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Merge tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm...
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / kernel / sys.c
1 /*
2 * linux/kernel/sys.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 */
6
7 #include <linux/export.h>
8 #include <linux/mm.h>
9 #include <linux/utsname.h>
10 #include <linux/mman.h>
11 #include <linux/reboot.h>
12 #include <linux/prctl.h>
13 #include <linux/highuid.h>
14 #include <linux/fs.h>
15 #include <linux/kmod.h>
16 #include <linux/perf_event.h>
17 #include <linux/resource.h>
18 #include <linux/kernel.h>
19 #include <linux/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/file.h>
40 #include <linux/mount.h>
41 #include <linux/gfp.h>
42 #include <linux/syscore_ops.h>
43 #include <linux/version.h>
44 #include <linux/ctype.h>
45
46 #include <linux/compat.h>
47 #include <linux/syscalls.h>
48 #include <linux/kprobes.h>
49 #include <linux/user_namespace.h>
50 #include <linux/binfmts.h>
51
52 #include <linux/sched.h>
53 #include <linux/rcupdate.h>
54 #include <linux/uidgid.h>
55 #include <linux/cred.h>
56
57 #include <linux/kmsg_dump.h>
58 /* Move somewhere else to avoid recompiling? */
59 #include <generated/utsrelease.h>
60
61 #include <asm/uaccess.h>
62 #include <asm/io.h>
63 #include <asm/unistd.h>
64
65 #ifndef SET_UNALIGN_CTL
66 # define SET_UNALIGN_CTL(a,b) (-EINVAL)
67 #endif
68 #ifndef GET_UNALIGN_CTL
69 # define GET_UNALIGN_CTL(a,b) (-EINVAL)
70 #endif
71 #ifndef SET_FPEMU_CTL
72 # define SET_FPEMU_CTL(a,b) (-EINVAL)
73 #endif
74 #ifndef GET_FPEMU_CTL
75 # define GET_FPEMU_CTL(a,b) (-EINVAL)
76 #endif
77 #ifndef SET_FPEXC_CTL
78 # define SET_FPEXC_CTL(a,b) (-EINVAL)
79 #endif
80 #ifndef GET_FPEXC_CTL
81 # define GET_FPEXC_CTL(a,b) (-EINVAL)
82 #endif
83 #ifndef GET_ENDIAN
84 # define GET_ENDIAN(a,b) (-EINVAL)
85 #endif
86 #ifndef SET_ENDIAN
87 # define SET_ENDIAN(a,b) (-EINVAL)
88 #endif
89 #ifndef GET_TSC_CTL
90 # define GET_TSC_CTL(a) (-EINVAL)
91 #endif
92 #ifndef SET_TSC_CTL
93 # define SET_TSC_CTL(a) (-EINVAL)
94 #endif
95
96 /*
97 * this is where the system-wide overflow UID and GID are defined, for
98 * architectures that now have 32-bit UID/GID but didn't in the past
99 */
100
101 int overflowuid = DEFAULT_OVERFLOWUID;
102 int overflowgid = DEFAULT_OVERFLOWGID;
103
104 EXPORT_SYMBOL(overflowuid);
105 EXPORT_SYMBOL(overflowgid);
106
107 /*
108 * the same as above, but for filesystems which can only store a 16-bit
109 * UID and GID. as such, this is needed on all architectures
110 */
111
112 int fs_overflowuid = DEFAULT_FS_OVERFLOWUID;
113 int fs_overflowgid = DEFAULT_FS_OVERFLOWUID;
114
115 EXPORT_SYMBOL(fs_overflowuid);
116 EXPORT_SYMBOL(fs_overflowgid);
117
118 /*
119 * this indicates whether you can reboot with ctrl-alt-del: the default is yes
120 */
121
122 int C_A_D = 1;
123 struct pid *cad_pid;
124 EXPORT_SYMBOL(cad_pid);
125
126 /*
127 * If set, this is used for preparing the system to power off.
128 */
129
130 void (*pm_power_off_prepare)(void);
131
132 /*
133 * Returns true if current's euid is same as p's uid or euid,
134 * or has CAP_SYS_NICE to p's user_ns.
135 *
136 * Called with rcu_read_lock, creds are safe
137 */
138 static bool set_one_prio_perm(struct task_struct *p)
139 {
140 const struct cred *cred = current_cred(), *pcred = __task_cred(p);
141
142 if (uid_eq(pcred->uid, cred->euid) ||
143 uid_eq(pcred->euid, cred->euid))
144 return true;
145 if (ns_capable(pcred->user_ns, CAP_SYS_NICE))
146 return true;
147 return false;
148 }
149
150 /*
151 * set the priority of a task
152 * - the caller must hold the RCU read lock
153 */
154 static int set_one_prio(struct task_struct *p, int niceval, int error)
155 {
156 int no_nice;
157
158 if (!set_one_prio_perm(p)) {
159 error = -EPERM;
160 goto out;
161 }
162 if (niceval < task_nice(p) && !can_nice(p, niceval)) {
163 error = -EACCES;
164 goto out;
165 }
166 no_nice = security_task_setnice(p, niceval);
167 if (no_nice) {
168 error = no_nice;
169 goto out;
170 }
171 if (error == -ESRCH)
172 error = 0;
173 set_user_nice(p, niceval);
174 out:
175 return error;
176 }
177
178 SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval)
179 {
180 struct task_struct *g, *p;
181 struct user_struct *user;
182 const struct cred *cred = current_cred();
183 int error = -EINVAL;
184 struct pid *pgrp;
185 kuid_t uid;
186
187 if (which > PRIO_USER || which < PRIO_PROCESS)
188 goto out;
189
190 /* normalize: avoid signed division (rounding problems) */
191 error = -ESRCH;
192 if (niceval < -20)
193 niceval = -20;
194 if (niceval > 19)
195 niceval = 19;
196
197 rcu_read_lock();
198 read_lock(&tasklist_lock);
199 switch (which) {
200 case PRIO_PROCESS:
201 if (who)
202 p = find_task_by_vpid(who);
203 else
204 p = current;
205 if (p)
206 error = set_one_prio(p, niceval, error);
207 break;
208 case PRIO_PGRP:
209 if (who)
210 pgrp = find_vpid(who);
211 else
212 pgrp = task_pgrp(current);
213 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
214 error = set_one_prio(p, niceval, error);
215 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
216 break;
217 case PRIO_USER:
218 uid = make_kuid(cred->user_ns, who);
219 user = cred->user;
220 if (!who)
221 uid = cred->uid;
222 else if (!uid_eq(uid, cred->uid) &&
223 !(user = find_user(uid)))
224 goto out_unlock; /* No processes for this user */
225
226 do_each_thread(g, p) {
227 if (uid_eq(task_uid(p), uid))
228 error = set_one_prio(p, niceval, error);
229 } while_each_thread(g, p);
230 if (!uid_eq(uid, cred->uid))
231 free_uid(user); /* For find_user() */
232 break;
233 }
234 out_unlock:
235 read_unlock(&tasklist_lock);
236 rcu_read_unlock();
237 out:
238 return error;
239 }
240
241 /*
242 * Ugh. To avoid negative return values, "getpriority()" will
243 * not return the normal nice-value, but a negated value that
244 * has been offset by 20 (ie it returns 40..1 instead of -20..19)
245 * to stay compatible.
246 */
247 SYSCALL_DEFINE2(getpriority, int, which, int, who)
248 {
249 struct task_struct *g, *p;
250 struct user_struct *user;
251 const struct cred *cred = current_cred();
252 long niceval, retval = -ESRCH;
253 struct pid *pgrp;
254 kuid_t uid;
255
256 if (which > PRIO_USER || which < PRIO_PROCESS)
257 return -EINVAL;
258
259 rcu_read_lock();
260 read_lock(&tasklist_lock);
261 switch (which) {
262 case PRIO_PROCESS:
263 if (who)
264 p = find_task_by_vpid(who);
265 else
266 p = current;
267 if (p) {
268 niceval = 20 - task_nice(p);
269 if (niceval > retval)
270 retval = niceval;
271 }
272 break;
273 case PRIO_PGRP:
274 if (who)
275 pgrp = find_vpid(who);
276 else
277 pgrp = task_pgrp(current);
278 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
279 niceval = 20 - task_nice(p);
280 if (niceval > retval)
281 retval = niceval;
282 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
283 break;
284 case PRIO_USER:
285 uid = make_kuid(cred->user_ns, who);
286 user = cred->user;
287 if (!who)
288 uid = cred->uid;
289 else if (!uid_eq(uid, cred->uid) &&
290 !(user = find_user(uid)))
291 goto out_unlock; /* No processes for this user */
292
293 do_each_thread(g, p) {
294 if (uid_eq(task_uid(p), uid)) {
295 niceval = 20 - task_nice(p);
296 if (niceval > retval)
297 retval = niceval;
298 }
299 } while_each_thread(g, p);
300 if (!uid_eq(uid, cred->uid))
301 free_uid(user); /* for find_user() */
302 break;
303 }
304 out_unlock:
305 read_unlock(&tasklist_lock);
306 rcu_read_unlock();
307
308 return retval;
309 }
310
311 /**
312 * emergency_restart - reboot the system
313 *
314 * Without shutting down any hardware or taking any locks
315 * reboot the system. This is called when we know we are in
316 * trouble so this is our best effort to reboot. This is
317 * safe to call in interrupt context.
318 */
319 void emergency_restart(void)
320 {
321 kmsg_dump(KMSG_DUMP_EMERG);
322 machine_emergency_restart();
323 }
324 EXPORT_SYMBOL_GPL(emergency_restart);
325
326 void kernel_restart_prepare(char *cmd)
327 {
328 blocking_notifier_call_chain(&reboot_notifier_list, SYS_RESTART, cmd);
329 system_state = SYSTEM_RESTART;
330 usermodehelper_disable();
331 device_shutdown();
332 }
333
334 /**
335 * register_reboot_notifier - Register function to be called at reboot time
336 * @nb: Info about notifier function to be called
337 *
338 * Registers a function with the list of functions
339 * to be called at reboot time.
340 *
341 * Currently always returns zero, as blocking_notifier_chain_register()
342 * always returns zero.
343 */
344 int register_reboot_notifier(struct notifier_block *nb)
345 {
346 return blocking_notifier_chain_register(&reboot_notifier_list, nb);
347 }
348 EXPORT_SYMBOL(register_reboot_notifier);
349
350 /**
351 * unregister_reboot_notifier - Unregister previously registered reboot notifier
352 * @nb: Hook to be unregistered
353 *
354 * Unregisters a previously registered reboot
355 * notifier function.
