Re: [PATCH 2/5] PM / hibernate: Generate and verify signature for snapshot image

Dan Carpenter
2019-01-07T19:00:16Z

Hi Chun-Yi,

url: https://github.com/0day-ci/linux/commits/Lee-Chun-Yi/Encryption-and-authentication-for-hibernate-snapshot-image/20190104-062004

smatch warnings:
kernel/power/user.c:411 snapshot_ioctl() warn: inconsistent returns 'mutex:&system_transition_mutex'.
Locked on: line 265
Unlocked on: line 213

[ There are some returns missing. I don't know how/why... -dan ]

# https://github.com/0day-ci/linux/commit/1e583ff7a095d508d78bea4d35a916594c2fc23c
git remote add linux-review https://github.com/0day-ci/linux
git remote update linux-review
git checkout 1e583ff7a095d508d78bea4d35a916594c2fc23c
vim +411 kernel/power/user.c

6e1819d61 Rafael J. Wysocki 2006-03-23 203
52d11025d Alan Cox 2008-06-11 204 static long snapshot_ioctl(struct file *filp, unsigned int cmd,
52d11025d Alan Cox 2008-06-11 205 unsigned long arg)
6e1819d61 Rafael J. Wysocki 2006-03-23 206 {
6e1819d61 Rafael J. Wysocki 2006-03-23 207 int error = 0;
6e1819d61 Rafael J. Wysocki 2006-03-23 208 struct snapshot_data *data;
af508b34d Rafael J. Wysocki 2007-10-26 209 loff_t size;
3aef83e0e Rafael J. Wysocki 2006-12-06 210 sector_t offset;
6e1819d61 Rafael J. Wysocki 2006-03-23 211
6e1819d61 Rafael J. Wysocki 2006-03-23 212 if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC)
6e1819d61 Rafael J. Wysocki 2006-03-23 213 return -ENOTTY;
6e1819d61 Rafael J. Wysocki 2006-03-23 214 if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR)
6e1819d61 Rafael J. Wysocki 2006-03-23 215 return -ENOTTY;
6e1819d61 Rafael J. Wysocki 2006-03-23 216 if (!capable(CAP_SYS_ADMIN))
6e1819d61 Rafael J. Wysocki 2006-03-23 217 return -EPERM;
6e1819d61 Rafael J. Wysocki 2006-03-23 218
55f2503c3 Pingfan Liu 2018-07-31 219 if (!mutex_trylock(&system_transition_mutex))
25f2f3daa Rafael J. Wysocki 2008-06-11 220 return -EBUSY;
6e1819d61 Rafael J. Wysocki 2006-03-23 221
942f40155 Rafael J. Wysocki 2013-08-30 222 lock_device_hotplug();
25f2f3daa Rafael J. Wysocki 2008-06-11 223 data = filp->private_data;
52d11025d Alan Cox 2008-06-11 224
6e1819d61 Rafael J. Wysocki 2006-03-23 225 switch (cmd) {
6e1819d61 Rafael J. Wysocki 2006-03-23 226
6e1819d61 Rafael J. Wysocki 2006-03-23 227 case SNAPSHOT_FREEZE:
6e1819d61 Rafael J. Wysocki 2006-03-23 228 if (data->frozen)
6e1819d61 Rafael J. Wysocki 2006-03-23 229 break;
1bfcf1304 Rafael J. Wysocki 2008-10-15 230
232b14328 Rafael J. Wysocki 2007-10-18 231 printk("Syncing filesystems ... ");
70f68ee81 Dominik Brodowski 2018-03-14 232 ksys_sync();
232b14328 Rafael J. Wysocki 2007-10-18 233 printk("done.\n");
232b14328 Rafael J. Wysocki 2007-10-18 234
1bfcf1304 Rafael J. Wysocki 2008-10-15 235 error = freeze_processes();
8fd37a4c9 Rafael J. Wysocki 2013-08-30 236 if (error)
8fd37a4c9 Rafael J. Wysocki 2013-08-30 237 break;
8fd37a4c9 Rafael J. Wysocki 2013-08-30 238
8fd37a4c9 Rafael J. Wysocki 2013-08-30 239 error = create_basic_memory_bitmaps();
8fd37a4c9 Rafael J. Wysocki 2013-08-30 240 if (error)
8fd37a4c9 Rafael J. Wysocki 2013-08-30 241 thaw_processes();
8fd37a4c9 Rafael J. Wysocki 2013-08-30 242 else
7bc9b1cff Rafael J. Wysocki 2013-10-18 243 data->frozen = true;
8fd37a4c9 Rafael J. Wysocki 2013-08-30 244
6e1819d61 Rafael J. Wysocki 2006-03-23 245 break;
6e1819d61 Rafael J. Wysocki 2006-03-23 246
6e1819d61 Rafael J. Wysocki 2006-03-23 247 case SNAPSHOT_UNFREEZE:
2f41dddbb Rafael J. Wysocki 2007-06-16 248 if (!data->frozen || data->ready)
6e1819d61 Rafael J. Wysocki 2006-03-23 249 break;
c9e664f1f Rafael J. Wysocki 2010-12-03 250 pm_restore_gfp_mask();
1e583ff7a Lee, Chun-Yi 2019-01-03 251 snapshot_restore_trampoline();
8fd37a4c9 Rafael J. Wysocki 2013-08-30 252 free_basic_memory_bitmaps();
aab172891 Rafael J. Wysocki 2013-09-30 253 data->free_bitmaps = false;
6e1819d61 Rafael J. Wysocki 2006-03-23 254 thaw_processes();
7bc9b1cff Rafael J. Wysocki 2013-10-18 255 data->frozen = false;
6e1819d61 Rafael J. Wysocki 2006-03-23 256 break;
6e1819d61 Rafael J. Wysocki 2006-03-23 257
b694e52eb Jiri Slaby 2010-01-27 258 case SNAPSHOT_CREATE_IMAGE:
6e1819d61 Rafael J. Wysocki 2006-03-23 259 if (data->mode != O_RDONLY || !data->frozen || data->ready) {
6e1819d61 Rafael J. Wysocki 2006-03-23 260 error = -EPERM;
6e1819d61 Rafael J. Wysocki 2006-03-23 261 break;
6e1819d61 Rafael J. Wysocki 2006-03-23 262 }
1e583ff7a Lee, Chun-Yi 2019-01-03 263 error = snapshot_key_init();
1e583ff7a Lee, Chun-Yi 2019-01-03 264 if (error)
1e583ff7a Lee, Chun-Yi 2019-01-03 265 return error;
^^^^^^^^^^^^^

