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platform/x86: dell-smbios: Rename dell-smbios source to dell-smbios-base
[mirror_ubuntu-bionic-kernel.git] / kernel / sys.c
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * linux/kernel/sys.c
4 *
5 * Copyright (C) 1991, 1992 Linus Torvalds
6 */
7
8 #include <linux/export.h>
9 #include <linux/mm.h>
10 #include <linux/utsname.h>
11 #include <linux/mman.h>
12 #include <linux/reboot.h>
13 #include <linux/prctl.h>
14 #include <linux/highuid.h>
15 #include <linux/fs.h>
16 #include <linux/kmod.h>
17 #include <linux/perf_event.h>
18 #include <linux/resource.h>
19 #include <linux/kernel.h>
20 #include <linux/workqueue.h>
21 #include <linux/capability.h>
22 #include <linux/device.h>
23 #include <linux/key.h>
24 #include <linux/times.h>
25 #include <linux/posix-timers.h>
26 #include <linux/security.h>
27 #include <linux/dcookies.h>
28 #include <linux/suspend.h>
29 #include <linux/tty.h>
30 #include <linux/signal.h>
31 #include <linux/cn_proc.h>
32 #include <linux/getcpu.h>
33 #include <linux/task_io_accounting_ops.h>
34 #include <linux/seccomp.h>
35 #include <linux/cpu.h>
36 #include <linux/personality.h>
37 #include <linux/ptrace.h>
38 #include <linux/fs_struct.h>
39 #include <linux/file.h>
40 #include <linux/mount.h>
41 #include <linux/gfp.h>
42 #include <linux/syscore_ops.h>
43 #include <linux/version.h>
44 #include <linux/ctype.h>
45
46 #include <linux/compat.h>
47 #include <linux/syscalls.h>
48 #include <linux/kprobes.h>
49 #include <linux/user_namespace.h>
50 #include <linux/binfmts.h>
51
52 #include <linux/sched.h>
53 #include <linux/sched/autogroup.h>
54 #include <linux/sched/loadavg.h>
55 #include <linux/sched/stat.h>
56 #include <linux/sched/mm.h>
57 #include <linux/sched/coredump.h>
58 #include <linux/sched/task.h>
59 #include <linux/sched/cputime.h>
60 #include <linux/rcupdate.h>
61 #include <linux/uidgid.h>
62 #include <linux/cred.h>
63
64 #include <linux/nospec.h>
65
66 #include <linux/kmsg_dump.h>
67 /* Move somewhere else to avoid recompiling? */
68 #include <generated/utsrelease.h>
69
70 #include <linux/uaccess.h>
71 #include <asm/io.h>
72 #include <asm/unistd.h>
73
74 #ifndef SET_UNALIGN_CTL
75 # define SET_UNALIGN_CTL(a, b) (-EINVAL)
76 #endif
77 #ifndef GET_UNALIGN_CTL
78 # define GET_UNALIGN_CTL(a, b) (-EINVAL)
79 #endif
80 #ifndef SET_FPEMU_CTL
81 # define SET_FPEMU_CTL(a, b) (-EINVAL)
82 #endif
83 #ifndef GET_FPEMU_CTL
84 # define GET_FPEMU_CTL(a, b) (-EINVAL)
85 #endif
86 #ifndef SET_FPEXC_CTL
87 # define SET_FPEXC_CTL(a, b) (-EINVAL)
88 #endif
89 #ifndef GET_FPEXC_CTL
90 # define GET_FPEXC_CTL(a, b) (-EINVAL)
91 #endif
92 #ifndef GET_ENDIAN
93 # define GET_ENDIAN(a, b) (-EINVAL)
94 #endif
95 #ifndef SET_ENDIAN
96 # define SET_ENDIAN(a, b) (-EINVAL)
97 #endif
98 #ifndef GET_TSC_CTL
99 # define GET_TSC_CTL(a) (-EINVAL)
100 #endif
101 #ifndef SET_TSC_CTL
102 # define SET_TSC_CTL(a) (-EINVAL)
103 #endif
104 #ifndef MPX_ENABLE_MANAGEMENT
105 # define MPX_ENABLE_MANAGEMENT() (-EINVAL)
106 #endif
107 #ifndef MPX_DISABLE_MANAGEMENT
108 # define MPX_DISABLE_MANAGEMENT() (-EINVAL)
109 #endif
110 #ifndef GET_FP_MODE
111 # define GET_FP_MODE(a) (-EINVAL)
112 #endif
113 #ifndef SET_FP_MODE
114 # define SET_FP_MODE(a,b) (-EINVAL)
115 #endif
116 #ifndef SVE_SET_VL
117 # define SVE_SET_VL(a) (-EINVAL)
118 #endif
119 #ifndef SVE_GET_VL
120 # define SVE_GET_VL() (-EINVAL)
121 #endif
122
123 /*
124 * this is where the system-wide overflow UID and GID are defined, for
125 * architectures that now have 32-bit UID/GID but didn't in the past
126 */
127
128 int overflowuid = DEFAULT_OVERFLOWUID;
129 int overflowgid = DEFAULT_OVERFLOWGID;
130
131 EXPORT_SYMBOL(overflowuid);
132 EXPORT_SYMBOL(overflowgid);
133
134 /*
135 * the same as above, but for filesystems which can only store a 16-bit
136 * UID and GID. as such, this is needed on all architectures
137 */
138
139 int fs_overflowuid = DEFAULT_FS_OVERFLOWUID;
140 int fs_overflowgid = DEFAULT_FS_OVERFLOWUID;
141
142 EXPORT_SYMBOL(fs_overflowuid);
143 EXPORT_SYMBOL(fs_overflowgid);
144
145 /*
146 * Returns true if current's euid is same as p's uid or euid,
147 * or has CAP_SYS_NICE to p's user_ns.
148 *
149 * Called with rcu_read_lock, creds are safe
150 */
151 static bool set_one_prio_perm(struct task_struct *p)
152 {
153 const struct cred *cred = current_cred(), *pcred = __task_cred(p);
154
155 if (uid_eq(pcred->uid, cred->euid) ||
156 uid_eq(pcred->euid, cred->euid))
157 return true;
158 if (ns_capable(pcred->user_ns, CAP_SYS_NICE))
159 return true;
160 return false;
161 }
162
163 /*
164 * set the priority of a task
165 * - the caller must hold the RCU read lock
166 */
167 static int set_one_prio(struct task_struct *p, int niceval, int error)
168 {
169 int no_nice;
170
171 if (!set_one_prio_perm(p)) {
172 error = -EPERM;
173 goto out;
174 }
175 if (niceval < task_nice(p) && !can_nice(p, niceval)) {
176 error = -EACCES;
177 goto out;
178 }
179 no_nice = security_task_setnice(p, niceval);
180 if (no_nice) {
181 error = no_nice;
182 goto out;
183 }
184 if (error == -ESRCH)
185 error = 0;
186 set_user_nice(p, niceval);
187 out:
188 return error;
189 }
190
191 SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval)
192 {
193 struct task_struct *g, *p;
194 struct user_struct *user;
195 const struct cred *cred = current_cred();
196 int error = -EINVAL;
197 struct pid *pgrp;
198 kuid_t uid;
199
200 if (which > PRIO_USER || which < PRIO_PROCESS)
201 goto out;
202
203 /* normalize: avoid signed division (rounding problems) */
204 error = -ESRCH;
205 if (niceval < MIN_NICE)
206 niceval = MIN_NICE;
207 if (niceval > MAX_NICE)
208 niceval = MAX_NICE;
209
210 rcu_read_lock();
211 read_lock(&tasklist_lock);
212 switch (which) {
213 case PRIO_PROCESS:
214 if (who)
215 p = find_task_by_vpid(who);
216 else
217 p = current;
218 if (p)
219 error = set_one_prio(p, niceval, error);
220 break;
221 case PRIO_PGRP:
222 if (who)
223 pgrp = find_vpid(who);
224 else
225 pgrp = task_pgrp(current);
226 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
227 error = set_one_prio(p, niceval, error);
228 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
229 break;
230 case PRIO_USER:
231 uid = make_kuid(cred->user_ns, who);
232 user = cred->user;
233 if (!who)
234 uid = cred->uid;
235 else if (!uid_eq(uid, cred->uid)) {
236 user = find_user(uid);
237 if (!user)
238 goto out_unlock; /* No processes for this user */
239 }
240 do_each_thread(g, p) {
241 if (uid_eq(task_uid(p), uid) && task_pid_vnr(p))
242 error = set_one_prio(p, niceval, error);
243 } while_each_thread(g, p);
244 if (!uid_eq(uid, cred->uid))
245 free_uid(user); /* For find_user() */
246 break;
247 }
248 out_unlock:
249 read_unlock(&tasklist_lock);
250 rcu_read_unlock();
251 out:
252 return error;
253 }
254
255 /*
256 * Ugh. To avoid negative return values, "getpriority()" will
257 * not return the normal nice-value, but a negated value that
258 * has been offset by 20 (ie it returns 40..1 instead of -20..19)
259 * to stay compatible.
260 */
261 SYSCALL_DEFINE2(getpriority, int, which, int, who)
262 {
263 struct task_struct *g, *p;
264 struct user_struct *user;
265 const struct cred *cred = current_cred();
266 long niceval, retval = -ESRCH;
267 struct pid *pgrp;
268 kuid_t uid;
269
270 if (which > PRIO_USER || which < PRIO_PROCESS)
271 return -EINVAL;
272
273 rcu_read_lock();
274 read_lock(&tasklist_lock);
275 switch (which) {
276 case PRIO_PROCESS:
277 if (who)
278 p = find_task_by_vpid(who);
279 else
280 p = current;
281 if (p) {
282 niceval = nice_to_rlimit(task_nice(p));
283 if (niceval > retval)
284 retval = niceval;
285 }
286 break;
287 case PRIO_PGRP:
288 if (who)
289 pgrp = find_vpid(who);
290 else
291 pgrp = task_pgrp(current);
292 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
293 niceval = nice_to_rlimit(task_nice(p));
294 if (niceval > retval)
295 retval = niceval;
296 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
297 break;
298 case PRIO_USER:
299 uid = make_kuid(cred->user_ns, who);
300 user = cred->user;
301 if (!who)
302 uid = cred->uid;
303 else if (!uid_eq(uid, cred->uid)) {
304 user = find_user(uid);
305 if (!user)
306 goto out_unlock; /* No processes for this user */
307 }
308 do_each_thread(g, p) {
309 if (uid_eq(task_uid(p), uid) && task_pid_vnr(p)) {
310 niceval = nice_to_rlimit(task_nice(p));
311 if (niceval > retval)
312 retval = niceval;
313 }
314 } while_each_thread(g, p);
315 if (!uid_eq(uid, cred->uid))
316 free_uid(user); /* for find_user() */
317 break;
318 }
319 out_unlock:
320 read_unlock(&tasklist_lock);
321 rcu_read_unlock();
322
323 return retval;
324 }
325
326 /*
327 * Unprivileged users may change the real gid to the effective gid
328 * or vice versa. (BSD-style)
329 *
330 * If you set the real gid at all, or set the effective gid to a value not
331 * equal to the real gid, then the saved gid is set to the new effective gid.
332 *
333 * This makes it possible for a setgid program to completely drop its
334 * privileges, which is often a useful assertion to make when you are doing
335 * a security audit over a program.
