Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 2170 insertions, 0 deletions

diff --git a/security/apparmor/label.c b/security/apparmor/label.c
new file mode 100644
index 000000000..5a80a16a7
--- /dev/null
+++ b/security/apparmor/label.c
@@ -0,0 +1,2170 @@
+/*
+ * AppArmor security module
+ *
+ * This file contains AppArmor label definitions
+ *
+ * Copyright 2017 Canonical Ltd.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation, version 2 of the
+ * License.
+ */
+
+#include <linux/audit.h>
+#include <linux/seq_file.h>
+#include <linux/sort.h>
+
+#include "include/apparmor.h"
+#include "include/cred.h"
+#include "include/label.h"
+#include "include/policy.h"
+#include "include/secid.h"
+
+
+/*
+ * the aa_label represents the set of profiles confining an object
+ *
+ * Labels maintain a reference count to the set of pointers they reference
+ * Labels are ref counted by
+ *   tasks and object via the security field/security context off the field
+ *   code - will take a ref count on a label if it needs the label
+ *          beyond what is possible with an rcu_read_lock.
+ *   profiles - each profile is a label
+ *   secids - a pinned secid will keep a refcount of the label it is
+ *          referencing
+ *   objects - inode, files, sockets, ...
+ *
+ * Labels are not ref counted by the label set, so they maybe removed and
+ * freed when no longer in use.
+ *
+ */
+
+#define PROXY_POISON 97
+#define LABEL_POISON 100
+
+static void free_proxy(struct aa_proxy *proxy)
+{
+	if (proxy) {
+		/* p->label will not updated any more as p is dead */
+		aa_put_label(rcu_dereference_protected(proxy->label, true));
+		memset(proxy, 0, sizeof(*proxy));
+		RCU_INIT_POINTER(proxy->label, (struct aa_label *)PROXY_POISON);
+		kfree(proxy);
+	}
+}
+
+void aa_proxy_kref(struct kref *kref)
+{
+	struct aa_proxy *proxy = container_of(kref, struct aa_proxy, count);
+
+	free_proxy(proxy);
+}
+
+struct aa_proxy *aa_alloc_proxy(struct aa_label *label, gfp_t gfp)
+{
+	struct aa_proxy *new;
+
+	new = kzalloc(sizeof(struct aa_proxy), gfp);
+	if (new) {
+		kref_init(&new->count);
+		rcu_assign_pointer(new->label, aa_get_label(label));
+	}
+	return new;
+}
+
+/* requires profile list write lock held */
+void __aa_proxy_redirect(struct aa_label *orig, struct aa_label *new)
+{
+	struct aa_label *tmp;
+
+	AA_BUG(!orig);
+	AA_BUG(!new);
+	lockdep_assert_held_exclusive(&labels_set(orig)->lock);
+
+	tmp = rcu_dereference_protected(orig->proxy->label,
+					&labels_ns(orig)->lock);
+	rcu_assign_pointer(orig->proxy->label, aa_get_label(new));
+	orig->flags |= FLAG_STALE;
+	aa_put_label(tmp);
+}
+
+static void __proxy_share(struct aa_label *old, struct aa_label *new)
+{
+	struct aa_proxy *proxy = new->proxy;
+
+	new->proxy = aa_get_proxy(old->proxy);
+	__aa_proxy_redirect(old, new);
+	aa_put_proxy(proxy);
+}
+
+
+/**
+ * ns_cmp - compare ns for label set ordering
+ * @a: ns to compare (NOT NULL)
+ * @b: ns to compare (NOT NULL)
+ *
+ * Returns: <0 if a < b
+ *          ==0 if a == b
+ *          >0  if a > b
+ */
+static int ns_cmp(struct aa_ns *a, struct aa_ns *b)
+{
+	int res;
+
+	AA_BUG(!a);
+	AA_BUG(!b);
+	AA_BUG(!a->base.hname);
+	AA_BUG(!b->base.hname);
+
+	if (a == b)
+		return 0;
+
+	res = a->level - b->level;
+	if (res)
+		return res;
+
+	return strcmp(a->base.hname, b->base.hname);
+}
+
+/**
+ * profile_cmp - profile comparison for set ordering
+ * @a: profile to compare (NOT NULL)
+ * @b: profile to compare (NOT NULL)
+ *
+ * Returns: <0  if a < b
+ *          ==0 if a == b
+ *          >0  if a > b
+ */
+static int profile_cmp(struct aa_profile *a, struct aa_profile *b)
+{
+	int res;
+
+	AA_BUG(!a);
+	AA_BUG(!b);
+	AA_BUG(!a->ns);
+	AA_BUG(!b->ns);
+	AA_BUG(!a->base.hname);
+	AA_BUG(!b->base.hname);
+
+	if (a == b || a->base.hname == b->base.hname)
+		return 0;
+	res = ns_cmp(a->ns, b->ns);
+	if (res)
+		return res;
+
+	return strcmp(a->base.hname, b->base.hname);
+}
+
+/**
+ * vec_cmp - label comparison for set ordering
+ * @a: label to compare (NOT NULL)
+ * @vec: vector of profiles to compare (NOT NULL)
+ * @n: length of @vec
+ *
+ * Returns: <0  if a < vec
+ *          ==0 if a == vec
+ *          >0  if a > vec
+ */
+static int vec_cmp(struct aa_profile **a, int an, struct aa_profile **b, int bn)
+{
+	int i;
+
+	AA_BUG(!a);
+	AA_BUG(!*a);
+	AA_BUG(!b);
+	AA_BUG(!*b);
+	AA_BUG(an <= 0);
+	AA_BUG(bn <= 0);
+
+	for (i = 0; i < an && i < bn; i++) {
+		int res = profile_cmp(a[i], b[i]);
+
+		if (res != 0)
+			return res;
+	}
+
+	return an - bn;
+}
+
+static bool vec_is_stale(struct aa_profile **vec, int n)
+{
+	int i;
+
+	AA_BUG(!vec);
+
+	for (i = 0; i < n; i++) {
+		if (profile_is_stale(vec[i]))
+			return true;
+	}
+
+	return false;
+}
+
+static bool vec_unconfined(struct aa_profile **vec, int n)
+{
+	int i;
+
+	AA_BUG(!vec);
+
+	for (i = 0; i < n; i++) {
+		if (!profile_unconfined(vec[i]))
+			return false;
+	}
+
+	return true;
+}
+
+static int sort_cmp(const void *a, const void *b)
+{
+	return profile_cmp(*(struct aa_profile **)a, *(struct aa_profile **)b);
+}
+
+/*
+ * assumes vec is sorted
+ * Assumes @vec has null terminator at vec[n], and will null terminate
+ * vec[n - dups]
+ */
+static inline int unique(struct aa_profile **vec, int n)
+{
+	int i, pos, dups = 0;
+
+	AA_BUG(n < 1);
+	AA_BUG(!vec);
+
+	pos = 0;
+	for (i = 1; i < n; i++) {
+		int res = profile_cmp(vec[pos], vec[i]);
+
+		AA_BUG(res > 0, "vec not sorted");
+		if (res == 0) {
+			/* drop duplicate */
+			aa_put_profile(vec[i]);
+			dups++;
+			continue;
+		}
+		pos++;
+		if (dups)
+			vec[pos] = vec[i];
+	}
+
+	AA_BUG(dups < 0);
+
+	return dups;
+}
+
+/**
+ * aa_vec_unique - canonical sort and unique a list of profiles
+ * @n: number of refcounted profiles in the list (@n > 0)
+ * @vec: list of profiles to sort and merge
+ *
+ * Returns: the number of duplicates eliminated == references put
+ *
+ * If @flags & VEC_FLAG_TERMINATE @vec has null terminator at vec[n], and will
+ * null terminate vec[n - dups]
+ */
+int aa_vec_unique(struct aa_profile **vec, int n, int flags)
+{
+	int i, dups = 0;
+
+	AA_BUG(n < 1);
+	AA_BUG(!vec);
+
+	/* vecs are usually small and inorder, have a fallback for larger */
+	if (n > 8) {
+		sort(vec, n, sizeof(struct aa_profile *), sort_cmp, NULL);
+		dups = unique(vec, n);
+		goto out;
+	}
+
+	/* insertion sort + unique in one */
+	for (i = 1; i < n; i++) {
+		struct aa_profile *tmp = vec[i];
