initial_commit

1 files changed, 1878 insertions, 0 deletions

diff --git a/kernel/sys.c b/kernel/sys.c
new file mode 100644
index 00000000..f88dadc8
--- /dev/null
+++ b/kernel/sys.c
@@ -0,0 +1,1878 @@
+/*
+ *  linux/kernel/sys.c
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ */
+
+#include <linux/module.h>
+#include <linux/mm.h>
+#include <linux/utsname.h>
+#include <linux/mman.h>
+#include <linux/notifier.h>
+#include <linux/reboot.h>
+#include <linux/prctl.h>
+#include <linux/highuid.h>
+#include <linux/fs.h>
+#include <linux/perf_event.h>
+#include <linux/resource.h>
+#include <linux/kernel.h>
+#include <linux/kexec.h>
+#include <linux/workqueue.h>
+#include <linux/capability.h>
+#include <linux/device.h>
+#include <linux/key.h>
+#include <linux/times.h>
+#include <linux/posix-timers.h>
+#include <linux/security.h>
+#include <linux/dcookies.h>
+#include <linux/suspend.h>
+#include <linux/tty.h>
+#include <linux/signal.h>
+#include <linux/cn_proc.h>
+#include <linux/getcpu.h>
+#include <linux/task_io_accounting_ops.h>
+#include <linux/seccomp.h>
+#include <linux/cpu.h>
+#include <linux/personality.h>
+#include <linux/ptrace.h>
+#include <linux/fs_struct.h>
+#include <linux/gfp.h>
+#include <linux/syscore_ops.h>
+#include <linux/version.h>
+#include <linux/ctype.h>
+
+#include <linux/compat.h>
+#include <linux/syscalls.h>
+#include <linux/kprobes.h>
+#include <linux/user_namespace.h>
+
+#include <linux/kmsg_dump.h>
+/* Move somewhere else to avoid recompiling? */
+#include <generated/utsrelease.h>
+
+#include <asm/uaccess.h>
+#include <asm/io.h>
+#include <asm/unistd.h>
+
+#ifndef SET_UNALIGN_CTL
+# define SET_UNALIGN_CTL(a,b)	(-EINVAL)
+#endif
+#ifndef GET_UNALIGN_CTL
+# define GET_UNALIGN_CTL(a,b)	(-EINVAL)
+#endif
+#ifndef SET_FPEMU_CTL
+# define SET_FPEMU_CTL(a,b)	(-EINVAL)
+#endif
+#ifndef GET_FPEMU_CTL
+# define GET_FPEMU_CTL(a,b)	(-EINVAL)
+#endif
+#ifndef SET_FPEXC_CTL
+# define SET_FPEXC_CTL(a,b)	(-EINVAL)
+#endif
+#ifndef GET_FPEXC_CTL
+# define GET_FPEXC_CTL(a,b)	(-EINVAL)
+#endif
+#ifndef GET_ENDIAN
+# define GET_ENDIAN(a,b)	(-EINVAL)
+#endif
+#ifndef SET_ENDIAN
+# define SET_ENDIAN(a,b)	(-EINVAL)
+#endif
+#ifndef GET_TSC_CTL
+# define GET_TSC_CTL(a)		(-EINVAL)
+#endif
+#ifndef SET_TSC_CTL
+# define SET_TSC_CTL(a)		(-EINVAL)
+#endif
+
+/*
+ * this is where the system-wide overflow UID and GID are defined, for
+ * architectures that now have 32-bit UID/GID but didn't in the past
+ */
+
+int overflowuid = DEFAULT_OVERFLOWUID;
+int overflowgid = DEFAULT_OVERFLOWGID;
+
+#ifdef CONFIG_UID16
+EXPORT_SYMBOL(overflowuid);
+EXPORT_SYMBOL(overflowgid);
+#endif
+
+/*
+ * the same as above, but for filesystems which can only store a 16-bit
+ * UID and GID. as such, this is needed on all architectures
+ */
+
+int fs_overflowuid = DEFAULT_FS_OVERFLOWUID;
+int fs_overflowgid = DEFAULT_FS_OVERFLOWUID;
+
+EXPORT_SYMBOL(fs_overflowuid);
+EXPORT_SYMBOL(fs_overflowgid);
+
+/*
+ * this indicates whether you can reboot with ctrl-alt-del: the default is yes
+ */
+
+int C_A_D = 1;
+struct pid *cad_pid;
+EXPORT_SYMBOL(cad_pid);
+
+/*
+ * If set, this is used for preparing the system to power off.
+ */
+
+void (*pm_power_off_prepare)(void);
+
+/*
+ * Returns true if current's euid is same as p's uid or euid,
+ * or has CAP_SYS_NICE to p's user_ns.
+ *
+ * Called with rcu_read_lock, creds are safe
+ */
+static bool set_one_prio_perm(struct task_struct *p)
+{
+	const struct cred *cred = current_cred(), *pcred = __task_cred(p);
+
+	if (pcred->user->user_ns == cred->user->user_ns &&
+	    (pcred->uid  == cred->euid ||
+	     pcred->euid == cred->euid))
+		return true;
+	if (ns_capable(pcred->user->user_ns, CAP_SYS_NICE))
+		return true;
+	return false;
+}
+
+/*
+ * set the priority of a task
+ * - the caller must hold the RCU read lock
+ */
+static int set_one_prio(struct task_struct *p, int niceval, int error)
+{
+	int no_nice;
+
+	if (!set_one_prio_perm(p)) {
+		error = -EPERM;
+		goto out;
+	}
+	if (niceval < task_nice(p) && !can_nice(p, niceval)) {
+		error = -EACCES;
+		goto out;
+	}
+	no_nice = security_task_setnice(p, niceval);
+	if (no_nice) {
+		error = no_nice;
+		goto out;
+	}
+	if (error == -ESRCH)
+		error = 0;
+	set_user_nice(p, niceval);
+out:
+	return error;
+}
+
+SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval)
+{
+	struct task_struct *g, *p;
+	struct user_struct *user;
+	const struct cred *cred = current_cred();
+	int error = -EINVAL;
+	struct pid *pgrp;
+
+	if (which > PRIO_USER || which < PRIO_PROCESS)
+		goto out;
+
+	/* normalize: avoid signed division (rounding problems) */
+	error = -ESRCH;
+	if (niceval < -20)
+		niceval = -20;
+	if (niceval > 19)
+		niceval = 19;
+
+	rcu_read_lock();
+	read_lock(&tasklist_lock);
+	switch (which) {
+		case PRIO_PROCESS:
+			if (who)
+				p = find_task_by_vpid(who);
+			else
+				p = current;
+			if (p)
+				error = set_one_prio(p, niceval, error);
+			break;
+		case PRIO_PGRP:
+			if (who)
+				pgrp = find_vpid(who);
+			else
+				pgrp = task_pgrp(current);
+			do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
+				error = set_one_prio(p, niceval, error);
+			} while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
+			break;
+		case PRIO_USER:
+			user = (struct user_struct *) cred->user;
+			if (!who)
+				who = cred->uid;
+			else if ((who != cred->uid) &&
+				 !(user = find_user(who)))
+				goto out_unlock;	/* No processes for this user */
+
+			do_each_thread(g, p) {
+				if (__task_cred(p)->uid == who)
+					error = set_one_prio(p, niceval, error);
+			} while_each_thread(g, p);
+			if (who != cred->uid)
+				free_uid(user);		/* For find_user() */
+			break;
+	}
+out_unlock:
+	read_unlock(&tasklist_lock);
+	rcu_read_unlock();
+out:
+	return error;
+}
+
+/*
+ * Ugh. To avoid negative return values, "getpriority()" will
+ * not return the normal nice-value, but a negated value that
+ * has been offset by 20 (ie it returns 40..1 instead of -20..19)
+ * to stay compatible.
