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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/mm_inline.h>
11#include <linux/utsname.h>
12#include <linux/mman.h>
13#include <linux/reboot.h>
14#include <linux/prctl.h>
15#include <linux/highuid.h>
16#include <linux/fs.h>
17#include <linux/kmod.h>
18#include <linux/ksm.h>
19#include <linux/perf_event.h>
20#include <linux/resource.h>
21#include <linux/kernel.h>
22#include <linux/workqueue.h>
23#include <linux/capability.h>
24#include <linux/device.h>
25#include <linux/key.h>
26#include <linux/times.h>
27#include <linux/posix-timers.h>
28#include <linux/security.h>
29#include <linux/random.h>
30#include <linux/suspend.h>
31#include <linux/tty.h>
32#include <linux/signal.h>
33#include <linux/cn_proc.h>
34#include <linux/getcpu.h>
35#include <linux/task_io_accounting_ops.h>
36#include <linux/seccomp.h>
37#include <linux/cpu.h>
38#include <linux/personality.h>
39#include <linux/ptrace.h>
40#include <linux/fs_struct.h>
41#include <linux/file.h>
42#include <linux/mount.h>
43#include <linux/gfp.h>
44#include <linux/syscore_ops.h>
45#include <linux/version.h>
46#include <linux/ctype.h>
47#include <linux/syscall_user_dispatch.h>
48
49#include <linux/compat.h>
50#include <linux/syscalls.h>
51#include <linux/kprobes.h>
52#include <linux/user_namespace.h>
53#include <linux/time_namespace.h>
54#include <linux/binfmts.h>
55
56#include <linux/sched.h>
57#include <linux/sched/autogroup.h>
58#include <linux/sched/loadavg.h>
59#include <linux/sched/stat.h>
60#include <linux/sched/mm.h>
61#include <linux/sched/coredump.h>
62#include <linux/sched/task.h>
63#include <linux/sched/cputime.h>
64#include <linux/rcupdate.h>
65#include <linux/uidgid.h>
66#include <linux/cred.h>
67
68#include <linux/nospec.h>
69
70#include <linux/kmsg_dump.h>
71/* Move somewhere else to avoid recompiling? */
72#include <generated/utsrelease.h>
73
74#include <linux/uaccess.h>
75#include <asm/io.h>
76#include <asm/unistd.h>
77
78#include "uid16.h"
79
80#ifndef SET_UNALIGN_CTL
81# define SET_UNALIGN_CTL(a, b) (-EINVAL)
82#endif
83#ifndef GET_UNALIGN_CTL
84# define GET_UNALIGN_CTL(a, b) (-EINVAL)
85#endif
86#ifndef SET_FPEMU_CTL
87# define SET_FPEMU_CTL(a, b) (-EINVAL)
88#endif
89#ifndef GET_FPEMU_CTL
90# define GET_FPEMU_CTL(a, b) (-EINVAL)
91#endif
92#ifndef SET_FPEXC_CTL
93# define SET_FPEXC_CTL(a, b) (-EINVAL)
94#endif
95#ifndef GET_FPEXC_CTL
96# define GET_FPEXC_CTL(a, b) (-EINVAL)
97#endif
98#ifndef GET_ENDIAN
99# define GET_ENDIAN(a, b) (-EINVAL)
100#endif
101#ifndef SET_ENDIAN
102# define SET_ENDIAN(a, b) (-EINVAL)
103#endif
104#ifndef GET_TSC_CTL
105# define GET_TSC_CTL(a) (-EINVAL)
106#endif
107#ifndef SET_TSC_CTL
108# define SET_TSC_CTL(a) (-EINVAL)
109#endif
110#ifndef GET_FP_MODE
111# define GET_FP_MODE(a) (-EINVAL)
112#endif
113#ifndef SET_FP_MODE
114# define SET_FP_MODE(a,b) (-EINVAL)
115#endif
116#ifndef SVE_SET_VL
117# define SVE_SET_VL(a) (-EINVAL)
118#endif
119#ifndef SVE_GET_VL
120# define SVE_GET_VL() (-EINVAL)
121#endif
122#ifndef SME_SET_VL
123# define SME_SET_VL(a) (-EINVAL)
124#endif
125#ifndef SME_GET_VL
126# define SME_GET_VL() (-EINVAL)
127#endif
128#ifndef PAC_RESET_KEYS
129# define PAC_RESET_KEYS(a, b) (-EINVAL)
130#endif
131#ifndef PAC_SET_ENABLED_KEYS
132# define PAC_SET_ENABLED_KEYS(a, b, c) (-EINVAL)
133#endif
134#ifndef PAC_GET_ENABLED_KEYS
135# define PAC_GET_ENABLED_KEYS(a) (-EINVAL)
136#endif
137#ifndef SET_TAGGED_ADDR_CTRL
138# define SET_TAGGED_ADDR_CTRL(a) (-EINVAL)
139#endif
140#ifndef GET_TAGGED_ADDR_CTRL
141# define GET_TAGGED_ADDR_CTRL() (-EINVAL)
142#endif
143#ifndef RISCV_V_SET_CONTROL
144# define RISCV_V_SET_CONTROL(a) (-EINVAL)
145#endif
146#ifndef RISCV_V_GET_CONTROL
147# define RISCV_V_GET_CONTROL() (-EINVAL)
148#endif
149
150/*
151 * this is where the system-wide overflow UID and GID are defined, for
152 * architectures that now have 32-bit UID/GID but didn't in the past
153 */
154
155int overflowuid = DEFAULT_OVERFLOWUID;
156int overflowgid = DEFAULT_OVERFLOWGID;
157
158EXPORT_SYMBOL(overflowuid);
159EXPORT_SYMBOL(overflowgid);
160
161/*
162 * the same as above, but for filesystems which can only store a 16-bit
163 * UID and GID. as such, this is needed on all architectures
164 */
165
166int fs_overflowuid = DEFAULT_FS_OVERFLOWUID;
167int fs_overflowgid = DEFAULT_FS_OVERFLOWGID;
168
169EXPORT_SYMBOL(fs_overflowuid);
170EXPORT_SYMBOL(fs_overflowgid);
171
172/*
173 * Returns true if current's euid is same as p's uid or euid,
174 * or has CAP_SYS_NICE to p's user_ns.
175 *
176 * Called with rcu_read_lock, creds are safe
177 */
178static bool set_one_prio_perm(struct task_struct *p)
179{
180 const struct cred *cred = current_cred(), *pcred = __task_cred(p);
181
182 if (uid_eq(pcred->uid, cred->euid) ||
183 uid_eq(pcred->euid, cred->euid))
184 return true;
185 if (ns_capable(pcred->user_ns, CAP_SYS_NICE))
186 return true;
187 return false;
188}
189
190/*
191 * set the priority of a task
192 * - the caller must hold the RCU read lock
193 */
194static int set_one_prio(struct task_struct *p, int niceval, int error)
195{
196 int no_nice;
197
198 if (!set_one_prio_perm(p)) {
199 error = -EPERM;
200 goto out;
201 }
202 if (niceval < task_nice(p) && !can_nice(p, niceval)) {
203 error = -EACCES;
204 goto out;
205 }
206 no_nice = security_task_setnice(p, niceval);
207 if (no_nice) {
208 error = no_nice;
209 goto out;
210 }
211 if (error == -ESRCH)
212 error = 0;
213 set_user_nice(p, niceval);
214out:
215 return error;
216}
217
218SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval)
219{
220 struct task_struct *g, *p;
221 struct user_struct *user;
222 const struct cred *cred = current_cred();
223 int error = -EINVAL;
224 struct pid *pgrp;
225 kuid_t uid;
226
227 if (which > PRIO_USER || which < PRIO_PROCESS)
228 goto out;
229
230 /* normalize: avoid signed division (rounding problems) */
231 error = -ESRCH;
232 if (niceval < MIN_NICE)
233 niceval = MIN_NICE;
234 if (niceval > MAX_NICE)
235 niceval = MAX_NICE;
236
237 rcu_read_lock();
238 switch (which) {
239 case PRIO_PROCESS:
240 if (who)
241 p = find_task_by_vpid(who);
242 else
243 p = current;
244 if (p)
245 error = set_one_prio(p, niceval, error);
246 break;
247 case PRIO_PGRP:
248 if (who)
249 pgrp = find_vpid(who);
250 else
251 pgrp = task_pgrp(current);
252 read_lock(&tasklist_lock);
253 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
254 error = set_one_prio(p, niceval, error);
255 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
256 read_unlock(&tasklist_lock);
257 break;
258 case PRIO_USER:
259 uid = make_kuid(cred->user_ns, who);
260 user = cred->user;
261 if (!who)
262 uid = cred->uid;
263 else if (!uid_eq(uid, cred->uid)) {
264 user = find_user(uid);
265 if (!user)
266 goto out_unlock; /* No processes for this user */
267 }
268 for_each_process_thread(g, p) {
269 if (uid_eq(task_uid(p), uid) && task_pid_vnr(p))
270 error = set_one_prio(p, niceval, error);
271 }
272 if (!uid_eq(uid, cred->uid))
273 free_uid(user); /* For find_user() */
274 break;
275 }
276out_unlock:
277 rcu_read_unlock();
278out:
279 return error;
280}
281
282/*
283 * Ugh. To avoid negative return values, "getpriority()" will
284 * not return the normal nice-value, but a negated value that
285 * has been offset by 20 (ie it returns 40..1 instead of -20..19)
286 * to stay compatible.
287 */
288SYSCALL_DEFINE2(getpriority, int, which, int, who)
289{
290 struct task_struct *g, *p;
291 struct user_struct *user;
292 const struct cred *cred = current_cred();
293 long niceval, retval = -ESRCH;
294 struct pid *pgrp;
295 kuid_t uid;
296
297 if (which > PRIO_USER || which < PRIO_PROCESS)
298 return -EINVAL;
299
300 rcu_read_lock();
301 switch (which) {
302 case PRIO_PROCESS:
303 if (who)
304 p = find_task_by_vpid(who);
305 else
306 p = current;
307 if (p) {
308 niceval = nice_to_rlimit(task_nice(p));
309 if (niceval > retval)
310 retval = niceval;
311 }
312 break;
313 case PRIO_PGRP:
314 if (who)
315 pgrp = find_vpid(who);
316 else
317 pgrp = task_pgrp(current);
318 read_lock(&tasklist_lock);
319 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
320 niceval = nice_to_rlimit(task_nice(p));
321 if (niceval > retval)
322 retval = niceval;
323 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
324 read_unlock(&tasklist_lock);
325 break;
326 case PRIO_USER:
327 uid = make_kuid(cred->user_ns, who);
328 user = cred->user;
329 if (!who)
330 uid = cred->uid;
331 else if (!uid_eq(uid, cred->uid)) {
332 user = find_user(uid);
333 if (!user)
334 goto out_unlock; /* No processes for this user */
335 }
336 for_each_process_thread(g, p) {
337 if (uid_eq(task_uid(p), uid) && task_pid_vnr(p)) {
338 niceval = nice_to_rlimit(task_nice(p));
339 if (niceval > retval)
340 retval = niceval;
341 }
342 }
343 if (!uid_eq(uid, cred->uid))
344 free_uid(user); /* for find_user() */
345 break;
346 }
347out_unlock:
348 rcu_read_unlock();
349
350 return retval;
351}
352
353/*
354 * Unprivileged users may change the real gid to the effective gid
355 * or vice versa. (BSD-style)
356 *
357 * If you set the real gid at all, or set the effective gid to a value not
358 * equal to the real gid, then the saved gid is set to the new effective gid.
359 *
360 * This makes it possible for a setgid program to completely drop its
361 * privileges, which is often a useful assertion to make when you are doing
362 * a security audit over a program.
363 *
364 * The general idea is that a program which uses just setregid() will be
365 * 100% compatible with BSD. A program which uses just setgid() will be
366 * 100% compatible with POSIX with saved IDs.
367 *
368 * SMP: There are not races, the GIDs are checked only by filesystem
369 * operations (as far as semantic preservation is concerned).
370 */
371#ifdef CONFIG_MULTIUSER
372long __sys_setregid(gid_t rgid, gid_t egid)
373{
374 struct user_namespace *ns = current_user_ns();
375 const struct cred *old;
376 struct cred *new;
377 int retval;
378 kgid_t krgid, kegid;
379
380 krgid = make_kgid(ns, rgid);
381 kegid = make_kgid(ns, egid);
382
383 if ((rgid != (gid_t) -1) && !gid_valid(krgid))
384 return -EINVAL;
385 if ((egid != (gid_t) -1) && !gid_valid(kegid))
386 return -EINVAL;
387
388 new = prepare_creds();
389 if (!new)
390 return -ENOMEM;
391 old = current_cred();
392
393 retval = -EPERM;
394 if (rgid != (gid_t) -1) {
395 if (gid_eq(old->gid, krgid) ||
396 gid_eq(old->egid, krgid) ||
397 ns_capable_setid(old->user_ns, CAP_SETGID))
398 new->gid = krgid;
399 else
400 goto error;
401 }
402 if (egid != (gid_t) -1) {
403 if (gid_eq(old->gid, kegid) ||
404 gid_eq(old->egid, kegid) ||
405 gid_eq(old->sgid, kegid) ||
406 ns_capable_setid(old->user_ns, CAP_SETGID))
407 new->egid = kegid;
408 else
409 goto error;
410 }
411
412 if (rgid != (gid_t) -1 ||
413 (egid != (gid_t) -1 && !gid_eq(kegid, old->gid)))
414 new->sgid = new->egid;
415 new->fsgid = new->egid;
416
417 retval = security_task_fix_setgid(new, old, LSM_SETID_RE);
418 if (retval < 0)
419 goto error;
420
421 return commit_creds(new);
422
423error:
424 abort_creds(new);
425 return retval;
426}
427
428SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid)
429{
430 return __sys_setregid(rgid, egid);
431}
432
433/*
434 * setgid() is implemented like SysV w/ SAVED_IDS
435 *
436 * SMP: Same implicit races as above.
437 */
438long __sys_setgid(gid_t gid)
439{
440 struct user_namespace *ns = current_user_ns();
441 const struct cred *old;
442 struct cred *new;
443 int retval;
444 kgid_t kgid;
445
446 kgid = make_kgid(ns, gid);
447 if (!gid_valid(kgid))
448 return -EINVAL;
449
450 new = prepare_creds();
451 if (!new)
452 return -ENOMEM;
453 old = current_cred();
454
455 retval = -EPERM;
456 if (ns_capable_setid(old->user_ns, CAP_SETGID))
457 new->gid = new->egid = new->sgid = new->fsgid = kgid;
458 else if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->sgid))
459 new->egid = new->fsgid = kgid;
460 else
461 goto error;
462
463 retval = security_task_fix_setgid(new, old, LSM_SETID_ID);
464 if (retval < 0)
465 goto error;
466
467 return commit_creds(new);
468
469error:
470 abort_creds(new);
471 return retval;
472}
473
474SYSCALL_DEFINE1(setgid, gid_t, gid)
475{
476 return __sys_setgid(gid);
477}
478
479/*
480 * change the user struct in a credentials set to match the new UID
481 */
482static int set_user(struct cred *new)
483{
484 struct user_struct *new_user;
485
486 new_user = alloc_uid(new->uid);
487 if (!new_user)
488 return -EAGAIN;
489
490 free_uid(new->user);
491 new->user = new_user;
492 return 0;
493}
494
495static void flag_nproc_exceeded(struct cred *new)
496{
497 if (new->ucounts == current_ucounts())
498 return;
499
500 /*
501 * We don't fail in case of NPROC limit excess here because too many
502 * poorly written programs don't check set*uid() return code, assuming
503 * it never fails if called by root. We may still enforce NPROC limit
504 * for programs doing set*uid()+execve() by harmlessly deferring the
505 * failure to the execve() stage.
506 */
507 if (is_rlimit_overlimit(new->ucounts, UCOUNT_RLIMIT_NPROC, rlimit(RLIMIT_NPROC)) &&
508 new->user != INIT_USER)
509 current->flags |= PF_NPROC_EXCEEDED;
510 else
511 current->flags &= ~PF_NPROC_EXCEEDED;
512}
513
514/*
515 * Unprivileged users may change the real uid to the effective uid
516 * or vice versa. (BSD-style)
517 *
518 * If you set the real uid at all, or set the effective uid to a value not
519 * equal to the real uid, then the saved uid is set to the new effective uid.
520 *
521 * This makes it possible for a setuid program to completely drop its
522 * privileges, which is often a useful assertion to make when you are doing
523 * a security audit over a program.
524 *
525 * The general idea is that a program which uses just setreuid() will be
526 * 100% compatible with BSD. A program which uses just setuid() will be
527 * 100% compatible with POSIX with saved IDs.
528 */
529long __sys_setreuid(uid_t ruid, uid_t euid)
530{
531 struct user_namespace *ns = current_user_ns();
532 const struct cred *old;
533 struct cred *new;
534 int retval;
535 kuid_t kruid, keuid;
536
537 kruid = make_kuid(ns, ruid);
538 keuid = make_kuid(ns, euid);
539
540 if ((ruid != (uid_t) -1) && !uid_valid(kruid))
541 return -EINVAL;
542 if ((euid != (uid_t) -1) && !uid_valid(keuid))
543 return -EINVAL;
544
545 new = prepare_creds();
546 if (!new)
547 return -ENOMEM;
548 old = current_cred();
549
550 retval = -EPERM;
551 if (ruid != (uid_t) -1) {
552 new->uid = kruid;
553 if (!uid_eq(old->uid, kruid) &&
554 !uid_eq(old->euid, kruid) &&
555 !ns_capable_setid(old->user_ns, CAP_SETUID))
556 goto error;
557 }
558
559 if (euid != (uid_t) -1) {
560 new->euid = keuid;
561 if (!uid_eq(old->uid, keuid) &&
562 !uid_eq(old->euid, keuid) &&
563 !uid_eq(old->suid, keuid) &&
564 !ns_capable_setid(old->user_ns, CAP_SETUID))
565 goto error;
566 }
567
568 if (!uid_eq(new->uid, old->uid)) {
569 retval = set_user(new);
570 if (retval < 0)
571 goto error;
572 }
573 if (ruid != (uid_t) -1 ||
574 (euid != (uid_t) -1 && !uid_eq(keuid, old->uid)))
575 new->suid = new->euid;
576 new->fsuid = new->euid;
577
578 retval = security_task_fix_setuid(new, old, LSM_SETID_RE);
579 if (retval < 0)
580 goto error;
581
582 retval = set_cred_ucounts(new);
583 if (retval < 0)
584 goto error;
585
586 flag_nproc_exceeded(new);
587 return commit_creds(new);
588
589error:
590 abort_creds(new);
591 return retval;
592}
593
594SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid)
595{
596 return __sys_setreuid(ruid, euid);
597}
598
599/*
600 * setuid() is implemented like SysV with SAVED_IDS
601 *
602 * Note that SAVED_ID's is deficient in that a setuid root program
603 * like sendmail, for example, cannot set its uid to be a normal
604 * user and then switch back, because if you're root, setuid() sets
605 * the saved uid too. If you don't like this, blame the bright people
606 * in the POSIX committee and/or USG. Note that the BSD-style setreuid()
607 * will allow a root program to temporarily drop privileges and be able to
608 * regain them by swapping the real and effective uid.
609 */
610long __sys_setuid(uid_t uid)
611{
612 struct user_namespace *ns = current_user_ns();
613 const struct cred *old;
614 struct cred *new;
615 int retval;
616 kuid_t kuid;
617
618 kuid = make_kuid(ns, uid);
619 if (!uid_valid(kuid))
620 return -EINVAL;
621
622 new = prepare_creds();
623 if (!new)
624 return -ENOMEM;
625 old = current_cred();
626
627 retval = -EPERM;
628 if (ns_capable_setid(old->user_ns, CAP_SETUID)) {
629 new->suid = new->uid = kuid;
630 if (!uid_eq(kuid, old->uid)) {
631 retval = set_user(new);
632 if (retval < 0)
633 goto error;
634 }
635 } else if (!uid_eq(kuid, old->uid) && !uid_eq(kuid, new->suid)) {
636 goto error;
637 }
638
639 new->fsuid = new->euid = kuid;
640
641 retval = security_task_fix_setuid(new, old, LSM_SETID_ID);
642 if (retval < 0)
643 goto error;
644
645 retval = set_cred_ucounts(new);
646 if (retval < 0)
647 goto error;
648
649 flag_nproc_exceeded(new);
650 return commit_creds(new);
651
652error:
653 abort_creds(new);
654 return retval;
655}
656
657SYSCALL_DEFINE1(setuid, uid_t, uid)
658{
659 return __sys_setuid(uid);
660}
661
662
663/*
664 * This function implements a generic ability to update ruid, euid,
665 * and suid. This allows you to implement the 4.4 compatible seteuid().
