 {
 49         struct snapshot_data *data;
 50         int error;
 51 
 52         lock_system_sleep();
 53 
 54         if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
 55                 error = -EBUSY;
 56                 goto Unlock;
 57         }
 58 
 59         if ((filp->f_flags & O_ACCMODE) == O_RDWR) {
 60                 atomic_inc(&snapshot_device_available);
 61                 error = -ENOSYS;
 62                 goto Unlock;
 63         }
 64         nonseekable_open(inode, filp);
 65         data = &snapshot_state;
 66         filp->private_data = data;
 67         memset(&data->handle, 0, sizeof(struct snapshot_handle));
 68         if ((filp->f_flags & O_ACCMODE) == O_RDONLY) {
 69                 /* Hibernating.  The image device should be accessible. */
 70                 data->swap = swsusp_resume_device ?
 71                         swap_type_of(swsusp_resume_device, 0, NULL) : -1;
 72                 data->mode = O_RDONLY;
 73                 data->free_bitmaps = false;
 74                 error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
 75                 if (error)
 76                         pm_notifier_call_chain(PM_POST_HIBERNATION);
 77         } else {
 78                 /*
 79                  * Resuming.  We may need to wait for the image device to
 80                  * appear.
 81                  */
 82                 wait_for_device_probe();
 83 
 84                 data->swap = -1;
 85                 data->mode = O_WRONLY;
 86                 error = pm_notifier_call_chain(PM_RESTORE_PREPARE);
 87                 if (!error) {
 88                         error = create_basic_memory_bitmaps();
 89                         data->free_bitmaps = !error;
 90                 }
 91                 if (error)
 92                         pm_notifier_call_chain(PM_POST_RESTORE);
 93         }
 94         if (error)
 95                 atomic_inc(&snapshot_device_available);
 96 
 97         data->frozen = false;
 98         data->ready = false;
 99         data->platform_support = false;
100 
101  Unlock:
102         unlock_system_sleep();
103 
104         return error;
105 }
106 
107 static 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         data = filp->private_data;
115         free_all_swap_pages(data->swap);
116         if (data->frozen) {
117                 pm_restore_gfp_mask();
118                 free_basic_memory_bitmaps();
119                 thaw_processes();
120         } else if (data->free_bitmaps) {
121                 free_basic_memory_bitmaps();
122         }
123         pm_notifier_call_chain(data->mode == O_RDONLY ?
124                         PM_POST_HIBERNATION : PM_POST_RESTORE);
125         atomic_inc(&snapshot_device_available);
126 
127         unlock_system_sleep();
128 
129         return 0;
130 }
131 
132 static ssize_t snapshot_read(struct file *filp, char __user *buf,
133                              size_t count, loff_t *offp)
134 {
135         struct snapshot_data *data;
136         ssize_t res;
137         loff_t pg_offp = *offp & ~PAGE_MASK;
138 
139         lock_system_sleep();
140 
141         data = filp->private_data;
142         if (!data->ready) {
143                 res = -ENODATA;
144                 goto Unlock;
145         }
146         if (!pg_offp) { /* on page boundary? */
147                 res = snapshot_read_next(&data->handle);
148                 if (res <= 0)
149                         goto Unlock;
150         } else {
151                 res = PAGE_SIZE - pg_offp;
152         }
153 
154         res = simple_read_from_buffer(buf, count, &pg_offp,
155                         data_of(data->handle), res);
156         if (res > 0)
157                 *offp += res;
158 
159  Unlock:
160         unlock_system_sleep();
161 
162         return res;
163 }
164 
165 static ssize_t snapshot_write(struct file *filp, const char __user *buf,
166                               size_t count, loff_t *offp)
167 {
168         struct snapshot_data *data;
169         ssize_t res;
170         loff_t pg_offp = *offp & ~PAGE_MASK;
171 
172         lock_system_sleep();
173 
174         data = filp->private_data;
175 
176         if (!pg_offp) {
177                 res = snapshot_write_next(&data->handle);
178                 if (res <= 0)
179                         goto unlock;
180         } else {
181                 res = PAGE_SIZE - pg_offp;
182         }
183 
184         res = simple_write_to_buffer(data_of(data->handle), res, &pg_offp,
185                         buf, count);
186         if (res > 0)
187                 *offp += res;
188 unlock:
189         unlock_system_sleep();
190 
191         return res;
192 }
193 
194 static long snapshot_ioctl(struct file *filp, unsigned int cmd,
195                                                         unsigned long arg)
196 {
197         int error = 0;
198         struct snapshot_data *data;
199         loff_t size;
200         sector_t offset;
201 
202         if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC)
