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/pr.h>
   9 #include <linux/slab.h>
  10 #include <linux/syscalls.h>
  11 #include <linux/types.h>
  12 #include <linux/uaccess.h>
  13
  14 static int compat_put_ushort(unsigned long arg, unsigned short val)
  15 {
  16         return put_user(val, (unsigned short __user *)compat_ptr(arg));
  17 }
  18
  19 static int compat_put_int(unsigned long arg, int val)
  20 {
  21         return put_user(val, (compat_int_t __user *)compat_ptr(arg));
  22 }
  23
  24 static int compat_put_uint(unsigned long arg, unsigned int val)
  25 {
  26         return put_user(val, (compat_uint_t __user *)compat_ptr(arg));
  27 }
  28
  29 static int compat_put_long(unsigned long arg, long val)
  30 {
  31         return put_user(val, (compat_long_t __user *)compat_ptr(arg));
  32 }
  33
  34 static int compat_put_ulong(unsigned long arg, compat_ulong_t val)
  35 {
  36         return put_user(val, (compat_ulong_t __user *)compat_ptr(arg));
  37 }
  38
  39 static int compat_put_u64(unsigned long arg, u64 val)
  40 {
  41         return put_user(val, (compat_u64 __user *)compat_ptr(arg));
  42 }
  43
  44 struct compat_hd_geometry {
  45         unsigned char heads;
  46         unsigned char sectors;
  47         unsigned short cylinders;
  48         u32 start;
  49 };
  50
  51 static int compat_hdio_getgeo(struct gendisk *disk, struct block_device *bdev,
  52                         struct compat_hd_geometry __user *ugeo)
  53 {
  54         struct hd_geometry geo;
  55         int ret;
  56
  57         if (!ugeo)
  58                 return -EINVAL;
  59         if (!disk->fops->getgeo)
  60                 return -ENOTTY;
  61
  62         memset(&geo, 0, sizeof(geo));
  63         /*
  64          * We need to set the startsect first, the driver may
  65          * want to override it.
  66          */
  67         geo.start = get_start_sect(bdev);
  68         ret = disk->fops->getgeo(bdev, &geo);
  69         if (ret)
  70                 return ret;
  71
  72         ret = copy_to_user(ugeo, &geo, 4);
  73         ret |= put_user(geo.start, &ugeo->start);
  74         if (ret)
  75                 ret = -EFAULT;
  76
  77         return ret;
  78 }
  79
  80 static int compat_hdio_ioctl(struct block_device *bdev, fmode_t mode,
  81                 unsigned int cmd, unsigned long arg)
  82 {
  83         mm_segment_t old_fs = get_fs();
  84         unsigned long kval;
  85         unsigned int __user *uvp;
  86         int error;
  87
  88         set_fs(KERNEL_DS);
  89         error = __blkdev_driver_ioctl(bdev, mode,
  90                                 cmd, (unsigned long)(&kval));
  91         set_fs(old_fs);
  92
  93         if (error == 0) {
  94                 uvp = compat_ptr(arg);
  95                 if (put_user(kval, uvp))
  96                         error = -EFAULT;
  97         }
  98         return error;
  99 }
 100
 101 struct compat_cdrom_read_audio {
 102         union cdrom_addr        addr;
 103         u8                      addr_format;
 104         compat_int_t            nframes;
 105         compat_caddr_t          buf;
 106 };
 107
 108 struct compat_cdrom_generic_command {
 109         unsigned char   cmd[CDROM_PACKET_SIZE];
 110         compat_caddr_t  buffer;
 111         compat_uint_t   buflen;
 112         compat_int_t    stat;
 113         compat_caddr_t  sense;
 114         unsigned char   data_direction;
 115         compat_int_t    quiet;
 116         compat_int_t    timeout;
 117         compat_caddr_t  reserved[1];
 118 };
 119
 120 static int compat_cdrom_read_audio(struct block_device *bdev, fmode_t mode,
 121                 unsigned int cmd, unsigned long arg)
 122 {
 123         struct cdrom_read_audio __user *cdread_audio;
 124         struct compat_cdrom_read_audio __user *cdread_audio32;
 125         __u32 data;
 126         void __user *datap;
 127
 128         cdread_audio = compat_alloc_user_space(sizeof(*cdread_audio));
 129         cdread_audio32 = compat_ptr(arg);
 130
 131         if (copy_in_user(&cdread_audio->addr,
 132                          &cdread_audio32->addr,
