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decnet: always not take dst->__refcnt when inserting dst into hash table
[linux/fpc-iii.git] / kernel / sys.c
blob7ff6d1b10cecac8e66583f3bc233fd6fcb445b5c
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
119 int overflowuid = DEFAULT_OVERFLOWUID;
120 int overflowgid = DEFAULT_OVERFLOWGID;
121
122 EXPORT_SYMBOL(overflowuid);
123 EXPORT_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
130 int fs_overflowuid = DEFAULT_FS_OVERFLOWUID;
131 int fs_overflowgid = DEFAULT_FS_OVERFLOWUID;
132
133 EXPORT_SYMBOL(fs_overflowuid);
134 EXPORT_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 */
142 static 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 */
158 static 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);
178 out:
179 return error;
180 }
181
182 SYSCALL_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 }
239 out_unlock:
240 read_unlock(&tasklist_lock);
241 rcu_read_unlock();
242 out:
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 */
252 SYSCALL_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 }
310 out_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
336 SYSCALL_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
383 error:
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 */
393 SYSCALL_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
420 error:
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 */
428 static 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 */
469 SYSCALL_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
524 error:
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 */
540 SYSCALL_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
577 error:
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 */
587 SYSCALL_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
647 error:
648 abort_creds(new);
649 return retval;
650 }
651
652 SYSCALL_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 */
674 SYSCALL_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
721 error:
722 abort_creds(new);
723 return retval;
724 }
725
726 SYSCALL_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 */
753 SYSCALL_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
784 change_okay:
785 commit_creds(new);
786 return old_fsuid;
787 }
788
789 /*
790 * Samma på svenska..
791 */
792 SYSCALL_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
822 change_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 */
837 SYSCALL_DEFINE0(getpid)
838 {
839 return task_tgid_vnr(current);
840 }
841
842 /* Thread ID - the internal kernel "pid" */
843 SYSCALL_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 */
854 SYSCALL_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
865 SYSCALL_DEFINE0(getuid)
866 {
867 /* Only we change this so SMP safe */
868 return from_kuid_munged(current_user_ns(), current_uid());
869 }
870
871 SYSCALL_DEFINE0(geteuid)
872 {
873 /* Only we change this so SMP safe */
874 return from_kuid_munged(current_user_ns(), current_euid());
875 }
876
877 SYSCALL_DEFINE0(getgid)
878 {
879 /* Only we change this so SMP safe */
880 return from_kgid_munged(current_user_ns(), current_gid());
881 }
882
883 SYSCALL_DEFINE0(getegid)
884 {
885 /* Only we change this so SMP safe */
886 return from_kgid_munged(current_user_ns(), current_egid());
887 }
888
889 void 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
902 SYSCALL_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 */
926 SYSCALL_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;
990 out:
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
997 SYSCALL_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);
1020 out:
1021 rcu_read_unlock();
1022 return retval;
1023 }
1024
1025 #ifdef __ARCH_WANT_SYS_GETPGRP
1026
1027 SYSCALL_DEFINE0(getpgrp)
1028 {
1029 return sys_getpgid(0);
1030 }
1031
1032 #endif
1033
1034 SYSCALL_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);
1057 out:
1058 rcu_read_unlock();
1059 return retval;
1060 }
1061
1062 static 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
1073 SYSCALL_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;
1097 out:
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
1106 DECLARE_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 */
1122 static 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
1148 SYSCALL_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 */
1168 SYSCALL_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
1187 SYSCALL_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
1222 SYSCALL_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
1248 SYSCALL_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 */
1273 SYSCALL_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
1297 SYSCALL_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 */
1314 SYSCALL_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
1333 static 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
1342 static 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
1354 static 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 */
1367 int 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->group_leader,
