block/compat_ioctl.c

   1 #include <linux/blkdev.h>
   2 #include <linux/blkpg.h>
   3 #include <linux/blktrace_api.h>
   4 #include <linux/cdrom.h>
   5 #include <linux/compat.h>
   6 #include <linux/elevator.h>
   7 #include <linux/hdreg.h>
   8 #include <linux/slab.h>
   9 #include <linux/syscalls.h>
  10 #include <linux/types.h>
  11 #include <linux/uaccess.h>
  12
  13 static int compat_put_ushort(unsigned long arg, unsigned short val)
  14 {
  15         return put_user(val, (unsigned short __user *)compat_ptr(arg));
  16 }
  17
  18 static int compat_put_int(unsigned long arg, int val)
  19 {
  20         return put_user(val, (compat_int_t __user *)compat_ptr(arg));
  21 }
  22
  23 static int compat_put_uint(unsigned long arg, unsigned int val)
  24 {
  25         return put_user(val, (compat_uint_t __user *)compat_ptr(arg));
  26 }
  27
  28 static int compat_put_long(unsigned long arg, long val)
  29 {
  30         return put_user(val, (compat_long_t __user *)compat_ptr(arg));
  31 }
  32
  33 static int compat_put_ulong(unsigned long arg, compat_ulong_t val)
  34 {
  35         return put_user(val, (compat_ulong_t __user *)compat_ptr(arg));
  36 }
  37
  38 static int compat_put_u64(unsigned long arg, u64 val)
  39 {
  40         return put_user(val, (compat_u64 __user *)compat_ptr(arg));
  41 }
  42
  43 struct compat_hd_geometry {
  44         unsigned char heads;
  45         unsigned char sectors;
  46         unsigned short cylinders;
  47         u32 start;
  48 };
  49
  50 static int compat_hdio_getgeo(struct gendisk *disk, struct block_device *bdev,
  51                         struct compat_hd_geometry __user *ugeo)
  52 {
  53         struct hd_geometry geo;
  54         int ret;
  55
  56         if (!ugeo)
  57                 return -EINVAL;
  58         if (!disk->fops->getgeo)
  59                 return -ENOTTY;
  60
  61         memset(&geo, 0, sizeof(geo));
  62         /*
  63          * We need to set the startsect first, the driver may
  64          * want to override it.
  65          */
  66         geo.start = get_start_sect(bdev);
  67         ret = disk->fops->getgeo(bdev, &geo);
  68         if (ret)
  69                 return ret;
  70
  71         ret = copy_to_user(ugeo, &geo, 4);
  72         ret |= put_user(geo.start, &ugeo->start);
  73         if (ret)
  74                 ret = -EFAULT;
  75
  76         return ret;
  77 }
  78
  79 static int compat_hdio_ioctl(struct block_device *bdev, fmode_t mode,
  80                 unsigned int cmd, unsigned long arg)
  81 {
  82         mm_segment_t old_fs = get_fs();
  83         unsigned long kval;
  84         unsigned int __user *uvp;
  85         int error;
  86
  87         set_fs(KERNEL_DS);
  88         error = __blkdev_driver_ioctl(bdev, mode,
  89                                 cmd, (unsigned long)(&kval));
  90         set_fs(old_fs);
  91
  92         if (error == 0) {
  93                 uvp = compat_ptr(arg);
  94                 if (put_user(kval, uvp))
  95                         error = -EFAULT;
  96         }
  97         return error;
  98 }
  99
 100 struct compat_cdrom_read_audio {
 101         union cdrom_addr        addr;
 102         u8                      addr_format;
 103         compat_int_t            nframes;
 104         compat_caddr_t          buf;
 105 };
 106
 107 struct compat_cdrom_generic_command {
 108         unsigned char   cmd[CDROM_PACKET_SIZE];
 109         compat_caddr_t  buffer;
 110         compat_uint_t   buflen;
 111         compat_int_t    stat;
 112         compat_caddr_t  sense;
 113         unsigned char   data_direction;
 114         compat_int_t    quiet;
 115         compat_int_t    timeout;
 116         compat_caddr_t  reserved[1];
 117 };
 118
 119 static int compat_cdrom_read_audio(struct block_device *bdev, fmode_t mode,
 120                 unsigned int cmd, unsigned long arg)
 121 {
 122         struct cdrom_read_audio __user *cdread_audio;
 123         struct compat_cdrom_read_audio __user *cdread_audio32;
 124         __u32 data;
 125         void __user *datap;
 126
 127         cdread_audio = compat_alloc_user_space(sizeof(*cdread_audio));
 128         cdread_audio32 = compat_ptr(arg);
 129
 130         if (copy_in_user(&cdread_audio->addr,
