4 * Copyright (C) 1991, 1992 Linus Torvalds
7 #include <linux/export.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>
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>
46 #include <linux/compat.h>
47 #include <linux/syscalls.h>
48 #include <linux/kprobes.h>
49 #include <linux/user_namespace.h>
51 #include <linux/kmsg_dump.h>
52 /* Move somewhere else to avoid recompiling? */
53 #include <generated/utsrelease.h>
55 #include <asm/uaccess.h>
57 #include <asm/unistd.h>
59 #ifndef SET_UNALIGN_CTL
60 # define SET_UNALIGN_CTL(a,b) (-EINVAL)
62 #ifndef GET_UNALIGN_CTL
63 # define GET_UNALIGN_CTL(a,b) (-EINVAL)
66 # define SET_FPEMU_CTL(a,b) (-EINVAL)
69 # define GET_FPEMU_CTL(a,b) (-EINVAL)
72 # define SET_FPEXC_CTL(a,b) (-EINVAL)
75 # define GET_FPEXC_CTL(a,b) (-EINVAL)
78 # define GET_ENDIAN(a,b) (-EINVAL)
81 # define SET_ENDIAN(a,b) (-EINVAL)
84 # define GET_TSC_CTL(a) (-EINVAL)
87 # define SET_TSC_CTL(a) (-EINVAL)
91 * this is where the system-wide overflow UID and GID are defined, for
92 * architectures that now have 32-bit UID/GID but didn't in the past
95 int overflowuid = DEFAULT_OVERFLOWUID;
96 int overflowgid = DEFAULT_OVERFLOWGID;
98 EXPORT_SYMBOL(overflowuid);
99 EXPORT_SYMBOL(overflowgid);
102 * the same as above, but for filesystems which can only store a 16-bit
103 * UID and GID. as such, this is needed on all architectures
106 int fs_overflowuid = DEFAULT_FS_OVERFLOWUID;
107 int fs_overflowgid = DEFAULT_FS_OVERFLOWUID;
109 EXPORT_SYMBOL(fs_overflowuid);
110 EXPORT_SYMBOL(fs_overflowgid);
113 * this indicates whether you can reboot with ctrl-alt-del: the default is yes
118 EXPORT_SYMBOL(cad_pid);
121 * If set, this is used for preparing the system to power off.
124 void (*pm_power_off_prepare)(void);
127 * Returns true if current's euid is same as p's uid or euid,
128 * or has CAP_SYS_NICE to p's user_ns.
130 * Called with rcu_read_lock, creds are safe
132 static bool set_one_prio_perm(struct task_struct *p)
134 const struct cred *cred = current_cred(), *pcred = __task_cred(p);
136 if (uid_eq(pcred->uid, cred->euid) ||
137 uid_eq(pcred->euid, cred->euid))
139 if (ns_capable(pcred->user_ns, CAP_SYS_NICE))
145 * set the priority of a task
146 * - the caller must hold the RCU read lock
148 static int set_one_prio(struct task_struct *p, int niceval, int error)
152 if (!set_one_prio_perm(p)) {
156 if (niceval < task_nice(p) && !can_nice(p, niceval)) {
160 no_nice = security_task_setnice(p, niceval);
167 set_user_nice(p, niceval);
172 SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval)
174 struct task_struct *g, *p;
175 struct user_struct *user;
176 const struct cred *cred = current_cred();
181 if (which > PRIO_USER || which < PRIO_PROCESS)
184 /* normalize: avoid signed division (rounding problems) */
192 read_lock(&tasklist_lock);
196 p = find_task_by_vpid(who);
200 error = set_one_prio(p, niceval, error);
204 pgrp = find_vpid(who);
206 pgrp = task_pgrp(current);
207 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
208 error = set_one_prio(p, niceval, error);
209 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
212 uid = make_kuid(cred->user_ns, who);
216 else if (!uid_eq(uid, cred->uid) &&
217 !(user = find_user(uid)))
218 goto out_unlock; /* No processes for this user */
220 do_each_thread(g, p) {
221 if (uid_eq(task_uid(p), uid))
222 error = set_one_prio(p, niceval, error);
223 } while_each_thread(g, p);
224 if (!uid_eq(uid, cred->uid))
225 free_uid(user); /* For find_user() */
229 read_unlock(&tasklist_lock);
236 * Ugh. To avoid negative return values, "getpriority()" will
237 * not return the normal nice-value, but a negated value that
238 * has been offset by 20 (ie it returns 40..1 instead of -20..19)
239 * to stay compatible.
241 SYSCALL_DEFINE2(getpriority, int, which, int, who)
243 struct task_struct *g, *p;
244 struct user_struct *user;
245 const struct cred *cred = current_cred();
246 long niceval, retval = -ESRCH;
250 if (which > PRIO_USER || which < PRIO_PROCESS)
254 read_lock(&tasklist_lock);
258 p = find_task_by_vpid(who);
262 niceval = 20 - task_nice(p);
263 if (niceval > retval)
269 pgrp = find_vpid(who);
271 pgrp = task_pgrp(current);
272 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
273 niceval = 20 - task_nice(p);
274 if (niceval > retval)
276 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
279 uid = make_kuid(cred->user_ns, who);
283 else if (!uid_eq(uid, cred->uid) &&
284 !(user = find_user(uid)))
285 goto out_unlock; /* No processes for this user */
287 do_each_thread(g, p) {
288 if (uid_eq(task_uid(p), uid)) {
289 niceval = 20 - task_nice(p);
290 if (niceval > retval)
293 } while_each_thread(g, p);
294 if (!uid_eq(uid, cred->uid))
295 free_uid(user); /* for find_user() */
299 read_unlock(&tasklist_lock);
306 * emergency_restart - reboot the system
308 * Without shutting down any hardware or taking any locks
309 * reboot the system. This is called when we know we are in
310 * trouble so this is our best effort to reboot. This is
311 * safe to call in interrupt context.
313 void emergency_restart(void)
315 kmsg_dump(KMSG_DUMP_EMERG);
316 machine_emergency_restart();
318 EXPORT_SYMBOL_GPL(emergency_restart);
320 void kernel_restart_prepare(char *cmd)
322 blocking_notifier_call_chain(&reboot_notifier_list, SYS_RESTART, cmd);
323 system_state = SYSTEM_RESTART;
324 usermodehelper_disable();
330 * register_reboot_notifier - Register function to be called at reboot time
331 * @nb: Info about notifier function to be called
333 * Registers a function with the list of functions
334 * to be called at reboot time.
336 * Currently always returns zero, as blocking_notifier_chain_register()
337 * always returns zero.
