4 * Copyright (C) 1991, 1992 Linus Torvalds
7 #include <linux/module.h>
9 #include <linux/utsname.h>
10 #include <linux/mman.h>
11 #include <linux/smp_lock.h>
12 #include <linux/notifier.h>
13 #include <linux/reboot.h>
14 #include <linux/prctl.h>
15 #include <linux/highuid.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>
37 #include <linux/compat.h>
38 #include <linux/syscalls.h>
39 #include <linux/kprobes.h>
40 #include <linux/user_namespace.h>
42 #include <asm/uaccess.h>
44 #include <asm/unistd.h>
46 #ifndef SET_UNALIGN_CTL
47 # define SET_UNALIGN_CTL(a,b) (-EINVAL)
49 #ifndef GET_UNALIGN_CTL
50 # define GET_UNALIGN_CTL(a,b) (-EINVAL)
53 # define SET_FPEMU_CTL(a,b) (-EINVAL)
56 # define GET_FPEMU_CTL(a,b) (-EINVAL)
59 # define SET_FPEXC_CTL(a,b) (-EINVAL)
62 # define GET_FPEXC_CTL(a,b) (-EINVAL)
65 # define GET_ENDIAN(a,b) (-EINVAL)
68 # define SET_ENDIAN(a,b) (-EINVAL)
71 # define GET_TSC_CTL(a) (-EINVAL)
74 # define SET_TSC_CTL(a) (-EINVAL)
78 * this is where the system-wide overflow UID and GID are defined, for
79 * architectures that now have 32-bit UID/GID but didn't in the past
82 int overflowuid = DEFAULT_OVERFLOWUID;
83 int overflowgid = DEFAULT_OVERFLOWGID;
86 EXPORT_SYMBOL(overflowuid);
87 EXPORT_SYMBOL(overflowgid);
91 * the same as above, but for filesystems which can only store a 16-bit
92 * UID and GID. as such, this is needed on all architectures
95 int fs_overflowuid = DEFAULT_FS_OVERFLOWUID;
96 int fs_overflowgid = DEFAULT_FS_OVERFLOWUID;
98 EXPORT_SYMBOL(fs_overflowuid);
99 EXPORT_SYMBOL(fs_overflowgid);
102 * this indicates whether you can reboot with ctrl-alt-del: the default is yes
107 EXPORT_SYMBOL(cad_pid);
110 * If set, this is used for preparing the system to power off.
113 void (*pm_power_off_prepare)(void);
115 static int set_one_prio(struct task_struct *p, int niceval, int error)
119 if (p->uid != current->euid &&
120 p->euid != current->euid && !capable(CAP_SYS_NICE)) {
124 if (niceval < task_nice(p) && !can_nice(p, niceval)) {
128 no_nice = security_task_setnice(p, niceval);
135 set_user_nice(p, niceval);
140 asmlinkage long sys_setpriority(int which, int who, int niceval)
142 struct task_struct *g, *p;
143 struct user_struct *user;
147 if (which > PRIO_USER || which < PRIO_PROCESS)
150 /* normalize: avoid signed division (rounding problems) */
157 read_lock(&tasklist_lock);
161 p = find_task_by_vpid(who);
165 error = set_one_prio(p, niceval, error);
169 pgrp = find_vpid(who);
171 pgrp = task_pgrp(current);
172 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
173 error = set_one_prio(p, niceval, error);
174 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
177 user = current->user;
181 if ((who != current->uid) && !(user = find_user(who)))
182 goto out_unlock; /* No processes for this user */
186 error = set_one_prio(p, niceval, error);
187 while_each_thread(g, p);
188 if (who != current->uid)
189 free_uid(user); /* For find_user() */
193 read_unlock(&tasklist_lock);
199 * Ugh. To avoid negative return values, "getpriority()" will
200 * not return the normal nice-value, but a negated value that
201 * has been offset by 20 (ie it returns 40..1 instead of -20..19)
202 * to stay compatible.
204 asmlinkage long sys_getpriority(int which, int who)
206 struct task_struct *g, *p;
207 struct user_struct *user;
208 long niceval, retval = -ESRCH;
211 if (which > PRIO_USER || which < PRIO_PROCESS)
214 read_lock(&tasklist_lock);
218 p = find_task_by_vpid(who);
222 niceval = 20 - task_nice(p);
223 if (niceval > retval)
229 pgrp = find_vpid(who);
231 pgrp = task_pgrp(current);
232 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
233 niceval = 20 - task_nice(p);
234 if (niceval > retval)
236 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
239 user = current->user;
243 if ((who != current->uid) && !(user = find_user(who)))
244 goto out_unlock; /* No processes for this user */
248 niceval = 20 - task_nice(p);
249 if (niceval > retval)
252 while_each_thread(g, p);
253 if (who != current->uid)
254 free_uid(user); /* for find_user() */
258 read_unlock(&tasklist_lock);
264 * emergency_restart - reboot the system
266 * Without shutting down any hardware or taking any locks
267 * reboot the system. This is called when we know we are in
268 * trouble so this is our best effort to reboot. This is
269 * safe to call in interrupt context.
