root/fs/quota/compat.c

DEFINITIONS

1. COMPAT_SYSCALL_DEFINE4

   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 COMPAT_SYSCALL_DEFINE4(quotactl32, unsigned int, cmd,
  45                        const char __user *, special, qid_t, id,
  46                        void __user *, addr)
  47 {
  48         unsigned int cmds;
  49         struct if_dqblk __user *dqblk;
  50         struct compat_if_dqblk __user *compat_dqblk;
  51         struct fs_quota_stat __user *fsqstat;
  52         struct compat_fs_quota_stat __user *compat_fsqstat;
  53         compat_uint_t data;
  54         u16 xdata;
  55         long ret;
  56 
  57         cmds = cmd >> SUBCMDSHIFT;
  58 
  59         switch (cmds) {
  60         case Q_GETQUOTA:
  61                 dqblk = compat_alloc_user_space(sizeof(struct if_dqblk));
  62                 compat_dqblk = addr;
  63                 ret = kernel_quotactl(cmd, special, id, dqblk);
  64                 if (ret)
  65                         break;
  66                 if (copy_in_user(compat_dqblk, dqblk, sizeof(*compat_dqblk)) ||
  67                         get_user(data, &dqblk->dqb_valid) ||
  68                         put_user(data, &compat_dqblk->dqb_valid))
  69                         ret = -EFAULT;
  70                 break;
  71         case Q_SETQUOTA:
  72                 dqblk = compat_alloc_user_space(sizeof(struct if_dqblk));
  73                 compat_dqblk = addr;
  74                 ret = -EFAULT;
  75                 if (copy_in_user(dqblk, compat_dqblk, sizeof(*compat_dqblk)) ||
  76                         get_user(data, &compat_dqblk->dqb_valid) ||
  77                         put_user(data, &dqblk->dqb_valid))
  78                         break;
  79                 ret = kernel_quotactl(cmd, special, id, dqblk);
  80                 break;
  81         case Q_XGETQSTAT:
  82                 fsqstat = compat_alloc_user_space(sizeof(struct fs_quota_stat));
  83                 compat_fsqstat = addr;
  84                 ret = kernel_quotactl(cmd, special, id, fsqstat);
  85                 if (ret)
  86                         break;
  87                 ret = -EFAULT;
  88                 /* Copying qs_version, qs_flags, qs_pad */
  89                 if (copy_in_user(compat_fsqstat, fsqstat,
  90                         offsetof(struct compat_fs_quota_stat, qs_uquota)))
  91                         break;
  92                 /* Copying qs_uquota */
  93                 if (copy_in_user(&compat_fsqstat->qs_uquota,
  94                         &fsqstat->qs_uquota,
  95                         sizeof(compat_fsqstat->qs_uquota)) ||
  96                         get_user(data, &fsqstat->qs_uquota.qfs_nextents) ||
  97                         put_user(data, &compat_fsqstat->qs_uquota.qfs_nextents))
  98                         break;
  99                 /* Copying qs_gquota */
 100                 if (copy_in_user(&compat_fsqstat->qs_gquota,
 101                         &fsqstat->qs_gquota,
 102                         sizeof(compat_fsqstat->qs_gquota)) ||
 103                         get_user(data, &fsqstat->qs_gquota.qfs_nextents) ||
 104                         put_user(data, &compat_fsqstat->qs_gquota.qfs_nextents))
 105                         break;
 106                 /* Copying the rest */
 107                 if (copy_in_user(&compat_fsqstat->qs_incoredqs,
 108                         &fsqstat->qs_incoredqs,
 109                         sizeof(struct compat_fs_quota_stat) -
 110                         offsetof(struct compat_fs_quota_stat, qs_incoredqs)) ||
 111                         get_user(xdata, &fsqstat->qs_iwarnlimit) ||
 112                         put_user(xdata, &compat_fsqstat->qs_iwarnlimit))
 113                         break;
 114                 ret = 0;
 115                 break;
 116         default:
 117                 ret = kernel_quotactl(cmd, special, id, addr);
 118         }
 119         return ret;
 120 }