+		int pos, j;
+
+		for (pos = i - 1 - dups; pos >= 0; pos--) {
+			int res = profile_cmp(vec[pos], tmp);
+
+			if (res == 0) {
+				/* drop duplicate entry */
+				aa_put_profile(tmp);
+				dups++;
+				goto continue_outer;
+			} else if (res < 0)
+				break;
+		}
+		/* pos is at entry < tmp, or index -1. Set to insert pos */
+		pos++;
+
+		for (j = i - dups; j > pos; j--)
+			vec[j] = vec[j - 1];
+		vec[pos] = tmp;
+continue_outer:
+		;
+	}
+
+	AA_BUG(dups < 0);
+
+out:
+	if (flags & VEC_FLAG_TERMINATE)
+		vec[n - dups] = NULL;
+
+	return dups;
+}
+
+
+static void label_destroy(struct aa_label *label)
+{
+	struct aa_label *tmp;
+
+	AA_BUG(!label);
+
+	if (!label_isprofile(label)) {
+		struct aa_profile *profile;
+		struct label_it i;
+
+		aa_put_str(label->hname);
+
+		label_for_each(i, label, profile) {
+			aa_put_profile(profile);
+			label->vec[i.i] = (struct aa_profile *)
+					   (LABEL_POISON + (long) i.i);
+		}
+	}
+
+	if (rcu_dereference_protected(label->proxy->label, true) == label)
+		rcu_assign_pointer(label->proxy->label, NULL);
+
+	aa_free_secid(label->secid);
+
+	tmp = rcu_dereference_protected(label->proxy->label, true);
+	if (tmp == label)
+		rcu_assign_pointer(label->proxy->label, NULL);
+
+	aa_put_proxy(label->proxy);
+	label->proxy = (struct aa_proxy *) PROXY_POISON + 1;
+}
+
+void aa_label_free(struct aa_label *label)
+{
+	if (!label)
+		return;
+
+	label_destroy(label);
+	kfree(label);
+}
+
+static void label_free_switch(struct aa_label *label)
+{
+	if (label->flags & FLAG_NS_COUNT)
+		aa_free_ns(labels_ns(label));
+	else if (label_isprofile(label))
+		aa_free_profile(labels_profile(label));
+	else
+		aa_label_free(label);
+}
+
+static void label_free_rcu(struct rcu_head *head)
+{
+	struct aa_label *label = container_of(head, struct aa_label, rcu);
+
+	if (label->flags & FLAG_IN_TREE)
+		(void) aa_label_remove(label);
+	label_free_switch(label);
+}
+
+void aa_label_kref(struct kref *kref)
+{
+	struct aa_label *label = container_of(kref, struct aa_label, count);
+	struct aa_ns *ns = labels_ns(label);
+
+	if (!ns) {
+		/* never live, no rcu callback needed, just using the fn */
+		label_free_switch(label);
+		return;
+	}
+	/* TODO: update labels_profile macro so it works here */
+	AA_BUG(label_isprofile(label) &&
+	       on_list_rcu(&label->vec[0]->base.profiles));
+	AA_BUG(label_isprofile(label) &&
+	       on_list_rcu(&label->vec[0]->base.list));
+
+	/* TODO: if compound label and not stale add to reclaim cache */
+	call_rcu(&label->rcu, label_free_rcu);
+}
+
+static void label_free_or_put_new(struct aa_label *label, struct aa_label *new)
+{
+	if (label != new)
+		/* need to free directly to break circular ref with proxy */
+		aa_label_free(new);
+	else
+		aa_put_label(new);
+}
+
+bool aa_label_init(struct aa_label *label, int size, gfp_t gfp)
+{
+	AA_BUG(!label);
+	AA_BUG(size < 1);
+
+	if (aa_alloc_secid(label, gfp) < 0)
+		return false;
+
+	label->size = size;			/* doesn't include null */
+	label->vec[size] = NULL;		/* null terminate */
+	kref_init(&label->count);
+	RB_CLEAR_NODE(&label->node);
+
+	return true;
+}
+
+/**
+ * aa_label_alloc - allocate a label with a profile vector of @size length
+ * @size: size of profile vector in the label
+ * @proxy: proxy to use OR null if to allocate a new one
+ * @gfp: memory allocation type
+ *
+ * Returns: new label
+ *     else NULL if failed
+ */
+struct aa_label *aa_label_alloc(int size, struct aa_proxy *proxy, gfp_t gfp)
+{
+	struct aa_label *new;
+
+	AA_BUG(size < 1);
+
+	/*  + 1 for null terminator entry on vec */
+	new = kzalloc(sizeof(*new) + sizeof(struct aa_profile *) * (size + 1),
+			gfp);
+	AA_DEBUG("%s (%p)\n", __func__, new);
+	if (!new)
+		goto fail;
+
+	if (!aa_label_init(new, size, gfp))
+		goto fail;
+
+	if (!proxy) {
+		proxy = aa_alloc_proxy(new, gfp);
+		if (!proxy)
+			goto fail;
+	} else
+		aa_get_proxy(proxy);
+	/* just set new's proxy, don't redirect proxy here if it was passed in*/
+	new->proxy = proxy;
+
+	return new;
+
+fail:
+	kfree(new);
+
+	return NULL;
+}
+
+
+/**
+ * label_cmp - label comparison for set ordering
+ * @a: label to compare (NOT NULL)
+ * @b: label to compare (NOT NULL)
+ *
+ * Returns: <0  if a < b
+ *          ==0 if a == b
+ *          >0  if a > b
+ */
+static int label_cmp(struct aa_label *a, struct aa_label *b)
+{
+	AA_BUG(!b);
+
+	if (a == b)
+		return 0;
+
+	return vec_cmp(a->vec, a->size, b->vec, b->size);
+}
+
+/* helper fn for label_for_each_confined */
+int aa_label_next_confined(struct aa_label *label, int i)
+{
+	AA_BUG(!label);
+	AA_BUG(i < 0);
+
+	for (; i < label->size; i++) {
+		if (!profile_unconfined(label->vec[i]))
+			return i;
+	}
+
+	return i;
+}
+
+/**
+ * aa_label_next_not_in_set - return the next profile of @sub not in @set
+ * @I: label iterator
+ * @set: label to test against
+ * @sub: label to if is subset of @set
+ *
+ * Returns: profile in @sub that is not in @set, with iterator set pos after
+ *     else NULL if @sub is a subset of @set
+ */
+struct aa_profile *__aa_label_next_not_in_set(struct label_it *I,
+					      struct aa_label *set,
+					      struct aa_label *sub)
+{
+	AA_BUG(!set);
+	AA_BUG(!I);
+	AA_BUG(I->i < 0);
+	AA_BUG(I->i > set->size);
+	AA_BUG(!sub);
+	AA_BUG(I->j < 0);
+	AA_BUG(I->j > sub->size);
+
+	while (I->j < sub->size && I->i < set->size) {
+		int res = profile_cmp(sub->vec[I->j], set->vec[I->i]);
+
+		if (res == 0) {
+			(I->j)++;
+			(I->i)++;
+		} else if (res > 0)
+			(I->i)++;
+		else
+			return sub->vec[(I->j)++];
+	}
+
+	if (I->j < sub->size)
+		return sub->vec[(I->j)++];
+
+	return NULL;
+}
+
+/**
+ * aa_label_is_subset - test if @sub is a subset of @set
+ * @set: label to test against
+ * @sub: label to test if is subset of @set
+ *
+ * Returns: true if @sub is subset of @set
+ *     else false
+ */
+bool aa_label_is_subset(struct aa_label *set, struct aa_label *sub)
+{
+	struct label_it i = { };
+
+	AA_BUG(!set);
+	AA_BUG(!sub);
+
+	if (sub == set)
+		return true;
+
+	return __aa_label_next_not_in_set(&i, set, sub) == NULL;
+}
+
+/**
+ * aa_label_is_unconfined_subset - test if @sub is a subset of @set
+ * @set: label to test against
+ * @sub: label to test if is subset of @set
+ *
+ * This checks for subset but taking into account unconfined. IF
+ * @sub contains an unconfined profile that does not have a matching
+ * unconfined in @set then this will not cause the test to fail.