271 void emergency_restart(void)
273 machine_emergency_restart();
275 EXPORT_SYMBOL_GPL(emergency_restart);
277 void kernel_restart_prepare(char *cmd)
279 blocking_notifier_call_chain(&reboot_notifier_list, SYS_RESTART, cmd);
280 system_state = SYSTEM_RESTART;
286 * kernel_restart - reboot the system
287 * @cmd: pointer to buffer containing command to execute for restart
290 * Shutdown everything and perform a clean reboot.
291 * This is not safe to call in interrupt context.
293 void kernel_restart(char *cmd)
295 kernel_restart_prepare(cmd);
297 printk(KERN_EMERG "Restarting system.\n");
299 printk(KERN_EMERG "Restarting system with command '%s'.\n", cmd);
300 machine_restart(cmd);
302 EXPORT_SYMBOL_GPL(kernel_restart);
304 static void kernel_shutdown_prepare(enum system_states state)
306 blocking_notifier_call_chain(&reboot_notifier_list,
307 (state == SYSTEM_HALT)?SYS_HALT:SYS_POWER_OFF, NULL);
308 system_state = state;
312 * kernel_halt - halt the system
314 * Shutdown everything and perform a clean system halt.
316 void kernel_halt(void)
318 kernel_shutdown_prepare(SYSTEM_HALT);
320 printk(KERN_EMERG "System halted.\n");
324 EXPORT_SYMBOL_GPL(kernel_halt);
327 * kernel_power_off - power_off the system
329 * Shutdown everything and perform a clean system power_off.
331 void kernel_power_off(void)
333 kernel_shutdown_prepare(SYSTEM_POWER_OFF);
334 if (pm_power_off_prepare)
335 pm_power_off_prepare();
336 disable_nonboot_cpus();
338 printk(KERN_EMERG "Power down.\n");
341 EXPORT_SYMBOL_GPL(kernel_power_off);
343 * Reboot system call: for obvious reasons only root may call it,
344 * and even root needs to set up some magic numbers in the registers
345 * so that some mistake won't make this reboot the whole machine.
346 * You can also set the meaning of the ctrl-alt-del-key here.
348 * reboot doesn't sync: do that yourself before calling this.
350 asmlinkage long sys_reboot(int magic1, int magic2, unsigned int cmd, void __user * arg)
354 /* We only trust the superuser with rebooting the system. */
355 if (!capable(CAP_SYS_BOOT))
358 /* For safety, we require "magic" arguments. */
359 if (magic1 != LINUX_REBOOT_MAGIC1 ||
360 (magic2 != LINUX_REBOOT_MAGIC2 &&
361 magic2 != LINUX_REBOOT_MAGIC2A &&
362 magic2 != LINUX_REBOOT_MAGIC2B &&
363 magic2 != LINUX_REBOOT_MAGIC2C))
366 /* Instead of trying to make the power_off code look like
367 * halt when pm_power_off is not set do it the easy way.
369 if ((cmd == LINUX_REBOOT_CMD_POWER_OFF) && !pm_power_off)
370 cmd = LINUX_REBOOT_CMD_HALT;
374 case LINUX_REBOOT_CMD_RESTART:
375 kernel_restart(NULL);
378 case LINUX_REBOOT_CMD_CAD_ON:
382 case LINUX_REBOOT_CMD_CAD_OFF:
386 case LINUX_REBOOT_CMD_HALT:
392 case LINUX_REBOOT_CMD_POWER_OFF:
398 case LINUX_REBOOT_CMD_RESTART2:
399 if (strncpy_from_user(&buffer[0], arg, sizeof(buffer) - 1) < 0) {
403 buffer[sizeof(buffer) - 1] = '\0';
405 kernel_restart(buffer);
409 case LINUX_REBOOT_CMD_KEXEC:
412 ret = kernel_kexec();
418 #ifdef CONFIG_HIBERNATION
419 case LINUX_REBOOT_CMD_SW_SUSPEND:
421 int ret = hibernate();
435 static void deferred_cad(struct work_struct *dummy)
437 kernel_restart(NULL);
441 * This function gets called by ctrl-alt-del - ie the keyboard interrupt.
442 * As it's called within an interrupt, it may NOT sync: the only choice
443 * is whether to reboot at once, or just ignore the ctrl-alt-del.
445 void ctrl_alt_del(void)
447 static DECLARE_WORK(cad_work, deferred_cad);
450 schedule_work(&cad_work);
452 kill_cad_pid(SIGINT, 1);
456 * Unprivileged users may change the real gid to the effective gid
457 * or vice versa. (BSD-style)
459 * If you set the real gid at all, or set the effective gid to a value not
460 * equal to the real gid, then the saved gid is set to the new effective gid.
462 * This makes it possible for a setgid program to completely drop its
463 * privileges, which is often a useful assertion to make when you are doing
464 * a security audit over a program.
466 * The general idea is that a program which uses just setregid() will be
467 * 100% compatible with BSD. A program which uses just setgid() will be
468 * 100% compatible with POSIX with saved IDs.
470 * SMP: There are not races, the GIDs are checked only by filesystem
471 * operations (as far as semantic preservation is concerned).