203                 return -ENOTTY;
204         if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR)
205                 return -ENOTTY;
206         if (!capable(CAP_SYS_ADMIN))
207                 return -EPERM;
208 
209         if (!mutex_trylock(&pm_mutex))
210                 return -EBUSY;
211 
212         lock_device_hotplug();
213         data = filp->private_data;
214 
215         switch (cmd) {
216 
217         case SNAPSHOT_FREEZE:
218                 if (data->frozen)
219                         break;
220 
221                 printk("Syncing filesystems ... ");
222                 sys_sync();
223                 printk("done.\n");
224 
225                 error = freeze_processes();
226                 if (error)
227                         break;
228 
229                 error = create_basic_memory_bitmaps();
230                 if (error)
231                         thaw_processes();
232                 else
233                         data->frozen = true;
234 
235                 break;
236 
237         case SNAPSHOT_UNFREEZE:
238                 if (!data->frozen || data->ready)
239                         break;
240                 pm_restore_gfp_mask();
241                 free_basic_memory_bitmaps();
242                 data->free_bitmaps = false;
243                 thaw_processes();
244                 data->frozen = false;
245                 break;
246 
247         case SNAPSHOT_CREATE_IMAGE:
248                 if (data->mode != O_RDONLY || !data->frozen  || data->ready) {
249                         error = -EPERM;
250                         break;
251                 }
252                 pm_restore_gfp_mask();
253                 error = hibernation_snapshot(data->platform_support);
254                 if (!error) {
255                         error = put_user(in_suspend, (int __user *)arg);
256                         data->ready = !freezer_test_done && !error;
257                         freezer_test_done = false;
258                 }
259                 break;
260 
261         case SNAPSHOT_ATOMIC_RESTORE:
262                 snapshot_write_finalize(&data->handle);
263                 if (data->mode != O_WRONLY || !data->frozen ||
264                     !snapshot_image_loaded(&data->handle)) {
265                         error = -EPERM;
266                         break;
267                 }
268                 error = hibernation_restore(data->platform_support);
269                 break;
270 
271         case SNAPSHOT_FREE:
272                 swsusp_free();
273                 memset(&data->handle, 0, sizeof(struct snapshot_handle));
274                 data->ready = false;
275                 /*
276                  * It is necessary to thaw kernel threads here, because
277                  * SNAPSHOT_CREATE_IMAGE may be invoked directly after
278                  * SNAPSHOT_FREE.  In that case, if kernel threads were not
279                  * thawed, the preallocation of memory carried out by
280                  * hibernation_snapshot() might run into problems (i.e. it
281                  * might fail or even deadlock).
282                  */
283                 thaw_kernel_threads();
284                 break;
285 
286         case SNAPSHOT_PREF_IMAGE_SIZE:
287                 image_size = arg;
288                 break;
289 
290         case SNAPSHOT_GET_IMAGE_SIZE:
291                 if (!data->ready) {
292                         error = -ENODATA;
293                         break;
294                 }
295                 size = snapshot_get_image_size();
296                 size <<= PAGE_SHIFT;
297                 error = put_user(size, (loff_t __user *)arg);
298                 break;
299 
300         case SNAPSHOT_AVAIL_SWAP_SIZE:
301                 size = count_swap_pages(data->swap, 1);
302                 size <<= PAGE_SHIFT;
303                 error = put_user(size, (loff_t __user *)arg);
304                 break;
305 
306         case SNAPSHOT_ALLOC_SWAP_PAGE:
307                 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
308                         error = -ENODEV;
309                         break;
310                 }
311                 offset = alloc_swapdev_block(data->swap);
312                 if (offset) {
313                         offset <<= PAGE_SHIFT;
314                         error = put_user(offset, (loff_t __user *)arg);
315                 } else {
316                         error = -ENOSPC;
317                 }
318                 break;
319 
320         case SNAPSHOT_FREE_SWAP_PAGES:
321                 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
322                         error = -ENODEV;
323                         break;
324                 }
325                 free_all_swap_pages(data->swap);
326                 break;
327 
328         case SNAPSHOT_S2RAM:
329                 if (!data->frozen) {
330                         error = -EPERM;
331                         break;
332                 }
333                 /*
