/*
 *  linux/kernel/sys.c
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 */

#include <linux/config.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/times.h>
#include <linux/utsname.h>
#include <linux/param.h>
#include <linux/resource.h>
#include <linux/signal.h>
#include <linux/string.h>
#include <linux/ptrace.h>
#include <linux/stat.h>
#include <linux/mman.h>
#include <linux/mm.h>
#include <linux/fcntl.h>
#include <linux/acct.h>
#include <linux/tty.h>
#include <linux/smp.h>
#include <linux/smp_lock.h>
#if defined(CONFIG_APM) && defined(CONFIG_APM_POWER_OFF)
#include <linux/apm_bios.h>
#endif
#include <linux/notifier.h>

#include <asm/uaccess.h>
#include <asm/io.h>

/*
 * this indicates whether you can reboot with ctrl-alt-del: the default is yes
 */

int C_A_D = 1;

/*
 *	List of functions to call at shutdown. This is used to stop any
 *	idling DMA operations and the like. 
 */
 
struct notifier_block *boot_notifier_list=NULL;

extern void adjust_clock(void);

asmlinkage int sys_ni_syscall(void)
{
	return -ENOSYS;
}

static int proc_sel(struct task_struct *p, int which, int who)
{
	if(p->pid)
	{
		switch (which) {
			case PRIO_PROCESS:
				if (!who && p == current)
					return 1;
				return(p->pid == who);
			case PRIO_PGRP:
				if (!who)
					who = current->pgrp;
				return(p->pgrp == who);
			case PRIO_USER:
				if (!who)
					who = current->uid;
				return(p->uid == who);
		}
	}
	return 0;
}

asmlinkage int sys_setpriority(int which, int who, int niceval)
{
	struct task_struct *p;
	int error = EINVAL;
	unsigned int priority;

	lock_kernel();
	if (which > 2 || which < 0)
		goto out;

	/* normalize: avoid signed division (rounding problems) */
	error = ESRCH;
	priority = niceval;
	if (niceval < 0)
		priority = -niceval;
	if (priority > 20)
		priority = 20;
	priority = (priority * DEF_PRIORITY + 10) / 20 + DEF_PRIORITY;

	if (niceval >= 0) {
		priority = 2*DEF_PRIORITY - priority;
		if (!priority)
			priority = 1;
	}

	for_each_task(p) {
		if (!proc_sel(p, which, who))
			continue;
		if (p->uid != current->euid &&
			p->uid != current->uid && !suser()) {
			error = EPERM;
			continue;
		}
		if (error == ESRCH)
			error = 0;
		if (priority > p->priority && !suser())
			error = EACCES;
		else
			p->priority = priority;
	}
out:
	unlock_kernel();
	return -error;
}

/*
 * Ugh. To avoid negative return values, "getpriority()" will
 * not return the normal nice-value, but a value that has been
 * offset by 20 (ie it returns 0..40 instead of -20..20)
 */
asmlinkage int sys_getpriority(int which, int who)
{
	struct task_struct *p;
	long max_prio = -ESRCH;
	int ret = -EINVAL;

	lock_kernel();
	if (which > 2 || which < 0)
		goto out;

	for_each_task (p) {
		if (!proc_sel(p, which, who))
			continue;
		if (p->priority > max_prio)
			max_prio = p->priority;
	}

	/* scale the priority from timeslice to 0..40 */
	if (max_prio > 0)
		max_prio = (max_prio * 20 + DEF_PRIORITY/2) / DEF_PRIORITY;
	ret = max_prio;
out:
	unlock_kernel();
	return ret;
}