339 int register_reboot_notifier(struct notifier_block *nb)
341 return blocking_notifier_chain_register(&reboot_notifier_list, nb);
343 EXPORT_SYMBOL(register_reboot_notifier);
346 * unregister_reboot_notifier - Unregister previously registered reboot notifier
347 * @nb: Hook to be unregistered
349 * Unregisters a previously registered reboot
352 * Returns zero on success, or %-ENOENT on failure.
354 int unregister_reboot_notifier(struct notifier_block *nb)
356 return blocking_notifier_chain_unregister(&reboot_notifier_list, nb);
358 EXPORT_SYMBOL(unregister_reboot_notifier);
361 * kernel_restart - reboot the system
362 * @cmd: pointer to buffer containing command to execute for restart
365 * Shutdown everything and perform a clean reboot.
366 * This is not safe to call in interrupt context.
368 void kernel_restart(char *cmd)
370 kernel_restart_prepare(cmd);
372 printk(KERN_EMERG "Restarting system.\n");
374 printk(KERN_EMERG "Restarting system with command '%s'.\n", cmd);
375 kmsg_dump(KMSG_DUMP_RESTART);
376 machine_restart(cmd);
378 EXPORT_SYMBOL_GPL(kernel_restart);
380 static void kernel_shutdown_prepare(enum system_states state)
382 blocking_notifier_call_chain(&reboot_notifier_list,
383 (state == SYSTEM_HALT)?SYS_HALT:SYS_POWER_OFF, NULL);
384 system_state = state;
385 usermodehelper_disable();
389 * kernel_halt - halt the system
391 * Shutdown everything and perform a clean system halt.
393 void kernel_halt(void)
395 kernel_shutdown_prepare(SYSTEM_HALT);
397 printk(KERN_EMERG "System halted.\n");
398 kmsg_dump(KMSG_DUMP_HALT);
402 EXPORT_SYMBOL_GPL(kernel_halt);
405 * kernel_power_off - power_off the system
407 * Shutdown everything and perform a clean system power_off.
409 void kernel_power_off(void)
411 kernel_shutdown_prepare(SYSTEM_POWER_OFF);
412 if (pm_power_off_prepare)
413 pm_power_off_prepare();
414 disable_nonboot_cpus();
416 printk(KERN_EMERG "Power down.\n");
417 kmsg_dump(KMSG_DUMP_POWEROFF);
420 EXPORT_SYMBOL_GPL(kernel_power_off);
422 static DEFINE_MUTEX(reboot_mutex);
425 * Reboot system call: for obvious reasons only root may call it,
426 * and even root needs to set up some magic numbers in the registers
427 * so that some mistake won't make this reboot the whole machine.
428 * You can also set the meaning of the ctrl-alt-del-key here.
430 * reboot doesn't sync: do that yourself before calling this.
432 SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd,
438 /* We only trust the superuser with rebooting the system. */
439 if (!capable(CAP_SYS_BOOT))
442 /* For safety, we require "magic" arguments. */
443 if (magic1 != LINUX_REBOOT_MAGIC1 ||
444 (magic2 != LINUX_REBOOT_MAGIC2 &&
445 magic2 != LINUX_REBOOT_MAGIC2A &&
446 magic2 != LINUX_REBOOT_MAGIC2B &&
447 magic2 != LINUX_REBOOT_MAGIC2C))
451 * If pid namespaces are enabled and the current task is in a child
452 * pid_namespace, the command is handled by reboot_pid_ns() which will
455 ret = reboot_pid_ns(task_active_pid_ns(current), cmd);
459 /* Instead of trying to make the power_off code look like
460 * halt when pm_power_off is not set do it the easy way.
462 if ((cmd == LINUX_REBOOT_CMD_POWER_OFF) && !pm_power_off)
463 cmd = LINUX_REBOOT_CMD_HALT;
465 mutex_lock(&reboot_mutex);
467 case LINUX_REBOOT_CMD_RESTART:
468 kernel_restart(NULL);
471 case LINUX_REBOOT_CMD_CAD_ON:
475 case LINUX_REBOOT_CMD_CAD_OFF:
479 case LINUX_REBOOT_CMD_HALT:
482 panic("cannot halt");
484 case LINUX_REBOOT_CMD_POWER_OFF:
489 case LINUX_REBOOT_CMD_RESTART2:
490 if (strncpy_from_user(&buffer[0], arg, sizeof(buffer) - 1) < 0) {
494 buffer[sizeof(buffer) - 1] = '\0';
496 kernel_restart(buffer);
500 case LINUX_REBOOT_CMD_KEXEC:
501 ret = kernel_kexec();
505 #ifdef CONFIG_HIBERNATION
506 case LINUX_REBOOT_CMD_SW_SUSPEND:
515 mutex_unlock(&reboot_mutex);
519 static void deferred_cad(struct work_struct *dummy)
521 kernel_restart(NULL);
525 * This function gets called by ctrl-alt-del - ie the keyboard interrupt.
526 * As it's called within an interrupt, it may NOT sync: the only choice
527 * is whether to reboot at once, or just ignore the ctrl-alt-del.
529 void ctrl_alt_del(void)
531 static DECLARE_WORK(cad_work, deferred_cad);
534 schedule_work(&cad_work);
536 kill_cad_pid(SIGINT, 1);
540 * Unprivileged users may change the real gid to the effective gid
541 * or vice versa. (BSD-style)
543 * If you set the real gid at all, or set the effective gid to a value not
544 * equal to the real gid, then the saved gid is set to the new effective gid.
546 * This makes it possible for a setgid program to completely drop its
547 * privileges, which is often a useful assertion to make when you are doing
548 * a security audit over a program.
550 * The general idea is that a program which uses just setregid() will be
551 * 100% compatible with BSD. A program which uses just setgid() will be
552 * 100% compatible with POSIX with saved IDs.
554 * SMP: There are not races, the GIDs are checked only by filesystem
555 * operations (as far as semantic preservation is concerned).
557 SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid)
559 struct user_namespace *ns = current_user_ns();
560 const struct cred *old;
565 krgid = make_kgid(ns, rgid);
566 kegid = make_kgid(ns, egid);
568 if ((rgid != (gid_t) -1) && !gid_valid(krgid))
570 if ((egid != (gid_t) -1) && !gid_valid(kegid))
573 new = prepare_creds();
576 old = current_cred();
579 if (rgid != (gid_t) -1) {
580 if (gid_eq(old->gid, krgid) ||
581 gid_eq(old->egid, krgid) ||
582 nsown_capable(CAP_SETGID))
587 if (egid != (gid_t) -1) {
588 if (gid_eq(old->gid, kegid) ||
589 gid_eq(old->egid, kegid) ||
590 gid_eq(old->sgid, kegid) ||
591 nsown_capable(CAP_SETGID))
597 if (rgid != (gid_t) -1 ||
598 (egid != (gid_t) -1 && !gid_eq(kegid, old->gid)))
599 new->sgid = new->egid;
600 new->fsgid = new->egid;
602 return commit_creds(new);
610 * setgid() is implemented like SysV w/ SAVED_IDS
612 * SMP: Same implicit races as above.
