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Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
[cris-mirror.git] / kernel / sys.c
blobf2289de20e19a9ff285c1b88f9b62bd08a830a2e
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * linux/kernel/sys.c
4 *
5 * Copyright (C) 1991, 1992 Linus Torvalds
6 */
7
8 #include <linux/export.h>
9 #include <linux/mm.h>
10 #include <linux/utsname.h>
11 #include <linux/mman.h>
12 #include <linux/reboot.h>
13 #include <linux/prctl.h>
14 #include <linux/highuid.h>
15 #include <linux/fs.h>
16 #include <linux/kmod.h>
17 #include <linux/perf_event.h>
18 #include <linux/resource.h>
19 #include <linux/kernel.h>
20 #include <linux/workqueue.h>
21 #include <linux/capability.h>
22 #include <linux/device.h>
23 #include <linux/key.h>
24 #include <linux/times.h>
25 #include <linux/posix-timers.h>
26 #include <linux/security.h>
27 #include <linux/dcookies.h>
28 #include <linux/suspend.h>
29 #include <linux/tty.h>
30 #include <linux/signal.h>
31 #include <linux/cn_proc.h>
32 #include <linux/getcpu.h>
33 #include <linux/task_io_accounting_ops.h>
34 #include <linux/seccomp.h>
35 #include <linux/cpu.h>
36 #include <linux/personality.h>
37 #include <linux/ptrace.h>
38 #include <linux/fs_struct.h>
39 #include <linux/file.h>
40 #include <linux/mount.h>
41 #include <linux/gfp.h>
42 #include <linux/syscore_ops.h>
43 #include <linux/version.h>
44 #include <linux/ctype.h>
45
46 #include <linux/compat.h>
47 #include <linux/syscalls.h>
48 #include <linux/kprobes.h>
49 #include <linux/user_namespace.h>
50 #include <linux/binfmts.h>
51
52 #include <linux/sched.h>
53 #include <linux/sched/autogroup.h>
54 #include <linux/sched/loadavg.h>
55 #include <linux/sched/stat.h>
56 #include <linux/sched/mm.h>
57 #include <linux/sched/coredump.h>
58 #include <linux/sched/task.h>
59 #include <linux/sched/cputime.h>
60 #include <linux/rcupdate.h>
61 #include <linux/uidgid.h>
62 #include <linux/cred.h>
63
64 #include <linux/kmsg_dump.h>
65 /* Move somewhere else to avoid recompiling? */
66 #include <generated/utsrelease.h>
67
68 #include <linux/uaccess.h>
69 #include <asm/io.h>
70 #include <asm/unistd.h>
71
72 #ifndef SET_UNALIGN_CTL
73 # define SET_UNALIGN_CTL(a, b) (-EINVAL)
74 #endif
75 #ifndef GET_UNALIGN_CTL
76 # define GET_UNALIGN_CTL(a, b) (-EINVAL)
77 #endif
78 #ifndef SET_FPEMU_CTL
79 # define SET_FPEMU_CTL(a, b) (-EINVAL)
80 #endif
81 #ifndef GET_FPEMU_CTL
82 # define GET_FPEMU_CTL(a, b) (-EINVAL)
83 #endif
84 #ifndef SET_FPEXC_CTL
85 # define SET_FPEXC_CTL(a, b) (-EINVAL)
86 #endif
87 #ifndef GET_FPEXC_CTL
88 # define GET_FPEXC_CTL(a, b) (-EINVAL)
89 #endif
90 #ifndef GET_ENDIAN
91 # define GET_ENDIAN(a, b) (-EINVAL)
92 #endif
93 #ifndef SET_ENDIAN
94 # define SET_ENDIAN(a, b) (-EINVAL)
95 #endif
96 #ifndef GET_TSC_CTL
97 # define GET_TSC_CTL(a) (-EINVAL)
98 #endif
99 #ifndef SET_TSC_CTL
100 # define SET_TSC_CTL(a) (-EINVAL)
101 #endif
102 #ifndef MPX_ENABLE_MANAGEMENT
103 # define MPX_ENABLE_MANAGEMENT() (-EINVAL)
104 #endif
105 #ifndef MPX_DISABLE_MANAGEMENT
106 # define MPX_DISABLE_MANAGEMENT() (-EINVAL)
107 #endif
108 #ifndef GET_FP_MODE
109 # define GET_FP_MODE(a) (-EINVAL)
110 #endif
111 #ifndef SET_FP_MODE
112 # define SET_FP_MODE(a,b) (-EINVAL)
113 #endif
114 #ifndef SVE_SET_VL
115 # define SVE_SET_VL(a) (-EINVAL)
116 #endif
117 #ifndef SVE_GET_VL
118 # define SVE_GET_VL() (-EINVAL)
119 #endif
120
121 /*
122 * this is where the system-wide overflow UID and GID are defined, for
123 * architectures that now have 32-bit UID/GID but didn't in the past
124 */
125
126 int overflowuid = DEFAULT_OVERFLOWUID;
127 int overflowgid = DEFAULT_OVERFLOWGID;
128
129 EXPORT_SYMBOL(overflowuid);
130 EXPORT_SYMBOL(overflowgid);
131
132 /*
133 * the same as above, but for filesystems which can only store a 16-bit
134 * UID and GID. as such, this is needed on all architectures
135 */
136
137 int fs_overflowuid = DEFAULT_FS_OVERFLOWUID;
138 int fs_overflowgid = DEFAULT_FS_OVERFLOWGID;
139
140 EXPORT_SYMBOL(fs_overflowuid);
141 EXPORT_SYMBOL(fs_overflowgid);
142
143 /*
144 * Returns true if current's euid is same as p's uid or euid,
145 * or has CAP_SYS_NICE to p's user_ns.
146 *
147 * Called with rcu_read_lock, creds are safe
148 */
149 static bool set_one_prio_perm(struct task_struct *p)
150 {
151 const struct cred *cred = current_cred(), *pcred = __task_cred(p);
152
153 if (uid_eq(pcred->uid, cred->euid) ||
154 uid_eq(pcred->euid, cred->euid))
155 return true;
156 if (ns_capable(pcred->user_ns, CAP_SYS_NICE))
157 return true;
158 return false;
159 }
160
161 /*
162 * set the priority of a task
163 * - the caller must hold the RCU read lock
164 */
165 static int set_one_prio(struct task_struct *p, int niceval, int error)
166 {
167 int no_nice;
168
169 if (!set_one_prio_perm(p)) {
170 error = -EPERM;
171 goto out;
172 }
173 if (niceval < task_nice(p) && !can_nice(p, niceval)) {
174 error = -EACCES;
175 goto out;
176 }
177 no_nice = security_task_setnice(p, niceval);
178 if (no_nice) {
179 error = no_nice;
180 goto out;
181 }
182 if (error == -ESRCH)
183 error = 0;
184 set_user_nice(p, niceval);
185 out:
186 return error;
187 }
188
189 SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval)
190 {
191 struct task_struct *g, *p;
192 struct user_struct *user;
193 const struct cred *cred = current_cred();
194 int error = -EINVAL;
195 struct pid *pgrp;
196 kuid_t uid;
197
198 if (which > PRIO_USER || which < PRIO_PROCESS)
199 goto out;
200
201 /* normalize: avoid signed division (rounding problems) */
202 error = -ESRCH;
203 if (niceval < MIN_NICE)
204 niceval = MIN_NICE;
205 if (niceval > MAX_NICE)
206 niceval = MAX_NICE;
207
208 rcu_read_lock();
209 read_lock(&tasklist_lock);
210 switch (which) {
211 case PRIO_PROCESS:
212 if (who)
213 p = find_task_by_vpid(who);
214 else
215 p = current;
216 if (p)
217 error = set_one_prio(p, niceval, error);
218 break;
219 case PRIO_PGRP:
220 if (who)
221 pgrp = find_vpid(who);
222 else
223 pgrp = task_pgrp(current);
224 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
225 error = set_one_prio(p, niceval, error);
226 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
227 break;
228 case PRIO_USER:
229 uid = make_kuid(cred->user_ns, who);
230 user = cred->user;
231 if (!who)
232 uid = cred->uid;
233 else if (!uid_eq(uid, cred->uid)) {
234 user = find_user(uid);
235 if (!user)
236 goto out_unlock; /* No processes for this user */
237 }
238 do_each_thread(g, p) {
239 if (uid_eq(task_uid(p), uid) && task_pid_vnr(p))
240 error = set_one_prio(p, niceval, error);
241 } while_each_thread(g, p);
242 if (!uid_eq(uid, cred->uid))
243 free_uid(user); /* For find_user() */
244 break;
245 }
246 out_unlock:
247 read_unlock(&tasklist_lock);
248 rcu_read_unlock();
249 out:
250 return error;
251 }
252
253 /*
254 * Ugh. To avoid negative return values, "getpriority()" will
255 * not return the normal nice-value, but a negated value that
256 * has been offset by 20 (ie it returns 40..1 instead of -20..19)
257 * to stay compatible.
258 */
259 SYSCALL_DEFINE2(getpriority, int, which, int, who)
260 {
261 struct task_struct *g, *p;
262 struct user_struct *user;
263 const struct cred *cred = current_cred();
264 long niceval, retval = -ESRCH;
265 struct pid *pgrp;
266 kuid_t uid;
267
268 if (which > PRIO_USER || which < PRIO_PROCESS)
269 return -EINVAL;
270
271 rcu_read_lock();
272 read_lock(&tasklist_lock);
273 switch (which) {
274 case PRIO_PROCESS:
275 if (who)
276 p = find_task_by_vpid(who);
277 else
278 p = current;
279 if (p) {
280 niceval = nice_to_rlimit(task_nice(p));
281 if (niceval > retval)
282 retval = niceval;
283 }
284 break;
285 case PRIO_PGRP:
286 if (who)
287 pgrp = find_vpid(who);
288 else
289 pgrp = task_pgrp(current);
290 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
291 niceval = nice_to_rlimit(task_nice(p));
292 if (niceval > retval)
293 retval = niceval;
294 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
295 break;
296 case PRIO_USER:
297 uid = make_kuid(cred->user_ns, who);
298 user = cred->user;
299 if (!who)
300 uid = cred->uid;
301 else if (!uid_eq(uid, cred->uid)) {
302 user = find_user(uid);
303 if (!user)
304 goto out_unlock; /* No processes for this user */
305 }
306 do_each_thread(g, p) {
307 if (uid_eq(task_uid(p), uid) && task_pid_vnr(p)) {
308 niceval = nice_to_rlimit(task_nice(p));
309 if (niceval > retval)
310 retval = niceval;
311 }
312 } while_each_thread(g, p);
313 if (!uid_eq(uid, cred->uid))
314 free_uid(user); /* for find_user() */
315 break;
316 }
317 out_unlock:
318 read_unlock(&tasklist_lock);
319 rcu_read_unlock();
320
321 return retval;
322 }
323
324 /*
325 * Unprivileged users may change the real gid to the effective gid
326 * or vice versa. (BSD-style)
327 *
328 * If you set the real gid at all, or set the effective gid to a value not
329 * equal to the real gid, then the saved gid is set to the new effective gid.
