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Merge tag 'drm/tegra/for-3.18-rc5' of git://people.freedesktop.org/~tagr/linux into...
[linux/fpc-iii.git] / kernel / sys.c
blob1eaa2f0b02460b5c2a7670af0d1e058444da9eb5
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
95 /*
96 * this is where the system-wide overflow UID and GID are defined, for
97 * architectures that now have 32-bit UID/GID but didn't in the past
98 */
99
100 int overflowuid = DEFAULT_OVERFLOWUID;
101 int overflowgid = DEFAULT_OVERFLOWGID;
102
103 EXPORT_SYMBOL(overflowuid);
104 EXPORT_SYMBOL(overflowgid);
105
106 /*
107 * the same as above, but for filesystems which can only store a 16-bit
108 * UID and GID. as such, this is needed on all architectures
109 */
110
111 int fs_overflowuid = DEFAULT_FS_OVERFLOWUID;
112 int fs_overflowgid = DEFAULT_FS_OVERFLOWUID;
113
114 EXPORT_SYMBOL(fs_overflowuid);
115 EXPORT_SYMBOL(fs_overflowgid);
116
117 /*
118 * Returns true if current's euid is same as p's uid or euid,
119 * or has CAP_SYS_NICE to p's user_ns.
120 *
121 * Called with rcu_read_lock, creds are safe
122 */
123 static bool set_one_prio_perm(struct task_struct *p)
124 {
125 const struct cred *cred = current_cred(), *pcred = __task_cred(p);
126
127 if (uid_eq(pcred->uid, cred->euid) ||
128 uid_eq(pcred->euid, cred->euid))
129 return true;
130 if (ns_capable(pcred->user_ns, CAP_SYS_NICE))
131 return true;
132 return false;
133 }
134
135 /*
136 * set the priority of a task
137 * - the caller must hold the RCU read lock
138 */
139 static int set_one_prio(struct task_struct *p, int niceval, int error)
140 {
141 int no_nice;
142
143 if (!set_one_prio_perm(p)) {
144 error = -EPERM;
145 goto out;
146 }
147 if (niceval < task_nice(p) && !can_nice(p, niceval)) {
148 error = -EACCES;
149 goto out;
150 }
151 no_nice = security_task_setnice(p, niceval);
152 if (no_nice) {
153 error = no_nice;
154 goto out;
155 }
156 if (error == -ESRCH)
157 error = 0;
158 set_user_nice(p, niceval);
159 out:
160 return error;
161 }
162
163 SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval)
164 {
165 struct task_struct *g, *p;
166 struct user_struct *user;
167 const struct cred *cred = current_cred();
168 int error = -EINVAL;
169 struct pid *pgrp;
170 kuid_t uid;
171
172 if (which > PRIO_USER || which < PRIO_PROCESS)
173 goto out;
174
175 /* normalize: avoid signed division (rounding problems) */
176 error = -ESRCH;
177 if (niceval < MIN_NICE)
178 niceval = MIN_NICE;
179 if (niceval > MAX_NICE)
180 niceval = MAX_NICE;
181
182 rcu_read_lock();
183 read_lock(&tasklist_lock);
184 switch (which) {
185 case PRIO_PROCESS:
186 if (who)
187 p = find_task_by_vpid(who);
188 else
189 p = current;
190 if (p)
191 error = set_one_prio(p, niceval, error);
192 break;
193 case PRIO_PGRP:
194 if (who)
195 pgrp = find_vpid(who);
196 else
197 pgrp = task_pgrp(current);
198 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
199 error = set_one_prio(p, niceval, error);
200 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
201 break;
202 case PRIO_USER:
203 uid = make_kuid(cred->user_ns, who);
204 user = cred->user;
205 if (!who)
206 uid = cred->uid;
207 else if (!uid_eq(uid, cred->uid)) {
208 user = find_user(uid);
209 if (!user)
210 goto out_unlock; /* No processes for this user */
211 }
212 do_each_thread(g, p) {
213 if (uid_eq(task_uid(p), uid))
214 error = set_one_prio(p, niceval, error);
215 } while_each_thread(g, p);
216 if (!uid_eq(uid, cred->uid))
217 free_uid(user); /* For find_user() */
218 break;
219 }
220 out_unlock:
221 read_unlock(&tasklist_lock);
222 rcu_read_unlock();
223 out:
224 return error;
225 }
226
227 /*
228 * Ugh. To avoid negative return values, "getpriority()" will
229 * not return the normal nice-value, but a negated value that
230 * has been offset by 20 (ie it returns 40..1 instead of -20..19)
231 * to stay compatible.
232 */
233 SYSCALL_DEFINE2(getpriority, int, which, int, who)
234 {
235 struct task_struct *g, *p;
236 struct user_struct *user;
237 const struct cred *cred = current_cred();
238 long niceval, retval = -ESRCH;
239 struct pid *pgrp;
240 kuid_t uid;
241
242 if (which > PRIO_USER || which < PRIO_PROCESS)
243 return -EINVAL;
244
245 rcu_read_lock();
246 read_lock(&tasklist_lock);
247 switch (which) {
248 case PRIO_PROCESS:
249 if (who)
250 p = find_task_by_vpid(who);
251 else
252 p = current;
253 if (p) {
254 niceval = nice_to_rlimit(task_nice(p));
255 if (niceval > retval)
256 retval = niceval;
257 }
258 break;
259 case PRIO_PGRP:
260 if (who)
261 pgrp = find_vpid(who);
262 else
263 pgrp = task_pgrp(current);
264 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
265 niceval = nice_to_rlimit(task_nice(p));
266 if (niceval > retval)
267 retval = niceval;
268 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
269 break;
270 case PRIO_USER:
271 uid = make_kuid(cred->user_ns, who);
272 user = cred->user;
273 if (!who)
274 uid = cred->uid;
275 else if (!uid_eq(uid, cred->uid)) {
276 user = find_user(uid);
277 if (!user)
278 goto out_unlock; /* No processes for this user */
279 }
280 do_each_thread(g, p) {
281 if (uid_eq(task_uid(p), uid)) {
282 niceval = nice_to_rlimit(task_nice(p));
283 if (niceval > retval)
284 retval = niceval;
285 }
286 } while_each_thread(g, p);
287 if (!uid_eq(uid, cred->uid))
288 free_uid(user); /* for find_user() */
289 break;
290 }
291 out_unlock:
292 read_unlock(&tasklist_lock);
293 rcu_read_unlock();
294
295 return retval;
296 }
297
298 /*
299 * Unprivileged users may change the real gid to the effective gid
300 * or vice versa. (BSD-style)
301 *
302 * If you set the real gid at all, or set the effective gid to a value not
303 * equal to the real gid, then the saved gid is set to the new effective gid.
304 *
305 * This makes it possible for a setgid program to completely drop its
306 * privileges, which is often a useful assertion to make when you are doing
307 * a security audit over a program.
308 *
309 * The general idea is that a program which uses just setregid() will be
310 * 100% compatible with BSD. A program which uses just setgid() will be
311 * 100% compatible with POSIX with saved IDs.
312 *
313 * SMP: There are not races, the GIDs are checked only by filesystem
314 * operations (as far as semantic preservation is concerned).
315 */
316 SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid)
317 {
318 struct user_namespace *ns = current_user_ns();
319 const struct cred *old;
320 struct cred *new;
321 int retval;
322 kgid_t krgid, kegid;
323
324 krgid = make_kgid(ns, rgid);
325 kegid = make_kgid(ns, egid);
326
327 if ((rgid != (gid_t) -1) && !gid_valid(krgid))
328 return -EINVAL;
329 if ((egid != (gid_t) -1) && !gid_valid(kegid))
330 return -EINVAL;
331
332 new = prepare_creds();
333 if (!new)
334 return -ENOMEM;
335 old = current_cred();
336
337 retval = -EPERM;
338 if (rgid != (gid_t) -1) {
339 if (gid_eq(old->gid, krgid) ||
340 gid_eq(old->egid, krgid) ||
341 ns_capable(old->user_ns, CAP_SETGID))
342 new->gid = krgid;
343 else
344 goto error;
345 }
346 if (egid != (gid_t) -1) {
347 if (gid_eq(old->gid, kegid) ||
348 gid_eq(old->egid, kegid) ||
349 gid_eq(old->sgid, kegid) ||
350 ns_capable(old->user_ns, CAP_SETGID))
351 new->egid = kegid;
352 else
353 goto error;
354 }
355
356 if (rgid != (gid_t) -1 ||
357 (egid != (gid_t) -1 && !gid_eq(kegid, old->gid)))
358 new->sgid = new->egid;
359 new->fsgid = new->egid;
360
361 return commit_creds(new);
362
363 error:
364 abort_creds(new);
365 return retval;
366 }
367
368 /*
369 * setgid() is implemented like SysV w/ SAVED_IDS
370 *
371 * SMP: Same implicit races as above.
372 */
373 SYSCALL_DEFINE1(setgid, gid_t, gid)
374 {
375 struct user_namespace *ns = current_user_ns();
376 const struct cred *old;
377 struct cred *new;
378 int retval;
379 kgid_t kgid;
380
381 kgid = make_kgid(ns, gid);
382 if (!gid_valid(kgid))
383 return -EINVAL;
384
385 new = prepare_creds();
386 if (!new)
387 return -ENOMEM;
388 old = current_cred();
389
390 retval = -EPERM;
391 if (ns_capable(old->user_ns, CAP_SETGID))
392 new->gid = new->egid = new->sgid = new->fsgid = kgid;
393 else if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->sgid))
394 new->egid = new->fsgid = kgid;
395 else
396 goto error;
397
398 return commit_creds(new);
399
400 error:
401 abort_creds(new);
402 return retval;
403 }
404
405 /*
406 * change the user struct in a credentials set to match the new UID
407 */
408 static int set_user(struct cred *new)
409 {
410 struct user_struct *new_user;
411
412 new_user = alloc_uid(new->uid);
413 if (!new_user)
414 return -EAGAIN;
415
416 /*
417 * We don't fail in case of NPROC limit excess here because too many
418 * poorly written programs don't check set*uid() return code, assuming
419 * it never fails if called by root. We may still enforce NPROC limit
420 * for programs doing set*uid()+execve() by harmlessly deferring the
421 * failure to the execve() stage.