1400 resource, new_rlim);
1401 if (resource == RLIMIT_CPU && new_rlim->rlim_cur == 0) {
1402 /*
1403 * The caller is asking for an immediate RLIMIT_CPU
1404 * expiry. But we use the zero value to mean "it was
1405 * never set". So let's cheat and make it one second
1406 * instead
1407 */
1408 new_rlim->rlim_cur = 1;
1409 }
1410 }
1411 if (!retval) {
1412 if (old_rlim)
1413 *old_rlim = *rlim;
1414 if (new_rlim)
1415 *rlim = *new_rlim;
1416 }
1417 task_unlock(tsk->group_leader);
1418
1419 /*
1420 * RLIMIT_CPU handling. Note that the kernel fails to return an error
1421 * code if it rejected the user's attempt to set RLIMIT_CPU. This is a
1422 * very long-standing error, and fixing it now risks breakage of
1423 * applications, so we live with it
1424 */
1425 if (!retval && new_rlim && resource == RLIMIT_CPU &&
1426 new_rlim->rlim_cur != RLIM_INFINITY &&
1427 IS_ENABLED(CONFIG_POSIX_TIMERS))
1428 update_rlimit_cpu(tsk, new_rlim->rlim_cur);
1429 out:
1430 read_unlock(&tasklist_lock);
1431 return retval;
1432 }
1433
1434 /* rcu lock must be held */
1435 static int check_prlimit_permission(struct task_struct *task)
1436 {
1437 const struct cred *cred = current_cred(), *tcred;
1438
1439 if (current == task)
1440 return 0;
1441
1442 tcred = __task_cred(task);
1443 if (uid_eq(cred->uid, tcred->euid) &&
1444 uid_eq(cred->uid, tcred->suid) &&
1445 uid_eq(cred->uid, tcred->uid) &&
1446 gid_eq(cred->gid, tcred->egid) &&
1447 gid_eq(cred->gid, tcred->sgid) &&
1448 gid_eq(cred->gid, tcred->gid))
1449 return 0;
1450 if (ns_capable(tcred->user_ns, CAP_SYS_RESOURCE))
1451 return 0;
1452
1453 return -EPERM;
1454 }
1455
1456 SYSCALL_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 int ret;
1464
1465 if (new_rlim) {
1466 if (copy_from_user(&new64, new_rlim, sizeof(new64)))
1467 return -EFAULT;
1468 rlim64_to_rlim(&new64, &new);
1469 }
1470
1471 rcu_read_lock();
1472 tsk = pid ? find_task_by_vpid(pid) : current;
1473 if (!tsk) {
1474 rcu_read_unlock();
1475 return -ESRCH;
1476 }
1477 ret = check_prlimit_permission(tsk);
1478 if (ret) {
1479 rcu_read_unlock();
1480 return ret;
1481 }
1482 get_task_struct(tsk);
1483 rcu_read_unlock();
1484
1485 ret = do_prlimit(tsk, resource, new_rlim ? &new : NULL,
1486 old_rlim ? &old : NULL);
1487
1488 if (!ret && old_rlim) {
1489 rlim_to_rlim64(&old, &old64);
1490 if (copy_to_user(old_rlim, &old64, sizeof(old64)))
1491 ret = -EFAULT;
1492 }
1493
1494 put_task_struct(tsk);
1495 return ret;
1496 }
1497
1498 SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim)
1499 {
1500 struct rlimit new_rlim;
1501
1502 if (copy_from_user(&new_rlim, rlim, sizeof(*rlim)))
1503 return -EFAULT;
1504 return do_prlimit(current, resource, &new_rlim, NULL);
1505 }
1506
1507 /*
1508 * It would make sense to put struct rusage in the task_struct,
1509 * except that would make the task_struct be *really big*. After
1510 * task_struct gets moved into malloc'ed memory, it would
1511 * make sense to do this. It will make moving the rest of the information
1512 * a lot simpler! (Which we're not doing right now because we're not
1513 * measuring them yet).
1514 *
1515 * When sampling multiple threads for RUSAGE_SELF, under SMP we might have
1516 * races with threads incrementing their own counters. But since word
1517 * reads are atomic, we either get new values or old values and we don't
1518 * care which for the sums. We always take the siglock to protect reading
1519 * the c* fields from p->signal from races with exit.c updating those
1520 * fields when reaping, so a sample either gets all the additions of a
1521 * given child after it's reaped, or none so this sample is before reaping.
1522 *
1523 * Locking:
1524 * We need to take the siglock for CHILDEREN, SELF and BOTH
1525 * for the cases current multithreaded, non-current single threaded
1526 * non-current multithreaded. Thread traversal is now safe with
1527 * the siglock held.
1528 * Strictly speaking, we donot need to take the siglock if we are current and
1529 * single threaded, as no one else can take our signal_struct away, no one
1530 * else can reap the children to update signal->c* counters, and no one else
1531 * can race with the signal-> fields. If we do not take any lock, the
1532 * signal-> fields could be read out of order while another thread was just
1533 * exiting. So we should place a read memory barrier when we avoid the lock.
1534 * On the writer side, write memory barrier is implied in __exit_signal
1535 * as __exit_signal releases the siglock spinlock after updating the signal->
1536 * fields. But we don't do this yet to keep things simple.
1537 *
1538 */
1539
1540 static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r)
1541 {
1542 r->ru_nvcsw += t->nvcsw;
1543 r->ru_nivcsw += t->nivcsw;
1544 r->ru_minflt += t->min_flt;
1545 r->ru_majflt += t->maj_flt;
1546 r->ru_inblock += task_io_get_inblock(t);
1547 r->ru_oublock += task_io_get_oublock(t);
1548 }
1549
1550 static void k_getrusage(struct task_struct *p, int who, struct rusage *r)
1551 {
1552 struct task_struct *t;
1553 unsigned long flags;
1554 u64 tgutime, tgstime, utime, stime;
1555 unsigned long maxrss = 0;
