diff options
author | Alexey Dobriyan <adobriyan@gmail.com> | 2009-06-16 18:33:40 -0400 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-06-16 22:47:48 -0400 |
commit | 30639b6af85a92491b22dd14c17b14ca11da60e6 (patch) | |
tree | f21c4dd631da5b8750678958b29947d4d0e90cb0 /kernel/sys.c | |
parent | 8b0b1db0133e4218a9b45c09e53793c039edebe1 (diff) |
groups: move code to kernel/groups.c
Move supplementary groups implementation to kernel/groups.c .
kernel/sys.c already accumulated quite a few random stuff.
Do strictly copy/paste + add required headers to compile. Compile-tested
on many configs and archs.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/sys.c')
-rw-r--r-- | kernel/sys.c | 283 |
1 files changed, 0 insertions, 283 deletions
diff --git a/kernel/sys.c b/kernel/sys.c index 438d99a38c87..b3f1097c76fa 100644 --- a/kernel/sys.c +++ b/kernel/sys.c | |||
@@ -1113,289 +1113,6 @@ out: | |||
1113 | return err; | 1113 | return err; |
1114 | } | 1114 | } |
1115 | 1115 | ||
1116 | /* | ||
1117 | * Supplementary group IDs | ||
1118 | */ | ||
1119 | |||
1120 | /* init to 2 - one for init_task, one to ensure it is never freed */ | ||
1121 | struct group_info init_groups = { .usage = ATOMIC_INIT(2) }; | ||
1122 | |||
1123 | struct group_info *groups_alloc(int gidsetsize) | ||
1124 | { | ||
1125 | struct group_info *group_info; | ||
1126 | int nblocks; | ||
1127 | int i; | ||
1128 | |||
1129 | nblocks = (gidsetsize + NGROUPS_PER_BLOCK - 1) / NGROUPS_PER_BLOCK; | ||
1130 | /* Make sure we always allocate at least one indirect block pointer */ | ||
1131 | nblocks = nblocks ? : 1; | ||
1132 | group_info = kmalloc(sizeof(*group_info) + nblocks*sizeof(gid_t *), GFP_USER); | ||
1133 | if (!group_info) | ||
1134 | return NULL; | ||
1135 | group_info->ngroups = gidsetsize; | ||
1136 | group_info->nblocks = nblocks; | ||
1137 | atomic_set(&group_info->usage, 1); | ||
1138 | |||
1139 | if (gidsetsize <= NGROUPS_SMALL) | ||
1140 | group_info->blocks[0] = group_info->small_block; | ||
1141 | else { | ||
1142 | for (i = 0; i < nblocks; i++) { | ||
1143 | gid_t *b; | ||
1144 | b = (void *)__get_free_page(GFP_USER); | ||
1145 | if (!b) | ||
1146 | goto out_undo_partial_alloc; | ||
1147 | group_info->blocks[i] = b; | ||
1148 | } | ||
1149 | } | ||
1150 | return group_info; | ||
1151 | |||
1152 | out_undo_partial_alloc: | ||
1153 | while (--i >= 0) { | ||
1154 | free_page((unsigned long)group_info->blocks[i]); | ||
1155 | } | ||
1156 | kfree(group_info); | ||
1157 | return NULL; | ||
1158 | } | ||
1159 | |||
1160 | EXPORT_SYMBOL(groups_alloc); | ||
1161 | |||
1162 | void groups_free(struct group_info *group_info) | ||
1163 | { | ||
1164 | if (group_info->blocks[0] != group_info->small_block) { | ||
1165 | int i; | ||
1166 | for (i = 0; i < group_info->nblocks; i++) | ||
1167 | free_page((unsigned long)group_info->blocks[i]); | ||
1168 | } | ||
1169 | kfree(group_info); | ||
1170 | } | ||
1171 | |||
1172 | EXPORT_SYMBOL(groups_free); | ||
1173 | |||
1174 | /* export the group_info to a user-space array */ | ||
1175 | static int groups_to_user(gid_t __user *grouplist, | ||
1176 | const struct group_info *group_info) | ||
1177 | { | ||
1178 | int i; | ||
1179 | unsigned int count = group_info->ngroups; | ||
1180 | |||
1181 | for (i = 0; i < group_info->nblocks; i++) { | ||
1182 | unsigned int cp_count = min(NGROUPS_PER_BLOCK, count); | ||
1183 | unsigned int len = cp_count * sizeof(*grouplist); | ||