#ifndef __alpha__

/*
 * Why do these exist?  Binary compatibility with some other standard?
 * If so, maybe they should be moved into the appropriate arch
 * directory.
 */

asmlinkage int sys_profil(void)
{
	return -ENOSYS;
}

asmlinkage int sys_ftime(void)
{
	return -ENOSYS;
}

asmlinkage int sys_break(void)
{
	return -ENOSYS;
}

asmlinkage int sys_stty(void)
{
	return -ENOSYS;
}

asmlinkage int sys_gtty(void)
{
	return -ENOSYS;
}

asmlinkage int sys_prof(void)
{
	return -ENOSYS;
}

#endif

extern void hard_reset_now(void);
#ifdef __sparc__
extern void halt_now(void);
#endif
extern asmlinkage int sys_kill(int, int);

/*
 * 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.
 */
asmlinkage int sys_reboot(int magic, int magic_too, int flag)
{
	if (!suser())
		return -EPERM;
	if (magic != 0xfee1dead || 
	    (magic_too != 672274793 && magic_too != 85072278))
		return -EINVAL;


	if (flag == 0x01234567)
	{
		/* SMP: We need to lock during the shutdown still */
		lock_kernel();
		notifier_call_chain(&boot_notifier_list, SYS_DOWN, NULL);
		hard_reset_now();
	}
	else if (flag == 0x89ABCDEF)
		C_A_D = 1;
	else if (!flag)
		C_A_D = 0;
	else if (flag == 0xCDEF0123) {
		/* SMP: We need to lock during the shutdown still */
		lock_kernel();
		printk(KERN_EMERG "System halted\n");
#ifdef __sparc__
		halt_now();
#endif	
		sys_kill(-1, SIGKILL);
#if defined(CONFIG_APM) && defined(CONFIG_APM_POWER_OFF)
		apm_set_power_state(APM_STATE_OFF);
#endif
		notifier_call_chain(&boot_notifier_list, SYS_HALT, NULL);
		do_exit(0);
	} else
		return -EINVAL;
	return 0;
}

/*
 * 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)
{
	if (C_A_D)
	{
		notifier_call_chain(&boot_notifier_list, SYS_DOWN, NULL);
		hard_reset_now();
	}
	else
		kill_proc(1, 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 w/ Saved ID's. 
 */
asmlinkage int sys_setregid(gid_t rgid, gid_t egid)
{
	int old_rgid = current->gid;
	int old_egid = current->egid;
	int err = -EPERM;

	lock_kernel();
	if (rgid != (gid_t) -1) {
		if ((old_rgid == rgid) ||
		    (current->egid==rgid) ||
		    suser())
			current->gid = rgid;
		else
			goto out;
	}
	if (egid != (gid_t) -1) {
		if ((old_rgid == egid) ||
		    (current->egid == egid) ||
		    (current->sgid == egid) ||
		    suser())
			current->fsgid = current->egid = egid;
		else {
			current->gid = old_rgid;
			goto out;
		}
	}
	if (rgid != (gid_t) -1 ||
	    (egid != (gid_t) -1 && egid != old_rgid))
		current->sgid = current->egid;
	current->fsgid = current->egid;
	if (current->egid != old_egid)
		current->dumpable = 0;
	err = 0;
out:
	unlock_kernel();
	return err;
}

/*
 * setgid() is implemented like SysV w/ SAVED_IDS 
 */
asmlinkage int sys_setgid(gid_t gid)
{
	int old_egid = current->egid;
	int err = -EPERM;

	lock_kernel();
	if (suser())
		current->gid = current->egid = current->sgid = current->fsgid = gid;
	else if ((gid == current->gid) || (gid == current->sgid))
		current->egid = current->fsgid = gid;
	else
		goto out;
	err = 0;
	if (current->egid != old_egid)
		current->dumpable = 0;
out:
	unlock_kernel();
	return err;
}
  
static char acct_active = 0;
static struct file acct_file;

int acct_process(long exitcode)
{
   struct acct ac;
   unsigned short fs;