+ */
+SYSCALL_DEFINE2(getpriority, int, which, int, who)
+{
+	struct task_struct *g, *p;
+	struct user_struct *user;
+	const struct cred *cred = current_cred();
+	long niceval, retval = -ESRCH;
+	struct pid *pgrp;
+
+	if (which > PRIO_USER || which < PRIO_PROCESS)
+		return -EINVAL;
+
+	rcu_read_lock();
+	read_lock(&tasklist_lock);
+	switch (which) {
+		case PRIO_PROCESS:
+			if (who)
+				p = find_task_by_vpid(who);
+			else
+				p = current;
+			if (p) {
+				niceval = 20 - task_nice(p);
+				if (niceval > retval)
+					retval = niceval;
+			}
+			break;
+		case PRIO_PGRP:
+			if (who)
+				pgrp = find_vpid(who);
+			else
+				pgrp = task_pgrp(current);
+			do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
+				niceval = 20 - task_nice(p);
+				if (niceval > retval)
+					retval = niceval;
+			} while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
+			break;
+		case PRIO_USER:
+			user = (struct user_struct *) cred->user;
+			if (!who)
+				who = cred->uid;
+			else if ((who != cred->uid) &&
+				 !(user = find_user(who)))
+				goto out_unlock;	/* No processes for this user */
+
+			do_each_thread(g, p) {
+				if (__task_cred(p)->uid == who) {
+					niceval = 20 - task_nice(p);
+					if (niceval > retval)
+						retval = niceval;
+				}
+			} while_each_thread(g, p);
+			if (who != cred->uid)
+				free_uid(user);		/* for find_user() */
+			break;
+	}
+out_unlock:
+	read_unlock(&tasklist_lock);
+	rcu_read_unlock();
+
+	return retval;
+}
+
+/**
+ *	emergency_restart - reboot the system
+ *
+ *	Without shutting down any hardware or taking any locks
+ *	reboot the system.  This is called when we know we are in
+ *	trouble so this is our best effort to reboot.  This is
+ *	safe to call in interrupt context.
+ */
+void emergency_restart(void)
+{
+	kmsg_dump(KMSG_DUMP_EMERG);
+	machine_emergency_restart();
+}
+EXPORT_SYMBOL_GPL(emergency_restart);
+
+void kernel_restart_prepare(char *cmd)
+{
+	blocking_notifier_call_chain(&reboot_notifier_list, SYS_RESTART, cmd);
+	system_state = SYSTEM_RESTART;
+	usermodehelper_disable();
+	device_shutdown();
+	syscore_shutdown();
+}
+
+/**
+ *	kernel_restart - reboot the system
+ *	@cmd: pointer to buffer containing command to execute for restart
+ *		or %NULL
+ *
+ *	Shutdown everything and perform a clean reboot.
+ *	This is not safe to call in interrupt context.
+ */
+void kernel_restart(char *cmd)
+{
+	kernel_restart_prepare(cmd);
+	if (!cmd)
+		printk(KERN_EMERG "Restarting system.\n");
+	else
+		printk(KERN_EMERG "Restarting system with command '%s'.\n", cmd);
+	kmsg_dump(KMSG_DUMP_RESTART);
+	machine_restart(cmd);
+}
+EXPORT_SYMBOL_GPL(kernel_restart);
+
+static void kernel_shutdown_prepare(enum system_states state)
+{
+	blocking_notifier_call_chain(&reboot_notifier_list,
+		(state == SYSTEM_HALT)?SYS_HALT:SYS_POWER_OFF, NULL);
+	system_state = state;
+	usermodehelper_disable();
+	device_shutdown();
+}
+/**
+ *	kernel_halt - halt the system
+ *
+ *	Shutdown everything and perform a clean system halt.
+ */
+void kernel_halt(void)
+{
+	kernel_shutdown_prepare(SYSTEM_HALT);
+	syscore_shutdown();
+	printk(KERN_EMERG "System halted.\n");
+	kmsg_dump(KMSG_DUMP_HALT);
+	machine_halt();
+}
+
+EXPORT_SYMBOL_GPL(kernel_halt);
+
+/**
+ *	kernel_power_off - power_off the system
+ *
+ *	Shutdown everything and perform a clean system power_off.
+ */
+void kernel_power_off(void)
+{
+	kernel_shutdown_prepare(SYSTEM_POWER_OFF);
+	if (pm_power_off_prepare)
+		pm_power_off_prepare();
+	disable_nonboot_cpus();
+	syscore_shutdown();
+	printk(KERN_EMERG "Power down.\n");
+	kmsg_dump(KMSG_DUMP_POWEROFF);
+	machine_power_off();
+}
+EXPORT_SYMBOL_GPL(kernel_power_off);
+
+static DEFINE_MUTEX(reboot_mutex);
+
+/*
+ * Reboot system call: for obvious reasons only root may call it,
+ * and even root needs to set up some magic numbers in the registers
+ * so that some mistake won't make this reboot the whole machine.
+ * You can also set the meaning of the ctrl-alt-del-key here.
+ *
+ * reboot doesn't sync: do that yourself before calling this.
+ */
+SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd,
+		void __user *, arg)
+{
+	char buffer[256];
+	int ret = 0;
+
+	/* We only trust the superuser with rebooting the system. */
+	if (!capable(CAP_SYS_BOOT))
+		return -EPERM;
+
+	/* For safety, we require "magic" arguments. */
+	if (magic1 != LINUX_REBOOT_MAGIC1 ||
+	    (magic2 != LINUX_REBOOT_MAGIC2 &&
+	                magic2 != LINUX_REBOOT_MAGIC2A &&
+			magic2 != LINUX_REBOOT_MAGIC2B &&
+	                magic2 != LINUX_REBOOT_MAGIC2C))
+		return -EINVAL;
+
+	/* Instead of trying to make the power_off code look like
+	 * halt when pm_power_off is not set do it the easy way.
+	 */
+	if ((cmd == LINUX_REBOOT_CMD_POWER_OFF) && !pm_power_off)
+		cmd = LINUX_REBOOT_CMD_HALT;
+
+	mutex_lock(&reboot_mutex);
+	switch (cmd) {
+	case LINUX_REBOOT_CMD_RESTART:
+		kernel_restart(NULL);
+		break;
+
+	case LINUX_REBOOT_CMD_CAD_ON:
+		C_A_D = 1;
+		break;
+
+	case LINUX_REBOOT_CMD_CAD_OFF:
+		C_A_D = 0;
+		break;
+
+	case LINUX_REBOOT_CMD_HALT:
+		kernel_halt();
+		do_exit(0);
+		panic("cannot halt");
+
+	case LINUX_REBOOT_CMD_POWER_OFF:
+		kernel_power_off();
+		do_exit(0);
+		break;
+
+	case LINUX_REBOOT_CMD_RESTART2:
+		if (strncpy_from_user(&buffer[0], arg, sizeof(buffer) - 1) < 0) {
+			ret = -EFAULT;
+			break;
+		}
+		buffer[sizeof(buffer) - 1] = '\0';
+
+		kernel_restart(buffer);
+		break;
+
+#ifdef CONFIG_KEXEC
+	case LINUX_REBOOT_CMD_KEXEC:
+		ret = kernel_kexec();
+		break;
+#endif
+
+#ifdef CONFIG_HIBERNATION
+	case LINUX_REBOOT_CMD_SW_SUSPEND:
+		ret = hibernate();
+		break;
+#endif
+
+	default:
+		ret = -EINVAL;
+		break;
+	}
+	mutex_unlock(&reboot_mutex);
+	return ret;
+}
+
+static void deferred_cad(struct work_struct *dummy)
+{
+	kernel_restart(NULL);
+}
+
+/*
+ * This function gets called by ctrl-alt-del - ie the keyboard interrupt.
