arch/mips/kernel/sysmips.c

   1 /*
   2  * MIPS specific syscalls
   3  *
   4  * This file is subject to the terms and conditions of the GNU General Public
   5  * License.  See the file "COPYING" in the main directory of this archive
   6  * for more details.
   7  *
   8  * Copyright (C) 1995, 1996, 1997 by Ralf Baechle
   9  *
  10  * $Id: sysmips.c,v 1.6 1998/08/25 09:14:42 ralf Exp $
  11  */
  12 #include <linux/errno.h>
  13 #include <linux/linkage.h>
  14 #include <linux/mm.h>
  15 #include <linux/smp.h>
  16 #include <linux/smp_lock.h>
  17 #include <linux/sched.h>
  18 #include <linux/string.h>
  19 #include <linux/utsname.h>
  20
  21 #include <asm/cachectl.h>
  22 #include <asm/pgtable.h>
  23 #include <asm/sysmips.h>
  24 #include <asm/uaccess.h>
  25
  26 /*
  27  * How long a hostname can we get from user space?
  28  *  -EFAULT if invalid area or too long
  29  *  0 if ok
  30  *  >0 EFAULT after xx bytes
  31  */
  32 static inline int
  33 get_max_hostname(unsigned long address)
  34 {
  35         struct vm_area_struct * vma;
  36
  37         vma = find_vma(current->mm, address);
  38         if (!vma || vma->vm_start > address || !(vma->vm_flags & VM_READ))
  39                 return -EFAULT;
  40         address = vma->vm_end - address;
  41         if (address > PAGE_SIZE)
  42                 return 0;
  43         if (vma->vm_next && vma->vm_next->vm_start == vma->vm_end &&
  44            (vma->vm_next->vm_flags & VM_READ))
  45                 return 0;
  46         return address;
  47 }
  48
  49 asmlinkage int
  50 sys_sysmips(int cmd, int arg1, int arg2, int arg3)
  51 {
  52         int     *p;
  53         char    *name;
  54         int     flags, tmp, len, retval;
  55
  56         lock_kernel();
  57         switch(cmd)
  58         {
  59         case SETNAME:
  60                 retval = -EPERM;
  61                 if (!capable(CAP_SYS_ADMIN))
  62                         goto out;
  63
  64                 name = (char *) arg1;
  65                 len = strlen_user(name);
  66
  67                 retval = len;
  68                 if (len < 0)
  69                         goto out;
  70
  71                 retval = -EINVAL;
  72                 if (len == 0 || len > __NEW_UTS_LEN)
  73                         goto out;
  74
  75                 copy_from_user(system_utsname.nodename, name, len);
  76                 system_utsname.nodename[len] = '\0';
  77                 retval = 0;
  78                 goto out;
  79
  80         case MIPS_ATOMIC_SET:
  81                 /* This is broken in case of page faults and SMP ...
  82                    Risc/OS fauls after maximum 20 tries with EAGAIN.  */
  83                 p = (int *) arg1;
  84                 retval = verify_area(VERIFY_WRITE, p, sizeof(*p));
  85                 if (retval)
  86                         goto out;
  87                 save_and_cli(flags);
  88                 retval = *p;
  89                 *p = arg2;
  90                 restore_flags(flags);
  91                 goto out;
  92
  93         case MIPS_FIXADE:
  94                 tmp = current->tss.mflags & ~3;
  95                 current->tss.mflags = tmp | (arg1 & 3);
  96                 retval = 0;
  97                 goto out;
  98
  99         case FLUSH_CACHE:
 100                 flush_cache_all();
 101                 retval = 0;
 102                 goto out;
 103
 104         case MIPS_RDNVRAM:
 105                 retval = -EIO;
 106                 goto out;
 107
 108         default:
 109                 retval = -EINVAL;
 110                 goto out;
 111         }
 112
 113 out:
 114         unlock_kernel();
 115         return retval;
 116 }
 117
 118 /*
 119  * No implemented yet ...
 120  */
 121 asmlinkage int
 122 sys_cachectl(char *addr, int nbytes, int op)
 123 {
 124         return -ENOSYS;
 125 }