Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
fs: Replace user_access_{begin/end} by scoped user access
Scoped user access reduces code complexity and seamlessly bring
masked user access on architectures that support it.
Replace user_access_begin/user_access_end blocks by
scoped user access.
Signed-off-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Link: https://patch.msgid.link/16daf33a8190a771a93e294d050bd8153521ffca.1774350128.git.chleroy@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
authored by
Christophe Leroy (CS GROUP)
and committed by
Christian Brauner
b98f7363
4bf798e0
+49
-74
+35
-53
fs/readdir.c
+35
-53
fs/readdir.c
···
200
200
}
201
201
buf->result++;
202
202
dirent = buf->dirent;
203
-
if (!user_write_access_begin(dirent, dirent_size(dirent, namlen + 1)))
204
-
goto efault;
205
-
unsafe_put_user(d_ino, &dirent->d_ino, efault_end);
206
-
unsafe_put_user(offset, &dirent->d_offset, efault_end);
207
-
unsafe_put_user(namlen, &dirent->d_namlen, efault_end);
208
-
unsafe_copy_dirent_name(dirent->d_name, name, namlen, efault_end);
209
-
user_write_access_end();
203
+
scoped_user_write_access_size(dirent, dirent_size(dirent, namlen + 1), efault) {
204
+
unsafe_put_user(d_ino, &dirent->d_ino, efault);
205
+
unsafe_put_user(offset, &dirent->d_offset, efault);
206
+
unsafe_put_user(namlen, &dirent->d_namlen, efault);
207
+
unsafe_copy_dirent_name(dirent->d_name, name, namlen, efault);
208
+
}
210
209
return true;
211
-
efault_end:
212
-
user_write_access_end();
213
210
efault:
214
211
buf->result = -EFAULT;
215
212
return false;
···
283
286
return false;
284
287
dirent = buf->current_dir;
285
288
prev = (void __user *) dirent - prev_reclen;
286
-
if (!user_write_access_begin(prev, reclen + prev_reclen))
287
-
goto efault;
288
-
289
-
/* This might be 'dirent->d_off', but if so it will get overwritten */
290
-
unsafe_put_user(offset, &prev->d_off, efault_end);
291
-
unsafe_put_user(d_ino, &dirent->d_ino, efault_end);
292
-
unsafe_put_user(reclen, &dirent->d_reclen, efault_end);
293
-
unsafe_put_user(d_type, (char __user *) dirent + reclen - 1, efault_end);
294
-
unsafe_copy_dirent_name(dirent->d_name, name, namlen, efault_end);
295
-
user_write_access_end();
289
+
scoped_user_write_access_size(prev, reclen + prev_reclen, efault) {
290
+
/* This might be 'dirent->d_off', but if so it will get overwritten */
291
+
unsafe_put_user(offset, &prev->d_off, efault);
292
+
unsafe_put_user(d_ino, &dirent->d_ino, efault);
293
+
unsafe_put_user(reclen, &dirent->d_reclen, efault);
294
+
unsafe_put_user(d_type, (char __user *)dirent + reclen - 1, efault);
295
+
unsafe_copy_dirent_name(dirent->d_name, name, namlen, efault);
296
+
}
296
297
297
298
buf->current_dir = (void __user *)dirent + reclen;
298
299
buf->prev_reclen = reclen;
299
300
ctx->count -= reclen;
300
301
return true;
301
-
efault_end:
302
-
user_write_access_end();
303
302
efault:
304
303
buf->error = -EFAULT;
305
304
return false;
···
362
369
return false;
363
370
dirent = buf->current_dir;
364
371
prev = (void __user *)dirent - prev_reclen;
365
-
if (!user_write_access_begin(prev, reclen + prev_reclen))
366
-
goto efault;
367
-
368
-
/* This might be 'dirent->d_off', but if so it will get overwritten */
369
-
unsafe_put_user(offset, &prev->d_off, efault_end);
370
-
unsafe_put_user(ino, &dirent->d_ino, efault_end);
371
-
unsafe_put_user(reclen, &dirent->d_reclen, efault_end);
372
-
unsafe_put_user(d_type, &dirent->d_type, efault_end);
373
-
unsafe_copy_dirent_name(dirent->d_name, name, namlen, efault_end);
374
-
user_write_access_end();
372
+
scoped_user_write_access_size(prev, reclen + prev_reclen, efault) {
373
+
/* This might be 'dirent->d_off', but if so it will get overwritten */
374
+
unsafe_put_user(offset, &prev->d_off, efault);
375
+
unsafe_put_user(ino, &dirent->d_ino, efault);
376
+
unsafe_put_user(reclen, &dirent->d_reclen, efault);
377
+
unsafe_put_user(d_type, &dirent->d_type, efault);
378
+
unsafe_copy_dirent_name(dirent->d_name, name, namlen, efault);
379
+
}
375
380
376
381
buf->prev_reclen = reclen;
377
382
buf->current_dir = (void __user *)dirent + reclen;
