LXR linux/block/compat

   1// SPDX-License-Identifier: GPL-2.0
   2#include <linux/blkdev.h>
   3#include <linux/blkpg.h>
   4#include <linux/blktrace_api.h>
   5#include <linux/cdrom.h>
   6#include <linux/compat.h>
   7#include <linux/elevator.h>
   8#include <linux/hdreg.h>
   9#include <linux/slab.h>
  10#include <linux/syscalls.h>
  11#include <linux/types.h>
  12#include <linux/uaccess.h>
  13
  14static int compat_put_ushort(unsigned long arg, unsigned short val)
  15{
  16        return put_user(val, (unsigned short __user *)compat_ptr(arg));
  17}
  18
  19static int compat_put_int(unsigned long arg, int val)
  20{
  21        return put_user(val, (compat_int_t __user *)compat_ptr(arg));
  22}
  23
  24static 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
  29static int compat_put_long(unsigned long arg, long val)
  30{
  31        return put_user(val, (compat_long_t __user *)compat_ptr(arg));
  32}
  33
  34static 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
  39static int compat_put_u64(unsigned long arg, u64 val)
  40{
  41        return put_user(val, (compat_u64 __user *)compat_ptr(arg));
  42}
  43
  44struct compat_hd_geometry {
  45        unsigned char heads;
  46        unsigned char sectors;
  47        unsigned short cylinders;
  48        u32 start;
  49};
  50
  51static 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
  80static int compat_hdio_ioctl(struct block_device *bdev, fmode_t mode,
  81                unsigned int cmd, unsigned long arg)
  82{
  83        unsigned long __user *p;
  84        int error;
  85
  86        p = compat_alloc_user_space(sizeof(unsigned long));
  87        error = __blkdev_driver_ioctl(bdev, mode,
  88                                cmd, (unsigned long)p);
  89        if (error == 0) {
  90                unsigned int __user *uvp = compat_ptr(arg);
  91                unsigned long v;
  92                if (get_user(v, p) || put_user(v, uvp))
  93                        error = -EFAULT;
  94        }
  95        return error;
  96}
  97
  98struct compat_cdrom_read_audio {
  99        union cdrom_addr        addr;
 100        u8                      addr_format;
 101        compat_int_t            nframes;
 102        compat_caddr_t          buf;
 103};
 104
 105struct compat_cdrom_generic_command {
 106        unsigned char   cmd[CDROM_PACKET_SIZE];
 107        compat_caddr_t  buffer;
 108        compat_uint_t   buflen;
 109        compat_int_t    stat;
 110        compat_caddr_t  sense;
 111        unsigned char   data_direction;
 112        compat_int_t    quiet;
 113        compat_int_t    timeout;
 114        compat_caddr_t  reserved[1];
 115};
 116
 117static int compat_cdrom_read_audio(struct block_device *bdev, fmode_t mode,
 118                unsigned int cmd, unsigned long arg)
 119{
 120        struct cdrom_read_audio __user *cdread_audio;
 121        struct compat_cdrom_read_audio __user *cdread_audio32;
 122        __u32 data;
 123        void __user *datap;
 124
 125        cdread_audio = compat_alloc_user_space(sizeof(*cdread_audio));
 126        cdread_audio32 = compat_ptr(arg);
 127
 128        if (copy_in_user(&cdread_audio->addr,
 129                         &cdread_audio32->addr,
 130                         (sizeof(*cdread_audio32) -
 131                          sizeof(compat_caddr_t))))
 132                return -EFAULT;
 133
 134        if (get_user(data, &cdread_audio32->buf))
 135                return -EFAULT;
 136        datap = compat_ptr(data);
 137        if (put_user(datap, &cdread_audio->buf))
 138                return -EFAULT;
 139
 140        return __blkdev_driver_ioctl(bdev, mode, cmd,