   if (acct_active) {
      strncpy(ac.ac_comm, current->comm, ACCT_COMM);
      ac.ac_comm[ACCT_COMM-1] = '\0';
      ac.ac_utime = current->utime;
      ac.ac_stime = current->stime;
      ac.ac_btime = CT_TO_SECS(current->start_time) + (xtime.tv_sec - (jiffies / HZ));
      ac.ac_etime = CURRENT_TIME - ac.ac_btime;
      ac.ac_uid   = current->uid;
      ac.ac_gid   = current->gid;
      ac.ac_tty   = (current)->tty == NULL ? -1 :
	  kdev_t_to_nr(current->tty->device);
      ac.ac_flag  = 0;
      if (current->flags & PF_FORKNOEXEC)
         ac.ac_flag |= AFORK;
      if (current->flags & PF_SUPERPRIV)
         ac.ac_flag |= ASU;
      if (current->flags & PF_DUMPCORE)
         ac.ac_flag |= ACORE;
      if (current->flags & PF_SIGNALED)
         ac.ac_flag |= AXSIG;
      ac.ac_minflt = current->min_flt;
      ac.ac_majflt = current->maj_flt;
      ac.ac_exitcode = exitcode;

      /* Kernel segment override */
      fs = get_fs();
      set_fs(KERNEL_DS);

      acct_file.f_op->write(acct_file.f_inode, &acct_file,
                             (char *)&ac, sizeof(struct acct));

      set_fs(fs);
   }
   return 0;
}

asmlinkage int sys_acct(const char *name)
{
	struct inode *inode = (struct inode *)0;
	char *tmp;
	int error = -EPERM;

	lock_kernel();
	if (!suser())
		goto out;

	if (name == (char *)0) {
		if (acct_active) {
			if (acct_file.f_op->release)
				acct_file.f_op->release(acct_file.f_inode, &acct_file);

			if (acct_file.f_inode != (struct inode *) 0)
				iput(acct_file.f_inode);

			acct_active = 0;
		}
		error = 0;
	} else {
		error = -EBUSY;
		if (!acct_active) {
			if ((error = getname(name, &tmp)) != 0)
				goto out;

			error = open_namei(tmp, O_RDWR, 0600, &inode, 0);
			putname(tmp);
			if (error)
				goto out;

			error = -EACCES;
			if (!S_ISREG(inode->i_mode)) {
				iput(inode);
				goto out;
			}

			error = -EIO;
			if (!inode->i_op || !inode->i_op->default_file_ops || 
			    !inode->i_op->default_file_ops->write) {
				iput(inode);
				goto out;
			}

			acct_file.f_mode = 3;
			acct_file.f_flags = 0;
			acct_file.f_count = 1;
			acct_file.f_inode = inode;
			acct_file.f_pos = inode->i_size;
			acct_file.f_reada = 0;
			acct_file.f_op = inode->i_op->default_file_ops;

			if(acct_file.f_op->open)
				if(acct_file.f_op->open(acct_file.f_inode, &acct_file)) {
					iput(inode);
					goto out;
				}

			acct_active = 1;
			error = 0;
		}
	}
out:
	unlock_kernel();
	return error;
}

#ifndef __alpha__

/*
 * Why do these exist?  Binary compatibility with some other standard?
 * If so, maybe they should be moved into the appropriate arch
 * directory.
 */

asmlinkage int sys_phys(void)
{
	return -ENOSYS;
}

asmlinkage int sys_lock(void)
{
	return -ENOSYS;
}

asmlinkage int sys_mpx(void)
{
	return -ENOSYS;
}

asmlinkage int sys_ulimit(void)
{
	return -ENOSYS;
}

asmlinkage int sys_old_syscall(void)
{
	return -ENOSYS;
}

#endif

/*
 * 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 w/ Saved ID's. 
 */
asmlinkage int sys_setreuid(uid_t ruid, uid_t euid)
{
	int old_ruid;
	int old_euid;
	int err = -EPERM;