473 asmlinkage long sys_setregid(gid_t rgid, gid_t egid)
475 int old_rgid = current->gid;
476 int old_egid = current->egid;
477 int new_rgid = old_rgid;
478 int new_egid = old_egid;
481 retval = security_task_setgid(rgid, egid, (gid_t)-1, LSM_SETID_RE);
485 if (rgid != (gid_t) -1) {
486 if ((old_rgid == rgid) ||
487 (current->egid==rgid) ||
493 if (egid != (gid_t) -1) {
494 if ((old_rgid == egid) ||
495 (current->egid == egid) ||
496 (current->sgid == egid) ||
502 if (new_egid != old_egid) {
503 set_dumpable(current->mm, suid_dumpable);
506 if (rgid != (gid_t) -1 ||
507 (egid != (gid_t) -1 && egid != old_rgid))
508 current->sgid = new_egid;
509 current->fsgid = new_egid;
510 current->egid = new_egid;
511 current->gid = new_rgid;
512 key_fsgid_changed(current);
513 proc_id_connector(current, PROC_EVENT_GID);
518 * setgid() is implemented like SysV w/ SAVED_IDS
520 * SMP: Same implicit races as above.
522 asmlinkage long sys_setgid(gid_t gid)
524 int old_egid = current->egid;
527 retval = security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_ID);
531 if (capable(CAP_SETGID)) {
532 if (old_egid != gid) {
533 set_dumpable(current->mm, suid_dumpable);
536 current->gid = current->egid = current->sgid = current->fsgid = gid;
537 } else if ((gid == current->gid) || (gid == current->sgid)) {
538 if (old_egid != gid) {
539 set_dumpable(current->mm, suid_dumpable);
542 current->egid = current->fsgid = gid;
547 key_fsgid_changed(current);
548 proc_id_connector(current, PROC_EVENT_GID);
552 static int set_user(uid_t new_ruid, int dumpclear)
554 struct user_struct *new_user;
556 new_user = alloc_uid(current->nsproxy->user_ns, new_ruid);
560 if (atomic_read(&new_user->processes) >=
561 current->signal->rlim[RLIMIT_NPROC].rlim_cur &&
562 new_user != current->nsproxy->user_ns->root_user) {
567 switch_uid(new_user);
570 set_dumpable(current->mm, suid_dumpable);
573 current->uid = new_ruid;
578 * Unprivileged users may change the real uid to the effective uid
579 * or vice versa. (BSD-style)
581 * If you set the real uid at all, or set the effective uid to a value not
582 * equal to the real uid, then the saved uid is set to the new effective uid.
584 * This makes it possible for a setuid program to completely drop its
585 * privileges, which is often a useful assertion to make when you are doing
586 * a security audit over a program.
588 * The general idea is that a program which uses just setreuid() will be
589 * 100% compatible with BSD. A program which uses just setuid() will be
590 * 100% compatible with POSIX with saved IDs.
592 asmlinkage long sys_setreuid(uid_t ruid, uid_t euid)
594 int old_ruid, old_euid, old_suid, new_ruid, new_euid;
597 retval = security_task_setuid(ruid, euid, (uid_t)-1, LSM_SETID_RE);
601 new_ruid = old_ruid = current->uid;
602 new_euid = old_euid = current->euid;
603 old_suid = current->suid;
605 if (ruid != (uid_t) -1) {
607 if ((old_ruid != ruid) &&
608 (current->euid != ruid) &&
609 !capable(CAP_SETUID))
613 if (euid != (uid_t) -1) {
615 if ((old_ruid != euid) &&
616 (current->euid != euid) &&
617 (current->suid != euid) &&
618 !capable(CAP_SETUID))
622 if (new_ruid != old_ruid && set_user(new_ruid, new_euid != old_euid) < 0)
625 if (new_euid != old_euid) {
626 set_dumpable(current->mm, suid_dumpable);
629 current->fsuid = current->euid = new_euid;
630 if (ruid != (uid_t) -1 ||
631 (euid != (uid_t) -1 && euid != old_ruid))
632 current->suid = current->euid;
633 current->fsuid = current->euid;
635 key_fsuid_changed(current);
636 proc_id_connector(current, PROC_EVENT_UID);
638 return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_RE);
644 * setuid() is implemented like SysV with SAVED_IDS
646 * Note that SAVED_ID's is deficient in that a setuid root program
647 * like sendmail, for example, cannot set its uid to be a normal
648 * user and then switch back, because if you're root, setuid() sets
649 * the saved uid too. If you don't like this, blame the bright people
650 * in the POSIX committee and/or USG. Note that the BSD-style setreuid()
651 * will allow a root program to temporarily drop privileges and be able to
652 * regain them by swapping the real and effective uid.
654 asmlinkage long sys_setuid(uid_t uid)
656 int old_euid = current->euid;
657 int old_ruid, old_suid, new_suid;
660 retval = security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_ID);
664 old_ruid = current->uid;
665 old_suid = current->suid;
668 if (capable(CAP_SETUID)) {
669 if (uid != old_ruid && set_user(uid, old_euid != uid) < 0)
672 } else if ((uid != current->uid) && (uid != new_suid))
675 if (old_euid != uid) {
676 set_dumpable(current->mm, suid_dumpable);
679 current->fsuid = current->euid = uid;
680 current->suid = new_suid;
682 key_fsuid_changed(current);
683 proc_id_connector(current, PROC_EVENT_UID);
685 return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_ID);
690 * This function implements a generic ability to update ruid, euid,
691 * and suid. This allows you to implement the 4.4 compatible seteuid().