1184 | |||
1185 | if (copy_to_user(grouplist, group_info->blocks[i], len)) | ||
1186 | return -EFAULT; | ||
1187 | |||
1188 | grouplist += NGROUPS_PER_BLOCK; | ||
1189 | count -= cp_count; | ||
1190 | } | ||
1191 | return 0; | ||
1192 | } | ||
1193 | |||
1194 | /* fill a group_info from a user-space array - it must be allocated already */ | ||
1195 | static int groups_from_user(struct group_info *group_info, | ||
1196 | gid_t __user *grouplist) | ||
1197 | { | ||
1198 | int i; | ||
1199 | unsigned int count = group_info->ngroups; | ||
1200 | |||
1201 | for (i = 0; i < group_info->nblocks; i++) { | ||
1202 | unsigned int cp_count = min(NGROUPS_PER_BLOCK, count); | ||
1203 | unsigned int len = cp_count * sizeof(*grouplist); | ||
1204 | |||
1205 | if (copy_from_user(group_info->blocks[i], grouplist, len)) | ||
1206 | return -EFAULT; | ||
1207 | |||
1208 | grouplist += NGROUPS_PER_BLOCK; | ||
1209 | count -= cp_count; | ||
1210 | } | ||
1211 | return 0; | ||
1212 | } | ||
1213 | |||
1214 | /* a simple Shell sort */ | ||
1215 | static void groups_sort(struct group_info *group_info) | ||
1216 | { | ||
1217 | int base, max, stride; | ||
1218 | int gidsetsize = group_info->ngroups; | ||
1219 | |||
1220 | for (stride = 1; stride < gidsetsize; stride = 3 * stride + 1) | ||
1221 | ; /* nothing */ | ||
1222 | stride /= 3; | ||
1223 | |||
1224 | while (stride) { | ||
1225 | max = gidsetsize - stride; | ||
1226 | for (base = 0; base < max; base++) { | ||
1227 | int left = base; | ||
1228 | int right = left + stride; | ||
1229 | gid_t tmp = GROUP_AT(group_info, right); | ||
1230 | |||
1231 | while (left >= 0 && GROUP_AT(group_info, left) > tmp) { | ||
1232 | GROUP_AT(group_info, right) = | ||
1233 | GROUP_AT(group_info, left); | ||
1234 | right = left; | ||
1235 | left -= stride; | ||
1236 | } | ||
1237 | GROUP_AT(group_info, right) = tmp; | ||
1238 | } | ||
1239 | stride /= 3; | ||
1240 | } | ||
1241 | } | ||
1242 | |||
1243 | /* a simple bsearch */ | ||
1244 | int groups_search(const struct group_info *group_info, gid_t grp) | ||
1245 | { | ||
1246 | unsigned int left, right; | ||
1247 | |||
1248 | if (!group_info) | ||
1249 | return 0; | ||
1250 | |||
1251 | left = 0; | ||
1252 | right = group_info->ngroups; | ||
1253 | while (left < right) { | ||
1254 | unsigned int mid = (left+right)/2; | ||
1255 | int cmp = grp - GROUP_AT(group_info, mid); | ||
1256 | if (cmp > 0) | ||
1257 | left = mid + 1; | ||
1258 | else if (cmp < 0) | ||
1259 | right = mid; | ||
1260 | else | ||
1261 | return 1; | ||
1262 | } | ||
1263 | return 0; | ||
1264 | } | ||
1265 | |||
1266 | /** | ||
1267 | * set_groups - Change a group subscription in a set of credentials | ||
1268 | * @new: The newly prepared set of credentials to alter | ||
1269 | * @group_info: The group list to install | ||
1270 | * | ||
1271 | * Validate a group subscription and, if valid, insert it into a set | ||
1272 | * of credentials. | ||
1273 | */ | ||
1274 | int set_groups(struct cred *new, struct group_info *group_info) | ||
1275 | { | ||
1276 | int retval; | ||
1277 | |||
1278 | retval = security_task_setgroups(group_info); | ||
1279 | if (retval) | ||
1280 | return retval; | ||
1281 | |||
1282 | put_group_info(new->group_info); | ||
1283 | groups_sort(group_info); | ||
1284 | get_group_info(group_info); | ||
1285 | new->group_info = group_info; | ||
1286 | return 0; | ||
1287 | } | ||
1288 | |||
1289 | EXPORT_SYMBOL(set_groups); | ||
1290 | |||
