-/*
- * Supplementary group IDs
- */
-
-/* init to 2 - one for init_task, one to ensure it is never freed */
-struct group_info init_groups = { .usage = ATOMIC_INIT(2) };
-
-struct group_info *groups_alloc(int gidsetsize)
-{
- struct group_info *group_info;
- int nblocks;
- int i;
-
- nblocks = (gidsetsize + NGROUPS_PER_BLOCK - 1) / NGROUPS_PER_BLOCK;
- /* Make sure we always allocate at least one indirect block pointer */
- nblocks = nblocks ? : 1;
- group_info = kmalloc(sizeof(*group_info) + nblocks*sizeof(gid_t *), GFP_USER);
- if (!group_info)
- return NULL;
- group_info->ngroups = gidsetsize;
- group_info->nblocks = nblocks;
- atomic_set(&group_info->usage, 1);
-
- if (gidsetsize <= NGROUPS_SMALL)
- group_info->blocks[0] = group_info->small_block;
- else {
- for (i = 0; i < nblocks; i++) {
- gid_t *b;
- b = (void *)__get_free_page(GFP_USER);
- if (!b)
- goto out_undo_partial_alloc;
- group_info->blocks[i] = b;
- }
- }
- return group_info;
-
-out_undo_partial_alloc:
- while (--i >= 0) {
- free_page((unsigned long)group_info->blocks[i]);
- }
- kfree(group_info);
- return NULL;
-}
-
-EXPORT_SYMBOL(groups_alloc);
-
-void groups_free(struct group_info *group_info)
-{
- if (group_info->blocks[0] != group_info->small_block) {
- int i;
- for (i = 0; i < group_info->nblocks; i++)
- free_page((unsigned long)group_info->blocks[i]);
- }
- kfree(group_info);
-}
-
-EXPORT_SYMBOL(groups_free);
-
-/* export the group_info to a user-space array */
-static int groups_to_user(gid_t __user *grouplist,
- struct group_info *group_info)
-{
- int i;
- unsigned int count = group_info->ngroups;
-
- for (i = 0; i < group_info->nblocks; i++) {
- unsigned int cp_count = min(NGROUPS_PER_BLOCK, count);
- unsigned int len = cp_count * sizeof(*grouplist);
-
- if (copy_to_user(grouplist, group_info->blocks[i], len))
- return -EFAULT;
-
- grouplist += NGROUPS_PER_BLOCK;
- count -= cp_count;
- }
- return 0;
-}
-
-/* fill a group_info from a user-space array - it must be allocated already */
-static int groups_from_user(struct group_info *group_info,
- gid_t __user *grouplist)
-{
- int i;
- unsigned int count = group_info->ngroups;
-
- for (i = 0; i < group_info->nblocks; i++) {
- unsigned int cp_count = min(NGROUPS_PER_BLOCK, count);
- unsigned int len = cp_count * sizeof(*grouplist);
-
- if (copy_from_user(group_info->blocks[i], grouplist, len))
- return -EFAULT;
-
- grouplist += NGROUPS_PER_BLOCK;
- count -= cp_count;
- }
- return 0;
-}
-
-/* a simple Shell sort */
-static void groups_sort(struct group_info *group_info)
-{
- int base, max, stride;
- int gidsetsize = group_info->ngroups;
-
- for (stride = 1; stride < gidsetsize; stride = 3 * stride + 1)
- ; /* nothing */
- stride /= 3;
-
- while (stride) {
- max = gidsetsize - stride;
- for (base = 0; base < max; base++) {
- int left = base;
- int right = left + stride;
- gid_t tmp = GROUP_AT(group_info, right);
-
- while (left >= 0 && GROUP_AT(group_info, left) > tmp) {
- GROUP_AT(group_info, right) =
- GROUP_AT(group_info, left);
- right = left;
- left -= stride;
- }
- GROUP_AT(group_info, right) = tmp;
- }
- stride /= 3;
- }
-}
-
-/* a simple bsearch */
-int groups_search(struct group_info *group_info, gid_t grp)
-{
- unsigned int left, right;
-
- if (!group_info)
- return 0;
-
- left = 0;
- right = group_info->ngroups;
- while (left < right) {
- unsigned int mid = (left+right)/2;
- int cmp = grp - GROUP_AT(group_info, mid);
- if (cmp > 0)
- left = mid + 1;
- else if (cmp < 0)
- right = mid;
- else
- return 1;
- }
- return 0;
-}
-
-/* validate and set current->group_info */
-int set_current_groups(struct group_info *group_info)
-{
- int retval;
- struct group_info *old_info;
-
- retval = security_task_setgroups(group_info);
- if (retval)
- return retval;
-
- groups_sort(group_info);
- get_group_info(group_info);
-
- task_lock(current);
- old_info = current->group_info;
- current->group_info = group_info;
- task_unlock(current);
-
- put_group_info(old_info);
-
- return 0;
-}