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x86, fpu: Fix math_state_restore() race with kernel_fpu_begin()
[linux/fpc-iii.git] / kernel / sys.c
bloba8c9f5a7dda68f9afd60449a3f9fe0b7d048a6f1
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
101 /*
102 * this is where the system-wide overflow UID and GID are defined, for
103 * architectures that now have 32-bit UID/GID but didn't in the past
104 */
105
106 int overflowuid = DEFAULT_OVERFLOWUID;
107 int overflowgid = DEFAULT_OVERFLOWGID;
108
109 EXPORT_SYMBOL(overflowuid);
110 EXPORT_SYMBOL(overflowgid);
111
112 /*
113 * the same as above, but for filesystems which can only store a 16-bit
114 * UID and GID. as such, this is needed on all architectures
115 */
116
117 int fs_overflowuid = DEFAULT_FS_OVERFLOWUID;
118 int fs_overflowgid = DEFAULT_FS_OVERFLOWUID;
119
120 EXPORT_SYMBOL(fs_overflowuid);
121 EXPORT_SYMBOL(fs_overflowgid);
122
123 /*
124 * Returns true if current's euid is same as p's uid or euid,
125 * or has CAP_SYS_NICE to p's user_ns.
126 *
127 * Called with rcu_read_lock, creds are safe
128 */
129 static bool set_one_prio_perm(struct task_struct *p)
130 {
131 const struct cred *cred = current_cred(), *pcred = __task_cred(p);
132
133 if (uid_eq(pcred->uid, cred->euid) ||
134 uid_eq(pcred->euid, cred->euid))
135 return true;
136 if (ns_capable(pcred->user_ns, CAP_SYS_NICE))
137 return true;
138 return false;
139 }
140
141 /*
142 * set the priority of a task
143 * - the caller must hold the RCU read lock
144 */
145 static int set_one_prio(struct task_struct *p, int niceval, int error)
146 {
147 int no_nice;
148
149 if (!set_one_prio_perm(p)) {
150 error = -EPERM;
151 goto out;
152 }
153 if (niceval < task_nice(p) && !can_nice(p, niceval)) {
154 error = -EACCES;
155 goto out;
156 }
157 no_nice = security_task_setnice(p, niceval);
158 if (no_nice) {
159 error = no_nice;
160 goto out;
161 }
162 if (error == -ESRCH)
163 error = 0;
164 set_user_nice(p, niceval);
165 out:
166 return error;
167 }
168
169 SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval)
170 {
171 struct task_struct *g, *p;
172 struct user_struct *user;
173 const struct cred *cred = current_cred();
174 int error = -EINVAL;
175 struct pid *pgrp;
176 kuid_t uid;
177
178 if (which > PRIO_USER || which < PRIO_PROCESS)
179 goto out;
180
181 /* normalize: avoid signed division (rounding problems) */
182 error = -ESRCH;
183 if (niceval < MIN_NICE)
184 niceval = MIN_NICE;
185 if (niceval > MAX_NICE)
186 niceval = MAX_NICE;
187
188 rcu_read_lock();
189 read_lock(&tasklist_lock);
190 switch (which) {
191 case PRIO_PROCESS:
192 if (who)
193 p = find_task_by_vpid(who);
194 else
195 p = current;
196 if (p)
197 error = set_one_prio(p, niceval, error);
198 break;
199 case PRIO_PGRP:
200 if (who)
201 pgrp = find_vpid(who);
202 else
203 pgrp = task_pgrp(current);
204 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
205 error = set_one_prio(p, niceval, error);
206 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
207 break;
208 case PRIO_USER:
209 uid = make_kuid(cred->user_ns, who);
210 user = cred->user;
211 if (!who)
212 uid = cred->uid;
213 else if (!uid_eq(uid, cred->uid)) {
214 user = find_user(uid);
215 if (!user)
216 goto out_unlock; /* No processes for this user */
217 }
218 do_each_thread(g, p) {
219 if (uid_eq(task_uid(p), uid))
220 error = set_one_prio(p, niceval, error);
221 } while_each_thread(g, p);
222 if (!uid_eq(uid, cred->uid))
223 free_uid(user); /* For find_user() */
224 break;
225 }
226 out_unlock:
227 read_unlock(&tasklist_lock);
228 rcu_read_unlock();
229 out:
230 return error;
231 }
232
233 /*
234 * Ugh. To avoid negative return values, "getpriority()" will
235 * not return the normal nice-value, but a negated value that
236 * has been offset by 20 (ie it returns 40..1 instead of -20..19)
237 * to stay compatible.
238 */
239 SYSCALL_DEFINE2(getpriority, int, which, int, who)
240 {
241 struct task_struct *g, *p;
242 struct user_struct *user;
243 const struct cred *cred = current_cred();
244 long niceval, retval = -ESRCH;
245 struct pid *pgrp;
246 kuid_t uid;
247
248 if (which > PRIO_USER || which < PRIO_PROCESS)
249 return -EINVAL;
250
251 rcu_read_lock();
252 read_lock(&tasklist_lock);
253 switch (which) {
254 case PRIO_PROCESS:
255 if (who)
256 p = find_task_by_vpid(who);
257 else
258 p = current;
259 if (p) {
260 niceval = nice_to_rlimit(task_nice(p));
261 if (niceval > retval)
262 retval = niceval;
263 }
264 break;
265 case PRIO_PGRP:
266 if (who)
267 pgrp = find_vpid(who);
268 else
269 pgrp = task_pgrp(current);
270 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
271 niceval = nice_to_rlimit(task_nice(p));
272 if (niceval > retval)
273 retval = niceval;
274 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
275 break;
276 case PRIO_USER:
277 uid = make_kuid(cred->user_ns, who);
278 user = cred->user;
279 if (!who)
280 uid = cred->uid;
281 else if (!uid_eq(uid, cred->uid)) {
282 user = find_user(uid);
283 if (!user)
284 goto out_unlock; /* No processes for this user */
285 }
286 do_each_thread(g, p) {
287 if (uid_eq(task_uid(p), uid)) {
288 niceval = nice_to_rlimit(task_nice(p));
289 if (niceval > retval)
290 retval = niceval;
291 }
292 } while_each_thread(g, p);
293 if (!uid_eq(uid, cred->uid))
294 free_uid(user); /* for find_user() */
295 break;
296 }
297 out_unlock:
298 read_unlock(&tasklist_lock);
299 rcu_read_unlock();
300
301 return retval;
302 }
303
304 /*
305 * Unprivileged users may change the real gid to the effective gid
306 * or vice versa. (BSD-style)
307 *
308 * If you set the real gid at all, or set the effective gid to a value not
309 * equal to the real gid, then the saved gid is set to the new effective gid.
310 *
311 * This makes it possible for a setgid program to completely drop its
312 * privileges, which is often a useful assertion to make when you are doing
313 * a security audit over a program.
314 *
315 * The general idea is that a program which uses just setregid() will be
316 * 100% compatible with BSD. A program which uses just setgid() will be
317 * 100% compatible with POSIX with saved IDs.
318 *
319 * SMP: There are not races, the GIDs are checked only by filesystem
320 * operations (as far as semantic preservation is concerned).
321 */
322 SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid)
323 {
324 struct user_namespace *ns = current_user_ns();
325 const struct cred *old;
326 struct cred *new;
327 int retval;
328 kgid_t krgid, kegid;
329
330 krgid = make_kgid(ns, rgid);
331 kegid = make_kgid(ns, egid);
332
333 if ((rgid != (gid_t) -1) && !gid_valid(krgid))
334 return -EINVAL;
335 if ((egid != (gid_t) -1) && !gid_valid(kegid))
336 return -EINVAL;
337
338 new = prepare_creds();
339 if (!new)
340 return -ENOMEM;
341 old = current_cred();
342
343 retval = -EPERM;
344 if (rgid != (gid_t) -1) {
345 if (gid_eq(old->gid, krgid) ||
346 gid_eq(old->egid, krgid) ||
347 ns_capable(old->user_ns, CAP_SETGID))
348 new->gid = krgid;
349 else
350 goto error;
351 }
352 if (egid != (gid_t) -1) {
353 if (gid_eq(old->gid, kegid) ||
354 gid_eq(old->egid, kegid) ||
355 gid_eq(old->sgid, kegid) ||
356 ns_capable(old->user_ns, CAP_SETGID))
357 new->egid = kegid;
358 else
359 goto error;
360 }
361
362 if (rgid != (gid_t) -1 ||
363 (egid != (gid_t) -1 && !gid_eq(kegid, old->gid)))
364 new->sgid = new->egid;
365 new->fsgid = new->egid;
366
367 return commit_creds(new);
368
369 error:
370 abort_creds(new);
371 return retval;
372 }
373
374 /*
375 * setgid() is implemented like SysV w/ SAVED_IDS
376 *
377 * SMP: Same implicit races as above.
378 */
379 SYSCALL_DEFINE1(setgid, gid_t, gid)
380 {
381 struct user_namespace *ns = current_user_ns();
382 const struct cred *old;
383 struct cred *new;
384 int retval;
385 kgid_t kgid;
386
387 kgid = make_kgid(ns, gid);
388 if (!gid_valid(kgid))
389 return -EINVAL;
390
391 new = prepare_creds();
392 if (!new)
393 return -ENOMEM;
394 old = current_cred();
395
396 retval = -EPERM;
397 if (ns_capable(old->user_ns, CAP_SETGID))
398 new->gid = new->egid = new->sgid = new->fsgid = kgid;
399 else if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->sgid))
400 new->egid = new->fsgid = kgid;
401 else
402 goto error;
403
404 return commit_creds(new);
405
406 error:
407 abort_creds(new);
408 return retval;
409 }
410
411 /*
412 * change the user struct in a credentials set to match the new UID
413 */
414 static int set_user(struct cred *new)
415 {
416 struct user_struct *new_user;
417
418 new_user = alloc_uid(new->uid);
419 if (!new_user)
420 return -EAGAIN;
421
422 /*
423 * We don't fail in case of NPROC limit excess here because too many
424 * poorly written programs don't check set*uid() return code, assuming
425 * it never fails if called by root. We may still enforce NPROC limit
426 * for programs doing set*uid()+execve() by harmlessly deferring the
427 * failure to the execve() stage.