356 *
357 * Returns zero on success, or %-ENOENT on failure.
358 */
359 int unregister_reboot_notifier(struct notifier_block *nb)
360 {
361 return blocking_notifier_chain_unregister(&reboot_notifier_list, nb);
362 }
363 EXPORT_SYMBOL(unregister_reboot_notifier);
364
365 /* Add backwards compatibility for stable trees. */
366 #ifndef PF_NO_SETAFFINITY
367 #define PF_NO_SETAFFINITY PF_THREAD_BOUND
368 #endif
369
370 static void migrate_to_reboot_cpu(void)
371 {
372 /* The boot cpu is always logical cpu 0 */
373 int cpu = 0;
374
375 cpu_hotplug_disable();
376
377 /* Make certain the cpu I'm about to reboot on is online */
378 if (!cpu_online(cpu))
379 cpu = cpumask_first(cpu_online_mask);
380
381 /* Prevent races with other tasks migrating this task */
382 current->flags |= PF_NO_SETAFFINITY;
383
384 /* Make certain I only run on the appropriate processor */
385 set_cpus_allowed_ptr(current, cpumask_of(cpu));
386 }
387
388 /**
389 * kernel_restart - reboot the system
390 * @cmd: pointer to buffer containing command to execute for restart
391 * or %NULL
392 *
393 * Shutdown everything and perform a clean reboot.
394 * This is not safe to call in interrupt context.
395 */
396 void kernel_restart(char *cmd)
397 {
398 kernel_restart_prepare(cmd);
399 migrate_to_reboot_cpu();
400 syscore_shutdown();
401 if (!cmd)
402 printk(KERN_EMERG "Restarting system.\n");
403 else
404 printk(KERN_EMERG "Restarting system with command '%s'.\n", cmd);
405 kmsg_dump(KMSG_DUMP_RESTART);
406 machine_restart(cmd);
407 }
408 EXPORT_SYMBOL_GPL(kernel_restart);
409
410 static void kernel_shutdown_prepare(enum system_states state)
411 {
412 blocking_notifier_call_chain(&reboot_notifier_list,
413 (state == SYSTEM_HALT)?SYS_HALT:SYS_POWER_OFF, NULL);
414 system_state = state;
415 usermodehelper_disable();
416 device_shutdown();
417 }
418 /**
419 * kernel_halt - halt the system
420 *
421 * Shutdown everything and perform a clean system halt.
422 */
423 void kernel_halt(void)
424 {
425 kernel_shutdown_prepare(SYSTEM_HALT);
426 migrate_to_reboot_cpu();
427 syscore_shutdown();
428 printk(KERN_EMERG "System halted.\n");
429 kmsg_dump(KMSG_DUMP_HALT);
430 machine_halt();
431 }
432
433 EXPORT_SYMBOL_GPL(kernel_halt);
434
435 /**
436 * kernel_power_off - power_off the system
437 *
438 * Shutdown everything and perform a clean system power_off.
439 */
440 void kernel_power_off(void)
441 {
442 kernel_shutdown_prepare(SYSTEM_POWER_OFF);
443 if (pm_power_off_prepare)
444 pm_power_off_prepare();
445 migrate_to_reboot_cpu();
446 syscore_shutdown();
447 printk(KERN_EMERG "Power down.\n");
448 kmsg_dump(KMSG_DUMP_POWEROFF);
449 machine_power_off();
450 }
451 EXPORT_SYMBOL_GPL(kernel_power_off);
452
453 static DEFINE_MUTEX(reboot_mutex);
454
455 /*
456 * Reboot system call: for obvious reasons only root may call it,
457 * and even root needs to set up some magic numbers in the registers
458 * so that some mistake won't make this reboot the whole machine.
459 * You can also set the meaning of the ctrl-alt-del-key here.
460 *
461 * reboot doesn't sync: do that yourself before calling this.
462 */
463 SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd,
464 void __user *, arg)
465 {
466 struct pid_namespace *pid_ns = task_active_pid_ns(current);
467 char buffer[256];
468 int ret = 0;
469
470 /* We only trust the superuser with rebooting the system. */
471 if (!ns_capable(pid_ns->user_ns, CAP_SYS_BOOT))
472 return -EPERM;
473
474 /* For safety, we require "magic" arguments. */
475 if (magic1 != LINUX_REBOOT_MAGIC1 ||
476 (magic2 != LINUX_REBOOT_MAGIC2 &&
477 magic2 != LINUX_REBOOT_MAGIC2A &&
478 magic2 != LINUX_REBOOT_MAGIC2B &&
479 magic2 != LINUX_REBOOT_MAGIC2C))
480 return -EINVAL;
481
482 /*
483 * If pid namespaces are enabled and the current task is in a child
484 * pid_namespace, the command is handled by reboot_pid_ns() which will
485 * call do_exit().
486 */
487 ret = reboot_pid_ns(pid_ns, cmd);
488 if (ret)
489 return ret;
490
491 /* Instead of trying to make the power_off code look like
492 * halt when pm_power_off is not set do it the easy way.
493 */
494 if ((cmd == LINUX_REBOOT_CMD_POWER_OFF) && !pm_power_off)
495 cmd = LINUX_REBOOT_CMD_HALT;
496
497 mutex_lock(&reboot_mutex);
498 switch (cmd) {
499 case LINUX_REBOOT_CMD_RESTART:
500 kernel_restart(NULL);
501 break;
502
503 case LINUX_REBOOT_CMD_CAD_ON:
504 C_A_D = 1;
505 break;
506
507 case LINUX_REBOOT_CMD_CAD_OFF:
508 C_A_D = 0;
509 break;
510
511 case LINUX_REBOOT_CMD_HALT:
512 kernel_halt();
513 do_exit(0);
514 panic("cannot halt");
515
516 case LINUX_REBOOT_CMD_POWER_OFF:
517 kernel_power_off();
518 do_exit(0);
519 break;
520
521 case LINUX_REBOOT_CMD_RESTART2:
522 if (strncpy_from_user(&buffer[0], arg, sizeof(buffer) - 1) < 0) {
523 ret = -EFAULT;
524 break;
525 }
526 buffer[sizeof(buffer) - 1] = '\0';
527
528 kernel_restart(buffer);
529 break;
530
531 #ifdef CONFIG_KEXEC
532 case LINUX_REBOOT_CMD_KEXEC:
533 ret = kernel_kexec();
534 break;
535 #endif
536
537 #ifdef CONFIG_HIBERNATION
538 case LINUX_REBOOT_CMD_SW_SUSPEND:
539 ret = hibernate();
540 break;
541 #endif
542
543 default:
544 ret = -EINVAL;
545 break;
546 }
547 mutex_unlock(&reboot_mutex);
548 return ret;
549 }
550
551 static void deferred_cad(struct work_struct *dummy)
552 {
553 kernel_restart(NULL);
554 }
555
556 /*
557 * This function gets called by ctrl-alt-del - ie the keyboard interrupt.
558 * As it's called within an interrupt, it may NOT sync: the only choice
559 * is whether to reboot at once, or just ignore the ctrl-alt-del.
560 */
561 void ctrl_alt_del(void)
562 {
563 static DECLARE_WORK(cad_work, deferred_cad);
564
565 if (C_A_D)
566 schedule_work(&cad_work);
567 else
568 kill_cad_pid(SIGINT, 1);
569 }
570
571 /*
572 * Unprivileged users may change the real gid to the effective gid
573 * or vice versa. (BSD-style)
574 *
575 * If you set the real gid at all, or set the effective gid to a value not
576 * equal to the real gid, then the saved gid is set to the new effective gid.
577 *
578 * This makes it possible for a setgid program to completely drop its
579 * privileges, which is often a useful assertion to make when you are doing
580 * a security audit over a program.
581 *
582 * The general idea is that a program which uses just setregid() will be
583 * 100% compatible with BSD. A program which uses just setgid() will be
584 * 100% compatible with POSIX with saved IDs.
585 *
586 * SMP: There are not races, the GIDs are checked only by filesystem
587 * operations (as far as semantic preservation is concerned).
588 */
589 SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid)
590 {
591 struct user_namespace *ns = current_user_ns();
592 const struct cred *old;
593 struct cred *new;
594 int retval;
595 kgid_t krgid, kegid;
596
597 krgid = make_kgid(ns, rgid);
598 kegid = make_kgid(ns, egid);
599
600 if ((rgid != (gid_t) -1) && !gid_valid(krgid))
601 return -EINVAL;
602 if ((egid != (gid_t) -1) && !gid_valid(kegid))
603 return -EINVAL;
604
605 new = prepare_creds();
606 if (!new)
607 return -ENOMEM;
608 old = current_cred();
609
610 retval = -EPERM;
611 if (rgid != (gid_t) -1) {
612 if (gid_eq(old->gid, krgid) ||
613 gid_eq(old->egid, krgid) ||
614 nsown_capable(CAP_SETGID))
615 new->gid = krgid;
616 else
617 goto error;
618 }
619 if (egid != (gid_t) -1) {
620 if (gid_eq(old->gid, kegid) ||
621 gid_eq(old->egid, kegid) ||
622 gid_eq(old->sgid, kegid) ||
623 nsown_capable(CAP_SETGID))
624 new->egid = kegid;
625 else
626 goto error;
627 }
628
629 if (rgid != (gid_t) -1 ||
630 (egid != (gid_t) -1 && !gid_eq(kegid, old->gid)))
631 new->sgid = new->egid;
632 new->fsgid = new->egid;
633
634 return commit_creds(new);
635
636 error:
637 abort_creds(new);
638 return retval;
639 }
640
641 /*
642 * setgid() is implemented like SysV w/ SAVED_IDS
643 *
644 * SMP: Same implicit races as above.
