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[ACPI] fix reboot upon suspend-to-disk
[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/config.h>
8 #include <linux/module.h>
9 #include <linux/mm.h>
10 #include <linux/utsname.h>
11 #include <linux/mman.h>
12 #include <linux/smp_lock.h>
13 #include <linux/notifier.h>
14 #include <linux/reboot.h>
15 #include <linux/prctl.h>
16 #include <linux/init.h>
17 #include <linux/highuid.h>
18 #include <linux/fs.h>
19 #include <linux/kernel.h>
20 #include <linux/kexec.h>
21 #include <linux/workqueue.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
33 #include <linux/compat.h>
34 #include <linux/syscalls.h>
35 #include <linux/kprobes.h>
36
37 #include <asm/uaccess.h>
38 #include <asm/io.h>
39 #include <asm/unistd.h>
40
41 #ifndef SET_UNALIGN_CTL
42 # define SET_UNALIGN_CTL(a,b) (-EINVAL)
43 #endif
44 #ifndef GET_UNALIGN_CTL
45 # define GET_UNALIGN_CTL(a,b) (-EINVAL)
46 #endif
47 #ifndef SET_FPEMU_CTL
48 # define SET_FPEMU_CTL(a,b) (-EINVAL)
49 #endif
50 #ifndef GET_FPEMU_CTL
51 # define GET_FPEMU_CTL(a,b) (-EINVAL)
52 #endif
53 #ifndef SET_FPEXC_CTL
54 # define SET_FPEXC_CTL(a,b) (-EINVAL)
55 #endif
56 #ifndef GET_FPEXC_CTL
57 # define GET_FPEXC_CTL(a,b) (-EINVAL)
58 #endif
59
60 /*
61 * this is where the system-wide overflow UID and GID are defined, for
62 * architectures that now have 32-bit UID/GID but didn't in the past
63 */
64
65 int overflowuid = DEFAULT_OVERFLOWUID;
66 int overflowgid = DEFAULT_OVERFLOWGID;
67
68 #ifdef CONFIG_UID16
69 EXPORT_SYMBOL(overflowuid);
70 EXPORT_SYMBOL(overflowgid);
71 #endif
72
73 /*
74 * the same as above, but for filesystems which can only store a 16-bit
75 * UID and GID. as such, this is needed on all architectures
76 */
77
78 int fs_overflowuid = DEFAULT_FS_OVERFLOWUID;
79 int fs_overflowgid = DEFAULT_FS_OVERFLOWUID;
80
81 EXPORT_SYMBOL(fs_overflowuid);
82 EXPORT_SYMBOL(fs_overflowgid);
83
84 /*
85 * this indicates whether you can reboot with ctrl-alt-del: the default is yes
86 */
87
88 int C_A_D = 1;
89 int cad_pid = 1;
90
91 /*
92 * Notifier list for kernel code which wants to be called
93 * at shutdown. This is used to stop any idling DMA operations
94 * and the like.
95 */
96
97 static struct notifier_block *reboot_notifier_list;
98 static DEFINE_RWLOCK(notifier_lock);
99
100 /**
101 * notifier_chain_register - Add notifier to a notifier chain
102 * @list: Pointer to root list pointer
103 * @n: New entry in notifier chain
104 *
105 * Adds a notifier to a notifier chain.
106 *
107 * Currently always returns zero.
108 */
109
110 int notifier_chain_register(struct notifier_block **list, struct notifier_block *n)
111 {
112 write_lock(&notifier_lock);
113 while(*list)
114 {
115 if(n->priority > (*list)->priority)
116 break;
117 list= &((*list)->next);
118 }
119 n->next = *list;
120 *list=n;
121 write_unlock(&notifier_lock);
122 return 0;
123 }
124
125 EXPORT_SYMBOL(notifier_chain_register);
126
127 /**
128 * notifier_chain_unregister - Remove notifier from a notifier chain
129 * @nl: Pointer to root list pointer
130 * @n: New entry in notifier chain
131 *
132 * Removes a notifier from a notifier chain.
133 *
134 * Returns zero on success, or %-ENOENT on failure.
135 */
136
137 int notifier_chain_unregister(struct notifier_block **nl, struct notifier_block *n)
138 {
139 write_lock(&notifier_lock);
140 while((*nl)!=NULL)
141 {
142 if((*nl)==n)
143 {
144 *nl=n->next;
145 write_unlock(&notifier_lock);
146 return 0;
147 }
148 nl=&((*nl)->next);
149 }
150 write_unlock(&notifier_lock);
151 return -ENOENT;
152 }
153
154 EXPORT_SYMBOL(notifier_chain_unregister);
155
156 /**
157 * notifier_call_chain - Call functions in a notifier chain
158 * @n: Pointer to root pointer of notifier chain
159 * @val: Value passed unmodified to notifier function
160 * @v: Pointer passed unmodified to notifier function
161 *
162 * Calls each function in a notifier chain in turn.
163 *
164 * If the return value of the notifier can be and'd
165 * with %NOTIFY_STOP_MASK, then notifier_call_chain
166 * will return immediately, with the return value of
167 * the notifier function which halted execution.
168 * Otherwise, the return value is the return value
169 * of the last notifier function called.
170 */
171
172 int __kprobes notifier_call_chain(struct notifier_block **n, unsigned long val, void *v)
173 {
174 int ret=NOTIFY_DONE;
175 struct notifier_block *nb = *n;
176
177 while(nb)
178 {
179 ret=nb->notifier_call(nb,val,v);
180 if(ret&NOTIFY_STOP_MASK)
181 {
182 return ret;
183 }
184 nb=nb->next;
185 }
186 return ret;
187 }
188
189 EXPORT_SYMBOL(notifier_call_chain);
190
191 /**
192 * register_reboot_notifier - Register function to be called at reboot time
193 * @nb: Info about notifier function to be called
194 *
195 * Registers a function with the list of functions
196 * to be called at reboot time.
197 *
198 * Currently always returns zero, as notifier_chain_register
199 * always returns zero.
200 */
201
202 int register_reboot_notifier(struct notifier_block * nb)
203 {
204 return notifier_chain_register(&reboot_notifier_list, nb);
205 }
206
207 EXPORT_SYMBOL(register_reboot_notifier);
208
209 /**
210 * unregister_reboot_notifier - Unregister previously registered reboot notifier
211 * @nb: Hook to be unregistered
212 *
213 * Unregisters a previously registered reboot
214 * notifier function.
215 *
216 * Returns zero on success, or %-ENOENT on failure.