+ * As it's called within an interrupt, it may NOT sync: the only choice
+ * is whether to reboot at once, or just ignore the ctrl-alt-del.
+ */
+void ctrl_alt_del(void)
+{
+	static DECLARE_WORK(cad_work, deferred_cad);
+
+	if (C_A_D)
+		schedule_work(&cad_work);
+	else
+		kill_cad_pid(SIGINT, 1);
+}
+	
+/*
+ * Unprivileged users may change the real gid to the effective gid
+ * or vice versa.  (BSD-style)
+ *
+ * If you set the real gid at all, or set the effective gid to a value not
+ * equal to the real gid, then the saved gid is set to the new effective gid.
+ *
+ * This makes it possible for a setgid program to completely drop its
+ * privileges, which is often a useful assertion to make when you are doing
+ * a security audit over a program.
+ *
+ * The general idea is that a program which uses just setregid() will be
+ * 100% compatible with BSD.  A program which uses just setgid() will be
+ * 100% compatible with POSIX with saved IDs. 
+ *
+ * SMP: There are not races, the GIDs are checked only by filesystem
+ *      operations (as far as semantic preservation is concerned).
+ */
+SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid)
+{
+	const struct cred *old;
+	struct cred *new;
+	int retval;
+
+	new = prepare_creds();
+	if (!new)
+		return -ENOMEM;
+	old = current_cred();
+
+	retval = -EPERM;
+	if (rgid != (gid_t) -1) {
+		if (old->gid == rgid ||
+		    old->egid == rgid ||
+		    nsown_capable(CAP_SETGID))
+			new->gid = rgid;
+		else
+			goto error;
+	}
+	if (egid != (gid_t) -1) {
+		if (old->gid == egid ||
+		    old->egid == egid ||
+		    old->sgid == egid ||
+		    nsown_capable(CAP_SETGID))
+			new->egid = egid;
+		else
+			goto error;
+	}
+
+	if (rgid != (gid_t) -1 ||
+	    (egid != (gid_t) -1 && egid != old->gid))
+		new->sgid = new->egid;
+	new->fsgid = new->egid;
+
+	return commit_creds(new);
+
+error:
+	abort_creds(new);
+	return retval;
+}
+
+/*
+ * setgid() is implemented like SysV w/ SAVED_IDS 
+ *
+ * SMP: Same implicit races as above.
+ */
+SYSCALL_DEFINE1(setgid, gid_t, gid)
+{
+	const struct cred *old;
+	struct cred *new;
+	int retval;
+
+	new = prepare_creds();
+	if (!new)
+		return -ENOMEM;
+	old = current_cred();
+
+	retval = -EPERM;
+	if (nsown_capable(CAP_SETGID))
+		new->gid = new->egid = new->sgid = new->fsgid = gid;
+	else if (gid == old->gid || gid == old->sgid)
+		new->egid = new->fsgid = gid;
+	else
+		goto error;
+
+	return commit_creds(new);
+
+error:
+	abort_creds(new);
+	return retval;
+}
+
+/*
+ * change the user struct in a credentials set to match the new UID
+ */
+static int set_user(struct cred *new)
+{
+	struct user_struct *new_user;
+
+	new_user = alloc_uid(current_user_ns(), new->uid);
+	if (!new_user)
+		return -EAGAIN;
+
+	if (atomic_read(&new_user->processes) >= rlimit(RLIMIT_NPROC) &&
+			new_user != INIT_USER) {
+		free_uid(new_user);
+		return -EAGAIN;
+	}
+
+	free_uid(new->user);
+	new->user = new_user;
+	return 0;
+}
+
+/*
+ * Unprivileged users may change the real uid to the effective uid
+ * or vice versa.  (BSD-style)
+ *
+ * If you set the real uid at all, or set the effective uid to a value not
+ * equal to the real uid, then the saved uid is set to the new effective uid.
+ *
+ * This makes it possible for a setuid program to completely drop its
+ * privileges, which is often a useful assertion to make when you are doing
+ * a security audit over a program.
+ *
+ * The general idea is that a program which uses just setreuid() will be
+ * 100% compatible with BSD.  A program which uses just setuid() will be
+ * 100% compatible with POSIX with saved IDs. 
+ */
+SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid)
+{
+	const struct cred *old;
+	struct cred *new;
+	int retval;
+
+	new = prepare_creds();
+	if (!new)
+		return -ENOMEM;
+	old = current_cred();
+
+	retval = -EPERM;
+	if (ruid != (uid_t) -1) {
+		new->uid = ruid;
+		if (old->uid != ruid &&
+		    old->euid != ruid &&
+		    !nsown_capable(CAP_SETUID))
+			goto error;
+	}
+
+	if (euid != (uid_t) -1) {
+		new->euid = euid;
+		if (old->uid != euid &&
+		    old->euid != euid &&
+		    old->suid != euid &&
+		    !nsown_capable(CAP_SETUID))
+			goto error;
+	}
+
+	if (new->uid != old->uid) {
+		retval = set_user(new);
+		if (retval < 0)
+			goto error;
+	}
+	if (ruid != (uid_t) -1 ||
+	    (euid != (uid_t) -1 && euid != old->uid))
+		new->suid = new->euid;
+	new->fsuid = new->euid;
+
+	retval = security_task_fix_setuid(new, old, LSM_SETID_RE);
+	if (retval < 0)
+		goto error;
+
+	return commit_creds(new);
+
+error:
+	abort_creds(new);
+	return retval;
+}
+		
+/*
+ * setuid() is implemented like SysV with SAVED_IDS 
+ * 
+ * Note that SAVED_ID's is deficient in that a setuid root program
+ * like sendmail, for example, cannot set its uid to be a normal 
+ * user and then switch back, because if you're root, setuid() sets
+ * the saved uid too.  If you don't like this, blame the bright people
+ * in the POSIX committee and/or USG.  Note that the BSD-style setreuid()
+ * will allow a root program to temporarily drop privileges and be able to
+ * regain them by swapping the real and effective uid.  
+ */
+SYSCALL_DEFINE1(setuid, uid_t, uid)
+{
+	const struct cred *old;
+	struct cred *new;
+	int retval;
+
+	new = prepare_creds();
+	if (!new)
+		return -ENOMEM;
+	old = current_cred();
+
+	retval = -EPERM;
+	if (nsown_capable(CAP_SETUID)) {
+		new->suid = new->uid = uid;
+		if (uid != old->uid) {
+			retval = set_user(new);
+			if (retval < 0)
+				goto error;
+		}
+	} else if (uid != old->uid && uid != new->suid) {
+		goto error;
+	}
+
+	new->fsuid = new->euid = uid;
+
+	retval = security_task_fix_setuid(new, old, LSM_SETID_ID);
+	if (retval < 0)
+		goto error;
+
+	return commit_creds(new);
+
+error:
+	abort_creds(new);
+	return retval;
+}
+
+
+/*
+ * This function implements a generic ability to update ruid, euid,
+ * and suid.  This allows you to implement the 4.4 compatible seteuid().
