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Linux 4.1.18
[linux/fpc-iii.git] / kernel / sys.c
blob25ae8d2e65e2d2db755a2c255440e958069c318f
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/rcupdate.h>
53 #include <linux/uidgid.h>
54 #include <linux/cred.h>
55
56 #include <linux/kmsg_dump.h>
57 /* Move somewhere else to avoid recompiling? */
58 #include <generated/utsrelease.h>
59
60 #include <asm/uaccess.h>
61 #include <asm/io.h>
62 #include <asm/unistd.h>
63
64 #ifndef SET_UNALIGN_CTL
65 # define SET_UNALIGN_CTL(a, b) (-EINVAL)
66 #endif
67 #ifndef GET_UNALIGN_CTL
68 # define GET_UNALIGN_CTL(a, b) (-EINVAL)
69 #endif
70 #ifndef SET_FPEMU_CTL
71 # define SET_FPEMU_CTL(a, b) (-EINVAL)
72 #endif
73 #ifndef GET_FPEMU_CTL
74 # define GET_FPEMU_CTL(a, b) (-EINVAL)
75 #endif
76 #ifndef SET_FPEXC_CTL
77 # define SET_FPEXC_CTL(a, b) (-EINVAL)
78 #endif
79 #ifndef GET_FPEXC_CTL
80 # define GET_FPEXC_CTL(a, b) (-EINVAL)
81 #endif
82 #ifndef GET_ENDIAN
83 # define GET_ENDIAN(a, b) (-EINVAL)
84 #endif
85 #ifndef SET_ENDIAN
86 # define SET_ENDIAN(a, b) (-EINVAL)
87 #endif
88 #ifndef GET_TSC_CTL
89 # define GET_TSC_CTL(a) (-EINVAL)
90 #endif
91 #ifndef SET_TSC_CTL
92 # define SET_TSC_CTL(a) (-EINVAL)
93 #endif
94 #ifndef MPX_ENABLE_MANAGEMENT
95 # define MPX_ENABLE_MANAGEMENT(a) (-EINVAL)
96 #endif
97 #ifndef MPX_DISABLE_MANAGEMENT
98 # define MPX_DISABLE_MANAGEMENT(a) (-EINVAL)
99 #endif
100 #ifndef GET_FP_MODE
101 # define GET_FP_MODE(a) (-EINVAL)
102 #endif
103 #ifndef SET_FP_MODE
104 # define SET_FP_MODE(a,b) (-EINVAL)
105 #endif
106
107 /*
108 * this is where the system-wide overflow UID and GID are defined, for
109 * architectures that now have 32-bit UID/GID but didn't in the past
110 */
111
112 int overflowuid = DEFAULT_OVERFLOWUID;
113 int overflowgid = DEFAULT_OVERFLOWGID;
114
115 EXPORT_SYMBOL(overflowuid);
116 EXPORT_SYMBOL(overflowgid);
117
118 /*
119 * the same as above, but for filesystems which can only store a 16-bit
120 * UID and GID. as such, this is needed on all architectures
121 */
122
123 int fs_overflowuid = DEFAULT_FS_OVERFLOWUID;
124 int fs_overflowgid = DEFAULT_FS_OVERFLOWUID;
125
126 EXPORT_SYMBOL(fs_overflowuid);
127 EXPORT_SYMBOL(fs_overflowgid);
128
129 /*
130 * Returns true if current's euid is same as p's uid or euid,
131 * or has CAP_SYS_NICE to p's user_ns.
132 *
133 * Called with rcu_read_lock, creds are safe
134 */
135 static bool set_one_prio_perm(struct task_struct *p)
136 {
137 const struct cred *cred = current_cred(), *pcred = __task_cred(p);
138
139 if (uid_eq(pcred->uid, cred->euid) ||
140 uid_eq(pcred->euid, cred->euid))
141 return true;
142 if (ns_capable(pcred->user_ns, CAP_SYS_NICE))
143 return true;
144 return false;
145 }
146
147 /*
148 * set the priority of a task
149 * - the caller must hold the RCU read lock
150 */
151 static int set_one_prio(struct task_struct *p, int niceval, int error)
152 {
153 int no_nice;
154
155 if (!set_one_prio_perm(p)) {
156 error = -EPERM;
157 goto out;
158 }
159 if (niceval < task_nice(p) && !can_nice(p, niceval)) {
160 error = -EACCES;
161 goto out;
162 }
163 no_nice = security_task_setnice(p, niceval);
164 if (no_nice) {
165 error = no_nice;
166 goto out;
167 }
168 if (error == -ESRCH)
169 error = 0;
170 set_user_nice(p, niceval);
171 out:
172 return error;
173 }
174
175 SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval)
176 {
177 struct task_struct *g, *p;
178 struct user_struct *user;
179 const struct cred *cred = current_cred();
180 int error = -EINVAL;
181 struct pid *pgrp;
182 kuid_t uid;
183
184 if (which > PRIO_USER || which < PRIO_PROCESS)
185 goto out;
186
187 /* normalize: avoid signed division (rounding problems) */
188 error = -ESRCH;
189 if (niceval < MIN_NICE)
190 niceval = MIN_NICE;
191 if (niceval > MAX_NICE)
192 niceval = MAX_NICE;
193
194 rcu_read_lock();
195 read_lock(&tasklist_lock);
196 switch (which) {
197 case PRIO_PROCESS:
198 if (who)
199 p = find_task_by_vpid(who);
200 else
201 p = current;
202 if (p)
203 error = set_one_prio(p, niceval, error);
204 break;
205 case PRIO_PGRP:
206 if (who)
207 pgrp = find_vpid(who);
208 else
209 pgrp = task_pgrp(current);
210 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
211 error = set_one_prio(p, niceval, error);
212 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
213 break;
214 case PRIO_USER:
215 uid = make_kuid(cred->user_ns, who);
216 user = cred->user;
217 if (!who)
218 uid = cred->uid;
219 else if (!uid_eq(uid, cred->uid)) {
220 user = find_user(uid);
221 if (!user)
222 goto out_unlock; /* No processes for this user */
223 }
224 do_each_thread(g, p) {
225 if (uid_eq(task_uid(p), uid))
226 error = set_one_prio(p, niceval, error);
227 } while_each_thread(g, p);
228 if (!uid_eq(uid, cred->uid))
229 free_uid(user); /* For find_user() */
230 break;
231 }
232 out_unlock:
233 read_unlock(&tasklist_lock);
234 rcu_read_unlock();
235 out:
236 return error;
237 }
238
239 /*
240 * Ugh. To avoid negative return values, "getpriority()" will
241 * not return the normal nice-value, but a negated value that
242 * has been offset by 20 (ie it returns 40..1 instead of -20..19)
243 * to stay compatible.
244 */
245 SYSCALL_DEFINE2(getpriority, int, which, int, who)
246 {
247 struct task_struct *g, *p;
248 struct user_struct *user;
249 const struct cred *cred = current_cred();
250 long niceval, retval = -ESRCH;
251 struct pid *pgrp;
252 kuid_t uid;
253
254 if (which > PRIO_USER || which < PRIO_PROCESS)
255 return -EINVAL;
256
257 rcu_read_lock();
258 read_lock(&tasklist_lock);
259 switch (which) {
260 case PRIO_PROCESS:
261 if (who)
262 p = find_task_by_vpid(who);
263 else
264 p = current;
265 if (p) {
266 niceval = nice_to_rlimit(task_nice(p));
267 if (niceval > retval)
268 retval = niceval;
269 }
270 break;
271 case PRIO_PGRP:
272 if (who)
273 pgrp = find_vpid(who);
274 else
275 pgrp = task_pgrp(current);
276 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
277 niceval = nice_to_rlimit(task_nice(p));
278 if (niceval > retval)
279 retval = niceval;
280 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
281 break;
282 case PRIO_USER:
283 uid = make_kuid(cred->user_ns, who);
284 user = cred->user;
285 if (!who)
286 uid = cred->uid;
287 else if (!uid_eq(uid, cred->uid)) {
288 user = find_user(uid);
289 if (!user)
290 goto out_unlock; /* No processes for this user */
291 }
292 do_each_thread(g, p) {
293 if (uid_eq(task_uid(p), uid)) {
294 niceval = nice_to_rlimit(task_nice(p));
295 if (niceval > retval)
296 retval = niceval;
297 }
298 } while_each_thread(g, p);
299 if (!uid_eq(uid, cred->uid))
300 free_uid(user); /* for find_user() */
301 break;
302 }
303 out_unlock:
304 read_unlock(&tasklist_lock);
305 rcu_read_unlock();
306
307 return retval;
308 }
309
310 /*
311 * Unprivileged users may change the real gid to the effective gid
312 * or vice versa. (BSD-style)
313 *
314 * If you set the real gid at all, or set the effective gid to a value not
315 * equal to the real gid, then the saved gid is set to the new effective gid.
316 *
317 * This makes it possible for a setgid program to completely drop its
318 * privileges, which is often a useful assertion to make when you are doing
319 * a security audit over a program.
320 *
321 * The general idea is that a program which uses just setregid() will be
322 * 100% compatible with BSD. A program which uses just setgid() will be
323 * 100% compatible with POSIX with saved IDs.
324 *
325 * SMP: There are not races, the GIDs are checked only by filesystem
326 * operations (as far as semantic preservation is concerned).
327 */
328 #ifdef CONFIG_MULTIUSER
329 SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid)
330 {
331 struct user_namespace *ns = current_user_ns();
332 const struct cred *old;
333 struct cred *new;
334 int retval;
335 kgid_t krgid, kegid;
336
337 krgid = make_kgid(ns, rgid);
338 kegid = make_kgid(ns, egid);
339
340 if ((rgid != (gid_t) -1) && !gid_valid(krgid))
341 return -EINVAL;
342 if ((egid != (gid_t) -1) && !gid_valid(kegid))
343 return -EINVAL;
344
345 new = prepare_creds();
346 if (!new)
347 return -ENOMEM;
348 old = current_cred();
349
350 retval = -EPERM;
351 if (rgid != (gid_t) -1) {
352 if (gid_eq(old->gid, krgid) ||
353 gid_eq(old->egid, krgid) ||
354 ns_capable(old->user_ns, CAP_SETGID))
355 new->gid = krgid;
356 else
357 goto error;
358 }
359 if (egid != (gid_t) -1) {
360 if (gid_eq(old->gid, kegid) ||
361 gid_eq(old->egid, kegid) ||
362 gid_eq(old->sgid, kegid) ||
363 ns_capable(old->user_ns, CAP_SETGID))
364 new->egid = kegid;
365 else
366 goto error;
367 }
368
369 if (rgid != (gid_t) -1 ||
370 (egid != (gid_t) -1 && !gid_eq(kegid, old->gid)))
371 new->sgid = new->egid;
372 new->fsgid = new->egid;
373
374 return commit_creds(new);
375
376 error:
377 abort_creds(new);
378 return retval;
379 }
380
381 /*
382 * setgid() is implemented like SysV w/ SAVED_IDS
383 *
384 * SMP: Same implicit races as above.
