projects/linux·blob v6.8-rc2 · refs

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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/mm_inline.h>
11#include <linux/utsname.h>
12#include <linux/mman.h>
13#include <linux/reboot.h>
14#include <linux/prctl.h>
15#include <linux/highuid.h>
16#include <linux/fs.h>
17#include <linux/kmod.h>
18#include <linux/ksm.h>
19#include <linux/perf_event.h>
20#include <linux/resource.h>
21#include <linux/kernel.h>
22#include <linux/workqueue.h>
23#include <linux/capability.h>
24#include <linux/device.h>
25#include <linux/key.h>
26#include <linux/times.h>
27#include <linux/posix-timers.h>
28#include <linux/security.h>
29#include <linux/random.h>
30#include <linux/suspend.h>
31#include <linux/tty.h>
32#include <linux/signal.h>
33#include <linux/cn_proc.h>
34#include <linux/getcpu.h>
35#include <linux/task_io_accounting_ops.h>
36#include <linux/seccomp.h>
37#include <linux/cpu.h>
38#include <linux/personality.h>
39#include <linux/ptrace.h>
40#include <linux/fs_struct.h>
41#include <linux/file.h>
42#include <linux/mount.h>
43#include <linux/gfp.h>
44#include <linux/syscore_ops.h>
45#include <linux/version.h>
46#include <linux/ctype.h>
47#include <linux/syscall_user_dispatch.h>
48
49#include <linux/compat.h>
50#include <linux/syscalls.h>
51#include <linux/kprobes.h>
52#include <linux/user_namespace.h>
53#include <linux/time_namespace.h>
54#include <linux/binfmts.h>
55
56#include <linux/sched.h>
57#include <linux/sched/autogroup.h>
58#include <linux/sched/loadavg.h>
59#include <linux/sched/stat.h>
60#include <linux/sched/mm.h>
61#include <linux/sched/coredump.h>
62#include <linux/sched/task.h>
63#include <linux/sched/cputime.h>
64#include <linux/rcupdate.h>
65#include <linux/uidgid.h>
66#include <linux/cred.h>
67
68#include <linux/nospec.h>
69
70#include <linux/kmsg_dump.h>
71/* Move somewhere else to avoid recompiling? */
72#include <generated/utsrelease.h>
73
74#include <linux/uaccess.h>
75#include <asm/io.h>
76#include <asm/unistd.h>
77
78#include "uid16.h"
79
80#ifndef SET_UNALIGN_CTL
81# define SET_UNALIGN_CTL(a, b) (-EINVAL)
82#endif
83#ifndef GET_UNALIGN_CTL
84# define GET_UNALIGN_CTL(a, b) (-EINVAL)
85#endif
86#ifndef SET_FPEMU_CTL
87# define SET_FPEMU_CTL(a, b) (-EINVAL)
88#endif
89#ifndef GET_FPEMU_CTL
90# define GET_FPEMU_CTL(a, b) (-EINVAL)
91#endif
92#ifndef SET_FPEXC_CTL
93# define SET_FPEXC_CTL(a, b) (-EINVAL)
94#endif
95#ifndef GET_FPEXC_CTL
96# define GET_FPEXC_CTL(a, b) (-EINVAL)
97#endif
98#ifndef GET_ENDIAN
99# define GET_ENDIAN(a, b) (-EINVAL)
100#endif
101#ifndef SET_ENDIAN
102# define SET_ENDIAN(a, b) (-EINVAL)
103#endif
104#ifndef GET_TSC_CTL
105# define GET_TSC_CTL(a) (-EINVAL)
106#endif
107#ifndef SET_TSC_CTL
108# define SET_TSC_CTL(a) (-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#ifndef SME_SET_VL
123# define SME_SET_VL(a) (-EINVAL)
124#endif
125#ifndef SME_GET_VL
126# define SME_GET_VL() (-EINVAL)
127#endif
128#ifndef PAC_RESET_KEYS
129# define PAC_RESET_KEYS(a, b) (-EINVAL)
130#endif
131#ifndef PAC_SET_ENABLED_KEYS
132# define PAC_SET_ENABLED_KEYS(a, b, c) (-EINVAL)
133#endif
134#ifndef PAC_GET_ENABLED_KEYS
135# define PAC_GET_ENABLED_KEYS(a) (-EINVAL)
136#endif
137#ifndef SET_TAGGED_ADDR_CTRL
138# define SET_TAGGED_ADDR_CTRL(a) (-EINVAL)
139#endif
140#ifndef GET_TAGGED_ADDR_CTRL
141# define GET_TAGGED_ADDR_CTRL() (-EINVAL)
142#endif
143#ifndef RISCV_V_SET_CONTROL
144# define RISCV_V_SET_CONTROL(a) (-EINVAL)
145#endif
146#ifndef RISCV_V_GET_CONTROL
147# define RISCV_V_GET_CONTROL() (-EINVAL)
148#endif
149
150/*
151 * this is where the system-wide overflow UID and GID are defined, for
152 * architectures that now have 32-bit UID/GID but didn't in the past
153 */
154
155int overflowuid = DEFAULT_OVERFLOWUID;
156int overflowgid = DEFAULT_OVERFLOWGID;
157
158EXPORT_SYMBOL(overflowuid);
159EXPORT_SYMBOL(overflowgid);
160
161/*
162 * the same as above, but for filesystems which can only store a 16-bit
163 * UID and GID. as such, this is needed on all architectures
164 */
165
166int fs_overflowuid = DEFAULT_FS_OVERFLOWUID;
167int fs_overflowgid = DEFAULT_FS_OVERFLOWGID;
168
169EXPORT_SYMBOL(fs_overflowuid);
170EXPORT_SYMBOL(fs_overflowgid);
171
172/*
173 * Returns true if current's euid is same as p's uid or euid,
174 * or has CAP_SYS_NICE to p's user_ns.
175 *
176 * Called with rcu_read_lock, creds are safe
177 */
178static bool set_one_prio_perm(struct task_struct *p)
179{
180 const struct cred *cred = current_cred(), *pcred = __task_cred(p);
181
182 if (uid_eq(pcred->uid, cred->euid) ||
183 uid_eq(pcred->euid, cred->euid))
184 return true;
185 if (ns_capable(pcred->user_ns, CAP_SYS_NICE))
186 return true;
187 return false;
188}
189
190/*
191 * set the priority of a task
192 * - the caller must hold the RCU read lock
193 */
194static int set_one_prio(struct task_struct *p, int niceval, int error)
195{
196 int no_nice;
197
198 if (!set_one_prio_perm(p)) {
199 error = -EPERM;
200 goto out;
201 }
202 if (niceval < task_nice(p) && !can_nice(p, niceval)) {
203 error = -EACCES;
204 goto out;
205 }
206 no_nice = security_task_setnice(p, niceval);
207 if (no_nice) {
208 error = no_nice;
209 goto out;
210 }
211 if (error == -ESRCH)
212 error = 0;
213 set_user_nice(p, niceval);
214out:
215 return error;
216}
217
218SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval)
219{
220 struct task_struct *g, *p;
221 struct user_struct *user;
222 const struct cred *cred = current_cred();
223 int error = -EINVAL;
224 struct pid *pgrp;
225 kuid_t uid;
226
227 if (which > PRIO_USER || which < PRIO_PROCESS)
228 goto out;
229
230 /* normalize: avoid signed division (rounding problems) */
231 error = -ESRCH;
232 if (niceval < MIN_NICE)
233 niceval = MIN_NICE;
234 if (niceval > MAX_NICE)
235 niceval = MAX_NICE;
236
237 rcu_read_lock();
238 switch (which) {
239 case PRIO_PROCESS:
240 if (who)
241 p = find_task_by_vpid(who);
242 else
243 p = current;
244 if (p)
245 error = set_one_prio(p, niceval, error);
246 break;
247 case PRIO_PGRP:
248 if (who)
249 pgrp = find_vpid(who);
250 else
251 pgrp = task_pgrp(current);
252 read_lock(&tasklist_lock);
253 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
254 error = set_one_prio(p, niceval, error);
255 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
256 read_unlock(&tasklist_lock);
257 break;
258 case PRIO_USER:
259 uid = make_kuid(cred->user_ns, who);
260 user = cred->user;
261 if (!who)
262 uid = cred->uid;
263 else if (!uid_eq(uid, cred->uid)) {
264 user = find_user(uid);
265 if (!user)
266 goto out_unlock; /* No processes for this user */
267 }
268 for_each_process_thread(g, p) {
269 if (uid_eq(task_uid(p), uid) && task_pid_vnr(p))
270 error = set_one_prio(p, niceval, error);
271 }
272 if (!uid_eq(uid, cred->uid))
273 free_uid(user); /* For find_user() */
274 break;
275 }
276out_unlock:
277 rcu_read_unlock();
278out:
279 return error;
280}
281
282/*
283 * Ugh. To avoid negative return values, "getpriority()" will
284 * not return the normal nice-value, but a negated value that
285 * has been offset by 20 (ie it returns 40..1 instead of -20..19)
286 * to stay compatible.
287 */
288SYSCALL_DEFINE2(getpriority, int, which, int, who)
289{
290 struct task_struct *g, *p;
291 struct user_struct *user;
292 const struct cred *cred = current_cred();
293 long niceval, retval = -ESRCH;
294 struct pid *pgrp;
295 kuid_t uid;
296
297 if (which > PRIO_USER || which < PRIO_PROCESS)
298 return -EINVAL;
299
300 rcu_read_lock();
301 switch (which) {
302 case PRIO_PROCESS:
303 if (who)
304 p = find_task_by_vpid(who);
305 else
306 p = current;
307 if (p) {
308 niceval = nice_to_rlimit(task_nice(p));
309 if (niceval > retval)
310 retval = niceval;
311 }
312 break;
313 case PRIO_PGRP:
314 if (who)
315 pgrp = find_vpid(who);
316 else
317 pgrp = task_pgrp(current);
318 read_lock(&tasklist_lock);
319 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
320 niceval = nice_to_rlimit(task_nice(p));
321 if (niceval > retval)
322 retval = niceval;
323 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
324 read_unlock(&tasklist_lock);
325 break;
326 case PRIO_USER:
327 uid = make_kuid(cred->user_ns, who);
328 user = cred->user;
329 if (!who)
330 uid = cred->uid;
331 else if (!uid_eq(uid, cred->uid)) {
332 user = find_user(uid);
333 if (!user)
334 goto out_unlock; /* No processes for this user */
335 }
336 for_each_process_thread(g, p) {
337 if (uid_eq(task_uid(p), uid) && task_pid_vnr(p)) {
338 niceval = nice_to_rlimit(task_nice(p));
339 if (niceval > retval)
340 retval = niceval;
341 }
342 }
343 if (!uid_eq(uid, cred->uid))
344 free_uid(user); /* for find_user() */
345 break;
346 }
347out_unlock:
348 rcu_read_unlock();
349
350 return retval;
351}
352
353/*
354 * Unprivileged users may change the real gid to the effective gid
355 * or vice versa. (BSD-style)
356 *
357 * If you set the real gid at all, or set the effective gid to a value not
358 * equal to the real gid, then the saved gid is set to the new effective gid.
359 *
360 * This makes it possible for a setgid program to completely drop its
361 * privileges, which is often a useful assertion to make when you are doing
362 * a security audit over a program.
363 *
364 * The general idea is that a program which uses just setregid() will be
365 * 100% compatible with BSD. A program which uses just setgid() will be
366 * 100% compatible with POSIX with saved IDs.
367 *
368 * SMP: There are not races, the GIDs are checked only by filesystem
369 * operations (as far as semantic preservation is concerned).
370 */
371#ifdef CONFIG_MULTIUSER
372long __sys_setregid(gid_t rgid, gid_t egid)
373{
374 struct user_namespace *ns = current_user_ns();
375 const struct cred *old;
376 struct cred *new;
377 int retval;
378 kgid_t krgid, kegid;
379
380 krgid = make_kgid(ns, rgid);
381 kegid = make_kgid(ns, egid);
382
383 if ((rgid != (gid_t) -1) && !gid_valid(krgid))
384 return -EINVAL;
385 if ((egid != (gid_t) -1) && !gid_valid(kegid))
386 return -EINVAL;
387
388 new = prepare_creds();
389 if (!new)
390 return -ENOMEM;
391 old = current_cred();
392
393 retval = -EPERM;
394 if (rgid != (gid_t) -1) {
395 if (gid_eq(old->gid, krgid) ||
396 gid_eq(old->egid, krgid) ||
397 ns_capable_setid(old->user_ns, CAP_SETGID))
398 new->gid = krgid;
399 else
400 goto error;
401 }
402 if (egid != (gid_t) -1) {
403 if (gid_eq(old->gid, kegid) ||
404 gid_eq(old->egid, kegid) ||
405 gid_eq(old->sgid, kegid) ||
406 ns_capable_setid(old->user_ns, CAP_SETGID))
407 new->egid = kegid;
408 else
409 goto error;
410 }
411
412 if (rgid != (gid_t) -1 ||
413 (egid != (gid_t) -1 && !gid_eq(kegid, old->gid)))
414 new->sgid = new->egid;
415 new->fsgid = new->egid;
416
417 retval = security_task_fix_setgid(new, old, LSM_SETID_RE);
418 if (retval < 0)
419 goto error;
420
421 return commit_creds(new);
422
423error:
424 abort_creds(new);
425 return retval;
426}
427
428SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid)
429{
430 return __sys_setregid(rgid, egid);
431}
432
433/*
434 * setgid() is implemented like SysV w/ SAVED_IDS
435 *
436 * SMP: Same implicit races as above.
