LXR linux/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 */
  11struct 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 */
  24struct compat_fs_qfilestat {
  25        compat_u64 dqb_bhardlimit;
  26        compat_u64 qfs_nblks;
  27        compat_uint_t qfs_nextents;
  28};
  29
  30struct 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
  44COMPAT_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}
 121