693 asmlinkage long sys_setresuid(uid_t ruid, uid_t euid, uid_t suid)
695 int old_ruid = current->uid;
696 int old_euid = current->euid;
697 int old_suid = current->suid;
700 retval = security_task_setuid(ruid, euid, suid, LSM_SETID_RES);
704 if (!capable(CAP_SETUID)) {
705 if ((ruid != (uid_t) -1) && (ruid != current->uid) &&
706 (ruid != current->euid) && (ruid != current->suid))
708 if ((euid != (uid_t) -1) && (euid != current->uid) &&
709 (euid != current->euid) && (euid != current->suid))
711 if ((suid != (uid_t) -1) && (suid != current->uid) &&
712 (suid != current->euid) && (suid != current->suid))
715 if (ruid != (uid_t) -1) {
716 if (ruid != current->uid && set_user(ruid, euid != current->euid) < 0)
719 if (euid != (uid_t) -1) {
720 if (euid != current->euid) {
721 set_dumpable(current->mm, suid_dumpable);
724 current->euid = euid;
726 current->fsuid = current->euid;
727 if (suid != (uid_t) -1)
728 current->suid = suid;
730 key_fsuid_changed(current);
731 proc_id_connector(current, PROC_EVENT_UID);
733 return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_RES);
736 asmlinkage long sys_getresuid(uid_t __user *ruid, uid_t __user *euid, uid_t __user *suid)
740 if (!(retval = put_user(current->uid, ruid)) &&
741 !(retval = put_user(current->euid, euid)))
742 retval = put_user(current->suid, suid);
748 * Same as above, but for rgid, egid, sgid.
750 asmlinkage long sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid)
754 retval = security_task_setgid(rgid, egid, sgid, LSM_SETID_RES);
758 if (!capable(CAP_SETGID)) {
759 if ((rgid != (gid_t) -1) && (rgid != current->gid) &&
760 (rgid != current->egid) && (rgid != current->sgid))
762 if ((egid != (gid_t) -1) && (egid != current->gid) &&
763 (egid != current->egid) && (egid != current->sgid))
765 if ((sgid != (gid_t) -1) && (sgid != current->gid) &&
766 (sgid != current->egid) && (sgid != current->sgid))
769 if (egid != (gid_t) -1) {
770 if (egid != current->egid) {
771 set_dumpable(current->mm, suid_dumpable);
774 current->egid = egid;
776 current->fsgid = current->egid;
777 if (rgid != (gid_t) -1)
779 if (sgid != (gid_t) -1)
780 current->sgid = sgid;
782 key_fsgid_changed(current);
783 proc_id_connector(current, PROC_EVENT_GID);
787 asmlinkage long sys_getresgid(gid_t __user *rgid, gid_t __user *egid, gid_t __user *sgid)
791 if (!(retval = put_user(current->gid, rgid)) &&
792 !(retval = put_user(current->egid, egid)))
793 retval = put_user(current->sgid, sgid);
800 * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This
801 * is used for "access()" and for the NFS daemon (letting nfsd stay at
802 * whatever uid it wants to). It normally shadows "euid", except when
803 * explicitly set by setfsuid() or for access..
805 asmlinkage long sys_setfsuid(uid_t uid)
809 old_fsuid = current->fsuid;
810 if (security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS))
813 if (uid == current->uid || uid == current->euid ||
814 uid == current->suid || uid == current->fsuid ||
815 capable(CAP_SETUID)) {
816 if (uid != old_fsuid) {
817 set_dumpable(current->mm, suid_dumpable);
820 current->fsuid = uid;
823 key_fsuid_changed(current);
824 proc_id_connector(current, PROC_EVENT_UID);
826 security_task_post_setuid(old_fsuid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS);
832 * Samma på svenska..
834 asmlinkage long sys_setfsgid(gid_t gid)
838 old_fsgid = current->fsgid;
839 if (security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_FS))
842 if (gid == current->gid || gid == current->egid ||
843 gid == current->sgid || gid == current->fsgid ||
844 capable(CAP_SETGID)) {
845 if (gid != old_fsgid) {
846 set_dumpable(current->mm, suid_dumpable);
849 current->fsgid = gid;
850 key_fsgid_changed(current);
851 proc_id_connector(current, PROC_EVENT_GID);
856 void do_sys_times(struct tms *tms)
858 struct task_cputime cputime;
859 cputime_t cutime, cstime;
861 spin_lock_irq(¤t->sighand->siglock);
862 thread_group_cputime(current, &cputime);
863 cutime = current->signal->cutime;
864 cstime = current->signal->cstime;
865 spin_unlock_irq(¤t->sighand->siglock);
866 tms->tms_utime = cputime_to_clock_t(cputime.utime);
867 tms->tms_stime = cputime_to_clock_t(cputime.stime);
868 tms->tms_cutime = cputime_to_clock_t(cutime);
869 tms->tms_cstime = cputime_to_clock_t(cstime);
872 asmlinkage long sys_times(struct tms __user * tbuf)
878 if (copy_to_user(tbuf, &tmp, sizeof(struct tms)))
881 return (long) jiffies_64_to_clock_t(get_jiffies_64());
885 * This needs some heavy checking ...
886 * I just haven't the stomach for it. I also don't fully
887 * understand sessions/pgrp etc. Let somebody who does explain it.