330 *
331 * This makes it possible for a setgid program to completely drop its
332 * privileges, which is often a useful assertion to make when you are doing
333 * a security audit over a program.
334 *
335 * The general idea is that a program which uses just setregid() will be
336 * 100% compatible with BSD. A program which uses just setgid() will be
337 * 100% compatible with POSIX with saved IDs.
338 *
339 * SMP: There are not races, the GIDs are checked only by filesystem
340 * operations (as far as semantic preservation is concerned).
341 */
342 #ifdef CONFIG_MULTIUSER
343 SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid)
344 {
345 struct user_namespace *ns = current_user_ns();
346 const struct cred *old;
347 struct cred *new;
348 int retval;
349 kgid_t krgid, kegid;
350
351 krgid = make_kgid(ns, rgid);
352 kegid = make_kgid(ns, egid);
353
354 if ((rgid != (gid_t) -1) && !gid_valid(krgid))
355 return -EINVAL;
356 if ((egid != (gid_t) -1) && !gid_valid(kegid))
357 return -EINVAL;
358
359 new = prepare_creds();
360 if (!new)
361 return -ENOMEM;
362 old = current_cred();
363
364 retval = -EPERM;
365 if (rgid != (gid_t) -1) {
366 if (gid_eq(old->gid, krgid) ||
367 gid_eq(old->egid, krgid) ||
368 ns_capable(old->user_ns, CAP_SETGID))
369 new->gid = krgid;
370 else
371 goto error;
372 }
373 if (egid != (gid_t) -1) {
374 if (gid_eq(old->gid, kegid) ||
375 gid_eq(old->egid, kegid) ||
376 gid_eq(old->sgid, kegid) ||
377 ns_capable(old->user_ns, CAP_SETGID))
378 new->egid = kegid;
379 else
380 goto error;
381 }
382
383 if (rgid != (gid_t) -1 ||
384 (egid != (gid_t) -1 && !gid_eq(kegid, old->gid)))
385 new->sgid = new->egid;
386 new->fsgid = new->egid;
387
388 return commit_creds(new);
389
390 error:
391 abort_creds(new);
392 return retval;
393 }
394
395 /*
396 * setgid() is implemented like SysV w/ SAVED_IDS
397 *
398 * SMP: Same implicit races as above.
399 */
400 SYSCALL_DEFINE1(setgid, gid_t, gid)
401 {
402 struct user_namespace *ns = current_user_ns();
403 const struct cred *old;
404 struct cred *new;
405 int retval;
406 kgid_t kgid;
407
408 kgid = make_kgid(ns, gid);
409 if (!gid_valid(kgid))
410 return -EINVAL;
411
412 new = prepare_creds();
413 if (!new)
414 return -ENOMEM;
415 old = current_cred();
416
417 retval = -EPERM;
418 if (ns_capable(old->user_ns, CAP_SETGID))
419 new->gid = new->egid = new->sgid = new->fsgid = kgid;
420 else if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->sgid))
421 new->egid = new->fsgid = kgid;
422 else
423 goto error;
424
425 return commit_creds(new);
426
427 error:
428 abort_creds(new);
429 return retval;
430 }
431
432 /*
433 * change the user struct in a credentials set to match the new UID
434 */
435 static int set_user(struct cred *new)
436 {
437 struct user_struct *new_user;
438
439 new_user = alloc_uid(new->uid);
440 if (!new_user)
441 return -EAGAIN;
442
443 /*
444 * We don't fail in case of NPROC limit excess here because too many
445 * poorly written programs don't check set*uid() return code, assuming
446 * it never fails if called by root. We may still enforce NPROC limit
447 * for programs doing set*uid()+execve() by harmlessly deferring the
448 * failure to the execve() stage.
449 */
450 if (atomic_read(&new_user->processes) >= rlimit(RLIMIT_NPROC) &&
451 new_user != INIT_USER)
452 current->flags |= PF_NPROC_EXCEEDED;
453 else
454 current->flags &= ~PF_NPROC_EXCEEDED;
455
456 free_uid(new->user);
457 new->user = new_user;
458 return 0;
459 }
460
461 /*
462 * Unprivileged users may change the real uid to the effective uid
463 * or vice versa. (BSD-style)
464 *
465 * If you set the real uid at all, or set the effective uid to a value not
466 * equal to the real uid, then the saved uid is set to the new effective uid.
467 *
468 * This makes it possible for a setuid program to completely drop its
469 * privileges, which is often a useful assertion to make when you are doing
470 * a security audit over a program.
471 *
472 * The general idea is that a program which uses just setreuid() will be
473 * 100% compatible with BSD. A program which uses just setuid() will be
474 * 100% compatible with POSIX with saved IDs.
475 */
476 SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid)
477 {
478 struct user_namespace *ns = current_user_ns();
479 const struct cred *old;
480 struct cred *new;
481 int retval;
482 kuid_t kruid, keuid;
483
484 kruid = make_kuid(ns, ruid);
485 keuid = make_kuid(ns, euid);
486
487 if ((ruid != (uid_t) -1) && !uid_valid(kruid))
488 return -EINVAL;
489 if ((euid != (uid_t) -1) && !uid_valid(keuid))
490 return -EINVAL;
491
492 new = prepare_creds();
493 if (!new)
494 return -ENOMEM;
495 old = current_cred();
496
497 retval = -EPERM;
498 if (ruid != (uid_t) -1) {
499 new->uid = kruid;
500 if (!uid_eq(old->uid, kruid) &&
501 !uid_eq(old->euid, kruid) &&
502 !ns_capable(old->user_ns, CAP_SETUID))
503 goto error;
504 }
505
506 if (euid != (uid_t) -1) {
507 new->euid = keuid;
508 if (!uid_eq(old->uid, keuid) &&
509 !uid_eq(old->euid, keuid) &&
510 !uid_eq(old->suid, keuid) &&
511 !ns_capable(old->user_ns, CAP_SETUID))
512 goto error;
513 }
514
515 if (!uid_eq(new->uid, old->uid)) {
516 retval = set_user(new);
517 if (retval < 0)
518 goto error;
519 }
520 if (ruid != (uid_t) -1 ||
521 (euid != (uid_t) -1 && !uid_eq(keuid, old->uid)))
522 new->suid = new->euid;
523 new->fsuid = new->euid;
524
525 retval = security_task_fix_setuid(new, old, LSM_SETID_RE);
526 if (retval < 0)
527 goto error;
528
529 return commit_creds(new);
530
531 error:
532 abort_creds(new);
533 return retval;
534 }
535
536 /*
537 * setuid() is implemented like SysV with SAVED_IDS
538 *
539 * Note that SAVED_ID's is deficient in that a setuid root program
540 * like sendmail, for example, cannot set its uid to be a normal
541 * user and then switch back, because if you're root, setuid() sets
542 * the saved uid too. If you don't like this, blame the bright people
543 * in the POSIX committee and/or USG. Note that the BSD-style setreuid()
544 * will allow a root program to temporarily drop privileges and be able to
545 * regain them by swapping the real and effective uid.
546 */
547 SYSCALL_DEFINE1(setuid, uid_t, uid)
548 {
549 struct user_namespace *ns = current_user_ns();
550 const struct cred *old;
551 struct cred *new;
552 int retval;
553 kuid_t kuid;
554
555 kuid = make_kuid(ns, uid);
556 if (!uid_valid(kuid))
557 return -EINVAL;
558
559 new = prepare_creds();
560 if (!new)
561 return -ENOMEM;
562 old = current_cred();
563
564 retval = -EPERM;
565 if (ns_capable(old->user_ns, CAP_SETUID)) {
566 new->suid = new->uid = kuid;
567 if (!uid_eq(kuid, old->uid)) {
568 retval = set_user(new);
569 if (retval < 0)
570 goto error;
571 }
572 } else if (!uid_eq(kuid, old->uid) && !uid_eq(kuid, new->suid)) {
573 goto error;
574 }
575
576 new->fsuid = new->euid = kuid;
577
578 retval = security_task_fix_setuid(new, old, LSM_SETID_ID);
579 if (retval < 0)
580 goto error;
581
582 return commit_creds(new);
583
584 error:
585 abort_creds(new);
586 return retval;
587 }
588
589
590 /*
591 * This function implements a generic ability to update ruid, euid,
592 * and suid. This allows you to implement the 4.4 compatible seteuid().
593 */
594 SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid)
595 {
596 struct user_namespace *ns = current_user_ns();
597 const struct cred *old;
598 struct cred *new;
599 int retval;
600 kuid_t kruid, keuid, ksuid;
601
602 kruid = make_kuid(ns, ruid);
603 keuid = make_kuid(ns, euid);
604 ksuid = make_kuid(ns, suid);
605
606 if ((ruid != (uid_t) -1) && !uid_valid(kruid))
607 return -EINVAL;
608
609 if ((euid != (uid_t) -1) && !uid_valid(keuid))
610 return -EINVAL;
611
612 if ((suid != (uid_t) -1) && !uid_valid(ksuid))
613 return -EINVAL;
614
615 new = prepare_creds();
616 if (!new)
617 return -ENOMEM;
618
619 old = current_cred();
620
621 retval = -EPERM;
622 if (!ns_capable(old->user_ns, CAP_SETUID)) {
623 if (ruid != (uid_t) -1 && !uid_eq(kruid, old->uid) &&
624 !uid_eq(kruid, old->euid) && !uid_eq(kruid, old->suid))
625 goto error;
626 if (euid != (uid_t) -1 && !uid_eq(keuid, old->uid) &&
627 !uid_eq(keuid, old->euid) && !uid_eq(keuid, old->suid))
628 goto error;
629 if (suid != (uid_t) -1 && !uid_eq(ksuid, old->uid) &&
630 !uid_eq(ksuid, old->euid) && !uid_eq(ksuid, old->suid))
631 goto error;
632 }
633
634 if (ruid != (uid_t) -1) {
635 new->uid = kruid;
636 if (!uid_eq(kruid, old->uid)) {
637 retval = set_user(new);
638 if (retval < 0)
639 goto error;
640 }
641 }
642 if (euid != (uid_t) -1)
643 new->euid = keuid;
644 if (suid != (uid_t) -1)
645 new->suid = ksuid;
646 new->fsuid = new->euid;
647
648 retval = security_task_fix_setuid(new, old, LSM_SETID_RES);
649 if (retval < 0)
650 goto error;
651
652 return commit_creds(new);
653
654 error:
655 abort_creds(new);
656 return retval;
657 }
658
659 SYSCALL_DEFINE3(getresuid, uid_t __user *, ruidp, uid_t __user *, euidp, uid_t __user *, suidp)
660 {
661 const struct cred *cred = current_cred();
662 int retval;
663 uid_t ruid, euid, suid;
664
665 ruid = from_kuid_munged(cred->user_ns, cred->uid);
666 euid = from_kuid_munged(cred->user_ns, cred->euid);
667 suid = from_kuid_munged(cred->user_ns, cred->suid);
668
669 retval = put_user(ruid, ruidp);
670 if (!retval) {
671 retval = put_user(euid, euidp);
672 if (!retval)
673 return put_user(suid, suidp);
674 }
675 return retval;
676 }
677
678 /*
679 * Same as above, but for rgid, egid, sgid.