 133                          (sizeof(*cdread_audio32) -
 134                           sizeof(compat_caddr_t))))
 135                 return -EFAULT;
 136
 137         if (get_user(data, &cdread_audio32->buf))
 138                 return -EFAULT;
 139         datap = compat_ptr(data);
 140         if (put_user(datap, &cdread_audio->buf))
 141                 return -EFAULT;
 142
 143         return __blkdev_driver_ioctl(bdev, mode, cmd,
 144                         (unsigned long)cdread_audio);
 145 }
 146
 147 static int compat_cdrom_generic_command(struct block_device *bdev, fmode_t mode,
 148                 unsigned int cmd, unsigned long arg)
 149 {
 150         struct cdrom_generic_command __user *cgc;
 151         struct compat_cdrom_generic_command __user *cgc32;
 152         u32 data;
 153         unsigned char dir;
 154         int itmp;
 155
 156         cgc = compat_alloc_user_space(sizeof(*cgc));
 157         cgc32 = compat_ptr(arg);
 158
 159         if (copy_in_user(&cgc->cmd, &cgc32->cmd, sizeof(cgc->cmd)) ||
 160             get_user(data, &cgc32->buffer) ||
 161             put_user(compat_ptr(data), &cgc->buffer) ||
 162             copy_in_user(&cgc->buflen, &cgc32->buflen,
 163                          (sizeof(unsigned int) + sizeof(int))) ||
 164             get_user(data, &cgc32->sense) ||
 165             put_user(compat_ptr(data), &cgc->sense) ||
 166             get_user(dir, &cgc32->data_direction) ||
 167             put_user(dir, &cgc->data_direction) ||
 168             get_user(itmp, &cgc32->quiet) ||
 169             put_user(itmp, &cgc->quiet) ||
 170             get_user(itmp, &cgc32->timeout) ||
 171             put_user(itmp, &cgc->timeout) ||
 172             get_user(data, &cgc32->reserved[0]) ||
 173             put_user(compat_ptr(data), &cgc->reserved[0]))
 174                 return -EFAULT;
 175
 176         return __blkdev_driver_ioctl(bdev, mode, cmd, (unsigned long)cgc);
 177 }
 178
 179 struct compat_blkpg_ioctl_arg {
 180         compat_int_t op;
 181         compat_int_t flags;
 182         compat_int_t datalen;
 183         compat_caddr_t data;
 184 };
 185
 186 static int compat_blkpg_ioctl(struct block_device *bdev, fmode_t mode,
 187                 unsigned int cmd, struct compat_blkpg_ioctl_arg __user *ua32)
 188 {
 189         struct blkpg_ioctl_arg __user *a = compat_alloc_user_space(sizeof(*a));
 190         compat_caddr_t udata;
 191         compat_int_t n;
 192         int err;
 193
 194         err = get_user(n, &ua32->op);
 195         err |= put_user(n, &a->op);
 196         err |= get_user(n, &ua32->flags);
 197         err |= put_user(n, &a->flags);
 198         err |= get_user(n, &ua32->datalen);
 199         err |= put_user(n, &a->datalen);
 200         err |= get_user(udata, &ua32->data);
 201         err |= put_user(compat_ptr(udata), &a->data);
 202         if (err)
 203                 return err;
 204
 205         return blkdev_ioctl(bdev, mode, cmd, (unsigned long)a);
 206 }
 207
 208 #define BLKBSZGET_32            _IOR(0x12, 112, int)
 209 #define BLKBSZSET_32            _IOW(0x12, 113, int)
 210 #define BLKGETSIZE64_32         _IOR(0x12, 114, int)
 211
 212 static int compat_blkdev_driver_ioctl(struct block_device *bdev, fmode_t mode,
 213                         unsigned cmd, unsigned long arg)
 214 {
 215         switch (cmd) {
 216         case HDIO_GET_UNMASKINTR:
 217         case HDIO_GET_MULTCOUNT:
 218         case HDIO_GET_KEEPSETTINGS:
 219         case HDIO_GET_32BIT:
 220         case HDIO_GET_NOWERR:
 221         case HDIO_GET_DMA:
 222         case HDIO_GET_NICE:
 223         case HDIO_GET_WCACHE:
 224         case HDIO_GET_ACOUSTIC:
 225         case HDIO_GET_ADDRESS:
 226         case HDIO_GET_BUSSTATE:
 227                 return compat_hdio_ioctl(bdev, mode, cmd, arg);
 228         case CDROMREADAUDIO:
 229                 return compat_cdrom_read_audio(bdev, mode, cmd, arg);
 230         case CDROM_SEND_PACKET:
 231                 return compat_cdrom_generic_command(bdev, mode, cmd, arg);
 232
 233         /*
 234          * No handler required for the ones below, we just need to
 235          * convert arg to a 64 bit pointer.