336 *
337 * The general idea is that a program which uses just setregid() will be
338 * 100% compatible with BSD. A program which uses just setgid() will be
339 * 100% compatible with POSIX with saved IDs.
340 *
341 * SMP: There are not races, the GIDs are checked only by filesystem
342 * operations (as far as semantic preservation is concerned).
343 */
344 #ifdef CONFIG_MULTIUSER
345 SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid)
346 {
347 struct user_namespace *ns = current_user_ns();
348 const struct cred *old;
349 struct cred *new;
350 int retval;
351 kgid_t krgid, kegid;
352
353 krgid = make_kgid(ns, rgid);
354 kegid = make_kgid(ns, egid);
355
356 if ((rgid != (gid_t) -1) && !gid_valid(krgid))
357 return -EINVAL;
358 if ((egid != (gid_t) -1) && !gid_valid(kegid))
359 return -EINVAL;
360
361 new = prepare_creds();
362 if (!new)
363 return -ENOMEM;
364 old = current_cred();
365
366 retval = -EPERM;
367 if (rgid != (gid_t) -1) {
368 if (gid_eq(old->gid, krgid) ||
369 gid_eq(old->egid, krgid) ||
370 ns_capable(old->user_ns, CAP_SETGID))
371 new->gid = krgid;
372 else
373 goto error;
374 }
375 if (egid != (gid_t) -1) {
376 if (gid_eq(old->gid, kegid) ||
377 gid_eq(old->egid, kegid) ||
378 gid_eq(old->sgid, kegid) ||
379 ns_capable(old->user_ns, CAP_SETGID))
380 new->egid = kegid;
381 else
382 goto error;
383 }
384
385 if (rgid != (gid_t) -1 ||
386 (egid != (gid_t) -1 && !gid_eq(kegid, old->gid)))
387 new->sgid = new->egid;
388 new->fsgid = new->egid;
389
390 return commit_creds(new);
391
392 error:
393 abort_creds(new);
394 return retval;
395 }
396
397 /*
398 * setgid() is implemented like SysV w/ SAVED_IDS
399 *
400 * SMP: Same implicit races as above.
401 */
402 SYSCALL_DEFINE1(setgid, gid_t, gid)
403 {
404 struct user_namespace *ns = current_user_ns();
405 const struct cred *old;
406 struct cred *new;
407 int retval;
408 kgid_t kgid;
409
410 kgid = make_kgid(ns, gid);
411 if (!gid_valid(kgid))
412 return -EINVAL;
413
414 new = prepare_creds();
415 if (!new)
416 return -ENOMEM;
417 old = current_cred();
418
419 retval = -EPERM;
420 if (ns_capable(old->user_ns, CAP_SETGID))
421 new->gid = new->egid = new->sgid = new->fsgid = kgid;
422 else if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->sgid))
423 new->egid = new->fsgid = kgid;
424 else
425 goto error;
426
427 return commit_creds(new);
428
429 error:
430 abort_creds(new);
431 return retval;
432 }
433
434 /*
435 * change the user struct in a credentials set to match the new UID
436 */
437 static int set_user(struct cred *new)
438 {
439 struct user_struct *new_user;
440
441 new_user = alloc_uid(new->uid);
442 if (!new_user)
443 return -EAGAIN;
444
445 /*
446 * We don't fail in case of NPROC limit excess here because too many
447 * poorly written programs don't check set*uid() return code, assuming
448 * it never fails if called by root. We may still enforce NPROC limit
449 * for programs doing set*uid()+execve() by harmlessly deferring the
450 * failure to the execve() stage.
451 */
452 if (atomic_read(&new_user->processes) >= rlimit(RLIMIT_NPROC) &&
453 new_user != INIT_USER)
454 current->flags |= PF_NPROC_EXCEEDED;
455 else
456 current->flags &= ~PF_NPROC_EXCEEDED;
457
458 free_uid(new->user);
459 new->user = new_user;
460 return 0;
461 }
462
463 /*
464 * Unprivileged users may change the real uid to the effective uid
465 * or vice versa. (BSD-style)
466 *
467 * If you set the real uid at all, or set the effective uid to a value not
468 * equal to the real uid, then the saved uid is set to the new effective uid.
469 *
470 * This makes it possible for a setuid program to completely drop its
471 * privileges, which is often a useful assertion to make when you are doing
472 * a security audit over a program.
473 *
474 * The general idea is that a program which uses just setreuid() will be
475 * 100% compatible with BSD. A program which uses just setuid() will be
476 * 100% compatible with POSIX with saved IDs.
477 */
478 SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid)
479 {
480 struct user_namespace *ns = current_user_ns();
481 const struct cred *old;
482 struct cred *new;
483 int retval;
484 kuid_t kruid, keuid;
485
486 kruid = make_kuid(ns, ruid);
487 keuid = make_kuid(ns, euid);
488
489 if ((ruid != (uid_t) -1) && !uid_valid(kruid))
490 return -EINVAL;
491 if ((euid != (uid_t) -1) && !uid_valid(keuid))
492 return -EINVAL;
493
494 new = prepare_creds();
495 if (!new)
496 return -ENOMEM;
497 old = current_cred();
498
499 retval = -EPERM;
500 if (ruid != (uid_t) -1) {
501 new->uid = kruid;
502 if (!uid_eq(old->uid, kruid) &&
503 !uid_eq(old->euid, kruid) &&
504 !ns_capable(old->user_ns, CAP_SETUID))
505 goto error;
506 }
507
508 if (euid != (uid_t) -1) {
509 new->euid = keuid;
510 if (!uid_eq(old->uid, keuid) &&
511 !uid_eq(old->euid, keuid) &&
512 !uid_eq(old->suid, keuid) &&
513 !ns_capable(old->user_ns, CAP_SETUID))
514 goto error;
515 }
516
517 if (!uid_eq(new->uid, old->uid)) {
518 retval = set_user(new);
519 if (retval < 0)
520 goto error;
521 }
522 if (ruid != (uid_t) -1 ||
523 (euid != (uid_t) -1 && !uid_eq(keuid, old->uid)))
524 new->suid = new->euid;
525 new->fsuid = new->euid;
526
527 retval = security_task_fix_setuid(new, old, LSM_SETID_RE);
528 if (retval < 0)
529 goto error;
530
531 return commit_creds(new);
532
533 error:
534 abort_creds(new);
535 return retval;
536 }
537
538 /*
539 * setuid() is implemented like SysV with SAVED_IDS
540 *
541 * Note that SAVED_ID's is deficient in that a setuid root program
542 * like sendmail, for example, cannot set its uid to be a normal
543 * user and then switch back, because if you're root, setuid() sets
544 * the saved uid too. If you don't like this, blame the bright people
545 * in the POSIX committee and/or USG. Note that the BSD-style setreuid()
546 * will allow a root program to temporarily drop privileges and be able to
547 * regain them by swapping the real and effective uid.
548 */
549 SYSCALL_DEFINE1(setuid, uid_t, uid)
550 {
551 struct user_namespace *ns = current_user_ns();
552 const struct cred *old;
553 struct cred *new;
554 int retval;
555 kuid_t kuid;
556
557 kuid = make_kuid(ns, uid);
558 if (!uid_valid(kuid))
559 return -EINVAL;
560
561 new = prepare_creds();
562 if (!new)
563 return -ENOMEM;
564 old = current_cred();
565
566 retval = -EPERM;
567 if (ns_capable(old->user_ns, CAP_SETUID)) {
568 new->suid = new->uid = kuid;
569 if (!uid_eq(kuid, old->uid)) {
570 retval = set_user(new);
571 if (retval < 0)
572 goto error;
573 }
574 } else if (!uid_eq(kuid, old->uid) && !uid_eq(kuid, new->suid)) {
575 goto error;
576 }
577
578 new->fsuid = new->euid = kuid;
579
580 retval = security_task_fix_setuid(new, old, LSM_SETID_ID);
581 if (retval < 0)
582 goto error;
583
584 return commit_creds(new);
585
586 error:
587 abort_creds(new);
588 return retval;
589 }
590
591
592 /*
593 * This function implements a generic ability to update ruid, euid,
594 * and suid. This allows you to implement the 4.4 compatible seteuid().
595 */
596 SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid)
597 {
598 struct user_namespace *ns = current_user_ns();
599 const struct cred *old;
600 struct cred *new;
601 int retval;
602 kuid_t kruid, keuid, ksuid;
603
604 kruid = make_kuid(ns, ruid);
605 keuid = make_kuid(ns, euid);
606 ksuid = make_kuid(ns, suid);
607
608 if ((ruid != (uid_t) -1) && !uid_valid(kruid))
609 return -EINVAL;
610
611 if ((euid != (uid_t) -1) && !uid_valid(keuid))
612 return -EINVAL;
613
614 if ((suid != (uid_t) -1) && !uid_valid(ksuid))
615 return -EINVAL;
616
617 new = prepare_creds();
618 if (!new)
619 return -ENOMEM;
620
621 old = current_cred();
622
623 retval = -EPERM;
624 if (!ns_capable(old->user_ns, CAP_SETUID)) {
625 if (ruid != (uid_t) -1 && !uid_eq(kruid, old->uid) &&
626 !uid_eq(kruid, old->euid) && !uid_eq(kruid, old->suid))
627 goto error;
628 if (euid != (uid_t) -1 && !uid_eq(keuid, old->uid) &&
629 !uid_eq(keuid, old->euid) && !uid_eq(keuid, old->suid))
630 goto error;
631 if (suid != (uid_t) -1 && !uid_eq(ksuid, old->uid) &&
632 !uid_eq(ksuid, old->euid) && !uid_eq(ksuid, old->suid))
633 goto error;
634 }
635
636 if (ruid != (uid_t) -1) {
637 new->uid = kruid;
638 if (!uid_eq(kruid, old->uid)) {
639 retval = set_user(new);
640 if (retval < 0)
641 goto error;
642 }
643 }
644 if (euid != (uid_t) -1)
645 new->euid = keuid;
646 if (suid != (uid_t) -1)
647 new->suid = ksuid;
648 new->fsuid = new->euid;
649
650 retval = security_task_fix_setuid(new, old, LSM_SETID_RES);
651 if (retval < 0)
652 goto error;
653
654 return commit_creds(new);
655
656 error:
657 abort_creds(new);
658 return retval;
659 }
660
661 SYSCALL_DEFINE3(getresuid, uid_t __user *, ruidp, uid_t __user *, euidp, uid_t __user *, suidp)
662 {
663 const struct cred *cred = current_cred();
664 int retval;
665 uid_t ruid, euid, suid;
666
667 ruid = from_kuid_munged(cred->user_ns, cred->uid);
668 euid = from_kuid_munged(cred->user_ns, cred->euid);
669 suid = from_kuid_munged(cred->user_ns, cred->suid);
670
671 retval = put_user(ruid, ruidp);
672 if (!retval) {
673 retval = put_user(euid, euidp);
674 if (!retval)
675 return put_user(suid, suidp);
676 }
677 return retval;
678 }
679
680 /*
681 * Same as above, but for rgid, egid, sgid.