217 */
218
219 int unregister_reboot_notifier(struct notifier_block * nb)
220 {
221 return notifier_chain_unregister(&reboot_notifier_list, nb);
222 }
223
224 EXPORT_SYMBOL(unregister_reboot_notifier);
225
226 static int set_one_prio(struct task_struct *p, int niceval, int error)
227 {
228 int no_nice;
229
230 if (p->uid != current->euid &&
231 p->euid != current->euid && !capable(CAP_SYS_NICE)) {
232 error = -EPERM;
233 goto out;
234 }
235 if (niceval < task_nice(p) && !can_nice(p, niceval)) {
236 error = -EACCES;
237 goto out;
238 }
239 no_nice = security_task_setnice(p, niceval);
240 if (no_nice) {
241 error = no_nice;
242 goto out;
243 }
244 if (error == -ESRCH)
245 error = 0;
246 set_user_nice(p, niceval);
247 out:
248 return error;
249 }
250
251 asmlinkage long sys_setpriority(int which, int who, int niceval)
252 {
253 struct task_struct *g, *p;
254 struct user_struct *user;
255 int error = -EINVAL;
256
257 if (which > 2 || which < 0)
258 goto out;
259
260 /* normalize: avoid signed division (rounding problems) */
261 error = -ESRCH;
262 if (niceval < -20)
263 niceval = -20;
264 if (niceval > 19)
265 niceval = 19;
266
267 read_lock(&tasklist_lock);
268 switch (which) {
269 case PRIO_PROCESS:
270 if (!who)
271 who = current->pid;
272 p = find_task_by_pid(who);
273 if (p)
274 error = set_one_prio(p, niceval, error);
275 break;
276 case PRIO_PGRP:
277 if (!who)
278 who = process_group(current);
279 do_each_task_pid(who, PIDTYPE_PGID, p) {
280 error = set_one_prio(p, niceval, error);
281 } while_each_task_pid(who, PIDTYPE_PGID, p);
282 break;
283 case PRIO_USER:
284 user = current->user;
285 if (!who)
286 who = current->uid;
287 else
288 if ((who != current->uid) && !(user = find_user(who)))
289 goto out_unlock; /* No processes for this user */
290
291 do_each_thread(g, p)
292 if (p->uid == who)
293 error = set_one_prio(p, niceval, error);
294 while_each_thread(g, p);
295 if (who != current->uid)
296 free_uid(user); /* For find_user() */
297 break;
298 }
299 out_unlock:
300 read_unlock(&tasklist_lock);
301 out:
302 return error;
303 }
304
305 /*
306 * Ugh. To avoid negative return values, "getpriority()" will
307 * not return the normal nice-value, but a negated value that
308 * has been offset by 20 (ie it returns 40..1 instead of -20..19)
309 * to stay compatible.
310 */
311 asmlinkage long sys_getpriority(int which, int who)
312 {
313 struct task_struct *g, *p;
314 struct user_struct *user;
315 long niceval, retval = -ESRCH;
316
317 if (which > 2 || which < 0)
318 return -EINVAL;
319
320 read_lock(&tasklist_lock);
321 switch (which) {
322 case PRIO_PROCESS:
323 if (!who)
324 who = current->pid;
325 p = find_task_by_pid(who);
326 if (p) {
327 niceval = 20 - task_nice(p);
328 if (niceval > retval)
329 retval = niceval;
330 }
331 break;
332 case PRIO_PGRP:
333 if (!who)
334 who = process_group(current);
335 do_each_task_pid(who, PIDTYPE_PGID, p) {
336 niceval = 20 - task_nice(p);
337 if (niceval > retval)
338 retval = niceval;
339 } while_each_task_pid(who, PIDTYPE_PGID, p);
340 break;
341 case PRIO_USER:
342 user = current->user;
343 if (!who)
344 who = current->uid;
345 else
346 if ((who != current->uid) && !(user = find_user(who)))
347 goto out_unlock; /* No processes for this user */
348
349 do_each_thread(g, p)
350 if (p->uid == who) {
351 niceval = 20 - task_nice(p);
352 if (niceval > retval)
353 retval = niceval;
354 }
355 while_each_thread(g, p);
356 if (who != current->uid)
357 free_uid(user); /* for find_user() */
358 break;
359 }
360 out_unlock:
361 read_unlock(&tasklist_lock);
362
363 return retval;
364 }
365
366 /**
367 * emergency_restart - reboot the system
368 *
369 * Without shutting down any hardware or taking any locks
370 * reboot the system. This is called when we know we are in
371 * trouble so this is our best effort to reboot. This is
372 * safe to call in interrupt context.
373 */
374 void emergency_restart(void)
375 {
376 machine_emergency_restart();
377 }
378 EXPORT_SYMBOL_GPL(emergency_restart);
379
380 void kernel_restart_prepare(char *cmd)
381 {
382 notifier_call_chain(&reboot_notifier_list, SYS_RESTART, cmd);
383 system_state = SYSTEM_RESTART;
384 device_shutdown();
385 }
386
387 /**
388 * kernel_restart - reboot the system
389 * @cmd: pointer to buffer containing command to execute for restart
390 * or %NULL
391 *
392 * Shutdown everything and perform a clean reboot.
393 * This is not safe to call in interrupt context.
394 */
395 void kernel_restart(char *cmd)
396 {
397 kernel_restart_prepare(cmd);
398 if (!cmd) {
399 printk(KERN_EMERG "Restarting system.\n");
400 } else {
401 printk(KERN_EMERG "Restarting system with command '%s'.\n", cmd);
402 }
403 printk(".\n");
404 machine_restart(cmd);
405 }
406 EXPORT_SYMBOL_GPL(kernel_restart);
407
408 /**
409 * kernel_kexec - reboot the system
410 *
411 * Move into place and start executing a preloaded standalone
412 * executable. If nothing was preloaded return an error.
413 */
414 void kernel_kexec(void)
415 {
416 #ifdef CONFIG_KEXEC
417 struct kimage *image;
418 image = xchg(&kexec_image, 0);
419 if (!image) {
420 return;
421 }
422 kernel_restart_prepare(NULL);
423 printk(KERN_EMERG "Starting new kernel\n");
424 machine_shutdown();
425 machine_kexec(image);
426 #endif
427 }
428 EXPORT_SYMBOL_GPL(kernel_kexec);
429
430 void kernel_shutdown_prepare(enum system_states state)
431 {
432 notifier_call_chain(&reboot_notifier_list,
433 (state == SYSTEM_HALT)?SYS_HALT:SYS_POWER_OFF, NULL);
434 system_state = state;
435 device_shutdown();
436 }
437 /**
438 * kernel_halt - halt the system
439 *
440 * Shutdown everything and perform a clean system halt.
441 */
442 void kernel_halt(void)
443 {
444 kernel_shutdown_prepare(SYSTEM_HALT);
445 printk(KERN_EMERG "System halted.\n");
446 machine_halt();
447 }
448
449 EXPORT_SYMBOL_GPL(kernel_halt);
450
451 /**
452 * kernel_power_off - power_off the system
453 *
454 * Shutdown everything and perform a clean system power_off.
455 */
456 void kernel_power_off(void)
457 {
458 kernel_shutdown_prepare(SYSTEM_POWER_OFF);
459 printk(KERN_EMERG "Power down.\n");
460 machine_power_off();
461 }
462 EXPORT_SYMBOL_GPL(kernel_power_off);
463 /*
464 * Reboot system call: for obvious reasons only root may call it,
465 * and even root needs to set up some magic numbers in the registers
466 * so that some mistake won't make this reboot the whole machine.
467 * You can also set the meaning of the ctrl-alt-del-key here.
468 *
469 * reboot doesn't sync: do that yourself before calling this.