422 */
423 if (atomic_read(&new_user->processes) >= rlimit(RLIMIT_NPROC) &&
424 new_user != INIT_USER)
425 current->flags |= PF_NPROC_EXCEEDED;
426 else
427 current->flags &= ~PF_NPROC_EXCEEDED;
428
429 free_uid(new->user);
430 new->user = new_user;
431 return 0;
432 }
433
434 /*
435 * Unprivileged users may change the real uid to the effective uid
436 * or vice versa. (BSD-style)
437 *
438 * If you set the real uid at all, or set the effective uid to a value not
439 * equal to the real uid, then the saved uid is set to the new effective uid.
440 *
441 * This makes it possible for a setuid program to completely drop its
442 * privileges, which is often a useful assertion to make when you are doing
443 * a security audit over a program.
444 *
445 * The general idea is that a program which uses just setreuid() will be
446 * 100% compatible with BSD. A program which uses just setuid() will be
447 * 100% compatible with POSIX with saved IDs.
448 */
449 SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid)
450 {
451 struct user_namespace *ns = current_user_ns();
452 const struct cred *old;
453 struct cred *new;
454 int retval;
455 kuid_t kruid, keuid;
456
457 kruid = make_kuid(ns, ruid);
458 keuid = make_kuid(ns, euid);
459
460 if ((ruid != (uid_t) -1) && !uid_valid(kruid))
461 return -EINVAL;
462 if ((euid != (uid_t) -1) && !uid_valid(keuid))
463 return -EINVAL;
464
465 new = prepare_creds();
466 if (!new)
467 return -ENOMEM;
468 old = current_cred();
469
470 retval = -EPERM;
471 if (ruid != (uid_t) -1) {
472 new->uid = kruid;
473 if (!uid_eq(old->uid, kruid) &&
474 !uid_eq(old->euid, kruid) &&
475 !ns_capable(old->user_ns, CAP_SETUID))
476 goto error;
477 }
478
479 if (euid != (uid_t) -1) {
480 new->euid = keuid;
481 if (!uid_eq(old->uid, keuid) &&
482 !uid_eq(old->euid, keuid) &&
483 !uid_eq(old->suid, keuid) &&
484 !ns_capable(old->user_ns, CAP_SETUID))
485 goto error;
486 }
487
488 if (!uid_eq(new->uid, old->uid)) {
489 retval = set_user(new);
490 if (retval < 0)
491 goto error;
492 }
493 if (ruid != (uid_t) -1 ||
494 (euid != (uid_t) -1 && !uid_eq(keuid, old->uid)))
495 new->suid = new->euid;
496 new->fsuid = new->euid;
497
498 retval = security_task_fix_setuid(new, old, LSM_SETID_RE);
499 if (retval < 0)
500 goto error;
501
502 return commit_creds(new);
503
504 error:
505 abort_creds(new);
506 return retval;
507 }
508
509 /*
510 * setuid() is implemented like SysV with SAVED_IDS
511 *
512 * Note that SAVED_ID's is deficient in that a setuid root program
513 * like sendmail, for example, cannot set its uid to be a normal
514 * user and then switch back, because if you're root, setuid() sets
515 * the saved uid too. If you don't like this, blame the bright people
516 * in the POSIX committee and/or USG. Note that the BSD-style setreuid()
517 * will allow a root program to temporarily drop privileges and be able to
518 * regain them by swapping the real and effective uid.
519 */
520 SYSCALL_DEFINE1(setuid, uid_t, uid)
521 {
522 struct user_namespace *ns = current_user_ns();
523 const struct cred *old;
524 struct cred *new;
525 int retval;
526 kuid_t kuid;
527
528 kuid = make_kuid(ns, uid);
529 if (!uid_valid(kuid))
530 return -EINVAL;
531
532 new = prepare_creds();
533 if (!new)
534 return -ENOMEM;
535 old = current_cred();
536
537 retval = -EPERM;
538 if (ns_capable(old->user_ns, CAP_SETUID)) {
539 new->suid = new->uid = kuid;
540 if (!uid_eq(kuid, old->uid)) {
541 retval = set_user(new);
542 if (retval < 0)
543 goto error;
544 }
545 } else if (!uid_eq(kuid, old->uid) && !uid_eq(kuid, new->suid)) {
546 goto error;
547 }
548
549 new->fsuid = new->euid = kuid;
550
551 retval = security_task_fix_setuid(new, old, LSM_SETID_ID);
552 if (retval < 0)
553 goto error;
554
555 return commit_creds(new);
556
557 error:
558 abort_creds(new);
559 return retval;
560 }
561
562
563 /*
564 * This function implements a generic ability to update ruid, euid,
565 * and suid. This allows you to implement the 4.4 compatible seteuid().
566 */
567 SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid)
568 {
569 struct user_namespace *ns = current_user_ns();
570 const struct cred *old;
571 struct cred *new;
572 int retval;
573 kuid_t kruid, keuid, ksuid;
574
575 kruid = make_kuid(ns, ruid);
576 keuid = make_kuid(ns, euid);
577 ksuid = make_kuid(ns, suid);
578
579 if ((ruid != (uid_t) -1) && !uid_valid(kruid))
580 return -EINVAL;
581
582 if ((euid != (uid_t) -1) && !uid_valid(keuid))
583 return -EINVAL;
584
585 if ((suid != (uid_t) -1) && !uid_valid(ksuid))
586 return -EINVAL;
587
588 new = prepare_creds();
589 if (!new)
590 return -ENOMEM;
591
592 old = current_cred();
593
594 retval = -EPERM;
595 if (!ns_capable(old->user_ns, CAP_SETUID)) {
596 if (ruid != (uid_t) -1 && !uid_eq(kruid, old->uid) &&
597 !uid_eq(kruid, old->euid) && !uid_eq(kruid, old->suid))
598 goto error;
599 if (euid != (uid_t) -1 && !uid_eq(keuid, old->uid) &&
600 !uid_eq(keuid, old->euid) && !uid_eq(keuid, old->suid))
601 goto error;
602 if (suid != (uid_t) -1 && !uid_eq(ksuid, old->uid) &&
603 !uid_eq(ksuid, old->euid) && !uid_eq(ksuid, old->suid))
604 goto error;
605 }
606
607 if (ruid != (uid_t) -1) {
608 new->uid = kruid;
609 if (!uid_eq(kruid, old->uid)) {
610 retval = set_user(new);
611 if (retval < 0)
612 goto error;
613 }
614 }
615 if (euid != (uid_t) -1)
616 new->euid = keuid;
617 if (suid != (uid_t) -1)
618 new->suid = ksuid;
619 new->fsuid = new->euid;
620
621 retval = security_task_fix_setuid(new, old, LSM_SETID_RES);
622 if (retval < 0)
623 goto error;
624
625 return commit_creds(new);
626
627 error:
628 abort_creds(new);
629 return retval;
630 }
631
632 SYSCALL_DEFINE3(getresuid, uid_t __user *, ruidp, uid_t __user *, euidp, uid_t __user *, suidp)
633 {
634 const struct cred *cred = current_cred();
635 int retval;
636 uid_t ruid, euid, suid;
637
638 ruid = from_kuid_munged(cred->user_ns, cred->uid);
639 euid = from_kuid_munged(cred->user_ns, cred->euid);
640 suid = from_kuid_munged(cred->user_ns, cred->suid);
641
642 retval = put_user(ruid, ruidp);
643 if (!retval) {
644 retval = put_user(euid, euidp);
645 if (!retval)
646 return put_user(suid, suidp);
647 }
648 return retval;
649 }
650
651 /*
652 * Same as above, but for rgid, egid, sgid.
653 */
654 SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid)
655 {
656 struct user_namespace *ns = current_user_ns();
657 const struct cred *old;
658 struct cred *new;
659 int retval;
660 kgid_t krgid, kegid, ksgid;
661
662 krgid = make_kgid(ns, rgid);
663 kegid = make_kgid(ns, egid);
664 ksgid = make_kgid(ns, sgid);
665
666 if ((rgid != (gid_t) -1) && !gid_valid(krgid))
667 return -EINVAL;
668 if ((egid != (gid_t) -1) && !gid_valid(kegid))
669 return -EINVAL;
670 if ((sgid != (gid_t) -1) && !gid_valid(ksgid))
671 return -EINVAL;
672
673 new = prepare_creds();
674 if (!new)
675 return -ENOMEM;
676 old = current_cred();
677
678 retval = -EPERM;
679 if (!ns_capable(old->user_ns, CAP_SETGID)) {
680 if (rgid != (gid_t) -1 && !gid_eq(krgid, old->gid) &&
681 !gid_eq(krgid, old->egid) && !gid_eq(krgid, old->sgid))
682 goto error;
683 if (egid != (gid_t) -1 && !gid_eq(kegid, old->gid) &&
684 !gid_eq(kegid, old->egid) && !gid_eq(kegid, old->sgid))
685 goto error;
686 if (sgid != (gid_t) -1 && !gid_eq(ksgid, old->gid) &&
687 !gid_eq(ksgid, old->egid) && !gid_eq(ksgid, old->sgid))
688 goto error;
689 }
690
691 if (rgid != (gid_t) -1)
692 new->gid = krgid;
693 if (egid != (gid_t) -1)
694 new->egid = kegid;
695 if (sgid != (gid_t) -1)
696 new->sgid = ksgid;
697 new->fsgid = new->egid;
698
699 return commit_creds(new);
700
701 error:
702 abort_creds(new);
703 return retval;
704 }
705
706 SYSCALL_DEFINE3(getresgid, gid_t __user *, rgidp, gid_t __user *, egidp, gid_t __user *, sgidp)
707 {
708 const struct cred *cred = current_cred();
709 int retval;
710 gid_t rgid, egid, sgid;
711
712 rgid = from_kgid_munged(cred->user_ns, cred->gid);
713 egid = from_kgid_munged(cred->user_ns, cred->egid);
714 sgid = from_kgid_munged(cred->user_ns, cred->sgid);
715
716 retval = put_user(rgid, rgidp);
717 if (!retval) {
718 retval = put_user(egid, egidp);
719 if (!retval)
720 retval = put_user(sgid, sgidp);
721 }
722
723 return retval;
724 }
725
726
727 /*
728 * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This
729 * is used for "access()" and for the NFS daemon (letting nfsd stay at
730 * whatever uid it wants to). It normally shadows "euid", except when
731 * explicitly set by setfsuid() or for access..
