arch/i386/kernel/sys_i386.c

   1 /*
   2  * linux/arch/i386/kernel/sys_i386.c
   3  *
   4  * This file contains various random system calls that
   5  * have a non-standard calling sequence on the Linux/i386
   6  * platform.
   7  */
   8
   9 #include <linux/errno.h>
  10 #include <linux/sched.h>
  11 #include <linux/mm.h>
  12 #include <linux/smp.h>
  13 #include <linux/smp_lock.h>
  14 #include <linux/sem.h>
  15 #include <linux/msg.h>
  16 #include <linux/shm.h>
  17 #include <linux/stat.h>
  18 #include <linux/syscalls.h>
  19 #include <linux/mman.h>
  20 #include <linux/file.h>
  21 #include <linux/utsname.h>
  22
  23 #include <asm/uaccess.h>
  24 #include <asm/ipc.h>
  25
  26 /*
  27  * sys_pipe() is the normal C calling standard for creating
  28  * a pipe. It's not the way Unix traditionally does this, though.
  29  */
  30 asmlinkage int sys_pipe(unsigned long __user * fildes)
  31 {
  32         int fd[2];
  33         int error;
  34
  35         error = do_pipe(fd);
  36         if (!error) {
  37                 if (copy_to_user(fildes, fd, 2*sizeof(int)))
  38                         error = -EFAULT;
  39         }
  40         return error;
  41 }
  42
  43 /* common code for old and new mmaps */
  44 static inline long do_mmap2(
  45         unsigned long addr, unsigned long len,
  46         unsigned long prot, unsigned long flags,
  47         unsigned long fd, unsigned long pgoff)
  48 {
  49         int error = -EBADF;
  50         struct file * file = NULL;
  51
  52         flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
  53         if (!(flags & MAP_ANONYMOUS)) {
  54                 file = fget(fd);
  55                 if (!file)
  56                         goto out;
  57         }
  58
  59         down_write(&current->mm->mmap_sem);
  60         error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
  61         up_write(&current->mm->mmap_sem);
  62
  63         if (file)
  64                 fput(file);
  65 out:
  66         return error;
  67 }
  68
  69 asmlinkage long sys_mmap2(unsigned long addr, unsigned long len,
  70         unsigned long prot, unsigned long flags,
  71         unsigned long fd, unsigned long pgoff)
  72 {
  73         return do_mmap2(addr, len, prot, flags, fd, pgoff);
  74 }
  75
  76 /*
  77  * Perform the select(nd, in, out, ex, tv) and mmap() system
  78  * calls. Linux/i386 didn't use to be able to handle more than
  79  * 4 system call parameters, so these system calls used a memory
  80  * block for parameter passing..
  81  */
  82
  83 struct mmap_arg_struct {
  84         unsigned long addr;
  85         unsigned long len;
  86         unsigned long prot;
  87         unsigned long flags;
  88         unsigned long fd;
  89         unsigned long offset;
  90 };
  91
  92 asmlinkage int old_mmap(struct mmap_arg_struct __user *arg)
  93 {
  94         struct mmap_arg_struct a;
  95         int err = -EFAULT;
  96
  97         if (copy_from_user(&a, arg, sizeof(a)))
  98                 goto out;
  99
 100         err = -EINVAL;
 101         if (a.offset & ~PAGE_MASK)
 102                 goto out;
 103
 104         err = do_mmap2(a.addr, a.len, a.prot, a.flags, a.fd, a.offset >> PAGE_SHIFT);
 105 out:
 106         return err;
 107 }
 108
 109
 110 struct sel_arg_struct {
 111         unsigned long n;
 112         fd_set __user *inp, *outp, *exp;
 113         struct timeval __user *tvp;
 114 };
 115
 116 asmlinkage int old_select(struct sel_arg_struct __user *arg)
 117 {
 118         struct sel_arg_struct a;
 119
 120         if (copy_from_user(&a, arg, sizeof(a)))
 121                 return -EFAULT;
 122         /* sys_select() does the appropriate kernel locking */
 123         return sys_select(a.n, a.inp, a.outp, a.exp, a.tvp);
 124 }
 125
 126 /*
 127  * sys_ipc() is the de-multiplexer for the SysV IPC calls..
 128  *
 129  * This is really horribly ugly.