385 */
386 SYSCALL_DEFINE1(setgid, gid_t, gid)
387 {
388 struct user_namespace *ns = current_user_ns();
389 const struct cred *old;
390 struct cred *new;
391 int retval;
392 kgid_t kgid;
393
394 kgid = make_kgid(ns, gid);
395 if (!gid_valid(kgid))
396 return -EINVAL;
397
398 new = prepare_creds();
399 if (!new)
400 return -ENOMEM;
401 old = current_cred();
402
403 retval = -EPERM;
404 if (ns_capable(old->user_ns, CAP_SETGID))
405 new->gid = new->egid = new->sgid = new->fsgid = kgid;
406 else if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->sgid))
407 new->egid = new->fsgid = kgid;
408 else
409 goto error;
410
411 return commit_creds(new);
412
413 error:
414 abort_creds(new);
415 return retval;
416 }
417
418 /*
419 * change the user struct in a credentials set to match the new UID
420 */
421 static int set_user(struct cred *new)
422 {
423 struct user_struct *new_user;
424
425 new_user = alloc_uid(new->uid);
426 if (!new_user)
427 return -EAGAIN;
428
429 /*
430 * We don't fail in case of NPROC limit excess here because too many
431 * poorly written programs don't check set*uid() return code, assuming
432 * it never fails if called by root. We may still enforce NPROC limit
433 * for programs doing set*uid()+execve() by harmlessly deferring the
434 * failure to the execve() stage.
435 */
436 if (atomic_read(&new_user->processes) >= rlimit(RLIMIT_NPROC) &&
437 new_user != INIT_USER)
438 current->flags |= PF_NPROC_EXCEEDED;
439 else
440 current->flags &= ~PF_NPROC_EXCEEDED;
441
442 free_uid(new->user);
443 new->user = new_user;
444 return 0;
445 }
446
447 /*
448 * Unprivileged users may change the real uid to the effective uid
449 * or vice versa. (BSD-style)
450 *
451 * If you set the real uid at all, or set the effective uid to a value not
452 * equal to the real uid, then the saved uid is set to the new effective uid.
453 *
454 * This makes it possible for a setuid program to completely drop its
455 * privileges, which is often a useful assertion to make when you are doing
456 * a security audit over a program.
457 *
458 * The general idea is that a program which uses just setreuid() will be
459 * 100% compatible with BSD. A program which uses just setuid() will be
460 * 100% compatible with POSIX with saved IDs.
461 */
462 SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid)
463 {
464 struct user_namespace *ns = current_user_ns();
465 const struct cred *old;
466 struct cred *new;
467 int retval;
468 kuid_t kruid, keuid;
469
470 kruid = make_kuid(ns, ruid);
471 keuid = make_kuid(ns, euid);
472
473 if ((ruid != (uid_t) -1) && !uid_valid(kruid))
474 return -EINVAL;
475 if ((euid != (uid_t) -1) && !uid_valid(keuid))
476 return -EINVAL;
477
478 new = prepare_creds();
479 if (!new)
480 return -ENOMEM;
481 old = current_cred();
482
483 retval = -EPERM;
484 if (ruid != (uid_t) -1) {
485 new->uid = kruid;
486 if (!uid_eq(old->uid, kruid) &&
487 !uid_eq(old->euid, kruid) &&
488 !ns_capable(old->user_ns, CAP_SETUID))
489 goto error;
490 }
491
492 if (euid != (uid_t) -1) {
493 new->euid = keuid;
494 if (!uid_eq(old->uid, keuid) &&
495 !uid_eq(old->euid, keuid) &&
496 !uid_eq(old->suid, keuid) &&
497 !ns_capable(old->user_ns, CAP_SETUID))
498 goto error;
499 }
500
501 if (!uid_eq(new->uid, old->uid)) {
502 retval = set_user(new);
503 if (retval < 0)
504 goto error;
505 }
506 if (ruid != (uid_t) -1 ||
507 (euid != (uid_t) -1 && !uid_eq(keuid, old->uid)))
508 new->suid = new->euid;
509 new->fsuid = new->euid;
510
511 retval = security_task_fix_setuid(new, old, LSM_SETID_RE);
512 if (retval < 0)
513 goto error;
514
515 return commit_creds(new);
516
517 error:
518 abort_creds(new);
519 return retval;
520 }
521
522 /*
523 * setuid() is implemented like SysV with SAVED_IDS
524 *
525 * Note that SAVED_ID's is deficient in that a setuid root program
526 * like sendmail, for example, cannot set its uid to be a normal
527 * user and then switch back, because if you're root, setuid() sets
528 * the saved uid too. If you don't like this, blame the bright people
529 * in the POSIX committee and/or USG. Note that the BSD-style setreuid()
530 * will allow a root program to temporarily drop privileges and be able to
531 * regain them by swapping the real and effective uid.
532 */
533 SYSCALL_DEFINE1(setuid, uid_t, uid)
534 {
535 struct user_namespace *ns = current_user_ns();
536 const struct cred *old;
537 struct cred *new;
538 int retval;
539 kuid_t kuid;
540
541 kuid = make_kuid(ns, uid);
542 if (!uid_valid(kuid))
543 return -EINVAL;
544
545 new = prepare_creds();
546 if (!new)
547 return -ENOMEM;
548 old = current_cred();
549
550 retval = -EPERM;
551 if (ns_capable(old->user_ns, CAP_SETUID)) {
552 new->suid = new->uid = kuid;
553 if (!uid_eq(kuid, old->uid)) {
554 retval = set_user(new);
555 if (retval < 0)
556 goto error;
557 }
558 } else if (!uid_eq(kuid, old->uid) && !uid_eq(kuid, new->suid)) {
559 goto error;
560 }
561
562 new->fsuid = new->euid = kuid;
563
564 retval = security_task_fix_setuid(new, old, LSM_SETID_ID);
565 if (retval < 0)
566 goto error;
567
568 return commit_creds(new);
569
570 error:
571 abort_creds(new);
572 return retval;
573 }
574
575
576 /*
577 * This function implements a generic ability to update ruid, euid,
578 * and suid. This allows you to implement the 4.4 compatible seteuid().
579 */
580 SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid)
581 {
582 struct user_namespace *ns = current_user_ns();
583 const struct cred *old;
584 struct cred *new;
585 int retval;
586 kuid_t kruid, keuid, ksuid;
587
588 kruid = make_kuid(ns, ruid);
589 keuid = make_kuid(ns, euid);
590 ksuid = make_kuid(ns, suid);
591
592 if ((ruid != (uid_t) -1) && !uid_valid(kruid))
593 return -EINVAL;
594
595 if ((euid != (uid_t) -1) && !uid_valid(keuid))
596 return -EINVAL;
597
598 if ((suid != (uid_t) -1) && !uid_valid(ksuid))
599 return -EINVAL;
600
601 new = prepare_creds();
602 if (!new)
603 return -ENOMEM;
604
605 old = current_cred();
606
607 retval = -EPERM;
608 if (!ns_capable(old->user_ns, CAP_SETUID)) {
609 if (ruid != (uid_t) -1 && !uid_eq(kruid, old->uid) &&
610 !uid_eq(kruid, old->euid) && !uid_eq(kruid, old->suid))
611 goto error;
612 if (euid != (uid_t) -1 && !uid_eq(keuid, old->uid) &&
613 !uid_eq(keuid, old->euid) && !uid_eq(keuid, old->suid))
614 goto error;
615 if (suid != (uid_t) -1 && !uid_eq(ksuid, old->uid) &&
616 !uid_eq(ksuid, old->euid) && !uid_eq(ksuid, old->suid))
617 goto error;
618 }
619
620 if (ruid != (uid_t) -1) {
621 new->uid = kruid;
622 if (!uid_eq(kruid, old->uid)) {
623 retval = set_user(new);
624 if (retval < 0)
625 goto error;
626 }
627 }
628 if (euid != (uid_t) -1)
629 new->euid = keuid;
630 if (suid != (uid_t) -1)
631 new->suid = ksuid;
632 new->fsuid = new->euid;
633
634 retval = security_task_fix_setuid(new, old, LSM_SETID_RES);
635 if (retval < 0)
636 goto error;
637
638 return commit_creds(new);
639
640 error:
641 abort_creds(new);
642 return retval;
643 }
644
645 SYSCALL_DEFINE3(getresuid, uid_t __user *, ruidp, uid_t __user *, euidp, uid_t __user *, suidp)
646 {
647 const struct cred *cred = current_cred();
648 int retval;
649 uid_t ruid, euid, suid;
650
651 ruid = from_kuid_munged(cred->user_ns, cred->uid);
652 euid = from_kuid_munged(cred->user_ns, cred->euid);
653 suid = from_kuid_munged(cred->user_ns, cred->suid);
654
655 retval = put_user(ruid, ruidp);
656 if (!retval) {
657 retval = put_user(euid, euidp);
658 if (!retval)
659 return put_user(suid, suidp);
660 }
661 return retval;
662 }
663
664 /*
665 * Same as above, but for rgid, egid, sgid.