732 */
733 SYSCALL_DEFINE1(setfsuid, uid_t, uid)
734 {
735 const struct cred *old;
736 struct cred *new;
737 uid_t old_fsuid;
738 kuid_t kuid;
739
740 old = current_cred();
741 old_fsuid = from_kuid_munged(old->user_ns, old->fsuid);
742
743 kuid = make_kuid(old->user_ns, uid);
744 if (!uid_valid(kuid))
745 return old_fsuid;
746
747 new = prepare_creds();
748 if (!new)
749 return old_fsuid;
750
751 if (uid_eq(kuid, old->uid) || uid_eq(kuid, old->euid) ||
752 uid_eq(kuid, old->suid) || uid_eq(kuid, old->fsuid) ||
753 ns_capable(old->user_ns, CAP_SETUID)) {
754 if (!uid_eq(kuid, old->fsuid)) {
755 new->fsuid = kuid;
756 if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0)
757 goto change_okay;
758 }
759 }
760
761 abort_creds(new);
762 return old_fsuid;
763
764 change_okay:
765 commit_creds(new);
766 return old_fsuid;
767 }
768
769 /*
770 * Samma på svenska..
771 */
772 SYSCALL_DEFINE1(setfsgid, gid_t, gid)
773 {
774 const struct cred *old;
775 struct cred *new;
776 gid_t old_fsgid;
777 kgid_t kgid;
778
779 old = current_cred();
780 old_fsgid = from_kgid_munged(old->user_ns, old->fsgid);
781
782 kgid = make_kgid(old->user_ns, gid);
783 if (!gid_valid(kgid))
784 return old_fsgid;
785
786 new = prepare_creds();
787 if (!new)
788 return old_fsgid;
789
790 if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->egid) ||
791 gid_eq(kgid, old->sgid) || gid_eq(kgid, old->fsgid) ||
792 ns_capable(old->user_ns, CAP_SETGID)) {
793 if (!gid_eq(kgid, old->fsgid)) {
794 new->fsgid = kgid;
795 goto change_okay;
796 }
797 }
798
799 abort_creds(new);
800 return old_fsgid;
801
802 change_okay:
803 commit_creds(new);
804 return old_fsgid;
805 }
806
807 /**
808 * sys_getpid - return the thread group id of the current process
809 *
810 * Note, despite the name, this returns the tgid not the pid. The tgid and
811 * the pid are identical unless CLONE_THREAD was specified on clone() in
812 * which case the tgid is the same in all threads of the same group.
813 *
814 * This is SMP safe as current->tgid does not change.
815 */
816 SYSCALL_DEFINE0(getpid)
817 {
818 return task_tgid_vnr(current);
819 }
820
821 /* Thread ID - the internal kernel "pid" */
822 SYSCALL_DEFINE0(gettid)
823 {
824 return task_pid_vnr(current);
825 }
826
827 /*
828 * Accessing ->real_parent is not SMP-safe, it could
829 * change from under us. However, we can use a stale
830 * value of ->real_parent under rcu_read_lock(), see
831 * release_task()->call_rcu(delayed_put_task_struct).
832 */
833 SYSCALL_DEFINE0(getppid)
834 {
835 int pid;
836
837 rcu_read_lock();
838 pid = task_tgid_vnr(rcu_dereference(current->real_parent));
839 rcu_read_unlock();
840
841 return pid;
842 }
843
844 SYSCALL_DEFINE0(getuid)
845 {
846 /* Only we change this so SMP safe */
847 return from_kuid_munged(current_user_ns(), current_uid());
848 }
849
850 SYSCALL_DEFINE0(geteuid)
851 {
852 /* Only we change this so SMP safe */
853 return from_kuid_munged(current_user_ns(), current_euid());
854 }
855
856 SYSCALL_DEFINE0(getgid)
857 {
858 /* Only we change this so SMP safe */
859 return from_kgid_munged(current_user_ns(), current_gid());
860 }
861
862 SYSCALL_DEFINE0(getegid)
863 {
864 /* Only we change this so SMP safe */
865 return from_kgid_munged(current_user_ns(), current_egid());
866 }
867
868 void do_sys_times(struct tms *tms)
869 {
870 cputime_t tgutime, tgstime, cutime, cstime;
871
872 thread_group_cputime_adjusted(current, &tgutime, &tgstime);
873 cutime = current->signal->cutime;
874 cstime = current->signal->cstime;
875 tms->tms_utime = cputime_to_clock_t(tgutime);
876 tms->tms_stime = cputime_to_clock_t(tgstime);
877 tms->tms_cutime = cputime_to_clock_t(cutime);
878 tms->tms_cstime = cputime_to_clock_t(cstime);
879 }
880
881 SYSCALL_DEFINE1(times, struct tms __user *, tbuf)
882 {
883 if (tbuf) {
884 struct tms tmp;
885
886 do_sys_times(&tmp);
887 if (copy_to_user(tbuf, &tmp, sizeof(struct tms)))
888 return -EFAULT;
889 }
890 force_successful_syscall_return();
891 return (long) jiffies_64_to_clock_t(get_jiffies_64());
892 }
893
894 /*
895 * This needs some heavy checking ...
896 * I just haven't the stomach for it. I also don't fully
897 * understand sessions/pgrp etc. Let somebody who does explain it.
898 *
899 * OK, I think I have the protection semantics right.... this is really
900 * only important on a multi-user system anyway, to make sure one user
901 * can't send a signal to a process owned by another. -TYT, 12/12/91
902 *
903 * !PF_FORKNOEXEC check to conform completely to POSIX.
904 */
905 SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid)
906 {
907 struct task_struct *p;
908 struct task_struct *group_leader = current->group_leader;
909 struct pid *pgrp;
910 int err;
911
912 if (!pid)
913 pid = task_pid_vnr(group_leader);
914 if (!pgid)
915 pgid = pid;
916 if (pgid < 0)
917 return -EINVAL;
918 rcu_read_lock();
919
920 /* From this point forward we keep holding onto the tasklist lock
921 * so that our parent does not change from under us. -DaveM
922 */
923 write_lock_irq(&tasklist_lock);
924
925 err = -ESRCH;
926 p = find_task_by_vpid(pid);
927 if (!p)
928 goto out;
929
930 err = -EINVAL;
931 if (!thread_group_leader(p))
932 goto out;
933
934 if (same_thread_group(p->real_parent, group_leader)) {
935 err = -EPERM;
936 if (task_session(p) != task_session(group_leader))
937 goto out;
938 err = -EACCES;
939 if (!(p->flags & PF_FORKNOEXEC))
940 goto out;
941 } else {
942 err = -ESRCH;
943 if (p != group_leader)
944 goto out;
945 }
946
947 err = -EPERM;
948 if (p->signal->leader)
949 goto out;
950
951 pgrp = task_pid(p);
952 if (pgid != pid) {
953 struct task_struct *g;
954
955 pgrp = find_vpid(pgid);
956 g = pid_task(pgrp, PIDTYPE_PGID);
957 if (!g || task_session(g) != task_session(group_leader))
958 goto out;
959 }
960
961 err = security_task_setpgid(p, pgid);
962 if (err)
963 goto out;
964
965 if (task_pgrp(p) != pgrp)
966 change_pid(p, PIDTYPE_PGID, pgrp);
967
968 err = 0;
969 out:
970 /* All paths lead to here, thus we are safe. -DaveM */
971 write_unlock_irq(&tasklist_lock);
972 rcu_read_unlock();
973 return err;
974 }
975
976 SYSCALL_DEFINE1(getpgid, pid_t, pid)
977 {
978 struct task_struct *p;
979 struct pid *grp;
980 int retval;
981
982 rcu_read_lock();
983 if (!pid)
984 grp = task_pgrp(current);
985 else {
986 retval = -ESRCH;
987 p = find_task_by_vpid(pid);
988 if (!p)
989 goto out;
990 grp = task_pgrp(p);
991 if (!grp)
992 goto out;
993
994 retval = security_task_getpgid(p);
995 if (retval)
996 goto out;
997 }
998 retval = pid_vnr(grp);
999 out:
1000 rcu_read_unlock();
1001 return retval;
1002 }
1003
1004 #ifdef __ARCH_WANT_SYS_GETPGRP
1005
1006 SYSCALL_DEFINE0(getpgrp)
1007 {
1008 return sys_getpgid(0);
1009 }
1010
1011 #endif
1012
1013 SYSCALL_DEFINE1(getsid, pid_t, pid)
1014 {
1015 struct task_struct *p;
1016 struct pid *sid;
1017 int retval;
1018
1019 rcu_read_lock();
1020 if (!pid)
1021 sid = task_session(current);
1022 else {
1023 retval = -ESRCH;
1024 p = find_task_by_vpid(pid);
1025 if (!p)
1026 goto out;
1027 sid = task_session(p);
1028 if (!sid)
1029 goto out;
1030
1031 retval = security_task_getsid(p);
1032 if (retval)
1033 goto out;
1034 }
1035 retval = pid_vnr(sid);
1036 out:
1037 rcu_read_unlock();
1038 return retval;
1039 }
1040
1041 static void set_special_pids(struct pid *pid)
1042 {
1043 struct task_struct *curr = current->group_leader;
1044
1045 if (task_session(curr) != pid)
1046 change_pid(curr, PIDTYPE_SID, pid);
1047
1048 if (task_pgrp(curr) != pid)
1049 change_pid(curr, PIDTYPE_PGID, pid);
1050 }
1051
1052 SYSCALL_DEFINE0(setsid)
1053 {
1054 struct task_struct *group_leader = current->group_leader;
1055 struct pid *sid = task_pid(group_leader);
1056 pid_t session = pid_vnr(sid);
1057 int err = -EPERM;
1058
1059 write_lock_irq(&tasklist_lock);
1060 /* Fail if I am already a session leader */
1061 if (group_leader->signal->leader)
1062 goto out;
1063
1064 /* Fail if a process group id already exists that equals the
1065 * proposed session id.