428 */
429 if (atomic_read(&new_user->processes) >= rlimit(RLIMIT_NPROC) &&
430 new_user != INIT_USER)
431 current->flags |= PF_NPROC_EXCEEDED;
432 else
433 current->flags &= ~PF_NPROC_EXCEEDED;
434
435 free_uid(new->user);
436 new->user = new_user;
437 return 0;
438 }
439
440 /*
441 * Unprivileged users may change the real uid to the effective uid
442 * or vice versa. (BSD-style)
443 *
444 * If you set the real uid at all, or set the effective uid to a value not
445 * equal to the real uid, then the saved uid is set to the new effective uid.
446 *
447 * This makes it possible for a setuid program to completely drop its
448 * privileges, which is often a useful assertion to make when you are doing
449 * a security audit over a program.
450 *
451 * The general idea is that a program which uses just setreuid() will be
452 * 100% compatible with BSD. A program which uses just setuid() will be
453 * 100% compatible with POSIX with saved IDs.
454 */
455 SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid)
456 {
457 struct user_namespace *ns = current_user_ns();
458 const struct cred *old;
459 struct cred *new;
460 int retval;
461 kuid_t kruid, keuid;
462
463 kruid = make_kuid(ns, ruid);
464 keuid = make_kuid(ns, euid);
465
466 if ((ruid != (uid_t) -1) && !uid_valid(kruid))
467 return -EINVAL;
468 if ((euid != (uid_t) -1) && !uid_valid(keuid))
469 return -EINVAL;
470
471 new = prepare_creds();
472 if (!new)
473 return -ENOMEM;
474 old = current_cred();
475
476 retval = -EPERM;
477 if (ruid != (uid_t) -1) {
478 new->uid = kruid;
479 if (!uid_eq(old->uid, kruid) &&
480 !uid_eq(old->euid, kruid) &&
481 !ns_capable(old->user_ns, CAP_SETUID))
482 goto error;
483 }
484
485 if (euid != (uid_t) -1) {
486 new->euid = keuid;
487 if (!uid_eq(old->uid, keuid) &&
488 !uid_eq(old->euid, keuid) &&
489 !uid_eq(old->suid, keuid) &&
490 !ns_capable(old->user_ns, CAP_SETUID))
491 goto error;
492 }
493
494 if (!uid_eq(new->uid, old->uid)) {
495 retval = set_user(new);
496 if (retval < 0)
497 goto error;
498 }
499 if (ruid != (uid_t) -1 ||
500 (euid != (uid_t) -1 && !uid_eq(keuid, old->uid)))
501 new->suid = new->euid;
502 new->fsuid = new->euid;
503
504 retval = security_task_fix_setuid(new, old, LSM_SETID_RE);
505 if (retval < 0)
506 goto error;
507
508 return commit_creds(new);
509
510 error:
511 abort_creds(new);
512 return retval;
513 }
514
515 /*
516 * setuid() is implemented like SysV with SAVED_IDS
517 *
518 * Note that SAVED_ID's is deficient in that a setuid root program
519 * like sendmail, for example, cannot set its uid to be a normal
520 * user and then switch back, because if you're root, setuid() sets
521 * the saved uid too. If you don't like this, blame the bright people
522 * in the POSIX committee and/or USG. Note that the BSD-style setreuid()
523 * will allow a root program to temporarily drop privileges and be able to
524 * regain them by swapping the real and effective uid.
525 */
526 SYSCALL_DEFINE1(setuid, uid_t, uid)
527 {
528 struct user_namespace *ns = current_user_ns();
529 const struct cred *old;
530 struct cred *new;
531 int retval;
532 kuid_t kuid;
533
534 kuid = make_kuid(ns, uid);
535 if (!uid_valid(kuid))
536 return -EINVAL;
537
538 new = prepare_creds();
539 if (!new)
540 return -ENOMEM;
541 old = current_cred();
542
543 retval = -EPERM;
544 if (ns_capable(old->user_ns, CAP_SETUID)) {
545 new->suid = new->uid = kuid;
546 if (!uid_eq(kuid, old->uid)) {
547 retval = set_user(new);
548 if (retval < 0)
549 goto error;
550 }
551 } else if (!uid_eq(kuid, old->uid) && !uid_eq(kuid, new->suid)) {
552 goto error;
553 }
554
555 new->fsuid = new->euid = kuid;
556
557 retval = security_task_fix_setuid(new, old, LSM_SETID_ID);
558 if (retval < 0)
559 goto error;
560
561 return commit_creds(new);
562
563 error:
564 abort_creds(new);
565 return retval;
566 }
567
568
569 /*
570 * This function implements a generic ability to update ruid, euid,
571 * and suid. This allows you to implement the 4.4 compatible seteuid().
572 */
573 SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid)
574 {
575 struct user_namespace *ns = current_user_ns();
576 const struct cred *old;
577 struct cred *new;
578 int retval;
579 kuid_t kruid, keuid, ksuid;
580
581 kruid = make_kuid(ns, ruid);
582 keuid = make_kuid(ns, euid);
583 ksuid = make_kuid(ns, suid);
584
585 if ((ruid != (uid_t) -1) && !uid_valid(kruid))
586 return -EINVAL;
587
588 if ((euid != (uid_t) -1) && !uid_valid(keuid))
589 return -EINVAL;
590
591 if ((suid != (uid_t) -1) && !uid_valid(ksuid))
592 return -EINVAL;
593
594 new = prepare_creds();
595 if (!new)
596 return -ENOMEM;
597
598 old = current_cred();
599
600 retval = -EPERM;
601 if (!ns_capable(old->user_ns, CAP_SETUID)) {
602 if (ruid != (uid_t) -1 && !uid_eq(kruid, old->uid) &&
603 !uid_eq(kruid, old->euid) && !uid_eq(kruid, old->suid))
604 goto error;
605 if (euid != (uid_t) -1 && !uid_eq(keuid, old->uid) &&
606 !uid_eq(keuid, old->euid) && !uid_eq(keuid, old->suid))
607 goto error;
608 if (suid != (uid_t) -1 && !uid_eq(ksuid, old->uid) &&
609 !uid_eq(ksuid, old->euid) && !uid_eq(ksuid, old->suid))
610 goto error;
611 }
612
613 if (ruid != (uid_t) -1) {
614 new->uid = kruid;
615 if (!uid_eq(kruid, old->uid)) {
616 retval = set_user(new);
617 if (retval < 0)
618 goto error;
619 }
620 }
621 if (euid != (uid_t) -1)
622 new->euid = keuid;
623 if (suid != (uid_t) -1)
624 new->suid = ksuid;
625 new->fsuid = new->euid;
626
627 retval = security_task_fix_setuid(new, old, LSM_SETID_RES);
628 if (retval < 0)
629 goto error;
630
631 return commit_creds(new);
632
633 error:
634 abort_creds(new);
635 return retval;
636 }
637
638 SYSCALL_DEFINE3(getresuid, uid_t __user *, ruidp, uid_t __user *, euidp, uid_t __user *, suidp)
639 {
640 const struct cred *cred = current_cred();
641 int retval;
642 uid_t ruid, euid, suid;
643
644 ruid = from_kuid_munged(cred->user_ns, cred->uid);
645 euid = from_kuid_munged(cred->user_ns, cred->euid);
646 suid = from_kuid_munged(cred->user_ns, cred->suid);
647
648 retval = put_user(ruid, ruidp);
649 if (!retval) {
650 retval = put_user(euid, euidp);
651 if (!retval)
652 return put_user(suid, suidp);
653 }
654 return retval;
655 }
656
657 /*
658 * Same as above, but for rgid, egid, sgid.
659 */
660 SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid)
661 {
662 struct user_namespace *ns = current_user_ns();
663 const struct cred *old;
664 struct cred *new;
665 int retval;
666 kgid_t krgid, kegid, ksgid;
667
668 krgid = make_kgid(ns, rgid);
669 kegid = make_kgid(ns, egid);
670 ksgid = make_kgid(ns, sgid);
671
672 if ((rgid != (gid_t) -1) && !gid_valid(krgid))
673 return -EINVAL;
674 if ((egid != (gid_t) -1) && !gid_valid(kegid))
675 return -EINVAL;
676 if ((sgid != (gid_t) -1) && !gid_valid(ksgid))
677 return -EINVAL;
678
679 new = prepare_creds();
680 if (!new)
681 return -ENOMEM;
682 old = current_cred();
683
684 retval = -EPERM;
685 if (!ns_capable(old->user_ns, CAP_SETGID)) {
686 if (rgid != (gid_t) -1 && !gid_eq(krgid, old->gid) &&
687 !gid_eq(krgid, old->egid) && !gid_eq(krgid, old->sgid))
688 goto error;
689 if (egid != (gid_t) -1 && !gid_eq(kegid, old->gid) &&
690 !gid_eq(kegid, old->egid) && !gid_eq(kegid, old->sgid))
691 goto error;
692 if (sgid != (gid_t) -1 && !gid_eq(ksgid, old->gid) &&
693 !gid_eq(ksgid, old->egid) && !gid_eq(ksgid, old->sgid))
694 goto error;
695 }
696
697 if (rgid != (gid_t) -1)
698 new->gid = krgid;
699 if (egid != (gid_t) -1)
700 new->egid = kegid;
701 if (sgid != (gid_t) -1)
702 new->sgid = ksgid;
703 new->fsgid = new->egid;
704
705 return commit_creds(new);
706
707 error:
708 abort_creds(new);
709 return retval;
710 }
711
712 SYSCALL_DEFINE3(getresgid, gid_t __user *, rgidp, gid_t __user *, egidp, gid_t __user *, sgidp)
713 {
714 const struct cred *cred = current_cred();
715 int retval;
716 gid_t rgid, egid, sgid;
717
718 rgid = from_kgid_munged(cred->user_ns, cred->gid);
719 egid = from_kgid_munged(cred->user_ns, cred->egid);
720 sgid = from_kgid_munged(cred->user_ns, cred->sgid);
721
722 retval = put_user(rgid, rgidp);
723 if (!retval) {
724 retval = put_user(egid, egidp);
725 if (!retval)
726 retval = put_user(sgid, sgidp);
727 }
728
729 return retval;
730 }
731
732
733 /*
734 * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This
735 * is used for "access()" and for the NFS daemon (letting nfsd stay at
736 * whatever uid it wants to). It normally shadows "euid", except when
737 * explicitly set by setfsuid() or for access..