666 */
667long __sys_setresuid(uid_t ruid, uid_t euid, uid_t suid)
668{
669 struct user_namespace *ns = current_user_ns();
670 const struct cred *old;
671 struct cred *new;
672 int retval;
673 kuid_t kruid, keuid, ksuid;
674 bool ruid_new, euid_new, suid_new;
675
676 kruid = make_kuid(ns, ruid);
677 keuid = make_kuid(ns, euid);
678 ksuid = make_kuid(ns, suid);
679
680 if ((ruid != (uid_t) -1) && !uid_valid(kruid))
681 return -EINVAL;
682
683 if ((euid != (uid_t) -1) && !uid_valid(keuid))
684 return -EINVAL;
685
686 if ((suid != (uid_t) -1) && !uid_valid(ksuid))
687 return -EINVAL;
688
689 old = current_cred();
690
691 /* check for no-op */
692 if ((ruid == (uid_t) -1 || uid_eq(kruid, old->uid)) &&
693 (euid == (uid_t) -1 || (uid_eq(keuid, old->euid) &&
694 uid_eq(keuid, old->fsuid))) &&
695 (suid == (uid_t) -1 || uid_eq(ksuid, old->suid)))
696 return 0;
697
698 ruid_new = ruid != (uid_t) -1 && !uid_eq(kruid, old->uid) &&
699 !uid_eq(kruid, old->euid) && !uid_eq(kruid, old->suid);
700 euid_new = euid != (uid_t) -1 && !uid_eq(keuid, old->uid) &&
701 !uid_eq(keuid, old->euid) && !uid_eq(keuid, old->suid);
702 suid_new = suid != (uid_t) -1 && !uid_eq(ksuid, old->uid) &&
703 !uid_eq(ksuid, old->euid) && !uid_eq(ksuid, old->suid);
704 if ((ruid_new || euid_new || suid_new) &&
705 !ns_capable_setid(old->user_ns, CAP_SETUID))
706 return -EPERM;
707
708 new = prepare_creds();
709 if (!new)
710 return -ENOMEM;
711
712 if (ruid != (uid_t) -1) {
713 new->uid = kruid;
714 if (!uid_eq(kruid, old->uid)) {
715 retval = set_user(new);
716 if (retval < 0)
717 goto error;
718 }
719 }
720 if (euid != (uid_t) -1)
721 new->euid = keuid;
722 if (suid != (uid_t) -1)
723 new->suid = ksuid;
724 new->fsuid = new->euid;
725
726 retval = security_task_fix_setuid(new, old, LSM_SETID_RES);
727 if (retval < 0)
728 goto error;
729
730 retval = set_cred_ucounts(new);
731 if (retval < 0)
732 goto error;
733
734 flag_nproc_exceeded(new);
735 return commit_creds(new);
736
737error:
738 abort_creds(new);
739 return retval;
740}
741
742SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid)
743{
744 return __sys_setresuid(ruid, euid, suid);
745}
746
747SYSCALL_DEFINE3(getresuid, uid_t __user *, ruidp, uid_t __user *, euidp, uid_t __user *, suidp)
748{
749 const struct cred *cred = current_cred();
750 int retval;
751 uid_t ruid, euid, suid;
752
753 ruid = from_kuid_munged(cred->user_ns, cred->uid);
754 euid = from_kuid_munged(cred->user_ns, cred->euid);
755 suid = from_kuid_munged(cred->user_ns, cred->suid);
756
757 retval = put_user(ruid, ruidp);
758 if (!retval) {
759 retval = put_user(euid, euidp);
760 if (!retval)
761 return put_user(suid, suidp);
762 }
763 return retval;
764}
765
766/*
767 * Same as above, but for rgid, egid, sgid.
768 */
769long __sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid)
770{
771 struct user_namespace *ns = current_user_ns();
772 const struct cred *old;
773 struct cred *new;
774 int retval;
775 kgid_t krgid, kegid, ksgid;
776 bool rgid_new, egid_new, sgid_new;
777
778 krgid = make_kgid(ns, rgid);
779 kegid = make_kgid(ns, egid);
780 ksgid = make_kgid(ns, sgid);
781
782 if ((rgid != (gid_t) -1) && !gid_valid(krgid))
783 return -EINVAL;
784 if ((egid != (gid_t) -1) && !gid_valid(kegid))
785 return -EINVAL;
786 if ((sgid != (gid_t) -1) && !gid_valid(ksgid))
787 return -EINVAL;
788
789 old = current_cred();
790
791 /* check for no-op */
792 if ((rgid == (gid_t) -1 || gid_eq(krgid, old->gid)) &&
793 (egid == (gid_t) -1 || (gid_eq(kegid, old->egid) &&
794 gid_eq(kegid, old->fsgid))) &&
795 (sgid == (gid_t) -1 || gid_eq(ksgid, old->sgid)))
796 return 0;
797
798 rgid_new = rgid != (gid_t) -1 && !gid_eq(krgid, old->gid) &&
799 !gid_eq(krgid, old->egid) && !gid_eq(krgid, old->sgid);
800 egid_new = egid != (gid_t) -1 && !gid_eq(kegid, old->gid) &&
801 !gid_eq(kegid, old->egid) && !gid_eq(kegid, old->sgid);
802 sgid_new = sgid != (gid_t) -1 && !gid_eq(ksgid, old->gid) &&
803 !gid_eq(ksgid, old->egid) && !gid_eq(ksgid, old->sgid);
804 if ((rgid_new || egid_new || sgid_new) &&
805 !ns_capable_setid(old->user_ns, CAP_SETGID))
806 return -EPERM;
807
808 new = prepare_creds();
809 if (!new)
810 return -ENOMEM;
811
812 if (rgid != (gid_t) -1)
813 new->gid = krgid;
814 if (egid != (gid_t) -1)
815 new->egid = kegid;
816 if (sgid != (gid_t) -1)
817 new->sgid = ksgid;
818 new->fsgid = new->egid;
819
820 retval = security_task_fix_setgid(new, old, LSM_SETID_RES);
821 if (retval < 0)
822 goto error;
823
824 return commit_creds(new);
825
826error:
827 abort_creds(new);
828 return retval;
829}
830
831SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid)
832{
833 return __sys_setresgid(rgid, egid, sgid);
834}
835
836SYSCALL_DEFINE3(getresgid, gid_t __user *, rgidp, gid_t __user *, egidp, gid_t __user *, sgidp)
837{
838 const struct cred *cred = current_cred();
839 int retval;
840 gid_t rgid, egid, sgid;
841
842 rgid = from_kgid_munged(cred->user_ns, cred->gid);
843 egid = from_kgid_munged(cred->user_ns, cred->egid);
844 sgid = from_kgid_munged(cred->user_ns, cred->sgid);
845
846 retval = put_user(rgid, rgidp);
847 if (!retval) {
848 retval = put_user(egid, egidp);
849 if (!retval)
850 retval = put_user(sgid, sgidp);
851 }
852
853 return retval;
854}
855
856
857/*
858 * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This
859 * is used for "access()" and for the NFS daemon (letting nfsd stay at
860 * whatever uid it wants to). It normally shadows "euid", except when
861 * explicitly set by setfsuid() or for access..
862 */
863long __sys_setfsuid(uid_t uid)
864{
865 const struct cred *old;
866 struct cred *new;
867 uid_t old_fsuid;
868 kuid_t kuid;
869
870 old = current_cred();
871 old_fsuid = from_kuid_munged(old->user_ns, old->fsuid);
872
873 kuid = make_kuid(old->user_ns, uid);
874 if (!uid_valid(kuid))
875 return old_fsuid;
876
877 new = prepare_creds();
878 if (!new)
879 return old_fsuid;
880
881 if (uid_eq(kuid, old->uid) || uid_eq(kuid, old->euid) ||
882 uid_eq(kuid, old->suid) || uid_eq(kuid, old->fsuid) ||
883 ns_capable_setid(old->user_ns, CAP_SETUID)) {
884 if (!uid_eq(kuid, old->fsuid)) {
885 new->fsuid = kuid;
886 if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0)
887 goto change_okay;
888 }
889 }
890
891 abort_creds(new);
892 return old_fsuid;
893
894change_okay:
895 commit_creds(new);
896 return old_fsuid;
897}
898
899SYSCALL_DEFINE1(setfsuid, uid_t, uid)
900{
901 return __sys_setfsuid(uid);
902}
903
904/*
905 * Samma på svenska..
906 */
907long __sys_setfsgid(gid_t gid)
908{
909 const struct cred *old;
910 struct cred *new;
911 gid_t old_fsgid;
912 kgid_t kgid;
913
914 old = current_cred();
915 old_fsgid = from_kgid_munged(old->user_ns, old->fsgid);
916
917 kgid = make_kgid(old->user_ns, gid);
918 if (!gid_valid(kgid))
919 return old_fsgid;
920
921 new = prepare_creds();
922 if (!new)
923 return old_fsgid;
924
925 if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->egid) ||
926 gid_eq(kgid, old->sgid) || gid_eq(kgid, old->fsgid) ||
927 ns_capable_setid(old->user_ns, CAP_SETGID)) {
928 if (!gid_eq(kgid, old->fsgid)) {
929 new->fsgid = kgid;
930 if (security_task_fix_setgid(new,old,LSM_SETID_FS) == 0)
931 goto change_okay;
932 }
933 }
934
935 abort_creds(new);
936 return old_fsgid;
937
938change_okay:
939 commit_creds(new);
940 return old_fsgid;
941}
942
943SYSCALL_DEFINE1(setfsgid, gid_t, gid)
944{
945 return __sys_setfsgid(gid);
946}
947#endif /* CONFIG_MULTIUSER */
948
949/**
950 * sys_getpid - return the thread group id of the current process
951 *
952 * Note, despite the name, this returns the tgid not the pid. The tgid and
953 * the pid are identical unless CLONE_THREAD was specified on clone() in
954 * which case the tgid is the same in all threads of the same group.
955 *
956 * This is SMP safe as current->tgid does not change.
957 */
958SYSCALL_DEFINE0(getpid)
959{
960 return task_tgid_vnr(current);
961}
962
963/* Thread ID - the internal kernel "pid" */
964SYSCALL_DEFINE0(gettid)
965{
966 return task_pid_vnr(current);
967}
968
969/*
970 * Accessing ->real_parent is not SMP-safe, it could
971 * change from under us. However, we can use a stale
972 * value of ->real_parent under rcu_read_lock(), see
973 * release_task()->call_rcu(delayed_put_task_struct).
974 */
975SYSCALL_DEFINE0(getppid)
976{
977 int pid;
978
979 rcu_read_lock();
980 pid = task_tgid_vnr(rcu_dereference(current->real_parent));
981 rcu_read_unlock();
982
983 return pid;
984}
985
986SYSCALL_DEFINE0(getuid)
987{
988 /* Only we change this so SMP safe */
989 return from_kuid_munged(current_user_ns(), current_uid());
990}
991
992SYSCALL_DEFINE0(geteuid)
993{
994 /* Only we change this so SMP safe */
995 return from_kuid_munged(current_user_ns(), current_euid());
996}
997
998SYSCALL_DEFINE0(getgid)
999{
1000 /* Only we change this so SMP safe */
1001 return from_kgid_munged(current_user_ns(), current_gid());
1002}
1003
1004SYSCALL_DEFINE0(getegid)
1005{
1006 /* Only we change this so SMP safe */
1007 return from_kgid_munged(current_user_ns(), current_egid());
1008}
1009
1010static void do_sys_times(struct tms *tms)
1011{
1012 u64 tgutime, tgstime, cutime, cstime;
1013
1014 thread_group_cputime_adjusted(current, &tgutime, &tgstime);
1015 cutime = current->signal->cutime;
1016 cstime = current->signal->cstime;
1017 tms->tms_utime = nsec_to_clock_t(tgutime);
1018 tms->tms_stime = nsec_to_clock_t(tgstime);
1019 tms->tms_cutime = nsec_to_clock_t(cutime);
1020 tms->tms_cstime = nsec_to_clock_t(cstime);
1021}
1022
1023SYSCALL_DEFINE1(times, struct tms __user *, tbuf)
1024{
1025 if (tbuf) {
1026 struct tms tmp;
1027
1028 do_sys_times(&tmp);
1029 if (copy_to_user(tbuf, &tmp, sizeof(struct tms)))
1030 return -EFAULT;
1031 }
1032 force_successful_syscall_return();
1033 return (long) jiffies_64_to_clock_t(get_jiffies_64());
1034}
1035
1036#ifdef CONFIG_COMPAT
1037static compat_clock_t clock_t_to_compat_clock_t(clock_t x)
1038{
1039 return compat_jiffies_to_clock_t(clock_t_to_jiffies(x));
1040}
1041
1042COMPAT_SYSCALL_DEFINE1(times, struct compat_tms __user *, tbuf)
1043{
1044 if (tbuf) {
1045 struct tms tms;
1046 struct compat_tms tmp;
1047
1048 do_sys_times(&tms);
1049 /* Convert our struct tms to the compat version. */
1050 tmp.tms_utime = clock_t_to_compat_clock_t(tms.tms_utime);
1051 tmp.tms_stime = clock_t_to_compat_clock_t(tms.tms_stime);
1052 tmp.tms_cutime = clock_t_to_compat_clock_t(tms.tms_cutime);
1053 tmp.tms_cstime = clock_t_to_compat_clock_t(tms.tms_cstime);
1054 if (copy_to_user(tbuf, &tmp, sizeof(tmp)))
1055 return -EFAULT;
1056 }
1057 force_successful_syscall_return();
1058 return compat_jiffies_to_clock_t(jiffies);
1059}
1060#endif
1061
1062/*
1063 * This needs some heavy checking ...
1064 * I just haven't the stomach for it. I also don't fully
1065 * understand sessions/pgrp etc. Let somebody who does explain it.
1066 *
1067 * OK, I think I have the protection semantics right.... this is really
1068 * only important on a multi-user system anyway, to make sure one user
1069 * can't send a signal to a process owned by another. -TYT, 12/12/91
1070 *
1071 * !PF_FORKNOEXEC check to conform completely to POSIX.
1072 */
1073SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid)
1074{
1075 struct task_struct *p;
1076 struct task_struct *group_leader = current->group_leader;
1077 struct pid *pgrp;
1078 int err;
1079
1080 if (!pid)
1081 pid = task_pid_vnr(group_leader);
1082 if (!pgid)
1083 pgid = pid;
1084 if (pgid < 0)
1085 return -EINVAL;
1086 rcu_read_lock();
1087
1088 /* From this point forward we keep holding onto the tasklist lock
1089 * so that our parent does not change from under us. -DaveM
1090 */
1091 write_lock_irq(&tasklist_lock);
1092
1093 err = -ESRCH;
1094 p = find_task_by_vpid(pid);
1095 if (!p)
1096 goto out;
1097
1098 err = -EINVAL;
1099 if (!thread_group_leader(p))
1100 goto out;
1101
1102 if (same_thread_group(p->real_parent, group_leader)) {
1103 err = -EPERM;
1104 if (task_session(p) != task_session(group_leader))
1105 goto out;
1106 err = -EACCES;
1107 if (!(p->flags & PF_FORKNOEXEC))
1108 goto out;
1109 } else {
1110 err = -ESRCH;
1111 if (p != group_leader)
1112 goto out;
1113 }
1114
1115 err = -EPERM;
1116 if (p->signal->leader)
1117 goto out;
1118
1119 pgrp = task_pid(p);
1120 if (pgid != pid) {
1121 struct task_struct *g;
1122
1123 pgrp = find_vpid(pgid);
1124 g = pid_task(pgrp, PIDTYPE_PGID);
1125 if (!g || task_session(g) != task_session(group_leader))
1126 goto out;
1127 }
1128
1129 err = security_task_setpgid(p, pgid);
1130 if (err)
1131 goto out;
1132
1133 if (task_pgrp(p) != pgrp)
1134 change_pid(p, PIDTYPE_PGID, pgrp);
1135
1136 err = 0;
1137out:
1138 /* All paths lead to here, thus we are safe. -DaveM */
1139 write_unlock_irq(&tasklist_lock);
1140 rcu_read_unlock();
1141 return err;
1142}
1143
1144static int do_getpgid(pid_t pid)
1145{
1146 struct task_struct *p;
1147 struct pid *grp;
1148 int retval;
1149
1150 rcu_read_lock();
1151 if (!pid)
1152 grp = task_pgrp(current);
1153 else {
1154 retval = -ESRCH;
1155 p = find_task_by_vpid(pid);
1156 if (!p)
1157 goto out;
1158 grp = task_pgrp(p);
1159 if (!grp)
1160 goto out;
1161
1162 retval = security_task_getpgid(p);
1163 if (retval)
1164 goto out;
1165 }
1166 retval = pid_vnr(grp);
1167out:
1168 rcu_read_unlock();
1169 return retval;
1170}
1171
1172SYSCALL_DEFINE1(getpgid, pid_t, pid)
1173{
1174 return do_getpgid(pid);
1175}
1176
1177#ifdef __ARCH_WANT_SYS_GETPGRP
1178
1179SYSCALL_DEFINE0(getpgrp)
1180{
1181 return do_getpgid(0);
1182}
1183
1184#endif
1185
1186SYSCALL_DEFINE1(getsid, pid_t, pid)
1187{
1188 struct task_struct *p;
1189 struct pid *sid;
1190 int retval;
1191
1192 rcu_read_lock();
1193 if (!pid)
1194 sid = task_session(current);
1195 else {
1196 retval = -ESRCH;
1197 p = find_task_by_vpid(pid);
1198 if (!p)
1199 goto out;
1200 sid = task_session(p);
1201 if (!sid)
1202 goto out;
1203
1204 retval = security_task_getsid(p);
1205 if (retval)
1206 goto out;
1207 }
1208 retval = pid_vnr(sid);
1209out:
1210 rcu_read_unlock();
1211 return retval;
1212}
1213
1214static void set_special_pids(struct pid *pid)
1215{
1216 struct task_struct *curr = current->group_leader;
1217
1218 if (task_session(curr) != pid)
1219 change_pid(curr, PIDTYPE_SID, pid);
1220
1221 if (task_pgrp(curr) != pid)
1222 change_pid(curr, PIDTYPE_PGID, pid);
1223}
1224
1225int ksys_setsid(void)
1226{
1227 struct task_struct *group_leader = current->group_leader;
1228 struct pid *sid = task_pid(group_leader);
1229 pid_t session = pid_vnr(sid);
1230 int err = -EPERM;
1231
1232 write_lock_irq(&tasklist_lock);
1233 /* Fail if I am already a session leader */
1234 if (group_leader->signal->leader)
1235 goto out;
1236
1237 /* Fail if a process group id already exists that equals the
1238 * proposed session id.
1239 */
1240 if (pid_task(sid, PIDTYPE_PGID))
1241 goto out;
1242
1243 group_leader->signal->leader = 1;
1244 set_special_pids(sid);
1245
1246 proc_clear_tty(group_leader);
1247
1248 err = session;
1249out:
1250 write_unlock_irq(&tasklist_lock);
1251 if (err > 0) {
1252 proc_sid_connector(group_leader);
1253 sched_autogroup_create_attach(group_leader);
1254 }
1255 return err;
1256}
1257
1258SYSCALL_DEFINE0(setsid)
1259{
1260 return ksys_setsid();
1261}
1262
1263DECLARE_RWSEM(uts_sem);
1264
1265#ifdef COMPAT_UTS_MACHINE
1266#define override_architecture(name) \
1267 (personality(current->personality) == PER_LINUX32 && \
1268 copy_to_user(name->machine, COMPAT_UTS_MACHINE, \
1269 sizeof(COMPAT_UTS_MACHINE)))
1270#else
1271#define override_architecture(name) 0
1272#endif
1273
1274/*
1275 * Work around broken programs that cannot handle "Linux 3.0".
1276 * Instead we map 3.x to 2.6.40+x, so e.g. 3.0 would be 2.6.40
1277 * And we map 4.x and later versions to 2.6.60+x, so 4.0/5.0/6.0/... would be
1278 * 2.6.60.
1279 */
1280static int override_release(char __user *release, size_t len)
1281{
1282 int ret = 0;
1283
1284 if (current->personality & UNAME26) {
1285 const char *rest = UTS_RELEASE;
1286 char buf[65] = { 0 };
1287 int ndots = 0;
1288 unsigned v;
1289 size_t copy;
1290
1291 while (*rest) {
1292 if (*rest == '.' && ++ndots >= 3)
1293 break;
1294 if (!isdigit(*rest) && *rest != '.')