645 */
646 SYSCALL_DEFINE1(setgid, gid_t, gid)
647 {
648 struct user_namespace *ns = current_user_ns();
649 const struct cred *old;
650 struct cred *new;
651 int retval;
652 kgid_t kgid;
653
654 kgid = make_kgid(ns, gid);
655 if (!gid_valid(kgid))
656 return -EINVAL;
657
658 new = prepare_creds();
659 if (!new)
660 return -ENOMEM;
661 old = current_cred();
662
663 retval = -EPERM;
664 if (nsown_capable(CAP_SETGID))
665 new->gid = new->egid = new->sgid = new->fsgid = kgid;
666 else if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->sgid))
667 new->egid = new->fsgid = kgid;
668 else
669 goto error;
670
671 return commit_creds(new);
672
673 error:
674 abort_creds(new);
675 return retval;
676 }
677
678 /*
679 * change the user struct in a credentials set to match the new UID
680 */
681 static int set_user(struct cred *new)
682 {
683 struct user_struct *new_user;
684
685 new_user = alloc_uid(new->uid);
686 if (!new_user)
687 return -EAGAIN;
688
689 /*
690 * We don't fail in case of NPROC limit excess here because too many
691 * poorly written programs don't check set*uid() return code, assuming
692 * it never fails if called by root. We may still enforce NPROC limit
693 * for programs doing set*uid()+execve() by harmlessly deferring the
694 * failure to the execve() stage.
695 */
696 if (atomic_read(&new_user->processes) >= rlimit(RLIMIT_NPROC) &&
697 new_user != INIT_USER)
698 current->flags |= PF_NPROC_EXCEEDED;
699 else
700 current->flags &= ~PF_NPROC_EXCEEDED;
701
702 free_uid(new->user);
703 new->user = new_user;
704 return 0;
705 }
706
707 /*
708 * Unprivileged users may change the real uid to the effective uid
709 * or vice versa. (BSD-style)
710 *
711 * If you set the real uid at all, or set the effective uid to a value not
712 * equal to the real uid, then the saved uid is set to the new effective uid.
713 *
714 * This makes it possible for a setuid program to completely drop its
715 * privileges, which is often a useful assertion to make when you are doing
716 * a security audit over a program.
717 *
718 * The general idea is that a program which uses just setreuid() will be
719 * 100% compatible with BSD. A program which uses just setuid() will be
720 * 100% compatible with POSIX with saved IDs.
721 */
722 SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid)
723 {
724 struct user_namespace *ns = current_user_ns();
725 const struct cred *old;
726 struct cred *new;
727 int retval;
728 kuid_t kruid, keuid;
729
730 kruid = make_kuid(ns, ruid);
731 keuid = make_kuid(ns, euid);
732
733 if ((ruid != (uid_t) -1) && !uid_valid(kruid))
734 return -EINVAL;
735 if ((euid != (uid_t) -1) && !uid_valid(keuid))
736 return -EINVAL;
737
738 new = prepare_creds();
739 if (!new)
740 return -ENOMEM;
741 old = current_cred();
742
743 retval = -EPERM;
744 if (ruid != (uid_t) -1) {
745 new->uid = kruid;
746 if (!uid_eq(old->uid, kruid) &&
747 !uid_eq(old->euid, kruid) &&
748 !nsown_capable(CAP_SETUID))
749 goto error;
750 }
751
752 if (euid != (uid_t) -1) {
753 new->euid = keuid;
754 if (!uid_eq(old->uid, keuid) &&
755 !uid_eq(old->euid, keuid) &&
756 !uid_eq(old->suid, keuid) &&
757 !nsown_capable(CAP_SETUID))
758 goto error;
759 }
760
761 if (!uid_eq(new->uid, old->uid)) {
762 retval = set_user(new);
763 if (retval < 0)
764 goto error;
765 }
766 if (ruid != (uid_t) -1 ||
767 (euid != (uid_t) -1 && !uid_eq(keuid, old->uid)))
768 new->suid = new->euid;
769 new->fsuid = new->euid;
770
771 retval = security_task_fix_setuid(new, old, LSM_SETID_RE);
772 if (retval < 0)
773 goto error;
774
775 return commit_creds(new);
776
777 error:
778 abort_creds(new);
779 return retval;
780 }
781
782 /*
783 * setuid() is implemented like SysV with SAVED_IDS
784 *
785 * Note that SAVED_ID's is deficient in that a setuid root program
786 * like sendmail, for example, cannot set its uid to be a normal
787 * user and then switch back, because if you're root, setuid() sets
788 * the saved uid too. If you don't like this, blame the bright people
789 * in the POSIX committee and/or USG. Note that the BSD-style setreuid()
790 * will allow a root program to temporarily drop privileges and be able to
791 * regain them by swapping the real and effective uid.
792 */
793 SYSCALL_DEFINE1(setuid, uid_t, uid)
794 {
795 struct user_namespace *ns = current_user_ns();
796 const struct cred *old;
797 struct cred *new;
798 int retval;
799 kuid_t kuid;
800
801 kuid = make_kuid(ns, uid);
802 if (!uid_valid(kuid))
803 return -EINVAL;
804
805 new = prepare_creds();
806 if (!new)
807 return -ENOMEM;
808 old = current_cred();
809
810 retval = -EPERM;
811 if (nsown_capable(CAP_SETUID)) {
812 new->suid = new->uid = kuid;
813 if (!uid_eq(kuid, old->uid)) {
814 retval = set_user(new);
815 if (retval < 0)
816 goto error;
817 }
818 } else if (!uid_eq(kuid, old->uid) && !uid_eq(kuid, new->suid)) {
819 goto error;
820 }
821
822 new->fsuid = new->euid = kuid;
823
824 retval = security_task_fix_setuid(new, old, LSM_SETID_ID);
825 if (retval < 0)
826 goto error;
827
828 return commit_creds(new);
829
830 error:
831 abort_creds(new);
832 return retval;
833 }
834
835
836 /*
837 * This function implements a generic ability to update ruid, euid,
838 * and suid. This allows you to implement the 4.4 compatible seteuid().
839 */
840 SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid)
841 {
842 struct user_namespace *ns = current_user_ns();
843 const struct cred *old;
844 struct cred *new;
845 int retval;
846 kuid_t kruid, keuid, ksuid;
847
848 kruid = make_kuid(ns, ruid);
849 keuid = make_kuid(ns, euid);
850 ksuid = make_kuid(ns, suid);
851
852 if ((ruid != (uid_t) -1) && !uid_valid(kruid))
853 return -EINVAL;
854
855 if ((euid != (uid_t) -1) && !uid_valid(keuid))
856 return -EINVAL;
857
858 if ((suid != (uid_t) -1) && !uid_valid(ksuid))
859 return -EINVAL;
860
861 new = prepare_creds();
862 if (!new)
863 return -ENOMEM;
864
865 old = current_cred();
866
867 retval = -EPERM;
868 if (!nsown_capable(CAP_SETUID)) {
869 if (ruid != (uid_t) -1 && !uid_eq(kruid, old->uid) &&
870 !uid_eq(kruid, old->euid) && !uid_eq(kruid, old->suid))
871 goto error;
872 if (euid != (uid_t) -1 && !uid_eq(keuid, old->uid) &&
873 !uid_eq(keuid, old->euid) && !uid_eq(keuid, old->suid))
874 goto error;
875 if (suid != (uid_t) -1 && !uid_eq(ksuid, old->uid) &&
876 !uid_eq(ksuid, old->euid) && !uid_eq(ksuid, old->suid))
877 goto error;
878 }
879
880 if (ruid != (uid_t) -1) {
881 new->uid = kruid;
882 if (!uid_eq(kruid, old->uid)) {
883 retval = set_user(new);
884 if (retval < 0)
885 goto error;
886 }
887 }
888 if (euid != (uid_t) -1)
889 new->euid = keuid;
890 if (suid != (uid_t) -1)
891 new->suid = ksuid;
892 new->fsuid = new->euid;
893
894 retval = security_task_fix_setuid(new, old, LSM_SETID_RES);
895 if (retval < 0)
896 goto error;
897
898 return commit_creds(new);
899
900 error:
901 abort_creds(new);
902 return retval;
903 }
904
905 SYSCALL_DEFINE3(getresuid, uid_t __user *, ruidp, uid_t __user *, euidp, uid_t __user *, suidp)
906 {
907 const struct cred *cred = current_cred();
908 int retval;
909 uid_t ruid, euid, suid;
910
911 ruid = from_kuid_munged(cred->user_ns, cred->uid);
912 euid = from_kuid_munged(cred->user_ns, cred->euid);
913 suid = from_kuid_munged(cred->user_ns, cred->suid);
914
915 if (!(retval = put_user(ruid, ruidp)) &&
916 !(retval = put_user(euid, euidp)))
917 retval = put_user(suid, suidp);
918
919 return retval;
920 }
921
922 /*
923 * Same as above, but for rgid, egid, sgid.
924 */
925 SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid)
926 {
927 struct user_namespace *ns = current_user_ns();
928 const struct cred *old;
929 struct cred *new;
930 int retval;
931 kgid_t krgid, kegid, ksgid;
932
933 krgid = make_kgid(ns, rgid);
934 kegid = make_kgid(ns, egid);
935 ksgid = make_kgid(ns, sgid);
936
937 if ((rgid != (gid_t) -1) && !gid_valid(krgid))
938 return -EINVAL;
939 if ((egid != (gid_t) -1) && !gid_valid(kegid))
940 return -EINVAL;
941 if ((sgid != (gid_t) -1) && !gid_valid(ksgid))
942 return -EINVAL;
943
944 new = prepare_creds();
945 if (!new)
946 return -ENOMEM;
947 old = current_cred();
948
949 retval = -EPERM;
950 if (!nsown_capable(CAP_SETGID)) {
951 if (rgid != (gid_t) -1 && !gid_eq(krgid, old->gid) &&
952 !gid_eq(krgid, old->egid) && !gid_eq(krgid, old->sgid))
953 goto error;
954 if (egid != (gid_t) -1 && !gid_eq(kegid, old->gid) &&
955 !gid_eq(kegid, old->egid) && !gid_eq(kegid, old->sgid))
956 goto error;
957 if (sgid != (gid_t) -1 && !gid_eq(ksgid, old->gid) &&
958 !gid_eq(ksgid, old->egid) && !gid_eq(ksgid, old->sgid))
959 goto error;
960 }
961
962 if (rgid != (gid_t) -1)
963 new->gid = krgid;
964 if (egid != (gid_t) -1)
965 new->egid = kegid;
966 if (sgid != (gid_t) -1)
967 new->sgid = ksgid;
968 new->fsgid = new->egid;
969
970 return commit_creds(new);
971
972 error:
973 abort_creds(new);
974 return retval;
975 }
976
977 SYSCALL_DEFINE3(getresgid, gid_t __user *, rgidp, gid_t __user *, egidp, gid_t __user *, sgidp)
978 {
979 const struct cred *cred = current_cred();
980 int retval;
981 gid_t rgid, egid, sgid;
982
983 rgid = from_kgid_munged(cred->user_ns, cred->gid);
984 egid = from_kgid_munged(cred->user_ns, cred->egid);
985 sgid = from_kgid_munged(cred->user_ns, cred->sgid);
986
987 if (!(retval = put_user(rgid, rgidp)) &&
988 !(retval = put_user(egid, egidp)))
989 retval = put_user(sgid, sgidp);
990
991 return retval;
992 }
993
994
995 /*
996 * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This
997 * is used for "access()" and for the NFS daemon (letting nfsd stay at
998 * whatever uid it wants to). It normally shadows "euid", except when
999 * explicitly set by setfsuid() or for access..