378
383
ctx->count -= reclen;
379
384
return true;
380
385
381
-
efault_end:
382
-
user_write_access_end();
383
386
efault:
384
387
buf->error = -EFAULT;
385
388
return false;
···
447
458
}
448
459
buf->result++;
449
460
dirent = buf->dirent;
450
-
if (!user_write_access_begin(dirent, dirent_size(dirent, namlen + 1)))
451
-
goto efault;
452
-
unsafe_put_user(d_ino, &dirent->d_ino, efault_end);
453
-
unsafe_put_user(offset, &dirent->d_offset, efault_end);
454
-
unsafe_put_user(namlen, &dirent->d_namlen, efault_end);
455
-
unsafe_copy_dirent_name(dirent->d_name, name, namlen, efault_end);
456
-
user_write_access_end();
461
+
scoped_user_write_access_size(dirent, dirent_size(dirent, namlen + 1), efault) {
462
+
unsafe_put_user(d_ino, &dirent->d_ino, efault);
463
+
unsafe_put_user(offset, &dirent->d_offset, efault);
464
+
unsafe_put_user(namlen, &dirent->d_namlen, efault);
465
+
unsafe_copy_dirent_name(dirent->d_name, name, namlen, efault);
466
+
}
457
467
return true;
458
-
efault_end:
459
-
user_write_access_end();
460
468
efault:
461
469
buf->result = -EFAULT;
462
470
return false;
···
524
538
return false;
525
539
dirent = buf->current_dir;
526
540
prev = (void __user *) dirent - prev_reclen;
527
-
if (!user_write_access_begin(prev, reclen + prev_reclen))
528
-
goto efault;
529
-
530
-
unsafe_put_user(offset, &prev->d_off, efault_end);
531
-
unsafe_put_user(d_ino, &dirent->d_ino, efault_end);
532
-
unsafe_put_user(reclen, &dirent->d_reclen, efault_end);
533
-
unsafe_put_user(d_type, (char __user *) dirent + reclen - 1, efault_end);
534
-
unsafe_copy_dirent_name(dirent->d_name, name, namlen, efault_end);
535
-
user_write_access_end();
541
+
scoped_user_write_access_size(prev, reclen + prev_reclen, efault) {
542
+
unsafe_put_user(offset, &prev->d_off, efault);
543
+
unsafe_put_user(d_ino, &dirent->d_ino, efault);
544
+
unsafe_put_user(reclen, &dirent->d_reclen, efault);
545
+
unsafe_put_user(d_type, (char __user *)dirent + reclen - 1, efault);
546
+
unsafe_copy_dirent_name(dirent->d_name, name, namlen, efault);
547
+
}
536
548
537
549
buf->prev_reclen = reclen;
538
550
buf->current_dir = (void __user *)dirent + reclen;
539
551
ctx->count -= reclen;
540
552
return true;
541
-
efault_end:
542
-
user_write_access_end();
543
553
efault:
544
554
buf->error = -EFAULT;
545
555
return false;
+14
-21
fs/select.c
+14
-21
fs/select.c
···
1005
1005
fdcount = do_poll(head, &table, end_time);
1006
1006
poll_freewait(&table);
1007
1007
1008
-
if (!user_write_access_begin(ufds, nfds * sizeof(*ufds)))
1009
-
goto out_fds;
1008
+
scoped_user_write_access_size(ufds, nfds * sizeof(*ufds), out_fds) {
1009
+
struct pollfd __user *_ufds = ufds;
1010
1010
1011
-
for (walk = head; walk; walk = walk->next) {
1012
-
struct pollfd *fds = walk->entries;
1013
-
unsigned int j;
1011
+
for (walk = head; walk; walk = walk->next) {
1012
+
struct pollfd *fds = walk->entries;
1013
+
unsigned int j;
1014
1014
1015
-
for (j = walk->len; j; fds++, ufds++, j--)
1016
-
unsafe_put_user(fds->revents, &ufds->revents, Efault);
1017
-
}
1018
-
user_write_access_end();
1015
+
for (j = walk->len; j; fds++, _ufds++, j--)
1016
+
unsafe_put_user(fds->revents, &_ufds->revents, out_fds);
1017
+
}
1018
+
}
1019
1019
1020
1020
err = fdcount;
1021
1021
out_fds:
···
1027
1027
}
1028
1028
1029
1029
return err;
1030
-
1031
-
Efault:
1032
-
user_write_access_end();
1033
-
err = -EFAULT;
1034
-
goto out_fds;
1035
1030
}
1036
1031
1037
1032
static long do_restart_poll(struct restart_block *restart_block)
···
1334
1339
struct compat_sigset_argpack __user *from)
1335
1340
{
1336
1341
if (from) {
1337
-
if (!user_read_access_begin(from, sizeof(*from)))
1338
-
return -EFAULT;
1339
-
unsafe_get_user(to->p, &from->p, Efault);
1340
-
unsafe_get_user(to->size, &from->size, Efault);
1341
-
user_read_access_end();
1342
+
scoped_user_read_access(from, efault) {
1343
+
unsafe_get_user(to->p, &from->p, efault);
1344
+
unsafe_get_user(to->size, &from->size, efault);
1345
+
}
1342
1346
}
1343
1347
return 0;
1344
-
Efault:
1345
-
user_read_access_end();
1348
+
efault:
1346
1349
return -EFAULT;
1347
1350
}
1348
1351