+ * Conversely we don't care about an unconfined in @set that is not in
+ * @sub
+ *
+ * Returns: true if @sub is special_subset of @set
+ *     else false
+ */
+bool aa_label_is_unconfined_subset(struct aa_label *set, struct aa_label *sub)
+{
+	struct label_it i = { };
+	struct aa_profile *p;
+
+	AA_BUG(!set);
+	AA_BUG(!sub);
+
+	if (sub == set)
+		return true;
+
+	do {
+		p = __aa_label_next_not_in_set(&i, set, sub);
+		if (p && !profile_unconfined(p))
+			break;
+	} while (p);
+
+	return p == NULL;
+}
+
+
+/**
+ * __label_remove - remove @label from the label set
+ * @l: label to remove
+ * @new: label to redirect to
+ *
+ * Requires: labels_set(@label)->lock write_lock
+ * Returns:  true if the label was in the tree and removed
+ */
+static bool __label_remove(struct aa_label *label, struct aa_label *new)
+{
+	struct aa_labelset *ls = labels_set(label);
+
+	AA_BUG(!ls);
+	AA_BUG(!label);
+	lockdep_assert_held_exclusive(&ls->lock);
+
+	if (new)
+		__aa_proxy_redirect(label, new);
+
+	if (!label_is_stale(label))
+		__label_make_stale(label);
+
+	if (label->flags & FLAG_IN_TREE) {
+		rb_erase(&label->node, &ls->root);
+		label->flags &= ~FLAG_IN_TREE;
+		return true;
+	}
+
+	return false;
+}
+
+/**
+ * __label_replace - replace @old with @new in label set
+ * @old: label to remove from label set
+ * @new: label to replace @old with
+ *
+ * Requires: labels_set(@old)->lock write_lock
+ *           valid ref count be held on @new
+ * Returns: true if @old was in set and replaced by @new
+ *
+ * Note: current implementation requires label set be order in such a way
+ *       that @new directly replaces @old position in the set (ie.
+ *       using pointer comparison of the label address would not work)
+ */
+static bool __label_replace(struct aa_label *old, struct aa_label *new)
+{
+	struct aa_labelset *ls = labels_set(old);
+
+	AA_BUG(!ls);
+	AA_BUG(!old);
+	AA_BUG(!new);
+	lockdep_assert_held_exclusive(&ls->lock);
+	AA_BUG(new->flags & FLAG_IN_TREE);
+
+	if (!label_is_stale(old))
+		__label_make_stale(old);
+
+	if (old->flags & FLAG_IN_TREE) {
+		rb_replace_node(&old->node, &new->node, &ls->root);
+		old->flags &= ~FLAG_IN_TREE;
+		new->flags |= FLAG_IN_TREE;
+		return true;
+	}
+
+	return false;
+}
+
+/**
+ * __label_insert - attempt to insert @l into a label set
+ * @ls: set of labels to insert @l into (NOT NULL)
+ * @label: new label to insert (NOT NULL)
+ * @replace: whether insertion should replace existing entry that is not stale
+ *
+ * Requires: @ls->lock
+ *           caller to hold a valid ref on l
+ *           if @replace is true l has a preallocated proxy associated
+ * Returns: @l if successful in inserting @l - with additional refcount
+ *          else ref counted equivalent label that is already in the set,
+ *          the else condition only happens if @replace is false
+ */
+static struct aa_label *__label_insert(struct aa_labelset *ls,
+				       struct aa_label *label, bool replace)
+{
+	struct rb_node **new, *parent = NULL;
+
+	AA_BUG(!ls);
+	AA_BUG(!label);
+	AA_BUG(labels_set(label) != ls);
+	lockdep_assert_held_exclusive(&ls->lock);
+	AA_BUG(label->flags & FLAG_IN_TREE);
+
+	/* Figure out where to put new node */
+	new = &ls->root.rb_node;
+	while (*new) {
+		struct aa_label *this = rb_entry(*new, struct aa_label, node);
+		int result = label_cmp(label, this);
+
+		parent = *new;
+		if (result == 0) {
+			/* !__aa_get_label means queued for destruction,
+			 * so replace in place, however the label has
+			 * died before the replacement so do not share
+			 * the proxy
+			 */
+			if (!replace && !label_is_stale(this)) {
+				if (__aa_get_label(this))
+					return this;
+			} else
+				__proxy_share(this, label);
+			AA_BUG(!__label_replace(this, label));
+			return aa_get_label(label);
+		} else if (result < 0)
+			new = &((*new)->rb_left);
+		else /* (result > 0) */
+			new = &((*new)->rb_right);
+	}
+
+	/* Add new node and rebalance tree. */
+	rb_link_node(&label->node, parent, new);
+	rb_insert_color(&label->node, &ls->root);
+	label->flags |= FLAG_IN_TREE;
+
+	return aa_get_label(label);
+}
+
+/**
+ * __vec_find - find label that matches @vec in label set
+ * @vec: vec of profiles to find matching label for (NOT NULL)
+ * @n: length of @vec
+ *
+ * Requires: @vec_labelset(vec) lock held
+ *           caller to hold a valid ref on l
+ *
+ * Returns: ref counted @label if matching label is in tree
+ *          ref counted label that is equiv to @l in tree
+ *     else NULL if @vec equiv is not in tree
+ */
+static struct aa_label *__vec_find(struct aa_profile **vec, int n)
+{
+	struct rb_node *node;
+
+	AA_BUG(!vec);
+	AA_BUG(!*vec);
+	AA_BUG(n <= 0);
+
+	node = vec_labelset(vec, n)->root.rb_node;
+	while (node) {
+		struct aa_label *this = rb_entry(node, struct aa_label, node);
+		int result = vec_cmp(this->vec, this->size, vec, n);
+
+		if (result > 0)
+			node = node->rb_left;
+		else if (result < 0)
+			node = node->rb_right;
+		else
+			return __aa_get_label(this);
+	}
+
+	return NULL;
+}
+
+/**
+ * __label_find - find label @label in label set
+ * @label: label to find (NOT NULL)
+ *
+ * Requires: labels_set(@label)->lock held
+ *           caller to hold a valid ref on l
+ *
+ * Returns: ref counted @label if @label is in tree OR
+ *          ref counted label that is equiv to @label in tree
+ *     else NULL if @label or equiv is not in tree
+ */
+static struct aa_label *__label_find(struct aa_label *label)
+{
+	AA_BUG(!label);
+
+	return __vec_find(label->vec, label->size);
+}
+
+
+/**
+ * aa_label_remove - remove a label from the labelset
+ * @label: label to remove
+ *
+ * Returns: true if @label was removed from the tree
+ *     else @label was not in tree so it could not be removed
+ */
+bool aa_label_remove(struct aa_label *label)
+{
+	struct aa_labelset *ls = labels_set(label);
+	unsigned long flags;
+	bool res;
+
+	AA_BUG(!ls);
+
+	write_lock_irqsave(&ls->lock, flags);
+	res = __label_remove(label, ns_unconfined(labels_ns(label)));
+	write_unlock_irqrestore(&ls->lock, flags);
+
+	return res;
+}
+
+/**
+ * aa_label_replace - replace a label @old with a new version @new
+ * @old: label to replace
+ * @new: label replacing @old
+ *
