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PM: Remove sysdev suspend, resume and shutdown operations
[deliverable/linux.git] / kernel / sys.c
1 /*
2 * linux/kernel/sys.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 */
6
7 #include <linux/module.h>
8 #include <linux/mm.h>
9 #include <linux/utsname.h>
10 #include <linux/mman.h>
11 #include <linux/notifier.h>
12 #include <linux/reboot.h>
13 #include <linux/prctl.h>
14 #include <linux/highuid.h>
15 #include <linux/fs.h>
16 #include <linux/perf_event.h>
17 #include <linux/resource.h>
18 #include <linux/kernel.h>
19 #include <linux/kexec.h>
20 #include <linux/workqueue.h>
21 #include <linux/capability.h>
22 #include <linux/device.h>
23 #include <linux/key.h>
24 #include <linux/times.h>
25 #include <linux/posix-timers.h>
26 #include <linux/security.h>
27 #include <linux/dcookies.h>
28 #include <linux/suspend.h>
29 #include <linux/tty.h>
30 #include <linux/signal.h>
31 #include <linux/cn_proc.h>
32 #include <linux/getcpu.h>
33 #include <linux/task_io_accounting_ops.h>
34 #include <linux/seccomp.h>
35 #include <linux/cpu.h>
36 #include <linux/personality.h>
37 #include <linux/ptrace.h>
38 #include <linux/fs_struct.h>
39 #include <linux/gfp.h>
40 #include <linux/syscore_ops.h>
41
42 #include <linux/compat.h>
43 #include <linux/syscalls.h>
44 #include <linux/kprobes.h>
45 #include <linux/user_namespace.h>
46
47 #include <linux/kmsg_dump.h>
48
49 #include <asm/uaccess.h>
50 #include <asm/io.h>
51 #include <asm/unistd.h>
52
53 #ifndef SET_UNALIGN_CTL
54 # define SET_UNALIGN_CTL(a,b) (-EINVAL)
55 #endif
56 #ifndef GET_UNALIGN_CTL
57 # define GET_UNALIGN_CTL(a,b) (-EINVAL)
58 #endif
59 #ifndef SET_FPEMU_CTL
60 # define SET_FPEMU_CTL(a,b) (-EINVAL)
61 #endif
62 #ifndef GET_FPEMU_CTL
63 # define GET_FPEMU_CTL(a,b) (-EINVAL)
64 #endif
65 #ifndef SET_FPEXC_CTL
66 # define SET_FPEXC_CTL(a,b) (-EINVAL)
67 #endif
68 #ifndef GET_FPEXC_CTL
69 # define GET_FPEXC_CTL(a,b) (-EINVAL)
70 #endif
71 #ifndef GET_ENDIAN
72 # define GET_ENDIAN(a,b) (-EINVAL)
73 #endif
74 #ifndef SET_ENDIAN
75 # define SET_ENDIAN(a,b) (-EINVAL)
76 #endif
77 #ifndef GET_TSC_CTL
78 # define GET_TSC_CTL(a) (-EINVAL)
79 #endif
80 #ifndef SET_TSC_CTL
81 # define SET_TSC_CTL(a) (-EINVAL)
82 #endif
83
84 /*
85 * this is where the system-wide overflow UID and GID are defined, for
86 * architectures that now have 32-bit UID/GID but didn't in the past
87 */
88
89 int overflowuid = DEFAULT_OVERFLOWUID;
90 int overflowgid = DEFAULT_OVERFLOWGID;
91
92 #ifdef CONFIG_UID16
93 EXPORT_SYMBOL(overflowuid);
94 EXPORT_SYMBOL(overflowgid);
95 #endif
96
97 /*
98 * the same as above, but for filesystems which can only store a 16-bit
99 * UID and GID. as such, this is needed on all architectures
100 */
101
102 int fs_overflowuid = DEFAULT_FS_OVERFLOWUID;
103 int fs_overflowgid = DEFAULT_FS_OVERFLOWUID;
104
105 EXPORT_SYMBOL(fs_overflowuid);
106 EXPORT_SYMBOL(fs_overflowgid);
107
108 /*
109 * this indicates whether you can reboot with ctrl-alt-del: the default is yes
110 */
111
112 int C_A_D = 1;
113 struct pid *cad_pid;
114 EXPORT_SYMBOL(cad_pid);
115
116 /*
117 * If set, this is used for preparing the system to power off.
118 */
119
120 void (*pm_power_off_prepare)(void);
121
122 /*
123 * Returns true if current's euid is same as p's uid or euid,
124 * or has CAP_SYS_NICE to p's user_ns.
125 *
126 * Called with rcu_read_lock, creds are safe
127 */
128 static bool set_one_prio_perm(struct task_struct *p)
129 {
130 const struct cred *cred = current_cred(), *pcred = __task_cred(p);
131
132 if (pcred->user->user_ns == cred->user->user_ns &&
133 (pcred->uid == cred->euid ||
134 pcred->euid == cred->euid))
135 return true;
136 if (ns_capable(pcred->user->user_ns, CAP_SYS_NICE))
137 return true;
138 return false;
139 }
140
141 /*
142 * set the priority of a task
143 * - the caller must hold the RCU read lock
144 */
145 static int set_one_prio(struct task_struct *p, int niceval, int error)
146 {
147 int no_nice;
148
149 if (!set_one_prio_perm(p)) {
150 error = -EPERM;
151 goto out;
152 }
153 if (niceval < task_nice(p) && !can_nice(p, niceval)) {
154 error = -EACCES;
155 goto out;
156 }
157 no_nice = security_task_setnice(p, niceval);
158 if (no_nice) {
159 error = no_nice;
160 goto out;
161 }
162 if (error == -ESRCH)
163 error = 0;
164 set_user_nice(p, niceval);
165 out:
166 return error;
167 }
168
169 SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval)
170 {
171 struct task_struct *g, *p;
172 struct user_struct *user;
173 const struct cred *cred = current_cred();
174 int error = -EINVAL;
175 struct pid *pgrp;
176
177 if (which > PRIO_USER || which < PRIO_PROCESS)
178 goto out;
179
180 /* normalize: avoid signed division (rounding problems) */
181 error = -ESRCH;
182 if (niceval < -20)
183 niceval = -20;
184 if (niceval > 19)
185 niceval = 19;
186
187 rcu_read_lock();
188 read_lock(&tasklist_lock);
189 switch (which) {
190 case PRIO_PROCESS:
191 if (who)
192 p = find_task_by_vpid(who);
193 else
194 p = current;
195 if (p)
196 error = set_one_prio(p, niceval, error);
197 break;
198 case PRIO_PGRP:
199 if (who)
200 pgrp = find_vpid(who);
201 else
202 pgrp = task_pgrp(current);
203 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
204 error = set_one_prio(p, niceval, error);
205 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
206 break;
207 case PRIO_USER:
208 user = (struct user_struct *) cred->user;
209 if (!who)
210 who = cred->uid;
211 else if ((who != cred->uid) &&
212 !(user = find_user(who)))
213 goto out_unlock; /* No processes for this user */
214
215 do_each_thread(g, p) {
216 if (__task_cred(p)->uid == who)
217 error = set_one_prio(p, niceval, error);
218 } while_each_thread(g, p);
219 if (who != cred->uid)
220 free_uid(user); /* For find_user() */
221 break;
222 }
223 out_unlock:
224 read_unlock(&tasklist_lock);
225 rcu_read_unlock();
226 out:
227 return error;
228 }
229
230 /*
231 * Ugh. To avoid negative return values, "getpriority()" will
232 * not return the normal nice-value, but a negated value that
233 * has been offset by 20 (ie it returns 40..1 instead of -20..19)
234 * to stay compatible.