1066 */
1067 if (pid_task(sid, PIDTYPE_PGID))
1068 goto out;
1069
1070 group_leader->signal->leader = 1;
1071 set_special_pids(sid);
1072
1073 proc_clear_tty(group_leader);
1074
1075 err = session;
1076 out:
1077 write_unlock_irq(&tasklist_lock);
1078 if (err > 0) {
1079 proc_sid_connector(group_leader);
1080 sched_autogroup_create_attach(group_leader);
1081 }
1082 return err;
1083 }
1084
1085 DECLARE_RWSEM(uts_sem);
1086
1087 #ifdef COMPAT_UTS_MACHINE
1088 #define override_architecture(name) \
1089 (personality(current->personality) == PER_LINUX32 && \
1090 copy_to_user(name->machine, COMPAT_UTS_MACHINE, \
1091 sizeof(COMPAT_UTS_MACHINE)))
1092 #else
1093 #define override_architecture(name) 0
1094 #endif
1095
1096 /*
1097 * Work around broken programs that cannot handle "Linux 3.0".
1098 * Instead we map 3.x to 2.6.40+x, so e.g. 3.0 would be 2.6.40
1099 */
1100 static int override_release(char __user *release, size_t len)
1101 {
1102 int ret = 0;
1103
1104 if (current->personality & UNAME26) {
1105 const char *rest = UTS_RELEASE;
1106 char buf[65] = { 0 };
1107 int ndots = 0;
1108 unsigned v;
1109 size_t copy;
1110
1111 while (*rest) {
1112 if (*rest == '.' && ++ndots >= 3)
1113 break;
1114 if (!isdigit(*rest) && *rest != '.')
1115 break;
1116 rest++;
1117 }
1118 v = ((LINUX_VERSION_CODE >> 8) & 0xff) + 40;
1119 copy = clamp_t(size_t, len, 1, sizeof(buf));
1120 copy = scnprintf(buf, copy, "2.6.%u%s", v, rest);
1121 ret = copy_to_user(release, buf, copy + 1);
1122 }
1123 return ret;
1124 }
1125
1126 SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name)
1127 {
1128 int errno = 0;
1129
1130 down_read(&uts_sem);
1131 if (copy_to_user(name, utsname(), sizeof *name))
1132 errno = -EFAULT;
1133 up_read(&uts_sem);
1134
1135 if (!errno && override_release(name->release, sizeof(name->release)))
1136 errno = -EFAULT;
1137 if (!errno && override_architecture(name))
1138 errno = -EFAULT;
1139 return errno;
1140 }
1141
1142 #ifdef __ARCH_WANT_SYS_OLD_UNAME
1143 /*
1144 * Old cruft
1145 */
1146 SYSCALL_DEFINE1(uname, struct old_utsname __user *, name)
1147 {
1148 int error = 0;
1149
1150 if (!name)
1151 return -EFAULT;
1152
1153 down_read(&uts_sem);
1154 if (copy_to_user(name, utsname(), sizeof(*name)))
1155 error = -EFAULT;
1156 up_read(&uts_sem);
1157
1158 if (!error && override_release(name->release, sizeof(name->release)))
1159 error = -EFAULT;
1160 if (!error && override_architecture(name))
1161 error = -EFAULT;
1162 return error;
1163 }
1164
1165 SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name)
1166 {
1167 int error;
1168
1169 if (!name)
1170 return -EFAULT;
1171 if (!access_ok(VERIFY_WRITE, name, sizeof(struct oldold_utsname)))
1172 return -EFAULT;
1173
1174 down_read(&uts_sem);
1175 error = __copy_to_user(&name->sysname, &utsname()->sysname,
1176 __OLD_UTS_LEN);
1177 error |= __put_user(0, name->sysname + __OLD_UTS_LEN);
1178 error |= __copy_to_user(&name->nodename, &utsname()->nodename,
1179 __OLD_UTS_LEN);
1180 error |= __put_user(0, name->nodename + __OLD_UTS_LEN);
1181 error |= __copy_to_user(&name->release, &utsname()->release,
1182 __OLD_UTS_LEN);
1183 error |= __put_user(0, name->release + __OLD_UTS_LEN);
1184 error |= __copy_to_user(&name->version, &utsname()->version,
1185 __OLD_UTS_LEN);
1186 error |= __put_user(0, name->version + __OLD_UTS_LEN);
1187 error |= __copy_to_user(&name->machine, &utsname()->machine,
1188 __OLD_UTS_LEN);
1189 error |= __put_user(0, name->machine + __OLD_UTS_LEN);
1190 up_read(&uts_sem);
1191
1192 if (!error && override_architecture(name))
1193 error = -EFAULT;
1194 if (!error && override_release(name->release, sizeof(name->release)))
1195 error = -EFAULT;
1196 return error ? -EFAULT : 0;
1197 }
1198 #endif
1199
1200 SYSCALL_DEFINE2(sethostname, char __user *, name, int, len)
1201 {
1202 int errno;
1203 char tmp[__NEW_UTS_LEN];
1204
1205 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN))
1206 return -EPERM;
1207
1208 if (len < 0 || len > __NEW_UTS_LEN)
1209 return -EINVAL;
1210 down_write(&uts_sem);
1211 errno = -EFAULT;
1212 if (!copy_from_user(tmp, name, len)) {
1213 struct new_utsname *u = utsname();
1214
1215 memcpy(u->nodename, tmp, len);
1216 memset(u->nodename + len, 0, sizeof(u->nodename) - len);
1217 errno = 0;
1218 uts_proc_notify(UTS_PROC_HOSTNAME);
1219 }
1220 up_write(&uts_sem);
1221 return errno;
1222 }
1223
1224 #ifdef __ARCH_WANT_SYS_GETHOSTNAME
1225
1226 SYSCALL_DEFINE2(gethostname, char __user *, name, int, len)
1227 {
1228 int i, errno;
1229 struct new_utsname *u;
1230
1231 if (len < 0)
1232 return -EINVAL;
1233 down_read(&uts_sem);
1234 u = utsname();
1235 i = 1 + strlen(u->nodename);
1236 if (i > len)
1237 i = len;
1238 errno = 0;
1239 if (copy_to_user(name, u->nodename, i))
1240 errno = -EFAULT;
1241 up_read(&uts_sem);
1242 return errno;
1243 }
1244
1245 #endif
1246
1247 /*
1248 * Only setdomainname; getdomainname can be implemented by calling
1249 * uname()
1250 */
1251 SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len)
1252 {
1253 int errno;
1254 char tmp[__NEW_UTS_LEN];
1255
1256 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN))
1257 return -EPERM;
1258 if (len < 0 || len > __NEW_UTS_LEN)
1259 return -EINVAL;
1260
1261 down_write(&uts_sem);
1262 errno = -EFAULT;
1263 if (!copy_from_user(tmp, name, len)) {
1264 struct new_utsname *u = utsname();
1265
1266 memcpy(u->domainname, tmp, len);
1267 memset(u->domainname + len, 0, sizeof(u->domainname) - len);
1268 errno = 0;
1269 uts_proc_notify(UTS_PROC_DOMAINNAME);
1270 }
1271 up_write(&uts_sem);
1272 return errno;
1273 }
1274
1275 SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim)
1276 {
1277 struct rlimit value;
1278 int ret;
1279
1280 ret = do_prlimit(current, resource, NULL, &value);
1281 if (!ret)
1282 ret = copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0;
1283
1284 return ret;
1285 }
1286
1287 #ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT
1288
1289 /*
1290 * Back compatibility for getrlimit. Needed for some apps.
