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[/] [test_project/] [trunk/] [linux_sd_driver/] [kernel/] [sys.c] - Blame information for rev 62

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/*
 *  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/smp_lock.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <linux/prctl.h>
#include <linux/highuid.h>
#include <linux/fs.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/compat.h>
#include <linux/syscalls.h>
#include <linux/kprobes.h>
#include <linux/user_namespace.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
 
/*
 * 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);
 
static int set_one_prio(struct task_struct *p, int niceval, int error)
{
        int no_nice;
 
        if (p->uid != current->euid &&
                p->euid != current->euid && !capable(CAP_SYS_NICE)) {
                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;
}
 
asmlinkage long sys_setpriority(int which, int who, int niceval)
{
        struct task_struct *g, *p;
        struct user_struct *user;
        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;
 
        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_task(pgrp, PIDTYPE_PGID, p) {
                                error = set_one_prio(p, niceval, error);
                        } while_each_pid_task(pgrp, PIDTYPE_PGID, p);
                        break;
                case PRIO_USER:
                        user = current->user;
                        if (!who)
                                who = current->uid;
                        else
                                if ((who != current->uid) && !(user = find_user(who)))
                                        goto out_unlock;        /* No processes for this user */
 
                        do_each_thread(g, p)
                                if (p->uid == who)
                                        error = set_one_prio(p, niceval, error);
                        while_each_thread(g, p);
                        if (who != current->uid)
                                free_uid(user);         /* For find_user() */
                        break;
        }
out_unlock:
        read_unlock(&tasklist_lock);
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.
 */
asmlinkage long sys_getpriority(int which, int who)
{
        struct task_struct *g, *p;
        struct user_struct *user;
        long niceval, retval = -ESRCH;
        struct pid *pgrp;
 
        if (which > PRIO_USER || which < PRIO_PROCESS)
                return -EINVAL;
 
        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_task(pgrp, PIDTYPE_PGID, p) {
                                niceval = 20 - task_nice(p);
                                if (niceval > retval)
                                        retval = niceval;
                        } while_each_pid_task(pgrp, PIDTYPE_PGID, p);
                        break;
                case PRIO_USER:
                        user = current->user;
                        if (!who)
                                who = current->uid;
                        else
                                if ((who != current->uid) && !(user = find_user(who)))
                                        goto out_unlock;        /* No processes for this user */
 
                        do_each_thread(g, p)
                                if (p->uid == who) {
                                        niceval = 20 - task_nice(p);
                                        if (niceval > retval)
                                                retval = niceval;
                                }
                        while_each_thread(g, p);
                        if (who != current->uid)
                                free_uid(user);         /* for find_user() */
                        break;
        }
out_unlock:
        read_unlock(&tasklist_lock);
 
        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)
{
        machine_emergency_restart();
}
EXPORT_SYMBOL_GPL(emergency_restart);
 
static void kernel_restart_prepare(char *cmd)
{
        blocking_notifier_call_chain(&reboot_notifier_list, SYS_RESTART, cmd);
        system_state = SYSTEM_RESTART;
        device_shutdown();
        sysdev_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);
        machine_restart(cmd);
}
EXPORT_SYMBOL_GPL(kernel_restart);
 
/**
 *      kernel_kexec - reboot the system
 *
 *      Move into place and start executing a preloaded standalone
 *      executable.  If nothing was preloaded return an error.
 */
static void kernel_kexec(void)
{
#ifdef CONFIG_KEXEC
        struct kimage *image;
        image = xchg(&kexec_image, NULL);
        if (!image)
                return;
        kernel_restart_prepare(NULL);
        printk(KERN_EMERG "Starting new kernel\n");
        machine_shutdown();
        machine_kexec(image);
#endif
}
 
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;
        device_shutdown();
}
/**
 *      kernel_halt - halt the system
 *
 *      Shutdown everything and perform a clean system halt.
 */
void kernel_halt(void)
{
        kernel_shutdown_prepare(SYSTEM_HALT);
        sysdev_shutdown();
        printk(KERN_EMERG "System halted.\n");
        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();
        sysdev_shutdown();
        printk(KERN_EMERG "Power down.\n");
        machine_power_off();
}
EXPORT_SYMBOL_GPL(kernel_power_off);
/*
 * 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 long sys_reboot(int magic1, int magic2, unsigned int cmd, void __user * arg)
{
        char buffer[256];
 
        /* 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;
 
        lock_kernel();
        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();
                unlock_kernel();
                do_exit(0);
                break;
 
        case LINUX_REBOOT_CMD_POWER_OFF:
                kernel_power_off();
                unlock_kernel();
                do_exit(0);
                break;
 
        case LINUX_REBOOT_CMD_RESTART2:
                if (strncpy_from_user(&buffer[0], arg, sizeof(buffer) - 1) < 0) {
                        unlock_kernel();
                        return -EFAULT;
                }
                buffer[sizeof(buffer) - 1] = '\0';
 
                kernel_restart(buffer);
                break;
 
        case LINUX_REBOOT_CMD_KEXEC:
                kernel_kexec();
                unlock_kernel();
                return -EINVAL;
 
#ifdef CONFIG_HIBERNATION
        case LINUX_REBOOT_CMD_SW_SUSPEND:
                {
                        int ret = hibernate();
                        unlock_kernel();
                        return ret;
                }
#endif
 
        default:
                unlock_kernel();
                return -EINVAL;
        }
        unlock_kernel();
        return 0;
}
 
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).
 */
asmlinkage long sys_setregid(gid_t rgid, gid_t egid)
{
        int old_rgid = current->gid;
        int old_egid = current->egid;
        int new_rgid = old_rgid;
        int new_egid = old_egid;
        int retval;
 
        retval = security_task_setgid(rgid, egid, (gid_t)-1, LSM_SETID_RE);
        if (retval)
                return retval;
 
        if (rgid != (gid_t) -1) {
                if ((old_rgid == rgid) ||
                    (current->egid==rgid) ||
                    capable(CAP_SETGID))
                        new_rgid = rgid;
                else
                        return -EPERM;
        }
        if (egid != (gid_t) -1) {
                if ((old_rgid == egid) ||
                    (current->egid == egid) ||
                    (current->sgid == egid) ||
                    capable(CAP_SETGID))
                        new_egid = egid;
                else
                        return -EPERM;
        }
        if (new_egid != old_egid) {
                set_dumpable(current->mm, suid_dumpable);
                smp_wmb();
        }
        if (rgid != (gid_t) -1 ||
            (egid != (gid_t) -1 && egid != old_rgid))
                current->sgid = new_egid;
        current->fsgid = new_egid;
        current->egid = new_egid;
        current->gid = new_rgid;
        key_fsgid_changed(current);
        proc_id_connector(current, PROC_EVENT_GID);
        return 0;
}
 
/*
 * setgid() is implemented like SysV w/ SAVED_IDS
 *
 * SMP: Same implicit races as above.
 */
asmlinkage long sys_setgid(gid_t gid)
{
        int old_egid = current->egid;
        int retval;
 
        retval = security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_ID);
        if (retval)
                return retval;
 
        if (capable(CAP_SETGID)) {
                if (old_egid != gid) {
                        set_dumpable(current->mm, suid_dumpable);
                        smp_wmb();
                }
                current->gid = current->egid = current->sgid = current->fsgid = gid;
        } else if ((gid == current->gid) || (gid == current->sgid)) {
                if (old_egid != gid) {
                        set_dumpable(current->mm, suid_dumpable);
                        smp_wmb();
                }
                current->egid = current->fsgid = gid;
        }
        else
                return -EPERM;
 
        key_fsgid_changed(current);
        proc_id_connector(current, PROC_EVENT_GID);
        return 0;
}
 
static int set_user(uid_t new_ruid, int dumpclear)
{
        struct user_struct *new_user;
 
        new_user = alloc_uid(current->nsproxy->user_ns, new_ruid);
        if (!new_user)
                return -EAGAIN;
 
        if (atomic_read(&new_user->processes) >=
                                current->signal->rlim[RLIMIT_NPROC].rlim_cur &&
                        new_user != current->nsproxy->user_ns->root_user) {
                free_uid(new_user);
                return -EAGAIN;
        }
 
        switch_uid(new_user);
 
        if (dumpclear) {
                set_dumpable(current->mm, suid_dumpable);
                smp_wmb();
        }
        current->uid = new_ruid;
        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.
 */
asmlinkage long sys_setreuid(uid_t ruid, uid_t euid)
{
        int old_ruid, old_euid, old_suid, new_ruid, new_euid;
        int retval;
 
        retval = security_task_setuid(ruid, euid, (uid_t)-1, LSM_SETID_RE);
        if (retval)
                return retval;
 
        new_ruid = old_ruid = current->uid;
        new_euid = old_euid = current->euid;
        old_suid = current->suid;
 
        if (ruid != (uid_t) -1) {
                new_ruid = ruid;
                if ((old_ruid != ruid) &&
                    (current->euid != ruid) &&
                    !capable(CAP_SETUID))
                        return -EPERM;
        }
 
        if (euid != (uid_t) -1) {
                new_euid = euid;
                if ((old_ruid != euid) &&
                    (current->euid != euid) &&
                    (current->suid != euid) &&
                    !capable(CAP_SETUID))
                        return -EPERM;
        }
 
        if (new_ruid != old_ruid && set_user(new_ruid, new_euid != old_euid) < 0)
                return -EAGAIN;
 
        if (new_euid != old_euid) {
                set_dumpable(current->mm, suid_dumpable);
                smp_wmb();
        }
        current->fsuid = current->euid = new_euid;
        if (ruid != (uid_t) -1 ||
            (euid != (uid_t) -1 && euid != old_ruid))
                current->suid = current->euid;
        current->fsuid = current->euid;
 
        key_fsuid_changed(current);
        proc_id_connector(current, PROC_EVENT_UID);
 
        return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_RE);
}
 
 
 
/*
 * 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.
 */
asmlinkage long sys_setuid(uid_t uid)
{
        int old_euid = current->euid;
        int old_ruid, old_suid, new_suid;
        int retval;
 
        retval = security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_ID);
        if (retval)
                return retval;
 
        old_ruid = current->uid;
        old_suid = current->suid;
        new_suid = old_suid;
 
        if (capable(CAP_SETUID)) {
                if (uid != old_ruid && set_user(uid, old_euid != uid) < 0)
                        return -EAGAIN;
                new_suid = uid;
        } else if ((uid != current->uid) && (uid != new_suid))
                return -EPERM;
 
        if (old_euid != uid) {
                set_dumpable(current->mm, suid_dumpable);
                smp_wmb();
        }
        current->fsuid = current->euid = uid;
        current->suid = new_suid;
 
        key_fsuid_changed(current);
        proc_id_connector(current, PROC_EVENT_UID);
 
        return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_ID);
}
 
 
/*
 * This function implements a generic ability to update ruid, euid,
 * and suid.  This allows you to implement the 4.4 compatible seteuid().
 */
asmlinkage long sys_setresuid(uid_t ruid, uid_t euid, uid_t suid)
{
        int old_ruid = current->uid;
        int old_euid = current->euid;
        int old_suid = current->suid;
        int retval;
 
        retval = security_task_setuid(ruid, euid, suid, LSM_SETID_RES);
        if (retval)
                return retval;
 
        if (!capable(CAP_SETUID)) {
                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) {
                if (ruid != current->uid && set_user(ruid, euid != current->euid) < 0)
                        return -EAGAIN;
        }
        if (euid != (uid_t) -1) {
                if (euid != current->euid) {
                        set_dumpable(current->mm, suid_dumpable);
                        smp_wmb();
                }
                current->euid = euid;
        }
        current->fsuid = current->euid;
        if (suid != (uid_t) -1)
                current->suid = suid;
 
        key_fsuid_changed(current);
        proc_id_connector(current, PROC_EVENT_UID);
 
        return security_task_post_setuid(old_ruid, old_euid, old_suid, LSM_SETID_RES);
}
 
asmlinkage long sys_getresuid(uid_t __user *ruid, uid_t __user *euid, uid_t __user *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 long sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid)
{
        int retval;
 
        retval = security_task_setgid(rgid, egid, sgid, LSM_SETID_RES);
        if (retval)
                return retval;
 
        if (!capable(CAP_SETGID)) {
                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 (egid != (gid_t) -1) {
                if (egid != current->egid) {
                        set_dumpable(current->mm, suid_dumpable);
                        smp_wmb();
                }
                current->egid = egid;
        }
        current->fsgid = current->egid;
        if (rgid != (gid_t) -1)
                current->gid = rgid;
        if (sgid != (gid_t) -1)
                current->sgid = sgid;
 
        key_fsgid_changed(current);
        proc_id_connector(current, PROC_EVENT_GID);
        return 0;
}
 
asmlinkage long sys_getresgid(gid_t __user *rgid, gid_t __user *egid, gid_t __user *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 long sys_setfsuid(uid_t uid)
{
        int old_fsuid;
 
        old_fsuid = current->fsuid;
        if (security_task_setuid(uid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS))
                return old_fsuid;
 
        if (uid == current->uid || uid == current->euid ||
            uid == current->suid || uid == current->fsuid ||
            capable(CAP_SETUID)) {
                if (uid != old_fsuid) {
                        set_dumpable(current->mm, suid_dumpable);
                        smp_wmb();
                }
                current->fsuid = uid;
        }
 
        key_fsuid_changed(current);
        proc_id_connector(current, PROC_EVENT_UID);
 
        security_task_post_setuid(old_fsuid, (uid_t)-1, (uid_t)-1, LSM_SETID_FS);
 
        return old_fsuid;
}
 
/*
 * Samma på svenska..
 */
asmlinkage long sys_setfsgid(gid_t gid)
{
        int old_fsgid;
 