+ * Returns: true if @old was in tree and replaced
+ *     else @old was not in tree, and @new was not inserted
+ */
+bool aa_label_replace(struct aa_label *old, struct aa_label *new)
+{
+	unsigned long flags;
+	bool res;
+
+	if (name_is_shared(old, new) && labels_ns(old) == labels_ns(new)) {
+		write_lock_irqsave(&labels_set(old)->lock, flags);
+		if (old->proxy != new->proxy)
+			__proxy_share(old, new);
+		else
+			__aa_proxy_redirect(old, new);
+		res = __label_replace(old, new);
+		write_unlock_irqrestore(&labels_set(old)->lock, flags);
+	} else {
+		struct aa_label *l;
+		struct aa_labelset *ls = labels_set(old);
+
+		write_lock_irqsave(&ls->lock, flags);
+		res = __label_remove(old, new);
+		if (labels_ns(old) != labels_ns(new)) {
+			write_unlock_irqrestore(&ls->lock, flags);
+			ls = labels_set(new);
+			write_lock_irqsave(&ls->lock, flags);
+		}
+		l = __label_insert(ls, new, true);
+		res = (l == new);
+		write_unlock_irqrestore(&ls->lock, flags);
+		aa_put_label(l);
+	}
+
+	return res;
+}
+
+/**
+ * vec_find - find label @l in label set
+ * @vec: array of profiles to find equiv label for (NOT NULL)
+ * @n: length of @vec
+ *
+ * Returns: refcounted label if @vec equiv is in tree
+ *     else NULL if @vec equiv is not in tree
+ */
+static struct aa_label *vec_find(struct aa_profile **vec, int n)
+{
+	struct aa_labelset *ls;
+	struct aa_label *label;
+	unsigned long flags;
+
+	AA_BUG(!vec);
+	AA_BUG(!*vec);
+	AA_BUG(n <= 0);
+
+	ls = vec_labelset(vec, n);
+	read_lock_irqsave(&ls->lock, flags);
+	label = __vec_find(vec, n);
+	read_unlock_irqrestore(&ls->lock, flags);
+
+	return label;
+}
+
+/* requires sort and merge done first */
+static struct aa_label *vec_create_and_insert_label(struct aa_profile **vec,
+						    int len, gfp_t gfp)
+{
+	struct aa_label *label = NULL;
+	struct aa_labelset *ls;
+	unsigned long flags;
+	struct aa_label *new;
+	int i;
+
+	AA_BUG(!vec);
+
+	if (len == 1)
+		return aa_get_label(&vec[0]->label);
+
+	ls = labels_set(&vec[len - 1]->label);
+
+	/* TODO: enable when read side is lockless
+	 * check if label exists before taking locks
+	 */
+	new = aa_label_alloc(len, NULL, gfp);
+	if (!new)
+		return NULL;
+
+	for (i = 0; i < len; i++)
+		new->vec[i] = aa_get_profile(vec[i]);
+
+	write_lock_irqsave(&ls->lock, flags);
+	label = __label_insert(ls, new, false);
+	write_unlock_irqrestore(&ls->lock, flags);
+	label_free_or_put_new(label, new);
+
+	return label;
+}
+
+struct aa_label *aa_vec_find_or_create_label(struct aa_profile **vec, int len,
+					     gfp_t gfp)
+{
+	struct aa_label *label = vec_find(vec, len);
+
+	if (label)
+		return label;
+
+	return vec_create_and_insert_label(vec, len, gfp);
+}
+
+/**
+ * aa_label_find - find label @label in label set
+ * @label: label to find (NOT NULL)
+ *
+ * Requires: caller to hold a valid ref on l
+ *
+ * Returns: refcounted @label if @label is in tree
+ *          refcounted label that is equiv to @label in tree
+ *     else NULL if @label or equiv is not in tree
+ */
+struct aa_label *aa_label_find(struct aa_label *label)
+{
+	AA_BUG(!label);
+
+	return vec_find(label->vec, label->size);
+}
+
+
+/**
+ * aa_label_insert - insert label @label into @ls or return existing label
+ * @ls - labelset to insert @label into
+ * @label - label to insert
+ *
+ * Requires: caller to hold a valid ref on @label
+ *
+ * Returns: ref counted @label if successful in inserting @label
+ *     else ref counted equivalent label that is already in the set
+ */
+struct aa_label *aa_label_insert(struct aa_labelset *ls, struct aa_label *label)
+{
+	struct aa_label *l;
+	unsigned long flags;
+
+	AA_BUG(!ls);
+	AA_BUG(!label);
+
+	/* check if label exists before taking lock */
+	if (!label_is_stale(label)) {
+		read_lock_irqsave(&ls->lock, flags);
+		l = __label_find(label);
+		read_unlock_irqrestore(&ls->lock, flags);
+		if (l)
+			return l;
+	}
+
+	write_lock_irqsave(&ls->lock, flags);
+	l = __label_insert(ls, label, false);
+	write_unlock_irqrestore(&ls->lock, flags);
+
+	return l;
+}
+
+
+/**
+ * aa_label_next_in_merge - find the next profile when merging @a and @b
+ * @I: label iterator
+ * @a: label to merge
+ * @b: label to merge
+ *
+ * Returns: next profile
+ *     else null if no more profiles
+ */
+struct aa_profile *aa_label_next_in_merge(struct label_it *I,
+					  struct aa_label *a,
+					  struct aa_label *b)
+{
+	AA_BUG(!a);
+	AA_BUG(!b);
+	AA_BUG(!I);
+	AA_BUG(I->i < 0);
+	AA_BUG(I->i > a->size);
+	AA_BUG(I->j < 0);
+	AA_BUG(I->j > b->size);
+
+	if (I->i < a->size) {
+		if (I->j < b->size) {
+			int res = profile_cmp(a->vec[I->i], b->vec[I->j]);
+
+			if (res > 0)
+				return b->vec[(I->j)++];
+			if (res == 0)
+				(I->j)++;
+		}
+
+		return a->vec[(I->i)++];
+	}
+
+	if (I->j < b->size)
+		return b->vec[(I->j)++];
+
+	return NULL;
+}
+
+/**
+ * label_merge_cmp - cmp of @a merging with @b against @z for set ordering
+ * @a: label to merge then compare (NOT NULL)
+ * @b: label to merge then compare (NOT NULL)
+ * @z: label to compare merge against (NOT NULL)
+ *
+ * Assumes: using the most recent versions of @a, @b, and @z
+ *
+ * Returns: <0  if a < b
+ *          ==0 if a == b
+ *          >0  if a > b
+ */
+static int label_merge_cmp(struct aa_label *a, struct aa_label *b,
+			   struct aa_label *z)
+{
+	struct aa_profile *p = NULL;
+	struct label_it i = { };
+	int k;
+
+	AA_BUG(!a);
+	AA_BUG(!b);
+	AA_BUG(!z);
+
+	for (k = 0;
+	     k < z->size && (p = aa_label_next_in_merge(&i, a, b));
+	     k++) {
+		int res = profile_cmp(p, z->vec[k]);
+
+		if (res != 0)
+			return res;
+	}
+
+	if (p)
+		return 1;
+	else if (k < z->size)
+		return -1;
+	return 0;
+}
+
+/**
+ * label_merge_insert - create a new label by merging @a and @b
+ * @new: preallocated label to merge into (NOT NULL)
+ * @a: label to merge with @b  (NOT NULL)
+ * @b: label to merge with @a  (NOT NULL)
+ *
+ * Requires: preallocated proxy
+ *
+ * Returns: ref counted label either @new if merge is unique
+ *          @a if @b is a subset of @a
+ *          @b if @a is a subset of @b
+ *
+ * NOTE: will not use @new if the merge results in @new == @a or @b
+ *
+ *       Must be used within labelset write lock to avoid racing with
+ *       setting labels stale.