470 */
471 asmlinkage long sys_reboot(int magic1, int magic2, unsigned int cmd, void __user * arg)
472 {
473 char buffer[256];
474
475 /* We only trust the superuser with rebooting the system. */
476 if (!capable(CAP_SYS_BOOT))
477 return -EPERM;
478
479 /* For safety, we require "magic" arguments. */
480 if (magic1 != LINUX_REBOOT_MAGIC1 ||
481 (magic2 != LINUX_REBOOT_MAGIC2 &&
482 magic2 != LINUX_REBOOT_MAGIC2A &&
483 magic2 != LINUX_REBOOT_MAGIC2B &&
484 magic2 != LINUX_REBOOT_MAGIC2C))
485 return -EINVAL;
486
487 lock_kernel();
488 switch (cmd) {
489 case LINUX_REBOOT_CMD_RESTART:
490 kernel_restart(NULL);
491 break;
492
493 case LINUX_REBOOT_CMD_CAD_ON:
494 C_A_D = 1;
495 break;
496
497 case LINUX_REBOOT_CMD_CAD_OFF:
498 C_A_D = 0;
499 break;
500
501 case LINUX_REBOOT_CMD_HALT:
502 kernel_halt();
503 unlock_kernel();
504 do_exit(0);
505 break;
506
507 case LINUX_REBOOT_CMD_POWER_OFF:
508 kernel_power_off();
509 unlock_kernel();
510 do_exit(0);
511 break;
512
513 case LINUX_REBOOT_CMD_RESTART2:
514 if (strncpy_from_user(&buffer[0], arg, sizeof(buffer) - 1) < 0) {
515 unlock_kernel();
516 return -EFAULT;
517 }
518 buffer[sizeof(buffer) - 1] = '\0';
519
520 kernel_restart(buffer);
521 break;
522
523 case LINUX_REBOOT_CMD_KEXEC:
524 kernel_kexec();
525 unlock_kernel();
526 return -EINVAL;
527
528 #ifdef CONFIG_SOFTWARE_SUSPEND
529 case LINUX_REBOOT_CMD_SW_SUSPEND:
530 {
531 int ret = software_suspend();
532 unlock_kernel();
533 return ret;
534 }
535 #endif
536
537 default:
538 unlock_kernel();
539 return -EINVAL;
540 }
541 unlock_kernel();
542 return 0;
543 }
544
545 static void deferred_cad(void *dummy)
546 {
547 kernel_restart(NULL);
548 }
549
550 /*
551 * This function gets called by ctrl-alt-del - ie the keyboard interrupt.
552 * As it's called within an interrupt, it may NOT sync: the only choice
553 * is whether to reboot at once, or just ignore the ctrl-alt-del.
554 */
555 void ctrl_alt_del(void)
556 {
557 static DECLARE_WORK(cad_work, deferred_cad, NULL);
558
559 if (C_A_D)
560 schedule_work(&cad_work);
561 else
562 kill_proc(cad_pid, SIGINT, 1);
563 }
564
565
566 /*
567 * Unprivileged users may change the real gid to the effective gid
568 * or vice versa. (BSD-style)
569 *
570 * If you set the real gid at all, or set the effective gid to a value not
571 * equal to the real gid, then the saved gid is set to the new effective gid.
572 *
573 * This makes it possible for a setgid program to completely drop its
574 * privileges, which is often a useful assertion to make when you are doing
575 * a security audit over a program.
576 *
577 * The general idea is that a program which uses just setregid() will be
578 * 100% compatible with BSD. A program which uses just setgid() will be
579 * 100% compatible with POSIX with saved IDs.
580 *
581 * SMP: There are not races, the GIDs are checked only by filesystem
582 * operations (as far as semantic preservation is concerned).
583 */
584 asmlinkage long sys_setregid(gid_t rgid, gid_t egid)
585 {
586 int old_rgid = current->gid;
587 int old_egid = current->egid;
588 int new_rgid = old_rgid;
589 int new_egid = old_egid;
590 int retval;
591
592 retval = security_task_setgid(rgid, egid, (gid_t)-1, LSM_SETID_RE);
593 if (retval)
594 return retval;
595
596 if (rgid != (gid_t) -1) {
597 if ((old_rgid == rgid) ||
598 (current->egid==rgid) ||
599 capable(CAP_SETGID))
600 new_rgid = rgid;
601 else
602 return -EPERM;
603 }
604 if (egid != (gid_t) -1) {
605 if ((old_rgid == egid) ||
606 (current->egid == egid) ||
607 (current->sgid == egid) ||
608 capable(CAP_SETGID))
609 new_egid = egid;
610 else {
611 return -EPERM;
612 }
613 }
614 if (new_egid != old_egid)
615 {
616 current->mm->dumpable = suid_dumpable;
617 smp_wmb();
618 }
619 if (rgid != (gid_t) -1 ||
620 (egid != (gid_t) -1 && egid != old_rgid))
621 current->sgid = new_egid;
622 current->fsgid = new_egid;
623 current->egid = new_egid;
624 current->gid = new_rgid;
625 key_fsgid_changed(current);
626 proc_id_connector(current, PROC_EVENT_GID);
627 return 0;
628 }
629
630 /*
631 * setgid() is implemented like SysV w/ SAVED_IDS
632 *
633 * SMP: Same implicit races as above.
634 */
635 asmlinkage long sys_setgid(gid_t gid)
636 {
637 int old_egid = current->egid;
638 int retval;
639
640 retval = security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_ID);
641 if (retval)
642 return retval;
643
644 if (capable(CAP_SETGID))
645 {
646 if(old_egid != gid)
647 {
648 current->mm->dumpable = suid_dumpable;
649 smp_wmb();
650 }
651 current->gid = current->egid = current->sgid = current->fsgid = gid;
652 }
653 else if ((gid == current->gid) || (gid == current->sgid))
654 {
655 if(old_egid != gid)
656 {
657 current->mm->dumpable = suid_dumpable;
658 smp_wmb();
659 }
660 current->egid = current->fsgid = gid;
661 }
662 else
663 return -EPERM;
664
665 key_fsgid_changed(current);
666 proc_id_connector(current, PROC_EVENT_GID);
667 return 0;
668 }
669
670 static int set_user(uid_t new_ruid, int dumpclear)
671 {
672 struct user_struct *new_user;
673
674 new_user = alloc_uid(new_ruid);
675 if (!new_user)
676 return -EAGAIN;
677
678 if (atomic_read(&new_user->processes) >=
679 current->signal->rlim[RLIMIT_NPROC].rlim_cur &&
680 new_user != &root_user) {
681 free_uid(new_user);
682 return -EAGAIN;
683 }
684
685 switch_uid(new_user);
686
687 if(dumpclear)
688 {
689 current->mm->dumpable = suid_dumpable;
690 smp_wmb();
691 }
692 current->uid = new_ruid;
693 return 0;
694 }
695
696 /*
697 * Unprivileged users may change the real uid to the effective uid
698 * or vice versa. (BSD-style)
699 *
700 * If you set the real uid at all, or set the effective uid to a value not
701 * equal to the real uid, then the saved uid is set to the new effective uid.
702 *
703 * This makes it possible for a setuid program to completely drop its
704 * privileges, which is often a useful assertion to make when you are doing
705 * a security audit over a program.
706 *
707 * The general idea is that a program which uses just setreuid() will be
708 * 100% compatible with BSD. A program which uses just setuid() will be
709 * 100% compatible with POSIX with saved IDs.