        old_fsgid = current->fsgid;
        if (security_task_setgid(gid, (gid_t)-1, (gid_t)-1, LSM_SETID_FS))
                return old_fsgid;
 
        if (gid == current->gid || gid == current->egid ||
            gid == current->sgid || gid == current->fsgid ||
            capable(CAP_SETGID)) {
                if (gid != old_fsgid) {
                        set_dumpable(current->mm, suid_dumpable);
                        smp_wmb();
                }
                current->fsgid = gid;
                key_fsgid_changed(current);
                proc_id_connector(current, PROC_EVENT_GID);
        }
        return old_fsgid;
}
 
asmlinkage long sys_times(struct tms __user * 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) {
                struct tms tmp;
                struct task_struct *tsk = current;
                struct task_struct *t;
                cputime_t utime, stime, cutime, cstime;
 
                spin_lock_irq(&tsk->sighand->siglock);
                utime = tsk->signal->utime;
                stime = tsk->signal->stime;
                t = tsk;
                do {
                        utime = cputime_add(utime, t->utime);
                        stime = cputime_add(stime, t->stime);
                        t = next_thread(t);
                } while (t != tsk);
 
                cutime = tsk->signal->cutime;
                cstime = tsk->signal->cstime;
                spin_unlock_irq(&tsk->sighand->siglock);
 
                tmp.tms_utime = cputime_to_clock_t(utime);
                tmp.tms_stime = cputime_to_clock_t(stime);
                tmp.tms_cutime = cputime_to_clock_t(cutime);
                tmp.tms_cstime = cputime_to_clock_t(cstime);
                if (copy_to_user(tbuf, &tmp, sizeof(struct tms)))
                        return -EFAULT;
        }
        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
 */
asmlinkage long sys_setpgid(pid_t pid, pid_t pgid)
{
        struct task_struct *p;
        struct task_struct *group_leader = current->group_leader;
        int err = -EINVAL;
        struct pid_namespace *ns;
 
        if (!pid)
                pid = task_pid_vnr(group_leader);
        if (!pgid)
                pgid = pid;
        if (pgid < 0)
                return -EINVAL;
 
        /* From this point forward we keep holding onto the tasklist lock
         * so that our parent does not change from under us. -DaveM
         */
        ns = current->nsproxy->pid_ns;
 
        write_lock_irq(&tasklist_lock);
 
        err = -ESRCH;
        p = find_task_by_pid_ns(pid, ns);
        if (!p)
                goto out;
 
        err = -EINVAL;
        if (!thread_group_leader(p))
                goto out;
 
        if (p->real_parent->tgid == group_leader->tgid) {
                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;
 
        if (pgid != pid) {
                struct task_struct *g;
 
                g = find_task_by_pid_type_ns(PIDTYPE_PGID, pgid, ns);
                if (!g || task_session(g) != task_session(group_leader))
                        goto out;
        }
 
        err = security_task_setpgid(p, pgid);
        if (err)
                goto out;
 
        if (task_pgrp_nr_ns(p, ns) != pgid) {
                struct pid *pid;
 
                detach_pid(p, PIDTYPE_PGID);
                pid = find_vpid(pgid);
                attach_pid(p, PIDTYPE_PGID, pid);
                set_task_pgrp(p, pid_nr(pid));
        }
 
        err = 0;
out:
        /* All paths lead to here, thus we are safe. -DaveM */
        write_unlock_irq(&tasklist_lock);
        return err;
}
 
asmlinkage long sys_getpgid(pid_t pid)
{
        if (!pid)
                return task_pgrp_vnr(current);
        else {
                int retval;
                struct task_struct *p;
                struct pid_namespace *ns;
 
                ns = current->nsproxy->pid_ns;
 
                read_lock(&tasklist_lock);
                p = find_task_by_pid_ns(pid, ns);
                retval = -ESRCH;
                if (p) {
                        retval = security_task_getpgid(p);
                        if (!retval)
                                retval = task_pgrp_nr_ns(p, ns);
                }
                read_unlock(&tasklist_lock);
                return retval;
        }
}
 
#ifdef __ARCH_WANT_SYS_GETPGRP
 
asmlinkage long sys_getpgrp(void)
{
        /* SMP - assuming writes are word atomic this is fine */
        return task_pgrp_vnr(current);
}
 
#endif
 
asmlinkage long sys_getsid(pid_t pid)
{
        if (!pid)
                return task_session_vnr(current);
        else {
                int retval;
                struct task_struct *p;
                struct pid_namespace *ns;
 
                ns = current->nsproxy->pid_ns;
 
                read_lock(&tasklist_lock);
                p = find_task_by_pid_ns(pid, ns);
                retval = -ESRCH;
                if (p) {
                        retval = security_task_getsid(p);
                        if (!retval)
                                retval = task_session_nr_ns(p, ns);
                }
                read_unlock(&tasklist_lock);
                return retval;
        }
}
 
asmlinkage long sys_setsid(void)
{
        struct task_struct *group_leader = current->group_leader;
        pid_t session;
        int err = -EPERM;
 
        write_lock_irq(&tasklist_lock);
 