889 * OK, I think I have the protection semantics right.... this is really
890 * only important on a multi-user system anyway, to make sure one user
891 * can't send a signal to a process owned by another. -TYT, 12/12/91
893 * Auch. Had to add the 'did_exec' flag to conform completely to POSIX.
896 asmlinkage long sys_setpgid(pid_t pid, pid_t pgid)
898 struct task_struct *p;
899 struct task_struct *group_leader = current->group_leader;
904 pid = task_pid_vnr(group_leader);
910 /* From this point forward we keep holding onto the tasklist lock
911 * so that our parent does not change from under us. -DaveM
913 write_lock_irq(&tasklist_lock);
916 p = find_task_by_vpid(pid);
921 if (!thread_group_leader(p))
924 if (same_thread_group(p->real_parent, group_leader)) {
926 if (task_session(p) != task_session(group_leader))
933 if (p != group_leader)
938 if (p->signal->leader)
943 struct task_struct *g;
945 pgrp = find_vpid(pgid);
946 g = pid_task(pgrp, PIDTYPE_PGID);
947 if (!g || task_session(g) != task_session(group_leader))
951 err = security_task_setpgid(p, pgid);
955 if (task_pgrp(p) != pgrp) {
956 change_pid(p, PIDTYPE_PGID, pgrp);
957 set_task_pgrp(p, pid_nr(pgrp));
962 /* All paths lead to here, thus we are safe. -DaveM */
963 write_unlock_irq(&tasklist_lock);
967 asmlinkage long sys_getpgid(pid_t pid)
969 struct task_struct *p;
975 grp = task_pgrp(current);
978 p = find_task_by_vpid(pid);
985 retval = security_task_getpgid(p);
989 retval = pid_vnr(grp);
995 #ifdef __ARCH_WANT_SYS_GETPGRP
997 asmlinkage long sys_getpgrp(void)
999 return sys_getpgid(0);
1004 asmlinkage long sys_getsid(pid_t pid)
1006 struct task_struct *p;
1012 sid = task_session(current);
1015 p = find_task_by_vpid(pid);
1018 sid = task_session(p);
1022 retval = security_task_getsid(p);
1026 retval = pid_vnr(sid);
1032 asmlinkage long sys_setsid(void)
1034 struct task_struct *group_leader = current->group_leader;
1035 struct pid *sid = task_pid(group_leader);
1036 pid_t session = pid_vnr(sid);
1039 write_lock_irq(&tasklist_lock);
1040 /* Fail if I am already a session leader */
1041 if (group_leader->signal->leader)
1044 /* Fail if a process group id already exists that equals the
1045 * proposed session id.
1047 if (pid_task(sid, PIDTYPE_PGID))
1050 group_leader->signal->leader = 1;
1051 __set_special_pids(sid);
1053 spin_lock(&group_leader->sighand->siglock);
1054 group_leader->signal->tty = NULL;
1055 spin_unlock(&group_leader->sighand->siglock);
1059 write_unlock_irq(&tasklist_lock);
1064 * Supplementary group IDs
1067 /* init to 2 - one for init_task, one to ensure it is never freed */
1068 struct group_info init_groups = { .usage = ATOMIC_INIT(2) };
1070 struct group_info *groups_alloc(int gidsetsize)
1072 struct group_info *group_info;
1076 nblocks = (gidsetsize + NGROUPS_PER_BLOCK - 1) / NGROUPS_PER_BLOCK;
1077 /* Make sure we always allocate at least one indirect block pointer */
1078 nblocks = nblocks ? : 1;
1079 group_info = kmalloc(sizeof(*group_info) + nblocks*sizeof(gid_t *), GFP_USER);
1082 group_info->ngroups = gidsetsize;
1083 group_info->nblocks = nblocks;
1084 atomic_set(&group_info->usage, 1);
1086 if (gidsetsize <= NGROUPS_SMALL)
1087 group_info->blocks[0] = group_info->small_block;
1089 for (i = 0; i < nblocks; i++) {
1091 b = (void *)__get_free_page(GFP_USER);
1093 goto out_undo_partial_alloc;
1094 group_info->blocks[i] = b;
1099 out_undo_partial_alloc:
1101 free_page((unsigned long)group_info->blocks[i]);
1107 EXPORT_SYMBOL(groups_alloc);
1109 void groups_free(struct group_info *group_info)
1111 if (group_info->blocks[0] != group_info->small_block) {
1113 for (i = 0; i < group_info->nblocks; i++)
1114 free_page((unsigned long)group_info->blocks[i]);
1119 EXPORT_SYMBOL(groups_free);
1121 /* export the group_info to a user-space array */
1122 static int groups_to_user(gid_t __user *grouplist,
1123 struct group_info *group_info)
1126 unsigned int count = group_info->ngroups;
1128 for (i = 0; i < group_info->nblocks; i++) {
1129 unsigned int cp_count = min(NGROUPS_PER_BLOCK, count);
1130 unsigned int len = cp_count * sizeof(*grouplist);
1132 if (copy_to_user(grouplist, group_info->blocks[i], len))
1135 grouplist += NGROUPS_PER_BLOCK;
1141 /* fill a group_info from a user-space array - it must be allocated already */
1142 static int groups_from_user(struct group_info *group_info,
1143 gid_t __user *grouplist)