 141                        (unsigned long)cdread_audio);
 142}
 143
 144static int compat_cdrom_generic_command(struct block_device *bdev, fmode_t mode,
 145                unsigned int cmd, unsigned long arg)
 146{
 147        struct cdrom_generic_command __user *cgc;
 148        struct compat_cdrom_generic_command __user *cgc32;
 149        u32 data;
 150        unsigned char dir;
 151        int itmp;
 152
 153        cgc = compat_alloc_user_space(sizeof(*cgc));
 154        cgc32 = compat_ptr(arg);
 155
 156        if (copy_in_user(&cgc->cmd, &cgc32->cmd, sizeof(cgc->cmd)) ||
 157            get_user(data, &cgc32->buffer) ||
 158            put_user(compat_ptr(data), &cgc->buffer) ||
 159            copy_in_user(&cgc->buflen, &cgc32->buflen,
 160                         (sizeof(unsigned int) + sizeof(int))) ||
 161            get_user(data, &cgc32->sense) ||
 162            put_user(compat_ptr(data), &cgc->sense) ||
 163            get_user(dir, &cgc32->data_direction) ||
 164            put_user(dir, &cgc->data_direction) ||
 165            get_user(itmp, &cgc32->quiet) ||
 166            put_user(itmp, &cgc->quiet) ||
 167            get_user(itmp, &cgc32->timeout) ||
 168            put_user(itmp, &cgc->timeout) ||
 169            get_user(data, &cgc32->reserved[0]) ||
 170            put_user(compat_ptr(data), &cgc->reserved[0]))
 171                return -EFAULT;
 172
 173        return __blkdev_driver_ioctl(bdev, mode, cmd, (unsigned long)cgc);
 174}
 175
 176struct compat_blkpg_ioctl_arg {
 177        compat_int_t op;
 178        compat_int_t flags;
 179        compat_int_t datalen;
 180        compat_caddr_t data;
 181};
 182
 183static int compat_blkpg_ioctl(struct block_device *bdev, fmode_t mode,
 184                unsigned int cmd, struct compat_blkpg_ioctl_arg __user *ua32)
 185{
 186        struct blkpg_ioctl_arg __user *a = compat_alloc_user_space(sizeof(*a));
 187        compat_caddr_t udata;
 188        compat_int_t n;
 189        int err;
 190
 191        err = get_user(n, &ua32->op);
 192        err |= put_user(n, &a->op);
 193        err |= get_user(n, &ua32->flags);
 194        err |= put_user(n, &a->flags);
 195        err |= get_user(n, &ua32->datalen);
 196        err |= put_user(n, &a->datalen);
 197        err |= get_user(udata, &ua32->data);
 198        err |= put_user(compat_ptr(udata), &a->data);
 199        if (err)
 200                return err;
 201
 202        return blkdev_ioctl(bdev, mode, cmd, (unsigned long)a);
 203}
 204
 205#define BLKBSZGET_32            _IOR(0x12, 112, int)
 206#define BLKBSZSET_32            _IOW(0x12, 113, int)
 207#define BLKGETSIZE64_32         _IOR(0x12, 114, int)
 208
 209static int compat_blkdev_driver_ioctl(struct block_device *bdev, fmode_t mode,
 210                        unsigned cmd, unsigned long arg)
 211{
 212        switch (cmd) {
 213        case HDIO_GET_UNMASKINTR:
 214        case HDIO_GET_MULTCOUNT:
 215        case HDIO_GET_KEEPSETTINGS:
 216        case HDIO_GET_32BIT:
 217        case HDIO_GET_NOWERR:
 218        case HDIO_GET_DMA:
 219        case HDIO_GET_NICE:
 220        case HDIO_GET_WCACHE:
 221        case HDIO_GET_ACOUSTIC:
 222        case HDIO_GET_ADDRESS:
 223        case HDIO_GET_BUSSTATE:
 224                return compat_hdio_ioctl(bdev, mode, cmd, arg);
 225        case CDROMREADAUDIO:
 226                return compat_cdrom_read_audio(bdev, mode, cmd, arg);
 227        case CDROM_SEND_PACKET:
 228                return compat_cdrom_generic_command(bdev, mode, cmd, arg);
 229
 230        /*
 231         * No handler required for the ones below, we just need to
 232         * convert arg to a 64 bit pointer.