682 */
683 SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid)
684 {
685 struct user_namespace *ns = current_user_ns();
686 const struct cred *old;
687 struct cred *new;
688 int retval;
689 kgid_t krgid, kegid, ksgid;
690
691 krgid = make_kgid(ns, rgid);
692 kegid = make_kgid(ns, egid);
693 ksgid = make_kgid(ns, sgid);
694
695 if ((rgid != (gid_t) -1) && !gid_valid(krgid))
696 return -EINVAL;
697 if ((egid != (gid_t) -1) && !gid_valid(kegid))
698 return -EINVAL;
699 if ((sgid != (gid_t) -1) && !gid_valid(ksgid))
700 return -EINVAL;
701
702 new = prepare_creds();
703 if (!new)
704 return -ENOMEM;
705 old = current_cred();
706
707 retval = -EPERM;
708 if (!ns_capable(old->user_ns, CAP_SETGID)) {
709 if (rgid != (gid_t) -1 && !gid_eq(krgid, old->gid) &&
710 !gid_eq(krgid, old->egid) && !gid_eq(krgid, old->sgid))
711 goto error;
712 if (egid != (gid_t) -1 && !gid_eq(kegid, old->gid) &&
713 !gid_eq(kegid, old->egid) && !gid_eq(kegid, old->sgid))
714 goto error;
715 if (sgid != (gid_t) -1 && !gid_eq(ksgid, old->gid) &&
716 !gid_eq(ksgid, old->egid) && !gid_eq(ksgid, old->sgid))
717 goto error;
718 }
719
720 if (rgid != (gid_t) -1)
721 new->gid = krgid;
722 if (egid != (gid_t) -1)
723 new->egid = kegid;
724 if (sgid != (gid_t) -1)
725 new->sgid = ksgid;
726 new->fsgid = new->egid;
727
728 return commit_creds(new);
729
730 error:
731 abort_creds(new);
732 return retval;
733 }
734
735 SYSCALL_DEFINE3(getresgid, gid_t __user *, rgidp, gid_t __user *, egidp, gid_t __user *, sgidp)
736 {
737 const struct cred *cred = current_cred();
738 int retval;
739 gid_t rgid, egid, sgid;
740
741 rgid = from_kgid_munged(cred->user_ns, cred->gid);
742 egid = from_kgid_munged(cred->user_ns, cred->egid);
743 sgid = from_kgid_munged(cred->user_ns, cred->sgid);
744
745 retval = put_user(rgid, rgidp);
746 if (!retval) {
747 retval = put_user(egid, egidp);
748 if (!retval)
749 retval = put_user(sgid, sgidp);
750 }
751
752 return retval;
753 }
754
755
756 /*
757 * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This
758 * is used for "access()" and for the NFS daemon (letting nfsd stay at
759 * whatever uid it wants to). It normally shadows "euid", except when
760 * explicitly set by setfsuid() or for access..
761 */
762 SYSCALL_DEFINE1(setfsuid, uid_t, uid)
763 {
764 const struct cred *old;
765 struct cred *new;
766 uid_t old_fsuid;
767 kuid_t kuid;
768
769 old = current_cred();
770 old_fsuid = from_kuid_munged(old->user_ns, old->fsuid);
771
772 kuid = make_kuid(old->user_ns, uid);
773 if (!uid_valid(kuid))
774 return old_fsuid;
775
776 new = prepare_creds();
777 if (!new)
778 return old_fsuid;
779
780 if (uid_eq(kuid, old->uid) || uid_eq(kuid, old->euid) ||
781 uid_eq(kuid, old->suid) || uid_eq(kuid, old->fsuid) ||
782 ns_capable(old->user_ns, CAP_SETUID)) {
783 if (!uid_eq(kuid, old->fsuid)) {
784 new->fsuid = kuid;
785 if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0)
786 goto change_okay;
787 }
788 }
789
790 abort_creds(new);
791 return old_fsuid;
792
793 change_okay:
794 commit_creds(new);
795 return old_fsuid;
796 }
797
798 /*
799 * Samma på svenska..
800 */
801 SYSCALL_DEFINE1(setfsgid, gid_t, gid)
802 {
803 const struct cred *old;
804 struct cred *new;
805 gid_t old_fsgid;
806 kgid_t kgid;
807
808 old = current_cred();
809 old_fsgid = from_kgid_munged(old->user_ns, old->fsgid);
810
811 kgid = make_kgid(old->user_ns, gid);
812 if (!gid_valid(kgid))
813 return old_fsgid;
814
815 new = prepare_creds();
816 if (!new)
817 return old_fsgid;
818
819 if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->egid) ||
820 gid_eq(kgid, old->sgid) || gid_eq(kgid, old->fsgid) ||
821 ns_capable(old->user_ns, CAP_SETGID)) {
822 if (!gid_eq(kgid, old->fsgid)) {
823 new->fsgid = kgid;
824 goto change_okay;
825 }
826 }
827
828 abort_creds(new);
829 return old_fsgid;
830
831 change_okay:
832 commit_creds(new);
833 return old_fsgid;
834 }
835 #endif /* CONFIG_MULTIUSER */
836
837 /**
838 * sys_getpid - return the thread group id of the current process
839 *
840 * Note, despite the name, this returns the tgid not the pid. The tgid and
841 * the pid are identical unless CLONE_THREAD was specified on clone() in
842 * which case the tgid is the same in all threads of the same group.
843 *
844 * This is SMP safe as current->tgid does not change.
845 */
846 SYSCALL_DEFINE0(getpid)
847 {
848 return task_tgid_vnr(current);
849 }
850
851 /* Thread ID - the internal kernel "pid" */
852 SYSCALL_DEFINE0(gettid)
853 {
854 return task_pid_vnr(current);
855 }
856
857 /*
858 * Accessing ->real_parent is not SMP-safe, it could
859 * change from under us. However, we can use a stale
860 * value of ->real_parent under rcu_read_lock(), see
861 * release_task()->call_rcu(delayed_put_task_struct).
862 */
863 SYSCALL_DEFINE0(getppid)
864 {
865 int pid;
866
867 rcu_read_lock();
868 pid = task_tgid_vnr(rcu_dereference(current->real_parent));
869 rcu_read_unlock();
870
871 return pid;
872 }
873
874 SYSCALL_DEFINE0(getuid)
875 {
876 /* Only we change this so SMP safe */
877 return from_kuid_munged(current_user_ns(), current_uid());
878 }
879
880 SYSCALL_DEFINE0(geteuid)
881 {
882 /* Only we change this so SMP safe */
883 return from_kuid_munged(current_user_ns(), current_euid());
884 }
885
886 SYSCALL_DEFINE0(getgid)
887 {
888 /* Only we change this so SMP safe */
889 return from_kgid_munged(current_user_ns(), current_gid());
890 }
891
892 SYSCALL_DEFINE0(getegid)
893 {
894 /* Only we change this so SMP safe */
895 return from_kgid_munged(current_user_ns(), current_egid());
896 }
897
898 static void do_sys_times(struct tms *tms)
899 {
900 u64 tgutime, tgstime, cutime, cstime;
901
902 thread_group_cputime_adjusted(current, &tgutime, &tgstime);
903 cutime = current->signal->cutime;
904 cstime = current->signal->cstime;
905 tms->tms_utime = nsec_to_clock_t(tgutime);
906 tms->tms_stime = nsec_to_clock_t(tgstime);
907 tms->tms_cutime = nsec_to_clock_t(cutime);
908 tms->tms_cstime = nsec_to_clock_t(cstime);
909 }
910
911 SYSCALL_DEFINE1(times, struct tms __user *, tbuf)
912 {
913 if (tbuf) {
914 struct tms tmp;
915
916 do_sys_times(&tmp);
917 if (copy_to_user(tbuf, &tmp, sizeof(struct tms)))
918 return -EFAULT;
919 }
920 force_successful_syscall_return();
921 return (long) jiffies_64_to_clock_t(get_jiffies_64());
922 }
923
924 #ifdef CONFIG_COMPAT
925 static compat_clock_t clock_t_to_compat_clock_t(clock_t x)
926 {
927 return compat_jiffies_to_clock_t(clock_t_to_jiffies(x));
928 }
929
930 COMPAT_SYSCALL_DEFINE1(times, struct compat_tms __user *, tbuf)
931 {
932 if (tbuf) {
933 struct tms tms;
934 struct compat_tms tmp;
935
936 do_sys_times(&tms);
937 /* Convert our struct tms to the compat version. */
938 tmp.tms_utime = clock_t_to_compat_clock_t(tms.tms_utime);
939 tmp.tms_stime = clock_t_to_compat_clock_t(tms.tms_stime);
940 tmp.tms_cutime = clock_t_to_compat_clock_t(tms.tms_cutime);
941 tmp.tms_cstime = clock_t_to_compat_clock_t(tms.tms_cstime);
942 if (copy_to_user(tbuf, &tmp, sizeof(tmp)))
943 return -EFAULT;
944 }
945 force_successful_syscall_return();
946 return compat_jiffies_to_clock_t(jiffies);
947 }
948 #endif
949
950 /*
951 * This needs some heavy checking ...
952 * I just haven't the stomach for it. I also don't fully
953 * understand sessions/pgrp etc. Let somebody who does explain it.
954 *
955 * OK, I think I have the protection semantics right.... this is really
956 * only important on a multi-user system anyway, to make sure one user
957 * can't send a signal to a process owned by another. -TYT, 12/12/91
958 *
959 * !PF_FORKNOEXEC check to conform completely to POSIX.
960 */
961 SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid)
962 {
963 struct task_struct *p;
964 struct task_struct *group_leader = current->group_leader;
965 struct pid *pgrp;
966 int err;
967
968 if (!pid)
969 pid = task_pid_vnr(group_leader);
970 if (!pgid)
971 pgid = pid;
972 if (pgid < 0)
973 return -EINVAL;
974 rcu_read_lock();
975
976 /* From this point forward we keep holding onto the tasklist lock
977 * so that our parent does not change from under us. -DaveM
978 */
979 write_lock_irq(&tasklist_lock);
980
981 err = -ESRCH;
982 p = find_task_by_vpid(pid);
983 if (!p)
984 goto out;
985
986 err = -EINVAL;
987 if (!thread_group_leader(p))
988 goto out;
989
990 if (same_thread_group(p->real_parent, group_leader)) {
991 err = -EPERM;
992 if (task_session(p) != task_session(group_leader))
993 goto out;
994 err = -EACCES;
995 if (!(p->flags & PF_FORKNOEXEC))
996 goto out;
997 } else {
998 err = -ESRCH;
999 if (p != group_leader)
1000 goto out;
1001 }
1002
1003 err = -EPERM;
1004 if (p->signal->leader)
1005 goto out;
1006
1007 pgrp = task_pid(p);
1008 if (pgid != pid) {
1009 struct task_struct *g;
1010
1011 pgrp = find_vpid(pgid);
1012 g = pid_task(pgrp, PIDTYPE_PGID);
1013 if (!g || task_session(g) != task_session(group_leader))
1014 goto out;
1015 }
1016
1017 err = security_task_setpgid(p, pgid);
1018 if (err)
1019 goto out;
1020
1021 if (task_pgrp(p) != pgrp)
1022 change_pid(p, PIDTYPE_PGID, pgrp);
1023
1024 err = 0;
1025 out:
1026 /* All paths lead to here, thus we are safe. -DaveM */
1027 write_unlock_irq(&tasklist_lock);
1028 rcu_read_unlock();
1029 return err;
1030 }
1031
1032 SYSCALL_DEFINE1(getpgid, pid_t, pid)
1033 {
1034 struct task_struct *p;
1035 struct pid *grp;
1036 int retval;
1037
1038 rcu_read_lock();
1039 if (!pid)
1040 grp = task_pgrp(current);
1041 else {
1042 retval = -ESRCH;
1043 p = find_task_by_vpid(pid);
1044 if (!p)
1045 goto out;
1046 grp = task_pgrp(p);
1047 if (!grp)
1048 goto out;
1049
1050 retval = security_task_getpgid(p);
1051 if (retval)
1052 goto out;
1053 }
1054 retval = pid_vnr(grp);
1055 out:
1056 rcu_read_unlock();
1057 return retval;
1058 }
1059
1060 #ifdef __ARCH_WANT_SYS_GETPGRP
1061
1062 SYSCALL_DEFINE0(getpgrp)
1063 {
1064 return sys_getpgid(0);
1065 }
1066
1067 #endif
1068
1069 SYSCALL_DEFINE1(getsid, pid_t, pid)
1070 {
1071 struct task_struct *p;
1072 struct pid *sid;
1073 int retval;
1074
1075 rcu_read_lock();
1076 if (!pid)
1077 sid = task_session(current);
1078 else {
1079 retval = -ESRCH;
1080 p = find_task_by_vpid(pid);
1081 if (!p)
1082 goto out;
1083 sid = task_session(p);
1084 if (!sid)
1085 goto out;
1086
1087 retval = security_task_getsid(p);
1088 if (retval)
1089 goto out;
1090 }
1091 retval = pid_vnr(sid);
1092 out:
1093 rcu_read_unlock();
1094 return retval;
1095 }
1096
1097 static void set_special_pids(struct pid *pid)
1098 {
1099 struct task_struct *curr = current->group_leader;
1100
1101 if (task_session(curr) != pid)
1102 change_pid(curr, PIDTYPE_SID, pid);
1103
1104 if (task_pgrp(curr) != pid)
1105 change_pid(curr, PIDTYPE_PGID, pid);
1106 }
1107
1108 SYSCALL_DEFINE0(setsid)
1109 {
1110 struct task_struct *group_leader = current->group_leader;
1111 struct pid *sid = task_pid(group_leader);
1112 pid_t session = pid_vnr(sid);
1113 int err = -EPERM;
1114
1115 write_lock_irq(&tasklist_lock);
1116 /* Fail if I am already a session leader */
1117 if (group_leader->signal->leader)
1118 goto out;
1119
1120 /* Fail if a process group id already exists that equals the
1121 * proposed session id.