738 */
739 SYSCALL_DEFINE1(setfsuid, uid_t, uid)
740 {
741 const struct cred *old;
742 struct cred *new;
743 uid_t old_fsuid;
744 kuid_t kuid;
745
746 old = current_cred();
747 old_fsuid = from_kuid_munged(old->user_ns, old->fsuid);
748
749 kuid = make_kuid(old->user_ns, uid);
750 if (!uid_valid(kuid))
751 return old_fsuid;
752
753 new = prepare_creds();
754 if (!new)
755 return old_fsuid;
756
757 if (uid_eq(kuid, old->uid) || uid_eq(kuid, old->euid) ||
758 uid_eq(kuid, old->suid) || uid_eq(kuid, old->fsuid) ||
759 ns_capable(old->user_ns, CAP_SETUID)) {
760 if (!uid_eq(kuid, old->fsuid)) {
761 new->fsuid = kuid;
762 if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0)
763 goto change_okay;
764 }
765 }
766
767 abort_creds(new);
768 return old_fsuid;
769
770 change_okay:
771 commit_creds(new);
772 return old_fsuid;
773 }
774
775 /*
776 * Samma på svenska..
777 */
778 SYSCALL_DEFINE1(setfsgid, gid_t, gid)
779 {
780 const struct cred *old;
781 struct cred *new;
782 gid_t old_fsgid;
783 kgid_t kgid;
784
785 old = current_cred();
786 old_fsgid = from_kgid_munged(old->user_ns, old->fsgid);
787
788 kgid = make_kgid(old->user_ns, gid);
789 if (!gid_valid(kgid))
790 return old_fsgid;
791
792 new = prepare_creds();
793 if (!new)
794 return old_fsgid;
795
796 if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->egid) ||
797 gid_eq(kgid, old->sgid) || gid_eq(kgid, old->fsgid) ||
798 ns_capable(old->user_ns, CAP_SETGID)) {
799 if (!gid_eq(kgid, old->fsgid)) {
800 new->fsgid = kgid;
801 goto change_okay;
802 }
803 }
804
805 abort_creds(new);
806 return old_fsgid;
807
808 change_okay:
809 commit_creds(new);
810 return old_fsgid;
811 }
812
813 /**
814 * sys_getpid - return the thread group id of the current process
815 *
816 * Note, despite the name, this returns the tgid not the pid. The tgid and
817 * the pid are identical unless CLONE_THREAD was specified on clone() in
818 * which case the tgid is the same in all threads of the same group.
819 *
820 * This is SMP safe as current->tgid does not change.
821 */
822 SYSCALL_DEFINE0(getpid)
823 {
824 return task_tgid_vnr(current);
825 }
826
827 /* Thread ID - the internal kernel "pid" */
828 SYSCALL_DEFINE0(gettid)
829 {
830 return task_pid_vnr(current);
831 }
832
833 /*
834 * Accessing ->real_parent is not SMP-safe, it could
835 * change from under us. However, we can use a stale
836 * value of ->real_parent under rcu_read_lock(), see
837 * release_task()->call_rcu(delayed_put_task_struct).
838 */
839 SYSCALL_DEFINE0(getppid)
840 {
841 int pid;
842
843 rcu_read_lock();
844 pid = task_tgid_vnr(rcu_dereference(current->real_parent));
845 rcu_read_unlock();
846
847 return pid;
848 }
849
850 SYSCALL_DEFINE0(getuid)
851 {
852 /* Only we change this so SMP safe */
853 return from_kuid_munged(current_user_ns(), current_uid());
854 }
855
856 SYSCALL_DEFINE0(geteuid)
857 {
858 /* Only we change this so SMP safe */
859 return from_kuid_munged(current_user_ns(), current_euid());
860 }
861
862 SYSCALL_DEFINE0(getgid)
863 {
864 /* Only we change this so SMP safe */
865 return from_kgid_munged(current_user_ns(), current_gid());
866 }
867
868 SYSCALL_DEFINE0(getegid)
869 {
870 /* Only we change this so SMP safe */
871 return from_kgid_munged(current_user_ns(), current_egid());
872 }
873
874 void do_sys_times(struct tms *tms)
875 {
876 cputime_t tgutime, tgstime, cutime, cstime;
877
878 thread_group_cputime_adjusted(current, &tgutime, &tgstime);
879 cutime = current->signal->cutime;
880 cstime = current->signal->cstime;
881 tms->tms_utime = cputime_to_clock_t(tgutime);
882 tms->tms_stime = cputime_to_clock_t(tgstime);
883 tms->tms_cutime = cputime_to_clock_t(cutime);
884 tms->tms_cstime = cputime_to_clock_t(cstime);
885 }
886
887 SYSCALL_DEFINE1(times, struct tms __user *, tbuf)
888 {
889 if (tbuf) {
890 struct tms tmp;
891
892 do_sys_times(&tmp);
893 if (copy_to_user(tbuf, &tmp, sizeof(struct tms)))
894 return -EFAULT;
895 }
896 force_successful_syscall_return();
897 return (long) jiffies_64_to_clock_t(get_jiffies_64());
898 }
899
900 /*
901 * This needs some heavy checking ...
902 * I just haven't the stomach for it. I also don't fully
903 * understand sessions/pgrp etc. Let somebody who does explain it.
904 *
905 * OK, I think I have the protection semantics right.... this is really
906 * only important on a multi-user system anyway, to make sure one user
907 * can't send a signal to a process owned by another. -TYT, 12/12/91
908 *
909 * !PF_FORKNOEXEC check to conform completely to POSIX.
910 */
911 SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid)
912 {
913 struct task_struct *p;
914 struct task_struct *group_leader = current->group_leader;
915 struct pid *pgrp;
916 int err;
917
918 if (!pid)
919 pid = task_pid_vnr(group_leader);
920 if (!pgid)
921 pgid = pid;
922 if (pgid < 0)
923 return -EINVAL;
924 rcu_read_lock();
925
926 /* From this point forward we keep holding onto the tasklist lock
927 * so that our parent does not change from under us. -DaveM
928 */
929 write_lock_irq(&tasklist_lock);
930
931 err = -ESRCH;
932 p = find_task_by_vpid(pid);
933 if (!p)
934 goto out;
935
936 err = -EINVAL;
937 if (!thread_group_leader(p))
938 goto out;
939
940 if (same_thread_group(p->real_parent, group_leader)) {
941 err = -EPERM;
942 if (task_session(p) != task_session(group_leader))
943 goto out;
944 err = -EACCES;
945 if (!(p->flags & PF_FORKNOEXEC))
946 goto out;
947 } else {
948 err = -ESRCH;
949 if (p != group_leader)
950 goto out;
951 }
952
953 err = -EPERM;
954 if (p->signal->leader)
955 goto out;
956
957 pgrp = task_pid(p);
958 if (pgid != pid) {
959 struct task_struct *g;
960
961 pgrp = find_vpid(pgid);
962 g = pid_task(pgrp, PIDTYPE_PGID);
963 if (!g || task_session(g) != task_session(group_leader))
964 goto out;
965 }
966
967 err = security_task_setpgid(p, pgid);
968 if (err)
969 goto out;
970
971 if (task_pgrp(p) != pgrp)
972 change_pid(p, PIDTYPE_PGID, pgrp);
973
974 err = 0;
975 out:
976 /* All paths lead to here, thus we are safe. -DaveM */
977 write_unlock_irq(&tasklist_lock);
978 rcu_read_unlock();
979 return err;
980 }
981
982 SYSCALL_DEFINE1(getpgid, pid_t, pid)
983 {
984 struct task_struct *p;
985 struct pid *grp;
986 int retval;
987
988 rcu_read_lock();
989 if (!pid)
990 grp = task_pgrp(current);
991 else {
992 retval = -ESRCH;
993 p = find_task_by_vpid(pid);
994 if (!p)
995 goto out;
996 grp = task_pgrp(p);
997 if (!grp)
998 goto out;
999
1000 retval = security_task_getpgid(p);
1001 if (retval)
1002 goto out;
1003 }
1004 retval = pid_vnr(grp);
1005 out:
1006 rcu_read_unlock();
1007 return retval;
1008 }
1009
1010 #ifdef __ARCH_WANT_SYS_GETPGRP
1011
1012 SYSCALL_DEFINE0(getpgrp)
1013 {
1014 return sys_getpgid(0);
1015 }
1016
1017 #endif
1018
1019 SYSCALL_DEFINE1(getsid, pid_t, pid)
1020 {
1021 struct task_struct *p;
1022 struct pid *sid;
1023 int retval;
1024
1025 rcu_read_lock();
1026 if (!pid)
1027 sid = task_session(current);
1028 else {
1029 retval = -ESRCH;
1030 p = find_task_by_vpid(pid);
1031 if (!p)
1032 goto out;
1033 sid = task_session(p);
1034 if (!sid)
1035 goto out;
1036
1037 retval = security_task_getsid(p);
1038 if (retval)
1039 goto out;
1040 }
1041 retval = pid_vnr(sid);
1042 out:
1043 rcu_read_unlock();
1044 return retval;
1045 }
1046
1047 static void set_special_pids(struct pid *pid)
1048 {
1049 struct task_struct *curr = current->group_leader;
1050
1051 if (task_session(curr) != pid)
1052 change_pid(curr, PIDTYPE_SID, pid);
1053
1054 if (task_pgrp(curr) != pid)
1055 change_pid(curr, PIDTYPE_PGID, pid);
1056 }
1057
1058 SYSCALL_DEFINE0(setsid)
1059 {
1060 struct task_struct *group_leader = current->group_leader;
1061 struct pid *sid = task_pid(group_leader);
1062 pid_t session = pid_vnr(sid);
1063 int err = -EPERM;
1064
1065 write_lock_irq(&tasklist_lock);
1066 /* Fail if I am already a session leader */
1067 if (group_leader->signal->leader)
1068 goto out;
1069
1070 /* Fail if a process group id already exists that equals the
1071 * proposed session id.