437 */
438long __sys_setgid(gid_t gid)
439{
440 struct user_namespace *ns = current_user_ns();
441 const struct cred *old;
442 struct cred *new;
443 int retval;
444 kgid_t kgid;
445
446 kgid = make_kgid(ns, gid);
447 if (!gid_valid(kgid))
448 return -EINVAL;
449
450 new = prepare_creds();
451 if (!new)
452 return -ENOMEM;
453 old = current_cred();
454
455 retval = -EPERM;
456 if (ns_capable_setid(old->user_ns, CAP_SETGID))
457 new->gid = new->egid = new->sgid = new->fsgid = kgid;
458 else if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->sgid))
459 new->egid = new->fsgid = kgid;
460 else
461 goto error;
462
463 retval = security_task_fix_setgid(new, old, LSM_SETID_ID);
464 if (retval < 0)
465 goto error;
466
467 return commit_creds(new);
468
469error:
470 abort_creds(new);
471 return retval;
472}
473
474SYSCALL_DEFINE1(setgid, gid_t, gid)
475{
476 return __sys_setgid(gid);
477}
478
479/*
480 * change the user struct in a credentials set to match the new UID
481 */
482static int set_user(struct cred *new)
483{
484 struct user_struct *new_user;
485
486 new_user = alloc_uid(new->uid);
487 if (!new_user)
488 return -EAGAIN;
489
490 free_uid(new->user);
491 new->user = new_user;
492 return 0;
493}
494
495static void flag_nproc_exceeded(struct cred *new)
496{
497 if (new->ucounts == current_ucounts())
498 return;
499
500 /*
501 * We don't fail in case of NPROC limit excess here because too many
502 * poorly written programs don't check set*uid() return code, assuming
503 * it never fails if called by root. We may still enforce NPROC limit
504 * for programs doing set*uid()+execve() by harmlessly deferring the
505 * failure to the execve() stage.
506 */
507 if (is_rlimit_overlimit(new->ucounts, UCOUNT_RLIMIT_NPROC, rlimit(RLIMIT_NPROC)) &&
508 new->user != INIT_USER)
509 current->flags |= PF_NPROC_EXCEEDED;
510 else
511 current->flags &= ~PF_NPROC_EXCEEDED;
512}
513
514/*
515 * Unprivileged users may change the real uid to the effective uid
516 * or vice versa. (BSD-style)
517 *
518 * If you set the real uid at all, or set the effective uid to a value not
519 * equal to the real uid, then the saved uid is set to the new effective uid.
520 *
521 * This makes it possible for a setuid program to completely drop its
522 * privileges, which is often a useful assertion to make when you are doing
523 * a security audit over a program.
524 *
525 * The general idea is that a program which uses just setreuid() will be
526 * 100% compatible with BSD. A program which uses just setuid() will be
527 * 100% compatible with POSIX with saved IDs.
528 */
529long __sys_setreuid(uid_t ruid, uid_t euid)
530{
531 struct user_namespace *ns = current_user_ns();
532 const struct cred *old;
533 struct cred *new;
534 int retval;
535 kuid_t kruid, keuid;
536
537 kruid = make_kuid(ns, ruid);
538 keuid = make_kuid(ns, euid);
539
540 if ((ruid != (uid_t) -1) && !uid_valid(kruid))
541 return -EINVAL;
542 if ((euid != (uid_t) -1) && !uid_valid(keuid))
543 return -EINVAL;
544
545 new = prepare_creds();
546 if (!new)
547 return -ENOMEM;
548 old = current_cred();
549
550 retval = -EPERM;
551 if (ruid != (uid_t) -1) {
552 new->uid = kruid;
553 if (!uid_eq(old->uid, kruid) &&
554 !uid_eq(old->euid, kruid) &&
555 !ns_capable_setid(old->user_ns, CAP_SETUID))
556 goto error;
557 }
558
559 if (euid != (uid_t) -1) {
560 new->euid = keuid;
561 if (!uid_eq(old->uid, keuid) &&
562 !uid_eq(old->euid, keuid) &&
563 !uid_eq(old->suid, keuid) &&
564 !ns_capable_setid(old->user_ns, CAP_SETUID))
565 goto error;
566 }
567
568 if (!uid_eq(new->uid, old->uid)) {
569 retval = set_user(new);
570 if (retval < 0)
571 goto error;
572 }
573 if (ruid != (uid_t) -1 ||
574 (euid != (uid_t) -1 && !uid_eq(keuid, old->uid)))
575 new->suid = new->euid;
576 new->fsuid = new->euid;
577
578 retval = security_task_fix_setuid(new, old, LSM_SETID_RE);
579 if (retval < 0)
580 goto error;
581
582 retval = set_cred_ucounts(new);
583 if (retval < 0)
584 goto error;
585
586 flag_nproc_exceeded(new);
587 return commit_creds(new);
588
589error:
590 abort_creds(new);
591 return retval;
592}
593
594SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid)
595{
596 return __sys_setreuid(ruid, euid);
597}
598
599/*
600 * setuid() is implemented like SysV with SAVED_IDS
601 *
602 * Note that SAVED_ID's is deficient in that a setuid root program
603 * like sendmail, for example, cannot set its uid to be a normal
604 * user and then switch back, because if you're root, setuid() sets
605 * the saved uid too. If you don't like this, blame the bright people
606 * in the POSIX committee and/or USG. Note that the BSD-style setreuid()
607 * will allow a root program to temporarily drop privileges and be able to
608 * regain them by swapping the real and effective uid.
609 */
610long __sys_setuid(uid_t uid)
611{
612 struct user_namespace *ns = current_user_ns();
613 const struct cred *old;
614 struct cred *new;
615 int retval;
616 kuid_t kuid;
617
618 kuid = make_kuid(ns, uid);
619 if (!uid_valid(kuid))
620 return -EINVAL;
621
622 new = prepare_creds();
623 if (!new)
624 return -ENOMEM;
625 old = current_cred();
626
627 retval = -EPERM;
628 if (ns_capable_setid(old->user_ns, CAP_SETUID)) {
629 new->suid = new->uid = kuid;
630 if (!uid_eq(kuid, old->uid)) {
631 retval = set_user(new);
632 if (retval < 0)
633 goto error;
634 }
635 } else if (!uid_eq(kuid, old->uid) && !uid_eq(kuid, new->suid)) {
636 goto error;
637 }
638
639 new->fsuid = new->euid = kuid;
640
641 retval = security_task_fix_setuid(new, old, LSM_SETID_ID);
642 if (retval < 0)
643 goto error;
644
645 retval = set_cred_ucounts(new);
646 if (retval < 0)
647 goto error;
648
649 flag_nproc_exceeded(new);
650 return commit_creds(new);
651
652error:
653 abort_creds(new);
654 return retval;
655}
656
657SYSCALL_DEFINE1(setuid, uid_t, uid)
658{
659 return __sys_setuid(uid);
660}
661
662
663/*
664 * This function implements a generic ability to update ruid, euid,
665 * and suid. This allows you to implement the 4.4 compatible seteuid().
666 */
667long __sys_setresuid(uid_t ruid, uid_t euid, uid_t suid)
668{
669 struct user_namespace *ns = current_user_ns();
670 const struct cred *old;
671 struct cred *new;
672 int retval;
673 kuid_t kruid, keuid, ksuid;
674 bool ruid_new, euid_new, suid_new;
675
676 kruid = make_kuid(ns, ruid);
677 keuid = make_kuid(ns, euid);
678 ksuid = make_kuid(ns, suid);
679
680 if ((ruid != (uid_t) -1) && !uid_valid(kruid))
681 return -EINVAL;
682
683 if ((euid != (uid_t) -1) && !uid_valid(keuid))
684 return -EINVAL;
685
686 if ((suid != (uid_t) -1) && !uid_valid(ksuid))
687 return -EINVAL;
688
689 old = current_cred();
690
691 /* check for no-op */
692 if ((ruid == (uid_t) -1 || uid_eq(kruid, old->uid)) &&
693 (euid == (uid_t) -1 || (uid_eq(keuid, old->euid) &&
694 uid_eq(keuid, old->fsuid))) &&
695 (suid == (uid_t) -1 || uid_eq(ksuid, old->suid)))
696 return 0;
697
698 ruid_new = ruid != (uid_t) -1 && !uid_eq(kruid, old->uid) &&
699 !uid_eq(kruid, old->euid) && !uid_eq(kruid, old->suid);
700 euid_new = euid != (uid_t) -1 && !uid_eq(keuid, old->uid) &&
701 !uid_eq(keuid, old->euid) && !uid_eq(keuid, old->suid);
702 suid_new = suid != (uid_t) -1 && !uid_eq(ksuid, old->uid) &&
703 !uid_eq(ksuid, old->euid) && !uid_eq(ksuid, old->suid);
704 if ((ruid_new || euid_new || suid_new) &&
705 !ns_capable_setid(old->user_ns, CAP_SETUID))
706 return -EPERM;
707
708 new = prepare_creds();
709 if (!new)
710 return -ENOMEM;
711
712 if (ruid != (uid_t) -1) {
713 new->uid = kruid;
714 if (!uid_eq(kruid, old->uid)) {
715 retval = set_user(new);
716 if (retval < 0)
717 goto error;
718 }
719 }
720 if (euid != (uid_t) -1)
721 new->euid = keuid;
722 if (suid != (uid_t) -1)
723 new->suid = ksuid;
724 new->fsuid = new->euid;
725
726 retval = security_task_fix_setuid(new, old, LSM_SETID_RES);
727 if (retval < 0)
728 goto error;
729
730 retval = set_cred_ucounts(new);
731 if (retval < 0)
732 goto error;
733
734 flag_nproc_exceeded(new);
735 return commit_creds(new);
736
737error:
738 abort_creds(new);
739 return retval;
740}
741
742SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid)
743{
744 return __sys_setresuid(ruid, euid, suid);
745}
746
747SYSCALL_DEFINE3(getresuid, uid_t __user *, ruidp, uid_t __user *, euidp, uid_t __user *, suidp)
748{
749 const struct cred *cred = current_cred();
750 int retval;
751 uid_t ruid, euid, suid;
752
753 ruid = from_kuid_munged(cred->user_ns, cred->uid);
754 euid = from_kuid_munged(cred->user_ns, cred->euid);
755 suid = from_kuid_munged(cred->user_ns, cred->suid);
756
757 retval = put_user(ruid, ruidp);
758 if (!retval) {
759 retval = put_user(euid, euidp);
760 if (!retval)
761 return put_user(suid, suidp);
762 }
763 return retval;
764}
765
766/*
767 * Same as above, but for rgid, egid, sgid.