614 SYSCALL_DEFINE1(setgid, gid_t, gid)
616 struct user_namespace *ns = current_user_ns();
617 const struct cred *old;
622 kgid = make_kgid(ns, gid);
623 if (!gid_valid(kgid))
626 new = prepare_creds();
629 old = current_cred();
632 if (nsown_capable(CAP_SETGID))
633 new->gid = new->egid = new->sgid = new->fsgid = kgid;
634 else if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->sgid))
635 new->egid = new->fsgid = kgid;
639 return commit_creds(new);
647 * change the user struct in a credentials set to match the new UID
649 static int set_user(struct cred *new)
651 struct user_struct *new_user;
653 new_user = alloc_uid(new->uid);
658 * We don't fail in case of NPROC limit excess here because too many
659 * poorly written programs don't check set*uid() return code, assuming
660 * it never fails if called by root. We may still enforce NPROC limit
661 * for programs doing set*uid()+execve() by harmlessly deferring the
662 * failure to the execve() stage.
664 if (atomic_read(&new_user->processes) >= rlimit(RLIMIT_NPROC) &&
665 new_user != INIT_USER)
666 current->flags |= PF_NPROC_EXCEEDED;
668 current->flags &= ~PF_NPROC_EXCEEDED;
671 new->user = new_user;
676 * Unprivileged users may change the real uid to the effective uid
677 * or vice versa. (BSD-style)
679 * If you set the real uid at all, or set the effective uid to a value not
680 * equal to the real uid, then the saved uid is set to the new effective uid.
682 * This makes it possible for a setuid program to completely drop its
683 * privileges, which is often a useful assertion to make when you are doing
684 * a security audit over a program.
686 * The general idea is that a program which uses just setreuid() will be
687 * 100% compatible with BSD. A program which uses just setuid() will be
688 * 100% compatible with POSIX with saved IDs.
690 SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid)
692 struct user_namespace *ns = current_user_ns();
693 const struct cred *old;
698 kruid = make_kuid(ns, ruid);
699 keuid = make_kuid(ns, euid);
701 if ((ruid != (uid_t) -1) && !uid_valid(kruid))
703 if ((euid != (uid_t) -1) && !uid_valid(keuid))
706 new = prepare_creds();
709 old = current_cred();
712 if (ruid != (uid_t) -1) {
714 if (!uid_eq(old->uid, kruid) &&
715 !uid_eq(old->euid, kruid) &&
716 !nsown_capable(CAP_SETUID))
720 if (euid != (uid_t) -1) {
722 if (!uid_eq(old->uid, keuid) &&
723 !uid_eq(old->euid, keuid) &&
724 !uid_eq(old->suid, keuid) &&
725 !nsown_capable(CAP_SETUID))
729 if (!uid_eq(new->uid, old->uid)) {
730 retval = set_user(new);
734 if (ruid != (uid_t) -1 ||
735 (euid != (uid_t) -1 && !uid_eq(keuid, old->uid)))
736 new->suid = new->euid;
737 new->fsuid = new->euid;
739 retval = security_task_fix_setuid(new, old, LSM_SETID_RE);
743 return commit_creds(new);
751 * setuid() is implemented like SysV with SAVED_IDS
753 * Note that SAVED_ID's is deficient in that a setuid root program
754 * like sendmail, for example, cannot set its uid to be a normal
755 * user and then switch back, because if you're root, setuid() sets
756 * the saved uid too. If you don't like this, blame the bright people
757 * in the POSIX committee and/or USG. Note that the BSD-style setreuid()
758 * will allow a root program to temporarily drop privileges and be able to
759 * regain them by swapping the real and effective uid.
761 SYSCALL_DEFINE1(setuid, uid_t, uid)
763 struct user_namespace *ns = current_user_ns();
764 const struct cred *old;
769 kuid = make_kuid(ns, uid);
770 if (!uid_valid(kuid))
773 new = prepare_creds();
776 old = current_cred();
779 if (nsown_capable(CAP_SETUID)) {
780 new->suid = new->uid = kuid;
781 if (!uid_eq(kuid, old->uid)) {
782 retval = set_user(new);
786 } else if (!uid_eq(kuid, old->uid) && !uid_eq(kuid, new->suid)) {
790 new->fsuid = new->euid = kuid;
792 retval = security_task_fix_setuid(new, old, LSM_SETID_ID);
796 return commit_creds(new);
805 * This function implements a generic ability to update ruid, euid,
806 * and suid. This allows you to implement the 4.4 compatible seteuid().
808 SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid)
810 struct user_namespace *ns = current_user_ns();
811 const struct cred *old;
814 kuid_t kruid, keuid, ksuid;
816 kruid = make_kuid(ns, ruid);
817 keuid = make_kuid(ns, euid);
818 ksuid = make_kuid(ns, suid);
820 if ((ruid != (uid_t) -1) && !uid_valid(kruid))
823 if ((euid != (uid_t) -1) && !uid_valid(keuid))
826 if ((suid != (uid_t) -1) && !uid_valid(ksuid))
829 new = prepare_creds();
833 old = current_cred();
836 if (!nsown_capable(CAP_SETUID)) {
837 if (ruid != (uid_t) -1 && !uid_eq(kruid, old->uid) &&
838 !uid_eq(kruid, old->euid) && !uid_eq(kruid, old->suid))
840 if (euid != (uid_t) -1 && !uid_eq(keuid, old->uid) &&
841 !uid_eq(keuid, old->euid) && !uid_eq(keuid, old->suid))
843 if (suid != (uid_t) -1 && !uid_eq(ksuid, old->uid) &&
844 !uid_eq(ksuid, old->euid) && !uid_eq(ksuid, old->suid))
848 if (ruid != (uid_t) -1) {
850 if (!uid_eq(kruid, old->uid)) {
851 retval = set_user(new);
856 if (euid != (uid_t) -1)
858 if (suid != (uid_t) -1)
860 new->fsuid = new->euid;
862 retval = security_task_fix_setuid(new, old, LSM_SETID_RES);
866 return commit_creds(new);
873 SYSCALL_DEFINE3(getresuid, uid_t __user *, ruidp, uid_t __user *, euidp, uid_t __user *, suidp)
875 const struct cred *cred = current_cred();
877 uid_t ruid, euid, suid;
879 ruid = from_kuid_munged(cred->user_ns, cred->uid);
880 euid = from_kuid_munged(cred->user_ns, cred->euid);
881 suid = from_kuid_munged(cred->user_ns, cred->suid);
883 if (!(retval = put_user(ruid, ruidp)) &&
884 !(retval = put_user(euid, euidp)))
885 retval = put_user(suid, suidp);
891 * Same as above, but for rgid, egid, sgid.