1295 break;
1296 rest++;
1297 }
1298 v = LINUX_VERSION_PATCHLEVEL + 60;
1299 copy = clamp_t(size_t, len, 1, sizeof(buf));
1300 copy = scnprintf(buf, copy, "2.6.%u%s", v, rest);
1301 ret = copy_to_user(release, buf, copy + 1);
1302 }
1303 return ret;
1304}
1305
1306SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name)
1307{
1308 struct new_utsname tmp;
1309
1310 down_read(&uts_sem);
1311 memcpy(&tmp, utsname(), sizeof(tmp));
1312 up_read(&uts_sem);
1313 if (copy_to_user(name, &tmp, sizeof(tmp)))
1314 return -EFAULT;
1315
1316 if (override_release(name->release, sizeof(name->release)))
1317 return -EFAULT;
1318 if (override_architecture(name))
1319 return -EFAULT;
1320 return 0;
1321}
1322
1323#ifdef __ARCH_WANT_SYS_OLD_UNAME
1324/*
1325 * Old cruft
1326 */
1327SYSCALL_DEFINE1(uname, struct old_utsname __user *, name)
1328{
1329 struct old_utsname tmp;
1330
1331 if (!name)
1332 return -EFAULT;
1333
1334 down_read(&uts_sem);
1335 memcpy(&tmp, utsname(), sizeof(tmp));
1336 up_read(&uts_sem);
1337 if (copy_to_user(name, &tmp, sizeof(tmp)))
1338 return -EFAULT;
1339
1340 if (override_release(name->release, sizeof(name->release)))
1341 return -EFAULT;
1342 if (override_architecture(name))
1343 return -EFAULT;
1344 return 0;
1345}
1346
1347SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name)
1348{
1349 struct oldold_utsname tmp;
1350
1351 if (!name)
1352 return -EFAULT;
1353
1354 memset(&tmp, 0, sizeof(tmp));
1355
1356 down_read(&uts_sem);
1357 memcpy(&tmp.sysname, &utsname()->sysname, __OLD_UTS_LEN);
1358 memcpy(&tmp.nodename, &utsname()->nodename, __OLD_UTS_LEN);
1359 memcpy(&tmp.release, &utsname()->release, __OLD_UTS_LEN);
1360 memcpy(&tmp.version, &utsname()->version, __OLD_UTS_LEN);
1361 memcpy(&tmp.machine, &utsname()->machine, __OLD_UTS_LEN);
1362 up_read(&uts_sem);
1363 if (copy_to_user(name, &tmp, sizeof(tmp)))
1364 return -EFAULT;
1365
1366 if (override_architecture(name))
1367 return -EFAULT;
1368 if (override_release(name->release, sizeof(name->release)))
1369 return -EFAULT;
1370 return 0;
1371}
1372#endif
1373
1374SYSCALL_DEFINE2(sethostname, char __user *, name, int, len)
1375{
1376 int errno;
1377 char tmp[__NEW_UTS_LEN];
1378
1379 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN))
1380 return -EPERM;
1381
1382 if (len < 0 || len > __NEW_UTS_LEN)
1383 return -EINVAL;
1384 errno = -EFAULT;
1385 if (!copy_from_user(tmp, name, len)) {
1386 struct new_utsname *u;
1387
1388 add_device_randomness(tmp, len);
1389 down_write(&uts_sem);
1390 u = utsname();
1391 memcpy(u->nodename, tmp, len);
1392 memset(u->nodename + len, 0, sizeof(u->nodename) - len);
1393 errno = 0;
1394 uts_proc_notify(UTS_PROC_HOSTNAME);
1395 up_write(&uts_sem);
1396 }
1397 return errno;
1398}
1399
1400#ifdef __ARCH_WANT_SYS_GETHOSTNAME
1401
1402SYSCALL_DEFINE2(gethostname, char __user *, name, int, len)
1403{
1404 int i;
1405 struct new_utsname *u;
1406 char tmp[__NEW_UTS_LEN + 1];
1407
1408 if (len < 0)
1409 return -EINVAL;
1410 down_read(&uts_sem);
1411 u = utsname();
1412 i = 1 + strlen(u->nodename);
1413 if (i > len)
1414 i = len;
1415 memcpy(tmp, u->nodename, i);
1416 up_read(&uts_sem);
1417 if (copy_to_user(name, tmp, i))
1418 return -EFAULT;
1419 return 0;
1420}
1421
1422#endif
1423
1424/*
1425 * Only setdomainname; getdomainname can be implemented by calling
1426 * uname()
1427 */
1428SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len)
1429{
1430 int errno;
1431 char tmp[__NEW_UTS_LEN];
1432
1433 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN))
1434 return -EPERM;
1435 if (len < 0 || len > __NEW_UTS_LEN)
1436 return -EINVAL;
1437
1438 errno = -EFAULT;
1439 if (!copy_from_user(tmp, name, len)) {
1440 struct new_utsname *u;
1441
1442 add_device_randomness(tmp, len);
1443 down_write(&uts_sem);
1444 u = utsname();
1445 memcpy(u->domainname, tmp, len);
1446 memset(u->domainname + len, 0, sizeof(u->domainname) - len);
1447 errno = 0;
1448 uts_proc_notify(UTS_PROC_DOMAINNAME);
1449 up_write(&uts_sem);
1450 }
1451 return errno;
1452}
1453
1454/* make sure you are allowed to change @tsk limits before calling this */
1455static int do_prlimit(struct task_struct *tsk, unsigned int resource,
1456 struct rlimit *new_rlim, struct rlimit *old_rlim)
1457{
1458 struct rlimit *rlim;
1459 int retval = 0;
1460
1461 if (resource >= RLIM_NLIMITS)
1462 return -EINVAL;
1463 resource = array_index_nospec(resource, RLIM_NLIMITS);
1464
1465 if (new_rlim) {
1466 if (new_rlim->rlim_cur > new_rlim->rlim_max)
1467 return -EINVAL;
1468 if (resource == RLIMIT_NOFILE &&
1469 new_rlim->rlim_max > sysctl_nr_open)
1470 return -EPERM;
1471 }
1472
1473 /* Holding a refcount on tsk protects tsk->signal from disappearing. */
1474 rlim = tsk->signal->rlim + resource;
1475 task_lock(tsk->group_leader);
1476 if (new_rlim) {
1477 /*
1478 * Keep the capable check against init_user_ns until cgroups can
1479 * contain all limits.
1480 */
1481 if (new_rlim->rlim_max > rlim->rlim_max &&
1482 !capable(CAP_SYS_RESOURCE))
1483 retval = -EPERM;
1484 if (!retval)
1485 retval = security_task_setrlimit(tsk, resource, new_rlim);
1486 }
1487 if (!retval) {
1488 if (old_rlim)
1489 *old_rlim = *rlim;
1490 if (new_rlim)
1491 *rlim = *new_rlim;
1492 }
1493 task_unlock(tsk->group_leader);
1494
1495 /*
1496 * RLIMIT_CPU handling. Arm the posix CPU timer if the limit is not
1497 * infinite. In case of RLIM_INFINITY the posix CPU timer code
1498 * ignores the rlimit.
1499 */
1500 if (!retval && new_rlim && resource == RLIMIT_CPU &&
1501 new_rlim->rlim_cur != RLIM_INFINITY &&
1502 IS_ENABLED(CONFIG_POSIX_TIMERS)) {
1503 /*
1504 * update_rlimit_cpu can fail if the task is exiting, but there
1505 * may be other tasks in the thread group that are not exiting,
1506 * and they need their cpu timers adjusted.
1507 *
1508 * The group_leader is the last task to be released, so if we
1509 * cannot update_rlimit_cpu on it, then the entire process is
1510 * exiting and we do not need to update at all.
1511 */
1512 update_rlimit_cpu(tsk->group_leader, new_rlim->rlim_cur);
1513 }
1514
1515 return retval;
1516}
1517
1518SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim)
1519{
1520 struct rlimit value;
1521 int ret;
1522
1523 ret = do_prlimit(current, resource, NULL, &value);
1524 if (!ret)
1525 ret = copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0;
1526
1527 return ret;
1528}
1529
1530#ifdef CONFIG_COMPAT
1531
1532COMPAT_SYSCALL_DEFINE2(setrlimit, unsigned int, resource,
1533 struct compat_rlimit __user *, rlim)
1534{
1535 struct rlimit r;
1536 struct compat_rlimit r32;
1537
1538 if (copy_from_user(&r32, rlim, sizeof(struct compat_rlimit)))
1539 return -EFAULT;
1540
1541 if (r32.rlim_cur == COMPAT_RLIM_INFINITY)
1542 r.rlim_cur = RLIM_INFINITY;
1543 else
1544 r.rlim_cur = r32.rlim_cur;
1545 if (r32.rlim_max == COMPAT_RLIM_INFINITY)
1546 r.rlim_max = RLIM_INFINITY;
1547 else
1548 r.rlim_max = r32.rlim_max;
1549 return do_prlimit(current, resource, &r, NULL);
1550}
1551
1552COMPAT_SYSCALL_DEFINE2(getrlimit, unsigned int, resource,
1553 struct compat_rlimit __user *, rlim)
1554{
1555 struct rlimit r;
1556 int ret;
1557
1558 ret = do_prlimit(current, resource, NULL, &r);
1559 if (!ret) {
1560 struct compat_rlimit r32;
1561 if (r.rlim_cur > COMPAT_RLIM_INFINITY)
1562 r32.rlim_cur = COMPAT_RLIM_INFINITY;
1563 else
1564 r32.rlim_cur = r.rlim_cur;
1565 if (r.rlim_max > COMPAT_RLIM_INFINITY)
1566 r32.rlim_max = COMPAT_RLIM_INFINITY;
1567 else
1568 r32.rlim_max = r.rlim_max;
1569
1570 if (copy_to_user(rlim, &r32, sizeof(struct compat_rlimit)))
1571 return -EFAULT;
1572 }
1573 return ret;
1574}
1575
1576#endif
1577
1578#ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT
1579
1580/*
1581 * Back compatibility for getrlimit. Needed for some apps.
1582 */
1583SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
1584 struct rlimit __user *, rlim)
1585{
1586 struct rlimit x;
1587 if (resource >= RLIM_NLIMITS)
1588 return -EINVAL;
1589
1590 resource = array_index_nospec(resource, RLIM_NLIMITS);
1591 task_lock(current->group_leader);
1592 x = current->signal->rlim[resource];
1593 task_unlock(current->group_leader);
1594 if (x.rlim_cur > 0x7FFFFFFF)
1595 x.rlim_cur = 0x7FFFFFFF;
1596 if (x.rlim_max > 0x7FFFFFFF)
1597 x.rlim_max = 0x7FFFFFFF;
1598 return copy_to_user(rlim, &x, sizeof(x)) ? -EFAULT : 0;
1599}
1600
1601#ifdef CONFIG_COMPAT
1602COMPAT_SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
1603 struct compat_rlimit __user *, rlim)
1604{
1605 struct rlimit r;
1606
1607 if (resource >= RLIM_NLIMITS)
1608 return -EINVAL;
1609
1610 resource = array_index_nospec(resource, RLIM_NLIMITS);
1611 task_lock(current->group_leader);
1612 r = current->signal->rlim[resource];
1613 task_unlock(current->group_leader);
1614 if (r.rlim_cur > 0x7FFFFFFF)
1615 r.rlim_cur = 0x7FFFFFFF;
1616 if (r.rlim_max > 0x7FFFFFFF)
1617 r.rlim_max = 0x7FFFFFFF;
1618
1619 if (put_user(r.rlim_cur, &rlim->rlim_cur) ||
1620 put_user(r.rlim_max, &rlim->rlim_max))
1621 return -EFAULT;
1622 return 0;
1623}
1624#endif
1625
1626#endif
1627
1628static inline bool rlim64_is_infinity(__u64 rlim64)
1629{
1630#if BITS_PER_LONG < 64
1631 return rlim64 >= ULONG_MAX;
1632#else
1633 return rlim64 == RLIM64_INFINITY;
1634#endif
1635}
1636
1637static void rlim_to_rlim64(const struct rlimit *rlim, struct rlimit64 *rlim64)
1638{
1639 if (rlim->rlim_cur == RLIM_INFINITY)
1640 rlim64->rlim_cur = RLIM64_INFINITY;
1641 else
1642 rlim64->rlim_cur = rlim->rlim_cur;
1643 if (rlim->rlim_max == RLIM_INFINITY)
1644 rlim64->rlim_max = RLIM64_INFINITY;
1645 else
1646 rlim64->rlim_max = rlim->rlim_max;
1647}
1648
1649static void rlim64_to_rlim(const struct rlimit64 *rlim64, struct rlimit *rlim)
1650{
1651 if (rlim64_is_infinity(rlim64->rlim_cur))
1652 rlim->rlim_cur = RLIM_INFINITY;
1653 else
1654 rlim->rlim_cur = (unsigned long)rlim64->rlim_cur;
1655 if (rlim64_is_infinity(rlim64->rlim_max))
1656 rlim->rlim_max = RLIM_INFINITY;
1657 else
1658 rlim->rlim_max = (unsigned long)rlim64->rlim_max;
1659}
1660
1661/* rcu lock must be held */
1662static int check_prlimit_permission(struct task_struct *task,
1663 unsigned int flags)
1664{
1665 const struct cred *cred = current_cred(), *tcred;
1666 bool id_match;
1667
1668 if (current == task)
1669 return 0;
1670
1671 tcred = __task_cred(task);
1672 id_match = (uid_eq(cred->uid, tcred->euid) &&
1673 uid_eq(cred->uid, tcred->suid) &&
1674 uid_eq(cred->uid, tcred->uid) &&
1675 gid_eq(cred->gid, tcred->egid) &&
1676 gid_eq(cred->gid, tcred->sgid) &&
1677 gid_eq(cred->gid, tcred->gid));
1678 if (!id_match && !ns_capable(tcred->user_ns, CAP_SYS_RESOURCE))
1679 return -EPERM;
1680
1681 return security_task_prlimit(cred, tcred, flags);
1682}
1683
1684SYSCALL_DEFINE4(prlimit64, pid_t, pid, unsigned int, resource,
1685 const struct rlimit64 __user *, new_rlim,
1686 struct rlimit64 __user *, old_rlim)
1687{
1688 struct rlimit64 old64, new64;
1689 struct rlimit old, new;
1690 struct task_struct *tsk;
1691 unsigned int checkflags = 0;
1692 int ret;
1693
1694 if (old_rlim)
1695 checkflags |= LSM_PRLIMIT_READ;
1696
1697 if (new_rlim) {
1698 if (copy_from_user(&new64, new_rlim, sizeof(new64)))
1699 return -EFAULT;
1700 rlim64_to_rlim(&new64, &new);
1701 checkflags |= LSM_PRLIMIT_WRITE;
1702 }
1703
1704 rcu_read_lock();
1705 tsk = pid ? find_task_by_vpid(pid) : current;
1706 if (!tsk) {
1707 rcu_read_unlock();
1708 return -ESRCH;
1709 }
1710 ret = check_prlimit_permission(tsk, checkflags);
1711 if (ret) {
1712 rcu_read_unlock();
1713 return ret;
1714 }
1715 get_task_struct(tsk);
1716 rcu_read_unlock();
1717
1718 ret = do_prlimit(tsk, resource, new_rlim ? &new : NULL,
1719 old_rlim ? &old : NULL);
1720
1721 if (!ret && old_rlim) {
1722 rlim_to_rlim64(&old, &old64);
1723 if (copy_to_user(old_rlim, &old64, sizeof(old64)))
1724 ret = -EFAULT;
1725 }
1726
1727 put_task_struct(tsk);
1728 return ret;
1729}
1730
1731SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim)
1732{
1733 struct rlimit new_rlim;
1734
1735 if (copy_from_user(&new_rlim, rlim, sizeof(*rlim)))
1736 return -EFAULT;
1737 return do_prlimit(current, resource, &new_rlim, NULL);
1738}
1739
1740/*
1741 * It would make sense to put struct rusage in the task_struct,
1742 * except that would make the task_struct be *really big*. After
1743 * task_struct gets moved into malloc'ed memory, it would
1744 * make sense to do this. It will make moving the rest of the information
1745 * a lot simpler! (Which we're not doing right now because we're not
1746 * measuring them yet).
1747 *
1748 * When sampling multiple threads for RUSAGE_SELF, under SMP we might have
1749 * races with threads incrementing their own counters. But since word
1750 * reads are atomic, we either get new values or old values and we don't
1751 * care which for the sums. We always take the siglock to protect reading
1752 * the c* fields from p->signal from races with exit.c updating those
1753 * fields when reaping, so a sample either gets all the additions of a
1754 * given child after it's reaped, or none so this sample is before reaping.
1755 *
1756 * Locking:
1757 * We need to take the siglock for CHILDEREN, SELF and BOTH
1758 * for the cases current multithreaded, non-current single threaded
1759 * non-current multithreaded. Thread traversal is now safe with
1760 * the siglock held.
1761 * Strictly speaking, we donot need to take the siglock if we are current and
1762 * single threaded, as no one else can take our signal_struct away, no one
1763 * else can reap the children to update signal->c* counters, and no one else
1764 * can race with the signal-> fields. If we do not take any lock, the
1765 * signal-> fields could be read out of order while another thread was just
1766 * exiting. So we should place a read memory barrier when we avoid the lock.
1767 * On the writer side, write memory barrier is implied in __exit_signal
1768 * as __exit_signal releases the siglock spinlock after updating the signal->
1769 * fields. But we don't do this yet to keep things simple.
1770 *
1771 */
1772
1773static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r)
1774{
1775 r->ru_nvcsw += t->nvcsw;
1776 r->ru_nivcsw += t->nivcsw;
1777 r->ru_minflt += t->min_flt;
1778 r->ru_majflt += t->maj_flt;
1779 r->ru_inblock += task_io_get_inblock(t);
1780 r->ru_oublock += task_io_get_oublock(t);
1781}
1782
1783void getrusage(struct task_struct *p, int who, struct rusage *r)
1784{
1785 struct task_struct *t;
1786 unsigned long flags;
1787 u64 tgutime, tgstime, utime, stime;
1788 unsigned long maxrss;
1789 struct mm_struct *mm;
1790 struct signal_struct *sig = p->signal;
1791 unsigned int seq = 0;
1792
1793retry:
1794 memset(r, 0, sizeof(*r));
1795 utime = stime = 0;
1796 maxrss = 0;
1797
1798 if (who == RUSAGE_THREAD) {
1799 task_cputime_adjusted(current, &utime, &stime);
1800 accumulate_thread_rusage(p, r);
1801 maxrss = sig->maxrss;
1802 goto out_thread;
1803 }
1804
1805 flags = read_seqbegin_or_lock_irqsave(&sig->stats_lock, &seq);
1806
1807 switch (who) {
1808 case RUSAGE_BOTH:
1809 case RUSAGE_CHILDREN:
1810 utime = sig->cutime;
1811 stime = sig->cstime;
1812 r->ru_nvcsw = sig->cnvcsw;
1813 r->ru_nivcsw = sig->cnivcsw;
1814 r->ru_minflt = sig->cmin_flt;
1815 r->ru_majflt = sig->cmaj_flt;
1816 r->ru_inblock = sig->cinblock;
1817 r->ru_oublock = sig->coublock;
1818 maxrss = sig->cmaxrss;
1819
1820 if (who == RUSAGE_CHILDREN)
1821 break;
1822 fallthrough;
1823
1824 case RUSAGE_SELF:
1825 r->ru_nvcsw += sig->nvcsw;
1826 r->ru_nivcsw += sig->nivcsw;
1827 r->ru_minflt += sig->min_flt;
1828 r->ru_majflt += sig->maj_flt;
1829 r->ru_inblock += sig->inblock;
1830 r->ru_oublock += sig->oublock;
1831 if (maxrss < sig->maxrss)
1832 maxrss = sig->maxrss;
1833
1834 rcu_read_lock();
1835 __for_each_thread(sig, t)
1836 accumulate_thread_rusage(t, r);
1837 rcu_read_unlock();
1838
1839 break;
1840
1841 default:
1842 BUG();
1843 }
1844
1845 if (need_seqretry(&sig->stats_lock, seq)) {
1846 seq = 1;
1847 goto retry;
1848 }
1849 done_seqretry_irqrestore(&sig->stats_lock, seq, flags);
1850
1851 if (who == RUSAGE_CHILDREN)
1852 goto out_children;
1853
1854 thread_group_cputime_adjusted(p, &tgutime, &tgstime);
1855 utime += tgutime;
1856 stime += tgstime;
1857
1858out_thread:
1859 mm = get_task_mm(p);
1860 if (mm) {
1861 setmax_mm_hiwater_rss(&maxrss, mm);
1862 mmput(mm);
1863 }
1864
1865out_children:
1866 r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */
1867 r->ru_utime = ns_to_kernel_old_timeval(utime);
1868 r->ru_stime = ns_to_kernel_old_timeval(stime);
1869}
1870
1871SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru)
1872{
1873 struct rusage r;
1874
1875 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
1876 who != RUSAGE_THREAD)
1877 return -EINVAL;
1878
1879 getrusage(current, who, &r);
1880 return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0;
1881}
1882
1883#ifdef CONFIG_COMPAT
1884COMPAT_SYSCALL_DEFINE2(getrusage, int, who, struct compat_rusage __user *, ru)
1885{
1886 struct rusage r;
1887
1888 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
1889 who != RUSAGE_THREAD)
1890 return -EINVAL;
1891
1892 getrusage(current, who, &r);
1893 return put_compat_rusage(&r, ru);
1894}
1895#endif
1896
1897SYSCALL_DEFINE1(umask, int, mask)
1898{
1899 mask = xchg(¤t->fs->umask, mask & S_IRWXUGO);
1900 return mask;
1901}
1902
1903static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd)
1904{
1905 struct fd exe;
1906 struct inode *inode;
1907 int err;
1908
1909 exe = fdget(fd);
1910 if (!exe.file)
1911 return -EBADF;
1912
1913 inode = file_inode(exe.file);
1914
1915 /*
1916 * Because the original mm->exe_file points to executable file, make
1917 * sure that this one is executable as well, to avoid breaking an
1918 * overall picture.
1919 */
1920 err = -EACCES;
1921 if (!S_ISREG(inode->i_mode) || path_noexec(&exe.file->f_path))
1922 goto exit;
1923
1924 err = file_permission(exe.file, MAY_EXEC);
1925 if (err)
1926 goto exit;
1927
1928 err = replace_mm_exe_file(mm, exe.file);
1929exit:
1930 fdput(exe);
1931 return err;
1932}
1933
1934/*
1935 * Check arithmetic relations of passed addresses.
1936 *
1937 * WARNING: we don't require any capability here so be very careful
1938 * in what is allowed for modification from userspace.
1939 */
1940static int validate_prctl_map_addr(struct prctl_mm_map *prctl_map)
1941{
1942 unsigned long mmap_max_addr = TASK_SIZE;
1943 int error = -EINVAL, i;
1944
1945 static const unsigned char offsets[] = {
1946 offsetof(struct prctl_mm_map, start_code),
1947 offsetof(struct prctl_mm_map, end_code),
1948 offsetof(struct prctl_mm_map, start_data),
1949 offsetof(struct prctl_mm_map, end_data),
1950 offsetof(struct prctl_mm_map, start_brk),
1951 offsetof(struct prctl_mm_map, brk),
1952 offsetof(struct prctl_mm_map, start_stack),
1953 offsetof(struct prctl_mm_map, arg_start),
1954 offsetof(struct prctl_mm_map, arg_end),
1955 offsetof(struct prctl_mm_map, env_start),
1956 offsetof(struct prctl_mm_map, env_end),
1957 };
1958
1959 /*
1960 * Make sure the members are not somewhere outside
1961 * of allowed address space.