 233         */
 234        case BLKSECTSET:
 235        /*
 236         * 0x03 -- HD/IDE ioctl's used by hdparm and friends.
 237         *         Some need translations, these do not.
 238         */
 239        case HDIO_GET_IDENTITY:
 240        case HDIO_DRIVE_TASK:
 241        case HDIO_DRIVE_CMD:
 242        /* 0x330 is reserved -- it used to be HDIO_GETGEO_BIG */
 243        case 0x330:
 244        /* CDROM stuff */
 245        case CDROMPAUSE:
 246        case CDROMRESUME:
 247        case CDROMPLAYMSF:
 248        case CDROMPLAYTRKIND:
 249        case CDROMREADTOCHDR:
 250        case CDROMREADTOCENTRY:
 251        case CDROMSTOP:
 252        case CDROMSTART:
 253        case CDROMEJECT:
 254        case CDROMVOLCTRL:
 255        case CDROMSUBCHNL:
 256        case CDROMMULTISESSION:
 257        case CDROM_GET_MCN:
 258        case CDROMRESET:
 259        case CDROMVOLREAD:
 260        case CDROMSEEK:
 261        case CDROMPLAYBLK:
 262        case CDROMCLOSETRAY:
 263        case CDROM_DISC_STATUS:
 264        case CDROM_CHANGER_NSLOTS:
 265        case CDROM_GET_CAPABILITY:
 266        /* Ignore cdrom.h about these next 5 ioctls, they absolutely do
 267         * not take a struct cdrom_read, instead they take a struct cdrom_msf
 268         * which is compatible.
 269         */
 270        case CDROMREADMODE2:
 271        case CDROMREADMODE1:
 272        case CDROMREADRAW:
 273        case CDROMREADCOOKED:
 274        case CDROMREADALL:
 275        /* DVD ioctls */
 276        case DVD_READ_STRUCT:
 277        case DVD_WRITE_STRUCT:
 278        case DVD_AUTH:
 279                arg = (unsigned long)compat_ptr(arg);
 280        /* These intepret arg as an unsigned long, not as a pointer,
 281         * so we must not do compat_ptr() conversion. */
 282        case HDIO_SET_MULTCOUNT:
 283        case HDIO_SET_UNMASKINTR:
 284        case HDIO_SET_KEEPSETTINGS:
 285        case HDIO_SET_32BIT:
 286        case HDIO_SET_NOWERR:
 287        case HDIO_SET_DMA:
 288        case HDIO_SET_PIO_MODE:
 289        case HDIO_SET_NICE:
 290        case HDIO_SET_WCACHE:
 291        case HDIO_SET_ACOUSTIC:
 292        case HDIO_SET_BUSSTATE:
 293        case HDIO_SET_ADDRESS:
 294        case CDROMEJECT_SW:
 295        case CDROM_SET_OPTIONS:
 296        case CDROM_CLEAR_OPTIONS:
 297        case CDROM_SELECT_SPEED:
 298        case CDROM_SELECT_DISC:
 299        case CDROM_MEDIA_CHANGED:
 300        case CDROM_DRIVE_STATUS:
 301        case CDROM_LOCKDOOR:
 302        case CDROM_DEBUG:
 303                break;
 304        default:
 305                /* unknown ioctl number */
 306                return -ENOIOCTLCMD;
 307        }
 308
 309        return __blkdev_driver_ioctl(bdev, mode, cmd, arg);
 310}
 311
 312/* Most of the generic ioctls are handled in the normal fallback path.
 313   This assumes the blkdev's low level compat_ioctl always returns
 314   ENOIOCTLCMD for unknown ioctls. */
 315long compat_blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg)
 316{
 317        int ret = -ENOIOCTLCMD;
 318        struct inode *inode = file->f_mapping->host;
 319        struct block_device *bdev = inode->i_bdev;
 320        struct gendisk *disk = bdev->bd_disk;
 321        fmode_t mode = file->f_mode;
 322        loff_t size;
 323        unsigned int max_sectors;
 324
 325        /*
 326         * O_NDELAY can be altered using fcntl(.., F_SETFL, ..), so we have
 327         * to updated it before every ioctl.