1291 */
1292 SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
1293 struct rlimit __user *, rlim)
1294 {
1295 struct rlimit x;
1296 if (resource >= RLIM_NLIMITS)
1297 return -EINVAL;
1298
1299 task_lock(current->group_leader);
1300 x = current->signal->rlim[resource];
1301 task_unlock(current->group_leader);
1302 if (x.rlim_cur > 0x7FFFFFFF)
1303 x.rlim_cur = 0x7FFFFFFF;
1304 if (x.rlim_max > 0x7FFFFFFF)
1305 x.rlim_max = 0x7FFFFFFF;
1306 return copy_to_user(rlim, &x, sizeof(x)) ? -EFAULT : 0;
1307 }
1308
1309 #endif
1310
1311 static inline bool rlim64_is_infinity(__u64 rlim64)
1312 {
1313 #if BITS_PER_LONG < 64
1314 return rlim64 >= ULONG_MAX;
1315 #else
1316 return rlim64 == RLIM64_INFINITY;
1317 #endif
1318 }
1319
1320 static void rlim_to_rlim64(const struct rlimit *rlim, struct rlimit64 *rlim64)
1321 {
1322 if (rlim->rlim_cur == RLIM_INFINITY)
1323 rlim64->rlim_cur = RLIM64_INFINITY;
1324 else
1325 rlim64->rlim_cur = rlim->rlim_cur;
1326 if (rlim->rlim_max == RLIM_INFINITY)
1327 rlim64->rlim_max = RLIM64_INFINITY;
1328 else
1329 rlim64->rlim_max = rlim->rlim_max;
1330 }
1331
1332 static void rlim64_to_rlim(const struct rlimit64 *rlim64, struct rlimit *rlim)
1333 {
1334 if (rlim64_is_infinity(rlim64->rlim_cur))
1335 rlim->rlim_cur = RLIM_INFINITY;
1336 else
1337 rlim->rlim_cur = (unsigned long)rlim64->rlim_cur;
1338 if (rlim64_is_infinity(rlim64->rlim_max))
1339 rlim->rlim_max = RLIM_INFINITY;
1340 else
1341 rlim->rlim_max = (unsigned long)rlim64->rlim_max;
1342 }
1343
1344 /* make sure you are allowed to change @tsk limits before calling this */
1345 int do_prlimit(struct task_struct *tsk, unsigned int resource,
1346 struct rlimit *new_rlim, struct rlimit *old_rlim)
1347 {
1348 struct rlimit *rlim;
1349 int retval = 0;
1350
1351 if (resource >= RLIM_NLIMITS)
1352 return -EINVAL;
1353 if (new_rlim) {
1354 if (new_rlim->rlim_cur > new_rlim->rlim_max)
1355 return -EINVAL;
1356 if (resource == RLIMIT_NOFILE &&
1357 new_rlim->rlim_max > sysctl_nr_open)
1358 return -EPERM;
1359 }
1360
1361 /* protect tsk->signal and tsk->sighand from disappearing */
1362 read_lock(&tasklist_lock);
1363 if (!tsk->sighand) {
1364 retval = -ESRCH;
1365 goto out;
1366 }
1367
1368 rlim = tsk->signal->rlim + resource;
1369 task_lock(tsk->group_leader);
1370 if (new_rlim) {
1371 /* Keep the capable check against init_user_ns until
1372 cgroups can contain all limits */
1373 if (new_rlim->rlim_max > rlim->rlim_max &&
1374 !capable(CAP_SYS_RESOURCE))
1375 retval = -EPERM;
1376 if (!retval)
1377 retval = security_task_setrlimit(tsk->group_leader,
1378 resource, new_rlim);
1379 if (resource == RLIMIT_CPU && new_rlim->rlim_cur == 0) {
1380 /*
1381 * The caller is asking for an immediate RLIMIT_CPU
1382 * expiry. But we use the zero value to mean "it was
1383 * never set". So let's cheat and make it one second
1384 * instead
1385 */
1386 new_rlim->rlim_cur = 1;
1387 }
1388 }
1389 if (!retval) {
1390 if (old_rlim)
1391 *old_rlim = *rlim;
1392 if (new_rlim)
1393 *rlim = *new_rlim;
1394 }
1395 task_unlock(tsk->group_leader);
1396
1397 /*
1398 * RLIMIT_CPU handling. Note that the kernel fails to return an error
1399 * code if it rejected the user's attempt to set RLIMIT_CPU. This is a
1400 * very long-standing error, and fixing it now risks breakage of
1401 * applications, so we live with it
1402 */
1403 if (!retval && new_rlim && resource == RLIMIT_CPU &&
1404 new_rlim->rlim_cur != RLIM_INFINITY)
1405 update_rlimit_cpu(tsk, new_rlim->rlim_cur);
1406 out:
1407 read_unlock(&tasklist_lock);
1408 return retval;
1409 }
1410
1411 /* rcu lock must be held */
1412 static int check_prlimit_permission(struct task_struct *task)
1413 {
1414 const struct cred *cred = current_cred(), *tcred;
1415
1416 if (current == task)
1417 return 0;
1418
1419 tcred = __task_cred(task);
1420 if (uid_eq(cred->uid, tcred->euid) &&
1421 uid_eq(cred->uid, tcred->suid) &&
1422 uid_eq(cred->uid, tcred->uid) &&
1423 gid_eq(cred->gid, tcred->egid) &&
1424 gid_eq(cred->gid, tcred->sgid) &&
1425 gid_eq(cred->gid, tcred->gid))
1426 return 0;
1427 if (ns_capable(tcred->user_ns, CAP_SYS_RESOURCE))
1428 return 0;
1429
1430 return -EPERM;
1431 }
1432
1433 SYSCALL_DEFINE4(prlimit64, pid_t, pid, unsigned int, resource,
1434 const struct rlimit64 __user *, new_rlim,
1435 struct rlimit64 __user *, old_rlim)
1436 {
1437 struct rlimit64 old64, new64;
1438 struct rlimit old, new;
1439 struct task_struct *tsk;
1440 int ret;
1441
1442 if (new_rlim) {
1443 if (copy_from_user(&new64, new_rlim, sizeof(new64)))
1444 return -EFAULT;
1445 rlim64_to_rlim(&new64, &new);
1446 }
1447
1448 rcu_read_lock();
1449 tsk = pid ? find_task_by_vpid(pid) : current;
1450 if (!tsk) {
1451 rcu_read_unlock();
1452 return -ESRCH;
1453 }
1454 ret = check_prlimit_permission(tsk);
1455 if (ret) {
1456 rcu_read_unlock();
1457 return ret;
1458 }
1459 get_task_struct(tsk);
1460 rcu_read_unlock();
1461
1462 ret = do_prlimit(tsk, resource, new_rlim ? &new : NULL,
1463 old_rlim ? &old : NULL);
1464
1465 if (!ret && old_rlim) {
1466 rlim_to_rlim64(&old, &old64);
1467 if (copy_to_user(old_rlim, &old64, sizeof(old64)))
1468 ret = -EFAULT;
1469 }
1470
1471 put_task_struct(tsk);
1472 return ret;
1473 }
1474
1475 SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim)
1476 {
1477 struct rlimit new_rlim;
1478
1479 if (copy_from_user(&new_rlim, rlim, sizeof(*rlim)))
1480 return -EFAULT;
1481 return do_prlimit(current, resource, &new_rlim, NULL);
1482 }
1483
1484 /*
1485 * It would make sense to put struct rusage in the task_struct,
1486 * except that would make the task_struct be *really big*. After
1487 * task_struct gets moved into malloc'ed memory, it would
1488 * make sense to do this. It will make moving the rest of the information
1489 * a lot simpler! (Which we're not doing right now because we're not
1490 * measuring them yet).
1491 *
1492 * When sampling multiple threads for RUSAGE_SELF, under SMP we might have
1493 * races with threads incrementing their own counters. But since word
1494 * reads are atomic, we either get new values or old values and we don't
1495 * care which for the sums. We always take the siglock to protect reading
1496 * the c* fields from p->signal from races with exit.c updating those
1497 * fields when reaping, so a sample either gets all the additions of a
1498 * given child after it's reaped, or none so this sample is before reaping.
1499 *
1500 * Locking:
1501 * We need to take the siglock for CHILDEREN, SELF and BOTH
1502 * for the cases current multithreaded, non-current single threaded
1503 * non-current multithreaded. Thread traversal is now safe with
1504 * the siglock held.
1505 * Strictly speaking, we donot need to take the siglock if we are current and
1506 * single threaded, as no one else can take our signal_struct away, no one
1507 * else can reap the children to update signal->c* counters, and no one else
1508 * can race with the signal-> fields. If we do not take any lock, the
1509 * signal-> fields could be read out of order while another thread was just
1510 * exiting. So we should place a read memory barrier when we avoid the lock.
1511 * On the writer side, write memory barrier is implied in __exit_signal
1512 * as __exit_signal releases the siglock spinlock after updating the signal->
1513 * fields. But we don't do this yet to keep things simple.