	lock_kernel();
	old_ruid = current->uid;
	old_euid = current->euid;
	if (ruid != (uid_t) -1) {
		if ((old_ruid == ruid) || 
		    (current->euid==ruid) ||
		    suser())
			current->uid = ruid;
		else
			goto out;
	}
	if (euid != (uid_t) -1) {
		if ((old_ruid == euid) ||
		    (current->euid == euid) ||
		    (current->suid == euid) ||
		    suser())
			current->fsuid = current->euid = euid;
		else {
			current->uid = old_ruid;
			goto out;
		}
	}
	if (ruid != (uid_t) -1 ||
	    (euid != (uid_t) -1 && euid != old_ruid))
		current->suid = current->euid;
	current->fsuid = current->euid;
	if (current->euid != old_euid)
		current->dumpable = 0;
	err = 0;
out:
	unlock_kernel();
	return err;
}

/*
 * setuid() is implemented like SysV w/ 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.  
 */
asmlinkage int sys_setuid(uid_t uid)
{
	int old_euid = current->euid;
	int retval = 0;

	lock_kernel();
	if (suser())
		current->uid = current->euid = current->suid = current->fsuid = uid;
	else if ((uid == current->uid) || (uid == current->suid))
		current->fsuid = current->euid = uid;
	else {
		retval = -EPERM;
		goto out;
	}
	if (current->euid != old_euid)
		current->dumpable = 0;
out:
	unlock_kernel();
	return retval;
}


/*
 * This function implementes a generic ability to update ruid, euid,
 * and suid.  This allows you to implement the 4.4 compatible seteuid().
 */
asmlinkage int sys_setresuid(uid_t ruid, uid_t euid, uid_t suid)
{
	uid_t old_ruid, old_euid, old_suid;
	int err = -EPERM;

	lock_kernel();
	old_ruid = current->uid;
	old_euid = current->euid;
	old_suid = current->suid;

	if ((ruid != (uid_t) -1) && (ruid != current->uid) &&
	    (ruid != current->euid) && (ruid != current->suid))
		goto out;
	if ((euid != (uid_t) -1) && (euid != current->uid) &&
	    (euid != current->euid) && (euid != current->suid))
		goto out;
	if ((suid != (uid_t) -1) && (suid != current->uid) &&
	    (suid != current->euid) && (suid != current->suid))
		goto out;
	if (ruid != (uid_t) -1)
		current->uid = ruid;
	if (euid != (uid_t) -1)
		current->euid = euid;
	if (suid != (uid_t) -1)
		current->suid = suid;
	err = 0;
out:
	unlock_kernel();
	return err;
}

asmlinkage int sys_getresuid(uid_t *ruid, uid_t *euid, uid_t *suid)
{
	int retval;

	lock_kernel();
	if (!(retval = put_user(current->uid, ruid)) &&
	    !(retval = put_user(current->euid, euid)))
		retval = put_user(current->suid, suid);
	unlock_kernel();
	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..
 */
asmlinkage int sys_setfsuid(uid_t uid)
{
	int old_fsuid;

	lock_kernel();
	old_fsuid = current->fsuid;
	if (uid == current->uid || uid == current->euid ||
	    uid == current->suid || uid == current->fsuid || suser())
		current->fsuid = uid;
	if (current->fsuid != old_fsuid)
		current->dumpable = 0;
	unlock_kernel();
	return old_fsuid;
}

/*
 * Samma på svenska..
 */
asmlinkage int sys_setfsgid(gid_t gid)
{
	int old_fsgid;

	lock_kernel();
	old_fsgid = current->fsgid;
	if (gid == current->gid || gid == current->egid ||
	    gid == current->sgid || gid == current->fsgid || suser())
		current->fsgid = gid;
	if (current->fsgid != old_fsgid)
		current->dumpable = 0;
	unlock_kernel();
	return old_fsgid;
}

asmlinkage long sys_times(struct tms * tbuf)
{
	/*
	 *	In the SMP world we might just be unlucky and have one of
	 *	the times increment as we use it. Since the value is an
	 *	atomically safe type this is just fine. Conceptually its
	 *	as if the syscall took an instant longer to occur.
	 */
	if (tbuf) 
	{
		if(put_user(current->utime,&tbuf->tms_utime)||
		   put_user(current->stime,&tbuf->tms_stime) ||
		   put_user(current->cutime,&tbuf->tms_cutime) ||
		   put_user(current->cstime,&tbuf->tms_cstime))
			return -EFAULT;
	}
	return jiffies;
}

