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 asmlinkage long sys_mmap2(unsigned long addr, unsigned long len,
  44                           unsigned long prot, unsigned long flags,
  45                           unsigned long fd, unsigned long pgoff)
  46 {
  47         int error = -EBADF;
  48         struct file *file = NULL;
  49         struct mm_struct *mm = current->mm;
  50
  51         flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
  52         if (!(flags & MAP_ANONYMOUS)) {
  53                 file = fget(fd);
  54                 if (!file)
  55                         goto out;
  56         }
  57
  58         down_write(&mm->mmap_sem);
  59         error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
  60         up_write(&mm->mmap_sem);
  61
  62         if (file)
  63                 fput(file);
  64 out:
  65         return error;
  66 }
  67
  68 /*
  69  * Perform the select(nd, in, out, ex, tv) and mmap() system
  70  * calls. Linux/i386 didn't use to be able to handle more than
  71  * 4 system call parameters, so these system calls used a memory
  72  * block for parameter passing..
  73  */
  74
  75 struct mmap_arg_struct {
  76         unsigned long addr;
  77         unsigned long len;
  78         unsigned long prot;
  79         unsigned long flags;
  80         unsigned long fd;
  81         unsigned long offset;
  82 };
  83
  84 asmlinkage int old_mmap(struct mmap_arg_struct __user *arg)
  85 {
  86         struct mmap_arg_struct a;
  87         int err = -EFAULT;
  88
  89         if (copy_from_user(&a, arg, sizeof(a)))
  90                 goto out;
  91
  92         err = -EINVAL;
  93         if (a.offset & ~PAGE_MASK)
  94                 goto out;
  95
  96         err = sys_mmap2(a.addr, a.len, a.prot, a.flags,
  97                         a.fd, a.offset >> PAGE_SHIFT);
  98 out:
  99         return err;
 100 }
 101
 102
 103 struct sel_arg_struct {
 104         unsigned long n;
 105         fd_set __user *inp, *outp, *exp;
 106         struct timeval __user *tvp;
 107 };
 108
 109 asmlinkage int old_select(struct sel_arg_struct __user *arg)
 110 {
 111         struct sel_arg_struct a;
 112
 113         if (copy_from_user(&a, arg, sizeof(a)))
 114                 return -EFAULT;
 115         /* sys_select() does the appropriate kernel locking */
 116         return sys_select(a.n, a.inp, a.outp, a.exp, a.tvp);
 117 }
 118
 119 /*
 120  * sys_ipc() is the de-multiplexer for the SysV IPC calls..
 121  *
 122  * This is really horribly ugly.
 123  */
 124 asmlinkage int sys_ipc (uint call, int first, int second,
 125                         int third, void __user *ptr, long fifth)
 126 {
 127         int version, ret;
 128
 129         version = call >> 16; /* hack for backward compatibility */
 130         call &= 0xffff;
 131
 132         switch (call) {
 133         case SEMOP:
 134                 return sys_semtimedop (first, (struct sembuf __user *)ptr, second, NULL);
 135         case SEMTIMEDOP:
 136                 return sys_semtimedop(first, (struct sembuf __user *)ptr, second,
 137                                         (const struct timespec __user *)fifth);
 138
 139         case SEMGET:
 140                 return sys_semget (first, second, third);
 141         case SEMCTL: {
 142                 union semun fourth;
 143                 if (!ptr)
 144                         return -EINVAL;
 145                 if (get_user(fourth.__pad, (void __user * __user *) ptr))
 146                         return -EFAULT;
 147                 return sys_semctl (first, second, third, fourth);
 148         }
 149
 150         case MSGSND:
 151                 return sys_msgsnd (first, (struct msgbuf __user *) ptr,
 152                                    second, third);
 153         case MSGRCV:
 154                 switch (version) {
 155                 case 0: {
 156                         struct ipc_kludge tmp;
 157                         if (!ptr)
 158                                 return -EINVAL;
 159
 160                         if (copy_from_user(&tmp,
 161                                            (struct ipc_kludge __user *) ptr,
 162                                            sizeof (tmp)))
 163                                 return -EFAULT;
 164                         return sys_msgrcv (first, tmp.msgp, second,
 165                                            tmp.msgtyp, third);
 166                 }
 167                 default:
 168                         return sys_msgrcv (first,
 169                                            (struct msgbuf __user *) ptr,
 170                                            second, fifth, third);
 171                 }
 172         case MSGGET:
 173                 return sys_msgget ((key_t) first, second);
 174         case MSGCTL:
 175                 return sys_msgctl (first, second, (struct msqid_ds __user *) ptr);
 176
 177         case SHMAT:
 178                 switch (version) {
 179                 default: {
 180                         ulong raddr;
 181                         ret = do_shmat (first, (char __user *) ptr, second, &raddr);
 182                         if (ret)
 183                                 return ret;
 184                         return put_user (raddr, (ulong __user *) third);
 185                 }
 186                 case 1: /* iBCS2 emulator entry point */
 187                         if (!segment_eq(get_fs(), get_ds()))
 188                                 return -EINVAL;
 189                         /* The "(ulong *) third" is valid _only_ because of the kernel segment thing */
 190                         return do_shmat (first, (char __user *) ptr, second, (ulong *) third);
 191                 }
 192         case SHMDT:
 193                 return sys_shmdt ((char __user *)ptr);
 194         case SHMGET:
 195                 return sys_shmget (first, second, third);
 196         case SHMCTL:
 197                 return sys_shmctl (first, second,
 198                                    (struct shmid_ds __user *) ptr);
 199         default:
 200                 return -ENOSYS;
 201         }
 202 }
 203
 204 /*
 205  * Old cruft
 206  */
 207 asmlinkage int sys_uname(struct old_utsname __user * name)
 208 {
 209         int err;
 210         if (!name)
 211                 return -EFAULT;
 212         down_read(&uts_sem);
 213         err=copy_to_user(name, &system_utsname, sizeof (*name));
 214         up_read(&uts_sem);
 215         return err?-EFAULT:0;
 216 }
 217
 218 asmlinkage int sys_olduname(struct oldold_utsname __user * name)
 219 {
 220         int error;
 221
 222         if (!name)
 223                 return -EFAULT;
 224         if (!access_ok(VERIFY_WRITE,name,sizeof(struct oldold_utsname)))
 225                 return -EFAULT;
 226
 227         down_read(&uts_sem);
 228
 229         error = __copy_to_user(&name->sysname,&system_utsname.sysname,__OLD_UTS_LEN);
 230         error |= __put_user(0,name->sysname+__OLD_UTS_LEN);
 231         error |= __copy_to_user(&name->nodename,&system_utsname.nodename,__OLD_UTS_LEN);
 232         error |= __put_user(0,name->nodename+__OLD_UTS_LEN);
 233         error |= __copy_to_user(&name->release,&system_utsname.release,__OLD_UTS_LEN);
 234         error |= __put_user(0,name->release+__OLD_UTS_LEN);
 235         error |= __copy_to_user(&name->version,&system_utsname.version,__OLD_UTS_LEN);
 236         error |= __put_user(0,name->version+__OLD_UTS_LEN);
 237         error |= __copy_to_user(&name->machine,&system_utsname.machine,__OLD_UTS_LEN);
 238         error |= __put_user(0,name->machine+__OLD_UTS_LEN);
 239
 240         up_read(&uts_sem);
 241
 242         error = error ? -EFAULT : 0;
 243
 244         return error;
 245 }