1962 */
1963 for (i = 0; i < ARRAY_SIZE(offsets); i++) {
1964 u64 val = *(u64 *)((char *)prctl_map + offsets[i]);
1965
1966 if ((unsigned long)val >= mmap_max_addr ||
1967 (unsigned long)val < mmap_min_addr)
1968 goto out;
1969 }
1970
1971 /*
1972 * Make sure the pairs are ordered.
1973 */
1974#define __prctl_check_order(__m1, __op, __m2) \
1975 ((unsigned long)prctl_map->__m1 __op \
1976 (unsigned long)prctl_map->__m2) ? 0 : -EINVAL
1977 error = __prctl_check_order(start_code, <, end_code);
1978 error |= __prctl_check_order(start_data,<=, end_data);
1979 error |= __prctl_check_order(start_brk, <=, brk);
1980 error |= __prctl_check_order(arg_start, <=, arg_end);
1981 error |= __prctl_check_order(env_start, <=, env_end);
1982 if (error)
1983 goto out;
1984#undef __prctl_check_order
1985
1986 error = -EINVAL;
1987
1988 /*
1989 * Neither we should allow to override limits if they set.
1990 */
1991 if (check_data_rlimit(rlimit(RLIMIT_DATA), prctl_map->brk,
1992 prctl_map->start_brk, prctl_map->end_data,
1993 prctl_map->start_data))
1994 goto out;
1995
1996 error = 0;
1997out:
1998 return error;
1999}
2000
2001#ifdef CONFIG_CHECKPOINT_RESTORE
2002static int prctl_set_mm_map(int opt, const void __user *addr, unsigned long data_size)
2003{
2004 struct prctl_mm_map prctl_map = { .exe_fd = (u32)-1, };
2005 unsigned long user_auxv[AT_VECTOR_SIZE];
2006 struct mm_struct *mm = current->mm;
2007 int error;
2008
2009 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv));
2010 BUILD_BUG_ON(sizeof(struct prctl_mm_map) > 256);
2011
2012 if (opt == PR_SET_MM_MAP_SIZE)
2013 return put_user((unsigned int)sizeof(prctl_map),
2014 (unsigned int __user *)addr);
2015
2016 if (data_size != sizeof(prctl_map))
2017 return -EINVAL;
2018
2019 if (copy_from_user(&prctl_map, addr, sizeof(prctl_map)))
2020 return -EFAULT;
2021
2022 error = validate_prctl_map_addr(&prctl_map);
2023 if (error)
2024 return error;
2025
2026 if (prctl_map.auxv_size) {
2027 /*
2028 * Someone is trying to cheat the auxv vector.
2029 */
2030 if (!prctl_map.auxv ||
2031 prctl_map.auxv_size > sizeof(mm->saved_auxv))
2032 return -EINVAL;
2033
2034 memset(user_auxv, 0, sizeof(user_auxv));
2035 if (copy_from_user(user_auxv,
2036 (const void __user *)prctl_map.auxv,
2037 prctl_map.auxv_size))
2038 return -EFAULT;
2039
2040 /* Last entry must be AT_NULL as specification requires */
2041 user_auxv[AT_VECTOR_SIZE - 2] = AT_NULL;
2042 user_auxv[AT_VECTOR_SIZE - 1] = AT_NULL;
2043 }
2044
2045 if (prctl_map.exe_fd != (u32)-1) {
2046 /*
2047 * Check if the current user is checkpoint/restore capable.
2048 * At the time of this writing, it checks for CAP_SYS_ADMIN
2049 * or CAP_CHECKPOINT_RESTORE.
2050 * Note that a user with access to ptrace can masquerade an
2051 * arbitrary program as any executable, even setuid ones.
2052 * This may have implications in the tomoyo subsystem.
2053 */
2054 if (!checkpoint_restore_ns_capable(current_user_ns()))
2055 return -EPERM;
2056
2057 error = prctl_set_mm_exe_file(mm, prctl_map.exe_fd);
2058 if (error)
2059 return error;
2060 }
2061
2062 /*
2063 * arg_lock protects concurrent updates but we still need mmap_lock for
2064 * read to exclude races with sys_brk.
2065 */
2066 mmap_read_lock(mm);
2067
2068 /*
2069 * We don't validate if these members are pointing to
2070 * real present VMAs because application may have correspond
2071 * VMAs already unmapped and kernel uses these members for statistics
2072 * output in procfs mostly, except
2073 *
2074 * - @start_brk/@brk which are used in do_brk_flags but kernel lookups
2075 * for VMAs when updating these members so anything wrong written
2076 * here cause kernel to swear at userspace program but won't lead
2077 * to any problem in kernel itself
2078 */
2079
2080 spin_lock(&mm->arg_lock);
2081 mm->start_code = prctl_map.start_code;
2082 mm->end_code = prctl_map.end_code;
2083 mm->start_data = prctl_map.start_data;
2084 mm->end_data = prctl_map.end_data;
2085 mm->start_brk = prctl_map.start_brk;
2086 mm->brk = prctl_map.brk;
2087 mm->start_stack = prctl_map.start_stack;
2088 mm->arg_start = prctl_map.arg_start;
2089 mm->arg_end = prctl_map.arg_end;
2090 mm->env_start = prctl_map.env_start;
2091 mm->env_end = prctl_map.env_end;
2092 spin_unlock(&mm->arg_lock);
2093
2094 /*
2095 * Note this update of @saved_auxv is lockless thus
2096 * if someone reads this member in procfs while we're
2097 * updating -- it may get partly updated results. It's
2098 * known and acceptable trade off: we leave it as is to
2099 * not introduce additional locks here making the kernel
2100 * more complex.
2101 */
2102 if (prctl_map.auxv_size)
2103 memcpy(mm->saved_auxv, user_auxv, sizeof(user_auxv));
2104
2105 mmap_read_unlock(mm);
2106 return 0;
2107}
2108#endif /* CONFIG_CHECKPOINT_RESTORE */
2109
2110static int prctl_set_auxv(struct mm_struct *mm, unsigned long addr,
2111 unsigned long len)
2112{
2113 /*
2114 * This doesn't move the auxiliary vector itself since it's pinned to
2115 * mm_struct, but it permits filling the vector with new values. It's
2116 * up to the caller to provide sane values here, otherwise userspace
2117 * tools which use this vector might be unhappy.
2118 */
2119 unsigned long user_auxv[AT_VECTOR_SIZE] = {};
2120
2121 if (len > sizeof(user_auxv))
2122 return -EINVAL;
2123
2124 if (copy_from_user(user_auxv, (const void __user *)addr, len))
2125 return -EFAULT;
2126
2127 /* Make sure the last entry is always AT_NULL */
2128 user_auxv[AT_VECTOR_SIZE - 2] = 0;
2129 user_auxv[AT_VECTOR_SIZE - 1] = 0;
2130
2131 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv));
2132
2133 task_lock(current);
2134 memcpy(mm->saved_auxv, user_auxv, len);
2135 task_unlock(current);
2136
2137 return 0;
2138}
2139
2140static int prctl_set_mm(int opt, unsigned long addr,
2141 unsigned long arg4, unsigned long arg5)
2142{
2143 struct mm_struct *mm = current->mm;
2144 struct prctl_mm_map prctl_map = {
2145 .auxv = NULL,
2146 .auxv_size = 0,
2147 .exe_fd = -1,
2148 };
2149 struct vm_area_struct *vma;
2150 int error;
2151
2152 if (arg5 || (arg4 && (opt != PR_SET_MM_AUXV &&
2153 opt != PR_SET_MM_MAP &&
2154 opt != PR_SET_MM_MAP_SIZE)))
2155 return -EINVAL;
2156
2157#ifdef CONFIG_CHECKPOINT_RESTORE
2158 if (opt == PR_SET_MM_MAP || opt == PR_SET_MM_MAP_SIZE)
2159 return prctl_set_mm_map(opt, (const void __user *)addr, arg4);
2160#endif
2161
2162 if (!capable(CAP_SYS_RESOURCE))
2163 return -EPERM;
2164
2165 if (opt == PR_SET_MM_EXE_FILE)
2166 return prctl_set_mm_exe_file(mm, (unsigned int)addr);
2167
2168 if (opt == PR_SET_MM_AUXV)
2169 return prctl_set_auxv(mm, addr, arg4);
2170
2171 if (addr >= TASK_SIZE || addr < mmap_min_addr)
2172 return -EINVAL;
2173
2174 error = -EINVAL;
2175
2176 /*
2177 * arg_lock protects concurrent updates of arg boundaries, we need
2178 * mmap_lock for a) concurrent sys_brk, b) finding VMA for addr
2179 * validation.
2180 */
2181 mmap_read_lock(mm);
2182 vma = find_vma(mm, addr);
2183
2184 spin_lock(&mm->arg_lock);
2185 prctl_map.start_code = mm->start_code;
2186 prctl_map.end_code = mm->end_code;
2187 prctl_map.start_data = mm->start_data;
2188 prctl_map.end_data = mm->end_data;
2189 prctl_map.start_brk = mm->start_brk;
2190 prctl_map.brk = mm->brk;
2191 prctl_map.start_stack = mm->start_stack;
2192 prctl_map.arg_start = mm->arg_start;
2193 prctl_map.arg_end = mm->arg_end;
2194 prctl_map.env_start = mm->env_start;
2195 prctl_map.env_end = mm->env_end;
2196
2197 switch (opt) {
2198 case PR_SET_MM_START_CODE:
2199 prctl_map.start_code = addr;
2200 break;
2201 case PR_SET_MM_END_CODE:
2202 prctl_map.end_code = addr;
2203 break;
2204 case PR_SET_MM_START_DATA:
2205 prctl_map.start_data = addr;
2206 break;
2207 case PR_SET_MM_END_DATA:
2208 prctl_map.end_data = addr;
2209 break;
2210 case PR_SET_MM_START_STACK:
2211 prctl_map.start_stack = addr;
2212 break;
2213 case PR_SET_MM_START_BRK:
2214 prctl_map.start_brk = addr;
2215 break;
2216 case PR_SET_MM_BRK:
2217 prctl_map.brk = addr;
2218 break;
2219 case PR_SET_MM_ARG_START:
2220 prctl_map.arg_start = addr;
2221 break;
2222 case PR_SET_MM_ARG_END:
2223 prctl_map.arg_end = addr;
2224 break;
2225 case PR_SET_MM_ENV_START:
2226 prctl_map.env_start = addr;
2227 break;
2228 case PR_SET_MM_ENV_END:
2229 prctl_map.env_end = addr;
2230 break;
2231 default:
2232 goto out;
2233 }
2234
2235 error = validate_prctl_map_addr(&prctl_map);
2236 if (error)
2237 goto out;
2238
2239 switch (opt) {
2240 /*
2241 * If command line arguments and environment
2242 * are placed somewhere else on stack, we can
2243 * set them up here, ARG_START/END to setup
2244 * command line arguments and ENV_START/END
2245 * for environment.
2246 */
2247 case PR_SET_MM_START_STACK:
2248 case PR_SET_MM_ARG_START:
2249 case PR_SET_MM_ARG_END:
2250 case PR_SET_MM_ENV_START:
2251 case PR_SET_MM_ENV_END:
2252 if (!vma) {
2253 error = -EFAULT;
2254 goto out;
2255 }
2256 }
2257
2258 mm->start_code = prctl_map.start_code;
2259 mm->end_code = prctl_map.end_code;
2260 mm->start_data = prctl_map.start_data;
2261 mm->end_data = prctl_map.end_data;
2262 mm->start_brk = prctl_map.start_brk;
2263 mm->brk = prctl_map.brk;
2264 mm->start_stack = prctl_map.start_stack;
2265 mm->arg_start = prctl_map.arg_start;
2266 mm->arg_end = prctl_map.arg_end;
2267 mm->env_start = prctl_map.env_start;
2268 mm->env_end = prctl_map.env_end;
2269
2270 error = 0;
2271out:
2272 spin_unlock(&mm->arg_lock);
2273 mmap_read_unlock(mm);
2274 return error;
2275}
2276
2277#ifdef CONFIG_CHECKPOINT_RESTORE
2278static int prctl_get_tid_address(struct task_struct *me, int __user * __user *tid_addr)
2279{
2280 return put_user(me->clear_child_tid, tid_addr);
2281}
2282#else
2283static int prctl_get_tid_address(struct task_struct *me, int __user * __user *tid_addr)
2284{
2285 return -EINVAL;
2286}
2287#endif
2288
2289static int propagate_has_child_subreaper(struct task_struct *p, void *data)
2290{
2291 /*
2292 * If task has has_child_subreaper - all its descendants
2293 * already have these flag too and new descendants will
2294 * inherit it on fork, skip them.
2295 *
2296 * If we've found child_reaper - skip descendants in
2297 * it's subtree as they will never get out pidns.
2298 */
2299 if (p->signal->has_child_subreaper ||
2300 is_child_reaper(task_pid(p)))
2301 return 0;
2302
2303 p->signal->has_child_subreaper = 1;
2304 return 1;
2305}
2306
2307int __weak arch_prctl_spec_ctrl_get(struct task_struct *t, unsigned long which)
2308{
2309 return -EINVAL;
2310}
2311
2312int __weak arch_prctl_spec_ctrl_set(struct task_struct *t, unsigned long which,
2313 unsigned long ctrl)
2314{
2315 return -EINVAL;
2316}
2317
2318#define PR_IO_FLUSHER (PF_MEMALLOC_NOIO | PF_LOCAL_THROTTLE)
2319
2320#ifdef CONFIG_ANON_VMA_NAME
2321
2322#define ANON_VMA_NAME_MAX_LEN 80
2323#define ANON_VMA_NAME_INVALID_CHARS "\\`$[]"
2324
2325static inline bool is_valid_name_char(char ch)
2326{
2327 /* printable ascii characters, excluding ANON_VMA_NAME_INVALID_CHARS */
2328 return ch > 0x1f && ch < 0x7f &&
2329 !strchr(ANON_VMA_NAME_INVALID_CHARS, ch);
2330}
2331
2332static int prctl_set_vma(unsigned long opt, unsigned long addr,
2333 unsigned long size, unsigned long arg)
2334{
2335 struct mm_struct *mm = current->mm;
2336 const char __user *uname;
2337 struct anon_vma_name *anon_name = NULL;
2338 int error;
2339
2340 switch (opt) {
2341 case PR_SET_VMA_ANON_NAME:
2342 uname = (const char __user *)arg;
2343 if (uname) {
2344 char *name, *pch;
2345
2346 name = strndup_user(uname, ANON_VMA_NAME_MAX_LEN);
2347 if (IS_ERR(name))
2348 return PTR_ERR(name);
2349
2350 for (pch = name; *pch != '\0'; pch++) {
2351 if (!is_valid_name_char(*pch)) {
2352 kfree(name);
2353 return -EINVAL;
2354 }
2355 }
2356 /* anon_vma has its own copy */
2357 anon_name = anon_vma_name_alloc(name);
2358 kfree(name);
2359 if (!anon_name)
2360 return -ENOMEM;
2361
2362 }
2363
2364 mmap_write_lock(mm);
2365 error = madvise_set_anon_name(mm, addr, size, anon_name);
2366 mmap_write_unlock(mm);
2367 anon_vma_name_put(anon_name);
2368 break;
2369 default:
2370 error = -EINVAL;
2371 }
2372
2373 return error;
2374}
2375
2376#else /* CONFIG_ANON_VMA_NAME */
2377static int prctl_set_vma(unsigned long opt, unsigned long start,
2378 unsigned long size, unsigned long arg)
2379{
2380 return -EINVAL;
2381}
2382#endif /* CONFIG_ANON_VMA_NAME */
2383
2384static inline unsigned long get_current_mdwe(void)
2385{
2386 unsigned long ret = 0;
2387
2388 if (test_bit(MMF_HAS_MDWE, ¤t->mm->flags))
2389 ret |= PR_MDWE_REFUSE_EXEC_GAIN;
2390 if (test_bit(MMF_HAS_MDWE_NO_INHERIT, ¤t->mm->flags))
2391 ret |= PR_MDWE_NO_INHERIT;
2392
2393 return ret;
2394}
2395
2396static inline int prctl_set_mdwe(unsigned long bits, unsigned long arg3,
2397 unsigned long arg4, unsigned long arg5)
2398{
2399 unsigned long current_bits;
2400
2401 if (arg3 || arg4 || arg5)
2402 return -EINVAL;
2403
2404 if (bits & ~(PR_MDWE_REFUSE_EXEC_GAIN | PR_MDWE_NO_INHERIT))
2405 return -EINVAL;
2406
2407 /* NO_INHERIT only makes sense with REFUSE_EXEC_GAIN */
2408 if (bits & PR_MDWE_NO_INHERIT && !(bits & PR_MDWE_REFUSE_EXEC_GAIN))
2409 return -EINVAL;
2410
2411 /* PARISC cannot allow mdwe as it needs writable stacks */
2412 if (IS_ENABLED(CONFIG_PARISC))
2413 return -EINVAL;
2414
2415 current_bits = get_current_mdwe();
2416 if (current_bits && current_bits != bits)
2417 return -EPERM; /* Cannot unset the flags */
2418
2419 if (bits & PR_MDWE_NO_INHERIT)
2420 set_bit(MMF_HAS_MDWE_NO_INHERIT, ¤t->mm->flags);
2421 if (bits & PR_MDWE_REFUSE_EXEC_GAIN)
2422 set_bit(MMF_HAS_MDWE, ¤t->mm->flags);
2423
2424 return 0;
2425}
2426
2427static inline int prctl_get_mdwe(unsigned long arg2, unsigned long arg3,
2428 unsigned long arg4, unsigned long arg5)
2429{
2430 if (arg2 || arg3 || arg4 || arg5)
2431 return -EINVAL;
2432 return get_current_mdwe();
2433}
2434
2435static int prctl_get_auxv(void __user *addr, unsigned long len)
2436{
2437 struct mm_struct *mm = current->mm;
2438 unsigned long size = min_t(unsigned long, sizeof(mm->saved_auxv), len);
2439
2440 if (size && copy_to_user(addr, mm->saved_auxv, size))
2441 return -EFAULT;
2442 return sizeof(mm->saved_auxv);
2443}
2444
2445SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
2446 unsigned long, arg4, unsigned long, arg5)
2447{
2448 struct task_struct *me = current;
2449 unsigned char comm[sizeof(me->comm)];
2450 long error;
2451
2452 error = security_task_prctl(option, arg2, arg3, arg4, arg5);
2453 if (error != -ENOSYS)
2454 return error;
2455
2456 error = 0;
2457 switch (option) {
2458 case PR_SET_PDEATHSIG:
2459 if (!valid_signal(arg2)) {
2460 error = -EINVAL;
2461 break;
2462 }
2463 me->pdeath_signal = arg2;
2464 break;
2465 case PR_GET_PDEATHSIG:
2466 error = put_user(me->pdeath_signal, (int __user *)arg2);
2467 break;
2468 case PR_GET_DUMPABLE:
2469 error = get_dumpable(me->mm);
2470 break;
2471 case PR_SET_DUMPABLE:
2472 if (arg2 != SUID_DUMP_DISABLE && arg2 != SUID_DUMP_USER) {
2473 error = -EINVAL;
2474 break;
2475 }
2476 set_dumpable(me->mm, arg2);
2477 break;
2478
2479 case PR_SET_UNALIGN:
2480 error = SET_UNALIGN_CTL(me, arg2);
2481 break;
2482 case PR_GET_UNALIGN:
2483 error = GET_UNALIGN_CTL(me, arg2);
2484 break;
2485 case PR_SET_FPEMU:
2486 error = SET_FPEMU_CTL(me, arg2);
2487 break;
2488 case PR_GET_FPEMU:
2489 error = GET_FPEMU_CTL(me, arg2);
2490 break;
2491 case PR_SET_FPEXC:
2492 error = SET_FPEXC_CTL(me, arg2);
2493 break;
2494 case PR_GET_FPEXC:
2495 error = GET_FPEXC_CTL(me, arg2);
2496 break;
2497 case PR_GET_TIMING:
2498 error = PR_TIMING_STATISTICAL;
2499 break;
2500 case PR_SET_TIMING:
2501 if (arg2 != PR_TIMING_STATISTICAL)
2502 error = -EINVAL;
2503 break;
2504 case PR_SET_NAME:
2505 comm[sizeof(me->comm) - 1] = 0;
2506 if (strncpy_from_user(comm, (char __user *)arg2,
2507 sizeof(me->comm) - 1) < 0)
2508 return -EFAULT;
2509 set_task_comm(me, comm);
2510 proc_comm_connector(me);
2511 break;
2512 case PR_GET_NAME:
2513 get_task_comm(comm, me);
2514 if (copy_to_user((char __user *)arg2, comm, sizeof(comm)))
2515 return -EFAULT;
2516 break;
2517 case PR_GET_ENDIAN:
2518 error = GET_ENDIAN(me, arg2);
2519 break;
2520 case PR_SET_ENDIAN:
2521 error = SET_ENDIAN(me, arg2);
2522 break;
2523 case PR_GET_SECCOMP:
2524 error = prctl_get_seccomp();
2525 break;
2526 case PR_SET_SECCOMP:
2527 error = prctl_set_seccomp(arg2, (char __user *)arg3);
2528 break;
2529 case PR_GET_TSC:
2530 error = GET_TSC_CTL(arg2);
2531 break;
2532 case PR_SET_TSC:
2533 error = SET_TSC_CTL(arg2);
2534 break;
2535 case PR_TASK_PERF_EVENTS_DISABLE:
2536 error = perf_event_task_disable();
2537 break;
2538 case PR_TASK_PERF_EVENTS_ENABLE:
2539 error = perf_event_task_enable();
2540 break;
2541 case PR_GET_TIMERSLACK:
2542 if (current->timer_slack_ns > ULONG_MAX)
2543 error = ULONG_MAX;
2544 else
2545 error = current->timer_slack_ns;
2546 break;
2547 case PR_SET_TIMERSLACK:
2548 if (arg2 <= 0)
2549 current->timer_slack_ns =
2550 current->default_timer_slack_ns;
2551 else
2552 current->timer_slack_ns = arg2;
2553 break;
2554 case PR_MCE_KILL:
2555 if (arg4 | arg5)
2556 return -EINVAL;
2557 switch (arg2) {
2558 case PR_MCE_KILL_CLEAR:
2559 if (arg3 != 0)
2560 return -EINVAL;
2561 current->flags &= ~PF_MCE_PROCESS;
2562 break;
2563 case PR_MCE_KILL_SET:
2564 current->flags |= PF_MCE_PROCESS;
2565 if (arg3 == PR_MCE_KILL_EARLY)
2566 current->flags |= PF_MCE_EARLY;
2567 else if (arg3 == PR_MCE_KILL_LATE)
2568 current->flags &= ~PF_MCE_EARLY;
2569 else if (arg3 == PR_MCE_KILL_DEFAULT)
2570 current->flags &=
2571 ~(PF_MCE_EARLY|PF_MCE_PROCESS);
2572 else
2573 return -EINVAL;
2574 break;
2575 default:
2576 return -EINVAL;
2577 }
2578 break;
2579 case PR_MCE_KILL_GET:
2580 if (arg2 | arg3 | arg4 | arg5)
2581 return -EINVAL;
2582 if (current->flags & PF_MCE_PROCESS)
2583 error = (current->flags & PF_MCE_EARLY) ?