/*
 * 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
 */

asmlinkage int sys_setpgid(pid_t pid, pid_t pgid)
{
	struct task_struct * p;
	int err = -EINVAL;

	lock_kernel();
	if (!pid)
		pid = current->pid;
	if (!pgid)
		pgid = pid;
	if (pgid < 0)
		goto out;
	for_each_task(p) {
		if (p->pid == pid)
			goto found_task;
	}
	err = -ESRCH;
	goto out;

found_task:
	err = -ESRCH;
	if (p->p_pptr == current || p->p_opptr == current) {
		err = -EPERM;
		if (p->session != current->session)
			goto out;
		err = -EACCES;
		if (p->did_exec)
			goto out;
	} else if (p != current)
		goto out;
	err = -EPERM;
	if (p->leader)
		goto out;
	if (pgid != pid) {
		struct task_struct * tmp;
		for_each_task (tmp) {
			if (tmp->pgrp == pgid &&
			    tmp->session == current->session)
				goto ok_pgid;
		}
		goto out;
	}

ok_pgid:
	p->pgrp = pgid;
	err = 0;
out:
	unlock_kernel();
	return err;
}

asmlinkage int sys_getpgid(pid_t pid)
{
	struct task_struct * p;
	int ret;

	lock_kernel();
	if (!pid) {
		ret = current->pgrp;
	} else {
		for_each_task(p) {
			if (p->pid == pid) {
				ret = p->pgrp;
				goto out;
			}
		}
		ret = -ESRCH;
	}
out:
	unlock_kernel();
	return ret;
}

asmlinkage int sys_getpgrp(void)
{
	/* SMP - assuming writes are word atomic this is fine */
	return current->pgrp;
}

asmlinkage int sys_getsid(pid_t pid)
{
	struct task_struct * p;
	int ret;

	/* SMP: The 'self' case requires no lock */
	if (!pid) {
		ret = current->session;
	} else {
		/* Walking the process table needs locks */
		lock_kernel();
		for_each_task(p) {
			if (p->pid == pid) {
				ret = p->session;
				goto out;
			}
		}
		ret = -ESRCH;
out:
		unlock_kernel();
	}
	return ret;
}

asmlinkage int sys_setsid(void)
{
	struct task_struct * p;
	int err = -EPERM;

	lock_kernel();
	for_each_task(p) {
		if (p->pgrp == current->pid)
		        goto out;
	}

	current->leader = 1;
	current->session = current->pgrp = current->pid;
	current->tty = NULL;
	current->tty_old_pgrp = 0;
	err = current->pgrp;
out:
	unlock_kernel();
	return err;
}

/*
 * Supplementary group ID's
 */
asmlinkage int sys_getgroups(int gidsetsize, gid_t *grouplist)
{
	int i;
	
	/*
	 *	SMP: Nobody else can change our grouplist. Thus we are
	 *	safe.
	 */

	if (gidsetsize < 0)
		return -EINVAL;
	i = current->ngroups;
	if (gidsetsize) {
		if (i > gidsetsize)
		        return -EINVAL;
		if (copy_to_user(grouplist, current->groups, sizeof(gid_t)*i))
			return -EFAULT;
	}
	return i;
}