+ */
+SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid)
+{
+	const struct cred *old;
+	struct cred *new;
+	int retval;
+
+	new = prepare_creds();
+	if (!new)
+		return -ENOMEM;
+
+	old = current_cred();
+
+	retval = -EPERM;
+	if (!nsown_capable(CAP_SETUID)) {
+		if (ruid != (uid_t) -1 && ruid != old->uid &&
+		    ruid != old->euid  && ruid != old->suid)
+			goto error;
+		if (euid != (uid_t) -1 && euid != old->uid &&
+		    euid != old->euid  && euid != old->suid)
+			goto error;
+		if (suid != (uid_t) -1 && suid != old->uid &&
+		    suid != old->euid  && suid != old->suid)
+			goto error;
+	}
+
+	if (ruid != (uid_t) -1) {
+		new->uid = ruid;
+		if (ruid != old->uid) {
+			retval = set_user(new);
+			if (retval < 0)
+				goto error;
+		}
+	}
+	if (euid != (uid_t) -1)
+		new->euid = euid;
+	if (suid != (uid_t) -1)
+		new->suid = suid;
+	new->fsuid = new->euid;
+
+	retval = security_task_fix_setuid(new, old, LSM_SETID_RES);
+	if (retval < 0)
+		goto error;
+
+	return commit_creds(new);
+
+error:
+	abort_creds(new);
+	return retval;
+}
+
+SYSCALL_DEFINE3(getresuid, uid_t __user *, ruid, uid_t __user *, euid, uid_t __user *, suid)
+{
+	const struct cred *cred = current_cred();
+	int retval;
+
+	if (!(retval   = put_user(cred->uid,  ruid)) &&
+	    !(retval   = put_user(cred->euid, euid)))
+		retval = put_user(cred->suid, suid);
+
+	return retval;
+}
+
+/*
+ * Same as above, but for rgid, egid, sgid.
+ */
+SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid)
+{
+	const struct cred *old;
+	struct cred *new;
+	int retval;
+
+	new = prepare_creds();
+	if (!new)
+		return -ENOMEM;
+	old = current_cred();
+
+	retval = -EPERM;
+	if (!nsown_capable(CAP_SETGID)) {
+		if (rgid != (gid_t) -1 && rgid != old->gid &&
+		    rgid != old->egid  && rgid != old->sgid)
+			goto error;
+		if (egid != (gid_t) -1 && egid != old->gid &&
+		    egid != old->egid  && egid != old->sgid)
+			goto error;
+		if (sgid != (gid_t) -1 && sgid != old->gid &&
+		    sgid != old->egid  && sgid != old->sgid)
+			goto error;
+	}
+
+	if (rgid != (gid_t) -1)
+		new->gid = rgid;
+	if (egid != (gid_t) -1)
+		new->egid = egid;
+	if (sgid != (gid_t) -1)
+		new->sgid = sgid;
+	new->fsgid = new->egid;
+
+	return commit_creds(new);
+
+error:
+	abort_creds(new);
+	return retval;
+}
+
+SYSCALL_DEFINE3(getresgid, gid_t __user *, rgid, gid_t __user *, egid, gid_t __user *, sgid)
+{
+	const struct cred *cred = current_cred();
+	int retval;
+
+	if (!(retval   = put_user(cred->gid,  rgid)) &&
+	    !(retval   = put_user(cred->egid, egid)))
+		retval = put_user(cred->sgid, sgid);
+
+	return retval;
+}
+
+
+/*
+ * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This
+ * is used for "access()" and for the NFS daemon (letting nfsd stay at
+ * whatever uid it wants to). It normally shadows "euid", except when
+ * explicitly set by setfsuid() or for access..
+ */
+SYSCALL_DEFINE1(setfsuid, uid_t, uid)
+{
+	const struct cred *old;
+	struct cred *new;
+	uid_t old_fsuid;
+
+	new = prepare_creds();
+	if (!new)
+		return current_fsuid();
+	old = current_cred();
+	old_fsuid = old->fsuid;
+
+	if (uid == old->uid  || uid == old->euid  ||
+	    uid == old->suid || uid == old->fsuid ||
+	    nsown_capable(CAP_SETUID)) {
+		if (uid != old_fsuid) {
+			new->fsuid = uid;
+			if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0)
+				goto change_okay;
+		}
+	}
+
+	abort_creds(new);
+	return old_fsuid;
+
+change_okay:
+	commit_creds(new);
+	return old_fsuid;
+}
+
+/*
+ * Samma på svenska..
+ */
+SYSCALL_DEFINE1(setfsgid, gid_t, gid)
+{
+	const struct cred *old;
+	struct cred *new;
+	gid_t old_fsgid;
+
+	new = prepare_creds();
+	if (!new)
+		return current_fsgid();
+	old = current_cred();
+	old_fsgid = old->fsgid;
+
+	if (gid == old->gid  || gid == old->egid  ||
+	    gid == old->sgid || gid == old->fsgid ||
+	    nsown_capable(CAP_SETGID)) {
+		if (gid != old_fsgid) {
+			new->fsgid = gid;
+			goto change_okay;
+		}
+	}
+
+	abort_creds(new);
+	return old_fsgid;
+
+change_okay:
+	commit_creds(new);
+	return old_fsgid;
+}
+
+void do_sys_times(struct tms *tms)
+{
+	cputime_t tgutime, tgstime, cutime, cstime;
+
+	spin_lock_irq(&current->sighand->siglock);
+	thread_group_times(current, &tgutime, &tgstime);
+	cutime = current->signal->cutime;
+	cstime = current->signal->cstime;
+	spin_unlock_irq(&current->sighand->siglock);
+	tms->tms_utime = cputime_to_clock_t(tgutime);
+	tms->tms_stime = cputime_to_clock_t(tgstime);
+	tms->tms_cutime = cputime_to_clock_t(cutime);
+	tms->tms_cstime = cputime_to_clock_t(cstime);
+}
+
+SYSCALL_DEFINE1(times, struct tms __user *, tbuf)
+{
+	if (tbuf) {
+		struct tms tmp;
+
+		do_sys_times(&tmp);
+		if (copy_to_user(tbuf, &tmp, sizeof(struct tms)))
+			return -EFAULT;
+	}
+	force_successful_syscall_return();
+	return (long) jiffies_64_to_clock_t(get_jiffies_64());
+}
+
+/*
+ * This needs some heavy checking ...
+ * I just haven't the stomach for it. I also don't fully
+ * understand sessions/pgrp etc. Let somebody who does explain it.
+ *
+ * OK, I think I have the protection semantics right.... this is really
+ * only important on a multi-user system anyway, to make sure one user
+ * can't send a signal to a process owned by another.  -TYT, 12/12/91
+ *
+ * Auch. Had to add the 'did_exec' flag to conform completely to POSIX.