768 */
769long __sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid)
770{
771 struct user_namespace *ns = current_user_ns();
772 const struct cred *old;
773 struct cred *new;
774 int retval;
775 kgid_t krgid, kegid, ksgid;
776 bool rgid_new, egid_new, sgid_new;
777
778 krgid = make_kgid(ns, rgid);
779 kegid = make_kgid(ns, egid);
780 ksgid = make_kgid(ns, sgid);
781
782 if ((rgid != (gid_t) -1) && !gid_valid(krgid))
783 return -EINVAL;
784 if ((egid != (gid_t) -1) && !gid_valid(kegid))
785 return -EINVAL;
786 if ((sgid != (gid_t) -1) && !gid_valid(ksgid))
787 return -EINVAL;
788
789 old = current_cred();
790
791 /* check for no-op */
792 if ((rgid == (gid_t) -1 || gid_eq(krgid, old->gid)) &&
793 (egid == (gid_t) -1 || (gid_eq(kegid, old->egid) &&
794 gid_eq(kegid, old->fsgid))) &&
795 (sgid == (gid_t) -1 || gid_eq(ksgid, old->sgid)))
796 return 0;
797
798 rgid_new = rgid != (gid_t) -1 && !gid_eq(krgid, old->gid) &&
799 !gid_eq(krgid, old->egid) && !gid_eq(krgid, old->sgid);
800 egid_new = egid != (gid_t) -1 && !gid_eq(kegid, old->gid) &&
801 !gid_eq(kegid, old->egid) && !gid_eq(kegid, old->sgid);
802 sgid_new = sgid != (gid_t) -1 && !gid_eq(ksgid, old->gid) &&
803 !gid_eq(ksgid, old->egid) && !gid_eq(ksgid, old->sgid);
804 if ((rgid_new || egid_new || sgid_new) &&
805 !ns_capable_setid(old->user_ns, CAP_SETGID))
806 return -EPERM;
807
808 new = prepare_creds();
809 if (!new)
810 return -ENOMEM;
811
812 if (rgid != (gid_t) -1)
813 new->gid = krgid;
814 if (egid != (gid_t) -1)
815 new->egid = kegid;
816 if (sgid != (gid_t) -1)
817 new->sgid = ksgid;
818 new->fsgid = new->egid;
819
820 retval = security_task_fix_setgid(new, old, LSM_SETID_RES);
821 if (retval < 0)
822 goto error;
823
824 return commit_creds(new);
825
826error:
827 abort_creds(new);
828 return retval;
829}
830
831SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid)
832{
833 return __sys_setresgid(rgid, egid, sgid);
834}
835
836SYSCALL_DEFINE3(getresgid, gid_t __user *, rgidp, gid_t __user *, egidp, gid_t __user *, sgidp)
837{
838 const struct cred *cred = current_cred();
839 int retval;
840 gid_t rgid, egid, sgid;
841
842 rgid = from_kgid_munged(cred->user_ns, cred->gid);
843 egid = from_kgid_munged(cred->user_ns, cred->egid);
844 sgid = from_kgid_munged(cred->user_ns, cred->sgid);
845
846 retval = put_user(rgid, rgidp);
847 if (!retval) {
848 retval = put_user(egid, egidp);
849 if (!retval)
850 retval = put_user(sgid, sgidp);
851 }
852
853 return retval;
854}
855
856
857/*
858 * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This
859 * is used for "access()" and for the NFS daemon (letting nfsd stay at
860 * whatever uid it wants to). It normally shadows "euid", except when
861 * explicitly set by setfsuid() or for access..
862 */
863long __sys_setfsuid(uid_t uid)
864{
865 const struct cred *old;
866 struct cred *new;
867 uid_t old_fsuid;
868 kuid_t kuid;
869
870 old = current_cred();
871 old_fsuid = from_kuid_munged(old->user_ns, old->fsuid);
872
873 kuid = make_kuid(old->user_ns, uid);
874 if (!uid_valid(kuid))
875 return old_fsuid;
876
877 new = prepare_creds();
878 if (!new)
879 return old_fsuid;
880
881 if (uid_eq(kuid, old->uid) || uid_eq(kuid, old->euid) ||
882 uid_eq(kuid, old->suid) || uid_eq(kuid, old->fsuid) ||
883 ns_capable_setid(old->user_ns, CAP_SETUID)) {
884 if (!uid_eq(kuid, old->fsuid)) {
885 new->fsuid = kuid;
886 if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0)
887 goto change_okay;
888 }
889 }
890
891 abort_creds(new);
892 return old_fsuid;
893
894change_okay:
895 commit_creds(new);
896 return old_fsuid;
897}
898
899SYSCALL_DEFINE1(setfsuid, uid_t, uid)
900{
901 return __sys_setfsuid(uid);
902}
903
904/*
905 * Samma på svenska..
906 */
907long __sys_setfsgid(gid_t gid)
908{
909 const struct cred *old;
910 struct cred *new;
911 gid_t old_fsgid;
912 kgid_t kgid;
913
914 old = current_cred();
915 old_fsgid = from_kgid_munged(old->user_ns, old->fsgid);
916
917 kgid = make_kgid(old->user_ns, gid);
918 if (!gid_valid(kgid))
919 return old_fsgid;
920
921 new = prepare_creds();
922 if (!new)
923 return old_fsgid;
924
925 if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->egid) ||
926 gid_eq(kgid, old->sgid) || gid_eq(kgid, old->fsgid) ||
927 ns_capable_setid(old->user_ns, CAP_SETGID)) {
928 if (!gid_eq(kgid, old->fsgid)) {
929 new->fsgid = kgid;
930 if (security_task_fix_setgid(new,old,LSM_SETID_FS) == 0)
931 goto change_okay;
932 }
933 }
934
935 abort_creds(new);
936 return old_fsgid;
937
938change_okay:
939 commit_creds(new);
940 return old_fsgid;
941}
942
943SYSCALL_DEFINE1(setfsgid, gid_t, gid)
944{
945 return __sys_setfsgid(gid);
946}
947#endif /* CONFIG_MULTIUSER */
948
949/**
950 * sys_getpid - return the thread group id of the current process
951 *
952 * Note, despite the name, this returns the tgid not the pid. The tgid and
953 * the pid are identical unless CLONE_THREAD was specified on clone() in
954 * which case the tgid is the same in all threads of the same group.
955 *
956 * This is SMP safe as current->tgid does not change.
957 */
958SYSCALL_DEFINE0(getpid)
959{
960 return task_tgid_vnr(current);
961}
962
963/* Thread ID - the internal kernel "pid" */
964SYSCALL_DEFINE0(gettid)
965{
966 return task_pid_vnr(current);
967}
968
969/*
970 * Accessing ->real_parent is not SMP-safe, it could
971 * change from under us. However, we can use a stale
972 * value of ->real_parent under rcu_read_lock(), see
973 * release_task()->call_rcu(delayed_put_task_struct).
974 */
975SYSCALL_DEFINE0(getppid)
976{
977 int pid;
978
979 rcu_read_lock();
980 pid = task_tgid_vnr(rcu_dereference(current->real_parent));
981 rcu_read_unlock();
982
983 return pid;
984}
985
986SYSCALL_DEFINE0(getuid)
987{
988 /* Only we change this so SMP safe */
989 return from_kuid_munged(current_user_ns(), current_uid());
990}
991
992SYSCALL_DEFINE0(geteuid)
993{
994 /* Only we change this so SMP safe */
995 return from_kuid_munged(current_user_ns(), current_euid());
996}
997
998SYSCALL_DEFINE0(getgid)
999{
1000 /* Only we change this so SMP safe */
1001 return from_kgid_munged(current_user_ns(), current_gid());
1002}
1003
1004SYSCALL_DEFINE0(getegid)
1005{
1006 /* Only we change this so SMP safe */
1007 return from_kgid_munged(current_user_ns(), current_egid());
1008}
1009
1010static void do_sys_times(struct tms *tms)
1011{
1012 u64 tgutime, tgstime, cutime, cstime;
1013
1014 thread_group_cputime_adjusted(current, &tgutime, &tgstime);
1015 cutime = current->signal->cutime;
1016 cstime = current->signal->cstime;
1017 tms->tms_utime = nsec_to_clock_t(tgutime);
1018 tms->tms_stime = nsec_to_clock_t(tgstime);
1019 tms->tms_cutime = nsec_to_clock_t(cutime);
1020 tms->tms_cstime = nsec_to_clock_t(cstime);
1021}
1022
1023SYSCALL_DEFINE1(times, struct tms __user *, tbuf)
1024{
1025 if (tbuf) {
1026 struct tms tmp;
1027
1028 do_sys_times(&tmp);
1029 if (copy_to_user(tbuf, &tmp, sizeof(struct tms)))
1030 return -EFAULT;
1031 }
1032 force_successful_syscall_return();
1033 return (long) jiffies_64_to_clock_t(get_jiffies_64());
1034}
1035
1036#ifdef CONFIG_COMPAT
1037static compat_clock_t clock_t_to_compat_clock_t(clock_t x)
1038{
1039 return compat_jiffies_to_clock_t(clock_t_to_jiffies(x));
1040}
1041
1042COMPAT_SYSCALL_DEFINE1(times, struct compat_tms __user *, tbuf)
1043{
1044 if (tbuf) {
1045 struct tms tms;
1046 struct compat_tms tmp;
1047
1048 do_sys_times(&tms);
1049 /* Convert our struct tms to the compat version. */
1050 tmp.tms_utime = clock_t_to_compat_clock_t(tms.tms_utime);
1051 tmp.tms_stime = clock_t_to_compat_clock_t(tms.tms_stime);
1052 tmp.tms_cutime = clock_t_to_compat_clock_t(tms.tms_cutime);
1053 tmp.tms_cstime = clock_t_to_compat_clock_t(tms.tms_cstime);
1054 if (copy_to_user(tbuf, &tmp, sizeof(tmp)))
1055 return -EFAULT;
1056 }
1057 force_successful_syscall_return();
1058 return compat_jiffies_to_clock_t(jiffies);
1059}
1060#endif
1061
1062/*
1063 * This needs some heavy checking ...
1064 * I just haven't the stomach for it. I also don't fully
1065 * understand sessions/pgrp etc. Let somebody who does explain it.
1066 *
1067 * OK, I think I have the protection semantics right.... this is really
1068 * only important on a multi-user system anyway, to make sure one user
1069 * can't send a signal to a process owned by another. -TYT, 12/12/91
1070 *
1071 * !PF_FORKNOEXEC check to conform completely to POSIX.
1072 */
1073SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid)
1074{
1075 struct task_struct *p;
1076 struct task_struct *group_leader = current->group_leader;
1077 struct pid *pgrp;
1078 int err;
1079
1080 if (!pid)
1081 pid = task_pid_vnr(group_leader);
1082 if (!pgid)
1083 pgid = pid;
1084 if (pgid < 0)
1085 return -EINVAL;
1086 rcu_read_lock();
1087
1088 /* From this point forward we keep holding onto the tasklist lock
1089 * so that our parent does not change from under us. -DaveM
1090 */
1091 write_lock_irq(&tasklist_lock);
1092
1093 err = -ESRCH;
1094 p = find_task_by_vpid(pid);
1095 if (!p)
1096 goto out;
1097
1098 err = -EINVAL;
1099 if (!thread_group_leader(p))
1100 goto out;
1101
1102 if (same_thread_group(p->real_parent, group_leader)) {
1103 err = -EPERM;
1104 if (task_session(p) != task_session(group_leader))
1105 goto out;
1106 err = -EACCES;
1107 if (!(p->flags & PF_FORKNOEXEC))
1108 goto out;
1109 } else {
1110 err = -ESRCH;
1111 if (p != group_leader)
1112 goto out;
1113 }
1114
1115 err = -EPERM;
1116 if (p->signal->leader)
1117 goto out;
1118
1119 pgrp = task_pid(p);
1120 if (pgid != pid) {
1121 struct task_struct *g;
1122
1123 pgrp = find_vpid(pgid);
1124 g = pid_task(pgrp, PIDTYPE_PGID);
1125 if (!g || task_session(g) != task_session(group_leader))
1126 goto out;
1127 }
1128
1129 err = security_task_setpgid(p, pgid);
1130 if (err)
1131 goto out;
1132
1133 if (task_pgrp(p) != pgrp)
1134 change_pid(p, PIDTYPE_PGID, pgrp);
1135
1136 err = 0;
1137out:
1138 /* All paths lead to here, thus we are safe. -DaveM */
1139 write_unlock_irq(&tasklist_lock);
1140 rcu_read_unlock();
1141 return err;
1142}
1143
1144static int do_getpgid(pid_t pid)
1145{
1146 struct task_struct *p;
1147 struct pid *grp;
1148 int retval;
1149
1150 rcu_read_lock();
1151 if (!pid)
1152 grp = task_pgrp(current);
1153 else {
1154 retval = -ESRCH;
1155 p = find_task_by_vpid(pid);
1156 if (!p)
1157 goto out;
1158 grp = task_pgrp(p);
1159 if (!grp)
1160 goto out;
1161
1162 retval = security_task_getpgid(p);
1163 if (retval)
1164 goto out;
1165 }
1166 retval = pid_vnr(grp);
1167out:
1168 rcu_read_unlock();
1169 return retval;
1170}
1171
1172SYSCALL_DEFINE1(getpgid, pid_t, pid)
1173{
1174 return do_getpgid(pid);
1175}
1176
1177#ifdef __ARCH_WANT_SYS_GETPGRP
1178
1179SYSCALL_DEFINE0(getpgrp)
1180{
1181 return do_getpgid(0);
1182}
1183
1184#endif
1185
1186SYSCALL_DEFINE1(getsid, pid_t, pid)
1187{
1188 struct task_struct *p;
1189 struct pid *sid;
1190 int retval;
1191
1192 rcu_read_lock();
1193 if (!pid)
1194 sid = task_session(current);
1195 else {
1196 retval = -ESRCH;
1197 p = find_task_by_vpid(pid);
1198 if (!p)
1199 goto out;
1200 sid = task_session(p);
1201 if (!sid)
1202 goto out;
1203
1204 retval = security_task_getsid(p);
1205 if (retval)
1206 goto out;
1207 }
1208 retval = pid_vnr(sid);
1209out:
1210 rcu_read_unlock();
1211 return retval;
1212}
1213
1214static void set_special_pids(struct pid *pid)
1215{
1216 struct task_struct *curr = current->group_leader;
1217
1218 if (task_session(curr) != pid)
1219 change_pid(curr, PIDTYPE_SID, pid);
1220
1221 if (task_pgrp(curr) != pid)
1222 change_pid(curr, PIDTYPE_PGID, pid);
1223}
1224
1225int ksys_setsid(void)
1226{
1227 struct task_struct *group_leader = current->group_leader;
1228 struct pid *sid = task_pid(group_leader);
1229 pid_t session = pid_vnr(sid);
1230 int err = -EPERM;
1231
1232 write_lock_irq(&tasklist_lock);
1233 /* Fail if I am already a session leader */
1234 if (group_leader->signal->leader)
1235 goto out;
1236
1237 /* Fail if a process group id already exists that equals the
1238 * proposed session id.