235 */
236 SYSCALL_DEFINE2(getpriority, int, which, int, who)
237 {
238 struct task_struct *g, *p;
239 struct user_struct *user;
240 const struct cred *cred = current_cred();
241 long niceval, retval = -ESRCH;
242 struct pid *pgrp;
243
244 if (which > PRIO_USER || which < PRIO_PROCESS)
245 return -EINVAL;
246
247 rcu_read_lock();
248 read_lock(&tasklist_lock);
249 switch (which) {
250 case PRIO_PROCESS:
251 if (who)
252 p = find_task_by_vpid(who);
253 else
254 p = current;
255 if (p) {
256 niceval = 20 - task_nice(p);
257 if (niceval > retval)
258 retval = niceval;
259 }
260 break;
261 case PRIO_PGRP:
262 if (who)
263 pgrp = find_vpid(who);
264 else
265 pgrp = task_pgrp(current);
266 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
267 niceval = 20 - task_nice(p);
268 if (niceval > retval)
269 retval = niceval;
270 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
271 break;
272 case PRIO_USER:
273 user = (struct user_struct *) cred->user;
274 if (!who)
275 who = cred->uid;
276 else if ((who != cred->uid) &&
277 !(user = find_user(who)))
278 goto out_unlock; /* No processes for this user */
279
280 do_each_thread(g, p) {
281 if (__task_cred(p)->uid == who) {
282 niceval = 20 - task_nice(p);
283 if (niceval > retval)
284 retval = niceval;
285 }
286 } while_each_thread(g, p);
287 if (who != cred->uid)
288 free_uid(user); /* for find_user() */
289 break;
290 }
291 out_unlock:
292 read_unlock(&tasklist_lock);
293 rcu_read_unlock();
294
295 return retval;
296 }
297
298 /**
299 * emergency_restart - reboot the system
300 *
301 * Without shutting down any hardware or taking any locks
302 * reboot the system. This is called when we know we are in
303 * trouble so this is our best effort to reboot. This is
304 * safe to call in interrupt context.
305 */
306 void emergency_restart(void)
307 {
308 kmsg_dump(KMSG_DUMP_EMERG);
309 machine_emergency_restart();
310 }
311 EXPORT_SYMBOL_GPL(emergency_restart);
312
313 void kernel_restart_prepare(char *cmd)
314 {
315 blocking_notifier_call_chain(&reboot_notifier_list, SYS_RESTART, cmd);
316 system_state = SYSTEM_RESTART;
317 device_shutdown();
318 syscore_shutdown();
319 }
320
321 /**
322 * kernel_restart - reboot the system
323 * @cmd: pointer to buffer containing command to execute for restart
324 * or %NULL
325 *
326 * Shutdown everything and perform a clean reboot.
327 * This is not safe to call in interrupt context.
328 */
329 void kernel_restart(char *cmd)
330 {
331 kernel_restart_prepare(cmd);
332 if (!cmd)
333 printk(KERN_EMERG "Restarting system.\n");
334 else
335 printk(KERN_EMERG "Restarting system with command '%s'.\n", cmd);
336 kmsg_dump(KMSG_DUMP_RESTART);
337 machine_restart(cmd);
338 }
339 EXPORT_SYMBOL_GPL(kernel_restart);
340
341 static void kernel_shutdown_prepare(enum system_states state)
342 {
343 blocking_notifier_call_chain(&reboot_notifier_list,
344 (state == SYSTEM_HALT)?SYS_HALT:SYS_POWER_OFF, NULL);
345 system_state = state;
346 device_shutdown();
347 }
348 /**
349 * kernel_halt - halt the system
350 *
351 * Shutdown everything and perform a clean system halt.
352 */
353 void kernel_halt(void)
354 {
355 kernel_shutdown_prepare(SYSTEM_HALT);
356 syscore_shutdown();
357 printk(KERN_EMERG "System halted.\n");
358 kmsg_dump(KMSG_DUMP_HALT);
359 machine_halt();
360 }
361
362 EXPORT_SYMBOL_GPL(kernel_halt);
363
364 /**
365 * kernel_power_off - power_off the system
366 *
367 * Shutdown everything and perform a clean system power_off.
368 */
369 void kernel_power_off(void)
370 {
371 kernel_shutdown_prepare(SYSTEM_POWER_OFF);
372 if (pm_power_off_prepare)
373 pm_power_off_prepare();
374 disable_nonboot_cpus();
375 syscore_shutdown();
376 printk(KERN_EMERG "Power down.\n");
377 kmsg_dump(KMSG_DUMP_POWEROFF);
378 machine_power_off();
379 }
380 EXPORT_SYMBOL_GPL(kernel_power_off);
381
382 static DEFINE_MUTEX(reboot_mutex);
383
384 /*
385 * Reboot system call: for obvious reasons only root may call it,
386 * and even root needs to set up some magic numbers in the registers
387 * so that some mistake won't make this reboot the whole machine.
388 * You can also set the meaning of the ctrl-alt-del-key here.
389 *
390 * reboot doesn't sync: do that yourself before calling this.
391 */
392 SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd,
393 void __user *, arg)
394 {
395 char buffer[256];
396 int ret = 0;
397
398 /* We only trust the superuser with rebooting the system. */
399 if (!capable(CAP_SYS_BOOT))
400 return -EPERM;
401
402 /* For safety, we require "magic" arguments. */
403 if (magic1 != LINUX_REBOOT_MAGIC1 ||
404 (magic2 != LINUX_REBOOT_MAGIC2 &&
405 magic2 != LINUX_REBOOT_MAGIC2A &&
406 magic2 != LINUX_REBOOT_MAGIC2B &&
407 magic2 != LINUX_REBOOT_MAGIC2C))
408 return -EINVAL;
409
410 /* Instead of trying to make the power_off code look like
411 * halt when pm_power_off is not set do it the easy way.
412 */
413 if ((cmd == LINUX_REBOOT_CMD_POWER_OFF) && !pm_power_off)
414 cmd = LINUX_REBOOT_CMD_HALT;
415
416 mutex_lock(&reboot_mutex);
417 switch (cmd) {
418 case LINUX_REBOOT_CMD_RESTART:
419 kernel_restart(NULL);
420 break;
421
422 case LINUX_REBOOT_CMD_CAD_ON:
423 C_A_D = 1;
424 break;
425
426 case LINUX_REBOOT_CMD_CAD_OFF:
427 C_A_D = 0;
428 break;
429
430 case LINUX_REBOOT_CMD_HALT:
431 kernel_halt();
432 do_exit(0);
433 panic("cannot halt");
434
435 case LINUX_REBOOT_CMD_POWER_OFF:
436 kernel_power_off();
437 do_exit(0);
438 break;
439
440 case LINUX_REBOOT_CMD_RESTART2:
441 if (strncpy_from_user(&buffer[0], arg, sizeof(buffer) - 1) < 0) {
442 ret = -EFAULT;
443 break;
444 }
445 buffer[sizeof(buffer) - 1] = '\0';
446
447 kernel_restart(buffer);
448 break;
449
450 #ifdef CONFIG_KEXEC
451 case LINUX_REBOOT_CMD_KEXEC:
452 ret = kernel_kexec();
453 break;
454 #endif
455
456 #ifdef CONFIG_HIBERNATION
457 case LINUX_REBOOT_CMD_SW_SUSPEND:
458 ret = hibernate();
459 break;
460 #endif
461
462 default:
463 ret = -EINVAL;
464 break;
465 }
466 mutex_unlock(&reboot_mutex);
467 return ret;
468 }
469
470 static void deferred_cad(struct work_struct *dummy)
471 {
472 kernel_restart(NULL);
473 }
474
475 /*
476 * This function gets called by ctrl-alt-del - ie the keyboard interrupt.
477 * As it's called within an interrupt, it may NOT sync: the only choice
478 * is whether to reboot at once, or just ignore the ctrl-alt-del.
479 */
480 void ctrl_alt_del(void)
481 {
482 static DECLARE_WORK(cad_work, deferred_cad);
483
484 if (C_A_D)
485 schedule_work(&cad_work);
486 else
487 kill_cad_pid(SIGINT, 1);
488 }
489
490 /*
491 * Unprivileged users may change the real gid to the effective gid
492 * or vice versa. (BSD-style)
493 *
494 * If you set the real gid at all, or set the effective gid to a value not
495 * equal to the real gid, then the saved gid is set to the new effective gid.
496 *
497 * This makes it possible for a setgid program to completely drop its
498 * privileges, which is often a useful assertion to make when you are doing
499 * a security audit over a program.
500 *
501 * The general idea is that a program which uses just setregid() will be
502 * 100% compatible with BSD. A program which uses just setgid() will be
503 * 100% compatible with POSIX with saved IDs.
504 *
505 * SMP: There are not races, the GIDs are checked only by filesystem
506 * operations (as far as semantic preservation is concerned).
507 */
508 SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid)
509 {
510 const struct cred *old;
511 struct cred *new;
512 int retval;
513
514 new = prepare_creds();
515 if (!new)
516 return -ENOMEM;
517 old = current_cred();
518
519 retval = -EPERM;
520 if (rgid != (gid_t) -1) {
521 if (old->gid == rgid ||
522 old->egid == rgid ||
523 nsown_capable(CAP_SETGID))
524 new->gid = rgid;
525 else
526 goto error;
527 }
528 if (egid != (gid_t) -1) {
529 if (old->gid == egid ||
530 old->egid == egid ||
531 old->sgid == egid ||
532 nsown_capable(CAP_SETGID))
533 new->egid = egid;
534 else
535 goto error;
536 }
537
538 if (rgid != (gid_t) -1 ||
539 (egid != (gid_t) -1 && egid != old->gid))
540 new->sgid = new->egid;
541 new->fsgid = new->egid;
542
543 return commit_creds(new);
544
545 error:
546 abort_creds(new);
547 return retval;
548 }
549
550 /*
551 * setgid() is implemented like SysV w/ SAVED_IDS
552 *
553 * SMP: Same implicit races as above.
554 */
555 SYSCALL_DEFINE1(setgid, gid_t, gid)
556 {
557 const struct cred *old;
558 struct cred *new;
559 int retval;
560
561 new = prepare_creds();
562 if (!new)
563 return -ENOMEM;
564 old = current_cred();
565
566 retval = -EPERM;
567 if (nsown_capable(CAP_SETGID))
568 new->gid = new->egid = new->sgid = new->fsgid = gid;
569 else if (gid == old->gid || gid == old->sgid)
570 new->egid = new->fsgid = gid;
571 else
572 goto error;
573
574 return commit_creds(new);
575
576 error:
577 abort_creds(new);
578 return retval;
579 }
580
581 /*
582 * change the user struct in a credentials set to match the new UID
583 */
584 static int set_user(struct cred *new)
585 {
586 struct user_struct *new_user;
587
588 new_user = alloc_uid(current_user_ns(), new->uid);
589 if (!new_user)
590 return -EAGAIN;
591
592 if (atomic_read(&new_user->processes) >= rlimit(RLIMIT_NPROC) &&
593 new_user != INIT_USER) {
594 free_uid(new_user);
595 return -EAGAIN;
596 }
597
598 free_uid(new->user);
599 new->user = new_user;
600 return 0;
601 }
602
603 /*
604 * Unprivileged users may change the real uid to the effective uid
605 * or vice versa. (BSD-style)
606 *
607 * If you set the real uid at all, or set the effective uid to a value not
608 * equal to the real uid, then the saved uid is set to the new effective uid.
609 *
610 * This makes it possible for a setuid program to completely drop its
611 * privileges, which is often a useful assertion to make when you are doing
612 * a security audit over a program.
613 *
614 * The general idea is that a program which uses just setreuid() will be
615 * 100% compatible with BSD. A program which uses just setuid() will be
616 * 100% compatible with POSIX with saved IDs.
617 */
618 SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid)
619 {
620 const struct cred *old;
621 struct cred *new;
622 int retval;
623
624 new = prepare_creds();
625 if (!new)
626 return -ENOMEM;
627 old = current_cred();
628
629 retval = -EPERM;
630 if (ruid != (uid_t) -1) {
631 new->uid = ruid;
632 if (old->uid != ruid &&
633 old->euid != ruid &&
634 !nsown_capable(CAP_SETUID))
635 goto error;
636 }
637
638 if (euid != (uid_t) -1) {
639 new->euid = euid;
640 if (old->uid != euid &&
641 old->euid != euid &&
642 old->suid != euid &&
643 !nsown_capable(CAP_SETUID))
644 goto error;
645 }
646
647 if (new->uid != old->uid) {
648 retval = set_user(new);
649 if (retval < 0)
650 goto error;
651 }
652 if (ruid != (uid_t) -1 ||
653 (euid != (uid_t) -1 && euid != old->uid))
654 new->suid = new->euid;
655 new->fsuid = new->euid;
656
657 retval = security_task_fix_setuid(new, old, LSM_SETID_RE);
658 if (retval < 0)
659 goto error;
660
661 return commit_creds(new);
662
663 error:
664 abort_creds(new);
665 return retval;
666 }
667
668 /*
669 * setuid() is implemented like SysV with SAVED_IDS
670 *
671 * Note that SAVED_ID's is deficient in that a setuid root program
672 * like sendmail, for example, cannot set its uid to be a normal
673 * user and then switch back, because if you're root, setuid() sets
674 * the saved uid too. If you don't like this, blame the bright people
675 * in the POSIX committee and/or USG. Note that the BSD-style setreuid()
676 * will allow a root program to temporarily drop privileges and be able to
677 * regain them by swapping the real and effective uid.
678 */
679 SYSCALL_DEFINE1(setuid, uid_t, uid)
680 {
681 const struct cred *old;
682 struct cred *new;
683 int retval;
684
685 new = prepare_creds();
686 if (!new)
687 return -ENOMEM;
688 old = current_cred();
689
690 retval = -EPERM;
691 if (nsown_capable(CAP_SETUID)) {
692 new->suid = new->uid = uid;
693 if (uid != old->uid) {
694 retval = set_user(new);
695 if (retval < 0)
696 goto error;
697 }
698 } else if (uid != old->uid && uid != new->suid) {
699 goto error;
700 }
701
702 new->fsuid = new->euid = uid;
703
704 retval = security_task_fix_setuid(new, old, LSM_SETID_ID);
705 if (retval < 0)
706 goto error;
707
708 return commit_creds(new);
709
710 error:
711 abort_creds(new);
712 return retval;
713 }
714
715
716 /*
717 * This function implements a generic ability to update ruid, euid,
718 * and suid. This allows you to implement the 4.4 compatible seteuid().