710 */
711 asmlinkage long sys_setreuid(uid_t ruid, uid_t euid)
712 {
713 int old_ruid, old_euid, old_suid, new_ruid, new_euid;
714 int retval;
715
716 retval = security_task_setuid(ruid, euid, (uid_t)-1, LSM_SETID_RE);
717 if (retval)
718 return retval;
719
720 new_ruid = old_ruid = current->uid;
721 new_euid = old_euid = current->euid;
722 old_suid = current->suid;
723
724 if (ruid != (uid_t) -1) {
725 new_ruid = ruid;
726 if ((old_ruid != ruid) &&
727 (current->euid != ruid) &&
728 !capable(CAP_SETUID))
729 return -EPERM;
730 }
731
732 if (euid != (uid_t) -1) {
733 new_euid = euid;
734 if ((old_ruid != euid) &&
735 (current->euid != euid) &&
736 (current->suid != euid) &&
737 !capable(CAP_SETUID))
738 return -EPERM;
739 }
740
741 if (new_ruid != old_ruid && set_user(new_ruid, new_euid != old_euid) < 0)
742 return -EAGAIN;
743
744 if (new_euid != old_euid)
745 {
746 current->mm->dumpable = suid_dumpable;
747 smp_wmb();
748 }
749 current->fsuid = current->euid = new_euid;
750 if (ruid != (uid_t) -1 ||
751 (euid != (uid_t) -1 && euid != old_ruid))
752 current->suid = current->euid;
753 current->fsuid = current->euid;
754
755 key_fsuid_changed(current);
756 proc_id_connector(current, PROC_EVENT_UID);
757
758 return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_RE);
759 }
760
761
762
763 /*
764 * setuid() is implemented like SysV with SAVED_IDS
765 *
766 * Note that SAVED_ID's is deficient in that a setuid root program
767 * like sendmail, for example, cannot set its uid to be a normal
768 * user and then switch back, because if you're root, setuid() sets
769 * the saved uid too. If you don't like this, blame the bright people
770 * in the POSIX committee and/or USG. Note that the BSD-style setreuid()
771 * will allow a root program to temporarily drop privileges and be able to
772 * regain them by swapping the real and effective uid.
773 */
774 asmlinkage long sys_setuid(uid_t uid)
775 {
776 int old_euid = current->euid;
777 int old_ruid, old_suid, new_ruid, new_suid;
778 int retval;
779
780 retval = security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_ID);
781 if (retval)
782 return retval;
783
784 old_ruid = new_ruid = current->uid;
785 old_suid = current->suid;
786 new_suid = old_suid;
787
788 if (capable(CAP_SETUID)) {
789 if (uid != old_ruid && set_user(uid, old_euid != uid) < 0)
790 return -EAGAIN;
791 new_suid = uid;
792 } else if ((uid != current->uid) && (uid != new_suid))
793 return -EPERM;
794
795 if (old_euid != uid)
796 {
797 current->mm->dumpable = suid_dumpable;
798 smp_wmb();
799 }
800 current->fsuid = current->euid = uid;
801 current->suid = new_suid;
802
803 key_fsuid_changed(current);
804 proc_id_connector(current, PROC_EVENT_UID);
805
806 return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_ID);
807 }
808
809
810 /*
811 * This function implements a generic ability to update ruid, euid,
812 * and suid. This allows you to implement the 4.4 compatible seteuid().
813 */
814 asmlinkage long sys_setresuid(uid_t ruid, uid_t euid, uid_t suid)
815 {
816 int old_ruid = current->uid;
817 int old_euid = current->euid;
818 int old_suid = current->suid;
819 int retval;
820
821 retval = security_task_setuid(ruid, euid, suid, LSM_SETID_RES);
822 if (retval)
823 return retval;
824
825 if (!capable(CAP_SETUID)) {
826 if ((ruid != (uid_t) -1) && (ruid != current->uid) &&
827 (ruid != current->euid) && (ruid != current->suid))
828 return -EPERM;
829 if ((euid != (uid_t) -1) && (euid != current->uid) &&
830 (euid != current->euid) && (euid != current->suid))
831 return -EPERM;
832 if ((suid != (uid_t) -1) && (suid != current->uid) &&
833 (suid != current->euid) && (suid != current->suid))
834 return -EPERM;
835 }
836 if (ruid != (uid_t) -1) {
837 if (ruid != current->uid && set_user(ruid, euid != current->euid) < 0)
838 return -EAGAIN;
839 }
840 if (euid != (uid_t) -1) {
841 if (euid != current->euid)
842 {
843 current->mm->dumpable = suid_dumpable;
844 smp_wmb();
845 }
846 current->euid = euid;
847 }
848 current->fsuid = current->euid;
849 if (suid != (uid_t) -1)
850 current->suid = suid;
851
852 key_fsuid_changed(current);
853 proc_id_connector(current, PROC_EVENT_UID);
854
855 return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_RES);
856 }
857
858 asmlinkage long sys_getresuid(uid_t __user *ruid, uid_t __user *euid, uid_t __user *suid)
859 {
860 int retval;
861
862 if (!(retval = put_user(current->uid, ruid)) &&
863 !(retval = put_user(current->euid, euid)))
864 retval = put_user(current->suid, suid);
865
866 return retval;
867 }
868
869 /*
870 * Same as above, but for rgid, egid, sgid.
871 */
872 asmlinkage long sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid)
873 {
874 int retval;
875
876 retval = security_task_setgid(rgid, egid, sgid, LSM_SETID_RES);
877 if (retval)
878 return retval;
879
880 if (!capable(CAP_SETGID)) {
881 if ((rgid != (gid_t) -1) && (rgid != current->gid) &&
882 (rgid != current->egid) && (rgid != current->sgid))
883 return -EPERM;
884 if ((egid != (gid_t) -1) && (egid != current->gid) &&
885 (egid != current->egid) && (egid != current->sgid))
886 return -EPERM;
887 if ((sgid != (gid_t) -1) && (sgid != current->gid) &&
888 (sgid != current->egid) && (sgid != current->sgid))
889 return -EPERM;
890 }
891 if (egid != (gid_t) -1) {
892 if (egid != current->egid)
893 {
894 current->mm->dumpable = suid_dumpable;
895 smp_wmb();
896 }
897 current->egid = egid;
898 }
899 current->fsgid = current->egid;
900 if (rgid != (gid_t) -1)
901 current->gid = rgid;
902 if (sgid != (gid_t) -1)
903 current->sgid = sgid;
904
905 key_fsgid_changed(current);
906 proc_id_connector(current, PROC_EVENT_GID);
907 return 0;
908 }
909
910 asmlinkage long sys_getresgid(gid_t __user *rgid, gid_t __user *egid, gid_t __user *sgid)
911 {
912 int retval;
913
914 if (!(retval = put_user(current->gid, rgid)) &&
915 !(retval = put_user(current->egid, egid)))
916 retval = put_user(current->sgid, sgid);
917
918 return retval;
919 }
920
921
922 /*
923 * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This
924 * is used for "access()" and for the NFS daemon (letting nfsd stay at
925 * whatever uid it wants to). It normally shadows "euid", except when
926 * explicitly set by setfsuid() or for access..
927 */
928 asmlinkage long sys_setfsuid(uid_t uid)
929 {
930 int old_fsuid;
931
932 old_fsuid = current->fsuid;
933 if (security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS))
934 return old_fsuid;
935
936 if (uid == current->uid || uid == current->euid ||
937 uid == current->suid || uid == current->fsuid ||
938 capable(CAP_SETUID))
939 {
940 if (uid != old_fsuid)
941 {
942 current->mm->dumpable = suid_dumpable;
943 smp_wmb();
944 }
945 current->fsuid = uid;
946 }
947
948 key_fsuid_changed(current);
949 proc_id_connector(current, PROC_EVENT_UID);
950
951 security_task_post_setuid(old_fsuid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS);
952
953 return old_fsuid;
954 }
955
956 /*
957 * Samma på svenska..