666 */
667 SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid)
668 {
669 struct user_namespace *ns = current_user_ns();
670 const struct cred *old;
671 struct cred *new;
672 int retval;
673 kgid_t krgid, kegid, ksgid;
674
675 krgid = make_kgid(ns, rgid);
676 kegid = make_kgid(ns, egid);
677 ksgid = make_kgid(ns, sgid);
678
679 if ((rgid != (gid_t) -1) && !gid_valid(krgid))
680 return -EINVAL;
681 if ((egid != (gid_t) -1) && !gid_valid(kegid))
682 return -EINVAL;
683 if ((sgid != (gid_t) -1) && !gid_valid(ksgid))
684 return -EINVAL;
685
686 new = prepare_creds();
687 if (!new)
688 return -ENOMEM;
689 old = current_cred();
690
691 retval = -EPERM;
692 if (!ns_capable(old->user_ns, CAP_SETGID)) {
693 if (rgid != (gid_t) -1 && !gid_eq(krgid, old->gid) &&
694 !gid_eq(krgid, old->egid) && !gid_eq(krgid, old->sgid))
695 goto error;
696 if (egid != (gid_t) -1 && !gid_eq(kegid, old->gid) &&
697 !gid_eq(kegid, old->egid) && !gid_eq(kegid, old->sgid))
698 goto error;
699 if (sgid != (gid_t) -1 && !gid_eq(ksgid, old->gid) &&
700 !gid_eq(ksgid, old->egid) && !gid_eq(ksgid, old->sgid))
701 goto error;
702 }
703
704 if (rgid != (gid_t) -1)
705 new->gid = krgid;
706 if (egid != (gid_t) -1)
707 new->egid = kegid;
708 if (sgid != (gid_t) -1)
709 new->sgid = ksgid;
710 new->fsgid = new->egid;
711
712 return commit_creds(new);
713
714 error:
715 abort_creds(new);
716 return retval;
717 }
718
719 SYSCALL_DEFINE3(getresgid, gid_t __user *, rgidp, gid_t __user *, egidp, gid_t __user *, sgidp)
720 {
721 const struct cred *cred = current_cred();
722 int retval;
723 gid_t rgid, egid, sgid;
724
725 rgid = from_kgid_munged(cred->user_ns, cred->gid);
726 egid = from_kgid_munged(cred->user_ns, cred->egid);
727 sgid = from_kgid_munged(cred->user_ns, cred->sgid);
728
729 retval = put_user(rgid, rgidp);
730 if (!retval) {
731 retval = put_user(egid, egidp);
732 if (!retval)
733 retval = put_user(sgid, sgidp);
734 }
735
736 return retval;
737 }
738
739
740 /*
741 * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This
742 * is used for "access()" and for the NFS daemon (letting nfsd stay at
743 * whatever uid it wants to). It normally shadows "euid", except when
744 * explicitly set by setfsuid() or for access..
745 */
746 SYSCALL_DEFINE1(setfsuid, uid_t, uid)
747 {
748 const struct cred *old;
749 struct cred *new;
750 uid_t old_fsuid;
751 kuid_t kuid;
752
753 old = current_cred();
754 old_fsuid = from_kuid_munged(old->user_ns, old->fsuid);
755
756 kuid = make_kuid(old->user_ns, uid);
757 if (!uid_valid(kuid))
758 return old_fsuid;
759
760 new = prepare_creds();
761 if (!new)
762 return old_fsuid;
763
764 if (uid_eq(kuid, old->uid) || uid_eq(kuid, old->euid) ||
765 uid_eq(kuid, old->suid) || uid_eq(kuid, old->fsuid) ||
766 ns_capable(old->user_ns, CAP_SETUID)) {
767 if (!uid_eq(kuid, old->fsuid)) {
768 new->fsuid = kuid;
769 if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0)
770 goto change_okay;
771 }
772 }
773
774 abort_creds(new);
775 return old_fsuid;
776
777 change_okay:
778 commit_creds(new);
779 return old_fsuid;
780 }
781
782 /*
783 * Samma på svenska..
784 */
785 SYSCALL_DEFINE1(setfsgid, gid_t, gid)
786 {
787 const struct cred *old;
788 struct cred *new;
789 gid_t old_fsgid;
790 kgid_t kgid;
791
792 old = current_cred();
793 old_fsgid = from_kgid_munged(old->user_ns, old->fsgid);
794
795 kgid = make_kgid(old->user_ns, gid);
796 if (!gid_valid(kgid))
797 return old_fsgid;
798
799 new = prepare_creds();
800 if (!new)
801 return old_fsgid;
802
803 if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->egid) ||
804 gid_eq(kgid, old->sgid) || gid_eq(kgid, old->fsgid) ||
805 ns_capable(old->user_ns, CAP_SETGID)) {
806 if (!gid_eq(kgid, old->fsgid)) {
807 new->fsgid = kgid;
808 goto change_okay;
809 }
810 }
811
812 abort_creds(new);
813 return old_fsgid;
814
815 change_okay:
816 commit_creds(new);
817 return old_fsgid;
818 }
819 #endif /* CONFIG_MULTIUSER */
820
821 /**
822 * sys_getpid - return the thread group id of the current process
823 *
824 * Note, despite the name, this returns the tgid not the pid. The tgid and
825 * the pid are identical unless CLONE_THREAD was specified on clone() in
826 * which case the tgid is the same in all threads of the same group.
827 *
828 * This is SMP safe as current->tgid does not change.
829 */
830 SYSCALL_DEFINE0(getpid)
831 {
832 return task_tgid_vnr(current);
833 }
834
835 /* Thread ID - the internal kernel "pid" */
836 SYSCALL_DEFINE0(gettid)
837 {
838 return task_pid_vnr(current);
839 }
840
841 /*
842 * Accessing ->real_parent is not SMP-safe, it could
843 * change from under us. However, we can use a stale
844 * value of ->real_parent under rcu_read_lock(), see
845 * release_task()->call_rcu(delayed_put_task_struct).
846 */
847 SYSCALL_DEFINE0(getppid)
848 {
849 int pid;
850
851 rcu_read_lock();
852 pid = task_tgid_vnr(rcu_dereference(current->real_parent));
853 rcu_read_unlock();
854
855 return pid;
856 }
857
858 SYSCALL_DEFINE0(getuid)
859 {
860 /* Only we change this so SMP safe */
861 return from_kuid_munged(current_user_ns(), current_uid());
862 }
863
864 SYSCALL_DEFINE0(geteuid)
865 {
866 /* Only we change this so SMP safe */
867 return from_kuid_munged(current_user_ns(), current_euid());
868 }
869
870 SYSCALL_DEFINE0(getgid)
871 {
872 /* Only we change this so SMP safe */
873 return from_kgid_munged(current_user_ns(), current_gid());
874 }
875
876 SYSCALL_DEFINE0(getegid)
877 {
878 /* Only we change this so SMP safe */
879 return from_kgid_munged(current_user_ns(), current_egid());
880 }
881
882 void do_sys_times(struct tms *tms)
883 {
884 cputime_t tgutime, tgstime, cutime, cstime;
885
886 thread_group_cputime_adjusted(current, &tgutime, &tgstime);
887 cutime = current->signal->cutime;
888 cstime = current->signal->cstime;
889 tms->tms_utime = cputime_to_clock_t(tgutime);
890 tms->tms_stime = cputime_to_clock_t(tgstime);
891 tms->tms_cutime = cputime_to_clock_t(cutime);
892 tms->tms_cstime = cputime_to_clock_t(cstime);
893 }
894
895 SYSCALL_DEFINE1(times, struct tms __user *, tbuf)
896 {
897 if (tbuf) {
898 struct tms tmp;
899
900 do_sys_times(&tmp);
901 if (copy_to_user(tbuf, &tmp, sizeof(struct tms)))
902 return -EFAULT;
903 }
904 force_successful_syscall_return();
905 return (long) jiffies_64_to_clock_t(get_jiffies_64());
906 }
907
908 /*
909 * This needs some heavy checking ...
910 * I just haven't the stomach for it. I also don't fully
911 * understand sessions/pgrp etc. Let somebody who does explain it.
912 *
913 * OK, I think I have the protection semantics right.... this is really
914 * only important on a multi-user system anyway, to make sure one user
915 * can't send a signal to a process owned by another. -TYT, 12/12/91
916 *
917 * !PF_FORKNOEXEC check to conform completely to POSIX.