1514 *
1515 */
1516
1517 static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r)
1518 {
1519 r->ru_nvcsw += t->nvcsw;
1520 r->ru_nivcsw += t->nivcsw;
1521 r->ru_minflt += t->min_flt;
1522 r->ru_majflt += t->maj_flt;
1523 r->ru_inblock += task_io_get_inblock(t);
1524 r->ru_oublock += task_io_get_oublock(t);
1525 }
1526
1527 static void k_getrusage(struct task_struct *p, int who, struct rusage *r)
1528 {
1529 struct task_struct *t;
1530 unsigned long flags;
1531 cputime_t tgutime, tgstime, utime, stime;
1532 unsigned long maxrss = 0;
1533
1534 memset((char *)r, 0, sizeof (*r));
1535 utime = stime = 0;
1536
1537 if (who == RUSAGE_THREAD) {
1538 task_cputime_adjusted(current, &utime, &stime);
1539 accumulate_thread_rusage(p, r);
1540 maxrss = p->signal->maxrss;
1541 goto out;
1542 }
1543
1544 if (!lock_task_sighand(p, &flags))
1545 return;
1546
1547 switch (who) {
1548 case RUSAGE_BOTH:
1549 case RUSAGE_CHILDREN:
1550 utime = p->signal->cutime;
1551 stime = p->signal->cstime;
1552 r->ru_nvcsw = p->signal->cnvcsw;
1553 r->ru_nivcsw = p->signal->cnivcsw;
1554 r->ru_minflt = p->signal->cmin_flt;
1555 r->ru_majflt = p->signal->cmaj_flt;
1556 r->ru_inblock = p->signal->cinblock;
1557 r->ru_oublock = p->signal->coublock;
1558 maxrss = p->signal->cmaxrss;
1559
1560 if (who == RUSAGE_CHILDREN)
1561 break;
1562
1563 case RUSAGE_SELF:
1564 thread_group_cputime_adjusted(p, &tgutime, &tgstime);
1565 utime += tgutime;
1566 stime += tgstime;
1567 r->ru_nvcsw += p->signal->nvcsw;
1568 r->ru_nivcsw += p->signal->nivcsw;
1569 r->ru_minflt += p->signal->min_flt;
1570 r->ru_majflt += p->signal->maj_flt;
1571 r->ru_inblock += p->signal->inblock;
1572 r->ru_oublock += p->signal->oublock;
1573 if (maxrss < p->signal->maxrss)
1574 maxrss = p->signal->maxrss;
1575 t = p;
1576 do {
1577 accumulate_thread_rusage(t, r);
1578 } while_each_thread(p, t);
1579 break;
1580
1581 default:
1582 BUG();
1583 }
1584 unlock_task_sighand(p, &flags);
1585
1586 out:
1587 cputime_to_timeval(utime, &r->ru_utime);
1588 cputime_to_timeval(stime, &r->ru_stime);
1589
1590 if (who != RUSAGE_CHILDREN) {
1591 struct mm_struct *mm = get_task_mm(p);
1592
1593 if (mm) {
1594 setmax_mm_hiwater_rss(&maxrss, mm);
1595 mmput(mm);
1596 }
1597 }
1598 r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */
1599 }
1600
1601 int getrusage(struct task_struct *p, int who, struct rusage __user *ru)
1602 {
1603 struct rusage r;
1604
1605 k_getrusage(p, who, &r);
1606 return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0;
1607 }
1608
1609 SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru)
1610 {
1611 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
1612 who != RUSAGE_THREAD)
1613 return -EINVAL;
1614 return getrusage(current, who, ru);
1615 }
1616
1617 #ifdef CONFIG_COMPAT
1618 COMPAT_SYSCALL_DEFINE2(getrusage, int, who, struct compat_rusage __user *, ru)
1619 {
1620 struct rusage r;
1621
1622 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
1623 who != RUSAGE_THREAD)
1624 return -EINVAL;
1625
1626 k_getrusage(current, who, &r);
1627 return put_compat_rusage(&r, ru);
1628 }
1629 #endif
1630
1631 SYSCALL_DEFINE1(umask, int, mask)
1632 {
1633 mask = xchg(&current->fs->umask, mask & S_IRWXUGO);
1634 return mask;
1635 }
1636
1637 static int prctl_set_mm_exe_file_locked(struct mm_struct *mm, unsigned int fd)
1638 {
1639 struct fd exe;
1640 struct inode *inode;
1641 int err;
1642
1643 VM_BUG_ON_MM(!rwsem_is_locked(&mm->mmap_sem), mm);
1644
1645 exe = fdget(fd);
1646 if (!exe.file)
1647 return -EBADF;
1648
1649 inode = file_inode(exe.file);
1650
1651 /*
1652 * Because the original mm->exe_file points to executable file, make
1653 * sure that this one is executable as well, to avoid breaking an
1654 * overall picture.
1655 */
1656 err = -EACCES;
1657 if (!S_ISREG(inode->i_mode) ||
1658 exe.file->f_path.mnt->mnt_flags & MNT_NOEXEC)
1659 goto exit;
1660
1661 err = inode_permission(inode, MAY_EXEC);
1662 if (err)
1663 goto exit;
1664
1665 /*
1666 * Forbid mm->exe_file change if old file still mapped.
1667 */
1668 err = -EBUSY;
1669 if (mm->exe_file) {
1670 struct vm_area_struct *vma;
1671
1672 for (vma = mm->mmap; vma; vma = vma->vm_next)
1673 if (vma->vm_file &&
1674 path_equal(&vma->vm_file->f_path,
1675 &mm->exe_file->f_path))
1676 goto exit;
1677 }
1678
1679 /*
1680 * The symlink can be changed only once, just to disallow arbitrary
1681 * transitions malicious software might bring in. This means one
1682 * could make a snapshot over all processes running and monitor
1683 * /proc/pid/exe changes to notice unusual activity if needed.
1684 */
1685 err = -EPERM;
1686 if (test_and_set_bit(MMF_EXE_FILE_CHANGED, &mm->flags))
1687 goto exit;
1688
1689 err = 0;
1690 set_mm_exe_file(mm, exe.file); /* this grabs a reference to exe.file */
1691 exit:
1692 fdput(exe);
1693 return err;
1694 }
1695
1696 #ifdef CONFIG_CHECKPOINT_RESTORE
1697 /*
1698 * WARNING: we don't require any capability here so be very careful
1699 * in what is allowed for modification from userspace.
1700 */
1701 static int validate_prctl_map(struct prctl_mm_map *prctl_map)
1702 {
1703 unsigned long mmap_max_addr = TASK_SIZE;
1704 struct mm_struct *mm = current->mm;
1705 int error = -EINVAL, i;
1706
1707 static const unsigned char offsets[] = {
1708 offsetof(struct prctl_mm_map, start_code),
1709 offsetof(struct prctl_mm_map, end_code),
1710 offsetof(struct prctl_mm_map, start_data),
1711 offsetof(struct prctl_mm_map, end_data),
1712 offsetof(struct prctl_mm_map, start_brk),
1713 offsetof(struct prctl_mm_map, brk),
1714 offsetof(struct prctl_mm_map, start_stack),
1715 offsetof(struct prctl_mm_map, arg_start),
1716 offsetof(struct prctl_mm_map, arg_end),
1717 offsetof(struct prctl_mm_map, env_start),
1718 offsetof(struct prctl_mm_map, env_end),
1719 };
1720
1721 /*
1722 * Make sure the members are not somewhere outside
1723 * of allowed address space.
1724 */
1725 for (i = 0; i < ARRAY_SIZE(offsets); i++) {
1726 u64 val = *(u64 *)((char *)prctl_map + offsets[i]);
1727
1728 if ((unsigned long)val >= mmap_max_addr ||
1729 (unsigned long)val < mmap_min_addr)
1730 goto out;
1731 }
1732
1733 /*
1734 * Make sure the pairs are ordered.
1735 */
1736 #define __prctl_check_order(__m1, __op, __m2) \
1737 ((unsigned long)prctl_map->__m1 __op \
1738 (unsigned long)prctl_map->__m2) ? 0 : -EINVAL
1739 error = __prctl_check_order(start_code, <, end_code);
1740 error |= __prctl_check_order(start_data, <, end_data);
1741 error |= __prctl_check_order(start_brk, <=, brk);
1742 error |= __prctl_check_order(arg_start, <=, arg_end);
1743 error |= __prctl_check_order(env_start, <=, env_end);
1744 if (error)
1745 goto out;
1746 #undef __prctl_check_order
1747
1748 error = -EINVAL;
1749
1750 /*
1751 * @brk should be after @end_data in traditional maps.
1752 */
1753 if (prctl_map->start_brk <= prctl_map->end_data ||
1754 prctl_map->brk <= prctl_map->end_data)
1755 goto out;
1756
1757 /*
1758 * Neither we should allow to override limits if they set.
1759 */
1760 if (check_data_rlimit(rlimit(RLIMIT_DATA), prctl_map->brk,
1761 prctl_map->start_brk, prctl_map->end_data,
1762 prctl_map->start_data))
1763 goto out;
1764
1765 /*
1766 * Someone is trying to cheat the auxv vector.
1767 */
1768 if (prctl_map->auxv_size) {
1769 if (!prctl_map->auxv || prctl_map->auxv_size > sizeof(mm->saved_auxv))
1770 goto out;
1771 }
1772
1773 /*
1774 * Finally, make sure the caller has the rights to
1775 * change /proc/pid/exe link: only local root should
1776 * be allowed to.
1777 */
1778 if (prctl_map->exe_fd != (u32)-1) {
1779 struct user_namespace *ns = current_user_ns();
1780 const struct cred *cred = current_cred();
1781
1782 if (!uid_eq(cred->uid, make_kuid(ns, 0)) ||
1783 !gid_eq(cred->gid, make_kgid(ns, 0)))
1784 goto out;
1785 }
1786
1787 error = 0;
1788 out:
1789 return error;
1790 }
1791
1792 static int prctl_set_mm_map(int opt, const void __user *addr, unsigned long data_size)
1793 {
1794 struct prctl_mm_map prctl_map = { .exe_fd = (u32)-1, };
1795 unsigned long user_auxv[AT_VECTOR_SIZE];
1796 struct mm_struct *mm = current->mm;
1797 int error;
1798
1799 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv));
1800 BUILD_BUG_ON(sizeof(struct prctl_mm_map) > 256);
1801
1802 if (opt == PR_SET_MM_MAP_SIZE)
1803 return put_user((unsigned int)sizeof(prctl_map),
1804 (unsigned int __user *)addr);
1805
1806 if (data_size != sizeof(prctl_map))
1807 return -EINVAL;
1808
1809 if (copy_from_user(&prctl_map, addr, sizeof(prctl_map)))
1810 return -EFAULT;
1811
1812 error = validate_prctl_map(&prctl_map);
1813 if (error)
1814 return error;
1815
1816 if (prctl_map.auxv_size) {
1817 memset(user_auxv, 0, sizeof(user_auxv));
1818 if (copy_from_user(user_auxv,
1819 (const void __user *)prctl_map.auxv,
1820 prctl_map.auxv_size))
1821 return -EFAULT;
1822
1823 /* Last entry must be AT_NULL as specification requires */
1824 user_auxv[AT_VECTOR_SIZE - 2] = AT_NULL;
1825 user_auxv[AT_VECTOR_SIZE - 1] = AT_NULL;
1826 }
1827
1828 down_write(&mm->mmap_sem);
1829 if (prctl_map.exe_fd != (u32)-1)
1830 error = prctl_set_mm_exe_file_locked(mm, prctl_map.exe_fd);
1831 downgrade_write(&mm->mmap_sem);
1832 if (error)
1833 goto out;
1834
1835 /*
1836 * We don't validate if these members are pointing to
1837 * real present VMAs because application may have correspond
1838 * VMAs already unmapped and kernel uses these members for statistics
1839 * output in procfs mostly, except
1840 *
1841 * - @start_brk/@brk which are used in do_brk but kernel lookups
1842 * for VMAs when updating these memvers so anything wrong written
1843 * here cause kernel to swear at userspace program but won't lead
1844 * to any problem in kernel itself
1845 */
1846
1847 mm->start_code = prctl_map.start_code;
1848 mm->end_code = prctl_map.end_code;
1849 mm->start_data = prctl_map.start_data;
1850 mm->end_data = prctl_map.end_data;
1851 mm->start_brk = prctl_map.start_brk;
1852 mm->brk = prctl_map.brk;
1853 mm->start_stack = prctl_map.start_stack;
1854 mm->arg_start = prctl_map.arg_start;
1855 mm->arg_end = prctl_map.arg_end;
1856 mm->env_start = prctl_map.env_start;
1857 mm->env_end = prctl_map.env_end;
1858
1859 /*
1860 * Note this update of @saved_auxv is lockless thus
1861 * if someone reads this member in procfs while we're
1862 * updating -- it may get partly updated results. It's
1863 * known and acceptable trade off: we leave it as is to
1864 * not introduce additional locks here making the kernel
1865 * more complex.