680 */
681 SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid)
682 {
683 struct user_namespace *ns = current_user_ns();
684 const struct cred *old;
685 struct cred *new;
686 int retval;
687 kgid_t krgid, kegid, ksgid;
688
689 krgid = make_kgid(ns, rgid);
690 kegid = make_kgid(ns, egid);
691 ksgid = make_kgid(ns, sgid);
692
693 if ((rgid != (gid_t) -1) && !gid_valid(krgid))
694 return -EINVAL;
695 if ((egid != (gid_t) -1) && !gid_valid(kegid))
696 return -EINVAL;
697 if ((sgid != (gid_t) -1) && !gid_valid(ksgid))
698 return -EINVAL;
699
700 new = prepare_creds();
701 if (!new)
702 return -ENOMEM;
703 old = current_cred();
704
705 retval = -EPERM;
706 if (!ns_capable(old->user_ns, CAP_SETGID)) {
707 if (rgid != (gid_t) -1 && !gid_eq(krgid, old->gid) &&
708 !gid_eq(krgid, old->egid) && !gid_eq(krgid, old->sgid))
709 goto error;
710 if (egid != (gid_t) -1 && !gid_eq(kegid, old->gid) &&
711 !gid_eq(kegid, old->egid) && !gid_eq(kegid, old->sgid))
712 goto error;
713 if (sgid != (gid_t) -1 && !gid_eq(ksgid, old->gid) &&
714 !gid_eq(ksgid, old->egid) && !gid_eq(ksgid, old->sgid))
715 goto error;
716 }
717
718 if (rgid != (gid_t) -1)
719 new->gid = krgid;
720 if (egid != (gid_t) -1)
721 new->egid = kegid;
722 if (sgid != (gid_t) -1)
723 new->sgid = ksgid;
724 new->fsgid = new->egid;
725
726 return commit_creds(new);
727
728 error:
729 abort_creds(new);
730 return retval;
731 }
732
733 SYSCALL_DEFINE3(getresgid, gid_t __user *, rgidp, gid_t __user *, egidp, gid_t __user *, sgidp)
734 {
735 const struct cred *cred = current_cred();
736 int retval;
737 gid_t rgid, egid, sgid;
738
739 rgid = from_kgid_munged(cred->user_ns, cred->gid);
740 egid = from_kgid_munged(cred->user_ns, cred->egid);
741 sgid = from_kgid_munged(cred->user_ns, cred->sgid);
742
743 retval = put_user(rgid, rgidp);
744 if (!retval) {
745 retval = put_user(egid, egidp);
746 if (!retval)
747 retval = put_user(sgid, sgidp);
748 }
749
750 return retval;
751 }
752
753
754 /*
755 * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This
756 * is used for "access()" and for the NFS daemon (letting nfsd stay at
757 * whatever uid it wants to). It normally shadows "euid", except when
758 * explicitly set by setfsuid() or for access..
759 */
760 SYSCALL_DEFINE1(setfsuid, uid_t, uid)
761 {
762 const struct cred *old;
763 struct cred *new;
764 uid_t old_fsuid;
765 kuid_t kuid;
766
767 old = current_cred();
768 old_fsuid = from_kuid_munged(old->user_ns, old->fsuid);
769
770 kuid = make_kuid(old->user_ns, uid);
771 if (!uid_valid(kuid))
772 return old_fsuid;
773
774 new = prepare_creds();
775 if (!new)
776 return old_fsuid;
777
778 if (uid_eq(kuid, old->uid) || uid_eq(kuid, old->euid) ||
779 uid_eq(kuid, old->suid) || uid_eq(kuid, old->fsuid) ||
780 ns_capable(old->user_ns, CAP_SETUID)) {
781 if (!uid_eq(kuid, old->fsuid)) {
782 new->fsuid = kuid;
783 if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0)
784 goto change_okay;
785 }
786 }
787
788 abort_creds(new);
789 return old_fsuid;
790
791 change_okay:
792 commit_creds(new);
793 return old_fsuid;
794 }
795
796 /*
797 * Samma på svenska..
798 */
799 SYSCALL_DEFINE1(setfsgid, gid_t, gid)
800 {
801 const struct cred *old;
802 struct cred *new;
803 gid_t old_fsgid;
804 kgid_t kgid;
805
806 old = current_cred();
807 old_fsgid = from_kgid_munged(old->user_ns, old->fsgid);
808
809 kgid = make_kgid(old->user_ns, gid);
810 if (!gid_valid(kgid))
811 return old_fsgid;
812
813 new = prepare_creds();
814 if (!new)
815 return old_fsgid;
816
817 if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->egid) ||
818 gid_eq(kgid, old->sgid) || gid_eq(kgid, old->fsgid) ||
819 ns_capable(old->user_ns, CAP_SETGID)) {
820 if (!gid_eq(kgid, old->fsgid)) {
821 new->fsgid = kgid;
822 goto change_okay;
823 }
824 }
825
826 abort_creds(new);
827 return old_fsgid;
828
829 change_okay:
830 commit_creds(new);
831 return old_fsgid;
832 }
833 #endif /* CONFIG_MULTIUSER */
834
835 /**
836 * sys_getpid - return the thread group id of the current process
837 *
838 * Note, despite the name, this returns the tgid not the pid. The tgid and
839 * the pid are identical unless CLONE_THREAD was specified on clone() in
840 * which case the tgid is the same in all threads of the same group.
841 *
842 * This is SMP safe as current->tgid does not change.
843 */
844 SYSCALL_DEFINE0(getpid)
845 {
846 return task_tgid_vnr(current);
847 }
848
849 /* Thread ID - the internal kernel "pid" */
850 SYSCALL_DEFINE0(gettid)
851 {
852 return task_pid_vnr(current);
853 }
854
855 /*
856 * Accessing ->real_parent is not SMP-safe, it could
857 * change from under us. However, we can use a stale
858 * value of ->real_parent under rcu_read_lock(), see
859 * release_task()->call_rcu(delayed_put_task_struct).
860 */
861 SYSCALL_DEFINE0(getppid)
862 {
863 int pid;
864
865 rcu_read_lock();
866 pid = task_tgid_vnr(rcu_dereference(current->real_parent));
867 rcu_read_unlock();
868
869 return pid;
870 }
871
872 SYSCALL_DEFINE0(getuid)
873 {
874 /* Only we change this so SMP safe */
875 return from_kuid_munged(current_user_ns(), current_uid());
876 }
877
878 SYSCALL_DEFINE0(geteuid)
879 {
880 /* Only we change this so SMP safe */
881 return from_kuid_munged(current_user_ns(), current_euid());
882 }
883
884 SYSCALL_DEFINE0(getgid)
885 {
886 /* Only we change this so SMP safe */
887 return from_kgid_munged(current_user_ns(), current_gid());
888 }
889
890 SYSCALL_DEFINE0(getegid)
891 {
892 /* Only we change this so SMP safe */
893 return from_kgid_munged(current_user_ns(), current_egid());
894 }
895
896 static void do_sys_times(struct tms *tms)
897 {
898 u64 tgutime, tgstime, cutime, cstime;
899
900 thread_group_cputime_adjusted(current, &tgutime, &tgstime);
901 cutime = current->signal->cutime;
902 cstime = current->signal->cstime;
903 tms->tms_utime = nsec_to_clock_t(tgutime);
904 tms->tms_stime = nsec_to_clock_t(tgstime);
905 tms->tms_cutime = nsec_to_clock_t(cutime);
906 tms->tms_cstime = nsec_to_clock_t(cstime);
907 }
908
909 SYSCALL_DEFINE1(times, struct tms __user *, tbuf)
910 {
911 if (tbuf) {
912 struct tms tmp;
913
914 do_sys_times(&tmp);
915 if (copy_to_user(tbuf, &tmp, sizeof(struct tms)))
916 return -EFAULT;
917 }
918 force_successful_syscall_return();
919 return (long) jiffies_64_to_clock_t(get_jiffies_64());
920 }
921
922 #ifdef CONFIG_COMPAT
923 static compat_clock_t clock_t_to_compat_clock_t(clock_t x)
924 {
925 return compat_jiffies_to_clock_t(clock_t_to_jiffies(x));
926 }
927
928 COMPAT_SYSCALL_DEFINE1(times, struct compat_tms __user *, tbuf)
929 {
930 if (tbuf) {
931 struct tms tms;
932 struct compat_tms tmp;
933
934 do_sys_times(&tms);
935 /* Convert our struct tms to the compat version. */
936 tmp.tms_utime = clock_t_to_compat_clock_t(tms.tms_utime);
937 tmp.tms_stime = clock_t_to_compat_clock_t(tms.tms_stime);
938 tmp.tms_cutime = clock_t_to_compat_clock_t(tms.tms_cutime);
939 tmp.tms_cstime = clock_t_to_compat_clock_t(tms.tms_cstime);
940 if (copy_to_user(tbuf, &tmp, sizeof(tmp)))
941 return -EFAULT;
942 }
943 force_successful_syscall_return();
944 return compat_jiffies_to_clock_t(jiffies);
945 }
946 #endif
947
948 /*
949 * This needs some heavy checking ...
950 * I just haven't the stomach for it. I also don't fully
951 * understand sessions/pgrp etc. Let somebody who does explain it.
952 *
953 * OK, I think I have the protection semantics right.... this is really
954 * only important on a multi-user system anyway, to make sure one user
955 * can't send a signal to a process owned by another. -TYT, 12/12/91
956 *
957 * !PF_FORKNOEXEC check to conform completely to POSIX.