+ */
+static struct aa_label *label_merge_insert(struct aa_label *new,
+					   struct aa_label *a,
+					   struct aa_label *b)
+{
+	struct aa_label *label;
+	struct aa_labelset *ls;
+	struct aa_profile *next;
+	struct label_it i;
+	unsigned long flags;
+	int k = 0, invcount = 0;
+	bool stale = false;
+
+	AA_BUG(!a);
+	AA_BUG(a->size < 0);
+	AA_BUG(!b);
+	AA_BUG(b->size < 0);
+	AA_BUG(!new);
+	AA_BUG(new->size < a->size + b->size);
+
+	label_for_each_in_merge(i, a, b, next) {
+		AA_BUG(!next);
+		if (profile_is_stale(next)) {
+			new->vec[k] = aa_get_newest_profile(next);
+			AA_BUG(!new->vec[k]->label.proxy);
+			AA_BUG(!new->vec[k]->label.proxy->label);
+			if (next->label.proxy != new->vec[k]->label.proxy)
+				invcount++;
+			k++;
+			stale = true;
+		} else
+			new->vec[k++] = aa_get_profile(next);
+	}
+	/* set to actual size which is <= allocated len */
+	new->size = k;
+	new->vec[k] = NULL;
+
+	if (invcount) {
+		new->size -= aa_vec_unique(&new->vec[0], new->size,
+					   VEC_FLAG_TERMINATE);
+		/* TODO: deal with reference labels */
+		if (new->size == 1) {
+			label = aa_get_label(&new->vec[0]->label);
+			return label;
+		}
+	} else if (!stale) {
+		/*
+		 * merge could be same as a || b, note: it is not possible
+		 * for new->size == a->size == b->size unless a == b
+		 */
+		if (k == a->size)
+			return aa_get_label(a);
+		else if (k == b->size)
+			return aa_get_label(b);
+	}
+	if (vec_unconfined(new->vec, new->size))
+		new->flags |= FLAG_UNCONFINED;
+	ls = labels_set(new);
+	write_lock_irqsave(&ls->lock, flags);
+	label = __label_insert(labels_set(new), new, false);
+	write_unlock_irqrestore(&ls->lock, flags);
+
+	return label;
+}
+
+/**
+ * labelset_of_merge - find which labelset a merged label should be inserted
+ * @a: label to merge and insert
+ * @b: label to merge and insert
+ *
+ * Returns: labelset that the merged label should be inserted into
+ */
+static struct aa_labelset *labelset_of_merge(struct aa_label *a,
+					     struct aa_label *b)
+{
+	struct aa_ns *nsa = labels_ns(a);
+	struct aa_ns *nsb = labels_ns(b);
+
+	if (ns_cmp(nsa, nsb) <= 0)
+		return &nsa->labels;
+	return &nsb->labels;
+}
+
+/**
+ * __label_find_merge - find label that is equiv to merge of @a and @b
+ * @ls: set of labels to search (NOT NULL)
+ * @a: label to merge with @b  (NOT NULL)
+ * @b: label to merge with @a  (NOT NULL)
+ *
+ * Requires: ls->lock read_lock held
+ *
+ * Returns: ref counted label that is equiv to merge of @a and @b
+ *     else NULL if merge of @a and @b is not in set
+ */
+static struct aa_label *__label_find_merge(struct aa_labelset *ls,
+					   struct aa_label *a,
+					   struct aa_label *b)
+{
+	struct rb_node *node;
+
+	AA_BUG(!ls);
+	AA_BUG(!a);
+	AA_BUG(!b);
+
+	if (a == b)
+		return __label_find(a);
+
+	node  = ls->root.rb_node;
+	while (node) {
+		struct aa_label *this = container_of(node, struct aa_label,
+						     node);
+		int result = label_merge_cmp(a, b, this);
+
+		if (result < 0)
+			node = node->rb_left;
+		else if (result > 0)
+			node = node->rb_right;
+		else
+			return __aa_get_label(this);
+	}
+
+	return NULL;
+}
+
+
+/**
+ * aa_label_find_merge - find label that is equiv to merge of @a and @b
+ * @a: label to merge with @b  (NOT NULL)
+ * @b: label to merge with @a  (NOT NULL)
+ *
+ * Requires: labels be fully constructed with a valid ns
+ *
+ * Returns: ref counted label that is equiv to merge of @a and @b
+ *     else NULL if merge of @a and @b is not in set
+ */
+struct aa_label *aa_label_find_merge(struct aa_label *a, struct aa_label *b)
+{
+	struct aa_labelset *ls;
+	struct aa_label *label, *ar = NULL, *br = NULL;
+	unsigned long flags;
+
+	AA_BUG(!a);
+	AA_BUG(!b);
+
+	if (label_is_stale(a))
+		a = ar = aa_get_newest_label(a);
+	if (label_is_stale(b))
+		b = br = aa_get_newest_label(b);
+	ls = labelset_of_merge(a, b);
+	read_lock_irqsave(&ls->lock, flags);
+	label = __label_find_merge(ls, a, b);
+	read_unlock_irqrestore(&ls->lock, flags);
+	aa_put_label(ar);
+	aa_put_label(br);
+
+	return label;
+}
+
+/**
+ * aa_label_merge - attempt to insert new merged label of @a and @b
+ * @ls: set of labels to insert label into (NOT NULL)
+ * @a: label to merge with @b  (NOT NULL)
+ * @b: label to merge with @a  (NOT NULL)
+ * @gfp: memory allocation type
+ *
+ * Requires: caller to hold valid refs on @a and @b
+ *           labels be fully constructed with a valid ns
+ *
+ * Returns: ref counted new label if successful in inserting merge of a & b
+ *     else ref counted equivalent label that is already in the set.
+ *     else NULL if could not create label (-ENOMEM)
+ */
+struct aa_label *aa_label_merge(struct aa_label *a, struct aa_label *b,
+				gfp_t gfp)
+{
+	struct aa_label *label = NULL;
+
+	AA_BUG(!a);
+	AA_BUG(!b);
+
+	if (a == b)
+		return aa_get_newest_label(a);
+
+	/* TODO: enable when read side is lockless
+	 * check if label exists before taking locks
+	if (!label_is_stale(a) && !label_is_stale(b))
+		label = aa_label_find_merge(a, b);
+	*/
+
+	if (!label) {
+		struct aa_label *new;
+
+		a = aa_get_newest_label(a);
+		b = aa_get_newest_label(b);
+
+		/* could use label_merge_len(a, b), but requires double
+		 * comparison for small savings
+		 */
+		new = aa_label_alloc(a->size + b->size, NULL, gfp);
+		if (!new)
+			goto out;
+
+		label = label_merge_insert(new, a, b);
+		label_free_or_put_new(label, new);
+out:
+		aa_put_label(a);
+		aa_put_label(b);
+	}
+
+	return label;
+}
+
+static inline bool label_is_visible(struct aa_profile *profile,
+				    struct aa_label *label)
+{
+	return aa_ns_visible(profile->ns, labels_ns(label), true);
+}
+
+/* match a profile and its associated ns component if needed
+ * Assumes visibility test has already been done.
+ * If a subns profile is not to be matched should be prescreened with
+ * visibility test.
+ */
+static inline unsigned int match_component(struct aa_profile *profile,
+					   struct aa_profile *tp,
+					   unsigned int state)
+{
+	const char *ns_name;
+
+	if (profile->ns == tp->ns)
+		return aa_dfa_match(profile->policy.dfa, state, tp->base.hname);
+
+	/* try matching with namespace name and then profile */
+	ns_name = aa_ns_name(profile->ns, tp->ns, true);
+	state = aa_dfa_match_len(profile->policy.dfa, state, ":", 1);
+	state = aa_dfa_match(profile->policy.dfa, state, ns_name);
+	state = aa_dfa_match_len(profile->policy.dfa, state, ":", 1);
+	return aa_dfa_match(profile->policy.dfa, state, tp->base.hname);
+}
+
+/**
+ * label_compound_match - find perms for full compound label
+ * @profile: profile to find perms for
+ * @label: label to check access permissions for
+ * @start: state to start match in
+ * @subns: whether to do permission checks on components in a subns
+ * @request: permissions to request
+ * @perms: perms struct to set
+ *
+ * Returns: 0 on success else ERROR
+ *
+ * For the label A//&B//&C this does the perm match for A//&B//&C
+ * @perms should be preinitialized with allperms OR a previous permission
+ *        check to be stacked.
+ */
+static int label_compound_match(struct aa_profile *profile,
+				struct aa_label *label,
+				unsigned int state, bool subns, u32 request,
+				struct aa_perms *perms)
+{
+	struct aa_profile *tp;
+	struct label_it i;
+
+	/* find first subcomponent that is visible */
+	label_for_each(i, label, tp) {
+		if (!aa_ns_visible(profile->ns, tp->ns, subns))
+			continue;
+		state = match_component(profile, tp, state);
+		if (!state)
+			goto fail;
+		goto next;
+	}
+
+	/* no component visible */
+	*perms = allperms;
+	return 0;
+
+next:
+	label_for_each_cont(i, label, tp) {
+		if (!aa_ns_visible(profile->ns, tp->ns, subns))
+			continue;
+		state = aa_dfa_match(profile->policy.dfa, state, "//&");
+		state = match_component(profile, tp, state);
+		if (!state)
+			goto fail;
+	}
+	aa_compute_perms(profile->policy.dfa, state, perms);
+	aa_apply_modes_to_perms(profile, perms);
+	if ((perms->allow & request) != request)
+		return -EACCES;
+
+	return 0;
+
+fail:
+	*perms = nullperms;
+	return state;
+}
+
+/**
+ * label_components_match - find perms for all subcomponents of a label
+ * @profile: profile to find perms for
+ * @label: label to check access permissions for
+ * @start: state to start match in
+ * @subns: whether to do permission checks on components in a subns
+ * @request: permissions to request
+ * @perms: an initialized perms struct to add accumulation to
+ *
+ * Returns: 0 on success else ERROR
+ *
+ * For the label A//&B//&C this does the perm match for each of A and B and C
+ * @perms should be preinitialized with allperms OR a previous permission
+ *        check to be stacked.