719 */
720 SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid)
721 {
722 const struct cred *old;
723 struct cred *new;
724 int retval;
725
726 new = prepare_creds();
727 if (!new)
728 return -ENOMEM;
729
730 old = current_cred();
731
732 retval = -EPERM;
733 if (!nsown_capable(CAP_SETUID)) {
734 if (ruid != (uid_t) -1 && ruid != old->uid &&
735 ruid != old->euid && ruid != old->suid)
736 goto error;
737 if (euid != (uid_t) -1 && euid != old->uid &&
738 euid != old->euid && euid != old->suid)
739 goto error;
740 if (suid != (uid_t) -1 && suid != old->uid &&
741 suid != old->euid && suid != old->suid)
742 goto error;
743 }
744
745 if (ruid != (uid_t) -1) {
746 new->uid = ruid;
747 if (ruid != old->uid) {
748 retval = set_user(new);
749 if (retval < 0)
750 goto error;
751 }
752 }
753 if (euid != (uid_t) -1)
754 new->euid = euid;
755 if (suid != (uid_t) -1)
756 new->suid = suid;
757 new->fsuid = new->euid;
758
759 retval = security_task_fix_setuid(new, old, LSM_SETID_RES);
760 if (retval < 0)
761 goto error;
762
763 return commit_creds(new);
764
765 error:
766 abort_creds(new);
767 return retval;
768 }
769
770 SYSCALL_DEFINE3(getresuid, uid_t __user *, ruid, uid_t __user *, euid, uid_t __user *, suid)
771 {
772 const struct cred *cred = current_cred();
773 int retval;
774
775 if (!(retval = put_user(cred->uid, ruid)) &&
776 !(retval = put_user(cred->euid, euid)))
777 retval = put_user(cred->suid, suid);
778
779 return retval;
780 }
781
782 /*
783 * Same as above, but for rgid, egid, sgid.
784 */
785 SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid)
786 {
787 const struct cred *old;
788 struct cred *new;
789 int retval;
790
791 new = prepare_creds();
792 if (!new)
793 return -ENOMEM;
794 old = current_cred();
795
796 retval = -EPERM;
797 if (!nsown_capable(CAP_SETGID)) {
798 if (rgid != (gid_t) -1 && rgid != old->gid &&
799 rgid != old->egid && rgid != old->sgid)
800 goto error;
801 if (egid != (gid_t) -1 && egid != old->gid &&
802 egid != old->egid && egid != old->sgid)
803 goto error;
804 if (sgid != (gid_t) -1 && sgid != old->gid &&
805 sgid != old->egid && sgid != old->sgid)
806 goto error;
807 }
808
809 if (rgid != (gid_t) -1)
810 new->gid = rgid;
811 if (egid != (gid_t) -1)
812 new->egid = egid;
813 if (sgid != (gid_t) -1)
814 new->sgid = sgid;
815 new->fsgid = new->egid;
816
817 return commit_creds(new);
818
819 error:
820 abort_creds(new);
821 return retval;
822 }
823
824 SYSCALL_DEFINE3(getresgid, gid_t __user *, rgid, gid_t __user *, egid, gid_t __user *, sgid)
825 {
826 const struct cred *cred = current_cred();
827 int retval;
828
829 if (!(retval = put_user(cred->gid, rgid)) &&
830 !(retval = put_user(cred->egid, egid)))
831 retval = put_user(cred->sgid, sgid);
832
833 return retval;
834 }
835
836
837 /*
838 * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This
839 * is used for "access()" and for the NFS daemon (letting nfsd stay at
840 * whatever uid it wants to). It normally shadows "euid", except when
841 * explicitly set by setfsuid() or for access..
842 */
843 SYSCALL_DEFINE1(setfsuid, uid_t, uid)
844 {
845 const struct cred *old;
846 struct cred *new;
847 uid_t old_fsuid;
848
849 new = prepare_creds();
850 if (!new)
851 return current_fsuid();
852 old = current_cred();
853 old_fsuid = old->fsuid;
854
855 if (uid == old->uid || uid == old->euid ||
856 uid == old->suid || uid == old->fsuid ||
857 nsown_capable(CAP_SETUID)) {
858 if (uid != old_fsuid) {
859 new->fsuid = uid;
860 if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0)
861 goto change_okay;
862 }
863 }
864
865 abort_creds(new);
866 return old_fsuid;
867
868 change_okay:
869 commit_creds(new);
870 return old_fsuid;
871 }
872
873 /*
874 * Samma på svenska..
875 */
876 SYSCALL_DEFINE1(setfsgid, gid_t, gid)
877 {
878 const struct cred *old;
879 struct cred *new;
880 gid_t old_fsgid;
881
882 new = prepare_creds();
883 if (!new)
884 return current_fsgid();
885 old = current_cred();
886 old_fsgid = old->fsgid;
887
888 if (gid == old->gid || gid == old->egid ||
889 gid == old->sgid || gid == old->fsgid ||
890 nsown_capable(CAP_SETGID)) {
891 if (gid != old_fsgid) {
892 new->fsgid = gid;
893 goto change_okay;
894 }
895 }
896
897 abort_creds(new);
898 return old_fsgid;
899
900 change_okay:
901 commit_creds(new);
902 return old_fsgid;
903 }
904
905 void do_sys_times(struct tms *tms)
906 {
907 cputime_t tgutime, tgstime, cutime, cstime;
908
909 spin_lock_irq(&current->sighand->siglock);
910 thread_group_times(current, &tgutime, &tgstime);
911 cutime = current->signal->cutime;
912 cstime = current->signal->cstime;
913 spin_unlock_irq(&current->sighand->siglock);
914 tms->tms_utime = cputime_to_clock_t(tgutime);
915 tms->tms_stime = cputime_to_clock_t(tgstime);
916 tms->tms_cutime = cputime_to_clock_t(cutime);
917 tms->tms_cstime = cputime_to_clock_t(cstime);
918 }
919
920 SYSCALL_DEFINE1(times, struct tms __user *, tbuf)
921 {
922 if (tbuf) {
923 struct tms tmp;
924
925 do_sys_times(&tmp);
926 if (copy_to_user(tbuf, &tmp, sizeof(struct tms)))
927 return -EFAULT;
928 }
929 force_successful_syscall_return();
930 return (long) jiffies_64_to_clock_t(get_jiffies_64());
931 }
932
933 /*
934 * This needs some heavy checking ...
935 * I just haven't the stomach for it. I also don't fully
936 * understand sessions/pgrp etc. Let somebody who does explain it.
937 *
938 * OK, I think I have the protection semantics right.... this is really
939 * only important on a multi-user system anyway, to make sure one user
940 * can't send a signal to a process owned by another. -TYT, 12/12/91
941 *
942 * Auch. Had to add the 'did_exec' flag to conform completely to POSIX.