918 */
919 SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid)
920 {
921 struct task_struct *p;
922 struct task_struct *group_leader = current->group_leader;
923 struct pid *pgrp;
924 int err;
925
926 if (!pid)
927 pid = task_pid_vnr(group_leader);
928 if (!pgid)
929 pgid = pid;
930 if (pgid < 0)
931 return -EINVAL;
932 rcu_read_lock();
933
934 /* From this point forward we keep holding onto the tasklist lock
935 * so that our parent does not change from under us. -DaveM
936 */
937 write_lock_irq(&tasklist_lock);
938
939 err = -ESRCH;
940 p = find_task_by_vpid(pid);
941 if (!p)
942 goto out;
943
944 err = -EINVAL;
945 if (!thread_group_leader(p))
946 goto out;
947
948 if (same_thread_group(p->real_parent, group_leader)) {
949 err = -EPERM;
950 if (task_session(p) != task_session(group_leader))
951 goto out;
952 err = -EACCES;
953 if (!(p->flags & PF_FORKNOEXEC))
954 goto out;
955 } else {
956 err = -ESRCH;
957 if (p != group_leader)
958 goto out;
959 }
960
961 err = -EPERM;
962 if (p->signal->leader)
963 goto out;
964
965 pgrp = task_pid(p);
966 if (pgid != pid) {
967 struct task_struct *g;
968
969 pgrp = find_vpid(pgid);
970 g = pid_task(pgrp, PIDTYPE_PGID);
971 if (!g || task_session(g) != task_session(group_leader))
972 goto out;
973 }
974
975 err = security_task_setpgid(p, pgid);
976 if (err)
977 goto out;
978
979 if (task_pgrp(p) != pgrp)
980 change_pid(p, PIDTYPE_PGID, pgrp);
981
982 err = 0;
983 out:
984 /* All paths lead to here, thus we are safe. -DaveM */
985 write_unlock_irq(&tasklist_lock);
986 rcu_read_unlock();
987 return err;
988 }
989
990 SYSCALL_DEFINE1(getpgid, pid_t, pid)
991 {
992 struct task_struct *p;
993 struct pid *grp;
994 int retval;
995
996 rcu_read_lock();
997 if (!pid)
998 grp = task_pgrp(current);
999 else {
1000 retval = -ESRCH;
1001 p = find_task_by_vpid(pid);
1002 if (!p)
1003 goto out;
1004 grp = task_pgrp(p);
1005 if (!grp)
1006 goto out;
1007
1008 retval = security_task_getpgid(p);
1009 if (retval)
1010 goto out;
1011 }
1012 retval = pid_vnr(grp);
1013 out:
1014 rcu_read_unlock();
1015 return retval;
1016 }
1017
1018 #ifdef __ARCH_WANT_SYS_GETPGRP
1019
1020 SYSCALL_DEFINE0(getpgrp)
1021 {
1022 return sys_getpgid(0);
1023 }
1024
1025 #endif
1026
1027 SYSCALL_DEFINE1(getsid, pid_t, pid)
1028 {
1029 struct task_struct *p;
1030 struct pid *sid;
1031 int retval;
1032
1033 rcu_read_lock();
1034 if (!pid)
1035 sid = task_session(current);
1036 else {
1037 retval = -ESRCH;
1038 p = find_task_by_vpid(pid);
1039 if (!p)
1040 goto out;
1041 sid = task_session(p);
1042 if (!sid)
1043 goto out;
1044
1045 retval = security_task_getsid(p);
1046 if (retval)
1047 goto out;
1048 }
1049 retval = pid_vnr(sid);
1050 out:
1051 rcu_read_unlock();
1052 return retval;
1053 }
1054
1055 static void set_special_pids(struct pid *pid)
1056 {
1057 struct task_struct *curr = current->group_leader;
1058
1059 if (task_session(curr) != pid)
1060 change_pid(curr, PIDTYPE_SID, pid);
1061
1062 if (task_pgrp(curr) != pid)
1063 change_pid(curr, PIDTYPE_PGID, pid);
1064 }
1065
1066 SYSCALL_DEFINE0(setsid)
1067 {
1068 struct task_struct *group_leader = current->group_leader;
1069 struct pid *sid = task_pid(group_leader);
1070 pid_t session = pid_vnr(sid);
1071 int err = -EPERM;
1072
1073 write_lock_irq(&tasklist_lock);
1074 /* Fail if I am already a session leader */
1075 if (group_leader->signal->leader)
1076 goto out;
1077
1078 /* Fail if a process group id already exists that equals the
1079 * proposed session id.
1080 */
1081 if (pid_task(sid, PIDTYPE_PGID))
1082 goto out;
1083
1084 group_leader->signal->leader = 1;
1085 set_special_pids(sid);
1086
1087 proc_clear_tty(group_leader);
1088
1089 err = session;
1090 out:
1091 write_unlock_irq(&tasklist_lock);
1092 if (err > 0) {
1093 proc_sid_connector(group_leader);
1094 sched_autogroup_create_attach(group_leader);
1095 }
1096 return err;
1097 }
1098
1099 DECLARE_RWSEM(uts_sem);
1100
1101 #ifdef COMPAT_UTS_MACHINE
1102 #define override_architecture(name) \
1103 (personality(current->personality) == PER_LINUX32 && \
1104 copy_to_user(name->machine, COMPAT_UTS_MACHINE, \
1105 sizeof(COMPAT_UTS_MACHINE)))
1106 #else
1107 #define override_architecture(name) 0
1108 #endif
1109
1110 /*
1111 * Work around broken programs that cannot handle "Linux 3.0".
1112 * Instead we map 3.x to 2.6.40+x, so e.g. 3.0 would be 2.6.40
1113 * And we map 4.x to 2.6.60+x, so 4.0 would be 2.6.60.
1114 */
1115 static int override_release(char __user *release, size_t len)
1116 {
1117 int ret = 0;
1118
1119 if (current->personality & UNAME26) {
1120 const char *rest = UTS_RELEASE;
1121 char buf[65] = { 0 };
1122 int ndots = 0;
1123 unsigned v;
1124 size_t copy;
1125
1126 while (*rest) {
1127 if (*rest == '.' && ++ndots >= 3)
1128 break;
1129 if (!isdigit(*rest) && *rest != '.')
1130 break;
1131 rest++;
1132 }
1133 v = ((LINUX_VERSION_CODE >> 8) & 0xff) + 60;
1134 copy = clamp_t(size_t, len, 1, sizeof(buf));
1135 copy = scnprintf(buf, copy, "2.6.%u%s", v, rest);
1136 ret = copy_to_user(release, buf, copy + 1);
1137 }
1138 return ret;
1139 }
1140
1141 SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name)
1142 {
1143 int errno = 0;
1144
1145 down_read(&uts_sem);
1146 if (copy_to_user(name, utsname(), sizeof *name))
1147 errno = -EFAULT;
1148 up_read(&uts_sem);
1149
1150 if (!errno && override_release(name->release, sizeof(name->release)))
1151 errno = -EFAULT;
1152 if (!errno && override_architecture(name))
1153 errno = -EFAULT;
1154 return errno;
1155 }
1156
1157 #ifdef __ARCH_WANT_SYS_OLD_UNAME
1158 /*
1159 * Old cruft
1160 */
1161 SYSCALL_DEFINE1(uname, struct old_utsname __user *, name)
1162 {
1163 int error = 0;
1164
1165 if (!name)
1166 return -EFAULT;
1167
1168 down_read(&uts_sem);
1169 if (copy_to_user(name, utsname(), sizeof(*name)))
1170 error = -EFAULT;
1171 up_read(&uts_sem);
1172
1173 if (!error && override_release(name->release, sizeof(name->release)))
1174 error = -EFAULT;
1175 if (!error && override_architecture(name))
1176 error = -EFAULT;
1177 return error;
1178 }
1179
1180 SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name)
1181 {
1182 int error;
1183
1184 if (!name)
1185 return -EFAULT;
1186 if (!access_ok(VERIFY_WRITE, name, sizeof(struct oldold_utsname)))
1187 return -EFAULT;
1188
1189 down_read(&uts_sem);
1190 error = __copy_to_user(&name->sysname, &utsname()->sysname,
1191 __OLD_UTS_LEN);
1192 error |= __put_user(0, name->sysname + __OLD_UTS_LEN);
1193 error |= __copy_to_user(&name->nodename, &utsname()->nodename,
1194 __OLD_UTS_LEN);
1195 error |= __put_user(0, name->nodename + __OLD_UTS_LEN);
1196 error |= __copy_to_user(&name->release, &utsname()->release,
1197 __OLD_UTS_LEN);
1198 error |= __put_user(0, name->release + __OLD_UTS_LEN);
1199 error |= __copy_to_user(&name->version, &utsname()->version,
1200 __OLD_UTS_LEN);
1201 error |= __put_user(0, name->version + __OLD_UTS_LEN);
1202 error |= __copy_to_user(&name->machine, &utsname()->machine,
1203 __OLD_UTS_LEN);
1204 error |= __put_user(0, name->machine + __OLD_UTS_LEN);
1205 up_read(&uts_sem);
1206
1207 if (!error && override_architecture(name))
1208 error = -EFAULT;
1209 if (!error && override_release(name->release, sizeof(name->release)))
1210 error = -EFAULT;
1211 return error ? -EFAULT : 0;
1212 }
1213 #endif
1214
1215 SYSCALL_DEFINE2(sethostname, char __user *, name, int, len)
1216 {
1217 int errno;
1218 char tmp[__NEW_UTS_LEN];
1219
1220 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN))
1221 return -EPERM;
1222
1223 if (len < 0 || len > __NEW_UTS_LEN)
1224 return -EINVAL;
1225 down_write(&uts_sem);
1226 errno = -EFAULT;
1227 if (!copy_from_user(tmp, name, len)) {
1228 struct new_utsname *u = utsname();
1229
1230 memcpy(u->nodename, tmp, len);
1231 memset(u->nodename + len, 0, sizeof(u->nodename) - len);
1232 errno = 0;
1233 uts_proc_notify(UTS_PROC_HOSTNAME);
1234 }
1235 up_write(&uts_sem);
1236 return errno;
1237 }
1238
1239 #ifdef __ARCH_WANT_SYS_GETHOSTNAME
1240
1241 SYSCALL_DEFINE2(gethostname, char __user *, name, int, len)
1242 {
1243 int i, errno;
1244 struct new_utsname *u;
1245
1246 if (len < 0)
1247 return -EINVAL;
1248 down_read(&uts_sem);
1249 u = utsname();
1250 i = 1 + strlen(u->nodename);
1251 if (i > len)
1252 i = len;
1253 errno = 0;
1254 if (copy_to_user(name, u->nodename, i))
1255 errno = -EFAULT;
1256 up_read(&uts_sem);
1257 return errno;
1258 }
1259
1260 #endif
1261
1262 /*
1263 * Only setdomainname; getdomainname can be implemented by calling
1264 * uname()
1265 */
1266 SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len)
1267 {
1268 int errno;
1269 char tmp[__NEW_UTS_LEN];
1270
1271 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN))
1272 return -EPERM;
1273 if (len < 0 || len > __NEW_UTS_LEN)
1274 return -EINVAL;
1275
1276 down_write(&uts_sem);
1277 errno = -EFAULT;
1278 if (!copy_from_user(tmp, name, len)) {
1279 struct new_utsname *u = utsname();
1280
1281 memcpy(u->domainname, tmp, len);
1282 memset(u->domainname + len, 0, sizeof(u->domainname) - len);
1283 errno = 0;
1284 uts_proc_notify(UTS_PROC_DOMAINNAME);
1285 }
1286 up_write(&uts_sem);
1287 return errno;
1288 }
1289
1290 SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim)
1291 {
1292 struct rlimit value;
1293 int ret;
1294
1295 ret = do_prlimit(current, resource, NULL, &value);
1296 if (!ret)
1297 ret = copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0;
1298
1299 return ret;
1300 }
1301
1302 #ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT
1303
1304 /*
1305 * Back compatibility for getrlimit. Needed for some apps.