958 */
959 asmlinkage long sys_setfsgid(gid_t gid)
960 {
961 int old_fsgid;
962
963 old_fsgid = current->fsgid;
964 if (security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_FS))
965 return old_fsgid;
966
967 if (gid == current->gid || gid == current->egid ||
968 gid == current->sgid || gid == current->fsgid ||
969 capable(CAP_SETGID))
970 {
971 if (gid != old_fsgid)
972 {
973 current->mm->dumpable = suid_dumpable;
974 smp_wmb();
975 }
976 current->fsgid = gid;
977 key_fsgid_changed(current);
978 proc_id_connector(current, PROC_EVENT_GID);
979 }
980 return old_fsgid;
981 }
982
983 asmlinkage long sys_times(struct tms __user * tbuf)
984 {
985 /*
986 * In the SMP world we might just be unlucky and have one of
987 * the times increment as we use it. Since the value is an
988 * atomically safe type this is just fine. Conceptually its
989 * as if the syscall took an instant longer to occur.
990 */
991 if (tbuf) {
992 struct tms tmp;
993 cputime_t utime, stime, cutime, cstime;
994
995 #ifdef CONFIG_SMP
996 if (thread_group_empty(current)) {
997 /*
998 * Single thread case without the use of any locks.
999 *
1000 * We may race with release_task if two threads are
1001 * executing. However, release task first adds up the
1002 * counters (__exit_signal) before removing the task
1003 * from the process tasklist (__unhash_process).
1004 * __exit_signal also acquires and releases the
1005 * siglock which results in the proper memory ordering
1006 * so that the list modifications are always visible
1007 * after the counters have been updated.
1008 *
1009 * If the counters have been updated by the second thread
1010 * but the thread has not yet been removed from the list
1011 * then the other branch will be executing which will
1012 * block on tasklist_lock until the exit handling of the
1013 * other task is finished.
1014 *
1015 * This also implies that the sighand->siglock cannot
1016 * be held by another processor. So we can also
1017 * skip acquiring that lock.
1018 */
1019 utime = cputime_add(current->signal->utime, current->utime);
1020 stime = cputime_add(current->signal->utime, current->stime);
1021 cutime = current->signal->cutime;
1022 cstime = current->signal->cstime;
1023 } else
1024 #endif
1025 {
1026
1027 /* Process with multiple threads */
1028 struct task_struct *tsk = current;
1029 struct task_struct *t;
1030
1031 read_lock(&tasklist_lock);
1032 utime = tsk->signal->utime;
1033 stime = tsk->signal->stime;
1034 t = tsk;
1035 do {
1036 utime = cputime_add(utime, t->utime);
1037 stime = cputime_add(stime, t->stime);
1038 t = next_thread(t);
1039 } while (t != tsk);
1040
1041 /*
1042 * While we have tasklist_lock read-locked, no dying thread
1043 * can be updating current->signal->[us]time. Instead,
1044 * we got their counts included in the live thread loop.
1045 * However, another thread can come in right now and
1046 * do a wait call that updates current->signal->c[us]time.
1047 * To make sure we always see that pair updated atomically,
1048 * we take the siglock around fetching them.
1049 */
1050 spin_lock_irq(&tsk->sighand->siglock);
1051 cutime = tsk->signal->cutime;
1052 cstime = tsk->signal->cstime;
1053 spin_unlock_irq(&tsk->sighand->siglock);
1054 read_unlock(&tasklist_lock);
1055 }
1056 tmp.tms_utime = cputime_to_clock_t(utime);
1057 tmp.tms_stime = cputime_to_clock_t(stime);
1058 tmp.tms_cutime = cputime_to_clock_t(cutime);
1059 tmp.tms_cstime = cputime_to_clock_t(cstime);
1060 if (copy_to_user(tbuf, &tmp, sizeof(struct tms)))
1061 return -EFAULT;
1062 }
1063 return (long) jiffies_64_to_clock_t(get_jiffies_64());
1064 }
1065
1066 /*
1067 * This needs some heavy checking ...
1068 * I just haven't the stomach for it. I also don't fully
1069 * understand sessions/pgrp etc. Let somebody who does explain it.
1070 *
1071 * OK, I think I have the protection semantics right.... this is really
1072 * only important on a multi-user system anyway, to make sure one user
1073 * can't send a signal to a process owned by another. -TYT, 12/12/91
1074 *
1075 * Auch. Had to add the 'did_exec' flag to conform completely to POSIX.
1076 * LBT 04.03.94
1077 */
1078
1079 asmlinkage long sys_setpgid(pid_t pid, pid_t pgid)
1080 {
1081 struct task_struct *p;
1082 int err = -EINVAL;
1083
1084 if (!pid)
1085 pid = current->pid;
1086 if (!pgid)
1087 pgid = pid;
1088 if (pgid < 0)
1089 return -EINVAL;
1090
1091 /* From this point forward we keep holding onto the tasklist lock
1092 * so that our parent does not change from under us. -DaveM
1093 */
1094 write_lock_irq(&tasklist_lock);
1095
1096 err = -ESRCH;
1097 p = find_task_by_pid(pid);
1098 if (!p)
1099 goto out;
1100
1101 err = -EINVAL;
1102 if (!thread_group_leader(p))
1103 goto out;
1104
1105 if (p->parent == current || p->real_parent == current) {
1106 err = -EPERM;
1107 if (p->signal->session != current->signal->session)
1108 goto out;
1109 err = -EACCES;
1110 if (p->did_exec)
1111 goto out;
1112 } else {
1113 err = -ESRCH;
1114 if (p != current)
1115 goto out;
1116 }
1117
1118 err = -EPERM;
1119 if (p->signal->leader)
1120 goto out;
1121
1122 if (pgid != pid) {
1123 struct task_struct *p;
1124
1125 do_each_task_pid(pgid, PIDTYPE_PGID, p) {
1126 if (p->signal->session == current->signal->session)
1127 goto ok_pgid;
1128 } while_each_task_pid(pgid, PIDTYPE_PGID, p);
1129 goto out;
1130 }
1131
1132 ok_pgid:
1133 err = security_task_setpgid(p, pgid);
1134 if (err)
1135 goto out;
1136
1137 if (process_group(p) != pgid) {
1138 detach_pid(p, PIDTYPE_PGID);
1139 p->signal->pgrp = pgid;
1140 attach_pid(p, PIDTYPE_PGID, pgid);
1141 }
1142
1143 err = 0;
1144 out:
1145 /* All paths lead to here, thus we are safe. -DaveM */
1146 write_unlock_irq(&tasklist_lock);
1147 return err;
1148 }
1149
1150 asmlinkage long sys_getpgid(pid_t pid)
1151 {
1152 if (!pid) {
1153 return process_group(current);
1154 } else {
1155 int retval;
1156 struct task_struct *p;
1157
1158 read_lock(&tasklist_lock);
1159 p = find_task_by_pid(pid);
1160
1161 retval = -ESRCH;
1162 if (p) {
1163 retval = security_task_getpgid(p);
1164 if (!retval)
1165 retval = process_group(p);
1166 }
1167 read_unlock(&tasklist_lock);
1168 return retval;
1169 }
1170 }
1171
1172 #ifdef __ARCH_WANT_SYS_GETPGRP
1173
1174 asmlinkage long sys_getpgrp(void)
1175 {
1176 /* SMP - assuming writes are word atomic this is fine */
1177 return process_group(current);