943 * LBT 04.03.94
944 */
945 SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid)
946 {
947 struct task_struct *p;
948 struct task_struct *group_leader = current->group_leader;
949 struct pid *pgrp;
950 int err;
951
952 if (!pid)
953 pid = task_pid_vnr(group_leader);
954 if (!pgid)
955 pgid = pid;
956 if (pgid < 0)
957 return -EINVAL;
958 rcu_read_lock();
959
960 /* From this point forward we keep holding onto the tasklist lock
961 * so that our parent does not change from under us. -DaveM
962 */
963 write_lock_irq(&tasklist_lock);
964
965 err = -ESRCH;
966 p = find_task_by_vpid(pid);
967 if (!p)
968 goto out;
969
970 err = -EINVAL;
971 if (!thread_group_leader(p))
972 goto out;
973
974 if (same_thread_group(p->real_parent, group_leader)) {
975 err = -EPERM;
976 if (task_session(p) != task_session(group_leader))
977 goto out;
978 err = -EACCES;
979 if (p->did_exec)
980 goto out;
981 } else {
982 err = -ESRCH;
983 if (p != group_leader)
984 goto out;
985 }
986
987 err = -EPERM;
988 if (p->signal->leader)
989 goto out;
990
991 pgrp = task_pid(p);
992 if (pgid != pid) {
993 struct task_struct *g;
994
995 pgrp = find_vpid(pgid);
996 g = pid_task(pgrp, PIDTYPE_PGID);
997 if (!g || task_session(g) != task_session(group_leader))
998 goto out;
999 }
1000
1001 err = security_task_setpgid(p, pgid);
1002 if (err)
1003 goto out;
1004
1005 if (task_pgrp(p) != pgrp)
1006 change_pid(p, PIDTYPE_PGID, pgrp);
1007
1008 err = 0;
1009 out:
1010 /* All paths lead to here, thus we are safe. -DaveM */
1011 write_unlock_irq(&tasklist_lock);
1012 rcu_read_unlock();
1013 return err;
1014 }
1015
1016 SYSCALL_DEFINE1(getpgid, pid_t, pid)
1017 {
1018 struct task_struct *p;
1019 struct pid *grp;
1020 int retval;
1021
1022 rcu_read_lock();
1023 if (!pid)
1024 grp = task_pgrp(current);
1025 else {
1026 retval = -ESRCH;
1027 p = find_task_by_vpid(pid);
1028 if (!p)
1029 goto out;
1030 grp = task_pgrp(p);
1031 if (!grp)
1032 goto out;
1033
1034 retval = security_task_getpgid(p);
1035 if (retval)
1036 goto out;
1037 }
1038 retval = pid_vnr(grp);
1039 out:
1040 rcu_read_unlock();
1041 return retval;
1042 }
1043
1044 #ifdef __ARCH_WANT_SYS_GETPGRP
1045
1046 SYSCALL_DEFINE0(getpgrp)
1047 {
1048 return sys_getpgid(0);
1049 }
1050
1051 #endif
1052
1053 SYSCALL_DEFINE1(getsid, pid_t, pid)
1054 {
1055 struct task_struct *p;
1056 struct pid *sid;
1057 int retval;
1058
1059 rcu_read_lock();
1060 if (!pid)
1061 sid = task_session(current);
1062 else {
1063 retval = -ESRCH;
1064 p = find_task_by_vpid(pid);
1065 if (!p)
1066 goto out;
1067 sid = task_session(p);
1068 if (!sid)
1069 goto out;
1070
1071 retval = security_task_getsid(p);
1072 if (retval)
1073 goto out;
1074 }
1075 retval = pid_vnr(sid);
1076 out:
1077 rcu_read_unlock();
1078 return retval;
1079 }
1080
1081 SYSCALL_DEFINE0(setsid)
1082 {
1083 struct task_struct *group_leader = current->group_leader;
1084 struct pid *sid = task_pid(group_leader);
1085 pid_t session = pid_vnr(sid);
1086 int err = -EPERM;
1087
1088 write_lock_irq(&tasklist_lock);
1089 /* Fail if I am already a session leader */
1090 if (group_leader->signal->leader)
1091 goto out;
1092
1093 /* Fail if a process group id already exists that equals the
1094 * proposed session id.
1095 */
1096 if (pid_task(sid, PIDTYPE_PGID))
1097 goto out;
1098
1099 group_leader->signal->leader = 1;
1100 __set_special_pids(sid);
1101
1102 proc_clear_tty(group_leader);
1103
1104 err = session;
1105 out:
1106 write_unlock_irq(&tasklist_lock);
1107 if (err > 0) {
1108 proc_sid_connector(group_leader);
1109 sched_autogroup_create_attach(group_leader);
1110 }
1111 return err;
1112 }
1113
1114 DECLARE_RWSEM(uts_sem);
1115
1116 #ifdef COMPAT_UTS_MACHINE
1117 #define override_architecture(name) \
1118 (personality(current->personality) == PER_LINUX32 && \
1119 copy_to_user(name->machine, COMPAT_UTS_MACHINE, \
1120 sizeof(COMPAT_UTS_MACHINE)))
1121 #else
1122 #define override_architecture(name) 0
1123 #endif
1124
1125 SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name)
1126 {
1127 int errno = 0;
1128
1129 down_read(&uts_sem);
1130 if (copy_to_user(name, utsname(), sizeof *name))
1131 errno = -EFAULT;
1132 up_read(&uts_sem);
1133
1134 if (!errno && override_architecture(name))
1135 errno = -EFAULT;
1136 return errno;
1137 }
1138
1139 #ifdef __ARCH_WANT_SYS_OLD_UNAME
1140 /*
1141 * Old cruft
1142 */
1143 SYSCALL_DEFINE1(uname, struct old_utsname __user *, name)
1144 {
1145 int error = 0;
1146
1147 if (!name)
1148 return -EFAULT;
1149
1150 down_read(&uts_sem);
1151 if (copy_to_user(name, utsname(), sizeof(*name)))
1152 error = -EFAULT;
1153 up_read(&uts_sem);
1154
1155 if (!error && override_architecture(name))
1156 error = -EFAULT;
1157 return error;
1158 }
1159
1160 SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name)
1161 {
1162 int error;
1163
1164 if (!name)
1165 return -EFAULT;
1166 if (!access_ok(VERIFY_WRITE, name, sizeof(struct oldold_utsname)))
1167 return -EFAULT;
1168
1169 down_read(&uts_sem);
1170 error = __copy_to_user(&name->sysname, &utsname()->sysname,
1171 __OLD_UTS_LEN);
1172 error |= __put_user(0, name->sysname + __OLD_UTS_LEN);
1173 error |= __copy_to_user(&name->nodename, &utsname()->nodename,
1174 __OLD_UTS_LEN);
1175 error |= __put_user(0, name->nodename + __OLD_UTS_LEN);
1176 error |= __copy_to_user(&name->release, &utsname()->release,
1177 __OLD_UTS_LEN);
1178 error |= __put_user(0, name->release + __OLD_UTS_LEN);
1179 error |= __copy_to_user(&name->version, &utsname()->version,
1180 __OLD_UTS_LEN);
1181 error |= __put_user(0, name->version + __OLD_UTS_LEN);
1182 error |= __copy_to_user(&name->machine, &utsname()->machine,
1183 __OLD_UTS_LEN);
1184 error |= __put_user(0, name->machine + __OLD_UTS_LEN);
1185 up_read(&uts_sem);
1186
1187 if (!error && override_architecture(name))
1188 error = -EFAULT;
1189 return error ? -EFAULT : 0;
1190 }
1191 #endif
1192
1193 SYSCALL_DEFINE2(sethostname, char __user *, name, int, len)
1194 {
1195 int errno;
1196 char tmp[__NEW_UTS_LEN];
1197
1198 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN))
1199 return -EPERM;
1200
1201 if (len < 0 || len > __NEW_UTS_LEN)
1202 return -EINVAL;
1203 down_write(&uts_sem);
1204 errno = -EFAULT;
1205 if (!copy_from_user(tmp, name, len)) {
1206 struct new_utsname *u = utsname();
1207
1208 memcpy(u->nodename, tmp, len);
1209 memset(u->nodename + len, 0, sizeof(u->nodename) - len);
1210 errno = 0;
1211 }
1212 up_write(&uts_sem);
1213 return errno;
1214 }
1215
1216 #ifdef __ARCH_WANT_SYS_GETHOSTNAME
1217
1218 SYSCALL_DEFINE2(gethostname, char __user *, name, int, len)
1219 {
1220 int i, errno;
1221 struct new_utsname *u;
1222
1223 if (len < 0)
1224 return -EINVAL;
1225 down_read(&uts_sem);
1226 u = utsname();
1227 i = 1 + strlen(u->nodename);
1228 if (i > len)
1229 i = len;
1230 errno = 0;
1231 if (copy_to_user(name, u->nodename, i))
1232 errno = -EFAULT;
1233 up_read(&uts_sem);
1234 return errno;
1235 }
1236
1237 #endif
1238
1239 /*
1240 * Only setdomainname; getdomainname can be implemented by calling
1241 * uname()
1242 */
1243 SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len)
1244 {
1245 int errno;
1246 char tmp[__NEW_UTS_LEN];
1247
1248 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN))
1249 return -EPERM;
1250 if (len < 0 || len > __NEW_UTS_LEN)
1251 return -EINVAL;
1252
1253 down_write(&uts_sem);
1254 errno = -EFAULT;
1255 if (!copy_from_user(tmp, name, len)) {
1256 struct new_utsname *u = utsname();
1257
1258 memcpy(u->domainname, tmp, len);
1259 memset(u->domainname + len, 0, sizeof(u->domainname) - len);
1260 errno = 0;
1261 }
1262 up_write(&uts_sem);
1263 return errno;
1264 }
1265
1266 SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim)
1267 {
1268 struct rlimit value;
1269 int ret;
1270
1271 ret = do_prlimit(current, resource, NULL, &value);
1272 if (!ret)
1273 ret = copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0;
1274
1275 return ret;
1276 }
1277
1278 #ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT
1279
1280 /*
1281 * Back compatibility for getrlimit. Needed for some apps.