 131                          &cdread_audio32->addr,
 132                          (sizeof(*cdread_audio32) -
 133                           sizeof(compat_caddr_t))))
 134                 return -EFAULT;
 135
 136         if (get_user(data, &cdread_audio32->buf))
 137                 return -EFAULT;
 138         datap = compat_ptr(data);
 139         if (put_user(datap, &cdread_audio->buf))
 140                 return -EFAULT;
 141
 142         return __blkdev_driver_ioctl(bdev, mode, cmd,
 143                         (unsigned long)cdread_audio);
 144 }
 145
 146 static int compat_cdrom_generic_command(struct block_device *bdev, fmode_t mode,
 147                 unsigned int cmd, unsigned long arg)
 148 {
 149         struct cdrom_generic_command __user *cgc;
 150         struct compat_cdrom_generic_command __user *cgc32;
 151         u32 data;
 152         unsigned char dir;
 153         int itmp;
 154
 155         cgc = compat_alloc_user_space(sizeof(*cgc));
 156         cgc32 = compat_ptr(arg);
 157
 158         if (copy_in_user(&cgc->cmd, &cgc32->cmd, sizeof(cgc->cmd)) ||
 159             get_user(data, &cgc32->buffer) ||
 160             put_user(compat_ptr(data), &cgc->buffer) ||
 161             copy_in_user(&cgc->buflen, &cgc32->buflen,
 162                          (sizeof(unsigned int) + sizeof(int))) ||
 163             get_user(data, &cgc32->sense) ||
 164             put_user(compat_ptr(data), &cgc->sense) ||
 165             get_user(dir, &cgc32->data_direction) ||
 166             put_user(dir, &cgc->data_direction) ||
 167             get_user(itmp, &cgc32->quiet) ||
 168             put_user(itmp, &cgc->quiet) ||
 169             get_user(itmp, &cgc32->timeout) ||
 170             put_user(itmp, &cgc->timeout) ||
 171             get_user(data, &cgc32->reserved[0]) ||
 172             put_user(compat_ptr(data), &cgc->reserved[0]))
 173                 return -EFAULT;
 174
 175         return __blkdev_driver_ioctl(bdev, mode, cmd, (unsigned long)cgc);
 176 }
 177
 178 struct compat_blkpg_ioctl_arg {
 179         compat_int_t op;
 180         compat_int_t flags;
 181         compat_int_t datalen;
 182         compat_caddr_t data;
 183 };
 184
 185 static int compat_blkpg_ioctl(struct block_device *bdev, fmode_t mode,
 186                 unsigned int cmd, struct compat_blkpg_ioctl_arg __user *ua32)
 187 {
 188         struct blkpg_ioctl_arg __user *a = compat_alloc_user_space(sizeof(*a));
 189         compat_caddr_t udata;
 190         compat_int_t n;
 191         int err;
 192
 193         err = get_user(n, &ua32->op);
 194         err |= put_user(n, &a->op);
 195         err |= get_user(n, &ua32->flags);
 196         err |= put_user(n, &a->flags);
 197         err |= get_user(n, &ua32->datalen);
 198         err |= put_user(n, &a->datalen);
 199         err |= get_user(udata, &ua32->data);
 200         err |= put_user(compat_ptr(udata), &a->data);
 201         if (err)
 202                 return err;
 203
 204         return blkdev_ioctl(bdev, mode, cmd, (unsigned long)a);
 205 }
 206
 207 #define BLKBSZGET_32            _IOR(0x12, 112, int)
 208 #define BLKBSZSET_32            _IOW(0x12, 113, int)
 209 #define BLKGETSIZE64_32         _IOR(0x12, 114, int)
 210
 211 static int compat_blkdev_driver_ioctl(struct block_device *bdev, fmode_t mode,
 212                         unsigned cmd, unsigned long arg)
 213 {
 214         switch (cmd) {
 215         case HDIO_GET_UNMASKINTR:
 216         case HDIO_GET_MULTCOUNT:
 217         case HDIO_GET_KEEPSETTINGS:
 218         case HDIO_GET_32BIT:
 219         case HDIO_GET_NOWERR:
 220         case HDIO_GET_DMA:
 221         case HDIO_GET_NICE:
 222         case HDIO_GET_WCACHE:
 223         case HDIO_GET_ACOUSTIC:
 224         case HDIO_GET_ADDRESS:
 225         case HDIO_GET_BUSSTATE:
 226                 return compat_hdio_ioctl(bdev, mode, cmd, arg);
 227         case CDROMREADAUDIO:
 228                 return compat_cdrom_read_audio(bdev, mode, cmd, arg);
 229         case CDROM_SEND_PACKET:
 230                 return compat_cdrom_generic_command(bdev, mode, cmd, arg);
 231
 232         /*
 233          * No handler required for the ones below, we just need to
 234          * convert arg to a 64 bit pointer.