1072 */
1073 if (pid_task(sid, PIDTYPE_PGID))
1074 goto out;
1075
1076 group_leader->signal->leader = 1;
1077 set_special_pids(sid);
1078
1079 proc_clear_tty(group_leader);
1080
1081 err = session;
1082 out:
1083 write_unlock_irq(&tasklist_lock);
1084 if (err > 0) {
1085 proc_sid_connector(group_leader);
1086 sched_autogroup_create_attach(group_leader);
1087 }
1088 return err;
1089 }
1090
1091 DECLARE_RWSEM(uts_sem);
1092
1093 #ifdef COMPAT_UTS_MACHINE
1094 #define override_architecture(name) \
1095 (personality(current->personality) == PER_LINUX32 && \
1096 copy_to_user(name->machine, COMPAT_UTS_MACHINE, \
1097 sizeof(COMPAT_UTS_MACHINE)))
1098 #else
1099 #define override_architecture(name) 0
1100 #endif
1101
1102 /*
1103 * Work around broken programs that cannot handle "Linux 3.0".
1104 * Instead we map 3.x to 2.6.40+x, so e.g. 3.0 would be 2.6.40
1105 */
1106 static int override_release(char __user *release, size_t len)
1107 {
1108 int ret = 0;
1109
1110 if (current->personality & UNAME26) {
1111 const char *rest = UTS_RELEASE;
1112 char buf[65] = { 0 };
1113 int ndots = 0;
1114 unsigned v;
1115 size_t copy;
1116
1117 while (*rest) {
1118 if (*rest == '.' && ++ndots >= 3)
1119 break;
1120 if (!isdigit(*rest) && *rest != '.')
1121 break;
1122 rest++;
1123 }
1124 v = ((LINUX_VERSION_CODE >> 8) & 0xff) + 40;
1125 copy = clamp_t(size_t, len, 1, sizeof(buf));
1126 copy = scnprintf(buf, copy, "2.6.%u%s", v, rest);
1127 ret = copy_to_user(release, buf, copy + 1);
1128 }
1129 return ret;
1130 }
1131
1132 SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name)
1133 {
1134 int errno = 0;
1135
1136 down_read(&uts_sem);
1137 if (copy_to_user(name, utsname(), sizeof *name))
1138 errno = -EFAULT;
1139 up_read(&uts_sem);
1140
1141 if (!errno && override_release(name->release, sizeof(name->release)))
1142 errno = -EFAULT;
1143 if (!errno && override_architecture(name))
1144 errno = -EFAULT;
1145 return errno;
1146 }
1147
1148 #ifdef __ARCH_WANT_SYS_OLD_UNAME
1149 /*
1150 * Old cruft
1151 */
1152 SYSCALL_DEFINE1(uname, struct old_utsname __user *, name)
1153 {
1154 int error = 0;
1155
1156 if (!name)
1157 return -EFAULT;
1158
1159 down_read(&uts_sem);
1160 if (copy_to_user(name, utsname(), sizeof(*name)))
1161 error = -EFAULT;
1162 up_read(&uts_sem);
1163
1164 if (!error && override_release(name->release, sizeof(name->release)))
1165 error = -EFAULT;
1166 if (!error && override_architecture(name))
1167 error = -EFAULT;
1168 return error;
1169 }
1170
1171 SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name)
1172 {
1173 int error;
1174
1175 if (!name)
1176 return -EFAULT;
1177 if (!access_ok(VERIFY_WRITE, name, sizeof(struct oldold_utsname)))
1178 return -EFAULT;
1179
1180 down_read(&uts_sem);
1181 error = __copy_to_user(&name->sysname, &utsname()->sysname,
1182 __OLD_UTS_LEN);
1183 error |= __put_user(0, name->sysname + __OLD_UTS_LEN);
1184 error |= __copy_to_user(&name->nodename, &utsname()->nodename,
1185 __OLD_UTS_LEN);
1186 error |= __put_user(0, name->nodename + __OLD_UTS_LEN);
1187 error |= __copy_to_user(&name->release, &utsname()->release,
1188 __OLD_UTS_LEN);
1189 error |= __put_user(0, name->release + __OLD_UTS_LEN);
1190 error |= __copy_to_user(&name->version, &utsname()->version,
1191 __OLD_UTS_LEN);
1192 error |= __put_user(0, name->version + __OLD_UTS_LEN);
1193 error |= __copy_to_user(&name->machine, &utsname()->machine,
1194 __OLD_UTS_LEN);
1195 error |= __put_user(0, name->machine + __OLD_UTS_LEN);
1196 up_read(&uts_sem);
1197
1198 if (!error && override_architecture(name))
1199 error = -EFAULT;
1200 if (!error && override_release(name->release, sizeof(name->release)))
1201 error = -EFAULT;
1202 return error ? -EFAULT : 0;
1203 }
1204 #endif
1205
1206 SYSCALL_DEFINE2(sethostname, char __user *, name, int, len)
1207 {
1208 int errno;
1209 char tmp[__NEW_UTS_LEN];
1210
1211 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN))
1212 return -EPERM;
1213
1214 if (len < 0 || len > __NEW_UTS_LEN)
1215 return -EINVAL;
1216 down_write(&uts_sem);
1217 errno = -EFAULT;
1218 if (!copy_from_user(tmp, name, len)) {
1219 struct new_utsname *u = utsname();
1220
1221 memcpy(u->nodename, tmp, len);
1222 memset(u->nodename + len, 0, sizeof(u->nodename) - len);
1223 errno = 0;
1224 uts_proc_notify(UTS_PROC_HOSTNAME);
1225 }
1226 up_write(&uts_sem);
1227 return errno;
1228 }
1229
1230 #ifdef __ARCH_WANT_SYS_GETHOSTNAME
1231
1232 SYSCALL_DEFINE2(gethostname, char __user *, name, int, len)
1233 {
1234 int i, errno;
1235 struct new_utsname *u;
1236
1237 if (len < 0)
1238 return -EINVAL;
1239 down_read(&uts_sem);
1240 u = utsname();
1241 i = 1 + strlen(u->nodename);
1242 if (i > len)
1243 i = len;
1244 errno = 0;
1245 if (copy_to_user(name, u->nodename, i))
1246 errno = -EFAULT;
1247 up_read(&uts_sem);
1248 return errno;
1249 }
1250
1251 #endif
1252
1253 /*
1254 * Only setdomainname; getdomainname can be implemented by calling
1255 * uname()
1256 */
1257 SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len)
1258 {
1259 int errno;
1260 char tmp[__NEW_UTS_LEN];
1261
1262 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN))
1263 return -EPERM;
1264 if (len < 0 || len > __NEW_UTS_LEN)
1265 return -EINVAL;
1266
1267 down_write(&uts_sem);
1268 errno = -EFAULT;
1269 if (!copy_from_user(tmp, name, len)) {
1270 struct new_utsname *u = utsname();
1271
1272 memcpy(u->domainname, tmp, len);
1273 memset(u->domainname + len, 0, sizeof(u->domainname) - len);
1274 errno = 0;
1275 uts_proc_notify(UTS_PROC_DOMAINNAME);
1276 }
1277 up_write(&uts_sem);
1278 return errno;
1279 }
1280
1281 SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim)
1282 {
1283 struct rlimit value;
1284 int ret;
1285
1286 ret = do_prlimit(current, resource, NULL, &value);
1287 if (!ret)
1288 ret = copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0;
1289
1290 return ret;
1291 }
1292
1293 #ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT
1294
1295 /*
1296 * Back compatibility for getrlimit. Needed for some apps.