 328         */
 329        if (file->f_flags & O_NDELAY)
 330                mode |= FMODE_NDELAY;
 331        else
 332                mode &= ~FMODE_NDELAY;
 333
 334        switch (cmd) {
 335        case HDIO_GETGEO:
 336                return compat_hdio_getgeo(disk, bdev, compat_ptr(arg));
 337        case BLKPBSZGET:
 338                return compat_put_uint(arg, bdev_physical_block_size(bdev));
 339        case BLKIOMIN:
 340                return compat_put_uint(arg, bdev_io_min(bdev));
 341        case BLKIOOPT:
 342                return compat_put_uint(arg, bdev_io_opt(bdev));
 343        case BLKALIGNOFF:
 344                return compat_put_int(arg, bdev_alignment_offset(bdev));
 345        case BLKDISCARDZEROES:
 346                return compat_put_uint(arg, 0);
 347        case BLKFLSBUF:
 348        case BLKROSET:
 349        case BLKDISCARD:
 350        case BLKSECDISCARD:
 351        case BLKZEROOUT:
 352        /*
 353         * the ones below are implemented in blkdev_locked_ioctl,
 354         * but we call blkdev_ioctl, which gets the lock for us
 355         */
 356        case BLKRRPART:
 357                return blkdev_ioctl(bdev, mode, cmd,
 358                                (unsigned long)compat_ptr(arg));
 359        case BLKBSZSET_32:
 360                return blkdev_ioctl(bdev, mode, BLKBSZSET,
 361                                (unsigned long)compat_ptr(arg));
 362        case BLKPG:
 363                return compat_blkpg_ioctl(bdev, mode, cmd, compat_ptr(arg));
 364        case BLKRAGET:
 365        case BLKFRAGET:
 366                if (!arg)
 367                        return -EINVAL;
 368                return compat_put_long(arg,
 369                               (bdev->bd_bdi->ra_pages * PAGE_SIZE) / 512);
 370        case BLKROGET: /* compatible */
 371                return compat_put_int(arg, bdev_read_only(bdev) != 0);
 372        case BLKBSZGET_32: /* get the logical block size (cf. BLKSSZGET) */
 373                return compat_put_int(arg, block_size(bdev));
 374        case BLKSSZGET: /* get block device hardware sector size */
 375                return compat_put_int(arg, bdev_logical_block_size(bdev));
 376        case BLKSECTGET:
 377                max_sectors = min_t(unsigned int, USHRT_MAX,
 378                                    queue_max_sectors(bdev_get_queue(bdev)));
 379                return compat_put_ushort(arg, max_sectors);
 380        case BLKROTATIONAL:
 381                return compat_put_ushort(arg,
 382                                         !blk_queue_nonrot(bdev_get_queue(bdev)));
 383        case BLKRASET: /* compatible, but no compat_ptr (!) */
 384        case BLKFRASET:
 385                if (!capable(CAP_SYS_ADMIN))
 386                        return -EACCES;
 387                bdev->bd_bdi->ra_pages = (arg * 512) / PAGE_SIZE;
 388                return 0;
 389        case BLKGETSIZE:
 390                size = i_size_read(bdev->bd_inode);
 391                if ((size >> 9) > ~0UL)
 392                        return -EFBIG;
 393                return compat_put_ulong(arg, size >> 9);
 394
 395        case BLKGETSIZE64_32:
 396                return compat_put_u64(arg, i_size_read(bdev->bd_inode));
 397
 398        case BLKTRACESETUP32:
 399        case BLKTRACESTART: /* compatible */
 400        case BLKTRACESTOP:  /* compatible */
 401        case BLKTRACETEARDOWN: /* compatible */
 402                ret = blk_trace_ioctl(bdev, cmd, compat_ptr(arg));
 403                return ret;
 404        default:
 405                if (disk->fops->compat_ioctl)
 406                        ret = disk->fops->compat_ioctl(bdev, mode, cmd, arg);
 407                if (ret == -ENOIOCTLCMD)
 408                        ret = compat_blkdev_driver_ioctl(bdev, mode, cmd, arg);
 409                return ret;
 410        }
 411}
 412