 235          */
 236         case BLKSECTSET:
 237         /*
 238          * 0x03 -- HD/IDE ioctl's used by hdparm and friends.
 239          *         Some need translations, these do not.
 240          */
 241         case HDIO_GET_IDENTITY:
 242         case HDIO_DRIVE_TASK:
 243         case HDIO_DRIVE_CMD:
 244         /* 0x330 is reserved -- it used to be HDIO_GETGEO_BIG */
 245         case 0x330:
 246         /* CDROM stuff */
 247         case CDROMPAUSE:
 248         case CDROMRESUME:
 249         case CDROMPLAYMSF:
 250         case CDROMPLAYTRKIND:
 251         case CDROMREADTOCHDR:
 252         case CDROMREADTOCENTRY:
 253         case CDROMSTOP:
 254         case CDROMSTART:
 255         case CDROMEJECT:
 256         case CDROMVOLCTRL:
 257         case CDROMSUBCHNL:
 258         case CDROMMULTISESSION:
 259         case CDROM_GET_MCN:
 260         case CDROMRESET:
 261         case CDROMVOLREAD:
 262         case CDROMSEEK:
 263         case CDROMPLAYBLK:
 264         case CDROMCLOSETRAY:
 265         case CDROM_DISC_STATUS:
 266         case CDROM_CHANGER_NSLOTS:
 267         case CDROM_GET_CAPABILITY:
 268         /* Ignore cdrom.h about these next 5 ioctls, they absolutely do
 269          * not take a struct cdrom_read, instead they take a struct cdrom_msf
 270          * which is compatible.
 271          */
 272         case CDROMREADMODE2:
 273         case CDROMREADMODE1:
 274         case CDROMREADRAW:
 275         case CDROMREADCOOKED:
 276         case CDROMREADALL:
 277         /* DVD ioctls */
 278         case DVD_READ_STRUCT:
 279         case DVD_WRITE_STRUCT:
 280         case DVD_AUTH:
 281                 arg = (unsigned long)compat_ptr(arg);
 282         /* These intepret arg as an unsigned long, not as a pointer,
 283          * so we must not do compat_ptr() conversion. */
 284         case HDIO_SET_MULTCOUNT:
 285         case HDIO_SET_UNMASKINTR:
 286         case HDIO_SET_KEEPSETTINGS:
 287         case HDIO_SET_32BIT:
 288         case HDIO_SET_NOWERR:
 289         case HDIO_SET_DMA:
 290         case HDIO_SET_PIO_MODE:
 291         case HDIO_SET_NICE:
 292         case HDIO_SET_WCACHE:
 293         case HDIO_SET_ACOUSTIC:
 294         case HDIO_SET_BUSSTATE:
 295         case HDIO_SET_ADDRESS:
 296         case CDROMEJECT_SW:
 297         case CDROM_SET_OPTIONS:
 298         case CDROM_CLEAR_OPTIONS:
 299         case CDROM_SELECT_SPEED:
 300         case CDROM_SELECT_DISC:
 301         case CDROM_MEDIA_CHANGED:
 302         case CDROM_DRIVE_STATUS:
 303         case CDROM_LOCKDOOR:
 304         case CDROM_DEBUG:
 305                 break;
 306         default:
 307                 /* unknown ioctl number */
 308                 return -ENOIOCTLCMD;
 309         }
 310
 311         return __blkdev_driver_ioctl(bdev, mode, cmd, arg);
 312 }
 313
 314 /* Most of the generic ioctls are handled in the normal fallback path.
 315    This assumes the blkdev's low level compat_ioctl always returns
 316    ENOIOCTLCMD for unknown ioctls. */
 317 long compat_blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg)
 318 {
 319         int ret = -ENOIOCTLCMD;
 320         struct inode *inode = file->f_mapping->host;
 321         struct block_device *bdev = inode->i_bdev;
 322         struct gendisk *disk = bdev->bd_disk;
 323         fmode_t mode = file->f_mode;
 324         struct backing_dev_info *bdi;
 325         loff_t size;
 326         unsigned int max_sectors;
 327
 328         /*
 329          * O_NDELAY can be altered using fcntl(.., F_SETFL, ..), so we have
 330          * to updated it before every ioctl.
