Merge branch 'next' into for-linus

7 files changed, 266 insertions, 213 deletions

diff --git a/security/selinux/ss/context.h b/security/selinux/ss/context.h
index d9dd7a2f6a8a..45e8fb0515f8 100644
--- a/security/selinux/ss/context.h
+++ b/security/selinux/ss/context.h
@@ -41,9 +41,6 @@ static inline int mls_context_cpy(struct context *dst, struct context *src)
 {
         int rc;
 
-        if (!selinux_mls_enabled)
-                return 0;
-
         dst->range.level[0].sens = src->range.level[0].sens;
         rc = ebitmap_cpy(&dst->range.level[0].cat, &src->range.level[0].cat);
         if (rc)
@@ -64,9 +61,6 @@ static inline int mls_context_cpy_low(struct context *dst, struct context *src)
 {
         int rc;
 
-        if (!selinux_mls_enabled)
-                return 0;
-
         dst->range.level[0].sens = src->range.level[0].sens;
         rc = ebitmap_cpy(&dst->range.level[0].cat, &src->range.level[0].cat);
         if (rc)
@@ -82,9 +76,6 @@ out:
 
 static inline int mls_context_cmp(struct context *c1, struct context *c2)
 {
-        if (!selinux_mls_enabled)
-                return 1;
-
         return ((c1->range.level[0].sens == c2->range.level[0].sens) &&
                 ebitmap_cmp(&c1->range.level[0].cat, &c2->range.level[0].cat) &&
                 (c1->range.level[1].sens == c2->range.level[1].sens) &&
@@ -93,9 +84,6 @@ static inline int mls_context_cmp(struct context *c1, struct context *c2)
 
 static inline void mls_context_destroy(struct context *c)
 {
-        if (!selinux_mls_enabled)
-                return;
-
         ebitmap_destroy(&c->range.level[0].cat);
         ebitmap_destroy(&c->range.level[1].cat);
         mls_context_init(c);
diff --git a/security/selinux/ss/mls.c b/security/selinux/ss/mls.c
index 3f2b2706b5bb..372b773f8210 100644
--- a/security/selinux/ss/mls.c
+++ b/security/selinux/ss/mls.c
@@ -39,7 +39,7 @@ int mls_compute_context_len(struct context *context)
         struct ebitmap *e;
         struct ebitmap_node *node;
 
-        if (!selinux_mls_enabled)
+        if (!policydb.mls_enabled)
                 return 0;
 
         len = 1; /* for the beginning ":" */
@@ -93,7 +93,7 @@ void mls_sid_to_context(struct context *context,
         struct ebitmap *e;
         struct ebitmap_node *node;
 
-        if (!selinux_mls_enabled)
+        if (!policydb.mls_enabled)
                 return;
 
         scontextp = *scontext;
@@ -200,7 +200,7 @@ int mls_context_isvalid(struct policydb *p, struct context *c)
 {
         struct user_datum *usrdatum;
 
-        if (!selinux_mls_enabled)
+        if (!p->mls_enabled)
                 return 1;
 
         if (!mls_range_isvalid(p, &c->range))
@@ -253,7 +253,7 @@ int mls_context_to_sid(struct policydb *pol,
         struct cat_datum *catdatum, *rngdatum;
         int l, rc = -EINVAL;
 
-        if (!selinux_mls_enabled) {
+        if (!pol->mls_enabled) {
                 if (def_sid != SECSID_NULL && oldc)
                         *scontext += strlen(*scontext)+1;
                 return 0;
@@ -387,7 +387,7 @@ int mls_from_string(char *str, struct context *context, gfp_t gfp_mask)
         char *tmpstr, *freestr;
         int rc;
 
-        if (!selinux_mls_enabled)
+        if (!policydb.mls_enabled)
                 return -EINVAL;
 
         /* we need freestr because mls_context_to_sid will change
@@ -407,7 +407,7 @@ int mls_from_string(char *str, struct context *context, gfp_t gfp_mask)
 /*
  * Copies the MLS range `range' into `context'.
  */
-static inline int mls_range_set(struct context *context,
+int mls_range_set(struct context *context,
                                 struct mls_range *range)
 {
         int l, rc = 0;
@@ -427,7 +427,7 @@ static inline int mls_range_set(struct context *context,
 int mls_setup_user_range(struct context *fromcon, struct user_datum *user,
                          struct context *usercon)
 {
-        if (selinux_mls_enabled) {
+        if (policydb.mls_enabled) {
                 struct mls_level *fromcon_sen = &(fromcon->range.level[0]);
                 struct mls_level *fromcon_clr = &(fromcon->range.level[1]);
                 struct mls_level *user_low = &(user->range.level[0]);
@@ -477,7 +477,7 @@ int mls_convert_context(struct policydb *oldp,
         struct ebitmap_node *node;
         int l, i;
 
