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softirq: Allow to drop the softirq-BKL lock on PREEMPT_RT
[linux.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/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 #include <linux/futex.h>
56
57 #include <linux/sched.h>
58 #include <linux/sched/autogroup.h>
59 #include <linux/sched/loadavg.h>
60 #include <linux/sched/stat.h>
61 #include <linux/sched/mm.h>
62 #include <linux/sched/coredump.h>
63 #include <linux/sched/task.h>
64 #include <linux/sched/cputime.h>
65 #include <linux/rcupdate.h>
66 #include <linux/uidgid.h>
67 #include <linux/cred.h>
68
69 #include <linux/nospec.h>
70
71 #include <linux/kmsg_dump.h>
72 /* Move somewhere else to avoid recompiling? */
73 #include <generated/utsrelease.h>
74
75 #include <linux/uaccess.h>
76 #include <asm/io.h>
77 #include <asm/unistd.h>
78
79 #include <trace/events/task.h>
80
81 #include "uid16.h"
82
83 #ifndef SET_UNALIGN_CTL
84 # define SET_UNALIGN_CTL(a, b) (-EINVAL)
85 #endif
86 #ifndef GET_UNALIGN_CTL
87 # define GET_UNALIGN_CTL(a, b) (-EINVAL)
88 #endif
89 #ifndef SET_FPEMU_CTL
90 # define SET_FPEMU_CTL(a, b) (-EINVAL)
91 #endif
92 #ifndef GET_FPEMU_CTL
93 # define GET_FPEMU_CTL(a, b) (-EINVAL)
94 #endif
95 #ifndef SET_FPEXC_CTL
96 # define SET_FPEXC_CTL(a, b) (-EINVAL)
97 #endif
98 #ifndef GET_FPEXC_CTL
99 # define GET_FPEXC_CTL(a, b) (-EINVAL)
100 #endif
101 #ifndef GET_ENDIAN
102 # define GET_ENDIAN(a, b) (-EINVAL)
103 #endif
104 #ifndef SET_ENDIAN
105 # define SET_ENDIAN(a, b) (-EINVAL)
106 #endif
107 #ifndef GET_TSC_CTL
108 # define GET_TSC_CTL(a) (-EINVAL)
109 #endif
110 #ifndef SET_TSC_CTL
111 # define SET_TSC_CTL(a) (-EINVAL)
112 #endif
113 #ifndef GET_FP_MODE
114 # define GET_FP_MODE(a) (-EINVAL)
115 #endif
116 #ifndef SET_FP_MODE
117 # define SET_FP_MODE(a,b) (-EINVAL)
118 #endif
119 #ifndef SVE_SET_VL
120 # define SVE_SET_VL(a) (-EINVAL)
121 #endif
122 #ifndef SVE_GET_VL
123 # define SVE_GET_VL() (-EINVAL)
124 #endif
125 #ifndef SME_SET_VL
126 # define SME_SET_VL(a) (-EINVAL)
127 #endif
128 #ifndef SME_GET_VL
129 # define SME_GET_VL() (-EINVAL)
130 #endif
131 #ifndef PAC_RESET_KEYS
132 # define PAC_RESET_KEYS(a, b) (-EINVAL)
133 #endif
134 #ifndef PAC_SET_ENABLED_KEYS
135 # define PAC_SET_ENABLED_KEYS(a, b, c) (-EINVAL)
136 #endif
137 #ifndef PAC_GET_ENABLED_KEYS
138 # define PAC_GET_ENABLED_KEYS(a) (-EINVAL)
139 #endif
140 #ifndef SET_TAGGED_ADDR_CTRL
141 # define SET_TAGGED_ADDR_CTRL(a) (-EINVAL)
142 #endif
143 #ifndef GET_TAGGED_ADDR_CTRL
144 # define GET_TAGGED_ADDR_CTRL() (-EINVAL)
145 #endif
146 #ifndef RISCV_V_SET_CONTROL
147 # define RISCV_V_SET_CONTROL(a) (-EINVAL)
148 #endif
149 #ifndef RISCV_V_GET_CONTROL
150 # define RISCV_V_GET_CONTROL() (-EINVAL)
151 #endif
152 #ifndef RISCV_SET_ICACHE_FLUSH_CTX
153 # define RISCV_SET_ICACHE_FLUSH_CTX(a, b) (-EINVAL)
154 #endif
155 #ifndef PPC_GET_DEXCR_ASPECT
156 # define PPC_GET_DEXCR_ASPECT(a, b) (-EINVAL)
157 #endif
158 #ifndef PPC_SET_DEXCR_ASPECT
159 # define PPC_SET_DEXCR_ASPECT(a, b, c) (-EINVAL)
160 #endif
161
162 /*
163 * this is where the system-wide overflow UID and GID are defined, for
164 * architectures that now have 32-bit UID/GID but didn't in the past
165 */
166
167 int overflowuid = DEFAULT_OVERFLOWUID;
168 int overflowgid = DEFAULT_OVERFLOWGID;
169
170 EXPORT_SYMBOL(overflowuid);
171 EXPORT_SYMBOL(overflowgid);
172
173 /*
174 * the same as above, but for filesystems which can only store a 16-bit
175 * UID and GID. as such, this is needed on all architectures
176 */
177
178 int fs_overflowuid = DEFAULT_FS_OVERFLOWUID;
179 int fs_overflowgid = DEFAULT_FS_OVERFLOWGID;
180
181 EXPORT_SYMBOL(fs_overflowuid);
182 EXPORT_SYMBOL(fs_overflowgid);
183
184 static const struct ctl_table overflow_sysctl_table[] = {
185 {
186 .procname = "overflowuid",
187 .data = &overflowuid,
188 .maxlen = sizeof(int),
189 .mode = 0644,
190 .proc_handler = proc_dointvec_minmax,
191 .extra1 = SYSCTL_ZERO,
192 .extra2 = SYSCTL_MAXOLDUID,
193 },
194 {
195 .procname = "overflowgid",
196 .data = &overflowgid,
197 .maxlen = sizeof(int),
198 .mode = 0644,
199 .proc_handler = proc_dointvec_minmax,
200 .extra1 = SYSCTL_ZERO,
201 .extra2 = SYSCTL_MAXOLDUID,
202 },
203 };
204
205 static int __init init_overflow_sysctl(void)
206 {
207 register_sysctl_init("kernel", overflow_sysctl_table);
208 return 0;
209 }
210
211 postcore_initcall(init_overflow_sysctl);
212
213 /*
214 * Returns true if current's euid is same as p's uid or euid,
215 * or has CAP_SYS_NICE to p's user_ns.
216 *
217 * Called with rcu_read_lock, creds are safe
218 */
219 static bool set_one_prio_perm(struct task_struct *p)
220 {
221 const struct cred *cred = current_cred(), *pcred = __task_cred(p);
222
223 if (uid_eq(pcred->uid, cred->euid) ||
224 uid_eq(pcred->euid, cred->euid))
225 return true;
226 if (ns_capable(pcred->user_ns, CAP_SYS_NICE))
227 return true;
228 return false;
229 }
230
231 /*
232 * set the priority of a task
233 * - the caller must hold the RCU read lock
234 */
235 static int set_one_prio(struct task_struct *p, int niceval, int error)
236 {
237 int no_nice;
238
239 if (!set_one_prio_perm(p)) {
240 error = -EPERM;
241 goto out;
242 }
243 if (niceval < task_nice(p) && !can_nice(p, niceval)) {
244 error = -EACCES;
245 goto out;
246 }
247 no_nice = security_task_setnice(p, niceval);
248 if (no_nice) {
249 error = no_nice;
250 goto out;
251 }
252 if (error == -ESRCH)
253 error = 0;
254 set_user_nice(p, niceval);
255 out:
256 return error;
257 }
258
259 SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval)
260 {
261 struct task_struct *g, *p;
262 struct user_struct *user;
263 const struct cred *cred = current_cred();
264 int error = -EINVAL;
265 struct pid *pgrp;
266 kuid_t uid;
267
268 if (which > PRIO_USER || which < PRIO_PROCESS)
269 goto out;
270
271 /* normalize: avoid signed division (rounding problems) */
272 error = -ESRCH;
273 if (niceval < MIN_NICE)
274 niceval = MIN_NICE;
275 if (niceval > MAX_NICE)
276 niceval = MAX_NICE;
277
278 rcu_read_lock();
279 switch (which) {
280 case PRIO_PROCESS:
281 if (who)
282 p = find_task_by_vpid(who);
283 else
284 p = current;
285 if (p)
286 error = set_one_prio(p, niceval, error);
287 break;
288 case PRIO_PGRP:
289 if (who)
290 pgrp = find_vpid(who);
291 else
292 pgrp = task_pgrp(current);
293 read_lock(&tasklist_lock);
294 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
295 error = set_one_prio(p, niceval, error);
296 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
297 read_unlock(&tasklist_lock);
298 break;
299 case PRIO_USER:
300 uid = make_kuid(cred->user_ns, who);
301 user = cred->user;
302 if (!who)
303 uid = cred->uid;
304 else if (!uid_eq(uid, cred->uid)) {
305 user = find_user(uid);
306 if (!user)
307 goto out_unlock; /* No processes for this user */
308 }
309 for_each_process_thread(g, p) {
310 if (uid_eq(task_uid(p), uid) && task_pid_vnr(p))
311 error = set_one_prio(p, niceval, error);
312 }
313 if (!uid_eq(uid, cred->uid))
314 free_uid(user); /* For find_user() */
315 break;
316 }
317 out_unlock:
318 rcu_read_unlock();
319 out:
320 return error;
321 }
322
323 /*
324 * Ugh. To avoid negative return values, "getpriority()" will
325 * not return the normal nice-value, but a negated value that
326 * has been offset by 20 (ie it returns 40..1 instead of -20..19)
327 * to stay compatible.
328 */
329 SYSCALL_DEFINE2(getpriority, int, which, int, who)
330 {
331 struct task_struct *g, *p;
332 struct user_struct *user;
333 const struct cred *cred = current_cred();
334 long niceval, retval = -ESRCH;
335 struct pid *pgrp;
336 kuid_t uid;
337
338 if (which > PRIO_USER || which < PRIO_PROCESS)
339 return -EINVAL;
340
341 rcu_read_lock();
342 switch (which) {
343 case PRIO_PROCESS:
344 if (who)
345 p = find_task_by_vpid(who);
346 else
347 p = current;
348 if (p) {
349 niceval = nice_to_rlimit(task_nice(p));
350 if (niceval > retval)
351 retval = niceval;
352 }
353 break;
354 case PRIO_PGRP:
355 if (who)
356 pgrp = find_vpid(who);
357 else
358 pgrp = task_pgrp(current);
359 read_lock(&tasklist_lock);
360 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
361 niceval = nice_to_rlimit(task_nice(p));
362 if (niceval > retval)
363 retval = niceval;
364 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
365 read_unlock(&tasklist_lock);
366 break;
367 case PRIO_USER:
368 uid = make_kuid(cred->user_ns, who);
369 user = cred->user;
370 if (!who)
371 uid = cred->uid;
372 else if (!uid_eq(uid, cred->uid)) {
373 user = find_user(uid);
374 if (!user)
375 goto out_unlock; /* No processes for this user */
376 }
377 for_each_process_thread(g, p) {
378 if (uid_eq(task_uid(p), uid) && task_pid_vnr(p)) {
379 niceval = nice_to_rlimit(task_nice(p));
380 if (niceval > retval)
381 retval = niceval;
382 }
383 }
384 if (!uid_eq(uid, cred->uid))
385 free_uid(user); /* for find_user() */
386 break;
387 }
388 out_unlock:
389 rcu_read_unlock();
390
391 return retval;
392 }
393
394 /*
395 * Unprivileged users may change the real gid to the effective gid
396 * or vice versa. (BSD-style)
397 *
398 * If you set the real gid at all, or set the effective gid to a value not
399 * equal to the real gid, then the saved gid is set to the new effective gid.
400 *
401 * This makes it possible for a setgid program to completely drop its
402 * privileges, which is often a useful assertion to make when you are doing
403 * a security audit over a program.
404 *
405 * The general idea is that a program which uses just setregid() will be
406 * 100% compatible with BSD. A program which uses just setgid() will be
407 * 100% compatible with POSIX with saved IDs.
408 *
409 * SMP: There are not races, the GIDs are checked only by filesystem
410 * operations (as far as semantic preservation is concerned).
411 */
412 #ifdef CONFIG_MULTIUSER
413 long __sys_setregid(gid_t rgid, gid_t egid)
414 {
415 struct user_namespace *ns = current_user_ns();
416 const struct cred *old;
417 struct cred *new;
418 int retval;
419 kgid_t krgid, kegid;
420
421 krgid = make_kgid(ns, rgid);
422 kegid = make_kgid(ns, egid);
423
424 if ((rgid != (gid_t) -1) && !gid_valid(krgid))
425 return -EINVAL;
426 if ((egid != (gid_t) -1) && !gid_valid(kegid))
427 return -EINVAL;
428
429 new = prepare_creds();
430 if (!new)
431 return -ENOMEM;
432 old = current_cred();
433
434 retval = -EPERM;
435 if (rgid != (gid_t) -1) {
436 if (gid_eq(old->gid, krgid) ||
437 gid_eq(old->egid, krgid) ||
438 ns_capable_setid(old->user_ns, CAP_SETGID))
439 new->gid = krgid;
440 else
441 goto error;
442 }
443 if (egid != (gid_t) -1) {
444 if (gid_eq(old->gid, kegid) ||
445 gid_eq(old->egid, kegid) ||
446 gid_eq(old->sgid, kegid) ||
447 ns_capable_setid(old->user_ns, CAP_SETGID))
448 new->egid = kegid;
449 else
450 goto error;
451 }
452
453 if (rgid != (gid_t) -1 ||
454 (egid != (gid_t) -1 && !gid_eq(kegid, old->gid)))
455 new->sgid = new->egid;
456 new->fsgid = new->egid;
457
458 retval = security_task_fix_setgid(new, old, LSM_SETID_RE);
459 if (retval < 0)
460 goto error;
461
462 return commit_creds(new);
463
464 error:
465 abort_creds(new);
466 return retval;
467 }
468
469 SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid)
470 {
471 return __sys_setregid(rgid, egid);
472 }
473
474 /*
475 * setgid() is implemented like SysV w/ SAVED_IDS
476 *
477 * SMP: Same implicit races as above.
478 */
479 long __sys_setgid(gid_t gid)
480 {
481 struct user_namespace *ns = current_user_ns();
482 const struct cred *old;
483 struct cred *new;
484 int retval;
485 kgid_t kgid;
486
487 kgid = make_kgid(ns, gid);
488 if (!gid_valid(kgid))
489 return -EINVAL;
490
491 new = prepare_creds();
492 if (!new)
493 return -ENOMEM;
494 old = current_cred();
495
496 retval = -EPERM;
497 if (ns_capable_setid(old->user_ns, CAP_SETGID))
498 new->gid = new->egid = new->sgid = new->fsgid = kgid;
499 else if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->sgid))
500 new->egid = new->fsgid = kgid;
501 else
502 goto error;
503
504 retval = security_task_fix_setgid(new, old, LSM_SETID_ID);
505 if (retval < 0)
506 goto error;
507
508 return commit_creds(new);
509
510 error:
511 abort_creds(new);
512 return retval;
513 }
514
515 SYSCALL_DEFINE1(setgid, gid_t, gid)
516 {
517 return __sys_setgid(gid);
518 }
519
520 /*
521 * change the user struct in a credentials set to match the new UID
522 */
523 static int set_user(struct cred *new)
524 {
525 struct user_struct *new_user;
526
527 new_user = alloc_uid(new->uid);
528 if (!new_user)
529 return -EAGAIN;
530
531 free_uid(new->user);
532 new->user = new_user;
533 return 0;
534 }
535
536 static void flag_nproc_exceeded(struct cred *new)
537 {
538 if (new->ucounts == current_ucounts())
539 return;
540
541 /*
542 * We don't fail in case of NPROC limit excess here because too many
543 * poorly written programs don't check set*uid() return code, assuming
544 * it never fails if called by root. We may still enforce NPROC limit
545 * for programs doing set*uid()+execve() by harmlessly deferring the
546 * failure to the execve() stage.
547 */
548 if (is_rlimit_overlimit(new->ucounts, UCOUNT_RLIMIT_NPROC, rlimit(RLIMIT_NPROC)) &&
549 new->user != INIT_USER)
550 current->flags |= PF_NPROC_EXCEEDED;
551 else
552 current->flags &= ~PF_NPROC_EXCEEDED;
553 }
554
555 /*
556 * Unprivileged users may change the real uid to the effective uid
557 * or vice versa. (BSD-style)
558 *
559 * If you set the real uid at all, or set the effective uid to a value not
560 * equal to the real uid, then the saved uid is set to the new effective uid.
561 *
562 * This makes it possible for a setuid program to completely drop its
563 * privileges, which is often a useful assertion to make when you are doing
564 * a security audit over a program.
565 *
566 * The general idea is that a program which uses just setreuid() will be
567 * 100% compatible with BSD. A program which uses just setuid() will be
568 * 100% compatible with POSIX with saved IDs.
569 */
570 long __sys_setreuid(uid_t ruid, uid_t euid)
571 {
572 struct user_namespace *ns = current_user_ns();
573 const struct cred *old;
574 struct cred *new;
575 int retval;
576 kuid_t kruid, keuid;
577
578 kruid = make_kuid(ns, ruid);
579 keuid = make_kuid(ns, euid);
580
581 if ((ruid != (uid_t) -1) && !uid_valid(kruid))
582 return -EINVAL;
583 if ((euid != (uid_t) -1) && !uid_valid(keuid))
584 return -EINVAL;
585
586 new = prepare_creds();
587 if (!new)
588 return -ENOMEM;
589 old = current_cred();
590
591 retval = -EPERM;
592 if (ruid != (uid_t) -1) {
593 new->uid = kruid;
594 if (!uid_eq(old->uid, kruid) &&
595 !uid_eq(old->euid, kruid) &&
596 !ns_capable_setid(old->user_ns, CAP_SETUID))
597 goto error;
598 }
599
600 if (euid != (uid_t) -1) {
601 new->euid = keuid;
602 if (!uid_eq(old->uid, keuid) &&
603 !uid_eq(old->euid, keuid) &&
604 !uid_eq(old->suid, keuid) &&
605 !ns_capable_setid(old->user_ns, CAP_SETUID))
606 goto error;
607 }
608
609 if (!uid_eq(new->uid, old->uid)) {
610 retval = set_user(new);
611 if (retval < 0)
612 goto error;
613 }
614 if (ruid != (uid_t) -1 ||
615 (euid != (uid_t) -1 && !uid_eq(keuid, old->uid)))
616 new->suid = new->euid;
617 new->fsuid = new->euid;
618
619 retval = security_task_fix_setuid(new, old, LSM_SETID_RE);
620 if (retval < 0)
621 goto error;
622
623 retval = set_cred_ucounts(new);
624 if (retval < 0)
625 goto error;
626
627 flag_nproc_exceeded(new);
628 return commit_creds(new);
629
630 error:
631 abort_creds(new);
632 return retval;
633 }
634
635 SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid)
636 {
637 return __sys_setreuid(ruid, euid);
638 }
639
640 /*
641 * setuid() is implemented like SysV with SAVED_IDS
642 *
643 * Note that SAVED_ID's is deficient in that a setuid root program
644 * like sendmail, for example, cannot set its uid to be a normal
645 * user and then switch back, because if you're root, setuid() sets
646 * the saved uid too. If you don't like this, blame the bright people
647 * in the POSIX committee and/or USG. Note that the BSD-style setreuid()
648 * will allow a root program to temporarily drop privileges and be able to
649 * regain them by swapping the real and effective uid.
650 */
651 long __sys_setuid(uid_t uid)
652 {
653 struct user_namespace *ns = current_user_ns();
654 const struct cred *old;
655 struct cred *new;
656 int retval;
657 kuid_t kuid;
658
659 kuid = make_kuid(ns, uid);
660 if (!uid_valid(kuid))
661 return -EINVAL;
662
663 new = prepare_creds();
664 if (!new)
665 return -ENOMEM;
666 old = current_cred();
667
668 retval = -EPERM;
669 if (ns_capable_setid(old->user_ns, CAP_SETUID)) {
670 new->suid = new->uid = kuid;
671 if (!uid_eq(kuid, old->uid)) {
672 retval = set_user(new);
673 if (retval < 0)
674 goto error;
675 }
676 } else if (!uid_eq(kuid, old->uid) && !uid_eq(kuid, new->suid)) {
677 goto error;
678 }
679
680 new->fsuid = new->euid = kuid;
681
682 retval = security_task_fix_setuid(new, old, LSM_SETID_ID);
683 if (retval < 0)
684 goto error;
685
686 retval = set_cred_ucounts(new);
687 if (retval < 0)
688 goto error;
689
690 flag_nproc_exceeded(new);
691 return commit_creds(new);
692
693 error:
694 abort_creds(new);
695 return retval;
696 }
697
698 SYSCALL_DEFINE1(setuid, uid_t, uid)
699 {
700 return __sys_setuid(uid);
701 }
702
703
704 /*
705 * This function implements a generic ability to update ruid, euid,
706 * and suid. This allows you to implement the 4.4 compatible seteuid().
707 */
708 long __sys_setresuid(uid_t ruid, uid_t euid, uid_t suid)
709 {
710 struct user_namespace *ns = current_user_ns();
711 const struct cred *old;
712 struct cred *new;
713 int retval;
714 kuid_t kruid, keuid, ksuid;
715 bool ruid_new, euid_new, suid_new;
716
717 kruid = make_kuid(ns, ruid);
718 keuid = make_kuid(ns, euid);
719 ksuid = make_kuid(ns, suid);
720
721 if ((ruid != (uid_t) -1) && !uid_valid(kruid))
722 return -EINVAL;
723
724 if ((euid != (uid_t) -1) && !uid_valid(keuid))
725 return -EINVAL;
726
727 if ((suid != (uid_t) -1) && !uid_valid(ksuid))
728 return -EINVAL;
729
730 old = current_cred();
731
732 /* check for no-op */
733 if ((ruid == (uid_t) -1 || uid_eq(kruid, old->uid)) &&
734 (euid == (uid_t) -1 || (uid_eq(keuid, old->euid) &&
735 uid_eq(keuid, old->fsuid))) &&
736 (suid == (uid_t) -1 || uid_eq(ksuid, old->suid)))
737 return 0;
738
739 ruid_new = ruid != (uid_t) -1 && !uid_eq(kruid, old->uid) &&
740 !uid_eq(kruid, old->euid) && !uid_eq(kruid, old->suid);
741 euid_new = euid != (uid_t) -1 && !uid_eq(keuid, old->uid) &&
742 !uid_eq(keuid, old->euid) && !uid_eq(keuid, old->suid);
743 suid_new = suid != (uid_t) -1 && !uid_eq(ksuid, old->uid) &&
744 !uid_eq(ksuid, old->euid) && !uid_eq(ksuid, old->suid);
745 if ((ruid_new || euid_new || suid_new) &&
746 !ns_capable_setid(old->user_ns, CAP_SETUID))
747 return -EPERM;
748
749 new = prepare_creds();
750 if (!new)
751 return -ENOMEM;
752
753 if (ruid != (uid_t) -1) {
754 new->uid = kruid;
755 if (!uid_eq(kruid, old->uid)) {
756 retval = set_user(new);
757 if (retval < 0)
758 goto error;
759 }
760 }
761 if (euid != (uid_t) -1)
762 new->euid = keuid;
763 if (suid != (uid_t) -1)
764 new->suid = ksuid;
765 new->fsuid = new->euid;
766
767 retval = security_task_fix_setuid(new, old, LSM_SETID_RES);
768 if (retval < 0)
769 goto error;
770
771 retval = set_cred_ucounts(new);
772 if (retval < 0)
773 goto error;
774
775 flag_nproc_exceeded(new);
776 return commit_creds(new);
777
778 error:
779 abort_creds(new);
780 return retval;
781 }
782
783 SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid)
784 {
785 return __sys_setresuid(ruid, euid, suid);
786 }
787
788 SYSCALL_DEFINE3(getresuid, uid_t __user *, ruidp, uid_t __user *, euidp, uid_t __user *, suidp)
789 {
790 const struct cred *cred = current_cred();
791 int retval;
792 uid_t ruid, euid, suid;
793
794 ruid = from_kuid_munged(cred->user_ns, cred->uid);
795 euid = from_kuid_munged(cred->user_ns, cred->euid);
796 suid = from_kuid_munged(cred->user_ns, cred->suid);
797
798 retval = put_user(ruid, ruidp);
799 if (!retval) {
800 retval = put_user(euid, euidp);
801 if (!retval)
802 return put_user(suid, suidp);
803 }
804 return retval;
805 }
806
807 /*
808 * Same as above, but for rgid, egid, sgid.
809 */
810 long __sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid)
811 {
812 struct user_namespace *ns = current_user_ns();
813 const struct cred *old;
814 struct cred *new;
815 int retval;
816 kgid_t krgid, kegid, ksgid;
817 bool rgid_new, egid_new, sgid_new;
818
819 krgid = make_kgid(ns, rgid);
820 kegid = make_kgid(ns, egid);
821 ksgid = make_kgid(ns, sgid);
822
823 if ((rgid != (gid_t) -1) && !gid_valid(krgid))
824 return -EINVAL;
825 if ((egid != (gid_t) -1) && !gid_valid(kegid))
826 return -EINVAL;
827 if ((sgid != (gid_t) -1) && !gid_valid(ksgid))
828 return -EINVAL;
829
830 old = current_cred();
831
832 /* check for no-op */
833 if ((rgid == (gid_t) -1 || gid_eq(krgid, old->gid)) &&
834 (egid == (gid_t) -1 || (gid_eq(kegid, old->egid) &&
835 gid_eq(kegid, old->fsgid))) &&
836 (sgid == (gid_t) -1 || gid_eq(ksgid, old->sgid)))
837 return 0;
838
839 rgid_new = rgid != (gid_t) -1 && !gid_eq(krgid, old->gid) &&
840 !gid_eq(krgid, old->egid) && !gid_eq(krgid, old->sgid);
841 egid_new = egid != (gid_t) -1 && !gid_eq(kegid, old->gid) &&
842 !gid_eq(kegid, old->egid) && !gid_eq(kegid, old->sgid);
843 sgid_new = sgid != (gid_t) -1 && !gid_eq(ksgid, old->gid) &&
844 !gid_eq(ksgid, old->egid) && !gid_eq(ksgid, old->sgid);
845 if ((rgid_new || egid_new || sgid_new) &&
846 !ns_capable_setid(old->user_ns, CAP_SETGID))
847 return -EPERM;
848
849 new = prepare_creds();
850 if (!new)
851 return -ENOMEM;
852
853 if (rgid != (gid_t) -1)
854 new->gid = krgid;
855 if (egid != (gid_t) -1)
856 new->egid = kegid;
857 if (sgid != (gid_t) -1)
858 new->sgid = ksgid;
859 new->fsgid = new->egid;
860
861 retval = security_task_fix_setgid(new, old, LSM_SETID_RES);
862 if (retval < 0)
863 goto error;
864
865 return commit_creds(new);
866
867 error:
868 abort_creds(new);
869 return retval;
870 }
871
872 SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid)
873 {
874 return __sys_setresgid(rgid, egid, sgid);
875 }
876
877 SYSCALL_DEFINE3(getresgid, gid_t __user *, rgidp, gid_t __user *, egidp, gid_t __user *, sgidp)
878 {
879 const struct cred *cred = current_cred();
880 int retval;
881 gid_t rgid, egid, sgid;
882
883 rgid = from_kgid_munged(cred->user_ns, cred->gid);
884 egid = from_kgid_munged(cred->user_ns, cred->egid);
885 sgid = from_kgid_munged(cred->user_ns, cred->sgid);
886
887 retval = put_user(rgid, rgidp);
888 if (!retval) {
889 retval = put_user(egid, egidp);
890 if (!retval)
891 retval = put_user(sgid, sgidp);
892 }
893
894 return retval;
895 }
896
897
898 /*
899 * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This
900 * is used for "access()" and for the NFS daemon (letting nfsd stay at
901 * whatever uid it wants to). It normally shadows "euid", except when
902 * explicitly set by setfsuid() or for access..
903 */
904 long __sys_setfsuid(uid_t uid)
905 {
906 const struct cred *old;
907 struct cred *new;
908 uid_t old_fsuid;
909 kuid_t kuid;
910
911 old = current_cred();
912 old_fsuid = from_kuid_munged(old->user_ns, old->fsuid);
913
914 kuid = make_kuid(old->user_ns, uid);
915 if (!uid_valid(kuid))
916 return old_fsuid;
917
918 new = prepare_creds();
919 if (!new)
920 return old_fsuid;
921
922 if (uid_eq(kuid, old->uid) || uid_eq(kuid, old->euid) ||
923 uid_eq(kuid, old->suid) || uid_eq(kuid, old->fsuid) ||
924 ns_capable_setid(old->user_ns, CAP_SETUID)) {
925 if (!uid_eq(kuid, old->fsuid)) {
926 new->fsuid = kuid;
927 if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0)
928 goto change_okay;
929 }
930 }
931
932 abort_creds(new);
933 return old_fsuid;
934
935 change_okay:
936 commit_creds(new);
937 return old_fsuid;
938 }
939
940 SYSCALL_DEFINE1(setfsuid, uid_t, uid)
941 {
942 return __sys_setfsuid(uid);
943 }
944
945 /*
946 * Samma på svenska..
947 */
948 long __sys_setfsgid(gid_t gid)
949 {
950 const struct cred *old;
951 struct cred *new;
952 gid_t old_fsgid;
953 kgid_t kgid;
954
955 old = current_cred();
956 old_fsgid = from_kgid_munged(old->user_ns, old->fsgid);
957
958 kgid = make_kgid(old->user_ns, gid);
959 if (!gid_valid(kgid))
960 return old_fsgid;
961
962 new = prepare_creds();
963 if (!new)
964 return old_fsgid;
965
966 if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->egid) ||
967 gid_eq(kgid, old->sgid) || gid_eq(kgid, old->fsgid) ||
968 ns_capable_setid(old->user_ns, CAP_SETGID)) {
969 if (!gid_eq(kgid, old->fsgid)) {
970 new->fsgid = kgid;
971 if (security_task_fix_setgid(new,old,LSM_SETID_FS) == 0)
972 goto change_okay;
973 }
974 }
975
976 abort_creds(new);
977 return old_fsgid;
978
979 change_okay:
980 commit_creds(new);
981 return old_fsgid;
982 }
983
984 SYSCALL_DEFINE1(setfsgid, gid_t, gid)
985 {
986 return __sys_setfsgid(gid);
987 }
988 #endif /* CONFIG_MULTIUSER */
989
990 /**
991 * sys_getpid - return the thread group id of the current process
992 *
993 * Note, despite the name, this returns the tgid not the pid. The tgid and
994 * the pid are identical unless CLONE_THREAD was specified on clone() in
995 * which case the tgid is the same in all threads of the same group.
996 *
997 * This is SMP safe as current->tgid does not change.
998 */
999 SYSCALL_DEFINE0(getpid)
1000 {
1001 return task_tgid_vnr(current);
1002 }
1003
1004 /* Thread ID - the internal kernel "pid" */
1005 SYSCALL_DEFINE0(gettid)
1006 {
1007 return task_pid_vnr(current);
1008 }
1009
1010 /*
1011 * Accessing ->real_parent is not SMP-safe, it could
1012 * change from under us. However, we can use a stale
1013 * value of ->real_parent under rcu_read_lock(), see
1014 * release_task()->call_rcu(delayed_put_task_struct).
1015 */
1016 SYSCALL_DEFINE0(getppid)
1017 {
1018 int pid;
1019
1020 rcu_read_lock();
1021 pid = task_tgid_vnr(rcu_dereference(current->real_parent));
1022 rcu_read_unlock();
1023
1024 return pid;
1025 }
1026
1027 SYSCALL_DEFINE0(getuid)
1028 {
1029 /* Only we change this so SMP safe */
1030 return from_kuid_munged(current_user_ns(), current_uid());
1031 }
1032
1033 SYSCALL_DEFINE0(geteuid)
1034 {
1035 /* Only we change this so SMP safe */
1036 return from_kuid_munged(current_user_ns(), current_euid());
1037 }
1038
1039 SYSCALL_DEFINE0(getgid)
1040 {
1041 /* Only we change this so SMP safe */
1042 return from_kgid_munged(current_user_ns(), current_gid());
1043 }
1044
1045 SYSCALL_DEFINE0(getegid)
1046 {
1047 /* Only we change this so SMP safe */
1048 return from_kgid_munged(current_user_ns(), current_egid());
1049 }
1050
1051 static void do_sys_times(struct tms *tms)
1052 {
1053 u64 tgutime, tgstime, cutime, cstime;
1054
1055 thread_group_cputime_adjusted(current, &tgutime, &tgstime);
1056 cutime = current->signal->cutime;
1057 cstime = current->signal->cstime;
1058 tms->tms_utime = nsec_to_clock_t(tgutime);
1059 tms->tms_stime = nsec_to_clock_t(tgstime);
1060 tms->tms_cutime = nsec_to_clock_t(cutime);
1061 tms->tms_cstime = nsec_to_clock_t(cstime);
1062 }
1063
1064 SYSCALL_DEFINE1(times, struct tms __user *, tbuf)
1065 {
1066 if (tbuf) {
1067 struct tms tmp;
1068
1069 do_sys_times(&tmp);
1070 if (copy_to_user(tbuf, &tmp, sizeof(struct tms)))
1071 return -EFAULT;
1072 }
1073 force_successful_syscall_return();
1074 return (long) jiffies_64_to_clock_t(get_jiffies_64());
1075 }
1076
1077 #ifdef CONFIG_COMPAT
1078 static compat_clock_t clock_t_to_compat_clock_t(clock_t x)
1079 {
1080 return compat_jiffies_to_clock_t(clock_t_to_jiffies(x));
1081 }
1082
1083 COMPAT_SYSCALL_DEFINE1(times, struct compat_tms __user *, tbuf)
1084 {
1085 if (tbuf) {
1086 struct tms tms;
1087 struct compat_tms tmp;
1088
1089 do_sys_times(&tms);
1090 /* Convert our struct tms to the compat version. */
1091 tmp.tms_utime = clock_t_to_compat_clock_t(tms.tms_utime);
1092 tmp.tms_stime = clock_t_to_compat_clock_t(tms.tms_stime);
1093 tmp.tms_cutime = clock_t_to_compat_clock_t(tms.tms_cutime);
1094 tmp.tms_cstime = clock_t_to_compat_clock_t(tms.tms_cstime);
1095 if (copy_to_user(tbuf, &tmp, sizeof(tmp)))
1096 return -EFAULT;
1097 }
1098 force_successful_syscall_return();
1099 return compat_jiffies_to_clock_t(jiffies);
1100 }
1101 #endif
1102
1103 /*
1104 * This needs some heavy checking ...
1105 * I just haven't the stomach for it. I also don't fully
1106 * understand sessions/pgrp etc. Let somebody who does explain it.
1107 *
1108 * OK, I think I have the protection semantics right.... this is really
1109 * only important on a multi-user system anyway, to make sure one user
1110 * can't send a signal to a process owned by another. -TYT, 12/12/91
1111 *
1112 * !PF_FORKNOEXEC check to conform completely to POSIX.
1113 */
1114 SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid)
1115 {
1116 struct task_struct *p;
1117 struct task_struct *group_leader = current->group_leader;
1118 struct pid *pids[PIDTYPE_MAX] = { 0 };
1119 struct pid *pgrp;
1120 int err;
1121
1122 if (!pid)
1123 pid = task_pid_vnr(group_leader);
1124 if (!pgid)
1125 pgid = pid;
1126 if (pgid < 0)
1127 return -EINVAL;
1128 rcu_read_lock();
1129
1130 /* From this point forward we keep holding onto the tasklist lock
1131 * so that our parent does not change from under us. -DaveM
1132 */
1133 write_lock_irq(&tasklist_lock);
1134
1135 err = -ESRCH;
1136 p = find_task_by_vpid(pid);
1137 if (!p)
1138 goto out;
1139
1140 err = -EINVAL;
1141 if (!thread_group_leader(p))
1142 goto out;
1143
1144 if (same_thread_group(p->real_parent, group_leader)) {
1145 err = -EPERM;
1146 if (task_session(p) != task_session(group_leader))
1147 goto out;
1148 err = -EACCES;
1149 if (!(p->flags & PF_FORKNOEXEC))
1150 goto out;
1151 } else {
1152 err = -ESRCH;
1153 if (p != group_leader)
1154 goto out;
1155 }
1156
1157 err = -EPERM;
1158 if (p->signal->leader)
1159 goto out;
1160
1161 pgrp = task_pid(p);
1162 if (pgid != pid) {
1163 struct task_struct *g;
1164
1165 pgrp = find_vpid(pgid);
1166 g = pid_task(pgrp, PIDTYPE_PGID);
1167 if (!g || task_session(g) != task_session(group_leader))
1168 goto out;
1169 }
1170
1171 err = security_task_setpgid(p, pgid);
1172 if (err)
1173 goto out;
1174
1175 if (task_pgrp(p) != pgrp)
1176 change_pid(pids, p, PIDTYPE_PGID, pgrp);
1177
1178 err = 0;
1179 out:
1180 /* All paths lead to here, thus we are safe. -DaveM */
1181 write_unlock_irq(&tasklist_lock);
1182 rcu_read_unlock();
1183 free_pids(pids);
1184 return err;
1185 }
1186
1187 static int do_getpgid(pid_t pid)
1188 {
1189 struct task_struct *p;
1190 struct pid *grp;
1191 int retval;
1192
1193 rcu_read_lock();
1194 if (!pid)
1195 grp = task_pgrp(current);
1196 else {
1197 retval = -ESRCH;
1198 p = find_task_by_vpid(pid);
1199 if (!p)
1200 goto out;
1201 grp = task_pgrp(p);
1202 if (!grp)
1203 goto out;
1204
1205 retval = security_task_getpgid(p);
1206 if (retval)
1207 goto out;
1208 }
1209 retval = pid_vnr(grp);
1210 out:
1211 rcu_read_unlock();
1212 return retval;
1213 }
1214
1215 SYSCALL_DEFINE1(getpgid, pid_t, pid)
1216 {
1217 return do_getpgid(pid);
1218 }
1219
1220 #ifdef __ARCH_WANT_SYS_GETPGRP
1221
1222 SYSCALL_DEFINE0(getpgrp)
1223 {
1224 return do_getpgid(0);
1225 }
1226
1227 #endif
1228
1229 SYSCALL_DEFINE1(getsid, pid_t, pid)
1230 {
1231 struct task_struct *p;
1232 struct pid *sid;
1233 int retval;
1234
1235 rcu_read_lock();
1236 if (!pid)
1237 sid = task_session(current);
1238 else {
1239 retval = -ESRCH;
1240 p = find_task_by_vpid(pid);
1241 if (!p)
1242 goto out;
1243 sid = task_session(p);
1244 if (!sid)
1245 goto out;
1246
1247 retval = security_task_getsid(p);
1248 if (retval)
1249 goto out;
1250 }
1251 retval = pid_vnr(sid);
1252 out:
1253 rcu_read_unlock();
1254 return retval;
1255 }
1256
1257 static void set_special_pids(struct pid **pids, struct pid *pid)
1258 {
1259 struct task_struct *curr = current->group_leader;
1260
1261 if (task_session(curr) != pid)
1262 change_pid(pids, curr, PIDTYPE_SID, pid);
1263
1264 if (task_pgrp(curr) != pid)
1265 change_pid(pids, curr, PIDTYPE_PGID, pid);
1266 }
1267
1268 int ksys_setsid(void)
1269 {
1270 struct task_struct *group_leader = current->group_leader;
1271 struct pid *sid = task_pid(group_leader);
1272 struct pid *pids[PIDTYPE_MAX] = { 0 };
1273 pid_t session = pid_vnr(sid);
1274 int err = -EPERM;
1275
1276 write_lock_irq(&tasklist_lock);
1277 /* Fail if I am already a session leader */
1278 if (group_leader->signal->leader)
1279 goto out;
1280
1281 /* Fail if a process group id already exists that equals the
1282 * proposed session id.
1283 */
1284 if (pid_task(sid, PIDTYPE_PGID))
1285 goto out;
1286
1287 group_leader->signal->leader = 1;
1288 set_special_pids(pids, sid);
1289
1290 proc_clear_tty(group_leader);
1291
1292 err = session;
1293 out:
1294 write_unlock_irq(&tasklist_lock);
1295 free_pids(pids);
1296 if (err > 0) {
1297 proc_sid_connector(group_leader);
1298 sched_autogroup_create_attach(group_leader);
1299 }
1300 return err;
1301 }
1302
1303 SYSCALL_DEFINE0(setsid)
1304 {
1305 return ksys_setsid();
1306 }
1307
1308 DECLARE_RWSEM(uts_sem);
1309
1310 #ifdef COMPAT_UTS_MACHINE
1311 #define override_architecture(name) \
1312 (personality(current->personality) == PER_LINUX32 && \
1313 copy_to_user(name->machine, COMPAT_UTS_MACHINE, \
1314 sizeof(COMPAT_UTS_MACHINE)))
1315 #else
1316 #define override_architecture(name) 0
1317 #endif
1318
1319 /*
1320 * Work around broken programs that cannot handle "Linux 3.0".
1321 * Instead we map 3.x to 2.6.40+x, so e.g. 3.0 would be 2.6.40
1322 * And we map 4.x and later versions to 2.6.60+x, so 4.0/5.0/6.0/... would be
1323 * 2.6.60.
1324 */
1325 static int override_release(char __user *release, size_t len)
1326 {
1327 int ret = 0;
1328
1329 if (current->personality & UNAME26) {
1330 const char *rest = UTS_RELEASE;
1331 char buf[65] = { 0 };
1332 int ndots = 0;
1333 unsigned v;
1334 size_t copy;
1335
1336 while (*rest) {
1337 if (*rest == '.' && ++ndots >= 3)
1338 break;
1339 if (!isdigit(*rest) && *rest != '.')
1340 break;
1341 rest++;
1342 }
1343 v = LINUX_VERSION_PATCHLEVEL + 60;
1344 copy = clamp_t(size_t, len, 1, sizeof(buf));
1345 copy = scnprintf(buf, copy, "2.6.%u%s", v, rest);
1346 ret = copy_to_user(release, buf, copy + 1);
1347 }
1348 return ret;
1349 }
1350
1351 SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name)
1352 {
1353 struct new_utsname tmp;
1354
1355 down_read(&uts_sem);
1356 memcpy(&tmp, utsname(), sizeof(tmp));
1357 up_read(&uts_sem);
1358 if (copy_to_user(name, &tmp, sizeof(tmp)))
1359 return -EFAULT;
1360
1361 if (override_release(name->release, sizeof(name->release)))
1362 return -EFAULT;
1363 if (override_architecture(name))
1364 return -EFAULT;
1365 return 0;
1366 }
1367
1368 #ifdef __ARCH_WANT_SYS_OLD_UNAME
1369 /*
1370 * Old cruft
1371 */
1372 SYSCALL_DEFINE1(uname, struct old_utsname __user *, name)
1373 {
1374 struct old_utsname tmp;
1375
1376 if (!name)
1377 return -EFAULT;
1378
1379 down_read(&uts_sem);
1380 memcpy(&tmp, utsname(), sizeof(tmp));
1381 up_read(&uts_sem);
1382 if (copy_to_user(name, &tmp, sizeof(tmp)))
1383 return -EFAULT;
1384
1385 if (override_release(name->release, sizeof(name->release)))
1386 return -EFAULT;
1387 if (override_architecture(name))
1388 return -EFAULT;
1389 return 0;
1390 }
1391
1392 SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name)
1393 {
1394 struct oldold_utsname tmp;
1395
1396 if (!name)
1397 return -EFAULT;
1398
1399 memset(&tmp, 0, sizeof(tmp));
1400
1401 down_read(&uts_sem);
1402 memcpy(&tmp.sysname, &utsname()->sysname, __OLD_UTS_LEN);
1403 memcpy(&tmp.nodename, &utsname()->nodename, __OLD_UTS_LEN);
1404 memcpy(&tmp.release, &utsname()->release, __OLD_UTS_LEN);
1405 memcpy(&tmp.version, &utsname()->version, __OLD_UTS_LEN);
1406 memcpy(&tmp.machine, &utsname()->machine, __OLD_UTS_LEN);
1407 up_read(&uts_sem);
1408 if (copy_to_user(name, &tmp, sizeof(tmp)))
1409 return -EFAULT;
1410
1411 if (override_architecture(name))
1412 return -EFAULT;
1413 if (override_release(name->release, sizeof(name->release)))
1414 return -EFAULT;
1415 return 0;
1416 }
1417 #endif
1418
1419 SYSCALL_DEFINE2(sethostname, char __user *, name, int, len)
1420 {
1421 int errno;
1422 char tmp[__NEW_UTS_LEN];
1423
1424 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN))
1425 return -EPERM;
1426
1427 if (len < 0 || len > __NEW_UTS_LEN)
1428 return -EINVAL;
1429 errno = -EFAULT;
1430 if (!copy_from_user(tmp, name, len)) {
1431 struct new_utsname *u;
1432
1433 add_device_randomness(tmp, len);
1434 down_write(&uts_sem);
1435 u = utsname();
1436 memcpy(u->nodename, tmp, len);
1437 memset(u->nodename + len, 0, sizeof(u->nodename) - len);
1438 errno = 0;
1439 uts_proc_notify(UTS_PROC_HOSTNAME);
1440 up_write(&uts_sem);
1441 }
1442 return errno;
1443 }
1444
1445 #ifdef __ARCH_WANT_SYS_GETHOSTNAME
1446
1447 SYSCALL_DEFINE2(gethostname, char __user *, name, int, len)
1448 {
1449 int i;
1450 struct new_utsname *u;
1451 char tmp[__NEW_UTS_LEN + 1];
1452
1453 if (len < 0)
1454 return -EINVAL;
1455 down_read(&uts_sem);
1456 u = utsname();
1457 i = 1 + strlen(u->nodename);
1458 if (i > len)
1459 i = len;
1460 memcpy(tmp, u->nodename, i);
1461 up_read(&uts_sem);
1462 if (copy_to_user(name, tmp, i))
1463 return -EFAULT;
1464 return 0;
1465 }
1466
1467 #endif
1468
1469 /*
1470 * Only setdomainname; getdomainname can be implemented by calling
1471 * uname()
1472 */
1473 SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len)
1474 {
1475 int errno;
1476 char tmp[__NEW_UTS_LEN];
1477
1478 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN))
1479 return -EPERM;
1480 if (len < 0 || len > __NEW_UTS_LEN)
1481 return -EINVAL;
1482
1483 errno = -EFAULT;
1484 if (!copy_from_user(tmp, name, len)) {
1485 struct new_utsname *u;
1486
1487 add_device_randomness(tmp, len);
1488 down_write(&uts_sem);
1489 u = utsname();
1490 memcpy(u->domainname, tmp, len);
1491 memset(u->domainname + len, 0, sizeof(u->domainname) - len);
1492 errno = 0;
1493 uts_proc_notify(UTS_PROC_DOMAINNAME);
1494 up_write(&uts_sem);
1495 }
1496 return errno;
1497 }
1498
1499 /* make sure you are allowed to change @tsk limits before calling this */
1500 static int do_prlimit(struct task_struct *tsk, unsigned int resource,
1501 struct rlimit *new_rlim, struct rlimit *old_rlim)
1502 {
1503 struct rlimit *rlim;
1504 int retval = 0;
1505
1506 if (resource >= RLIM_NLIMITS)
1507 return -EINVAL;
1508 resource = array_index_nospec(resource, RLIM_NLIMITS);
1509
1510 if (new_rlim) {
1511 if (new_rlim->rlim_cur > new_rlim->rlim_max)
1512 return -EINVAL;
1513 if (resource == RLIMIT_NOFILE &&
1514 new_rlim->rlim_max > sysctl_nr_open)
1515 return -EPERM;
1516 }
1517
1518 /* Holding a refcount on tsk protects tsk->signal from disappearing. */
1519 rlim = tsk->signal->rlim + resource;
1520 task_lock(tsk->group_leader);
1521 if (new_rlim) {
1522 /*
1523 * Keep the capable check against init_user_ns until cgroups can
1524 * contain all limits.
1525 */
1526 if (new_rlim->rlim_max > rlim->rlim_max &&
1527 !capable(CAP_SYS_RESOURCE))
1528 retval = -EPERM;
1529 if (!retval)
1530 retval = security_task_setrlimit(tsk, resource, new_rlim);
1531 }
1532 if (!retval) {
1533 if (old_rlim)
1534 *old_rlim = *rlim;
1535 if (new_rlim)
1536 *rlim = *new_rlim;
1537 }
1538 task_unlock(tsk->group_leader);
1539
1540 /*
1541 * RLIMIT_CPU handling. Arm the posix CPU timer if the limit is not
1542 * infinite. In case of RLIM_INFINITY the posix CPU timer code
1543 * ignores the rlimit.
1544 */
1545 if (!retval && new_rlim && resource == RLIMIT_CPU &&
1546 new_rlim->rlim_cur != RLIM_INFINITY &&
1547 IS_ENABLED(CONFIG_POSIX_TIMERS)) {
1548 /*
1549 * update_rlimit_cpu can fail if the task is exiting, but there
1550 * may be other tasks in the thread group that are not exiting,
1551 * and they need their cpu timers adjusted.
1552 *
1553 * The group_leader is the last task to be released, so if we
1554 * cannot update_rlimit_cpu on it, then the entire process is
1555 * exiting and we do not need to update at all.
1556 */
1557 update_rlimit_cpu(tsk->group_leader, new_rlim->rlim_cur);
1558 }
1559
1560 return retval;
1561 }
1562
1563 SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim)
1564 {
1565 struct rlimit value;
1566 int ret;
1567
1568 ret = do_prlimit(current, resource, NULL, &value);
1569 if (!ret)
1570 ret = copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0;
1571
1572 return ret;
1573 }
1574
1575 #ifdef CONFIG_COMPAT
1576
1577 COMPAT_SYSCALL_DEFINE2(setrlimit, unsigned int, resource,
1578 struct compat_rlimit __user *, rlim)
1579 {
1580 struct rlimit r;
1581 struct compat_rlimit r32;
1582
1583 if (copy_from_user(&r32, rlim, sizeof(struct compat_rlimit)))
1584 return -EFAULT;
1585
1586 if (r32.rlim_cur == COMPAT_RLIM_INFINITY)
1587 r.rlim_cur = RLIM_INFINITY;
1588 else
1589 r.rlim_cur = r32.rlim_cur;
1590 if (r32.rlim_max == COMPAT_RLIM_INFINITY)
1591 r.rlim_max = RLIM_INFINITY;
1592 else
1593 r.rlim_max = r32.rlim_max;
1594 return do_prlimit(current, resource, &r, NULL);
1595 }
1596
1597 COMPAT_SYSCALL_DEFINE2(getrlimit, unsigned int, resource,
1598 struct compat_rlimit __user *, rlim)
1599 {
1600 struct rlimit r;
1601 int ret;
1602
1603 ret = do_prlimit(current, resource, NULL, &r);
1604 if (!ret) {
1605 struct compat_rlimit r32;
1606 if (r.rlim_cur > COMPAT_RLIM_INFINITY)
1607 r32.rlim_cur = COMPAT_RLIM_INFINITY;
1608 else
1609 r32.rlim_cur = r.rlim_cur;
1610 if (r.rlim_max > COMPAT_RLIM_INFINITY)
1611 r32.rlim_max = COMPAT_RLIM_INFINITY;
1612 else
1613 r32.rlim_max = r.rlim_max;
1614
1615 if (copy_to_user(rlim, &r32, sizeof(struct compat_rlimit)))
1616 return -EFAULT;
1617 }
1618 return ret;
1619 }
1620
1621 #endif
1622
1623 #ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT
1624
1625 /*
1626 * Back compatibility for getrlimit. Needed for some apps.
1627 */
1628 SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
1629 struct rlimit __user *, rlim)
1630 {
1631 struct rlimit x;
1632 if (resource >= RLIM_NLIMITS)
1633 return -EINVAL;
1634
1635 resource = array_index_nospec(resource, RLIM_NLIMITS);
1636 task_lock(current->group_leader);
1637 x = current->signal->rlim[resource];
1638 task_unlock(current->group_leader);
1639 if (x.rlim_cur > 0x7FFFFFFF)
1640 x.rlim_cur = 0x7FFFFFFF;
1641 if (x.rlim_max > 0x7FFFFFFF)
1642 x.rlim_max = 0x7FFFFFFF;
1643 return copy_to_user(rlim, &x, sizeof(x)) ? -EFAULT : 0;
1644 }
1645
1646 #ifdef CONFIG_COMPAT
1647 COMPAT_SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
1648 struct compat_rlimit __user *, rlim)
1649 {
1650 struct rlimit r;
1651
1652 if (resource >= RLIM_NLIMITS)
1653 return -EINVAL;
1654
1655 resource = array_index_nospec(resource, RLIM_NLIMITS);
1656 task_lock(current->group_leader);
1657 r = current->signal->rlim[resource];
1658 task_unlock(current->group_leader);
1659 if (r.rlim_cur > 0x7FFFFFFF)
1660 r.rlim_cur = 0x7FFFFFFF;
1661 if (r.rlim_max > 0x7FFFFFFF)
1662 r.rlim_max = 0x7FFFFFFF;
1663
1664 if (put_user(r.rlim_cur, &rlim->rlim_cur) ||
1665 put_user(r.rlim_max, &rlim->rlim_max))
1666 return -EFAULT;
1667 return 0;
1668 }
1669 #endif
1670
1671 #endif
1672
1673 static inline bool rlim64_is_infinity(__u64 rlim64)
1674 {
1675 #if BITS_PER_LONG < 64
1676 return rlim64 >= ULONG_MAX;
1677 #else
1678 return rlim64 == RLIM64_INFINITY;
1679 #endif
1680 }
1681
1682 static void rlim_to_rlim64(const struct rlimit *rlim, struct rlimit64 *rlim64)
1683 {
1684 if (rlim->rlim_cur == RLIM_INFINITY)
1685 rlim64->rlim_cur = RLIM64_INFINITY;
1686 else
1687 rlim64->rlim_cur = rlim->rlim_cur;
1688 if (rlim->rlim_max == RLIM_INFINITY)
1689 rlim64->rlim_max = RLIM64_INFINITY;
1690 else
1691 rlim64->rlim_max = rlim->rlim_max;
1692 }
1693
1694 static void rlim64_to_rlim(const struct rlimit64 *rlim64, struct rlimit *rlim)
1695 {
1696 if (rlim64_is_infinity(rlim64->rlim_cur))
1697 rlim->rlim_cur = RLIM_INFINITY;
1698 else
1699 rlim->rlim_cur = (unsigned long)rlim64->rlim_cur;
1700 if (rlim64_is_infinity(rlim64->rlim_max))
1701 rlim->rlim_max = RLIM_INFINITY;
1702 else
1703 rlim->rlim_max = (unsigned long)rlim64->rlim_max;
1704 }
1705
1706 /* rcu lock must be held */
1707 static int check_prlimit_permission(struct task_struct *task,
1708 unsigned int flags)
1709 {
1710 const struct cred *cred = current_cred(), *tcred;
1711 bool id_match;
1712
1713 if (current == task)
1714 return 0;
1715
1716 tcred = __task_cred(task);
1717 id_match = (uid_eq(cred->uid, tcred->euid) &&
1718 uid_eq(cred->uid, tcred->suid) &&
1719 uid_eq(cred->uid, tcred->uid) &&
1720 gid_eq(cred->gid, tcred->egid) &&
1721 gid_eq(cred->gid, tcred->sgid) &&
1722 gid_eq(cred->gid, tcred->gid));
1723 if (!id_match && !ns_capable(tcred->user_ns, CAP_SYS_RESOURCE))
1724 return -EPERM;
1725
1726 return security_task_prlimit(cred, tcred, flags);
1727 }
1728
1729 SYSCALL_DEFINE4(prlimit64, pid_t, pid, unsigned int, resource,
1730 const struct rlimit64 __user *, new_rlim,
1731 struct rlimit64 __user *, old_rlim)
1732 {
1733 struct rlimit64 old64, new64;
1734 struct rlimit old, new;
1735 struct task_struct *tsk;
1736 unsigned int checkflags = 0;
1737 int ret;
1738
1739 if (old_rlim)
1740 checkflags |= LSM_PRLIMIT_READ;
1741
1742 if (new_rlim) {
1743 if (copy_from_user(&new64, new_rlim, sizeof(new64)))
1744 return -EFAULT;
1745 rlim64_to_rlim(&new64, &new);
1746 checkflags |= LSM_PRLIMIT_WRITE;
1747 }
1748
1749 rcu_read_lock();
1750 tsk = pid ? find_task_by_vpid(pid) : current;
1751 if (!tsk) {
1752 rcu_read_unlock();
1753 return -ESRCH;
1754 }
1755 ret = check_prlimit_permission(tsk, checkflags);
1756 if (ret) {
1757 rcu_read_unlock();
1758 return ret;
1759 }
1760 get_task_struct(tsk);
1761 rcu_read_unlock();
1762
1763 ret = do_prlimit(tsk, resource, new_rlim ? &new : NULL,
1764 old_rlim ? &old : NULL);
1765
1766 if (!ret && old_rlim) {
1767 rlim_to_rlim64(&old, &old64);
1768 if (copy_to_user(old_rlim, &old64, sizeof(old64)))
1769 ret = -EFAULT;
1770 }
1771
1772 put_task_struct(tsk);
1773 return ret;
1774 }
1775
1776 SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim)
1777 {
1778 struct rlimit new_rlim;
1779
1780 if (copy_from_user(&new_rlim, rlim, sizeof(*rlim)))
1781 return -EFAULT;
1782 return do_prlimit(current, resource, &new_rlim, NULL);
1783 }
1784
1785 /*
1786 * It would make sense to put struct rusage in the task_struct,
1787 * except that would make the task_struct be *really big*. After
1788 * task_struct gets moved into malloc'ed memory, it would
1789 * make sense to do this. It will make moving the rest of the information
1790 * a lot simpler! (Which we're not doing right now because we're not
1791 * measuring them yet).
1792 *
1793 * When sampling multiple threads for RUSAGE_SELF, under SMP we might have
1794 * races with threads incrementing their own counters. But since word
1795 * reads are atomic, we either get new values or old values and we don't
1796 * care which for the sums. We always take the siglock to protect reading
1797 * the c* fields from p->signal from races with exit.c updating those
1798 * fields when reaping, so a sample either gets all the additions of a
1799 * given child after it's reaped, or none so this sample is before reaping.
1800 *
1801 * Locking:
1802 * We need to take the siglock for CHILDEREN, SELF and BOTH
1803 * for the cases current multithreaded, non-current single threaded
1804 * non-current multithreaded. Thread traversal is now safe with
1805 * the siglock held.
1806 * Strictly speaking, we donot need to take the siglock if we are current and
1807 * single threaded, as no one else can take our signal_struct away, no one
1808 * else can reap the children to update signal->c* counters, and no one else
1809 * can race with the signal-> fields. If we do not take any lock, the
1810 * signal-> fields could be read out of order while another thread was just
1811 * exiting. So we should place a read memory barrier when we avoid the lock.
1812 * On the writer side, write memory barrier is implied in __exit_signal
1813 * as __exit_signal releases the siglock spinlock after updating the signal->
1814 * fields. But we don't do this yet to keep things simple.
1815 *
1816 */
1817
1818 static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r)
1819 {
1820 r->ru_nvcsw += t->nvcsw;
1821 r->ru_nivcsw += t->nivcsw;
1822 r->ru_minflt += t->min_flt;
1823 r->ru_majflt += t->maj_flt;
1824 r->ru_inblock += task_io_get_inblock(t);
1825 r->ru_oublock += task_io_get_oublock(t);
1826 }
1827
1828 void getrusage(struct task_struct *p, int who, struct rusage *r)
1829 {
1830 struct task_struct *t;
1831 unsigned long flags;
1832 u64 tgutime, tgstime, utime, stime;
1833 unsigned long maxrss;
1834 struct mm_struct *mm;
1835 struct signal_struct *sig = p->signal;
1836 unsigned int seq = 0;
1837
1838 retry:
1839 memset(r, 0, sizeof(*r));
1840 utime = stime = 0;
1841 maxrss = 0;
1842
1843 if (who == RUSAGE_THREAD) {
1844 task_cputime_adjusted(current, &utime, &stime);
1845 accumulate_thread_rusage(p, r);
1846 maxrss = sig->maxrss;
1847 goto out_thread;
1848 }
1849
1850 flags = read_seqbegin_or_lock_irqsave(&sig->stats_lock, &seq);
1851
1852 switch (who) {
1853 case RUSAGE_BOTH:
1854 case RUSAGE_CHILDREN:
1855 utime = sig->cutime;
1856 stime = sig->cstime;
1857 r->ru_nvcsw = sig->cnvcsw;
1858 r->ru_nivcsw = sig->cnivcsw;
1859 r->ru_minflt = sig->cmin_flt;
1860 r->ru_majflt = sig->cmaj_flt;
1861 r->ru_inblock = sig->cinblock;
1862 r->ru_oublock = sig->coublock;
1863 maxrss = sig->cmaxrss;
1864
1865 if (who == RUSAGE_CHILDREN)
1866 break;
1867 fallthrough;
1868
1869 case RUSAGE_SELF:
1870 r->ru_nvcsw += sig->nvcsw;
1871 r->ru_nivcsw += sig->nivcsw;
1872 r->ru_minflt += sig->min_flt;
1873 r->ru_majflt += sig->maj_flt;
1874 r->ru_inblock += sig->inblock;
1875 r->ru_oublock += sig->oublock;
1876 if (maxrss < sig->maxrss)
1877 maxrss = sig->maxrss;
1878
1879 rcu_read_lock();
1880 __for_each_thread(sig, t)
1881 accumulate_thread_rusage(t, r);
1882 rcu_read_unlock();
1883
1884 break;
1885
1886 default:
1887 BUG();
1888 }
1889
1890 if (need_seqretry(&sig->stats_lock, seq)) {
1891 seq = 1;
1892 goto retry;
1893 }
1894 done_seqretry_irqrestore(&sig->stats_lock, seq, flags);
1895
1896 if (who == RUSAGE_CHILDREN)
1897 goto out_children;
1898
1899 thread_group_cputime_adjusted(p, &tgutime, &tgstime);
1900 utime += tgutime;
1901 stime += tgstime;
1902
1903 out_thread:
1904 mm = get_task_mm(p);
1905 if (mm) {
1906 setmax_mm_hiwater_rss(&maxrss, mm);
1907 mmput(mm);
1908 }
1909
1910 out_children:
1911 r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */
1912 r->ru_utime = ns_to_kernel_old_timeval(utime);
1913 r->ru_stime = ns_to_kernel_old_timeval(stime);
1914 }
1915
1916 SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru)
1917 {
1918 struct rusage r;
1919
1920 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
1921 who != RUSAGE_THREAD)
1922 return -EINVAL;
1923
1924 getrusage(current, who, &r);
1925 return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0;
1926 }
1927
1928 #ifdef CONFIG_COMPAT
1929 COMPAT_SYSCALL_DEFINE2(getrusage, int, who, struct compat_rusage __user *, ru)
1930 {
1931 struct rusage r;
1932
1933 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
1934 who != RUSAGE_THREAD)
1935 return -EINVAL;
1936
1937 getrusage(current, who, &r);
1938 return put_compat_rusage(&r, ru);
1939 }
1940 #endif
1941
1942 SYSCALL_DEFINE1(umask, int, mask)
1943 {
1944 mask = xchg(&current->fs->umask, mask & S_IRWXUGO);
1945 return mask;
1946 }
1947
1948 static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd)
1949 {
1950 CLASS(fd, exe)(fd);
1951 struct inode *inode;
1952 int err;
1953
1954 if (fd_empty(exe))
1955 return -EBADF;
1956
1957 inode = file_inode(fd_file(exe));
1958
1959 /*
1960 * Because the original mm->exe_file points to executable file, make
1961 * sure that this one is executable as well, to avoid breaking an
1962 * overall picture.
1963 */
1964 if (!S_ISREG(inode->i_mode) || path_noexec(&fd_file(exe)->f_path))
1965 return -EACCES;
1966
1967 err = file_permission(fd_file(exe), MAY_EXEC);
1968 if (err)
1969 return err;
1970
1971 return replace_mm_exe_file(mm, fd_file(exe));
1972 }
1973
1974 /*
1975 * Check arithmetic relations of passed addresses.
1976 *
1977 * WARNING: we don't require any capability here so be very careful
1978 * in what is allowed for modification from userspace.
1979 */
1980 static int validate_prctl_map_addr(struct prctl_mm_map *prctl_map)
1981 {
1982 unsigned long mmap_max_addr = TASK_SIZE;
1983 int error = -EINVAL, i;
1984
1985 static const unsigned char offsets[] = {
1986 offsetof(struct prctl_mm_map, start_code),
1987 offsetof(struct prctl_mm_map, end_code),
1988 offsetof(struct prctl_mm_map, start_data),
1989 offsetof(struct prctl_mm_map, end_data),
1990 offsetof(struct prctl_mm_map, start_brk),
1991 offsetof(struct prctl_mm_map, brk),
1992 offsetof(struct prctl_mm_map, start_stack),
1993 offsetof(struct prctl_mm_map, arg_start),
1994 offsetof(struct prctl_mm_map, arg_end),
1995 offsetof(struct prctl_mm_map, env_start),
1996 offsetof(struct prctl_mm_map, env_end),
1997 };
1998
1999 /*
2000 * Make sure the members are not somewhere outside
2001 * of allowed address space.
2002 */
2003 for (i = 0; i < ARRAY_SIZE(offsets); i++) {
2004 u64 val = *(u64 *)((char *)prctl_map + offsets[i]);
2005
2006 if ((unsigned long)val >= mmap_max_addr ||
2007 (unsigned long)val < mmap_min_addr)
2008 goto out;
2009 }
2010
2011 /*
2012 * Make sure the pairs are ordered.
2013 */
2014 #define __prctl_check_order(__m1, __op, __m2) \
2015 ((unsigned long)prctl_map->__m1 __op \
2016 (unsigned long)prctl_map->__m2) ? 0 : -EINVAL
2017 error = __prctl_check_order(start_code, <, end_code);
2018 error |= __prctl_check_order(start_data,<=, end_data);
2019 error |= __prctl_check_order(start_brk, <=, brk);
2020 error |= __prctl_check_order(arg_start, <=, arg_end);
2021 error |= __prctl_check_order(env_start, <=, env_end);
2022 if (error)
2023 goto out;
2024 #undef __prctl_check_order
2025
2026 error = -EINVAL;
2027
2028 /*
2029 * Neither we should allow to override limits if they set.
2030 */
2031 if (check_data_rlimit(rlimit(RLIMIT_DATA), prctl_map->brk,
2032 prctl_map->start_brk, prctl_map->end_data,
2033 prctl_map->start_data))
2034 goto out;
2035
2036 error = 0;
2037 out:
2038 return error;
2039 }
2040
2041 #ifdef CONFIG_CHECKPOINT_RESTORE
2042 static int prctl_set_mm_map(int opt, const void __user *addr, unsigned long data_size)
2043 {
2044 struct prctl_mm_map prctl_map = { .exe_fd = (u32)-1, };
2045 unsigned long user_auxv[AT_VECTOR_SIZE];
2046 struct mm_struct *mm = current->mm;
2047 int error;
2048
2049 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv));
2050 BUILD_BUG_ON(sizeof(struct prctl_mm_map) > 256);
2051
2052 if (opt == PR_SET_MM_MAP_SIZE)
2053 return put_user((unsigned int)sizeof(prctl_map),
2054 (unsigned int __user *)addr);
2055
2056 if (data_size != sizeof(prctl_map))
2057 return -EINVAL;
2058
2059 if (copy_from_user(&prctl_map, addr, sizeof(prctl_map)))
2060 return -EFAULT;
2061
2062 error = validate_prctl_map_addr(&prctl_map);
2063 if (error)
2064 return error;
2065
2066 if (prctl_map.auxv_size) {
2067 /*
2068 * Someone is trying to cheat the auxv vector.
2069 */
2070 if (!prctl_map.auxv ||
2071 prctl_map.auxv_size > sizeof(mm->saved_auxv))
2072 return -EINVAL;
2073
2074 memset(user_auxv, 0, sizeof(user_auxv));
2075 if (copy_from_user(user_auxv,
2076 (const void __user *)prctl_map.auxv,
2077 prctl_map.auxv_size))
2078 return -EFAULT;
2079
2080 /* Last entry must be AT_NULL as specification requires */
2081 user_auxv[AT_VECTOR_SIZE - 2] = AT_NULL;
2082 user_auxv[AT_VECTOR_SIZE - 1] = AT_NULL;
2083 }
2084
2085 if (prctl_map.exe_fd != (u32)-1) {
2086 /*
2087 * Check if the current user is checkpoint/restore capable.
2088 * At the time of this writing, it checks for CAP_SYS_ADMIN
2089 * or CAP_CHECKPOINT_RESTORE.
2090 * Note that a user with access to ptrace can masquerade an
2091 * arbitrary program as any executable, even setuid ones.
2092 * This may have implications in the tomoyo subsystem.
2093 */
2094 if (!checkpoint_restore_ns_capable(current_user_ns()))
2095 return -EPERM;
2096
2097 error = prctl_set_mm_exe_file(mm, prctl_map.exe_fd);
2098 if (error)
2099 return error;
2100 }
2101
2102 /*
2103 * arg_lock protects concurrent updates but we still need mmap_lock for
2104 * read to exclude races with sys_brk.
2105 */
2106 mmap_read_lock(mm);
2107
2108 /*
2109 * We don't validate if these members are pointing to
2110 * real present VMAs because application may have correspond
2111 * VMAs already unmapped and kernel uses these members for statistics
2112 * output in procfs mostly, except
2113 *
2114 * - @start_brk/@brk which are used in do_brk_flags but kernel lookups
2115 * for VMAs when updating these members so anything wrong written
2116 * here cause kernel to swear at userspace program but won't lead
2117 * to any problem in kernel itself
2118 */
2119
2120 spin_lock(&mm->arg_lock);
2121 mm->start_code = prctl_map.start_code;
2122 mm->end_code = prctl_map.end_code;
2123 mm->start_data = prctl_map.start_data;
2124 mm->end_data = prctl_map.end_data;
2125 mm->start_brk = prctl_map.start_brk;
2126 mm->brk = prctl_map.brk;
2127 mm->start_stack = prctl_map.start_stack;
2128 mm->arg_start = prctl_map.arg_start;
2129 mm->arg_end = prctl_map.arg_end;
2130 mm->env_start = prctl_map.env_start;
2131 mm->env_end = prctl_map.env_end;
2132 spin_unlock(&mm->arg_lock);
2133
2134 /*
2135 * Note this update of @saved_auxv is lockless thus
2136 * if someone reads this member in procfs while we're
2137 * updating -- it may get partly updated results. It's
2138 * known and acceptable trade off: we leave it as is to
2139 * not introduce additional locks here making the kernel
2140 * more complex.
2141 */
2142 if (prctl_map.auxv_size)
2143 memcpy(mm->saved_auxv, user_auxv, sizeof(user_auxv));
2144
2145 mmap_read_unlock(mm);
2146 return 0;
2147 }
2148 #endif /* CONFIG_CHECKPOINT_RESTORE */
2149
2150 static int prctl_set_auxv(struct mm_struct *mm, unsigned long addr,
2151 unsigned long len)
2152 {
2153 /*
2154 * This doesn't move the auxiliary vector itself since it's pinned to
2155 * mm_struct, but it permits filling the vector with new values. It's
2156 * up to the caller to provide sane values here, otherwise userspace
2157 * tools which use this vector might be unhappy.
2158 */
2159 unsigned long user_auxv[AT_VECTOR_SIZE] = {};
2160
2161 if (len > sizeof(user_auxv))
2162 return -EINVAL;
2163
2164 if (copy_from_user(user_auxv, (const void __user *)addr, len))
2165 return -EFAULT;
2166
2167 /* Make sure the last entry is always AT_NULL */
2168 user_auxv[AT_VECTOR_SIZE - 2] = 0;
2169 user_auxv[AT_VECTOR_SIZE - 1] = 0;
2170
2171 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv));
2172
2173 task_lock(current);
2174 memcpy(mm->saved_auxv, user_auxv, len);
2175 task_unlock(current);
2176
2177 return 0;
2178 }
2179
2180 static int prctl_set_mm(int opt, unsigned long addr,
2181 unsigned long arg4, unsigned long arg5)
2182 {
2183 struct mm_struct *mm = current->mm;
2184 struct prctl_mm_map prctl_map = {
2185 .auxv = NULL,
2186 .auxv_size = 0,
2187 .exe_fd = -1,
2188 };
2189 struct vm_area_struct *vma;
2190 int error;
2191
2192 if (arg5 || (arg4 && (opt != PR_SET_MM_AUXV &&
2193 opt != PR_SET_MM_MAP &&
2194 opt != PR_SET_MM_MAP_SIZE)))
2195 return -EINVAL;
2196
2197 #ifdef CONFIG_CHECKPOINT_RESTORE
2198 if (opt == PR_SET_MM_MAP || opt == PR_SET_MM_MAP_SIZE)
2199 return prctl_set_mm_map(opt, (const void __user *)addr, arg4);
2200 #endif
2201
2202 if (!capable(CAP_SYS_RESOURCE))
2203 return -EPERM;
2204
2205 if (opt == PR_SET_MM_EXE_FILE)
2206 return prctl_set_mm_exe_file(mm, (unsigned int)addr);
2207
2208 if (opt == PR_SET_MM_AUXV)
2209 return prctl_set_auxv(mm, addr, arg4);
2210
2211 if (addr >= TASK_SIZE || addr < mmap_min_addr)
2212 return -EINVAL;
2213
2214 error = -EINVAL;
2215
2216 /*
2217 * arg_lock protects concurrent updates of arg boundaries, we need
2218 * mmap_lock for a) concurrent sys_brk, b) finding VMA for addr
2219 * validation.
2220 */
2221 mmap_read_lock(mm);
2222 vma = find_vma(mm, addr);
2223
2224 spin_lock(&mm->arg_lock);
2225 prctl_map.start_code = mm->start_code;
2226 prctl_map.end_code = mm->end_code;
2227 prctl_map.start_data = mm->start_data;
2228 prctl_map.end_data = mm->end_data;
2229 prctl_map.start_brk = mm->start_brk;
2230 prctl_map.brk = mm->brk;
2231 prctl_map.start_stack = mm->start_stack;
2232 prctl_map.arg_start = mm->arg_start;
2233 prctl_map.arg_end = mm->arg_end;
2234 prctl_map.env_start = mm->env_start;
2235 prctl_map.env_end = mm->env_end;
2236
2237 switch (opt) {
2238 case PR_SET_MM_START_CODE:
2239 prctl_map.start_code = addr;
2240 break;
2241 case PR_SET_MM_END_CODE:
2242 prctl_map.end_code = addr;
2243 break;
2244 case PR_SET_MM_START_DATA:
2245 prctl_map.start_data = addr;
2246 break;
2247 case PR_SET_MM_END_DATA:
2248 prctl_map.end_data = addr;
2249 break;
2250 case PR_SET_MM_START_STACK:
2251 prctl_map.start_stack = addr;
2252 break;
2253 case PR_SET_MM_START_BRK:
2254 prctl_map.start_brk = addr;
2255 break;
2256 case PR_SET_MM_BRK:
2257 prctl_map.brk = addr;
2258 break;
2259 case PR_SET_MM_ARG_START:
2260 prctl_map.arg_start = addr;
2261 break;
2262 case PR_SET_MM_ARG_END:
2263 prctl_map.arg_end = addr;
2264 break;
2265 case PR_SET_MM_ENV_START:
2266 prctl_map.env_start = addr;
2267 break;
2268 case PR_SET_MM_ENV_END:
2269 prctl_map.env_end = addr;
2270 break;
2271 default:
2272 goto out;
2273 }
2274
2275 error = validate_prctl_map_addr(&prctl_map);
2276 if (error)
2277 goto out;
2278
2279 switch (opt) {
2280 /*
2281 * If command line arguments and environment
2282 * are placed somewhere else on stack, we can
2283 * set them up here, ARG_START/END to setup
2284 * command line arguments and ENV_START/END
2285 * for environment.
2286 */
2287 case PR_SET_MM_START_STACK:
2288 case PR_SET_MM_ARG_START:
2289 case PR_SET_MM_ARG_END:
2290 case PR_SET_MM_ENV_START:
2291 case PR_SET_MM_ENV_END:
2292 if (!vma) {
2293 error = -EFAULT;
2294 goto out;
2295 }
2296 }
2297
2298 mm->start_code = prctl_map.start_code;
2299 mm->end_code = prctl_map.end_code;
2300 mm->start_data = prctl_map.start_data;
2301 mm->end_data = prctl_map.end_data;
2302 mm->start_brk = prctl_map.start_brk;
2303 mm->brk = prctl_map.brk;
2304 mm->start_stack = prctl_map.start_stack;
2305 mm->arg_start = prctl_map.arg_start;
2306 mm->arg_end = prctl_map.arg_end;
2307 mm->env_start = prctl_map.env_start;
2308 mm->env_end = prctl_map.env_end;
2309
2310 error = 0;
2311 out:
2312 spin_unlock(&mm->arg_lock);
2313 mmap_read_unlock(mm);
2314 return error;
2315 }
2316
2317 #ifdef CONFIG_CHECKPOINT_RESTORE
2318 static int prctl_get_tid_address(struct task_struct *me, int __user * __user *tid_addr)
2319 {
2320 return put_user(me->clear_child_tid, tid_addr);
2321 }
2322 #else
2323 static int prctl_get_tid_address(struct task_struct *me, int __user * __user *tid_addr)
2324 {
2325 return -EINVAL;
2326 }
2327 #endif
2328
2329 static int propagate_has_child_subreaper(struct task_struct *p, void *data)
2330 {
2331 /*
2332 * If task has has_child_subreaper - all its descendants
2333 * already have these flag too and new descendants will
2334 * inherit it on fork, skip them.
2335 *
2336 * If we've found child_reaper - skip descendants in
2337 * it's subtree as they will never get out pidns.
2338 */
2339 if (p->signal->has_child_subreaper ||
2340 is_child_reaper(task_pid(p)))
2341 return 0;
2342
2343 p->signal->has_child_subreaper = 1;
2344 return 1;
2345 }
2346
2347 int __weak arch_prctl_spec_ctrl_get(struct task_struct *t, unsigned long which)
2348 {
2349 return -EINVAL;
2350 }
2351
2352 int __weak arch_prctl_spec_ctrl_set(struct task_struct *t, unsigned long which,
2353 unsigned long ctrl)
2354 {
2355 return -EINVAL;
2356 }
2357
2358 int __weak arch_get_shadow_stack_status(struct task_struct *t, unsigned long __user *status)
2359 {
2360 return -EINVAL;
2361 }
2362
2363 int __weak arch_set_shadow_stack_status(struct task_struct *t, unsigned long status)
2364 {
2365 return -EINVAL;
2366 }
2367
2368 int __weak arch_lock_shadow_stack_status(struct task_struct *t, unsigned long status)
2369 {
2370 return -EINVAL;
2371 }
2372
2373 #define PR_IO_FLUSHER (PF_MEMALLOC_NOIO | PF_LOCAL_THROTTLE)
2374
2375 static int prctl_set_vma(unsigned long opt, unsigned long addr,
2376 unsigned long size, unsigned long arg)
2377 {
2378 int error;
2379
2380 switch (opt) {
2381 case PR_SET_VMA_ANON_NAME:
2382 error = set_anon_vma_name(addr, size, (const char __user *)arg);
2383 break;
2384 default:
2385 error = -EINVAL;
2386 }
2387
2388 return error;
2389 }
2390
2391 static inline unsigned long get_current_mdwe(void)
2392 {
2393 unsigned long ret = 0;
2394
2395 if (test_bit(MMF_HAS_MDWE, &current->mm->flags))
2396 ret |= PR_MDWE_REFUSE_EXEC_GAIN;
2397 if (test_bit(MMF_HAS_MDWE_NO_INHERIT, &current->mm->flags))
2398 ret |= PR_MDWE_NO_INHERIT;
2399
2400 return ret;
2401 }
2402
2403 static inline int prctl_set_mdwe(unsigned long bits, unsigned long arg3,
2404 unsigned long arg4, unsigned long arg5)
2405 {
2406 unsigned long current_bits;
2407
2408 if (arg3 || arg4 || arg5)
2409 return -EINVAL;
2410
2411 if (bits & ~(PR_MDWE_REFUSE_EXEC_GAIN | PR_MDWE_NO_INHERIT))
2412 return -EINVAL;
2413
2414 /* NO_INHERIT only makes sense with REFUSE_EXEC_GAIN */
2415 if (bits & PR_MDWE_NO_INHERIT && !(bits & PR_MDWE_REFUSE_EXEC_GAIN))
2416 return -EINVAL;
2417
2418 /*
2419 * EOPNOTSUPP might be more appropriate here in principle, but
2420 * existing userspace depends on EINVAL specifically.
2421 */
2422 if (!arch_memory_deny_write_exec_supported())
2423 return -EINVAL;
2424
2425 current_bits = get_current_mdwe();
2426 if (current_bits && current_bits != bits)
2427 return -EPERM; /* Cannot unset the flags */
2428
2429 if (bits & PR_MDWE_NO_INHERIT)
2430 set_bit(MMF_HAS_MDWE_NO_INHERIT, &current->mm->flags);
2431 if (bits & PR_MDWE_REFUSE_EXEC_GAIN)
2432 set_bit(MMF_HAS_MDWE, &current->mm->flags);
2433
2434 return 0;
2435 }
2436
2437 static inline int prctl_get_mdwe(unsigned long arg2, unsigned long arg3,
2438 unsigned long arg4, unsigned long arg5)
2439 {
2440 if (arg2 || arg3 || arg4 || arg5)
2441 return -EINVAL;
2442 return get_current_mdwe();
2443 }
2444
2445 static int prctl_get_auxv(void __user *addr, unsigned long len)
2446 {
2447 struct mm_struct *mm = current->mm;
2448 unsigned long size = min_t(unsigned long, sizeof(mm->saved_auxv), len);
2449
2450 if (size && copy_to_user(addr, mm->saved_auxv, size))
2451 return -EFAULT;
2452 return sizeof(mm->saved_auxv);
2453 }
2454
2455 SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
2456 unsigned long, arg4, unsigned long, arg5)
2457 {
2458 struct task_struct *me = current;
2459 unsigned char comm[sizeof(me->comm)];
2460 long error;
2461
2462 error = security_task_prctl(option, arg2, arg3, arg4, arg5);
2463 if (error != -ENOSYS)
2464 return error;
2465
2466 error = 0;
2467 switch (option) {
2468 case PR_SET_PDEATHSIG:
2469 if (!valid_signal(arg2)) {
2470 error = -EINVAL;
2471 break;
2472 }
2473 me->pdeath_signal = arg2;
2474 break;
2475 case PR_GET_PDEATHSIG:
2476 error = put_user(me->pdeath_signal, (int __user *)arg2);
2477 break;
2478 case PR_GET_DUMPABLE:
2479 error = get_dumpable(me->mm);
2480 break;
2481 case PR_SET_DUMPABLE:
2482 if (arg2 != SUID_DUMP_DISABLE && arg2 != SUID_DUMP_USER) {
2483 error = -EINVAL;
2484 break;
2485 }
2486 set_dumpable(me->mm, arg2);
2487 break;
2488
2489 case PR_SET_UNALIGN:
2490 error = SET_UNALIGN_CTL(me, arg2);
2491 break;
2492 case PR_GET_UNALIGN:
2493 error = GET_UNALIGN_CTL(me, arg2);
2494 break;
2495 case PR_SET_FPEMU:
2496 error = SET_FPEMU_CTL(me, arg2);
2497 break;
2498 case PR_GET_FPEMU:
2499 error = GET_FPEMU_CTL(me, arg2);
2500 break;
2501 case PR_SET_FPEXC:
2502 error = SET_FPEXC_CTL(me, arg2);
2503 break;
2504 case PR_GET_FPEXC:
2505 error = GET_FPEXC_CTL(me, arg2);
2506 break;
2507 case PR_GET_TIMING:
2508 error = PR_TIMING_STATISTICAL;
2509 break;
2510 case PR_SET_TIMING:
2511 if (arg2 != PR_TIMING_STATISTICAL)
2512 error = -EINVAL;
2513 break;
2514 case PR_SET_NAME:
2515 comm[sizeof(me->comm) - 1] = 0;
2516 if (strncpy_from_user(comm, (char __user *)arg2,
2517 sizeof(me->comm) - 1) < 0)
2518 return -EFAULT;
2519 set_task_comm(me, comm);
2520 proc_comm_connector(me);
2521 break;
2522 case PR_GET_NAME:
2523 get_task_comm(comm, me);
2524 if (copy_to_user((char __user *)arg2, comm, sizeof(comm)))
2525 return -EFAULT;
2526 break;
2527 case PR_GET_ENDIAN:
2528 error = GET_ENDIAN(me, arg2);
2529 break;
2530 case PR_SET_ENDIAN:
2531 error = SET_ENDIAN(me, arg2);
2532 break;
2533 case PR_GET_SECCOMP:
2534 error = prctl_get_seccomp();
2535 break;
2536 case PR_SET_SECCOMP:
2537 error = prctl_set_seccomp(arg2, (char __user *)arg3);
2538 break;
2539 case PR_GET_TSC:
2540 error = GET_TSC_CTL(arg2);
2541 break;
2542 case PR_SET_TSC:
2543 error = SET_TSC_CTL(arg2);
2544 break;
2545 case PR_TASK_PERF_EVENTS_DISABLE:
2546 error = perf_event_task_disable();
2547 break;
2548 case PR_TASK_PERF_EVENTS_ENABLE:
2549 error = perf_event_task_enable();
2550 break;
2551 case PR_GET_TIMERSLACK:
2552 if (current->timer_slack_ns > ULONG_MAX)
2553 error = ULONG_MAX;
2554 else
2555 error = current->timer_slack_ns;
2556 break;
2557 case PR_SET_TIMERSLACK:
2558 if (rt_or_dl_task_policy(current))
2559 break;
2560 if (arg2 <= 0)
2561 current->timer_slack_ns =
2562 current->default_timer_slack_ns;
2563 else
2564 current->timer_slack_ns = arg2;
2565 break;
2566 case PR_MCE_KILL:
2567 if (arg4 | arg5)
2568 return -EINVAL;
2569 switch (arg2) {
2570 case PR_MCE_KILL_CLEAR:
2571 if (arg3 != 0)
2572 return -EINVAL;
2573 current->flags &= ~PF_MCE_PROCESS;
2574 break;
2575 case PR_MCE_KILL_SET:
2576 current->flags |= PF_MCE_PROCESS;
2577 if (arg3 == PR_MCE_KILL_EARLY)
2578 current->flags |= PF_MCE_EARLY;
2579 else if (arg3 == PR_MCE_KILL_LATE)
2580 current->flags &= ~PF_MCE_EARLY;
2581 else if (arg3 == PR_MCE_KILL_DEFAULT)
2582 current->flags &=
2583 ~(PF_MCE_EARLY|PF_MCE_PROCESS);
2584 else
2585 return -EINVAL;
2586 break;
2587 default:
2588 return -EINVAL;
2589 }
2590 break;
2591 case PR_MCE_KILL_GET:
2592 if (arg2 | arg3 | arg4 | arg5)
2593 return -EINVAL;
2594 if (current->flags & PF_MCE_PROCESS)
2595 error = (current->flags & PF_MCE_EARLY) ?
2596 PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE;
2597 else
2598 error = PR_MCE_KILL_DEFAULT;
2599 break;
2600 case PR_SET_MM:
2601 error = prctl_set_mm(arg2, arg3, arg4, arg5);
2602 break;
2603 case PR_GET_TID_ADDRESS:
2604 error = prctl_get_tid_address(me, (int __user * __user *)arg2);
2605 break;
2606 case PR_SET_CHILD_SUBREAPER:
2607 me->signal->is_child_subreaper = !!arg2;
2608 if (!arg2)
2609 break;
2610
2611 walk_process_tree(me, propagate_has_child_subreaper, NULL);
2612 break;
2613 case PR_GET_CHILD_SUBREAPER:
2614 error = put_user(me->signal->is_child_subreaper,
2615 (int __user *)arg2);
2616 break;
2617 case PR_SET_NO_NEW_PRIVS:
2618 if (arg2 != 1 || arg3 || arg4 || arg5)
2619 return -EINVAL;
2620
2621 task_set_no_new_privs(current);
2622 break;
2623 case PR_GET_NO_NEW_PRIVS:
2624 if (arg2 || arg3 || arg4 || arg5)
2625 return -EINVAL;
2626 return task_no_new_privs(current) ? 1 : 0;
2627 case PR_GET_THP_DISABLE:
2628 if (arg2 || arg3 || arg4 || arg5)
2629 return -EINVAL;
2630 error = !!test_bit(MMF_DISABLE_THP, &me->mm->flags);
2631 break;
2632 case PR_SET_THP_DISABLE:
2633 if (arg3 || arg4 || arg5)
2634 return -EINVAL;
2635 if (mmap_write_lock_killable(me->mm))
2636 return -EINTR;
2637 if (arg2)
2638 set_bit(MMF_DISABLE_THP, &me->mm->flags);
2639 else
2640 clear_bit(MMF_DISABLE_THP, &me->mm->flags);
2641 mmap_write_unlock(me->mm);
2642 break;
2643 case PR_MPX_ENABLE_MANAGEMENT:
2644 case PR_MPX_DISABLE_MANAGEMENT:
2645 /* No longer implemented: */
2646 return -EINVAL;
2647 case PR_SET_FP_MODE:
2648 error = SET_FP_MODE(me, arg2);
2649 break;
2650 case PR_GET_FP_MODE:
2651 error = GET_FP_MODE(me);
2652 break;
2653 case PR_SVE_SET_VL:
2654 error = SVE_SET_VL(arg2);
2655 break;
2656 case PR_SVE_GET_VL:
2657 error = SVE_GET_VL();
2658 break;
2659 case PR_SME_SET_VL:
2660 error = SME_SET_VL(arg2);
2661 break;
2662 case PR_SME_GET_VL:
2663 error = SME_GET_VL();
2664 break;
2665 case PR_GET_SPECULATION_CTRL:
2666 if (arg3 || arg4 || arg5)
2667 return -EINVAL;
2668 error = arch_prctl_spec_ctrl_get(me, arg2);
2669 break;
2670 case PR_SET_SPECULATION_CTRL:
2671 if (arg4 || arg5)
2672 return -EINVAL;
2673 error = arch_prctl_spec_ctrl_set(me, arg2, arg3);
2674 break;
2675 case PR_PAC_RESET_KEYS:
2676 if (arg3 || arg4 || arg5)
2677 return -EINVAL;
2678 error = PAC_RESET_KEYS(me, arg2);
2679 break;
2680 case PR_PAC_SET_ENABLED_KEYS:
2681 if (arg4 || arg5)
2682 return -EINVAL;
2683 error = PAC_SET_ENABLED_KEYS(me, arg2, arg3);
2684 break;
2685 case PR_PAC_GET_ENABLED_KEYS:
2686 if (arg2 || arg3 || arg4 || arg5)
2687 return -EINVAL;
2688 error = PAC_GET_ENABLED_KEYS(me);
2689 break;
2690 case PR_SET_TAGGED_ADDR_CTRL:
2691 if (arg3 || arg4 || arg5)
2692 return -EINVAL;
2693 error = SET_TAGGED_ADDR_CTRL(arg2);
2694 break;
2695 case PR_GET_TAGGED_ADDR_CTRL:
2696 if (arg2 || arg3 || arg4 || arg5)
2697 return -EINVAL;
2698 error = GET_TAGGED_ADDR_CTRL();
2699 break;
2700 case PR_SET_IO_FLUSHER:
2701 if (!capable(CAP_SYS_RESOURCE))
2702 return -EPERM;
2703
2704 if (arg3 || arg4 || arg5)
2705 return -EINVAL;
2706
2707 if (arg2 == 1)
2708 current->flags |= PR_IO_FLUSHER;
2709 else if (!arg2)
2710 current->flags &= ~PR_IO_FLUSHER;
2711 else
2712 return -EINVAL;
2713 break;
2714 case PR_GET_IO_FLUSHER:
2715 if (!capable(CAP_SYS_RESOURCE))
2716 return -EPERM;
2717
2718 if (arg2 || arg3 || arg4 || arg5)
2719 return -EINVAL;
2720
2721 error = (current->flags & PR_IO_FLUSHER) == PR_IO_FLUSHER;
2722 break;
2723 case PR_SET_SYSCALL_USER_DISPATCH:
2724 error = set_syscall_user_dispatch(arg2, arg3, arg4,
2725 (char __user *) arg5);
2726 break;
2727 #ifdef CONFIG_SCHED_CORE
2728 case PR_SCHED_CORE:
2729 error = sched_core_share_pid(arg2, arg3, arg4, arg5);
2730 break;
2731 #endif
2732 case PR_SET_MDWE:
2733 error = prctl_set_mdwe(arg2, arg3, arg4, arg5);
2734 break;
2735 case PR_GET_MDWE:
2736 error = prctl_get_mdwe(arg2, arg3, arg4, arg5);
2737 break;
2738 case PR_PPC_GET_DEXCR:
2739 if (arg3 || arg4 || arg5)
2740 return -EINVAL;
2741 error = PPC_GET_DEXCR_ASPECT(me, arg2);
2742 break;
2743 case PR_PPC_SET_DEXCR:
2744 if (arg4 || arg5)
2745 return -EINVAL;
2746 error = PPC_SET_DEXCR_ASPECT(me, arg2, arg3);
2747 break;
2748 case PR_SET_VMA:
2749 error = prctl_set_vma(arg2, arg3, arg4, arg5);
2750 break;
2751 case PR_GET_AUXV:
2752 if (arg4 || arg5)
2753 return -EINVAL;
2754 error = prctl_get_auxv((void __user *)arg2, arg3);
2755 break;
2756 #ifdef CONFIG_KSM
2757 case PR_SET_MEMORY_MERGE:
2758 if (arg3 || arg4 || arg5)
2759 return -EINVAL;
2760 if (mmap_write_lock_killable(me->mm))
2761 return -EINTR;
2762
2763 if (arg2)
2764 error = ksm_enable_merge_any(me->mm);
2765 else
2766 error = ksm_disable_merge_any(me->mm);
2767 mmap_write_unlock(me->mm);
2768 break;
2769 case PR_GET_MEMORY_MERGE:
2770 if (arg2 || arg3 || arg4 || arg5)
2771 return -EINVAL;
2772
2773 error = !!test_bit(MMF_VM_MERGE_ANY, &me->mm->flags);
2774 break;
2775 #endif
2776 case PR_RISCV_V_SET_CONTROL:
2777 error = RISCV_V_SET_CONTROL(arg2);
2778 break;
2779 case PR_RISCV_V_GET_CONTROL:
2780 error = RISCV_V_GET_CONTROL();
2781 break;
2782 case PR_RISCV_SET_ICACHE_FLUSH_CTX:
2783 error = RISCV_SET_ICACHE_FLUSH_CTX(arg2, arg3);
2784 break;
2785 case PR_GET_SHADOW_STACK_STATUS:
2786 if (arg3 || arg4 || arg5)
2787 return -EINVAL;
2788 error = arch_get_shadow_stack_status(me, (unsigned long __user *) arg2);
2789 break;
2790 case PR_SET_SHADOW_STACK_STATUS:
2791 if (arg3 || arg4 || arg5)
2792 return -EINVAL;
2793 error = arch_set_shadow_stack_status(me, arg2);
2794 break;
2795 case PR_LOCK_SHADOW_STACK_STATUS:
2796 if (arg3 || arg4 || arg5)
2797 return -EINVAL;
2798 error = arch_lock_shadow_stack_status(me, arg2);
2799 break;
2800 case PR_TIMER_CREATE_RESTORE_IDS:
2801 if (arg3 || arg4 || arg5)
2802 return -EINVAL;
2803 error = posixtimer_create_prctl(arg2);
2804 break;
2805 case PR_FUTEX_HASH:
2806 error = futex_hash_prctl(arg2, arg3, arg4);
2807 break;
2808 default:
2809 trace_task_prctl_unknown(option, arg2, arg3, arg4, arg5);
2810 error = -EINVAL;
2811 break;
2812 }
2813 return error;
2814 }
2815
2816 SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep,
2817 struct getcpu_cache __user *, unused)
2818 {
2819 int err = 0;
2820 int cpu = raw_smp_processor_id();
2821
2822 if (cpup)
2823 err |= put_user(cpu, cpup);
2824 if (nodep)
2825 err |= put_user(cpu_to_node(cpu), nodep);
2826 return err ? -EFAULT : 0;
2827 }
2828
2829 /**
2830 * do_sysinfo - fill in sysinfo struct
2831 * @info: pointer to buffer to fill
2832 */
2833 static int do_sysinfo(struct sysinfo *info)
2834 {
2835 unsigned long mem_total, sav_total;
2836 unsigned int mem_unit, bitcount;
2837 struct timespec64 tp;
2838
2839 memset(info, 0, sizeof(struct sysinfo));
2840
2841 ktime_get_boottime_ts64(&tp);
2842 timens_add_boottime(&tp);
2843 info->uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0);
2844
2845 get_avenrun(info->loads, 0, SI_LOAD_SHIFT - FSHIFT);
2846
2847 info->procs = nr_threads;
2848
2849 si_meminfo(info);
2850 si_swapinfo(info);
2851
2852 /*
2853 * If the sum of all the available memory (i.e. ram + swap)
2854 * is less than can be stored in a 32 bit unsigned long then
2855 * we can be binary compatible with 2.2.x kernels. If not,
2856 * well, in that case 2.2.x was broken anyways...
2857 *
2858 * -Erik Andersen <andersee@debian.org>
2859 */
2860
2861 mem_total = info->totalram + info->totalswap;
2862 if (mem_total < info->totalram || mem_total < info->totalswap)
2863 goto out;
2864 bitcount = 0;
2865 mem_unit = info->mem_unit;
2866 while (mem_unit > 1) {
2867 bitcount++;
2868 mem_unit >>= 1;
2869 sav_total = mem_total;
2870 mem_total <<= 1;
2871 if (mem_total < sav_total)
2872 goto out;
2873 }
2874
2875 /*
2876 * If mem_total did not overflow, multiply all memory values by
2877 * info->mem_unit and set it to 1. This leaves things compatible
2878 * with 2.2.x, and also retains compatibility with earlier 2.4.x
2879 * kernels...
2880 */
2881
2882 info->mem_unit = 1;
2883 info->totalram <<= bitcount;
2884 info->freeram <<= bitcount;
2885 info->sharedram <<= bitcount;
2886 info->bufferram <<= bitcount;
2887 info->totalswap <<= bitcount;
2888 info->freeswap <<= bitcount;
2889 info->totalhigh <<= bitcount;
2890 info->freehigh <<= bitcount;
2891
2892 out:
2893 return 0;
2894 }
2895
2896 SYSCALL_DEFINE1(sysinfo, struct sysinfo __user *, info)
2897 {
2898 struct sysinfo val;
2899
2900 do_sysinfo(&val);
2901
2902 if (copy_to_user(info, &val, sizeof(struct sysinfo)))
2903 return -EFAULT;
2904
2905 return 0;
2906 }
2907
2908 #ifdef CONFIG_COMPAT
2909 struct compat_sysinfo {
2910 s32 uptime;
2911 u32 loads[3];
2912 u32 totalram;
2913 u32 freeram;
2914 u32 sharedram;
2915 u32 bufferram;
2916 u32 totalswap;
2917 u32 freeswap;
2918 u16 procs;
2919 u16 pad;
2920 u32 totalhigh;
2921 u32 freehigh;
2922 u32 mem_unit;
2923 char _f[20-2*sizeof(u32)-sizeof(int)];
2924 };
2925
2926 COMPAT_SYSCALL_DEFINE1(sysinfo, struct compat_sysinfo __user *, info)
2927 {
2928 struct sysinfo s;
2929 struct compat_sysinfo s_32;
2930
2931 do_sysinfo(&s);
2932
2933 /* Check to see if any memory value is too large for 32-bit and scale
2934 * down if needed
2935 */
2936 if (upper_32_bits(s.totalram) || upper_32_bits(s.totalswap)) {
2937 int bitcount = 0;
2938
2939 while (s.mem_unit < PAGE_SIZE) {
2940 s.mem_unit <<= 1;
2941 bitcount++;
2942 }
2943
2944 s.totalram >>= bitcount;
2945 s.freeram >>= bitcount;
2946 s.sharedram >>= bitcount;
2947 s.bufferram >>= bitcount;
2948 s.totalswap >>= bitcount;
2949 s.freeswap >>= bitcount;
2950 s.totalhigh >>= bitcount;
2951 s.freehigh >>= bitcount;
2952 }
2953
2954 memset(&s_32, 0, sizeof(s_32));
2955 s_32.uptime = s.uptime;
2956 s_32.loads[0] = s.loads[0];
2957 s_32.loads[1] = s.loads[1];
2958 s_32.loads[2] = s.loads[2];
2959 s_32.totalram = s.totalram;
2960 s_32.freeram = s.freeram;
2961 s_32.sharedram = s.sharedram;
2962 s_32.bufferram = s.bufferram;
2963 s_32.totalswap = s.totalswap;
2964 s_32.freeswap = s.freeswap;
2965 s_32.procs = s.procs;
2966 s_32.totalhigh = s.totalhigh;
2967 s_32.freehigh = s.freehigh;
2968 s_32.mem_unit = s.mem_unit;
2969 if (copy_to_user(info, &s_32, sizeof(s_32)))
2970 return -EFAULT;
2971 return 0;
2972 }
2973 #endif /* CONFIG_COMPAT */
Upstream Linux kernel source code