+ * LBT 04.03.94
+ */
+SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid)
+{
+	struct task_struct *p;
+	struct task_struct *group_leader = current->group_leader;
+	struct pid *pgrp;
+	int err;
+
+	if (!pid)
+		pid = task_pid_vnr(group_leader);
+	if (!pgid)
+		pgid = pid;
+	if (pgid < 0)
+		return -EINVAL;
+	rcu_read_lock();
+
+	/* From this point forward we keep holding onto the tasklist lock
+	 * so that our parent does not change from under us. -DaveM
+	 */
+	write_lock_irq(&tasklist_lock);
+
+	err = -ESRCH;
+	p = find_task_by_vpid(pid);
+	if (!p)
+		goto out;
+
+	err = -EINVAL;
+	if (!thread_group_leader(p))
+		goto out;
+
+	if (same_thread_group(p->real_parent, group_leader)) {
+		err = -EPERM;
+		if (task_session(p) != task_session(group_leader))
+			goto out;
+		err = -EACCES;
+		if (p->did_exec)
+			goto out;
+	} else {
+		err = -ESRCH;
+		if (p != group_leader)
+			goto out;
+	}
+
+	err = -EPERM;
+	if (p->signal->leader)
+		goto out;
+
+	pgrp = task_pid(p);
+	if (pgid != pid) {
+		struct task_struct *g;
+
+		pgrp = find_vpid(pgid);
+		g = pid_task(pgrp, PIDTYPE_PGID);
+		if (!g || task_session(g) != task_session(group_leader))
+			goto out;
+	}
+
+	err = security_task_setpgid(p, pgid);
+	if (err)
+		goto out;
+
+	if (task_pgrp(p) != pgrp)
+		change_pid(p, PIDTYPE_PGID, pgrp);
+
+	err = 0;
+out:
+	/* All paths lead to here, thus we are safe. -DaveM */
+	write_unlock_irq(&tasklist_lock);
+	rcu_read_unlock();
+	return err;
+}
+
+SYSCALL_DEFINE1(getpgid, pid_t, pid)
+{
+	struct task_struct *p;
+	struct pid *grp;
+	int retval;
+
+	rcu_read_lock();
+	if (!pid)
+		grp = task_pgrp(current);
+	else {
+		retval = -ESRCH;
+		p = find_task_by_vpid(pid);
+		if (!p)
+			goto out;
+		grp = task_pgrp(p);
+		if (!grp)
+			goto out;
+
+		retval = security_task_getpgid(p);
+		if (retval)
+			goto out;
+	}
+	retval = pid_vnr(grp);
+out:
+	rcu_read_unlock();
+	return retval;
+}
+
+#ifdef __ARCH_WANT_SYS_GETPGRP
+
+SYSCALL_DEFINE0(getpgrp)
+{
+	return sys_getpgid(0);
+}
+
+#endif
+
+SYSCALL_DEFINE1(getsid, pid_t, pid)
+{
+	struct task_struct *p;
+	struct pid *sid;
+	int retval;
+
+	rcu_read_lock();
+	if (!pid)
+		sid = task_session(current);
+	else {
+		retval = -ESRCH;
+		p = find_task_by_vpid(pid);
+		if (!p)
+			goto out;
+		sid = task_session(p);
+		if (!sid)
+			goto out;
+
+		retval = security_task_getsid(p);
+		if (retval)
+			goto out;
+	}
+	retval = pid_vnr(sid);
+out:
+	rcu_read_unlock();
+	return retval;
+}
+
+SYSCALL_DEFINE0(setsid)
+{
+	struct task_struct *group_leader = current->group_leader;
+	struct pid *sid = task_pid(group_leader);
+	pid_t session = pid_vnr(sid);
+	int err = -EPERM;
+
+	write_lock_irq(&tasklist_lock);
+	/* Fail if I am already a session leader */
+	if (group_leader->signal->leader)
+		goto out;
+
+	/* Fail if a process group id already exists that equals the
+	 * proposed session id.
+	 */
+	if (pid_task(sid, PIDTYPE_PGID))
+		goto out;
+
+	group_leader->signal->leader = 1;
+	__set_special_pids(sid);
+
+	proc_clear_tty(group_leader);
+
+	err = session;
+out:
+	write_unlock_irq(&tasklist_lock);
+	if (err > 0) {
+		proc_sid_connector(group_leader);
+		sched_autogroup_create_attach(group_leader);
+	}
+	return err;
+}
+
+DECLARE_RWSEM(uts_sem);
+
+#ifdef COMPAT_UTS_MACHINE
+#define override_architecture(name) \
+	(personality(current->personality) == PER_LINUX32 && \
+	 copy_to_user(name->machine, COMPAT_UTS_MACHINE, \
+		      sizeof(COMPAT_UTS_MACHINE)))
+#else
+#define override_architecture(name)	0
+#endif
+
+/*
+ * Work around broken programs that cannot handle "Linux 3.0".
+ * Instead we map 3.x to 2.6.40+x, so e.g. 3.0 would be 2.6.40
+ */
+static int override_release(char __user *release, int len)
+{
+	int ret = 0;
+	char buf[65];
+
+	if (current->personality & UNAME26) {
+		char *rest = UTS_RELEASE;
+		int ndots = 0;
+		unsigned v;
+
+		while (*rest) {
+			if (*rest == '.' && ++ndots >= 3)
+				break;
+			if (!isdigit(*rest) && *rest != '.')
+				break;
+			rest++;
+		}
+		v = ((LINUX_VERSION_CODE >> 8) & 0xff) + 40;
+		snprintf(buf, len, "2.6.%u%s", v, rest);
+		ret = copy_to_user(release, buf, len);
+	}
+	return ret;
+}
+
+SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name)
+{
+	int errno = 0;
+
+	down_read(&uts_sem);
+	if (copy_to_user(name, utsname(), sizeof *name))
+		errno = -EFAULT;
+	up_read(&uts_sem);
+
+	if (!errno && override_release(name->release, sizeof(name->release)))
+		errno = -EFAULT;
+	if (!errno && override_architecture(name))
+		errno = -EFAULT;
+	return errno;
+}
+
+#ifdef __ARCH_WANT_SYS_OLD_UNAME
+/*
+ * Old cruft
+ */
+SYSCALL_DEFINE1(uname, struct old_utsname __user *, name)
+{
+	int error = 0;
+
+	if (!name)
+		return -EFAULT;
+
+	down_read(&uts_sem);
+	if (copy_to_user(name, utsname(), sizeof(*name)))
+		error = -EFAULT;
+	up_read(&uts_sem);
+
+	if (!error && override_release(name->release, sizeof(name->release)))
+		error = -EFAULT;
+	if (!error && override_architecture(name))
+		error = -EFAULT;
+	return error;
+}
+
+SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name)
+{
+	int error;
+
+	if (!name)
+		return -EFAULT;
+	if (!access_ok(VERIFY_WRITE, name, sizeof(struct oldold_utsname)))
+		return -EFAULT;
+
+	down_read(&uts_sem);
+	error = __copy_to_user(&name->sysname, &utsname()->sysname,
+			       __OLD_UTS_LEN);
+	error |= __put_user(0, name->sysname + __OLD_UTS_LEN);
+	error |= __copy_to_user(&name->nodename, &utsname()->nodename,
+				__OLD_UTS_LEN);
+	error |= __put_user(0, name->nodename + __OLD_UTS_LEN);
+	error |= __copy_to_user(&name->release, &utsname()->release,
+				__OLD_UTS_LEN);
+	error |= __put_user(0, name->release + __OLD_UTS_LEN);
+	error |= __copy_to_user(&name->version, &utsname()->version,
+				__OLD_UTS_LEN);