1297 */
1298 SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
1299 struct rlimit __user *, rlim)
1300 {
1301 struct rlimit x;
1302 if (resource >= RLIM_NLIMITS)
1303 return -EINVAL;
1304
1305 task_lock(current->group_leader);
1306 x = current->signal->rlim[resource];
1307 task_unlock(current->group_leader);
1308 if (x.rlim_cur > 0x7FFFFFFF)
1309 x.rlim_cur = 0x7FFFFFFF;
1310 if (x.rlim_max > 0x7FFFFFFF)
1311 x.rlim_max = 0x7FFFFFFF;
1312 return copy_to_user(rlim, &x, sizeof(x)) ? -EFAULT : 0;
1313 }
1314
1315 #endif
1316
1317 static inline bool rlim64_is_infinity(__u64 rlim64)
1318 {
1319 #if BITS_PER_LONG < 64
1320 return rlim64 >= ULONG_MAX;
1321 #else
1322 return rlim64 == RLIM64_INFINITY;
1323 #endif
1324 }
1325
1326 static void rlim_to_rlim64(const struct rlimit *rlim, struct rlimit64 *rlim64)
1327 {
1328 if (rlim->rlim_cur == RLIM_INFINITY)
1329 rlim64->rlim_cur = RLIM64_INFINITY;
1330 else
1331 rlim64->rlim_cur = rlim->rlim_cur;
1332 if (rlim->rlim_max == RLIM_INFINITY)
1333 rlim64->rlim_max = RLIM64_INFINITY;
1334 else
1335 rlim64->rlim_max = rlim->rlim_max;
1336 }
1337
1338 static void rlim64_to_rlim(const struct rlimit64 *rlim64, struct rlimit *rlim)
1339 {
1340 if (rlim64_is_infinity(rlim64->rlim_cur))
1341 rlim->rlim_cur = RLIM_INFINITY;
1342 else
1343 rlim->rlim_cur = (unsigned long)rlim64->rlim_cur;
1344 if (rlim64_is_infinity(rlim64->rlim_max))
1345 rlim->rlim_max = RLIM_INFINITY;
1346 else
1347 rlim->rlim_max = (unsigned long)rlim64->rlim_max;
1348 }
1349
1350 /* make sure you are allowed to change @tsk limits before calling this */
1351 int do_prlimit(struct task_struct *tsk, unsigned int resource,
1352 struct rlimit *new_rlim, struct rlimit *old_rlim)
1353 {
1354 struct rlimit *rlim;
1355 int retval = 0;
1356
1357 if (resource >= RLIM_NLIMITS)
1358 return -EINVAL;
1359 if (new_rlim) {
1360 if (new_rlim->rlim_cur > new_rlim->rlim_max)
1361 return -EINVAL;
1362 if (resource == RLIMIT_NOFILE &&
1363 new_rlim->rlim_max > sysctl_nr_open)
1364 return -EPERM;
1365 }
1366
1367 /* protect tsk->signal and tsk->sighand from disappearing */
1368 read_lock(&tasklist_lock);
1369 if (!tsk->sighand) {
1370 retval = -ESRCH;
1371 goto out;
1372 }
1373
1374 rlim = tsk->signal->rlim + resource;
1375 task_lock(tsk->group_leader);
1376 if (new_rlim) {
1377 /* Keep the capable check against init_user_ns until
1378 cgroups can contain all limits */
1379 if (new_rlim->rlim_max > rlim->rlim_max &&
1380 !capable(CAP_SYS_RESOURCE))
1381 retval = -EPERM;
1382 if (!retval)
1383 retval = security_task_setrlimit(tsk->group_leader,
1384 resource, new_rlim);
1385 if (resource == RLIMIT_CPU && new_rlim->rlim_cur == 0) {
1386 /*
1387 * The caller is asking for an immediate RLIMIT_CPU
1388 * expiry. But we use the zero value to mean "it was
1389 * never set". So let's cheat and make it one second
1390 * instead
1391 */
1392 new_rlim->rlim_cur = 1;
1393 }
1394 }
1395 if (!retval) {
1396 if (old_rlim)
1397 *old_rlim = *rlim;
1398 if (new_rlim)
1399 *rlim = *new_rlim;
1400 }
1401 task_unlock(tsk->group_leader);
1402
1403 /*
1404 * RLIMIT_CPU handling. Note that the kernel fails to return an error
1405 * code if it rejected the user's attempt to set RLIMIT_CPU. This is a
1406 * very long-standing error, and fixing it now risks breakage of
1407 * applications, so we live with it
1408 */
1409 if (!retval && new_rlim && resource == RLIMIT_CPU &&
1410 new_rlim->rlim_cur != RLIM_INFINITY)
1411 update_rlimit_cpu(tsk, new_rlim->rlim_cur);
1412 out:
1413 read_unlock(&tasklist_lock);
1414 return retval;
1415 }
1416
1417 /* rcu lock must be held */
1418 static int check_prlimit_permission(struct task_struct *task)
1419 {
1420 const struct cred *cred = current_cred(), *tcred;
1421
1422 if (current == task)
1423 return 0;
1424
1425 tcred = __task_cred(task);
1426 if (uid_eq(cred->uid, tcred->euid) &&
1427 uid_eq(cred->uid, tcred->suid) &&
1428 uid_eq(cred->uid, tcred->uid) &&
1429 gid_eq(cred->gid, tcred->egid) &&
1430 gid_eq(cred->gid, tcred->sgid) &&
1431 gid_eq(cred->gid, tcred->gid))
1432 return 0;
1433 if (ns_capable(tcred->user_ns, CAP_SYS_RESOURCE))
1434 return 0;
1435
1436 return -EPERM;
1437 }
1438
1439 SYSCALL_DEFINE4(prlimit64, pid_t, pid, unsigned int, resource,
1440 const struct rlimit64 __user *, new_rlim,
1441 struct rlimit64 __user *, old_rlim)
1442 {
1443 struct rlimit64 old64, new64;
1444 struct rlimit old, new;
1445 struct task_struct *tsk;
1446 int ret;
1447
1448 if (new_rlim) {
1449 if (copy_from_user(&new64, new_rlim, sizeof(new64)))
1450 return -EFAULT;
1451 rlim64_to_rlim(&new64, &new);
1452 }
1453
1454 rcu_read_lock();
1455 tsk = pid ? find_task_by_vpid(pid) : current;
1456 if (!tsk) {
1457 rcu_read_unlock();
1458 return -ESRCH;
1459 }
1460 ret = check_prlimit_permission(tsk);
1461 if (ret) {
1462 rcu_read_unlock();
1463 return ret;
1464 }
1465 get_task_struct(tsk);
1466 rcu_read_unlock();
1467
1468 ret = do_prlimit(tsk, resource, new_rlim ? &new : NULL,
1469 old_rlim ? &old : NULL);
1470
1471 if (!ret && old_rlim) {
1472 rlim_to_rlim64(&old, &old64);
1473 if (copy_to_user(old_rlim, &old64, sizeof(old64)))
1474 ret = -EFAULT;
1475 }
1476
1477 put_task_struct(tsk);
1478 return ret;
1479 }
1480
1481 SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim)
1482 {
1483 struct rlimit new_rlim;
1484
1485 if (copy_from_user(&new_rlim, rlim, sizeof(*rlim)))
1486 return -EFAULT;
1487 return do_prlimit(current, resource, &new_rlim, NULL);
1488 }
1489
1490 /*
1491 * It would make sense to put struct rusage in the task_struct,
1492 * except that would make the task_struct be *really big*. After
1493 * task_struct gets moved into malloc'ed memory, it would
1494 * make sense to do this. It will make moving the rest of the information
1495 * a lot simpler! (Which we're not doing right now because we're not
1496 * measuring them yet).
1497 *
1498 * When sampling multiple threads for RUSAGE_SELF, under SMP we might have
1499 * races with threads incrementing their own counters. But since word
1500 * reads are atomic, we either get new values or old values and we don't
1501 * care which for the sums. We always take the siglock to protect reading
1502 * the c* fields from p->signal from races with exit.c updating those
1503 * fields when reaping, so a sample either gets all the additions of a
1504 * given child after it's reaped, or none so this sample is before reaping.
1505 *
1506 * Locking:
1507 * We need to take the siglock for CHILDEREN, SELF and BOTH
1508 * for the cases current multithreaded, non-current single threaded
1509 * non-current multithreaded. Thread traversal is now safe with
1510 * the siglock held.
1511 * Strictly speaking, we donot need to take the siglock if we are current and
1512 * single threaded, as no one else can take our signal_struct away, no one
1513 * else can reap the children to update signal->c* counters, and no one else
1514 * can race with the signal-> fields. If we do not take any lock, the
1515 * signal-> fields could be read out of order while another thread was just
1516 * exiting. So we should place a read memory barrier when we avoid the lock.
1517 * On the writer side, write memory barrier is implied in __exit_signal
1518 * as __exit_signal releases the siglock spinlock after updating the signal->
1519 * fields. But we don't do this yet to keep things simple.
