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 }