Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/security/selinux/ss/avtab.c b/security/selinux/ss/avtab.c
index c0417cf..8c58007 100644
--- a/security/selinux/ss/avtab.c
+++ b/security/selinux/ss/avtab.c
@@ -93,12 +93,10 @@
 		newnode->next = prev->next;
 		prev->next = newnode;
 	} else {
-		newnode->next = flex_array_get_ptr(h->htable, hvalue);
-		if (flex_array_put_ptr(h->htable, hvalue, newnode,
-				       GFP_KERNEL|__GFP_ZERO)) {
-			kmem_cache_free(avtab_node_cachep, newnode);
-			return NULL;
-		}
+		struct avtab_node **n = &h->htable[hvalue];
+
+		newnode->next = *n;
+		*n = newnode;
 	}
 
 	h->nel++;
@@ -111,11 +109,11 @@
 	struct avtab_node *prev, *cur, *newnode;
 	u16 specified = key->specified & ~(AVTAB_ENABLED|AVTAB_ENABLED_OLD);
 
-	if (!h || !h->htable)
+	if (!h)
 		return -EINVAL;
 
 	hvalue = avtab_hash(key, h->mask);
-	for (prev = NULL, cur = flex_array_get_ptr(h->htable, hvalue);
+	for (prev = NULL, cur = h->htable[hvalue];
 	     cur;
 	     prev = cur, cur = cur->next) {
 		if (key->source_type == cur->key.source_type &&
@@ -156,10 +154,10 @@
 	struct avtab_node *prev, *cur;
 	u16 specified = key->specified & ~(AVTAB_ENABLED|AVTAB_ENABLED_OLD);
 
-	if (!h || !h->htable)
+	if (!h)
 		return NULL;
 	hvalue = avtab_hash(key, h->mask);
-	for (prev = NULL, cur = flex_array_get_ptr(h->htable, hvalue);
+	for (prev = NULL, cur = h->htable[hvalue];
 	     cur;
 	     prev = cur, cur = cur->next) {
 		if (key->source_type == cur->key.source_type &&
@@ -186,11 +184,11 @@
 	struct avtab_node *cur;
 	u16 specified = key->specified & ~(AVTAB_ENABLED|AVTAB_ENABLED_OLD);
 
-	if (!h || !h->htable)
+	if (!h)
 		return NULL;
 
 	hvalue = avtab_hash(key, h->mask);
-	for (cur = flex_array_get_ptr(h->htable, hvalue); cur;
+	for (cur = h->htable[hvalue]; cur;
 	     cur = cur->next) {
 		if (key->source_type == cur->key.source_type &&
 		    key->target_type == cur->key.target_type &&
@@ -222,11 +220,11 @@
 	struct avtab_node *cur;
 	u16 specified = key->specified & ~(AVTAB_ENABLED|AVTAB_ENABLED_OLD);
 
-	if (!h || !h->htable)
+	if (!h)
 		return NULL;
 
 	hvalue = avtab_hash(key, h->mask);
-	for (cur = flex_array_get_ptr(h->htable, hvalue); cur;
+	for (cur = h->htable[hvalue]; cur;
 	     cur = cur->next) {
 		if (key->source_type == cur->key.source_type &&
 		    key->target_type == cur->key.target_type &&
@@ -281,11 +279,11 @@
 	int i;
 	struct avtab_node *cur, *temp;
 
-	if (!h || !h->htable)
+	if (!h)
 		return;
 
 	for (i = 0; i < h->nslot; i++) {
-		cur = flex_array_get_ptr(h->htable, i);
+		cur = h->htable[i];
 		while (cur) {
 			temp = cur;
 			cur = cur->next;
@@ -295,7 +293,7 @@
 			kmem_cache_free(avtab_node_cachep, temp);
 		}
 	}
-	flex_array_free(h->htable);
+	kvfree(h->htable);
 	h->htable = NULL;
 	h->nslot = 0;
 	h->mask = 0;
@@ -303,6 +301,7 @@
 
 int avtab_init(struct avtab *h)
 {
+	kvfree(h->htable);
 	h->htable = NULL;
 	h->nel = 0;
 	return 0;
@@ -329,8 +328,7 @@
 		nslot = MAX_AVTAB_HASH_BUCKETS;
 	mask = nslot - 1;
 
-	h->htable = flex_array_alloc(sizeof(struct avtab_node *), nslot,
-				     GFP_KERNEL | __GFP_ZERO);
+	h->htable = kvcalloc(nslot, sizeof(void *), GFP_KERNEL);
 	if (!h->htable)
 		return -ENOMEM;
 
@@ -353,7 +351,7 @@
 	max_chain_len = 0;
 	chain2_len_sum = 0;
 	for (i = 0; i < h->nslot; i++) {
-		cur = flex_array_get_ptr(h->htable, i);
+		cur = h->htable[i];
 		if (cur) {
 			slots_used++;
 			chain_len = 0;
@@ -646,7 +644,7 @@
 		return rc;
 
 	for (i = 0; i < a->nslot; i++) {
-		for (cur = flex_array_get_ptr(a->htable, i); cur;
+		for (cur = a->htable[i]; cur;
 		     cur = cur->next) {
 			rc = avtab_write_item(p, cur, fp);
 			if (rc)
diff --git a/security/selinux/ss/avtab.h b/security/selinux/ss/avtab.h
index 0d652fa..837e938 100644
--- a/security/selinux/ss/avtab.h
+++ b/security/selinux/ss/avtab.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
 /*
  * An access vector table (avtab) is a hash table
  * of access vectors and transition types indexed
@@ -13,9 +14,6 @@
  * 	Added conditional policy language extensions
  *
  * Copyright (C) 2003 Tresys Technology, LLC
- *	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.
  *
  * Updated: Yuichi Nakamura <ynakam@hitachisoft.jp>
  * 	Tuned number of hash slots for avtab to reduce memory usage
@@ -24,7 +22,6 @@
 #define _SS_AVTAB_H_
 
 #include "security.h"
-#include <linux/flex_array.h>
 
 struct avtab_key {
 	u16 source_type;	/* source type */
@@ -84,11 +81,10 @@
 };
 
 struct avtab {
-	struct flex_array *htable;
+	struct avtab_node **htable;
 	u32 nel;	/* number of elements */
 	u32 nslot;      /* number of hash slots */
 	u32 mask;       /* mask to compute hash func */
-
 };
 
 int avtab_init(struct avtab *);
diff --git a/security/selinux/ss/conditional.c b/security/selinux/ss/conditional.c
index f49e522..70c378e 100644
--- a/security/selinux/ss/conditional.c
+++ b/security/selinux/ss/conditional.c
@@ -1,10 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /* Authors: Karl MacMillan <kmacmillan@tresys.com>
  *	    Frank Mayer <mayerf@tresys.com>
  *
  * Copyright (C) 2003 - 2004 Tresys Technology, LLC
- *	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.
  */
 
 #include <linux/kernel.h>
@@ -195,7 +193,6 @@
 {
 	struct policydb *p;
 	struct cond_bool_datum *booldatum;
-	struct flex_array *fa;
 
 	booldatum = datum;
 	p = datap;
@@ -203,10 +200,7 @@
 	if (!booldatum->value || booldatum->value > p->p_bools.nprim)
 		return -EINVAL;
 
-	fa = p->sym_val_to_name[SYM_BOOLS];
-	if (flex_array_put_ptr(fa, booldatum->value - 1, key,
-			       GFP_KERNEL | __GFP_ZERO))
-		BUG();
+	p->sym_val_to_name[SYM_BOOLS][booldatum->value - 1] = key;
 	p->bool_val_to_struct[booldatum->value - 1] = booldatum;
 
 	return 0;
diff --git a/security/selinux/ss/conditional.h b/security/selinux/ss/conditional.h
index ddb43e7..ec846e4 100644
--- a/security/selinux/ss/conditional.h
+++ b/security/selinux/ss/conditional.h
@@ -1,10 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
 /* Authors: Karl MacMillan <kmacmillan@tresys.com>
  *          Frank Mayer <mayerf@tresys.com>
  *
  * Copyright (C) 2003 - 2004 Tresys Technology, LLC
- *	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.
  */
 
 #ifndef _CONDITIONAL_H_
diff --git a/security/selinux/ss/ebitmap.c b/security/selinux/ss/ebitmap.c
index 8f624f8..09929fc 100644
--- a/security/selinux/ss/ebitmap.c
+++ b/security/selinux/ss/ebitmap.c
@@ -347,7 +347,9 @@
 {
 	struct ebitmap_node *n = NULL;
 	u32 mapunit, count, startbit, index;
+	__le32 ebitmap_start;
 	u64 map;
+	__le64 mapbits;
 	__le32 buf[3];
 	int rc, i;
 
@@ -381,12 +383,12 @@
 		goto bad;
 
 	for (i = 0; i < count; i++) {
-		rc = next_entry(&startbit, fp, sizeof(u32));
+		rc = next_entry(&ebitmap_start, fp, sizeof(u32));
 		if (rc < 0) {
 			pr_err("SELinux: ebitmap: truncated map\n");
 			goto bad;
 		}
-		startbit = le32_to_cpu(startbit);
+		startbit = le32_to_cpu(ebitmap_start);
 
 		if (startbit & (mapunit - 1)) {
 			pr_err("SELinux: ebitmap start bit (%d) is "
@@ -423,12 +425,12 @@
 			goto bad;
 		}
 
-		rc = next_entry(&map, fp, sizeof(u64));
+		rc = next_entry(&mapbits, fp, sizeof(u64));
 		if (rc < 0) {
 			pr_err("SELinux: ebitmap: truncated map\n");
 			goto bad;
 		}
-		map = le64_to_cpu(map);
+		map = le64_to_cpu(mapbits);
 
 		index = (startbit - n->startbit) / EBITMAP_UNIT_SIZE;
 		while (map) {
diff --git a/security/selinux/ss/mls.c b/security/selinux/ss/mls.c
index 39475fb..5e05f5b 100644
--- a/security/selinux/ss/mls.c
+++ b/security/selinux/ss/mls.c
@@ -218,9 +218,7 @@
 /*
  * Set the MLS fields in the security context structure
  * `context' based on the string representation in
- * the string `*scontext'.  Update `*scontext' to
- * point to the end of the string representation of
- * the MLS fields.
+ * the string `scontext'.
  *
  * This function modifies the string in place, inserting
  * NULL characters to terminate the MLS fields.
@@ -235,21 +233,24 @@
  */
 int mls_context_to_sid(struct policydb *pol,
 		       char oldc,
-		       char **scontext,
+		       char *scontext,
 		       struct context *context,
 		       struct sidtab *s,
 		       u32 def_sid)
 {
-
-	char delim;
-	char *scontextp, *p, *rngptr;
+	char *sensitivity, *cur_cat, *next_cat, *rngptr;
 	struct level_datum *levdatum;
 	struct cat_datum *catdatum, *rngdatum;
-	int l, rc = -EINVAL;
+	int l, rc, i;
+	char *rangep[2];
 
 	if (!pol->mls_enabled) {
-		if (def_sid != SECSID_NULL && oldc)
-			*scontext += strlen(*scontext) + 1;
+		/*
+		 * With no MLS, only return -EINVAL if there is a MLS field
+		 * and it did not come from an xattr.
+		 */
+		if (oldc && def_sid == SECSID_NULL)
+			return -EINVAL;
 		return 0;
 	}
 
@@ -261,113 +262,94 @@
 		struct context *defcon;
 
 		if (def_sid == SECSID_NULL)
-			goto out;
+			return -EINVAL;
 
 		defcon = sidtab_search(s, def_sid);
 		if (!defcon)
-			goto out;
+			return -EINVAL;
 
-		rc = mls_context_cpy(context, defcon);
-		goto out;
+		return mls_context_cpy(context, defcon);
 	}
 
-	/* Extract low sensitivity. */
-	scontextp = p = *scontext;
-	while (*p && *p != ':' && *p != '-')
-		p++;
+	/*
+	 * If we're dealing with a range, figure out where the two parts
+	 * of the range begin.
+	 */
+	rangep[0] = scontext;
+	rangep[1] = strchr(scontext, '-');
+	if (rangep[1]) {
+		rangep[1][0] = '\0';
+		rangep[1]++;
+	}
 
-	delim = *p;
-	if (delim != '\0')
-		*p++ = '\0';
-
+	/* For each part of the range: */
 	for (l = 0; l < 2; l++) {
-		levdatum = hashtab_search(pol->p_levels.table, scontextp);
-		if (!levdatum) {
-			rc = -EINVAL;
-			goto out;
-		}
+		/* Split sensitivity and category set. */
+		sensitivity = rangep[l];
+		if (sensitivity == NULL)
+			break;
+		next_cat = strchr(sensitivity, ':');
+		if (next_cat)
+			*(next_cat++) = '\0';
 
+		/* Parse sensitivity. */
+		levdatum = hashtab_search(pol->p_levels.table, sensitivity);
+		if (!levdatum)
+			return -EINVAL;
 		context->range.level[l].sens = levdatum->level->sens;
 
-		if (delim == ':') {
-			/* Extract category set. */
-			while (1) {
-				scontextp = p;
-				while (*p && *p != ',' && *p != '-')
-					p++;
-				delim = *p;
-				if (delim != '\0')
-					*p++ = '\0';
+		/* Extract category set. */
+		while (next_cat != NULL) {
+			cur_cat = next_cat;
+			next_cat = strchr(next_cat, ',');
+			if (next_cat != NULL)
+				*(next_cat++) = '\0';
 
-				/* Separate into range if exists */
-				rngptr = strchr(scontextp, '.');
-				if (rngptr != NULL) {
-					/* Remove '.' */
-					*rngptr++ = '\0';
-				}
+			/* Separate into range if exists */
+			rngptr = strchr(cur_cat, '.');
+			if (rngptr != NULL) {
+				/* Remove '.' */
+				*rngptr++ = '\0';
+			}
 
-				catdatum = hashtab_search(pol->p_cats.table,
-							  scontextp);
-				if (!catdatum) {
-					rc = -EINVAL;
-					goto out;
-				}
+			catdatum = hashtab_search(pol->p_cats.table, cur_cat);
+			if (!catdatum)
+				return -EINVAL;
 