1282 */
1283
1284 SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
1285 struct rlimit __user *, rlim)
1286 {
1287 struct rlimit x;
1288 if (resource >= RLIM_NLIMITS)
1289 return -EINVAL;
1290
1291 task_lock(current->group_leader);
1292 x = current->signal->rlim[resource];
1293 task_unlock(current->group_leader);
1294 if (x.rlim_cur > 0x7FFFFFFF)
1295 x.rlim_cur = 0x7FFFFFFF;
1296 if (x.rlim_max > 0x7FFFFFFF)
1297 x.rlim_max = 0x7FFFFFFF;
1298 return copy_to_user(rlim, &x, sizeof(x))?-EFAULT:0;
1299 }
1300
1301 #endif
1302
1303 static inline bool rlim64_is_infinity(__u64 rlim64)
1304 {
1305 #if BITS_PER_LONG < 64
1306 return rlim64 >= ULONG_MAX;
1307 #else
1308 return rlim64 == RLIM64_INFINITY;
1309 #endif
1310 }
1311
1312 static void rlim_to_rlim64(const struct rlimit *rlim, struct rlimit64 *rlim64)
1313 {
1314 if (rlim->rlim_cur == RLIM_INFINITY)
1315 rlim64->rlim_cur = RLIM64_INFINITY;
1316 else
1317 rlim64->rlim_cur = rlim->rlim_cur;
1318 if (rlim->rlim_max == RLIM_INFINITY)
1319 rlim64->rlim_max = RLIM64_INFINITY;
1320 else
1321 rlim64->rlim_max = rlim->rlim_max;
1322 }
1323
1324 static void rlim64_to_rlim(const struct rlimit64 *rlim64, struct rlimit *rlim)
1325 {
1326 if (rlim64_is_infinity(rlim64->rlim_cur))
1327 rlim->rlim_cur = RLIM_INFINITY;
1328 else
1329 rlim->rlim_cur = (unsigned long)rlim64->rlim_cur;
1330 if (rlim64_is_infinity(rlim64->rlim_max))
1331 rlim->rlim_max = RLIM_INFINITY;
1332 else
1333 rlim->rlim_max = (unsigned long)rlim64->rlim_max;
1334 }
1335
1336 /* make sure you are allowed to change @tsk limits before calling this */
1337 int do_prlimit(struct task_struct *tsk, unsigned int resource,
1338 struct rlimit *new_rlim, struct rlimit *old_rlim)
1339 {
1340 struct rlimit *rlim;
1341 int retval = 0;
1342
1343 if (resource >= RLIM_NLIMITS)
1344 return -EINVAL;
1345 if (new_rlim) {
1346 if (new_rlim->rlim_cur > new_rlim->rlim_max)
1347 return -EINVAL;
1348 if (resource == RLIMIT_NOFILE &&
1349 new_rlim->rlim_max > sysctl_nr_open)
1350 return -EPERM;
1351 }
1352
1353 /* protect tsk->signal and tsk->sighand from disappearing */
1354 read_lock(&tasklist_lock);
1355 if (!tsk->sighand) {
1356 retval = -ESRCH;
1357 goto out;
1358 }
1359
1360 rlim = tsk->signal->rlim + resource;
1361 task_lock(tsk->group_leader);
1362 if (new_rlim) {
1363 /* Keep the capable check against init_user_ns until
1364 cgroups can contain all limits */
1365 if (new_rlim->rlim_max > rlim->rlim_max &&
1366 !capable(CAP_SYS_RESOURCE))
1367 retval = -EPERM;
1368 if (!retval)
1369 retval = security_task_setrlimit(tsk->group_leader,
1370 resource, new_rlim);
1371 if (resource == RLIMIT_CPU && new_rlim->rlim_cur == 0) {
1372 /*
1373 * The caller is asking for an immediate RLIMIT_CPU
1374 * expiry. But we use the zero value to mean "it was
1375 * never set". So let's cheat and make it one second
1376 * instead
1377 */
1378 new_rlim->rlim_cur = 1;
1379 }
1380 }
1381 if (!retval) {
1382 if (old_rlim)
1383 *old_rlim = *rlim;
1384 if (new_rlim)
1385 *rlim = *new_rlim;
1386 }
1387 task_unlock(tsk->group_leader);
1388
1389 /*
1390 * RLIMIT_CPU handling. Note that the kernel fails to return an error
1391 * code if it rejected the user's attempt to set RLIMIT_CPU. This is a
1392 * very long-standing error, and fixing it now risks breakage of
1393 * applications, so we live with it
1394 */
1395 if (!retval && new_rlim && resource == RLIMIT_CPU &&
1396 new_rlim->rlim_cur != RLIM_INFINITY)
1397 update_rlimit_cpu(tsk, new_rlim->rlim_cur);
1398 out:
1399 read_unlock(&tasklist_lock);
1400 return retval;
1401 }
1402
1403 /* rcu lock must be held */
1404 static int check_prlimit_permission(struct task_struct *task)
1405 {
1406 const struct cred *cred = current_cred(), *tcred;
1407
1408 if (current == task)
1409 return 0;
1410
1411 tcred = __task_cred(task);
1412 if (cred->user->user_ns == tcred->user->user_ns &&
1413 (cred->uid == tcred->euid &&
1414 cred->uid == tcred->suid &&
1415 cred->uid == tcred->uid &&
1416 cred->gid == tcred->egid &&
1417 cred->gid == tcred->sgid &&
1418 cred->gid == tcred->gid))
1419 return 0;
1420 if (ns_capable(tcred->user->user_ns, CAP_SYS_RESOURCE))
1421 return 0;
1422
1423 return -EPERM;
1424 }
1425
1426 SYSCALL_DEFINE4(prlimit64, pid_t, pid, unsigned int, resource,
1427 const struct rlimit64 __user *, new_rlim,
1428 struct rlimit64 __user *, old_rlim)
1429 {
1430 struct rlimit64 old64, new64;
1431 struct rlimit old, new;
1432 struct task_struct *tsk;
1433 int ret;
1434
1435 if (new_rlim) {
1436 if (copy_from_user(&new64, new_rlim, sizeof(new64)))
1437 return -EFAULT;
1438 rlim64_to_rlim(&new64, &new);
1439 }
1440
1441 rcu_read_lock();
1442 tsk = pid ? find_task_by_vpid(pid) : current;
1443 if (!tsk) {
1444 rcu_read_unlock();
1445 return -ESRCH;
1446 }
1447 ret = check_prlimit_permission(tsk);
1448 if (ret) {
1449 rcu_read_unlock();
1450 return ret;
1451 }
1452 get_task_struct(tsk);
1453 rcu_read_unlock();
1454
1455 ret = do_prlimit(tsk, resource, new_rlim ? &new : NULL,
1456 old_rlim ? &old : NULL);
1457
1458 if (!ret && old_rlim) {
1459 rlim_to_rlim64(&old, &old64);
1460 if (copy_to_user(old_rlim, &old64, sizeof(old64)))
1461 ret = -EFAULT;
1462 }
1463
1464 put_task_struct(tsk);
1465 return ret;
1466 }
1467
1468 SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim)
1469 {
1470 struct rlimit new_rlim;
1471
1472 if (copy_from_user(&new_rlim, rlim, sizeof(*rlim)))
1473 return -EFAULT;
1474 return do_prlimit(current, resource, &new_rlim, NULL);
1475 }
1476
1477 /*
1478 * It would make sense to put struct rusage in the task_struct,
1479 * except that would make the task_struct be *really big*. After
1480 * task_struct gets moved into malloc'ed memory, it would
1481 * make sense to do this. It will make moving the rest of the information
1482 * a lot simpler! (Which we're not doing right now because we're not
1483 * measuring them yet).
