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/mman.h>
  19 #include <linux/file.h>
  20 #include <linux/utsname.h>
  21
  22 #include <asm/uaccess.h>
  23 #include <asm/ipc.h>
  24
  25 /*
  26  * sys_pipe() is the normal C calling standard for creating
  27  * a pipe. It's not the way Unix traditionally does this, though.
  28  */
  29 asmlinkage int sys_pipe(unsigned long * fildes)
  30 {
  31         int fd[2];
  32         int error;
  33
  34         error = do_pipe(fd);
  35         if (!error) {
  36                 if (copy_to_user(fildes, fd, 2*sizeof(int)))
  37                         error = -EFAULT;
  38         }
  39         return error;
  40 }
  41
  42 /* common code for old and new mmaps */
  43 static inline long do_mmap2(
  44         unsigned long addr, unsigned long len,
  45         unsigned long prot, unsigned long flags,
  46         unsigned long fd, unsigned long pgoff)
  47 {
  48         int error = -EBADF;
  49         struct file * file = NULL;
  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(&current->mm->mmap_sem);
  59         error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
  60         up(&current->mm->mmap_sem);
  61
  62         if (file)
  63                 fput(file);
  64 out:
  65         return error;
  66 }
  67
  68 asmlinkage long sys_mmap2(unsigned long addr, unsigned long len,
  69         unsigned long prot, unsigned long flags,
  70         unsigned long fd, unsigned long pgoff)
  71 {
  72         return do_mmap2(addr, len, prot, flags, fd, pgoff);
  73 }
  74
  75 /*
  76  * Perform the select(nd, in, out, ex, tv) and mmap() system
  77  * calls. Linux/i386 didn't use to be able to handle more than
  78  * 4 system call parameters, so these system calls used a memory
  79  * block for parameter passing..
  80  */
  81
  82 struct mmap_arg_struct {
  83         unsigned long addr;
  84         unsigned long len;
  85         unsigned long prot;
  86         unsigned long flags;
  87         unsigned long fd;
  88         unsigned long offset;
  89 };
  90
  91 asmlinkage int old_mmap(struct mmap_arg_struct *arg)
  92 {
  93         struct mmap_arg_struct a;
  94         int err = -EFAULT;
  95
  96         if (copy_from_user(&a, arg, sizeof(a)))
  97                 goto out;
  98
  99         err = -EINVAL;
 100         if (a.offset & ~PAGE_MASK)
 101                 goto out;
 102
 103         err = do_mmap2(a.addr, a.len, a.prot, a.flags, a.fd, a.offset >> PAGE_SHIFT);
 104 out:
 105         return err;
 106 }
 107
 108
 109 extern asmlinkage int sys_select(int, fd_set *, fd_set *, fd_set *, struct timeval *);
 110
 111 struct sel_arg_struct {
 112         unsigned long n;
 113         fd_set *inp, *outp, *exp;
 114         struct timeval *tvp;
 115 };
 116
 117 asmlinkage int old_select(struct sel_arg_struct *arg)
 118 {
 119         struct sel_arg_struct a;
 120
 121         if (copy_from_user(&a, arg, sizeof(a)))
 122                 return -EFAULT;
 123         /* sys_select() does the appropriate kernel locking */
 124         return sys_select(a.n, a.inp, a.outp, a.exp, a.tvp);
 125 }
 126
 127 /*
 128  * sys_ipc() is the de-multiplexer for the SysV IPC calls..
 129  *
 130  * This is really horribly ugly.