 236          */
 237         case BLKSECTSET:
 238         /*
 239          * 0x03 -- HD/IDE ioctl's used by hdparm and friends.
 240          *         Some need translations, these do not.
 241          */
 242         case HDIO_GET_IDENTITY:
 243         case HDIO_DRIVE_TASK:
 244         case HDIO_DRIVE_CMD:
 245         /* 0x330 is reserved -- it used to be HDIO_GETGEO_BIG */
 246         case 0x330:
 247         /* CDROM stuff */
 248         case CDROMPAUSE:
 249         case CDROMRESUME:
 250         case CDROMPLAYMSF:
 251         case CDROMPLAYTRKIND:
 252         case CDROMREADTOCHDR:
 253         case CDROMREADTOCENTRY:
 254         case CDROMSTOP:
 255         case CDROMSTART:
 256         case CDROMEJECT:
 257         case CDROMVOLCTRL:
 258         case CDROMSUBCHNL:
 259         case CDROMMULTISESSION:
 260         case CDROM_GET_MCN:
 261         case CDROMRESET:
 262         case CDROMVOLREAD:
 263         case CDROMSEEK:
 264         case CDROMPLAYBLK:
 265         case CDROMCLOSETRAY:
 266         case CDROM_DISC_STATUS:
 267         case CDROM_CHANGER_NSLOTS:
 268         case CDROM_GET_CAPABILITY:
 269         /* Ignore cdrom.h about these next 5 ioctls, they absolutely do
 270          * not take a struct cdrom_read, instead they take a struct cdrom_msf
 271          * which is compatible.
 272          */
 273         case CDROMREADMODE2:
 274         case CDROMREADMODE1:
 275         case CDROMREADRAW:
 276         case CDROMREADCOOKED:
 277         case CDROMREADALL:
 278         /* DVD ioctls */
 279         case DVD_READ_STRUCT:
 280         case DVD_WRITE_STRUCT:
 281         case DVD_AUTH:
 282                 arg = (unsigned long)compat_ptr(arg);
 283         /* These intepret arg as an unsigned long, not as a pointer,
 284          * so we must not do compat_ptr() conversion. */
 285         case HDIO_SET_MULTCOUNT:
 286         case HDIO_SET_UNMASKINTR:
 287         case HDIO_SET_KEEPSETTINGS:
 288         case HDIO_SET_32BIT:
 289         case HDIO_SET_NOWERR:
 290         case HDIO_SET_DMA:
 291         case HDIO_SET_PIO_MODE:
 292         case HDIO_SET_NICE:
 293         case HDIO_SET_WCACHE:
 294         case HDIO_SET_ACOUSTIC:
 295         case HDIO_SET_BUSSTATE:
 296         case HDIO_SET_ADDRESS:
 297         case CDROMEJECT_SW:
 298         case CDROM_SET_OPTIONS:
 299         case CDROM_CLEAR_OPTIONS:
 300         case CDROM_SELECT_SPEED:
 301         case CDROM_SELECT_DISC:
 302         case CDROM_MEDIA_CHANGED:
 303         case CDROM_DRIVE_STATUS:
 304         case CDROM_LOCKDOOR:
 305         case CDROM_DEBUG:
 306                 break;
 307         default:
 308                 /* unknown ioctl number */
 309                 return -ENOIOCTLCMD;
 310         }
 311
 312         return __blkdev_driver_ioctl(bdev, mode, cmd, arg);
 313 }
 314
 315 /* Most of the generic ioctls are handled in the normal fallback path.
 316    This assumes the blkdev's low level compat_ioctl always returns
 317    ENOIOCTLCMD for unknown ioctls. */
 318 long compat_blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg)
 319 {
 320         int ret = -ENOIOCTLCMD;
 321         struct inode *inode = file->f_mapping->host;
 322         struct block_device *bdev = inode->i_bdev;
 323         struct gendisk *disk = bdev->bd_disk;
 324         fmode_t mode = file->f_mode;
 325         struct backing_dev_info *bdi;
 326         loff_t size;
 327         unsigned int max_sectors;
 328
 329         /*
 330          * O_NDELAY can be altered using fcntl(.., F_SETFL, ..), so we have
 331          * to updated it before every ioctl.
