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