958 */
959 SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid)
960 {
961 struct task_struct *p;
962 struct task_struct *group_leader = current->group_leader;
963 struct pid *pgrp;
964 int err;
965
966 if (!pid)
967 pid = task_pid_vnr(group_leader);
968 if (!pgid)
969 pgid = pid;
970 if (pgid < 0)
971 return -EINVAL;
972 rcu_read_lock();
973
974 /* From this point forward we keep holding onto the tasklist lock
975 * so that our parent does not change from under us. -DaveM
976 */
977 write_lock_irq(&tasklist_lock);
978
979 err = -ESRCH;
980 p = find_task_by_vpid(pid);
981 if (!p)
982 goto out;
983
984 err = -EINVAL;
985 if (!thread_group_leader(p))
986 goto out;
987
988 if (same_thread_group(p->real_parent, group_leader)) {
989 err = -EPERM;
990 if (task_session(p) != task_session(group_leader))
991 goto out;
992 err = -EACCES;
993 if (!(p->flags & PF_FORKNOEXEC))
994 goto out;
995 } else {
996 err = -ESRCH;
997 if (p != group_leader)
998 goto out;
999 }
1000
1001 err = -EPERM;
1002 if (p->signal->leader)
1003 goto out;
1004
1005 pgrp = task_pid(p);
1006 if (pgid != pid) {
1007 struct task_struct *g;
1008
1009 pgrp = find_vpid(pgid);
1010 g = pid_task(pgrp, PIDTYPE_PGID);
1011 if (!g || task_session(g) != task_session(group_leader))
1012 goto out;
1013 }
1014
1015 err = security_task_setpgid(p, pgid);
1016 if (err)
1017 goto out;
1018
1019 if (task_pgrp(p) != pgrp)
1020 change_pid(p, PIDTYPE_PGID, pgrp);
1021
1022 err = 0;
1023 out:
1024 /* All paths lead to here, thus we are safe. -DaveM */
1025 write_unlock_irq(&tasklist_lock);
1026 rcu_read_unlock();
1027 return err;
1028 }
1029
1030 SYSCALL_DEFINE1(getpgid, pid_t, pid)
1031 {
1032 struct task_struct *p;
1033 struct pid *grp;
1034 int retval;
1035
1036 rcu_read_lock();
1037 if (!pid)
1038 grp = task_pgrp(current);
1039 else {
1040 retval = -ESRCH;
1041 p = find_task_by_vpid(pid);
1042 if (!p)
1043 goto out;
1044 grp = task_pgrp(p);
1045 if (!grp)
1046 goto out;
1047
1048 retval = security_task_getpgid(p);
1049 if (retval)
1050 goto out;
1051 }
1052 retval = pid_vnr(grp);
1053 out:
1054 rcu_read_unlock();
1055 return retval;
1056 }
1057
1058 #ifdef __ARCH_WANT_SYS_GETPGRP
1059
1060 SYSCALL_DEFINE0(getpgrp)
1061 {
1062 return sys_getpgid(0);
1063 }
1064
1065 #endif
1066
1067 SYSCALL_DEFINE1(getsid, pid_t, pid)
1068 {
1069 struct task_struct *p;
1070 struct pid *sid;
1071 int retval;
1072
1073 rcu_read_lock();
1074 if (!pid)
1075 sid = task_session(current);
1076 else {
1077 retval = -ESRCH;
1078 p = find_task_by_vpid(pid);
1079 if (!p)
1080 goto out;
1081 sid = task_session(p);
1082 if (!sid)
1083 goto out;
1084
1085 retval = security_task_getsid(p);
1086 if (retval)
1087 goto out;
1088 }
1089 retval = pid_vnr(sid);
1090 out:
1091 rcu_read_unlock();
1092 return retval;
1093 }
1094
1095 static void set_special_pids(struct pid *pid)
1096 {
1097 struct task_struct *curr = current->group_leader;
1098
1099 if (task_session(curr) != pid)
1100 change_pid(curr, PIDTYPE_SID, pid);
1101
1102 if (task_pgrp(curr) != pid)
1103 change_pid(curr, PIDTYPE_PGID, pid);
1104 }
1105
1106 SYSCALL_DEFINE0(setsid)
1107 {
1108 struct task_struct *group_leader = current->group_leader;
1109 struct pid *sid = task_pid(group_leader);
1110 pid_t session = pid_vnr(sid);
1111 int err = -EPERM;
1112
1113 write_lock_irq(&tasklist_lock);
1114 /* Fail if I am already a session leader */
1115 if (group_leader->signal->leader)
1116 goto out;
1117
1118 /* Fail if a process group id already exists that equals the
1119 * proposed session id.
1120 */
1121 if (pid_task(sid, PIDTYPE_PGID))
1122 goto out;
1123
1124 group_leader->signal->leader = 1;
1125 set_special_pids(sid);
1126
1127 proc_clear_tty(group_leader);
1128
1129 err = session;
1130 out:
1131 write_unlock_irq(&tasklist_lock);
1132 if (err > 0) {
1133 proc_sid_connector(group_leader);
1134 sched_autogroup_create_attach(group_leader);
1135 }
1136 return err;
1137 }
1138
1139 DECLARE_RWSEM(uts_sem);
1140
1141 #ifdef COMPAT_UTS_MACHINE
1142 #define override_architecture(name) \
1143 (personality(current->personality) == PER_LINUX32 && \
1144 copy_to_user(name->machine, COMPAT_UTS_MACHINE, \
1145 sizeof(COMPAT_UTS_MACHINE)))
1146 #else
1147 #define override_architecture(name) 0
1148 #endif
1149
1150 /*
1151 * Work around broken programs that cannot handle "Linux 3.0".
1152 * Instead we map 3.x to 2.6.40+x, so e.g. 3.0 would be 2.6.40
1153 * And we map 4.x to 2.6.60+x, so 4.0 would be 2.6.60.
1154 */
1155 static int override_release(char __user *release, size_t len)
1156 {
1157 int ret = 0;
1158
1159 if (current->personality & UNAME26) {
1160 const char *rest = UTS_RELEASE;
1161 char buf[65] = { 0 };
1162 int ndots = 0;
1163 unsigned v;
1164 size_t copy;
1165
1166 while (*rest) {
1167 if (*rest == '.' && ++ndots >= 3)
1168 break;
1169 if (!isdigit(*rest) && *rest != '.')
1170 break;
1171 rest++;
1172 }
1173 v = ((LINUX_VERSION_CODE >> 8) & 0xff) + 60;
1174 copy = clamp_t(size_t, len, 1, sizeof(buf));
1175 copy = scnprintf(buf, copy, "2.6.%u%s", v, rest);
1176 ret = copy_to_user(release, buf, copy + 1);
1177 }
1178 return ret;
1179 }
1180
1181 SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name)
1182 {
1183 int errno = 0;
1184
1185 down_read(&uts_sem);
1186 if (copy_to_user(name, utsname(), sizeof *name))
1187 errno = -EFAULT;
1188 up_read(&uts_sem);
1189
1190 if (!errno && override_release(name->release, sizeof(name->release)))
1191 errno = -EFAULT;
1192 if (!errno && override_architecture(name))
1193 errno = -EFAULT;
1194 return errno;
1195 }
1196
1197 #ifdef __ARCH_WANT_SYS_OLD_UNAME
1198 /*
1199 * Old cruft
1200 */
1201 SYSCALL_DEFINE1(uname, struct old_utsname __user *, name)
1202 {
1203 int error = 0;
1204
1205 if (!name)
1206 return -EFAULT;
1207
1208 down_read(&uts_sem);
1209 if (copy_to_user(name, utsname(), sizeof(*name)))
1210 error = -EFAULT;
1211 up_read(&uts_sem);
1212
1213 if (!error && override_release(name->release, sizeof(name->release)))
1214 error = -EFAULT;
1215 if (!error && override_architecture(name))
1216 error = -EFAULT;
1217 return error;
1218 }
1219
1220 SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name)
1221 {
1222 int error;
1223
1224 if (!name)
1225 return -EFAULT;
1226 if (!access_ok(VERIFY_WRITE, name, sizeof(struct oldold_utsname)))
1227 return -EFAULT;
1228
1229 down_read(&uts_sem);
1230 error = __copy_to_user(&name->sysname, &utsname()->sysname,
1231 __OLD_UTS_LEN);
1232 error |= __put_user(0, name->sysname + __OLD_UTS_LEN);
1233 error |= __copy_to_user(&name->nodename, &utsname()->nodename,
1234 __OLD_UTS_LEN);
1235 error |= __put_user(0, name->nodename + __OLD_UTS_LEN);
1236 error |= __copy_to_user(&name->release, &utsname()->release,
1237 __OLD_UTS_LEN);
1238 error |= __put_user(0, name->release + __OLD_UTS_LEN);
1239 error |= __copy_to_user(&name->version, &utsname()->version,
1240 __OLD_UTS_LEN);
1241 error |= __put_user(0, name->version + __OLD_UTS_LEN);
1242 error |= __copy_to_user(&name->machine, &utsname()->machine,
1243 __OLD_UTS_LEN);
1244 error |= __put_user(0, name->machine + __OLD_UTS_LEN);
1245 up_read(&uts_sem);
1246
1247 if (!error && override_architecture(name))
1248 error = -EFAULT;
1249 if (!error && override_release(name->release, sizeof(name->release)))
1250 error = -EFAULT;
1251 return error ? -EFAULT : 0;
1252 }
1253 #endif
1254
1255 SYSCALL_DEFINE2(sethostname, char __user *, name, int, len)
1256 {
1257 int errno;
1258 char tmp[__NEW_UTS_LEN];
1259
1260 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN))
1261 return -EPERM;
1262
1263 if (len < 0 || len > __NEW_UTS_LEN)
1264 return -EINVAL;
1265 down_write(&uts_sem);
1266 errno = -EFAULT;
1267 if (!copy_from_user(tmp, name, len)) {
1268 struct new_utsname *u = utsname();
1269
1270 memcpy(u->nodename, tmp, len);
1271 memset(u->nodename + len, 0, sizeof(u->nodename) - len);
1272 errno = 0;
1273 uts_proc_notify(UTS_PROC_HOSTNAME);
1274 }
1275 up_write(&uts_sem);
1276 return errno;
1277 }
1278
1279 #ifdef __ARCH_WANT_SYS_GETHOSTNAME
1280
1281 SYSCALL_DEFINE2(gethostname, char __user *, name, int, len)
1282 {
1283 int i, errno;
1284 struct new_utsname *u;
1285
1286 if (len < 0)
1287 return -EINVAL;
1288 down_read(&uts_sem);
1289 u = utsname();
1290 i = 1 + strlen(u->nodename);
1291 if (i > len)
1292 i = len;
1293 errno = 0;
1294 if (copy_to_user(name, u->nodename, i))
1295 errno = -EFAULT;
1296 up_read(&uts_sem);
1297 return errno;
1298 }
1299
1300 #endif
1301
1302 /*
1303 * Only setdomainname; getdomainname can be implemented by calling
1304 * uname()
1305 */
1306 SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len)
1307 {
1308 int errno;
1309 char tmp[__NEW_UTS_LEN];
1310
1311 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN))
1312 return -EPERM;
1313 if (len < 0 || len > __NEW_UTS_LEN)
1314 return -EINVAL;
1315
1316 down_write(&uts_sem);
1317 errno = -EFAULT;
1318 if (!copy_from_user(tmp, name, len)) {
1319 struct new_utsname *u = utsname();
1320
1321 memcpy(u->domainname, tmp, len);
1322 memset(u->domainname + len, 0, sizeof(u->domainname) - len);
1323 errno = 0;
1324 uts_proc_notify(UTS_PROC_DOMAINNAME);
1325 }
1326 up_write(&uts_sem);
1327 return errno;
1328 }
1329
1330 SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim)
1331 {
1332 struct rlimit value;
1333 int ret;
1334
1335 ret = do_prlimit(current, resource, NULL, &value);
1336 if (!ret)
1337 ret = copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0;
1338
1339 return ret;
1340 }
1341
1342 #ifdef CONFIG_COMPAT
1343
1344 COMPAT_SYSCALL_DEFINE2(setrlimit, unsigned int, resource,
1345 struct compat_rlimit __user *, rlim)
1346 {
1347 struct rlimit r;
1348 struct compat_rlimit r32;
1349
1350 if (copy_from_user(&r32, rlim, sizeof(struct compat_rlimit)))
1351 return -EFAULT;
1352
1353 if (r32.rlim_cur == COMPAT_RLIM_INFINITY)
1354 r.rlim_cur = RLIM_INFINITY;
1355 else
1356 r.rlim_cur = r32.rlim_cur;
1357 if (r32.rlim_max == COMPAT_RLIM_INFINITY)
1358 r.rlim_max = RLIM_INFINITY;
1359 else
1360 r.rlim_max = r32.rlim_max;
1361 return do_prlimit(current, resource, &r, NULL);
1362 }
1363
1364 COMPAT_SYSCALL_DEFINE2(getrlimit, unsigned int, resource,
1365 struct compat_rlimit __user *, rlim)
1366 {
1367 struct rlimit r;
1368 int ret;
1369
1370 ret = do_prlimit(current, resource, NULL, &r);
1371 if (!ret) {
1372 struct compat_rlimit r32;
1373 if (r.rlim_cur > COMPAT_RLIM_INFINITY)
1374 r32.rlim_cur = COMPAT_RLIM_INFINITY;
1375 else
1376 r32.rlim_cur = r.rlim_cur;
1377 if (r.rlim_max > COMPAT_RLIM_INFINITY)
1378 r32.rlim_max = COMPAT_RLIM_INFINITY;
1379 else
1380 r32.rlim_max = r.rlim_max;
1381
1382 if (copy_to_user(rlim, &r32, sizeof(struct compat_rlimit)))
1383 return -EFAULT;
1384 }
1385 return ret;
1386 }
1387
1388 #endif
1389
1390 #ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT
1391
1392 /*
1393 * Back compatibility for getrlimit. Needed for some apps.