-				rc = ebitmap_set_bit(&context->range.level[l].cat,
-						     catdatum->value - 1, 1);
+			rc = ebitmap_set_bit(&context->range.level[l].cat,
+					     catdatum->value - 1, 1);
+			if (rc)
+				return rc;
+
+			/* If range, set all categories in range */
+			if (rngptr == NULL)
+				continue;
+
+			rngdatum = hashtab_search(pol->p_cats.table, rngptr);
+			if (!rngdatum)
+				return -EINVAL;
+
+			if (catdatum->value >= rngdatum->value)
+				return -EINVAL;
+
+			for (i = catdatum->value; i < rngdatum->value; i++) {
+				rc = ebitmap_set_bit(&context->range.level[l].cat, i, 1);
 				if (rc)
-					goto out;
-
-				/* If range, set all categories in range */
-				if (rngptr) {
-					int i;
-
-					rngdatum = hashtab_search(pol->p_cats.table, rngptr);
-					if (!rngdatum) {
-						rc = -EINVAL;
-						goto out;
-					}
-
-					if (catdatum->value >= rngdatum->value) {
-						rc = -EINVAL;
-						goto out;
-					}
-
-					for (i = catdatum->value; i < rngdatum->value; i++) {
-						rc = ebitmap_set_bit(&context->range.level[l].cat, i, 1);
-						if (rc)
-							goto out;
-					}
-				}
-
-				if (delim != ',')
-					break;
+					return rc;
 			}
 		}
-		if (delim == '-') {
-			/* Extract high sensitivity. */
-			scontextp = p;
-			while (*p && *p != ':')
-				p++;
-
-			delim = *p;
-			if (delim != '\0')
-				*p++ = '\0';
-		} else
-			break;
 	}
 
-	if (l == 0) {
+	/* If we didn't see a '-', the range start is also the range end. */
+	if (rangep[1] == NULL) {
 		context->range.level[1].sens = context->range.level[0].sens;
 		rc = ebitmap_cpy(&context->range.level[1].cat,
 				 &context->range.level[0].cat);
 		if (rc)
-			goto out;
+			return rc;
 	}
-	*scontext = ++p;
-	rc = 0;
-out:
-	return rc;
+
+	return 0;
 }
 
 /*
@@ -379,21 +361,19 @@
 int mls_from_string(struct policydb *p, char *str, struct context *context,
 		    gfp_t gfp_mask)
 {
-	char *tmpstr, *freestr;
+	char *tmpstr;
 	int rc;
 
 	if (!p->mls_enabled)
 		return -EINVAL;
 
-	/* we need freestr because mls_context_to_sid will change
-	   the value of tmpstr */
-	tmpstr = freestr = kstrdup(str, gfp_mask);
+	tmpstr = kstrdup(str, gfp_mask);
 	if (!tmpstr) {
 		rc = -ENOMEM;
 	} else {
-		rc = mls_context_to_sid(p, ':', &tmpstr, context,
+		rc = mls_context_to_sid(p, ':', tmpstr, context,
 					NULL, SECSID_NULL);
-		kfree(freestr);
+		kfree(tmpstr);
 	}
 
 	return rc;
@@ -460,16 +440,17 @@
 
 /*
  * Convert the MLS fields in the security context
- * structure `c' from the values specified in the
- * policy `oldp' to the values specified in the policy `newp'.
+ * structure `oldc' from the values specified in the
+ * policy `oldp' to the values specified in the policy `newp',
+ * storing the resulting context in `newc'.
  */
 int mls_convert_context(struct policydb *oldp,
 			struct policydb *newp,
-			struct context *c)
+			struct context *oldc,
+			struct context *newc)
 {
 	struct level_datum *levdatum;
 	struct cat_datum *catdatum;
-	struct ebitmap bitmap;
 	struct ebitmap_node *node;
 	int l, i;
 
@@ -479,28 +460,25 @@
 	for (l = 0; l < 2; l++) {
 		levdatum = hashtab_search(newp->p_levels.table,
 					  sym_name(oldp, SYM_LEVELS,
-						   c->range.level[l].sens - 1));
+						   oldc->range.level[l].sens - 1));
 
 		if (!levdatum)
 			return -EINVAL;
-		c->range.level[l].sens = levdatum->level->sens;
+		newc->range.level[l].sens = levdatum->level->sens;
 
-		ebitmap_init(&bitmap);
-		ebitmap_for_each_positive_bit(&c->range.level[l].cat, node, i) {
+		ebitmap_for_each_positive_bit(&oldc->range.level[l].cat,
+					      node, i) {
 			int rc;
 
 			catdatum = hashtab_search(newp->p_cats.table,
 						  sym_name(oldp, SYM_CATS, i));
 			if (!catdatum)
 				return -EINVAL;
-			rc = ebitmap_set_bit(&bitmap, catdatum->value - 1, 1);
+			rc = ebitmap_set_bit(&newc->range.level[l].cat,
+					     catdatum->value - 1, 1);
 			if (rc)
 				return rc;
-
-			cond_resched();
 		}
-		ebitmap_destroy(&c->range.level[l].cat);
-		c->range.level[l].cat = bitmap;
 	}
 
 	return 0;
diff --git a/security/selinux/ss/mls.h b/security/selinux/ss/mls.h
index 9a3ff7a..7954b1e 100644
--- a/security/selinux/ss/mls.h
+++ b/security/selinux/ss/mls.h
@@ -34,7 +34,7 @@
 
 int mls_context_to_sid(struct policydb *p,
 		       char oldc,
-		       char **scontext,
+		       char *scontext,
 		       struct context *context,
 		       struct sidtab *s,
 		       u32 def_sid);
@@ -46,7 +46,8 @@
 
 int mls_convert_context(struct policydb *oldp,
 			struct policydb *newp,
-			struct context *context);
+			struct context *oldc,
+			struct context *newc);
 
 int mls_compute_sid(struct policydb *p,
 		    struct context *scontext,
diff --git a/security/selinux/ss/policydb.c b/security/selinux/ss/policydb.c
index f4eadd3..1260f5f 100644
--- a/security/selinux/ss/policydb.c
+++ b/security/selinux/ss/policydb.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Implementation of the policy database.
  *
@@ -25,9 +26,6 @@
  * Copyright (C) 2007 Hewlett-Packard Development Company, L.P.
  * Copyright (C) 2004-2005 Trusted Computer Solutions, Inc.
  * Copyright (C) 2003 - 2004 Tresys Technology, LLC
- *	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.
  */
 
 #include <linux/kernel.h>
@@ -36,7 +34,6 @@
 #include <linux/string.h>
 #include <linux/errno.h>
 #include <linux/audit.h>
-#include <linux/flex_array.h>
 #include "security.h"
 
 #include "policydb.h"
@@ -180,433 +177,6 @@
 }
 
 /*
- * Initialize the role table.
- */
-static int roles_init(struct policydb *p)
-{
-	char *key = NULL;
-	int rc;
-	struct role_datum *role;
-
-	role = kzalloc(sizeof(*role), GFP_KERNEL);
-	if (!role)
-		return -ENOMEM;
-
-	rc = -EINVAL;
-	role->value = ++p->p_roles.nprim;
-	if (role->value != OBJECT_R_VAL)
-		goto out;
-
-	rc = -ENOMEM;
-	key = kstrdup(OBJECT_R, GFP_KERNEL);
-	if (!key)
-		goto out;
-
-	rc = hashtab_insert(p->p_roles.table, key, role);
-	if (rc)
-		goto out;
-
-	return 0;
-out:
-	kfree(key);
-	kfree(role);
-	return rc;
-}
-
-static u32 filenametr_hash(struct hashtab *h, const void *k)
-{
-	const struct filename_trans *ft = k;
-	unsigned long hash;
-	unsigned int byte_num;
-	unsigned char focus;
-
-	hash = ft->stype ^ ft->ttype ^ ft->tclass;
-
-	byte_num = 0;
-	while ((focus = ft->name[byte_num++]))
-		hash = partial_name_hash(focus, hash);
-	return hash & (h->size - 1);
-}
-
-static int filenametr_cmp(struct hashtab *h, const void *k1, const void *k2)
-{
-	const struct filename_trans *ft1 = k1;
-	const struct filename_trans *ft2 = k2;
-	int v;
-
-	v = ft1->stype - ft2->stype;
-	if (v)
-		return v;
-
-	v = ft1->ttype - ft2->ttype;
-	if (v)
-		return v;
-
-	v = ft1->tclass - ft2->tclass;
-	if (v)
-		return v;
-
-	return strcmp(ft1->name, ft2->name);
-
-}
-
-static u32 rangetr_hash(struct hashtab *h, const void *k)
-{
-	const struct range_trans *key = k;
-	return (key->source_type + (key->target_type << 3) +
-		(key->target_class << 5)) & (h->size - 1);
-}
-
-static int rangetr_cmp(struct hashtab *h, const void *k1, const void *k2)
-{
-	const struct range_trans *key1 = k1, *key2 = k2;
-	int v;
-
-	v = key1->source_type - key2->source_type;
-	if (v)
-		return v;
-
-	v = key1->target_type - key2->target_type;
-	if (v)
-		return v;
-
-	v = key1->target_class - key2->target_class;
-
-	return v;
-}
-
-/*
- * Initialize a policy database structure.
- */
-static int policydb_init(struct policydb *p)
-{
-	int i, rc;
-
-	memset(p, 0, sizeof(*p));
-
-	for (i = 0; i < SYM_NUM; i++) {
-		rc = symtab_init(&p->symtab[i], symtab_sizes[i]);
-		if (rc)
-			goto out;
-	}
-
-	rc = avtab_init(&p->te_avtab);
-	if (rc)
-		goto out;
-
-	rc = roles_init(p);
-	if (rc)
-		goto out;
-
-	rc = cond_policydb_init(p);
-	if (rc)
-		goto out;
-
-	p->filename_trans = hashtab_create(filenametr_hash, filenametr_cmp, (1 << 10));
-	if (!p->filename_trans) {
-		rc = -ENOMEM;
-		goto out;
-	}
-
-	p->range_tr = hashtab_create(rangetr_hash, rangetr_cmp, 256);
-	if (!p->range_tr) {
-		rc = -ENOMEM;
-		goto out;
-	}
-
-	ebitmap_init(&p->filename_trans_ttypes);
-	ebitmap_init(&p->policycaps);
-	ebitmap_init(&p->permissive_map);
-
-	return 0;
-out:
-	hashtab_destroy(p->filename_trans);
-	hashtab_destroy(p->range_tr);
-	for (i = 0; i < SYM_NUM; i++)
-		hashtab_destroy(p->symtab[i].table);
-	return rc;
-}
-
-/*
- * The following *_index functions are used to
- * define the val_to_name and val_to_struct arrays
- * in a policy database structure.  The val_to_name
- * arrays are used when converting security context
- * structures into string representations.  The
- * val_to_struct arrays are used when the attributes
- * of a class, role, or user are needed.
- */
-
-static int common_index(void *key, void *datum, void *datap)
-{
-	struct policydb *p;
-	struct common_datum *comdatum;
-	struct flex_array *fa;
-
-	comdatum = datum;
-	p = datap;
-	if (!comdatum->value || comdatum->value > p->p_commons.nprim)
-		return -EINVAL;
-
-	fa = p->sym_val_to_name[SYM_COMMONS];
-	if (flex_array_put_ptr(fa, comdatum->value - 1, key,
-			       GFP_KERNEL | __GFP_ZERO))
-		BUG();
-	return 0;
-}
-
-static int class_index(void *key, void *datum, void *datap)
-{
-	struct policydb *p;
-	struct class_datum *cladatum;
-	struct flex_array *fa;
-
-	cladatum = datum;
-	p = datap;
-	if (!cladatum->value || cladatum->value > p->p_classes.nprim)
-		return -EINVAL;
-	fa = p->sym_val_to_name[SYM_CLASSES];
-	if (flex_array_put_ptr(fa, cladatum->value - 1, key,
-			       GFP_KERNEL | __GFP_ZERO))
-		BUG();
-	p->class_val_to_struct[cladatum->value - 1] = cladatum;
-	return 0;
-}
-
-static int role_index(void *key, void *datum, void *datap)
-{
-	struct policydb *p;
-	struct role_datum *role;
-	struct flex_array *fa;
-
-	role = datum;
-	p = datap;
-	if (!role->value
-	    || role->value > p->p_roles.nprim
-	    || role->bounds > p->p_roles.nprim)
-		return -EINVAL;
-
-	fa = p->sym_val_to_name[SYM_ROLES];
-	if (flex_array_put_ptr(fa, role->value - 1, key,
-			       GFP_KERNEL | __GFP_ZERO))
-		BUG();
-	p->role_val_to_struct[role->value - 1] = role;
-	return 0;
-}
-
-static int type_index(void *key, void *datum, void *datap)
-{
-	struct policydb *p;
-	struct type_datum *typdatum;
-	struct flex_array *fa;
-
-	typdatum = datum;
-	p = datap;
-
-	if (typdatum->primary) {
-		if (!typdatum->value
-		    || typdatum->value > p->p_types.nprim
-		    || typdatum->bounds > p->p_types.nprim)
-			return -EINVAL;
-		fa = p->sym_val_to_name[SYM_TYPES];
-		if (flex_array_put_ptr(fa, typdatum->value - 1, key,
-				       GFP_KERNEL | __GFP_ZERO))
-			BUG();
-
-		fa = p->type_val_to_struct_array;
-		if (flex_array_put_ptr(fa, typdatum->value - 1, typdatum,
-				       GFP_KERNEL | __GFP_ZERO))
-			BUG();
-	}
-
-	return 0;
-}
-
-static int user_index(void *key, void *datum, void *datap)
-{
-	struct policydb *p;
-	struct user_datum *usrdatum;
-	struct flex_array *fa;
-
-	usrdatum = datum;
-	p = datap;
-	if (!usrdatum->value
-	    || usrdatum->value > p->p_users.nprim
-	    || usrdatum->bounds > p->p_users.nprim)
-		return -EINVAL;
-
-	fa = p->sym_val_to_name[SYM_USERS];
-	if (flex_array_put_ptr(fa, usrdatum->value - 1, key,
-			       GFP_KERNEL | __GFP_ZERO))
-		BUG();
-	p->user_val_to_struct[usrdatum->value - 1] = usrdatum;
-	return 0;
-}
-
-static int sens_index(void *key, void *datum, void *datap)
-{
-	struct policydb *p;
-	struct level_datum *levdatum;
-	struct flex_array *fa;
-
-	levdatum = datum;
-	p = datap;
-
-	if (!levdatum->isalias) {
-		if (!levdatum->level->sens ||
-		    levdatum->level->sens > p->p_levels.nprim)
-			return -EINVAL;
-		fa = p->sym_val_to_name[SYM_LEVELS];
-		if (flex_array_put_ptr(fa, levdatum->level->sens - 1, key,
-				       GFP_KERNEL | __GFP_ZERO))
-			BUG();
-	}
-
-	return 0;
-}
-
-static int cat_index(void *key, void *datum, void *datap)
-{
-	struct policydb *p;
-	struct cat_datum *catdatum;
-	struct flex_array *fa;
-
-	catdatum = datum;
-	p = datap;
-
-	if (!catdatum->isalias) {
-		if (!catdatum->value || catdatum->value > p->p_cats.nprim)
-			return -EINVAL;
-		fa = p->sym_val_to_name[SYM_CATS];
-		if (flex_array_put_ptr(fa, catdatum->value - 1, key,
-				       GFP_KERNEL | __GFP_ZERO))
-			BUG();
-	}
-
-	return 0;
-}
-
-static int (*index_f[SYM_NUM]) (void *key, void *datum, void *datap) =
-{
-	common_index,
-	class_index,
-	role_index,
-	type_index,
-	user_index,
-	cond_index_bool,
-	sens_index,
-	cat_index,
-};
-
-#ifdef DEBUG_HASHES
-static void hash_eval(struct hashtab *h, const char *hash_name)
-{
-	struct hashtab_info info;
-
-	hashtab_stat(h, &info);
-	pr_debug("SELinux: %s:  %d entries and %d/%d buckets used, "
-	       "longest chain length %d\n", hash_name, h->nel,
-	       info.slots_used, h->size, info.max_chain_len);
-}
-
-static void symtab_hash_eval(struct symtab *s)
-{
-	int i;
-
-	for (i = 0; i < SYM_NUM; i++)
-		hash_eval(s[i].table, symtab_name[i]);
-}
-
-#else
-static inline void hash_eval(struct hashtab *h, char *hash_name)
-{
-}
-#endif
-
-/*
- * Define the other val_to_name and val_to_struct arrays
- * in a policy database structure.
- *
- * Caller must clean up on failure.
- */
-static int policydb_index(struct policydb *p)
-{
-	int i, rc;
-
-	if (p->mls_enabled)
-		pr_debug("SELinux:  %d users, %d roles, %d types, %d bools, %d sens, %d cats\n",
-			 p->p_users.nprim, p->p_roles.nprim, p->p_types.nprim,
-			 p->p_bools.nprim, p->p_levels.nprim, p->p_cats.nprim);
-	else
-		pr_debug("SELinux:  %d users, %d roles, %d types, %d bools\n",
-			 p->p_users.nprim, p->p_roles.nprim, p->p_types.nprim,
-			 p->p_bools.nprim);
-
-	pr_debug("SELinux:  %d classes, %d rules\n",
-		 p->p_classes.nprim, p->te_avtab.nel);
-
-#ifdef DEBUG_HASHES
-	avtab_hash_eval(&p->te_avtab, "rules");
-	symtab_hash_eval(p->symtab);
-#endif
-
-	p->class_val_to_struct = kcalloc(p->p_classes.nprim,
-					 sizeof(*p->class_val_to_struct),
-					 GFP_KERNEL);
-	if (!p->class_val_to_struct)
-		return -ENOMEM;
-
-	p->role_val_to_struct = kcalloc(p->p_roles.nprim,
-					sizeof(*p->role_val_to_struct),
-					GFP_KERNEL);
-	if (!p->role_val_to_struct)
-		return -ENOMEM;
-
-	p->user_val_to_struct = kcalloc(p->p_users.nprim,
-					sizeof(*p->user_val_to_struct),
-					GFP_KERNEL);
-	if (!p->user_val_to_struct)
-		return -ENOMEM;
-
-	/* Yes, I want the sizeof the pointer, not the structure */
-	p->type_val_to_struct_array = flex_array_alloc(sizeof(struct type_datum *),
-						       p->p_types.nprim,
-						       GFP_KERNEL | __GFP_ZERO);
-	if (!p->type_val_to_struct_array)
-		return -ENOMEM;
-
-	rc = flex_array_prealloc(p->type_val_to_struct_array, 0,
-				 p->p_types.nprim, GFP_KERNEL | __GFP_ZERO);
-	if (rc)
-		goto out;
-
-	rc = cond_init_bool_indexes(p);
-	if (rc)
-		goto out;
-
-	for (i = 0; i < SYM_NUM; i++) {
-		p->sym_val_to_name[i] = flex_array_alloc(sizeof(char *),
-							 p->symtab[i].nprim,
-							 GFP_KERNEL | __GFP_ZERO);
-		if (!p->sym_val_to_name[i])
-			return -ENOMEM;
-
-		rc = flex_array_prealloc(p->sym_val_to_name[i],
-					 0, p->symtab[i].nprim,
-					 GFP_KERNEL | __GFP_ZERO);
-		if (rc)
-			goto out;
-
-		rc = hashtab_map(p->symtab[i].table, index_f[i], p);
-		if (rc)
-			goto out;
-	}
-	rc = 0;
-out:
-	return rc;
-}
-
-/*
  * The following *_destroy functions are used to
  * free any memory allocated for each kind of
  * symbol data in the policy database.
@@ -732,7 +302,8 @@
 	kfree(key);
 	if (datum) {
 		levdatum = datum;
-		ebitmap_destroy(&levdatum->level->cat);
+		if (levdatum->level)
+			ebitmap_destroy(&levdatum->level->cat);
 		kfree(levdatum->level);
 	}
 	kfree(datum);
@@ -761,6 +332,7 @@
 static int filenametr_destroy(void *key, void *datum, void *p)
 {
 	struct filename_trans *ft = key;
+
 	kfree(ft->name);
 	kfree(key);
 	kfree(datum);
@@ -771,6 +343,7 @@
 static int range_tr_destroy(void *key, void *datum, void *p)
 {
 	struct mls_range *rt = datum;
+
 	kfree(key);
 	ebitmap_destroy(&rt->level[0].cat);
 	ebitmap_destroy(&rt->level[1].cat);
@@ -793,6 +366,397 @@
 }
 
