/*
 *  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>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <linux/prctl.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;


/*
 *      Notifier list for kernel code which wants to be called
 *      at shutdown. This is used to stop any idling DMA operations
 *      and the like. 
 */

struct notifier_block *reboot_notifier_list = NULL;

int register_reboot_notifier(struct notifier_block * nb)
{
        return notifier_chain_register(&reboot_notifier_list, nb);
}

int unregister_reboot_notifier(struct notifier_block * nb)
{
        return notifier_chain_unregister(&reboot_notifier_list, nb);
}



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;
        unsigned int priority;
        int error;

        if (which > 2 || which < 0)
                return -EINVAL;

        /* 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;
        }

        read_lock(&tasklist_lock);
        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;
        }
        read_unlock(&tasklist_lock);

        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;

        if (which > 2 || which < 0)
                return -EINVAL;

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

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


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 magic1, int magic2, int cmd, void * arg)
{
        char buffer[256];

        /* We only trust the superuser with rebooting the system. */
        if (!suser())
                return -EPERM;

        /* For safety, we require "magic" arguments. */
        if (magic1 != LINUX_REBOOT_MAGIC1 ||
            (magic2 != LINUX_REBOOT_MAGIC2 && magic2 != LINUX_REBOOT_MAGIC2A))
                return -EINVAL;

        lock_kernel();
        switch (cmd) {
        case LINUX_REBOOT_CMD_RESTART:
                notifier_call_chain(&reboot_notifier_list, SYS_RESTART, NULL);
                printk(KERN_EMERG "Restarting system.\n");
                machine_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:
                notifier_call_chain(&reboot_notifier_list, SYS_HALT, NULL);
                printk(KERN_EMERG "System halted.\n");
                machine_halt();
                do_exit(0);
                break;

        case LINUX_REBOOT_CMD_POWER_OFF:
                notifier_call_chain(&reboot_notifier_list, SYS_POWER_OFF, NULL);
                printk(KERN_EMERG "Power down.\n");
                machine_power_off();
                do_exit(0);
                break;

        case LINUX_REBOOT_CMD_RESTART2:
                if (strncpy_from_user(&buffer[0], (char *)arg, sizeof(buffer) - 1) < 0) {
                        unlock_kernel();
                        return -EFAULT;
                }
                buffer[sizeof(buffer) - 1] = '\0';

                notifier_call_chain(&reboot_notifier_list, SYS_RESTART, buffer);
                printk(KERN_EMERG "Restarting system with command '%s'.\n", buffer);
                machine_restart(buffer);
                break;

        default:
                unlock_kernel();
                return -EINVAL;
                break;
        };
        unlock_kernel();
        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(&reboot_notifier_list, SYS_RESTART, NULL);
                machine_restart(NULL);
        } 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. 
 *
 * SMP: There are not races, the gid's are checked only by filesystem
 *      operations (as far as semantic preservation is concerned).
 */
asmlinkage int sys_setregid(gid_t rgid, gid_t egid)
{
        int old_rgid = current->gid;
        int old_egid = current->egid;

        if (rgid != (gid_t) -1) {
                if ((old_rgid == rgid) ||
                    (current->egid==rgid) ||
                    suser())
                        current->gid = rgid;
                else
                        return -EPERM;
        }
        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;
                        return -EPERM;
                }
        }
        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;
        return 0;
}

/*
 * setgid() is implemented like SysV w/ SAVED_IDS 
 *
 * SMP: Same implicit races as above.
 */
asmlinkage int sys_setgid(gid_t gid)
{
        int old_egid = current->egid;

        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
                return -EPERM;

        if (current->egid != old_egid)
                current->dumpable = 0;
        return 0;
}
  
static char acct_active = 0;
static struct file acct_file;

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

   if (acct_active) {
      strncpy(ac.ac_comm, current->comm, ACCT_COMM);
      ac.ac_comm[ACCT_COMM-1] = '\0';
      ac.ac_utime = current->times.tms_utime;
      ac.ac_stime = current->times.tms_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_dentry->d_inode, &acct_file,
                             (char *)&ac, sizeof(struct acct));
      set_fs(fs);
   }
   return 0;
}

asmlinkage int sys_acct(const char *name)
{
        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_dentry->d_inode, &acct_file);

                        if (acct_file.f_dentry != NULL)
                                dput(acct_file.f_dentry);

                        acct_active = 0;
                }
                error = 0;
        } else {
                error = -EBUSY;
                if (!acct_active) {
                        struct dentry *dentry;
                        struct inode *inode;
                        char *tmp;

                        tmp = getname(name);
                        error = PTR_ERR(tmp);
                        if (IS_ERR(tmp))
                                goto out;

                        dentry = open_namei(tmp, O_RDWR, 0600);
                        putname(tmp);

                        error = PTR_ERR(dentry);
                        if (IS_ERR(dentry))
                                goto out;
                        inode = dentry->d_inode;