-        if (!selinux_mls_enabled)
+        if (!policydb.mls_enabled)
                 return 0;
 
         for (l = 0; l < 2; l++) {
@@ -513,23 +513,21 @@ int mls_compute_sid(struct context *scontext,
                     u32 specified,
                     struct context *newcontext)
 {
-        struct range_trans *rtr;
+        struct range_trans rtr;
+        struct mls_range *r;
 
-        if (!selinux_mls_enabled)
+        if (!policydb.mls_enabled)
                 return 0;
 
         switch (specified) {
         case AVTAB_TRANSITION:
                 /* Look for a range transition rule. */
-                for (rtr = policydb.range_tr; rtr; rtr = rtr->next) {
-                        if (rtr->source_type == scontext->type &&
-                            rtr->target_type == tcontext->type &&
-                            rtr->target_class == tclass) {
-                                /* Set the range from the rule */
-                                return mls_range_set(newcontext,
-                                                     &rtr->target_range);
-                        }
-                }
+                rtr.source_type = scontext->type;
+                rtr.target_type = tcontext->type;
+                rtr.target_class = tclass;
+                r = hashtab_search(policydb.range_tr, &rtr);
+                if (r)
+                        return mls_range_set(newcontext, r);
                 /* Fallthrough */
         case AVTAB_CHANGE:
                 if (tclass == policydb.process_class)
@@ -541,8 +539,8 @@ int mls_compute_sid(struct context *scontext,
         case AVTAB_MEMBER:
                 /* Use the process effective MLS attributes. */
                 return mls_context_cpy_low(newcontext, scontext);
-        default:
-                return -EINVAL;
+
+        /* fall through */
         }
         return -EINVAL;
 }
@@ -561,7 +559,7 @@ int mls_compute_sid(struct context *scontext,
 void mls_export_netlbl_lvl(struct context *context,
                            struct netlbl_lsm_secattr *secattr)
 {
-        if (!selinux_mls_enabled)
+        if (!policydb.mls_enabled)
                 return;
 
         secattr->attr.mls.lvl = context->range.level[0].sens - 1;
@@ -581,7 +579,7 @@ void mls_export_netlbl_lvl(struct context *context,
 void mls_import_netlbl_lvl(struct context *context,
                            struct netlbl_lsm_secattr *secattr)
 {
-        if (!selinux_mls_enabled)
+        if (!policydb.mls_enabled)
                 return;
 
         context->range.level[0].sens = secattr->attr.mls.lvl + 1;
@@ -603,7 +601,7 @@ int mls_export_netlbl_cat(struct context *context,
 {
         int rc;
 
-        if (!selinux_mls_enabled)
+        if (!policydb.mls_enabled)
                 return 0;
 
         rc = ebitmap_netlbl_export(&context->range.level[0].cat,
@@ -631,7 +629,7 @@ int mls_import_netlbl_cat(struct context *context,
 {
         int rc;
 
-        if (!selinux_mls_enabled)
+        if (!policydb.mls_enabled)
                 return 0;
 
         rc = ebitmap_netlbl_import(&context->range.level[0].cat,
diff --git a/security/selinux/ss/mls.h b/security/selinux/ss/mls.h
index 1276715aaa8b..cd9152632e54 100644
--- a/security/selinux/ss/mls.h
+++ b/security/selinux/ss/mls.h
@@ -39,6 +39,8 @@ int mls_context_to_sid(struct policydb *p,
 
 int mls_from_string(char *str, struct context *context, gfp_t gfp_mask);
 
+int mls_range_set(struct context *context, struct mls_range *range);
+
 int mls_convert_context(struct policydb *oldp,
                         struct policydb *newp,
                         struct context *context);
diff --git a/security/selinux/ss/mls_types.h b/security/selinux/ss/mls_types.h
index b6e943a21061..03bed52a8052 100644
--- a/security/selinux/ss/mls_types.h
+++ b/security/selinux/ss/mls_types.h
@@ -15,6 +15,7 @@
 #define _SS_MLS_TYPES_H_
 