1239 */
1240 if (pid_task(sid, PIDTYPE_PGID))
1241 goto out;
1242
1243 group_leader->signal->leader = 1;
1244 set_special_pids(sid);
1245
1246 proc_clear_tty(group_leader);
1247
1248 err = session;
1249out:
1250 write_unlock_irq(&tasklist_lock);
1251 if (err > 0) {
1252 proc_sid_connector(group_leader);
1253 sched_autogroup_create_attach(group_leader);
1254 }
1255 return err;
1256}
1257
1258SYSCALL_DEFINE0(setsid)
1259{
1260 return ksys_setsid();
1261}
1262
1263DECLARE_RWSEM(uts_sem);
1264
1265#ifdef COMPAT_UTS_MACHINE
1266#define override_architecture(name) \
1267 (personality(current->personality) == PER_LINUX32 && \
1268 copy_to_user(name->machine, COMPAT_UTS_MACHINE, \
1269 sizeof(COMPAT_UTS_MACHINE)))
1270#else
1271#define override_architecture(name) 0
1272#endif
1273
1274/*
1275 * Work around broken programs that cannot handle "Linux 3.0".
1276 * Instead we map 3.x to 2.6.40+x, so e.g. 3.0 would be 2.6.40
1277 * And we map 4.x and later versions to 2.6.60+x, so 4.0/5.0/6.0/... would be
1278 * 2.6.60.
1279 */
1280static int override_release(char __user *release, size_t len)
1281{
1282 int ret = 0;
1283
1284 if (current->personality & UNAME26) {
1285 const char *rest = UTS_RELEASE;
1286 char buf[65] = { 0 };
1287 int ndots = 0;
1288 unsigned v;
1289 size_t copy;
1290
1291 while (*rest) {
1292 if (*rest == '.' && ++ndots >= 3)
1293 break;
1294 if (!isdigit(*rest) && *rest != '.')
1295 break;
1296 rest++;
1297 }
1298 v = LINUX_VERSION_PATCHLEVEL + 60;
1299 copy = clamp_t(size_t, len, 1, sizeof(buf));
1300 copy = scnprintf(buf, copy, "2.6.%u%s", v, rest);
1301 ret = copy_to_user(release, buf, copy + 1);
1302 }
1303 return ret;
1304}
1305
1306SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name)
1307{
1308 struct new_utsname tmp;
1309
1310 down_read(&uts_sem);
1311 memcpy(&tmp, utsname(), sizeof(tmp));
1312 up_read(&uts_sem);
1313 if (copy_to_user(name, &tmp, sizeof(tmp)))
1314 return -EFAULT;
1315
1316 if (override_release(name->release, sizeof(name->release)))
1317 return -EFAULT;
1318 if (override_architecture(name))
1319 return -EFAULT;
1320 return 0;
1321}
1322
1323#ifdef __ARCH_WANT_SYS_OLD_UNAME
1324/*
1325 * Old cruft
1326 */
1327SYSCALL_DEFINE1(uname, struct old_utsname __user *, name)
1328{
1329 struct old_utsname tmp;
1330
1331 if (!name)
1332 return -EFAULT;
1333
1334 down_read(&uts_sem);
1335 memcpy(&tmp, utsname(), sizeof(tmp));
1336 up_read(&uts_sem);
1337 if (copy_to_user(name, &tmp, sizeof(tmp)))
1338 return -EFAULT;
1339
1340 if (override_release(name->release, sizeof(name->release)))
1341 return -EFAULT;
1342 if (override_architecture(name))
1343 return -EFAULT;
1344 return 0;
1345}
1346
1347SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name)
1348{
1349 struct oldold_utsname tmp;
1350
1351 if (!name)
1352 return -EFAULT;
1353
1354 memset(&tmp, 0, sizeof(tmp));
1355
1356 down_read(&uts_sem);
1357 memcpy(&tmp.sysname, &utsname()->sysname, __OLD_UTS_LEN);
1358 memcpy(&tmp.nodename, &utsname()->nodename, __OLD_UTS_LEN);
1359 memcpy(&tmp.release, &utsname()->release, __OLD_UTS_LEN);
1360 memcpy(&tmp.version, &utsname()->version, __OLD_UTS_LEN);
1361 memcpy(&tmp.machine, &utsname()->machine, __OLD_UTS_LEN);
1362 up_read(&uts_sem);
1363 if (copy_to_user(name, &tmp, sizeof(tmp)))
1364 return -EFAULT;
1365
1366 if (override_architecture(name))
1367 return -EFAULT;
1368 if (override_release(name->release, sizeof(name->release)))
1369 return -EFAULT;
1370 return 0;
1371}
1372#endif
1373
1374SYSCALL_DEFINE2(sethostname, char __user *, name, int, len)
1375{
1376 int errno;
1377 char tmp[__NEW_UTS_LEN];
1378
1379 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN))
1380 return -EPERM;
1381
1382 if (len < 0 || len > __NEW_UTS_LEN)
1383 return -EINVAL;
1384 errno = -EFAULT;
1385 if (!copy_from_user(tmp, name, len)) {
1386 struct new_utsname *u;
1387
1388 add_device_randomness(tmp, len);
1389 down_write(&uts_sem);
1390 u = utsname();
1391 memcpy(u->nodename, tmp, len);
1392 memset(u->nodename + len, 0, sizeof(u->nodename) - len);
1393 errno = 0;
1394 uts_proc_notify(UTS_PROC_HOSTNAME);
1395 up_write(&uts_sem);
1396 }
1397 return errno;
1398}
1399
1400#ifdef __ARCH_WANT_SYS_GETHOSTNAME
1401
1402SYSCALL_DEFINE2(gethostname, char __user *, name, int, len)
1403{
1404 int i;
1405 struct new_utsname *u;
1406 char tmp[__NEW_UTS_LEN + 1];
1407
1408 if (len < 0)
1409 return -EINVAL;
1410 down_read(&uts_sem);
1411 u = utsname();
1412 i = 1 + strlen(u->nodename);
1413 if (i > len)
1414 i = len;
1415 memcpy(tmp, u->nodename, i);
1416 up_read(&uts_sem);
1417 if (copy_to_user(name, tmp, i))
1418 return -EFAULT;
1419 return 0;
1420}
1421
1422#endif
1423
1424/*
1425 * Only setdomainname; getdomainname can be implemented by calling
1426 * uname()
1427 */
1428SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len)
1429{
1430 int errno;
1431 char tmp[__NEW_UTS_LEN];
1432
1433 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN))
1434 return -EPERM;
1435 if (len < 0 || len > __NEW_UTS_LEN)
1436 return -EINVAL;
1437
1438 errno = -EFAULT;
1439 if (!copy_from_user(tmp, name, len)) {
1440 struct new_utsname *u;
1441
1442 add_device_randomness(tmp, len);
1443 down_write(&uts_sem);
1444 u = utsname();
1445 memcpy(u->domainname, tmp, len);
1446 memset(u->domainname + len, 0, sizeof(u->domainname) - len);
1447 errno = 0;
1448 uts_proc_notify(UTS_PROC_DOMAINNAME);
1449 up_write(&uts_sem);
1450 }
1451 return errno;
1452}
1453
1454/* make sure you are allowed to change @tsk limits before calling this */
1455static int do_prlimit(struct task_struct *tsk, unsigned int resource,
1456 struct rlimit *new_rlim, struct rlimit *old_rlim)
1457{
1458 struct rlimit *rlim;
1459 int retval = 0;
1460
1461 if (resource >= RLIM_NLIMITS)
1462 return -EINVAL;
1463 resource = array_index_nospec(resource, RLIM_NLIMITS);
1464
1465 if (new_rlim) {
1466 if (new_rlim->rlim_cur > new_rlim->rlim_max)
1467 return -EINVAL;
1468 if (resource == RLIMIT_NOFILE &&
1469 new_rlim->rlim_max > sysctl_nr_open)
1470 return -EPERM;
1471 }
1472
1473 /* Holding a refcount on tsk protects tsk->signal from disappearing. */
1474 rlim = tsk->signal->rlim + resource;
1475 task_lock(tsk->group_leader);
1476 if (new_rlim) {
1477 /*
1478 * Keep the capable check against init_user_ns until cgroups can
1479 * contain all limits.
1480 */
1481 if (new_rlim->rlim_max > rlim->rlim_max &&
1482 !capable(CAP_SYS_RESOURCE))
1483 retval = -EPERM;
1484 if (!retval)
1485 retval = security_task_setrlimit(tsk, resource, new_rlim);
1486 }
1487 if (!retval) {
1488 if (old_rlim)
1489 *old_rlim = *rlim;
1490 if (new_rlim)
1491 *rlim = *new_rlim;
1492 }
1493 task_unlock(tsk->group_leader);
1494
1495 /*
1496 * RLIMIT_CPU handling. Arm the posix CPU timer if the limit is not
1497 * infinite. In case of RLIM_INFINITY the posix CPU timer code
1498 * ignores the rlimit.
1499 */
1500 if (!retval && new_rlim && resource == RLIMIT_CPU &&
1501 new_rlim->rlim_cur != RLIM_INFINITY &&
1502 IS_ENABLED(CONFIG_POSIX_TIMERS)) {
1503 /*
1504 * update_rlimit_cpu can fail if the task is exiting, but there
1505 * may be other tasks in the thread group that are not exiting,
1506 * and they need their cpu timers adjusted.
1507 *
1508 * The group_leader is the last task to be released, so if we
1509 * cannot update_rlimit_cpu on it, then the entire process is
1510 * exiting and we do not need to update at all.
1511 */
1512 update_rlimit_cpu(tsk->group_leader, new_rlim->rlim_cur);
1513 }
1514
1515 return retval;
1516}
1517
1518SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim)
1519{
1520 struct rlimit value;
1521 int ret;
1522
1523 ret = do_prlimit(current, resource, NULL, &value);
1524 if (!ret)
1525 ret = copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0;
1526
1527 return ret;
1528}
1529
1530#ifdef CONFIG_COMPAT
1531
1532COMPAT_SYSCALL_DEFINE2(setrlimit, unsigned int, resource,
1533 struct compat_rlimit __user *, rlim)
1534{
1535 struct rlimit r;
1536 struct compat_rlimit r32;
1537
1538 if (copy_from_user(&r32, rlim, sizeof(struct compat_rlimit)))
1539 return -EFAULT;
1540
1541 if (r32.rlim_cur == COMPAT_RLIM_INFINITY)
1542 r.rlim_cur = RLIM_INFINITY;
1543 else
1544 r.rlim_cur = r32.rlim_cur;
1545 if (r32.rlim_max == COMPAT_RLIM_INFINITY)
1546 r.rlim_max = RLIM_INFINITY;
1547 else
1548 r.rlim_max = r32.rlim_max;
1549 return do_prlimit(current, resource, &r, NULL);
1550}
1551
1552COMPAT_SYSCALL_DEFINE2(getrlimit, unsigned int, resource,
1553 struct compat_rlimit __user *, rlim)
1554{
1555 struct rlimit r;
1556 int ret;
1557
1558 ret = do_prlimit(current, resource, NULL, &r);
1559 if (!ret) {
1560 struct compat_rlimit r32;
1561 if (r.rlim_cur > COMPAT_RLIM_INFINITY)
1562 r32.rlim_cur = COMPAT_RLIM_INFINITY;
1563 else
1564 r32.rlim_cur = r.rlim_cur;
1565 if (r.rlim_max > COMPAT_RLIM_INFINITY)
1566 r32.rlim_max = COMPAT_RLIM_INFINITY;
1567 else
1568 r32.rlim_max = r.rlim_max;
1569
1570 if (copy_to_user(rlim, &r32, sizeof(struct compat_rlimit)))
1571 return -EFAULT;
1572 }
1573 return ret;
1574}
1575
1576#endif
1577
1578#ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT
1579
1580/*
1581 * Back compatibility for getrlimit. Needed for some apps.