2584 PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE;
2585 else
2586 error = PR_MCE_KILL_DEFAULT;
2587 break;
2588 case PR_SET_MM:
2589 error = prctl_set_mm(arg2, arg3, arg4, arg5);
2590 break;
2591 case PR_GET_TID_ADDRESS:
2592 error = prctl_get_tid_address(me, (int __user * __user *)arg2);
2593 break;
2594 case PR_SET_CHILD_SUBREAPER:
2595 me->signal->is_child_subreaper = !!arg2;
2596 if (!arg2)
2597 break;
2598
2599 walk_process_tree(me, propagate_has_child_subreaper, NULL);
2600 break;
2601 case PR_GET_CHILD_SUBREAPER:
2602 error = put_user(me->signal->is_child_subreaper,
2603 (int __user *)arg2);
2604 break;
2605 case PR_SET_NO_NEW_PRIVS:
2606 if (arg2 != 1 || arg3 || arg4 || arg5)
2607 return -EINVAL;
2608
2609 task_set_no_new_privs(current);
2610 break;
2611 case PR_GET_NO_NEW_PRIVS:
2612 if (arg2 || arg3 || arg4 || arg5)
2613 return -EINVAL;
2614 return task_no_new_privs(current) ? 1 : 0;
2615 case PR_GET_THP_DISABLE:
2616 if (arg2 || arg3 || arg4 || arg5)
2617 return -EINVAL;
2618 error = !!test_bit(MMF_DISABLE_THP, &me->mm->flags);
2619 break;
2620 case PR_SET_THP_DISABLE:
2621 if (arg3 || arg4 || arg5)
2622 return -EINVAL;
2623 if (mmap_write_lock_killable(me->mm))
2624 return -EINTR;
2625 if (arg2)
2626 set_bit(MMF_DISABLE_THP, &me->mm->flags);
2627 else
2628 clear_bit(MMF_DISABLE_THP, &me->mm->flags);
2629 mmap_write_unlock(me->mm);
2630 break;
2631 case PR_MPX_ENABLE_MANAGEMENT:
2632 case PR_MPX_DISABLE_MANAGEMENT:
2633 /* No longer implemented: */
2634 return -EINVAL;
2635 case PR_SET_FP_MODE:
2636 error = SET_FP_MODE(me, arg2);
2637 break;
2638 case PR_GET_FP_MODE:
2639 error = GET_FP_MODE(me);
2640 break;
2641 case PR_SVE_SET_VL:
2642 error = SVE_SET_VL(arg2);
2643 break;
2644 case PR_SVE_GET_VL:
2645 error = SVE_GET_VL();
2646 break;
2647 case PR_SME_SET_VL:
2648 error = SME_SET_VL(arg2);
2649 break;
2650 case PR_SME_GET_VL:
2651 error = SME_GET_VL();
2652 break;
2653 case PR_GET_SPECULATION_CTRL:
2654 if (arg3 || arg4 || arg5)
2655 return -EINVAL;
2656 error = arch_prctl_spec_ctrl_get(me, arg2);
2657 break;
2658 case PR_SET_SPECULATION_CTRL:
2659 if (arg4 || arg5)
2660 return -EINVAL;
2661 error = arch_prctl_spec_ctrl_set(me, arg2, arg3);
2662 break;
2663 case PR_PAC_RESET_KEYS:
2664 if (arg3 || arg4 || arg5)
2665 return -EINVAL;
2666 error = PAC_RESET_KEYS(me, arg2);
2667 break;
2668 case PR_PAC_SET_ENABLED_KEYS:
2669 if (arg4 || arg5)
2670 return -EINVAL;
2671 error = PAC_SET_ENABLED_KEYS(me, arg2, arg3);
2672 break;
2673 case PR_PAC_GET_ENABLED_KEYS:
2674 if (arg2 || arg3 || arg4 || arg5)
2675 return -EINVAL;
2676 error = PAC_GET_ENABLED_KEYS(me);
2677 break;
2678 case PR_SET_TAGGED_ADDR_CTRL:
2679 if (arg3 || arg4 || arg5)
2680 return -EINVAL;
2681 error = SET_TAGGED_ADDR_CTRL(arg2);
2682 break;
2683 case PR_GET_TAGGED_ADDR_CTRL:
2684 if (arg2 || arg3 || arg4 || arg5)
2685 return -EINVAL;
2686 error = GET_TAGGED_ADDR_CTRL();
2687 break;
2688 case PR_SET_IO_FLUSHER:
2689 if (!capable(CAP_SYS_RESOURCE))
2690 return -EPERM;
2691
2692 if (arg3 || arg4 || arg5)
2693 return -EINVAL;
2694
2695 if (arg2 == 1)
2696 current->flags |= PR_IO_FLUSHER;
2697 else if (!arg2)
2698 current->flags &= ~PR_IO_FLUSHER;
2699 else
2700 return -EINVAL;
2701 break;
2702 case PR_GET_IO_FLUSHER:
2703 if (!capable(CAP_SYS_RESOURCE))
2704 return -EPERM;
2705
2706 if (arg2 || arg3 || arg4 || arg5)
2707 return -EINVAL;
2708
2709 error = (current->flags & PR_IO_FLUSHER) == PR_IO_FLUSHER;
2710 break;
2711 case PR_SET_SYSCALL_USER_DISPATCH:
2712 error = set_syscall_user_dispatch(arg2, arg3, arg4,
2713 (char __user *) arg5);
2714 break;
2715#ifdef CONFIG_SCHED_CORE
2716 case PR_SCHED_CORE:
2717 error = sched_core_share_pid(arg2, arg3, arg4, arg5);
2718 break;
2719#endif
2720 case PR_SET_MDWE:
2721 error = prctl_set_mdwe(arg2, arg3, arg4, arg5);
2722 break;
2723 case PR_GET_MDWE:
2724 error = prctl_get_mdwe(arg2, arg3, arg4, arg5);
2725 break;
2726 case PR_SET_VMA:
2727 error = prctl_set_vma(arg2, arg3, arg4, arg5);
2728 break;
2729 case PR_GET_AUXV:
2730 if (arg4 || arg5)
2731 return -EINVAL;
2732 error = prctl_get_auxv((void __user *)arg2, arg3);
2733 break;
2734#ifdef CONFIG_KSM
2735 case PR_SET_MEMORY_MERGE:
2736 if (arg3 || arg4 || arg5)
2737 return -EINVAL;
2738 if (mmap_write_lock_killable(me->mm))
2739 return -EINTR;
2740
2741 if (arg2)
2742 error = ksm_enable_merge_any(me->mm);
2743 else
2744 error = ksm_disable_merge_any(me->mm);
2745 mmap_write_unlock(me->mm);
2746 break;
2747 case PR_GET_MEMORY_MERGE:
2748 if (arg2 || arg3 || arg4 || arg5)
2749 return -EINVAL;
2750
2751 error = !!test_bit(MMF_VM_MERGE_ANY, &me->mm->flags);
2752 break;
2753#endif
2754 case PR_RISCV_V_SET_CONTROL:
2755 error = RISCV_V_SET_CONTROL(arg2);
2756 break;
2757 case PR_RISCV_V_GET_CONTROL:
2758 error = RISCV_V_GET_CONTROL();
2759 break;
2760 default:
2761 error = -EINVAL;
2762 break;
2763 }
2764 return error;
2765}
2766
2767SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep,
2768 struct getcpu_cache __user *, unused)
2769{
2770 int err = 0;
2771 int cpu = raw_smp_processor_id();
2772
2773 if (cpup)
2774 err |= put_user(cpu, cpup);
2775 if (nodep)
2776 err |= put_user(cpu_to_node(cpu), nodep);
2777 return err ? -EFAULT : 0;
2778}
2779
2780/**
2781 * do_sysinfo - fill in sysinfo struct
2782 * @info: pointer to buffer to fill
2783 */
2784static int do_sysinfo(struct sysinfo *info)
2785{
2786 unsigned long mem_total, sav_total;
2787 unsigned int mem_unit, bitcount;
2788 struct timespec64 tp;
2789
2790 memset(info, 0, sizeof(struct sysinfo));
2791
2792 ktime_get_boottime_ts64(&tp);
2793 timens_add_boottime(&tp);
2794 info->uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0);
2795
2796 get_avenrun(info->loads, 0, SI_LOAD_SHIFT - FSHIFT);
2797
2798 info->procs = nr_threads;
2799
2800 si_meminfo(info);
2801 si_swapinfo(info);
2802
2803 /*
2804 * If the sum of all the available memory (i.e. ram + swap)
2805 * is less than can be stored in a 32 bit unsigned long then
2806 * we can be binary compatible with 2.2.x kernels. If not,
2807 * well, in that case 2.2.x was broken anyways...
2808 *
2809 * -Erik Andersen <andersee@debian.org>
2810 */
2811
2812 mem_total = info->totalram + info->totalswap;
2813 if (mem_total < info->totalram || mem_total < info->totalswap)
2814 goto out;
2815 bitcount = 0;
2816 mem_unit = info->mem_unit;
2817 while (mem_unit > 1) {
2818 bitcount++;
2819 mem_unit >>= 1;
2820 sav_total = mem_total;
2821 mem_total <<= 1;
2822 if (mem_total < sav_total)
2823 goto out;
2824 }
2825
2826 /*
2827 * If mem_total did not overflow, multiply all memory values by
2828 * info->mem_unit and set it to 1. This leaves things compatible
2829 * with 2.2.x, and also retains compatibility with earlier 2.4.x
2830 * kernels...
2831 */
2832
2833 info->mem_unit = 1;
2834 info->totalram <<= bitcount;
2835 info->freeram <<= bitcount;
2836 info->sharedram <<= bitcount;
2837 info->bufferram <<= bitcount;
2838 info->totalswap <<= bitcount;
2839 info->freeswap <<= bitcount;
2840 info->totalhigh <<= bitcount;
2841 info->freehigh <<= bitcount;
2842
2843out:
2844 return 0;
2845}
2846
2847SYSCALL_DEFINE1(sysinfo, struct sysinfo __user *, info)
2848{
2849 struct sysinfo val;
2850
2851 do_sysinfo(&val);
2852
2853 if (copy_to_user(info, &val, sizeof(struct sysinfo)))
2854 return -EFAULT;
2855
2856 return 0;
2857}
2858
2859#ifdef CONFIG_COMPAT
2860struct compat_sysinfo {
2861 s32 uptime;
2862 u32 loads[3];
2863 u32 totalram;
2864 u32 freeram;
2865 u32 sharedram;
2866 u32 bufferram;
2867 u32 totalswap;
2868 u32 freeswap;
2869 u16 procs;
2870 u16 pad;
2871 u32 totalhigh;
2872 u32 freehigh;
2873 u32 mem_unit;
2874 char _f[20-2*sizeof(u32)-sizeof(int)];
2875};
2876
2877COMPAT_SYSCALL_DEFINE1(sysinfo, struct compat_sysinfo __user *, info)
2878{
2879 struct sysinfo s;
2880 struct compat_sysinfo s_32;
2881
2882 do_sysinfo(&s);
2883
2884 /* Check to see if any memory value is too large for 32-bit and scale
2885 * down if needed
2886 */
2887 if (upper_32_bits(s.totalram) || upper_32_bits(s.totalswap)) {
2888 int bitcount = 0;
2889
2890 while (s.mem_unit < PAGE_SIZE) {
2891 s.mem_unit <<= 1;
2892 bitcount++;
2893 }
2894
2895 s.totalram >>= bitcount;
2896 s.freeram >>= bitcount;
2897 s.sharedram >>= bitcount;
2898 s.bufferram >>= bitcount;
2899 s.totalswap >>= bitcount;
2900 s.freeswap >>= bitcount;
2901 s.totalhigh >>= bitcount;
2902 s.freehigh >>= bitcount;
2903 }
2904
2905 memset(&s_32, 0, sizeof(s_32));
2906 s_32.uptime = s.uptime;
2907 s_32.loads[0] = s.loads[0];
2908 s_32.loads[1] = s.loads[1];
2909 s_32.loads[2] = s.loads[2];
2910 s_32.totalram = s.totalram;
2911 s_32.freeram = s.freeram;
2912 s_32.sharedram = s.sharedram;
2913 s_32.bufferram = s.bufferram;
2914 s_32.totalswap = s.totalswap;
2915 s_32.freeswap = s.freeswap;
2916 s_32.procs = s.procs;
2917 s_32.totalhigh = s.totalhigh;
2918 s_32.freehigh = s.freehigh;
2919 s_32.mem_unit = s.mem_unit;
2920 if (copy_to_user(info, &s_32, sizeof(s_32)))
2921 return -EFAULT;
2922 return 0;
2923}
2924#endif /* CONFIG_COMPAT */
1/*
2 * linux/kernel/sys.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 */
6
7#include <linux/export.h>
8#include <linux/mm.h>
9#include <linux/utsname.h>
10#include <linux/mman.h>
11#include <linux/reboot.h>
12#include <linux/prctl.h>
13#include <linux/highuid.h>
14#include <linux/fs.h>
15#include <linux/kmod.h>
16#include <linux/perf_event.h>
17#include <linux/resource.h>
18#include <linux/kernel.h>
19#include <linux/kexec.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
51#include <linux/kmsg_dump.h>
52/* Move somewhere else to avoid recompiling? */
53#include <generated/utsrelease.h>
54
55#include <asm/uaccess.h>
56#include <asm/io.h>
57#include <asm/unistd.h>
58
59#ifndef SET_UNALIGN_CTL
60# define SET_UNALIGN_CTL(a,b) (-EINVAL)
61#endif
62#ifndef GET_UNALIGN_CTL
63# define GET_UNALIGN_CTL(a,b) (-EINVAL)
64#endif
65#ifndef SET_FPEMU_CTL
66# define SET_FPEMU_CTL(a,b) (-EINVAL)
67#endif
68#ifndef GET_FPEMU_CTL
69# define GET_FPEMU_CTL(a,b) (-EINVAL)
70#endif
71#ifndef SET_FPEXC_CTL
72# define SET_FPEXC_CTL(a,b) (-EINVAL)
73#endif
74#ifndef GET_FPEXC_CTL
75# define GET_FPEXC_CTL(a,b) (-EINVAL)
76#endif
77#ifndef GET_ENDIAN
78# define GET_ENDIAN(a,b) (-EINVAL)
79#endif
80#ifndef SET_ENDIAN
81# define SET_ENDIAN(a,b) (-EINVAL)
82#endif
83#ifndef GET_TSC_CTL
84# define GET_TSC_CTL(a) (-EINVAL)
85#endif
86#ifndef SET_TSC_CTL
87# define SET_TSC_CTL(a) (-EINVAL)
88#endif
89
90/*
91 * this is where the system-wide overflow UID and GID are defined, for
92 * architectures that now have 32-bit UID/GID but didn't in the past
93 */
94
95int overflowuid = DEFAULT_OVERFLOWUID;
96int overflowgid = DEFAULT_OVERFLOWGID;
97
98EXPORT_SYMBOL(overflowuid);
99EXPORT_SYMBOL(overflowgid);
100
101/*
102 * the same as above, but for filesystems which can only store a 16-bit
103 * UID and GID. as such, this is needed on all architectures
104 */
105
106int fs_overflowuid = DEFAULT_FS_OVERFLOWUID;
107int fs_overflowgid = DEFAULT_FS_OVERFLOWUID;
108
109EXPORT_SYMBOL(fs_overflowuid);
110EXPORT_SYMBOL(fs_overflowgid);
111
112/*
113 * this indicates whether you can reboot with ctrl-alt-del: the default is yes
114 */
115
116int C_A_D = 1;
117struct pid *cad_pid;
118EXPORT_SYMBOL(cad_pid);
119
120/*
121 * If set, this is used for preparing the system to power off.
122 */
123
124void (*pm_power_off_prepare)(void);
125
126/*
127 * Returns true if current's euid is same as p's uid or euid,
128 * or has CAP_SYS_NICE to p's user_ns.
129 *
130 * Called with rcu_read_lock, creds are safe
131 */
132static bool set_one_prio_perm(struct task_struct *p)
133{
134 const struct cred *cred = current_cred(), *pcred = __task_cred(p);
135
136 if (uid_eq(pcred->uid, cred->euid) ||
137 uid_eq(pcred->euid, cred->euid))
138 return true;
139 if (ns_capable(pcred->user_ns, CAP_SYS_NICE))
140 return true;
141 return false;
142}
143
144/*
145 * set the priority of a task
146 * - the caller must hold the RCU read lock
147 */
148static int set_one_prio(struct task_struct *p, int niceval, int error)
149{
150 int no_nice;
151
152 if (!set_one_prio_perm(p)) {
153 error = -EPERM;
154 goto out;
155 }
156 if (niceval < task_nice(p) && !can_nice(p, niceval)) {
157 error = -EACCES;
158 goto out;
159 }
160 no_nice = security_task_setnice(p, niceval);
161 if (no_nice) {
162 error = no_nice;
163 goto out;
164 }
165 if (error == -ESRCH)
166 error = 0;
167 set_user_nice(p, niceval);
168out:
169 return error;
170}
171
172SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval)
173{
174 struct task_struct *g, *p;
175 struct user_struct *user;
176 const struct cred *cred = current_cred();
177 int error = -EINVAL;
178 struct pid *pgrp;
179 kuid_t uid;
180
181 if (which > PRIO_USER || which < PRIO_PROCESS)
182 goto out;
183
184 /* normalize: avoid signed division (rounding problems) */
185 error = -ESRCH;
186 if (niceval < -20)
187 niceval = -20;
188 if (niceval > 19)
189 niceval = 19;
190
191 rcu_read_lock();
192 read_lock(&tasklist_lock);
193 switch (which) {
194 case PRIO_PROCESS:
195 if (who)
196 p = find_task_by_vpid(who);
197 else
198 p = current;
199 if (p)
200 error = set_one_prio(p, niceval, error);
201 break;
202 case PRIO_PGRP:
203 if (who)
204 pgrp = find_vpid(who);
205 else
206 pgrp = task_pgrp(current);
207 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
208 error = set_one_prio(p, niceval, error);
209 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
210 break;
211 case PRIO_USER:
212 uid = make_kuid(cred->user_ns, who);
213 user = cred->user;
214 if (!who)
215 uid = cred->uid;
216 else if (!uid_eq(uid, cred->uid) &&
217 !(user = find_user(uid)))
218 goto out_unlock; /* No processes for this user */
219
220 do_each_thread(g, p) {
221 if (uid_eq(task_uid(p), uid))
222 error = set_one_prio(p, niceval, error);
223 } while_each_thread(g, p);
224 if (!uid_eq(uid, cred->uid))
225 free_uid(user); /* For find_user() */
226 break;
227 }
228out_unlock:
229 read_unlock(&tasklist_lock);
230 rcu_read_unlock();
231out:
232 return error;
233}
234
235/*
236 * Ugh. To avoid negative return values, "getpriority()" will
237 * not return the normal nice-value, but a negated value that
238 * has been offset by 20 (ie it returns 40..1 instead of -20..19)
239 * to stay compatible.
240 */
241SYSCALL_DEFINE2(getpriority, int, which, int, who)
242{
243 struct task_struct *g, *p;
244 struct user_struct *user;
245 const struct cred *cred = current_cred();
246 long niceval, retval = -ESRCH;
247 struct pid *pgrp;
248 kuid_t uid;
249
250 if (which > PRIO_USER || which < PRIO_PROCESS)
251 return -EINVAL;
252
253 rcu_read_lock();
254 read_lock(&tasklist_lock);
255 switch (which) {
256 case PRIO_PROCESS:
257 if (who)
258 p = find_task_by_vpid(who);
259 else
260 p = current;
261 if (p) {
262 niceval = 20 - task_nice(p);
263 if (niceval > retval)
264 retval = niceval;
265 }
266 break;
267 case PRIO_PGRP:
268 if (who)
269 pgrp = find_vpid(who);
270 else
271 pgrp = task_pgrp(current);
272 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
273 niceval = 20 - task_nice(p);
274 if (niceval > retval)
275 retval = niceval;
276 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
277 break;
278 case PRIO_USER:
279 uid = make_kuid(cred->user_ns, who);
280 user = cred->user;
281 if (!who)
282 uid = cred->uid;
283 else if (!uid_eq(uid, cred->uid) &&
284 !(user = find_user(uid)))
285 goto out_unlock; /* No processes for this user */
286
287 do_each_thread(g, p) {
288 if (uid_eq(task_uid(p), uid)) {
289 niceval = 20 - task_nice(p);
290 if (niceval > retval)
291 retval = niceval;
292 }
293 } while_each_thread(g, p);
294 if (!uid_eq(uid, cred->uid))
295 free_uid(user); /* for find_user() */
296 break;
297 }
298out_unlock:
299 read_unlock(&tasklist_lock);
300 rcu_read_unlock();
301
302 return retval;
303}
304
305/**
306 * emergency_restart - reboot the system
307 *
308 * Without shutting down any hardware or taking any locks
309 * reboot the system. This is called when we know we are in
310 * trouble so this is our best effort to reboot. This is
311 * safe to call in interrupt context.