1306 */
1307 SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
1308 struct rlimit __user *, rlim)
1309 {
1310 struct rlimit x;
1311 if (resource >= RLIM_NLIMITS)
1312 return -EINVAL;
1313
1314 task_lock(current->group_leader);
1315 x = current->signal->rlim[resource];
1316 task_unlock(current->group_leader);
1317 if (x.rlim_cur > 0x7FFFFFFF)
1318 x.rlim_cur = 0x7FFFFFFF;
1319 if (x.rlim_max > 0x7FFFFFFF)
1320 x.rlim_max = 0x7FFFFFFF;
1321 return copy_to_user(rlim, &x, sizeof(x)) ? -EFAULT : 0;
1322 }
1323
1324 #endif
1325
1326 static inline bool rlim64_is_infinity(__u64 rlim64)
1327 {
1328 #if BITS_PER_LONG < 64
1329 return rlim64 >= ULONG_MAX;
1330 #else
1331 return rlim64 == RLIM64_INFINITY;
1332 #endif
1333 }
1334
1335 static void rlim_to_rlim64(const struct rlimit *rlim, struct rlimit64 *rlim64)
1336 {
1337 if (rlim->rlim_cur == RLIM_INFINITY)
1338 rlim64->rlim_cur = RLIM64_INFINITY;
1339 else
1340 rlim64->rlim_cur = rlim->rlim_cur;
1341 if (rlim->rlim_max == RLIM_INFINITY)
1342 rlim64->rlim_max = RLIM64_INFINITY;
1343 else
1344 rlim64->rlim_max = rlim->rlim_max;
1345 }
1346
1347 static void rlim64_to_rlim(const struct rlimit64 *rlim64, struct rlimit *rlim)
1348 {
1349 if (rlim64_is_infinity(rlim64->rlim_cur))
1350 rlim->rlim_cur = RLIM_INFINITY;
1351 else
1352 rlim->rlim_cur = (unsigned long)rlim64->rlim_cur;
1353 if (rlim64_is_infinity(rlim64->rlim_max))
1354 rlim->rlim_max = RLIM_INFINITY;
1355 else
1356 rlim->rlim_max = (unsigned long)rlim64->rlim_max;
1357 }
1358
1359 /* make sure you are allowed to change @tsk limits before calling this */
1360 int do_prlimit(struct task_struct *tsk, unsigned int resource,
1361 struct rlimit *new_rlim, struct rlimit *old_rlim)
1362 {
1363 struct rlimit *rlim;
1364 int retval = 0;
1365
1366 if (resource >= RLIM_NLIMITS)
1367 return -EINVAL;
1368 if (new_rlim) {
1369 if (new_rlim->rlim_cur > new_rlim->rlim_max)
1370 return -EINVAL;
1371 if (resource == RLIMIT_NOFILE &&
1372 new_rlim->rlim_max > sysctl_nr_open)
1373 return -EPERM;
1374 }
1375
1376 /* protect tsk->signal and tsk->sighand from disappearing */
1377 read_lock(&tasklist_lock);
1378 if (!tsk->sighand) {
1379 retval = -ESRCH;
1380 goto out;
1381 }
1382
1383 rlim = tsk->signal->rlim + resource;
1384 task_lock(tsk->group_leader);
1385 if (new_rlim) {
1386 /* Keep the capable check against init_user_ns until
1387 cgroups can contain all limits */
1388 if (new_rlim->rlim_max > rlim->rlim_max &&
1389 !capable(CAP_SYS_RESOURCE))
1390 retval = -EPERM;
1391 if (!retval)
1392 retval = security_task_setrlimit(tsk->group_leader,
1393 resource, new_rlim);
1394 if (resource == RLIMIT_CPU && new_rlim->rlim_cur == 0) {
1395 /*
1396 * The caller is asking for an immediate RLIMIT_CPU
1397 * expiry. But we use the zero value to mean "it was
1398 * never set". So let's cheat and make it one second
1399 * instead
1400 */
1401 new_rlim->rlim_cur = 1;
1402 }
1403 }
1404 if (!retval) {
1405 if (old_rlim)
1406 *old_rlim = *rlim;
1407 if (new_rlim)
1408 *rlim = *new_rlim;
1409 }
1410 task_unlock(tsk->group_leader);
1411
1412 /*
1413 * RLIMIT_CPU handling. Note that the kernel fails to return an error
1414 * code if it rejected the user's attempt to set RLIMIT_CPU. This is a
1415 * very long-standing error, and fixing it now risks breakage of
1416 * applications, so we live with it
1417 */
1418 if (!retval && new_rlim && resource == RLIMIT_CPU &&
1419 new_rlim->rlim_cur != RLIM_INFINITY)
1420 update_rlimit_cpu(tsk, new_rlim->rlim_cur);
1421 out:
1422 read_unlock(&tasklist_lock);
1423 return retval;
1424 }
1425
1426 /* rcu lock must be held */
1427 static int check_prlimit_permission(struct task_struct *task)
1428 {
1429 const struct cred *cred = current_cred(), *tcred;
1430
1431 if (current == task)
1432 return 0;
1433
1434 tcred = __task_cred(task);
1435 if (uid_eq(cred->uid, tcred->euid) &&
1436 uid_eq(cred->uid, tcred->suid) &&
1437 uid_eq(cred->uid, tcred->uid) &&
1438 gid_eq(cred->gid, tcred->egid) &&
1439 gid_eq(cred->gid, tcred->sgid) &&
1440 gid_eq(cred->gid, tcred->gid))
1441 return 0;
1442 if (ns_capable(tcred->user_ns, CAP_SYS_RESOURCE))
1443 return 0;
1444
1445 return -EPERM;
1446 }
1447
1448 SYSCALL_DEFINE4(prlimit64, pid_t, pid, unsigned int, resource,
1449 const struct rlimit64 __user *, new_rlim,
1450 struct rlimit64 __user *, old_rlim)
1451 {
1452 struct rlimit64 old64, new64;
1453 struct rlimit old, new;
1454 struct task_struct *tsk;
1455 int ret;
1456
1457 if (new_rlim) {
1458 if (copy_from_user(&new64, new_rlim, sizeof(new64)))
1459 return -EFAULT;
1460 rlim64_to_rlim(&new64, &new);
1461 }
1462
1463 rcu_read_lock();
1464 tsk = pid ? find_task_by_vpid(pid) : current;
1465 if (!tsk) {
1466 rcu_read_unlock();
1467 return -ESRCH;
1468 }
1469 ret = check_prlimit_permission(tsk);
1470 if (ret) {
1471 rcu_read_unlock();
1472 return ret;
1473 }
1474 get_task_struct(tsk);
1475 rcu_read_unlock();
1476
1477 ret = do_prlimit(tsk, resource, new_rlim ? &new : NULL,
1478 old_rlim ? &old : NULL);
1479
1480 if (!ret && old_rlim) {
1481 rlim_to_rlim64(&old, &old64);
1482 if (copy_to_user(old_rlim, &old64, sizeof(old64)))
1483 ret = -EFAULT;
1484 }
1485
1486 put_task_struct(tsk);
1487 return ret;
1488 }
1489
1490 SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim)
1491 {
1492 struct rlimit new_rlim;
1493
1494 if (copy_from_user(&new_rlim, rlim, sizeof(*rlim)))
1495 return -EFAULT;
1496 return do_prlimit(current, resource, &new_rlim, NULL);
1497 }
1498
1499 /*
1500 * It would make sense to put struct rusage in the task_struct,
1501 * except that would make the task_struct be *really big*. After
1502 * task_struct gets moved into malloc'ed memory, it would
1503 * make sense to do this. It will make moving the rest of the information
1504 * a lot simpler! (Which we're not doing right now because we're not
1505 * measuring them yet).
1506 *
1507 * When sampling multiple threads for RUSAGE_SELF, under SMP we might have
1508 * races with threads incrementing their own counters. But since word
1509 * reads are atomic, we either get new values or old values and we don't
1510 * care which for the sums. We always take the siglock to protect reading
1511 * the c* fields from p->signal from races with exit.c updating those
1512 * fields when reaping, so a sample either gets all the additions of a
1513 * given child after it's reaped, or none so this sample is before reaping.
1514 *
1515 * Locking:
1516 * We need to take the siglock for CHILDEREN, SELF and BOTH
1517 * for the cases current multithreaded, non-current single threaded
1518 * non-current multithreaded. Thread traversal is now safe with
1519 * the siglock held.
1520 * Strictly speaking, we donot need to take the siglock if we are current and
1521 * single threaded, as no one else can take our signal_struct away, no one
1522 * else can reap the children to update signal->c* counters, and no one else
1523 * can race with the signal-> fields. If we do not take any lock, the
1524 * signal-> fields could be read out of order while another thread was just
1525 * exiting. So we should place a read memory barrier when we avoid the lock.
1526 * On the writer side, write memory barrier is implied in __exit_signal
1527 * as __exit_signal releases the siglock spinlock after updating the signal->
1528 * fields. But we don't do this yet to keep things simple.