1000 */
1001 SYSCALL_DEFINE1(setfsuid, uid_t, uid)
1002 {
1003 const struct cred *old;
1004 struct cred *new;
1005 uid_t old_fsuid;
1006 kuid_t kuid;
1007
1008 old = current_cred();
1009 old_fsuid = from_kuid_munged(old->user_ns, old->fsuid);
1010
1011 kuid = make_kuid(old->user_ns, uid);
1012 if (!uid_valid(kuid))
1013 return old_fsuid;
1014
1015 new = prepare_creds();
1016 if (!new)
1017 return old_fsuid;
1018
1019 if (uid_eq(kuid, old->uid) || uid_eq(kuid, old->euid) ||
1020 uid_eq(kuid, old->suid) || uid_eq(kuid, old->fsuid) ||
1021 nsown_capable(CAP_SETUID)) {
1022 if (!uid_eq(kuid, old->fsuid)) {
1023 new->fsuid = kuid;
1024 if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0)
1025 goto change_okay;
1026 }
1027 }
1028
1029 abort_creds(new);
1030 return old_fsuid;
1031
1032 change_okay:
1033 commit_creds(new);
1034 return old_fsuid;
1035 }
1036
1037 /*
1038 * Samma på svenska..
1039 */
1040 SYSCALL_DEFINE1(setfsgid, gid_t, gid)
1041 {
1042 const struct cred *old;
1043 struct cred *new;
1044 gid_t old_fsgid;
1045 kgid_t kgid;
1046
1047 old = current_cred();
1048 old_fsgid = from_kgid_munged(old->user_ns, old->fsgid);
1049
1050 kgid = make_kgid(old->user_ns, gid);
1051 if (!gid_valid(kgid))
1052 return old_fsgid;
1053
1054 new = prepare_creds();
1055 if (!new)
1056 return old_fsgid;
1057
1058 if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->egid) ||
1059 gid_eq(kgid, old->sgid) || gid_eq(kgid, old->fsgid) ||
1060 nsown_capable(CAP_SETGID)) {
1061 if (!gid_eq(kgid, old->fsgid)) {
1062 new->fsgid = kgid;
1063 goto change_okay;
1064 }
1065 }
1066
1067 abort_creds(new);
1068 return old_fsgid;
1069
1070 change_okay:
1071 commit_creds(new);
1072 return old_fsgid;
1073 }
1074
1075 /**
1076 * sys_getpid - return the thread group id of the current process
1077 *
1078 * Note, despite the name, this returns the tgid not the pid. The tgid and
1079 * the pid are identical unless CLONE_THREAD was specified on clone() in
1080 * which case the tgid is the same in all threads of the same group.
1081 *
1082 * This is SMP safe as current->tgid does not change.
1083 */
1084 SYSCALL_DEFINE0(getpid)
1085 {
1086 return task_tgid_vnr(current);
1087 }
1088
1089 /* Thread ID - the internal kernel "pid" */
1090 SYSCALL_DEFINE0(gettid)
1091 {
1092 return task_pid_vnr(current);
1093 }
1094
1095 /*
1096 * Accessing ->real_parent is not SMP-safe, it could
1097 * change from under us. However, we can use a stale
1098 * value of ->real_parent under rcu_read_lock(), see
1099 * release_task()->call_rcu(delayed_put_task_struct).
1100 */
1101 SYSCALL_DEFINE0(getppid)
1102 {
1103 int pid;
1104
1105 rcu_read_lock();
1106 pid = task_tgid_vnr(rcu_dereference(current->real_parent));
1107 rcu_read_unlock();
1108
1109 return pid;
1110 }
1111
1112 SYSCALL_DEFINE0(getuid)
1113 {
1114 /* Only we change this so SMP safe */
1115 return from_kuid_munged(current_user_ns(), current_uid());
1116 }
1117
1118 SYSCALL_DEFINE0(geteuid)
1119 {
1120 /* Only we change this so SMP safe */
1121 return from_kuid_munged(current_user_ns(), current_euid());
1122 }
1123
1124 SYSCALL_DEFINE0(getgid)
1125 {
1126 /* Only we change this so SMP safe */
1127 return from_kgid_munged(current_user_ns(), current_gid());
1128 }
1129
1130 SYSCALL_DEFINE0(getegid)
1131 {
1132 /* Only we change this so SMP safe */
1133 return from_kgid_munged(current_user_ns(), current_egid());
1134 }
1135
1136 void do_sys_times(struct tms *tms)
1137 {
1138 cputime_t tgutime, tgstime, cutime, cstime;
1139
1140 spin_lock_irq(&current->sighand->siglock);
1141 thread_group_cputime_adjusted(current, &tgutime, &tgstime);
1142 cutime = current->signal->cutime;
1143 cstime = current->signal->cstime;
1144 spin_unlock_irq(&current->sighand->siglock);
1145 tms->tms_utime = cputime_to_clock_t(tgutime);
1146 tms->tms_stime = cputime_to_clock_t(tgstime);
1147 tms->tms_cutime = cputime_to_clock_t(cutime);
1148 tms->tms_cstime = cputime_to_clock_t(cstime);
1149 }
1150
1151 SYSCALL_DEFINE1(times, struct tms __user *, tbuf)
1152 {
1153 if (tbuf) {
1154 struct tms tmp;
1155
1156 do_sys_times(&tmp);
1157 if (copy_to_user(tbuf, &tmp, sizeof(struct tms)))
1158 return -EFAULT;
1159 }
1160 force_successful_syscall_return();
1161 return (long) jiffies_64_to_clock_t(get_jiffies_64());
1162 }
1163
1164 /*
1165 * This needs some heavy checking ...
1166 * I just haven't the stomach for it. I also don't fully
1167 * understand sessions/pgrp etc. Let somebody who does explain it.
1168 *
1169 * OK, I think I have the protection semantics right.... this is really
1170 * only important on a multi-user system anyway, to make sure one user
1171 * can't send a signal to a process owned by another. -TYT, 12/12/91
1172 *
1173 * Auch. Had to add the 'did_exec' flag to conform completely to POSIX.
1174 * LBT 04.03.94
1175 */
1176 SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid)
1177 {
1178 struct task_struct *p;
1179 struct task_struct *group_leader = current->group_leader;
1180 struct pid *pgrp;
1181 int err;
1182
1183 if (!pid)
1184 pid = task_pid_vnr(group_leader);
1185 if (!pgid)
1186 pgid = pid;
1187 if (pgid < 0)
1188 return -EINVAL;
1189 rcu_read_lock();
1190
1191 /* From this point forward we keep holding onto the tasklist lock
1192 * so that our parent does not change from under us. -DaveM
1193 */
1194 write_lock_irq(&tasklist_lock);
1195
1196 err = -ESRCH;
1197 p = find_task_by_vpid(pid);
1198 if (!p)
1199 goto out;
1200
1201 err = -EINVAL;
1202 if (!thread_group_leader(p))
1203 goto out;
1204
1205 if (same_thread_group(p->real_parent, group_leader)) {
1206 err = -EPERM;
1207 if (task_session(p) != task_session(group_leader))
1208 goto out;
1209 err = -EACCES;
1210 if (p->did_exec)
1211 goto out;
1212 } else {
1213 err = -ESRCH;
1214 if (p != group_leader)
1215 goto out;
1216 }
1217
1218 err = -EPERM;
1219 if (p->signal->leader)
1220 goto out;
1221
1222 pgrp = task_pid(p);
1223 if (pgid != pid) {
1224 struct task_struct *g;
1225
1226 pgrp = find_vpid(pgid);
1227 g = pid_task(pgrp, PIDTYPE_PGID);
1228 if (!g || task_session(g) != task_session(group_leader))
1229 goto out;
1230 }
1231
1232 err = security_task_setpgid(p, pgid);
1233 if (err)
1234 goto out;
1235
1236 if (task_pgrp(p) != pgrp)
1237 change_pid(p, PIDTYPE_PGID, pgrp);
1238
1239 err = 0;
1240 out:
1241 /* All paths lead to here, thus we are safe. -DaveM */
1242 write_unlock_irq(&tasklist_lock);
1243 rcu_read_unlock();
1244 return err;
1245 }
1246
1247 SYSCALL_DEFINE1(getpgid, pid_t, pid)
1248 {
1249 struct task_struct *p;
1250 struct pid *grp;
1251 int retval;
1252
1253 rcu_read_lock();
1254 if (!pid)
1255 grp = task_pgrp(current);
1256 else {
1257 retval = -ESRCH;
1258 p = find_task_by_vpid(pid);
1259 if (!p)
1260 goto out;
1261 grp = task_pgrp(p);
1262 if (!grp)
1263 goto out;
1264
1265 retval = security_task_getpgid(p);
1266 if (retval)
1267 goto out;
1268 }
1269 retval = pid_vnr(grp);
1270 out:
1271 rcu_read_unlock();
1272 return retval;
1273 }
1274
1275 #ifdef __ARCH_WANT_SYS_GETPGRP
1276
1277 SYSCALL_DEFINE0(getpgrp)
1278 {
1279 return sys_getpgid(0);
1280 }
1281
1282 #endif
1283
1284 SYSCALL_DEFINE1(getsid, pid_t, pid)
1285 {
1286 struct task_struct *p;
1287 struct pid *sid;
1288 int retval;
1289
1290 rcu_read_lock();
1291 if (!pid)
1292 sid = task_session(current);
1293 else {
1294 retval = -ESRCH;
1295 p = find_task_by_vpid(pid);
1296 if (!p)
1297 goto out;
1298 sid = task_session(p);
1299 if (!sid)
1300 goto out;
1301
1302 retval = security_task_getsid(p);
1303 if (retval)
1304 goto out;
1305 }
1306 retval = pid_vnr(sid);
1307 out:
1308 rcu_read_unlock();
1309 return retval;
1310 }
1311
1312 SYSCALL_DEFINE0(setsid)
1313 {
1314 struct task_struct *group_leader = current->group_leader;
1315 struct pid *sid = task_pid(group_leader);
1316 pid_t session = pid_vnr(sid);
1317 int err = -EPERM;
1318
1319 write_lock_irq(&tasklist_lock);
1320 /* Fail if I am already a session leader */
1321 if (group_leader->signal->leader)
1322 goto out;
1323
1324 /* Fail if a process group id already exists that equals the
1325 * proposed session id.