 /*
+ * Initialize the role table.
+ */
+static int roles_init(struct policydb *p)
+{
+	char *key = NULL;
+	int rc;
+	struct role_datum *role;
+
+	role = kzalloc(sizeof(*role), GFP_KERNEL);
+	if (!role)
+		return -ENOMEM;
+
+	rc = -EINVAL;
+	role->value = ++p->p_roles.nprim;
+	if (role->value != OBJECT_R_VAL)
+		goto out;
+
+	rc = -ENOMEM;
+	key = kstrdup(OBJECT_R, GFP_KERNEL);
+	if (!key)
+		goto out;
+
+	rc = hashtab_insert(p->p_roles.table, key, role);
+	if (rc)
+		goto out;
+
+	return 0;
+out:
+	kfree(key);
+	kfree(role);
+	return rc;
+}
+
+static u32 filenametr_hash(struct hashtab *h, const void *k)
+{
+	const struct filename_trans *ft = k;
+	unsigned long hash;
+	unsigned int byte_num;
+	unsigned char focus;
+
+	hash = ft->stype ^ ft->ttype ^ ft->tclass;
+
+	byte_num = 0;
+	while ((focus = ft->name[byte_num++]))
+		hash = partial_name_hash(focus, hash);
+	return hash & (h->size - 1);
+}
+
+static int filenametr_cmp(struct hashtab *h, const void *k1, const void *k2)
+{
+	const struct filename_trans *ft1 = k1;
+	const struct filename_trans *ft2 = k2;
+	int v;
+
+	v = ft1->stype - ft2->stype;
+	if (v)
+		return v;
+
+	v = ft1->ttype - ft2->ttype;
+	if (v)
+		return v;
+
+	v = ft1->tclass - ft2->tclass;
+	if (v)
+		return v;
+
+	return strcmp(ft1->name, ft2->name);
+
+}
+
+static u32 rangetr_hash(struct hashtab *h, const void *k)
+{
+	const struct range_trans *key = k;
+
+	return (key->source_type + (key->target_type << 3) +
+		(key->target_class << 5)) & (h->size - 1);
+}
+
+static int rangetr_cmp(struct hashtab *h, const void *k1, const void *k2)
+{
+	const struct range_trans *key1 = k1, *key2 = k2;
+	int v;
+
+	v = key1->source_type - key2->source_type;
+	if (v)
+		return v;
+
+	v = key1->target_type - key2->target_type;
+	if (v)
+		return v;
+
+	v = key1->target_class - key2->target_class;
+
+	return v;
+}
+
+/*
+ * Initialize a policy database structure.
+ */
+static int policydb_init(struct policydb *p)
+{
+	int i, rc;
+
+	memset(p, 0, sizeof(*p));
+
+	for (i = 0; i < SYM_NUM; i++) {
+		rc = symtab_init(&p->symtab[i], symtab_sizes[i]);
+		if (rc)
+			goto out;
+	}
+
+	rc = avtab_init(&p->te_avtab);
+	if (rc)
+		goto out;
+
+	rc = roles_init(p);
+	if (rc)
+		goto out;
+
+	rc = cond_policydb_init(p);
+	if (rc)
+		goto out;
+
+	p->filename_trans = hashtab_create(filenametr_hash, filenametr_cmp,
+					   (1 << 10));
+	if (!p->filename_trans) {
+		rc = -ENOMEM;
+		goto out;
+	}
+
+	p->range_tr = hashtab_create(rangetr_hash, rangetr_cmp, 256);
+	if (!p->range_tr) {
+		rc = -ENOMEM;
+		goto out;
+	}
+
+	ebitmap_init(&p->filename_trans_ttypes);
+	ebitmap_init(&p->policycaps);
+	ebitmap_init(&p->permissive_map);
+
+	return 0;
+out:
+	hashtab_destroy(p->filename_trans);
+	hashtab_destroy(p->range_tr);
+	for (i = 0; i < SYM_NUM; i++) {
+		hashtab_map(p->symtab[i].table, destroy_f[i], NULL);
+		hashtab_destroy(p->symtab[i].table);
+	}
+	return rc;
+}
+
+/*
+ * The following *_index functions are used to
+ * define the val_to_name and val_to_struct arrays
+ * in a policy database structure.  The val_to_name
+ * arrays are used when converting security context
+ * structures into string representations.  The
+ * val_to_struct arrays are used when the attributes
+ * of a class, role, or user are needed.
+ */
+
+static int common_index(void *key, void *datum, void *datap)
+{
+	struct policydb *p;
+	struct common_datum *comdatum;
+
+	comdatum = datum;
+	p = datap;
+	if (!comdatum->value || comdatum->value > p->p_commons.nprim)
+		return -EINVAL;
+
+	p->sym_val_to_name[SYM_COMMONS][comdatum->value - 1] = key;
+
+	return 0;
+}
+
+static int class_index(void *key, void *datum, void *datap)
+{
+	struct policydb *p;
+	struct class_datum *cladatum;
+
+	cladatum = datum;
+	p = datap;
+	if (!cladatum->value || cladatum->value > p->p_classes.nprim)
+		return -EINVAL;
+
+	p->sym_val_to_name[SYM_CLASSES][cladatum->value - 1] = key;
+	p->class_val_to_struct[cladatum->value - 1] = cladatum;
+	return 0;
+}
+
+static int role_index(void *key, void *datum, void *datap)
+{
+	struct policydb *p;
+	struct role_datum *role;
+
+	role = datum;
+	p = datap;
+	if (!role->value
+	    || role->value > p->p_roles.nprim
+	    || role->bounds > p->p_roles.nprim)
+		return -EINVAL;
+
+	p->sym_val_to_name[SYM_ROLES][role->value - 1] = key;
+	p->role_val_to_struct[role->value - 1] = role;
+	return 0;
+}
+
+static int type_index(void *key, void *datum, void *datap)
+{
+	struct policydb *p;
+	struct type_datum *typdatum;
+
+	typdatum = datum;
+	p = datap;
+
+	if (typdatum->primary) {
+		if (!typdatum->value
+		    || typdatum->value > p->p_types.nprim
+		    || typdatum->bounds > p->p_types.nprim)
+			return -EINVAL;
+		p->sym_val_to_name[SYM_TYPES][typdatum->value - 1] = key;
+		p->type_val_to_struct[typdatum->value - 1] = typdatum;
+	}
+
+	return 0;
+}
+
+static int user_index(void *key, void *datum, void *datap)
+{
+	struct policydb *p;
+	struct user_datum *usrdatum;
+
+	usrdatum = datum;
+	p = datap;
+	if (!usrdatum->value
+	    || usrdatum->value > p->p_users.nprim
+	    || usrdatum->bounds > p->p_users.nprim)
+		return -EINVAL;
+
+	p->sym_val_to_name[SYM_USERS][usrdatum->value - 1] = key;
+	p->user_val_to_struct[usrdatum->value - 1] = usrdatum;
+	return 0;
+}
+
+static int sens_index(void *key, void *datum, void *datap)
+{
+	struct policydb *p;
+	struct level_datum *levdatum;
+
+	levdatum = datum;
+	p = datap;
+
+	if (!levdatum->isalias) {
+		if (!levdatum->level->sens ||
+		    levdatum->level->sens > p->p_levels.nprim)
+			return -EINVAL;
+
+		p->sym_val_to_name[SYM_LEVELS][levdatum->level->sens - 1] = key;
+	}
+
+	return 0;
+}
+
+static int cat_index(void *key, void *datum, void *datap)
+{
+	struct policydb *p;
+	struct cat_datum *catdatum;
+
+	catdatum = datum;
+	p = datap;
+
+	if (!catdatum->isalias) {
+		if (!catdatum->value || catdatum->value > p->p_cats.nprim)
+			return -EINVAL;
+
+		p->sym_val_to_name[SYM_CATS][catdatum->value - 1] = key;
+	}
+
+	return 0;
+}
+
+static int (*index_f[SYM_NUM]) (void *key, void *datum, void *datap) =
+{
+	common_index,
+	class_index,
+	role_index,
+	type_index,
+	user_index,
+	cond_index_bool,
+	sens_index,
+	cat_index,
+};
+
+#ifdef DEBUG_HASHES
+static void hash_eval(struct hashtab *h, const char *hash_name)
+{
+	struct hashtab_info info;
+
+	hashtab_stat(h, &info);
+	pr_debug("SELinux: %s:  %d entries and %d/%d buckets used, longest chain length %d\n",
+		 hash_name, h->nel, info.slots_used, h->size,
+		 info.max_chain_len);
+}
+
+static void symtab_hash_eval(struct symtab *s)
+{
+	int i;
+
+	for (i = 0; i < SYM_NUM; i++)
+		hash_eval(s[i].table, symtab_name[i]);
+}
+
+#else
+static inline void hash_eval(struct hashtab *h, char *hash_name)
+{
+}
+#endif
+
+/*
+ * Define the other val_to_name and val_to_struct arrays
+ * in a policy database structure.
+ *
+ * Caller must clean up on failure.
+ */
+static int policydb_index(struct policydb *p)
+{
+	int i, rc;
+
+	if (p->mls_enabled)
+		pr_debug("SELinux:  %d users, %d roles, %d types, %d bools, %d sens, %d cats\n",
+			 p->p_users.nprim, p->p_roles.nprim, p->p_types.nprim,
+			 p->p_bools.nprim, p->p_levels.nprim, p->p_cats.nprim);
+	else
+		pr_debug("SELinux:  %d users, %d roles, %d types, %d bools\n",
+			 p->p_users.nprim, p->p_roles.nprim, p->p_types.nprim,
+			 p->p_bools.nprim);
+
+	pr_debug("SELinux:  %d classes, %d rules\n",
+		 p->p_classes.nprim, p->te_avtab.nel);
+
+#ifdef DEBUG_HASHES
+	avtab_hash_eval(&p->te_avtab, "rules");
+	symtab_hash_eval(p->symtab);
+#endif
+
+	p->class_val_to_struct = kcalloc(p->p_classes.nprim,
+					 sizeof(*p->class_val_to_struct),
+					 GFP_KERNEL);
+	if (!p->class_val_to_struct)
+		return -ENOMEM;
+
+	p->role_val_to_struct = kcalloc(p->p_roles.nprim,
+					sizeof(*p->role_val_to_struct),
+					GFP_KERNEL);
+	if (!p->role_val_to_struct)
+		return -ENOMEM;
+
+	p->user_val_to_struct = kcalloc(p->p_users.nprim,
+					sizeof(*p->user_val_to_struct),
+					GFP_KERNEL);
+	if (!p->user_val_to_struct)
+		return -ENOMEM;
+
+	p->type_val_to_struct = kvcalloc(p->p_types.nprim,
+					 sizeof(*p->type_val_to_struct),
+					 GFP_KERNEL);
+	if (!p->type_val_to_struct)
+		return -ENOMEM;
+
+	rc = cond_init_bool_indexes(p);
+	if (rc)
+		goto out;
+
+	for (i = 0; i < SYM_NUM; i++) {
+		p->sym_val_to_name[i] = kvcalloc(p->symtab[i].nprim,
+						 sizeof(char *),
+						 GFP_KERNEL);
+		if (!p->sym_val_to_name[i])
+			return -ENOMEM;
+
+		rc = hashtab_map(p->symtab[i].table, index_f[i], p);
+		if (rc)
+			goto out;
+	}
+	rc = 0;
+out:
+	return rc;
+}
+
+/*
  * Free any memory allocated by a policy database structure.
  */
 void policydb_destroy(struct policydb *p)
@@ -809,16 +773,13 @@
 		hashtab_destroy(p->symtab[i].table);
 	}
 