+ */
+static int label_components_match(struct aa_profile *profile,
+				  struct aa_label *label, unsigned int start,
+				  bool subns, u32 request,
+				  struct aa_perms *perms)
+{
+	struct aa_profile *tp;
+	struct label_it i;
+	struct aa_perms tmp;
+	unsigned int state = 0;
+
+	/* find first subcomponent to test */
+	label_for_each(i, label, tp) {
+		if (!aa_ns_visible(profile->ns, tp->ns, subns))
+			continue;
+		state = match_component(profile, tp, start);
+		if (!state)
+			goto fail;
+		goto next;
+	}
+
+	/* no subcomponents visible - no change in perms */
+	return 0;
+
+next:
+	aa_compute_perms(profile->policy.dfa, state, &tmp);
+	aa_apply_modes_to_perms(profile, &tmp);
+	aa_perms_accum(perms, &tmp);
+	label_for_each_cont(i, label, tp) {
+		if (!aa_ns_visible(profile->ns, tp->ns, subns))
+			continue;
+		state = match_component(profile, tp, start);
+		if (!state)
+			goto fail;
+		aa_compute_perms(profile->policy.dfa, state, &tmp);
+		aa_apply_modes_to_perms(profile, &tmp);
+		aa_perms_accum(perms, &tmp);
+	}
+
+	if ((perms->allow & request) != request)
+		return -EACCES;
+
+	return 0;
+
+fail:
+	*perms = nullperms;
+	return -EACCES;
+}
+
+/**
+ * aa_label_match - do a multi-component label match
+ * @profile: profile to match against (NOT NULL)
+ * @label: label to match (NOT NULL)
+ * @state: state to start in
+ * @subns: whether to match subns components
+ * @request: permission request
+ * @perms: Returns computed perms (NOT NULL)
+ *
+ * Returns: the state the match finished in, may be the none matching state
+ */
+int aa_label_match(struct aa_profile *profile, struct aa_label *label,
+		   unsigned int state, bool subns, u32 request,
+		   struct aa_perms *perms)
+{
+	int error = label_compound_match(profile, label, state, subns, request,
+					 perms);
+	if (!error)
+		return error;
+
+	*perms = allperms;
+	return label_components_match(profile, label, state, subns, request,
+				      perms);
+}
+
+
+/**
+ * aa_update_label_name - update a label to have a stored name
+ * @ns: ns being viewed from (NOT NULL)
+ * @label: label to update (NOT NULL)
+ * @gfp: type of memory allocation
+ *
+ * Requires: labels_set(label) not locked in caller
+ *
+ * note: only updates the label name if it does not have a name already
+ *       and if it is in the labelset
+ */
+bool aa_update_label_name(struct aa_ns *ns, struct aa_label *label, gfp_t gfp)
+{
+	struct aa_labelset *ls;
+	unsigned long flags;
+	char __counted *name;
+	bool res = false;
+
+	AA_BUG(!ns);
+	AA_BUG(!label);
+
+	if (label->hname || labels_ns(label) != ns)
+		return res;
+
+	if (aa_label_acntsxprint(&name, ns, label, FLAGS_NONE, gfp) < 0)
+		return res;
+
+	ls = labels_set(label);
+	write_lock_irqsave(&ls->lock, flags);
+	if (!label->hname && label->flags & FLAG_IN_TREE) {
+		label->hname = name;
+		res = true;
+	} else
+		aa_put_str(name);
+	write_unlock_irqrestore(&ls->lock, flags);
+
+	return res;
+}
+
+/*
+ * cached label name is present and visible
+ * @label->hname only exists if label is namespace hierachical
+ */
+static inline bool use_label_hname(struct aa_ns *ns, struct aa_label *label,
+				   int flags)
+{
+	if (label->hname && (!ns || labels_ns(label) == ns) &&
+	    !(flags & ~FLAG_SHOW_MODE))
+		return true;
+
+	return false;
+}
+
+/* helper macro for snprint routines */
+#define update_for_len(total, len, size, str)	\
+do {					\
+	size_t ulen = len;		\
+					\
+	AA_BUG(len < 0);		\
+	total += ulen;			\
+	ulen = min(ulen, size);		\
+	size -= ulen;			\
+	str += ulen;			\
+} while (0)
+
+/**
+ * aa_profile_snxprint - print a profile name to a buffer
+ * @str: buffer to write to. (MAY BE NULL if @size == 0)
+ * @size: size of buffer
+ * @view: namespace profile is being viewed from
+ * @profile: profile to view (NOT NULL)
+ * @flags: whether to include the mode string
+ * @prev_ns: last ns printed when used in compound print
+ *
+ * Returns: size of name written or would be written if larger than
+ *          available buffer
+ *
+ * Note: will not print anything if the profile is not visible
+ */
+static int aa_profile_snxprint(char *str, size_t size, struct aa_ns *view,
+			       struct aa_profile *profile, int flags,
+			       struct aa_ns **prev_ns)
+{
+	const char *ns_name = NULL;
+
+	AA_BUG(!str && size != 0);
+	AA_BUG(!profile);
+
+	if (!view)
+		view = profiles_ns(profile);
+
+	if (view != profile->ns &&
+	    (!prev_ns || (*prev_ns != profile->ns))) {
+		if (prev_ns)
+			*prev_ns = profile->ns;
+		ns_name = aa_ns_name(view, profile->ns,
+				     flags & FLAG_VIEW_SUBNS);
+		if (ns_name == aa_hidden_ns_name) {
+			if (flags & FLAG_HIDDEN_UNCONFINED)
+				return snprintf(str, size, "%s", "unconfined");
+			return snprintf(str, size, "%s", ns_name);
+		}
+	}
+
+	if ((flags & FLAG_SHOW_MODE) && profile != profile->ns->unconfined) {
+		const char *modestr = aa_profile_mode_names[profile->mode];
+
+		if (ns_name)
+			return snprintf(str, size, ":%s:%s (%s)", ns_name,
+					profile->base.hname, modestr);
+		return snprintf(str, size, "%s (%s)", profile->base.hname,
+				modestr);
+	}
+
+	if (ns_name)
+		return snprintf(str, size, ":%s:%s", ns_name,
+				profile->base.hname);
+	return snprintf(str, size, "%s", profile->base.hname);
+}
+
+static const char *label_modename(struct aa_ns *ns, struct aa_label *label,
+				  int flags)
+{
+	struct aa_profile *profile;
+	struct label_it i;
+	int mode = -1, count = 0;
+
+	label_for_each(i, label, profile) {
+		if (aa_ns_visible(ns, profile->ns, flags & FLAG_VIEW_SUBNS)) {
+			count++;
+			if (profile == profile->ns->unconfined)
+				/* special case unconfined so stacks with
+				 * unconfined don't report as mixed. ie.
+				 * profile_foo//&:ns1:unconfined (mixed)
+				 */
+				continue;
+			if (mode == -1)
+				mode = profile->mode;
+			else if (mode != profile->mode)
+				return "mixed";
+		}
+	}
+
+	if (count == 0)
+		return "-";
+	if (mode == -1)
+		/* everything was unconfined */
+		mode = APPARMOR_UNCONFINED;
+
+	return aa_profile_mode_names[mode];
+}
+
+/* if any visible label is not unconfined the display_mode returns true */
+static inline bool display_mode(struct aa_ns *ns, struct aa_label *label,
+				int flags)
+{
+	if ((flags & FLAG_SHOW_MODE)) {
+		struct aa_profile *profile;
+		struct label_it i;
+
+		label_for_each(i, label, profile) {
+			if (aa_ns_visible(ns, profile->ns,
+					  flags & FLAG_VIEW_SUBNS) &&
+			    profile != profile->ns->unconfined)
+				return true;
+		}
+		/* only ns->unconfined in set of profiles in ns */
+		return false;
+	}
+
+	return false;
+}
+
+/**
+ * aa_label_snxprint - print a label name to a string buffer
+ * @str: buffer to write to. (MAY BE NULL if @size == 0)
+ * @size: size of buffer
+ * @ns: namespace profile is being viewed from
+ * @label: label to view (NOT NULL)
+ * @flags: whether to include the mode string
+ *
+ * Returns: size of name written or would be written if larger than
+ *          available buffer
+ *
+ * Note: labels do not have to be strictly hierarchical to the ns as
+ *       objects may be shared across different namespaces and thus
+ *       pickup labeling from each ns.  If a particular part of the
+ *       label is not visible it will just be excluded.  And if none
+ *       of the label is visible "---" will be used.