1556
1557 memset((char *)r, 0, sizeof (*r));
1558 utime = stime = 0;
1559
1560 if (who == RUSAGE_THREAD) {
1561 task_cputime_adjusted(current, &utime, &stime);
1562 accumulate_thread_rusage(p, r);
1563 maxrss = p->signal->maxrss;
1564 goto out;
1565 }
1566
1567 if (!lock_task_sighand(p, &flags))
1568 return;
1569
1570 switch (who) {
1571 case RUSAGE_BOTH:
1572 case RUSAGE_CHILDREN:
1573 utime = p->signal->cutime;
1574 stime = p->signal->cstime;
1575 r->ru_nvcsw = p->signal->cnvcsw;
1576 r->ru_nivcsw = p->signal->cnivcsw;
1577 r->ru_minflt = p->signal->cmin_flt;
1578 r->ru_majflt = p->signal->cmaj_flt;
1579 r->ru_inblock = p->signal->cinblock;
1580 r->ru_oublock = p->signal->coublock;
1581 maxrss = p->signal->cmaxrss;
1582
1583 if (who == RUSAGE_CHILDREN)
1584 break;
1585
1586 case RUSAGE_SELF:
1587 thread_group_cputime_adjusted(p, &tgutime, &tgstime);
1588 utime += tgutime;
1589 stime += tgstime;
1590 r->ru_nvcsw += p->signal->nvcsw;
1591 r->ru_nivcsw += p->signal->nivcsw;
1592 r->ru_minflt += p->signal->min_flt;
1593 r->ru_majflt += p->signal->maj_flt;
1594 r->ru_inblock += p->signal->inblock;
1595 r->ru_oublock += p->signal->oublock;
1596 if (maxrss < p->signal->maxrss)
1597 maxrss = p->signal->maxrss;
1598 t = p;
1599 do {
1600 accumulate_thread_rusage(t, r);
1601 } while_each_thread(p, t);
1602 break;
1603
1604 default:
1605 BUG();
1606 }
1607 unlock_task_sighand(p, &flags);
1608
1609 out:
1610 r->ru_utime = ns_to_timeval(utime);
1611 r->ru_stime = ns_to_timeval(stime);
1612
1613 if (who != RUSAGE_CHILDREN) {
1614 struct mm_struct *mm = get_task_mm(p);
1615
1616 if (mm) {
1617 setmax_mm_hiwater_rss(&maxrss, mm);
1618 mmput(mm);
1619 }
1620 }
1621 r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */
1622 }
1623
1624 int getrusage(struct task_struct *p, int who, struct rusage __user *ru)
1625 {
1626 struct rusage r;
1627
1628 k_getrusage(p, who, &r);
1629 return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0;
1630 }
1631
1632 SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru)
1633 {
1634 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
1635 who != RUSAGE_THREAD)
1636 return -EINVAL;
1637 return getrusage(current, who, ru);
1638 }
1639
1640 #ifdef CONFIG_COMPAT
1641 COMPAT_SYSCALL_DEFINE2(getrusage, int, who, struct compat_rusage __user *, ru)
1642 {
1643 struct rusage r;
1644
1645 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
1646 who != RUSAGE_THREAD)
1647 return -EINVAL;
1648
1649 k_getrusage(current, who, &r);
1650 return put_compat_rusage(&r, ru);
1651 }
1652 #endif
1653
1654 SYSCALL_DEFINE1(umask, int, mask)
1655 {
1656 mask = xchg(&current->fs->umask, mask & S_IRWXUGO);
1657 return mask;
1658 }
1659
1660 static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd)
1661 {
1662 struct fd exe;
1663 struct file *old_exe, *exe_file;
1664 struct inode *inode;
1665 int err;
1666
1667 exe = fdget(fd);
1668 if (!exe.file)
1669 return -EBADF;
1670
1671 inode = file_inode(exe.file);
1672
1673 /*
1674 * Because the original mm->exe_file points to executable file, make
1675 * sure that this one is executable as well, to avoid breaking an
1676 * overall picture.
1677 */
1678 err = -EACCES;
1679 if (!S_ISREG(inode->i_mode) || path_noexec(&exe.file->f_path))
1680 goto exit;
1681
1682 err = inode_permission(inode, MAY_EXEC);
1683 if (err)
1684 goto exit;
1685
1686 /*
1687 * Forbid mm->exe_file change if old file still mapped.
1688 */
1689 exe_file = get_mm_exe_file(mm);
1690 err = -EBUSY;
1691 if (exe_file) {
1692 struct vm_area_struct *vma;
1693
1694 down_read(&mm->mmap_sem);
1695 for (vma = mm->mmap; vma; vma = vma->vm_next) {
1696 if (!vma->vm_file)
1697 continue;
1698 if (path_equal(&vma->vm_file->f_path,
1699 &exe_file->f_path))
1700 goto exit_err;
1701 }
1702
1703 up_read(&mm->mmap_sem);
1704 fput(exe_file);
1705 }
1706
1707 err = 0;
1708 /* set the new file, lockless */
1709 get_file(exe.file);
1710 old_exe = xchg(&mm->exe_file, exe.file);
1711 if (old_exe)
1712 fput(old_exe);
1713 exit:
1714 fdput(exe);
1715 return err;
1716 exit_err:
1717 up_read(&mm->mmap_sem);
1718 fput(exe_file);
1719 goto exit;
1720 }
1721
1722 /*
1723 * WARNING: we don't require any capability here so be very careful
1724 * in what is allowed for modification from userspace.
1725 */
1726 static int validate_prctl_map(struct prctl_mm_map *prctl_map)
1727 {
1728 unsigned long mmap_max_addr = TASK_SIZE;
1729 struct mm_struct *mm = current->mm;
1730 int error = -EINVAL, i;
1731
1732 static const unsigned char offsets[] = {
1733 offsetof(struct prctl_mm_map, start_code),
1734 offsetof(struct prctl_mm_map, end_code),
1735 offsetof(struct prctl_mm_map, start_data),
1736 offsetof(struct prctl_mm_map, end_data),
1737 offsetof(struct prctl_mm_map, start_brk),
1738 offsetof(struct prctl_mm_map, brk),
1739 offsetof(struct prctl_mm_map, start_stack),
1740 offsetof(struct prctl_mm_map, arg_start),
1741 offsetof(struct prctl_mm_map, arg_end),
1742 offsetof(struct prctl_mm_map, env_start),
1743 offsetof(struct prctl_mm_map, env_end),
1744 };
1745
1746 /*
1747 * Make sure the members are not somewhere outside
1748 * of allowed address space.