1146 unsigned int count = group_info->ngroups;
1148 for (i = 0; i < group_info->nblocks; i++) {
1149 unsigned int cp_count = min(NGROUPS_PER_BLOCK, count);
1150 unsigned int len = cp_count * sizeof(*grouplist);
1152 if (copy_from_user(group_info->blocks[i], grouplist, len))
1155 grouplist += NGROUPS_PER_BLOCK;
1161 /* a simple Shell sort */
1162 static void groups_sort(struct group_info *group_info)
1164 int base, max, stride;
1165 int gidsetsize = group_info->ngroups;
1167 for (stride = 1; stride < gidsetsize; stride = 3 * stride + 1)
1172 max = gidsetsize - stride;
1173 for (base = 0; base < max; base++) {
1175 int right = left + stride;
1176 gid_t tmp = GROUP_AT(group_info, right);
1178 while (left >= 0 && GROUP_AT(group_info, left) > tmp) {
1179 GROUP_AT(group_info, right) =
1180 GROUP_AT(group_info, left);
1184 GROUP_AT(group_info, right) = tmp;
1190 /* a simple bsearch */
1191 int groups_search(struct group_info *group_info, gid_t grp)
1193 unsigned int left, right;
1199 right = group_info->ngroups;
1200 while (left < right) {
1201 unsigned int mid = (left+right)/2;
1202 int cmp = grp - GROUP_AT(group_info, mid);
1213 /* validate and set current->group_info */
1214 int set_current_groups(struct group_info *group_info)
1217 struct group_info *old_info;
1219 retval = security_task_setgroups(group_info);
1223 groups_sort(group_info);
1224 get_group_info(group_info);
1227 old_info = current->group_info;
1228 current->group_info = group_info;
1229 task_unlock(current);
1231 put_group_info(old_info);
1236 EXPORT_SYMBOL(set_current_groups);
1238 asmlinkage long sys_getgroups(int gidsetsize, gid_t __user *grouplist)
1243 * SMP: Nobody else can change our grouplist. Thus we are
1250 /* no need to grab task_lock here; it cannot change */
1251 i = current->group_info->ngroups;
1253 if (i > gidsetsize) {
1257 if (groups_to_user(grouplist, current->group_info)) {
1267 * SMP: Our groups are copy-on-write. We can set them safely
1268 * without another task interfering.
1271 asmlinkage long sys_setgroups(int gidsetsize, gid_t __user *grouplist)
1273 struct group_info *group_info;
1276 if (!capable(CAP_SETGID))
1278 if ((unsigned)gidsetsize > NGROUPS_MAX)
1281 group_info = groups_alloc(gidsetsize);
1284 retval = groups_from_user(group_info, grouplist);
1286 put_group_info(group_info);
1290 retval = set_current_groups(group_info);
1291 put_group_info(group_info);
1297 * Check whether we're fsgid/egid or in the supplemental group..
1299 int in_group_p(gid_t grp)
1302 if (grp != current->fsgid)
1303 retval = groups_search(current->group_info, grp);
1307 EXPORT_SYMBOL(in_group_p);
1309 int in_egroup_p(gid_t grp)
1312 if (grp != current->egid)
1313 retval = groups_search(current->group_info, grp);
1317 EXPORT_SYMBOL(in_egroup_p);
1319 DECLARE_RWSEM(uts_sem);
1321 asmlinkage long sys_newuname(struct new_utsname __user * name)
1325 down_read(&uts_sem);
1326 if (copy_to_user(name, utsname(), sizeof *name))
1332 asmlinkage long sys_sethostname(char __user *name, int len)
1335 char tmp[__NEW_UTS_LEN];
1337 if (!capable(CAP_SYS_ADMIN))
1339 if (len < 0 || len > __NEW_UTS_LEN)
1341 down_write(&uts_sem);
1343 if (!copy_from_user(tmp, name, len)) {
1344 memcpy(utsname()->nodename, tmp, len);
1345 utsname()->nodename[len] = 0;
1352 #ifdef __ARCH_WANT_SYS_GETHOSTNAME
1354 asmlinkage long sys_gethostname(char __user *name, int len)
1360 down_read(&uts_sem);
1361 i = 1 + strlen(utsname()->nodename);
1365 if (copy_to_user(name, utsname()->nodename, i))
1374 * Only setdomainname; getdomainname can be implemented by calling
1377 asmlinkage long sys_setdomainname(char __user *name, int len)
1380 char tmp[__NEW_UTS_LEN];
1382 if (!capable(CAP_SYS_ADMIN))
1384 if (len < 0 || len > __NEW_UTS_LEN)
1387 down_write(&uts_sem);
1389 if (!copy_from_user(tmp, name, len)) {
1390 memcpy(utsname()->domainname, tmp, len);
1391 utsname()->domainname[len] = 0;
1398 asmlinkage long sys_getrlimit(unsigned int resource, struct rlimit __user *rlim)
1400 if (resource >= RLIM_NLIMITS)
1403 struct rlimit value;
1404 task_lock(current->group_leader);
1405 value = current->signal->rlim[resource];
1406 task_unlock(current->group_leader);
1407 return copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0;
1411 #ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT
1414 * Back compatibility for getrlimit. Needed for some apps.