 130  */
 131 asmlinkage int sys_ipc (uint call, int first, int second,
 132                         int third, void __user *ptr, long fifth)
 133 {
 134         int version, ret;
 135
 136         version = call >> 16; /* hack for backward compatibility */
 137         call &= 0xffff;
 138
 139         switch (call) {
 140         case SEMOP:
 141                 return sys_semtimedop (first, (struct sembuf __user *)ptr, second, NULL);
 142         case SEMTIMEDOP:
 143                 return sys_semtimedop(first, (struct sembuf __user *)ptr, second,
 144                                         (const struct timespec __user *)fifth);
 145
 146         case SEMGET:
 147                 return sys_semget (first, second, third);
 148         case SEMCTL: {
 149                 union semun fourth;
 150                 if (!ptr)
 151                         return -EINVAL;
 152                 if (get_user(fourth.__pad, (void __user * __user *) ptr))
 153                         return -EFAULT;
 154                 return sys_semctl (first, second, third, fourth);
 155         }
 156
 157         case MSGSND:
 158                 return sys_msgsnd (first, (struct msgbuf __user *) ptr,
 159                                    second, third);
 160         case MSGRCV:
 161                 switch (version) {
 162                 case 0: {
 163                         struct ipc_kludge tmp;
 164                         if (!ptr)
 165                                 return -EINVAL;
 166
 167                         if (copy_from_user(&tmp,
 168                                            (struct ipc_kludge __user *) ptr,
 169                                            sizeof (tmp)))
 170                                 return -EFAULT;
 171                         return sys_msgrcv (first, tmp.msgp, second,
 172                                            tmp.msgtyp, third);
 173                 }
 174                 default:
 175                         return sys_msgrcv (first,
 176                                            (struct msgbuf __user *) ptr,
 177                                            second, fifth, third);
 178                 }
 179         case MSGGET:
 180                 return sys_msgget ((key_t) first, second);
 181         case MSGCTL:
 182                 return sys_msgctl (first, second, (struct msqid_ds __user *) ptr);
 183
 184         case SHMAT:
 185                 switch (version) {
 186                 default: {
 187                         ulong raddr;
 188                         ret = do_shmat (first, (char __user *) ptr, second, &raddr);
 189                         if (ret)
 190                                 return ret;
 191                         return put_user (raddr, (ulong __user *) third);
 192                 }
 193                 case 1: /* iBCS2 emulator entry point */
 194                         if (!segment_eq(get_fs(), get_ds()))
 195                                 return -EINVAL;
 196                         /* The "(ulong *) third" is valid _only_ because of the kernel segment thing */
 197                         return do_shmat (first, (char __user *) ptr, second, (ulong *) third);
 198                 }
 199         case SHMDT:
 200                 return sys_shmdt ((char __user *)ptr);
 201         case SHMGET:
 202                 return sys_shmget (first, second, third);
 203         case SHMCTL:
 204                 return sys_shmctl (first, second,
 205                                    (struct shmid_ds __user *) ptr);
 206         default:
 207                 return -ENOSYS;
 208         }
 209 }
 210
 211 /*
 212  * Old cruft
 213  */
 214 asmlinkage int sys_uname(struct old_utsname __user * name)
 215 {
 216         int err;
 217         if (!name)
 218                 return -EFAULT;
 219         down_read(&uts_sem);
 220         err=copy_to_user(name, &system_utsname, sizeof (*name));
 221         up_read(&uts_sem);
 222         return err?-EFAULT:0;
 223 }
 224
 225 asmlinkage int sys_olduname(struct oldold_utsname __user * name)
 226 {
 227         int error;
 228
 229         if (!name)
 230                 return -EFAULT;
 231         if (!access_ok(VERIFY_WRITE,name,sizeof(struct oldold_utsname)))
 232                 return -EFAULT;
 233
 234         down_read(&uts_sem);
 235
 236         error = __copy_to_user(&name->sysname,&system_utsname.sysname,__OLD_UTS_LEN);
 237         error |= __put_user(0,name->sysname+__OLD_UTS_LEN);
 238         error |= __copy_to_user(&name->nodename,&system_utsname.nodename,__OLD_UTS_LEN);
 239         error |= __put_user(0,name->nodename+__OLD_UTS_LEN);
 240         error |= __copy_to_user(&name->release,&system_utsname.release,__OLD_UTS_LEN);
 241         error |= __put_user(0,name->release+__OLD_UTS_LEN);
 242         error |= __copy_to_user(&name->version,&system_utsname.version,__OLD_UTS_LEN);
 243         error |= __put_user(0,name->version+__OLD_UTS_LEN);
 244         error |= __copy_to_user(&name->machine,&system_utsname.machine,__OLD_UTS_LEN);
 245         error |= __put_user(0,name->machine+__OLD_UTS_LEN);
 246
 247         up_read(&uts_sem);
 248
 249         error = error ? -EFAULT : 0;
 250
 251         return error;
 252 }