1582 */
1583SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
1584 struct rlimit __user *, rlim)
1585{
1586 struct rlimit x;
1587 if (resource >= RLIM_NLIMITS)
1588 return -EINVAL;
1589
1590 resource = array_index_nospec(resource, RLIM_NLIMITS);
1591 task_lock(current->group_leader);
1592 x = current->signal->rlim[resource];
1593 task_unlock(current->group_leader);
1594 if (x.rlim_cur > 0x7FFFFFFF)
1595 x.rlim_cur = 0x7FFFFFFF;
1596 if (x.rlim_max > 0x7FFFFFFF)
1597 x.rlim_max = 0x7FFFFFFF;
1598 return copy_to_user(rlim, &x, sizeof(x)) ? -EFAULT : 0;
1599}
1600
1601#ifdef CONFIG_COMPAT
1602COMPAT_SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
1603 struct compat_rlimit __user *, rlim)
1604{
1605 struct rlimit r;
1606
1607 if (resource >= RLIM_NLIMITS)
1608 return -EINVAL;
1609
1610 resource = array_index_nospec(resource, RLIM_NLIMITS);
1611 task_lock(current->group_leader);
1612 r = current->signal->rlim[resource];
1613 task_unlock(current->group_leader);
1614 if (r.rlim_cur > 0x7FFFFFFF)
1615 r.rlim_cur = 0x7FFFFFFF;
1616 if (r.rlim_max > 0x7FFFFFFF)
1617 r.rlim_max = 0x7FFFFFFF;
1618
1619 if (put_user(r.rlim_cur, &rlim->rlim_cur) ||
1620 put_user(r.rlim_max, &rlim->rlim_max))
1621 return -EFAULT;
1622 return 0;
1623}
1624#endif
1625
1626#endif
1627
1628static inline bool rlim64_is_infinity(__u64 rlim64)
1629{
1630#if BITS_PER_LONG < 64
1631 return rlim64 >= ULONG_MAX;
1632#else
1633 return rlim64 == RLIM64_INFINITY;
1634#endif
1635}
1636
1637static void rlim_to_rlim64(const struct rlimit *rlim, struct rlimit64 *rlim64)
1638{
1639 if (rlim->rlim_cur == RLIM_INFINITY)
1640 rlim64->rlim_cur = RLIM64_INFINITY;
1641 else
1642 rlim64->rlim_cur = rlim->rlim_cur;
1643 if (rlim->rlim_max == RLIM_INFINITY)
1644 rlim64->rlim_max = RLIM64_INFINITY;
1645 else
1646 rlim64->rlim_max = rlim->rlim_max;
1647}
1648
1649static void rlim64_to_rlim(const struct rlimit64 *rlim64, struct rlimit *rlim)
1650{
1651 if (rlim64_is_infinity(rlim64->rlim_cur))
1652 rlim->rlim_cur = RLIM_INFINITY;
1653 else
1654 rlim->rlim_cur = (unsigned long)rlim64->rlim_cur;
1655 if (rlim64_is_infinity(rlim64->rlim_max))
1656 rlim->rlim_max = RLIM_INFINITY;
1657 else
1658 rlim->rlim_max = (unsigned long)rlim64->rlim_max;
1659}
1660
1661/* rcu lock must be held */
1662static int check_prlimit_permission(struct task_struct *task,
1663 unsigned int flags)
1664{
1665 const struct cred *cred = current_cred(), *tcred;
1666 bool id_match;
1667
1668 if (current == task)
1669 return 0;
1670
1671 tcred = __task_cred(task);
1672 id_match = (uid_eq(cred->uid, tcred->euid) &&
1673 uid_eq(cred->uid, tcred->suid) &&
1674 uid_eq(cred->uid, tcred->uid) &&
1675 gid_eq(cred->gid, tcred->egid) &&
1676 gid_eq(cred->gid, tcred->sgid) &&
1677 gid_eq(cred->gid, tcred->gid));
1678 if (!id_match && !ns_capable(tcred->user_ns, CAP_SYS_RESOURCE))
1679 return -EPERM;
1680
1681 return security_task_prlimit(cred, tcred, flags);
1682}
1683
1684SYSCALL_DEFINE4(prlimit64, pid_t, pid, unsigned int, resource,
1685 const struct rlimit64 __user *, new_rlim,
1686 struct rlimit64 __user *, old_rlim)
1687{
1688 struct rlimit64 old64, new64;
1689 struct rlimit old, new;
1690 struct task_struct *tsk;
1691 unsigned int checkflags = 0;
1692 int ret;
1693
1694 if (old_rlim)
1695 checkflags |= LSM_PRLIMIT_READ;
1696
1697 if (new_rlim) {
1698 if (copy_from_user(&new64, new_rlim, sizeof(new64)))
1699 return -EFAULT;
1700 rlim64_to_rlim(&new64, &new);
1701 checkflags |= LSM_PRLIMIT_WRITE;
1702 }
1703
1704 rcu_read_lock();
1705 tsk = pid ? find_task_by_vpid(pid) : current;
1706 if (!tsk) {
1707 rcu_read_unlock();
1708 return -ESRCH;
1709 }
1710 ret = check_prlimit_permission(tsk, checkflags);
1711 if (ret) {
1712 rcu_read_unlock();
1713 return ret;
1714 }
1715 get_task_struct(tsk);
1716 rcu_read_unlock();
1717
1718 ret = do_prlimit(tsk, resource, new_rlim ? &new : NULL,
1719 old_rlim ? &old : NULL);
1720
1721 if (!ret && old_rlim) {
1722 rlim_to_rlim64(&old, &old64);
1723 if (copy_to_user(old_rlim, &old64, sizeof(old64)))
1724 ret = -EFAULT;
1725 }
1726
1727 put_task_struct(tsk);
1728 return ret;
1729}
1730
1731SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim)
1732{
1733 struct rlimit new_rlim;
1734
1735 if (copy_from_user(&new_rlim, rlim, sizeof(*rlim)))
1736 return -EFAULT;
1737 return do_prlimit(current, resource, &new_rlim, NULL);
1738}
1739
1740/*
1741 * It would make sense to put struct rusage in the task_struct,
1742 * except that would make the task_struct be *really big*. After
1743 * task_struct gets moved into malloc'ed memory, it would
1744 * make sense to do this. It will make moving the rest of the information
1745 * a lot simpler! (Which we're not doing right now because we're not
1746 * measuring them yet).
1747 *
1748 * When sampling multiple threads for RUSAGE_SELF, under SMP we might have
1749 * races with threads incrementing their own counters. But since word
1750 * reads are atomic, we either get new values or old values and we don't
1751 * care which for the sums. We always take the siglock to protect reading
1752 * the c* fields from p->signal from races with exit.c updating those
1753 * fields when reaping, so a sample either gets all the additions of a
1754 * given child after it's reaped, or none so this sample is before reaping.
1755 *
1756 * Locking:
1757 * We need to take the siglock for CHILDEREN, SELF and BOTH
1758 * for the cases current multithreaded, non-current single threaded
1759 * non-current multithreaded. Thread traversal is now safe with
1760 * the siglock held.
1761 * Strictly speaking, we donot need to take the siglock if we are current and
1762 * single threaded, as no one else can take our signal_struct away, no one
1763 * else can reap the children to update signal->c* counters, and no one else
1764 * can race with the signal-> fields. If we do not take any lock, the
1765 * signal-> fields could be read out of order while another thread was just
1766 * exiting. So we should place a read memory barrier when we avoid the lock.
1767 * On the writer side, write memory barrier is implied in __exit_signal
1768 * as __exit_signal releases the siglock spinlock after updating the signal->
1769 * fields. But we don't do this yet to keep things simple.
1770 *
1771 */
1772
1773static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r)
1774{
1775 r->ru_nvcsw += t->nvcsw;
1776 r->ru_nivcsw += t->nivcsw;
1777 r->ru_minflt += t->min_flt;
1778 r->ru_majflt += t->maj_flt;
1779 r->ru_inblock += task_io_get_inblock(t);
1780 r->ru_oublock += task_io_get_oublock(t);
1781}
1782
1783void getrusage(struct task_struct *p, int who, struct rusage *r)
1784{
1785 struct task_struct *t;
1786 unsigned long flags;
1787 u64 tgutime, tgstime, utime, stime;
1788 unsigned long maxrss = 0;
1789 struct signal_struct *sig = p->signal;
1790
1791 memset((char *)r, 0, sizeof (*r));
1792 utime = stime = 0;
1793
1794 if (who == RUSAGE_THREAD) {
1795 task_cputime_adjusted(current, &utime, &stime);
1796 accumulate_thread_rusage(p, r);
1797 maxrss = sig->maxrss;
1798 goto out;
1799 }
1800
1801 if (!lock_task_sighand(p, &flags))
1802 return;
1803
1804 switch (who) {
1805 case RUSAGE_BOTH:
1806 case RUSAGE_CHILDREN:
1807 utime = sig->cutime;
1808 stime = sig->cstime;
1809 r->ru_nvcsw = sig->cnvcsw;
1810 r->ru_nivcsw = sig->cnivcsw;
1811 r->ru_minflt = sig->cmin_flt;
1812 r->ru_majflt = sig->cmaj_flt;
1813 r->ru_inblock = sig->cinblock;
1814 r->ru_oublock = sig->coublock;
1815 maxrss = sig->cmaxrss;
1816
1817 if (who == RUSAGE_CHILDREN)
1818 break;
1819 fallthrough;
1820
1821 case RUSAGE_SELF:
1822 thread_group_cputime_adjusted(p, &tgutime, &tgstime);
1823 utime += tgutime;
1824 stime += tgstime;
1825 r->ru_nvcsw += sig->nvcsw;
1826 r->ru_nivcsw += sig->nivcsw;
1827 r->ru_minflt += sig->min_flt;
1828 r->ru_majflt += sig->maj_flt;
1829 r->ru_inblock += sig->inblock;
1830 r->ru_oublock += sig->oublock;
1831 if (maxrss < sig->maxrss)
1832 maxrss = sig->maxrss;
1833 __for_each_thread(sig, t)
1834 accumulate_thread_rusage(t, r);
1835 break;
1836
1837 default:
1838 BUG();
1839 }
1840 unlock_task_sighand(p, &flags);
1841
1842out:
1843 r->ru_utime = ns_to_kernel_old_timeval(utime);
1844 r->ru_stime = ns_to_kernel_old_timeval(stime);
1845
1846 if (who != RUSAGE_CHILDREN) {
1847 struct mm_struct *mm = get_task_mm(p);
1848
1849 if (mm) {
1850 setmax_mm_hiwater_rss(&maxrss, mm);
1851 mmput(mm);
1852 }
1853 }
1854 r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */
1855}
1856
1857SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru)
1858{
1859 struct rusage r;
1860
1861 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
1862 who != RUSAGE_THREAD)
1863 return -EINVAL;
1864
1865 getrusage(current, who, &r);
1866 return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0;
1867}
1868
1869#ifdef CONFIG_COMPAT
1870COMPAT_SYSCALL_DEFINE2(getrusage, int, who, struct compat_rusage __user *, ru)
1871{
1872 struct rusage r;
1873
1874 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
1875 who != RUSAGE_THREAD)
1876 return -EINVAL;
1877
1878 getrusage(current, who, &r);
1879 return put_compat_rusage(&r, ru);
1880}
1881#endif
1882
1883SYSCALL_DEFINE1(umask, int, mask)
1884{
1885 mask = xchg(&current->fs->umask, mask & S_IRWXUGO);
1886 return mask;
1887}
1888
1889static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd)
1890{
1891 struct fd exe;
1892 struct inode *inode;
1893 int err;
1894
1895 exe = fdget(fd);
1896 if (!exe.file)
1897 return -EBADF;
1898
1899 inode = file_inode(exe.file);
1900
1901 /*
1902 * Because the original mm->exe_file points to executable file, make
1903 * sure that this one is executable as well, to avoid breaking an
1904 * overall picture.