1178 }
1179
1180 #endif
1181
1182 asmlinkage long sys_getsid(pid_t pid)
1183 {
1184 if (!pid) {
1185 return current->signal->session;
1186 } else {
1187 int retval;
1188 struct task_struct *p;
1189
1190 read_lock(&tasklist_lock);
1191 p = find_task_by_pid(pid);
1192
1193 retval = -ESRCH;
1194 if(p) {
1195 retval = security_task_getsid(p);
1196 if (!retval)
1197 retval = p->signal->session;
1198 }
1199 read_unlock(&tasklist_lock);
1200 return retval;
1201 }
1202 }
1203
1204 asmlinkage long sys_setsid(void)
1205 {
1206 struct pid *pid;
1207 int err = -EPERM;
1208
1209 if (!thread_group_leader(current))
1210 return -EINVAL;
1211
1212 down(&tty_sem);
1213 write_lock_irq(&tasklist_lock);
1214
1215 pid = find_pid(PIDTYPE_PGID, current->pid);
1216 if (pid)
1217 goto out;
1218
1219 current->signal->leader = 1;
1220 __set_special_pids(current->pid, current->pid);
1221 current->signal->tty = NULL;
1222 current->signal->tty_old_pgrp = 0;
1223 err = process_group(current);
1224 out:
1225 write_unlock_irq(&tasklist_lock);
1226 up(&tty_sem);
1227 return err;
1228 }
1229
1230 /*
1231 * Supplementary group IDs
1232 */
1233
1234 /* init to 2 - one for init_task, one to ensure it is never freed */
1235 struct group_info init_groups = { .usage = ATOMIC_INIT(2) };
1236
1237 struct group_info *groups_alloc(int gidsetsize)
1238 {
1239 struct group_info *group_info;
1240 int nblocks;
1241 int i;
1242
1243 nblocks = (gidsetsize + NGROUPS_PER_BLOCK - 1) / NGROUPS_PER_BLOCK;
1244 /* Make sure we always allocate at least one indirect block pointer */
1245 nblocks = nblocks ? : 1;
1246 group_info = kmalloc(sizeof(*group_info) + nblocks*sizeof(gid_t *), GFP_USER);
1247 if (!group_info)
1248 return NULL;
1249 group_info->ngroups = gidsetsize;
1250 group_info->nblocks = nblocks;
1251 atomic_set(&group_info->usage, 1);
1252
1253 if (gidsetsize <= NGROUPS_SMALL) {
1254 group_info->blocks[0] = group_info->small_block;
1255 } else {
1256 for (i = 0; i < nblocks; i++) {
1257 gid_t *b;
1258 b = (void *)__get_free_page(GFP_USER);
1259 if (!b)
1260 goto out_undo_partial_alloc;
1261 group_info->blocks[i] = b;
1262 }
1263 }
1264 return group_info;
1265
1266 out_undo_partial_alloc:
1267 while (--i >= 0) {
1268 free_page((unsigned long)group_info->blocks[i]);
1269 }
1270 kfree(group_info);
1271 return NULL;
1272 }
1273
1274 EXPORT_SYMBOL(groups_alloc);
1275
1276 void groups_free(struct group_info *group_info)
1277 {
1278 if (group_info->blocks[0] != group_info->small_block) {
1279 int i;
1280 for (i = 0; i < group_info->nblocks; i++)
1281 free_page((unsigned long)group_info->blocks[i]);
1282 }
1283 kfree(group_info);
1284 }
1285
1286 EXPORT_SYMBOL(groups_free);
1287
1288 /* export the group_info to a user-space array */
1289 static int groups_to_user(gid_t __user *grouplist,
1290 struct group_info *group_info)
1291 {
1292 int i;
1293 int count = group_info->ngroups;
1294
1295 for (i = 0; i < group_info->nblocks; i++) {
1296 int cp_count = min(NGROUPS_PER_BLOCK, count);
1297 int off = i * NGROUPS_PER_BLOCK;
1298 int len = cp_count * sizeof(*grouplist);
1299
1300 if (copy_to_user(grouplist+off, group_info->blocks[i], len))
1301 return -EFAULT;
1302
1303 count -= cp_count;
1304 }
1305 return 0;
1306 }
1307
1308 /* fill a group_info from a user-space array - it must be allocated already */
1309 static int groups_from_user(struct group_info *group_info,
1310 gid_t __user *grouplist)
1311 {
1312 int i;
1313 int count = group_info->ngroups;
1314
1315 for (i = 0; i < group_info->nblocks; i++) {
1316 int cp_count = min(NGROUPS_PER_BLOCK, count);
1317 int off = i * NGROUPS_PER_BLOCK;
1318 int len = cp_count * sizeof(*grouplist);
1319
1320 if (copy_from_user(group_info->blocks[i], grouplist+off, len))
1321 return -EFAULT;
1322
1323 count -= cp_count;
1324 }
1325 return 0;
1326 }
1327
1328 /* a simple Shell sort */
1329 static void groups_sort(struct group_info *group_info)
1330 {
1331 int base, max, stride;
1332 int gidsetsize = group_info->ngroups;
1333
1334 for (stride = 1; stride < gidsetsize; stride = 3 * stride + 1)
1335 ; /* nothing */
1336 stride /= 3;
1337
1338 while (stride) {
1339 max = gidsetsize - stride;
1340 for (base = 0; base < max; base++) {
1341 int left = base;
1342 int right = left + stride;
1343 gid_t tmp = GROUP_AT(group_info, right);
1344
1345 while (left >= 0 && GROUP_AT(group_info, left) > tmp) {
1346 GROUP_AT(group_info, right) =
1347 GROUP_AT(group_info, left);
1348 right = left;
1349 left -= stride;
1350 }
1351 GROUP_AT(group_info, right) = tmp;
1352 }
1353 stride /= 3;
1354 }
1355 }
1356
1357 /* a simple bsearch */
1358 int groups_search(struct group_info *group_info, gid_t grp)
1359 {
1360 int left, right;
1361
1362 if (!group_info)
1363 return 0;
1364
1365 left = 0;
1366 right = group_info->ngroups;
1367 while (left < right) {
1368 int mid = (left+right)/2;
1369 int cmp = grp - GROUP_AT(group_info, mid);
1370 if (cmp > 0)
1371 left = mid + 1;
1372 else if (cmp < 0)
1373 right = mid;
1374 else
1375 return 1;
1376 }
1377 return 0;
1378 }
1379
1380 /* validate and set current->group_info */
1381 int set_current_groups(struct group_info *group_info)
1382 {
1383 int retval;
1384 struct group_info *old_info;
1385
1386 retval = security_task_setgroups(group_info);
1387 if (retval)
1388 return retval;
1389
1390 groups_sort(group_info);
1391 get_group_info(group_info);
1392
1393 task_lock(current);
1394 old_info = current->group_info;
1395 current->group_info = group_info;
1396 task_unlock(current);
1397
1398 put_group_info(old_info);
1399
1400 return 0;
1401 }
1402
1403 EXPORT_SYMBOL(set_current_groups);
1404
1405 asmlinkage long sys_getgroups(int gidsetsize, gid_t __user *grouplist)
1406 {
1407 int i = 0;
1408
1409 /*
1410 * SMP: Nobody else can change our grouplist. Thus we are
1411 * safe.
1412 */
1413
1414 if (gidsetsize < 0)
1415 return -EINVAL;
1416
1417 /* no need to grab task_lock here; it cannot change */
1418 get_group_info(current->group_info);
1419 i = current->group_info->ngroups;
1420 if (gidsetsize) {
1421 if (i > gidsetsize) {
1422 i = -EINVAL;
1423 goto out;
1424 }
1425 if (groups_to_user(grouplist, current->group_info)) {
1426 i = -EFAULT;
1427 goto out;
1428 }
1429 }
1430 out:
1431 put_group_info(current->group_info);
1432 return i;
1433 }
1434
1435 /*
1436 * SMP: Our groups are copy-on-write. We can set them safely
1437 * without another task interfering.