1122 */
1123 if (pid_task(sid, PIDTYPE_PGID))
1124 goto out;
1125
1126 group_leader->signal->leader = 1;
1127 set_special_pids(sid);
1128
1129 proc_clear_tty(group_leader);
1130
1131 err = session;
1132 out:
1133 write_unlock_irq(&tasklist_lock);
1134 if (err > 0) {
1135 proc_sid_connector(group_leader);
1136 sched_autogroup_create_attach(group_leader);
1137 }
1138 return err;
1139 }
1140
1141 DECLARE_RWSEM(uts_sem);
1142
1143 #ifdef COMPAT_UTS_MACHINE
1144 static char compat_uts_machine[__OLD_UTS_LEN+1] = COMPAT_UTS_MACHINE;
1145
1146 static int __init parse_compat_uts_machine(char *arg)
1147 {
1148 strncpy(compat_uts_machine, arg, __OLD_UTS_LEN);
1149 compat_uts_machine[__OLD_UTS_LEN] = 0;
1150 return 0;
1151 }
1152 early_param("compat_uts_machine", parse_compat_uts_machine);
1153
1154 #undef COMPAT_UTS_MACHINE
1155 #define COMPAT_UTS_MACHINE compat_uts_machine
1156 #endif
1157
1158 #ifdef COMPAT_UTS_MACHINE
1159 #define override_architecture(name) \
1160 (personality(current->personality) == PER_LINUX32 && \
1161 copy_to_user(name->machine, COMPAT_UTS_MACHINE, \
1162 sizeof(COMPAT_UTS_MACHINE)))
1163 #else
1164 #define override_architecture(name) 0
1165 #endif
1166
1167 /*
1168 * Work around broken programs that cannot handle "Linux 3.0".
1169 * Instead we map 3.x to 2.6.40+x, so e.g. 3.0 would be 2.6.40
1170 * And we map 4.x to 2.6.60+x, so 4.0 would be 2.6.60.
1171 */
1172 static int override_release(char __user *release, size_t len)
1173 {
1174 int ret = 0;
1175
1176 if (current->personality & UNAME26) {
1177 const char *rest = UTS_RELEASE;
1178 char buf[65] = { 0 };
1179 int ndots = 0;
1180 unsigned v;
1181 size_t copy;
1182
1183 while (*rest) {
1184 if (*rest == '.' && ++ndots >= 3)
1185 break;
1186 if (!isdigit(*rest) && *rest != '.')
1187 break;
1188 rest++;
1189 }
1190 v = ((LINUX_VERSION_CODE >> 8) & 0xff) + 60;
1191 copy = clamp_t(size_t, len, 1, sizeof(buf));
1192 copy = scnprintf(buf, copy, "2.6.%u%s", v, rest);
1193 ret = copy_to_user(release, buf, copy + 1);
1194 }
1195 return ret;
1196 }
1197
1198 SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name)
1199 {
1200 int errno = 0;
1201
1202 down_read(&uts_sem);
1203 if (copy_to_user(name, utsname(), sizeof *name))
1204 errno = -EFAULT;
1205 up_read(&uts_sem);
1206
1207 if (!errno && override_release(name->release, sizeof(name->release)))
1208 errno = -EFAULT;
1209 if (!errno && override_architecture(name))
1210 errno = -EFAULT;
1211 return errno;
1212 }
1213
1214 #ifdef __ARCH_WANT_SYS_OLD_UNAME
1215 /*
1216 * Old cruft
1217 */
1218 SYSCALL_DEFINE1(uname, struct old_utsname __user *, name)
1219 {
1220 int error = 0;
1221
1222 if (!name)
1223 return -EFAULT;
1224
1225 down_read(&uts_sem);
1226 if (copy_to_user(name, utsname(), sizeof(*name)))
1227 error = -EFAULT;
1228 up_read(&uts_sem);
1229
1230 if (!error && override_release(name->release, sizeof(name->release)))
1231 error = -EFAULT;
1232 if (!error && override_architecture(name))
1233 error = -EFAULT;
1234 return error;
1235 }
1236
1237 SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name)
1238 {
1239 int error;
1240
1241 if (!name)
1242 return -EFAULT;
1243 if (!access_ok(VERIFY_WRITE, name, sizeof(struct oldold_utsname)))
1244 return -EFAULT;
1245
1246 down_read(&uts_sem);
1247 error = __copy_to_user(&name->sysname, &utsname()->sysname,
1248 __OLD_UTS_LEN);
1249 error |= __put_user(0, name->sysname + __OLD_UTS_LEN);
1250 error |= __copy_to_user(&name->nodename, &utsname()->nodename,
1251 __OLD_UTS_LEN);
1252 error |= __put_user(0, name->nodename + __OLD_UTS_LEN);
1253 error |= __copy_to_user(&name->release, &utsname()->release,
1254 __OLD_UTS_LEN);
1255 error |= __put_user(0, name->release + __OLD_UTS_LEN);
1256 error |= __copy_to_user(&name->version, &utsname()->version,
1257 __OLD_UTS_LEN);
1258 error |= __put_user(0, name->version + __OLD_UTS_LEN);
1259 error |= __copy_to_user(&name->machine, &utsname()->machine,
1260 __OLD_UTS_LEN);
1261 error |= __put_user(0, name->machine + __OLD_UTS_LEN);
1262 up_read(&uts_sem);
1263
1264 if (!error && override_architecture(name))
1265 error = -EFAULT;
1266 if (!error && override_release(name->release, sizeof(name->release)))
1267 error = -EFAULT;
1268 return error ? -EFAULT : 0;
1269 }
1270 #endif
1271
1272 SYSCALL_DEFINE2(sethostname, char __user *, name, int, len)
1273 {
1274 int errno;
1275 char tmp[__NEW_UTS_LEN];
1276
1277 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN))
1278 return -EPERM;
1279
1280 if (len < 0 || len > __NEW_UTS_LEN)
1281 return -EINVAL;
1282 down_write(&uts_sem);
1283 errno = -EFAULT;
1284 if (!copy_from_user(tmp, name, len)) {
1285 struct new_utsname *u = utsname();
1286
1287 memcpy(u->nodename, tmp, len);
1288 memset(u->nodename + len, 0, sizeof(u->nodename) - len);
1289 errno = 0;
1290 uts_proc_notify(UTS_PROC_HOSTNAME);
1291 }
1292 up_write(&uts_sem);
1293 return errno;
1294 }
1295
1296 #ifdef __ARCH_WANT_SYS_GETHOSTNAME
1297
1298 SYSCALL_DEFINE2(gethostname, char __user *, name, int, len)
1299 {
1300 int i, errno;
1301 struct new_utsname *u;
1302
1303 if (len < 0)
1304 return -EINVAL;
1305 down_read(&uts_sem);
1306 u = utsname();
1307 i = 1 + strlen(u->nodename);
1308 if (i > len)
1309 i = len;
1310 errno = 0;
1311 if (copy_to_user(name, u->nodename, i))
1312 errno = -EFAULT;
1313 up_read(&uts_sem);
1314 return errno;
1315 }
1316
1317 #endif
1318
1319 /*
1320 * Only setdomainname; getdomainname can be implemented by calling
1321 * uname()
1322 */
1323 SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len)
1324 {
1325 int errno;
1326 char tmp[__NEW_UTS_LEN];
1327
1328 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN))
1329 return -EPERM;
1330 if (len < 0 || len > __NEW_UTS_LEN)
1331 return -EINVAL;
1332
1333 down_write(&uts_sem);
1334 errno = -EFAULT;
1335 if (!copy_from_user(tmp, name, len)) {
1336 struct new_utsname *u = utsname();
1337
1338 memcpy(u->domainname, tmp, len);
1339 memset(u->domainname + len, 0, sizeof(u->domainname) - len);
1340 errno = 0;
1341 uts_proc_notify(UTS_PROC_DOMAINNAME);
1342 }
1343 up_write(&uts_sem);
1344 return errno;
1345 }
1346
1347 SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim)
1348 {
1349 struct rlimit value;
1350 int ret;
1351
1352 ret = do_prlimit(current, resource, NULL, &value);
1353 if (!ret)
1354 ret = copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0;
1355
1356 return ret;
1357 }
1358
1359 #ifdef CONFIG_COMPAT
1360
1361 COMPAT_SYSCALL_DEFINE2(setrlimit, unsigned int, resource,
1362 struct compat_rlimit __user *, rlim)
1363 {
1364 struct rlimit r;
1365 struct compat_rlimit r32;
1366
1367 if (copy_from_user(&r32, rlim, sizeof(struct compat_rlimit)))
1368 return -EFAULT;
1369
1370 if (r32.rlim_cur == COMPAT_RLIM_INFINITY)
1371 r.rlim_cur = RLIM_INFINITY;
1372 else
1373 r.rlim_cur = r32.rlim_cur;
1374 if (r32.rlim_max == COMPAT_RLIM_INFINITY)
1375 r.rlim_max = RLIM_INFINITY;
1376 else
1377 r.rlim_max = r32.rlim_max;
1378 return do_prlimit(current, resource, &r, NULL);
1379 }
1380
1381 COMPAT_SYSCALL_DEFINE2(getrlimit, unsigned int, resource,
1382 struct compat_rlimit __user *, rlim)
1383 {
1384 struct rlimit r;
1385 int ret;
1386
1387 ret = do_prlimit(current, resource, NULL, &r);
1388 if (!ret) {
1389 struct compat_rlimit r32;
1390 if (r.rlim_cur > COMPAT_RLIM_INFINITY)
1391 r32.rlim_cur = COMPAT_RLIM_INFINITY;
1392 else
1393 r32.rlim_cur = r.rlim_cur;
1394 if (r.rlim_max > COMPAT_RLIM_INFINITY)
1395 r32.rlim_max = COMPAT_RLIM_INFINITY;
1396 else
1397 r32.rlim_max = r.rlim_max;
1398
1399 if (copy_to_user(rlim, &r32, sizeof(struct compat_rlimit)))
1400 return -EFAULT;
1401 }
1402 return ret;
1403 }
1404
1405 #endif
1406
1407 #ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT
1408
1409 /*
1410 * Back compatibility for getrlimit. Needed for some apps.