334                  * Tasks are frozen and the notifiers have been called with
335                  * PM_HIBERNATION_PREPARE
336                  */
337                 error = suspend_devices_and_enter(PM_SUSPEND_MEM);
338                 data->ready = false;
339                 break;
340 
341         case SNAPSHOT_PLATFORM_SUPPORT:
342                 data->platform_support = !!arg;
343                 break;
344 
345         case SNAPSHOT_POWER_OFF:
346                 if (data->platform_support)
347                         error = hibernation_platform_enter();
348                 break;
349 
350         case SNAPSHOT_SET_SWAP_AREA:
351                 if (swsusp_swap_in_use()) {
352                         error = -EPERM;
353                 } else {
354                         struct resume_swap_area swap_area;
355                         dev_t swdev;
356 
357                         error = copy_from_user(&swap_area, (void __user *)arg,
358                                         sizeof(struct resume_swap_area));
359                         if (error) {
360                                 error = -EFAULT;
361                                 break;
362                         }
363 
364                         /*
365                          * User space encodes device types as two-byte values,
366                          * so we need to recode them
367                          */
368                         swdev = new_decode_dev(swap_area.dev);
369                         if (swdev) {
370                                 offset = swap_area.offset;
371                                 data->swap = swap_type_of(swdev, offset, NULL);
372                                 if (data->swap < 0)
373                                         error = -ENODEV;
374                         } else {
375                                 data->swap = -1;
376                                 error = -EINVAL;
377                         }
378                 }
379                 break;
380 
381         default:
382                 error = -ENOTTY;
383 
384         }
385 
386         unlock_device_hotplug();
387         mutex_unlock(&pm_mutex);
388 
389         return error;
390 }
391 
392 #ifdef CONFIG_COMPAT
393 
394 struct compat_resume_swap_area {
395         compat_loff_t offset;
396         u32 dev;
397 } __packed;
398 
399 static long
400 snapshot_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
401 {
402         BUILD_BUG_ON(sizeof(loff_t) != sizeof(compat_loff_t));
403 
404         switch (cmd) {
405         case SNAPSHOT_GET_IMAGE_SIZE:
406         case SNAPSHOT_AVAIL_SWAP_SIZE:
407         case SNAPSHOT_ALLOC_SWAP_PAGE: {
408                 compat_loff_t __user *uoffset = compat_ptr(arg);
409                 loff_t offset;
410                 mm_segment_t old_fs;
411                 int err;
412 
413                 old_fs = get_fs();
414                 set_fs(KERNEL_DS);
415                 err = snapshot_ioctl(file, cmd, (unsigned long) &offset);
416                 set_fs(old_fs);
417                 if (!err && put_user(offset, uoffset))
418                         err = -EFAULT;
419                 return err;
420         }
421 
422         case SNAPSHOT_CREATE_IMAGE:
423                 return snapshot_ioctl(file, cmd,
424                                       (unsigned long) compat_ptr(arg));
425 
426         case SNAPSHOT_SET_SWAP_AREA: {
427                 struct compat_resume_swap_area __user *u_swap_area =
428                         compat_ptr(arg);
429                 struct resume_swap_area swap_area;
430                 mm_segment_t old_fs;
431                 int err;
432 
433                 err = get_user(swap_area.offset, &u_swap_area->offset);
434                 err |= get_user(swap_area.dev, &u_swap_area->dev);
435                 if (err)
436                         return -EFAULT;
437                 old_fs = get_fs();
438                 set_fs(KERNEL_DS);
439                 err = snapshot_ioctl(file, SNAPSHOT_SET_SWAP_AREA,
440                                      (unsigned long) &swap_area);
441                 set_fs(old_fs);
442                 return err;
443         }
444 
445         default:
446                 return snapshot_ioctl(file, cmd, arg);
447         }
448 }
449 
450 #endif /* CONFIG_COMPAT */
451 
452 static const struct file_operations snapshot_fops = {
453         .open = snapshot_open,
454         .release = snapshot_release,
455         .read = snapshot_read,
456         .write = snapshot_write,
457         .llseek = no_llseek,
458         .unlocked_ioctl = snapshot_ioctl,
459 #ifdef CONFIG_COMPAT
460         .compat_ioctl = snapshot_compat_ioctl,
461 #endif
462 };
463 
464 static struct miscdevice snapshot_device = {
465         .minor = SNAPSHOT_MINOR,
466         .name = "snapshot",
467         .fops = &snapshot_fops,
468 };
469 
470 static int __init snapshot_device_init(void)
471 {
472         return misc_register(&snapshot_device);
473 };
474 
475 device_initcall(snapshot_device_init);
476 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp