/*
 *  linux/arch/arm/kernel/sys_arm.c
 *
 *  Copyright (C) People who wrote linux/arch/i386/kernel/sys_i386.c
 *  Copyright (C) 1995, 1996 Russell King.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 *  This file contains various random system calls that
 *  have a non-standard calling sequence on the Linux/arm
 *  platform.
 */
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/mm.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/fs.h>
#include <linux/file.h>
#include <linux/utsname.h>

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

extern unsigned long do_mremap(unsigned long addr, unsigned long old_len,
                               unsigned long new_len, unsigned long flags,
                               unsigned long new_addr);

/*
 * sys_pipe() is the normal C calling standard for creating
 * a pipe. It's not the way unix traditionally does this, though.
 */
asmlinkage int sys_pipe(unsigned long __user *fildes)
{
        int fd[2];
        int error;

        error = do_pipe(fd);
        if (!error) {
                if (copy_to_user(fildes, fd, 2*sizeof(int)))
                        error = -EFAULT;
        }
        return error;
}

/*
 * This is the lowest virtual address we can permit any user space
 * mapping to be mapped at.  This is particularly important for
 * non-high vector CPUs.
 */
#define MIN_MAP_ADDR    (PAGE_SIZE)

/* common code for old and new mmaps */
inline long do_mmap2(
        unsigned long addr, unsigned long len,
        unsigned long prot, unsigned long flags,
        unsigned long fd, unsigned long pgoff)
{
        int error = -EINVAL;
        struct file * file = NULL;

        flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);

        if (flags & MAP_FIXED && addr < MIN_MAP_ADDR)
                goto out;

        error = -EBADF;
        if (!(flags & MAP_ANONYMOUS)) {
                file = fget(fd);
                if (!file)
                        goto out;
        }

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

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

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)
{
        int error = -EFAULT;
        struct mmap_arg_struct a;

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

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

        error = do_mmap2(a.addr, a.len, a.prot, a.flags, a.fd, a.offset >> PAGE_SHIFT);
out:
        return error;
}

asmlinkage unsigned long
sys_arm_mremap(unsigned long addr, unsigned long old_len,
               unsigned long new_len, unsigned long flags,
               unsigned long new_addr)
{
        unsigned long ret = -EINVAL;

        if (flags & MREMAP_FIXED && new_addr < MIN_MAP_ADDR)
                goto out;

        down_write(&current->mm->mmap_sem);
        ret = do_mremap(addr, old_len, new_len, flags, new_addr);
        up_write(&current->mm->mmap_sem);

out:
        return ret;
}

/*
 * Perform the select(nd, in, out, ex, tv) and mmap() system
 * calls.
 */

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_semop(first, (struct sembuf __user *)ptr, second);
        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: /* Of course, we don't support iBCS2! */
                        return -EINVAL;
                }
        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;
        }
}

/* Fork a new task - this creates a new program thread.
 * This is called indirectly via a small wrapper
 */
asmlinkage int sys_fork(struct pt_regs *regs)
{
        return do_fork(SIGCHLD, regs->ARM_sp, regs, 0, NULL, NULL);
}

/* Clone a task - this clones the calling program thread.
 * This is called indirectly via a small wrapper
 */
asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
                         int __user *parent_tidptr, int tls_val,
                         int __user *child_tidptr, struct pt_regs *regs)
{
        if (!newsp)
                newsp = regs->ARM_sp;

        return do_fork(clone_flags, newsp, regs, 0, parent_tidptr, child_tidptr);
}

asmlinkage int sys_vfork(struct pt_regs *regs)
{
        return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->ARM_sp, regs, 0, NULL, NULL);
}

/* sys_execve() executes a new program.
 * This is called indirectly via a small wrapper
 */
asmlinkage int sys_execve(char __user *filenamei, char __user * __user *argv,
                          char __user * __user *envp, struct pt_regs *regs)
{
        int error;
        char * filename;

        filename = getname(filenamei);
        error = PTR_ERR(filename);
        if (IS_ERR(filename))
                goto out;
        error = do_execve(filename, argv, envp, regs);
        putname(filename);
out:
        return error;
}

long execve(const char *filename, char **argv, char **envp)
{
        struct pt_regs regs;
        int ret;

        memset(&regs, 0, sizeof(struct pt_regs));
        ret = do_execve((char *)filename, (char __user * __user *)argv,
                        (char __user * __user *)envp, &regs);
        if (ret < 0)
                goto out;

        /*
         * Save argc to the register structure for userspace.
         */
        regs.ARM_r0 = ret;

        /*
         * We were successful.  We won't be returning to our caller, but
         * instead to user space by manipulating the kernel stack.
         */
        asm(    "add    r0, %0, %1\n\t"
                "mov    r1, %2\n\t"
                "mov    r2, %3\n\t"
                "bl     memmove\n\t"    /* copy regs to top of stack */
                "mov    r8, #0\n\t"     /* not a syscall */
                "mov    r9, %0\n\t"     /* thread structure */
                "mov    sp, r0\n\t"     /* reposition stack pointer */
                "b      ret_to_user"
                :
                : "r" (current_thread_info()),
                  "Ir" (THREAD_SIZE - 8 - sizeof(regs)),
                  "r" (&regs),
                  "Ir" (sizeof(regs))
                : "r0", "r1", "r2", "r3", "ip", "memory");

 out:
        return ret;
}
EXPORT_SYMBOL(execve);