893 SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid)
895 struct user_namespace *ns = current_user_ns();
896 const struct cred *old;
899 kgid_t krgid, kegid, ksgid;
901 krgid = make_kgid(ns, rgid);
902 kegid = make_kgid(ns, egid);
903 ksgid = make_kgid(ns, sgid);
905 if ((rgid != (gid_t) -1) && !gid_valid(krgid))
907 if ((egid != (gid_t) -1) && !gid_valid(kegid))
909 if ((sgid != (gid_t) -1) && !gid_valid(ksgid))
912 new = prepare_creds();
915 old = current_cred();
918 if (!nsown_capable(CAP_SETGID)) {
919 if (rgid != (gid_t) -1 && !gid_eq(krgid, old->gid) &&
920 !gid_eq(krgid, old->egid) && !gid_eq(krgid, old->sgid))
922 if (egid != (gid_t) -1 && !gid_eq(kegid, old->gid) &&
923 !gid_eq(kegid, old->egid) && !gid_eq(kegid, old->sgid))
925 if (sgid != (gid_t) -1 && !gid_eq(ksgid, old->gid) &&
926 !gid_eq(ksgid, old->egid) && !gid_eq(ksgid, old->sgid))
930 if (rgid != (gid_t) -1)
932 if (egid != (gid_t) -1)
934 if (sgid != (gid_t) -1)
936 new->fsgid = new->egid;
938 return commit_creds(new);
945 SYSCALL_DEFINE3(getresgid, gid_t __user *, rgidp, gid_t __user *, egidp, gid_t __user *, sgidp)
947 const struct cred *cred = current_cred();
949 gid_t rgid, egid, sgid;
951 rgid = from_kgid_munged(cred->user_ns, cred->gid);
952 egid = from_kgid_munged(cred->user_ns, cred->egid);
953 sgid = from_kgid_munged(cred->user_ns, cred->sgid);
955 if (!(retval = put_user(rgid, rgidp)) &&
956 !(retval = put_user(egid, egidp)))
957 retval = put_user(sgid, sgidp);
964 * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This
965 * is used for "access()" and for the NFS daemon (letting nfsd stay at
966 * whatever uid it wants to). It normally shadows "euid", except when
967 * explicitly set by setfsuid() or for access..
969 SYSCALL_DEFINE1(setfsuid, uid_t, uid)
971 const struct cred *old;
976 old = current_cred();
977 old_fsuid = from_kuid_munged(old->user_ns, old->fsuid);
979 kuid = make_kuid(old->user_ns, uid);
980 if (!uid_valid(kuid))
983 new = prepare_creds();
987 if (uid_eq(kuid, old->uid) || uid_eq(kuid, old->euid) ||
988 uid_eq(kuid, old->suid) || uid_eq(kuid, old->fsuid) ||
989 nsown_capable(CAP_SETUID)) {
990 if (!uid_eq(kuid, old->fsuid)) {
992 if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0)
1006 * Samma på svenska..
1008 SYSCALL_DEFINE1(setfsgid, gid_t, gid)
1010 const struct cred *old;
1015 old = current_cred();
1016 old_fsgid = from_kgid_munged(old->user_ns, old->fsgid);
1018 kgid = make_kgid(old->user_ns, gid);
1019 if (!gid_valid(kgid))
1022 new = prepare_creds();
1026 if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->egid) ||
1027 gid_eq(kgid, old->sgid) || gid_eq(kgid, old->fsgid) ||
1028 nsown_capable(CAP_SETGID)) {
1029 if (!gid_eq(kgid, old->fsgid)) {
1043 void do_sys_times(struct tms *tms)
1045 cputime_t tgutime, tgstime, cutime, cstime;
1047 spin_lock_irq(¤t->sighand->siglock);
1048 thread_group_times(current, &tgutime, &tgstime);
1049 cutime = current->signal->cutime;
1050 cstime = current->signal->cstime;
1051 spin_unlock_irq(¤t->sighand->siglock);
1052 tms->tms_utime = cputime_to_clock_t(tgutime);
1053 tms->tms_stime = cputime_to_clock_t(tgstime);
1054 tms->tms_cutime = cputime_to_clock_t(cutime);
1055 tms->tms_cstime = cputime_to_clock_t(cstime);
1058 SYSCALL_DEFINE1(times, struct tms __user *, tbuf)
1064 if (copy_to_user(tbuf, &tmp, sizeof(struct tms)))
1067 force_successful_syscall_return();
1068 return (long) jiffies_64_to_clock_t(get_jiffies_64());
1072 * This needs some heavy checking ...
1073 * I just haven't the stomach for it. I also don't fully
1074 * understand sessions/pgrp etc. Let somebody who does explain it.
1076 * OK, I think I have the protection semantics right.... this is really
1077 * only important on a multi-user system anyway, to make sure one user
1078 * can't send a signal to a process owned by another. -TYT, 12/12/91
1080 * Auch. Had to add the 'did_exec' flag to conform completely to POSIX.
1083 SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid)
1085 struct task_struct *p;
1086 struct task_struct *group_leader = current->group_leader;
1091 pid = task_pid_vnr(group_leader);
1098 /* From this point forward we keep holding onto the tasklist lock
1099 * so that our parent does not change from under us. -DaveM
1101 write_lock_irq(&tasklist_lock);
1104 p = find_task_by_vpid(pid);
1109 if (!thread_group_leader(p))
1112 if (same_thread_group(p->real_parent, group_leader)) {
1114 if (task_session(p) != task_session(group_leader))
1121 if (p != group_leader)
1126 if (p->signal->leader)
1131 struct task_struct *g;
1133 pgrp = find_vpid(pgid);
1134 g = pid_task(pgrp, PIDTYPE_PGID);
1135 if (!g || task_session(g) != task_session(group_leader))
1139 err = security_task_setpgid(p, pgid);
1143 if (task_pgrp(p) != pgrp)
1144 change_pid(p, PIDTYPE_PGID, pgrp);
1148 /* All paths lead to here, thus we are safe. -DaveM */
1149 write_unlock_irq(&tasklist_lock);
1154 SYSCALL_DEFINE1(getpgid, pid_t, pid)
1156 struct task_struct *p;
1162 grp = task_pgrp(current);
1165 p = find_task_by_vpid(pid);
1172 retval = security_task_getpgid(p);
1176 retval = pid_vnr(grp);
1182 #ifdef __ARCH_WANT_SYS_GETPGRP
1184 SYSCALL_DEFINE0(getpgrp)
1186 return sys_getpgid(0);
1191 SYSCALL_DEFINE1(getsid, pid_t, pid)
1193 struct task_struct *p;
1199 sid = task_session(current);
1202 p = find_task_by_vpid(pid);
1205 sid = task_session(p);
1209 retval = security_task_getsid(p);
1213 retval = pid_vnr(sid);
1219 SYSCALL_DEFINE0(setsid)
1221 struct task_struct *group_leader = current->group_leader;
1222 struct pid *sid = task_pid(group_leader);
1223 pid_t session = pid_vnr(sid);
1226 write_lock_irq(&tasklist_lock);
1227 /* Fail if I am already a session leader */
1228 if (group_leader->signal->leader)
1231 /* Fail if a process group id already exists that equals the
1232 * proposed session id.