1529 *
1530 */
1531
1532 static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r)
1533 {
1534 r->ru_nvcsw += t->nvcsw;
1535 r->ru_nivcsw += t->nivcsw;
1536 r->ru_minflt += t->min_flt;
1537 r->ru_majflt += t->maj_flt;
1538 r->ru_inblock += task_io_get_inblock(t);
1539 r->ru_oublock += task_io_get_oublock(t);
1540 }
1541
1542 static void k_getrusage(struct task_struct *p, int who, struct rusage *r)
1543 {
1544 struct task_struct *t;
1545 unsigned long flags;
1546 cputime_t tgutime, tgstime, utime, stime;
1547 unsigned long maxrss = 0;
1548
1549 memset((char *)r, 0, sizeof (*r));
1550 utime = stime = 0;
1551
1552 if (who == RUSAGE_THREAD) {
1553 task_cputime_adjusted(current, &utime, &stime);
1554 accumulate_thread_rusage(p, r);
1555 maxrss = p->signal->maxrss;
1556 goto out;
1557 }
1558
1559 if (!lock_task_sighand(p, &flags))
1560 return;
1561
1562 switch (who) {
1563 case RUSAGE_BOTH:
1564 case RUSAGE_CHILDREN:
1565 utime = p->signal->cutime;
1566 stime = p->signal->cstime;
1567 r->ru_nvcsw = p->signal->cnvcsw;
1568 r->ru_nivcsw = p->signal->cnivcsw;
1569 r->ru_minflt = p->signal->cmin_flt;
1570 r->ru_majflt = p->signal->cmaj_flt;
1571 r->ru_inblock = p->signal->cinblock;
1572 r->ru_oublock = p->signal->coublock;
1573 maxrss = p->signal->cmaxrss;
1574
1575 if (who == RUSAGE_CHILDREN)
1576 break;
1577
1578 case RUSAGE_SELF:
1579 thread_group_cputime_adjusted(p, &tgutime, &tgstime);
1580 utime += tgutime;
1581 stime += tgstime;
1582 r->ru_nvcsw += p->signal->nvcsw;
1583 r->ru_nivcsw += p->signal->nivcsw;
1584 r->ru_minflt += p->signal->min_flt;
1585 r->ru_majflt += p->signal->maj_flt;
1586 r->ru_inblock += p->signal->inblock;
1587 r->ru_oublock += p->signal->oublock;
1588 if (maxrss < p->signal->maxrss)
1589 maxrss = p->signal->maxrss;
1590 t = p;
1591 do {
1592 accumulate_thread_rusage(t, r);
1593 } while_each_thread(p, t);
1594 break;
1595
1596 default:
1597 BUG();
1598 }
1599 unlock_task_sighand(p, &flags);
1600
1601 out:
1602 cputime_to_timeval(utime, &r->ru_utime);
1603 cputime_to_timeval(stime, &r->ru_stime);
1604
1605 if (who != RUSAGE_CHILDREN) {
1606 struct mm_struct *mm = get_task_mm(p);
1607
1608 if (mm) {
1609 setmax_mm_hiwater_rss(&maxrss, mm);
1610 mmput(mm);
1611 }
1612 }
1613 r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */
1614 }
1615
1616 int getrusage(struct task_struct *p, int who, struct rusage __user *ru)
1617 {
1618 struct rusage r;
1619
1620 k_getrusage(p, who, &r);
1621 return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0;
1622 }
1623
1624 SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru)
1625 {
1626 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
1627 who != RUSAGE_THREAD)
1628 return -EINVAL;
1629 return getrusage(current, who, ru);
1630 }
1631
1632 #ifdef CONFIG_COMPAT
1633 COMPAT_SYSCALL_DEFINE2(getrusage, int, who, struct compat_rusage __user *, ru)
1634 {
1635 struct rusage r;
1636
1637 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
1638 who != RUSAGE_THREAD)
1639 return -EINVAL;
1640
1641 k_getrusage(current, who, &r);
1642 return put_compat_rusage(&r, ru);
1643 }
1644 #endif
1645
1646 SYSCALL_DEFINE1(umask, int, mask)
1647 {
1648 mask = xchg(&current->fs->umask, mask & S_IRWXUGO);
1649 return mask;
1650 }
1651
1652 static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd)
1653 {
1654 struct fd exe;
1655 struct file *old_exe, *exe_file;
1656 struct inode *inode;
1657 int err;
1658
1659 exe = fdget(fd);
1660 if (!exe.file)
1661 return -EBADF;
1662
1663 inode = file_inode(exe.file);
1664
1665 /*
1666 * Because the original mm->exe_file points to executable file, make
1667 * sure that this one is executable as well, to avoid breaking an
1668 * overall picture.
1669 */
1670 err = -EACCES;
1671 if (!S_ISREG(inode->i_mode) ||
1672 exe.file->f_path.mnt->mnt_flags & MNT_NOEXEC)
1673 goto exit;
1674
1675 err = inode_permission(inode, MAY_EXEC);
1676 if (err)
1677 goto exit;
1678
1679 /*
1680 * Forbid mm->exe_file change if old file still mapped.
1681 */
1682 exe_file = get_mm_exe_file(mm);
1683 err = -EBUSY;
1684 if (exe_file) {
1685 struct vm_area_struct *vma;
1686
1687 down_read(&mm->mmap_sem);
1688 for (vma = mm->mmap; vma; vma = vma->vm_next) {
1689 if (!vma->vm_file)
1690 continue;
1691 if (path_equal(&vma->vm_file->f_path,
1692 &exe_file->f_path))
1693 goto exit_err;
1694 }
1695
1696 up_read(&mm->mmap_sem);
1697 fput(exe_file);
1698 }
1699
1700 /*
1701 * The symlink can be changed only once, just to disallow arbitrary
1702 * transitions malicious software might bring in. This means one
1703 * could make a snapshot over all processes running and monitor
1704 * /proc/pid/exe changes to notice unusual activity if needed.
1705 */
1706 err = -EPERM;
1707 if (test_and_set_bit(MMF_EXE_FILE_CHANGED, &mm->flags))
1708 goto exit;
1709
1710 err = 0;
1711 /* set the new file, lockless */
1712 get_file(exe.file);
1713 old_exe = xchg(&mm->exe_file, exe.file);
1714 if (old_exe)
1715 fput(old_exe);
1716 exit:
1717 fdput(exe);
1718 return err;
1719 exit_err:
1720 up_read(&mm->mmap_sem);
1721 fput(exe_file);
1722 goto exit;
1723 }
1724
1725 #ifdef CONFIG_CHECKPOINT_RESTORE
1726 /*
1727 * WARNING: we don't require any capability here so be very careful
1728 * in what is allowed for modification from userspace.
1729 */
1730 static int validate_prctl_map(struct prctl_mm_map *prctl_map)
1731 {
1732 unsigned long mmap_max_addr = TASK_SIZE;
1733 struct mm_struct *mm = current->mm;
1734 int error = -EINVAL, i;
1735
1736 static const unsigned char offsets[] = {
1737 offsetof(struct prctl_mm_map, start_code),
1738 offsetof(struct prctl_mm_map, end_code),
1739 offsetof(struct prctl_mm_map, start_data),
1740 offsetof(struct prctl_mm_map, end_data),
1741 offsetof(struct prctl_mm_map, start_brk),
1742 offsetof(struct prctl_mm_map, brk),
1743 offsetof(struct prctl_mm_map, start_stack),
1744 offsetof(struct prctl_mm_map, arg_start),
1745 offsetof(struct prctl_mm_map, arg_end),
1746 offsetof(struct prctl_mm_map, env_start),
1747 offsetof(struct prctl_mm_map, env_end),
1748 };
1749
1750 /*
1751 * Make sure the members are not somewhere outside
1752 * of allowed address space.
1753 */
1754 for (i = 0; i < ARRAY_SIZE(offsets); i++) {
1755 u64 val = *(u64 *)((char *)prctl_map + offsets[i]);
1756
1757 if ((unsigned long)val >= mmap_max_addr ||
1758 (unsigned long)val < mmap_min_addr)
1759 goto out;
1760 }
1761
1762 /*
1763 * Make sure the pairs are ordered.
1764 */
1765 #define __prctl_check_order(__m1, __op, __m2) \
1766 ((unsigned long)prctl_map->__m1 __op \
1767 (unsigned long)prctl_map->__m2) ? 0 : -EINVAL
1768 error = __prctl_check_order(start_code, <, end_code);
1769 error |= __prctl_check_order(start_data, <, end_data);
1770 error |= __prctl_check_order(start_brk, <=, brk);
1771 error |= __prctl_check_order(arg_start, <=, arg_end);
1772 error |= __prctl_check_order(env_start, <=, env_end);
1773 if (error)
1774 goto out;
1775 #undef __prctl_check_order
1776
1777 error = -EINVAL;
1778
1779 /*
1780 * @brk should be after @end_data in traditional maps.
1781 */
1782 if (prctl_map->start_brk <= prctl_map->end_data ||
1783 prctl_map->brk <= prctl_map->end_data)
1784 goto out;
1785
1786 /*
1787 * Neither we should allow to override limits if they set.
1788 */
1789 if (check_data_rlimit(rlimit(RLIMIT_DATA), prctl_map->brk,
1790 prctl_map->start_brk, prctl_map->end_data,
1791 prctl_map->start_data))
1792 goto out;
1793
1794 /*
1795 * Someone is trying to cheat the auxv vector.
1796 */
1797 if (prctl_map->auxv_size) {
1798 if (!prctl_map->auxv || prctl_map->auxv_size > sizeof(mm->saved_auxv))
1799 goto out;
1800 }
1801
1802 /*
1803 * Finally, make sure the caller has the rights to
1804 * change /proc/pid/exe link: only local root should
1805 * be allowed to.
1806 */
1807 if (prctl_map->exe_fd != (u32)-1) {
1808 struct user_namespace *ns = current_user_ns();
1809 const struct cred *cred = current_cred();
1810
1811 if (!uid_eq(cred->uid, make_kuid(ns, 0)) ||
1812 !gid_eq(cred->gid, make_kgid(ns, 0)))
1813 goto out;
1814 }
1815
1816 error = 0;
1817 out:
1818 return error;
1819 }
1820
1821 static int prctl_set_mm_map(int opt, const void __user *addr, unsigned long data_size)
1822 {
1823 struct prctl_mm_map prctl_map = { .exe_fd = (u32)-1, };
1824 unsigned long user_auxv[AT_VECTOR_SIZE];
1825 struct mm_struct *mm = current->mm;
1826 int error;
1827
1828 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv));
1829 BUILD_BUG_ON(sizeof(struct prctl_mm_map) > 256);
1830
1831 if (opt == PR_SET_MM_MAP_SIZE)
1832 return put_user((unsigned int)sizeof(prctl_map),
1833 (unsigned int __user *)addr);
1834
1835 if (data_size != sizeof(prctl_map))
1836 return -EINVAL;
1837
1838 if (copy_from_user(&prctl_map, addr, sizeof(prctl_map)))
1839 return -EFAULT;
1840
1841 error = validate_prctl_map(&prctl_map);
1842 if (error)
1843 return error;
1844
1845 if (prctl_map.auxv_size) {
1846 memset(user_auxv, 0, sizeof(user_auxv));
1847 if (copy_from_user(user_auxv,
1848 (const void __user *)prctl_map.auxv,
1849 prctl_map.auxv_size))
1850 return -EFAULT;
1851
1852 /* Last entry must be AT_NULL as specification requires */
1853 user_auxv[AT_VECTOR_SIZE - 2] = AT_NULL;
1854 user_auxv[AT_VECTOR_SIZE - 1] = AT_NULL;
1855 }
1856
1857 if (prctl_map.exe_fd != (u32)-1) {
1858 error = prctl_set_mm_exe_file(mm, prctl_map.exe_fd);
1859 if (error)
1860 return error;
1861 }
1862
1863 down_write(&mm->mmap_sem);
1864
1865 /*
1866 * We don't validate if these members are pointing to
1867 * real present VMAs because application may have correspond
1868 * VMAs already unmapped and kernel uses these members for statistics
1869 * output in procfs mostly, except
1870 *
1871 * - @start_brk/@brk which are used in do_brk but kernel lookups
1872 * for VMAs when updating these memvers so anything wrong written
1873 * here cause kernel to swear at userspace program but won't lead
1874 * to any problem in kernel itself
1875 */
1876
1877 mm->start_code = prctl_map.start_code;
1878 mm->end_code = prctl_map.end_code;
1879 mm->start_data = prctl_map.start_data;
1880 mm->end_data = prctl_map.end_data;
1881 mm->start_brk = prctl_map.start_brk;
1882 mm->brk = prctl_map.brk;
1883 mm->start_stack = prctl_map.start_stack;
1884 mm->arg_start = prctl_map.arg_start;
1885 mm->arg_end = prctl_map.arg_end;
1886 mm->env_start = prctl_map.env_start;
1887 mm->env_end = prctl_map.env_end;
1888
1889 /*
1890 * Note this update of @saved_auxv is lockless thus
1891 * if someone reads this member in procfs while we're
1892 * updating -- it may get partly updated results. It's
1893 * known and acceptable trade off: we leave it as is to
1894 * not introduce additional locks here making the kernel
1895 * more complex.
