+static int audit_match_filetype(struct audit_context *ctx, int which)
+{
+ unsigned index = which & ~S_IFMT;
+ mode_t mode = which & S_IFMT;
+ if (index >= ctx->name_count)
+ return 0;
+ if (ctx->names[index].ino == -1)
+ return 0;
+ if ((ctx->names[index].mode ^ mode) & S_IFMT)
+ return 0;
+ return 1;
+}
+
+/*
+ * We keep a linked list of fixed-sized (31 pointer) arrays of audit_chunk *;
+ * ->first_trees points to its beginning, ->trees - to the current end of data.
+ * ->tree_count is the number of free entries in array pointed to by ->trees.
+ * Original condition is (NULL, NULL, 0); as soon as it grows we never revert to NULL,
+ * "empty" becomes (p, p, 31) afterwards. We don't shrink the list (and seriously,
+ * it's going to remain 1-element for almost any setup) until we free context itself.
+ * References in it _are_ dropped - at the same time we free/drop aux stuff.
+ */
+
+#ifdef CONFIG_AUDIT_TREE
+static int put_tree_ref(struct audit_context *ctx, struct audit_chunk *chunk)
+{
+ struct audit_tree_refs *p = ctx->trees;
+ int left = ctx->tree_count;
+ if (likely(left)) {
+ p->c[--left] = chunk;
+ ctx->tree_count = left;
+ return 1;
+ }
+ if (!p)
+ return 0;
+ p = p->next;
+ if (p) {
+ p->c[30] = chunk;
+ ctx->trees = p;
+ ctx->tree_count = 30;
+ return 1;
+ }
+ return 0;
+}
+
+static int grow_tree_refs(struct audit_context *ctx)
+{
+ struct audit_tree_refs *p = ctx->trees;
+ ctx->trees = kzalloc(sizeof(struct audit_tree_refs), GFP_KERNEL);
+ if (!ctx->trees) {
+ ctx->trees = p;
+ return 0;
+ }
+ if (p)
+ p->next = ctx->trees;
+ else
+ ctx->first_trees = ctx->trees;
+ ctx->tree_count = 31;
+ return 1;
+}
+#endif
+
+static void unroll_tree_refs(struct audit_context *ctx,
+ struct audit_tree_refs *p, int count)
+{
+#ifdef CONFIG_AUDIT_TREE
+ struct audit_tree_refs *q;
+ int n;
+ if (!p) {
+ /* we started with empty chain */
+ p = ctx->first_trees;
+ count = 31;
+ /* if the very first allocation has failed, nothing to do */
+ if (!p)
+ return;
+ }
+ n = count;
+ for (q = p; q != ctx->trees; q = q->next, n = 31) {
+ while (n--) {
+ audit_put_chunk(q->c[n]);
+ q->c[n] = NULL;
+ }
+ }
+ while (n-- > ctx->tree_count) {
+ audit_put_chunk(q->c[n]);
+ q->c[n] = NULL;
+ }
+ ctx->trees = p;
+ ctx->tree_count = count;
+#endif
+}
+
+static void free_tree_refs(struct audit_context *ctx)
+{
+ struct audit_tree_refs *p, *q;
+ for (p = ctx->first_trees; p; p = q) {
+ q = p->next;
+ kfree(p);
+ }
+}
+
+static int match_tree_refs(struct audit_context *ctx, struct audit_tree *tree)
+{
+#ifdef CONFIG_AUDIT_TREE
+ struct audit_tree_refs *p;
+ int n;
+ if (!tree)
+ return 0;
+ /* full ones */
+ for (p = ctx->first_trees; p != ctx->trees; p = p->next) {
+ for (n = 0; n < 31; n++)
+ if (audit_tree_match(p->c[n], tree))
+ return 1;
+ }
+ /* partial */
+ if (p) {
+ for (n = ctx->tree_count; n < 31; n++)
+ if (audit_tree_match(p->c[n], tree))
+ return 1;
+ }
+#endif
+ return 0;
+}
+