Root/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 */
10struct 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 */
23struct compat_fs_qfilestat {
24    compat_u64 dqb_bhardlimit;
25    compat_u64 qfs_nblks;
26    compat_uint_t qfs_nextents;
27};
28
29struct 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
43asmlinkage 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}
119

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