1326 */
1327 if (pid_task(sid, PIDTYPE_PGID))
1328 goto out;
1329
1330 group_leader->signal->leader = 1;
1331 __set_special_pids(sid);
1332
1333 proc_clear_tty(group_leader);
1334
1335 err = session;
1336 out:
1337 write_unlock_irq(&tasklist_lock);
1338 if (err > 0) {
1339 proc_sid_connector(group_leader);
1340 sched_autogroup_create_attach(group_leader);
1341 }
1342 return err;
1343 }
1344
1345 DECLARE_RWSEM(uts_sem);
1346
1347 #ifdef COMPAT_UTS_MACHINE
1348 #define override_architecture(name) \
1349 (personality(current->personality) == PER_LINUX32 && \
1350 copy_to_user(name->machine, COMPAT_UTS_MACHINE, \
1351 sizeof(COMPAT_UTS_MACHINE)))
1352 #else
1353 #define override_architecture(name) 0
1354 #endif
1355
1356 /*
1357 * Work around broken programs that cannot handle "Linux 3.0".
1358 * Instead we map 3.x to 2.6.40+x, so e.g. 3.0 would be 2.6.40
1359 */
1360 static int override_release(char __user *release, size_t len)
1361 {
1362 int ret = 0;
1363
1364 if (current->personality & UNAME26) {
1365 const char *rest = UTS_RELEASE;
1366 char buf[65] = { 0 };
1367 int ndots = 0;
1368 unsigned v;
1369 size_t copy;
1370
1371 while (*rest) {
1372 if (*rest == '.' && ++ndots >= 3)
1373 break;
1374 if (!isdigit(*rest) && *rest != '.')
1375 break;
1376 rest++;
1377 }
1378 v = ((LINUX_VERSION_CODE >> 8) & 0xff) + 40;
1379 copy = clamp_t(size_t, len, 1, sizeof(buf));
1380 copy = scnprintf(buf, copy, "2.6.%u%s", v, rest);
1381 ret = copy_to_user(release, buf, copy + 1);
1382 }
1383 return ret;
1384 }
1385
1386 SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name)
1387 {
1388 int errno = 0;
1389
1390 down_read(&uts_sem);
1391 if (copy_to_user(name, utsname(), sizeof *name))
1392 errno = -EFAULT;
1393 up_read(&uts_sem);
1394
1395 if (!errno && override_release(name->release, sizeof(name->release)))
1396 errno = -EFAULT;
1397 if (!errno && override_architecture(name))
1398 errno = -EFAULT;
1399 return errno;
1400 }
1401
1402 #ifdef __ARCH_WANT_SYS_OLD_UNAME
1403 /*
1404 * Old cruft
1405 */
1406 SYSCALL_DEFINE1(uname, struct old_utsname __user *, name)
1407 {
1408 int error = 0;
1409
1410 if (!name)
1411 return -EFAULT;
1412
1413 down_read(&uts_sem);
1414 if (copy_to_user(name, utsname(), sizeof(*name)))
1415 error = -EFAULT;
1416 up_read(&uts_sem);
1417
1418 if (!error && override_release(name->release, sizeof(name->release)))
1419 error = -EFAULT;
1420 if (!error && override_architecture(name))
1421 error = -EFAULT;
1422 return error;
1423 }
1424
1425 SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name)
1426 {
1427 int error;
1428
1429 if (!name)
1430 return -EFAULT;
1431 if (!access_ok(VERIFY_WRITE, name, sizeof(struct oldold_utsname)))
1432 return -EFAULT;
1433
1434 down_read(&uts_sem);
1435 error = __copy_to_user(&name->sysname, &utsname()->sysname,
1436 __OLD_UTS_LEN);
1437 error |= __put_user(0, name->sysname + __OLD_UTS_LEN);
1438 error |= __copy_to_user(&name->nodename, &utsname()->nodename,
1439 __OLD_UTS_LEN);
1440 error |= __put_user(0, name->nodename + __OLD_UTS_LEN);
1441 error |= __copy_to_user(&name->release, &utsname()->release,
1442 __OLD_UTS_LEN);
1443 error |= __put_user(0, name->release + __OLD_UTS_LEN);
1444 error |= __copy_to_user(&name->version, &utsname()->version,
1445 __OLD_UTS_LEN);
1446 error |= __put_user(0, name->version + __OLD_UTS_LEN);
1447 error |= __copy_to_user(&name->machine, &utsname()->machine,
1448 __OLD_UTS_LEN);
1449 error |= __put_user(0, name->machine + __OLD_UTS_LEN);
1450 up_read(&uts_sem);
1451
1452 if (!error && override_architecture(name))
1453 error = -EFAULT;
1454 if (!error && override_release(name->release, sizeof(name->release)))
1455 error = -EFAULT;
1456 return error ? -EFAULT : 0;
1457 }
1458 #endif
1459
1460 SYSCALL_DEFINE2(sethostname, char __user *, name, int, len)
1461 {
1462 int errno;
1463 char tmp[__NEW_UTS_LEN];
1464
1465 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN))
1466 return -EPERM;
1467
1468 if (len < 0 || len > __NEW_UTS_LEN)
1469 return -EINVAL;
1470 down_write(&uts_sem);
1471 errno = -EFAULT;
1472 if (!copy_from_user(tmp, name, len)) {
1473 struct new_utsname *u = utsname();
1474
1475 memcpy(u->nodename, tmp, len);
1476 memset(u->nodename + len, 0, sizeof(u->nodename) - len);
1477 errno = 0;
1478 uts_proc_notify(UTS_PROC_HOSTNAME);
1479 }
1480 up_write(&uts_sem);
1481 return errno;
1482 }
1483
1484 #ifdef __ARCH_WANT_SYS_GETHOSTNAME
1485
1486 SYSCALL_DEFINE2(gethostname, char __user *, name, int, len)
1487 {
1488 int i, errno;
1489 struct new_utsname *u;
1490
1491 if (len < 0)
1492 return -EINVAL;
1493 down_read(&uts_sem);
1494 u = utsname();
1495 i = 1 + strlen(u->nodename);
1496 if (i > len)
1497 i = len;
1498 errno = 0;
1499 if (copy_to_user(name, u->nodename, i))
1500 errno = -EFAULT;
1501 up_read(&uts_sem);
1502 return errno;
1503 }
1504
1505 #endif
1506
1507 /*
1508 * Only setdomainname; getdomainname can be implemented by calling
1509 * uname()
1510 */
1511 SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len)
1512 {
1513 int errno;
1514 char tmp[__NEW_UTS_LEN];
1515
1516 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN))
1517 return -EPERM;
1518 if (len < 0 || len > __NEW_UTS_LEN)
1519 return -EINVAL;
1520
1521 down_write(&uts_sem);
1522 errno = -EFAULT;
1523 if (!copy_from_user(tmp, name, len)) {
1524 struct new_utsname *u = utsname();
1525
1526 memcpy(u->domainname, tmp, len);
1527 memset(u->domainname + len, 0, sizeof(u->domainname) - len);
1528 errno = 0;
1529 uts_proc_notify(UTS_PROC_DOMAINNAME);
1530 }
1531 up_write(&uts_sem);
1532 return errno;
1533 }
1534
1535 SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim)
1536 {
1537 struct rlimit value;
1538 int ret;
1539
1540 ret = do_prlimit(current, resource, NULL, &value);
1541 if (!ret)
1542 ret = copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0;
1543
1544 return ret;
1545 }
1546
1547 #ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT
1548
1549 /*
1550 * Back compatibility for getrlimit. Needed for some apps.
