kernel/fs/quota/compat.c

   1
   2 #include <linux/syscalls.h>
   3 #include <linux/compat.h>
   4 #include <linux/quotaops.h>
   5
   6 /*
   7  * This code works only for 32 bit quota tools over 64 bit OS (x86_64, ia64)
   8  * and is necessary due to alignment problems.
   9  */
  10 struct compat_if_dqblk {
  11         compat_u64 dqb_bhardlimit;
  12         compat_u64 dqb_bsoftlimit;
  13         compat_u64 dqb_curspace;
  14         compat_u64 dqb_ihardlimit;
  15         compat_u64 dqb_isoftlimit;
  16         compat_u64 dqb_curinodes;
  17         compat_u64 dqb_btime;
  18         compat_u64 dqb_itime;
  19         compat_uint_t dqb_valid;
  20 };
  21
  22 /* XFS structures */
  23 struct compat_fs_qfilestat {
  24         compat_u64 dqb_bhardlimit;
  25         compat_u64 qfs_nblks;
  26         compat_uint_t qfs_nextents;
  27 };
  28
  29 struct compat_fs_quota_stat {
  30         __s8            qs_version;
  31         __u16           qs_flags;
  32         __s8            qs_pad;
  33         struct compat_fs_qfilestat      qs_uquota;
  34         struct compat_fs_qfilestat      qs_gquota;
  35         compat_uint_t   qs_incoredqs;
  36         compat_int_t    qs_btimelimit;
  37         compat_int_t    qs_itimelimit;
  38         compat_int_t    qs_rtbtimelimit;
  39         __u16           qs_bwarnlimit;
  40         __u16           qs_iwarnlimit;
  41 };
  42
  43 asmlinkage long sys32_quotactl(unsigned int cmd, const char __user *special,
  44                                                 qid_t id, void __user *addr)
  45 {
  46         unsigned int cmds;
  47         struct if_dqblk __user *dqblk;
  48         struct compat_if_dqblk __user *compat_dqblk;
  49         struct fs_quota_stat __user *fsqstat;
  50         struct compat_fs_quota_stat __user *compat_fsqstat;
  51         compat_uint_t data;
  52         u16 xdata;
  53         long ret;
  54
  55         cmds = cmd >> SUBCMDSHIFT;
  56
  57         switch (cmds) {
  58         case Q_GETQUOTA:
  59                 dqblk = compat_alloc_user_space(sizeof(struct if_dqblk));
  60                 compat_dqblk = addr;
  61                 ret = sys_quotactl(cmd, special, id, dqblk);
  62                 if (ret)
  63                         break;
  64                 if (copy_in_user(compat_dqblk, dqblk, sizeof(*compat_dqblk)) ||
  65                         get_user(data, &dqblk->dqb_valid) ||
  66                         put_user(data, &compat_dqblk->dqb_valid))
  67                         ret = -EFAULT;
  68                 break;
  69         case Q_SETQUOTA:
  70                 dqblk = compat_alloc_user_space(sizeof(struct if_dqblk));
  71                 compat_dqblk = addr;
  72                 ret = -EFAULT;
  73                 if (copy_in_user(dqblk, compat_dqblk, sizeof(*compat_dqblk)) ||
  74                         get_user(data, &compat_dqblk->dqb_valid) ||
  75                         put_user(data, &dqblk->dqb_valid))
  76                         break;
  77                 ret = sys_quotactl(cmd, special, id, dqblk);
  78                 break;
  79         case Q_XGETQSTAT:
  80                 fsqstat = compat_alloc_user_space(sizeof(struct fs_quota_stat));
  81                 compat_fsqstat = addr;
  82                 ret = sys_quotactl(cmd, special, id, fsqstat);
  83                 if (ret)
  84                         break;
  85                 ret = -EFAULT;
  86                 /* Copying qs_version, qs_flags, qs_pad */
  87                 if (copy_in_user(compat_fsqstat, fsqstat,
  88                         offsetof(struct compat_fs_quota_stat, qs_uquota)))
  89                         break;
  90                 /* Copying qs_uquota */
  91                 if (copy_in_user(&compat_fsqstat->qs_uquota,
  92                         &fsqstat->qs_uquota,
  93                         sizeof(compat_fsqstat->qs_uquota)) ||
  94                         get_user(data, &fsqstat->qs_uquota.qfs_nextents) ||
  95                         put_user(data, &compat_fsqstat->qs_uquota.qfs_nextents))
  96                         break;
  97                 /* Copying qs_gquota */
  98                 if (copy_in_user(&compat_fsqstat->qs_gquota,
  99                         &fsqstat->qs_gquota,
 100                         sizeof(compat_fsqstat->qs_gquota)) ||
 101                         get_user(data, &fsqstat->qs_gquota.qfs_nextents) ||
 102                         put_user(data, &compat_fsqstat->qs_gquota.qfs_nextents))
 103                         break;
 104                 /* Copying the rest */
 105                 if (copy_in_user(&compat_fsqstat->qs_incoredqs,
 106                         &fsqstat->qs_incoredqs,
 107                         sizeof(struct compat_fs_quota_stat) -
 108                         offsetof(struct compat_fs_quota_stat, qs_incoredqs)) ||
 109                         get_user(xdata, &fsqstat->qs_iwarnlimit) ||
 110                         put_user(xdata, &compat_fsqstat->qs_iwarnlimit))
 111                         break;
 112                 ret = 0;
 113                 break;
 114         default:
 115                 ret = sys_quotactl(cmd, special, id, addr);
 116         }
 117         return ret;
 118 }