-	for (i = 0; i < SYM_NUM; i++) {
-		if (p->sym_val_to_name[i])
-			flex_array_free(p->sym_val_to_name[i]);
-	}
+	for (i = 0; i < SYM_NUM; i++)
+		kvfree(p->sym_val_to_name[i]);
 
 	kfree(p->class_val_to_struct);
 	kfree(p->role_val_to_struct);
 	kfree(p->user_val_to_struct);
-	if (p->type_val_to_struct_array)
-		flex_array_free(p->type_val_to_struct_array);
+	kvfree(p->type_val_to_struct);
 
 	avtab_destroy(&p->te_avtab);
 
@@ -872,15 +833,9 @@
 	hashtab_destroy(p->range_tr);
 
 	if (p->type_attr_map_array) {
-		for (i = 0; i < p->p_types.nprim; i++) {
-			struct ebitmap *e;
-
-			e = flex_array_get(p->type_attr_map_array, i);
-			if (!e)
-				continue;
-			ebitmap_destroy(e);
-		}
-		flex_array_free(p->type_attr_map_array);
+		for (i = 0; i < p->p_types.nprim; i++)
+			ebitmap_destroy(&p->type_attr_map_array[i]);
+		kvfree(p->type_attr_map_array);
 	}
 
 	ebitmap_destroy(&p->filename_trans_ttypes);
@@ -909,13 +864,21 @@
 		if (!c->context[0].user) {
 			pr_err("SELinux:  SID %s was never defined.\n",
 				c->u.name);
+			sidtab_destroy(s);
+			goto out;
+		}
+		if (c->sid[0] == SECSID_NULL || c->sid[0] > SECINITSID_NUM) {
+			pr_err("SELinux:  Initial SID %s out of range.\n",
+				c->u.name);
+			sidtab_destroy(s);
 			goto out;
 		}
 
-		rc = sidtab_insert(s, c->sid[0], &c->context[0]);
+		rc = sidtab_set_initial(s, c->sid[0], &c->context[0]);
 		if (rc) {
 			pr_err("SELinux:  unable to load initial SID %s.\n",
 				c->u.name);
+			sidtab_destroy(s);
 			goto out;
 		}
 	}
@@ -1761,8 +1724,7 @@
 			return -EINVAL;
 		}
 
-		upper = flex_array_get_ptr(p->type_val_to_struct_array,
-					   upper->bounds - 1);
+		upper = p->type_val_to_struct[upper->bounds - 1];
 		BUG_ON(!upper);
 
 		if (upper->attribute) {
@@ -2108,6 +2070,7 @@
 {
 	int i, j, rc;
 	u32 nel, len;
+	__be64 prefixbuf[1];
 	__le32 buf[3];
 	struct ocontext *l, *c;
 	u32 nodebuf[8];
@@ -2217,21 +2180,30 @@
 					goto out;
 				break;
 			}
-			case OCON_IBPKEY:
-				rc = next_entry(nodebuf, fp, sizeof(u32) * 4);
+			case OCON_IBPKEY: {
+				u32 pkey_lo, pkey_hi;
+
+				rc = next_entry(prefixbuf, fp, sizeof(u64));
 				if (rc)
 					goto out;
 
-				c->u.ibpkey.subnet_prefix = be64_to_cpu(*((__be64 *)nodebuf));
+				/* we need to have subnet_prefix in CPU order */
+				c->u.ibpkey.subnet_prefix = be64_to_cpu(prefixbuf[0]);
 
-				if (nodebuf[2] > 0xffff ||
-				    nodebuf[3] > 0xffff) {
+				rc = next_entry(buf, fp, sizeof(u32) * 2);
+				if (rc)
+					goto out;
+
+				pkey_lo = le32_to_cpu(buf[0]);
+				pkey_hi = le32_to_cpu(buf[1]);
+
+				if (pkey_lo > U16_MAX || pkey_hi > U16_MAX) {
 					rc = -EINVAL;
 					goto out;
 				}
 
-				c->u.ibpkey.low_pkey = le32_to_cpu(nodebuf[2]);
-				c->u.ibpkey.high_pkey = le32_to_cpu(nodebuf[3]);
+				c->u.ibpkey.low_pkey  = pkey_lo;
+				c->u.ibpkey.high_pkey = pkey_hi;
 
 				rc = context_read_and_validate(&c->context[0],
 							       p,
@@ -2239,7 +2211,10 @@
 				if (rc)
 					goto out;
 				break;
-			case OCON_IBENDPORT:
+			}
+			case OCON_IBENDPORT: {
+				u32 port;
+
 				rc = next_entry(buf, fp, sizeof(u32) * 2);
 				if (rc)
 					goto out;
@@ -2249,12 +2224,13 @@
 				if (rc)
 					goto out;
 
-				if (buf[1] > 0xff || buf[1] == 0) {
+				port = le32_to_cpu(buf[1]);
+				if (port > U8_MAX || port == 0) {
 					rc = -EINVAL;
 					goto out;
 				}
 
-				c->u.ibendport.port = le32_to_cpu(buf[1]);
+				c->u.ibendport.port = port;
 
 				rc = context_read_and_validate(&c->context[0],
 							       p,
@@ -2262,7 +2238,8 @@
 				if (rc)
 					goto out;
 				break;
-			}
+			} /* end case */
+			} /* end switch */
 		}
 	}
 	rc = 0;
@@ -2519,24 +2496,19 @@
 	if (rc)
 		goto bad;
 
-	rc = -ENOMEM;
-	p->type_attr_map_array = flex_array_alloc(sizeof(struct ebitmap),
-						  p->p_types.nprim,
-						  GFP_KERNEL | __GFP_ZERO);
+	p->type_attr_map_array = kvcalloc(p->p_types.nprim,
+					  sizeof(*p->type_attr_map_array),
+					  GFP_KERNEL);
 	if (!p->type_attr_map_array)
 		goto bad;
 
-	/* preallocate so we don't have to worry about the put ever failing */
-	rc = flex_array_prealloc(p->type_attr_map_array, 0, p->p_types.nprim,
-				 GFP_KERNEL | __GFP_ZERO);
-	if (rc)
-		goto bad;
+	/* just in case ebitmap_init() becomes more than just a memset(0): */
+	for (i = 0; i < p->p_types.nprim; i++)
+		ebitmap_init(&p->type_attr_map_array[i]);
 
 	for (i = 0; i < p->p_types.nprim; i++) {
-		struct ebitmap *e = flex_array_get(p->type_attr_map_array, i);
+		struct ebitmap *e = &p->type_attr_map_array[i];
 
-		BUG_ON(!e);
-		ebitmap_init(e);
 		if (p->policyvers >= POLICYDB_VERSION_AVTAB) {
 			rc = ebitmap_read(e, fp);
 			if (rc)
@@ -3105,6 +3077,7 @@
 {
 	unsigned int i, j, rc;
 	size_t nel, len;
+	__be64 prefixbuf[1];
 	__le32 buf[3];
 	u32 nodebuf[8];
 	struct ocontext *c;
@@ -3192,12 +3165,17 @@
 					return rc;
 				break;
 			case OCON_IBPKEY:
-				*((__be64 *)nodebuf) = cpu_to_be64(c->u.ibpkey.subnet_prefix);
+				/* subnet_prefix is in CPU order */
+				prefixbuf[0] = cpu_to_be64(c->u.ibpkey.subnet_prefix);
 
-				nodebuf[2] = cpu_to_le32(c->u.ibpkey.low_pkey);
-				nodebuf[3] = cpu_to_le32(c->u.ibpkey.high_pkey);
+				rc = put_entry(prefixbuf, sizeof(u64), 1, fp);
+				if (rc)
+					return rc;
 
-				rc = put_entry(nodebuf, sizeof(u32), 4, fp);
+				buf[0] = cpu_to_le32(c->u.ibpkey.low_pkey);
+				buf[1] = cpu_to_le32(c->u.ibpkey.high_pkey);
+
+				rc = put_entry(buf, sizeof(u32), 2, fp);
 				if (rc)
 					return rc;
 				rc = context_write(p, &c->context[0], fp);
@@ -3524,9 +3502,8 @@
 		return rc;
 
 	for (i = 0; i < p->p_types.nprim; i++) {
-		struct ebitmap *e = flex_array_get(p->type_attr_map_array, i);
+		struct ebitmap *e = &p->type_attr_map_array[i];
 
-		BUG_ON(!e);
 		rc = ebitmap_write(e, fp);
 		if (rc)
 			return rc;
diff --git a/security/selinux/ss/policydb.h b/security/selinux/ss/policydb.h
index 215f8f3..162d0e7 100644
--- a/security/selinux/ss/policydb.h
+++ b/security/selinux/ss/policydb.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
 /*
  * A policy database (policydb) specifies the
  * configuration data for the security policy.
@@ -16,16 +17,11 @@
  *
  * Copyright (C) 2004-2005 Trusted Computer Solutions, Inc.
  * Copyright (C) 2003 - 2004 Tresys Technology, LLC
- *	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.
  */
 
 #ifndef _SS_POLICYDB_H_
 #define _SS_POLICYDB_H_
 
-#include <linux/flex_array.h>
-
 #include "symtab.h"
 #include "avtab.h"
 #include "sidtab.h"
@@ -251,13 +247,13 @@
 #define p_cats symtab[SYM_CATS]
 
 	/* symbol names indexed by (value - 1) */
-	struct flex_array *sym_val_to_name[SYM_NUM];
+	char		**sym_val_to_name[SYM_NUM];
 
 	/* class, role, and user attributes indexed by (value - 1) */
 	struct class_datum **class_val_to_struct;
 	struct role_datum **role_val_to_struct;
 	struct user_datum **user_val_to_struct;
-	struct flex_array *type_val_to_struct_array;
+	struct type_datum **type_val_to_struct;
 
 	/* type enforcement access vectors and transitions */
 	struct avtab te_avtab;
@@ -294,7 +290,7 @@
 	struct hashtab *range_tr;
 
 	/* type -> attribute reverse mapping */
-	struct flex_array *type_attr_map_array;
+	struct ebitmap *type_attr_map_array;
 
 	struct ebitmap policycaps;
 