+	error |= __put_user(0, name->version + __OLD_UTS_LEN);
+	error |= __copy_to_user(&name->machine, &utsname()->machine,
+				__OLD_UTS_LEN);
+	error |= __put_user(0, name->machine + __OLD_UTS_LEN);
+	up_read(&uts_sem);
+
+	if (!error && override_architecture(name))
+		error = -EFAULT;
+	if (!error && override_release(name->release, sizeof(name->release)))
+		error = -EFAULT;
+	return error ? -EFAULT : 0;
+}
+#endif
+
+SYSCALL_DEFINE2(sethostname, char __user *, name, int, len)
+{
+	int errno;
+	char tmp[__NEW_UTS_LEN];
+
+	if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN))
+		return -EPERM;
+
+	if (len < 0 || len > __NEW_UTS_LEN)
+		return -EINVAL;
+	down_write(&uts_sem);
+	errno = -EFAULT;
+	if (!copy_from_user(tmp, name, len)) {
+		struct new_utsname *u = utsname();
+
+		memcpy(u->nodename, tmp, len);
+		memset(u->nodename + len, 0, sizeof(u->nodename) - len);
+		errno = 0;
+	}
+	up_write(&uts_sem);
+	return errno;
+}
+
+#ifdef __ARCH_WANT_SYS_GETHOSTNAME
+
+SYSCALL_DEFINE2(gethostname, char __user *, name, int, len)
+{
+	int i, errno;
+	struct new_utsname *u;
+
+	if (len < 0)
+		return -EINVAL;
+	down_read(&uts_sem);
+	u = utsname();
+	i = 1 + strlen(u->nodename);
+	if (i > len)
+		i = len;
+	errno = 0;
+	if (copy_to_user(name, u->nodename, i))
+		errno = -EFAULT;
+	up_read(&uts_sem);
+	return errno;
+}
+
+#endif
+
+/*
+ * Only setdomainname; getdomainname can be implemented by calling
+ * uname()
+ */
+SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len)
+{
+	int errno;
+	char tmp[__NEW_UTS_LEN];
+
+	if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN))
+		return -EPERM;
+	if (len < 0 || len > __NEW_UTS_LEN)
+		return -EINVAL;
+
+	down_write(&uts_sem);
+	errno = -EFAULT;
+	if (!copy_from_user(tmp, name, len)) {
+		struct new_utsname *u = utsname();
+
+		memcpy(u->domainname, tmp, len);
+		memset(u->domainname + len, 0, sizeof(u->domainname) - len);
+		errno = 0;
+	}
+	up_write(&uts_sem);
+	return errno;
+}
+
+SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim)
+{
+	struct rlimit value;
+	int ret;
+
+	ret = do_prlimit(current, resource, NULL, &value);
+	if (!ret)
+		ret = copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0;
+
+	return ret;
+}
+
+#ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT
+
+/*
+ *	Back compatibility for getrlimit. Needed for some apps.
+ */
+ 
+SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
+		struct rlimit __user *, rlim)
+{
+	struct rlimit x;
+	if (resource >= RLIM_NLIMITS)
+		return -EINVAL;
+
+	task_lock(current->group_leader);
+	x = current->signal->rlim[resource];
+	task_unlock(current->group_leader);
+	if (x.rlim_cur > 0x7FFFFFFF)
+		x.rlim_cur = 0x7FFFFFFF;
+	if (x.rlim_max > 0x7FFFFFFF)
+		x.rlim_max = 0x7FFFFFFF;
+	return copy_to_user(rlim, &x, sizeof(x))?-EFAULT:0;
+}
+
+#endif
+
+static inline bool rlim64_is_infinity(__u64 rlim64)
+{
+#if BITS_PER_LONG < 64
+	return rlim64 >= ULONG_MAX;
+#else
+	return rlim64 == RLIM64_INFINITY;
+#endif
+}
+
+static void rlim_to_rlim64(const struct rlimit *rlim, struct rlimit64 *rlim64)
+{
+	if (rlim->rlim_cur == RLIM_INFINITY)
+		rlim64->rlim_cur = RLIM64_INFINITY;
+	else
+		rlim64->rlim_cur = rlim->rlim_cur;
+	if (rlim->rlim_max == RLIM_INFINITY)
+		rlim64->rlim_max = RLIM64_INFINITY;
+	else
+		rlim64->rlim_max = rlim->rlim_max;
+}
+
+static void rlim64_to_rlim(const struct rlimit64 *rlim64, struct rlimit *rlim)
+{
+	if (rlim64_is_infinity(rlim64->rlim_cur))
+		rlim->rlim_cur = RLIM_INFINITY;
+	else
+		rlim->rlim_cur = (unsigned long)rlim64->rlim_cur;
+	if (rlim64_is_infinity(rlim64->rlim_max))
+		rlim->rlim_max = RLIM_INFINITY;
+	else
+		rlim->rlim_max = (unsigned long)rlim64->rlim_max;
+}
+
+/* make sure you are allowed to change @tsk limits before calling this */
+int do_prlimit(struct task_struct *tsk, unsigned int resource,
+		struct rlimit *new_rlim, struct rlimit *old_rlim)
+{
+	struct rlimit *rlim;
+	int retval = 0;
+
+	if (resource >= RLIM_NLIMITS)
+		return -EINVAL;
+	if (new_rlim) {
+		if (new_rlim->rlim_cur > new_rlim->rlim_max)
+			return -EINVAL;
+		if (resource == RLIMIT_NOFILE &&
+				new_rlim->rlim_max > sysctl_nr_open)
+			return -EPERM;
+	}
+
+	/* protect tsk->signal and tsk->sighand from disappearing */
+	read_lock(&tasklist_lock);
+	if (!tsk->sighand) {
+		retval = -ESRCH;
+		goto out;
+	}
+
+	rlim = tsk->signal->rlim + resource;
+	task_lock(tsk->group_leader);
+	if (new_rlim) {
+		/* Keep the capable check against init_user_ns until
+		   cgroups can contain all limits */
+		if (new_rlim->rlim_max > rlim->rlim_max &&
+				!capable(CAP_SYS_RESOURCE))
+			retval = -EPERM;
+		if (!retval)
+			retval = security_task_setrlimit(tsk->group_leader,
+					resource, new_rlim);
+		if (resource == RLIMIT_CPU && new_rlim->rlim_cur == 0) {
+			/*
+			 * The caller is asking for an immediate RLIMIT_CPU
+			 * expiry.  But we use the zero value to mean "it was
+			 * never set".  So let's cheat and make it one second
+			 * instead
+			 */
+			new_rlim->rlim_cur = 1;
+		}
+	}
+	if (!retval) {
+		if (old_rlim)
+			*old_rlim = *rlim;
+		if (new_rlim)
+			*rlim = *new_rlim;
+	}
+	task_unlock(tsk->group_leader);
+
+	/*
+	 * RLIMIT_CPU handling.   Note that the kernel fails to return an error
+	 * code if it rejected the user's attempt to set RLIMIT_CPU.  This is a
+	 * very long-standing error, and fixing it now risks breakage of
+	 * applications, so we live with it
+	 */
+	 if (!retval && new_rlim && resource == RLIMIT_CPU &&
+			 new_rlim->rlim_cur != RLIM_INFINITY)
+		update_rlimit_cpu(tsk, new_rlim->rlim_cur);
+out:
+	read_unlock(&tasklist_lock);
+	return retval;
+}
+
+/* rcu lock must be held */
+static int check_prlimit_permission(struct task_struct *task)
+{
+	const struct cred *cred = current_cred(), *tcred;