1866 */
1867 if (prctl_map.auxv_size)
1868 memcpy(mm->saved_auxv, user_auxv, sizeof(user_auxv));
1869
1870 error = 0;
1871 out:
1872 up_read(&mm->mmap_sem);
1873 return error;
1874 }
1875 #endif /* CONFIG_CHECKPOINT_RESTORE */
1876
1877 static int prctl_set_mm(int opt, unsigned long addr,
1878 unsigned long arg4, unsigned long arg5)
1879 {
1880 struct mm_struct *mm = current->mm;
1881 struct vm_area_struct *vma;
1882 int error;
1883
1884 if (arg5 || (arg4 && (opt != PR_SET_MM_AUXV &&
1885 opt != PR_SET_MM_MAP &&
1886 opt != PR_SET_MM_MAP_SIZE)))
1887 return -EINVAL;
1888
1889 #ifdef CONFIG_CHECKPOINT_RESTORE
1890 if (opt == PR_SET_MM_MAP || opt == PR_SET_MM_MAP_SIZE)
1891 return prctl_set_mm_map(opt, (const void __user *)addr, arg4);
1892 #endif
1893
1894 if (!capable(CAP_SYS_RESOURCE))
1895 return -EPERM;
1896
1897 if (opt == PR_SET_MM_EXE_FILE) {
1898 down_write(&mm->mmap_sem);
1899 error = prctl_set_mm_exe_file_locked(mm, (unsigned int)addr);
1900 up_write(&mm->mmap_sem);
1901 return error;
1902 }
1903
1904 if (addr >= TASK_SIZE || addr < mmap_min_addr)
1905 return -EINVAL;
1906
1907 error = -EINVAL;
1908
1909 down_read(&mm->mmap_sem);
1910 vma = find_vma(mm, addr);
1911
1912 switch (opt) {
1913 case PR_SET_MM_START_CODE:
1914 mm->start_code = addr;
1915 break;
1916 case PR_SET_MM_END_CODE:
1917 mm->end_code = addr;
1918 break;
1919 case PR_SET_MM_START_DATA:
1920 mm->start_data = addr;
1921 break;
1922 case PR_SET_MM_END_DATA:
1923 mm->end_data = addr;
1924 break;
1925
1926 case PR_SET_MM_START_BRK:
1927 if (addr <= mm->end_data)
1928 goto out;
1929
1930 if (check_data_rlimit(rlimit(RLIMIT_DATA), mm->brk, addr,
1931 mm->end_data, mm->start_data))
1932 goto out;
1933
1934 mm->start_brk = addr;
1935 break;
1936
1937 case PR_SET_MM_BRK:
1938 if (addr <= mm->end_data)
1939 goto out;
1940
1941 if (check_data_rlimit(rlimit(RLIMIT_DATA), addr, mm->start_brk,
1942 mm->end_data, mm->start_data))
1943 goto out;
1944
1945 mm->brk = addr;
1946 break;
1947
1948 /*
1949 * If command line arguments and environment
1950 * are placed somewhere else on stack, we can
1951 * set them up here, ARG_START/END to setup
1952 * command line argumets and ENV_START/END
1953 * for environment.
1954 */
1955 case PR_SET_MM_START_STACK:
1956 case PR_SET_MM_ARG_START:
1957 case PR_SET_MM_ARG_END:
1958 case PR_SET_MM_ENV_START:
1959 case PR_SET_MM_ENV_END:
1960 if (!vma) {
1961 error = -EFAULT;
1962 goto out;
1963 }
1964 if (opt == PR_SET_MM_START_STACK)
1965 mm->start_stack = addr;
1966 else if (opt == PR_SET_MM_ARG_START)
1967 mm->arg_start = addr;
1968 else if (opt == PR_SET_MM_ARG_END)
1969 mm->arg_end = addr;
1970 else if (opt == PR_SET_MM_ENV_START)
1971 mm->env_start = addr;
1972 else if (opt == PR_SET_MM_ENV_END)
1973 mm->env_end = addr;
1974 break;
1975
1976 /*
1977 * This doesn't move auxiliary vector itself
1978 * since it's pinned to mm_struct, but allow
1979 * to fill vector with new values. It's up
1980 * to a caller to provide sane values here
1981 * otherwise user space tools which use this
1982 * vector might be unhappy.
1983 */
1984 case PR_SET_MM_AUXV: {
1985 unsigned long user_auxv[AT_VECTOR_SIZE];
1986
1987 if (arg4 > sizeof(user_auxv))
1988 goto out;
1989 up_read(&mm->mmap_sem);
1990
1991 if (copy_from_user(user_auxv, (const void __user *)addr, arg4))
1992 return -EFAULT;
1993
1994 /* Make sure the last entry is always AT_NULL */
1995 user_auxv[AT_VECTOR_SIZE - 2] = 0;
1996 user_auxv[AT_VECTOR_SIZE - 1] = 0;
1997
1998 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv));
1999
2000 task_lock(current);
2001 memcpy(mm->saved_auxv, user_auxv, arg4);
2002 task_unlock(current);
2003
2004 return 0;
2005 }
2006 default:
2007 goto out;
2008 }
2009
2010 error = 0;
2011 out:
2012 up_read(&mm->mmap_sem);
2013 return error;
2014 }
2015
2016 #ifdef CONFIG_CHECKPOINT_RESTORE
2017 static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr)
2018 {
2019 return put_user(me->clear_child_tid, tid_addr);
2020 }
2021 #else
2022 static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr)
2023 {
2024 return -EINVAL;
2025 }
2026 #endif
2027
2028 SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
2029 unsigned long, arg4, unsigned long, arg5)
2030 {
2031 struct task_struct *me = current;
2032 unsigned char comm[sizeof(me->comm)];
2033 long error;
2034
2035 error = security_task_prctl(option, arg2, arg3, arg4, arg5);
2036 if (error != -ENOSYS)
2037 return error;
2038
2039 error = 0;
2040 switch (option) {
2041 case PR_SET_PDEATHSIG:
2042 if (!valid_signal(arg2)) {
2043 error = -EINVAL;
2044 break;
2045 }
2046 me->pdeath_signal = arg2;
2047 break;
2048 case PR_GET_PDEATHSIG:
2049 error = put_user(me->pdeath_signal, (int __user *)arg2);
2050 break;
2051 case PR_GET_DUMPABLE:
2052 error = get_dumpable(me->mm);
2053 break;
2054 case PR_SET_DUMPABLE:
2055 if (arg2 != SUID_DUMP_DISABLE && arg2 != SUID_DUMP_USER) {
2056 error = -EINVAL;
2057 break;
2058 }
2059 set_dumpable(me->mm, arg2);
2060 break;
2061
2062 case PR_SET_UNALIGN:
2063 error = SET_UNALIGN_CTL(me, arg2);
2064 break;
2065 case PR_GET_UNALIGN:
2066 error = GET_UNALIGN_CTL(me, arg2);
2067 break;
2068 case PR_SET_FPEMU:
2069 error = SET_FPEMU_CTL(me, arg2);
2070 break;
2071 case PR_GET_FPEMU:
2072 error = GET_FPEMU_CTL(me, arg2);
2073 break;
2074 case PR_SET_FPEXC:
2075 error = SET_FPEXC_CTL(me, arg2);
2076 break;
2077 case PR_GET_FPEXC:
2078 error = GET_FPEXC_CTL(me, arg2);
2079 break;
2080 case PR_GET_TIMING:
2081 error = PR_TIMING_STATISTICAL;
2082 break;
2083 case PR_SET_TIMING:
2084 if (arg2 != PR_TIMING_STATISTICAL)
2085 error = -EINVAL;
2086 break;
2087 case PR_SET_NAME:
2088 comm[sizeof(me->comm) - 1] = 0;
2089 if (strncpy_from_user(comm, (char __user *)arg2,
2090 sizeof(me->comm) - 1) < 0)
2091 return -EFAULT;
2092 set_task_comm(me, comm);
2093 proc_comm_connector(me);
2094 break;
2095 case PR_GET_NAME:
2096 get_task_comm(comm, me);
2097 if (copy_to_user((char __user *)arg2, comm, sizeof(comm)))
2098 return -EFAULT;
2099 break;
2100 case PR_GET_ENDIAN:
2101 error = GET_ENDIAN(me, arg2);
2102 break;
2103 case PR_SET_ENDIAN:
2104 error = SET_ENDIAN(me, arg2);
2105 break;
2106 case PR_GET_SECCOMP:
2107 error = prctl_get_seccomp();
2108 break;
2109 case PR_SET_SECCOMP:
2110 error = prctl_set_seccomp(arg2, (char __user *)arg3);
2111 break;
2112 case PR_GET_TSC:
2113 error = GET_TSC_CTL(arg2);
2114 break;
2115 case PR_SET_TSC:
2116 error = SET_TSC_CTL(arg2);
2117 break;
2118 case PR_TASK_PERF_EVENTS_DISABLE:
2119 error = perf_event_task_disable();
2120 break;
2121 case PR_TASK_PERF_EVENTS_ENABLE:
2122 error = perf_event_task_enable();
2123 break;
2124 case PR_GET_TIMERSLACK:
2125 error = current->timer_slack_ns;
2126 break;
2127 case PR_SET_TIMERSLACK:
2128 if (arg2 <= 0)
2129 current->timer_slack_ns =
2130 current->default_timer_slack_ns;
2131 else
2132 current->timer_slack_ns = arg2;
2133 break;
2134 case PR_MCE_KILL:
2135 if (arg4 | arg5)
2136 return -EINVAL;
2137 switch (arg2) {
2138 case PR_MCE_KILL_CLEAR:
2139 if (arg3 != 0)
2140 return -EINVAL;
2141 current->flags &= ~PF_MCE_PROCESS;
2142 break;
2143 case PR_MCE_KILL_SET:
2144 current->flags |= PF_MCE_PROCESS;
2145 if (arg3 == PR_MCE_KILL_EARLY)
2146 current->flags |= PF_MCE_EARLY;
2147 else if (arg3 == PR_MCE_KILL_LATE)
2148 current->flags &= ~PF_MCE_EARLY;
2149 else if (arg3 == PR_MCE_KILL_DEFAULT)
2150 current->flags &=
2151 ~(PF_MCE_EARLY|PF_MCE_PROCESS);
2152 else
2153 return -EINVAL;
2154 break;
2155 default:
2156 return -EINVAL;
2157 }
2158 break;
2159 case PR_MCE_KILL_GET:
2160 if (arg2 | arg3 | arg4 | arg5)
2161 return -EINVAL;
2162 if (current->flags & PF_MCE_PROCESS)
2163 error = (current->flags & PF_MCE_EARLY) ?