1551 */
1552
1553 SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
1554 struct rlimit __user *, rlim)
1555 {
1556 struct rlimit x;
1557 if (resource >= RLIM_NLIMITS)
1558 return -EINVAL;
1559
1560 task_lock(current->group_leader);
1561 x = current->signal->rlim[resource];
1562 task_unlock(current->group_leader);
1563 if (x.rlim_cur > 0x7FFFFFFF)
1564 x.rlim_cur = 0x7FFFFFFF;
1565 if (x.rlim_max > 0x7FFFFFFF)
1566 x.rlim_max = 0x7FFFFFFF;
1567 return copy_to_user(rlim, &x, sizeof(x))?-EFAULT:0;
1568 }
1569
1570 #endif
1571
1572 static inline bool rlim64_is_infinity(__u64 rlim64)
1573 {
1574 #if BITS_PER_LONG < 64
1575 return rlim64 >= ULONG_MAX;
1576 #else
1577 return rlim64 == RLIM64_INFINITY;
1578 #endif
1579 }
1580
1581 static void rlim_to_rlim64(const struct rlimit *rlim, struct rlimit64 *rlim64)
1582 {
1583 if (rlim->rlim_cur == RLIM_INFINITY)
1584 rlim64->rlim_cur = RLIM64_INFINITY;
1585 else
1586 rlim64->rlim_cur = rlim->rlim_cur;
1587 if (rlim->rlim_max == RLIM_INFINITY)
1588 rlim64->rlim_max = RLIM64_INFINITY;
1589 else
1590 rlim64->rlim_max = rlim->rlim_max;
1591 }
1592
1593 static void rlim64_to_rlim(const struct rlimit64 *rlim64, struct rlimit *rlim)
1594 {
1595 if (rlim64_is_infinity(rlim64->rlim_cur))
1596 rlim->rlim_cur = RLIM_INFINITY;
1597 else
1598 rlim->rlim_cur = (unsigned long)rlim64->rlim_cur;
1599 if (rlim64_is_infinity(rlim64->rlim_max))
1600 rlim->rlim_max = RLIM_INFINITY;
1601 else
1602 rlim->rlim_max = (unsigned long)rlim64->rlim_max;
1603 }
1604
1605 /* make sure you are allowed to change @tsk limits before calling this */
1606 int do_prlimit(struct task_struct *tsk, unsigned int resource,
1607 struct rlimit *new_rlim, struct rlimit *old_rlim)
1608 {
1609 struct rlimit *rlim;
1610 int retval = 0;
1611
1612 if (resource >= RLIM_NLIMITS)
1613 return -EINVAL;
1614 if (new_rlim) {
1615 if (new_rlim->rlim_cur > new_rlim->rlim_max)
1616 return -EINVAL;
1617 if (resource == RLIMIT_NOFILE &&
1618 new_rlim->rlim_max > sysctl_nr_open)
1619 return -EPERM;
1620 }
1621
1622 /* protect tsk->signal and tsk->sighand from disappearing */
1623 read_lock(&tasklist_lock);
1624 if (!tsk->sighand) {
1625 retval = -ESRCH;
1626 goto out;
1627 }
1628
1629 rlim = tsk->signal->rlim + resource;
1630 task_lock(tsk->group_leader);
1631 if (new_rlim) {
1632 /* Keep the capable check against init_user_ns until
1633 cgroups can contain all limits */
1634 if (new_rlim->rlim_max > rlim->rlim_max &&
1635 !capable(CAP_SYS_RESOURCE))
1636 retval = -EPERM;
1637 if (!retval)
1638 retval = security_task_setrlimit(tsk->group_leader,
1639 resource, new_rlim);
1640 if (resource == RLIMIT_CPU && new_rlim->rlim_cur == 0) {
1641 /*
1642 * The caller is asking for an immediate RLIMIT_CPU
1643 * expiry. But we use the zero value to mean "it was
1644 * never set". So let's cheat and make it one second
1645 * instead
1646 */
1647 new_rlim->rlim_cur = 1;
1648 }
1649 }
1650 if (!retval) {
1651 if (old_rlim)
1652 *old_rlim = *rlim;
1653 if (new_rlim)
1654 *rlim = *new_rlim;
1655 }
1656 task_unlock(tsk->group_leader);
1657
1658 /*
1659 * RLIMIT_CPU handling. Note that the kernel fails to return an error
1660 * code if it rejected the user's attempt to set RLIMIT_CPU. This is a
1661 * very long-standing error, and fixing it now risks breakage of
1662 * applications, so we live with it
1663 */
1664 if (!retval && new_rlim && resource == RLIMIT_CPU &&
1665 new_rlim->rlim_cur != RLIM_INFINITY)
1666 update_rlimit_cpu(tsk, new_rlim->rlim_cur);
1667 out:
1668 read_unlock(&tasklist_lock);
1669 return retval;
1670 }
1671
1672 /* rcu lock must be held */
1673 static int check_prlimit_permission(struct task_struct *task)
1674 {
1675 const struct cred *cred = current_cred(), *tcred;
1676
1677 if (current == task)
1678 return 0;
1679
1680 tcred = __task_cred(task);
1681 if (uid_eq(cred->uid, tcred->euid) &&
1682 uid_eq(cred->uid, tcred->suid) &&
1683 uid_eq(cred->uid, tcred->uid) &&
1684 gid_eq(cred->gid, tcred->egid) &&
1685 gid_eq(cred->gid, tcred->sgid) &&
1686 gid_eq(cred->gid, tcred->gid))
1687 return 0;
1688 if (ns_capable(tcred->user_ns, CAP_SYS_RESOURCE))
1689 return 0;
1690
1691 return -EPERM;
1692 }
1693
1694 SYSCALL_DEFINE4(prlimit64, pid_t, pid, unsigned int, resource,
1695 const struct rlimit64 __user *, new_rlim,
1696 struct rlimit64 __user *, old_rlim)
1697 {
1698 struct rlimit64 old64, new64;
1699 struct rlimit old, new;
1700 struct task_struct *tsk;
1701 int ret;
1702
1703 if (new_rlim) {
1704 if (copy_from_user(&new64, new_rlim, sizeof(new64)))
1705 return -EFAULT;
1706 rlim64_to_rlim(&new64, &new);
1707 }
1708
1709 rcu_read_lock();
1710 tsk = pid ? find_task_by_vpid(pid) : current;
1711 if (!tsk) {
1712 rcu_read_unlock();
1713 return -ESRCH;
1714 }
1715 ret = check_prlimit_permission(tsk);
1716 if (ret) {
1717 rcu_read_unlock();
1718 return ret;
1719 }
1720 get_task_struct(tsk);
1721 rcu_read_unlock();
1722
1723 ret = do_prlimit(tsk, resource, new_rlim ? &new : NULL,
1724 old_rlim ? &old : NULL);
1725
1726 if (!ret && old_rlim) {
1727 rlim_to_rlim64(&old, &old64);
1728 if (copy_to_user(old_rlim, &old64, sizeof(old64)))
1729 ret = -EFAULT;
1730 }
1731
1732 put_task_struct(tsk);
1733 return ret;
1734 }
1735
1736 SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim)
1737 {
1738 struct rlimit new_rlim;
1739
1740 if (copy_from_user(&new_rlim, rlim, sizeof(*rlim)))
1741 return -EFAULT;
1742 return do_prlimit(current, resource, &new_rlim, NULL);
1743 }
1744
1745 /*
1746 * It would make sense to put struct rusage in the task_struct,
1747 * except that would make the task_struct be *really big*. After
1748 * task_struct gets moved into malloc'ed memory, it would
1749 * make sense to do this. It will make moving the rest of the information
1750 * a lot simpler! (Which we're not doing right now because we're not
1751 * measuring them yet).
1752 *
1753 * When sampling multiple threads for RUSAGE_SELF, under SMP we might have
1754 * races with threads incrementing their own counters. But since word
1755 * reads are atomic, we either get new values or old values and we don't
1756 * care which for the sums. We always take the siglock to protect reading
1757 * the c* fields from p->signal from races with exit.c updating those
1758 * fields when reaping, so a sample either gets all the additions of a
1759 * given child after it's reaped, or none so this sample is before reaping.
1760 *
1761 * Locking:
1762 * We need to take the siglock for CHILDEREN, SELF and BOTH
1763 * for the cases current multithreaded, non-current single threaded
1764 * non-current multithreaded. Thread traversal is now safe with
1765 * the siglock held.
1766 * Strictly speaking, we donot need to take the siglock if we are current and
1767 * single threaded, as no one else can take our signal_struct away, no one
1768 * else can reap the children to update signal->c* counters, and no one else
1769 * can race with the signal-> fields. If we do not take any lock, the
1770 * signal-> fields could be read out of order while another thread was just
1771 * exiting. So we should place a read memory barrier when we avoid the lock.
1772 * On the writer side, write memory barrier is implied in __exit_signal
1773 * as __exit_signal releases the siglock spinlock after updating the signal->
1774 * fields. But we don't do this yet to keep things simple.
1775 *
1776 */
1777
1778 static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r)
1779 {
1780 r->ru_nvcsw += t->nvcsw;
1781 r->ru_nivcsw += t->nivcsw;
1782 r->ru_minflt += t->min_flt;
1783 r->ru_majflt += t->maj_flt;
1784 r->ru_inblock += task_io_get_inblock(t);
1785 r->ru_oublock += task_io_get_oublock(t);
1786 }
1787
1788 static void k_getrusage(struct task_struct *p, int who, struct rusage *r)
1789 {
1790 struct task_struct *t;
1791 unsigned long flags;
1792 cputime_t tgutime, tgstime, utime, stime;
1793 unsigned long maxrss = 0;
1794
1795 memset((char *) r, 0, sizeof *r);
1796 utime = stime = 0;
1797
1798 if (who == RUSAGE_THREAD) {
1799 task_cputime_adjusted(current, &utime, &stime);
1800 accumulate_thread_rusage(p, r);
1801 maxrss = p->signal->maxrss;
1802 goto out;
1803 }
1804
1805 if (!lock_task_sighand(p, &flags))
1806 return;
1807
1808 switch (who) {
1809 case RUSAGE_BOTH:
1810 case RUSAGE_CHILDREN:
1811 utime = p->signal->cutime;
1812 stime = p->signal->cstime;
1813 r->ru_nvcsw = p->signal->cnvcsw;
1814 r->ru_nivcsw = p->signal->cnivcsw;
1815 r->ru_minflt = p->signal->cmin_flt;
1816 r->ru_majflt = p->signal->cmaj_flt;
1817 r->ru_inblock = p->signal->cinblock;
1818 r->ru_oublock = p->signal->coublock;
1819 maxrss = p->signal->cmaxrss;
1820
1821 if (who == RUSAGE_CHILDREN)
1822 break;
1823
1824 case RUSAGE_SELF:
1825 thread_group_cputime_adjusted(p, &tgutime, &tgstime);
1826 utime += tgutime;
1827 stime += tgstime;
1828 r->ru_nvcsw += p->signal->nvcsw;
1829 r->ru_nivcsw += p->signal->nivcsw;
1830 r->ru_minflt += p->signal->min_flt;
1831 r->ru_majflt += p->signal->maj_flt;
1832 r->ru_inblock += p->signal->inblock;
1833 r->ru_oublock += p->signal->oublock;
1834 if (maxrss < p->signal->maxrss)
1835 maxrss = p->signal->maxrss;
1836 t = p;
1837 do {
1838 accumulate_thread_rusage(t, r);
1839 t = next_thread(t);
1840 } while (t != p);
1841 break;
1842
1843 default:
1844 BUG();
1845 }
1846 unlock_task_sighand(p, &flags);
1847
1848 out:
1849 cputime_to_timeval(utime, &r->ru_utime);
1850 cputime_to_timeval(stime, &r->ru_stime);
1851
1852 if (who != RUSAGE_CHILDREN) {
1853 struct mm_struct *mm = get_task_mm(p);
1854 if (mm) {
1855 setmax_mm_hiwater_rss(&maxrss, mm);
1856 mmput(mm);
1857 }
1858 }
1859 r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */
1860 }
1861
1862 int getrusage(struct task_struct *p, int who, struct rusage __user *ru)
1863 {
1864 struct rusage r;
1865 k_getrusage(p, who, &r);
1866 return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0;
1867 }
1868
1869 SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru)
1870 {
1871 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
1872 who != RUSAGE_THREAD)
1873 return -EINVAL;
1874 return getrusage(current, who, ru);
1875 }
1876
1877 #ifdef CONFIG_COMPAT
1878 COMPAT_SYSCALL_DEFINE2(getrusage, int, who, struct compat_rusage __user *, ru)
1879 {
1880 struct rusage r;
1881
1882 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
1883 who != RUSAGE_THREAD)
1884 return -EINVAL;
1885
1886 k_getrusage(current, who, &r);
1887 return put_compat_rusage(&r, ru);
1888 }
1889 #endif
1890
1891 SYSCALL_DEFINE1(umask, int, mask)
1892 {
1893 mask = xchg(&current->fs->umask, mask & S_IRWXUGO);
1894 return mask;
1895 }
1896
1897 static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd)
1898 {
1899 struct fd exe;
1900 struct inode *inode;
1901 int err;
1902
1903 exe = fdget(fd);
1904 if (!exe.file)
1905 return -EBADF;
1906
1907 inode = file_inode(exe.file);
1908
1909 /*
1910 * Because the original mm->exe_file points to executable file, make
1911 * sure that this one is executable as well, to avoid breaking an
1912 * overall picture.