/*
 *	SMP: Our groups are not shared. We can copy to/from them safely
 *	without another task interfering.
 */
 
asmlinkage int sys_setgroups(int gidsetsize, gid_t *grouplist)
{
	if (!suser())
		return -EPERM;
	if ((unsigned) gidsetsize > NGROUPS)
		return -EINVAL;
	if(copy_from_user(current->groups, grouplist, gidsetsize * sizeof(gid_t)))
		return -EFAULT;
	current->ngroups = gidsetsize;
	return 0;
}

int in_group_p(gid_t grp)
{
	if (grp != current->fsgid) {
		int i = current->ngroups;
		if (i) {
			gid_t *groups = current->groups;
			do {
				if (*groups == grp)
					goto out;
				groups++;
				i--;
			} while (i);
		}
		return 0;
	}
out:
	return 1;
}

asmlinkage int sys_newuname(struct new_utsname * name)
{
	int err = -EFAULT;

	lock_kernel();
	if (!name)
		goto out;
	if (copy_to_user(name,&system_utsname,sizeof *name))
		goto out;
	err = 0;
out:
	unlock_kernel();
	return err;
}

#ifndef __alpha__

/*
 * Move these to arch dependent dir since they are for
 * backward compatibility only?
 */
asmlinkage int sys_uname(struct old_utsname * name)
{
	int error = -EFAULT;

	lock_kernel();
	if (name && !copy_to_user(name, &system_utsname, sizeof (*name)))
		error = 0;
	unlock_kernel();
	return error;
}

asmlinkage int sys_olduname(struct oldold_utsname * name)
{
	int error = -EFAULT;

	lock_kernel();
	if (!name)
		goto out;
	error = copy_to_user(&name->sysname,&system_utsname.sysname,__OLD_UTS_LEN);
	if (!error)
		error = put_user(0,name->sysname+__OLD_UTS_LEN);
	if (!error)
		error = copy_to_user(&name->nodename,&system_utsname.nodename,__OLD_UTS_LEN);
	if (!error)
		error = put_user(0,name->nodename+__OLD_UTS_LEN);
	if (!error)
		error = copy_to_user(&name->release,&system_utsname.release,__OLD_UTS_LEN);
	if (!error)
		error = put_user(0,name->release+__OLD_UTS_LEN);
	if (!error)
		error = copy_to_user(&name->version,&system_utsname.version,__OLD_UTS_LEN);
	if (!error)
		error = put_user(0,name->version+__OLD_UTS_LEN);
	if (!error)
		error = copy_to_user(&name->machine,&system_utsname.machine,__OLD_UTS_LEN);
	if (!error)
		error = put_user(0,name->machine+__OLD_UTS_LEN);
	error = error ? -EFAULT : 0;
out:
	unlock_kernel();
	return error;
}

#endif

asmlinkage int sys_sethostname(char *name, int len)
{
	int error = -EPERM;

	lock_kernel();
	if (!suser())
		goto out;
	error = -EINVAL;
	if (len < 0 || len > __NEW_UTS_LEN)
		goto out;
	error = copy_from_user(system_utsname.nodename, name, len);
	if (error) {
		error = -EFAULT;
		goto out;
	}
	system_utsname.nodename[len] = 0;
out:
	unlock_kernel();
	return error;
}

asmlinkage int sys_gethostname(char *name, int len)
{
	int i, err = -EINVAL;

	lock_kernel();
	if (len < 0)
		goto out;
	i = 1+strlen(system_utsname.nodename);
	if (i > len)
		i = len;
	err = copy_to_user(name, system_utsname.nodename, i) ? -EFAULT : 0;
out:
	unlock_kernel();
	return err;
}