2164 PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE;
2165 else
2166 error = PR_MCE_KILL_DEFAULT;
2167 break;
2168 case PR_SET_MM:
2169 error = prctl_set_mm(arg2, arg3, arg4, arg5);
2170 break;
2171 case PR_GET_TID_ADDRESS:
2172 error = prctl_get_tid_address(me, (int __user **)arg2);
2173 break;
2174 case PR_SET_CHILD_SUBREAPER:
2175 me->signal->is_child_subreaper = !!arg2;
2176 break;
2177 case PR_GET_CHILD_SUBREAPER:
2178 error = put_user(me->signal->is_child_subreaper,
2179 (int __user *)arg2);
2180 break;
2181 case PR_SET_NO_NEW_PRIVS:
2182 if (arg2 != 1 || arg3 || arg4 || arg5)
2183 return -EINVAL;
2184
2185 task_set_no_new_privs(current);
2186 break;
2187 case PR_GET_NO_NEW_PRIVS:
2188 if (arg2 || arg3 || arg4 || arg5)
2189 return -EINVAL;
2190 return task_no_new_privs(current) ? 1 : 0;
2191 case PR_GET_THP_DISABLE:
2192 if (arg2 || arg3 || arg4 || arg5)
2193 return -EINVAL;
2194 error = !!(me->mm->def_flags & VM_NOHUGEPAGE);
2195 break;
2196 case PR_SET_THP_DISABLE:
2197 if (arg3 || arg4 || arg5)
2198 return -EINVAL;
2199 down_write(&me->mm->mmap_sem);
2200 if (arg2)
2201 me->mm->def_flags |= VM_NOHUGEPAGE;
2202 else
2203 me->mm->def_flags &= ~VM_NOHUGEPAGE;
2204 up_write(&me->mm->mmap_sem);
2205 break;
2206 default:
2207 error = -EINVAL;
2208 break;
2209 }
2210 return error;
2211 }
2212
2213 SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep,
2214 struct getcpu_cache __user *, unused)
2215 {
2216 int err = 0;
2217 int cpu = raw_smp_processor_id();
2218
2219 if (cpup)
2220 err |= put_user(cpu, cpup);
2221 if (nodep)
2222 err |= put_user(cpu_to_node(cpu), nodep);
2223 return err ? -EFAULT : 0;
2224 }
2225
2226 /**
2227 * do_sysinfo - fill in sysinfo struct
2228 * @info: pointer to buffer to fill
2229 */
2230 static int do_sysinfo(struct sysinfo *info)
2231 {
2232 unsigned long mem_total, sav_total;
2233 unsigned int mem_unit, bitcount;
2234 struct timespec tp;
2235
2236 memset(info, 0, sizeof(struct sysinfo));
2237
2238 get_monotonic_boottime(&tp);
2239 info->uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0);
2240
2241 get_avenrun(info->loads, 0, SI_LOAD_SHIFT - FSHIFT);
2242
2243 info->procs = nr_threads;
2244
2245 si_meminfo(info);
2246 si_swapinfo(info);
2247
2248 /*
2249 * If the sum of all the available memory (i.e. ram + swap)
2250 * is less than can be stored in a 32 bit unsigned long then
2251 * we can be binary compatible with 2.2.x kernels. If not,
2252 * well, in that case 2.2.x was broken anyways...
2253 *
2254 * -Erik Andersen <andersee@debian.org>
2255 */
2256
2257 mem_total = info->totalram + info->totalswap;
2258 if (mem_total < info->totalram || mem_total < info->totalswap)
2259 goto out;
2260 bitcount = 0;
2261 mem_unit = info->mem_unit;
2262 while (mem_unit > 1) {
2263 bitcount++;
2264 mem_unit >>= 1;
2265 sav_total = mem_total;
2266 mem_total <<= 1;
2267 if (mem_total < sav_total)
2268 goto out;
2269 }
2270
2271 /*
2272 * If mem_total did not overflow, multiply all memory values by
2273 * info->mem_unit and set it to 1. This leaves things compatible
2274 * with 2.2.x, and also retains compatibility with earlier 2.4.x
2275 * kernels...
2276 */
2277
2278 info->mem_unit = 1;
2279 info->totalram <<= bitcount;
2280 info->freeram <<= bitcount;
2281 info->sharedram <<= bitcount;
2282 info->bufferram <<= bitcount;
2283 info->totalswap <<= bitcount;
2284 info->freeswap <<= bitcount;
2285 info->totalhigh <<= bitcount;
2286 info->freehigh <<= bitcount;
2287
2288 out:
2289 return 0;
2290 }
2291
2292 SYSCALL_DEFINE1(sysinfo, struct sysinfo __user *, info)
2293 {
2294 struct sysinfo val;
2295
2296 do_sysinfo(&val);
2297
2298 if (copy_to_user(info, &val, sizeof(struct sysinfo)))
2299 return -EFAULT;
2300
2301 return 0;
2302 }
2303
2304 #ifdef CONFIG_COMPAT
2305 struct compat_sysinfo {
2306 s32 uptime;
2307 u32 loads[3];
2308 u32 totalram;
2309 u32 freeram;
2310 u32 sharedram;
2311 u32 bufferram;
2312 u32 totalswap;
2313 u32 freeswap;
2314 u16 procs;
2315 u16 pad;
2316 u32 totalhigh;
2317 u32 freehigh;
2318 u32 mem_unit;
2319 char _f[20-2*sizeof(u32)-sizeof(int)];
2320 };
2321
2322 COMPAT_SYSCALL_DEFINE1(sysinfo, struct compat_sysinfo __user *, info)
2323 {
2324 struct sysinfo s;
2325
2326 do_sysinfo(&s);
2327
2328 /* Check to see if any memory value is too large for 32-bit and scale
2329 * down if needed
2330 */
2331 if (upper_32_bits(s.totalram) || upper_32_bits(s.totalswap)) {
2332 int bitcount = 0;
2333
2334 while (s.mem_unit < PAGE_SIZE) {
2335 s.mem_unit <<= 1;
2336 bitcount++;
2337 }
2338
2339 s.totalram >>= bitcount;
2340 s.freeram >>= bitcount;
2341 s.sharedram >>= bitcount;
2342 s.bufferram >>= bitcount;
2343 s.totalswap >>= bitcount;
2344 s.freeswap >>= bitcount;
2345 s.totalhigh >>= bitcount;
2346 s.freehigh >>= bitcount;
2347 }
2348
2349 if (!access_ok(VERIFY_WRITE, info, sizeof(struct compat_sysinfo)) ||
2350 __put_user(s.uptime, &info->uptime) ||
2351 __put_user(s.loads[0], &info->loads[0]) ||
2352 __put_user(s.loads[1], &info->loads[1]) ||
2353 __put_user(s.loads[2], &info->loads[2]) ||
2354 __put_user(s.totalram, &info->totalram) ||
2355 __put_user(s.freeram, &info->freeram) ||
2356 __put_user(s.sharedram, &info->sharedram) ||
2357 __put_user(s.bufferram, &info->bufferram) ||
2358 __put_user(s.totalswap, &info->totalswap) ||
2359 __put_user(s.freeswap, &info->freeswap) ||
2360 __put_user(s.procs, &info->procs) ||
2361 __put_user(s.totalhigh, &info->totalhigh) ||
2362 __put_user(s.freehigh, &info->freehigh) ||
2363 __put_user(s.mem_unit, &info->mem_unit))
2364 return -EFAULT;
2365
2366 return 0;
2367 }
2368 #endif /* CONFIG_COMPAT */
Linux with added FPC-III support