+
+	if (current == task)
+		return 0;
+
+	tcred = __task_cred(task);
+	if (cred->user->user_ns == tcred->user->user_ns &&
+	    (cred->uid == tcred->euid &&
+	     cred->uid == tcred->suid &&
+	     cred->uid == tcred->uid  &&
+	     cred->gid == tcred->egid &&
+	     cred->gid == tcred->sgid &&
+	     cred->gid == tcred->gid))
+		return 0;
+	if (ns_capable(tcred->user->user_ns, CAP_SYS_RESOURCE))
+		return 0;
+
+	return -EPERM;
+}
+
+SYSCALL_DEFINE4(prlimit64, pid_t, pid, unsigned int, resource,
+		const struct rlimit64 __user *, new_rlim,
+		struct rlimit64 __user *, old_rlim)
+{
+	struct rlimit64 old64, new64;
+	struct rlimit old, new;
+	struct task_struct *tsk;
+	int ret;
+
+	if (new_rlim) {
+		if (copy_from_user(&new64, new_rlim, sizeof(new64)))
+			return -EFAULT;
+		rlim64_to_rlim(&new64, &new);
+	}
+
+	rcu_read_lock();
+	tsk = pid ? find_task_by_vpid(pid) : current;
+	if (!tsk) {
+		rcu_read_unlock();
+		return -ESRCH;
+	}
+	ret = check_prlimit_permission(tsk);
+	if (ret) {
+		rcu_read_unlock();
+		return ret;
+	}
+	get_task_struct(tsk);
+	rcu_read_unlock();
+
+	ret = do_prlimit(tsk, resource, new_rlim ? &new : NULL,
+			old_rlim ? &old : NULL);
+
+	if (!ret && old_rlim) {
+		rlim_to_rlim64(&old, &old64);
+		if (copy_to_user(old_rlim, &old64, sizeof(old64)))
+			ret = -EFAULT;
+	}
+
+	put_task_struct(tsk);
+	return ret;
+}
+
+SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim)
+{
+	struct rlimit new_rlim;
+
+	if (copy_from_user(&new_rlim, rlim, sizeof(*rlim)))
+		return -EFAULT;
+	return do_prlimit(current, resource, &new_rlim, NULL);
+}
+
+/*
+ * It would make sense to put struct rusage in the task_struct,
+ * except that would make the task_struct be *really big*.  After
+ * task_struct gets moved into malloc'ed memory, it would
+ * make sense to do this.  It will make moving the rest of the information
+ * a lot simpler!  (Which we're not doing right now because we're not
+ * measuring them yet).
+ *
+ * When sampling multiple threads for RUSAGE_SELF, under SMP we might have
+ * races with threads incrementing their own counters.  But since word
+ * reads are atomic, we either get new values or old values and we don't
+ * care which for the sums.  We always take the siglock to protect reading
+ * the c* fields from p->signal from races with exit.c updating those
+ * fields when reaping, so a sample either gets all the additions of a
+ * given child after it's reaped, or none so this sample is before reaping.
+ *
+ * Locking:
+ * We need to take the siglock for CHILDEREN, SELF and BOTH
+ * for  the cases current multithreaded, non-current single threaded
+ * non-current multithreaded.  Thread traversal is now safe with
+ * the siglock held.
+ * Strictly speaking, we donot need to take the siglock if we are current and
+ * single threaded,  as no one else can take our signal_struct away, no one
+ * else can  reap the  children to update signal->c* counters, and no one else
+ * can race with the signal-> fields. If we do not take any lock, the
+ * signal-> fields could be read out of order while another thread was just
+ * exiting. So we should  place a read memory barrier when we avoid the lock.
+ * On the writer side,  write memory barrier is implied in  __exit_signal
+ * as __exit_signal releases  the siglock spinlock after updating the signal->
+ * fields. But we don't do this yet to keep things simple.
+ *
+ */
+
+static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r)
+{
+	r->ru_nvcsw += t->nvcsw;
+	r->ru_nivcsw += t->nivcsw;
+	r->ru_minflt += t->min_flt;
+	r->ru_majflt += t->maj_flt;
+	r->ru_inblock += task_io_get_inblock(t);
+	r->ru_oublock += task_io_get_oublock(t);
+}
+
+static void k_getrusage(struct task_struct *p, int who, struct rusage *r)
+{
+	struct task_struct *t;
+	unsigned long flags;
+	cputime_t tgutime, tgstime, utime, stime;
+	unsigned long maxrss = 0;
+
+	memset((char *) r, 0, sizeof *r);
+	utime = stime = cputime_zero;
+
+	if (who == RUSAGE_THREAD) {
+		task_times(current, &utime, &stime);
+		accumulate_thread_rusage(p, r);
+		maxrss = p->signal->maxrss;
+		goto out;
+	}
+
+	if (!lock_task_sighand(p, &flags))
+		return;
+
+	switch (who) {
+		case RUSAGE_BOTH:
+		case RUSAGE_CHILDREN:
+			utime = p->signal->cutime;
+			stime = p->signal->cstime;
+			r->ru_nvcsw = p->signal->cnvcsw;
+			r->ru_nivcsw = p->signal->cnivcsw;
+			r->ru_minflt = p->signal->cmin_flt;
+			r->ru_majflt = p->signal->cmaj_flt;
+			r->ru_inblock = p->signal->cinblock;
+			r->ru_oublock = p->signal->coublock;
+			maxrss = p->signal->cmaxrss;
+
+			if (who == RUSAGE_CHILDREN)
+				break;
+
+		case RUSAGE_SELF:
+			thread_group_times(p, &tgutime, &tgstime);
+			utime = cputime_add(utime, tgutime);
+			stime = cputime_add(stime, tgstime);
+			r->ru_nvcsw += p->signal->nvcsw;
+			r->ru_nivcsw += p->signal->nivcsw;
+			r->ru_minflt += p->signal->min_flt;
+			r->ru_majflt += p->signal->maj_flt;
+			r->ru_inblock += p->signal->inblock;
+			r->ru_oublock += p->signal->oublock;
+			if (maxrss < p->signal->maxrss)
+				maxrss = p->signal->maxrss;
+			t = p;
+			do {
+				accumulate_thread_rusage(t, r);
+				t = next_thread(t);
+			} while (t != p);
+			break;
+
+		default:
+			BUG();
+	}
+	unlock_task_sighand(p, &flags);
+
+out:
+	cputime_to_timeval(utime, &r->ru_utime);
+	cputime_to_timeval(stime, &r->ru_stime);
+
+	if (who != RUSAGE_CHILDREN) {
+		struct mm_struct *mm = get_task_mm(p);
+		if (mm) {
+			setmax_mm_hiwater_rss(&maxrss, mm);
+			mmput(mm);
+		}
+	}
+	r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */
+}
+
+int getrusage(struct task_struct *p, int who, struct rusage __user *ru)
+{
+	struct rusage r;
+	k_getrusage(p, who, &r);
+	return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0;