312 */
313void emergency_restart(void)
314{
315 kmsg_dump(KMSG_DUMP_EMERG);
316 machine_emergency_restart();
317}
318EXPORT_SYMBOL_GPL(emergency_restart);
319
320void kernel_restart_prepare(char *cmd)
321{
322 blocking_notifier_call_chain(&reboot_notifier_list, SYS_RESTART, cmd);
323 system_state = SYSTEM_RESTART;
324 usermodehelper_disable();
325 device_shutdown();
326 syscore_shutdown();
327}
328
329/**
330 * register_reboot_notifier - Register function to be called at reboot time
331 * @nb: Info about notifier function to be called
332 *
333 * Registers a function with the list of functions
334 * to be called at reboot time.
335 *
336 * Currently always returns zero, as blocking_notifier_chain_register()
337 * always returns zero.
338 */
339int register_reboot_notifier(struct notifier_block *nb)
340{
341 return blocking_notifier_chain_register(&reboot_notifier_list, nb);
342}
343EXPORT_SYMBOL(register_reboot_notifier);
344
345/**
346 * unregister_reboot_notifier - Unregister previously registered reboot notifier
347 * @nb: Hook to be unregistered
348 *
349 * Unregisters a previously registered reboot
350 * notifier function.
351 *
352 * Returns zero on success, or %-ENOENT on failure.
353 */
354int unregister_reboot_notifier(struct notifier_block *nb)
355{
356 return blocking_notifier_chain_unregister(&reboot_notifier_list, nb);
357}
358EXPORT_SYMBOL(unregister_reboot_notifier);
359
360/**
361 * kernel_restart - reboot the system
362 * @cmd: pointer to buffer containing command to execute for restart
363 * or %NULL
364 *
365 * Shutdown everything and perform a clean reboot.
366 * This is not safe to call in interrupt context.
367 */
368void kernel_restart(char *cmd)
369{
370 kernel_restart_prepare(cmd);
371 if (!cmd)
372 printk(KERN_EMERG "Restarting system.\n");
373 else
374 printk(KERN_EMERG "Restarting system with command '%s'.\n", cmd);
375 kmsg_dump(KMSG_DUMP_RESTART);
376 machine_restart(cmd);
377}
378EXPORT_SYMBOL_GPL(kernel_restart);
379
380static void kernel_shutdown_prepare(enum system_states state)
381{
382 blocking_notifier_call_chain(&reboot_notifier_list,
383 (state == SYSTEM_HALT)?SYS_HALT:SYS_POWER_OFF, NULL);
384 system_state = state;
385 usermodehelper_disable();
386 device_shutdown();
387}
388/**
389 * kernel_halt - halt the system
390 *
391 * Shutdown everything and perform a clean system halt.
392 */
393void kernel_halt(void)
394{
395 kernel_shutdown_prepare(SYSTEM_HALT);
396 syscore_shutdown();
397 printk(KERN_EMERG "System halted.\n");
398 kmsg_dump(KMSG_DUMP_HALT);
399 machine_halt();
400}
401
402EXPORT_SYMBOL_GPL(kernel_halt);
403
404/**
405 * kernel_power_off - power_off the system
406 *
407 * Shutdown everything and perform a clean system power_off.
408 */
409void kernel_power_off(void)
410{
411 kernel_shutdown_prepare(SYSTEM_POWER_OFF);
412 if (pm_power_off_prepare)
413 pm_power_off_prepare();
414 disable_nonboot_cpus();
415 syscore_shutdown();
416 printk(KERN_EMERG "Power down.\n");
417 kmsg_dump(KMSG_DUMP_POWEROFF);
418 machine_power_off();
419}
420EXPORT_SYMBOL_GPL(kernel_power_off);
421
422static DEFINE_MUTEX(reboot_mutex);
423
424/*
425 * Reboot system call: for obvious reasons only root may call it,
426 * and even root needs to set up some magic numbers in the registers
427 * so that some mistake won't make this reboot the whole machine.
428 * You can also set the meaning of the ctrl-alt-del-key here.
429 *
430 * reboot doesn't sync: do that yourself before calling this.
431 */
432SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd,
433 void __user *, arg)
434{
435 char buffer[256];
436 int ret = 0;
437
438 /* We only trust the superuser with rebooting the system. */
439 if (!capable(CAP_SYS_BOOT))
440 return -EPERM;
441
442 /* For safety, we require "magic" arguments. */
443 if (magic1 != LINUX_REBOOT_MAGIC1 ||
444 (magic2 != LINUX_REBOOT_MAGIC2 &&
445 magic2 != LINUX_REBOOT_MAGIC2A &&
446 magic2 != LINUX_REBOOT_MAGIC2B &&
447 magic2 != LINUX_REBOOT_MAGIC2C))
448 return -EINVAL;
449
450 /*
451 * If pid namespaces are enabled and the current task is in a child
452 * pid_namespace, the command is handled by reboot_pid_ns() which will
453 * call do_exit().
454 */
455 ret = reboot_pid_ns(task_active_pid_ns(current), cmd);
456 if (ret)
457 return ret;
458
459 /* Instead of trying to make the power_off code look like
460 * halt when pm_power_off is not set do it the easy way.
461 */
462 if ((cmd == LINUX_REBOOT_CMD_POWER_OFF) && !pm_power_off)
463 cmd = LINUX_REBOOT_CMD_HALT;
464
465 mutex_lock(&reboot_mutex);
466 switch (cmd) {
467 case LINUX_REBOOT_CMD_RESTART:
468 kernel_restart(NULL);
469 break;
470
471 case LINUX_REBOOT_CMD_CAD_ON:
472 C_A_D = 1;
473 break;
474
475 case LINUX_REBOOT_CMD_CAD_OFF:
476 C_A_D = 0;
477 break;
478
479 case LINUX_REBOOT_CMD_HALT:
480 kernel_halt();
481 do_exit(0);
482 panic("cannot halt");
483
484 case LINUX_REBOOT_CMD_POWER_OFF:
485 kernel_power_off();
486 do_exit(0);
487 break;
488
489 case LINUX_REBOOT_CMD_RESTART2:
490 if (strncpy_from_user(&buffer[0], arg, sizeof(buffer) - 1) < 0) {
491 ret = -EFAULT;
492 break;
493 }
494 buffer[sizeof(buffer) - 1] = '\0';
495
496 kernel_restart(buffer);
497 break;
498
499#ifdef CONFIG_KEXEC
500 case LINUX_REBOOT_CMD_KEXEC:
501 ret = kernel_kexec();
502 break;
503#endif
504
505#ifdef CONFIG_HIBERNATION
506 case LINUX_REBOOT_CMD_SW_SUSPEND:
507 ret = hibernate();
508 break;
509#endif
510
511 default:
512 ret = -EINVAL;
513 break;
514 }
515 mutex_unlock(&reboot_mutex);
516 return ret;
517}
518
519static void deferred_cad(struct work_struct *dummy)
520{
521 kernel_restart(NULL);
522}
523
524/*
525 * This function gets called by ctrl-alt-del - ie the keyboard interrupt.
526 * As it's called within an interrupt, it may NOT sync: the only choice
527 * is whether to reboot at once, or just ignore the ctrl-alt-del.
528 */
529void ctrl_alt_del(void)
530{
531 static DECLARE_WORK(cad_work, deferred_cad);
532
533 if (C_A_D)
534 schedule_work(&cad_work);
535 else
536 kill_cad_pid(SIGINT, 1);
537}
538
539/*
540 * Unprivileged users may change the real gid to the effective gid
541 * or vice versa. (BSD-style)
542 *
543 * If you set the real gid at all, or set the effective gid to a value not
544 * equal to the real gid, then the saved gid is set to the new effective gid.
545 *
546 * This makes it possible for a setgid program to completely drop its
547 * privileges, which is often a useful assertion to make when you are doing
548 * a security audit over a program.
549 *
550 * The general idea is that a program which uses just setregid() will be
551 * 100% compatible with BSD. A program which uses just setgid() will be
552 * 100% compatible with POSIX with saved IDs.
553 *
554 * SMP: There are not races, the GIDs are checked only by filesystem
555 * operations (as far as semantic preservation is concerned).
556 */
557SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid)
558{
559 struct user_namespace *ns = current_user_ns();
560 const struct cred *old;
561 struct cred *new;
562 int retval;
563 kgid_t krgid, kegid;
564
565 krgid = make_kgid(ns, rgid);
566 kegid = make_kgid(ns, egid);
567
568 if ((rgid != (gid_t) -1) && !gid_valid(krgid))
569 return -EINVAL;
570 if ((egid != (gid_t) -1) && !gid_valid(kegid))
571 return -EINVAL;
572
573 new = prepare_creds();
574 if (!new)
575 return -ENOMEM;
576 old = current_cred();
577
578 retval = -EPERM;
579 if (rgid != (gid_t) -1) {
580 if (gid_eq(old->gid, krgid) ||
581 gid_eq(old->egid, krgid) ||
582 nsown_capable(CAP_SETGID))
583 new->gid = krgid;
584 else
585 goto error;
586 }
587 if (egid != (gid_t) -1) {
588 if (gid_eq(old->gid, kegid) ||
589 gid_eq(old->egid, kegid) ||
590 gid_eq(old->sgid, kegid) ||
591 nsown_capable(CAP_SETGID))
592 new->egid = kegid;
593 else
594 goto error;
595 }
596
597 if (rgid != (gid_t) -1 ||
598 (egid != (gid_t) -1 && !gid_eq(kegid, old->gid)))
599 new->sgid = new->egid;
600 new->fsgid = new->egid;
601
602 return commit_creds(new);
603
604error:
605 abort_creds(new);
606 return retval;
607}
608
609/*
610 * setgid() is implemented like SysV w/ SAVED_IDS
611 *
612 * SMP: Same implicit races as above.
613 */
614SYSCALL_DEFINE1(setgid, gid_t, gid)
615{
616 struct user_namespace *ns = current_user_ns();
617 const struct cred *old;
618 struct cred *new;
619 int retval;
620 kgid_t kgid;
621
622 kgid = make_kgid(ns, gid);
623 if (!gid_valid(kgid))
624 return -EINVAL;
625
626 new = prepare_creds();
627 if (!new)
628 return -ENOMEM;
629 old = current_cred();
630
631 retval = -EPERM;
632 if (nsown_capable(CAP_SETGID))
633 new->gid = new->egid = new->sgid = new->fsgid = kgid;
634 else if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->sgid))
635 new->egid = new->fsgid = kgid;
636 else
637 goto error;
638
639 return commit_creds(new);
640
641error:
642 abort_creds(new);
643 return retval;
644}
645
646/*
647 * change the user struct in a credentials set to match the new UID
648 */
649static int set_user(struct cred *new)
650{
651 struct user_struct *new_user;
652
653 new_user = alloc_uid(new->uid);
654 if (!new_user)
655 return -EAGAIN;
656
657 /*
658 * We don't fail in case of NPROC limit excess here because too many
659 * poorly written programs don't check set*uid() return code, assuming
660 * it never fails if called by root. We may still enforce NPROC limit
661 * for programs doing set*uid()+execve() by harmlessly deferring the
662 * failure to the execve() stage.
663 */
664 if (atomic_read(&new_user->processes) >= rlimit(RLIMIT_NPROC) &&
665 new_user != INIT_USER)
666 current->flags |= PF_NPROC_EXCEEDED;
667 else
668 current->flags &= ~PF_NPROC_EXCEEDED;
669
670 free_uid(new->user);
671 new->user = new_user;
672 return 0;
673}
674
675/*
676 * Unprivileged users may change the real uid to the effective uid
677 * or vice versa. (BSD-style)
678 *
679 * If you set the real uid at all, or set the effective uid to a value not
680 * equal to the real uid, then the saved uid is set to the new effective uid.
681 *
682 * This makes it possible for a setuid program to completely drop its
683 * privileges, which is often a useful assertion to make when you are doing
684 * a security audit over a program.
685 *
686 * The general idea is that a program which uses just setreuid() will be
687 * 100% compatible with BSD. A program which uses just setuid() will be
688 * 100% compatible with POSIX with saved IDs.
689 */
690SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid)
691{
692 struct user_namespace *ns = current_user_ns();
693 const struct cred *old;
694 struct cred *new;
695 int retval;
696 kuid_t kruid, keuid;
697
698 kruid = make_kuid(ns, ruid);
699 keuid = make_kuid(ns, euid);
700
701 if ((ruid != (uid_t) -1) && !uid_valid(kruid))
702 return -EINVAL;
703 if ((euid != (uid_t) -1) && !uid_valid(keuid))
704 return -EINVAL;
705
706 new = prepare_creds();
707 if (!new)
708 return -ENOMEM;
709 old = current_cred();
710
711 retval = -EPERM;
712 if (ruid != (uid_t) -1) {
713 new->uid = kruid;
714 if (!uid_eq(old->uid, kruid) &&
715 !uid_eq(old->euid, kruid) &&
716 !nsown_capable(CAP_SETUID))
717 goto error;
718 }
719
720 if (euid != (uid_t) -1) {
721 new->euid = keuid;
722 if (!uid_eq(old->uid, keuid) &&
723 !uid_eq(old->euid, keuid) &&
724 !uid_eq(old->suid, keuid) &&
725 !nsown_capable(CAP_SETUID))
726 goto error;
727 }
728
729 if (!uid_eq(new->uid, old->uid)) {
730 retval = set_user(new);
731 if (retval < 0)
732 goto error;
733 }
734 if (ruid != (uid_t) -1 ||
735 (euid != (uid_t) -1 && !uid_eq(keuid, old->uid)))
736 new->suid = new->euid;
737 new->fsuid = new->euid;
738
739 retval = security_task_fix_setuid(new, old, LSM_SETID_RE);
740 if (retval < 0)
741 goto error;
742
743 return commit_creds(new);
744
745error:
746 abort_creds(new);
747 return retval;
748}
749
750/*
751 * setuid() is implemented like SysV with SAVED_IDS
752 *
753 * Note that SAVED_ID's is deficient in that a setuid root program
754 * like sendmail, for example, cannot set its uid to be a normal
755 * user and then switch back, because if you're root, setuid() sets
756 * the saved uid too. If you don't like this, blame the bright people
757 * in the POSIX committee and/or USG. Note that the BSD-style setreuid()
758 * will allow a root program to temporarily drop privileges and be able to
759 * regain them by swapping the real and effective uid.
760 */
761SYSCALL_DEFINE1(setuid, uid_t, uid)
762{
763 struct user_namespace *ns = current_user_ns();
764 const struct cred *old;
765 struct cred *new;
766 int retval;
767 kuid_t kuid;
768
769 kuid = make_kuid(ns, uid);
770 if (!uid_valid(kuid))
771 return -EINVAL;
772
773 new = prepare_creds();
774 if (!new)
775 return -ENOMEM;
776 old = current_cred();
777
778 retval = -EPERM;
779 if (nsown_capable(CAP_SETUID)) {
780 new->suid = new->uid = kuid;
781 if (!uid_eq(kuid, old->uid)) {
782 retval = set_user(new);
783 if (retval < 0)
784 goto error;
785 }
786 } else if (!uid_eq(kuid, old->uid) && !uid_eq(kuid, new->suid)) {
787 goto error;
788 }
789
790 new->fsuid = new->euid = kuid;
791
792 retval = security_task_fix_setuid(new, old, LSM_SETID_ID);
793 if (retval < 0)
794 goto error;
795
796 return commit_creds(new);
797
798error:
799 abort_creds(new);
800 return retval;
801}
802
803
804/*
805 * This function implements a generic ability to update ruid, euid,
806 * and suid. This allows you to implement the 4.4 compatible seteuid().
807 */
808SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid)
809{
810 struct user_namespace *ns = current_user_ns();
811 const struct cred *old;
812 struct cred *new;
813 int retval;
814 kuid_t kruid, keuid, ksuid;
815
816 kruid = make_kuid(ns, ruid);
817 keuid = make_kuid(ns, euid);
818 ksuid = make_kuid(ns, suid);
819
820 if ((ruid != (uid_t) -1) && !uid_valid(kruid))
821 return -EINVAL;
822
823 if ((euid != (uid_t) -1) && !uid_valid(keuid))
824 return -EINVAL;
825
826 if ((suid != (uid_t) -1) && !uid_valid(ksuid))
827 return -EINVAL;
828
829 new = prepare_creds();
830 if (!new)
831 return -ENOMEM;
832
833 old = current_cred();
834
835 retval = -EPERM;
836 if (!nsown_capable(CAP_SETUID)) {
837 if (ruid != (uid_t) -1 && !uid_eq(kruid, old->uid) &&
838 !uid_eq(kruid, old->euid) && !uid_eq(kruid, old->suid))
839 goto error;
840 if (euid != (uid_t) -1 && !uid_eq(keuid, old->uid) &&
841 !uid_eq(keuid, old->euid) && !uid_eq(keuid, old->suid))
842 goto error;
843 if (suid != (uid_t) -1 && !uid_eq(ksuid, old->uid) &&
844 !uid_eq(ksuid, old->euid) && !uid_eq(ksuid, old->suid))
845 goto error;
846 }
847
848 if (ruid != (uid_t) -1) {
849 new->uid = kruid;
850 if (!uid_eq(kruid, old->uid)) {
851 retval = set_user(new);
852 if (retval < 0)
853 goto error;
854 }
855 }
856 if (euid != (uid_t) -1)
857 new->euid = keuid;
858 if (suid != (uid_t) -1)
859 new->suid = ksuid;
860 new->fsuid = new->euid;
861
862 retval = security_task_fix_setuid(new, old, LSM_SETID_RES);
863 if (retval < 0)
864 goto error;
865
866 return commit_creds(new);
867
868error:
869 abort_creds(new);
870 return retval;
871}
872
873SYSCALL_DEFINE3(getresuid, uid_t __user *, ruidp, uid_t __user *, euidp, uid_t __user *, suidp)
874{
875 const struct cred *cred = current_cred();
876 int retval;
877 uid_t ruid, euid, suid;
878
879 ruid = from_kuid_munged(cred->user_ns, cred->uid);
880 euid = from_kuid_munged(cred->user_ns, cred->euid);
881 suid = from_kuid_munged(cred->user_ns, cred->suid);
882
883 if (!(retval = put_user(ruid, ruidp)) &&
884 !(retval = put_user(euid, euidp)))
885 retval = put_user(suid, suidp);
886
887 return retval;
888}
889
890/*
891 * Same as above, but for rgid, egid, sgid.
892 */
893SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid)
894{
895 struct user_namespace *ns = current_user_ns();
896 const struct cred *old;
897 struct cred *new;
898 int retval;
899 kgid_t krgid, kegid, ksgid;
900
901 krgid = make_kgid(ns, rgid);
902 kegid = make_kgid(ns, egid);
903 ksgid = make_kgid(ns, sgid);
904
905 if ((rgid != (gid_t) -1) && !gid_valid(krgid))
906 return -EINVAL;
907 if ((egid != (gid_t) -1) && !gid_valid(kegid))
908 return -EINVAL;
909 if ((sgid != (gid_t) -1) && !gid_valid(ksgid))
910 return -EINVAL;
911
912 new = prepare_creds();
913 if (!new)
914 return -ENOMEM;
915 old = current_cred();
916
917 retval = -EPERM;
918 if (!nsown_capable(CAP_SETGID)) {
919 if (rgid != (gid_t) -1 && !gid_eq(krgid, old->gid) &&
920 !gid_eq(krgid, old->egid) && !gid_eq(krgid, old->sgid))
921 goto error;
922 if (egid != (gid_t) -1 && !gid_eq(kegid, old->gid) &&
923 !gid_eq(kegid, old->egid) && !gid_eq(kegid, old->sgid))
924 goto error;
925 if (sgid != (gid_t) -1 && !gid_eq(ksgid, old->gid) &&
926 !gid_eq(ksgid, old->egid) && !gid_eq(ksgid, old->sgid))
927 goto error;
928 }
929
930 if (rgid != (gid_t) -1)
931 new->gid = krgid;
932 if (egid != (gid_t) -1)
933 new->egid = kegid;
934 if (sgid != (gid_t) -1)
935 new->sgid = ksgid;
936 new->fsgid = new->egid;
937
938 return commit_creds(new);
939
940error:
941 abort_creds(new);
942 return retval;
943}
944
945SYSCALL_DEFINE3(getresgid, gid_t __user *, rgidp, gid_t __user *, egidp, gid_t __user *, sgidp)
946{
947 const struct cred *cred = current_cred();
948 int retval;
949 gid_t rgid, egid, sgid;
950
951 rgid = from_kgid_munged(cred->user_ns, cred->gid);
952 egid = from_kgid_munged(cred->user_ns, cred->egid);
953 sgid = from_kgid_munged(cred->user_ns, cred->sgid);
954
955 if (!(retval = put_user(rgid, rgidp)) &&
956 !(retval = put_user(egid, egidp)))
957 retval = put_user(sgid, sgidp);
958
959 return retval;
960}
961
962
963/*
964 * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This
965 * is used for "access()" and for the NFS daemon (letting nfsd stay at
966 * whatever uid it wants to). It normally shadows "euid", except when
967 * explicitly set by setfsuid() or for access..