1234 if (pid_task(sid, PIDTYPE_PGID))
1237 group_leader->signal->leader = 1;
1238 __set_special_pids(sid);
1240 proc_clear_tty(group_leader);
1244 write_unlock_irq(&tasklist_lock);
1246 proc_sid_connector(group_leader);
1247 sched_autogroup_create_attach(group_leader);
1252 DECLARE_RWSEM(uts_sem);
1254 #ifdef COMPAT_UTS_MACHINE
1255 #define override_architecture(name) \
1256 (personality(current->personality) == PER_LINUX32 && \
1257 copy_to_user(name->machine, COMPAT_UTS_MACHINE, \
1258 sizeof(COMPAT_UTS_MACHINE)))
1260 #define override_architecture(name) 0
1264 * Work around broken programs that cannot handle "Linux 3.0".
1265 * Instead we map 3.x to 2.6.40+x, so e.g. 3.0 would be 2.6.40
1267 static int override_release(char __user *release, int len)
1272 if (current->personality & UNAME26) {
1273 char *rest = UTS_RELEASE;
1278 if (*rest == '.' && ++ndots >= 3)
1280 if (!isdigit(*rest) && *rest != '.')
1284 v = ((LINUX_VERSION_CODE >> 8) & 0xff) + 40;
1285 snprintf(buf, len, "2.6.%u%s", v, rest);
1286 ret = copy_to_user(release, buf, len);
1291 SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name)
1295 down_read(&uts_sem);
1296 if (copy_to_user(name, utsname(), sizeof *name))
1300 if (!errno && override_release(name->release, sizeof(name->release)))
1302 if (!errno && override_architecture(name))
1307 #ifdef __ARCH_WANT_SYS_OLD_UNAME
1311 SYSCALL_DEFINE1(uname, struct old_utsname __user *, name)
1318 down_read(&uts_sem);
1319 if (copy_to_user(name, utsname(), sizeof(*name)))
1323 if (!error && override_release(name->release, sizeof(name->release)))
1325 if (!error && override_architecture(name))
1330 SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name)
1336 if (!access_ok(VERIFY_WRITE, name, sizeof(struct oldold_utsname)))
1339 down_read(&uts_sem);
1340 error = __copy_to_user(&name->sysname, &utsname()->sysname,
1342 error |= __put_user(0, name->sysname + __OLD_UTS_LEN);
1343 error |= __copy_to_user(&name->nodename, &utsname()->nodename,
1345 error |= __put_user(0, name->nodename + __OLD_UTS_LEN);
1346 error |= __copy_to_user(&name->release, &utsname()->release,
1348 error |= __put_user(0, name->release + __OLD_UTS_LEN);
1349 error |= __copy_to_user(&name->version, &utsname()->version,
1351 error |= __put_user(0, name->version + __OLD_UTS_LEN);
1352 error |= __copy_to_user(&name->machine, &utsname()->machine,
1354 error |= __put_user(0, name->machine + __OLD_UTS_LEN);
1357 if (!error && override_architecture(name))
1359 if (!error && override_release(name->release, sizeof(name->release)))
1361 return error ? -EFAULT : 0;
1365 SYSCALL_DEFINE2(sethostname, char __user *, name, int, len)
1368 char tmp[__NEW_UTS_LEN];
1370 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN))
1373 if (len < 0 || len > __NEW_UTS_LEN)
1375 down_write(&uts_sem);
1377 if (!copy_from_user(tmp, name, len)) {
1378 struct new_utsname *u = utsname();
1380 memcpy(u->nodename, tmp, len);
1381 memset(u->nodename + len, 0, sizeof(u->nodename) - len);
1383 uts_proc_notify(UTS_PROC_HOSTNAME);
1389 #ifdef __ARCH_WANT_SYS_GETHOSTNAME
1391 SYSCALL_DEFINE2(gethostname, char __user *, name, int, len)
1394 struct new_utsname *u;
1398 down_read(&uts_sem);
1400 i = 1 + strlen(u->nodename);
1404 if (copy_to_user(name, u->nodename, i))
1413 * Only setdomainname; getdomainname can be implemented by calling
1416 SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len)
1419 char tmp[__NEW_UTS_LEN];
1421 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN))
1423 if (len < 0 || len > __NEW_UTS_LEN)
1426 down_write(&uts_sem);
1428 if (!copy_from_user(tmp, name, len)) {
1429 struct new_utsname *u = utsname();
1431 memcpy(u->domainname, tmp, len);
1432 memset(u->domainname + len, 0, sizeof(u->domainname) - len);
1434 uts_proc_notify(UTS_PROC_DOMAINNAME);
1440 SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim)
1442 struct rlimit value;
1445 ret = do_prlimit(current, resource, NULL, &value);
1447 ret = copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0;
1452 #ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT
1455 * Back compatibility for getrlimit. Needed for some apps.