1905 */
1906 err = -EACCES;
1907 if (!S_ISREG(inode->i_mode) || path_noexec(&exe.file->f_path))
1908 goto exit;
1909
1910 err = file_permission(exe.file, MAY_EXEC);
1911 if (err)
1912 goto exit;
1913
1914 err = replace_mm_exe_file(mm, exe.file);
1915exit:
1916 fdput(exe);
1917 return err;
1918}
1919
1920/*
1921 * Check arithmetic relations of passed addresses.
1922 *
1923 * WARNING: we don't require any capability here so be very careful
1924 * in what is allowed for modification from userspace.
1925 */
1926static int validate_prctl_map_addr(struct prctl_mm_map *prctl_map)
1927{
1928 unsigned long mmap_max_addr = TASK_SIZE;
1929 int error = -EINVAL, i;
1930
1931 static const unsigned char offsets[] = {
1932 offsetof(struct prctl_mm_map, start_code),
1933 offsetof(struct prctl_mm_map, end_code),
1934 offsetof(struct prctl_mm_map, start_data),
1935 offsetof(struct prctl_mm_map, end_data),
1936 offsetof(struct prctl_mm_map, start_brk),
1937 offsetof(struct prctl_mm_map, brk),
1938 offsetof(struct prctl_mm_map, start_stack),
1939 offsetof(struct prctl_mm_map, arg_start),
1940 offsetof(struct prctl_mm_map, arg_end),
1941 offsetof(struct prctl_mm_map, env_start),
1942 offsetof(struct prctl_mm_map, env_end),
1943 };
1944
1945 /*
1946 * Make sure the members are not somewhere outside
1947 * of allowed address space.
1948 */
1949 for (i = 0; i < ARRAY_SIZE(offsets); i++) {
1950 u64 val = *(u64 *)((char *)prctl_map + offsets[i]);
1951
1952 if ((unsigned long)val >= mmap_max_addr ||
1953 (unsigned long)val < mmap_min_addr)
1954 goto out;
1955 }
1956
1957 /*
1958 * Make sure the pairs are ordered.
1959 */
1960#define __prctl_check_order(__m1, __op, __m2) \
1961 ((unsigned long)prctl_map->__m1 __op \
1962 (unsigned long)prctl_map->__m2) ? 0 : -EINVAL
1963 error = __prctl_check_order(start_code, <, end_code);
1964 error |= __prctl_check_order(start_data,<=, end_data);
1965 error |= __prctl_check_order(start_brk, <=, brk);
1966 error |= __prctl_check_order(arg_start, <=, arg_end);
1967 error |= __prctl_check_order(env_start, <=, env_end);
1968 if (error)
1969 goto out;
1970#undef __prctl_check_order
1971
1972 error = -EINVAL;
1973
1974 /*
1975 * Neither we should allow to override limits if they set.
1976 */
1977 if (check_data_rlimit(rlimit(RLIMIT_DATA), prctl_map->brk,
1978 prctl_map->start_brk, prctl_map->end_data,
1979 prctl_map->start_data))
1980 goto out;
1981
1982 error = 0;
1983out:
1984 return error;
1985}
1986
1987#ifdef CONFIG_CHECKPOINT_RESTORE
1988static int prctl_set_mm_map(int opt, const void __user *addr, unsigned long data_size)
1989{
1990 struct prctl_mm_map prctl_map = { .exe_fd = (u32)-1, };
1991 unsigned long user_auxv[AT_VECTOR_SIZE];
1992 struct mm_struct *mm = current->mm;
1993 int error;
1994
1995 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv));
1996 BUILD_BUG_ON(sizeof(struct prctl_mm_map) > 256);
1997
1998 if (opt == PR_SET_MM_MAP_SIZE)
1999 return put_user((unsigned int)sizeof(prctl_map),
2000 (unsigned int __user *)addr);
2001
2002 if (data_size != sizeof(prctl_map))
2003 return -EINVAL;
2004
2005 if (copy_from_user(&prctl_map, addr, sizeof(prctl_map)))
2006 return -EFAULT;
2007
2008 error = validate_prctl_map_addr(&prctl_map);
2009 if (error)
2010 return error;
2011
2012 if (prctl_map.auxv_size) {
2013 /*
2014 * Someone is trying to cheat the auxv vector.
2015 */
2016 if (!prctl_map.auxv ||
2017 prctl_map.auxv_size > sizeof(mm->saved_auxv))
2018 return -EINVAL;
2019
2020 memset(user_auxv, 0, sizeof(user_auxv));
2021 if (copy_from_user(user_auxv,
2022 (const void __user *)prctl_map.auxv,
2023 prctl_map.auxv_size))
2024 return -EFAULT;
2025
2026 /* Last entry must be AT_NULL as specification requires */
2027 user_auxv[AT_VECTOR_SIZE - 2] = AT_NULL;
2028 user_auxv[AT_VECTOR_SIZE - 1] = AT_NULL;
2029 }
2030
2031 if (prctl_map.exe_fd != (u32)-1) {
2032 /*
2033 * Check if the current user is checkpoint/restore capable.
2034 * At the time of this writing, it checks for CAP_SYS_ADMIN
2035 * or CAP_CHECKPOINT_RESTORE.
2036 * Note that a user with access to ptrace can masquerade an
2037 * arbitrary program as any executable, even setuid ones.
2038 * This may have implications in the tomoyo subsystem.
2039 */
2040 if (!checkpoint_restore_ns_capable(current_user_ns()))
2041 return -EPERM;
2042
2043 error = prctl_set_mm_exe_file(mm, prctl_map.exe_fd);
2044 if (error)
2045 return error;
2046 }
2047
2048 /*
2049 * arg_lock protects concurrent updates but we still need mmap_lock for
2050 * read to exclude races with sys_brk.
2051 */
2052 mmap_read_lock(mm);
2053
2054 /*
2055 * We don't validate if these members are pointing to
2056 * real present VMAs because application may have correspond
2057 * VMAs already unmapped and kernel uses these members for statistics
2058 * output in procfs mostly, except
2059 *
2060 * - @start_brk/@brk which are used in do_brk_flags but kernel lookups
2061 * for VMAs when updating these members so anything wrong written
2062 * here cause kernel to swear at userspace program but won't lead
2063 * to any problem in kernel itself
2064 */
2065
2066 spin_lock(&mm->arg_lock);
2067 mm->start_code = prctl_map.start_code;
2068 mm->end_code = prctl_map.end_code;
2069 mm->start_data = prctl_map.start_data;
2070 mm->end_data = prctl_map.end_data;
2071 mm->start_brk = prctl_map.start_brk;
2072 mm->brk = prctl_map.brk;
2073 mm->start_stack = prctl_map.start_stack;
2074 mm->arg_start = prctl_map.arg_start;
2075 mm->arg_end = prctl_map.arg_end;
2076 mm->env_start = prctl_map.env_start;
2077 mm->env_end = prctl_map.env_end;
2078 spin_unlock(&mm->arg_lock);
2079
2080 /*
2081 * Note this update of @saved_auxv is lockless thus
2082 * if someone reads this member in procfs while we're
2083 * updating -- it may get partly updated results. It's
2084 * known and acceptable trade off: we leave it as is to
2085 * not introduce additional locks here making the kernel
2086 * more complex.
2087 */
2088 if (prctl_map.auxv_size)
2089 memcpy(mm->saved_auxv, user_auxv, sizeof(user_auxv));
2090
2091 mmap_read_unlock(mm);
2092 return 0;
2093}
2094#endif /* CONFIG_CHECKPOINT_RESTORE */
2095
2096static int prctl_set_auxv(struct mm_struct *mm, unsigned long addr,
2097 unsigned long len)
2098{
2099 /*
2100 * This doesn't move the auxiliary vector itself since it's pinned to
2101 * mm_struct, but it permits filling the vector with new values. It's
2102 * up to the caller to provide sane values here, otherwise userspace
2103 * tools which use this vector might be unhappy.
2104 */
2105 unsigned long user_auxv[AT_VECTOR_SIZE] = {};
2106
2107 if (len > sizeof(user_auxv))
2108 return -EINVAL;
2109
2110 if (copy_from_user(user_auxv, (const void __user *)addr, len))
2111 return -EFAULT;
2112
2113 /* Make sure the last entry is always AT_NULL */
2114 user_auxv[AT_VECTOR_SIZE - 2] = 0;
2115 user_auxv[AT_VECTOR_SIZE - 1] = 0;
2116
2117 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv));
2118
2119 task_lock(current);
2120 memcpy(mm->saved_auxv, user_auxv, len);
2121 task_unlock(current);
2122
2123 return 0;
2124}
2125
2126static int prctl_set_mm(int opt, unsigned long addr,
2127 unsigned long arg4, unsigned long arg5)
2128{
2129 struct mm_struct *mm = current->mm;
2130 struct prctl_mm_map prctl_map = {
2131 .auxv = NULL,
2132 .auxv_size = 0,
2133 .exe_fd = -1,
2134 };
2135 struct vm_area_struct *vma;
2136 int error;
2137
2138 if (arg5 || (arg4 && (opt != PR_SET_MM_AUXV &&
2139 opt != PR_SET_MM_MAP &&
2140 opt != PR_SET_MM_MAP_SIZE)))
2141 return -EINVAL;
2142
2143#ifdef CONFIG_CHECKPOINT_RESTORE
2144 if (opt == PR_SET_MM_MAP || opt == PR_SET_MM_MAP_SIZE)
2145 return prctl_set_mm_map(opt, (const void __user *)addr, arg4);
2146#endif
2147
2148 if (!capable(CAP_SYS_RESOURCE))
2149 return -EPERM;
2150
2151 if (opt == PR_SET_MM_EXE_FILE)
2152 return prctl_set_mm_exe_file(mm, (unsigned int)addr);
2153
2154 if (opt == PR_SET_MM_AUXV)
2155 return prctl_set_auxv(mm, addr, arg4);
2156
2157 if (addr >= TASK_SIZE || addr < mmap_min_addr)
2158 return -EINVAL;
2159
2160 error = -EINVAL;
2161
2162 /*
2163 * arg_lock protects concurrent updates of arg boundaries, we need
2164 * mmap_lock for a) concurrent sys_brk, b) finding VMA for addr
2165 * validation.
2166 */
2167 mmap_read_lock(mm);
2168 vma = find_vma(mm, addr);
2169
2170 spin_lock(&mm->arg_lock);
2171 prctl_map.start_code = mm->start_code;
2172 prctl_map.end_code = mm->end_code;
2173 prctl_map.start_data = mm->start_data;
2174 prctl_map.end_data = mm->end_data;
2175 prctl_map.start_brk = mm->start_brk;
2176 prctl_map.brk = mm->brk;
2177 prctl_map.start_stack = mm->start_stack;
2178 prctl_map.arg_start = mm->arg_start;
2179 prctl_map.arg_end = mm->arg_end;
2180 prctl_map.env_start = mm->env_start;
2181 prctl_map.env_end = mm->env_end;
2182
2183 switch (opt) {
2184 case PR_SET_MM_START_CODE:
2185 prctl_map.start_code = addr;
2186 break;
2187 case PR_SET_MM_END_CODE:
2188 prctl_map.end_code = addr;
2189 break;
2190 case PR_SET_MM_START_DATA:
2191 prctl_map.start_data = addr;
2192 break;
2193 case PR_SET_MM_END_DATA:
2194 prctl_map.end_data = addr;
2195 break;
2196 case PR_SET_MM_START_STACK:
2197 prctl_map.start_stack = addr;
2198 break;
2199 case PR_SET_MM_START_BRK:
2200 prctl_map.start_brk = addr;
2201 break;
2202 case PR_SET_MM_BRK:
2203 prctl_map.brk = addr;
2204 break;
2205 case PR_SET_MM_ARG_START:
2206 prctl_map.arg_start = addr;
2207 break;
2208 case PR_SET_MM_ARG_END:
2209 prctl_map.arg_end = addr;
2210 break;
2211 case PR_SET_MM_ENV_START:
2212 prctl_map.env_start = addr;
2213 break;
2214 case PR_SET_MM_ENV_END:
2215 prctl_map.env_end = addr;
2216 break;
2217 default:
2218 goto out;
2219 }
2220
2221 error = validate_prctl_map_addr(&prctl_map);
2222 if (error)
2223 goto out;
2224
2225 switch (opt) {
2226 /*
2227 * If command line arguments and environment
2228 * are placed somewhere else on stack, we can
2229 * set them up here, ARG_START/END to setup
2230 * command line arguments and ENV_START/END
2231 * for environment.