1484 *
1485 * When sampling multiple threads for RUSAGE_SELF, under SMP we might have
1486 * races with threads incrementing their own counters. But since word
1487 * reads are atomic, we either get new values or old values and we don't
1488 * care which for the sums. We always take the siglock to protect reading
1489 * the c* fields from p->signal from races with exit.c updating those
1490 * fields when reaping, so a sample either gets all the additions of a
1491 * given child after it's reaped, or none so this sample is before reaping.
1492 *
1493 * Locking:
1494 * We need to take the siglock for CHILDEREN, SELF and BOTH
1495 * for the cases current multithreaded, non-current single threaded
1496 * non-current multithreaded. Thread traversal is now safe with
1497 * the siglock held.
1498 * Strictly speaking, we donot need to take the siglock if we are current and
1499 * single threaded, as no one else can take our signal_struct away, no one
1500 * else can reap the children to update signal->c* counters, and no one else
1501 * can race with the signal-> fields. If we do not take any lock, the
1502 * signal-> fields could be read out of order while another thread was just
1503 * exiting. So we should place a read memory barrier when we avoid the lock.
1504 * On the writer side, write memory barrier is implied in __exit_signal
1505 * as __exit_signal releases the siglock spinlock after updating the signal->
1506 * fields. But we don't do this yet to keep things simple.
1507 *
1508 */
1509
1510 static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r)
1511 {
1512 r->ru_nvcsw += t->nvcsw;
1513 r->ru_nivcsw += t->nivcsw;
1514 r->ru_minflt += t->min_flt;
1515 r->ru_majflt += t->maj_flt;
1516 r->ru_inblock += task_io_get_inblock(t);
1517 r->ru_oublock += task_io_get_oublock(t);
1518 }
1519
1520 static void k_getrusage(struct task_struct *p, int who, struct rusage *r)
1521 {
1522 struct task_struct *t;
1523 unsigned long flags;
1524 cputime_t tgutime, tgstime, utime, stime;
1525 unsigned long maxrss = 0;
1526
1527 memset((char *) r, 0, sizeof *r);
1528 utime = stime = cputime_zero;
1529
1530 if (who == RUSAGE_THREAD) {
1531 task_times(current, &utime, &stime);
1532 accumulate_thread_rusage(p, r);
1533 maxrss = p->signal->maxrss;
1534 goto out;
1535 }
1536
1537 if (!lock_task_sighand(p, &flags))
1538 return;
1539
1540 switch (who) {
1541 case RUSAGE_BOTH:
1542 case RUSAGE_CHILDREN:
1543 utime = p->signal->cutime;
1544 stime = p->signal->cstime;
1545 r->ru_nvcsw = p->signal->cnvcsw;
1546 r->ru_nivcsw = p->signal->cnivcsw;
1547 r->ru_minflt = p->signal->cmin_flt;
1548 r->ru_majflt = p->signal->cmaj_flt;
1549 r->ru_inblock = p->signal->cinblock;
1550 r->ru_oublock = p->signal->coublock;
1551 maxrss = p->signal->cmaxrss;
1552
1553 if (who == RUSAGE_CHILDREN)
1554 break;
1555
1556 case RUSAGE_SELF:
1557 thread_group_times(p, &tgutime, &tgstime);
1558 utime = cputime_add(utime, tgutime);
1559 stime = cputime_add(stime, tgstime);
1560 r->ru_nvcsw += p->signal->nvcsw;
1561 r->ru_nivcsw += p->signal->nivcsw;
1562 r->ru_minflt += p->signal->min_flt;
1563 r->ru_majflt += p->signal->maj_flt;
1564 r->ru_inblock += p->signal->inblock;
1565 r->ru_oublock += p->signal->oublock;
1566 if (maxrss < p->signal->maxrss)
1567 maxrss = p->signal->maxrss;
1568 t = p;
1569 do {
1570 accumulate_thread_rusage(t, r);
1571 t = next_thread(t);
1572 } while (t != p);
1573 break;
1574
1575 default:
1576 BUG();
1577 }
1578 unlock_task_sighand(p, &flags);
1579
1580 out:
1581 cputime_to_timeval(utime, &r->ru_utime);
1582 cputime_to_timeval(stime, &r->ru_stime);
1583
1584 if (who != RUSAGE_CHILDREN) {
1585 struct mm_struct *mm = get_task_mm(p);
1586 if (mm) {
1587 setmax_mm_hiwater_rss(&maxrss, mm);
1588 mmput(mm);
1589 }
1590 }
1591 r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */
1592 }
1593
1594 int getrusage(struct task_struct *p, int who, struct rusage __user *ru)
1595 {
1596 struct rusage r;
1597 k_getrusage(p, who, &r);
1598 return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0;
1599 }
1600
1601 SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru)
1602 {
1603 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
1604 who != RUSAGE_THREAD)
1605 return -EINVAL;
1606 return getrusage(current, who, ru);
1607 }
1608
1609 SYSCALL_DEFINE1(umask, int, mask)
1610 {
1611 mask = xchg(&current->fs->umask, mask & S_IRWXUGO);
1612 return mask;
1613 }
1614
1615 SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
1616 unsigned long, arg4, unsigned long, arg5)
1617 {
1618 struct task_struct *me = current;
1619 unsigned char comm[sizeof(me->comm)];
1620 long error;
1621
1622 error = security_task_prctl(option, arg2, arg3, arg4, arg5);
1623 if (error != -ENOSYS)
1624 return error;
1625
1626 error = 0;
1627 switch (option) {
1628 case PR_SET_PDEATHSIG:
1629 if (!valid_signal(arg2)) {
1630 error = -EINVAL;
1631 break;
1632 }
1633 me->pdeath_signal = arg2;
1634 error = 0;
1635 break;
1636 case PR_GET_PDEATHSIG:
1637 error = put_user(me->pdeath_signal, (int __user *)arg2);
1638 break;
1639 case PR_GET_DUMPABLE:
1640 error = get_dumpable(me->mm);