1520 *
1521 */
1522
1523 static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r)
1524 {
1525 r->ru_nvcsw += t->nvcsw;
1526 r->ru_nivcsw += t->nivcsw;
1527 r->ru_minflt += t->min_flt;
1528 r->ru_majflt += t->maj_flt;
1529 r->ru_inblock += task_io_get_inblock(t);
1530 r->ru_oublock += task_io_get_oublock(t);
1531 }
1532
1533 static void k_getrusage(struct task_struct *p, int who, struct rusage *r)
1534 {
1535 struct task_struct *t;
1536 unsigned long flags;
1537 cputime_t tgutime, tgstime, utime, stime;
1538 unsigned long maxrss = 0;
1539
1540 memset((char *)r, 0, sizeof (*r));
1541 utime = stime = 0;
1542
1543 if (who == RUSAGE_THREAD) {
1544 task_cputime_adjusted(current, &utime, &stime);
1545 accumulate_thread_rusage(p, r);
1546 maxrss = p->signal->maxrss;
1547 goto out;
1548 }
1549
1550 if (!lock_task_sighand(p, &flags))
1551 return;
1552
1553 switch (who) {
1554 case RUSAGE_BOTH:
1555 case RUSAGE_CHILDREN:
1556 utime = p->signal->cutime;
1557 stime = p->signal->cstime;
1558 r->ru_nvcsw = p->signal->cnvcsw;
1559 r->ru_nivcsw = p->signal->cnivcsw;
1560 r->ru_minflt = p->signal->cmin_flt;
1561 r->ru_majflt = p->signal->cmaj_flt;
1562 r->ru_inblock = p->signal->cinblock;
1563 r->ru_oublock = p->signal->coublock;
1564 maxrss = p->signal->cmaxrss;
1565
1566 if (who == RUSAGE_CHILDREN)
1567 break;
1568
1569 case RUSAGE_SELF:
1570 thread_group_cputime_adjusted(p, &tgutime, &tgstime);
1571 utime += tgutime;
1572 stime += tgstime;
1573 r->ru_nvcsw += p->signal->nvcsw;
1574 r->ru_nivcsw += p->signal->nivcsw;
1575 r->ru_minflt += p->signal->min_flt;
1576 r->ru_majflt += p->signal->maj_flt;
1577 r->ru_inblock += p->signal->inblock;
1578 r->ru_oublock += p->signal->oublock;
1579 if (maxrss < p->signal->maxrss)
1580 maxrss = p->signal->maxrss;
1581 t = p;
1582 do {
1583 accumulate_thread_rusage(t, r);
1584 } while_each_thread(p, t);
1585 break;
1586
1587 default:
1588 BUG();
1589 }
1590 unlock_task_sighand(p, &flags);
1591
1592 out:
1593 cputime_to_timeval(utime, &r->ru_utime);
1594 cputime_to_timeval(stime, &r->ru_stime);
1595
1596 if (who != RUSAGE_CHILDREN) {
1597 struct mm_struct *mm = get_task_mm(p);
1598
1599 if (mm) {
1600 setmax_mm_hiwater_rss(&maxrss, mm);
1601 mmput(mm);
1602 }
1603 }
1604 r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */
1605 }
1606
1607 int getrusage(struct task_struct *p, int who, struct rusage __user *ru)
1608 {
1609 struct rusage r;
1610
1611 k_getrusage(p, who, &r);
1612 return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0;
1613 }
1614
1615 SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru)
1616 {
1617 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
1618 who != RUSAGE_THREAD)
1619 return -EINVAL;
1620 return getrusage(current, who, ru);
1621 }
1622
1623 #ifdef CONFIG_COMPAT
1624 COMPAT_SYSCALL_DEFINE2(getrusage, int, who, struct compat_rusage __user *, ru)
1625 {
1626 struct rusage r;
1627
1628 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
1629 who != RUSAGE_THREAD)
1630 return -EINVAL;
1631
1632 k_getrusage(current, who, &r);
1633 return put_compat_rusage(&r, ru);
1634 }
1635 #endif
1636
1637 SYSCALL_DEFINE1(umask, int, mask)
1638 {
1639 mask = xchg(&current->fs->umask, mask & S_IRWXUGO);
1640 return mask;
1641 }
1642
1643 static int prctl_set_mm_exe_file_locked(struct mm_struct *mm, unsigned int fd)
1644 {
1645 struct fd exe;
1646 struct inode *inode;
1647 int err;
1648
1649 VM_BUG_ON_MM(!rwsem_is_locked(&mm->mmap_sem), mm);
1650
1651 exe = fdget(fd);
1652 if (!exe.file)
1653 return -EBADF;
1654
1655 inode = file_inode(exe.file);
1656
1657 /*
1658 * Because the original mm->exe_file points to executable file, make
1659 * sure that this one is executable as well, to avoid breaking an
1660 * overall picture.
1661 */
1662 err = -EACCES;
1663 if (!S_ISREG(inode->i_mode) ||
1664 exe.file->f_path.mnt->mnt_flags & MNT_NOEXEC)
1665 goto exit;
1666
1667 err = inode_permission(inode, MAY_EXEC);
1668 if (err)
1669 goto exit;
1670
1671 /*
1672 * Forbid mm->exe_file change if old file still mapped.
1673 */
1674 err = -EBUSY;
1675 if (mm->exe_file) {
1676 struct vm_area_struct *vma;
1677
1678 for (vma = mm->mmap; vma; vma = vma->vm_next)
1679 if (vma->vm_file &&
1680 path_equal(&vma->vm_file->f_path,
1681 &mm->exe_file->f_path))
1682 goto exit;
1683 }
1684
1685 /*
1686 * The symlink can be changed only once, just to disallow arbitrary
1687 * transitions malicious software might bring in. This means one
1688 * could make a snapshot over all processes running and monitor
1689 * /proc/pid/exe changes to notice unusual activity if needed.
1690 */
1691 err = -EPERM;
1692 if (test_and_set_bit(MMF_EXE_FILE_CHANGED, &mm->flags))
1693 goto exit;
1694
1695 err = 0;
1696 set_mm_exe_file(mm, exe.file); /* this grabs a reference to exe.file */
1697 exit:
1698 fdput(exe);
1699 return err;
1700 }
1701
1702 #ifdef CONFIG_CHECKPOINT_RESTORE
1703 /*
1704 * WARNING: we don't require any capability here so be very careful
1705 * in what is allowed for modification from userspace.
1706 */
1707 static int validate_prctl_map(struct prctl_mm_map *prctl_map)
1708 {
1709 unsigned long mmap_max_addr = TASK_SIZE;
1710 struct mm_struct *mm = current->mm;
1711 int error = -EINVAL, i;
1712
1713 static const unsigned char offsets[] = {
1714 offsetof(struct prctl_mm_map, start_code),
1715 offsetof(struct prctl_mm_map, end_code),
1716 offsetof(struct prctl_mm_map, start_data),
1717 offsetof(struct prctl_mm_map, end_data),
1718 offsetof(struct prctl_mm_map, start_brk),
1719 offsetof(struct prctl_mm_map, brk),
1720 offsetof(struct prctl_mm_map, start_stack),
1721 offsetof(struct prctl_mm_map, arg_start),
1722 offsetof(struct prctl_mm_map, arg_end),
1723 offsetof(struct prctl_mm_map, env_start),
1724 offsetof(struct prctl_mm_map, env_end),
1725 };
1726
1727 /*
1728 * Make sure the members are not somewhere outside
1729 * of allowed address space.
1730 */
1731 for (i = 0; i < ARRAY_SIZE(offsets); i++) {
1732 u64 val = *(u64 *)((char *)prctl_map + offsets[i]);
1733
1734 if ((unsigned long)val >= mmap_max_addr ||
1735 (unsigned long)val < mmap_min_addr)
1736 goto out;
1737 }
1738
1739 /*
1740 * Make sure the pairs are ordered.
1741 */
1742 #define __prctl_check_order(__m1, __op, __m2) \
1743 ((unsigned long)prctl_map->__m1 __op \
1744 (unsigned long)prctl_map->__m2) ? 0 : -EINVAL
1745 error = __prctl_check_order(start_code, <, end_code);
1746 error |= __prctl_check_order(start_data, <, end_data);
1747 error |= __prctl_check_order(start_brk, <=, brk);
1748 error |= __prctl_check_order(arg_start, <=, arg_end);
1749 error |= __prctl_check_order(env_start, <=, env_end);
1750 if (error)
1751 goto out;
1752 #undef __prctl_check_order
1753
1754 error = -EINVAL;
1755
1756 /*
1757 * @brk should be after @end_data in traditional maps.
1758 */
1759 if (prctl_map->start_brk <= prctl_map->end_data ||
1760 prctl_map->brk <= prctl_map->end_data)
1761 goto out;
1762
1763 /*
1764 * Neither we should allow to override limits if they set.
1765 */
1766 if (check_data_rlimit(rlimit(RLIMIT_DATA), prctl_map->brk,
1767 prctl_map->start_brk, prctl_map->end_data,
1768 prctl_map->start_data))
1769 goto out;
1770
1771 /*
1772 * Someone is trying to cheat the auxv vector.
1773 */
1774 if (prctl_map->auxv_size) {
1775 if (!prctl_map->auxv || prctl_map->auxv_size > sizeof(mm->saved_auxv))
1776 goto out;
1777 }
1778
1779 /*
1780 * Finally, make sure the caller has the rights to
1781 * change /proc/pid/exe link: only local root should
1782 * be allowed to.
1783 */
1784 if (prctl_map->exe_fd != (u32)-1) {
1785 struct user_namespace *ns = current_user_ns();
1786 const struct cred *cred = current_cred();
1787
1788 if (!uid_eq(cred->uid, make_kuid(ns, 0)) ||
1789 !gid_eq(cred->gid, make_kgid(ns, 0)))
1790 goto out;
1791 }
1792
1793 error = 0;
1794 out:
1795 return error;
1796 }
1797
1798 static int prctl_set_mm_map(int opt, const void __user *addr, unsigned long data_size)
1799 {
1800 struct prctl_mm_map prctl_map = { .exe_fd = (u32)-1, };
1801 unsigned long user_auxv[AT_VECTOR_SIZE];
1802 struct mm_struct *mm = current->mm;
1803 int error;
1804
1805 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv));
1806 BUILD_BUG_ON(sizeof(struct prctl_mm_map) > 256);
1807
1808 if (opt == PR_SET_MM_MAP_SIZE)
1809 return put_user((unsigned int)sizeof(prctl_map),
1810 (unsigned int __user *)addr);
1811
1812 if (data_size != sizeof(prctl_map))
1813 return -EINVAL;
1814
1815 if (copy_from_user(&prctl_map, addr, sizeof(prctl_map)))
1816 return -EFAULT;
1817
1818 error = validate_prctl_map(&prctl_map);
1819 if (error)
1820 return error;
1821
1822 if (prctl_map.auxv_size) {
1823 memset(user_auxv, 0, sizeof(user_auxv));
1824 if (copy_from_user(user_auxv,
1825 (const void __user *)prctl_map.auxv,
1826 prctl_map.auxv_size))
1827 return -EFAULT;
1828
1829 /* Last entry must be AT_NULL as specification requires */
1830 user_auxv[AT_VECTOR_SIZE - 2] = AT_NULL;
1831 user_auxv[AT_VECTOR_SIZE - 1] = AT_NULL;
1832 }
1833
1834 down_write(&mm->mmap_sem);
1835 if (prctl_map.exe_fd != (u32)-1)
1836 error = prctl_set_mm_exe_file_locked(mm, prctl_map.exe_fd);
1837 downgrade_write(&mm->mmap_sem);
1838 if (error)
1839 goto out;
1840
1841 /*
1842 * We don't validate if these members are pointing to
1843 * real present VMAs because application may have correspond
1844 * VMAs already unmapped and kernel uses these members for statistics
1845 * output in procfs mostly, except
1846 *
1847 * - @start_brk/@brk which are used in do_brk but kernel lookups
1848 * for VMAs when updating these memvers so anything wrong written
1849 * here cause kernel to swear at userspace program but won't lead
1850 * to any problem in kernel itself
1851 */
1852
1853 mm->start_code = prctl_map.start_code;
1854 mm->end_code = prctl_map.end_code;
1855 mm->start_data = prctl_map.start_data;
1856 mm->end_data = prctl_map.end_data;
1857 mm->start_brk = prctl_map.start_brk;
1858 mm->brk = prctl_map.brk;
1859 mm->start_stack = prctl_map.start_stack;
1860 mm->arg_start = prctl_map.arg_start;
1861 mm->arg_end = prctl_map.arg_end;
1862 mm->env_start = prctl_map.env_start;
1863 mm->env_end = prctl_map.env_end;
1864
1865 /*
1866 * Note this update of @saved_auxv is lockless thus
1867 * if someone reads this member in procfs while we're
1868 * updating -- it may get partly updated results. It's
1869 * known and acceptable trade off: we leave it as is to
1870 * not introduce additional locks here making the kernel
1871 * more complex.