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

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

                        acct_file.f_mode = 3;
                        acct_file.f_flags = 0;
                        acct_file.f_count = 1;
                        acct_file.f_dentry = dentry;
                        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) {
                                error = acct_file.f_op->open(inode, &acct_file);
                                if (error) {
                                        dput(dentry);
                                        goto out;
                                }
                        }

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


/*
 * 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, old_euid, new_ruid;

        new_ruid = old_ruid = current->uid;
        old_euid = current->euid;
        if (ruid != (uid_t) -1) {
                if ((old_ruid == ruid) || 
                    (current->euid==ruid) ||
                    suser())
                        new_ruid = ruid;
                else
                        return -EPERM;
        }
        if (euid != (uid_t) -1) {
                if ((old_ruid == euid) ||
                    (current->euid == euid) ||
                    (current->suid == euid) ||
                    suser())
                        current->fsuid = current->euid = euid;
                else
                        return -EPERM;
        }
        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;

        if(new_ruid != old_ruid) {
                /* What if a process setreuid()'s and this brings the
                 * new uid over his NPROC rlimit?  We can check this now
                 * cheaply with the new uid cache, so if it matters
                 * we should be checking for it.  -DaveM
                 */
                charge_uid(current, -1);
                current->uid = new_ruid;
                if(new_ruid)
                        charge_uid(current, 1);
        }
        return 0;
}

/*
 * 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 old_ruid, new_ruid;

        old_ruid = new_ruid = current->uid;
        if (suser())
                new_ruid = current->euid = current->suid = current->fsuid = uid;
        else if ((uid == current->uid) || (uid == current->suid))
                current->fsuid = current->euid = uid;
        else
                return -EPERM;

        if (current->euid != old_euid)
                current->dumpable = 0;

        if(new_ruid != old_ruid) {
                /* See comment above about NPROC rlimit issues... */
                charge_uid(current, -1);
                current->uid = new_ruid;
                if(new_ruid)
                        charge_uid(current, 1);
        }
        return 0;
}


/*
 * 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)
{
        if (current->uid != 0 && current->euid != 0 && current->suid != 0) {
                if ((ruid != (uid_t) -1) && (ruid != current->uid) &&
                    (ruid != current->euid) && (ruid != current->suid))
                        return -EPERM;
                if ((euid != (uid_t) -1) && (euid != current->uid) &&
                    (euid != current->euid) && (euid != current->suid))
                        return -EPERM;
                if ((suid != (uid_t) -1) && (suid != current->uid) &&
                    (suid != current->euid) && (suid != current->suid))
                        return -EPERM;
        }
        if (ruid != (uid_t) -1) {
                /* See above commentary about NPROC rlimit issues here. */
                charge_uid(current, -1);
                current->uid = ruid;
                if(ruid)
                        charge_uid(current, 1);
        }
        if (euid != (uid_t) -1) {
                if (euid != current->euid)
                        current->dumpable = 0;
                current->euid = euid;
                current->fsuid = euid;
        }
        if (suid != (uid_t) -1)
                current->suid = suid;
        return 0;
}

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

        if (!(retval = put_user(current->uid, ruid)) &&
            !(retval = put_user(current->euid, euid)))
                retval = put_user(current->suid, suid);

        return retval;
}

/*
 * Same as above, but for rgid, egid, sgid.
 */
asmlinkage int sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid)
{
        if (current->uid != 0 && current->euid != 0 && current->suid != 0) {
                if ((rgid != (gid_t) -1) && (rgid != current->gid) &&
                    (rgid != current->egid) && (rgid != current->sgid))
                        return -EPERM;
                if ((egid != (gid_t) -1) && (egid != current->gid) &&
                    (egid != current->egid) && (egid != current->sgid))
                        return -EPERM;
                if ((sgid != (gid_t) -1) && (sgid != current->gid) &&
                    (sgid != current->egid) && (sgid != current->sgid))
                        return -EPERM;
        }
        if (rgid != (gid_t) -1)
                current->gid = rgid;
        if (egid != (gid_t) -1) {
                if (egid != current->egid)
                        current->dumpable = 0;
                current->egid = egid;
                current->fsgid = egid;
        }
        if (sgid != (gid_t) -1)
                current->sgid = sgid;
        return 0;
}

asmlinkage int sys_getresgid(gid_t *rgid, gid_t *egid, gid_t *sgid)
{
        int retval;

        if (!(retval = put_user(current->gid, rgid)) &&
            !(retval = put_user(current->egid, egid)))
                retval = put_user(current->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..
 */
asmlinkage int sys_setfsuid(uid_t uid)
{
        int old_fsuid;

        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;

        return old_fsuid;
}

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

        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;

        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 (copy_to_user(tbuf, &current->times, sizeof(struct tms)))
                        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;

        if (!pid)
                pid = current->pid;
        if (!pgid)
                pgid = pid;
        if (pgid < 0)
                return -EINVAL;

        if((p = find_task_by_pid(pid)) == NULL)
                return -ESRCH;