1411 */
1412 SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
1413 struct rlimit __user *, rlim)
1414 {
1415 struct rlimit x;
1416 if (resource >= RLIM_NLIMITS)
1417 return -EINVAL;
1418
1419 resource = array_index_nospec(resource, RLIM_NLIMITS);
1420 task_lock(current->group_leader);
1421 x = current->signal->rlim[resource];
1422 task_unlock(current->group_leader);
1423 if (x.rlim_cur > 0x7FFFFFFF)
1424 x.rlim_cur = 0x7FFFFFFF;
1425 if (x.rlim_max > 0x7FFFFFFF)
1426 x.rlim_max = 0x7FFFFFFF;
1427 return copy_to_user(rlim, &x, sizeof(x)) ? -EFAULT : 0;
1428 }
1429
1430 #ifdef CONFIG_COMPAT
1431 COMPAT_SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
1432 struct compat_rlimit __user *, rlim)
1433 {
1434 struct rlimit r;
1435
1436 if (resource >= RLIM_NLIMITS)
1437 return -EINVAL;
1438
1439 resource = array_index_nospec(resource, RLIM_NLIMITS);
1440 task_lock(current->group_leader);
1441 r = current->signal->rlim[resource];
1442 task_unlock(current->group_leader);
1443 if (r.rlim_cur > 0x7FFFFFFF)
1444 r.rlim_cur = 0x7FFFFFFF;
1445 if (r.rlim_max > 0x7FFFFFFF)
1446 r.rlim_max = 0x7FFFFFFF;
1447
1448 if (put_user(r.rlim_cur, &rlim->rlim_cur) ||
1449 put_user(r.rlim_max, &rlim->rlim_max))
1450 return -EFAULT;
1451 return 0;
1452 }
1453 #endif
1454
1455 #endif
1456
1457 static inline bool rlim64_is_infinity(__u64 rlim64)
1458 {
1459 #if BITS_PER_LONG < 64
1460 return rlim64 >= ULONG_MAX;
1461 #else
1462 return rlim64 == RLIM64_INFINITY;
1463 #endif
1464 }
1465
1466 static void rlim_to_rlim64(const struct rlimit *rlim, struct rlimit64 *rlim64)
1467 {
1468 if (rlim->rlim_cur == RLIM_INFINITY)
1469 rlim64->rlim_cur = RLIM64_INFINITY;
1470 else
1471 rlim64->rlim_cur = rlim->rlim_cur;
1472 if (rlim->rlim_max == RLIM_INFINITY)
1473 rlim64->rlim_max = RLIM64_INFINITY;
1474 else
1475 rlim64->rlim_max = rlim->rlim_max;
1476 }
1477
1478 static void rlim64_to_rlim(const struct rlimit64 *rlim64, struct rlimit *rlim)
1479 {
1480 if (rlim64_is_infinity(rlim64->rlim_cur))
1481 rlim->rlim_cur = RLIM_INFINITY;
1482 else
1483 rlim->rlim_cur = (unsigned long)rlim64->rlim_cur;
1484 if (rlim64_is_infinity(rlim64->rlim_max))
1485 rlim->rlim_max = RLIM_INFINITY;
1486 else
1487 rlim->rlim_max = (unsigned long)rlim64->rlim_max;
1488 }
1489
1490 /* make sure you are allowed to change @tsk limits before calling this */
1491 int do_prlimit(struct task_struct *tsk, unsigned int resource,
1492 struct rlimit *new_rlim, struct rlimit *old_rlim)
1493 {
1494 struct rlimit *rlim;
1495 int retval = 0;
1496
1497 if (resource >= RLIM_NLIMITS)
1498 return -EINVAL;
1499 if (new_rlim) {
1500 if (new_rlim->rlim_cur > new_rlim->rlim_max)
1501 return -EINVAL;
1502 if (resource == RLIMIT_NOFILE &&
1503 new_rlim->rlim_max > sysctl_nr_open)
1504 return -EPERM;
1505 }
1506
1507 /* protect tsk->signal and tsk->sighand from disappearing */
1508 read_lock(&tasklist_lock);
1509 if (!tsk->sighand) {
1510 retval = -ESRCH;
1511 goto out;
1512 }
1513
1514 rlim = tsk->signal->rlim + resource;
1515 task_lock(tsk->group_leader);
1516 if (new_rlim) {
1517 /* Keep the capable check against init_user_ns until
1518 cgroups can contain all limits */
1519 if (new_rlim->rlim_max > rlim->rlim_max &&
1520 !capable(CAP_SYS_RESOURCE))
1521 retval = -EPERM;
1522 if (!retval)
1523 retval = security_task_setrlimit(tsk, resource, new_rlim);
1524 if (resource == RLIMIT_CPU && new_rlim->rlim_cur == 0) {
1525 /*
1526 * The caller is asking for an immediate RLIMIT_CPU
1527 * expiry. But we use the zero value to mean "it was
1528 * never set". So let's cheat and make it one second
1529 * instead
1530 */
1531 new_rlim->rlim_cur = 1;
1532 }
1533 }
1534 if (!retval) {
1535 if (old_rlim)
1536 *old_rlim = *rlim;
1537 if (new_rlim)
1538 *rlim = *new_rlim;
1539 }
1540 task_unlock(tsk->group_leader);
1541
1542 /*
1543 * RLIMIT_CPU handling. Note that the kernel fails to return an error
1544 * code if it rejected the user's attempt to set RLIMIT_CPU. This is a
1545 * very long-standing error, and fixing it now risks breakage of
1546 * applications, so we live with it
1547 */
1548 if (!retval && new_rlim && resource == RLIMIT_CPU &&
1549 new_rlim->rlim_cur != RLIM_INFINITY &&
1550 IS_ENABLED(CONFIG_POSIX_TIMERS))
1551 update_rlimit_cpu(tsk, new_rlim->rlim_cur);
1552 out:
1553 read_unlock(&tasklist_lock);
1554 return retval;
1555 }
1556
1557 /* rcu lock must be held */
1558 static int check_prlimit_permission(struct task_struct *task,
1559 unsigned int flags)
1560 {
1561 const struct cred *cred = current_cred(), *tcred;
1562 bool id_match;
1563
1564 if (current == task)
1565 return 0;
1566
1567 tcred = __task_cred(task);
1568 id_match = (uid_eq(cred->uid, tcred->euid) &&
1569 uid_eq(cred->uid, tcred->suid) &&
1570 uid_eq(cred->uid, tcred->uid) &&
1571 gid_eq(cred->gid, tcred->egid) &&
1572 gid_eq(cred->gid, tcred->sgid) &&
1573 gid_eq(cred->gid, tcred->gid));
1574 if (!id_match && !ns_capable(tcred->user_ns, CAP_SYS_RESOURCE))
1575 return -EPERM;
1576
1577 return security_task_prlimit(cred, tcred, flags);
1578 }
1579
1580 SYSCALL_DEFINE4(prlimit64, pid_t, pid, unsigned int, resource,
1581 const struct rlimit64 __user *, new_rlim,
1582 struct rlimit64 __user *, old_rlim)
1583 {
1584 struct rlimit64 old64, new64;
1585 struct rlimit old, new;
1586 struct task_struct *tsk;
1587 unsigned int checkflags = 0;
1588 int ret;
1589
1590 if (old_rlim)
1591 checkflags |= LSM_PRLIMIT_READ;
1592
1593 if (new_rlim) {
1594 if (copy_from_user(&new64, new_rlim, sizeof(new64)))
1595 return -EFAULT;
1596 rlim64_to_rlim(&new64, &new);
1597 checkflags |= LSM_PRLIMIT_WRITE;
1598 }
1599
1600 rcu_read_lock();
1601 tsk = pid ? find_task_by_vpid(pid) : current;
1602 if (!tsk) {
1603 rcu_read_unlock();
1604 return -ESRCH;
1605 }
1606 ret = check_prlimit_permission(tsk, checkflags);
1607 if (ret) {
1608 rcu_read_unlock();
1609 return ret;
1610 }
1611 get_task_struct(tsk);
1612 rcu_read_unlock();
1613
1614 ret = do_prlimit(tsk, resource, new_rlim ? &new : NULL,
1615 old_rlim ? &old : NULL);
1616
1617 if (!ret && old_rlim) {
1618 rlim_to_rlim64(&old, &old64);
1619 if (copy_to_user(old_rlim, &old64, sizeof(old64)))
1620 ret = -EFAULT;
1621 }
1622
1623 put_task_struct(tsk);
1624 return ret;
1625 }
1626
1627 SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim)
1628 {
1629 struct rlimit new_rlim;
1630
1631 if (copy_from_user(&new_rlim, rlim, sizeof(*rlim)))
1632 return -EFAULT;
1633 return do_prlimit(current, resource, &new_rlim, NULL);
1634 }
1635
1636 /*
1637 * It would make sense to put struct rusage in the task_struct,
1638 * except that would make the task_struct be *really big*. After
1639 * task_struct gets moved into malloc'ed memory, it would
1640 * make sense to do this. It will make moving the rest of the information
1641 * a lot simpler! (Which we're not doing right now because we're not
1642 * measuring them yet).
1643 *
1644 * When sampling multiple threads for RUSAGE_SELF, under SMP we might have
1645 * races with threads incrementing their own counters. But since word
1646 * reads are atomic, we either get new values or old values and we don't
1647 * care which for the sums. We always take the siglock to protect reading
1648 * the c* fields from p->signal from races with exit.c updating those
1649 * fields when reaping, so a sample either gets all the additions of a
1650 * given child after it's reaped, or none so this sample is before reaping.
1651 *
1652 * Locking:
1653 * We need to take the siglock for CHILDEREN, SELF and BOTH
1654 * for the cases current multithreaded, non-current single threaded
1655 * non-current multithreaded. Thread traversal is now safe with
1656 * the siglock held.
1657 * Strictly speaking, we donot need to take the siglock if we are current and
1658 * single threaded, as no one else can take our signal_struct away, no one
1659 * else can reap the children to update signal->c* counters, and no one else
1660 * can race with the signal-> fields. If we do not take any lock, the
1661 * signal-> fields could be read out of order while another thread was just
1662 * exiting. So we should place a read memory barrier when we avoid the lock.
1663 * On the writer side, write memory barrier is implied in __exit_signal
1664 * as __exit_signal releases the siglock spinlock after updating the signal->
1665 * fields. But we don't do this yet to keep things simple.