 331          */
 332         if (file->f_flags & O_NDELAY)
 333                 mode |= FMODE_NDELAY;
 334         else
 335                 mode &= ~FMODE_NDELAY;
 336
 337         switch (cmd) {
 338         case HDIO_GETGEO:
 339                 return compat_hdio_getgeo(disk, bdev, compat_ptr(arg));
 340         case BLKPBSZGET:
 341                 return compat_put_uint(arg, bdev_physical_block_size(bdev));
 342         case BLKIOMIN:
 343                 return compat_put_uint(arg, bdev_io_min(bdev));
 344         case BLKIOOPT:
 345                 return compat_put_uint(arg, bdev_io_opt(bdev));
 346         case BLKALIGNOFF:
 347                 return compat_put_int(arg, bdev_alignment_offset(bdev));
 348         case BLKDISCARDZEROES:
 349                 return compat_put_uint(arg, bdev_discard_zeroes_data(bdev));
 350         case BLKFLSBUF:
 351         case BLKROSET:
 352         case BLKDISCARD:
 353         case BLKSECDISCARD:
 354         case BLKZEROOUT:
 355         /*
 356          * the ones below are implemented in blkdev_locked_ioctl,
 357          * but we call blkdev_ioctl, which gets the lock for us
 358          */
 359         case BLKRRPART:
 360                 return blkdev_ioctl(bdev, mode, cmd,
 361                                 (unsigned long)compat_ptr(arg));
 362         case BLKBSZSET_32:
 363                 return blkdev_ioctl(bdev, mode, BLKBSZSET,
 364                                 (unsigned long)compat_ptr(arg));
 365         case BLKPG:
 366                 return compat_blkpg_ioctl(bdev, mode, cmd, compat_ptr(arg));
 367         case BLKRAGET:
 368         case BLKFRAGET:
 369                 if (!arg)
 370                         return -EINVAL;
 371                 bdi = blk_get_backing_dev_info(bdev);
 372                 return compat_put_long(arg,
 373                                        (bdi->ra_pages * PAGE_SIZE) / 512);
 374         case BLKROGET: /* compatible */
 375                 return compat_put_int(arg, bdev_read_only(bdev) != 0);
 376         case BLKBSZGET_32: /* get the logical block size (cf. BLKSSZGET) */
 377                 return compat_put_int(arg, block_size(bdev));
 378         case BLKSSZGET: /* get block device hardware sector size */
 379                 return compat_put_int(arg, bdev_logical_block_size(bdev));
 380         case BLKSECTGET:
 381                 max_sectors = min_t(unsigned int, USHRT_MAX,
 382                                     queue_max_sectors(bdev_get_queue(bdev)));
 383                 return compat_put_ushort(arg, max_sectors);
 384         case BLKROTATIONAL:
 385                 return compat_put_ushort(arg,
 386                                          !blk_queue_nonrot(bdev_get_queue(bdev)));
 387         case BLKRASET: /* compatible, but no compat_ptr (!) */
 388         case BLKFRASET:
 389                 if (!capable(CAP_SYS_ADMIN))
 390                         return -EACCES;
 391                 bdi = blk_get_backing_dev_info(bdev);
 392                 bdi->ra_pages = (arg * 512) / PAGE_SIZE;
 393                 return 0;
 394         case BLKGETSIZE:
 395                 size = i_size_read(bdev->bd_inode);
 396                 if ((size >> 9) > ~0UL)
 397                         return -EFBIG;
 398                 return compat_put_ulong(arg, size >> 9);
 399
 400         case BLKGETSIZE64_32:
 401                 return compat_put_u64(arg, i_size_read(bdev->bd_inode));
 402
 403         case BLKTRACESETUP32:
 404         case BLKTRACESTART: /* compatible */
 405         case BLKTRACESTOP:  /* compatible */
 406         case BLKTRACETEARDOWN: /* compatible */
 407                 ret = blk_trace_ioctl(bdev, cmd, compat_ptr(arg));
 408                 return ret;
 409         default:
 410                 if (disk->fops->compat_ioctl)
 411                         ret = disk->fops->compat_ioctl(bdev, mode, cmd, arg);
 412                 if (ret == -ENOIOCTLCMD)
 413                         ret = compat_blkdev_driver_ioctl(bdev, mode, cmd, arg);
 414                 return ret;
 415         }
 416 }