Linux Kernel  3.7.1
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compat.c
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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 }
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