2232 */
2233 case PR_SET_MM_START_STACK:
2234 case PR_SET_MM_ARG_START:
2235 case PR_SET_MM_ARG_END:
2236 case PR_SET_MM_ENV_START:
2237 case PR_SET_MM_ENV_END:
2238 if (!vma) {
2239 error = -EFAULT;
2240 goto out;
2241 }
2242 }
2243
2244 mm->start_code = prctl_map.start_code;
2245 mm->end_code = prctl_map.end_code;
2246 mm->start_data = prctl_map.start_data;
2247 mm->end_data = prctl_map.end_data;
2248 mm->start_brk = prctl_map.start_brk;
2249 mm->brk = prctl_map.brk;
2250 mm->start_stack = prctl_map.start_stack;
2251 mm->arg_start = prctl_map.arg_start;
2252 mm->arg_end = prctl_map.arg_end;
2253 mm->env_start = prctl_map.env_start;
2254 mm->env_end = prctl_map.env_end;
2255
2256 error = 0;
2257out:
2258 spin_unlock(&mm->arg_lock);
2259 mmap_read_unlock(mm);
2260 return error;
2261}
2262
2263#ifdef CONFIG_CHECKPOINT_RESTORE
2264static int prctl_get_tid_address(struct task_struct *me, int __user * __user *tid_addr)
2265{
2266 return put_user(me->clear_child_tid, tid_addr);
2267}
2268#else
2269static int prctl_get_tid_address(struct task_struct *me, int __user * __user *tid_addr)
2270{
2271 return -EINVAL;
2272}
2273#endif
2274
2275static int propagate_has_child_subreaper(struct task_struct *p, void *data)
2276{
2277 /*
2278 * If task has has_child_subreaper - all its descendants
2279 * already have these flag too and new descendants will
2280 * inherit it on fork, skip them.
2281 *
2282 * If we've found child_reaper - skip descendants in
2283 * it's subtree as they will never get out pidns.
2284 */
2285 if (p->signal->has_child_subreaper ||
2286 is_child_reaper(task_pid(p)))
2287 return 0;
2288
2289 p->signal->has_child_subreaper = 1;
2290 return 1;
2291}
2292
2293int __weak arch_prctl_spec_ctrl_get(struct task_struct *t, unsigned long which)
2294{
2295 return -EINVAL;
2296}
2297
2298int __weak arch_prctl_spec_ctrl_set(struct task_struct *t, unsigned long which,
2299 unsigned long ctrl)
2300{
2301 return -EINVAL;
2302}
2303
2304#define PR_IO_FLUSHER (PF_MEMALLOC_NOIO | PF_LOCAL_THROTTLE)
2305
2306#ifdef CONFIG_ANON_VMA_NAME
2307
2308#define ANON_VMA_NAME_MAX_LEN 80
2309#define ANON_VMA_NAME_INVALID_CHARS "\\`$[]"
2310
2311static inline bool is_valid_name_char(char ch)
2312{
2313 /* printable ascii characters, excluding ANON_VMA_NAME_INVALID_CHARS */
2314 return ch > 0x1f && ch < 0x7f &&
2315 !strchr(ANON_VMA_NAME_INVALID_CHARS, ch);
2316}
2317
2318static int prctl_set_vma(unsigned long opt, unsigned long addr,
2319 unsigned long size, unsigned long arg)
2320{
2321 struct mm_struct *mm = current->mm;
2322 const char __user *uname;
2323 struct anon_vma_name *anon_name = NULL;
2324 int error;
2325
2326 switch (opt) {
2327 case PR_SET_VMA_ANON_NAME:
2328 uname = (const char __user *)arg;
2329 if (uname) {
2330 char *name, *pch;
2331
2332 name = strndup_user(uname, ANON_VMA_NAME_MAX_LEN);
2333 if (IS_ERR(name))
2334 return PTR_ERR(name);
2335
2336 for (pch = name; *pch != '\0'; pch++) {
2337 if (!is_valid_name_char(*pch)) {
2338 kfree(name);
2339 return -EINVAL;
2340 }
2341 }
2342 /* anon_vma has its own copy */
2343 anon_name = anon_vma_name_alloc(name);
2344 kfree(name);
2345 if (!anon_name)
2346 return -ENOMEM;
2347
2348 }
2349
2350 mmap_write_lock(mm);
2351 error = madvise_set_anon_name(mm, addr, size, anon_name);
2352 mmap_write_unlock(mm);
2353 anon_vma_name_put(anon_name);
2354 break;
2355 default:
2356 error = -EINVAL;
2357 }
2358
2359 return error;
2360}
2361
2362#else /* CONFIG_ANON_VMA_NAME */
2363static int prctl_set_vma(unsigned long opt, unsigned long start,
2364 unsigned long size, unsigned long arg)
2365{
2366 return -EINVAL;
2367}
2368#endif /* CONFIG_ANON_VMA_NAME */
2369
2370static inline unsigned long get_current_mdwe(void)
2371{
2372 unsigned long ret = 0;
2373
2374 if (test_bit(MMF_HAS_MDWE, &current->mm->flags))
2375 ret |= PR_MDWE_REFUSE_EXEC_GAIN;
2376 if (test_bit(MMF_HAS_MDWE_NO_INHERIT, &current->mm->flags))
2377 ret |= PR_MDWE_NO_INHERIT;
2378
2379 return ret;
2380}
2381
2382static inline int prctl_set_mdwe(unsigned long bits, unsigned long arg3,
2383 unsigned long arg4, unsigned long arg5)
2384{
2385 unsigned long current_bits;
2386
2387 if (arg3 || arg4 || arg5)
2388 return -EINVAL;
2389
2390 if (bits & ~(PR_MDWE_REFUSE_EXEC_GAIN | PR_MDWE_NO_INHERIT))
2391 return -EINVAL;
2392
2393 /* NO_INHERIT only makes sense with REFUSE_EXEC_GAIN */
2394 if (bits & PR_MDWE_NO_INHERIT && !(bits & PR_MDWE_REFUSE_EXEC_GAIN))
2395 return -EINVAL;
2396
2397 /* PARISC cannot allow mdwe as it needs writable stacks */
2398 if (IS_ENABLED(CONFIG_PARISC))
2399 return -EINVAL;
2400
2401 current_bits = get_current_mdwe();
2402 if (current_bits && current_bits != bits)
2403 return -EPERM; /* Cannot unset the flags */
2404
2405 if (bits & PR_MDWE_NO_INHERIT)
2406 set_bit(MMF_HAS_MDWE_NO_INHERIT, &current->mm->flags);
2407 if (bits & PR_MDWE_REFUSE_EXEC_GAIN)
2408 set_bit(MMF_HAS_MDWE, &current->mm->flags);
2409
2410 return 0;
2411}
2412
2413static inline int prctl_get_mdwe(unsigned long arg2, unsigned long arg3,
2414 unsigned long arg4, unsigned long arg5)
2415{
2416 if (arg2 || arg3 || arg4 || arg5)
2417 return -EINVAL;
2418 return get_current_mdwe();
2419}
2420
2421static int prctl_get_auxv(void __user *addr, unsigned long len)
2422{
2423 struct mm_struct *mm = current->mm;
2424 unsigned long size = min_t(unsigned long, sizeof(mm->saved_auxv), len);
2425
2426 if (size && copy_to_user(addr, mm->saved_auxv, size))
2427 return -EFAULT;
2428 return sizeof(mm->saved_auxv);
2429}
2430
2431SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
2432 unsigned long, arg4, unsigned long, arg5)
2433{
2434 struct task_struct *me = current;
2435 unsigned char comm[sizeof(me->comm)];
2436 long error;
2437
2438 error = security_task_prctl(option, arg2, arg3, arg4, arg5);
2439 if (error != -ENOSYS)
2440 return error;
2441
2442 error = 0;
2443 switch (option) {
2444 case PR_SET_PDEATHSIG:
2445 if (!valid_signal(arg2)) {
2446 error = -EINVAL;
2447 break;
2448 }
2449 me->pdeath_signal = arg2;
2450 break;
2451 case PR_GET_PDEATHSIG:
2452 error = put_user(me->pdeath_signal, (int __user *)arg2);
2453 break;
2454 case PR_GET_DUMPABLE:
2455 error = get_dumpable(me->mm);
2456 break;
2457 case PR_SET_DUMPABLE:
2458 if (arg2 != SUID_DUMP_DISABLE && arg2 != SUID_DUMP_USER) {
2459 error = -EINVAL;
2460 break;
2461 }
2462 set_dumpable(me->mm, arg2);
2463 break;
2464
2465 case PR_SET_UNALIGN:
2466 error = SET_UNALIGN_CTL(me, arg2);
2467 break;
2468 case PR_GET_UNALIGN:
2469 error = GET_UNALIGN_CTL(me, arg2);
2470 break;
2471 case PR_SET_FPEMU:
2472 error = SET_FPEMU_CTL(me, arg2);
2473 break;
2474 case PR_GET_FPEMU:
2475 error = GET_FPEMU_CTL(me, arg2);
2476 break;
2477 case PR_SET_FPEXC:
2478 error = SET_FPEXC_CTL(me, arg2);
2479 break;
2480 case PR_GET_FPEXC:
2481 error = GET_FPEXC_CTL(me, arg2);
2482 break;
2483 case PR_GET_TIMING:
2484 error = PR_TIMING_STATISTICAL;
2485 break;
2486 case PR_SET_TIMING:
2487 if (arg2 != PR_TIMING_STATISTICAL)
2488 error = -EINVAL;
2489 break;
2490 case PR_SET_NAME:
2491 comm[sizeof(me->comm) - 1] = 0;
2492 if (strncpy_from_user(comm, (char __user *)arg2,
2493 sizeof(me->comm) - 1) < 0)
2494 return -EFAULT;
2495 set_task_comm(me, comm);
2496 proc_comm_connector(me);
2497 break;
2498 case PR_GET_NAME:
2499 get_task_comm(comm, me);
2500 if (copy_to_user((char __user *)arg2, comm, sizeof(comm)))
2501 return -EFAULT;
2502 break;
2503 case PR_GET_ENDIAN:
2504 error = GET_ENDIAN(me, arg2);
2505 break;
2506 case PR_SET_ENDIAN:
2507 error = SET_ENDIAN(me, arg2);
2508 break;
2509 case PR_GET_SECCOMP:
2510 error = prctl_get_seccomp();
2511 break;
2512 case PR_SET_SECCOMP:
2513 error = prctl_set_seccomp(arg2, (char __user *)arg3);
2514 break;
2515 case PR_GET_TSC:
2516 error = GET_TSC_CTL(arg2);
2517 break;
2518 case PR_SET_TSC:
2519 error = SET_TSC_CTL(arg2);
2520 break;
2521 case PR_TASK_PERF_EVENTS_DISABLE:
2522 error = perf_event_task_disable();
2523 break;
2524 case PR_TASK_PERF_EVENTS_ENABLE:
2525 error = perf_event_task_enable();
2526 break;
2527 case PR_GET_TIMERSLACK:
2528 if (current->timer_slack_ns > ULONG_MAX)
2529 error = ULONG_MAX;
2530 else
2531 error = current->timer_slack_ns;
2532 break;
2533 case PR_SET_TIMERSLACK:
2534 if (arg2 <= 0)
2535 current->timer_slack_ns =
2536 current->default_timer_slack_ns;
2537 else
2538 current->timer_slack_ns = arg2;
2539 break;
2540 case PR_MCE_KILL:
2541 if (arg4 | arg5)
2542 return -EINVAL;
2543 switch (arg2) {
2544 case PR_MCE_KILL_CLEAR:
2545 if (arg3 != 0)
2546 return -EINVAL;
2547 current->flags &= ~PF_MCE_PROCESS;
2548 break;
2549 case PR_MCE_KILL_SET:
2550 current->flags |= PF_MCE_PROCESS;
2551 if (arg3 == PR_MCE_KILL_EARLY)
2552 current->flags |= PF_MCE_EARLY;
2553 else if (arg3 == PR_MCE_KILL_LATE)
2554 current->flags &= ~PF_MCE_EARLY;
2555 else if (arg3 == PR_MCE_KILL_DEFAULT)
2556 current->flags &=
2557 ~(PF_MCE_EARLY|PF_MCE_PROCESS);
2558 else
2559 return -EINVAL;
2560 break;
2561 default:
2562 return -EINVAL;
2563 }
2564 break;
2565 case PR_MCE_KILL_GET:
2566 if (arg2 | arg3 | arg4 | arg5)
2567 return -EINVAL;
2568 if (current->flags & PF_MCE_PROCESS)
2569 error = (current->flags & PF_MCE_EARLY) ?