        /* From this point forward we keep holding onto the tasklist lock
         * so that our parent does not change from under us. -DaveM
         */
        read_lock(&tasklist_lock);
        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:
        /* All paths lead to here, thus we are safe. -DaveM */
        read_unlock(&tasklist_lock);
        return err;
}

asmlinkage int sys_getpgid(pid_t pid)
{
        if (!pid) {
                return current->pgrp;
        } else {
                struct task_struct *p = find_task_by_pid(pid);

                if(p)
                        return p->pgrp;
                else
                        return -ESRCH;
        }
}

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

asmlinkage int sys_getsid(pid_t pid)
{
        if (!pid) {
                return current->session;
        } else {
                struct task_struct *p = find_task_by_pid(pid);

                if(p)
                        return p->session;
                else
                        return -ESRCH;
        }
}

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

        read_lock(&tasklist_lock);
        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:
        read_unlock(&tasklist_lock);
        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)
{
        if (!name)
                return -EFAULT;
        if (copy_to_user(name,&system_utsname,sizeof *name))
                return -EFAULT;
        return 0;
}

asmlinkage int sys_sethostname(char *name, int len)
{
        if (!suser())
                return -EPERM;
        if (len < 0 || len > __NEW_UTS_LEN)
                return -EINVAL;
        if(copy_from_user(system_utsname.nodename, name, len))
                return -EFAULT;
        system_utsname.nodename[len] = 0;
#ifdef CONFIG_TRANS_NAMES
        translations_dirty = 1;
#endif
        return 0;
}

asmlinkage int sys_gethostname(char *name, int len)
{
        int i;

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

/*
 * Only setdomainname; getdomainname can be implemented by calling
 * uname()
 */
asmlinkage int sys_setdomainname(char *name, int len)
{
        if (!suser())
                return -EPERM;
        if (len < 0 || len > __NEW_UTS_LEN)
                return -EINVAL;
        if(copy_from_user(system_utsname.domainname, name, len))
                return -EFAULT;
        system_utsname.domainname[len] = 0;
#ifdef CONFIG_TRANS_NAMES
        translations_dirty = 1;
#endif
        return 0;
}

asmlinkage int sys_getrlimit(unsigned int resource, struct rlimit *rlim)
{
        if (resource >= RLIM_NLIMITS)
                return -EINVAL;
        else
                return copy_to_user(rlim, current->rlim + resource, sizeof(*rlim))
                        ? -EFAULT : 0;
}

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

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

/*
 * 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).
 *
 * This is SMP safe.  Either we are called from sys_getrusage on ourselves
 * below (we know we aren't going to exit/disappear and only we change our
 * rusage counters), or we are called from wait4() on a process which is
 * either stopped or zombied.  In the zombied case the task won't get
 * reaped till shortly after the call to getrusage(), in both cases the
 * task being examined is in a frozen state so the counters won't change.
 */
int getrusage(struct task_struct *p, int who, struct rusage *ru)
{
        struct rusage r;

        memset((char *) &r, 0, sizeof(r));
        switch (who) {
                case RUSAGE_SELF:
                        r.ru_utime.tv_sec = CT_TO_SECS(p->times.tms_utime);
                        r.ru_utime.tv_usec = CT_TO_USECS(p->times.tms_utime);
                        r.ru_stime.tv_sec = CT_TO_SECS(p->times.tms_stime);
                        r.ru_stime.tv_usec = CT_TO_USECS(p->times.tms_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->times.tms_cutime);
                        r.ru_utime.tv_usec = CT_TO_USECS(p->times.tms_cutime);
                        r.ru_stime.tv_sec = CT_TO_SECS(p->times.tms_cstime);
                        r.ru_stime.tv_usec = CT_TO_USECS(p->times.tms_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->times.tms_utime + p->times.tms_cutime);
                        r.ru_utime.tv_usec = CT_TO_USECS(p->times.tms_utime + p->times.tms_cutime);
                        r.ru_stime.tv_sec = CT_TO_SECS(p->times.tms_stime + p->times.tms_cstime);
                        r.ru_stime.tv_usec = CT_TO_USECS(p->times.tms_stime + p->times.tms_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;
        }
        return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0;
}

asmlinkage int sys_getrusage(int who, struct rusage *ru)
{
        if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN)
                return -EINVAL;

        return getrusage(current, who, ru);
}

asmlinkage int sys_umask(int mask)
{
        mask = xchg(&current->fs->umask, mask & S_IRWXUGO);
        return mask;
}
    
asmlinkage int sys_prctl(int option, unsigned long arg2, unsigned long arg3,
                         unsigned long arg4, unsigned long arg5)
{
        int error = 0;
        int sig;

        switch (option) {
                case PR_SET_PDEATHSIG:
                        sig = arg2;
                        if (sig > _NSIG) {
                                error = -EINVAL;
                                break;
                        }
                        current->pdeath_signal = sig;
                        break;
                default:
                        error = -EINVAL;
                        break;
        }
        return error;
}