+ */
+int aa_label_snxprint(char *str, size_t size, struct aa_ns *ns,
+		      struct aa_label *label, int flags)
+{
+	struct aa_profile *profile;
+	struct aa_ns *prev_ns = NULL;
+	struct label_it i;
+	int count = 0, total = 0;
+	ssize_t len;
+
+	AA_BUG(!str && size != 0);
+	AA_BUG(!label);
+
+	if (flags & FLAG_ABS_ROOT) {
+		ns = root_ns;
+		len = snprintf(str, size, "=");
+		update_for_len(total, len, size, str);
+	} else if (!ns) {
+		ns = labels_ns(label);
+	}
+
+	label_for_each(i, label, profile) {
+		if (aa_ns_visible(ns, profile->ns, flags & FLAG_VIEW_SUBNS)) {
+			if (count > 0) {
+				len = snprintf(str, size, "//&");
+				update_for_len(total, len, size, str);
+			}
+			len = aa_profile_snxprint(str, size, ns, profile,
+						  flags & FLAG_VIEW_SUBNS,
+						  &prev_ns);
+			update_for_len(total, len, size, str);
+			count++;
+		}
+	}
+
+	if (count == 0) {
+		if (flags & FLAG_HIDDEN_UNCONFINED)
+			return snprintf(str, size, "%s", "unconfined");
+		return snprintf(str, size, "%s", aa_hidden_ns_name);
+	}
+
+	/* count == 1 && ... is for backwards compat where the mode
+	 * is not displayed for 'unconfined' in the current ns
+	 */
+	if (display_mode(ns, label, flags)) {
+		len = snprintf(str, size, " (%s)",
+			       label_modename(ns, label, flags));
+		update_for_len(total, len, size, str);
+	}
+
+	return total;
+}
+#undef update_for_len
+
+/**
+ * aa_label_asxprint - allocate a string buffer and print label into it
+ * @strp: Returns - the allocated buffer with the label name. (NOT NULL)
+ * @ns: namespace profile is being viewed from
+ * @label: label to view (NOT NULL)
+ * @flags: flags controlling what label info is printed
+ * @gfp: kernel memory allocation type
+ *
+ * Returns: size of name written or would be written if larger than
+ *          available buffer
+ */
+int aa_label_asxprint(char **strp, struct aa_ns *ns, struct aa_label *label,
+		      int flags, gfp_t gfp)
+{
+	int size;
+
+	AA_BUG(!strp);
+	AA_BUG(!label);
+
+	size = aa_label_snxprint(NULL, 0, ns, label, flags);
+	if (size < 0)
+		return size;
+
+	*strp = kmalloc(size + 1, gfp);
+	if (!*strp)
+		return -ENOMEM;
+	return aa_label_snxprint(*strp, size + 1, ns, label, flags);
+}
+
+/**
+ * aa_label_acntsxprint - allocate a __counted string buffer and print label
+ * @strp: buffer to write to.
+ * @ns: namespace profile is being viewed from
+ * @label: label to view (NOT NULL)
+ * @flags: flags controlling what label info is printed
+ * @gfp: kernel memory allocation type
+ *
+ * Returns: size of name written or would be written if larger than
+ *          available buffer
+ */
+int aa_label_acntsxprint(char __counted **strp, struct aa_ns *ns,
+			 struct aa_label *label, int flags, gfp_t gfp)
+{
+	int size;
+
+	AA_BUG(!strp);
+	AA_BUG(!label);
+
+	size = aa_label_snxprint(NULL, 0, ns, label, flags);
+	if (size < 0)
+		return size;
+
+	*strp = aa_str_alloc(size + 1, gfp);
+	if (!*strp)
+		return -ENOMEM;
+	return aa_label_snxprint(*strp, size + 1, ns, label, flags);
+}
+
+
+void aa_label_xaudit(struct audit_buffer *ab, struct aa_ns *ns,
+		     struct aa_label *label, int flags, gfp_t gfp)
+{
+	const char *str;
+	char *name = NULL;
+	int len;
+
+	AA_BUG(!ab);
+	AA_BUG(!label);
+
+	if (!use_label_hname(ns, label, flags) ||
+	    display_mode(ns, label, flags)) {
+		len  = aa_label_asxprint(&name, ns, label, flags, gfp);
+		if (len == -1) {
+			AA_DEBUG("label print error");
+			return;
+		}
+		str = name;
+	} else {
+		str = (char *) label->hname;
+		len = strlen(str);
+	}
+	if (audit_string_contains_control(str, len))
+		audit_log_n_hex(ab, str, len);
+	else
+		audit_log_n_string(ab, str, len);
+
+	kfree(name);
+}
+
+void aa_label_seq_xprint(struct seq_file *f, struct aa_ns *ns,
+			 struct aa_label *label, int flags, gfp_t gfp)
+{
+	AA_BUG(!f);
+	AA_BUG(!label);
+
+	if (!use_label_hname(ns, label, flags)) {
+		char *str;
+		int len;
+
+		len = aa_label_asxprint(&str, ns, label, flags, gfp);
+		if (len == -1) {
+			AA_DEBUG("label print error");
+			return;
+		}
+		seq_printf(f, "%s", str);
+		kfree(str);
+	} else if (display_mode(ns, label, flags))
+		seq_printf(f, "%s (%s)", label->hname,
+			   label_modename(ns, label, flags));
+	else
+		seq_printf(f, "%s", label->hname);
+}
+
+void aa_label_xprintk(struct aa_ns *ns, struct aa_label *label, int flags,
+		      gfp_t gfp)
+{
+	AA_BUG(!label);
+
+	if (!use_label_hname(ns, label, flags)) {
+		char *str;
+		int len;
+
+		len = aa_label_asxprint(&str, ns, label, flags, gfp);
+		if (len == -1) {
+			AA_DEBUG("label print error");
+			return;
+		}
+		pr_info("%s", str);
+		kfree(str);
+	} else if (display_mode(ns, label, flags))
+		pr_info("%s (%s)", label->hname,
+		       label_modename(ns, label, flags));
+	else
+		pr_info("%s", label->hname);
+}
+
+void aa_label_audit(struct audit_buffer *ab, struct aa_label *label, gfp_t gfp)
+{
+	struct aa_ns *ns = aa_get_current_ns();
+
+	aa_label_xaudit(ab, ns, label, FLAG_VIEW_SUBNS, gfp);
+	aa_put_ns(ns);
+}
+
+void aa_label_seq_print(struct seq_file *f, struct aa_label *label, gfp_t gfp)
+{
+	struct aa_ns *ns = aa_get_current_ns();
+
+	aa_label_seq_xprint(f, ns, label, FLAG_VIEW_SUBNS, gfp);
+	aa_put_ns(ns);
+}
+
+void aa_label_printk(struct aa_label *label, gfp_t gfp)
+{
+	struct aa_ns *ns = aa_get_current_ns();
+
+	aa_label_xprintk(ns, label, FLAG_VIEW_SUBNS, gfp);
+	aa_put_ns(ns);
+}
+
+static int label_count_strn_entries(const char *str, size_t n)
+{
+	const char *end = str + n;
+	const char *split;
+	int count = 1;
+
+	AA_BUG(!str);
+
+	for (split = aa_label_strn_split(str, end - str);
+	     split;
+	     split = aa_label_strn_split(str, end - str)) {
+		count++;
+		str = split + 3;
+	}
+
+	return count;
+}
+
+/*
+ * ensure stacks with components like
+ *   :ns:A//&B
+ * have :ns: applied to both 'A' and 'B' by making the lookup relative
+ * to the base if the lookup specifies an ns, else making the stacked lookup
+ * relative to the last embedded ns in the string.