        /* Fail if I am already a session leader */
        if (group_leader->signal->leader)
                goto out;
 
        session = group_leader->pid;
        /* Fail if a process group id already exists that equals the
         * proposed session id.
         *
         * Don't check if session id == 1 because kernel threads use this
         * session id and so the check will always fail and make it so
         * init cannot successfully call setsid.
         */
        if (session > 1 && find_task_by_pid_type_ns(PIDTYPE_PGID,
                                session, &init_pid_ns))
                goto out;
 
        group_leader->signal->leader = 1;
        __set_special_pids(session, session);
 
        spin_lock(&group_leader->sighand->siglock);
        group_leader->signal->tty = NULL;
        spin_unlock(&group_leader->sighand->siglock);
 
        err = task_pgrp_vnr(group_leader);
out:
        write_unlock_irq(&tasklist_lock);
        return err;
}
 
/*
 * Supplementary group IDs
 */
 
/* init to 2 - one for init_task, one to ensure it is never freed */
struct group_info init_groups = { .usage = ATOMIC_INIT(2) };
 
struct group_info *groups_alloc(int gidsetsize)
{
        struct group_info *group_info;
        int nblocks;
        int i;
 
        nblocks = (gidsetsize + NGROUPS_PER_BLOCK - 1) / NGROUPS_PER_BLOCK;
        /* Make sure we always allocate at least one indirect block pointer */
        nblocks = nblocks ? : 1;
        group_info = kmalloc(sizeof(*group_info) + nblocks*sizeof(gid_t *), GFP_USER);
        if (!group_info)
                return NULL;
        group_info->ngroups = gidsetsize;
        group_info->nblocks = nblocks;
        atomic_set(&group_info->usage, 1);
 
        if (gidsetsize <= NGROUPS_SMALL)
                group_info->blocks[0] = group_info->small_block;
        else {
                for (i = 0; i < nblocks; i++) {
                        gid_t *b;
                        b = (void *)__get_free_page(GFP_USER);
                        if (!b)
                                goto out_undo_partial_alloc;
                        group_info->blocks[i] = b;
                }
        }
        return group_info;
 
out_undo_partial_alloc:
        while (--i >= 0) {
                free_page((unsigned long)group_info->blocks[i]);
        }
        kfree(group_info);
        return NULL;
}
 
EXPORT_SYMBOL(groups_alloc);
 
void groups_free(struct group_info *group_info)
{
        if (group_info->blocks[0] != group_info->small_block) {
                int i;
                for (i = 0; i < group_info->nblocks; i++)
                        free_page((unsigned long)group_info->blocks[i]);
        }
        kfree(group_info);
}
 
EXPORT_SYMBOL(groups_free);
 
/* export the group_info to a user-space array */
static int groups_to_user(gid_t __user *grouplist,
    struct group_info *group_info)
{
        int i;
        int count = group_info->ngroups;
 
        for (i = 0; i < group_info->nblocks; i++) {
                int cp_count = min(NGROUPS_PER_BLOCK, count);
                int off = i * NGROUPS_PER_BLOCK;
                int len = cp_count * sizeof(*grouplist);
 
                if (copy_to_user(grouplist+off, group_info->blocks[i], len))
                        return -EFAULT;
 
                count -= cp_count;
        }
        return 0;
}
 
/* fill a group_info from a user-space array - it must be allocated already */
static int groups_from_user(struct group_info *group_info,
    gid_t __user *grouplist)
{
        int i;
        int count = group_info->ngroups;
 
        for (i = 0; i < group_info->nblocks; i++) {
                int cp_count = min(NGROUPS_PER_BLOCK, count);
                int off = i * NGROUPS_PER_BLOCK;
                int len = cp_count * sizeof(*grouplist);
 
                if (copy_from_user(group_info->blocks[i], grouplist+off, len))
                        return -EFAULT;
 
                count -= cp_count;
        }
        return 0;
}
 
/* a simple Shell sort */
static void groups_sort(struct group_info *group_info)
{
        int base, max, stride;
        int gidsetsize = group_info->ngroups;
 
        for (stride = 1; stride < gidsetsize; stride = 3 * stride + 1)
                ; /* nothing */
        stride /= 3;
 
        while (stride) {
                max = gidsetsize - stride;
                for (base = 0; base < max; base++) {
                        int left = base;
                        int right = left + stride;
                        gid_t tmp = GROUP_AT(group_info, right);
 