1641 break;
1642 case PR_SET_DUMPABLE:
1643 if (arg2 < 0 || arg2 > 1) {
1644 error = -EINVAL;
1645 break;
1646 }
1647 set_dumpable(me->mm, arg2);
1648 error = 0;
1649 break;
1650
1651 case PR_SET_UNALIGN:
1652 error = SET_UNALIGN_CTL(me, arg2);
1653 break;
1654 case PR_GET_UNALIGN:
1655 error = GET_UNALIGN_CTL(me, arg2);
1656 break;
1657 case PR_SET_FPEMU:
1658 error = SET_FPEMU_CTL(me, arg2);
1659 break;
1660 case PR_GET_FPEMU:
1661 error = GET_FPEMU_CTL(me, arg2);
1662 break;
1663 case PR_SET_FPEXC:
1664 error = SET_FPEXC_CTL(me, arg2);
1665 break;
1666 case PR_GET_FPEXC:
1667 error = GET_FPEXC_CTL(me, arg2);
1668 break;
1669 case PR_GET_TIMING:
1670 error = PR_TIMING_STATISTICAL;
1671 break;
1672 case PR_SET_TIMING:
1673 if (arg2 != PR_TIMING_STATISTICAL)
1674 error = -EINVAL;
1675 else
1676 error = 0;
1677 break;
1678
1679 case PR_SET_NAME:
1680 comm[sizeof(me->comm)-1] = 0;
1681 if (strncpy_from_user(comm, (char __user *)arg2,
1682 sizeof(me->comm) - 1) < 0)
1683 return -EFAULT;
1684 set_task_comm(me, comm);
1685 return 0;
1686 case PR_GET_NAME:
1687 get_task_comm(comm, me);
1688 if (copy_to_user((char __user *)arg2, comm,
1689 sizeof(comm)))
1690 return -EFAULT;
1691 return 0;
1692 case PR_GET_ENDIAN:
1693 error = GET_ENDIAN(me, arg2);
1694 break;
1695 case PR_SET_ENDIAN:
1696 error = SET_ENDIAN(me, arg2);
1697 break;
1698
1699 case PR_GET_SECCOMP:
1700 error = prctl_get_seccomp();
1701 break;
1702 case PR_SET_SECCOMP:
1703 error = prctl_set_seccomp(arg2);
1704 break;
1705 case PR_GET_TSC:
1706 error = GET_TSC_CTL(arg2);
1707 break;
1708 case PR_SET_TSC:
1709 error = SET_TSC_CTL(arg2);
1710 break;
1711 case PR_TASK_PERF_EVENTS_DISABLE:
1712 error = perf_event_task_disable();
1713 break;
1714 case PR_TASK_PERF_EVENTS_ENABLE:
1715 error = perf_event_task_enable();
1716 break;
1717 case PR_GET_TIMERSLACK:
1718 error = current->timer_slack_ns;
1719 break;
1720 case PR_SET_TIMERSLACK:
1721 if (arg2 <= 0)
1722 current->timer_slack_ns =
1723 current->default_timer_slack_ns;
1724 else
1725 current->timer_slack_ns = arg2;
1726 error = 0;
1727 break;
1728 case PR_MCE_KILL:
1729 if (arg4 | arg5)
1730 return -EINVAL;
1731 switch (arg2) {
1732 case PR_MCE_KILL_CLEAR:
1733 if (arg3 != 0)
1734 return -EINVAL;
1735 current->flags &= ~PF_MCE_PROCESS;
1736 break;
1737 case PR_MCE_KILL_SET:
1738 current->flags |= PF_MCE_PROCESS;
1739 if (arg3 == PR_MCE_KILL_EARLY)
1740 current->flags |= PF_MCE_EARLY;
1741 else if (arg3 == PR_MCE_KILL_LATE)
1742 current->flags &= ~PF_MCE_EARLY;
1743 else if (arg3 == PR_MCE_KILL_DEFAULT)
1744 current->flags &=
1745 ~(PF_MCE_EARLY|PF_MCE_PROCESS);
1746 else
1747 return -EINVAL;
1748 break;
1749 default:
1750 return -EINVAL;
1751 }
1752 error = 0;
1753 break;
1754 case PR_MCE_KILL_GET:
1755 if (arg2 | arg3 | arg4 | arg5)
1756 return -EINVAL;
1757 if (current->flags & PF_MCE_PROCESS)
1758 error = (current->flags & PF_MCE_EARLY) ?
1759 PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE;
1760 else
1761 error = PR_MCE_KILL_DEFAULT;
1762 break;
1763 default:
1764 error = -EINVAL;
1765 break;
1766 }
1767 return error;
1768 }
1769
1770 SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep,
1771 struct getcpu_cache __user *, unused)
1772 {
1773 int err = 0;
1774 int cpu = raw_smp_processor_id();
1775 if (cpup)
1776 err |= put_user(cpu, cpup);
1777 if (nodep)
1778 err |= put_user(cpu_to_node(cpu), nodep);
1779 return err ? -EFAULT : 0;
1780 }
1781
1782 char poweroff_cmd[POWEROFF_CMD_PATH_LEN] = "/sbin/poweroff";
1783
1784 static void argv_cleanup(struct subprocess_info *info)
1785 {
1786 argv_free(info->argv);
1787 }
1788
1789 /**
1790 * orderly_poweroff - Trigger an orderly system poweroff
1791 * @force: force poweroff if command execution fails
1792 *
1793 * This may be called from any context to trigger a system shutdown.
1794 * If the orderly shutdown fails, it will force an immediate shutdown.
1795 */
1796 int orderly_poweroff(bool force)
1797 {
1798 int argc;
1799 char **argv = argv_split(GFP_ATOMIC, poweroff_cmd, &argc);
1800 static char *envp[] = {
1801 "HOME=/",
1802 "PATH=/sbin:/bin:/usr/sbin:/usr/bin",
1803 NULL
1804 };
1805 int ret = -ENOMEM;
1806 struct subprocess_info *info;
1807
1808 if (argv == NULL) {
1809 printk(KERN_WARNING "%s failed to allocate memory for \"%s\"\n",
1810 __func__, poweroff_cmd);
1811 goto out;
1812 }
1813
1814 info = call_usermodehelper_setup(argv[0], argv, envp, GFP_ATOMIC);
1815 if (info == NULL) {
1816 argv_free(argv);
1817 goto out;
1818 }
1819
1820 call_usermodehelper_setfns(info, NULL, argv_cleanup, NULL);
1821
1822 ret = call_usermodehelper_exec(info, UMH_NO_WAIT);
1823
1824 out:
1825 if (ret && force) {
1826 printk(KERN_WARNING "Failed to start orderly shutdown: "
1827 "forcing the issue\n");
1828
1829 /* I guess this should try to kick off some daemon to
1830 sync and poweroff asap. Or not even bother syncing
1831 if we're doing an emergency shutdown? */
1832 emergency_sync();
1833 kernel_power_off();
1834 }
1835
1836 return ret;
1837 }
1838 EXPORT_SYMBOL_GPL(orderly_poweroff);
Linux kernel - Deliverables
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