968 */
969SYSCALL_DEFINE1(setfsuid, uid_t, uid)
970{
971 const struct cred *old;
972 struct cred *new;
973 uid_t old_fsuid;
974 kuid_t kuid;
975
976 old = current_cred();
977 old_fsuid = from_kuid_munged(old->user_ns, old->fsuid);
978
979 kuid = make_kuid(old->user_ns, uid);
980 if (!uid_valid(kuid))
981 return old_fsuid;
982
983 new = prepare_creds();
984 if (!new)
985 return old_fsuid;
986
987 if (uid_eq(kuid, old->uid) || uid_eq(kuid, old->euid) ||
988 uid_eq(kuid, old->suid) || uid_eq(kuid, old->fsuid) ||
989 nsown_capable(CAP_SETUID)) {
990 if (!uid_eq(kuid, old->fsuid)) {
991 new->fsuid = kuid;
992 if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0)
993 goto change_okay;
994 }
995 }
996
997 abort_creds(new);
998 return old_fsuid;
999
1000change_okay:
1001 commit_creds(new);
1002 return old_fsuid;
1003}
1004
1005/*
1006 * Samma på svenska..
1007 */
1008SYSCALL_DEFINE1(setfsgid, gid_t, gid)
1009{
1010 const struct cred *old;
1011 struct cred *new;
1012 gid_t old_fsgid;
1013 kgid_t kgid;
1014
1015 old = current_cred();
1016 old_fsgid = from_kgid_munged(old->user_ns, old->fsgid);
1017
1018 kgid = make_kgid(old->user_ns, gid);
1019 if (!gid_valid(kgid))
1020 return old_fsgid;
1021
1022 new = prepare_creds();
1023 if (!new)
1024 return old_fsgid;
1025
1026 if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->egid) ||
1027 gid_eq(kgid, old->sgid) || gid_eq(kgid, old->fsgid) ||
1028 nsown_capable(CAP_SETGID)) {
1029 if (!gid_eq(kgid, old->fsgid)) {
1030 new->fsgid = kgid;
1031 goto change_okay;
1032 }
1033 }
1034
1035 abort_creds(new);
1036 return old_fsgid;
1037
1038change_okay:
1039 commit_creds(new);
1040 return old_fsgid;
1041}
1042
1043void do_sys_times(struct tms *tms)
1044{
1045 cputime_t tgutime, tgstime, cutime, cstime;
1046
1047 spin_lock_irq(¤t->sighand->siglock);
1048 thread_group_times(current, &tgutime, &tgstime);
1049 cutime = current->signal->cutime;
1050 cstime = current->signal->cstime;
1051 spin_unlock_irq(¤t->sighand->siglock);
1052 tms->tms_utime = cputime_to_clock_t(tgutime);
1053 tms->tms_stime = cputime_to_clock_t(tgstime);
1054 tms->tms_cutime = cputime_to_clock_t(cutime);
1055 tms->tms_cstime = cputime_to_clock_t(cstime);
1056}
1057
1058SYSCALL_DEFINE1(times, struct tms __user *, tbuf)
1059{
1060 if (tbuf) {
1061 struct tms tmp;
1062
1063 do_sys_times(&tmp);
1064 if (copy_to_user(tbuf, &tmp, sizeof(struct tms)))
1065 return -EFAULT;
1066 }
1067 force_successful_syscall_return();
1068 return (long) jiffies_64_to_clock_t(get_jiffies_64());
1069}
1070
1071/*
1072 * This needs some heavy checking ...
1073 * I just haven't the stomach for it. I also don't fully
1074 * understand sessions/pgrp etc. Let somebody who does explain it.
1075 *
1076 * OK, I think I have the protection semantics right.... this is really
1077 * only important on a multi-user system anyway, to make sure one user
1078 * can't send a signal to a process owned by another. -TYT, 12/12/91
1079 *
1080 * Auch. Had to add the 'did_exec' flag to conform completely to POSIX.
1081 * LBT 04.03.94
1082 */
1083SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid)
1084{
1085 struct task_struct *p;
1086 struct task_struct *group_leader = current->group_leader;
1087 struct pid *pgrp;
1088 int err;
1089
1090 if (!pid)
1091 pid = task_pid_vnr(group_leader);
1092 if (!pgid)
1093 pgid = pid;
1094 if (pgid < 0)
1095 return -EINVAL;
1096 rcu_read_lock();
1097
1098 /* From this point forward we keep holding onto the tasklist lock
1099 * so that our parent does not change from under us. -DaveM
1100 */
1101 write_lock_irq(&tasklist_lock);
1102
1103 err = -ESRCH;
1104 p = find_task_by_vpid(pid);
1105 if (!p)
1106 goto out;
1107
1108 err = -EINVAL;
1109 if (!thread_group_leader(p))
1110 goto out;
1111
1112 if (same_thread_group(p->real_parent, group_leader)) {
1113 err = -EPERM;
1114 if (task_session(p) != task_session(group_leader))
1115 goto out;
1116 err = -EACCES;
1117 if (p->did_exec)
1118 goto out;
1119 } else {
1120 err = -ESRCH;
1121 if (p != group_leader)
1122 goto out;
1123 }
1124
1125 err = -EPERM;
1126 if (p->signal->leader)
1127 goto out;
1128
1129 pgrp = task_pid(p);
1130 if (pgid != pid) {
1131 struct task_struct *g;
1132
1133 pgrp = find_vpid(pgid);
1134 g = pid_task(pgrp, PIDTYPE_PGID);
1135 if (!g || task_session(g) != task_session(group_leader))
1136 goto out;
1137 }
1138
1139 err = security_task_setpgid(p, pgid);
1140 if (err)
1141 goto out;
1142
1143 if (task_pgrp(p) != pgrp)
1144 change_pid(p, PIDTYPE_PGID, pgrp);
1145
1146 err = 0;
1147out:
1148 /* All paths lead to here, thus we are safe. -DaveM */
1149 write_unlock_irq(&tasklist_lock);
1150 rcu_read_unlock();
1151 return err;
1152}
1153
1154SYSCALL_DEFINE1(getpgid, pid_t, pid)
1155{
1156 struct task_struct *p;
1157 struct pid *grp;
1158 int retval;
1159
1160 rcu_read_lock();
1161 if (!pid)
1162 grp = task_pgrp(current);
1163 else {
1164 retval = -ESRCH;
1165 p = find_task_by_vpid(pid);
1166 if (!p)
1167 goto out;
1168 grp = task_pgrp(p);
1169 if (!grp)
1170 goto out;
1171
1172 retval = security_task_getpgid(p);
1173 if (retval)
1174 goto out;
1175 }
1176 retval = pid_vnr(grp);
1177out:
1178 rcu_read_unlock();
1179 return retval;
1180}
1181
1182#ifdef __ARCH_WANT_SYS_GETPGRP
1183
1184SYSCALL_DEFINE0(getpgrp)
1185{
1186 return sys_getpgid(0);
1187}
1188
1189#endif
1190
1191SYSCALL_DEFINE1(getsid, pid_t, pid)
1192{
1193 struct task_struct *p;
1194 struct pid *sid;
1195 int retval;
1196
1197 rcu_read_lock();
1198 if (!pid)
1199 sid = task_session(current);
1200 else {
1201 retval = -ESRCH;
1202 p = find_task_by_vpid(pid);
1203 if (!p)
1204 goto out;
1205 sid = task_session(p);
1206 if (!sid)
1207 goto out;
1208
1209 retval = security_task_getsid(p);
1210 if (retval)
1211 goto out;
1212 }
1213 retval = pid_vnr(sid);
1214out:
1215 rcu_read_unlock();
1216 return retval;
1217}
1218
1219SYSCALL_DEFINE0(setsid)
1220{
1221 struct task_struct *group_leader = current->group_leader;
1222 struct pid *sid = task_pid(group_leader);
1223 pid_t session = pid_vnr(sid);
1224 int err = -EPERM;
1225
1226 write_lock_irq(&tasklist_lock);
1227 /* Fail if I am already a session leader */
1228 if (group_leader->signal->leader)
1229 goto out;
1230
1231 /* Fail if a process group id already exists that equals the
1232 * proposed session id.
1233 */
1234 if (pid_task(sid, PIDTYPE_PGID))
1235 goto out;
1236
1237 group_leader->signal->leader = 1;
1238 __set_special_pids(sid);
1239
1240 proc_clear_tty(group_leader);
1241
1242 err = session;
1243out:
1244 write_unlock_irq(&tasklist_lock);
1245 if (err > 0) {
1246 proc_sid_connector(group_leader);
1247 sched_autogroup_create_attach(group_leader);
1248 }
1249 return err;
1250}
1251
1252DECLARE_RWSEM(uts_sem);
1253
1254#ifdef COMPAT_UTS_MACHINE
1255#define override_architecture(name) \
1256 (personality(current->personality) == PER_LINUX32 && \
1257 copy_to_user(name->machine, COMPAT_UTS_MACHINE, \
1258 sizeof(COMPAT_UTS_MACHINE)))
1259#else
1260#define override_architecture(name) 0
1261#endif
1262
1263/*
1264 * Work around broken programs that cannot handle "Linux 3.0".
1265 * Instead we map 3.x to 2.6.40+x, so e.g. 3.0 would be 2.6.40
1266 */
1267static int override_release(char __user *release, int len)
1268{
1269 int ret = 0;
1270 char buf[65];
1271
1272 if (current->personality & UNAME26) {
1273 char *rest = UTS_RELEASE;
1274 int ndots = 0;
1275 unsigned v;
1276
1277 while (*rest) {
1278 if (*rest == '.' && ++ndots >= 3)
1279 break;
1280 if (!isdigit(*rest) && *rest != '.')
1281 break;
1282 rest++;
1283 }
1284 v = ((LINUX_VERSION_CODE >> 8) & 0xff) + 40;
1285 snprintf(buf, len, "2.6.%u%s", v, rest);
1286 ret = copy_to_user(release, buf, len);
1287 }
1288 return ret;
1289}
1290
1291SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name)
1292{
1293 int errno = 0;
1294
1295 down_read(&uts_sem);
1296 if (copy_to_user(name, utsname(), sizeof *name))
1297 errno = -EFAULT;
1298 up_read(&uts_sem);
1299
1300 if (!errno && override_release(name->release, sizeof(name->release)))
1301 errno = -EFAULT;
1302 if (!errno && override_architecture(name))
1303 errno = -EFAULT;
1304 return errno;
1305}
1306
1307#ifdef __ARCH_WANT_SYS_OLD_UNAME
1308/*
1309 * Old cruft
1310 */
1311SYSCALL_DEFINE1(uname, struct old_utsname __user *, name)
1312{
1313 int error = 0;
1314
1315 if (!name)
1316 return -EFAULT;
1317
1318 down_read(&uts_sem);
1319 if (copy_to_user(name, utsname(), sizeof(*name)))
1320 error = -EFAULT;
1321 up_read(&uts_sem);
1322
1323 if (!error && override_release(name->release, sizeof(name->release)))
1324 error = -EFAULT;
1325 if (!error && override_architecture(name))
1326 error = -EFAULT;
1327 return error;
1328}
1329
1330SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name)
1331{
1332 int error;
1333
1334 if (!name)
1335 return -EFAULT;
1336 if (!access_ok(VERIFY_WRITE, name, sizeof(struct oldold_utsname)))
1337 return -EFAULT;
1338
1339 down_read(&uts_sem);
1340 error = __copy_to_user(&name->sysname, &utsname()->sysname,
1341 __OLD_UTS_LEN);
1342 error |= __put_user(0, name->sysname + __OLD_UTS_LEN);
1343 error |= __copy_to_user(&name->nodename, &utsname()->nodename,
1344 __OLD_UTS_LEN);
1345 error |= __put_user(0, name->nodename + __OLD_UTS_LEN);
1346 error |= __copy_to_user(&name->release, &utsname()->release,
1347 __OLD_UTS_LEN);
1348 error |= __put_user(0, name->release + __OLD_UTS_LEN);
1349 error |= __copy_to_user(&name->version, &utsname()->version,
1350 __OLD_UTS_LEN);
1351 error |= __put_user(0, name->version + __OLD_UTS_LEN);
1352 error |= __copy_to_user(&name->machine, &utsname()->machine,
1353 __OLD_UTS_LEN);
1354 error |= __put_user(0, name->machine + __OLD_UTS_LEN);
1355 up_read(&uts_sem);
1356
1357 if (!error && override_architecture(name))
1358 error = -EFAULT;
1359 if (!error && override_release(name->release, sizeof(name->release)))
1360 error = -EFAULT;
1361 return error ? -EFAULT : 0;
1362}
1363#endif
1364
1365SYSCALL_DEFINE2(sethostname, char __user *, name, int, len)
1366{
1367 int errno;
1368 char tmp[__NEW_UTS_LEN];
1369
1370 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN))
1371 return -EPERM;
1372
1373 if (len < 0 || len > __NEW_UTS_LEN)
1374 return -EINVAL;
1375 down_write(&uts_sem);
1376 errno = -EFAULT;
1377 if (!copy_from_user(tmp, name, len)) {
1378 struct new_utsname *u = utsname();
1379
1380 memcpy(u->nodename, tmp, len);
1381 memset(u->nodename + len, 0, sizeof(u->nodename) - len);
1382 errno = 0;
1383 uts_proc_notify(UTS_PROC_HOSTNAME);
1384 }
1385 up_write(&uts_sem);
1386 return errno;
1387}
1388
1389#ifdef __ARCH_WANT_SYS_GETHOSTNAME
1390
1391SYSCALL_DEFINE2(gethostname, char __user *, name, int, len)
1392{
1393 int i, errno;
1394 struct new_utsname *u;
1395
1396 if (len < 0)
1397 return -EINVAL;
1398 down_read(&uts_sem);
1399 u = utsname();
1400 i = 1 + strlen(u->nodename);
1401 if (i > len)
1402 i = len;
1403 errno = 0;
1404 if (copy_to_user(name, u->nodename, i))
1405 errno = -EFAULT;
1406 up_read(&uts_sem);
1407 return errno;
1408}
1409
1410#endif
1411
1412/*
1413 * Only setdomainname; getdomainname can be implemented by calling
1414 * uname()
1415 */
1416SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len)
1417{
1418 int errno;
1419 char tmp[__NEW_UTS_LEN];
1420
1421 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN))
1422 return -EPERM;
1423 if (len < 0 || len > __NEW_UTS_LEN)
1424 return -EINVAL;
1425
1426 down_write(&uts_sem);
1427 errno = -EFAULT;
1428 if (!copy_from_user(tmp, name, len)) {
1429 struct new_utsname *u = utsname();
1430
1431 memcpy(u->domainname, tmp, len);
1432 memset(u->domainname + len, 0, sizeof(u->domainname) - len);
1433 errno = 0;
1434 uts_proc_notify(UTS_PROC_DOMAINNAME);
1435 }
1436 up_write(&uts_sem);
1437 return errno;
1438}
1439
1440SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim)
1441{
1442 struct rlimit value;
1443 int ret;
1444
1445 ret = do_prlimit(current, resource, NULL, &value);
1446 if (!ret)
1447 ret = copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0;
1448
1449 return ret;
1450}
1451
1452#ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT
1453
1454/*
1455 * Back compatibility for getrlimit. Needed for some apps.
1456 */
1457
1458SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
1459 struct rlimit __user *, rlim)
1460{
1461 struct rlimit x;
1462 if (resource >= RLIM_NLIMITS)
1463 return -EINVAL;
1464
1465 task_lock(current->group_leader);
1466 x = current->signal->rlim[resource];
1467 task_unlock(current->group_leader);
1468 if (x.rlim_cur > 0x7FFFFFFF)
1469 x.rlim_cur = 0x7FFFFFFF;
1470 if (x.rlim_max > 0x7FFFFFFF)
1471 x.rlim_max = 0x7FFFFFFF;
1472 return copy_to_user(rlim, &x, sizeof(x))?-EFAULT:0;
1473}
1474
1475#endif
1476
1477static inline bool rlim64_is_infinity(__u64 rlim64)
1478{
1479#if BITS_PER_LONG < 64
1480 return rlim64 >= ULONG_MAX;
1481#else
1482 return rlim64 == RLIM64_INFINITY;
1483#endif
1484}
1485
1486static void rlim_to_rlim64(const struct rlimit *rlim, struct rlimit64 *rlim64)
1487{
1488 if (rlim->rlim_cur == RLIM_INFINITY)
1489 rlim64->rlim_cur = RLIM64_INFINITY;
1490 else
1491 rlim64->rlim_cur = rlim->rlim_cur;
1492 if (rlim->rlim_max == RLIM_INFINITY)
1493 rlim64->rlim_max = RLIM64_INFINITY;
1494 else
1495 rlim64->rlim_max = rlim->rlim_max;
1496}
1497
1498static void rlim64_to_rlim(const struct rlimit64 *rlim64, struct rlimit *rlim)
1499{
1500 if (rlim64_is_infinity(rlim64->rlim_cur))
1501 rlim->rlim_cur = RLIM_INFINITY;
1502 else
1503 rlim->rlim_cur = (unsigned long)rlim64->rlim_cur;
1504 if (rlim64_is_infinity(rlim64->rlim_max))
1505 rlim->rlim_max = RLIM_INFINITY;
1506 else
1507 rlim->rlim_max = (unsigned long)rlim64->rlim_max;
1508}
1509
1510/* make sure you are allowed to change @tsk limits before calling this */
1511int do_prlimit(struct task_struct *tsk, unsigned int resource,
1512 struct rlimit *new_rlim, struct rlimit *old_rlim)
1513{
1514 struct rlimit *rlim;
1515 int retval = 0;
1516
1517 if (resource >= RLIM_NLIMITS)
1518 return -EINVAL;
1519 if (new_rlim) {
1520 if (new_rlim->rlim_cur > new_rlim->rlim_max)
1521 return -EINVAL;
1522 if (resource == RLIMIT_NOFILE &&
1523 new_rlim->rlim_max > sysctl_nr_open)
1524 return -EPERM;
1525 }
1526
1527 /* protect tsk->signal and tsk->sighand from disappearing */
1528 read_lock(&tasklist_lock);
1529 if (!tsk->sighand) {
1530 retval = -ESRCH;
1531 goto out;
1532 }
1533
1534 rlim = tsk->signal->rlim + resource;
1535 task_lock(tsk->group_leader);
1536 if (new_rlim) {
1537 /* Keep the capable check against init_user_ns until
1538 cgroups can contain all limits */
1539 if (new_rlim->rlim_max > rlim->rlim_max &&
1540 !capable(CAP_SYS_RESOURCE))
1541 retval = -EPERM;
1542 if (!retval)
1543 retval = security_task_setrlimit(tsk->group_leader,
1544 resource, new_rlim);
1545 if (resource == RLIMIT_CPU && new_rlim->rlim_cur == 0) {
1546 /*
1547 * The caller is asking for an immediate RLIMIT_CPU
1548 * expiry. But we use the zero value to mean "it was
1549 * never set". So let's cheat and make it one second
1550 * instead
1551 */
1552 new_rlim->rlim_cur = 1;
1553 }
1554 }
1555 if (!retval) {
1556 if (old_rlim)
1557 *old_rlim = *rlim;
1558 if (new_rlim)
1559 *rlim = *new_rlim;
1560 }
1561 task_unlock(tsk->group_leader);
1562
1563 /*
1564 * RLIMIT_CPU handling. Note that the kernel fails to return an error
1565 * code if it rejected the user's attempt to set RLIMIT_CPU. This is a
1566 * very long-standing error, and fixing it now risks breakage of
1567 * applications, so we live with it
1568 */
1569 if (!retval && new_rlim && resource == RLIMIT_CPU &&
1570 new_rlim->rlim_cur != RLIM_INFINITY)
1571 update_rlimit_cpu(tsk, new_rlim->rlim_cur);
1572out:
1573 read_unlock(&tasklist_lock);
1574 return retval;
1575}
1576
1577/* rcu lock must be held */
1578static int check_prlimit_permission(struct task_struct *task)
1579{
1580 const struct cred *cred = current_cred(), *tcred;
1581
1582 if (current == task)
1583 return 0;
1584
1585 tcred = __task_cred(task);
1586 if (uid_eq(cred->uid, tcred->euid) &&
1587 uid_eq(cred->uid, tcred->suid) &&
1588 uid_eq(cred->uid, tcred->uid) &&
1589 gid_eq(cred->gid, tcred->egid) &&
1590 gid_eq(cred->gid, tcred->sgid) &&
1591 gid_eq(cred->gid, tcred->gid))
1592 return 0;
1593 if (ns_capable(tcred->user_ns, CAP_SYS_RESOURCE))
1594 return 0;
1595
1596 return -EPERM;
1597}
1598
1599SYSCALL_DEFINE4(prlimit64, pid_t, pid, unsigned int, resource,
1600 const struct rlimit64 __user *, new_rlim,
1601 struct rlimit64 __user *, old_rlim)
1602{
1603 struct rlimit64 old64, new64;
1604 struct rlimit old, new;
1605 struct task_struct *tsk;
1606 int ret;
1607
1608 if (new_rlim) {
1609 if (copy_from_user(&new64, new_rlim, sizeof(new64)))
1610 return -EFAULT;
1611 rlim64_to_rlim(&new64, &new);
1612 }
1613
1614 rcu_read_lock();
1615 tsk = pid ? find_task_by_vpid(pid) : current;
1616 if (!tsk) {
1617 rcu_read_unlock();
1618 return -ESRCH;
1619 }
1620 ret = check_prlimit_permission(tsk);
1621 if (ret) {
1622 rcu_read_unlock();
1623 return ret;
1624 }
1625 get_task_struct(tsk);
1626 rcu_read_unlock();
1627
1628 ret = do_prlimit(tsk, resource, new_rlim ? &new : NULL,
1629 old_rlim ? &old : NULL);
1630
1631 if (!ret && old_rlim) {
1632 rlim_to_rlim64(&old, &old64);
1633 if (copy_to_user(old_rlim, &old64, sizeof(old64)))
1634 ret = -EFAULT;
1635 }
1636
1637 put_task_struct(tsk);
1638 return ret;
1639}
1640
1641SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim)
1642{
1643 struct rlimit new_rlim;
1644
1645 if (copy_from_user(&new_rlim, rlim, sizeof(*rlim)))
1646 return -EFAULT;
1647 return do_prlimit(current, resource, &new_rlim, NULL);
1648}
1649
1650/*
1651 * It would make sense to put struct rusage in the task_struct,
1652 * except that would make the task_struct be *really big*. After
1653 * task_struct gets moved into malloc'ed memory, it would
1654 * make sense to do this. It will make moving the rest of the information
1655 * a lot simpler! (Which we're not doing right now because we're not
1656 * measuring them yet).