@@ -369,9 +365,7 @@
 
 static inline char *sym_name(struct policydb *p, unsigned int sym_num, unsigned int element_nr)
 {
-	struct flex_array *fa = p->sym_val_to_name[sym_num];
-
-	return flex_array_get_ptr(fa, element_nr);
+	return p->sym_val_to_name[sym_num][element_nr];
 }
 
 extern u16 string_to_security_class(struct policydb *p, const char *name);
diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
index f3def29..a5813c7 100644
--- a/security/selinux/ss/services.c
+++ b/security/selinux/ss/services.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * Implementation of the security services.
  *
@@ -35,9 +36,6 @@
  * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc.
  * Copyright (C) 2003 - 2004, 2006 Tresys Technology, LLC
  * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
- *	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.
  */
 #include <linux/kernel.h>
 #include <linux/slab.h>
@@ -49,8 +47,6 @@
 #include <linux/sched.h>
 #include <linux/audit.h>
 #include <linux/mutex.h>
-#include <linux/selinux.h>
-#include <linux/flex_array.h>
 #include <linux/vmalloc.h>
 #include <net/netlabel.h>
 
@@ -71,7 +67,7 @@
 #include "audit.h"
 
 /* Policy capability names */
-char *selinux_policycap_names[__POLICYDB_CAPABILITY_MAX] = {
+const char *selinux_policycap_names[__POLICYDB_CAPABILITY_MAX] = {
 	"network_peer_controls",
 	"open_perms",
 	"extended_socket_class",
@@ -546,15 +542,13 @@
 	struct type_datum *target;
 	u32 masked = 0;
 
-	source = flex_array_get_ptr(policydb->type_val_to_struct_array,
-				    scontext->type - 1);
+	source = policydb->type_val_to_struct[scontext->type - 1];
 	BUG_ON(!source);
 
 	if (!source->bounds)
 		return;
 
-	target = flex_array_get_ptr(policydb->type_val_to_struct_array,
-				    tcontext->type - 1);
+	target = policydb->type_val_to_struct[tcontext->type - 1];
 	BUG_ON(!target);
 
 	memset(&lo_avd, 0, sizeof(lo_avd));
@@ -654,12 +648,8 @@
 	 */
 	avkey.target_class = tclass;
 	avkey.specified = AVTAB_AV | AVTAB_XPERMS;
-	sattr = flex_array_get(policydb->type_attr_map_array,
-			       scontext->type - 1);
-	BUG_ON(!sattr);
-	tattr = flex_array_get(policydb->type_attr_map_array,
-			       tcontext->type - 1);
-	BUG_ON(!tattr);
+	sattr = &policydb->type_attr_map_array[scontext->type - 1];
+	tattr = &policydb->type_attr_map_array[tcontext->type - 1];
 	ebitmap_for_each_positive_bit(sattr, snode, i) {
 		ebitmap_for_each_positive_bit(tattr, tnode, j) {
 			avkey.source_type = i + 1;
@@ -776,7 +766,7 @@
 	read_lock(&state->ss->policy_rwlock);
 
 	policydb = &state->ss->policydb;
-	sidtab = &state->ss->sidtab;
+	sidtab = state->ss->sidtab;
 
 	if (!user)
 		tclass = unmap_class(&state->ss->map, orig_tclass);
@@ -876,7 +866,7 @@
 	read_lock(&state->ss->policy_rwlock);
 
 	policydb = &state->ss->policydb;
-	sidtab = &state->ss->sidtab;
+	sidtab = state->ss->sidtab;
 
 	rc = -EINVAL;
 	old_context = sidtab_search(sidtab, old_sid);
@@ -901,8 +891,7 @@
 
 	index = new_context->type;
 	while (true) {
-		type = flex_array_get_ptr(policydb->type_val_to_struct_array,
-					  index - 1);
+		type = policydb->type_val_to_struct[index - 1];
 		BUG_ON(!type);
 
 		/* not bounded anymore */
@@ -1034,7 +1023,7 @@
 		goto allow;
 
 	policydb = &state->ss->policydb;
-	sidtab = &state->ss->sidtab;
+	sidtab = state->ss->sidtab;
 
 	scontext = sidtab_search(sidtab, ssid);
 	if (!scontext) {
@@ -1065,12 +1054,8 @@
 
 	avkey.target_class = tclass;
 	avkey.specified = AVTAB_XPERMS;
-	sattr = flex_array_get(policydb->type_attr_map_array,
-				scontext->type - 1);
-	BUG_ON(!sattr);
-	tattr = flex_array_get(policydb->type_attr_map_array,
-				tcontext->type - 1);
-	BUG_ON(!tattr);
+	sattr = &policydb->type_attr_map_array[scontext->type - 1];
+	tattr = &policydb->type_attr_map_array[tcontext->type - 1];
 	ebitmap_for_each_positive_bit(sattr, snode, i) {
 		ebitmap_for_each_positive_bit(tattr, tnode, j) {
 			avkey.source_type = i + 1;
@@ -1123,7 +1108,7 @@
 		goto allow;
 
 	policydb = &state->ss->policydb;
-	sidtab = &state->ss->sidtab;
+	sidtab = state->ss->sidtab;
 
 	scontext = sidtab_search(sidtab, ssid);
 	if (!scontext) {
@@ -1177,7 +1162,7 @@
 		goto allow;
 
 	policydb = &state->ss->policydb;
-	sidtab = &state->ss->sidtab;
+	sidtab = state->ss->sidtab;
 
 	scontext = sidtab_search(sidtab, ssid);
 	if (!scontext) {
@@ -1281,7 +1266,8 @@
 
 static int security_sid_to_context_core(struct selinux_state *state,
 					u32 sid, char **scontext,
-					u32 *scontext_len, int force)
+					u32 *scontext_len, int force,
+					int only_invalid)
 {
 	struct policydb *policydb;
 	struct sidtab *sidtab;
@@ -1315,7 +1301,7 @@
 	}
 	read_lock(&state->ss->policy_rwlock);
 	policydb = &state->ss->policydb;
-	sidtab = &state->ss->sidtab;
+	sidtab = state->ss->sidtab;
 	if (force)
 		context = sidtab_search_force(sidtab, sid);
 	else
@@ -1326,8 +1312,11 @@
 		rc = -EINVAL;
 		goto out_unlock;
 	}
-	rc = context_struct_to_string(policydb, context, scontext,
-				      scontext_len);
+	if (only_invalid && !context->len)
+		rc = 0;
+	else
+		rc = context_struct_to_string(policydb, context, scontext,
+					      scontext_len);
 out_unlock:
 	read_unlock(&state->ss->policy_rwlock);
 out:
@@ -1349,14 +1338,34 @@
 			    u32 sid, char **scontext, u32 *scontext_len)
 {
 	return security_sid_to_context_core(state, sid, scontext,
-					    scontext_len, 0);
+					    scontext_len, 0, 0);
 }
 
 int security_sid_to_context_force(struct selinux_state *state, u32 sid,
 				  char **scontext, u32 *scontext_len)
 {
 	return security_sid_to_context_core(state, sid, scontext,
-					    scontext_len, 1);
+					    scontext_len, 1, 0);
+}
+
+/**
+ * security_sid_to_context_inval - Obtain a context for a given SID if it
+ *                                 is invalid.
+ * @sid: security identifier, SID
+ * @scontext: security context
+ * @scontext_len: length in bytes
+ *
+ * Write the string representation of the context associated with @sid
+ * into a dynamically allocated string of the correct size, but only if the
+ * context is invalid in the current policy.  Set @scontext to point to
+ * this string (or NULL if the context is valid) and set @scontext_len to
+ * the length of the string (or 0 if the context is valid).
+ */
+int security_sid_to_context_inval(struct selinux_state *state, u32 sid,
+				  char **scontext, u32 *scontext_len)
+{
+	return security_sid_to_context_core(state, sid, scontext,
+					    scontext_len, 1, 1);
 }
 
 /*
@@ -1365,7 +1374,6 @@
 static int string_to_context_struct(struct policydb *pol,
 				    struct sidtab *sidtabp,
 				    char *scontext,
-				    u32 scontext_len,
 				    struct context *ctx,
 				    u32 def_sid)
 {
@@ -1426,15 +1434,12 @@
 
 	ctx->type = typdatum->value;
 
-	rc = mls_context_to_sid(pol, oldc, &p, ctx, sidtabp, def_sid);
+	rc = mls_context_to_sid(pol, oldc, p, ctx, sidtabp, def_sid);
 	if (rc)
 		goto out;
 
-	rc = -EINVAL;
-	if ((p - scontext) < scontext_len)
-		goto out;
-
 	/* Check the validity of the new context. */
+	rc = -EINVAL;
 	if (!policydb_context_isvalid(pol, ctx))
 		goto out;
 	rc = 0;
@@ -1487,9 +1492,9 @@
 	}
 	read_lock(&state->ss->policy_rwlock);
 	policydb = &state->ss->policydb;
-	sidtab = &state->ss->sidtab;
+	sidtab = state->ss->sidtab;
 	rc = string_to_context_struct(policydb, sidtab, scontext2,
-				      scontext_len, &context, def_sid);
+				      &context, def_sid);
 	if (rc == -EINVAL && force) {
 		context.str = str;
 		context.len = strlen(str) + 1;
@@ -1577,6 +1582,7 @@
 	struct policydb *policydb = &state->ss->policydb;
 	char *s = NULL, *t = NULL, *n = NULL;
 	u32 slen, tlen, nlen;
+	struct audit_buffer *ab;
 
 	if (context_struct_to_string(policydb, scontext, &s, &slen))
 		goto out;
@@ -1584,12 +1590,14 @@
 		goto out;
 	if (context_struct_to_string(policydb, newcontext, &n, &nlen))
 		goto out;
-	audit_log(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR,
-		  "op=security_compute_sid invalid_context=%s"
-		  " scontext=%s"
-		  " tcontext=%s"
-		  " tclass=%s",
-		  n, s, t, sym_name(policydb, SYM_CLASSES, tclass-1));
+	ab = audit_log_start(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR);
+	audit_log_format(ab,
+			 "op=security_compute_sid invalid_context=");
+	/* no need to record the NUL with untrusted strings */
+	audit_log_n_untrustedstring(ab, n, nlen - 1);
+	audit_log_format(ab, " scontext=%s tcontext=%s tclass=%s",
+			 s, t, sym_name(policydb, SYM_CLASSES, tclass-1));
+	audit_log_end(ab);
 out:
 	kfree(s);
 	kfree(t);
@@ -1672,7 +1680,7 @@
 	}
 
 	policydb = &state->ss->policydb;
-	sidtab = &state->ss->sidtab;
+	sidtab = state->ss->sidtab;
 
 	scontext = sidtab_search(sidtab, ssid);
 	if (!scontext) {
@@ -1884,19 +1892,6 @@
 				    out_sid, false);
 }
 
-/* Clone the SID into the new SID table. */
-static int clone_sid(u32 sid,
-		     struct context *context,
-		     void *arg)
-{
-	struct sidtab *s = arg;
-
-	if (sid > SECINITSID_NUM)
-		return sidtab_insert(s, sid, context);
-	else
-		return 0;
-}
-
 static inline int convert_context_handle_invalid_context(
 	struct selinux_state *state,
 	struct context *context)
@@ -1924,101 +1919,91 @@
 
 /*
  * Convert the values in the security context
- * structure `c' from the values specified
+ * structure `oldc' from the values specified
  * in the policy `p->oldp' to the values specified
- * in the policy `p->newp'.  Verify that the
- * context is valid under the new policy.
+ * in the policy `p->newp', storing the new context
+ * in `newc'.  Verify that the context is valid
+ * under the new policy.
  */
-static int convert_context(u32 key,
-			   struct context *c,
-			   void *p)
+static int convert_context(struct context *oldc, struct context *newc, void *p)
 {
 	struct convert_context_args *args;
-	struct context oldc;
 	struct ocontext *oc;
-	struct mls_range *range;
 	struct role_datum *role;
 	struct type_datum *typdatum;
 	struct user_datum *usrdatum;
 	char *s;
 	u32 len;
-	int rc = 0;
-
-	if (key <= SECINITSID_NUM)
-		goto out;
+	int rc;
 
 	args = p;
 
-	if (c->str) {
-		struct context ctx;
-
-		rc = -ENOMEM;
-		s = kstrdup(c->str, GFP_KERNEL);
+	if (oldc->str) {
+		s = kstrdup(oldc->str, GFP_KERNEL);
 		if (!s)
-			goto out;
+			return -ENOMEM;
 
 		rc = string_to_context_struct(args->newp, NULL, s,
-					      c->len, &ctx, SECSID_NULL);
+					      newc, SECSID_NULL);
+		if (rc == -EINVAL) {
+			/*
+			 * Retain string representation for later mapping.
+			 *
+			 * IMPORTANT: We need to copy the contents of oldc->str
+			 * back into s again because string_to_context_struct()
+			 * may have garbled it.
+			 */
+			memcpy(s, oldc->str, oldc->len);
+			context_init(newc);
+			newc->str = s;
+			newc->len = oldc->len;
+			return 0;
+		}
 		kfree(s);
-		if (!rc) {
-			pr_info("SELinux:  Context %s became valid (mapped).\n",
-			       c->str);
-			/* Replace string with mapped representation. */
-			kfree(c->str);
-			memcpy(c, &ctx, sizeof(*c));
-			goto out;
-		} else if (rc == -EINVAL) {
-			/* Retain string representation for later mapping. */
-			rc = 0;
-			goto out;
-		} else {
+		if (rc) {
 			/* Other error condition, e.g. ENOMEM. */
 			pr_err("SELinux:   Unable to map context %s, rc = %d.\n",
-			       c->str, -rc);
-			goto out;
+			       oldc->str, -rc);
+			return rc;
 		}
+		pr_info("SELinux:  Context %s became valid (mapped).\n",
+			oldc->str);
+		return 0;
 	}
 
-	rc = context_cpy(&oldc, c);
-	if (rc)
-		goto out;
+	context_init(newc);
 
 	/* Convert the user. */
 	rc = -EINVAL;
 	usrdatum = hashtab_search(args->newp->p_users.table,
-				  sym_name(args->oldp, SYM_USERS, c->user - 1));
+				  sym_name(args->oldp,
+					   SYM_USERS, oldc->user - 1));
 	if (!usrdatum)
 		goto bad;
-	c->user = usrdatum->value;
+	newc->user = usrdatum->value;
 