1872 */
1873 if (prctl_map.auxv_size)
1874 memcpy(mm->saved_auxv, user_auxv, sizeof(user_auxv));
1875
1876 error = 0;
1877 out:
1878 up_read(&mm->mmap_sem);
1879 return error;
1880 }
1881 #endif /* CONFIG_CHECKPOINT_RESTORE */
1882
1883 static int prctl_set_mm(int opt, unsigned long addr,
1884 unsigned long arg4, unsigned long arg5)
1885 {
1886 struct mm_struct *mm = current->mm;
1887 struct vm_area_struct *vma;
1888 int error;
1889
1890 if (arg5 || (arg4 && (opt != PR_SET_MM_AUXV &&
1891 opt != PR_SET_MM_MAP &&
1892 opt != PR_SET_MM_MAP_SIZE)))
1893 return -EINVAL;
1894
1895 #ifdef CONFIG_CHECKPOINT_RESTORE
1896 if (opt == PR_SET_MM_MAP || opt == PR_SET_MM_MAP_SIZE)
1897 return prctl_set_mm_map(opt, (const void __user *)addr, arg4);
1898 #endif
1899
1900 if (!capable(CAP_SYS_RESOURCE))
1901 return -EPERM;
1902
1903 if (opt == PR_SET_MM_EXE_FILE) {
1904 down_write(&mm->mmap_sem);
1905 error = prctl_set_mm_exe_file_locked(mm, (unsigned int)addr);
1906 up_write(&mm->mmap_sem);
1907 return error;
1908 }
1909
1910 if (addr >= TASK_SIZE || addr < mmap_min_addr)
1911 return -EINVAL;
1912
1913 error = -EINVAL;
1914
1915 down_read(&mm->mmap_sem);
1916 vma = find_vma(mm, addr);
1917
1918 switch (opt) {
1919 case PR_SET_MM_START_CODE:
1920 mm->start_code = addr;
1921 break;
1922 case PR_SET_MM_END_CODE:
1923 mm->end_code = addr;
1924 break;
1925 case PR_SET_MM_START_DATA:
1926 mm->start_data = addr;
1927 break;
1928 case PR_SET_MM_END_DATA:
1929 mm->end_data = addr;
1930 break;
1931
1932 case PR_SET_MM_START_BRK:
1933 if (addr <= mm->end_data)
1934 goto out;
1935
1936 if (check_data_rlimit(rlimit(RLIMIT_DATA), mm->brk, addr,
1937 mm->end_data, mm->start_data))
1938 goto out;
1939
1940 mm->start_brk = addr;
1941 break;
1942
1943 case PR_SET_MM_BRK:
1944 if (addr <= mm->end_data)
1945 goto out;
1946
1947 if (check_data_rlimit(rlimit(RLIMIT_DATA), addr, mm->start_brk,
1948 mm->end_data, mm->start_data))
1949 goto out;
1950
1951 mm->brk = addr;
1952 break;
1953
1954 /*
1955 * If command line arguments and environment
1956 * are placed somewhere else on stack, we can
1957 * set them up here, ARG_START/END to setup
1958 * command line argumets and ENV_START/END
1959 * for environment.
1960 */
1961 case PR_SET_MM_START_STACK:
1962 case PR_SET_MM_ARG_START:
1963 case PR_SET_MM_ARG_END:
1964 case PR_SET_MM_ENV_START:
1965 case PR_SET_MM_ENV_END:
1966 if (!vma) {
1967 error = -EFAULT;
1968 goto out;
1969 }
1970 if (opt == PR_SET_MM_START_STACK)
1971 mm->start_stack = addr;
1972 else if (opt == PR_SET_MM_ARG_START)
1973 mm->arg_start = addr;
1974 else if (opt == PR_SET_MM_ARG_END)
1975 mm->arg_end = addr;
1976 else if (opt == PR_SET_MM_ENV_START)
1977 mm->env_start = addr;
1978 else if (opt == PR_SET_MM_ENV_END)
1979 mm->env_end = addr;
1980 break;
1981
1982 /*
1983 * This doesn't move auxiliary vector itself
1984 * since it's pinned to mm_struct, but allow
1985 * to fill vector with new values. It's up
1986 * to a caller to provide sane values here
1987 * otherwise user space tools which use this
1988 * vector might be unhappy.
1989 */
1990 case PR_SET_MM_AUXV: {
1991 unsigned long user_auxv[AT_VECTOR_SIZE];
1992
1993 if (arg4 > sizeof(user_auxv))
1994 goto out;
1995 up_read(&mm->mmap_sem);
1996
1997 if (copy_from_user(user_auxv, (const void __user *)addr, arg4))
1998 return -EFAULT;
1999
2000 /* Make sure the last entry is always AT_NULL */
2001 user_auxv[AT_VECTOR_SIZE - 2] = 0;
2002 user_auxv[AT_VECTOR_SIZE - 1] = 0;
2003
2004 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv));
2005
2006 task_lock(current);
2007 memcpy(mm->saved_auxv, user_auxv, arg4);
2008 task_unlock(current);
2009
2010 return 0;
2011 }
2012 default:
2013 goto out;
2014 }
2015
2016 error = 0;
2017 out:
2018 up_read(&mm->mmap_sem);
2019 return error;
2020 }
2021
2022 #ifdef CONFIG_CHECKPOINT_RESTORE
2023 static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr)
2024 {
2025 return put_user(me->clear_child_tid, tid_addr);
2026 }
2027 #else
2028 static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr)
2029 {
2030 return -EINVAL;
2031 }
2032 #endif
2033
2034 SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
2035 unsigned long, arg4, unsigned long, arg5)
2036 {
2037 struct task_struct *me = current;
2038 unsigned char comm[sizeof(me->comm)];
2039 long error;
2040
2041 error = security_task_prctl(option, arg2, arg3, arg4, arg5);
2042 if (error != -ENOSYS)
2043 return error;
2044
2045 error = 0;
2046 switch (option) {
2047 case PR_SET_PDEATHSIG:
2048 if (!valid_signal(arg2)) {
2049 error = -EINVAL;
2050 break;
2051 }
2052 me->pdeath_signal = arg2;
2053 break;
2054 case PR_GET_PDEATHSIG:
2055 error = put_user(me->pdeath_signal, (int __user *)arg2);
2056 break;
2057 case PR_GET_DUMPABLE:
2058 error = get_dumpable(me->mm);
2059 break;
2060 case PR_SET_DUMPABLE:
2061 if (arg2 != SUID_DUMP_DISABLE && arg2 != SUID_DUMP_USER) {
2062 error = -EINVAL;
2063 break;
2064 }
2065 set_dumpable(me->mm, arg2);
2066 break;
2067
2068 case PR_SET_UNALIGN:
2069 error = SET_UNALIGN_CTL(me, arg2);
2070 break;
2071 case PR_GET_UNALIGN:
2072 error = GET_UNALIGN_CTL(me, arg2);
2073 break;
2074 case PR_SET_FPEMU:
2075 error = SET_FPEMU_CTL(me, arg2);
2076 break;
2077 case PR_GET_FPEMU:
2078 error = GET_FPEMU_CTL(me, arg2);
2079 break;
2080 case PR_SET_FPEXC:
2081 error = SET_FPEXC_CTL(me, arg2);
2082 break;
2083 case PR_GET_FPEXC:
2084 error = GET_FPEXC_CTL(me, arg2);
2085 break;
2086 case PR_GET_TIMING:
2087 error = PR_TIMING_STATISTICAL;
2088 break;
2089 case PR_SET_TIMING:
2090 if (arg2 != PR_TIMING_STATISTICAL)
2091 error = -EINVAL;
2092 break;
2093 case PR_SET_NAME:
2094 comm[sizeof(me->comm) - 1] = 0;
2095 if (strncpy_from_user(comm, (char __user *)arg2,
2096 sizeof(me->comm) - 1) < 0)
2097 return -EFAULT;
2098 set_task_comm(me, comm);
2099 proc_comm_connector(me);
2100 break;
2101 case PR_GET_NAME:
2102 get_task_comm(comm, me);
2103 if (copy_to_user((char __user *)arg2, comm, sizeof(comm)))
2104 return -EFAULT;
2105 break;
2106 case PR_GET_ENDIAN:
2107 error = GET_ENDIAN(me, arg2);
2108 break;
2109 case PR_SET_ENDIAN:
2110 error = SET_ENDIAN(me, arg2);
2111 break;
2112 case PR_GET_SECCOMP:
2113 error = prctl_get_seccomp();
2114 break;
2115 case PR_SET_SECCOMP:
2116 error = prctl_set_seccomp(arg2, (char __user *)arg3);
2117 break;
2118 case PR_GET_TSC:
2119 error = GET_TSC_CTL(arg2);
2120 break;
2121 case PR_SET_TSC:
2122 error = SET_TSC_CTL(arg2);
2123 break;
2124 case PR_TASK_PERF_EVENTS_DISABLE:
2125 error = perf_event_task_disable();
2126 break;
2127 case PR_TASK_PERF_EVENTS_ENABLE:
2128 error = perf_event_task_enable();
2129 break;
2130 case PR_GET_TIMERSLACK:
2131 error = current->timer_slack_ns;
2132 break;
2133 case PR_SET_TIMERSLACK:
2134 if (arg2 <= 0)
2135 current->timer_slack_ns =
2136 current->default_timer_slack_ns;
2137 else
2138 current->timer_slack_ns = arg2;
2139 break;
2140 case PR_MCE_KILL:
2141 if (arg4 | arg5)
2142 return -EINVAL;
2143 switch (arg2) {
2144 case PR_MCE_KILL_CLEAR:
2145 if (arg3 != 0)
2146 return -EINVAL;
2147 current->flags &= ~PF_MCE_PROCESS;
2148 break;
2149 case PR_MCE_KILL_SET:
2150 current->flags |= PF_MCE_PROCESS;
2151 if (arg3 == PR_MCE_KILL_EARLY)
2152 current->flags |= PF_MCE_EARLY;
2153 else if (arg3 == PR_MCE_KILL_LATE)
2154 current->flags &= ~PF_MCE_EARLY;
2155 else if (arg3 == PR_MCE_KILL_DEFAULT)
2156 current->flags &=
2157 ~(PF_MCE_EARLY|PF_MCE_PROCESS);
2158 else
2159 return -EINVAL;
2160 break;
2161 default:
2162 return -EINVAL;
2163 }
2164 break;
2165 case PR_MCE_KILL_GET:
2166 if (arg2 | arg3 | arg4 | arg5)
2167 return -EINVAL;
2168 if (current->flags & PF_MCE_PROCESS)
2169 error = (current->flags & PF_MCE_EARLY) ?