1657 *
1658 * When sampling multiple threads for RUSAGE_SELF, under SMP we might have
1659 * races with threads incrementing their own counters. But since word
1660 * reads are atomic, we either get new values or old values and we don't
1661 * care which for the sums. We always take the siglock to protect reading
1662 * the c* fields from p->signal from races with exit.c updating those
1663 * fields when reaping, so a sample either gets all the additions of a
1664 * given child after it's reaped, or none so this sample is before reaping.
1665 *
1666 * Locking:
1667 * We need to take the siglock for CHILDEREN, SELF and BOTH
1668 * for the cases current multithreaded, non-current single threaded
1669 * non-current multithreaded. Thread traversal is now safe with
1670 * the siglock held.
1671 * Strictly speaking, we donot need to take the siglock if we are current and
1672 * single threaded, as no one else can take our signal_struct away, no one
1673 * else can reap the children to update signal->c* counters, and no one else
1674 * can race with the signal-> fields. If we do not take any lock, the
1675 * signal-> fields could be read out of order while another thread was just
1676 * exiting. So we should place a read memory barrier when we avoid the lock.
1677 * On the writer side, write memory barrier is implied in __exit_signal
1678 * as __exit_signal releases the siglock spinlock after updating the signal->
1679 * fields. But we don't do this yet to keep things simple.
1680 *
1681 */
1682
1683static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r)
1684{
1685 r->ru_nvcsw += t->nvcsw;
1686 r->ru_nivcsw += t->nivcsw;
1687 r->ru_minflt += t->min_flt;
1688 r->ru_majflt += t->maj_flt;
1689 r->ru_inblock += task_io_get_inblock(t);
1690 r->ru_oublock += task_io_get_oublock(t);
1691}
1692
1693static void k_getrusage(struct task_struct *p, int who, struct rusage *r)
1694{
1695 struct task_struct *t;
1696 unsigned long flags;
1697 cputime_t tgutime, tgstime, utime, stime;
1698 unsigned long maxrss = 0;
1699
1700 memset((char *) r, 0, sizeof *r);
1701 utime = stime = 0;
1702
1703 if (who == RUSAGE_THREAD) {
1704 task_times(current, &utime, &stime);
1705 accumulate_thread_rusage(p, r);
1706 maxrss = p->signal->maxrss;
1707 goto out;
1708 }
1709
1710 if (!lock_task_sighand(p, &flags))
1711 return;
1712
1713 switch (who) {
1714 case RUSAGE_BOTH:
1715 case RUSAGE_CHILDREN:
1716 utime = p->signal->cutime;
1717 stime = p->signal->cstime;
1718 r->ru_nvcsw = p->signal->cnvcsw;
1719 r->ru_nivcsw = p->signal->cnivcsw;
1720 r->ru_minflt = p->signal->cmin_flt;
1721 r->ru_majflt = p->signal->cmaj_flt;
1722 r->ru_inblock = p->signal->cinblock;
1723 r->ru_oublock = p->signal->coublock;
1724 maxrss = p->signal->cmaxrss;
1725
1726 if (who == RUSAGE_CHILDREN)
1727 break;
1728
1729 case RUSAGE_SELF:
1730 thread_group_times(p, &tgutime, &tgstime);
1731 utime += tgutime;
1732 stime += tgstime;
1733 r->ru_nvcsw += p->signal->nvcsw;
1734 r->ru_nivcsw += p->signal->nivcsw;
1735 r->ru_minflt += p->signal->min_flt;
1736 r->ru_majflt += p->signal->maj_flt;
1737 r->ru_inblock += p->signal->inblock;
1738 r->ru_oublock += p->signal->oublock;
1739 if (maxrss < p->signal->maxrss)
1740 maxrss = p->signal->maxrss;
1741 t = p;
1742 do {
1743 accumulate_thread_rusage(t, r);
1744 t = next_thread(t);
1745 } while (t != p);
1746 break;
1747
1748 default:
1749 BUG();
1750 }
1751 unlock_task_sighand(p, &flags);
1752
1753out:
1754 cputime_to_timeval(utime, &r->ru_utime);
1755 cputime_to_timeval(stime, &r->ru_stime);
1756
1757 if (who != RUSAGE_CHILDREN) {
1758 struct mm_struct *mm = get_task_mm(p);
1759 if (mm) {
1760 setmax_mm_hiwater_rss(&maxrss, mm);
1761 mmput(mm);
1762 }
1763 }
1764 r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */
1765}
1766
1767int getrusage(struct task_struct *p, int who, struct rusage __user *ru)
1768{
1769 struct rusage r;
1770 k_getrusage(p, who, &r);
1771 return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0;
1772}
1773
1774SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru)
1775{
1776 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
1777 who != RUSAGE_THREAD)
1778 return -EINVAL;
1779 return getrusage(current, who, ru);
1780}
1781
1782SYSCALL_DEFINE1(umask, int, mask)
1783{
1784 mask = xchg(¤t->fs->umask, mask & S_IRWXUGO);
1785 return mask;
1786}
1787
1788#ifdef CONFIG_CHECKPOINT_RESTORE
1789static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd)
1790{
1791 struct file *exe_file;
1792 struct dentry *dentry;
1793 int err;
1794
1795 exe_file = fget(fd);
1796 if (!exe_file)
1797 return -EBADF;
1798
1799 dentry = exe_file->f_path.dentry;
1800
1801 /*
1802 * Because the original mm->exe_file points to executable file, make
1803 * sure that this one is executable as well, to avoid breaking an
1804 * overall picture.
1805 */
1806 err = -EACCES;
1807 if (!S_ISREG(dentry->d_inode->i_mode) ||
1808 exe_file->f_path.mnt->mnt_flags & MNT_NOEXEC)
1809 goto exit;
1810
1811 err = inode_permission(dentry->d_inode, MAY_EXEC);
1812 if (err)
1813 goto exit;
1814
1815 down_write(&mm->mmap_sem);
1816
1817 /*
1818 * Forbid mm->exe_file change if old file still mapped.
1819 */
1820 err = -EBUSY;
1821 if (mm->exe_file) {
1822 struct vm_area_struct *vma;
1823
1824 for (vma = mm->mmap; vma; vma = vma->vm_next)
1825 if (vma->vm_file &&
1826 path_equal(&vma->vm_file->f_path,
1827 &mm->exe_file->f_path))
1828 goto exit_unlock;
1829 }
1830
1831 /*
1832 * The symlink can be changed only once, just to disallow arbitrary
1833 * transitions malicious software might bring in. This means one
1834 * could make a snapshot over all processes running and monitor
1835 * /proc/pid/exe changes to notice unusual activity if needed.
1836 */
1837 err = -EPERM;
1838 if (test_and_set_bit(MMF_EXE_FILE_CHANGED, &mm->flags))
1839 goto exit_unlock;
1840
1841 err = 0;
1842 set_mm_exe_file(mm, exe_file);
1843exit_unlock:
1844 up_write(&mm->mmap_sem);
1845
1846exit:
1847 fput(exe_file);
1848 return err;
1849}
1850
1851static int prctl_set_mm(int opt, unsigned long addr,
1852 unsigned long arg4, unsigned long arg5)
1853{
1854 unsigned long rlim = rlimit(RLIMIT_DATA);
1855 struct mm_struct *mm = current->mm;
1856 struct vm_area_struct *vma;
1857 int error;
1858
1859 if (arg5 || (arg4 && opt != PR_SET_MM_AUXV))
1860 return -EINVAL;
1861
1862 if (!capable(CAP_SYS_RESOURCE))
1863 return -EPERM;
1864
1865 if (opt == PR_SET_MM_EXE_FILE)
1866 return prctl_set_mm_exe_file(mm, (unsigned int)addr);
1867
1868 if (addr >= TASK_SIZE || addr < mmap_min_addr)
1869 return -EINVAL;
1870
1871 error = -EINVAL;
1872
1873 down_read(&mm->mmap_sem);
1874 vma = find_vma(mm, addr);
1875
1876 switch (opt) {
1877 case PR_SET_MM_START_CODE:
1878 mm->start_code = addr;
1879 break;
1880 case PR_SET_MM_END_CODE:
1881 mm->end_code = addr;
1882 break;
1883 case PR_SET_MM_START_DATA:
1884 mm->start_data = addr;
1885 break;
1886 case PR_SET_MM_END_DATA:
1887 mm->end_data = addr;
1888 break;
1889
1890 case PR_SET_MM_START_BRK:
1891 if (addr <= mm->end_data)
1892 goto out;
1893
1894 if (rlim < RLIM_INFINITY &&
1895 (mm->brk - addr) +
1896 (mm->end_data - mm->start_data) > rlim)
1897 goto out;
1898
1899 mm->start_brk = addr;
1900 break;
1901
1902 case PR_SET_MM_BRK:
1903 if (addr <= mm->end_data)
1904 goto out;
1905
1906 if (rlim < RLIM_INFINITY &&
1907 (addr - mm->start_brk) +
1908 (mm->end_data - mm->start_data) > rlim)
1909 goto out;
1910
1911 mm->brk = addr;
1912 break;
1913
1914 /*
1915 * If command line arguments and environment
1916 * are placed somewhere else on stack, we can
1917 * set them up here, ARG_START/END to setup
1918 * command line argumets and ENV_START/END
1919 * for environment.
1920 */
1921 case PR_SET_MM_START_STACK:
1922 case PR_SET_MM_ARG_START:
1923 case PR_SET_MM_ARG_END:
1924 case PR_SET_MM_ENV_START:
1925 case PR_SET_MM_ENV_END:
1926 if (!vma) {
1927 error = -EFAULT;
1928 goto out;
1929 }
1930 if (opt == PR_SET_MM_START_STACK)
1931 mm->start_stack = addr;
1932 else if (opt == PR_SET_MM_ARG_START)
1933 mm->arg_start = addr;
1934 else if (opt == PR_SET_MM_ARG_END)
1935 mm->arg_end = addr;
1936 else if (opt == PR_SET_MM_ENV_START)
1937 mm->env_start = addr;
1938 else if (opt == PR_SET_MM_ENV_END)
1939 mm->env_end = addr;
1940 break;
1941
1942 /*
1943 * This doesn't move auxiliary vector itself
1944 * since it's pinned to mm_struct, but allow
1945 * to fill vector with new values. It's up
1946 * to a caller to provide sane values here
1947 * otherwise user space tools which use this
1948 * vector might be unhappy.
1949 */
1950 case PR_SET_MM_AUXV: {
1951 unsigned long user_auxv[AT_VECTOR_SIZE];
1952
1953 if (arg4 > sizeof(user_auxv))
1954 goto out;
1955 up_read(&mm->mmap_sem);
1956
1957 if (copy_from_user(user_auxv, (const void __user *)addr, arg4))
1958 return -EFAULT;
1959
1960 /* Make sure the last entry is always AT_NULL */
1961 user_auxv[AT_VECTOR_SIZE - 2] = 0;
1962 user_auxv[AT_VECTOR_SIZE - 1] = 0;
1963
1964 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv));
1965
1966 task_lock(current);
1967 memcpy(mm->saved_auxv, user_auxv, arg4);
1968 task_unlock(current);
1969
1970 return 0;
1971 }
1972 default:
1973 goto out;
1974 }
1975
1976 error = 0;
1977out:
1978 up_read(&mm->mmap_sem);
1979 return error;
1980}
1981
1982static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr)
1983{
1984 return put_user(me->clear_child_tid, tid_addr);
1985}
1986
1987#else /* CONFIG_CHECKPOINT_RESTORE */
1988static int prctl_set_mm(int opt, unsigned long addr,
1989 unsigned long arg4, unsigned long arg5)
1990{
1991 return -EINVAL;
1992}
1993static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr)
1994{
1995 return -EINVAL;
1996}
1997#endif
1998
1999SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
2000 unsigned long, arg4, unsigned long, arg5)
2001{
2002 struct task_struct *me = current;
2003 unsigned char comm[sizeof(me->comm)];
2004 long error;
2005
2006 error = security_task_prctl(option, arg2, arg3, arg4, arg5);
2007 if (error != -ENOSYS)
2008 return error;
2009
2010 error = 0;
2011 switch (option) {
2012 case PR_SET_PDEATHSIG:
2013 if (!valid_signal(arg2)) {
2014 error = -EINVAL;
2015 break;
2016 }
2017 me->pdeath_signal = arg2;
2018 error = 0;
2019 break;
2020 case PR_GET_PDEATHSIG:
2021 error = put_user(me->pdeath_signal, (int __user *)arg2);
2022 break;
2023 case PR_GET_DUMPABLE:
2024 error = get_dumpable(me->mm);
2025 break;
2026 case PR_SET_DUMPABLE:
2027 if (arg2 < 0 || arg2 > 1) {
2028 error = -EINVAL;
2029 break;
2030 }
2031 set_dumpable(me->mm, arg2);
2032 error = 0;
2033 break;
2034
2035 case PR_SET_UNALIGN:
2036 error = SET_UNALIGN_CTL(me, arg2);
2037 break;
2038 case PR_GET_UNALIGN:
2039 error = GET_UNALIGN_CTL(me, arg2);
2040 break;
2041 case PR_SET_FPEMU:
2042 error = SET_FPEMU_CTL(me, arg2);
2043 break;
2044 case PR_GET_FPEMU:
2045 error = GET_FPEMU_CTL(me, arg2);
2046 break;
2047 case PR_SET_FPEXC:
2048 error = SET_FPEXC_CTL(me, arg2);
2049 break;
2050 case PR_GET_FPEXC:
2051 error = GET_FPEXC_CTL(me, arg2);
2052 break;
2053 case PR_GET_TIMING:
2054 error = PR_TIMING_STATISTICAL;
2055 break;
2056 case PR_SET_TIMING:
2057 if (arg2 != PR_TIMING_STATISTICAL)
2058 error = -EINVAL;
2059 else
2060 error = 0;
2061 break;
2062
2063 case PR_SET_NAME:
2064 comm[sizeof(me->comm)-1] = 0;
2065 if (strncpy_from_user(comm, (char __user *)arg2,
2066 sizeof(me->comm) - 1) < 0)
2067 return -EFAULT;
2068 set_task_comm(me, comm);
2069 proc_comm_connector(me);
2070 return 0;
2071 case PR_GET_NAME:
2072 get_task_comm(comm, me);
2073 if (copy_to_user((char __user *)arg2, comm,
2074 sizeof(comm)))
2075 return -EFAULT;
2076 return 0;
2077 case PR_GET_ENDIAN:
2078 error = GET_ENDIAN(me, arg2);
2079 break;
2080 case PR_SET_ENDIAN:
2081 error = SET_ENDIAN(me, arg2);
2082 break;
2083
2084 case PR_GET_SECCOMP:
2085 error = prctl_get_seccomp();
2086 break;
2087 case PR_SET_SECCOMP:
2088 error = prctl_set_seccomp(arg2, (char __user *)arg3);
2089 break;
2090 case PR_GET_TSC:
2091 error = GET_TSC_CTL(arg2);
2092 break;
2093 case PR_SET_TSC:
2094 error = SET_TSC_CTL(arg2);
2095 break;
2096 case PR_TASK_PERF_EVENTS_DISABLE:
2097 error = perf_event_task_disable();
2098 break;
2099 case PR_TASK_PERF_EVENTS_ENABLE:
2100 error = perf_event_task_enable();
2101 break;
2102 case PR_GET_TIMERSLACK:
2103 error = current->timer_slack_ns;
2104 break;
2105 case PR_SET_TIMERSLACK:
2106 if (arg2 <= 0)
2107 current->timer_slack_ns =
2108 current->default_timer_slack_ns;
2109 else
2110 current->timer_slack_ns = arg2;
2111 error = 0;
2112 break;
2113 case PR_MCE_KILL:
2114 if (arg4 | arg5)
2115 return -EINVAL;
2116 switch (arg2) {
2117 case PR_MCE_KILL_CLEAR:
2118 if (arg3 != 0)
2119 return -EINVAL;
2120 current->flags &= ~PF_MCE_PROCESS;
2121 break;
2122 case PR_MCE_KILL_SET:
2123 current->flags |= PF_MCE_PROCESS;
2124 if (arg3 == PR_MCE_KILL_EARLY)
2125 current->flags |= PF_MCE_EARLY;
2126 else if (arg3 == PR_MCE_KILL_LATE)
2127 current->flags &= ~PF_MCE_EARLY;
2128 else if (arg3 == PR_MCE_KILL_DEFAULT)
2129 current->flags &=
2130 ~(PF_MCE_EARLY|PF_MCE_PROCESS);
2131 else
2132 return -EINVAL;
2133 break;
2134 default:
2135 return -EINVAL;
2136 }
2137 error = 0;
2138 break;
2139 case PR_MCE_KILL_GET:
2140 if (arg2 | arg3 | arg4 | arg5)
2141 return -EINVAL;
2142 if (current->flags & PF_MCE_PROCESS)
2143 error = (current->flags & PF_MCE_EARLY) ?
2144 PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE;
2145 else
2146 error = PR_MCE_KILL_DEFAULT;
2147 break;
2148 case PR_SET_MM:
2149 error = prctl_set_mm(arg2, arg3, arg4, arg5);
2150 break;
2151 case PR_GET_TID_ADDRESS:
2152 error = prctl_get_tid_address(me, (int __user **)arg2);
2153 break;
2154 case PR_SET_CHILD_SUBREAPER:
2155 me->signal->is_child_subreaper = !!arg2;
2156 error = 0;
2157 break;
2158 case PR_GET_CHILD_SUBREAPER:
2159 error = put_user(me->signal->is_child_subreaper,
2160 (int __user *) arg2);
2161 break;
2162 case PR_SET_NO_NEW_PRIVS:
2163 if (arg2 != 1 || arg3 || arg4 || arg5)
2164 return -EINVAL;
2165
2166 current->no_new_privs = 1;
2167 break;
2168 case PR_GET_NO_NEW_PRIVS:
2169 if (arg2 || arg3 || arg4 || arg5)
2170 return -EINVAL;
2171 return current->no_new_privs ? 1 : 0;
2172 default:
2173 error = -EINVAL;
2174 break;
2175 }
2176 return error;
2177}
2178
2179SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep,
2180 struct getcpu_cache __user *, unused)
2181{
2182 int err = 0;
2183 int cpu = raw_smp_processor_id();
2184 if (cpup)
2185 err |= put_user(cpu, cpup);
2186 if (nodep)
2187 err |= put_user(cpu_to_node(cpu), nodep);
2188 return err ? -EFAULT : 0;
2189}
2190
2191char poweroff_cmd[POWEROFF_CMD_PATH_LEN] = "/sbin/poweroff";
2192
2193static void argv_cleanup(struct subprocess_info *info)
2194{
2195 argv_free(info->argv);
2196}
2197
2198/**
2199 * orderly_poweroff - Trigger an orderly system poweroff
2200 * @force: force poweroff if command execution fails
2201 *
2202 * This may be called from any context to trigger a system shutdown.
2203 * If the orderly shutdown fails, it will force an immediate shutdown.
2204 */
2205int orderly_poweroff(bool force)
2206{
2207 int argc;
2208 char **argv = argv_split(GFP_ATOMIC, poweroff_cmd, &argc);
2209 static char *envp[] = {
2210 "HOME=/",
2211 "PATH=/sbin:/bin:/usr/sbin:/usr/bin",
2212 NULL
2213 };
2214 int ret = -ENOMEM;
2215
2216 if (argv == NULL) {
2217 printk(KERN_WARNING "%s failed to allocate memory for \"%s\"\n",
2218 __func__, poweroff_cmd);
2219 goto out;
2220 }
2221
2222 ret = call_usermodehelper_fns(argv[0], argv, envp, UMH_NO_WAIT,
2223 NULL, argv_cleanup, NULL);
2224out:
2225 if (likely(!ret))
2226 return 0;
2227
2228 if (ret == -ENOMEM)
2229 argv_free(argv);
2230
2231 if (force) {
2232 printk(KERN_WARNING "Failed to start orderly shutdown: "
2233 "forcing the issue\n");
2234
2235 /* I guess this should try to kick off some daemon to
2236 sync and poweroff asap. Or not even bother syncing
2237 if we're doing an emergency shutdown? */
2238 emergency_sync();
2239 kernel_power_off();
2240 }
2241
2242 return ret;
2243}
2244EXPORT_SYMBOL_GPL(orderly_poweroff);