1e583ff7a Lee, Chun-Yi 2019-01-03 266 error = snapshot_create_trampoline();
1e583ff7a Lee, Chun-Yi 2019-01-03 267 if (error)
1e583ff7a Lee, Chun-Yi 2019-01-03 268 return error;
^^^^^^^^^^^^^
These should be break statements.

c9e664f1f Rafael J. Wysocki 2010-12-03 269 pm_restore_gfp_mask();
eb57c1cf0 Rafael J. Wysocki 2007-10-26 270 error = hibernation_snapshot(data->platform_support);
51d6ff7ac Srivatsa S. Bhat 2012-02-04 271 if (!error) {
cc5d207c8 Rafael J. Wysocki 2007-10-26 272 error = put_user(in_suspend, (int __user *)arg);
a556d5b58 Srivatsa S. Bhat 2012-02-04 273 data->ready = !freezer_test_done && !error;
97819a262 Srivatsa S. Bhat 2011-12-01 274 freezer_test_done = false;
97819a262 Srivatsa S. Bhat 2011-12-01 275 }
6e1819d61 Rafael J. Wysocki 2006-03-23 276 break;
6e1819d61 Rafael J. Wysocki 2006-03-23 277
6e1819d61 Rafael J. Wysocki 2006-03-23 278 case SNAPSHOT_ATOMIC_RESTORE:
8357376d3 Rafael J. Wysocki 2006-12-06 279 snapshot_write_finalize(&data->handle);
6e1819d61 Rafael J. Wysocki 2006-03-23 280 if (data->mode != O_WRONLY || !data->frozen ||
6e1819d61 Rafael J. Wysocki 2006-03-23 281 !snapshot_image_loaded(&data->handle)) {
6e1819d61 Rafael J. Wysocki 2006-03-23 282 error = -EPERM;
6e1819d61 Rafael J. Wysocki 2006-03-23 283 break;
6e1819d61 Rafael J. Wysocki 2006-03-23 284 }
1e583ff7a Lee, Chun-Yi 2019-01-03 285 if (snapshot_image_verify_decrypt()) {
1e583ff7a Lee, Chun-Yi 2019-01-03 286 error = -EPERM;
1e583ff7a Lee, Chun-Yi 2019-01-03 287 break;
1e583ff7a Lee, Chun-Yi 2019-01-03 288 }
1e583ff7a Lee, Chun-Yi 2019-01-03 289 snapshot_init_trampoline();
eb57c1cf0 Rafael J. Wysocki 2007-10-26 290 error = hibernation_restore(data->platform_support);
6e1819d61 Rafael J. Wysocki 2006-03-23 291 break;
6e1819d61 Rafael J. Wysocki 2006-03-23 292
6e1819d61 Rafael J. Wysocki 2006-03-23 293 case SNAPSHOT_FREE:
6e1819d61 Rafael J. Wysocki 2006-03-23 294 swsusp_free();
6e1819d61 Rafael J. Wysocki 2006-03-23 295 memset(&data->handle, 0, sizeof(struct snapshot_handle));
7bc9b1cff Rafael J. Wysocki 2013-10-18 296 data->ready = false;
181e9bdef Rafael J. Wysocki 2012-01-29 297 /*
181e9bdef Rafael J. Wysocki 2012-01-29 298 * It is necessary to thaw kernel threads here, because
181e9bdef Rafael J. Wysocki 2012-01-29 299 * SNAPSHOT_CREATE_IMAGE may be invoked directly after
181e9bdef Rafael J. Wysocki 2012-01-29 300 * SNAPSHOT_FREE. In that case, if kernel threads were not
181e9bdef Rafael J. Wysocki 2012-01-29 301 * thawed, the preallocation of memory carried out by
181e9bdef Rafael J. Wysocki 2012-01-29 302 * hibernation_snapshot() might run into problems (i.e. it
181e9bdef Rafael J. Wysocki 2012-01-29 303 * might fail or even deadlock).
181e9bdef Rafael J. Wysocki 2012-01-29 304 */
181e9bdef Rafael J. Wysocki 2012-01-29 305 thaw_kernel_threads();
6e1819d61 Rafael J. Wysocki 2006-03-23 306 break;
6e1819d61 Rafael J. Wysocki 2006-03-23 307
b694e52eb Jiri Slaby 2010-01-27 308 case SNAPSHOT_PREF_IMAGE_SIZE:
6e1819d61 Rafael J. Wysocki 2006-03-23 309 image_size = arg;
6e1819d61 Rafael J. Wysocki 2006-03-23 310 break;
6e1819d61 Rafael J. Wysocki 2006-03-23 311
af508b34d Rafael J. Wysocki 2007-10-26 312 case SNAPSHOT_GET_IMAGE_SIZE:
af508b34d Rafael J. Wysocki 2007-10-26 313 if (!data->ready) {
af508b34d Rafael J. Wysocki 2007-10-26 314 error = -ENODATA;
af508b34d Rafael J. Wysocki 2007-10-26 315 break;
af508b34d Rafael J. Wysocki 2007-10-26 316 }
af508b34d Rafael J. Wysocki 2007-10-26 317 size = snapshot_get_image_size();
af508b34d Rafael J. Wysocki 2007-10-26 318 size <<= PAGE_SHIFT;
af508b34d Rafael J. Wysocki 2007-10-26 319 error = put_user(size, (loff_t __user *)arg);
af508b34d Rafael J. Wysocki 2007-10-26 320 break;
af508b34d Rafael J. Wysocki 2007-10-26 321
b694e52eb Jiri Slaby 2010-01-27 322 case SNAPSHOT_AVAIL_SWAP_SIZE:
af508b34d Rafael J. Wysocki 2007-10-26 323 size = count_swap_pages(data->swap, 1);
af508b34d Rafael J. Wysocki 2007-10-26 324 size <<= PAGE_SHIFT;
af508b34d Rafael J. Wysocki 2007-10-26 325 error = put_user(size, (loff_t __user *)arg);
6e1819d61 Rafael J. Wysocki 2006-03-23 326 break;
6e1819d61 Rafael J. Wysocki 2006-03-23 327
b694e52eb Jiri Slaby 2010-01-27 328 case SNAPSHOT_ALLOC_SWAP_PAGE:
6e1819d61 Rafael J. Wysocki 2006-03-23 329 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
6e1819d61 Rafael J. Wysocki 2006-03-23 330 error = -ENODEV;
6e1819d61 Rafael J. Wysocki 2006-03-23 331 break;
6e1819d61 Rafael J. Wysocki 2006-03-23 332 }
d1d241cc2 Rafael J. Wysocki 2007-05-06 333 offset = alloc_swapdev_block(data->swap);
6e1819d61 Rafael J. Wysocki 2006-03-23 334 if (offset) {
6e1819d61 Rafael J. Wysocki 2006-03-23 335 offset <<= PAGE_SHIFT;
cc5d207c8 Rafael J. Wysocki 2007-10-26 336 error = put_user(offset, (loff_t __user *)arg);
6e1819d61 Rafael J. Wysocki 2006-03-23 337 } else {
6e1819d61 Rafael J. Wysocki 2006-03-23 338 error = -ENOSPC;
6e1819d61 Rafael J. Wysocki 2006-03-23 339 }
6e1819d61 Rafael J. Wysocki 2006-03-23 340 break;
6e1819d61 Rafael J. Wysocki 2006-03-23 341
6e1819d61 Rafael J. Wysocki 2006-03-23 342 case SNAPSHOT_FREE_SWAP_PAGES:
6e1819d61 Rafael J. Wysocki 2006-03-23 343 if (data->swap < 0 || data->swap >= MAX_SWAPFILES) {
6e1819d61 Rafael J. Wysocki 2006-03-23 344 error = -ENODEV;
6e1819d61 Rafael J. Wysocki 2006-03-23 345 break;
6e1819d61 Rafael J. Wysocki 2006-03-23 346 }
d1d241cc2 Rafael J. Wysocki 2007-05-06 347 free_all_swap_pages(data->swap);
6e1819d61 Rafael J. Wysocki 2006-03-23 348 break;
6e1819d61 Rafael J. Wysocki 2006-03-23 349
9b238205b Luca Tettamanti 2006-03-23 350 case SNAPSHOT_S2RAM:
9b238205b Luca Tettamanti 2006-03-23 351 if (!data->frozen) {
9b238205b Luca Tettamanti 2006-03-23 352 error = -EPERM;
9b238205b Luca Tettamanti 2006-03-23 353 break;
9b238205b Luca Tettamanti 2006-03-23 354 }
6c961dfb7 Rafael J. Wysocki 2007-07-19 355 /*
6c961dfb7 Rafael J. Wysocki 2007-07-19 356 * Tasks are frozen and the notifiers have been called with
6c961dfb7 Rafael J. Wysocki 2007-07-19 357 * PM_HIBERNATION_PREPARE
6c961dfb7 Rafael J. Wysocki 2007-07-19 358 */
6c961dfb7 Rafael J. Wysocki 2007-07-19 359 error = suspend_devices_and_enter(PM_SUSPEND_MEM);
7bc9b1cff Rafael J. Wysocki 2013-10-18 360 data->ready = false;
9b238205b Luca Tettamanti 2006-03-23 361 break;
9b238205b Luca Tettamanti 2006-03-23 362
eb57c1cf0 Rafael J. Wysocki 2007-10-26 363 case SNAPSHOT_PLATFORM_SUPPORT:
eb57c1cf0 Rafael J. Wysocki 2007-10-26 364 data->platform_support = !!arg;