1913 */
1914 err = -EACCES;
1915 if (!S_ISREG(inode->i_mode) ||
1916 exe.file->f_path.mnt->mnt_flags & MNT_NOEXEC)
1917 goto exit;
1918
1919 err = inode_permission(inode, MAY_EXEC);
1920 if (err)
1921 goto exit;
1922
1923 down_write(&mm->mmap_sem);
1924
1925 /*
1926 * Forbid mm->exe_file change if old file still mapped.
1927 */
1928 err = -EBUSY;
1929 if (mm->exe_file) {
1930 struct vm_area_struct *vma;
1931
1932 for (vma = mm->mmap; vma; vma = vma->vm_next)
1933 if (vma->vm_file &&
1934 path_equal(&vma->vm_file->f_path,
1935 &mm->exe_file->f_path))
1936 goto exit_unlock;
1937 }
1938
1939 /*
1940 * The symlink can be changed only once, just to disallow arbitrary
1941 * transitions malicious software might bring in. This means one
1942 * could make a snapshot over all processes running and monitor
1943 * /proc/pid/exe changes to notice unusual activity if needed.
1944 */
1945 err = -EPERM;
1946 if (test_and_set_bit(MMF_EXE_FILE_CHANGED, &mm->flags))
1947 goto exit_unlock;
1948
1949 err = 0;
1950 set_mm_exe_file(mm, exe.file); /* this grabs a reference to exe.file */
1951 exit_unlock:
1952 up_write(&mm->mmap_sem);
1953
1954 exit:
1955 fdput(exe);
1956 return err;
1957 }
1958
1959 static int prctl_set_mm(int opt, unsigned long addr,
1960 unsigned long arg4, unsigned long arg5)
1961 {
1962 unsigned long rlim = rlimit(RLIMIT_DATA);
1963 struct mm_struct *mm = current->mm;
1964 struct vm_area_struct *vma;
1965 int error;
1966
1967 if (arg5 || (arg4 && opt != PR_SET_MM_AUXV))
1968 return -EINVAL;
1969
1970 if (!capable(CAP_SYS_RESOURCE))
1971 return -EPERM;
1972
1973 if (opt == PR_SET_MM_EXE_FILE)
1974 return prctl_set_mm_exe_file(mm, (unsigned int)addr);
1975
1976 if (addr >= TASK_SIZE || addr < mmap_min_addr)
1977 return -EINVAL;
1978
1979 error = -EINVAL;
1980
1981 down_read(&mm->mmap_sem);
1982 vma = find_vma(mm, addr);
1983
1984 switch (opt) {
1985 case PR_SET_MM_START_CODE:
1986 mm->start_code = addr;
1987 break;
1988 case PR_SET_MM_END_CODE:
1989 mm->end_code = addr;
1990 break;
1991 case PR_SET_MM_START_DATA:
1992 mm->start_data = addr;
1993 break;
1994 case PR_SET_MM_END_DATA:
1995 mm->end_data = addr;
1996 break;
1997
1998 case PR_SET_MM_START_BRK:
1999 if (addr <= mm->end_data)
2000 goto out;
2001
2002 if (rlim < RLIM_INFINITY &&
2003 (mm->brk - addr) +
2004 (mm->end_data - mm->start_data) > rlim)
2005 goto out;
2006
2007 mm->start_brk = addr;
2008 break;
2009
2010 case PR_SET_MM_BRK:
2011 if (addr <= mm->end_data)
2012 goto out;
2013
2014 if (rlim < RLIM_INFINITY &&
2015 (addr - mm->start_brk) +
2016 (mm->end_data - mm->start_data) > rlim)
2017 goto out;
2018
2019 mm->brk = addr;
2020 break;
2021
2022 /*
2023 * If command line arguments and environment
2024 * are placed somewhere else on stack, we can
2025 * set them up here, ARG_START/END to setup
2026 * command line argumets and ENV_START/END
2027 * for environment.
2028 */
2029 case PR_SET_MM_START_STACK:
2030 case PR_SET_MM_ARG_START:
2031 case PR_SET_MM_ARG_END:
2032 case PR_SET_MM_ENV_START:
2033 case PR_SET_MM_ENV_END:
2034 if (!vma) {
2035 error = -EFAULT;
2036 goto out;
2037 }
2038 if (opt == PR_SET_MM_START_STACK)
2039 mm->start_stack = addr;
2040 else if (opt == PR_SET_MM_ARG_START)
2041 mm->arg_start = addr;
2042 else if (opt == PR_SET_MM_ARG_END)
2043 mm->arg_end = addr;
2044 else if (opt == PR_SET_MM_ENV_START)
2045 mm->env_start = addr;
2046 else if (opt == PR_SET_MM_ENV_END)
2047 mm->env_end = addr;
2048 break;
2049
2050 /*
2051 * This doesn't move auxiliary vector itself
2052 * since it's pinned to mm_struct, but allow
2053 * to fill vector with new values. It's up
2054 * to a caller to provide sane values here
2055 * otherwise user space tools which use this
2056 * vector might be unhappy.
2057 */
2058 case PR_SET_MM_AUXV: {
2059 unsigned long user_auxv[AT_VECTOR_SIZE];
2060
2061 if (arg4 > sizeof(user_auxv))
2062 goto out;
2063 up_read(&mm->mmap_sem);
2064
2065 if (copy_from_user(user_auxv, (const void __user *)addr, arg4))
2066 return -EFAULT;
2067
2068 /* Make sure the last entry is always AT_NULL */
2069 user_auxv[AT_VECTOR_SIZE - 2] = 0;
2070 user_auxv[AT_VECTOR_SIZE - 1] = 0;
2071
2072 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv));
2073
2074 task_lock(current);
2075 memcpy(mm->saved_auxv, user_auxv, arg4);
2076 task_unlock(current);
2077
2078 return 0;
2079 }
2080 default:
2081 goto out;
2082 }
2083
2084 error = 0;
2085 out:
2086 up_read(&mm->mmap_sem);
2087 return error;
2088 }
2089
2090 #ifdef CONFIG_CHECKPOINT_RESTORE
2091 static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr)
2092 {
2093 return put_user(me->clear_child_tid, tid_addr);
2094 }
2095 #else
2096 static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr)
2097 {
2098 return -EINVAL;
2099 }
2100 #endif
2101
2102 SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
2103 unsigned long, arg4, unsigned long, arg5)
2104 {
2105 struct task_struct *me = current;
2106 unsigned char comm[sizeof(me->comm)];
2107 long error;
2108
2109 error = security_task_prctl(option, arg2, arg3, arg4, arg5);
2110 if (error != -ENOSYS)
2111 return error;
2112
2113 error = 0;
2114 switch (option) {
2115 case PR_SET_PDEATHSIG:
2116 if (!valid_signal(arg2)) {
2117 error = -EINVAL;
2118 break;
2119 }
2120 me->pdeath_signal = arg2;
2121 break;
2122 case PR_GET_PDEATHSIG:
2123 error = put_user(me->pdeath_signal, (int __user *)arg2);
2124 break;
2125 case PR_GET_DUMPABLE:
2126 error = get_dumpable(me->mm);
2127 break;
2128 case PR_SET_DUMPABLE:
2129 if (arg2 != SUID_DUMP_DISABLE && arg2 != SUID_DUMP_USER) {
2130 error = -EINVAL;
2131 break;
2132 }
2133 set_dumpable(me->mm, arg2);
2134 break;
2135
2136 case PR_SET_UNALIGN:
2137 error = SET_UNALIGN_CTL(me, arg2);
2138 break;
2139 case PR_GET_UNALIGN:
2140 error = GET_UNALIGN_CTL(me, arg2);
2141 break;
2142 case PR_SET_FPEMU:
2143 error = SET_FPEMU_CTL(me, arg2);
2144 break;
2145 case PR_GET_FPEMU:
2146 error = GET_FPEMU_CTL(me, arg2);
2147 break;
2148 case PR_SET_FPEXC:
2149 error = SET_FPEXC_CTL(me, arg2);
2150 break;
2151 case PR_GET_FPEXC:
2152 error = GET_FPEXC_CTL(me, arg2);
2153 break;
2154 case PR_GET_TIMING:
2155 error = PR_TIMING_STATISTICAL;
2156 break;
2157 case PR_SET_TIMING:
2158 if (arg2 != PR_TIMING_STATISTICAL)
2159 error = -EINVAL;
2160 break;
2161 case PR_SET_NAME:
2162 comm[sizeof(me->comm) - 1] = 0;
2163 if (strncpy_from_user(comm, (char __user *)arg2,
2164 sizeof(me->comm) - 1) < 0)
2165 return -EFAULT;
2166 set_task_comm(me, comm);
2167 proc_comm_connector(me);
2168 break;
2169 case PR_GET_NAME:
2170 get_task_comm(comm, me);
2171 if (copy_to_user((char __user *)arg2, comm, sizeof(comm)))
2172 return -EFAULT;
2173 break;
2174 case PR_GET_ENDIAN:
2175 error = GET_ENDIAN(me, arg2);
2176 break;
2177 case PR_SET_ENDIAN:
2178 error = SET_ENDIAN(me, arg2);
2179 break;
2180 case PR_GET_SECCOMP:
2181 error = prctl_get_seccomp();
2182 break;
2183 case PR_SET_SECCOMP:
2184 error = prctl_set_seccomp(arg2, (char __user *)arg3);
2185 break;
2186 case PR_GET_TSC:
2187 error = GET_TSC_CTL(arg2);
2188 break;
2189 case PR_SET_TSC:
2190 error = SET_TSC_CTL(arg2);
2191 break;
2192 case PR_TASK_PERF_EVENTS_DISABLE:
2193 error = perf_event_task_disable();
2194 break;
2195 case PR_TASK_PERF_EVENTS_ENABLE:
2196 error = perf_event_task_enable();
2197 break;
2198 case PR_GET_TIMERSLACK:
2199 error = current->timer_slack_ns;
2200 break;
2201 case PR_SET_TIMERSLACK:
2202 if (arg2 <= 0)
2203 current->timer_slack_ns =
2204 current->default_timer_slack_ns;
2205 else
2206 current->timer_slack_ns = arg2;
2207 break;
2208 case PR_MCE_KILL:
2209 if (arg4 | arg5)
2210 return -EINVAL;
2211 switch (arg2) {
2212 case PR_MCE_KILL_CLEAR:
2213 if (arg3 != 0)
2214 return -EINVAL;
2215 current->flags &= ~PF_MCE_PROCESS;
2216 break;
2217 case PR_MCE_KILL_SET:
2218 current->flags |= PF_MCE_PROCESS;
2219 if (arg3 == PR_MCE_KILL_EARLY)
2220 current->flags |= PF_MCE_EARLY;
2221 else if (arg3 == PR_MCE_KILL_LATE)
2222 current->flags &= ~PF_MCE_EARLY;
2223 else if (arg3 == PR_MCE_KILL_DEFAULT)
2224 current->flags &=
2225 ~(PF_MCE_EARLY|PF_MCE_PROCESS);
2226 else
2227 return -EINVAL;
2228 break;
2229 default:
2230 return -EINVAL;
2231 }
2232 break;
2233 case PR_MCE_KILL_GET:
2234 if (arg2 | arg3 | arg4 | arg5)
2235 return -EINVAL;
2236 if (current->flags & PF_MCE_PROCESS)
2237 error = (current->flags & PF_MCE_EARLY) ?