1666 *
1667 */
1668
1669 static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r)
1670 {
1671 r->ru_nvcsw += t->nvcsw;
1672 r->ru_nivcsw += t->nivcsw;
1673 r->ru_minflt += t->min_flt;
1674 r->ru_majflt += t->maj_flt;
1675 r->ru_inblock += task_io_get_inblock(t);
1676 r->ru_oublock += task_io_get_oublock(t);
1677 }
1678
1679 void getrusage(struct task_struct *p, int who, struct rusage *r)
1680 {
1681 struct task_struct *t;
1682 unsigned long flags;
1683 u64 tgutime, tgstime, utime, stime;
1684 unsigned long maxrss = 0;
1685
1686 memset((char *)r, 0, sizeof (*r));
1687 utime = stime = 0;
1688
1689 if (who == RUSAGE_THREAD) {
1690 task_cputime_adjusted(current, &utime, &stime);
1691 accumulate_thread_rusage(p, r);
1692 maxrss = p->signal->maxrss;
1693 goto out;
1694 }
1695
1696 if (!lock_task_sighand(p, &flags))
1697 return;
1698
1699 switch (who) {
1700 case RUSAGE_BOTH:
1701 case RUSAGE_CHILDREN:
1702 utime = p->signal->cutime;
1703 stime = p->signal->cstime;
1704 r->ru_nvcsw = p->signal->cnvcsw;
1705 r->ru_nivcsw = p->signal->cnivcsw;
1706 r->ru_minflt = p->signal->cmin_flt;
1707 r->ru_majflt = p->signal->cmaj_flt;
1708 r->ru_inblock = p->signal->cinblock;
1709 r->ru_oublock = p->signal->coublock;
1710 maxrss = p->signal->cmaxrss;
1711
1712 if (who == RUSAGE_CHILDREN)
1713 break;
1714
1715 case RUSAGE_SELF:
1716 thread_group_cputime_adjusted(p, &tgutime, &tgstime);
1717 utime += tgutime;
1718 stime += tgstime;
1719 r->ru_nvcsw += p->signal->nvcsw;
1720 r->ru_nivcsw += p->signal->nivcsw;
1721 r->ru_minflt += p->signal->min_flt;
1722 r->ru_majflt += p->signal->maj_flt;
1723 r->ru_inblock += p->signal->inblock;
1724 r->ru_oublock += p->signal->oublock;
1725 if (maxrss < p->signal->maxrss)
1726 maxrss = p->signal->maxrss;
1727 t = p;
1728 do {
1729 accumulate_thread_rusage(t, r);
1730 } while_each_thread(p, t);
1731 break;
1732
1733 default:
1734 BUG();
1735 }
1736 unlock_task_sighand(p, &flags);
1737
1738 out:
1739 r->ru_utime = ns_to_timeval(utime);
1740 r->ru_stime = ns_to_timeval(stime);
1741
1742 if (who != RUSAGE_CHILDREN) {
1743 struct mm_struct *mm = get_task_mm(p);
1744
1745 if (mm) {
1746 setmax_mm_hiwater_rss(&maxrss, mm);
1747 mmput(mm);
1748 }
1749 }
1750 r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */
1751 }
1752
1753 SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru)
1754 {
1755 struct rusage r;
1756
1757 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
1758 who != RUSAGE_THREAD)
1759 return -EINVAL;
1760
1761 getrusage(current, who, &r);
1762 return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0;
1763 }
1764
1765 #ifdef CONFIG_COMPAT
1766 COMPAT_SYSCALL_DEFINE2(getrusage, int, who, struct compat_rusage __user *, ru)
1767 {
1768 struct rusage r;
1769
1770 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
1771 who != RUSAGE_THREAD)
1772 return -EINVAL;
1773
1774 getrusage(current, who, &r);
1775 return put_compat_rusage(&r, ru);
1776 }
1777 #endif
1778
1779 SYSCALL_DEFINE1(umask, int, mask)
1780 {
1781 mask = xchg(&current->fs->umask, mask & S_IRWXUGO);
1782 return mask;
1783 }
1784
1785 static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd)
1786 {
1787 struct fd exe;
1788 struct file *old_exe, *exe_file;
1789 struct inode *inode;
1790 int err;
1791
1792 exe = fdget(fd);
1793 if (!exe.file)
1794 return -EBADF;
1795
1796 inode = file_inode(exe.file);
1797
1798 /*
1799 * Because the original mm->exe_file points to executable file, make
1800 * sure that this one is executable as well, to avoid breaking an
1801 * overall picture.
1802 */
1803 err = -EACCES;
1804 if (!S_ISREG(inode->i_mode) || path_noexec(&exe.file->f_path))
1805 goto exit;
1806
1807 err = inode_permission(inode, MAY_EXEC);
1808 if (err)
1809 goto exit;
1810
1811 /*
1812 * Forbid mm->exe_file change if old file still mapped.
1813 */
1814 exe_file = get_mm_exe_file(mm);
1815 err = -EBUSY;
1816 if (exe_file) {
1817 struct vm_area_struct *vma;
1818
1819 down_read(&mm->mmap_sem);
1820 for (vma = mm->mmap; vma; vma = vma->vm_next) {
1821 if (!vma->vm_file)
1822 continue;
1823 if (path_equal(&vma->vm_file->f_path,
1824 &exe_file->f_path))
1825 goto exit_err;
1826 }
1827
1828 up_read(&mm->mmap_sem);
1829 fput(exe_file);
1830 }
1831
1832 err = 0;
1833 /* set the new file, lockless */
1834 get_file(exe.file);
1835 old_exe = xchg(&mm->exe_file, exe.file);
1836 if (old_exe)
1837 fput(old_exe);
1838 exit:
1839 fdput(exe);
1840 return err;
1841 exit_err:
1842 up_read(&mm->mmap_sem);
1843 fput(exe_file);
1844 goto exit;
1845 }
1846
1847 /*
1848 * WARNING: we don't require any capability here so be very careful
1849 * in what is allowed for modification from userspace.
1850 */
1851 static int validate_prctl_map(struct prctl_mm_map *prctl_map)
1852 {
1853 unsigned long mmap_max_addr = TASK_SIZE;
1854 struct mm_struct *mm = current->mm;
1855 int error = -EINVAL, i;
1856
1857 static const unsigned char offsets[] = {
1858 offsetof(struct prctl_mm_map, start_code),
1859 offsetof(struct prctl_mm_map, end_code),
1860 offsetof(struct prctl_mm_map, start_data),
1861 offsetof(struct prctl_mm_map, end_data),
1862 offsetof(struct prctl_mm_map, start_brk),
1863 offsetof(struct prctl_mm_map, brk),
1864 offsetof(struct prctl_mm_map, start_stack),
1865 offsetof(struct prctl_mm_map, arg_start),
1866 offsetof(struct prctl_mm_map, arg_end),
1867 offsetof(struct prctl_mm_map, env_start),
1868 offsetof(struct prctl_mm_map, env_end),
1869 };
1870
1871 /*
1872 * Make sure the members are not somewhere outside
1873 * of allowed address space.
1874 */
1875 for (i = 0; i < ARRAY_SIZE(offsets); i++) {
1876 u64 val = *(u64 *)((char *)prctl_map + offsets[i]);
1877
1878 if ((unsigned long)val >= mmap_max_addr ||
1879 (unsigned long)val < mmap_min_addr)
1880 goto out;
1881 }
1882
1883 /*
1884 * Make sure the pairs are ordered.
1885 */
1886 #define __prctl_check_order(__m1, __op, __m2) \
1887 ((unsigned long)prctl_map->__m1 __op \
1888 (unsigned long)prctl_map->__m2) ? 0 : -EINVAL
1889 error = __prctl_check_order(start_code, <, end_code);
1890 error |= __prctl_check_order(start_data, <, end_data);
1891 error |= __prctl_check_order(start_brk, <=, brk);
1892 error |= __prctl_check_order(arg_start, <=, arg_end);
1893 error |= __prctl_check_order(env_start, <=, env_end);
1894 if (error)
1895 goto out;
1896 #undef __prctl_check_order
1897
1898 error = -EINVAL;
1899
1900 /*
1901 * @brk should be after @end_data in traditional maps.
1902 */
1903 if (prctl_map->start_brk <= prctl_map->end_data ||
1904 prctl_map->brk <= prctl_map->end_data)
1905 goto out;
1906
1907 /*
1908 * Neither we should allow to override limits if they set.
1909 */
1910 if (check_data_rlimit(rlimit(RLIMIT_DATA), prctl_map->brk,
1911 prctl_map->start_brk, prctl_map->end_data,
1912 prctl_map->start_data))
1913 goto out;
1914
1915 /*
1916 * Someone is trying to cheat the auxv vector.
1917 */
1918 if (prctl_map->auxv_size) {
1919 if (!prctl_map->auxv || prctl_map->auxv_size > sizeof(mm->saved_auxv))
1920 goto out;
1921 }
1922
1923 /*
1924 * Finally, make sure the caller has the rights to
1925 * change /proc/pid/exe link: only local sys admin should
1926 * be allowed to.
1927 */
1928 if (prctl_map->exe_fd != (u32)-1) {
1929 if (!ns_capable(current_user_ns(), CAP_SYS_ADMIN))
1930 goto out;
1931 }
1932
1933 error = 0;
1934 out:
1935 return error;
1936 }
1937
1938 #ifdef CONFIG_CHECKPOINT_RESTORE
1939 static int prctl_set_mm_map(int opt, const void __user *addr, unsigned long data_size)
1940 {
1941 struct prctl_mm_map prctl_map = { .exe_fd = (u32)-1, };
1942 unsigned long user_auxv[AT_VECTOR_SIZE];
1943 struct mm_struct *mm = current->mm;
1944 int error;
1945
1946 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv));
1947 BUILD_BUG_ON(sizeof(struct prctl_mm_map) > 256);
1948
1949 if (opt == PR_SET_MM_MAP_SIZE)
1950 return put_user((unsigned int)sizeof(prctl_map),
1951 (unsigned int __user *)addr);
1952
1953 if (data_size != sizeof(prctl_map))
1954 return -EINVAL;
1955
1956 if (copy_from_user(&prctl_map, addr, sizeof(prctl_map)))
1957 return -EFAULT;
1958
1959 error = validate_prctl_map(&prctl_map);
1960 if (error)
1961 return error;
1962
1963 if (prctl_map.auxv_size) {
1964 memset(user_auxv, 0, sizeof(user_auxv));
1965 if (copy_from_user(user_auxv,
1966 (const void __user *)prctl_map.auxv,
1967 prctl_map.auxv_size))
1968 return -EFAULT;
1969
1970 /* Last entry must be AT_NULL as specification requires */
1971 user_auxv[AT_VECTOR_SIZE - 2] = AT_NULL;
1972 user_auxv[AT_VECTOR_SIZE - 1] = AT_NULL;
1973 }
1974
1975 if (prctl_map.exe_fd != (u32)-1) {
1976 error = prctl_set_mm_exe_file(mm, prctl_map.exe_fd);
1977 if (error)
1978 return error;
1979 }
1980
1981 down_write(&mm->mmap_sem);
1982
1983 /*
1984 * We don't validate if these members are pointing to
1985 * real present VMAs because application may have correspond
1986 * VMAs already unmapped and kernel uses these members for statistics
1987 * output in procfs mostly, except
1988 *
1989 * - @start_brk/@brk which are used in do_brk but kernel lookups
1990 * for VMAs when updating these memvers so anything wrong written
1991 * here cause kernel to swear at userspace program but won't lead
1992 * to any problem in kernel itself
1993 */
1994
1995 mm->start_code = prctl_map.start_code;
1996 mm->end_code = prctl_map.end_code;
1997 mm->start_data = prctl_map.start_data;
1998 mm->end_data = prctl_map.end_data;
1999 mm->start_brk = prctl_map.start_brk;
2000 mm->brk = prctl_map.brk;
2001 mm->start_stack = prctl_map.start_stack;
2002 mm->arg_start = prctl_map.arg_start;
2003 mm->arg_end = prctl_map.arg_end;
2004 mm->env_start = prctl_map.env_start;
2005 mm->env_end = prctl_map.env_end;
2006
2007 /*
2008 * Note this update of @saved_auxv is lockless thus
2009 * if someone reads this member in procfs while we're
2010 * updating -- it may get partly updated results. It's
2011 * known and acceptable trade off: we leave it as is to
2012 * not introduce additional locks here making the kernel
2013 * more complex.