eb57c1cf0 Rafael J. Wysocki 2007-10-26 365 break;
eb57c1cf0 Rafael J. Wysocki 2007-10-26 366
eb57c1cf0 Rafael J. Wysocki 2007-10-26 367 case SNAPSHOT_POWER_OFF:
eb57c1cf0 Rafael J. Wysocki 2007-10-26 368 if (data->platform_support)
eb57c1cf0 Rafael J. Wysocki 2007-10-26 369 error = hibernation_platform_enter();
eb57c1cf0 Rafael J. Wysocki 2007-10-26 370 break;
eb57c1cf0 Rafael J. Wysocki 2007-10-26 371
37b2ba12d Rafael J. Wysocki 2006-12-06 372 case SNAPSHOT_SET_SWAP_AREA:
d1d241cc2 Rafael J. Wysocki 2007-05-06 373 if (swsusp_swap_in_use()) {
37b2ba12d Rafael J. Wysocki 2006-12-06 374 error = -EPERM;
37b2ba12d Rafael J. Wysocki 2006-12-06 375 } else {
37b2ba12d Rafael J. Wysocki 2006-12-06 376 struct resume_swap_area swap_area;
37b2ba12d Rafael J. Wysocki 2006-12-06 377 dev_t swdev;
37b2ba12d Rafael J. Wysocki 2006-12-06 378
37b2ba12d Rafael J. Wysocki 2006-12-06 379 error = copy_from_user(&swap_area, (void __user *)arg,
37b2ba12d Rafael J. Wysocki 2006-12-06 380 sizeof(struct resume_swap_area));
37b2ba12d Rafael J. Wysocki 2006-12-06 381 if (error) {
37b2ba12d Rafael J. Wysocki 2006-12-06 382 error = -EFAULT;
37b2ba12d Rafael J. Wysocki 2006-12-06 383 break;
37b2ba12d Rafael J. Wysocki 2006-12-06 384 }
37b2ba12d Rafael J. Wysocki 2006-12-06 385
37b2ba12d Rafael J. Wysocki 2006-12-06 386 /*
37b2ba12d Rafael J. Wysocki 2006-12-06 387 * User space encodes device types as two-byte values,
37b2ba12d Rafael J. Wysocki 2006-12-06 388 * so we need to recode them
37b2ba12d Rafael J. Wysocki 2006-12-06 389 */
d88d4050d Jiri Slaby 2010-04-10 390 swdev = new_decode_dev(swap_area.dev);
37b2ba12d Rafael J. Wysocki 2006-12-06 391 if (swdev) {
37b2ba12d Rafael J. Wysocki 2006-12-06 392 offset = swap_area.offset;
7bf236874 Rafael J. Wysocki 2007-01-05 393 data->swap = swap_type_of(swdev, offset, NULL);
37b2ba12d Rafael J. Wysocki 2006-12-06 394 if (data->swap < 0)
37b2ba12d Rafael J. Wysocki 2006-12-06 395 error = -ENODEV;
37b2ba12d Rafael J. Wysocki 2006-12-06 396 } else {
37b2ba12d Rafael J. Wysocki 2006-12-06 397 data->swap = -1;
37b2ba12d Rafael J. Wysocki 2006-12-06 398 error = -EINVAL;
37b2ba12d Rafael J. Wysocki 2006-12-06 399 }
37b2ba12d Rafael J. Wysocki 2006-12-06 400 }
37b2ba12d Rafael J. Wysocki 2006-12-06 401 break;
37b2ba12d Rafael J. Wysocki 2006-12-06 402
6e1819d61 Rafael J. Wysocki 2006-03-23 403 default:
6e1819d61 Rafael J. Wysocki 2006-03-23 404 error = -ENOTTY;
6e1819d61 Rafael J. Wysocki 2006-03-23 405
6e1819d61 Rafael J. Wysocki 2006-03-23 406 }
25f2f3daa Rafael J. Wysocki 2008-06-11 407
942f40155 Rafael J. Wysocki 2013-08-30 408 unlock_device_hotplug();
55f2503c3 Pingfan Liu 2018-07-31 409 mutex_unlock(&system_transition_mutex);
25f2f3daa Rafael J. Wysocki 2008-06-11 410
6e1819d61 Rafael J. Wysocki 2006-03-23 @411 return error;
6e1819d61 Rafael J. Wysocki 2006-03-23 412 }
6e1819d61 Rafael J. Wysocki 2006-03-23 413

:::::: The code at line 411 was first introduced by commit
:::::: 6e1819d615f24ce0726a7d0bd3dd0152d7b21654 [PATCH] swsusp: userland interface

:::::: TO: Rafael J. Wysocki <rjw@sisk.pl>
:::::: CC: Linus Torvalds <torvalds@g5.osdl.org>

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