1896 */
1897 if (prctl_map.auxv_size)
1898 memcpy(mm->saved_auxv, user_auxv, sizeof(user_auxv));
1899
1900 up_write(&mm->mmap_sem);
1901 return 0;
1902 }
1903 #endif /* CONFIG_CHECKPOINT_RESTORE */
1904
1905 static int prctl_set_mm(int opt, unsigned long addr,
1906 unsigned long arg4, unsigned long arg5)
1907 {
1908 struct mm_struct *mm = current->mm;
1909 struct vm_area_struct *vma;
1910 int error;
1911
1912 if (arg5 || (arg4 && (opt != PR_SET_MM_AUXV &&
1913 opt != PR_SET_MM_MAP &&
1914 opt != PR_SET_MM_MAP_SIZE)))
1915 return -EINVAL;
1916
1917 #ifdef CONFIG_CHECKPOINT_RESTORE
1918 if (opt == PR_SET_MM_MAP || opt == PR_SET_MM_MAP_SIZE)
1919 return prctl_set_mm_map(opt, (const void __user *)addr, arg4);
1920 #endif
1921
1922 if (!capable(CAP_SYS_RESOURCE))
1923 return -EPERM;
1924
1925 if (opt == PR_SET_MM_EXE_FILE)
1926 return prctl_set_mm_exe_file(mm, (unsigned int)addr);
1927
1928 if (addr >= TASK_SIZE || addr < mmap_min_addr)
1929 return -EINVAL;
1930
1931 error = -EINVAL;
1932
1933 down_write(&mm->mmap_sem);
1934 vma = find_vma(mm, addr);
1935
1936 switch (opt) {
1937 case PR_SET_MM_START_CODE:
1938 mm->start_code = addr;
1939 break;
1940 case PR_SET_MM_END_CODE:
1941 mm->end_code = addr;
1942 break;
1943 case PR_SET_MM_START_DATA:
1944 mm->start_data = addr;
1945 break;
1946 case PR_SET_MM_END_DATA:
1947 mm->end_data = addr;
1948 break;
1949
1950 case PR_SET_MM_START_BRK:
1951 if (addr <= mm->end_data)
1952 goto out;
1953
1954 if (check_data_rlimit(rlimit(RLIMIT_DATA), mm->brk, addr,
1955 mm->end_data, mm->start_data))
1956 goto out;
1957
1958 mm->start_brk = addr;
1959 break;
1960
1961 case PR_SET_MM_BRK:
1962 if (addr <= mm->end_data)
1963 goto out;
1964
1965 if (check_data_rlimit(rlimit(RLIMIT_DATA), addr, mm->start_brk,
1966 mm->end_data, mm->start_data))
1967 goto out;
1968
1969 mm->brk = addr;
1970 break;
1971
1972 /*
1973 * If command line arguments and environment
1974 * are placed somewhere else on stack, we can
1975 * set them up here, ARG_START/END to setup
1976 * command line argumets and ENV_START/END
1977 * for environment.
1978 */
1979 case PR_SET_MM_START_STACK:
1980 case PR_SET_MM_ARG_START:
1981 case PR_SET_MM_ARG_END:
1982 case PR_SET_MM_ENV_START:
1983 case PR_SET_MM_ENV_END:
1984 if (!vma) {
1985 error = -EFAULT;
1986 goto out;
1987 }
1988 if (opt == PR_SET_MM_START_STACK)
1989 mm->start_stack = addr;
1990 else if (opt == PR_SET_MM_ARG_START)
1991 mm->arg_start = addr;
1992 else if (opt == PR_SET_MM_ARG_END)
1993 mm->arg_end = addr;
1994 else if (opt == PR_SET_MM_ENV_START)
1995 mm->env_start = addr;
1996 else if (opt == PR_SET_MM_ENV_END)
1997 mm->env_end = addr;
1998 break;
1999
2000 /*
2001 * This doesn't move auxiliary vector itself
2002 * since it's pinned to mm_struct, but allow
2003 * to fill vector with new values. It's up
2004 * to a caller to provide sane values here
2005 * otherwise user space tools which use this
2006 * vector might be unhappy.
2007 */
2008 case PR_SET_MM_AUXV: {
2009 unsigned long user_auxv[AT_VECTOR_SIZE];
2010
2011 if (arg4 > sizeof(user_auxv))
2012 goto out;
2013 up_read(&mm->mmap_sem);
2014
2015 if (copy_from_user(user_auxv, (const void __user *)addr, arg4))
2016 return -EFAULT;
2017
2018 /* Make sure the last entry is always AT_NULL */
2019 user_auxv[AT_VECTOR_SIZE - 2] = 0;
2020 user_auxv[AT_VECTOR_SIZE - 1] = 0;
2021
2022 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv));
2023
2024 task_lock(current);
2025 memcpy(mm->saved_auxv, user_auxv, arg4);
2026 task_unlock(current);
2027
2028 return 0;
2029 }
2030 default:
2031 goto out;
2032 }
2033
2034 error = 0;
2035 out:
2036 up_write(&mm->mmap_sem);
2037 return error;
2038 }
2039
2040 #ifdef CONFIG_CHECKPOINT_RESTORE
2041 static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr)
2042 {
2043 return put_user(me->clear_child_tid, tid_addr);
2044 }
2045 #else
2046 static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr)
2047 {
2048 return -EINVAL;
2049 }
2050 #endif
2051
2052 SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
2053 unsigned long, arg4, unsigned long, arg5)
2054 {
2055 struct task_struct *me = current;
2056 unsigned char comm[sizeof(me->comm)];
2057 long error;
2058
2059 error = security_task_prctl(option, arg2, arg3, arg4, arg5);
2060 if (error != -ENOSYS)
2061 return error;
2062
2063 error = 0;
2064 switch (option) {
2065 case PR_SET_PDEATHSIG:
2066 if (!valid_signal(arg2)) {
2067 error = -EINVAL;
2068 break;
2069 }
2070 me->pdeath_signal = arg2;
2071 break;
2072 case PR_GET_PDEATHSIG:
2073 error = put_user(me->pdeath_signal, (int __user *)arg2);
2074 break;
2075 case PR_GET_DUMPABLE:
2076 error = get_dumpable(me->mm);
2077 break;
2078 case PR_SET_DUMPABLE:
2079 if (arg2 != SUID_DUMP_DISABLE && arg2 != SUID_DUMP_USER) {
2080 error = -EINVAL;
2081 break;
2082 }
2083 set_dumpable(me->mm, arg2);
2084 break;
2085
2086 case PR_SET_UNALIGN:
2087 error = SET_UNALIGN_CTL(me, arg2);
2088 break;
2089 case PR_GET_UNALIGN:
2090 error = GET_UNALIGN_CTL(me, arg2);
2091 break;
2092 case PR_SET_FPEMU:
2093 error = SET_FPEMU_CTL(me, arg2);
2094 break;
2095 case PR_GET_FPEMU:
2096 error = GET_FPEMU_CTL(me, arg2);
2097 break;
2098 case PR_SET_FPEXC:
2099 error = SET_FPEXC_CTL(me, arg2);
2100 break;
2101 case PR_GET_FPEXC:
2102 error = GET_FPEXC_CTL(me, arg2);
2103 break;
2104 case PR_GET_TIMING:
2105 error = PR_TIMING_STATISTICAL;
2106 break;
2107 case PR_SET_TIMING:
2108 if (arg2 != PR_TIMING_STATISTICAL)
2109 error = -EINVAL;
2110 break;
2111 case PR_SET_NAME:
2112 comm[sizeof(me->comm) - 1] = 0;
2113 if (strncpy_from_user(comm, (char __user *)arg2,
2114 sizeof(me->comm) - 1) < 0)
2115 return -EFAULT;
2116 set_task_comm(me, comm);
2117 proc_comm_connector(me);
2118 break;
2119 case PR_GET_NAME:
2120 get_task_comm(comm, me);
2121 if (copy_to_user((char __user *)arg2, comm, sizeof(comm)))
2122 return -EFAULT;
2123 break;
2124 case PR_GET_ENDIAN:
2125 error = GET_ENDIAN(me, arg2);
2126 break;
2127 case PR_SET_ENDIAN:
2128 error = SET_ENDIAN(me, arg2);
2129 break;
2130 case PR_GET_SECCOMP:
2131 error = prctl_get_seccomp();
2132 break;
2133 case PR_SET_SECCOMP:
2134 error = prctl_set_seccomp(arg2, (char __user *)arg3);
2135 break;
2136 case PR_GET_TSC:
2137 error = GET_TSC_CTL(arg2);
2138 break;
2139 case PR_SET_TSC:
2140 error = SET_TSC_CTL(arg2);
2141 break;
2142 case PR_TASK_PERF_EVENTS_DISABLE:
2143 error = perf_event_task_disable();
2144 break;
2145 case PR_TASK_PERF_EVENTS_ENABLE:
2146 error = perf_event_task_enable();
2147 break;
2148 case PR_GET_TIMERSLACK:
2149 error = current->timer_slack_ns;
2150 break;
2151 case PR_SET_TIMERSLACK:
2152 if (arg2 <= 0)
2153 current->timer_slack_ns =
2154 current->default_timer_slack_ns;
2155 else
2156 current->timer_slack_ns = arg2;
2157 break;
2158 case PR_MCE_KILL:
2159 if (arg4 | arg5)
2160 return -EINVAL;
2161 switch (arg2) {
2162 case PR_MCE_KILL_CLEAR:
2163 if (arg3 != 0)
2164 return -EINVAL;
2165 current->flags &= ~PF_MCE_PROCESS;
2166 break;
2167 case PR_MCE_KILL_SET:
2168 current->flags |= PF_MCE_PROCESS;
2169 if (arg3 == PR_MCE_KILL_EARLY)
2170 current->flags |= PF_MCE_EARLY;
2171 else if (arg3 == PR_MCE_KILL_LATE)
2172 current->flags &= ~PF_MCE_EARLY;
2173 else if (arg3 == PR_MCE_KILL_DEFAULT)
2174 current->flags &=
2175 ~(PF_MCE_EARLY|PF_MCE_PROCESS);
2176 else
2177 return -EINVAL;
2178 break;
2179 default:
2180 return -EINVAL;
2181 }
2182 break;
2183 case PR_MCE_KILL_GET:
2184 if (arg2 | arg3 | arg4 | arg5)
2185 return -EINVAL;
2186 if (current->flags & PF_MCE_PROCESS)
2187 error = (current->flags & PF_MCE_EARLY) ?