2014 */
2015 if (prctl_map.auxv_size)
2016 memcpy(mm->saved_auxv, user_auxv, sizeof(user_auxv));
2017
2018 up_write(&mm->mmap_sem);
2019 return 0;
2020 }
2021 #endif /* CONFIG_CHECKPOINT_RESTORE */
2022
2023 static int prctl_set_auxv(struct mm_struct *mm, unsigned long addr,
2024 unsigned long len)
2025 {
2026 /*
2027 * This doesn't move the auxiliary vector itself since it's pinned to
2028 * mm_struct, but it permits filling the vector with new values. It's
2029 * up to the caller to provide sane values here, otherwise userspace
2030 * tools which use this vector might be unhappy.
2031 */
2032 unsigned long user_auxv[AT_VECTOR_SIZE];
2033
2034 if (len > sizeof(user_auxv))
2035 return -EINVAL;
2036
2037 if (copy_from_user(user_auxv, (const void __user *)addr, len))
2038 return -EFAULT;
2039
2040 /* Make sure the last entry is always AT_NULL */
2041 user_auxv[AT_VECTOR_SIZE - 2] = 0;
2042 user_auxv[AT_VECTOR_SIZE - 1] = 0;
2043
2044 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv));
2045
2046 task_lock(current);
2047 memcpy(mm->saved_auxv, user_auxv, len);
2048 task_unlock(current);
2049
2050 return 0;
2051 }
2052
2053 static int prctl_set_mm(int opt, unsigned long addr,
2054 unsigned long arg4, unsigned long arg5)
2055 {
2056 struct mm_struct *mm = current->mm;
2057 struct prctl_mm_map prctl_map;
2058 struct vm_area_struct *vma;
2059 int error;
2060
2061 if (arg5 || (arg4 && (opt != PR_SET_MM_AUXV &&
2062 opt != PR_SET_MM_MAP &&
2063 opt != PR_SET_MM_MAP_SIZE)))
2064 return -EINVAL;
2065
2066 #ifdef CONFIG_CHECKPOINT_RESTORE
2067 if (opt == PR_SET_MM_MAP || opt == PR_SET_MM_MAP_SIZE)
2068 return prctl_set_mm_map(opt, (const void __user *)addr, arg4);
2069 #endif
2070
2071 if (!capable(CAP_SYS_RESOURCE))
2072 return -EPERM;
2073
2074 if (opt == PR_SET_MM_EXE_FILE)
2075 return prctl_set_mm_exe_file(mm, (unsigned int)addr);
2076
2077 if (opt == PR_SET_MM_AUXV)
2078 return prctl_set_auxv(mm, addr, arg4);
2079
2080 if (addr >= TASK_SIZE || addr < mmap_min_addr)
2081 return -EINVAL;
2082
2083 error = -EINVAL;
2084
2085 down_write(&mm->mmap_sem);
2086 vma = find_vma(mm, addr);
2087
2088 prctl_map.start_code = mm->start_code;
2089 prctl_map.end_code = mm->end_code;
2090 prctl_map.start_data = mm->start_data;
2091 prctl_map.end_data = mm->end_data;
2092 prctl_map.start_brk = mm->start_brk;
2093 prctl_map.brk = mm->brk;
2094 prctl_map.start_stack = mm->start_stack;
2095 prctl_map.arg_start = mm->arg_start;
2096 prctl_map.arg_end = mm->arg_end;
2097 prctl_map.env_start = mm->env_start;
2098 prctl_map.env_end = mm->env_end;
2099 prctl_map.auxv = NULL;
2100 prctl_map.auxv_size = 0;
2101 prctl_map.exe_fd = -1;
2102
2103 switch (opt) {
2104 case PR_SET_MM_START_CODE:
2105 prctl_map.start_code = addr;
2106 break;
2107 case PR_SET_MM_END_CODE:
2108 prctl_map.end_code = addr;
2109 break;
2110 case PR_SET_MM_START_DATA:
2111 prctl_map.start_data = addr;
2112 break;
2113 case PR_SET_MM_END_DATA:
2114 prctl_map.end_data = addr;
2115 break;
2116 case PR_SET_MM_START_STACK:
2117 prctl_map.start_stack = addr;
2118 break;
2119 case PR_SET_MM_START_BRK:
2120 prctl_map.start_brk = addr;
2121 break;
2122 case PR_SET_MM_BRK:
2123 prctl_map.brk = addr;
2124 break;
2125 case PR_SET_MM_ARG_START:
2126 prctl_map.arg_start = addr;
2127 break;
2128 case PR_SET_MM_ARG_END:
2129 prctl_map.arg_end = addr;
2130 break;
2131 case PR_SET_MM_ENV_START:
2132 prctl_map.env_start = addr;
2133 break;
2134 case PR_SET_MM_ENV_END:
2135 prctl_map.env_end = addr;
2136 break;
2137 default:
2138 goto out;
2139 }
2140
2141 error = validate_prctl_map(&prctl_map);
2142 if (error)
2143 goto out;
2144
2145 switch (opt) {
2146 /*
2147 * If command line arguments and environment
2148 * are placed somewhere else on stack, we can
2149 * set them up here, ARG_START/END to setup
2150 * command line argumets and ENV_START/END
2151 * for environment.
2152 */
2153 case PR_SET_MM_START_STACK:
2154 case PR_SET_MM_ARG_START:
2155 case PR_SET_MM_ARG_END:
2156 case PR_SET_MM_ENV_START:
2157 case PR_SET_MM_ENV_END:
2158 if (!vma) {
2159 error = -EFAULT;
2160 goto out;
2161 }
2162 }
2163
2164 mm->start_code = prctl_map.start_code;
2165 mm->end_code = prctl_map.end_code;
2166 mm->start_data = prctl_map.start_data;
2167 mm->end_data = prctl_map.end_data;
2168 mm->start_brk = prctl_map.start_brk;
2169 mm->brk = prctl_map.brk;
2170 mm->start_stack = prctl_map.start_stack;
2171 mm->arg_start = prctl_map.arg_start;
2172 mm->arg_end = prctl_map.arg_end;
2173 mm->env_start = prctl_map.env_start;
2174 mm->env_end = prctl_map.env_end;
2175
2176 error = 0;
2177 out:
2178 up_write(&mm->mmap_sem);
2179 return error;
2180 }
2181
2182 #ifdef CONFIG_CHECKPOINT_RESTORE
2183 static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr)
2184 {
2185 return put_user(me->clear_child_tid, tid_addr);
2186 }
2187 #else
2188 static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr)
2189 {
2190 return -EINVAL;
2191 }
2192 #endif
2193
2194 static int propagate_has_child_subreaper(struct task_struct *p, void *data)
2195 {
2196 /*
2197 * If task has has_child_subreaper - all its decendants
2198 * already have these flag too and new decendants will
2199 * inherit it on fork, skip them.
2200 *
2201 * If we've found child_reaper - skip descendants in
2202 * it's subtree as they will never get out pidns.
2203 */
2204 if (p->signal->has_child_subreaper ||
2205 is_child_reaper(task_pid(p)))
2206 return 0;
2207
2208 p->signal->has_child_subreaper = 1;
2209 return 1;
2210 }
2211
2212 int __weak arch_prctl_spec_ctrl_get(struct task_struct *t, unsigned long which)
2213 {
2214 return -EINVAL;
2215 }
2216
2217 int __weak arch_prctl_spec_ctrl_set(struct task_struct *t, unsigned long which,
2218 unsigned long ctrl)
2219 {
2220 return -EINVAL;
2221 }
2222
2223 SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
2224 unsigned long, arg4, unsigned long, arg5)
2225 {
2226 struct task_struct *me = current;
2227 unsigned char comm[sizeof(me->comm)];
2228 long error;
2229
2230 error = security_task_prctl(option, arg2, arg3, arg4, arg5);
2231 if (error != -ENOSYS)
2232 return error;
2233
2234 error = 0;
2235 switch (option) {
2236 case PR_SET_PDEATHSIG:
2237 if (!valid_signal(arg2)) {
2238 error = -EINVAL;
2239 break;
2240 }
2241 me->pdeath_signal = arg2;
2242 break;
2243 case PR_GET_PDEATHSIG:
2244 error = put_user(me->pdeath_signal, (int __user *)arg2);
2245 break;
2246 case PR_GET_DUMPABLE:
2247 error = get_dumpable(me->mm);
2248 break;
2249 case PR_SET_DUMPABLE:
2250 if (arg2 != SUID_DUMP_DISABLE && arg2 != SUID_DUMP_USER) {
2251 error = -EINVAL;
2252 break;
2253 }
2254 set_dumpable(me->mm, arg2);
2255 break;
2256
2257 case PR_SET_UNALIGN:
2258 error = SET_UNALIGN_CTL(me, arg2);
2259 break;
2260 case PR_GET_UNALIGN:
2261 error = GET_UNALIGN_CTL(me, arg2);
2262 break;
2263 case PR_SET_FPEMU:
2264 error = SET_FPEMU_CTL(me, arg2);
2265 break;
2266 case PR_GET_FPEMU:
2267 error = GET_FPEMU_CTL(me, arg2);
2268 break;
2269 case PR_SET_FPEXC:
2270 error = SET_FPEXC_CTL(me, arg2);
2271 break;
2272 case PR_GET_FPEXC:
2273 error = GET_FPEXC_CTL(me, arg2);
2274 break;
2275 case PR_GET_TIMING:
2276 error = PR_TIMING_STATISTICAL;
2277 break;
2278 case PR_SET_TIMING:
2279 if (arg2 != PR_TIMING_STATISTICAL)
2280 error = -EINVAL;
2281 break;
2282 case PR_SET_NAME:
2283 comm[sizeof(me->comm) - 1] = 0;
2284 if (strncpy_from_user(comm, (char __user *)arg2,
2285 sizeof(me->comm) - 1) < 0)
2286 return -EFAULT;
2287 set_task_comm(me, comm);
2288 proc_comm_connector(me);
2289 break;
2290 case PR_GET_NAME:
2291 get_task_comm(comm, me);
2292 if (copy_to_user((char __user *)arg2, comm, sizeof(comm)))
2293 return -EFAULT;
2294 break;
2295 case PR_GET_ENDIAN:
2296 error = GET_ENDIAN(me, arg2);
2297 break;
2298 case PR_SET_ENDIAN:
2299 error = SET_ENDIAN(me, arg2);
2300 break;
2301 case PR_GET_SECCOMP:
2302 error = prctl_get_seccomp();
2303 break;
2304 case PR_SET_SECCOMP:
2305 error = prctl_set_seccomp(arg2, (char __user *)arg3);
2306 break;
2307 case PR_GET_TSC:
2308 error = GET_TSC_CTL(arg2);
2309 break;
2310 case PR_SET_TSC:
2311 error = SET_TSC_CTL(arg2);
2312 break;
2313 case PR_TASK_PERF_EVENTS_DISABLE:
2314 error = perf_event_task_disable();
2315 break;
2316 case PR_TASK_PERF_EVENTS_ENABLE:
2317 error = perf_event_task_enable();
2318 break;
2319 case PR_GET_TIMERSLACK:
2320 if (current->timer_slack_ns > ULONG_MAX)
2321 error = ULONG_MAX;
2322 else
2323 error = current->timer_slack_ns;
2324 break;
2325 case PR_SET_TIMERSLACK:
2326 if (arg2 <= 0)
2327 current->timer_slack_ns =
2328 current->default_timer_slack_ns;
2329 else
2330 current->timer_slack_ns = arg2;
2331 break;
2332 case PR_MCE_KILL:
2333 if (arg4 | arg5)
2334 return -EINVAL;
2335 switch (arg2) {
2336 case PR_MCE_KILL_CLEAR:
2337 if (arg3 != 0)
2338 return -EINVAL;
2339 current->flags &= ~PF_MCE_PROCESS;
2340 break;
2341 case PR_MCE_KILL_SET:
2342 current->flags |= PF_MCE_PROCESS;
2343 if (arg3 == PR_MCE_KILL_EARLY)
2344 current->flags |= PF_MCE_EARLY;
2345 else if (arg3 == PR_MCE_KILL_LATE)
2346 current->flags &= ~PF_MCE_EARLY;
2347 else if (arg3 == PR_MCE_KILL_DEFAULT)
2348 current->flags &=
2349 ~(PF_MCE_EARLY|PF_MCE_PROCESS);
2350 else
2351 return -EINVAL;
2352 break;
2353 default:
2354 return -EINVAL;
2355 }
2356 break;
2357 case PR_MCE_KILL_GET:
2358 if (arg2 | arg3 | arg4 | arg5)
2359 return -EINVAL;
2360 if (current->flags & PF_MCE_PROCESS)
2361 error = (current->flags & PF_MCE_EARLY) ?