1749 */
1750 for (i = 0; i < ARRAY_SIZE(offsets); i++) {
1751 u64 val = *(u64 *)((char *)prctl_map + offsets[i]);
1752
1753 if ((unsigned long)val >= mmap_max_addr ||
1754 (unsigned long)val < mmap_min_addr)
1755 goto out;
1756 }
1757
1758 /*
1759 * Make sure the pairs are ordered.
1760 */
1761 #define __prctl_check_order(__m1, __op, __m2) \
1762 ((unsigned long)prctl_map->__m1 __op \
1763 (unsigned long)prctl_map->__m2) ? 0 : -EINVAL
1764 error = __prctl_check_order(start_code, <, end_code);
1765 error |= __prctl_check_order(start_data, <, end_data);
1766 error |= __prctl_check_order(start_brk, <=, brk);
1767 error |= __prctl_check_order(arg_start, <=, arg_end);
1768 error |= __prctl_check_order(env_start, <=, env_end);
1769 if (error)
1770 goto out;
1771 #undef __prctl_check_order
1772
1773 error = -EINVAL;
1774
1775 /*
1776 * @brk should be after @end_data in traditional maps.
1777 */
1778 if (prctl_map->start_brk <= prctl_map->end_data ||
1779 prctl_map->brk <= prctl_map->end_data)
1780 goto out;
1781
1782 /*
1783 * Neither we should allow to override limits if they set.
1784 */
1785 if (check_data_rlimit(rlimit(RLIMIT_DATA), prctl_map->brk,
1786 prctl_map->start_brk, prctl_map->end_data,
1787 prctl_map->start_data))
1788 goto out;
1789
1790 /*
1791 * Someone is trying to cheat the auxv vector.
1792 */
1793 if (prctl_map->auxv_size) {
1794 if (!prctl_map->auxv || prctl_map->auxv_size > sizeof(mm->saved_auxv))
1795 goto out;
1796 }
1797
1798 /*
1799 * Finally, make sure the caller has the rights to
1800 * change /proc/pid/exe link: only local root should
1801 * be allowed to.
1802 */
1803 if (prctl_map->exe_fd != (u32)-1) {
1804 struct user_namespace *ns = current_user_ns();
1805 const struct cred *cred = current_cred();
1806
1807 if (!uid_eq(cred->uid, make_kuid(ns, 0)) ||
1808 !gid_eq(cred->gid, make_kgid(ns, 0)))
1809 goto out;
1810 }
1811
1812 error = 0;
1813 out:
1814 return error;
1815 }
1816
1817 #ifdef CONFIG_CHECKPOINT_RESTORE
1818 static int prctl_set_mm_map(int opt, const void __user *addr, unsigned long data_size)
1819 {
1820 struct prctl_mm_map prctl_map = { .exe_fd = (u32)-1, };
1821 unsigned long user_auxv[AT_VECTOR_SIZE];
1822 struct mm_struct *mm = current->mm;
1823 int error;
1824
1825 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv));
1826 BUILD_BUG_ON(sizeof(struct prctl_mm_map) > 256);
1827
1828 if (opt == PR_SET_MM_MAP_SIZE)
1829 return put_user((unsigned int)sizeof(prctl_map),
1830 (unsigned int __user *)addr);
1831
1832 if (data_size != sizeof(prctl_map))
1833 return -EINVAL;
1834
1835 if (copy_from_user(&prctl_map, addr, sizeof(prctl_map)))
1836 return -EFAULT;
1837
1838 error = validate_prctl_map(&prctl_map);
1839 if (error)
1840 return error;
1841
1842 if (prctl_map.auxv_size) {
1843 memset(user_auxv, 0, sizeof(user_auxv));
1844 if (copy_from_user(user_auxv,
1845 (const void __user *)prctl_map.auxv,
1846 prctl_map.auxv_size))
1847 return -EFAULT;
1848
1849 /* Last entry must be AT_NULL as specification requires */
1850 user_auxv[AT_VECTOR_SIZE - 2] = AT_NULL;
1851 user_auxv[AT_VECTOR_SIZE - 1] = AT_NULL;
1852 }
1853
1854 if (prctl_map.exe_fd != (u32)-1) {
1855 error = prctl_set_mm_exe_file(mm, prctl_map.exe_fd);
1856 if (error)
1857 return error;
1858 }
1859
1860 down_write(&mm->mmap_sem);
1861
1862 /*
1863 * We don't validate if these members are pointing to
1864 * real present VMAs because application may have correspond
1865 * VMAs already unmapped and kernel uses these members for statistics
1866 * output in procfs mostly, except
1867 *
1868 * - @start_brk/@brk which are used in do_brk but kernel lookups
1869 * for VMAs when updating these memvers so anything wrong written
1870 * here cause kernel to swear at userspace program but won't lead
1871 * to any problem in kernel itself
1872 */
1873
1874 mm->start_code = prctl_map.start_code;
1875 mm->end_code = prctl_map.end_code;
1876 mm->start_data = prctl_map.start_data;
1877 mm->end_data = prctl_map.end_data;
1878 mm->start_brk = prctl_map.start_brk;
1879 mm->brk = prctl_map.brk;
1880 mm->start_stack = prctl_map.start_stack;
1881 mm->arg_start = prctl_map.arg_start;
1882 mm->arg_end = prctl_map.arg_end;
1883 mm->env_start = prctl_map.env_start;
1884 mm->env_end = prctl_map.env_end;
1885
1886 /*
1887 * Note this update of @saved_auxv is lockless thus
1888 * if someone reads this member in procfs while we're
1889 * updating -- it may get partly updated results. It's
1890 * known and acceptable trade off: we leave it as is to
1891 * not introduce additional locks here making the kernel
1892 * more complex.