2170 PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE;
2171 else
2172 error = PR_MCE_KILL_DEFAULT;
2173 break;
2174 case PR_SET_MM:
2175 error = prctl_set_mm(arg2, arg3, arg4, arg5);
2176 break;
2177 case PR_GET_TID_ADDRESS:
2178 error = prctl_get_tid_address(me, (int __user **)arg2);
2179 break;
2180 case PR_SET_CHILD_SUBREAPER:
2181 me->signal->is_child_subreaper = !!arg2;
2182 break;
2183 case PR_GET_CHILD_SUBREAPER:
2184 error = put_user(me->signal->is_child_subreaper,
2185 (int __user *)arg2);
2186 break;
2187 case PR_SET_NO_NEW_PRIVS:
2188 if (arg2 != 1 || arg3 || arg4 || arg5)
2189 return -EINVAL;
2190
2191 task_set_no_new_privs(current);
2192 break;
2193 case PR_GET_NO_NEW_PRIVS:
2194 if (arg2 || arg3 || arg4 || arg5)
2195 return -EINVAL;
2196 return task_no_new_privs(current) ? 1 : 0;
2197 case PR_GET_THP_DISABLE:
2198 if (arg2 || arg3 || arg4 || arg5)
2199 return -EINVAL;
2200 error = !!(me->mm->def_flags & VM_NOHUGEPAGE);
2201 break;
2202 case PR_SET_THP_DISABLE:
2203 if (arg3 || arg4 || arg5)
2204 return -EINVAL;
2205 down_write(&me->mm->mmap_sem);
2206 if (arg2)
2207 me->mm->def_flags |= VM_NOHUGEPAGE;
2208 else
2209 me->mm->def_flags &= ~VM_NOHUGEPAGE;
2210 up_write(&me->mm->mmap_sem);
2211 break;
2212 case PR_MPX_ENABLE_MANAGEMENT:
2213 error = MPX_ENABLE_MANAGEMENT(me);
2214 break;
2215 case PR_MPX_DISABLE_MANAGEMENT:
2216 error = MPX_DISABLE_MANAGEMENT(me);
2217 break;
2218 default:
2219 error = -EINVAL;
2220 break;
2221 }
2222 return error;
2223 }
2224
2225 SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep,
2226 struct getcpu_cache __user *, unused)
2227 {
2228 int err = 0;
2229 int cpu = raw_smp_processor_id();
2230
2231 if (cpup)
2232 err |= put_user(cpu, cpup);
2233 if (nodep)
2234 err |= put_user(cpu_to_node(cpu), nodep);
2235 return err ? -EFAULT : 0;
2236 }
2237
2238 /**
2239 * do_sysinfo - fill in sysinfo struct
2240 * @info: pointer to buffer to fill
2241 */
2242 static int do_sysinfo(struct sysinfo *info)
2243 {
2244 unsigned long mem_total, sav_total;
2245 unsigned int mem_unit, bitcount;
2246 struct timespec tp;
2247
2248 memset(info, 0, sizeof(struct sysinfo));
2249
2250 get_monotonic_boottime(&tp);
2251 info->uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0);
2252
2253 get_avenrun(info->loads, 0, SI_LOAD_SHIFT - FSHIFT);
2254
2255 info->procs = nr_threads;
2256
2257 si_meminfo(info);
2258 si_swapinfo(info);
2259
2260 /*
2261 * If the sum of all the available memory (i.e. ram + swap)
2262 * is less than can be stored in a 32 bit unsigned long then
2263 * we can be binary compatible with 2.2.x kernels. If not,
2264 * well, in that case 2.2.x was broken anyways...
2265 *
2266 * -Erik Andersen <andersee@debian.org>
2267 */
2268
2269 mem_total = info->totalram + info->totalswap;
2270 if (mem_total < info->totalram || mem_total < info->totalswap)
2271 goto out;
2272 bitcount = 0;
2273 mem_unit = info->mem_unit;
2274 while (mem_unit > 1) {
2275 bitcount++;
2276 mem_unit >>= 1;
2277 sav_total = mem_total;
2278 mem_total <<= 1;
2279 if (mem_total < sav_total)
2280 goto out;
2281 }
2282
2283 /*
2284 * If mem_total did not overflow, multiply all memory values by
2285 * info->mem_unit and set it to 1. This leaves things compatible
2286 * with 2.2.x, and also retains compatibility with earlier 2.4.x
2287 * kernels...
2288 */
2289
2290 info->mem_unit = 1;
2291 info->totalram <<= bitcount;
2292 info->freeram <<= bitcount;
2293 info->sharedram <<= bitcount;
2294 info->bufferram <<= bitcount;
2295 info->totalswap <<= bitcount;
2296 info->freeswap <<= bitcount;
2297 info->totalhigh <<= bitcount;
2298 info->freehigh <<= bitcount;
2299
2300 out:
2301 return 0;
2302 }
2303
2304 SYSCALL_DEFINE1(sysinfo, struct sysinfo __user *, info)
2305 {
2306 struct sysinfo val;
2307
2308 do_sysinfo(&val);
2309
2310 if (copy_to_user(info, &val, sizeof(struct sysinfo)))
2311 return -EFAULT;
2312
2313 return 0;
2314 }
2315
2316 #ifdef CONFIG_COMPAT
2317 struct compat_sysinfo {
2318 s32 uptime;
2319 u32 loads[3];
2320 u32 totalram;
2321 u32 freeram;
2322 u32 sharedram;
2323 u32 bufferram;
2324 u32 totalswap;
2325 u32 freeswap;
2326 u16 procs;
2327 u16 pad;
2328 u32 totalhigh;
2329 u32 freehigh;
2330 u32 mem_unit;
2331 char _f[20-2*sizeof(u32)-sizeof(int)];
2332 };
2333
2334 COMPAT_SYSCALL_DEFINE1(sysinfo, struct compat_sysinfo __user *, info)
2335 {
2336 struct sysinfo s;
2337
2338 do_sysinfo(&s);
2339
2340 /* Check to see if any memory value is too large for 32-bit and scale
2341 * down if needed
2342 */
2343 if (upper_32_bits(s.totalram) || upper_32_bits(s.totalswap)) {
2344 int bitcount = 0;
2345
2346 while (s.mem_unit < PAGE_SIZE) {
2347 s.mem_unit <<= 1;
2348 bitcount++;
2349 }
2350
2351 s.totalram >>= bitcount;
2352 s.freeram >>= bitcount;
2353 s.sharedram >>= bitcount;
2354 s.bufferram >>= bitcount;
2355 s.totalswap >>= bitcount;
2356 s.freeswap >>= bitcount;
2357 s.totalhigh >>= bitcount;
2358 s.freehigh >>= bitcount;
2359 }
2360
2361 if (!access_ok(VERIFY_WRITE, info, sizeof(struct compat_sysinfo)) ||
2362 __put_user(s.uptime, &info->uptime) ||
2363 __put_user(s.loads[0], &info->loads[0]) ||
2364 __put_user(s.loads[1], &info->loads[1]) ||
2365 __put_user(s.loads[2], &info->loads[2]) ||
2366 __put_user(s.totalram, &info->totalram) ||
2367 __put_user(s.freeram, &info->freeram) ||
2368 __put_user(s.sharedram, &info->sharedram) ||
2369 __put_user(s.bufferram, &info->bufferram) ||
2370 __put_user(s.totalswap, &info->totalswap) ||
2371 __put_user(s.freeswap, &info->freeswap) ||
2372 __put_user(s.procs, &info->procs) ||
2373 __put_user(s.totalhigh, &info->totalhigh) ||
2374 __put_user(s.freehigh, &info->freehigh) ||
2375 __put_user(s.mem_unit, &info->mem_unit))
2376 return -EFAULT;
2377
2378 return 0;
2379 }
2380 #endif /* CONFIG_COMPAT */
Linux with added FPC-III support