                        while (left >= 0 && GROUP_AT(group_info, left) > tmp) {
                                GROUP_AT(group_info, right) =
                                    GROUP_AT(group_info, left);
                                right = left;
                                left -= stride;
                        }
                        GROUP_AT(group_info, right) = tmp;
                }
                stride /= 3;
        }
}
 
/* a simple bsearch */
int groups_search(struct group_info *group_info, gid_t grp)
{
        unsigned int left, right;
 
        if (!group_info)
                return 0;
 
        left = 0;
        right = group_info->ngroups;
        while (left < right) {
                unsigned int mid = (left+right)/2;
                int cmp = grp - GROUP_AT(group_info, mid);
                if (cmp > 0)
                        left = mid + 1;
                else if (cmp < 0)
                        right = mid;
                else
                        return 1;
        }
        return 0;
}
 
/* validate and set current->group_info */
int set_current_groups(struct group_info *group_info)
{
        int retval;
        struct group_info *old_info;
 
        retval = security_task_setgroups(group_info);
        if (retval)
                return retval;
 
        groups_sort(group_info);
        get_group_info(group_info);
 
        task_lock(current);
        old_info = current->group_info;
        current->group_info = group_info;
        task_unlock(current);
 
        put_group_info(old_info);
 
        return 0;
}
 
EXPORT_SYMBOL(set_current_groups);
 
asmlinkage long sys_getgroups(int gidsetsize, gid_t __user *grouplist)
{
        int i = 0;
 
        /*
         *      SMP: Nobody else can change our grouplist. Thus we are
         *      safe.
         */
 
        if (gidsetsize < 0)
                return -EINVAL;
 
        /* no need to grab task_lock here; it cannot change */
        i = current->group_info->ngroups;
        if (gidsetsize) {
                if (i > gidsetsize) {
                        i = -EINVAL;
                        goto out;
                }
                if (groups_to_user(grouplist, current->group_info)) {
                        i = -EFAULT;
                        goto out;
                }
        }
out:
        return i;
}
 
/*
 *      SMP: Our groups are copy-on-write. We can set them safely
 *      without another task interfering.
 */
 
asmlinkage long sys_setgroups(int gidsetsize, gid_t __user *grouplist)
{
        struct group_info *group_info;
        int retval;
 
        if (!capable(CAP_SETGID))
                return -EPERM;
        if ((unsigned)gidsetsize > NGROUPS_MAX)
                return -EINVAL;
 
        group_info = groups_alloc(gidsetsize);
        if (!group_info)
                return -ENOMEM;
        retval = groups_from_user(group_info, grouplist);
        if (retval) {
                put_group_info(group_info);
                return retval;
        }
 
        retval = set_current_groups(group_info);
        put_group_info(group_info);
 
        return retval;
}
 
/*
 * Check whether we're fsgid/egid or in the supplemental group..
 */
int in_group_p(gid_t grp)
{
        int retval = 1;
        if (grp != current->fsgid)
                retval = groups_search(current->group_info, grp);
        return retval;
}
 
EXPORT_SYMBOL(in_group_p);
 
int in_egroup_p(gid_t grp)
{
        int retval = 1;
        if (grp != current->egid)
                retval = groups_search(current->group_info, grp);
        return retval;
}
 
EXPORT_SYMBOL(in_egroup_p);
 
DECLARE_RWSEM(uts_sem);
 
EXPORT_SYMBOL(uts_sem);
 
asmlinkage long sys_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);
        return errno;
}
 
asmlinkage long sys_sethostname(char __user *name, int len)
{
        int errno;
        char tmp[__NEW_UTS_LEN];
 
        if (!capable(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)) {
                memcpy(utsname()->nodename, tmp, len);
                utsname()->nodename[len] = 0;
                errno = 0;
        }
        up_write(&uts_sem);
        return errno;
}
 
#ifdef __ARCH_WANT_SYS_GETHOSTNAME
 
asmlinkage long sys_gethostname(char __user *name, int len)
{
        int i, errno;
 
        if (len < 0)
                return -EINVAL;
        down_read(&uts_sem);
        i = 1 + strlen(utsname()->nodename);
        if (i > len)
                i = len;
        errno = 0;
        if (copy_to_user(name, utsname()->nodename, i))
                errno = -EFAULT;
        up_read(&uts_sem);
        return errno;
}
 
