fs/quota/compat.c

   1 // SPDX-License-Identifier: GPL-2.0
   2
   3 #include <linux/syscalls.h>
   4 #include <linux/compat.h>
   5 #include <linux/quotaops.h>
   6
   7 /*
   8  * This code works only for 32 bit quota tools over 64 bit OS (x86_64, ia64)
   9  * and is necessary due to alignment problems.
  10  */
  11 struct compat_if_dqblk {
  12         compat_u64 dqb_bhardlimit;
  13         compat_u64 dqb_bsoftlimit;
  14         compat_u64 dqb_curspace;
  15         compat_u64 dqb_ihardlimit;
  16         compat_u64 dqb_isoftlimit;
  17         compat_u64 dqb_curinodes;
  18         compat_u64 dqb_btime;
  19         compat_u64 dqb_itime;
  20         compat_uint_t dqb_valid;
  21 };
  22
  23 /* XFS structures */
  24 struct compat_fs_qfilestat {
  25         compat_u64 dqb_bhardlimit;
  26         compat_u64 qfs_nblks;
  27         compat_uint_t qfs_nextents;
  28 };
  29
  30 struct compat_fs_quota_stat {
  31         __s8            qs_version;
  32         __u16           qs_flags;
  33         __s8            qs_pad;
  34         struct compat_fs_qfilestat      qs_uquota;
  35         struct compat_fs_qfilestat      qs_gquota;
  36         compat_uint_t   qs_incoredqs;
  37         compat_int_t    qs_btimelimit;
  38         compat_int_t    qs_itimelimit;
  39         compat_int_t    qs_rtbtimelimit;
  40         __u16           qs_bwarnlimit;
  41         __u16           qs_iwarnlimit;
  42 };
  43
  44 asmlinkage long sys32_quotactl(unsigned int cmd, const char __user *special,
  45                                                 qid_t id, void __user *addr)
  46 {
  47         unsigned int cmds;
  48         struct if_dqblk __user *dqblk;
  49         struct compat_if_dqblk __user *compat_dqblk;
  50         struct fs_quota_stat __user *fsqstat;
  51         struct compat_fs_quota_stat __user *compat_fsqstat;
  52         compat_uint_t data;
  53         u16 xdata;
  54         long ret;
  55
  56         cmds = cmd >> SUBCMDSHIFT;
  57
  58         switch (cmds) {
  59         case Q_GETQUOTA:
  60                 dqblk = compat_alloc_user_space(sizeof(struct if_dqblk));
  61                 compat_dqblk = addr;
  62                 ret = sys_quotactl(cmd, special, id, dqblk);
  63                 if (ret)
  64                         break;
  65                 if (copy_in_user(compat_dqblk, dqblk, sizeof(*compat_dqblk)) ||
  66                         get_user(data, &dqblk->dqb_valid) ||
  67                         put_user(data, &compat_dqblk->dqb_valid))
  68                         ret = -EFAULT;
  69                 break;
  70         case Q_SETQUOTA:
  71                 dqblk = compat_alloc_user_space(sizeof(struct if_dqblk));
  72                 compat_dqblk = addr;
  73                 ret = -EFAULT;
  74                 if (copy_in_user(dqblk, compat_dqblk, sizeof(*compat_dqblk)) ||
  75                         get_user(data, &compat_dqblk->dqb_valid) ||
  76                         put_user(data, &dqblk->dqb_valid))
  77                         break;
  78                 ret = sys_quotactl(cmd, special, id, dqblk);
  79                 break;
  80         case Q_XGETQSTAT:
  81                 fsqstat = compat_alloc_user_space(sizeof(struct fs_quota_stat));
  82                 compat_fsqstat = addr;
  83                 ret = sys_quotactl(cmd, special, id, fsqstat);
  84                 if (ret)
  85                         break;
  86                 ret = -EFAULT;
  87                 /* Copying qs_version, qs_flags, qs_pad */
  88                 if (copy_in_user(compat_fsqstat, fsqstat,
  89                         offsetof(struct compat_fs_quota_stat, qs_uquota)))
  90                         break;
  91                 /* Copying qs_uquota */
  92                 if (copy_in_user(&compat_fsqstat->qs_uquota,
  93                         &fsqstat->qs_uquota,
  94                         sizeof(compat_fsqstat->qs_uquota)) ||
  95                         get_user(data, &fsqstat->qs_uquota.qfs_nextents) ||
  96                         put_user(data, &compat_fsqstat->qs_uquota.qfs_nextents))
  97                         break;
  98                 /* Copying qs_gquota */
  99                 if (copy_in_user(&compat_fsqstat->qs_gquota,
 100                         &fsqstat->qs_gquota,
 101                         sizeof(compat_fsqstat->qs_gquota)) ||
 102                         get_user(data, &fsqstat->qs_gquota.qfs_nextents) ||
 103                         put_user(data, &compat_fsqstat->qs_gquota.qfs_nextents))
 104                         break;
 105                 /* Copying the rest */
 106                 if (copy_in_user(&compat_fsqstat->qs_incoredqs,
 107                         &fsqstat->qs_incoredqs,
 108                         sizeof(struct compat_fs_quota_stat) -
 109                         offsetof(struct compat_fs_quota_stat, qs_incoredqs)) ||
 110                         get_user(xdata, &fsqstat->qs_iwarnlimit) ||
 111                         put_user(xdata, &compat_fsqstat->qs_iwarnlimit))
 112                         break;
 113                 ret = 0;
 114                 break;
 115         default:
 116                 ret = sys_quotactl(cmd, special, id, addr);
 117         }
 118         return ret;
 119 }