1417 asmlinkage long sys_old_getrlimit(unsigned int resource, struct rlimit __user *rlim)
1420 if (resource >= RLIM_NLIMITS)
1423 task_lock(current->group_leader);
1424 x = current->signal->rlim[resource];
1425 task_unlock(current->group_leader);
1426 if (x.rlim_cur > 0x7FFFFFFF)
1427 x.rlim_cur = 0x7FFFFFFF;
1428 if (x.rlim_max > 0x7FFFFFFF)
1429 x.rlim_max = 0x7FFFFFFF;
1430 return copy_to_user(rlim, &x, sizeof(x))?-EFAULT:0;
1435 asmlinkage long sys_setrlimit(unsigned int resource, struct rlimit __user *rlim)
1437 struct rlimit new_rlim, *old_rlim;
1440 if (resource >= RLIM_NLIMITS)
1442 if (copy_from_user(&new_rlim, rlim, sizeof(*rlim)))
1444 if (new_rlim.rlim_cur > new_rlim.rlim_max)
1446 old_rlim = current->signal->rlim + resource;
1447 if ((new_rlim.rlim_max > old_rlim->rlim_max) &&
1448 !capable(CAP_SYS_RESOURCE))
1450 if (resource == RLIMIT_NOFILE && new_rlim.rlim_max > sysctl_nr_open)
1453 retval = security_task_setrlimit(resource, &new_rlim);
1457 if (resource == RLIMIT_CPU && new_rlim.rlim_cur == 0) {
1459 * The caller is asking for an immediate RLIMIT_CPU
1460 * expiry. But we use the zero value to mean "it was
1461 * never set". So let's cheat and make it one second
1464 new_rlim.rlim_cur = 1;
1467 task_lock(current->group_leader);
1468 *old_rlim = new_rlim;
1469 task_unlock(current->group_leader);
1471 if (resource != RLIMIT_CPU)
1475 * RLIMIT_CPU handling. Note that the kernel fails to return an error
1476 * code if it rejected the user's attempt to set RLIMIT_CPU. This is a
1477 * very long-standing error, and fixing it now risks breakage of
1478 * applications, so we live with it
1480 if (new_rlim.rlim_cur == RLIM_INFINITY)
1483 update_rlimit_cpu(new_rlim.rlim_cur);
1489 * It would make sense to put struct rusage in the task_struct,
1490 * except that would make the task_struct be *really big*. After
1491 * task_struct gets moved into malloc'ed memory, it would
1492 * make sense to do this. It will make moving the rest of the information
1493 * a lot simpler! (Which we're not doing right now because we're not
1494 * measuring them yet).
1496 * When sampling multiple threads for RUSAGE_SELF, under SMP we might have
1497 * races with threads incrementing their own counters. But since word
1498 * reads are atomic, we either get new values or old values and we don't
1499 * care which for the sums. We always take the siglock to protect reading
1500 * the c* fields from p->signal from races with exit.c updating those
1501 * fields when reaping, so a sample either gets all the additions of a
1502 * given child after it's reaped, or none so this sample is before reaping.
1505 * We need to take the siglock for CHILDEREN, SELF and BOTH
1506 * for the cases current multithreaded, non-current single threaded
1507 * non-current multithreaded. Thread traversal is now safe with
1509 * Strictly speaking, we donot need to take the siglock if we are current and
1510 * single threaded, as no one else can take our signal_struct away, no one
1511 * else can reap the children to update signal->c* counters, and no one else
1512 * can race with the signal-> fields. If we do not take any lock, the
1513 * signal-> fields could be read out of order while another thread was just
1514 * exiting. So we should place a read memory barrier when we avoid the lock.
1515 * On the writer side, write memory barrier is implied in __exit_signal
1516 * as __exit_signal releases the siglock spinlock after updating the signal->
1517 * fields. But we don't do this yet to keep things simple.