 	/* Convert the role. */
 	rc = -EINVAL;
 	role = hashtab_search(args->newp->p_roles.table,
-			      sym_name(args->oldp, SYM_ROLES, c->role - 1));
+			      sym_name(args->oldp, SYM_ROLES, oldc->role - 1));
 	if (!role)
 		goto bad;
-	c->role = role->value;
+	newc->role = role->value;
 
 	/* Convert the type. */
 	rc = -EINVAL;
 	typdatum = hashtab_search(args->newp->p_types.table,
-				  sym_name(args->oldp, SYM_TYPES, c->type - 1));
+				  sym_name(args->oldp,
+					   SYM_TYPES, oldc->type - 1));
 	if (!typdatum)
 		goto bad;
-	c->type = typdatum->value;
+	newc->type = typdatum->value;
 
 	/* Convert the MLS fields if dealing with MLS policies */
 	if (args->oldp->mls_enabled && args->newp->mls_enabled) {
-		rc = mls_convert_context(args->oldp, args->newp, c);
+		rc = mls_convert_context(args->oldp, args->newp, oldc, newc);
 		if (rc)
 			goto bad;
-	} else if (args->oldp->mls_enabled && !args->newp->mls_enabled) {
-		/*
-		 * Switching between MLS and non-MLS policy:
-		 * free any storage used by the MLS fields in the
-		 * context for all existing entries in the sidtab.
-		 */
-		mls_context_destroy(c);
 	} else if (!args->oldp->mls_enabled && args->newp->mls_enabled) {
 		/*
 		 * Switching between non-MLS and MLS policy:
@@ -2036,38 +2021,30 @@
 				" the initial SIDs list\n");
 			goto bad;
 		}
-		range = &oc->context[0].range;
-		rc = mls_range_set(c, range);
+		rc = mls_range_set(newc, &oc->context[0].range);
 		if (rc)
 			goto bad;
 	}
 
 	/* Check the validity of the new context. */
-	if (!policydb_context_isvalid(args->newp, c)) {
-		rc = convert_context_handle_invalid_context(args->state,
-							    &oldc);
+	if (!policydb_context_isvalid(args->newp, newc)) {
+		rc = convert_context_handle_invalid_context(args->state, oldc);
 		if (rc)
 			goto bad;
 	}
 
-	context_destroy(&oldc);
-
-	rc = 0;
-out:
-	return rc;
+	return 0;
 bad:
 	/* Map old representation to string and save it. */
-	rc = context_struct_to_string(args->oldp, &oldc, &s, &len);
+	rc = context_struct_to_string(args->oldp, oldc, &s, &len);
 	if (rc)
 		return rc;
-	context_destroy(&oldc);
-	context_destroy(c);
-	c->str = s;
-	c->len = len;
+	context_destroy(newc);
+	newc->str = s;
+	newc->len = len;
 	pr_info("SELinux:  Context %s became invalid (unmapped).\n",
-	       c->str);
-	rc = 0;
-	goto out;
+		newc->str);
+	return 0;
 }
 
 static void security_load_policycaps(struct selinux_state *state)
@@ -2107,11 +2084,11 @@
 int security_load_policy(struct selinux_state *state, void *data, size_t len)
 {
 	struct policydb *policydb;
-	struct sidtab *sidtab;
+	struct sidtab *oldsidtab, *newsidtab;
 	struct policydb *oldpolicydb, *newpolicydb;
-	struct sidtab oldsidtab, newsidtab;
 	struct selinux_mapping *oldmapping;
 	struct selinux_map newmap;
+	struct sidtab_convert_params convert_params;
 	struct convert_context_args args;
 	u32 seqno;
 	int rc = 0;
@@ -2125,27 +2102,37 @@
 	newpolicydb = oldpolicydb + 1;
 
 	policydb = &state->ss->policydb;
-	sidtab = &state->ss->sidtab;
+
+	newsidtab = kmalloc(sizeof(*newsidtab), GFP_KERNEL);
+	if (!newsidtab) {
+		rc = -ENOMEM;
+		goto out;
+	}
 
 	if (!state->initialized) {
 		rc = policydb_read(policydb, fp);
-		if (rc)
+		if (rc) {
+			kfree(newsidtab);
 			goto out;
+		}
 
 		policydb->len = len;
 		rc = selinux_set_mapping(policydb, secclass_map,
 					 &state->ss->map);
 		if (rc) {
+			kfree(newsidtab);
 			policydb_destroy(policydb);
 			goto out;
 		}
 
-		rc = policydb_load_isids(policydb, sidtab);
+		rc = policydb_load_isids(policydb, newsidtab);
 		if (rc) {
+			kfree(newsidtab);
 			policydb_destroy(policydb);
 			goto out;
 		}
 
+		state->ss->sidtab = newsidtab;
 		security_load_policycaps(state);
 		state->initialized = 1;
 		seqno = ++state->ss->latest_granting;
@@ -2158,13 +2145,11 @@
 		goto out;
 	}
 
-#if 0
-	sidtab_hash_eval(sidtab, "sids");
-#endif
-
 	rc = policydb_read(newpolicydb, fp);
-	if (rc)
+	if (rc) {
+		kfree(newsidtab);
 		goto out;
+	}
 
 	newpolicydb->len = len;
 	/* If switching between different policy types, log MLS status */
@@ -2173,10 +2158,11 @@
 	else if (!policydb->mls_enabled && newpolicydb->mls_enabled)
 		pr_info("SELinux: Enabling MLS support...\n");
 
-	rc = policydb_load_isids(newpolicydb, &newsidtab);
+	rc = policydb_load_isids(newpolicydb, newsidtab);
 	if (rc) {
 		pr_err("SELinux:  unable to load the initial SIDs\n");
 		policydb_destroy(newpolicydb);
+		kfree(newsidtab);
 		goto out;
 	}
 
@@ -2190,12 +2176,7 @@
 		goto err;
 	}
 
-	/* Clone the SID table. */
-	sidtab_shutdown(sidtab);
-
-	rc = sidtab_map(sidtab, clone_sid, &newsidtab);
-	if (rc)
-		goto err;
+	oldsidtab = state->ss->sidtab;
 
 	/*
 	 * Convert the internal representations of contexts
@@ -2204,7 +2185,12 @@
 	args.state = state;
 	args.oldp = policydb;
 	args.newp = newpolicydb;
-	rc = sidtab_map(&newsidtab, convert_context, &args);
+
+	convert_params.func = convert_context;
+	convert_params.args = &args;
+	convert_params.target = newsidtab;
+
+	rc = sidtab_convert(oldsidtab, &convert_params);
 	if (rc) {
 		pr_err("SELinux:  unable to convert the internal"
 			" representation of contexts in the new SID"
@@ -2214,12 +2200,11 @@
 
 	/* Save the old policydb and SID table to free later. */
 	memcpy(oldpolicydb, policydb, sizeof(*policydb));
-	sidtab_set(&oldsidtab, sidtab);
 
 	/* Install the new policydb and SID table. */
 	write_lock_irq(&state->ss->policy_rwlock);
 	memcpy(policydb, newpolicydb, sizeof(*policydb));
-	sidtab_set(sidtab, &newsidtab);
+	state->ss->sidtab = newsidtab;
 	security_load_policycaps(state);
 	oldmapping = state->ss->map.mapping;
 	state->ss->map.mapping = newmap.mapping;
@@ -2229,7 +2214,8 @@
 
 	/* Free the old policydb and SID table. */
 	policydb_destroy(oldpolicydb);
-	sidtab_destroy(&oldsidtab);
+	sidtab_destroy(oldsidtab);
+	kfree(oldsidtab);
 	kfree(oldmapping);
 
 	avc_ss_reset(state->avc, seqno);
@@ -2243,7 +2229,8 @@
 
 err:
 	kfree(newmap.mapping);
-	sidtab_destroy(&newsidtab);
+	sidtab_destroy(newsidtab);
+	kfree(newsidtab);
 	policydb_destroy(newpolicydb);
 
 out:
@@ -2280,7 +2267,7 @@
 	read_lock(&state->ss->policy_rwlock);
 
 	policydb = &state->ss->policydb;
-	sidtab = &state->ss->sidtab;
+	sidtab = state->ss->sidtab;
 
 	c = policydb->ocontexts[OCON_PORT];
 	while (c) {
@@ -2326,7 +2313,7 @@
 	read_lock(&state->ss->policy_rwlock);
 
 	policydb = &state->ss->policydb;
-	sidtab = &state->ss->sidtab;
+	sidtab = state->ss->sidtab;
 
 	c = policydb->ocontexts[OCON_IBPKEY];
 	while (c) {
@@ -2372,7 +2359,7 @@
 	read_lock(&state->ss->policy_rwlock);
 
 	policydb = &state->ss->policydb;
-	sidtab = &state->ss->sidtab;
+	sidtab = state->ss->sidtab;
 
 	c = policydb->ocontexts[OCON_IBENDPORT];
 	while (c) {
@@ -2418,7 +2405,7 @@
 	read_lock(&state->ss->policy_rwlock);
 
 	policydb = &state->ss->policydb;
-	sidtab = &state->ss->sidtab;
+	sidtab = state->ss->sidtab;
 
 	c = policydb->ocontexts[OCON_NETIF];
 	while (c) {
@@ -2483,7 +2470,7 @@
 	read_lock(&state->ss->policy_rwlock);
 
 	policydb = &state->ss->policydb;
-	sidtab = &state->ss->sidtab;
+	sidtab = state->ss->sidtab;
 
 	switch (domain) {
 	case AF_INET: {
@@ -2583,7 +2570,7 @@
 	read_lock(&state->ss->policy_rwlock);
 
 	policydb = &state->ss->policydb;
-	sidtab = &state->ss->sidtab;
+	sidtab = state->ss->sidtab;
 
 	context_init(&usercon);
 
@@ -2685,7 +2672,7 @@
 				       u32 *sid)
 {
 	struct policydb *policydb = &state->ss->policydb;
-	struct sidtab *sidtab = &state->ss->sidtab;
+	struct sidtab *sidtab = state->ss->sidtab;
 	int len;
 	u16 sclass;
 	struct genfs *genfs;
@@ -2771,7 +2758,7 @@
 	read_lock(&state->ss->policy_rwlock);
 
 	policydb = &state->ss->policydb;
-	sidtab = &state->ss->sidtab;
+	sidtab = state->ss->sidtab;
 
 	c = policydb->ocontexts[OCON_FSUSE];
 	while (c) {
@@ -2977,7 +2964,7 @@
 			  u32 sid, u32 mls_sid, u32 *new_sid)
 {
 	struct policydb *policydb = &state->ss->policydb;
-	struct sidtab *sidtab = &state->ss->sidtab;
+	struct sidtab *sidtab = state->ss->sidtab;
 	struct context *context1;
 	struct context *context2;
 	struct context newcon;
@@ -3024,10 +3011,16 @@
 		if (rc) {
 			if (!context_struct_to_string(policydb, &newcon, &s,
 						      &len)) {
-				audit_log(audit_context(),
-					  GFP_ATOMIC, AUDIT_SELINUX_ERR,
-					  "op=security_sid_mls_copy "
-					  "invalid_context=%s", s);
+				struct audit_buffer *ab;
+
+				ab = audit_log_start(audit_context(),
+						     GFP_ATOMIC,
+						     AUDIT_SELINUX_ERR);
+				audit_log_format(ab,
+						 "op=security_sid_mls_copy invalid_context=");
+				/* don't record NUL with untrusted strings */
+				audit_log_n_untrustedstring(ab, s, len - 1);
+				audit_log_end(ab);
 				kfree(s);
 			}
 			goto out_unlock;
@@ -3068,7 +3061,7 @@
 				 u32 *peer_sid)
 {
 	struct policydb *policydb = &state->ss->policydb;
-	struct sidtab *sidtab = &state->ss->sidtab;
+	struct sidtab *sidtab = state->ss->sidtab;
 	int rc;
 	struct context *nlbl_ctx;
 	struct context *xfrm_ctx;
@@ -3408,8 +3401,7 @@
 	return 0;
 }
 
-int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
-			     struct audit_context *actx)
+int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule)
 {
 	struct selinux_state *state = &selinux_state;
 	struct context *ctxt;
@@ -3429,7 +3421,7 @@
 		goto out;
 	}
 
-	ctxt = sidtab_search(&state->ss->sidtab, sid);
+	ctxt = sidtab_search(state->ss->sidtab, sid);
 	if (unlikely(!ctxt)) {
 		WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n",
 			  sid);
@@ -3592,7 +3584,7 @@
 				   u32 *sid)
 {
 	struct policydb *policydb = &state->ss->policydb;
-	struct sidtab *sidtab = &state->ss->sidtab;
+	struct sidtab *sidtab = state->ss->sidtab;
 	int rc;
 	struct context *ctx;
 	struct context ctx_new;
@@ -3670,7 +3662,7 @@
 	read_lock(&state->ss->policy_rwlock);
 
 	rc = -ENOENT;
-	ctx = sidtab_search(&state->ss->sidtab, sid);
+	ctx = sidtab_search(state->ss->sidtab, sid);
 	if (ctx == NULL)
 		goto out;
 
diff --git a/security/selinux/ss/services.h b/security/selinux/ss/services.h
index 24c7bdc..9a36de8 100644
--- a/security/selinux/ss/services.h
+++ b/security/selinux/ss/services.h
@@ -24,7 +24,7 @@
 };
 
 struct selinux_ss {
-	struct sidtab sidtab;
+	struct sidtab *sidtab;
 	struct policydb policydb;
 	rwlock_t policy_rwlock;
 	u32 latest_granting;
diff --git a/security/selinux/ss/sidtab.c b/security/selinux/ss/sidtab.c
index fd75a12..7d49994 100644
--- a/security/selinux/ss/sidtab.c
+++ b/security/selinux/ss/sidtab.c
@@ -2,108 +2,162 @@
 /*
  * Implementation of the SID table type.
  *
- * Author : Stephen Smalley, <sds@tycho.nsa.gov>
+ * Original author: Stephen Smalley, <sds@tycho.nsa.gov>
+ * Author: Ondrej Mosnacek, <omosnacek@gmail.com>
+ *
+ * Copyright (C) 2018 Red Hat, Inc.
  */
+#include <linux/errno.h>
 #include <linux/kernel.h>
 #include <linux/slab.h>
+#include <linux/sched.h>
 #include <linux/spinlock.h>
-#include <linux/errno.h>
+#include <asm/barrier.h>
 #include "flask.h"
 #include "security.h"
 #include "sidtab.h"
 
