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/mman.h>
8#include <linux/notifier.h>
9#include <linux/reboot.h>
10#include <linux/prctl.h>
11#include <linux/capability.h>
12#include <linux/init.h>
13#include <linux/highuid.h>
14#include <linux/security.h>
15#include <linux/syscalls.h>
16
17#include <asm/uaccess.h>
18
19SYSCALL_DEFINE3(chown16, const char __user *, filename, old_uid_t, user, old_gid_t, group)
20{
21	long ret = sys_chown(filename, low2highuid(user), low2highgid(group));
22	/* avoid REGPARM breakage on x86: */
23	asmlinkage_protect(3, ret, filename, user, group);
24	return ret;
25}
26
27SYSCALL_DEFINE3(lchown16, const char __user *, filename, old_uid_t, user, old_gid_t, group)
28{
29	long ret = sys_lchown(filename, low2highuid(user), low2highgid(group));
30	/* avoid REGPARM breakage on x86: */
31	asmlinkage_protect(3, ret, filename, user, group);
32	return ret;
33}
34
35SYSCALL_DEFINE3(fchown16, unsigned int, fd, old_uid_t, user, old_gid_t, group)
36{
37	long ret = sys_fchown(fd, low2highuid(user), low2highgid(group));
38	/* avoid REGPARM breakage on x86: */
39	asmlinkage_protect(3, ret, fd, user, group);
40	return ret;
41}
42
43SYSCALL_DEFINE2(setregid16, old_gid_t, rgid, old_gid_t, egid)
44{
45	long ret = sys_setregid(low2highgid(rgid), low2highgid(egid));
46	/* avoid REGPARM breakage on x86: */
47	asmlinkage_protect(2, ret, rgid, egid);
48	return ret;
49}
50
51SYSCALL_DEFINE1(setgid16, old_gid_t, gid)
52{
53	long ret = sys_setgid(low2highgid(gid));
54	/* avoid REGPARM breakage on x86: */
55	asmlinkage_protect(1, ret, gid);
56	return ret;
57}
58
59SYSCALL_DEFINE2(setreuid16, old_uid_t, ruid, old_uid_t, euid)
60{
61	long ret = sys_setreuid(low2highuid(ruid), low2highuid(euid));
62	/* avoid REGPARM breakage on x86: */
63	asmlinkage_protect(2, ret, ruid, euid);
64	return ret;
65}
66
67SYSCALL_DEFINE1(setuid16, old_uid_t, uid)
68{
69	long ret = sys_setuid(low2highuid(uid));
70	/* avoid REGPARM breakage on x86: */
71	asmlinkage_protect(1, ret, uid);
72	return ret;
73}
74
75SYSCALL_DEFINE3(setresuid16, old_uid_t, ruid, old_uid_t, euid, old_uid_t, suid)
76{
77	long ret = sys_setresuid(low2highuid(ruid), low2highuid(euid),
78				 low2highuid(suid));
79	/* avoid REGPARM breakage on x86: */
80	asmlinkage_protect(3, ret, ruid, euid, suid);
81	return ret;
82}
83
84SYSCALL_DEFINE3(getresuid16, old_uid_t __user *, ruid, old_uid_t __user *, euid, old_uid_t __user *, suid)
85{
86	const struct cred *cred = current_cred();
87	int retval;
88
89	if (!(retval   = put_user(high2lowuid(cred->uid),  ruid)) &&
90	    !(retval   = put_user(high2lowuid(cred->euid), euid)))
91		retval = put_user(high2lowuid(cred->suid), suid);
92
93	return retval;
94}
95
96SYSCALL_DEFINE3(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	asmlinkage_protect(3, ret, rgid, egid, sgid);
102	return ret;
103}
104
105
106SYSCALL_DEFINE3(getresgid16, old_gid_t __user *, rgid, old_gid_t __user *, egid, old_gid_t __user *, sgid)
107{
108	const struct cred *cred = current_cred();
109	int retval;
110
111	if (!(retval   = put_user(high2lowgid(cred->gid),  rgid)) &&
112	    !(retval   = put_user(high2lowgid(cred->egid), egid)))
113		retval = put_user(high2lowgid(cred->sgid), sgid);
114
115	return retval;
116}
117
118SYSCALL_DEFINE1(setfsuid16, old_uid_t, uid)
119{
120	long ret = sys_setfsuid(low2highuid(uid));
121	/* avoid REGPARM breakage on x86: */
122	asmlinkage_protect(1, ret, uid);
123	return ret;
124}
125
126SYSCALL_DEFINE1(setfsgid16, old_gid_t, gid)
127{
128	long ret = sys_setfsgid(low2highgid(gid));
129	/* avoid REGPARM breakage on x86: */
130	asmlinkage_protect(1, ret, gid);
131	return ret;
132}
133
134static int groups16_to_user(old_gid_t __user *grouplist,
135    struct group_info *group_info)
136{
137	int i;
138	old_gid_t group;
139
140	for (i = 0; i < group_info->ngroups; i++) {
141		group = high2lowgid(GROUP_AT(group_info, i));
142		if (put_user(group, grouplist+i))
143			return -EFAULT;
144	}
145
146	return 0;
147}
148
149static int groups16_from_user(struct group_info *group_info,
150    old_gid_t __user *grouplist)
151{
152	int i;
153	old_gid_t group;
154
155	for (i = 0; i < group_info->ngroups; i++) {
156		if (get_user(group, grouplist+i))
157			return  -EFAULT;
158		GROUP_AT(group_info, i) = low2highgid(group);
159	}
160
161	return 0;
162}
163
164SYSCALL_DEFINE2(getgroups16, int, gidsetsize, old_gid_t __user *, grouplist)
165{
166	const struct cred *cred = current_cred();
167	int i;
168
169	if (gidsetsize < 0)
170		return -EINVAL;
171
172	i = cred->group_info->ngroups;
173	if (gidsetsize) {
174		if (i > gidsetsize) {
175			i = -EINVAL;
176			goto out;
177		}
178		if (groups16_to_user(grouplist, cred->group_info)) {
179			i = -EFAULT;
180			goto out;
181		}
182	}
183out:
184	return i;
185}
186
187SYSCALL_DEFINE2(setgroups16, int, gidsetsize, old_gid_t __user *, grouplist)
188{
189	struct group_info *group_info;
190	int retval;
191
192	if (!capable(CAP_SETGID))
193		return -EPERM;
194	if ((unsigned)gidsetsize > NGROUPS_MAX)
195		return -EINVAL;
196
197	group_info = groups_alloc(gidsetsize);
198	if (!group_info)
199		return -ENOMEM;
200	retval = groups16_from_user(group_info, grouplist);
201	if (retval) {
202		put_group_info(group_info);
203		return retval;
204	}
205
206	retval = set_current_groups(group_info);
207	put_group_info(group_info);
208
209	return retval;
210}
211
212SYSCALL_DEFINE0(getuid16)
213{
214	return high2lowuid(current_uid());
215}
216
217SYSCALL_DEFINE0(geteuid16)
218{
219	return high2lowuid(current_euid());
220}
221
222SYSCALL_DEFINE0(getgid16)
223{
224	return high2lowgid(current_gid());
225}
226
227SYSCALL_DEFINE0(getegid16)
228{
229	return high2lowgid(current_egid());
230}
231