+ */
+static struct aa_profile *fqlookupn_profile(struct aa_label *base,
+					    struct aa_label *currentbase,
+					    const char *str, size_t n)
+{
+	const char *first = skipn_spaces(str, n);
+
+	if (first && *first == ':')
+		return aa_fqlookupn_profile(base, str, n);
+
+	return aa_fqlookupn_profile(currentbase, str, n);
+}
+
+/**
+ * aa_label_strn_parse - parse, validate and convert a text string to a label
+ * @base: base label to use for lookups (NOT NULL)
+ * @str: null terminated text string (NOT NULL)
+ * @n: length of str to parse, will stop at \0 if encountered before n
+ * @gfp: allocation type
+ * @create: true if should create compound labels if they don't exist
+ * @force_stack: true if should stack even if no leading &
+ *
+ * Returns: the matching refcounted label if present
+ *     else ERRPTR
+ */
+struct aa_label *aa_label_strn_parse(struct aa_label *base, const char *str,
+				     size_t n, gfp_t gfp, bool create,
+				     bool force_stack)
+{
+	DEFINE_VEC(profile, vec);
+	struct aa_label *label, *currbase = base;
+	int i, len, stack = 0, error;
+	const char *end = str + n;
+	const char *split;
+
+	AA_BUG(!base);
+	AA_BUG(!str);
+
+	str = skipn_spaces(str, n);
+	if (str == NULL || (*str == '=' && base != &root_ns->unconfined->label))
+		return ERR_PTR(-EINVAL);
+
+	len = label_count_strn_entries(str, end - str);
+	if (*str == '&' || force_stack) {
+		/* stack on top of base */
+		stack = base->size;
+		len += stack;
+		if (*str == '&')
+			str++;
+	}
+
+	error = vec_setup(profile, vec, len, gfp);
+	if (error)
+		return ERR_PTR(error);
+
+	for (i = 0; i < stack; i++)
+		vec[i] = aa_get_profile(base->vec[i]);
+
+	for (split = aa_label_strn_split(str, end - str), i = stack;
+	     split && i < len; i++) {
+		vec[i] = fqlookupn_profile(base, currbase, str, split - str);
+		if (!vec[i])
+			goto fail;
+		/*
+		 * if component specified a new ns it becomes the new base
+		 * so that subsequent lookups are relative to it
+		 */
+		if (vec[i]->ns != labels_ns(currbase))
+			currbase = &vec[i]->label;
+		str = split + 3;
+		split = aa_label_strn_split(str, end - str);
+	}
+	/* last element doesn't have a split */
+	if (i < len) {
+		vec[i] = fqlookupn_profile(base, currbase, str, end - str);
+		if (!vec[i])
+			goto fail;
+	}
+	if (len == 1)
+		/* no need to free vec as len < LOCAL_VEC_ENTRIES */
+		return &vec[0]->label;
+
+	len -= aa_vec_unique(vec, len, VEC_FLAG_TERMINATE);
+	/* TODO: deal with reference labels */
+	if (len == 1) {
+		label = aa_get_label(&vec[0]->label);
+		goto out;
+	}
+
+	if (create)
+		label = aa_vec_find_or_create_label(vec, len, gfp);
+	else
+		label = vec_find(vec, len);
+	if (!label)
+		goto fail;
+
+out:
+	/* use adjusted len from after vec_unique, not original */
+	vec_cleanup(profile, vec, len);
+	return label;
+
+fail:
+	label = ERR_PTR(-ENOENT);
+	goto out;
+}
+
+struct aa_label *aa_label_parse(struct aa_label *base, const char *str,
+				gfp_t gfp, bool create, bool force_stack)
+{
+	return aa_label_strn_parse(base, str, strlen(str), gfp, create,
+				   force_stack);
+}
+
+/**
+ * aa_labelset_destroy - remove all labels from the label set
+ * @ls: label set to cleanup (NOT NULL)
+ *
+ * Labels that are removed from the set may still exist beyond the set
+ * being destroyed depending on their reference counting
+ */
+void aa_labelset_destroy(struct aa_labelset *ls)
+{
+	struct rb_node *node;
+	unsigned long flags;
+
+	AA_BUG(!ls);
+
+	write_lock_irqsave(&ls->lock, flags);
+	for (node = rb_first(&ls->root); node; node = rb_first(&ls->root)) {
+		struct aa_label *this = rb_entry(node, struct aa_label, node);
+
+		if (labels_ns(this) != root_ns)
+			__label_remove(this,
+				       ns_unconfined(labels_ns(this)->parent));
+		else
+			__label_remove(this, NULL);
+	}
+	write_unlock_irqrestore(&ls->lock, flags);
+}
+
+/*
+ * @ls: labelset to init (NOT NULL)
+ */
+void aa_labelset_init(struct aa_labelset *ls)
+{
+	AA_BUG(!ls);
+
+	rwlock_init(&ls->lock);
+	ls->root = RB_ROOT;
+}
+
+static struct aa_label *labelset_next_stale(struct aa_labelset *ls)
+{
+	struct aa_label *label;
+	struct rb_node *node;
+	unsigned long flags;
+
+	AA_BUG(!ls);
+
+	read_lock_irqsave(&ls->lock, flags);
+
+	__labelset_for_each(ls, node) {
+		label = rb_entry(node, struct aa_label, node);
+		if ((label_is_stale(label) ||
+		     vec_is_stale(label->vec, label->size)) &&
+		    __aa_get_label(label))
+			goto out;
+
+	}
+	label = NULL;
+
+out:
+	read_unlock_irqrestore(&ls->lock, flags);
+
+	return label;
+}
+
+/**
+ * __label_update - insert updated version of @label into labelset
+ * @label - the label to update/replace
+ *
+ * Returns: new label that is up to date
+ *     else NULL on failure
+ *
+ * Requires: @ns lock be held
+ *
+ * Note: worst case is the stale @label does not get updated and has
+ *       to be updated at a later time.
+ */
+static struct aa_label *__label_update(struct aa_label *label)
+{
+	struct aa_label *new, *tmp;
+	struct aa_labelset *ls;
+	unsigned long flags;
+	int i, invcount = 0;
+
+	AA_BUG(!label);
+	AA_BUG(!mutex_is_locked(&labels_ns(label)->lock));
+
+	new = aa_label_alloc(label->size, label->proxy, GFP_KERNEL);
+	if (!new)
+		return NULL;
+
+	/*
+	 * while holding the ns_lock will stop profile replacement, removal,
+	 * and label updates, label merging and removal can be occurring
+	 */
+	ls = labels_set(label);
+	write_lock_irqsave(&ls->lock, flags);
+	for (i = 0; i < label->size; i++) {
+		AA_BUG(!label->vec[i]);
+		new->vec[i] = aa_get_newest_profile(label->vec[i]);
+		AA_BUG(!new->vec[i]);
+		AA_BUG(!new->vec[i]->label.proxy);
+		AA_BUG(!new->vec[i]->label.proxy->label);
+		if (new->vec[i]->label.proxy != label->vec[i]->label.proxy)
+			invcount++;
+	}
+
+	/* updated stale label by being removed/renamed from labelset */
+	if (invcount) {
+		new->size -= aa_vec_unique(&new->vec[0], new->size,
+					   VEC_FLAG_TERMINATE);
+		/* TODO: deal with reference labels */
+		if (new->size == 1) {
+			tmp = aa_get_label(&new->vec[0]->label);
+			AA_BUG(tmp == label);
+			goto remove;
+		}
+		if (labels_set(label) != labels_set(new)) {
+			write_unlock_irqrestore(&ls->lock, flags);
+			tmp = aa_label_insert(labels_set(new), new);
+			write_lock_irqsave(&ls->lock, flags);
+			goto remove;
+		}
+	} else
+		AA_BUG(labels_ns(label) != labels_ns(new));
+
+	tmp = __label_insert(labels_set(label), new, true);
+remove:
+	/* ensure label is removed, and redirected correctly */
+	__label_remove(label, tmp);
+	write_unlock_irqrestore(&ls->lock, flags);
+	label_free_or_put_new(tmp, new);
+
+	return tmp;
+}
+
+/**
+ * __labelset_update - update labels in @ns
+ * @ns: namespace to update labels in  (NOT NULL)
+ *
+ * Requires: @ns lock be held
+ *
+ * Walk the labelset ensuring that all labels are up to date and valid
+ * Any label that has a stale component is marked stale and replaced and
+ * by an updated version.
+ *
+ * If failures happen due to memory pressures then stale labels will
+ * be left in place until the next pass.
+ */
+static void __labelset_update(struct aa_ns *ns)
+{
+	struct aa_label *label;
+
+	AA_BUG(!ns);
+	AA_BUG(!mutex_is_locked(&ns->lock));
+
+	do {
+		label = labelset_next_stale(&ns->labels);
+		if (label) {
+			struct aa_label *l = __label_update(label);
+
+			aa_put_label(l);
+			aa_put_label(label);
+		}
+	} while (label);
+}
+
+/**
+ * __aa_labelset_udate_subtree - update all labels with a stale component
+ * @ns: ns to start update at (NOT NULL)
+ *
+ * Requires: @ns lock be held
+ *
+ * Invalidates labels based on @p in @ns and any children namespaces.
+ */
+void __aa_labelset_update_subtree(struct aa_ns *ns)
+{
+	struct aa_ns *child;
+
+	AA_BUG(!ns);
+	AA_BUG(!mutex_is_locked(&ns->lock));
+
+	__labelset_update(ns);
+
+	list_for_each_entry(child, &ns->sub_ns, base.list) {
+		mutex_lock_nested(&child->lock, child->level);
+		__aa_labelset_update_subtree(child);
+		mutex_unlock(&child->lock);
+	}
+}