1521 static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r)
1523 r->ru_nvcsw += t->nvcsw;
1524 r->ru_nivcsw += t->nivcsw;
1525 r->ru_minflt += t->min_flt;
1526 r->ru_majflt += t->maj_flt;
1527 r->ru_inblock += task_io_get_inblock(t);
1528 r->ru_oublock += task_io_get_oublock(t);
1531 static void k_getrusage(struct task_struct *p, int who, struct rusage *r)
1533 struct task_struct *t;
1534 unsigned long flags;
1535 cputime_t utime, stime;
1536 struct task_cputime cputime;
1538 memset((char *) r, 0, sizeof *r);
1539 utime = stime = cputime_zero;
1541 if (who == RUSAGE_THREAD) {
1542 accumulate_thread_rusage(p, r);
1546 if (!lock_task_sighand(p, &flags))
1551 case RUSAGE_CHILDREN:
1552 utime = p->signal->cutime;
1553 stime = p->signal->cstime;
1554 r->ru_nvcsw = p->signal->cnvcsw;
1555 r->ru_nivcsw = p->signal->cnivcsw;
1556 r->ru_minflt = p->signal->cmin_flt;
1557 r->ru_majflt = p->signal->cmaj_flt;
1558 r->ru_inblock = p->signal->cinblock;
1559 r->ru_oublock = p->signal->coublock;
1561 if (who == RUSAGE_CHILDREN)
1565 thread_group_cputime(p, &cputime);
1566 utime = cputime_add(utime, cputime.utime);
1567 stime = cputime_add(stime, cputime.stime);
1568 r->ru_nvcsw += p->signal->nvcsw;
1569 r->ru_nivcsw += p->signal->nivcsw;
1570 r->ru_minflt += p->signal->min_flt;
1571 r->ru_majflt += p->signal->maj_flt;
1572 r->ru_inblock += p->signal->inblock;
1573 r->ru_oublock += p->signal->oublock;
1576 accumulate_thread_rusage(t, r);
1584 unlock_task_sighand(p, &flags);
1587 cputime_to_timeval(utime, &r->ru_utime);
1588 cputime_to_timeval(stime, &r->ru_stime);
1591 int getrusage(struct task_struct *p, int who, struct rusage __user *ru)
1594 k_getrusage(p, who, &r);
1595 return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0;
1598 asmlinkage long sys_getrusage(int who, struct rusage __user *ru)
1600 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
1601 who != RUSAGE_THREAD)
1603 return getrusage(current, who, ru);
1606 asmlinkage long sys_umask(int mask)
1608 mask = xchg(¤t->fs->umask, mask & S_IRWXUGO);
1612 asmlinkage long sys_prctl(int option, unsigned long arg2, unsigned long arg3,
1613 unsigned long arg4, unsigned long arg5)
1617 if (security_task_prctl(option, arg2, arg3, arg4, arg5, &error))
1621 case PR_SET_PDEATHSIG:
1622 if (!valid_signal(arg2)) {
1626 current->pdeath_signal = arg2;
1628 case PR_GET_PDEATHSIG:
1629 error = put_user(current->pdeath_signal, (int __user *)arg2);
1631 case PR_GET_DUMPABLE:
1632 error = get_dumpable(current->mm);
1634 case PR_SET_DUMPABLE:
1635 if (arg2 < 0 || arg2 > 1) {
1639 set_dumpable(current->mm, arg2);
1642 case PR_SET_UNALIGN:
1643 error = SET_UNALIGN_CTL(current, arg2);
1645 case PR_GET_UNALIGN:
1646 error = GET_UNALIGN_CTL(current, arg2);
1649 error = SET_FPEMU_CTL(current, arg2);
1652 error = GET_FPEMU_CTL(current, arg2);
1655 error = SET_FPEXC_CTL(current, arg2);
1658 error = GET_FPEXC_CTL(current, arg2);
1661 error = PR_TIMING_STATISTICAL;
1664 if (arg2 != PR_TIMING_STATISTICAL)
1669 struct task_struct *me = current;
1670 unsigned char ncomm[sizeof(me->comm)];
1672 ncomm[sizeof(me->comm)-1] = 0;
1673 if (strncpy_from_user(ncomm, (char __user *)arg2,
1674 sizeof(me->comm)-1) < 0)
1676 set_task_comm(me, ncomm);
1680 struct task_struct *me = current;
1681 unsigned char tcomm[sizeof(me->comm)];
1683 get_task_comm(tcomm, me);
1684 if (copy_to_user((char __user *)arg2, tcomm, sizeof(tcomm)))
1689 error = GET_ENDIAN(current, arg2);
1692 error = SET_ENDIAN(current, arg2);
1695 case PR_GET_SECCOMP:
1696 error = prctl_get_seccomp();
1698 case PR_SET_SECCOMP:
1699 error = prctl_set_seccomp(arg2);
1702 error = GET_TSC_CTL(arg2);
1705 error = SET_TSC_CTL(arg2);
1714 asmlinkage long sys_getcpu(unsigned __user *cpup, unsigned __user *nodep,
1715 struct getcpu_cache __user *unused)
1718 int cpu = raw_smp_processor_id();
1720 err |= put_user(cpu, cpup);
1722 err |= put_user(cpu_to_node(cpu), nodep);
1723 return err ? -EFAULT : 0;
1726 char poweroff_cmd[POWEROFF_CMD_PATH_LEN] = "/sbin/poweroff";
1728 static void argv_cleanup(char **argv, char **envp)
1734 * orderly_poweroff - Trigger an orderly system poweroff
1735 * @force: force poweroff if command execution fails
1737 * This may be called from any context to trigger a system shutdown.
1738 * If the orderly shutdown fails, it will force an immediate shutdown.
1740 int orderly_poweroff(bool force)
1743 char **argv = argv_split(GFP_ATOMIC, poweroff_cmd, &argc);
1744 static char *envp[] = {
1746 "PATH=/sbin:/bin:/usr/sbin:/usr/bin",
1750 struct subprocess_info *info;
1753 printk(KERN_WARNING "%s failed to allocate memory for \"%s\"\n",
1754 __func__, poweroff_cmd);
1758 info = call_usermodehelper_setup(argv[0], argv, envp, GFP_ATOMIC);
1764 call_usermodehelper_setcleanup(info, argv_cleanup);
1766 ret = call_usermodehelper_exec(info, UMH_NO_WAIT);
1770 printk(KERN_WARNING "Failed to start orderly shutdown: "
1771 "forcing the issue\n");
1773 /* I guess this should try to kick off some daemon to
1774 sync and poweroff asap. Or not even bother syncing
1775 if we're doing an emergency shutdown? */
1782 EXPORT_SYMBOL_GPL(orderly_poweroff);