projects/linux·blob v4.12-rc4 · refs

2460 lines · 58.2 KiB

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