1438 */
1439
1440 asmlinkage long sys_setgroups(int gidsetsize, gid_t __user *grouplist)
1441 {
1442 struct group_info *group_info;
1443 int retval;
1444
1445 if (!capable(CAP_SETGID))
1446 return -EPERM;
1447 if ((unsigned)gidsetsize > NGROUPS_MAX)
1448 return -EINVAL;
1449
1450 group_info = groups_alloc(gidsetsize);
1451 if (!group_info)
1452 return -ENOMEM;
1453 retval = groups_from_user(group_info, grouplist);
1454 if (retval) {
1455 put_group_info(group_info);
1456 return retval;
1457 }
1458
1459 retval = set_current_groups(group_info);
1460 put_group_info(group_info);
1461
1462 return retval;
1463 }
1464
1465 /*
1466 * Check whether we're fsgid/egid or in the supplemental group..
1467 */
1468 int in_group_p(gid_t grp)
1469 {
1470 int retval = 1;
1471 if (grp != current->fsgid) {
1472 get_group_info(current->group_info);
1473 retval = groups_search(current->group_info, grp);
1474 put_group_info(current->group_info);
1475 }
1476 return retval;
1477 }
1478
1479 EXPORT_SYMBOL(in_group_p);
1480
1481 int in_egroup_p(gid_t grp)
1482 {
1483 int retval = 1;
1484 if (grp != current->egid) {
1485 get_group_info(current->group_info);
1486 retval = groups_search(current->group_info, grp);
1487 put_group_info(current->group_info);
1488 }
1489 return retval;
1490 }
1491
1492 EXPORT_SYMBOL(in_egroup_p);
1493
1494 DECLARE_RWSEM(uts_sem);
1495
1496 EXPORT_SYMBOL(uts_sem);
1497
1498 asmlinkage long sys_newuname(struct new_utsname __user * name)
1499 {
1500 int errno = 0;
1501
1502 down_read(&uts_sem);
1503 if (copy_to_user(name,&system_utsname,sizeof *name))
1504 errno = -EFAULT;
1505 up_read(&uts_sem);
1506 return errno;
1507 }
1508
1509 asmlinkage long sys_sethostname(char __user *name, int len)
1510 {
1511 int errno;
1512 char tmp[__NEW_UTS_LEN];
1513
1514 if (!capable(CAP_SYS_ADMIN))
1515 return -EPERM;
1516 if (len < 0 || len > __NEW_UTS_LEN)
1517 return -EINVAL;
1518 down_write(&uts_sem);
1519 errno = -EFAULT;
1520 if (!copy_from_user(tmp, name, len)) {
1521 memcpy(system_utsname.nodename, tmp, len);
1522 system_utsname.nodename[len] = 0;
1523 errno = 0;
1524 }
1525 up_write(&uts_sem);
1526 return errno;
1527 }
1528
1529 #ifdef __ARCH_WANT_SYS_GETHOSTNAME
1530
1531 asmlinkage long sys_gethostname(char __user *name, int len)
1532 {
1533 int i, errno;
1534
1535 if (len < 0)
1536 return -EINVAL;
1537 down_read(&uts_sem);
1538 i = 1 + strlen(system_utsname.nodename);
1539 if (i > len)
1540 i = len;
1541 errno = 0;
1542 if (copy_to_user(name, system_utsname.nodename, i))
1543 errno = -EFAULT;
1544 up_read(&uts_sem);
1545 return errno;
1546 }
1547
1548 #endif
1549
1550 /*
1551 * Only setdomainname; getdomainname can be implemented by calling
1552 * uname()
1553 */
1554 asmlinkage long sys_setdomainname(char __user *name, int len)
1555 {
1556 int errno;
1557 char tmp[__NEW_UTS_LEN];
1558
1559 if (!capable(CAP_SYS_ADMIN))
1560 return -EPERM;
1561 if (len < 0 || len > __NEW_UTS_LEN)
1562 return -EINVAL;
1563
1564 down_write(&uts_sem);
1565 errno = -EFAULT;
1566 if (!copy_from_user(tmp, name, len)) {
1567 memcpy(system_utsname.domainname, tmp, len);
1568 system_utsname.domainname[len] = 0;
1569 errno = 0;
1570 }
1571 up_write(&uts_sem);
1572 return errno;
1573 }
1574
1575 asmlinkage long sys_getrlimit(unsigned int resource, struct rlimit __user *rlim)
1576 {
1577 if (resource >= RLIM_NLIMITS)
1578 return -EINVAL;
1579 else {
1580 struct rlimit value;
1581 task_lock(current->group_leader);
1582 value = current->signal->rlim[resource];
1583 task_unlock(current->group_leader);
1584 return copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0;
1585 }
1586 }
1587
1588 #ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT
1589
1590 /*
1591 * Back compatibility for getrlimit. Needed for some apps.
1592 */
1593
1594 asmlinkage long sys_old_getrlimit(unsigned int resource, struct rlimit __user *rlim)
1595 {
1596 struct rlimit x;
1597 if (resource >= RLIM_NLIMITS)
1598 return -EINVAL;
1599
1600 task_lock(current->group_leader);
1601 x = current->signal->rlim[resource];
1602 task_unlock(current->group_leader);
1603 if(x.rlim_cur > 0x7FFFFFFF)
1604 x.rlim_cur = 0x7FFFFFFF;
1605 if(x.rlim_max > 0x7FFFFFFF)
1606 x.rlim_max = 0x7FFFFFFF;
1607 return copy_to_user(rlim, &x, sizeof(x))?-EFAULT:0;
1608 }
1609
1610 #endif
1611
1612 asmlinkage long sys_setrlimit(unsigned int resource, struct rlimit __user *rlim)
1613 {
1614 struct rlimit new_rlim, *old_rlim;
1615 int retval;
1616
1617 if (resource >= RLIM_NLIMITS)
1618 return -EINVAL;
1619 if(copy_from_user(&new_rlim, rlim, sizeof(*rlim)))
1620 return -EFAULT;
1621 if (new_rlim.rlim_cur > new_rlim.rlim_max)
1622 return -EINVAL;
1623 old_rlim = current->signal->rlim + resource;
1624 if ((new_rlim.rlim_max > old_rlim->rlim_max) &&
1625 !capable(CAP_SYS_RESOURCE))
1626 return -EPERM;
1627 if (resource == RLIMIT_NOFILE && new_rlim.rlim_max > NR_OPEN)
1628 return -EPERM;
1629
1630 retval = security_task_setrlimit(resource, &new_rlim);
1631 if (retval)
1632 return retval;
1633
1634 task_lock(current->group_leader);
1635 *old_rlim = new_rlim;
1636 task_unlock(current->group_leader);
1637
1638 if (resource == RLIMIT_CPU && new_rlim.rlim_cur != RLIM_INFINITY &&
1639 (cputime_eq(current->signal->it_prof_expires, cputime_zero) ||
1640 new_rlim.rlim_cur <= cputime_to_secs(
1641 current->signal->it_prof_expires))) {
1642 cputime_t cputime = secs_to_cputime(new_rlim.rlim_cur);
1643 read_lock(&tasklist_lock);
1644 spin_lock_irq(&current->sighand->siglock);
1645 set_process_cpu_timer(current, CPUCLOCK_PROF,
1646 &cputime, NULL);
1647 spin_unlock_irq(&current->sighand->siglock);
1648 read_unlock(&tasklist_lock);
1649 }
1650
1651 return 0;
1652 }
1653
1654 /*
1655 * It would make sense to put struct rusage in the task_struct,
1656 * except that would make the task_struct be *really big*. After
1657 * task_struct gets moved into malloc'ed memory, it would
1658 * make sense to do this. It will make moving the rest of the information
1659 * a lot simpler! (Which we're not doing right now because we're not
1660 * measuring them yet).