1458 SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
1459 struct rlimit __user *, rlim)
1462 if (resource >= RLIM_NLIMITS)
1465 task_lock(current->group_leader);
1466 x = current->signal->rlim[resource];
1467 task_unlock(current->group_leader);
1468 if (x.rlim_cur > 0x7FFFFFFF)
1469 x.rlim_cur = 0x7FFFFFFF;
1470 if (x.rlim_max > 0x7FFFFFFF)
1471 x.rlim_max = 0x7FFFFFFF;
1472 return copy_to_user(rlim, &x, sizeof(x))?-EFAULT:0;
1477 static inline bool rlim64_is_infinity(__u64 rlim64)
1479 #if BITS_PER_LONG < 64
1480 return rlim64 >= ULONG_MAX;
1482 return rlim64 == RLIM64_INFINITY;
1486 static void rlim_to_rlim64(const struct rlimit *rlim, struct rlimit64 *rlim64)
1488 if (rlim->rlim_cur == RLIM_INFINITY)
1489 rlim64->rlim_cur = RLIM64_INFINITY;
1491 rlim64->rlim_cur = rlim->rlim_cur;
1492 if (rlim->rlim_max == RLIM_INFINITY)
1493 rlim64->rlim_max = RLIM64_INFINITY;
1495 rlim64->rlim_max = rlim->rlim_max;
1498 static void rlim64_to_rlim(const struct rlimit64 *rlim64, struct rlimit *rlim)
1500 if (rlim64_is_infinity(rlim64->rlim_cur))
1501 rlim->rlim_cur = RLIM_INFINITY;
1503 rlim->rlim_cur = (unsigned long)rlim64->rlim_cur;
1504 if (rlim64_is_infinity(rlim64->rlim_max))
1505 rlim->rlim_max = RLIM_INFINITY;
1507 rlim->rlim_max = (unsigned long)rlim64->rlim_max;
1510 /* make sure you are allowed to change @tsk limits before calling this */
1511 int do_prlimit(struct task_struct *tsk, unsigned int resource,
1512 struct rlimit *new_rlim, struct rlimit *old_rlim)
1514 struct rlimit *rlim;
1517 if (resource >= RLIM_NLIMITS)
1520 if (new_rlim->rlim_cur > new_rlim->rlim_max)
1522 if (resource == RLIMIT_NOFILE &&
1523 new_rlim->rlim_max > sysctl_nr_open)
1527 /* protect tsk->signal and tsk->sighand from disappearing */
1528 read_lock(&tasklist_lock);
1529 if (!tsk->sighand) {
1534 rlim = tsk->signal->rlim + resource;
1535 task_lock(tsk->group_leader);
1537 /* Keep the capable check against init_user_ns until
1538 cgroups can contain all limits */
1539 if (new_rlim->rlim_max > rlim->rlim_max &&
1540 !capable(CAP_SYS_RESOURCE))
1543 retval = security_task_setrlimit(tsk->group_leader,
1544 resource, new_rlim);
1545 if (resource == RLIMIT_CPU && new_rlim->rlim_cur == 0) {
1547 * The caller is asking for an immediate RLIMIT_CPU
1548 * expiry. But we use the zero value to mean "it was
1549 * never set". So let's cheat and make it one second
1552 new_rlim->rlim_cur = 1;
1561 task_unlock(tsk->group_leader);
1564 * RLIMIT_CPU handling. Note that the kernel fails to return an error
1565 * code if it rejected the user's attempt to set RLIMIT_CPU. This is a
1566 * very long-standing error, and fixing it now risks breakage of
1567 * applications, so we live with it
1569 if (!retval && new_rlim && resource == RLIMIT_CPU &&
1570 new_rlim->rlim_cur != RLIM_INFINITY)
1571 update_rlimit_cpu(tsk, new_rlim->rlim_cur);
1573 read_unlock(&tasklist_lock);
1577 /* rcu lock must be held */
1578 static int check_prlimit_permission(struct task_struct *task)
1580 const struct cred *cred = current_cred(), *tcred;
1582 if (current == task)
1585 tcred = __task_cred(task);
1586 if (uid_eq(cred->uid, tcred->euid) &&
1587 uid_eq(cred->uid, tcred->suid) &&
1588 uid_eq(cred->uid, tcred->uid) &&
1589 gid_eq(cred->gid, tcred->egid) &&
1590 gid_eq(cred->gid, tcred->sgid) &&
1591 gid_eq(cred->gid, tcred->gid))
1593 if (ns_capable(tcred->user_ns, CAP_SYS_RESOURCE))
1599 SYSCALL_DEFINE4(prlimit64, pid_t, pid, unsigned int, resource,
1600 const struct rlimit64 __user *, new_rlim,
1601 struct rlimit64 __user *, old_rlim)
1603 struct rlimit64 old64, new64;
1604 struct rlimit old, new;
1605 struct task_struct *tsk;
1609 if (copy_from_user(&new64, new_rlim, sizeof(new64)))
1611 rlim64_to_rlim(&new64, &new);
1615 tsk = pid ? find_task_by_vpid(pid) : current;
1620 ret = check_prlimit_permission(tsk);
1625 get_task_struct(tsk);
1628 ret = do_prlimit(tsk, resource, new_rlim ? &new : NULL,
1629 old_rlim ? &old : NULL);
1631 if (!ret && old_rlim) {
1632 rlim_to_rlim64(&old, &old64);
1633 if (copy_to_user(old_rlim, &old64, sizeof(old64)))
1637 put_task_struct(tsk);
1641 SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim)
1643 struct rlimit new_rlim;
1645 if (copy_from_user(&new_rlim, rlim, sizeof(*rlim)))
1647 return do_prlimit(current, resource, &new_rlim, NULL);
1651 * It would make sense to put struct rusage in the task_struct,
1652 * except that would make the task_struct be *really big*. After
1653 * task_struct gets moved into malloc'ed memory, it would
1654 * make sense to do this. It will make moving the rest of the information
1655 * a lot simpler! (Which we're not doing right now because we're not
1656 * measuring them yet).
1658 * When sampling multiple threads for RUSAGE_SELF, under SMP we might have
1659 * races with threads incrementing their own counters. But since word
1660 * reads are atomic, we either get new values or old values and we don't
1661 * care which for the sums. We always take the siglock to protect reading
1662 * the c* fields from p->signal from races with exit.c updating those
1663 * fields when reaping, so a sample either gets all the additions of a
1664 * given child after it's reaped, or none so this sample is before reaping.
1667 * We need to take the siglock for CHILDEREN, SELF and BOTH
1668 * for the cases current multithreaded, non-current single threaded
1669 * non-current multithreaded. Thread traversal is now safe with
1671 * Strictly speaking, we donot need to take the siglock if we are current and
1672 * single threaded, as no one else can take our signal_struct away, no one
1673 * else can reap the children to update signal->c* counters, and no one else
1674 * can race with the signal-> fields. If we do not take any lock, the
1675 * signal-> fields could be read out of order while another thread was just
1676 * exiting. So we should place a read memory barrier when we avoid the lock.
1677 * On the writer side, write memory barrier is implied in __exit_signal
1678 * as __exit_signal releases the siglock spinlock after updating the signal->
1679 * fields. But we don't do this yet to keep things simple.