1893 */
1894 if (prctl_map.auxv_size)
1895 memcpy(mm->saved_auxv, user_auxv, sizeof(user_auxv));
1896
1897 up_write(&mm->mmap_sem);
1898 return 0;
1899 }
1900 #endif /* CONFIG_CHECKPOINT_RESTORE */
1901
1902 static int prctl_set_auxv(struct mm_struct *mm, unsigned long addr,
1903 unsigned long len)
1904 {
1905 /*
1906 * This doesn't move the auxiliary vector itself since it's pinned to
1907 * mm_struct, but it permits filling the vector with new values. It's
1908 * up to the caller to provide sane values here, otherwise userspace
1909 * tools which use this vector might be unhappy.
1910 */
1911 unsigned long user_auxv[AT_VECTOR_SIZE];
1912
1913 if (len > sizeof(user_auxv))
1914 return -EINVAL;
1915
1916 if (copy_from_user(user_auxv, (const void __user *)addr, len))
1917 return -EFAULT;
1918
1919 /* Make sure the last entry is always AT_NULL */
1920 user_auxv[AT_VECTOR_SIZE - 2] = 0;
1921 user_auxv[AT_VECTOR_SIZE - 1] = 0;
1922
1923 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv));
1924
1925 task_lock(current);
1926 memcpy(mm->saved_auxv, user_auxv, len);
1927 task_unlock(current);
1928
1929 return 0;
1930 }
1931
1932 static int prctl_set_mm(int opt, unsigned long addr,
1933 unsigned long arg4, unsigned long arg5)
1934 {
1935 struct mm_struct *mm = current->mm;
1936 struct prctl_mm_map prctl_map;
1937 struct vm_area_struct *vma;
1938 int error;
1939
1940 if (arg5 || (arg4 && (opt != PR_SET_MM_AUXV &&
1941 opt != PR_SET_MM_MAP &&
1942 opt != PR_SET_MM_MAP_SIZE)))
1943 return -EINVAL;
1944
1945 #ifdef CONFIG_CHECKPOINT_RESTORE
1946 if (opt == PR_SET_MM_MAP || opt == PR_SET_MM_MAP_SIZE)
1947 return prctl_set_mm_map(opt, (const void __user *)addr, arg4);
1948 #endif
1949
1950 if (!capable(CAP_SYS_RESOURCE))
1951 return -EPERM;
1952
1953 if (opt == PR_SET_MM_EXE_FILE)
1954 return prctl_set_mm_exe_file(mm, (unsigned int)addr);
1955
1956 if (opt == PR_SET_MM_AUXV)
1957 return prctl_set_auxv(mm, addr, arg4);
1958
1959 if (addr >= TASK_SIZE || addr < mmap_min_addr)
1960 return -EINVAL;
1961
1962 error = -EINVAL;
1963
1964 down_write(&mm->mmap_sem);
1965 vma = find_vma(mm, addr);
1966
1967 prctl_map.start_code = mm->start_code;
1968 prctl_map.end_code = mm->end_code;
1969 prctl_map.start_data = mm->start_data;
1970 prctl_map.end_data = mm->end_data;
1971 prctl_map.start_brk = mm->start_brk;
1972 prctl_map.brk = mm->brk;
1973 prctl_map.start_stack = mm->start_stack;
1974 prctl_map.arg_start = mm->arg_start;
1975 prctl_map.arg_end = mm->arg_end;
1976 prctl_map.env_start = mm->env_start;
1977 prctl_map.env_end = mm->env_end;
1978 prctl_map.auxv = NULL;
1979 prctl_map.auxv_size = 0;
1980 prctl_map.exe_fd = -1;
1981
1982 switch (opt) {
1983 case PR_SET_MM_START_CODE:
1984 prctl_map.start_code = addr;
1985 break;
1986 case PR_SET_MM_END_CODE:
1987 prctl_map.end_code = addr;
1988 break;
1989 case PR_SET_MM_START_DATA:
1990 prctl_map.start_data = addr;
1991 break;
1992 case PR_SET_MM_END_DATA:
1993 prctl_map.end_data = addr;
1994 break;
1995 case PR_SET_MM_START_STACK:
1996 prctl_map.start_stack = addr;
1997 break;
1998 case PR_SET_MM_START_BRK:
1999 prctl_map.start_brk = addr;
2000 break;
2001 case PR_SET_MM_BRK:
2002 prctl_map.brk = addr;
2003 break;
2004 case PR_SET_MM_ARG_START:
2005 prctl_map.arg_start = addr;
2006 break;
2007 case PR_SET_MM_ARG_END:
2008 prctl_map.arg_end = addr;
2009 break;
2010 case PR_SET_MM_ENV_START:
2011 prctl_map.env_start = addr;
2012 break;
2013 case PR_SET_MM_ENV_END:
2014 prctl_map.env_end = addr;
2015 break;
2016 default:
2017 goto out;
2018 }
2019
2020 error = validate_prctl_map(&prctl_map);
2021 if (error)
2022 goto out;
2023
2024 switch (opt) {
2025 /*
2026 * If command line arguments and environment
2027 * are placed somewhere else on stack, we can
2028 * set them up here, ARG_START/END to setup
2029 * command line argumets and ENV_START/END
2030 * for environment.