1394 */
1395 SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
1396 struct rlimit __user *, rlim)
1397 {
1398 struct rlimit x;
1399 if (resource >= RLIM_NLIMITS)
1400 return -EINVAL;
1401
1402 task_lock(current->group_leader);
1403 x = current->signal->rlim[resource];
1404 task_unlock(current->group_leader);
1405 if (x.rlim_cur > 0x7FFFFFFF)
1406 x.rlim_cur = 0x7FFFFFFF;
1407 if (x.rlim_max > 0x7FFFFFFF)
1408 x.rlim_max = 0x7FFFFFFF;
1409 return copy_to_user(rlim, &x, sizeof(x)) ? -EFAULT : 0;
1410 }
1411
1412 #ifdef CONFIG_COMPAT
1413 COMPAT_SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
1414 struct compat_rlimit __user *, rlim)
1415 {
1416 struct rlimit r;
1417
1418 if (resource >= RLIM_NLIMITS)
1419 return -EINVAL;
1420
1421 task_lock(current->group_leader);
1422 r = current->signal->rlim[resource];
1423 task_unlock(current->group_leader);
1424 if (r.rlim_cur > 0x7FFFFFFF)
1425 r.rlim_cur = 0x7FFFFFFF;
1426 if (r.rlim_max > 0x7FFFFFFF)
1427 r.rlim_max = 0x7FFFFFFF;
1428
1429 if (put_user(r.rlim_cur, &rlim->rlim_cur) ||
1430 put_user(r.rlim_max, &rlim->rlim_max))
1431 return -EFAULT;
1432 return 0;
1433 }
1434 #endif
1435
1436 #endif
1437
1438 static inline bool rlim64_is_infinity(__u64 rlim64)
1439 {
1440 #if BITS_PER_LONG < 64
1441 return rlim64 >= ULONG_MAX;
1442 #else
1443 return rlim64 == RLIM64_INFINITY;
1444 #endif
1445 }
1446
1447 static void rlim_to_rlim64(const struct rlimit *rlim, struct rlimit64 *rlim64)
1448 {
1449 if (rlim->rlim_cur == RLIM_INFINITY)
1450 rlim64->rlim_cur = RLIM64_INFINITY;
1451 else
1452 rlim64->rlim_cur = rlim->rlim_cur;
1453 if (rlim->rlim_max == RLIM_INFINITY)
1454 rlim64->rlim_max = RLIM64_INFINITY;
1455 else
1456 rlim64->rlim_max = rlim->rlim_max;
1457 }
1458
1459 static void rlim64_to_rlim(const struct rlimit64 *rlim64, struct rlimit *rlim)
1460 {
1461 if (rlim64_is_infinity(rlim64->rlim_cur))
1462 rlim->rlim_cur = RLIM_INFINITY;
1463 else
1464 rlim->rlim_cur = (unsigned long)rlim64->rlim_cur;
1465 if (rlim64_is_infinity(rlim64->rlim_max))
1466 rlim->rlim_max = RLIM_INFINITY;
1467 else
1468 rlim->rlim_max = (unsigned long)rlim64->rlim_max;
1469 }
1470
1471 /* make sure you are allowed to change @tsk limits before calling this */
1472 int do_prlimit(struct task_struct *tsk, unsigned int resource,
1473 struct rlimit *new_rlim, struct rlimit *old_rlim)
1474 {
1475 struct rlimit *rlim;
1476 int retval = 0;
1477
1478 if (resource >= RLIM_NLIMITS)
1479 return -EINVAL;
1480 if (new_rlim) {
1481 if (new_rlim->rlim_cur > new_rlim->rlim_max)
1482 return -EINVAL;
1483 if (resource == RLIMIT_NOFILE &&
1484 new_rlim->rlim_max > sysctl_nr_open)
1485 return -EPERM;
1486 }
1487
1488 /* protect tsk->signal and tsk->sighand from disappearing */
1489 read_lock(&tasklist_lock);
1490 if (!tsk->sighand) {
1491 retval = -ESRCH;
1492 goto out;
1493 }
1494
1495 rlim = tsk->signal->rlim + resource;
1496 task_lock(tsk->group_leader);
1497 if (new_rlim) {
1498 /* Keep the capable check against init_user_ns until
1499 cgroups can contain all limits */
1500 if (new_rlim->rlim_max > rlim->rlim_max &&
1501 !capable(CAP_SYS_RESOURCE))
1502 retval = -EPERM;
1503 if (!retval)
1504 retval = security_task_setrlimit(tsk, resource, new_rlim);
1505 if (resource == RLIMIT_CPU && new_rlim->rlim_cur == 0) {
1506 /*
1507 * The caller is asking for an immediate RLIMIT_CPU
1508 * expiry. But we use the zero value to mean "it was
1509 * never set". So let's cheat and make it one second
1510 * instead
1511 */
1512 new_rlim->rlim_cur = 1;
1513 }
1514 }
1515 if (!retval) {
1516 if (old_rlim)
1517 *old_rlim = *rlim;
1518 if (new_rlim)
1519 *rlim = *new_rlim;
1520 }
1521 task_unlock(tsk->group_leader);
1522
1523 /*
1524 * RLIMIT_CPU handling. Note that the kernel fails to return an error
1525 * code if it rejected the user's attempt to set RLIMIT_CPU. This is a
1526 * very long-standing error, and fixing it now risks breakage of
1527 * applications, so we live with it
1528 */
1529 if (!retval && new_rlim && resource == RLIMIT_CPU &&
1530 new_rlim->rlim_cur != RLIM_INFINITY &&
1531 IS_ENABLED(CONFIG_POSIX_TIMERS))
1532 update_rlimit_cpu(tsk, new_rlim->rlim_cur);
1533 out:
1534 read_unlock(&tasklist_lock);
1535 return retval;
1536 }
1537
1538 /* rcu lock must be held */
1539 static int check_prlimit_permission(struct task_struct *task,
1540 unsigned int flags)
1541 {
1542 const struct cred *cred = current_cred(), *tcred;
1543 bool id_match;
1544
1545 if (current == task)
1546 return 0;
1547
1548 tcred = __task_cred(task);
1549 id_match = (uid_eq(cred->uid, tcred->euid) &&
1550 uid_eq(cred->uid, tcred->suid) &&
1551 uid_eq(cred->uid, tcred->uid) &&
1552 gid_eq(cred->gid, tcred->egid) &&
1553 gid_eq(cred->gid, tcred->sgid) &&
1554 gid_eq(cred->gid, tcred->gid));
1555 if (!id_match && !ns_capable(tcred->user_ns, CAP_SYS_RESOURCE))
1556 return -EPERM;
1557
1558 return security_task_prlimit(cred, tcred, flags);
1559 }
1560
1561 SYSCALL_DEFINE4(prlimit64, pid_t, pid, unsigned int, resource,
1562 const struct rlimit64 __user *, new_rlim,
1563 struct rlimit64 __user *, old_rlim)
1564 {
1565 struct rlimit64 old64, new64;
1566 struct rlimit old, new;
1567 struct task_struct *tsk;
1568 unsigned int checkflags = 0;
1569 int ret;
1570
1571 if (old_rlim)
1572 checkflags |= LSM_PRLIMIT_READ;
1573
1574 if (new_rlim) {
1575 if (copy_from_user(&new64, new_rlim, sizeof(new64)))
1576 return -EFAULT;
1577 rlim64_to_rlim(&new64, &new);
1578 checkflags |= LSM_PRLIMIT_WRITE;
1579 }
1580
1581 rcu_read_lock();
1582 tsk = pid ? find_task_by_vpid(pid) : current;
1583 if (!tsk) {
1584 rcu_read_unlock();
1585 return -ESRCH;
1586 }
1587 ret = check_prlimit_permission(tsk, checkflags);
1588 if (ret) {
1589 rcu_read_unlock();
1590 return ret;
1591 }
1592 get_task_struct(tsk);
1593 rcu_read_unlock();
1594
1595 ret = do_prlimit(tsk, resource, new_rlim ? &new : NULL,
1596 old_rlim ? &old : NULL);
1597
1598 if (!ret && old_rlim) {
1599 rlim_to_rlim64(&old, &old64);
1600 if (copy_to_user(old_rlim, &old64, sizeof(old64)))
1601 ret = -EFAULT;
1602 }
1603
1604 put_task_struct(tsk);
1605 return ret;
1606 }
1607
1608 SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim)
1609 {
1610 struct rlimit new_rlim;
1611
1612 if (copy_from_user(&new_rlim, rlim, sizeof(*rlim)))
1613 return -EFAULT;
1614 return do_prlimit(current, resource, &new_rlim, NULL);
1615 }
1616
1617 /*
1618 * It would make sense to put struct rusage in the task_struct,
1619 * except that would make the task_struct be *really big*. After
1620 * task_struct gets moved into malloc'ed memory, it would
1621 * make sense to do this. It will make moving the rest of the information
1622 * a lot simpler! (Which we're not doing right now because we're not
1623 * measuring them yet).
1624 *
1625 * When sampling multiple threads for RUSAGE_SELF, under SMP we might have
1626 * races with threads incrementing their own counters. But since word
1627 * reads are atomic, we either get new values or old values and we don't
1628 * care which for the sums. We always take the siglock to protect reading
1629 * the c* fields from p->signal from races with exit.c updating those
1630 * fields when reaping, so a sample either gets all the additions of a
1631 * given child after it's reaped, or none so this sample is before reaping.
1632 *
1633 * Locking:
1634 * We need to take the siglock for CHILDEREN, SELF and BOTH
1635 * for the cases current multithreaded, non-current single threaded
1636 * non-current multithreaded. Thread traversal is now safe with
1637 * the siglock held.
1638 * Strictly speaking, we donot need to take the siglock if we are current and
1639 * single threaded, as no one else can take our signal_struct away, no one
1640 * else can reap the children to update signal->c* counters, and no one else
1641 * can race with the signal-> fields. If we do not take any lock, the
1642 * signal-> fields could be read out of order while another thread was just
1643 * exiting. So we should place a read memory barrier when we avoid the lock.