1683 static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r)
1685 r->ru_nvcsw += t->nvcsw;
1686 r->ru_nivcsw += t->nivcsw;
1687 r->ru_minflt += t->min_flt;
1688 r->ru_majflt += t->maj_flt;
1689 r->ru_inblock += task_io_get_inblock(t);
1690 r->ru_oublock += task_io_get_oublock(t);
1693 static void k_getrusage(struct task_struct *p, int who, struct rusage *r)
1695 struct task_struct *t;
1696 unsigned long flags;
1697 cputime_t tgutime, tgstime, utime, stime;
1698 unsigned long maxrss = 0;
1700 memset((char *) r, 0, sizeof *r);
1703 if (who == RUSAGE_THREAD) {
1704 task_times(current, &utime, &stime);
1705 accumulate_thread_rusage(p, r);
1706 maxrss = p->signal->maxrss;
1710 if (!lock_task_sighand(p, &flags))
1715 case RUSAGE_CHILDREN:
1716 utime = p->signal->cutime;
1717 stime = p->signal->cstime;
1718 r->ru_nvcsw = p->signal->cnvcsw;
1719 r->ru_nivcsw = p->signal->cnivcsw;
1720 r->ru_minflt = p->signal->cmin_flt;
1721 r->ru_majflt = p->signal->cmaj_flt;
1722 r->ru_inblock = p->signal->cinblock;
1723 r->ru_oublock = p->signal->coublock;
1724 maxrss = p->signal->cmaxrss;
1726 if (who == RUSAGE_CHILDREN)
1730 thread_group_times(p, &tgutime, &tgstime);
1733 r->ru_nvcsw += p->signal->nvcsw;
1734 r->ru_nivcsw += p->signal->nivcsw;
1735 r->ru_minflt += p->signal->min_flt;
1736 r->ru_majflt += p->signal->maj_flt;
1737 r->ru_inblock += p->signal->inblock;
1738 r->ru_oublock += p->signal->oublock;
1739 if (maxrss < p->signal->maxrss)
1740 maxrss = p->signal->maxrss;
1743 accumulate_thread_rusage(t, r);
1751 unlock_task_sighand(p, &flags);
1754 cputime_to_timeval(utime, &r->ru_utime);
1755 cputime_to_timeval(stime, &r->ru_stime);
1757 if (who != RUSAGE_CHILDREN) {
1758 struct mm_struct *mm = get_task_mm(p);
1760 setmax_mm_hiwater_rss(&maxrss, mm);
1764 r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */
1767 int getrusage(struct task_struct *p, int who, struct rusage __user *ru)
1770 k_getrusage(p, who, &r);
1771 return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0;
1774 SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru)
1776 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
1777 who != RUSAGE_THREAD)
1779 return getrusage(current, who, ru);
1782 SYSCALL_DEFINE1(umask, int, mask)
1784 mask = xchg(¤t->fs->umask, mask & S_IRWXUGO);
1788 #ifdef CONFIG_CHECKPOINT_RESTORE
1789 static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd)
1791 struct file *exe_file;
1792 struct dentry *dentry;
1795 exe_file = fget(fd);
1799 dentry = exe_file->f_path.dentry;
1802 * Because the original mm->exe_file points to executable file, make
1803 * sure that this one is executable as well, to avoid breaking an
1807 if (!S_ISREG(dentry->d_inode->i_mode) ||
1808 exe_file->f_path.mnt->mnt_flags & MNT_NOEXEC)
1811 err = inode_permission(dentry->d_inode, MAY_EXEC);
1815 down_write(&mm->mmap_sem);
1818 * Forbid mm->exe_file change if old file still mapped.
1822 struct vm_area_struct *vma;
1824 for (vma = mm->mmap; vma; vma = vma->vm_next)
1826 path_equal(&vma->vm_file->f_path,
1827 &mm->exe_file->f_path))
1832 * The symlink can be changed only once, just to disallow arbitrary
1833 * transitions malicious software might bring in. This means one
1834 * could make a snapshot over all processes running and monitor
1835 * /proc/pid/exe changes to notice unusual activity if needed.
1838 if (test_and_set_bit(MMF_EXE_FILE_CHANGED, &mm->flags))
1842 set_mm_exe_file(mm, exe_file);
1844 up_write(&mm->mmap_sem);
1851 static int prctl_set_mm(int opt, unsigned long addr,
1852 unsigned long arg4, unsigned long arg5)
1854 unsigned long rlim = rlimit(RLIMIT_DATA);
1855 struct mm_struct *mm = current->mm;
1856 struct vm_area_struct *vma;
1859 if (arg5 || (arg4 && opt != PR_SET_MM_AUXV))
1862 if (!capable(CAP_SYS_RESOURCE))
1865 if (opt == PR_SET_MM_EXE_FILE)
1866 return prctl_set_mm_exe_file(mm, (unsigned int)addr);
1868 if (addr >= TASK_SIZE || addr < mmap_min_addr)
1873 down_read(&mm->mmap_sem);
1874 vma = find_vma(mm, addr);
1877 case PR_SET_MM_START_CODE:
1878 mm->start_code = addr;
1880 case PR_SET_MM_END_CODE:
1881 mm->end_code = addr;
1883 case PR_SET_MM_START_DATA:
1884 mm->start_data = addr;
1886 case PR_SET_MM_END_DATA:
1887 mm->end_data = addr;
1890 case PR_SET_MM_START_BRK:
1891 if (addr <= mm->end_data)
1894 if (rlim < RLIM_INFINITY &&
1896 (mm->end_data - mm->start_data) > rlim)
1899 mm->start_brk = addr;
1903 if (addr <= mm->end_data)
1906 if (rlim < RLIM_INFINITY &&
1907 (addr - mm->start_brk) +
1908 (mm->end_data - mm->start_data) > rlim)
1915 * If command line arguments and environment
1916 * are placed somewhere else on stack, we can
1917 * set them up here, ARG_START/END to setup
1918 * command line argumets and ENV_START/END
1921 case PR_SET_MM_START_STACK:
1922 case PR_SET_MM_ARG_START:
1923 case PR_SET_MM_ARG_END:
1924 case PR_SET_MM_ENV_START:
1925 case PR_SET_MM_ENV_END:
1930 if (opt == PR_SET_MM_START_STACK)
1931 mm->start_stack = addr;
1932 else if (opt == PR_SET_MM_ARG_START)
1933 mm->arg_start = addr;
1934 else if (opt == PR_SET_MM_ARG_END)
1936 else if (opt == PR_SET_MM_ENV_START)
1937 mm->env_start = addr;
1938 else if (opt == PR_SET_MM_ENV_END)
1943 * This doesn't move auxiliary vector itself
1944 * since it's pinned to mm_struct, but allow
1945 * to fill vector with new values. It's up
1946 * to a caller to provide sane values here
1947 * otherwise user space tools which use this
1948 * vector might be unhappy.