2362 PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE;
2363 else
2364 error = PR_MCE_KILL_DEFAULT;
2365 break;
2366 case PR_SET_MM:
2367 error = prctl_set_mm(arg2, arg3, arg4, arg5);
2368 break;
2369 case PR_GET_TID_ADDRESS:
2370 error = prctl_get_tid_address(me, (int __user **)arg2);
2371 break;
2372 case PR_SET_CHILD_SUBREAPER:
2373 me->signal->is_child_subreaper = !!arg2;
2374 if (!arg2)
2375 break;
2376
2377 walk_process_tree(me, propagate_has_child_subreaper, NULL);
2378 break;
2379 case PR_GET_CHILD_SUBREAPER:
2380 error = put_user(me->signal->is_child_subreaper,
2381 (int __user *)arg2);
2382 break;
2383 case PR_SET_NO_NEW_PRIVS:
2384 if (arg2 != 1 || arg3 || arg4 || arg5)
2385 return -EINVAL;
2386
2387 task_set_no_new_privs(current);
2388 break;
2389 case PR_GET_NO_NEW_PRIVS:
2390 if (arg2 || arg3 || arg4 || arg5)
2391 return -EINVAL;
2392 return task_no_new_privs(current) ? 1 : 0;
2393 case PR_GET_THP_DISABLE:
2394 if (arg2 || arg3 || arg4 || arg5)
2395 return -EINVAL;
2396 error = !!test_bit(MMF_DISABLE_THP, &me->mm->flags);
2397 break;
2398 case PR_SET_THP_DISABLE:
2399 if (arg3 || arg4 || arg5)
2400 return -EINVAL;
2401 if (down_write_killable(&me->mm->mmap_sem))
2402 return -EINTR;
2403 if (arg2)
2404 set_bit(MMF_DISABLE_THP, &me->mm->flags);
2405 else
2406 clear_bit(MMF_DISABLE_THP, &me->mm->flags);
2407 up_write(&me->mm->mmap_sem);
2408 break;
2409 case PR_MPX_ENABLE_MANAGEMENT:
2410 if (arg2 || arg3 || arg4 || arg5)
2411 return -EINVAL;
2412 error = MPX_ENABLE_MANAGEMENT();
2413 break;
2414 case PR_MPX_DISABLE_MANAGEMENT:
2415 if (arg2 || arg3 || arg4 || arg5)
2416 return -EINVAL;
2417 error = MPX_DISABLE_MANAGEMENT();
2418 break;
2419 case PR_SET_FP_MODE:
2420 error = SET_FP_MODE(me, arg2);
2421 break;
2422 case PR_GET_FP_MODE:
2423 error = GET_FP_MODE(me);
2424 break;
2425 case PR_SVE_SET_VL:
2426 error = SVE_SET_VL(arg2);
2427 break;
2428 case PR_SVE_GET_VL:
2429 error = SVE_GET_VL();
2430 break;
2431 case PR_GET_SPECULATION_CTRL:
2432 if (arg3 || arg4 || arg5)
2433 return -EINVAL;
2434 error = arch_prctl_spec_ctrl_get(me, arg2);
2435 break;
2436 case PR_SET_SPECULATION_CTRL:
2437 if (arg4 || arg5)
2438 return -EINVAL;
2439 error = arch_prctl_spec_ctrl_set(me, arg2, arg3);
2440 break;
2441 default:
2442 error = -EINVAL;
2443 break;
2444 }
2445 return error;
2446 }
2447
2448 SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep,
2449 struct getcpu_cache __user *, unused)
2450 {
2451 int err = 0;
2452 int cpu = raw_smp_processor_id();
2453
2454 if (cpup)
2455 err |= put_user(cpu, cpup);
2456 if (nodep)
2457 err |= put_user(cpu_to_node(cpu), nodep);
2458 return err ? -EFAULT : 0;
2459 }
2460
2461 /**
2462 * do_sysinfo - fill in sysinfo struct
2463 * @info: pointer to buffer to fill
2464 */
2465 static int do_sysinfo(struct sysinfo *info)
2466 {
2467 unsigned long mem_total, sav_total;
2468 unsigned int mem_unit, bitcount;
2469 struct timespec tp;
2470
2471 memset(info, 0, sizeof(struct sysinfo));
2472
2473 get_monotonic_boottime(&tp);
2474 info->uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0);
2475
2476 get_avenrun(info->loads, 0, SI_LOAD_SHIFT - FSHIFT);
2477
2478 info->procs = nr_threads;
2479
2480 si_meminfo(info);
2481 si_swapinfo(info);
2482
2483 /*
2484 * If the sum of all the available memory (i.e. ram + swap)
2485 * is less than can be stored in a 32 bit unsigned long then
2486 * we can be binary compatible with 2.2.x kernels. If not,
2487 * well, in that case 2.2.x was broken anyways...
2488 *
2489 * -Erik Andersen <andersee@debian.org>
2490 */
2491
2492 mem_total = info->totalram + info->totalswap;
2493 if (mem_total < info->totalram || mem_total < info->totalswap)
2494 goto out;
2495 bitcount = 0;
2496 mem_unit = info->mem_unit;
2497 while (mem_unit > 1) {
2498 bitcount++;
2499 mem_unit >>= 1;
2500 sav_total = mem_total;
2501 mem_total <<= 1;
2502 if (mem_total < sav_total)
2503 goto out;
2504 }
2505
2506 /*
2507 * If mem_total did not overflow, multiply all memory values by
2508 * info->mem_unit and set it to 1. This leaves things compatible
2509 * with 2.2.x, and also retains compatibility with earlier 2.4.x
2510 * kernels...
2511 */
2512
2513 info->mem_unit = 1;
2514 info->totalram <<= bitcount;
2515 info->freeram <<= bitcount;
2516 info->sharedram <<= bitcount;
2517 info->bufferram <<= bitcount;
2518 info->totalswap <<= bitcount;
2519 info->freeswap <<= bitcount;
2520 info->totalhigh <<= bitcount;
2521 info->freehigh <<= bitcount;
2522
2523 out:
2524 return 0;
2525 }
2526
2527 SYSCALL_DEFINE1(sysinfo, struct sysinfo __user *, info)
2528 {
2529 struct sysinfo val;
2530
2531 do_sysinfo(&val);
2532
2533 if (copy_to_user(info, &val, sizeof(struct sysinfo)))
2534 return -EFAULT;
2535
2536 return 0;
2537 }
2538
2539 #ifdef CONFIG_COMPAT
2540 struct compat_sysinfo {
2541 s32 uptime;
2542 u32 loads[3];
2543 u32 totalram;
2544 u32 freeram;
2545 u32 sharedram;
2546 u32 bufferram;
2547 u32 totalswap;
2548 u32 freeswap;
2549 u16 procs;
2550 u16 pad;
2551 u32 totalhigh;
2552 u32 freehigh;
2553 u32 mem_unit;
2554 char _f[20-2*sizeof(u32)-sizeof(int)];
2555 };
2556
2557 COMPAT_SYSCALL_DEFINE1(sysinfo, struct compat_sysinfo __user *, info)
2558 {
2559 struct sysinfo s;
2560
2561 do_sysinfo(&s);
2562
2563 /* Check to see if any memory value is too large for 32-bit and scale
2564 * down if needed
2565 */
2566 if (upper_32_bits(s.totalram) || upper_32_bits(s.totalswap)) {
2567 int bitcount = 0;
2568
2569 while (s.mem_unit < PAGE_SIZE) {
2570 s.mem_unit <<= 1;
2571 bitcount++;
2572 }
2573
2574 s.totalram >>= bitcount;
2575 s.freeram >>= bitcount;
2576 s.sharedram >>= bitcount;
2577 s.bufferram >>= bitcount;
2578 s.totalswap >>= bitcount;
2579 s.freeswap >>= bitcount;
2580 s.totalhigh >>= bitcount;
2581 s.freehigh >>= bitcount;
2582 }
2583
2584 if (!access_ok(VERIFY_WRITE, info, sizeof(struct compat_sysinfo)) ||
2585 __put_user(s.uptime, &info->uptime) ||
2586 __put_user(s.loads[0], &info->loads[0]) ||
2587 __put_user(s.loads[1], &info->loads[1]) ||
2588 __put_user(s.loads[2], &info->loads[2]) ||
2589 __put_user(s.totalram, &info->totalram) ||
2590 __put_user(s.freeram, &info->freeram) ||
2591 __put_user(s.sharedram, &info->sharedram) ||
2592 __put_user(s.bufferram, &info->bufferram) ||
2593 __put_user(s.totalswap, &info->totalswap) ||
2594 __put_user(s.freeswap, &info->freeswap) ||
2595 __put_user(s.procs, &info->procs) ||
2596 __put_user(s.totalhigh, &info->totalhigh) ||
2597 __put_user(s.freehigh, &info->freehigh) ||
2598 __put_user(s.mem_unit, &info->mem_unit))
2599 return -EFAULT;
2600
2601 return 0;
2602 }
2603 #endif /* CONFIG_COMPAT */
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