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syscalls.c

/*
 * arch/v850/kernel/syscalls.c -- Various system-call definitions not
 *    defined in machine-independent code
 *
 *  Copyright (C) 2001,02  NEC Corporation
 *  Copyright (C) 2001,02  Miles Bader <miles@gnu.org>
 *
 * This file is subject to the terms and conditions of the GNU General
 * Public License.  See the file COPYING in the main directory of this
 * archive for more details.
 *
 * This file was derived the ppc version, arch/ppc/kernel/syscalls.c
 * ... which was derived from "arch/i386/kernel/sys_i386.c" by Gary Thomas;
 *     modified by Cort Dougan (cort@cs.nmt.edu)
 *     and Paul Mackerras (paulus@cs.anu.edu.au).
 */

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

#include <asm/uaccess.h>
#include <asm/semaphore.h>
#include <asm/unistd.h>

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

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

      ret = -EINVAL;
      switch (call) {
      case SEMOP:
            ret = sys_semop (first, (struct sembuf *)ptr, second);
            break;
      case SEMGET:
            ret = sys_semget (first, second, third);
            break;
      case SEMCTL:
      {
            union semun fourth;

            if (!ptr)
                  break;
            if ((ret = access_ok(VERIFY_READ, ptr, sizeof(long)) ? 0 : -EFAULT)
                || (ret = get_user(fourth.__pad, (void **)ptr)))
                  break;
            ret = sys_semctl (first, second, third, fourth);
            break;
      }
      case MSGSND:
            ret = sys_msgsnd (first, (struct msgbuf *) ptr, second, third);
            break;
      case MSGRCV:
            switch (version) {
            case 0: {
                  struct ipc_kludge tmp;

                  if (!ptr)
                        break;
                  if ((ret = access_ok(VERIFY_READ, ptr, sizeof(tmp)) ? 0 : -EFAULT)
                      || (ret = copy_from_user(&tmp,
                                    (struct ipc_kludge *) ptr,
                                    sizeof (tmp))))
                        break;
                  ret = sys_msgrcv (first, tmp.msgp, second, tmp.msgtyp,
                                third);
                  break;
                  }
            default:
                  ret = sys_msgrcv (first, (struct msgbuf *) ptr,
                                second, fifth, third);
                  break;
            }
            break;
      case MSGGET:
            ret = sys_msgget ((key_t) first, second);
            break;
      case MSGCTL:
            ret = sys_msgctl (first, second, (struct msqid_ds *) ptr);
            break;
      case SHMAT:
            switch (version) {
            default: {
                  ulong raddr;

                  if ((ret = access_ok(VERIFY_WRITE, (ulong*) third,
                                     sizeof(ulong)) ? 0 : -EFAULT))
                        break;
                  ret = do_shmat (first, (char *) ptr, second, &raddr);
                  if (ret)
                        break;
                  ret = put_user (raddr, (ulong *) third);
                  break;
                  }
            case 1:     /* iBCS2 emulator entry point */
                  if (!segment_eq(get_fs(), get_ds()))
                        break;
                  ret = do_shmat (first, (char *) ptr, second,
                               (ulong *) third);
                  break;
            }
            break;
      case SHMDT: 
            ret = sys_shmdt ((char *)ptr);
            break;
      case SHMGET:
            ret = sys_shmget (first, second, third);
            break;
      case SHMCTL:
            ret = sys_shmctl (first, second, (struct shmid_ds *) ptr);
            break;
      }

      return ret;
}

/*
 * sys_pipe() is the normal C calling standard for creating
 * a pipe. It's not the way unix traditionally does this, though.
 */
int sys_pipe (int *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;
}

static inline unsigned long
do_mmap2 (unsigned long addr, size_t len,
       unsigned long prot, unsigned long flags,
       unsigned long fd, unsigned long pgoff)
{
      struct file * file = NULL;
      int ret = -EBADF;

      flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
      if (! (flags & MAP_ANONYMOUS)) {
            if (!(file = fget (fd)))
                  goto out;
      }
      
      down_write (&current->mm->mmap_sem);
      ret = do_mmap_pgoff (file, addr, len, prot, flags, pgoff);
      up_write (&current->mm->mmap_sem);
      if (file)
            fput (file);
out:
      return ret;
}

unsigned long sys_mmap2 (unsigned long addr, size_t len,
                  unsigned long prot, unsigned long flags,
                  unsigned long fd, unsigned long pgoff)
{
      return do_mmap2 (addr, len, prot, flags, fd, pgoff);
}

unsigned long sys_mmap (unsigned long addr, size_t len,
                   unsigned long prot, unsigned long flags,
                   unsigned long fd, off_t offset)
{
      int err = -EINVAL;

      if (offset & ~PAGE_MASK)
            goto out;

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

/*
 * 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[])
{
      register char *__a __asm__ ("r6") = filename;
      register void *__b __asm__ ("r7") = argv;
      register void *__c __asm__ ("r8") = envp;
      register unsigned long __syscall __asm__ ("r12") = __NR_execve;
      register unsigned long __ret __asm__ ("r10");
      __asm__ __volatile__ ("trap 0"
                  : "=r" (__ret), "=r" (__syscall)
                  : "1" (__syscall), "r" (__a), "r" (__b), "r" (__c)
                  : "r1", "r5", "r11", "r13", "r14",
                    "r15", "r16", "r17", "r18", "r19");
      return __ret;
}

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