1950 case PR_SET_MM_AUXV: {
1951 unsigned long user_auxv[AT_VECTOR_SIZE];
1953 if (arg4 > sizeof(user_auxv))
1955 up_read(&mm->mmap_sem);
1957 if (copy_from_user(user_auxv, (const void __user *)addr, arg4))
1960 /* Make sure the last entry is always AT_NULL */
1961 user_auxv[AT_VECTOR_SIZE - 2] = 0;
1962 user_auxv[AT_VECTOR_SIZE - 1] = 0;
1964 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv));
1967 memcpy(mm->saved_auxv, user_auxv, arg4);
1968 task_unlock(current);
1978 up_read(&mm->mmap_sem);
1982 static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr)
1984 return put_user(me->clear_child_tid, tid_addr);
1987 #else /* CONFIG_CHECKPOINT_RESTORE */
1988 static int prctl_set_mm(int opt, unsigned long addr,
1989 unsigned long arg4, unsigned long arg5)
1993 static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr)
1999 SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
2000 unsigned long, arg4, unsigned long, arg5)
2002 struct task_struct *me = current;
2003 unsigned char comm[sizeof(me->comm)];
2006 error = security_task_prctl(option, arg2, arg3, arg4, arg5);
2007 if (error != -ENOSYS)
2012 case PR_SET_PDEATHSIG:
2013 if (!valid_signal(arg2)) {
2017 me->pdeath_signal = arg2;
2019 case PR_GET_PDEATHSIG:
2020 error = put_user(me->pdeath_signal, (int __user *)arg2);
2022 case PR_GET_DUMPABLE:
2023 error = get_dumpable(me->mm);
2025 case PR_SET_DUMPABLE:
2026 if (arg2 < 0 || arg2 > 1) {
2030 set_dumpable(me->mm, arg2);
2033 case PR_SET_UNALIGN:
2034 error = SET_UNALIGN_CTL(me, arg2);
2036 case PR_GET_UNALIGN:
2037 error = GET_UNALIGN_CTL(me, arg2);
2040 error = SET_FPEMU_CTL(me, arg2);
2043 error = GET_FPEMU_CTL(me, arg2);
2046 error = SET_FPEXC_CTL(me, arg2);
2049 error = GET_FPEXC_CTL(me, arg2);
2052 error = PR_TIMING_STATISTICAL;
2055 if (arg2 != PR_TIMING_STATISTICAL)
2059 comm[sizeof(me->comm)-1] = 0;
2060 if (strncpy_from_user(comm, (char __user *)arg2,
2061 sizeof(me->comm) - 1) < 0)
2063 set_task_comm(me, comm);
2064 proc_comm_connector(me);
2067 get_task_comm(comm, me);
2068 if (copy_to_user((char __user *)arg2, comm,
2073 error = GET_ENDIAN(me, arg2);
2076 error = SET_ENDIAN(me, arg2);
2078 case PR_GET_SECCOMP:
2079 error = prctl_get_seccomp();
2081 case PR_SET_SECCOMP:
2082 error = prctl_set_seccomp(arg2, (char __user *)arg3);
2085 error = GET_TSC_CTL(arg2);
2088 error = SET_TSC_CTL(arg2);
2090 case PR_TASK_PERF_EVENTS_DISABLE:
2091 error = perf_event_task_disable();
2093 case PR_TASK_PERF_EVENTS_ENABLE:
2094 error = perf_event_task_enable();
2096 case PR_GET_TIMERSLACK:
2097 error = current->timer_slack_ns;
2099 case PR_SET_TIMERSLACK:
2101 current->timer_slack_ns =
2102 current->default_timer_slack_ns;
2104 current->timer_slack_ns = arg2;
2110 case PR_MCE_KILL_CLEAR:
2113 current->flags &= ~PF_MCE_PROCESS;
2115 case PR_MCE_KILL_SET:
2116 current->flags |= PF_MCE_PROCESS;
2117 if (arg3 == PR_MCE_KILL_EARLY)
2118 current->flags |= PF_MCE_EARLY;
2119 else if (arg3 == PR_MCE_KILL_LATE)
2120 current->flags &= ~PF_MCE_EARLY;
2121 else if (arg3 == PR_MCE_KILL_DEFAULT)
2123 ~(PF_MCE_EARLY|PF_MCE_PROCESS);
2131 case PR_MCE_KILL_GET:
2132 if (arg2 | arg3 | arg4 | arg5)
2134 if (current->flags & PF_MCE_PROCESS)
2135 error = (current->flags & PF_MCE_EARLY) ?
2136 PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE;
2138 error = PR_MCE_KILL_DEFAULT;
2141 error = prctl_set_mm(arg2, arg3, arg4, arg5);
2143 case PR_GET_TID_ADDRESS:
2144 error = prctl_get_tid_address(me, (int __user **)arg2);
2146 case PR_SET_CHILD_SUBREAPER:
2147 me->signal->is_child_subreaper = !!arg2;
2149 case PR_GET_CHILD_SUBREAPER:
2150 error = put_user(me->signal->is_child_subreaper,
2151 (int __user *) arg2);
2153 case PR_SET_NO_NEW_PRIVS:
2154 if (arg2 != 1 || arg3 || arg4 || arg5)
2157 current->no_new_privs = 1;
2159 case PR_GET_NO_NEW_PRIVS:
2160 if (arg2 || arg3 || arg4 || arg5)
2162 return current->no_new_privs ? 1 : 0;
2170 SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep,
2171 struct getcpu_cache __user *, unused)
2174 int cpu = raw_smp_processor_id();
2176 err |= put_user(cpu, cpup);
2178 err |= put_user(cpu_to_node(cpu), nodep);
2179 return err ? -EFAULT : 0;
2182 char poweroff_cmd[POWEROFF_CMD_PATH_LEN] = "/sbin/poweroff";
2184 static void argv_cleanup(struct subprocess_info *info)
2186 argv_free(info->argv);
2189 static int __orderly_poweroff(void)
2193 static char *envp[] = {
2195 "PATH=/sbin:/bin:/usr/sbin:/usr/bin",
2200 argv = argv_split(GFP_ATOMIC, poweroff_cmd, &argc);
2202 printk(KERN_WARNING "%s failed to allocate memory for \"%s\"\n",
2203 __func__, poweroff_cmd);
2207 ret = call_usermodehelper_fns(argv[0], argv, envp, UMH_NO_WAIT,
2208 NULL, argv_cleanup, NULL);
2216 * orderly_poweroff - Trigger an orderly system poweroff
2217 * @force: force poweroff if command execution fails
2219 * This may be called from any context to trigger a system shutdown.
2220 * If the orderly shutdown fails, it will force an immediate shutdown.
2222 int orderly_poweroff(bool force)
2224 int ret = __orderly_poweroff();
2227 printk(KERN_WARNING "Failed to start orderly shutdown: "
2228 "forcing the issue\n");
2231 * I guess this should try to kick off some daemon to sync and
2232 * poweroff asap. Or not even bother syncing if we're doing an
2233 * emergency shutdown?
2241 EXPORT_SYMBOL_GPL(orderly_poweroff);