/*
 * This file contains various random system calls that
 * have a non-standard calling sequence on the Linux/i386
 * platform.
 */

#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/fs.h>
#include <linux/smp.h>
#include <linux/sem.h>
#include <linux/msg.h>
#include <linux/shm.h>
#include <linux/stat.h>
#include <linux/syscalls.h>
#include <linux/mman.h>
#include <linux/file.h>
#include <linux/utsname.h>
#include <linux/ipc.h>

#include <linux/uaccess.h>
#include <linux/unistd.h>

#include <asm/syscalls.h>

asmlinkage long sys_mmap2(unsigned long addr, unsigned long len,
                          unsigned long prot, unsigned long flags,
                          unsigned long fd, unsigned long pgoff)
{
        int error = -EBADF;
        struct file *file = NULL;
        struct mm_struct *mm = current->mm;

        flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
        if (!(flags & MAP_ANONYMOUS)) {
                file = fget(fd);
                if (!file)
                        goto out;
        }

        down_write(&mm->mmap_sem);
        error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
        up_write(&mm->mmap_sem);

        if (file)
                fput(file);
out:
        return error;
}

/*
 * Perform the select(nd, in, out, ex, tv) and mmap() system
 * calls. Linux/i386 didn't use to be able to handle more than
 * 4 system call parameters, so these system calls used a memory
 * block for parameter passing..
 */

struct mmap_arg_struct {
        unsigned long addr;
        unsigned long len;
        unsigned long prot;
        unsigned long flags;
        unsigned long fd;
        unsigned long offset;
};

asmlinkage int old_mmap(struct mmap_arg_struct __user *arg)
{
        struct mmap_arg_struct a;
        int err = -EFAULT;

        if (copy_from_user(&a, arg, sizeof(a)))
                goto out;

        err = -EINVAL;
        if (a.offset & ~PAGE_MASK)
                goto out;

        err = sys_mmap2(a.addr, a.len, a.prot, a.flags,
                        a.fd, a.offset >> PAGE_SHIFT);
out:
        return err;
}


struct sel_arg_struct {
        unsigned long n;
        fd_set __user *inp, *outp, *exp;
        struct timeval __user *tvp;
};

asmlinkage int old_select(struct sel_arg_struct __user *arg)
{
        struct sel_arg_struct a;

        if (copy_from_user(&a, arg, sizeof(a)))
                return -EFAULT;
        /* sys_select() does the appropriate kernel locking */
        return sys_select(a.n, a.inp, a.outp, a.exp, a.tvp);
}

/*
 * sys_ipc() is the de-multiplexer for the SysV IPC calls..
 *
 * This is really horribly ugly.
 */
asmlinkage int sys_ipc(uint call, int first, int second,
                        int third, void __user *ptr, long fifth)
{
        int version, ret;

        version = call >> 16; /* hack for backward compatibility */
        call &= 0xffff;

        switch (call) {
        case SEMOP:
                return sys_semtimedop(first, (struct sembuf __user *)ptr, second, NULL);
        case SEMTIMEDOP:
                return sys_semtimedop(first, (struct sembuf __user *)ptr, second,
                                        (const struct timespec __user *)fifth);

        case SEMGET:
                return sys_semget(first, second, third);
        case SEMCTL: {
                union semun fourth;
                if (!ptr)
                        return -EINVAL;
                if (get_user(fourth.__pad, (void __user * __user *) ptr))
                        return -EFAULT;
                return sys_semctl(first, second, third, fourth);
        }

        case MSGSND:
                return sys_msgsnd(first, (struct msgbuf __user *) ptr,
                                   second, third);
        case MSGRCV:
                switch (version) {
                case 0: {
                        struct ipc_kludge tmp;
                        if (!ptr)
                                return -EINVAL;

                        if (copy_from_user(&tmp,
                                           (struct ipc_kludge __user *) ptr,
                                           sizeof(tmp)))
                                return -EFAULT;
                        return sys_msgrcv(first, tmp.msgp, second,
                                           tmp.msgtyp, third);
                }
                default:
                        return sys_msgrcv(first,
                                           (struct msgbuf __user *) ptr,
                                           second, fifth, third);
                }
        case MSGGET:
                return sys_msgget((key_t) first, second);
        case MSGCTL:
                return sys_msgctl(first, second, (struct msqid_ds __user *) ptr);

        case SHMAT:
                switch (version) {
                default: {
                        ulong raddr;
                        ret = do_shmat(first, (char __user *) ptr, second, &raddr);
                        if (ret)
                                return ret;
                        return put_user(raddr, (ulong __user *) third);
                }
                case 1: /* iBCS2 emulator entry point */
                        if (!segment_eq(get_fs(), get_ds()))
                                return -EINVAL;
                        /* The "(ulong *) third" is valid _only_ because of the kernel segment thing */
                        return do_shmat(first, (char __user *) ptr, second, (ulong *) third);
                }
        case SHMDT:
                return sys_shmdt((char __user *)ptr);
        case SHMGET:
                return sys_shmget(first, second, third);
        case SHMCTL:
                return sys_shmctl(first, second,
                                   (struct shmid_ds __user *) ptr);
        default:
                return -ENOSYS;
        }
}

/*
 * Old cruft
 */
asmlinkage int sys_uname(struct old_utsname __user *name)
{
        int err;
        if (!name)
                return -EFAULT;
        down_read(&uts_sem);
        err = copy_to_user(name, utsname(), sizeof(*name));
        up_read(&uts_sem);
        return err? -EFAULT:0;
}

asmlinkage int sys_olduname(struct oldold_utsname __user *name)
{
        int error;

        if (!name)
                return -EFAULT;
        if (!access_ok(VERIFY_WRITE, name, sizeof(struct oldold_utsname)))
                return -EFAULT;

        down_read(&uts_sem);

        error = __copy_to_user(&name->sysname, &utsname()->sysname,
                               __OLD_UTS_LEN);
        error |= __put_user(0, name->sysname + __OLD_UTS_LEN);
        error |= __copy_to_user(&name->nodename, &utsname()->nodename,
                                __OLD_UTS_LEN);
        error |= __put_user(0, name->nodename + __OLD_UTS_LEN);
        error |= __copy_to_user(&name->release, &utsname()->release,
                                __OLD_UTS_LEN);
        error |= __put_user(0, name->release + __OLD_UTS_LEN);
        error |= __copy_to_user(&name->version, &utsname()->version,
                                __OLD_UTS_LEN);
        error |= __put_user(0, name->version + __OLD_UTS_LEN);
        error |= __copy_to_user(&name->machine, &utsname()->machine,
                                __OLD_UTS_LEN);
        error |= __put_user(0, name->machine + __OLD_UTS_LEN);

        up_read(&uts_sem);

        error = error ? -EFAULT : 0;

        return error;
}


/*
 * Do a system call from kernel instead of calling sys_execve so we
 * end up with proper pt_regs.
 */
int kernel_execve(const char *filename, char *const argv[], char *const envp[])
{
        long __res;
        asm volatile ("push %%ebx ; movl %2,%%ebx ; int $0x80 ; pop %%ebx"
        : "=a" (__res)
        : "0" (__NR_execve), "ri" (filename), "c" (argv), "d" (envp) : "memory");
        return __res;
}