2238 PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE;
2239 else
2240 error = PR_MCE_KILL_DEFAULT;
2241 break;
2242 case PR_SET_MM:
2243 error = prctl_set_mm(arg2, arg3, arg4, arg5);
2244 break;
2245 case PR_GET_TID_ADDRESS:
2246 error = prctl_get_tid_address(me, (int __user **)arg2);
2247 break;
2248 case PR_SET_CHILD_SUBREAPER:
2249 me->signal->is_child_subreaper = !!arg2;
2250 break;
2251 case PR_GET_CHILD_SUBREAPER:
2252 error = put_user(me->signal->is_child_subreaper,
2253 (int __user *)arg2);
2254 break;
2255 case PR_SET_NO_NEW_PRIVS:
2256 if (arg2 != 1 || arg3 || arg4 || arg5)
2257 return -EINVAL;
2258
2259 current->no_new_privs = 1;
2260 break;
2261 case PR_GET_NO_NEW_PRIVS:
2262 if (arg2 || arg3 || arg4 || arg5)
2263 return -EINVAL;
2264 return current->no_new_privs ? 1 : 0;
2265 default:
2266 error = -EINVAL;
2267 break;
2268 }
2269 return error;
2270 }
2271
2272 SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep,
2273 struct getcpu_cache __user *, unused)
2274 {
2275 int err = 0;
2276 int cpu = raw_smp_processor_id();
2277 if (cpup)
2278 err |= put_user(cpu, cpup);
2279 if (nodep)
2280 err |= put_user(cpu_to_node(cpu), nodep);
2281 return err ? -EFAULT : 0;
2282 }
2283
2284 char poweroff_cmd[POWEROFF_CMD_PATH_LEN] = "/sbin/poweroff";
2285
2286 static int __orderly_poweroff(bool force)
2287 {
2288 char **argv;
2289 static char *envp[] = {
2290 "HOME=/",
2291 "PATH=/sbin:/bin:/usr/sbin:/usr/bin",
2292 NULL
2293 };
2294 int ret;
2295
2296 argv = argv_split(GFP_KERNEL, poweroff_cmd, NULL);
2297 if (argv) {
2298 ret = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_EXEC);
2299 argv_free(argv);
2300 } else {
2301 printk(KERN_WARNING "%s failed to allocate memory for \"%s\"\n",
2302 __func__, poweroff_cmd);
2303 ret = -ENOMEM;
2304 }
2305
2306 if (ret && force) {
2307 printk(KERN_WARNING "Failed to start orderly shutdown: "
2308 "forcing the issue\n");
2309 /*
2310 * I guess this should try to kick off some daemon to sync and
2311 * poweroff asap. Or not even bother syncing if we're doing an
2312 * emergency shutdown?
2313 */
2314 emergency_sync();
2315 kernel_power_off();
2316 }
2317
2318 return ret;
2319 }
2320
2321 static bool poweroff_force;
2322
2323 static void poweroff_work_func(struct work_struct *work)
2324 {
2325 __orderly_poweroff(poweroff_force);
2326 }
2327
2328 static DECLARE_WORK(poweroff_work, poweroff_work_func);
2329
2330 /**
2331 * orderly_poweroff - Trigger an orderly system poweroff
2332 * @force: force poweroff if command execution fails
2333 *
2334 * This may be called from any context to trigger a system shutdown.
2335 * If the orderly shutdown fails, it will force an immediate shutdown.
2336 */
2337 int orderly_poweroff(bool force)
2338 {
2339 if (force) /* do not override the pending "true" */
2340 poweroff_force = true;
2341 schedule_work(&poweroff_work);
2342 return 0;
2343 }
2344 EXPORT_SYMBOL_GPL(orderly_poweroff);
2345
2346 /**
2347 * do_sysinfo - fill in sysinfo struct
2348 * @info: pointer to buffer to fill
2349 */
2350 static int do_sysinfo(struct sysinfo *info)
2351 {
2352 unsigned long mem_total, sav_total;
2353 unsigned int mem_unit, bitcount;
2354 struct timespec tp;
2355
2356 memset(info, 0, sizeof(struct sysinfo));
2357
2358 ktime_get_ts(&tp);
2359 monotonic_to_bootbased(&tp);
2360 info->uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0);
2361
2362 get_avenrun(info->loads, 0, SI_LOAD_SHIFT - FSHIFT);
2363
2364 info->procs = nr_threads;
2365
2366 si_meminfo(info);
2367 si_swapinfo(info);
2368
2369 /*
2370 * If the sum of all the available memory (i.e. ram + swap)
2371 * is less than can be stored in a 32 bit unsigned long then
2372 * we can be binary compatible with 2.2.x kernels. If not,
2373 * well, in that case 2.2.x was broken anyways...
2374 *
2375 * -Erik Andersen <andersee@debian.org>
2376 */
2377
2378 mem_total = info->totalram + info->totalswap;
2379 if (mem_total < info->totalram || mem_total < info->totalswap)
2380 goto out;
2381 bitcount = 0;
2382 mem_unit = info->mem_unit;
2383 while (mem_unit > 1) {
2384 bitcount++;
2385 mem_unit >>= 1;
2386 sav_total = mem_total;
2387 mem_total <<= 1;
2388 if (mem_total < sav_total)
2389 goto out;
2390 }
2391
2392 /*
2393 * If mem_total did not overflow, multiply all memory values by
2394 * info->mem_unit and set it to 1. This leaves things compatible
2395 * with 2.2.x, and also retains compatibility with earlier 2.4.x
2396 * kernels...
2397 */
2398
2399 info->mem_unit = 1;
2400 info->totalram <<= bitcount;
2401 info->freeram <<= bitcount;
2402 info->sharedram <<= bitcount;
2403 info->bufferram <<= bitcount;
2404 info->totalswap <<= bitcount;
2405 info->freeswap <<= bitcount;
2406 info->totalhigh <<= bitcount;
2407 info->freehigh <<= bitcount;
2408
2409 out:
2410 return 0;
2411 }
2412
2413 SYSCALL_DEFINE1(sysinfo, struct sysinfo __user *, info)
2414 {
2415 struct sysinfo val;
2416
2417 do_sysinfo(&val);
2418
2419 if (copy_to_user(info, &val, sizeof(struct sysinfo)))
2420 return -EFAULT;
2421
2422 return 0;
2423 }
2424
2425 #ifdef CONFIG_COMPAT
2426 struct compat_sysinfo {
2427 s32 uptime;
2428 u32 loads[3];
2429 u32 totalram;
2430 u32 freeram;
2431 u32 sharedram;
2432 u32 bufferram;
2433 u32 totalswap;
2434 u32 freeswap;
2435 u16 procs;
2436 u16 pad;
2437 u32 totalhigh;
2438 u32 freehigh;
2439 u32 mem_unit;
2440 char _f[20-2*sizeof(u32)-sizeof(int)];
2441 };
2442
2443 COMPAT_SYSCALL_DEFINE1(sysinfo, struct compat_sysinfo __user *, info)
2444 {
2445 struct sysinfo s;
2446
2447 do_sysinfo(&s);
2448
2449 /* Check to see if any memory value is too large for 32-bit and scale
2450 * down if needed
2451 */
2452 if ((s.totalram >> 32) || (s.totalswap >> 32)) {
2453 int bitcount = 0;
2454
2455 while (s.mem_unit < PAGE_SIZE) {
2456 s.mem_unit <<= 1;
2457 bitcount++;
2458 }
2459
2460 s.totalram >>= bitcount;
2461 s.freeram >>= bitcount;
2462 s.sharedram >>= bitcount;
2463 s.bufferram >>= bitcount;
2464 s.totalswap >>= bitcount;
2465 s.freeswap >>= bitcount;
2466 s.totalhigh >>= bitcount;
2467 s.freehigh >>= bitcount;
2468 }
2469
2470 if (!access_ok(VERIFY_WRITE, info, sizeof(struct compat_sysinfo)) ||
2471 __put_user(s.uptime, &info->uptime) ||
2472 __put_user(s.loads[0], &info->loads[0]) ||
2473 __put_user(s.loads[1], &info->loads[1]) ||
2474 __put_user(s.loads[2], &info->loads[2]) ||
2475 __put_user(s.totalram, &info->totalram) ||
2476 __put_user(s.freeram, &info->freeram) ||
2477 __put_user(s.sharedram, &info->sharedram) ||
2478 __put_user(s.bufferram, &info->bufferram) ||
2479 __put_user(s.totalswap, &info->totalswap) ||
2480 __put_user(s.freeswap, &info->freeswap) ||
2481 __put_user(s.procs, &info->procs) ||
2482 __put_user(s.totalhigh, &info->totalhigh) ||
2483 __put_user(s.freehigh, &info->freehigh) ||
2484 __put_user(s.mem_unit, &info->mem_unit))
2485 return -EFAULT;
2486
2487 return 0;
2488 }
2489 #endif /* CONFIG_COMPAT */
kernel source for telekom puls (alcatel/mediatek)