2031 */
2032 case PR_SET_MM_START_STACK:
2033 case PR_SET_MM_ARG_START:
2034 case PR_SET_MM_ARG_END:
2035 case PR_SET_MM_ENV_START:
2036 case PR_SET_MM_ENV_END:
2037 if (!vma) {
2038 error = -EFAULT;
2039 goto out;
2040 }
2041 }
2042
2043 mm->start_code = prctl_map.start_code;
2044 mm->end_code = prctl_map.end_code;
2045 mm->start_data = prctl_map.start_data;
2046 mm->end_data = prctl_map.end_data;
2047 mm->start_brk = prctl_map.start_brk;
2048 mm->brk = prctl_map.brk;
2049 mm->start_stack = prctl_map.start_stack;
2050 mm->arg_start = prctl_map.arg_start;
2051 mm->arg_end = prctl_map.arg_end;
2052 mm->env_start = prctl_map.env_start;
2053 mm->env_end = prctl_map.env_end;
2054
2055 error = 0;
2056 out:
2057 up_write(&mm->mmap_sem);
2058 return error;
2059 }
2060
2061 #ifdef CONFIG_CHECKPOINT_RESTORE
2062 static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr)
2063 {
2064 return put_user(me->clear_child_tid, tid_addr);
2065 }
2066 #else
2067 static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr)
2068 {
2069 return -EINVAL;
2070 }
2071 #endif
2072
2073 static int propagate_has_child_subreaper(struct task_struct *p, void *data)
2074 {
2075 /*
2076 * If task has has_child_subreaper - all its decendants
2077 * already have these flag too and new decendants will
2078 * inherit it on fork, skip them.
2079 *
2080 * If we've found child_reaper - skip descendants in
2081 * it's subtree as they will never get out pidns.
2082 */
2083 if (p->signal->has_child_subreaper ||
2084 is_child_reaper(task_pid(p)))
2085 return 0;
2086
2087 p->signal->has_child_subreaper = 1;
2088 return 1;
2089 }
2090
2091 SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
2092 unsigned long, arg4, unsigned long, arg5)
2093 {
2094 struct task_struct *me = current;
2095 unsigned char comm[sizeof(me->comm)];
2096 long error;
2097
2098 error = security_task_prctl(option, arg2, arg3, arg4, arg5);
2099 if (error != -ENOSYS)
2100 return error;
2101
2102 error = 0;
2103 switch (option) {
2104 case PR_SET_PDEATHSIG:
2105 if (!valid_signal(arg2)) {
2106 error = -EINVAL;
2107 break;
2108 }
2109 me->pdeath_signal = arg2;
2110 break;
2111 case PR_GET_PDEATHSIG:
2112 error = put_user(me->pdeath_signal, (int __user *)arg2);
2113 break;
2114 case PR_GET_DUMPABLE:
2115 error = get_dumpable(me->mm);
2116 break;
2117 case PR_SET_DUMPABLE:
2118 if (arg2 != SUID_DUMP_DISABLE && arg2 != SUID_DUMP_USER) {
2119 error = -EINVAL;
2120 break;
2121 }
2122 set_dumpable(me->mm, arg2);
2123 break;
2124
2125 case PR_SET_UNALIGN:
2126 error = SET_UNALIGN_CTL(me, arg2);
2127 break;
2128 case PR_GET_UNALIGN:
2129 error = GET_UNALIGN_CTL(me, arg2);
2130 break;
2131 case PR_SET_FPEMU:
2132 error = SET_FPEMU_CTL(me, arg2);
2133 break;
2134 case PR_GET_FPEMU:
2135 error = GET_FPEMU_CTL(me, arg2);
2136 break;
2137 case PR_SET_FPEXC:
2138 error = SET_FPEXC_CTL(me, arg2);
2139 break;
2140 case PR_GET_FPEXC:
2141 error = GET_FPEXC_CTL(me, arg2);
2142 break;
2143 case PR_GET_TIMING:
2144 error = PR_TIMING_STATISTICAL;
2145 break;
2146 case PR_SET_TIMING:
2147 if (arg2 != PR_TIMING_STATISTICAL)
2148 error = -EINVAL;
2149 break;
2150 case PR_SET_NAME:
2151 comm[sizeof(me->comm) - 1] = 0;
2152 if (strncpy_from_user(comm, (char __user *)arg2,
2153 sizeof(me->comm) - 1) < 0)
2154 return -EFAULT;
2155 set_task_comm(me, comm);
2156 proc_comm_connector(me);
2157 break;
2158 case PR_GET_NAME:
2159 get_task_comm(comm, me);
2160 if (copy_to_user((char __user *)arg2, comm, sizeof(comm)))
2161 return -EFAULT;
2162 break;
2163 case PR_GET_ENDIAN:
2164 error = GET_ENDIAN(me, arg2);
2165 break;
2166 case PR_SET_ENDIAN:
2167 error = SET_ENDIAN(me, arg2);
2168 break;
2169 case PR_GET_SECCOMP:
2170 error = prctl_get_seccomp();
2171 break;
2172 case PR_SET_SECCOMP:
2173 error = prctl_set_seccomp(arg2, (char __user *)arg3);
2174 break;
2175 case PR_GET_TSC:
2176 error = GET_TSC_CTL(arg2);
2177 break;
2178 case PR_SET_TSC:
2179 error = SET_TSC_CTL(arg2);
2180 break;
2181 case PR_TASK_PERF_EVENTS_DISABLE:
2182 error = perf_event_task_disable();
2183 break;
2184 case PR_TASK_PERF_EVENTS_ENABLE:
2185 error = perf_event_task_enable();
2186 break;
2187 case PR_GET_TIMERSLACK:
2188 if (current->timer_slack_ns > ULONG_MAX)
2189 error = ULONG_MAX;
2190 else
2191 error = current->timer_slack_ns;
2192 break;
2193 case PR_SET_TIMERSLACK:
2194 if (arg2 <= 0)
2195 current->timer_slack_ns =
2196 current->default_timer_slack_ns;
2197 else
2198 current->timer_slack_ns = arg2;
2199 break;
2200 case PR_MCE_KILL:
2201 if (arg4 | arg5)
2202 return -EINVAL;
2203 switch (arg2) {
2204 case PR_MCE_KILL_CLEAR:
2205 if (arg3 != 0)
2206 return -EINVAL;
2207 current->flags &= ~PF_MCE_PROCESS;
2208 break;
2209 case PR_MCE_KILL_SET:
2210 current->flags |= PF_MCE_PROCESS;
2211 if (arg3 == PR_MCE_KILL_EARLY)
2212 current->flags |= PF_MCE_EARLY;
2213 else if (arg3 == PR_MCE_KILL_LATE)
2214 current->flags &= ~PF_MCE_EARLY;
2215 else if (arg3 == PR_MCE_KILL_DEFAULT)
2216 current->flags &=
2217 ~(PF_MCE_EARLY|PF_MCE_PROCESS);
2218 else
2219 return -EINVAL;
2220 break;
2221 default:
2222 return -EINVAL;
2223 }
2224 break;
2225 case PR_MCE_KILL_GET:
2226 if (arg2 | arg3 | arg4 | arg5)
2227 return -EINVAL;
2228 if (current->flags & PF_MCE_PROCESS)
2229 error = (current->flags & PF_MCE_EARLY) ?
2230 PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE;
2231 else
2232 error = PR_MCE_KILL_DEFAULT;
2233 break;
2234 case PR_SET_MM:
2235 error = prctl_set_mm(arg2, arg3, arg4, arg5);
2236 break;
2237 case PR_GET_TID_ADDRESS:
2238 error = prctl_get_tid_address(me, (int __user **)arg2);
2239 break;
2240 case PR_SET_CHILD_SUBREAPER:
2241 me->signal->is_child_subreaper = !!arg2;
2242 if (!arg2)
2243 break;
2244
2245 walk_process_tree(me, propagate_has_child_subreaper, NULL);
2246 break;
2247 case PR_GET_CHILD_SUBREAPER:
2248 error = put_user(me->signal->is_child_subreaper,
2249 (int __user *)arg2);
2250 break;
2251 case PR_SET_NO_NEW_PRIVS:
2252 if (arg2 != 1 || arg3 || arg4 || arg5)
2253 return -EINVAL;
2254
2255 task_set_no_new_privs(current);
2256 break;
2257 case PR_GET_NO_NEW_PRIVS:
2258 if (arg2 || arg3 || arg4 || arg5)
2259 return -EINVAL;
2260 return task_no_new_privs(current) ? 1 : 0;
2261 case PR_GET_THP_DISABLE:
2262 if (arg2 || arg3 || arg4 || arg5)
2263 return -EINVAL;
2264 error = !!(me->mm->def_flags & VM_NOHUGEPAGE);
2265 break;
2266 case PR_SET_THP_DISABLE:
2267 if (arg3 || arg4 || arg5)
2268 return -EINVAL;
2269 if (down_write_killable(&me->mm->mmap_sem))
2270 return -EINTR;
2271 if (arg2)
2272 me->mm->def_flags |= VM_NOHUGEPAGE;
2273 else
2274 me->mm->def_flags &= ~VM_NOHUGEPAGE;
2275 up_write(&me->mm->mmap_sem);
2276 break;
2277 case PR_MPX_ENABLE_MANAGEMENT:
2278 if (arg2 || arg3 || arg4 || arg5)
2279 return -EINVAL;
2280 error = MPX_ENABLE_MANAGEMENT();
2281 break;
2282 case PR_MPX_DISABLE_MANAGEMENT:
2283 if (arg2 || arg3 || arg4 || arg5)
2284 return -EINVAL;
2285 error = MPX_DISABLE_MANAGEMENT();
2286 break;
2287 case PR_SET_FP_MODE:
2288 error = SET_FP_MODE(me, arg2);
2289 break;
2290 case PR_GET_FP_MODE:
2291 error = GET_FP_MODE(me);
2292 break;
2293 default:
2294 error = -EINVAL;
2295 break;
2296 }
2297 return error;
2298 }
2299
2300 SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep,
2301 struct getcpu_cache __user *, unused)
2302 {
2303 int err = 0;
2304 int cpu = raw_smp_processor_id();
2305
2306 if (cpup)
2307 err |= put_user(cpu, cpup);
2308 if (nodep)
2309 err |= put_user(cpu_to_node(cpu), nodep);
2310 return err ? -EFAULT : 0;
2311 }
2312
2313 /**
2314 * do_sysinfo - fill in sysinfo struct
2315 * @info: pointer to buffer to fill
2316 */
2317 static int do_sysinfo(struct sysinfo *info)
2318 {
2319 unsigned long mem_total, sav_total;
2320 unsigned int mem_unit, bitcount;
2321 struct timespec tp;
2322
2323 memset(info, 0, sizeof(struct sysinfo));
2324
2325 get_monotonic_boottime(&tp);
2326 info->uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0);
2327
2328 get_avenrun(info->loads, 0, SI_LOAD_SHIFT - FSHIFT);
2329
2330 info->procs = nr_threads;
2331
2332 si_meminfo(info);
2333 si_swapinfo(info);
2334
2335 /*
2336 * If the sum of all the available memory (i.e. ram + swap)
2337 * is less than can be stored in a 32 bit unsigned long then
2338 * we can be binary compatible with 2.2.x kernels. If not,
2339 * well, in that case 2.2.x was broken anyways...