+}
+
+SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru)
+{
+	if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
+	    who != RUSAGE_THREAD)
+		return -EINVAL;
+	return getrusage(current, who, ru);
+}
+
+SYSCALL_DEFINE1(umask, int, mask)
+{
+	mask = xchg(&current->fs->umask, mask & S_IRWXUGO);
+	return mask;
+}
+
+SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
+		unsigned long, arg4, unsigned long, arg5)
+{
+	struct task_struct *me = current;
+	unsigned char comm[sizeof(me->comm)];
+	long error;
+
+	error = security_task_prctl(option, arg2, arg3, arg4, arg5);
+	if (error != -ENOSYS)
+		return error;
+
+	error = 0;
+	switch (option) {
+		case PR_SET_PDEATHSIG:
+			if (!valid_signal(arg2)) {
+				error = -EINVAL;
+				break;
+			}
+			me->pdeath_signal = arg2;
+			error = 0;
+			break;
+		case PR_GET_PDEATHSIG:
+			error = put_user(me->pdeath_signal, (int __user *)arg2);
+			break;
+		case PR_GET_DUMPABLE:
+			error = get_dumpable(me->mm);
+			break;
+		case PR_SET_DUMPABLE:
+			if (arg2 < 0 || arg2 > 1) {
+				error = -EINVAL;
+				break;
+			}
+			set_dumpable(me->mm, arg2);
+			error = 0;
+			break;
+
+		case PR_SET_UNALIGN:
+			error = SET_UNALIGN_CTL(me, arg2);
+			break;
+		case PR_GET_UNALIGN:
+			error = GET_UNALIGN_CTL(me, arg2);
+			break;
+		case PR_SET_FPEMU:
+			error = SET_FPEMU_CTL(me, arg2);
+			break;
+		case PR_GET_FPEMU:
+			error = GET_FPEMU_CTL(me, arg2);
+			break;
+		case PR_SET_FPEXC:
+			error = SET_FPEXC_CTL(me, arg2);
+			break;
+		case PR_GET_FPEXC:
+			error = GET_FPEXC_CTL(me, arg2);
+			break;
+		case PR_GET_TIMING:
+			error = PR_TIMING_STATISTICAL;
+			break;
+		case PR_SET_TIMING:
+			if (arg2 != PR_TIMING_STATISTICAL)
+				error = -EINVAL;
+			else
+				error = 0;
+			break;
+
+		case PR_SET_NAME:
+			comm[sizeof(me->comm)-1] = 0;
+			if (strncpy_from_user(comm, (char __user *)arg2,
+					      sizeof(me->comm) - 1) < 0)
+				return -EFAULT;
+			set_task_comm(me, comm);
+			return 0;
+		case PR_GET_NAME:
+			get_task_comm(comm, me);
+			if (copy_to_user((char __user *)arg2, comm,
+					 sizeof(comm)))
+				return -EFAULT;
+			return 0;
+		case PR_GET_ENDIAN:
+			error = GET_ENDIAN(me, arg2);
+			break;
+		case PR_SET_ENDIAN:
+			error = SET_ENDIAN(me, arg2);
+			break;
+
+		case PR_GET_SECCOMP:
+			error = prctl_get_seccomp();
+			break;
+		case PR_SET_SECCOMP:
+			error = prctl_set_seccomp(arg2);
+			break;
+		case PR_GET_TSC:
+			error = GET_TSC_CTL(arg2);
+			break;
+		case PR_SET_TSC:
+			error = SET_TSC_CTL(arg2);
+			break;
+		case PR_TASK_PERF_EVENTS_DISABLE:
+			error = perf_event_task_disable();
+			break;
+		case PR_TASK_PERF_EVENTS_ENABLE:
+			error = perf_event_task_enable();
+			break;
+		case PR_GET_TIMERSLACK:
+			error = current->timer_slack_ns;
+			break;
+		case PR_SET_TIMERSLACK:
+			if (arg2 <= 0)
+				current->timer_slack_ns =
+					current->default_timer_slack_ns;
+			else
+				current->timer_slack_ns = arg2;
+			error = 0;
+			break;
+		case PR_MCE_KILL:
+			if (arg4 | arg5)
+				return -EINVAL;
+			switch (arg2) {
+			case PR_MCE_KILL_CLEAR:
+				if (arg3 != 0)
+					return -EINVAL;
+				current->flags &= ~PF_MCE_PROCESS;
+				break;
+			case PR_MCE_KILL_SET:
+				current->flags |= PF_MCE_PROCESS;
+				if (arg3 == PR_MCE_KILL_EARLY)
+					current->flags |= PF_MCE_EARLY;
+				else if (arg3 == PR_MCE_KILL_LATE)
+					current->flags &= ~PF_MCE_EARLY;
+				else if (arg3 == PR_MCE_KILL_DEFAULT)
+					current->flags &=
+						~(PF_MCE_EARLY|PF_MCE_PROCESS);
+				else
+					return -EINVAL;
+				break;
+			default:
+				return -EINVAL;
+			}
+			error = 0;
+			break;
+		case PR_MCE_KILL_GET:
+			if (arg2 | arg3 | arg4 | arg5)
+				return -EINVAL;
+			if (current->flags & PF_MCE_PROCESS)
+				error = (current->flags & PF_MCE_EARLY) ?
+					PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE;
+			else
+				error = PR_MCE_KILL_DEFAULT;
+			break;
+		default:
+			error = -EINVAL;
+			break;
+	}
+	return error;
+}
+
+SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep,
+		struct getcpu_cache __user *, unused)
+{
+	int err = 0;
+	int cpu = raw_smp_processor_id();
+	if (cpup)
+		err |= put_user(cpu, cpup);
+	if (nodep)
+		err |= put_user(cpu_to_node(cpu), nodep);
+	return err ? -EFAULT : 0;
+}
+
+char poweroff_cmd[POWEROFF_CMD_PATH_LEN] = "/sbin/poweroff";
+
+static void argv_cleanup(struct subprocess_info *info)
+{
+	argv_free(info->argv);
+}
+
+/**
+ * orderly_poweroff - Trigger an orderly system poweroff
+ * @force: force poweroff if command execution fails
+ *
+ * This may be called from any context to trigger a system shutdown.
+ * If the orderly shutdown fails, it will force an immediate shutdown.
+ */
+int orderly_poweroff(bool force)
+{
+	int argc;
+	char **argv = argv_split(GFP_ATOMIC, poweroff_cmd, &argc);
+	static char *envp[] = {
+		"HOME=/",
+		"PATH=/sbin:/bin:/usr/sbin:/usr/bin",
+		NULL
+	};
+	int ret = -ENOMEM;
+	struct subprocess_info *info;
+
+	if (argv == NULL) {
+		printk(KERN_WARNING "%s failed to allocate memory for \"%s\"\n",
+		       __func__, poweroff_cmd);
+		goto out;
+	}
+
+	info = call_usermodehelper_setup(argv[0], argv, envp, GFP_ATOMIC);
+	if (info == NULL) {
+		argv_free(argv);
+		goto out;
+	}
+
+	call_usermodehelper_setfns(info, NULL, argv_cleanup, NULL);
+
+	ret = call_usermodehelper_exec(info, UMH_NO_WAIT);
+
+  out:
+	if (ret && force) {
+		printk(KERN_WARNING "Failed to start orderly shutdown: "
+		       "forcing the issue\n");
+
+		/* I guess this should try to kick off some daemon to
+		   sync and poweroff asap.  Or not even bother syncing
+		   if we're doing an emergency shutdown? */
+		emergency_sync();
+		kernel_power_off();
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(orderly_poweroff);