1644 * On the writer side, write memory barrier is implied in __exit_signal
1645 * as __exit_signal releases the siglock spinlock after updating the signal->
1646 * fields. But we don't do this yet to keep things simple.
1647 *
1648 */
1649
1650 static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r)
1651 {
1652 r->ru_nvcsw += t->nvcsw;
1653 r->ru_nivcsw += t->nivcsw;
1654 r->ru_minflt += t->min_flt;
1655 r->ru_majflt += t->maj_flt;
1656 r->ru_inblock += task_io_get_inblock(t);
1657 r->ru_oublock += task_io_get_oublock(t);
1658 }
1659
1660 void getrusage(struct task_struct *p, int who, struct rusage *r)
1661 {
1662 struct task_struct *t;
1663 unsigned long flags;
1664 u64 tgutime, tgstime, utime, stime;
1665 unsigned long maxrss = 0;
1666
1667 memset((char *)r, 0, sizeof (*r));
1668 utime = stime = 0;
1669
1670 if (who == RUSAGE_THREAD) {
1671 task_cputime_adjusted(current, &utime, &stime);
1672 accumulate_thread_rusage(p, r);
1673 maxrss = p->signal->maxrss;
1674 goto out;
1675 }
1676
1677 if (!lock_task_sighand(p, &flags))
1678 return;
1679
1680 switch (who) {
1681 case RUSAGE_BOTH:
1682 case RUSAGE_CHILDREN:
1683 utime = p->signal->cutime;
1684 stime = p->signal->cstime;
1685 r->ru_nvcsw = p->signal->cnvcsw;
1686 r->ru_nivcsw = p->signal->cnivcsw;
1687 r->ru_minflt = p->signal->cmin_flt;
1688 r->ru_majflt = p->signal->cmaj_flt;
1689 r->ru_inblock = p->signal->cinblock;
1690 r->ru_oublock = p->signal->coublock;
1691 maxrss = p->signal->cmaxrss;
1692
1693 if (who == RUSAGE_CHILDREN)
1694 break;
1695
1696 case RUSAGE_SELF:
1697 thread_group_cputime_adjusted(p, &tgutime, &tgstime);
1698 utime += tgutime;
1699 stime += tgstime;
1700 r->ru_nvcsw += p->signal->nvcsw;
1701 r->ru_nivcsw += p->signal->nivcsw;
1702 r->ru_minflt += p->signal->min_flt;
1703 r->ru_majflt += p->signal->maj_flt;
1704 r->ru_inblock += p->signal->inblock;
1705 r->ru_oublock += p->signal->oublock;
1706 if (maxrss < p->signal->maxrss)
1707 maxrss = p->signal->maxrss;
1708 t = p;
1709 do {
1710 accumulate_thread_rusage(t, r);
1711 } while_each_thread(p, t);
1712 break;
1713
1714 default:
1715 BUG();
1716 }
1717 unlock_task_sighand(p, &flags);
1718
1719 out:
1720 r->ru_utime = ns_to_timeval(utime);
1721 r->ru_stime = ns_to_timeval(stime);
1722
1723 if (who != RUSAGE_CHILDREN) {
1724 struct mm_struct *mm = get_task_mm(p);
1725
1726 if (mm) {
1727 setmax_mm_hiwater_rss(&maxrss, mm);
1728 mmput(mm);
1729 }
1730 }
1731 r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */
1732 }
1733
1734 SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru)
1735 {
1736 struct rusage r;
1737
1738 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
1739 who != RUSAGE_THREAD)
1740 return -EINVAL;
1741
1742 getrusage(current, who, &r);
1743 return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0;
1744 }
1745
1746 #ifdef CONFIG_COMPAT
1747 COMPAT_SYSCALL_DEFINE2(getrusage, int, who, struct compat_rusage __user *, ru)
1748 {
1749 struct rusage r;
1750
1751 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
1752 who != RUSAGE_THREAD)
1753 return -EINVAL;
1754
1755 getrusage(current, who, &r);
1756 return put_compat_rusage(&r, ru);
1757 }
1758 #endif
1759
1760 SYSCALL_DEFINE1(umask, int, mask)
1761 {
1762 mask = xchg(&current->fs->umask, mask & S_IRWXUGO);
1763 return mask;
1764 }
1765
1766 static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd)
1767 {
1768 struct fd exe;
1769 struct file *old_exe, *exe_file;
1770 struct inode *inode;
1771 int err;
1772
1773 exe = fdget(fd);
1774 if (!exe.file)
1775 return -EBADF;
1776
1777 inode = file_inode(exe.file);
1778
1779 /*
1780 * Because the original mm->exe_file points to executable file, make
1781 * sure that this one is executable as well, to avoid breaking an
1782 * overall picture.
1783 */
1784 err = -EACCES;
1785 if (!S_ISREG(inode->i_mode) || path_noexec(&exe.file->f_path))
1786 goto exit;
1787
1788 err = inode_permission(inode, MAY_EXEC);
1789 if (err)
1790 goto exit;
1791
1792 /*
1793 * Forbid mm->exe_file change if old file still mapped.
1794 */
1795 exe_file = get_mm_exe_file(mm);
1796 err = -EBUSY;
1797 if (exe_file) {
1798 struct vm_area_struct *vma;
1799
1800 down_read(&mm->mmap_sem);
1801 for (vma = mm->mmap; vma; vma = vma->vm_next) {
1802 if (!vma->vm_file)
1803 continue;
1804 if (path_equal(&vma->vm_file->f_path,
1805 &exe_file->f_path))
1806 goto exit_err;
1807 }
1808
1809 up_read(&mm->mmap_sem);
1810 fput(exe_file);
1811 }
1812
1813 err = 0;
1814 /* set the new file, lockless */
1815 get_file(exe.file);
1816 old_exe = xchg(&mm->exe_file, exe.file);
1817 if (old_exe)
1818 fput(old_exe);
1819 exit:
1820 fdput(exe);
1821 return err;
1822 exit_err:
1823 up_read(&mm->mmap_sem);
1824 fput(exe_file);
1825 goto exit;
1826 }
1827
1828 /*
1829 * WARNING: we don't require any capability here so be very careful
1830 * in what is allowed for modification from userspace.
1831 */
1832 static int validate_prctl_map(struct prctl_mm_map *prctl_map)
1833 {
1834 unsigned long mmap_max_addr = TASK_SIZE;
1835 struct mm_struct *mm = current->mm;
1836 int error = -EINVAL, i;
1837
1838 static const unsigned char offsets[] = {
1839 offsetof(struct prctl_mm_map, start_code),
1840 offsetof(struct prctl_mm_map, end_code),
1841 offsetof(struct prctl_mm_map, start_data),
1842 offsetof(struct prctl_mm_map, end_data),
1843 offsetof(struct prctl_mm_map, start_brk),
1844 offsetof(struct prctl_mm_map, brk),
1845 offsetof(struct prctl_mm_map, start_stack),
1846 offsetof(struct prctl_mm_map, arg_start),
1847 offsetof(struct prctl_mm_map, arg_end),
1848 offsetof(struct prctl_mm_map, env_start),
1849 offsetof(struct prctl_mm_map, env_end),
1850 };
1851
1852 /*
1853 * Make sure the members are not somewhere outside
1854 * of allowed address space.
1855 */
1856 for (i = 0; i < ARRAY_SIZE(offsets); i++) {
1857 u64 val = *(u64 *)((char *)prctl_map + offsets[i]);
1858
1859 if ((unsigned long)val >= mmap_max_addr ||
1860 (unsigned long)val < mmap_min_addr)
1861 goto out;
1862 }
1863
1864 /*
1865 * Make sure the pairs are ordered.
1866 */
1867 #define __prctl_check_order(__m1, __op, __m2) \
1868 ((unsigned long)prctl_map->__m1 __op \
1869 (unsigned long)prctl_map->__m2) ? 0 : -EINVAL
1870 error = __prctl_check_order(start_code, <, end_code);
1871 error |= __prctl_check_order(start_data, <, end_data);
1872 error |= __prctl_check_order(start_brk, <=, brk);
1873 error |= __prctl_check_order(arg_start, <=, arg_end);
1874 error |= __prctl_check_order(env_start, <=, env_end);
1875 if (error)
1876 goto out;
1877 #undef __prctl_check_order
1878
1879 error = -EINVAL;
1880
1881 /*
1882 * @brk should be after @end_data in traditional maps.
1883 */
1884 if (prctl_map->start_brk <= prctl_map->end_data ||
1885 prctl_map->brk <= prctl_map->end_data)
1886 goto out;
1887
1888 /*
1889 * Neither we should allow to override limits if they set.
1890 */
1891 if (check_data_rlimit(rlimit(RLIMIT_DATA), prctl_map->brk,
1892 prctl_map->start_brk, prctl_map->end_data,
1893 prctl_map->start_data))
1894 goto out;
1895
1896 /*
1897 * Someone is trying to cheat the auxv vector.
1898 */
1899 if (prctl_map->auxv_size) {
1900 if (!prctl_map->auxv || prctl_map->auxv_size > sizeof(mm->saved_auxv))
1901 goto out;
1902 }
1903
1904 /*
1905 * Finally, make sure the caller has the rights to
1906 * change /proc/pid/exe link: only local sys admin should
1907 * be allowed to.
1908 */
1909 if (prctl_map->exe_fd != (u32)-1) {
1910 if (!ns_capable(current_user_ns(), CAP_SYS_ADMIN))
1911 goto out;
1912 }
1913
1914 error = 0;
1915 out:
1916 return error;
1917 }
1918
1919 #ifdef CONFIG_CHECKPOINT_RESTORE
1920 static int prctl_set_mm_map(int opt, const void __user *addr, unsigned long data_size)
1921 {
1922 struct prctl_mm_map prctl_map = { .exe_fd = (u32)-1, };
1923 unsigned long user_auxv[AT_VECTOR_SIZE];
1924 struct mm_struct *mm = current->mm;
1925 int error;
1926
1927 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv));
1928 BUILD_BUG_ON(sizeof(struct prctl_mm_map) > 256);
1929
1930 if (opt == PR_SET_MM_MAP_SIZE)
1931 return put_user((unsigned int)sizeof(prctl_map),
1932 (unsigned int __user *)addr);
1933
1934 if (data_size != sizeof(prctl_map))
1935 return -EINVAL;
1936
1937 if (copy_from_user(&prctl_map, addr, sizeof(prctl_map)))
1938 return -EFAULT;
1939
1940 error = validate_prctl_map(&prctl_map);
1941 if (error)
1942 return error;
1943
1944 if (prctl_map.auxv_size) {
1945 memset(user_auxv, 0, sizeof(user_auxv));
1946 if (copy_from_user(user_auxv,
1947 (const void __user *)prctl_map.auxv,
1948 prctl_map.auxv_size))
1949 return -EFAULT;
1950
1951 /* Last entry must be AT_NULL as specification requires */
1952 user_auxv[AT_VECTOR_SIZE - 2] = AT_NULL;
1953 user_auxv[AT_VECTOR_SIZE - 1] = AT_NULL;
1954 }
1955
1956 if (prctl_map.exe_fd != (u32)-1) {
1957 error = prctl_set_mm_exe_file(mm, prctl_map.exe_fd);
1958 if (error)
1959 return error;
1960 }
1961
1962 down_write(&mm->mmap_sem);
1963
1964 /*
1965 * We don't validate if these members are pointing to
1966 * real present VMAs because application may have correspond
1967 * VMAs already unmapped and kernel uses these members for statistics
1968 * output in procfs mostly, except
1969 *
1970 * - @start_brk/@brk which are used in do_brk but kernel lookups
1971 * for VMAs when updating these memvers so anything wrong written
1972 * here cause kernel to swear at userspace program but won't lead
1973 * to any problem in kernel itself
1974 */
1975
1976 mm->start_code = prctl_map.start_code;
1977 mm->end_code = prctl_map.end_code;
1978 mm->start_data = prctl_map.start_data;
1979 mm->end_data = prctl_map.end_data;
1980 mm->start_brk = prctl_map.start_brk;
1981 mm->brk = prctl_map.brk;
1982 mm->start_stack = prctl_map.start_stack;
1983 mm->arg_start = prctl_map.arg_start;
1984 mm->arg_end = prctl_map.arg_end;
1985 mm->env_start = prctl_map.env_start;
1986 mm->env_end = prctl_map.env_end;
1987
1988 /*
1989 * Note this update of @saved_auxv is lockless thus
1990 * if someone reads this member in procfs while we're
1991 * updating -- it may get partly updated results. It's
1992 * known and acceptable trade off: we leave it as is to
1993 * not introduce additional locks here making the kernel
1994 * more complex.