-#define SIDTAB_HASH(sid) \
-(sid & SIDTAB_HASH_MASK)
-
 int sidtab_init(struct sidtab *s)
 {
-	int i;
+	u32 i;
 
-	s->htable = kmalloc_array(SIDTAB_SIZE, sizeof(*s->htable), GFP_ATOMIC);
-	if (!s->htable)
-		return -ENOMEM;
-	for (i = 0; i < SIDTAB_SIZE; i++)
-		s->htable[i] = NULL;
-	s->nel = 0;
-	s->next_sid = 1;
-	s->shutdown = 0;
+	memset(s->roots, 0, sizeof(s->roots));
+
+	/* max count is SIDTAB_MAX so valid index is always < SIDTAB_MAX */
+	for (i = 0; i < SIDTAB_RCACHE_SIZE; i++)
+		s->rcache[i] = SIDTAB_MAX;
+
+	for (i = 0; i < SECINITSID_NUM; i++)
+		s->isids[i].set = 0;
+
+	s->count = 0;
+	s->convert = NULL;
+
 	spin_lock_init(&s->lock);
 	return 0;
 }
 
-int sidtab_insert(struct sidtab *s, u32 sid, struct context *context)
+int sidtab_set_initial(struct sidtab *s, u32 sid, struct context *context)
 {
-	int hvalue;
-	struct sidtab_node *prev, *cur, *newnode;
+	struct sidtab_isid_entry *entry;
+	int rc;
 
-	if (!s)
-		return -ENOMEM;
+	if (sid == 0 || sid > SECINITSID_NUM)
+		return -EINVAL;
 
-	hvalue = SIDTAB_HASH(sid);
-	prev = NULL;
-	cur = s->htable[hvalue];
-	while (cur && sid > cur->sid) {
-		prev = cur;
-		cur = cur->next;
-	}
+	entry = &s->isids[sid - 1];
 
-	if (cur && sid == cur->sid)
-		return -EEXIST;
+	rc = context_cpy(&entry->context, context);
+	if (rc)
+		return rc;
 
-	newnode = kmalloc(sizeof(*newnode), GFP_ATOMIC);
-	if (!newnode)
-		return -ENOMEM;
-
-	newnode->sid = sid;
-	if (context_cpy(&newnode->context, context)) {
-		kfree(newnode);
-		return -ENOMEM;
-	}
-
-	if (prev) {
-		newnode->next = prev->next;
-		wmb();
-		prev->next = newnode;
-	} else {
-		newnode->next = s->htable[hvalue];
-		wmb();
-		s->htable[hvalue] = newnode;
-	}
-
-	s->nel++;
-	if (sid >= s->next_sid)
-		s->next_sid = sid + 1;
+	entry->set = 1;
 	return 0;
 }
 
+static u32 sidtab_level_from_count(u32 count)
+{
+	u32 capacity = SIDTAB_LEAF_ENTRIES;
+	u32 level = 0;
+
+	while (count > capacity) {
+		capacity <<= SIDTAB_INNER_SHIFT;
+		++level;
+	}
+	return level;
+}
+
+static int sidtab_alloc_roots(struct sidtab *s, u32 level)
+{
+	u32 l;
+
+	if (!s->roots[0].ptr_leaf) {
+		s->roots[0].ptr_leaf = kzalloc(SIDTAB_NODE_ALLOC_SIZE,
+					       GFP_ATOMIC);
+		if (!s->roots[0].ptr_leaf)
+			return -ENOMEM;
+	}
+	for (l = 1; l <= level; ++l)
+		if (!s->roots[l].ptr_inner) {
+			s->roots[l].ptr_inner = kzalloc(SIDTAB_NODE_ALLOC_SIZE,
+							GFP_ATOMIC);
+			if (!s->roots[l].ptr_inner)
+				return -ENOMEM;
+			s->roots[l].ptr_inner->entries[0] = s->roots[l - 1];
+		}
+	return 0;
+}
+
+static struct context *sidtab_do_lookup(struct sidtab *s, u32 index, int alloc)
+{
+	union sidtab_entry_inner *entry;
+	u32 level, capacity_shift, leaf_index = index / SIDTAB_LEAF_ENTRIES;
+
+	/* find the level of the subtree we need */
+	level = sidtab_level_from_count(index + 1);
+	capacity_shift = level * SIDTAB_INNER_SHIFT;
+
+	/* allocate roots if needed */
+	if (alloc && sidtab_alloc_roots(s, level) != 0)
+		return NULL;
+
+	/* lookup inside the subtree */
+	entry = &s->roots[level];
+	while (level != 0) {
+		capacity_shift -= SIDTAB_INNER_SHIFT;
+		--level;
+
+		entry = &entry->ptr_inner->entries[leaf_index >> capacity_shift];
+		leaf_index &= ((u32)1 << capacity_shift) - 1;
+
+		if (!entry->ptr_inner) {
+			if (alloc)
+				entry->ptr_inner = kzalloc(SIDTAB_NODE_ALLOC_SIZE,
+							   GFP_ATOMIC);
+			if (!entry->ptr_inner)
+				return NULL;
+		}
+	}
+	if (!entry->ptr_leaf) {
+		if (alloc)
+			entry->ptr_leaf = kzalloc(SIDTAB_NODE_ALLOC_SIZE,
+						  GFP_ATOMIC);
+		if (!entry->ptr_leaf)
+			return NULL;
+	}
+	return &entry->ptr_leaf->entries[index % SIDTAB_LEAF_ENTRIES].context;
+}
+
+static struct context *sidtab_lookup(struct sidtab *s, u32 index)
+{
+	/* read entries only after reading count */
+	u32 count = smp_load_acquire(&s->count);
+
+	if (index >= count)
+		return NULL;
+
+	return sidtab_do_lookup(s, index, 0);
+}
+
+static struct context *sidtab_lookup_initial(struct sidtab *s, u32 sid)
+{
+	return s->isids[sid - 1].set ? &s->isids[sid - 1].context : NULL;
+}
+
 static struct context *sidtab_search_core(struct sidtab *s, u32 sid, int force)
 {
-	int hvalue;
-	struct sidtab_node *cur;
+	struct context *context;
 
-	if (!s)
-		return NULL;
-
-	hvalue = SIDTAB_HASH(sid);
-	cur = s->htable[hvalue];
-	while (cur && sid > cur->sid)
-		cur = cur->next;
-
-	if (force && cur && sid == cur->sid && cur->context.len)
-		return &cur->context;
-
-	if (!cur || sid != cur->sid || cur->context.len) {
-		/* Remap invalid SIDs to the unlabeled SID. */
-		sid = SECINITSID_UNLABELED;
-		hvalue = SIDTAB_HASH(sid);
-		cur = s->htable[hvalue];
-		while (cur && sid > cur->sid)
-			cur = cur->next;
-		if (!cur || sid != cur->sid)
-			return NULL;
+	if (sid != 0) {
+		if (sid > SECINITSID_NUM)
+			context = sidtab_lookup(s, sid - (SECINITSID_NUM + 1));
+		else
+			context = sidtab_lookup_initial(s, sid);
+		if (context && (!context->len || force))
+			return context;
 	}
 
-	return &cur->context;
+	return sidtab_lookup_initial(s, SECINITSID_UNLABELED);
 }
 
 struct context *sidtab_search(struct sidtab *s, u32 sid)
@@ -116,191 +170,325 @@
 	return sidtab_search_core(s, sid, 1);
 }
 
-int sidtab_map(struct sidtab *s,
-	       int (*apply) (u32 sid,
-			     struct context *context,
-			     void *args),
-	       void *args)
+static int sidtab_find_context(union sidtab_entry_inner entry,
+			       u32 *pos, u32 count, u32 level,
+			       struct context *context, u32 *index)
 {
-	int i, rc = 0;
-	struct sidtab_node *cur;
+	int rc;
+	u32 i;
 
-	if (!s)
-		goto out;
+	if (level != 0) {
+		struct sidtab_node_inner *node = entry.ptr_inner;
 
-	for (i = 0; i < SIDTAB_SIZE; i++) {
-		cur = s->htable[i];
-		while (cur) {
-			rc = apply(cur->sid, &cur->context, args);
-			if (rc)
-				goto out;
-			cur = cur->next;
+		i = 0;
+		while (i < SIDTAB_INNER_ENTRIES && *pos < count) {
+			rc = sidtab_find_context(node->entries[i],
+						 pos, count, level - 1,
+						 context, index);
+			if (rc == 0)
+				return 0;
+			i++;
+		}
+	} else {
+		struct sidtab_node_leaf *node = entry.ptr_leaf;
+
+		i = 0;
+		while (i < SIDTAB_LEAF_ENTRIES && *pos < count) {
+			if (context_cmp(&node->entries[i].context, context)) {
+				*index = *pos;
+				return 0;
+			}
+			(*pos)++;
+			i++;
 		}
 	}
-out:
+	return -ENOENT;
+}
+
+static void sidtab_rcache_update(struct sidtab *s, u32 index, u32 pos)
+{
+	while (pos > 0) {
+		WRITE_ONCE(s->rcache[pos], READ_ONCE(s->rcache[pos - 1]));
+		--pos;
+	}
+	WRITE_ONCE(s->rcache[0], index);
+}
+
+static void sidtab_rcache_push(struct sidtab *s, u32 index)
+{
+	sidtab_rcache_update(s, index, SIDTAB_RCACHE_SIZE - 1);
+}
+
+static int sidtab_rcache_search(struct sidtab *s, struct context *context,
+				u32 *index)
+{
+	u32 i;
+
+	for (i = 0; i < SIDTAB_RCACHE_SIZE; i++) {
+		u32 v = READ_ONCE(s->rcache[i]);
+
+		if (v >= SIDTAB_MAX)
+			continue;
+
+		if (context_cmp(sidtab_do_lookup(s, v, 0), context)) {
+			sidtab_rcache_update(s, v, i);
+			*index = v;
+			return 0;
+		}
+	}
+	return -ENOENT;
+}
+
+static int sidtab_reverse_lookup(struct sidtab *s, struct context *context,
+				 u32 *index)
+{
+	unsigned long flags;
+	u32 count, count_locked, level, pos;
+	struct sidtab_convert_params *convert;
+	struct context *dst, *dst_convert;
+	int rc;
+
+	rc = sidtab_rcache_search(s, context, index);
+	if (rc == 0)
+		return 0;
+
+	/* read entries only after reading count */
+	count = smp_load_acquire(&s->count);
+	level = sidtab_level_from_count(count);
+
+	pos = 0;
+	rc = sidtab_find_context(s->roots[level], &pos, count, level,
+				 context, index);
+	if (rc == 0) {
+		sidtab_rcache_push(s, *index);
+		return 0;
+	}
+
+	/* lock-free search failed: lock, re-search, and insert if not found */
+	spin_lock_irqsave(&s->lock, flags);
+
+	convert = s->convert;
+	count_locked = s->count;
+	level = sidtab_level_from_count(count_locked);
+
+	/* if count has changed before we acquired the lock, then catch up */
+	while (count < count_locked) {
+		if (context_cmp(sidtab_do_lookup(s, count, 0), context)) {
+			sidtab_rcache_push(s, count);
+			*index = count;
+			rc = 0;
+			goto out_unlock;
+		}
+		++count;
+	}
+
+	/* bail out if we already reached max entries */
+	rc = -EOVERFLOW;
+	if (count >= SIDTAB_MAX)
+		goto out_unlock;
+
+	/* insert context into new entry */
+	rc = -ENOMEM;
+	dst = sidtab_do_lookup(s, count, 1);
+	if (!dst)
+		goto out_unlock;
+
+	rc = context_cpy(dst, context);
+	if (rc)
+		goto out_unlock;
+
+	/*
+	 * if we are building a new sidtab, we need to convert the context
+	 * and insert it there as well
+	 */
+	if (convert) {
+		rc = -ENOMEM;
+		dst_convert = sidtab_do_lookup(convert->target, count, 1);
+		if (!dst_convert) {
+			context_destroy(dst);
+			goto out_unlock;
+		}
+
+		rc = convert->func(context, dst_convert, convert->args);
+		if (rc) {
+			context_destroy(dst);
+			goto out_unlock;
+		}
+
+		/* at this point we know the insert won't fail */
+		convert->target->count = count + 1;
+	}
+
+	if (context->len)
+		pr_info("SELinux:  Context %s is not valid (left unmapped).\n",
+			context->str);
+
+	sidtab_rcache_push(s, count);
+	*index = count;
+
+	/* write entries before writing new count */
+	smp_store_release(&s->count, count + 1);
+
+	rc = 0;
+out_unlock:
+	spin_unlock_irqrestore(&s->lock, flags);
 	return rc;
 }
 
-static void sidtab_update_cache(struct sidtab *s, struct sidtab_node *n, int loc)
+int sidtab_context_to_sid(struct sidtab *s, struct context *context, u32 *sid)
 {
-	BUG_ON(loc >= SIDTAB_CACHE_LEN);
+	int rc;
+	u32 i;
 
-	while (loc > 0) {
-		s->cache[loc] = s->cache[loc - 1];
-		loc--;
-	}
-	s->cache[0] = n;
-}
+	for (i = 0; i < SECINITSID_NUM; i++) {
+		struct sidtab_isid_entry *entry = &s->isids[i];
 