2188 PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE;
2189 else
2190 error = PR_MCE_KILL_DEFAULT;
2191 break;
2192 case PR_SET_MM:
2193 error = prctl_set_mm(arg2, arg3, arg4, arg5);
2194 break;
2195 case PR_GET_TID_ADDRESS:
2196 error = prctl_get_tid_address(me, (int __user **)arg2);
2197 break;
2198 case PR_SET_CHILD_SUBREAPER:
2199 me->signal->is_child_subreaper = !!arg2;
2200 break;
2201 case PR_GET_CHILD_SUBREAPER:
2202 error = put_user(me->signal->is_child_subreaper,
2203 (int __user *)arg2);
2204 break;
2205 case PR_SET_NO_NEW_PRIVS:
2206 if (arg2 != 1 || arg3 || arg4 || arg5)
2207 return -EINVAL;
2208
2209 task_set_no_new_privs(current);
2210 break;
2211 case PR_GET_NO_NEW_PRIVS:
2212 if (arg2 || arg3 || arg4 || arg5)
2213 return -EINVAL;
2214 return task_no_new_privs(current) ? 1 : 0;
2215 case PR_GET_THP_DISABLE:
2216 if (arg2 || arg3 || arg4 || arg5)
2217 return -EINVAL;
2218 error = !!(me->mm->def_flags & VM_NOHUGEPAGE);
2219 break;
2220 case PR_SET_THP_DISABLE:
2221 if (arg3 || arg4 || arg5)
2222 return -EINVAL;
2223 down_write(&me->mm->mmap_sem);
2224 if (arg2)
2225 me->mm->def_flags |= VM_NOHUGEPAGE;
2226 else
2227 me->mm->def_flags &= ~VM_NOHUGEPAGE;
2228 up_write(&me->mm->mmap_sem);
2229 break;
2230 case PR_MPX_ENABLE_MANAGEMENT:
2231 if (arg2 || arg3 || arg4 || arg5)
2232 return -EINVAL;
2233 error = MPX_ENABLE_MANAGEMENT(me);
2234 break;
2235 case PR_MPX_DISABLE_MANAGEMENT:
2236 if (arg2 || arg3 || arg4 || arg5)
2237 return -EINVAL;
2238 error = MPX_DISABLE_MANAGEMENT(me);
2239 break;
2240 case PR_SET_FP_MODE:
2241 error = SET_FP_MODE(me, arg2);
2242 break;
2243 case PR_GET_FP_MODE:
2244 error = GET_FP_MODE(me);
2245 break;
2246 default:
2247 error = -EINVAL;
2248 break;
2249 }
2250 return error;
2251 }
2252
2253 SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep,
2254 struct getcpu_cache __user *, unused)
2255 {
2256 int err = 0;
2257 int cpu = raw_smp_processor_id();
2258
2259 if (cpup)
2260 err |= put_user(cpu, cpup);
2261 if (nodep)
2262 err |= put_user(cpu_to_node(cpu), nodep);
2263 return err ? -EFAULT : 0;
2264 }
2265
2266 /**
2267 * do_sysinfo - fill in sysinfo struct
2268 * @info: pointer to buffer to fill
2269 */
2270 static int do_sysinfo(struct sysinfo *info)
2271 {
2272 unsigned long mem_total, sav_total;
2273 unsigned int mem_unit, bitcount;
2274 struct timespec tp;
2275
2276 memset(info, 0, sizeof(struct sysinfo));
2277
2278 get_monotonic_boottime(&tp);
2279 info->uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0);
2280
2281 get_avenrun(info->loads, 0, SI_LOAD_SHIFT - FSHIFT);
2282
2283 info->procs = nr_threads;
2284
2285 si_meminfo(info);
2286 si_swapinfo(info);
2287
2288 /*
2289 * If the sum of all the available memory (i.e. ram + swap)
2290 * is less than can be stored in a 32 bit unsigned long then
2291 * we can be binary compatible with 2.2.x kernels. If not,
2292 * well, in that case 2.2.x was broken anyways...
2293 *
2294 * -Erik Andersen <andersee@debian.org>
2295 */
2296
2297 mem_total = info->totalram + info->totalswap;
2298 if (mem_total < info->totalram || mem_total < info->totalswap)
2299 goto out;
2300 bitcount = 0;
2301 mem_unit = info->mem_unit;
2302 while (mem_unit > 1) {
2303 bitcount++;
2304 mem_unit >>= 1;
2305 sav_total = mem_total;
2306 mem_total <<= 1;
2307 if (mem_total < sav_total)
2308 goto out;
2309 }
2310
2311 /*
2312 * If mem_total did not overflow, multiply all memory values by
2313 * info->mem_unit and set it to 1. This leaves things compatible
2314 * with 2.2.x, and also retains compatibility with earlier 2.4.x
2315 * kernels...
2316 */
2317
2318 info->mem_unit = 1;
2319 info->totalram <<= bitcount;
2320 info->freeram <<= bitcount;
2321 info->sharedram <<= bitcount;
2322 info->bufferram <<= bitcount;
2323 info->totalswap <<= bitcount;
2324 info->freeswap <<= bitcount;
2325 info->totalhigh <<= bitcount;
2326 info->freehigh <<= bitcount;
2327
2328 out:
2329 return 0;
2330 }
2331
2332 SYSCALL_DEFINE1(sysinfo, struct sysinfo __user *, info)
2333 {
2334 struct sysinfo val;
2335
2336 do_sysinfo(&val);
2337
2338 if (copy_to_user(info, &val, sizeof(struct sysinfo)))
2339 return -EFAULT;
2340
2341 return 0;
2342 }
2343
2344 #ifdef CONFIG_COMPAT
2345 struct compat_sysinfo {
2346 s32 uptime;
2347 u32 loads[3];
2348 u32 totalram;
2349 u32 freeram;
2350 u32 sharedram;
2351 u32 bufferram;
2352 u32 totalswap;
2353 u32 freeswap;
2354 u16 procs;
2355 u16 pad;
2356 u32 totalhigh;
2357 u32 freehigh;
2358 u32 mem_unit;
2359 char _f[20-2*sizeof(u32)-sizeof(int)];
2360 };
2361
2362 COMPAT_SYSCALL_DEFINE1(sysinfo, struct compat_sysinfo __user *, info)
2363 {
2364 struct sysinfo s;
2365
2366 do_sysinfo(&s);
2367
2368 /* Check to see if any memory value is too large for 32-bit and scale
2369 * down if needed
2370 */
2371 if (upper_32_bits(s.totalram) || upper_32_bits(s.totalswap)) {
2372 int bitcount = 0;
2373
2374 while (s.mem_unit < PAGE_SIZE) {
2375 s.mem_unit <<= 1;
2376 bitcount++;
2377 }
2378
2379 s.totalram >>= bitcount;
2380 s.freeram >>= bitcount;
2381 s.sharedram >>= bitcount;
2382 s.bufferram >>= bitcount;
2383 s.totalswap >>= bitcount;
2384 s.freeswap >>= bitcount;
2385 s.totalhigh >>= bitcount;
2386 s.freehigh >>= bitcount;
2387 }
2388
2389 if (!access_ok(VERIFY_WRITE, info, sizeof(struct compat_sysinfo)) ||
2390 __put_user(s.uptime, &info->uptime) ||
2391 __put_user(s.loads[0], &info->loads[0]) ||
2392 __put_user(s.loads[1], &info->loads[1]) ||
2393 __put_user(s.loads[2], &info->loads[2]) ||
2394 __put_user(s.totalram, &info->totalram) ||
2395 __put_user(s.freeram, &info->freeram) ||
2396 __put_user(s.sharedram, &info->sharedram) ||
2397 __put_user(s.bufferram, &info->bufferram) ||
2398 __put_user(s.totalswap, &info->totalswap) ||
2399 __put_user(s.freeswap, &info->freeswap) ||
2400 __put_user(s.procs, &info->procs) ||
2401 __put_user(s.totalhigh, &info->totalhigh) ||
2402 __put_user(s.freehigh, &info->freehigh) ||
2403 __put_user(s.mem_unit, &info->mem_unit))
2404 return -EFAULT;
2405
2406 return 0;
2407 }
2408 #endif /* CONFIG_COMPAT */
Linux with added FPC-III support