 131  */
 132 asmlinkage int sys_ipc (uint call, int first, int second,
 133                         int third, void *ptr, long fifth)
 134 {
 135         int version, ret;
 136
 137         version = call >> 16; /* hack for backward compatibility */
 138         call &= 0xffff;
 139
 140         switch (call) {
 141         case SEMOP:
 142                 return sys_semop (first, (struct sembuf *)ptr, second);
 143         case SEMGET:
 144                 return sys_semget (first, second, third);
 145         case SEMCTL: {
 146                 union semun fourth;
 147                 if (!ptr)
 148                         return -EINVAL;
 149                 if (get_user(fourth.__pad, (void **) ptr))
 150                         return -EFAULT;
 151                 return sys_semctl (first, second, third, fourth);
 152         }
 153
 154         case MSGSND:
 155                 return sys_msgsnd (first, (struct msgbuf *) ptr,
 156                                    second, third);
 157         case MSGRCV:
 158                 switch (version) {
 159                 case 0: {
 160                         struct ipc_kludge tmp;
 161                         if (!ptr)
 162                                 return -EINVAL;
 163
 164                         if (copy_from_user(&tmp,
 165                                            (struct ipc_kludge *) ptr,
 166                                            sizeof (tmp)))
 167                                 return -EFAULT;
 168                         return sys_msgrcv (first, tmp.msgp, second,
 169                                            tmp.msgtyp, third);
 170                 }
 171                 default:
 172                         return sys_msgrcv (first,
 173                                            (struct msgbuf *) ptr,
 174                                            second, fifth, third);
 175                 }
 176         case MSGGET:
 177                 return sys_msgget ((key_t) first, second);
 178         case MSGCTL:
 179                 return sys_msgctl (first, second, (struct msqid_ds *) ptr);
 180
 181         case SHMAT:
 182                 switch (version) {
 183                 default: {
 184                         ulong raddr;
 185                         ret = sys_shmat (first, (char *) ptr, second, &raddr);
 186                         if (ret)
 187                                 return ret;
 188                         return put_user (raddr, (ulong *) third);
 189                 }
 190                 case 1: /* iBCS2 emulator entry point */
 191                         if (!segment_eq(get_fs(), get_ds()))
 192                                 return -EINVAL;
 193                         return sys_shmat (first, (char *) ptr, second, (ulong *) third);
 194                 }
 195         case SHMDT:
 196                 return sys_shmdt ((char *)ptr);
 197         case SHMGET:
 198                 return sys_shmget (first, second, third);
 199         case SHMCTL:
 200                 return sys_shmctl (first, second,
 201                                    (struct shmid_ds *) ptr);
 202         default:
 203                 return -EINVAL;
 204         }
 205 }
 206
 207 /*
 208  * Old cruft
 209  */
 210 asmlinkage int sys_uname(struct old_utsname * name)
 211 {
 212         int err;
 213         if (!name)
 214                 return -EFAULT;
 215         down_read(&uts_sem);
 216         err=copy_to_user(name, &system_utsname, sizeof (*name));
 217         up_read(&uts_sem);
 218         return err?-EFAULT:0;
 219 }
 220
 221 asmlinkage int sys_olduname(struct oldold_utsname * name)
 222 {
 223         int error;
 224
 225         if (!name)
 226                 return -EFAULT;
 227         if (!access_ok(VERIFY_WRITE,name,sizeof(struct oldold_utsname)))
 228                 return -EFAULT;
 229
 230         down_read(&uts_sem);
 231
 232         error = __copy_to_user(&name->sysname,&system_utsname.sysname,__OLD_UTS_LEN);
 233         error |= __put_user(0,name->sysname+__OLD_UTS_LEN);
 234         error |= __copy_to_user(&name->nodename,&system_utsname.nodename,__OLD_UTS_LEN);
 235         error |= __put_user(0,name->nodename+__OLD_UTS_LEN);
 236         error |= __copy_to_user(&name->release,&system_utsname.release,__OLD_UTS_LEN);
 237         error |= __put_user(0,name->release+__OLD_UTS_LEN);
 238         error |= __copy_to_user(&name->version,&system_utsname.version,__OLD_UTS_LEN);
 239         error |= __put_user(0,name->version+__OLD_UTS_LEN);
 240         error |= __copy_to_user(&name->machine,&system_utsname.machine,__OLD_UTS_LEN);
 241         error |= __put_user(0,name->machine+__OLD_UTS_LEN);
 242
 243         up_read(&uts_sem);
 244
 245         error = error ? -EFAULT : 0;
 246
 247         return error;
 248 }
 249
 250 asmlinkage int sys_pause(void)
 251 {
 252         current->state = TASK_INTERRUPTIBLE;
 253         schedule();
 254         return -ERESTARTNOHAND;
 255 }
 256