 #include "security.h"
+#include "ebitmap.h"
 
 struct mls_level {
         u32 sens;               /* sensitivity */
@@ -27,18 +28,12 @@ struct mls_range {
 
 static inline int mls_level_eq(struct mls_level *l1, struct mls_level *l2)
 {
-        if (!selinux_mls_enabled)
-                return 1;
-
         return ((l1->sens == l2->sens) &&
                 ebitmap_cmp(&l1->cat, &l2->cat));
 }
 
 static inline int mls_level_dom(struct mls_level *l1, struct mls_level *l2)
 {
-        if (!selinux_mls_enabled)
-                return 1;
-
         return ((l1->sens >= l2->sens) &&
                 ebitmap_contains(&l1->cat, &l2->cat));
 }
diff --git a/security/selinux/ss/policydb.c b/security/selinux/ss/policydb.c
index f03667213ea8..23c6e53c102c 100644
--- a/security/selinux/ss/policydb.c
+++ b/security/selinux/ss/policydb.c
@@ -52,8 +52,6 @@ static char *symtab_name[SYM_NUM] = {
 };
 #endif
 
-int selinux_mls_enabled;
-
 static unsigned int symtab_sizes[SYM_NUM] = {
         2,
         32,
@@ -177,6 +175,21 @@ out_free_role:
         goto out;
 }
 
+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;
+        return (key1->source_type != key2->source_type ||
+                key1->target_type != key2->target_type ||
+                key1->target_class != key2->target_class);
+}
+
 /*
  * Initialize a policy database structure.
  */
@@ -204,6 +217,10 @@ static int policydb_init(struct policydb *p)
         if (rc)
                 goto out_free_symtab;
 
+        p->range_tr = hashtab_create(rangetr_hash, rangetr_cmp, 256);
+        if (!p->range_tr)
+                goto out_free_symtab;
+
         ebitmap_init(&p->policycaps);
         ebitmap_init(&p->permissive_map);
 
@@ -408,6 +425,20 @@ static void symtab_hash_eval(struct symtab *s)
                        info.slots_used, h->size, info.max_chain_len);
         }
 }
+
+static void rangetr_hash_eval(struct hashtab *h)
+{
+        struct hashtab_info info;
+
+        hashtab_stat(h, &info);
+        printk(KERN_DEBUG "SELinux: rangetr:  %d entries and %d/%d buckets used, "
+               "longest chain length %d\n", h->nel,
+               info.slots_used, h->size, info.max_chain_len);
+}
+#else
+static inline void rangetr_hash_eval(struct hashtab *h)
+{
+}
 #endif
 
 /*
@@ -422,7 +453,7 @@ static int policydb_index_others(struct policydb *p)
 
         printk(KERN_DEBUG "SELinux:  %d users, %d roles, %d types, %d bools",
                p->p_users.nprim, p->p_roles.nprim, p->p_types.nprim, p->p_bools.nprim);
-        if (selinux_mls_enabled)
+        if (p->mls_enabled)
                 printk(", %d sens, %d cats", p->p_levels.nprim,
                        p->p_cats.nprim);
         printk("\n");
@@ -612,6 +643,17 @@ static int (*destroy_f[SYM_NUM]) (void *key, void *datum, void *datap) =
         cat_destroy,
 };
 
+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);
+        kfree(datum);
+        cond_resched();
+        return 0;
+}
+
 static void ocontext_destroy(struct ocontext *c, int i)
 {
         context_destroy(&c->context[0]);
@@ -632,7 +674,6 @@ void policydb_destroy(struct policydb *p)
         int i;
         struct role_allow *ra, *lra = NULL;
         struct role_trans *tr, *ltr = NULL;
-        struct range_trans *rt, *lrt = NULL;
 
         for (i = 0; i < SYM_NUM; i++) {
                 cond_resched();
@@ -693,20 +734,8 @@ void policydb_destroy(struct policydb *p)
         }
         kfree(lra);
 
-        for (rt = p->range_tr; rt; rt = rt->next) {
-                cond_resched();
-                if (lrt) {
-                        ebitmap_destroy(&lrt->target_range.level[0].cat);
-                        ebitmap_destroy(&lrt->target_range.level[1].cat);
-                        kfree(lrt);
-                }
-                lrt = rt;
-        }
-        if (lrt) {
-                ebitmap_destroy(&lrt->target_range.level[0].cat);
-                ebitmap_destroy(&lrt->target_range.level[1].cat);
-                kfree(lrt);
-        }
+        hashtab_map(p->range_tr, range_tr_destroy, NULL);
+        hashtab_destroy(p->range_tr);
 
         if (p->type_attr_map) {
                 for (i = 0; i < p->p_types.nprim; i++)
@@ -1686,12 +1715,11 @@ int policydb_read(struct policydb *p, void *fp)
         int i, j, rc;
         __le32 buf[4];
         u32 nodebuf[8];
-        u32 len, len2, config, nprim, nel, nel2;
+        u32 len, len2, nprim, nel, nel2;
         char *policydb_str;
         struct policydb_compat_info *info;
-        struct range_trans *rt, *lrt;
-
-        config = 0;
+        struct range_trans *rt;
+        struct mls_range *r;
 
         rc = policydb_init(p);
         if (rc)
@@ -1740,7 +1768,7 @@ int policydb_read(struct policydb *p, void *fp)
         kfree(policydb_str);
         policydb_str = NULL;
 