1661 *
1662 * This expects to be called with tasklist_lock read-locked or better,
1663 * and the siglock not locked. It may momentarily take the siglock.
1664 *
1665 * When sampling multiple threads for RUSAGE_SELF, under SMP we might have
1666 * races with threads incrementing their own counters. But since word
1667 * reads are atomic, we either get new values or old values and we don't
1668 * care which for the sums. We always take the siglock to protect reading
1669 * the c* fields from p->signal from races with exit.c updating those
1670 * fields when reaping, so a sample either gets all the additions of a
1671 * given child after it's reaped, or none so this sample is before reaping.
1672 */
1673
1674 static void k_getrusage(struct task_struct *p, int who, struct rusage *r)
1675 {
1676 struct task_struct *t;
1677 unsigned long flags;
1678 cputime_t utime, stime;
1679
1680 memset((char *) r, 0, sizeof *r);
1681
1682 if (unlikely(!p->signal))
1683 return;
1684
1685 switch (who) {
1686 case RUSAGE_CHILDREN:
1687 spin_lock_irqsave(&p->sighand->siglock, flags);
1688 utime = p->signal->cutime;
1689 stime = p->signal->cstime;
1690 r->ru_nvcsw = p->signal->cnvcsw;
1691 r->ru_nivcsw = p->signal->cnivcsw;
1692 r->ru_minflt = p->signal->cmin_flt;
1693 r->ru_majflt = p->signal->cmaj_flt;
1694 spin_unlock_irqrestore(&p->sighand->siglock, flags);
1695 cputime_to_timeval(utime, &r->ru_utime);
1696 cputime_to_timeval(stime, &r->ru_stime);
1697 break;
1698 case RUSAGE_SELF:
1699 spin_lock_irqsave(&p->sighand->siglock, flags);
1700 utime = stime = cputime_zero;
1701 goto sum_group;
1702 case RUSAGE_BOTH:
1703 spin_lock_irqsave(&p->sighand->siglock, flags);
1704 utime = p->signal->cutime;
1705 stime = p->signal->cstime;
1706 r->ru_nvcsw = p->signal->cnvcsw;
1707 r->ru_nivcsw = p->signal->cnivcsw;
1708 r->ru_minflt = p->signal->cmin_flt;
1709 r->ru_majflt = p->signal->cmaj_flt;
1710 sum_group:
1711 utime = cputime_add(utime, p->signal->utime);
1712 stime = cputime_add(stime, p->signal->stime);
1713 r->ru_nvcsw += p->signal->nvcsw;
1714 r->ru_nivcsw += p->signal->nivcsw;
1715 r->ru_minflt += p->signal->min_flt;
1716 r->ru_majflt += p->signal->maj_flt;
1717 t = p;
1718 do {
1719 utime = cputime_add(utime, t->utime);
1720 stime = cputime_add(stime, t->stime);
1721 r->ru_nvcsw += t->nvcsw;
1722 r->ru_nivcsw += t->nivcsw;
1723 r->ru_minflt += t->min_flt;
1724 r->ru_majflt += t->maj_flt;
1725 t = next_thread(t);
1726 } while (t != p);
1727 spin_unlock_irqrestore(&p->sighand->siglock, flags);
1728 cputime_to_timeval(utime, &r->ru_utime);
1729 cputime_to_timeval(stime, &r->ru_stime);
1730 break;
1731 default:
1732 BUG();
1733 }
1734 }
1735
1736 int getrusage(struct task_struct *p, int who, struct rusage __user *ru)
1737 {
1738 struct rusage r;
1739 read_lock(&tasklist_lock);
1740 k_getrusage(p, who, &r);
1741 read_unlock(&tasklist_lock);
1742 return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0;
1743 }
1744
1745 asmlinkage long sys_getrusage(int who, struct rusage __user *ru)
1746 {
1747 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN)
1748 return -EINVAL;
1749 return getrusage(current, who, ru);
1750 }
1751
1752 asmlinkage long sys_umask(int mask)
1753 {
1754 mask = xchg(&current->fs->umask, mask & S_IRWXUGO);
1755 return mask;
1756 }
1757
1758 asmlinkage long sys_prctl(int option, unsigned long arg2, unsigned long arg3,
1759 unsigned long arg4, unsigned long arg5)
1760 {
1761 long error;
1762
1763 error = security_task_prctl(option, arg2, arg3, arg4, arg5);
1764 if (error)
1765 return error;
1766
1767 switch (option) {
1768 case PR_SET_PDEATHSIG:
1769 if (!valid_signal(arg2)) {
1770 error = -EINVAL;
1771 break;
1772 }
1773 current->pdeath_signal = arg2;
1774 break;
1775 case PR_GET_PDEATHSIG:
1776 error = put_user(current->pdeath_signal, (int __user *)arg2);
1777 break;
1778 case PR_GET_DUMPABLE:
1779 error = current->mm->dumpable;
1780 break;
1781 case PR_SET_DUMPABLE:
1782 if (arg2 < 0 || arg2 > 2) {
1783 error = -EINVAL;
1784 break;
1785 }
1786 current->mm->dumpable = arg2;
1787 break;
1788
1789 case PR_SET_UNALIGN:
1790 error = SET_UNALIGN_CTL(current, arg2);
1791 break;
1792 case PR_GET_UNALIGN:
1793 error = GET_UNALIGN_CTL(current, arg2);
1794 break;
1795 case PR_SET_FPEMU:
1796 error = SET_FPEMU_CTL(current, arg2);
1797 break;
1798 case PR_GET_FPEMU:
1799 error = GET_FPEMU_CTL(current, arg2);
1800 break;
1801 case PR_SET_FPEXC:
1802 error = SET_FPEXC_CTL(current, arg2);
1803 break;
1804 case PR_GET_FPEXC:
1805 error = GET_FPEXC_CTL(current, arg2);
1806 break;
1807 case PR_GET_TIMING:
1808 error = PR_TIMING_STATISTICAL;
1809 break;
1810 case PR_SET_TIMING:
1811 if (arg2 == PR_TIMING_STATISTICAL)
1812 error = 0;
1813 else
1814 error = -EINVAL;
1815 break;
1816
1817 case PR_GET_KEEPCAPS:
1818 if (current->keep_capabilities)
1819 error = 1;
1820 break;
1821 case PR_SET_KEEPCAPS:
1822 if (arg2 != 0 && arg2 != 1) {
1823 error = -EINVAL;
1824 break;
1825 }
1826 current->keep_capabilities = arg2;
1827 break;
1828 case PR_SET_NAME: {
1829 struct task_struct *me = current;
1830 unsigned char ncomm[sizeof(me->comm)];
1831
1832 ncomm[sizeof(me->comm)-1] = 0;
1833 if (strncpy_from_user(ncomm, (char __user *)arg2,
1834 sizeof(me->comm)-1) < 0)
1835 return -EFAULT;
1836 set_task_comm(me, ncomm);
1837 return 0;
1838 }
1839 case PR_GET_NAME: {
1840 struct task_struct *me = current;
1841 unsigned char tcomm[sizeof(me->comm)];
1842
1843 get_task_comm(tcomm, me);
1844 if (copy_to_user((char __user *)arg2, tcomm, sizeof(tcomm)))
1845 return -EFAULT;
1846 return 0;
1847 }
1848 default:
1849 error = -EINVAL;
1850 break;
1851 }
1852 return error;
1853 }
Linux kernel - Deliverables
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