2340 *
2341 * -Erik Andersen <andersee@debian.org>
2342 */
2343
2344 mem_total = info->totalram + info->totalswap;
2345 if (mem_total < info->totalram || mem_total < info->totalswap)
2346 goto out;
2347 bitcount = 0;
2348 mem_unit = info->mem_unit;
2349 while (mem_unit > 1) {
2350 bitcount++;
2351 mem_unit >>= 1;
2352 sav_total = mem_total;
2353 mem_total <<= 1;
2354 if (mem_total < sav_total)
2355 goto out;
2356 }
2357
2358 /*
2359 * If mem_total did not overflow, multiply all memory values by
2360 * info->mem_unit and set it to 1. This leaves things compatible
2361 * with 2.2.x, and also retains compatibility with earlier 2.4.x
2362 * kernels...
2363 */
2364
2365 info->mem_unit = 1;
2366 info->totalram <<= bitcount;
2367 info->freeram <<= bitcount;
2368 info->sharedram <<= bitcount;
2369 info->bufferram <<= bitcount;
2370 info->totalswap <<= bitcount;
2371 info->freeswap <<= bitcount;
2372 info->totalhigh <<= bitcount;
2373 info->freehigh <<= bitcount;
2374
2375 out:
2376 return 0;
2377 }
2378
2379 SYSCALL_DEFINE1(sysinfo, struct sysinfo __user *, info)
2380 {
2381 struct sysinfo val;
2382
2383 do_sysinfo(&val);
2384
2385 if (copy_to_user(info, &val, sizeof(struct sysinfo)))
2386 return -EFAULT;
2387
2388 return 0;
2389 }
2390
2391 #ifdef CONFIG_COMPAT
2392 struct compat_sysinfo {
2393 s32 uptime;
2394 u32 loads[3];
2395 u32 totalram;
2396 u32 freeram;
2397 u32 sharedram;
2398 u32 bufferram;
2399 u32 totalswap;
2400 u32 freeswap;
2401 u16 procs;
2402 u16 pad;
2403 u32 totalhigh;
2404 u32 freehigh;
2405 u32 mem_unit;
2406 char _f[20-2*sizeof(u32)-sizeof(int)];
2407 };
2408
2409 COMPAT_SYSCALL_DEFINE1(sysinfo, struct compat_sysinfo __user *, info)
2410 {
2411 struct sysinfo s;
2412
2413 do_sysinfo(&s);
2414
2415 /* Check to see if any memory value is too large for 32-bit and scale
2416 * down if needed
2417 */
2418 if (upper_32_bits(s.totalram) || upper_32_bits(s.totalswap)) {
2419 int bitcount = 0;
2420
2421 while (s.mem_unit < PAGE_SIZE) {
2422 s.mem_unit <<= 1;
2423 bitcount++;
2424 }
2425
2426 s.totalram >>= bitcount;
2427 s.freeram >>= bitcount;
2428 s.sharedram >>= bitcount;
2429 s.bufferram >>= bitcount;
2430 s.totalswap >>= bitcount;
2431 s.freeswap >>= bitcount;
2432 s.totalhigh >>= bitcount;
2433 s.freehigh >>= bitcount;
2434 }
2435
2436 if (!access_ok(VERIFY_WRITE, info, sizeof(struct compat_sysinfo)) ||
2437 __put_user(s.uptime, &info->uptime) ||
2438 __put_user(s.loads[0], &info->loads[0]) ||
2439 __put_user(s.loads[1], &info->loads[1]) ||
2440 __put_user(s.loads[2], &info->loads[2]) ||
2441 __put_user(s.totalram, &info->totalram) ||
2442 __put_user(s.freeram, &info->freeram) ||
2443 __put_user(s.sharedram, &info->sharedram) ||
2444 __put_user(s.bufferram, &info->bufferram) ||
2445 __put_user(s.totalswap, &info->totalswap) ||
2446 __put_user(s.freeswap, &info->freeswap) ||
2447 __put_user(s.procs, &info->procs) ||
2448 __put_user(s.totalhigh, &info->totalhigh) ||
2449 __put_user(s.freehigh, &info->freehigh) ||
2450 __put_user(s.mem_unit, &info->mem_unit))
2451 return -EFAULT;
2452
2453 return 0;
2454 }
2455 #endif /* CONFIG_COMPAT */
Linux with added FPC-III support