#endif
 
/*
 * Only setdomainname; getdomainname can be implemented by calling
 * uname()
 */
asmlinkage long sys_setdomainname(char __user *name, int len)
{
        int errno;
        char tmp[__NEW_UTS_LEN];
 
        if (!capable(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)) {
                memcpy(utsname()->domainname, tmp, len);
                utsname()->domainname[len] = 0;
                errno = 0;
        }
        up_write(&uts_sem);
        return errno;
}
 
asmlinkage long sys_getrlimit(unsigned int resource, struct rlimit __user *rlim)
{
        if (resource >= RLIM_NLIMITS)
                return -EINVAL;
        else {
                struct rlimit value;
                task_lock(current->group_leader);
                value = current->signal->rlim[resource];
                task_unlock(current->group_leader);
                return copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0;
        }
}
 
#ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT
 
/*
 *      Back compatibility for getrlimit. Needed for some apps.
 */
 
asmlinkage long sys_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
 
asmlinkage long sys_setrlimit(unsigned int resource, struct rlimit __user *rlim)
{
        struct rlimit new_rlim, *old_rlim;
        unsigned long it_prof_secs;
        int retval;
 
        if (resource >= RLIM_NLIMITS)
                return -EINVAL;
        if (copy_from_user(&new_rlim, rlim, sizeof(*rlim)))
                return -EFAULT;
        if (new_rlim.rlim_cur > new_rlim.rlim_max)
                return -EINVAL;
        old_rlim = current->signal->rlim + resource;
        if ((new_rlim.rlim_max > old_rlim->rlim_max) &&
            !capable(CAP_SYS_RESOURCE))
                return -EPERM;
        if (resource == RLIMIT_NOFILE && new_rlim.rlim_max > NR_OPEN)
                return -EPERM;
 
        retval = security_task_setrlimit(resource, &new_rlim);
        if (retval)
                return retval;
 
        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;
        }
 
        task_lock(current->group_leader);
        *old_rlim = new_rlim;
        task_unlock(current->group_leader);
 
        if (resource != RLIMIT_CPU)
                goto out;
 
        /*
         * 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 (new_rlim.rlim_cur == RLIM_INFINITY)
                goto out;
 
        it_prof_secs = cputime_to_secs(current->signal->it_prof_expires);
        if (it_prof_secs == 0 || new_rlim.rlim_cur <= it_prof_secs) {
                unsigned long rlim_cur = new_rlim.rlim_cur;
                cputime_t cputime;
 
                cputime = secs_to_cputime(rlim_cur);
                read_lock(&tasklist_lock);
                spin_lock_irq(&current->sighand->siglock);
                set_process_cpu_timer(current, CPUCLOCK_PROF, &cputime, NULL);
                spin_unlock_irq(&current->sighand->siglock);
                read_unlock(&tasklist_lock);
        }
out:
        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).
 *
 * 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 k_getrusage(struct task_struct *p, int who, struct rusage *r)
{
        struct task_struct *t;
        unsigned long flags;
        cputime_t utime, stime;
 
        memset((char *) r, 0, sizeof *r);
        utime = stime = cputime_zero;
 
        rcu_read_lock();
        if (!lock_task_sighand(p, &flags)) {
                rcu_read_unlock();
                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;
 
                        if (who == RUSAGE_CHILDREN)
                                break;
 
                case RUSAGE_SELF:
                        utime = cputime_add(utime, p->signal->utime);
                        stime = cputime_add(stime, p->signal->stime);
                        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;
                        t = p;
                        do {
                                utime = cputime_add(utime, t->utime);
                                stime = cputime_add(stime, t->stime);
                                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);
                                t = next_thread(t);
                        } while (t != p);
                        break;
 
                default:
                        BUG();
        }
 
        unlock_task_sighand(p, &flags);
        rcu_read_unlock();
 
        cputime_to_timeval(utime, &r->ru_utime);
        cputime_to_timeval(stime, &r->ru_stime);
}
 
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;
}
 
asmlinkage long sys_getrusage(int who, struct rusage __user *ru)
{
        if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN)
                return -EINVAL;
        return getrusage(current, who, ru);
}
 
asmlinkage long sys_umask(int mask)
{
        mask = xchg(&current->fs->umask, mask & S_IRWXUGO);
        return mask;
}
 
asmlinkage long sys_prctl(int option, unsigned long arg2, unsigned long arg3,
                          unsigned long arg4, unsigned long arg5)
{
        long error;
 
        error = security_task_prctl(option, arg2, arg3, arg4, arg5);
        if (error)
                return error;
 
        switch (option) {
                case PR_SET_PDEATHSIG:
                        if (!valid_signal(arg2)) {
                                error = -EINVAL;
                                break;
                        }
                        current->pdeath_signal = arg2;
                        break;
                case PR_GET_PDEATHSIG:
                        error = put_user(current->pdeath_signal, (int __user *)arg2);
                        break;
                case PR_GET_DUMPABLE:
                        error = get_dumpable(current->mm);
                        break;
                case PR_SET_DUMPABLE:
                        if (arg2 < 0 || arg2 > 1) {
                                error = -EINVAL;
                                break;
                        }
                        set_dumpable(current->mm, arg2);
                        break;
 