 332          */
 333         if (file->f_flags & O_NDELAY)
 334                 mode |= FMODE_NDELAY;
 335         else
 336                 mode &= ~FMODE_NDELAY;
 337
 338         switch (cmd) {
 339         case HDIO_GETGEO:
 340                 return compat_hdio_getgeo(disk, bdev, compat_ptr(arg));
 341         case BLKPBSZGET:
 342                 return compat_put_uint(arg, bdev_physical_block_size(bdev));
 343         case BLKIOMIN:
 344                 return compat_put_uint(arg, bdev_io_min(bdev));
 345         case BLKIOOPT:
 346                 return compat_put_uint(arg, bdev_io_opt(bdev));
 347         case BLKALIGNOFF:
 348                 return compat_put_int(arg, bdev_alignment_offset(bdev));
 349         case BLKDISCARDZEROES:
 350                 return compat_put_uint(arg, bdev_discard_zeroes_data(bdev));
 351         case BLKFLSBUF:
 352         case BLKROSET:
 353         case BLKDISCARD:
 354         case BLKSECDISCARD:
 355         case BLKZEROOUT:
 356         /*
 357          * the ones below are implemented in blkdev_locked_ioctl,
 358          * but we call blkdev_ioctl, which gets the lock for us
 359          */
 360         case BLKRRPART:
 361                 return blkdev_ioctl(bdev, mode, cmd,
 362                                 (unsigned long)compat_ptr(arg));
 363         case BLKBSZSET_32:
 364                 return blkdev_ioctl(bdev, mode, BLKBSZSET,
 365                                 (unsigned long)compat_ptr(arg));
 366         case BLKPG:
 367                 return compat_blkpg_ioctl(bdev, mode, cmd, compat_ptr(arg));
 368         case BLKRAGET:
 369         case BLKFRAGET:
 370                 if (!arg)
 371                         return -EINVAL;
 372                 bdi = blk_get_backing_dev_info(bdev);
 373                 return compat_put_long(arg,
 374                                        (bdi->ra_pages * PAGE_CACHE_SIZE) / 512);
 375         case BLKROGET: /* compatible */
 376                 return compat_put_int(arg, bdev_read_only(bdev) != 0);
 377         case BLKBSZGET_32: /* get the logical block size (cf. BLKSSZGET) */
 378                 return compat_put_int(arg, block_size(bdev));
 379         case BLKSSZGET: /* get block device hardware sector size */
 380                 return compat_put_int(arg, bdev_logical_block_size(bdev));
 381         case BLKSECTGET:
 382                 max_sectors = min_t(unsigned int, USHRT_MAX,
 383                                     queue_max_sectors(bdev_get_queue(bdev)));
 384                 return compat_put_ushort(arg, max_sectors);
 385         case BLKROTATIONAL:
 386                 return compat_put_ushort(arg,
 387                                          !blk_queue_nonrot(bdev_get_queue(bdev)));
 388         case BLKRASET: /* compatible, but no compat_ptr (!) */
 389         case BLKFRASET:
 390                 if (!capable(CAP_SYS_ADMIN))
 391                         return -EACCES;
 392                 bdi = blk_get_backing_dev_info(bdev);
 393                 bdi->ra_pages = (arg * 512) / PAGE_CACHE_SIZE;
 394                 return 0;
 395         case BLKGETSIZE:
 396                 size = i_size_read(bdev->bd_inode);
 397                 if ((size >> 9) > ~0UL)
 398                         return -EFBIG;
 399                 return compat_put_ulong(arg, size >> 9);
 400
 401         case BLKGETSIZE64_32:
 402                 return compat_put_u64(arg, i_size_read(bdev->bd_inode));
 403
 404         case BLKTRACESETUP32:
 405         case BLKTRACESTART: /* compatible */
 406         case BLKTRACESTOP:  /* compatible */
 407         case BLKTRACETEARDOWN: /* compatible */
 408                 ret = blk_trace_ioctl(bdev, cmd, compat_ptr(arg));
 409                 return ret;
 410         case IOC_PR_REGISTER:
 411         case IOC_PR_RESERVE:
 412         case IOC_PR_RELEASE:
 413         case IOC_PR_PREEMPT:
 414         case IOC_PR_PREEMPT_ABORT:
 415         case IOC_PR_CLEAR:
 416                 return blkdev_ioctl(bdev, mode, cmd,
 417                                 (unsigned long)compat_ptr(arg));
 418         default:
 419                 if (disk->fops->compat_ioctl)
 420                         ret = disk->fops->compat_ioctl(bdev, mode, cmd, arg);
 421                 if (ret == -ENOIOCTLCMD)
 422                         ret = compat_blkdev_driver_ioctl(bdev, mode, cmd, arg);
 423                 return ret;
 424         }
 425 }