/*
 * Only setdomainname; getdomainname can be implemented by calling
 * uname()
 */
asmlinkage int sys_setdomainname(char *name, int len)
{
	int error = -EPERM;
	
	lock_kernel();
	if (!suser())
		goto out;
	error = -EINVAL;
	if (len < 0 || len > __NEW_UTS_LEN)
		goto out;
	error = copy_from_user(system_utsname.domainname, name, len);
	if (error)
		error = -EFAULT;
	else
		system_utsname.domainname[len] = 0;
out:
	unlock_kernel();
	return error;
}

asmlinkage int sys_getrlimit(unsigned int resource, struct rlimit *rlim)
{
	int error;

	lock_kernel();
	if (resource >= RLIM_NLIMITS)
		error = -EINVAL;
	else
		error = copy_to_user(rlim, current->rlim + resource, sizeof(*rlim))
			? -EFAULT : 0;
	unlock_kernel();
	return error;
}

asmlinkage int sys_setrlimit(unsigned int resource, struct rlimit *rlim)
{
	struct rlimit new_rlim, *old_rlim;
	int err = -EINVAL;

	lock_kernel();
	if (resource >= RLIM_NLIMITS)
		goto out;
	err = copy_from_user(&new_rlim, rlim, sizeof(*rlim));
	if (err) {
		err = -EFAULT;
		goto out;
	}
	old_rlim = current->rlim + resource;
	err = -EPERM;
	if (((new_rlim.rlim_cur > old_rlim->rlim_max) ||
	     (new_rlim.rlim_max > old_rlim->rlim_max)) &&
	    !suser())
		goto out;
	if (resource == RLIMIT_NOFILE) {
		if (new_rlim.rlim_cur > NR_OPEN || new_rlim.rlim_max > NR_OPEN)
			goto out;
	}
	*old_rlim = new_rlim;
	err = 0;
out:
	unlock_kernel();
	return err;
}

/*
 * 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).
 */
int getrusage(struct task_struct *p, int who, struct rusage *ru)
{
	struct rusage r;
	int err;

	lock_kernel();
	memset((char *) &r, 0, sizeof(r));
	switch (who) {
		case RUSAGE_SELF:
			r.ru_utime.tv_sec = CT_TO_SECS(p->utime);
			r.ru_utime.tv_usec = CT_TO_USECS(p->utime);
			r.ru_stime.tv_sec = CT_TO_SECS(p->stime);
			r.ru_stime.tv_usec = CT_TO_USECS(p->stime);
			r.ru_minflt = p->min_flt;
			r.ru_majflt = p->maj_flt;
			r.ru_nswap = p->nswap;
			break;
		case RUSAGE_CHILDREN:
			r.ru_utime.tv_sec = CT_TO_SECS(p->cutime);
			r.ru_utime.tv_usec = CT_TO_USECS(p->cutime);
			r.ru_stime.tv_sec = CT_TO_SECS(p->cstime);
			r.ru_stime.tv_usec = CT_TO_USECS(p->cstime);
			r.ru_minflt = p->cmin_flt;
			r.ru_majflt = p->cmaj_flt;
			r.ru_nswap = p->cnswap;
			break;
		default:
			r.ru_utime.tv_sec = CT_TO_SECS(p->utime + p->cutime);
			r.ru_utime.tv_usec = CT_TO_USECS(p->utime + p->cutime);
			r.ru_stime.tv_sec = CT_TO_SECS(p->stime + p->cstime);
			r.ru_stime.tv_usec = CT_TO_USECS(p->stime + p->cstime);
			r.ru_minflt = p->min_flt + p->cmin_flt;
			r.ru_majflt = p->maj_flt + p->cmaj_flt;
			r.ru_nswap = p->nswap + p->cnswap;
			break;
	}
	err = copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0;
	unlock_kernel();
	return err;
}

asmlinkage int sys_getrusage(int who, struct rusage *ru)
{
	int err = -EINVAL;

	lock_kernel();
	if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN)
		goto out;
	err = getrusage(current, who, ru);
out:
	unlock_kernel();
	return err;
}

asmlinkage int sys_umask(int mask)
{
	/* The xchg() isn't SMP-safe on x86 right now.. */
	mask = xchg(&current->fs->umask, mask & S_IRWXUGO);
	return mask;
}