1291 | /** | ||
1292 | * set_current_groups - Change current's group subscription | ||
1293 | * @group_info: The group list to impose | ||
1294 | * | ||
1295 | * Validate a group subscription and, if valid, impose it upon current's task | ||
1296 | * security record. | ||
1297 | */ | ||
1298 | int set_current_groups(struct group_info *group_info) | ||
1299 | { | ||
1300 | struct cred *new; | ||
1301 | int ret; | ||
1302 | |||
1303 | new = prepare_creds(); | ||
1304 | if (!new) | ||
1305 | return -ENOMEM; | ||
1306 | |||
1307 | ret = set_groups(new, group_info); | ||
1308 | if (ret < 0) { | ||
1309 | abort_creds(new); | ||
1310 | return ret; | ||
1311 | } | ||
1312 | |||
1313 | return commit_creds(new); | ||
1314 | } | ||
1315 | |||
1316 | EXPORT_SYMBOL(set_current_groups); | ||
1317 | |||
1318 | SYSCALL_DEFINE2(getgroups, int, gidsetsize, gid_t __user *, grouplist) | ||
1319 | { | ||
1320 | const struct cred *cred = current_cred(); | ||
1321 | int i; | ||
1322 | |||
1323 | if (gidsetsize < 0) | ||
1324 | return -EINVAL; | ||
1325 | |||
1326 | /* no need to grab task_lock here; it cannot change */ | ||
1327 | i = cred->group_info->ngroups; | ||
1328 | if (gidsetsize) { | ||
1329 | if (i > gidsetsize) { | ||
1330 | i = -EINVAL; | ||
1331 | goto out; | ||
1332 | } | ||
1333 | if (groups_to_user(grouplist, cred->group_info)) { | ||
1334 | i = -EFAULT; | ||
1335 | goto out; | ||
1336 | } | ||
1337 | } | ||
1338 | out: | ||
1339 | return i; | ||
1340 | } | ||
1341 | |||
1342 | /* | ||
1343 | * SMP: Our groups are copy-on-write. We can set them safely | ||
1344 | * without another task interfering. | ||
1345 | */ | ||
1346 | |||
1347 | SYSCALL_DEFINE2(setgroups, int, gidsetsize, gid_t __user *, grouplist) | ||
1348 | { | ||
1349 | struct group_info *group_info; | ||
1350 | int retval; | ||
1351 | |||
1352 | if (!capable(CAP_SETGID)) | ||
1353 | return -EPERM; | ||
1354 | if ((unsigned)gidsetsize > NGROUPS_MAX) | ||
1355 | return -EINVAL; | ||
1356 | |||
1357 | group_info = groups_alloc(gidsetsize); | ||
1358 | if (!group_info) | ||
1359 | return -ENOMEM; | ||
1360 | retval = groups_from_user(group_info, grouplist); | ||
1361 | if (retval) { | ||
1362 | put_group_info(group_info); | ||
1363 | return retval; | ||
1364 | } | ||
1365 | |||
1366 | retval = set_current_groups(group_info); | ||
1367 | put_group_info(group_info); | ||
1368 | |||
1369 | return retval; | ||
1370 | } | ||
1371 | |||
1372 | /* | ||
1373 | * Check whether we're fsgid/egid or in the supplemental group.. | ||
1374 | */ | ||
1375 | int in_group_p(gid_t grp) | ||
1376 | { | ||
1377 | const struct cred *cred = current_cred(); | ||
1378 | int retval = 1; | ||
1379 | |||
1380 | if (grp != cred->fsgid) | ||
1381 | retval = groups_search(cred->group_info, grp); | ||
1382 | return retval; | ||
1383 | } | ||
1384 | |||
1385 | EXPORT_SYMBOL(in_group_p); | ||
1386 | |||
1387 | int in_egroup_p(gid_t grp) | ||
1388 | { | ||
1389 | const struct cred *cred = current_cred(); | ||
1390 | int retval = 1; | ||
1391 | |||
1392 | if (grp != cred->egid) | ||
1393 | retval = groups_search(cred->group_info, grp); | ||
1394 | return retval; | ||
1395 | } | ||
1396 | |||
1397 | EXPORT_SYMBOL(in_egroup_p); | ||
1398 | |||
1399 | DECLARE_RWSEM(uts_sem); | 1116 | DECLARE_RWSEM(uts_sem); |
1400 | 1117 | ||
1401 | SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name) | 1118 | SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name) |