1995 */
1996 if (prctl_map.auxv_size)
1997 memcpy(mm->saved_auxv, user_auxv, sizeof(user_auxv));
1998
1999 up_write(&mm->mmap_sem);
2000 return 0;
2001 }
2002 #endif /* CONFIG_CHECKPOINT_RESTORE */
2003
2004 static int prctl_set_auxv(struct mm_struct *mm, unsigned long addr,
2005 unsigned long len)
2006 {
2007 /*
2008 * This doesn't move the auxiliary vector itself since it's pinned to
2009 * mm_struct, but it permits filling the vector with new values. It's
2010 * up to the caller to provide sane values here, otherwise userspace
2011 * tools which use this vector might be unhappy.
2012 */
2013 unsigned long user_auxv[AT_VECTOR_SIZE];
2014
2015 if (len > sizeof(user_auxv))
2016 return -EINVAL;
2017
2018 if (copy_from_user(user_auxv, (const void __user *)addr, len))
2019 return -EFAULT;
2020
2021 /* Make sure the last entry is always AT_NULL */
2022 user_auxv[AT_VECTOR_SIZE - 2] = 0;
2023 user_auxv[AT_VECTOR_SIZE - 1] = 0;
2024
2025 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv));
2026
2027 task_lock(current);
2028 memcpy(mm->saved_auxv, user_auxv, len);
2029 task_unlock(current);
2030
2031 return 0;
2032 }
2033
2034 static int prctl_set_mm(int opt, unsigned long addr,
2035 unsigned long arg4, unsigned long arg5)
2036 {
2037 struct mm_struct *mm = current->mm;
2038 struct prctl_mm_map prctl_map;
2039 struct vm_area_struct *vma;
2040 int error;
2041
2042 if (arg5 || (arg4 && (opt != PR_SET_MM_AUXV &&
2043 opt != PR_SET_MM_MAP &&
2044 opt != PR_SET_MM_MAP_SIZE)))
2045 return -EINVAL;
2046
2047 #ifdef CONFIG_CHECKPOINT_RESTORE
2048 if (opt == PR_SET_MM_MAP || opt == PR_SET_MM_MAP_SIZE)
2049 return prctl_set_mm_map(opt, (const void __user *)addr, arg4);
2050 #endif
2051
2052 if (!capable(CAP_SYS_RESOURCE))
2053 return -EPERM;
2054
2055 if (opt == PR_SET_MM_EXE_FILE)
2056 return prctl_set_mm_exe_file(mm, (unsigned int)addr);
2057
2058 if (opt == PR_SET_MM_AUXV)
2059 return prctl_set_auxv(mm, addr, arg4);
2060
2061 if (addr >= TASK_SIZE || addr < mmap_min_addr)
2062 return -EINVAL;
2063
2064 error = -EINVAL;
2065
2066 down_write(&mm->mmap_sem);
2067 vma = find_vma(mm, addr);
2068
2069 prctl_map.start_code = mm->start_code;
2070 prctl_map.end_code = mm->end_code;
2071 prctl_map.start_data = mm->start_data;
2072 prctl_map.end_data = mm->end_data;
2073 prctl_map.start_brk = mm->start_brk;
2074 prctl_map.brk = mm->brk;
2075 prctl_map.start_stack = mm->start_stack;
2076 prctl_map.arg_start = mm->arg_start;
2077 prctl_map.arg_end = mm->arg_end;
2078 prctl_map.env_start = mm->env_start;
2079 prctl_map.env_end = mm->env_end;
2080 prctl_map.auxv = NULL;
2081 prctl_map.auxv_size = 0;
2082 prctl_map.exe_fd = -1;
2083
2084 switch (opt) {
2085 case PR_SET_MM_START_CODE:
2086 prctl_map.start_code = addr;
2087 break;
2088 case PR_SET_MM_END_CODE:
2089 prctl_map.end_code = addr;
2090 break;
2091 case PR_SET_MM_START_DATA:
2092 prctl_map.start_data = addr;
2093 break;
2094 case PR_SET_MM_END_DATA:
2095 prctl_map.end_data = addr;
2096 break;
2097 case PR_SET_MM_START_STACK:
2098 prctl_map.start_stack = addr;
2099 break;
2100 case PR_SET_MM_START_BRK:
2101 prctl_map.start_brk = addr;
2102 break;
2103 case PR_SET_MM_BRK:
2104 prctl_map.brk = addr;
2105 break;
2106 case PR_SET_MM_ARG_START:
2107 prctl_map.arg_start = addr;
2108 break;
2109 case PR_SET_MM_ARG_END:
2110 prctl_map.arg_end = addr;
2111 break;
2112 case PR_SET_MM_ENV_START:
2113 prctl_map.env_start = addr;
2114 break;
2115 case PR_SET_MM_ENV_END:
2116 prctl_map.env_end = addr;
2117 break;
2118 default:
2119 goto out;
2120 }
2121
2122 error = validate_prctl_map(&prctl_map);
2123 if (error)
2124 goto out;
2125
2126 switch (opt) {
2127 /*
2128 * If command line arguments and environment
2129 * are placed somewhere else on stack, we can
2130 * set them up here, ARG_START/END to setup
2131 * command line argumets and ENV_START/END
2132 * for environment.
2133 */
2134 case PR_SET_MM_START_STACK:
2135 case PR_SET_MM_ARG_START:
2136 case PR_SET_MM_ARG_END:
2137 case PR_SET_MM_ENV_START:
2138 case PR_SET_MM_ENV_END:
2139 if (!vma) {
2140 error = -EFAULT;
2141 goto out;
2142 }
2143 }
2144
2145 mm->start_code = prctl_map.start_code;
2146 mm->end_code = prctl_map.end_code;
2147 mm->start_data = prctl_map.start_data;
2148 mm->end_data = prctl_map.end_data;
2149 mm->start_brk = prctl_map.start_brk;
2150 mm->brk = prctl_map.brk;
2151 mm->start_stack = prctl_map.start_stack;
2152 mm->arg_start = prctl_map.arg_start;
2153 mm->arg_end = prctl_map.arg_end;
2154 mm->env_start = prctl_map.env_start;
2155 mm->env_end = prctl_map.env_end;
2156
2157 error = 0;
2158 out:
2159 up_write(&mm->mmap_sem);
2160 return error;
2161 }
2162
2163 #ifdef CONFIG_CHECKPOINT_RESTORE
2164 static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr)
2165 {
2166 return put_user(me->clear_child_tid, tid_addr);
2167 }
2168 #else
2169 static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr)
2170 {
2171 return -EINVAL;
2172 }
2173 #endif
2174
2175 static int propagate_has_child_subreaper(struct task_struct *p, void *data)
2176 {
2177 /*
2178 * If task has has_child_subreaper - all its decendants
2179 * already have these flag too and new decendants will
2180 * inherit it on fork, skip them.
2181 *
2182 * If we've found child_reaper - skip descendants in
2183 * it's subtree as they will never get out pidns.
2184 */
2185 if (p->signal->has_child_subreaper ||
2186 is_child_reaper(task_pid(p)))
2187 return 0;
2188
2189 p->signal->has_child_subreaper = 1;
2190 return 1;
2191 }
2192
2193 SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
2194 unsigned long, arg4, unsigned long, arg5)
2195 {
2196 struct task_struct *me = current;
2197 unsigned char comm[sizeof(me->comm)];
2198 long error;
2199
2200 error = security_task_prctl(option, arg2, arg3, arg4, arg5);
2201 if (error != -ENOSYS)
2202 return error;
2203
2204 error = 0;
2205 switch (option) {
2206 case PR_SET_PDEATHSIG:
2207 if (!valid_signal(arg2)) {
2208 error = -EINVAL;
2209 break;
2210 }
2211 me->pdeath_signal = arg2;
2212 break;
2213 case PR_GET_PDEATHSIG:
2214 error = put_user(me->pdeath_signal, (int __user *)arg2);
2215 break;
2216 case PR_GET_DUMPABLE:
2217 error = get_dumpable(me->mm);
2218 break;
2219 case PR_SET_DUMPABLE:
2220 if (arg2 != SUID_DUMP_DISABLE && arg2 != SUID_DUMP_USER) {
2221 error = -EINVAL;
2222 break;
2223 }
2224 set_dumpable(me->mm, arg2);
2225 break;
2226
2227 case PR_SET_UNALIGN:
2228 error = SET_UNALIGN_CTL(me, arg2);
2229 break;
2230 case PR_GET_UNALIGN:
2231 error = GET_UNALIGN_CTL(me, arg2);
2232 break;
2233 case PR_SET_FPEMU:
2234 error = SET_FPEMU_CTL(me, arg2);
2235 break;
2236 case PR_GET_FPEMU:
2237 error = GET_FPEMU_CTL(me, arg2);
2238 break;
2239 case PR_SET_FPEXC:
2240 error = SET_FPEXC_CTL(me, arg2);
2241 break;
2242 case PR_GET_FPEXC:
2243 error = GET_FPEXC_CTL(me, arg2);
2244 break;
2245 case PR_GET_TIMING:
2246 error = PR_TIMING_STATISTICAL;
2247 break;
2248 case PR_SET_TIMING:
2249 if (arg2 != PR_TIMING_STATISTICAL)
2250 error = -EINVAL;
2251 break;
2252 case PR_SET_NAME:
2253 comm[sizeof(me->comm) - 1] = 0;
2254 if (strncpy_from_user(comm, (char __user *)arg2,
2255 sizeof(me->comm) - 1) < 0)
2256 return -EFAULT;
2257 set_task_comm(me, comm);
2258 proc_comm_connector(me);
2259 break;
2260 case PR_GET_NAME:
2261 get_task_comm(comm, me);
2262 if (copy_to_user((char __user *)arg2, comm, sizeof(comm)))
2263 return -EFAULT;
2264 break;
2265 case PR_GET_ENDIAN:
2266 error = GET_ENDIAN(me, arg2);
2267 break;
2268 case PR_SET_ENDIAN:
2269 error = SET_ENDIAN(me, arg2);
2270 break;
2271 case PR_GET_SECCOMP:
2272 error = prctl_get_seccomp();
2273 break;
2274 case PR_SET_SECCOMP:
2275 error = prctl_set_seccomp(arg2, (char __user *)arg3);
2276 break;
2277 case PR_GET_TSC:
2278 error = GET_TSC_CTL(arg2);
2279 break;
2280 case PR_SET_TSC:
2281 error = SET_TSC_CTL(arg2);
2282 break;
2283 case PR_TASK_PERF_EVENTS_DISABLE:
2284 error = perf_event_task_disable();
2285 break;
2286 case PR_TASK_PERF_EVENTS_ENABLE:
2287 error = perf_event_task_enable();
2288 break;
2289 case PR_GET_TIMERSLACK:
2290 if (current->timer_slack_ns > ULONG_MAX)
2291 error = ULONG_MAX;
2292 else
2293 error = current->timer_slack_ns;
2294 break;
2295 case PR_SET_TIMERSLACK:
2296 if (arg2 <= 0)
2297 current->timer_slack_ns =
2298 current->default_timer_slack_ns;
2299 else
2300 current->timer_slack_ns = arg2;
2301 break;
2302 case PR_MCE_KILL:
2303 if (arg4 | arg5)
2304 return -EINVAL;
2305 switch (arg2) {
2306 case PR_MCE_KILL_CLEAR:
2307 if (arg3 != 0)
2308 return -EINVAL;
2309 current->flags &= ~PF_MCE_PROCESS;
2310 break;
2311 case PR_MCE_KILL_SET:
2312 current->flags |= PF_MCE_PROCESS;
2313 if (arg3 == PR_MCE_KILL_EARLY)
2314 current->flags |= PF_MCE_EARLY;
2315 else if (arg3 == PR_MCE_KILL_LATE)
2316 current->flags &= ~PF_MCE_EARLY;
2317 else if (arg3 == PR_MCE_KILL_DEFAULT)
2318 current->flags &=
2319 ~(PF_MCE_EARLY|PF_MCE_PROCESS);
2320 else
2321 return -EINVAL;
2322 break;
2323 default:
2324 return -EINVAL;
2325 }
2326 break;
2327 case PR_MCE_KILL_GET:
2328 if (arg2 | arg3 | arg4 | arg5)
2329 return -EINVAL;
2330 if (current->flags & PF_MCE_PROCESS)
2331 error = (current->flags & PF_MCE_EARLY) ?