2570 PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE;
2571 else
2572 error = PR_MCE_KILL_DEFAULT;
2573 break;
2574 case PR_SET_MM:
2575 error = prctl_set_mm(arg2, arg3, arg4, arg5);
2576 break;
2577 case PR_GET_TID_ADDRESS:
2578 error = prctl_get_tid_address(me, (int __user * __user *)arg2);
2579 break;
2580 case PR_SET_CHILD_SUBREAPER:
2581 me->signal->is_child_subreaper = !!arg2;
2582 if (!arg2)
2583 break;
2584
2585 walk_process_tree(me, propagate_has_child_subreaper, NULL);
2586 break;
2587 case PR_GET_CHILD_SUBREAPER:
2588 error = put_user(me->signal->is_child_subreaper,
2589 (int __user *)arg2);
2590 break;
2591 case PR_SET_NO_NEW_PRIVS:
2592 if (arg2 != 1 || arg3 || arg4 || arg5)
2593 return -EINVAL;
2594
2595 task_set_no_new_privs(current);
2596 break;
2597 case PR_GET_NO_NEW_PRIVS:
2598 if (arg2 || arg3 || arg4 || arg5)
2599 return -EINVAL;
2600 return task_no_new_privs(current) ? 1 : 0;
2601 case PR_GET_THP_DISABLE:
2602 if (arg2 || arg3 || arg4 || arg5)
2603 return -EINVAL;
2604 error = !!test_bit(MMF_DISABLE_THP, &me->mm->flags);
2605 break;
2606 case PR_SET_THP_DISABLE:
2607 if (arg3 || arg4 || arg5)
2608 return -EINVAL;
2609 if (mmap_write_lock_killable(me->mm))
2610 return -EINTR;
2611 if (arg2)
2612 set_bit(MMF_DISABLE_THP, &me->mm->flags);
2613 else
2614 clear_bit(MMF_DISABLE_THP, &me->mm->flags);
2615 mmap_write_unlock(me->mm);
2616 break;
2617 case PR_MPX_ENABLE_MANAGEMENT:
2618 case PR_MPX_DISABLE_MANAGEMENT:
2619 /* No longer implemented: */
2620 return -EINVAL;
2621 case PR_SET_FP_MODE:
2622 error = SET_FP_MODE(me, arg2);
2623 break;
2624 case PR_GET_FP_MODE:
2625 error = GET_FP_MODE(me);
2626 break;
2627 case PR_SVE_SET_VL:
2628 error = SVE_SET_VL(arg2);
2629 break;
2630 case PR_SVE_GET_VL:
2631 error = SVE_GET_VL();
2632 break;
2633 case PR_SME_SET_VL:
2634 error = SME_SET_VL(arg2);
2635 break;
2636 case PR_SME_GET_VL:
2637 error = SME_GET_VL();
2638 break;
2639 case PR_GET_SPECULATION_CTRL:
2640 if (arg3 || arg4 || arg5)
2641 return -EINVAL;
2642 error = arch_prctl_spec_ctrl_get(me, arg2);
2643 break;
2644 case PR_SET_SPECULATION_CTRL:
2645 if (arg4 || arg5)
2646 return -EINVAL;
2647 error = arch_prctl_spec_ctrl_set(me, arg2, arg3);
2648 break;
2649 case PR_PAC_RESET_KEYS:
2650 if (arg3 || arg4 || arg5)
2651 return -EINVAL;
2652 error = PAC_RESET_KEYS(me, arg2);
2653 break;
2654 case PR_PAC_SET_ENABLED_KEYS:
2655 if (arg4 || arg5)
2656 return -EINVAL;
2657 error = PAC_SET_ENABLED_KEYS(me, arg2, arg3);
2658 break;
2659 case PR_PAC_GET_ENABLED_KEYS:
2660 if (arg2 || arg3 || arg4 || arg5)
2661 return -EINVAL;
2662 error = PAC_GET_ENABLED_KEYS(me);
2663 break;
2664 case PR_SET_TAGGED_ADDR_CTRL:
2665 if (arg3 || arg4 || arg5)
2666 return -EINVAL;
2667 error = SET_TAGGED_ADDR_CTRL(arg2);
2668 break;
2669 case PR_GET_TAGGED_ADDR_CTRL:
2670 if (arg2 || arg3 || arg4 || arg5)
2671 return -EINVAL;
2672 error = GET_TAGGED_ADDR_CTRL();
2673 break;
2674 case PR_SET_IO_FLUSHER:
2675 if (!capable(CAP_SYS_RESOURCE))
2676 return -EPERM;
2677
2678 if (arg3 || arg4 || arg5)
2679 return -EINVAL;
2680
2681 if (arg2 == 1)
2682 current->flags |= PR_IO_FLUSHER;
2683 else if (!arg2)
2684 current->flags &= ~PR_IO_FLUSHER;
2685 else
2686 return -EINVAL;
2687 break;
2688 case PR_GET_IO_FLUSHER:
2689 if (!capable(CAP_SYS_RESOURCE))
2690 return -EPERM;
2691
2692 if (arg2 || arg3 || arg4 || arg5)
2693 return -EINVAL;
2694
2695 error = (current->flags & PR_IO_FLUSHER) == PR_IO_FLUSHER;
2696 break;
2697 case PR_SET_SYSCALL_USER_DISPATCH:
2698 error = set_syscall_user_dispatch(arg2, arg3, arg4,
2699 (char __user *) arg5);
2700 break;
2701#ifdef CONFIG_SCHED_CORE
2702 case PR_SCHED_CORE:
2703 error = sched_core_share_pid(arg2, arg3, arg4, arg5);
2704 break;
2705#endif
2706 case PR_SET_MDWE:
2707 error = prctl_set_mdwe(arg2, arg3, arg4, arg5);
2708 break;
2709 case PR_GET_MDWE:
2710 error = prctl_get_mdwe(arg2, arg3, arg4, arg5);
2711 break;
2712 case PR_SET_VMA:
2713 error = prctl_set_vma(arg2, arg3, arg4, arg5);
2714 break;
2715 case PR_GET_AUXV:
2716 if (arg4 || arg5)
2717 return -EINVAL;
2718 error = prctl_get_auxv((void __user *)arg2, arg3);
2719 break;
2720#ifdef CONFIG_KSM
2721 case PR_SET_MEMORY_MERGE:
2722 if (arg3 || arg4 || arg5)
2723 return -EINVAL;
2724 if (mmap_write_lock_killable(me->mm))
2725 return -EINTR;
2726
2727 if (arg2)
2728 error = ksm_enable_merge_any(me->mm);
2729 else
2730 error = ksm_disable_merge_any(me->mm);
2731 mmap_write_unlock(me->mm);
2732 break;
2733 case PR_GET_MEMORY_MERGE:
2734 if (arg2 || arg3 || arg4 || arg5)
2735 return -EINVAL;
2736
2737 error = !!test_bit(MMF_VM_MERGE_ANY, &me->mm->flags);
2738 break;
2739#endif
2740 case PR_RISCV_V_SET_CONTROL:
2741 error = RISCV_V_SET_CONTROL(arg2);
2742 break;
2743 case PR_RISCV_V_GET_CONTROL:
2744 error = RISCV_V_GET_CONTROL();
2745 break;
2746 default:
2747 error = -EINVAL;
2748 break;
2749 }
2750 return error;
2751}
2752
2753SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep,
2754 struct getcpu_cache __user *, unused)
2755{
2756 int err = 0;
2757 int cpu = raw_smp_processor_id();
2758
2759 if (cpup)
2760 err |= put_user(cpu, cpup);
2761 if (nodep)
2762 err |= put_user(cpu_to_node(cpu), nodep);
2763 return err ? -EFAULT : 0;
2764}
2765
2766/**
2767 * do_sysinfo - fill in sysinfo struct
2768 * @info: pointer to buffer to fill
2769 */
2770static int do_sysinfo(struct sysinfo *info)
2771{
2772 unsigned long mem_total, sav_total;
2773 unsigned int mem_unit, bitcount;
2774 struct timespec64 tp;
2775
2776 memset(info, 0, sizeof(struct sysinfo));
2777
2778 ktime_get_boottime_ts64(&tp);
2779 timens_add_boottime(&tp);
2780 info->uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0);
2781
2782 get_avenrun(info->loads, 0, SI_LOAD_SHIFT - FSHIFT);
2783
2784 info->procs = nr_threads;
2785
2786 si_meminfo(info);
2787 si_swapinfo(info);
2788
2789 /*
2790 * If the sum of all the available memory (i.e. ram + swap)
2791 * is less than can be stored in a 32 bit unsigned long then
2792 * we can be binary compatible with 2.2.x kernels. If not,
2793 * well, in that case 2.2.x was broken anyways...
2794 *
2795 * -Erik Andersen <[email protected]>
2796 */
2797
2798 mem_total = info->totalram + info->totalswap;
2799 if (mem_total < info->totalram || mem_total < info->totalswap)
2800 goto out;
2801 bitcount = 0;
2802 mem_unit = info->mem_unit;
2803 while (mem_unit > 1) {
2804 bitcount++;
2805 mem_unit >>= 1;
2806 sav_total = mem_total;
2807 mem_total <<= 1;
2808 if (mem_total < sav_total)
2809 goto out;
2810 }
2811
2812 /*
2813 * If mem_total did not overflow, multiply all memory values by
2814 * info->mem_unit and set it to 1. This leaves things compatible
2815 * with 2.2.x, and also retains compatibility with earlier 2.4.x
2816 * kernels...
2817 */
2818
2819 info->mem_unit = 1;
2820 info->totalram <<= bitcount;
2821 info->freeram <<= bitcount;
2822 info->sharedram <<= bitcount;
2823 info->bufferram <<= bitcount;
2824 info->totalswap <<= bitcount;
2825 info->freeswap <<= bitcount;
2826 info->totalhigh <<= bitcount;
2827 info->freehigh <<= bitcount;
2828
2829out:
2830 return 0;
2831}
2832
2833SYSCALL_DEFINE1(sysinfo, struct sysinfo __user *, info)
2834{
2835 struct sysinfo val;
2836
2837 do_sysinfo(&val);
2838
2839 if (copy_to_user(info, &val, sizeof(struct sysinfo)))
2840 return -EFAULT;
2841
2842 return 0;
2843}
2844
2845#ifdef CONFIG_COMPAT
2846struct compat_sysinfo {
2847 s32 uptime;
2848 u32 loads[3];
2849 u32 totalram;
2850 u32 freeram;
2851 u32 sharedram;
2852 u32 bufferram;
2853 u32 totalswap;
2854 u32 freeswap;
2855 u16 procs;
2856 u16 pad;
2857 u32 totalhigh;
2858 u32 freehigh;
2859 u32 mem_unit;
2860 char _f[20-2*sizeof(u32)-sizeof(int)];
2861};
2862
2863COMPAT_SYSCALL_DEFINE1(sysinfo, struct compat_sysinfo __user *, info)
2864{
2865 struct sysinfo s;
2866 struct compat_sysinfo s_32;
2867
2868 do_sysinfo(&s);
2869
2870 /* Check to see if any memory value is too large for 32-bit and scale
2871 * down if needed
2872 */
2873 if (upper_32_bits(s.totalram) || upper_32_bits(s.totalswap)) {
2874 int bitcount = 0;
2875
2876 while (s.mem_unit < PAGE_SIZE) {
2877 s.mem_unit <<= 1;
2878 bitcount++;
2879 }
2880
2881 s.totalram >>= bitcount;
2882 s.freeram >>= bitcount;
2883 s.sharedram >>= bitcount;
2884 s.bufferram >>= bitcount;
2885 s.totalswap >>= bitcount;
2886 s.freeswap >>= bitcount;
2887 s.totalhigh >>= bitcount;
2888 s.freehigh >>= bitcount;
2889 }
2890
2891 memset(&s_32, 0, sizeof(s_32));
2892 s_32.uptime = s.uptime;
2893 s_32.loads[0] = s.loads[0];
2894 s_32.loads[1] = s.loads[1];
2895 s_32.loads[2] = s.loads[2];
2896 s_32.totalram = s.totalram;
2897 s_32.freeram = s.freeram;
2898 s_32.sharedram = s.sharedram;
2899 s_32.bufferram = s.bufferram;
2900 s_32.totalswap = s.totalswap;
2901 s_32.freeswap = s.freeswap;
2902 s_32.procs = s.procs;
2903 s_32.totalhigh = s.totalhigh;
2904 s_32.freehigh = s.freehigh;
2905 s_32.mem_unit = s.mem_unit;
2906 if (copy_to_user(info, &s_32, sizeof(s_32)))
2907 return -EFAULT;
2908 return 0;
2909}
2910#endif /* CONFIG_COMPAT */