Merge branch 'upstream-linus' of master.kernel.org:/pub/scm/linux/kernel/git/jgarzik...
[linux-2.6] / kernel / uid16.c
1 /*
2  *      Wrapper functions for 16bit uid back compatibility. All nicely tied
3  *      together in the faint hope we can take the out in five years time.
4  */
5
6 #include <linux/mm.h>
7 #include <linux/utsname.h>
8 #include <linux/mman.h>
9 #include <linux/notifier.h>
10 #include <linux/reboot.h>
11 #include <linux/prctl.h>
12 #include <linux/capability.h>
13 #include <linux/init.h>
14 #include <linux/highuid.h>
15 #include <linux/security.h>
16 #include <linux/syscalls.h>
17
18 #include <asm/uaccess.h>
19
20 asmlinkage long sys_chown16(const char __user * filename, old_uid_t user, old_gid_t group)
21 {
22         long ret = sys_chown(filename, low2highuid(user), low2highgid(group));
23         /* avoid REGPARM breakage on x86: */
24         prevent_tail_call(ret);
25         return ret;
26 }
27
28 asmlinkage long sys_lchown16(const char __user * filename, old_uid_t user, old_gid_t group)
29 {
30         long ret = sys_lchown(filename, low2highuid(user), low2highgid(group));
31         /* avoid REGPARM breakage on x86: */
32         prevent_tail_call(ret);
33         return ret;
34 }
35
36 asmlinkage long sys_fchown16(unsigned int fd, old_uid_t user, old_gid_t group)
37 {
38         long ret = sys_fchown(fd, low2highuid(user), low2highgid(group));
39         /* avoid REGPARM breakage on x86: */
40         prevent_tail_call(ret);
41         return ret;
42 }
43
44 asmlinkage long sys_setregid16(old_gid_t rgid, old_gid_t egid)
45 {
46         long ret = sys_setregid(low2highgid(rgid), low2highgid(egid));
47         /* avoid REGPARM breakage on x86: */
48         prevent_tail_call(ret);
49         return ret;
50 }
51
52 asmlinkage long sys_setgid16(old_gid_t gid)
53 {
54         long ret = sys_setgid(low2highgid(gid));
55         /* avoid REGPARM breakage on x86: */
56         prevent_tail_call(ret);
57         return ret;
58 }
59
60 asmlinkage long sys_setreuid16(old_uid_t ruid, old_uid_t euid)
61 {
62         long ret = sys_setreuid(low2highuid(ruid), low2highuid(euid));
63         /* avoid REGPARM breakage on x86: */
64         prevent_tail_call(ret);
65         return ret;
66 }
67
68 asmlinkage long sys_setuid16(old_uid_t uid)
69 {
70         long ret = sys_setuid(low2highuid(uid));
71         /* avoid REGPARM breakage on x86: */
72         prevent_tail_call(ret);
73         return ret;
74 }
75
76 asmlinkage long sys_setresuid16(old_uid_t ruid, old_uid_t euid, old_uid_t suid)
77 {
78         long ret = sys_setresuid(low2highuid(ruid), low2highuid(euid),
79                                  low2highuid(suid));
80         /* avoid REGPARM breakage on x86: */
81         prevent_tail_call(ret);
82         return ret;
83 }
84
85 asmlinkage long sys_getresuid16(old_uid_t __user *ruid, old_uid_t __user *euid, old_uid_t __user *suid)
86 {
87         int retval;
88
89         if (!(retval = put_user(high2lowuid(current->uid), ruid)) &&
90             !(retval = put_user(high2lowuid(current->euid), euid)))
91                 retval = put_user(high2lowuid(current->suid), suid);
92
93         return retval;
94 }
95
96 asmlinkage long sys_setresgid16(old_gid_t rgid, old_gid_t egid, old_gid_t sgid)
97 {
98         long ret = sys_setresgid(low2highgid(rgid), low2highgid(egid),
99                                  low2highgid(sgid));
100         /* avoid REGPARM breakage on x86: */
101         prevent_tail_call(ret);
102         return ret;
103 }
104
105 asmlinkage long sys_getresgid16(old_gid_t __user *rgid, old_gid_t __user *egid, old_gid_t __user *sgid)
106 {
107         int retval;
108
109         if (!(retval = put_user(high2lowgid(current->gid), rgid)) &&
110             !(retval = put_user(high2lowgid(current->egid), egid)))
111                 retval = put_user(high2lowgid(current->sgid), sgid);
112
113         return retval;
114 }
115
116 asmlinkage long sys_setfsuid16(old_uid_t uid)
117 {
118         long ret = sys_setfsuid(low2highuid(uid));
119         /* avoid REGPARM breakage on x86: */
120         prevent_tail_call(ret);
121         return ret;
122 }
123
124 asmlinkage long sys_setfsgid16(old_gid_t gid)
125 {
126         long ret = sys_setfsgid(low2highgid(gid));
127         /* avoid REGPARM breakage on x86: */
128         prevent_tail_call(ret);
129         return ret;
130 }
131
132 static int groups16_to_user(old_gid_t __user *grouplist,
133     struct group_info *group_info)
134 {
135         int i;
136         old_gid_t group;
137
138         for (i = 0; i < group_info->ngroups; i++) {
139                 group = high2lowgid(GROUP_AT(group_info, i));
140                 if (put_user(group, grouplist+i))
141                         return -EFAULT;
142         }
143
144         return 0;
145 }
146
147 static int groups16_from_user(struct group_info *group_info,
148     old_gid_t __user *grouplist)
149 {
150         int i;
151         old_gid_t group;
152
153         for (i = 0; i < group_info->ngroups; i++) {
154                 if (get_user(group, grouplist+i))
155                         return  -EFAULT;
156                 GROUP_AT(group_info, i) = low2highgid(group);
157         }
158
159         return 0;
160 }
161
162 asmlinkage long sys_getgroups16(int gidsetsize, old_gid_t __user *grouplist)
163 {
164         int i = 0;
165
166         if (gidsetsize < 0)
167                 return -EINVAL;
168
169         get_group_info(current->group_info);
170         i = current->group_info->ngroups;
171         if (gidsetsize) {
172                 if (i > gidsetsize) {
173                         i = -EINVAL;
174                         goto out;
175                 }
176                 if (groups16_to_user(grouplist, current->group_info)) {
177                         i = -EFAULT;
178                         goto out;
179                 }
180         }
181 out:
182         put_group_info(current->group_info);
183         return i;
184 }
185
186 asmlinkage long sys_setgroups16(int gidsetsize, old_gid_t __user *grouplist)
187 {
188         struct group_info *group_info;
189         int retval;
190
191         if (!capable(CAP_SETGID))
192                 return -EPERM;
193         if ((unsigned)gidsetsize > NGROUPS_MAX)
194                 return -EINVAL;
195
196         group_info = groups_alloc(gidsetsize);
197         if (!group_info)
198                 return -ENOMEM;
199         retval = groups16_from_user(group_info, grouplist);
200         if (retval) {
201                 put_group_info(group_info);
202                 return retval;
203         }
204
205         retval = set_current_groups(group_info);
206         put_group_info(group_info);
207
208         return retval;
209 }
210
211 asmlinkage long sys_getuid16(void)
212 {
213         return high2lowuid(current->uid);
214 }
215
216 asmlinkage long sys_geteuid16(void)
217 {
218         return high2lowuid(current->euid);
219 }
220
221 asmlinkage long sys_getgid16(void)
222 {
223         return high2lowgid(current->gid);
224 }
225
226 asmlinkage long sys_getegid16(void)
227 {
228         return high2lowgid(current->egid);
229 }