2332 PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE;
2333 else
2334 error = PR_MCE_KILL_DEFAULT;
2335 break;
2336 case PR_SET_MM:
2337 error = prctl_set_mm(arg2, arg3, arg4, arg5);
2338 break;
2339 case PR_GET_TID_ADDRESS:
2340 error = prctl_get_tid_address(me, (int __user **)arg2);
2341 break;
2342 case PR_SET_CHILD_SUBREAPER:
2343 me->signal->is_child_subreaper = !!arg2;
2344 if (!arg2)
2345 break;
2346
2347 walk_process_tree(me, propagate_has_child_subreaper, NULL);
2348 break;
2349 case PR_GET_CHILD_SUBREAPER:
2350 error = put_user(me->signal->is_child_subreaper,
2351 (int __user *)arg2);
2352 break;
2353 case PR_SET_NO_NEW_PRIVS:
2354 if (arg2 != 1 || arg3 || arg4 || arg5)
2355 return -EINVAL;
2356
2357 task_set_no_new_privs(current);
2358 break;
2359 case PR_GET_NO_NEW_PRIVS:
2360 if (arg2 || arg3 || arg4 || arg5)
2361 return -EINVAL;
2362 return task_no_new_privs(current) ? 1 : 0;
2363 case PR_GET_THP_DISABLE:
2364 if (arg2 || arg3 || arg4 || arg5)
2365 return -EINVAL;
2366 error = !!test_bit(MMF_DISABLE_THP, &me->mm->flags);
2367 break;
2368 case PR_SET_THP_DISABLE:
2369 if (arg3 || arg4 || arg5)
2370 return -EINVAL;
2371 if (down_write_killable(&me->mm->mmap_sem))
2372 return -EINTR;
2373 if (arg2)
2374 set_bit(MMF_DISABLE_THP, &me->mm->flags);
2375 else
2376 clear_bit(MMF_DISABLE_THP, &me->mm->flags);
2377 up_write(&me->mm->mmap_sem);
2378 break;
2379 case PR_MPX_ENABLE_MANAGEMENT:
2380 if (arg2 || arg3 || arg4 || arg5)
2381 return -EINVAL;
2382 error = MPX_ENABLE_MANAGEMENT();
2383 break;
2384 case PR_MPX_DISABLE_MANAGEMENT:
2385 if (arg2 || arg3 || arg4 || arg5)
2386 return -EINVAL;
2387 error = MPX_DISABLE_MANAGEMENT();
2388 break;
2389 case PR_SET_FP_MODE:
2390 error = SET_FP_MODE(me, arg2);
2391 break;
2392 case PR_GET_FP_MODE:
2393 error = GET_FP_MODE(me);
2394 break;
2395 case PR_SVE_SET_VL:
2396 error = SVE_SET_VL(arg2);
2397 break;
2398 case PR_SVE_GET_VL:
2399 error = SVE_GET_VL();
2400 break;
2401 default:
2402 error = -EINVAL;
2403 break;
2404 }
2405 return error;
2406 }
2407
2408 SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep,
2409 struct getcpu_cache __user *, unused)
2410 {
2411 int err = 0;
2412 int cpu = raw_smp_processor_id();
2413
2414 if (cpup)
2415 err |= put_user(cpu, cpup);
2416 if (nodep)
2417 err |= put_user(cpu_to_node(cpu), nodep);
2418 return err ? -EFAULT : 0;
2419 }
2420
2421 /**
2422 * do_sysinfo - fill in sysinfo struct
2423 * @info: pointer to buffer to fill
2424 */
2425 static int do_sysinfo(struct sysinfo *info)
2426 {
2427 unsigned long mem_total, sav_total;
2428 unsigned int mem_unit, bitcount;
2429 struct timespec tp;
2430
2431 memset(info, 0, sizeof(struct sysinfo));
2432
2433 get_monotonic_boottime(&tp);
2434 info->uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0);
2435
2436 get_avenrun(info->loads, 0, SI_LOAD_SHIFT - FSHIFT);
2437
2438 info->procs = nr_threads;
2439
2440 si_meminfo(info);
2441 si_swapinfo(info);
2442
2443 /*
2444 * If the sum of all the available memory (i.e. ram + swap)
2445 * is less than can be stored in a 32 bit unsigned long then
2446 * we can be binary compatible with 2.2.x kernels. If not,
2447 * well, in that case 2.2.x was broken anyways...
2448 *
2449 * -Erik Andersen <andersee@debian.org>
2450 */
2451
2452 mem_total = info->totalram + info->totalswap;
2453 if (mem_total < info->totalram || mem_total < info->totalswap)
2454 goto out;
2455 bitcount = 0;
2456 mem_unit = info->mem_unit;
2457 while (mem_unit > 1) {
2458 bitcount++;
2459 mem_unit >>= 1;
2460 sav_total = mem_total;
2461 mem_total <<= 1;
2462 if (mem_total < sav_total)
2463 goto out;
2464 }
2465
2466 /*
2467 * If mem_total did not overflow, multiply all memory values by
2468 * info->mem_unit and set it to 1. This leaves things compatible
2469 * with 2.2.x, and also retains compatibility with earlier 2.4.x
2470 * kernels...
2471 */
2472
2473 info->mem_unit = 1;
2474 info->totalram <<= bitcount;
2475 info->freeram <<= bitcount;
2476 info->sharedram <<= bitcount;
2477 info->bufferram <<= bitcount;
2478 info->totalswap <<= bitcount;
2479 info->freeswap <<= bitcount;
2480 info->totalhigh <<= bitcount;
2481 info->freehigh <<= bitcount;
2482
2483 out:
2484 return 0;
2485 }
2486
2487 SYSCALL_DEFINE1(sysinfo, struct sysinfo __user *, info)
2488 {
2489 struct sysinfo val;
2490
2491 do_sysinfo(&val);
2492
2493 if (copy_to_user(info, &val, sizeof(struct sysinfo)))
2494 return -EFAULT;
2495
2496 return 0;
2497 }
2498
2499 #ifdef CONFIG_COMPAT
2500 struct compat_sysinfo {
2501 s32 uptime;
2502 u32 loads[3];
2503 u32 totalram;
2504 u32 freeram;
2505 u32 sharedram;
2506 u32 bufferram;
2507 u32 totalswap;
2508 u32 freeswap;
2509 u16 procs;
2510 u16 pad;
2511 u32 totalhigh;
2512 u32 freehigh;
2513 u32 mem_unit;
2514 char _f[20-2*sizeof(u32)-sizeof(int)];
2515 };
2516
2517 COMPAT_SYSCALL_DEFINE1(sysinfo, struct compat_sysinfo __user *, info)
2518 {
2519 struct sysinfo s;
2520
2521 do_sysinfo(&s);
2522
2523 /* Check to see if any memory value is too large for 32-bit and scale
2524 * down if needed
2525 */
2526 if (upper_32_bits(s.totalram) || upper_32_bits(s.totalswap)) {
2527 int bitcount = 0;
2528
2529 while (s.mem_unit < PAGE_SIZE) {
2530 s.mem_unit <<= 1;
2531 bitcount++;
2532 }
2533
2534 s.totalram >>= bitcount;
2535 s.freeram >>= bitcount;
2536 s.sharedram >>= bitcount;
2537 s.bufferram >>= bitcount;
2538 s.totalswap >>= bitcount;
2539 s.freeswap >>= bitcount;
2540 s.totalhigh >>= bitcount;
2541 s.freehigh >>= bitcount;
2542 }
2543
2544 if (!access_ok(VERIFY_WRITE, info, sizeof(struct compat_sysinfo)) ||
2545 __put_user(s.uptime, &info->uptime) ||
2546 __put_user(s.loads[0], &info->loads[0]) ||
2547 __put_user(s.loads[1], &info->loads[1]) ||
2548 __put_user(s.loads[2], &info->loads[2]) ||
2549 __put_user(s.totalram, &info->totalram) ||
2550 __put_user(s.freeram, &info->freeram) ||
2551 __put_user(s.sharedram, &info->sharedram) ||
2552 __put_user(s.bufferram, &info->bufferram) ||
2553 __put_user(s.totalswap, &info->totalswap) ||
2554 __put_user(s.freeswap, &info->freeswap) ||
2555 __put_user(s.procs, &info->procs) ||
2556 __put_user(s.totalhigh, &info->totalhigh) ||
2557 __put_user(s.freehigh, &info->freehigh) ||
2558 __put_user(s.mem_unit, &info->mem_unit))
2559 return -EFAULT;
2560
2561 return 0;
2562 }
2563 #endif /* CONFIG_COMPAT */
CRIS linux kernel tree