                case PR_SET_UNALIGN:
                        error = SET_UNALIGN_CTL(current, arg2);
                        break;
                case PR_GET_UNALIGN:
                        error = GET_UNALIGN_CTL(current, arg2);
                        break;
                case PR_SET_FPEMU:
                        error = SET_FPEMU_CTL(current, arg2);
                        break;
                case PR_GET_FPEMU:
                        error = GET_FPEMU_CTL(current, arg2);
                        break;
                case PR_SET_FPEXC:
                        error = SET_FPEXC_CTL(current, arg2);
                        break;
                case PR_GET_FPEXC:
                        error = GET_FPEXC_CTL(current, arg2);
                        break;
                case PR_GET_TIMING:
                        error = PR_TIMING_STATISTICAL;
                        break;
                case PR_SET_TIMING:
                        if (arg2 == PR_TIMING_STATISTICAL)
                                error = 0;
                        else
                                error = -EINVAL;
                        break;
 
                case PR_GET_KEEPCAPS:
                        if (current->keep_capabilities)
                                error = 1;
                        break;
                case PR_SET_KEEPCAPS:
                        if (arg2 != 0 && arg2 != 1) {
                                error = -EINVAL;
                                break;
                        }
                        current->keep_capabilities = arg2;
                        break;
                case PR_SET_NAME: {
                        struct task_struct *me = current;
                        unsigned char ncomm[sizeof(me->comm)];
 
                        ncomm[sizeof(me->comm)-1] = 0;
                        if (strncpy_from_user(ncomm, (char __user *)arg2,
                                                sizeof(me->comm)-1) < 0)
                                return -EFAULT;
                        set_task_comm(me, ncomm);
                        return 0;
                }
                case PR_GET_NAME: {
                        struct task_struct *me = current;
                        unsigned char tcomm[sizeof(me->comm)];
 
                        get_task_comm(tcomm, me);
                        if (copy_to_user((char __user *)arg2, tcomm, sizeof(tcomm)))
                                return -EFAULT;
                        return 0;
                }
                case PR_GET_ENDIAN:
                        error = GET_ENDIAN(current, arg2);
                        break;
                case PR_SET_ENDIAN:
                        error = SET_ENDIAN(current, arg2);
                        break;
 
                case PR_GET_SECCOMP:
                        error = prctl_get_seccomp();
                        break;
                case PR_SET_SECCOMP:
                        error = prctl_set_seccomp(arg2);
                        break;
 
                default:
                        error = -EINVAL;
                        break;
        }
        return error;
}
 
asmlinkage long sys_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(char **argv, char **envp)
{
        argv_free(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);
        if (info == NULL) {
                argv_free(argv);
                goto out;
        }
 
        call_usermodehelper_setcleanup(info, argv_cleanup);
 
        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);
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[/] [test_project/] [trunk/] [linux_sd_driver/] [kernel/] [sys.c] - Blame information for rev 62

Line No.	Rev	Author	Line
1	62	marcus.erl	`/*`
2			`* linux/kernel/sys.c`
3			`*`
4			`* Copyright (C) 1991, 1992 Linus Torvalds`
5			`*/`
6
7			`#include <linux/module.h>`
8			`#include <linux/mm.h>`
9			`#include <linux/utsname.h>`
10			`#include <linux/mman.h>`
11			`#include <linux/smp_lock.h>`
12			`#include <linux/notifier.h>`
13			`#include <linux/reboot.h>`
14			`#include <linux/prctl.h>`
15			`#include <linux/highuid.h>`
16			`#include <linux/fs.h>`
17			`#include <linux/resource.h>`
18			`#include <linux/kernel.h>`
19			`#include <linux/kexec.h>`
20			`#include <linux/workqueue.h>`
21			`#include <linux/capability.h>`
22			`#include <linux/device.h>`
23			`#include <linux/key.h>`
24			`#include <linux/times.h>`
25			`#include <linux/posix-timers.h>`
26			`#include <linux/security.h>`
27			`#include <linux/dcookies.h>`
28			`#include <linux/suspend.h>`
29			`#include <linux/tty.h>`
30			`#include <linux/signal.h>`
31			`#include <linux/cn_proc.h>`
32			`#include <linux/getcpu.h>`
33			`#include <linux/task_io_accounting_ops.h>`
34			`#include <linux/seccomp.h>`
35			`#include <linux/cpu.h>`
36
37			`#include <linux/compat.h>`
38			`#include <linux/syscalls.h>`
39			`#include <linux/kprobes.h>`
40			`#include <linux/user_namespace.h>`