-static inline u32 sidtab_search_context(struct sidtab *s,
-						  struct context *context)
-{
-	int i;
-	struct sidtab_node *cur;
-
-	for (i = 0; i < SIDTAB_SIZE; i++) {
-		cur = s->htable[i];
-		while (cur) {
-			if (context_cmp(&cur->context, context)) {
-				sidtab_update_cache(s, cur, SIDTAB_CACHE_LEN - 1);
-				return cur->sid;
-			}
-			cur = cur->next;
-		}
-	}
-	return 0;
-}
-
-static inline u32 sidtab_search_cache(struct sidtab *s, struct context *context)
-{
-	int i;
-	struct sidtab_node *node;
-
-	for (i = 0; i < SIDTAB_CACHE_LEN; i++) {
-		node = s->cache[i];
-		if (unlikely(!node))
+		if (entry->set && context_cmp(context, &entry->context)) {
+			*sid = i + 1;
 			return 0;
-		if (context_cmp(&node->context, context)) {
-			sidtab_update_cache(s, node, i);
-			return node->sid;
 		}
 	}
+
+	rc = sidtab_reverse_lookup(s, context, sid);
+	if (rc)
+		return rc;
+	*sid += SECINITSID_NUM + 1;
+	return 0;
+}
+
+static int sidtab_convert_tree(union sidtab_entry_inner *edst,
+			       union sidtab_entry_inner *esrc,
+			       u32 *pos, u32 count, u32 level,
+			       struct sidtab_convert_params *convert)
+{
+	int rc;
+	u32 i;
+
+	if (level != 0) {
+		if (!edst->ptr_inner) {
+			edst->ptr_inner = kzalloc(SIDTAB_NODE_ALLOC_SIZE,
+						  GFP_KERNEL);
+			if (!edst->ptr_inner)
+				return -ENOMEM;
+		}
+		i = 0;
+		while (i < SIDTAB_INNER_ENTRIES && *pos < count) {
+			rc = sidtab_convert_tree(&edst->ptr_inner->entries[i],
+						 &esrc->ptr_inner->entries[i],
+						 pos, count, level - 1,
+						 convert);
+			if (rc)
+				return rc;
+			i++;
+		}
+	} else {
+		if (!edst->ptr_leaf) {
+			edst->ptr_leaf = kzalloc(SIDTAB_NODE_ALLOC_SIZE,
+						 GFP_KERNEL);
+			if (!edst->ptr_leaf)
+				return -ENOMEM;
+		}
+		i = 0;
+		while (i < SIDTAB_LEAF_ENTRIES && *pos < count) {
+			rc = convert->func(&esrc->ptr_leaf->entries[i].context,
+					   &edst->ptr_leaf->entries[i].context,
+					   convert->args);
+			if (rc)
+				return rc;
+			(*pos)++;
+			i++;
+		}
+		cond_resched();
+	}
 	return 0;
 }
 
-int sidtab_context_to_sid(struct sidtab *s,
-			  struct context *context,
-			  u32 *out_sid)
+int sidtab_convert(struct sidtab *s, struct sidtab_convert_params *params)
 {
-	u32 sid;
-	int ret = 0;
 	unsigned long flags;
+	u32 count, level, pos;
+	int rc;
 
-	*out_sid = SECSID_NULL;
+	spin_lock_irqsave(&s->lock, flags);
 
-	sid  = sidtab_search_cache(s, context);
-	if (!sid)
-		sid = sidtab_search_context(s, context);
-	if (!sid) {
+	/* concurrent policy loads are not allowed */
+	if (s->convert) {
+		spin_unlock_irqrestore(&s->lock, flags);
+		return -EBUSY;
+	}
+
+	count = s->count;
+	level = sidtab_level_from_count(count);
+
+	/* allocate last leaf in the new sidtab (to avoid race with
+	 * live convert)
+	 */
+	rc = sidtab_do_lookup(params->target, count - 1, 1) ? 0 : -ENOMEM;
+	if (rc) {
+		spin_unlock_irqrestore(&s->lock, flags);
+		return rc;
+	}
+
+	/* set count in case no new entries are added during conversion */
+	params->target->count = count;
+
+	/* enable live convert of new entries */
+	s->convert = params;
+
+	/* we can safely do the rest of the conversion outside the lock */
+	spin_unlock_irqrestore(&s->lock, flags);
+
+	pr_info("SELinux:  Converting %u SID table entries...\n", count);
+
+	/* convert all entries not covered by live convert */
+	pos = 0;
+	rc = sidtab_convert_tree(&params->target->roots[level],
+				 &s->roots[level], &pos, count, level, params);
+	if (rc) {
+		/* we need to keep the old table - disable live convert */
 		spin_lock_irqsave(&s->lock, flags);
-		/* Rescan now that we hold the lock. */
-		sid = sidtab_search_context(s, context);
-		if (sid)
-			goto unlock_out;
-		/* No SID exists for the context.  Allocate a new one. */
-		if (s->next_sid == UINT_MAX || s->shutdown) {
-			ret = -ENOMEM;
-			goto unlock_out;
-		}
-		sid = s->next_sid++;
-		if (context->len)
-			pr_info("SELinux:  Context %s is not valid (left unmapped).\n",
-			       context->str);
-		ret = sidtab_insert(s, sid, context);
-		if (ret)
-			s->next_sid--;
-unlock_out:
+		s->convert = NULL;
 		spin_unlock_irqrestore(&s->lock, flags);
 	}
-
-	if (ret)
-		return ret;
-
-	*out_sid = sid;
-	return 0;
+	return rc;
 }
 
-void sidtab_hash_eval(struct sidtab *h, char *tag)
+static void sidtab_destroy_tree(union sidtab_entry_inner entry, u32 level)
 {
-	int i, chain_len, slots_used, max_chain_len;
-	struct sidtab_node *cur;
+	u32 i;
 
-	slots_used = 0;
-	max_chain_len = 0;
-	for (i = 0; i < SIDTAB_SIZE; i++) {
-		cur = h->htable[i];
-		if (cur) {
-			slots_used++;
-			chain_len = 0;
-			while (cur) {
-				chain_len++;
-				cur = cur->next;
-			}
+	if (level != 0) {
+		struct sidtab_node_inner *node = entry.ptr_inner;
 
-			if (chain_len > max_chain_len)
-				max_chain_len = chain_len;
-		}
+		if (!node)
+			return;
+
+		for (i = 0; i < SIDTAB_INNER_ENTRIES; i++)
+			sidtab_destroy_tree(node->entries[i], level - 1);
+		kfree(node);
+	} else {
+		struct sidtab_node_leaf *node = entry.ptr_leaf;
+
+		if (!node)
+			return;
+
+		for (i = 0; i < SIDTAB_LEAF_ENTRIES; i++)
+			context_destroy(&node->entries[i].context);
+		kfree(node);
 	}
-
-	pr_debug("%s:  %d entries and %d/%d buckets used, longest "
-	       "chain length %d\n", tag, h->nel, slots_used, SIDTAB_SIZE,
-	       max_chain_len);
 }
 
 void sidtab_destroy(struct sidtab *s)
 {
-	int i;
-	struct sidtab_node *cur, *temp;
+	u32 i, level;
 
-	if (!s)
-		return;
+	for (i = 0; i < SECINITSID_NUM; i++)
+		if (s->isids[i].set)
+			context_destroy(&s->isids[i].context);
 
-	for (i = 0; i < SIDTAB_SIZE; i++) {
-		cur = s->htable[i];
-		while (cur) {
-			temp = cur;
-			cur = cur->next;
-			context_destroy(&temp->context);
-			kfree(temp);
-		}
-		s->htable[i] = NULL;
-	}
-	kfree(s->htable);
-	s->htable = NULL;
-	s->nel = 0;
-	s->next_sid = 1;
-}
+	level = SIDTAB_MAX_LEVEL;
+	while (level && !s->roots[level].ptr_inner)
+		--level;
 
-void sidtab_set(struct sidtab *dst, struct sidtab *src)
-{
-	unsigned long flags;
-	int i;
-
-	spin_lock_irqsave(&src->lock, flags);
-	dst->htable = src->htable;
-	dst->nel = src->nel;
-	dst->next_sid = src->next_sid;
-	dst->shutdown = 0;
-	for (i = 0; i < SIDTAB_CACHE_LEN; i++)
-		dst->cache[i] = NULL;
-	spin_unlock_irqrestore(&src->lock, flags);
-}
-
-void sidtab_shutdown(struct sidtab *s)
-{
-	unsigned long flags;
-
-	spin_lock_irqsave(&s->lock, flags);
-	s->shutdown = 1;
-	spin_unlock_irqrestore(&s->lock, flags);
+	sidtab_destroy_tree(s->roots[level], level);
 }
diff --git a/security/selinux/ss/sidtab.h b/security/selinux/ss/sidtab.h
index a1a1d26..1f47631 100644
--- a/security/selinux/ss/sidtab.h
+++ b/security/selinux/ss/sidtab.h
@@ -1,56 +1,105 @@
 /* SPDX-License-Identifier: GPL-2.0 */
 /*
- * A security identifier table (sidtab) is a hash table
+ * A security identifier table (sidtab) is a lookup table
  * of security context structures indexed by SID value.
  *
- * Author : Stephen Smalley, <sds@tycho.nsa.gov>
+ * Original author: Stephen Smalley, <sds@tycho.nsa.gov>
+ * Author: Ondrej Mosnacek, <omosnacek@gmail.com>
+ *
+ * Copyright (C) 2018 Red Hat, Inc.
  */
 #ifndef _SS_SIDTAB_H_
 #define _SS_SIDTAB_H_
 
+#include <linux/spinlock_types.h>
+#include <linux/log2.h>
+
 #include "context.h"
 
-struct sidtab_node {
-	u32 sid;		/* security identifier */
-	struct context context;	/* security context structure */
-	struct sidtab_node *next;
+struct sidtab_entry_leaf {
+	struct context context;
 };
 
-#define SIDTAB_HASH_BITS 7
-#define SIDTAB_HASH_BUCKETS (1 << SIDTAB_HASH_BITS)
-#define SIDTAB_HASH_MASK (SIDTAB_HASH_BUCKETS-1)
+struct sidtab_node_inner;
+struct sidtab_node_leaf;
 
-#define SIDTAB_SIZE SIDTAB_HASH_BUCKETS
+union sidtab_entry_inner {
+	struct sidtab_node_inner *ptr_inner;
+	struct sidtab_node_leaf  *ptr_leaf;
+};
+
+/* align node size to page boundary */
+#define SIDTAB_NODE_ALLOC_SHIFT PAGE_SHIFT
+#define SIDTAB_NODE_ALLOC_SIZE  PAGE_SIZE
+
+#define size_to_shift(size) ((size) == 1 ? 1 : (const_ilog2((size) - 1) + 1))
+
+#define SIDTAB_INNER_SHIFT \
+	(SIDTAB_NODE_ALLOC_SHIFT - size_to_shift(sizeof(union sidtab_entry_inner)))
+#define SIDTAB_INNER_ENTRIES ((size_t)1 << SIDTAB_INNER_SHIFT)
+#define SIDTAB_LEAF_ENTRIES \
+	(SIDTAB_NODE_ALLOC_SIZE / sizeof(struct sidtab_entry_leaf))
+
+#define SIDTAB_MAX_BITS 32
+#define SIDTAB_MAX U32_MAX
+/* ensure enough tree levels for SIDTAB_MAX entries */
+#define SIDTAB_MAX_LEVEL \
+	DIV_ROUND_UP(SIDTAB_MAX_BITS - size_to_shift(SIDTAB_LEAF_ENTRIES), \
+		     SIDTAB_INNER_SHIFT)
+
+struct sidtab_node_leaf {
+	struct sidtab_entry_leaf entries[SIDTAB_LEAF_ENTRIES];
+};
+
+struct sidtab_node_inner {
+	union sidtab_entry_inner entries[SIDTAB_INNER_ENTRIES];
+};
+
+struct sidtab_isid_entry {
+	int set;
+	struct context context;
+};
+
+struct sidtab_convert_params {
+	int (*func)(struct context *oldc, struct context *newc, void *args);
+	void *args;
+	struct sidtab *target;
+};
+
+#define SIDTAB_RCACHE_SIZE 3
 
 struct sidtab {
-	struct sidtab_node **htable;
-	unsigned int nel;	/* number of elements */
-	unsigned int next_sid;	/* next SID to allocate */
-	unsigned char shutdown;
-#define SIDTAB_CACHE_LEN	3
-	struct sidtab_node *cache[SIDTAB_CACHE_LEN];
+	/*
+	 * lock-free read access only for as many items as a prior read of
+	 * 'count'
+	 */
+	union sidtab_entry_inner roots[SIDTAB_MAX_LEVEL + 1];
+	/*
+	 * access atomically via {READ|WRITE}_ONCE(); only increment under
+	 * spinlock
+	 */
+	u32 count;
+	/* access only under spinlock */
+	struct sidtab_convert_params *convert;
 	spinlock_t lock;
+
+	/* reverse lookup cache - access atomically via {READ|WRITE}_ONCE() */
+	u32 rcache[SIDTAB_RCACHE_SIZE];
+
+	/* index == SID - 1 (no entry for SECSID_NULL) */
+	struct sidtab_isid_entry isids[SECINITSID_NUM];
 };
 
 int sidtab_init(struct sidtab *s);
-int sidtab_insert(struct sidtab *s, u32 sid, struct context *context);
+int sidtab_set_initial(struct sidtab *s, u32 sid, struct context *context);
 struct context *sidtab_search(struct sidtab *s, u32 sid);
 struct context *sidtab_search_force(struct sidtab *s, u32 sid);
 
-int sidtab_map(struct sidtab *s,
-	       int (*apply) (u32 sid,
-			     struct context *context,
-			     void *args),
-	       void *args);
+int sidtab_convert(struct sidtab *s, struct sidtab_convert_params *params);
 
-int sidtab_context_to_sid(struct sidtab *s,
-			  struct context *context,
-			  u32 *sid);
+int sidtab_context_to_sid(struct sidtab *s, struct context *context, u32 *sid);
 
-void sidtab_hash_eval(struct sidtab *h, char *tag);
 void sidtab_destroy(struct sidtab *s);
-void sidtab_set(struct sidtab *dst, struct sidtab *src);
-void sidtab_shutdown(struct sidtab *s);
 
 #endif	/* _SS_SIDTAB_H_ */
 
diff --git a/security/selinux/ss/status.c b/security/selinux/ss/status.c
index a121de4..3c554a4 100644
--- a/security/selinux/ss/status.c
+++ b/security/selinux/ss/status.c
@@ -1,13 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * mmap based event notifications for SELinux
  *
  * Author: KaiGai Kohei <kaigai@ak.jp.nec.com>
  *
  * Copyright (C) 2010 NEC corporation
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2,
- * as published by the Free Software Foundation.
  */
 #include <linux/kernel.h>
 #include <linux/gfp.h>