-        /* Read the version, config, and table sizes. */
+        /* Read the version and table sizes. */
         rc = next_entry(buf, fp, sizeof(u32)*4);
         if (rc < 0)
                 goto bad;
@@ -1755,13 +1783,7 @@ int policydb_read(struct policydb *p, void *fp)
         }
 
         if ((le32_to_cpu(buf[1]) & POLICYDB_CONFIG_MLS)) {
-                if (ss_initialized && !selinux_mls_enabled) {
-                        printk(KERN_ERR "SELinux: Cannot switch between non-MLS"
-                                " and MLS policies\n");
-                        goto bad;
-                }
-                selinux_mls_enabled = 1;
-                config |= POLICYDB_CONFIG_MLS;
+                p->mls_enabled = 1;
 
                 if (p->policyvers < POLICYDB_VERSION_MLS) {
                         printk(KERN_ERR "SELinux: security policydb version %d "
@@ -1769,12 +1791,6 @@ int policydb_read(struct policydb *p, void *fp)
                                 p->policyvers);
                         goto bad;
                 }
-        } else {
-                if (ss_initialized && selinux_mls_enabled) {
-                        printk(KERN_ERR "SELinux: Cannot switch between MLS and"
-                                " non-MLS policies\n");
-                        goto bad;
-                }
         }
         p->reject_unknown = !!(le32_to_cpu(buf[1]) & REJECT_UNKNOWN);
         p->allow_unknown = !!(le32_to_cpu(buf[1]) & ALLOW_UNKNOWN);
@@ -2122,44 +2138,61 @@ int policydb_read(struct policydb *p, void *fp)
                 if (rc < 0)
                         goto bad;
                 nel = le32_to_cpu(buf[0]);
-                lrt = NULL;
                 for (i = 0; i < nel; i++) {
                         rt = kzalloc(sizeof(*rt), GFP_KERNEL);
                         if (!rt) {
                                 rc = -ENOMEM;
                                 goto bad;
                         }
-                        if (lrt)
-                                lrt->next = rt;
-                        else
-                                p->range_tr = rt;
                         rc = next_entry(buf, fp, (sizeof(u32) * 2));
-                        if (rc < 0)
+                        if (rc < 0) {
+                                kfree(rt);
                                 goto bad;
+                        }
                         rt->source_type = le32_to_cpu(buf[0]);
                         rt->target_type = le32_to_cpu(buf[1]);
                         if (new_rangetr) {
                                 rc = next_entry(buf, fp, sizeof(u32));
-                                if (rc < 0)
+                                if (rc < 0) {
+                                        kfree(rt);
                                         goto bad;
+                                }
                                 rt->target_class = le32_to_cpu(buf[0]);
                         } else
                                 rt->target_class = p->process_class;
                         if (!policydb_type_isvalid(p, rt->source_type) ||
                             !policydb_type_isvalid(p, rt->target_type) ||
                             !policydb_class_isvalid(p, rt->target_class)) {
+                                kfree(rt);
                                 rc = -EINVAL;
                                 goto bad;
                         }
-                        rc = mls_read_range_helper(&rt->target_range, fp);
-                        if (rc)
+                        r = kzalloc(sizeof(*r), GFP_KERNEL);
+                        if (!r) {
+                                kfree(rt);
+                                rc = -ENOMEM;
                                 goto bad;
-                        if (!mls_range_isvalid(p, &rt->target_range)) {
+                        }
+                        rc = mls_read_range_helper(r, fp);
+                        if (rc) {
+                                kfree(rt);
+                                kfree(r);
+                                goto bad;
+                        }
+                        if (!mls_range_isvalid(p, r)) {
                                 printk(KERN_WARNING "SELinux:  rangetrans:  invalid range\n");
+                                kfree(rt);
+                                kfree(r);
+                                goto bad;
+                        }
+                        rc = hashtab_insert(p->range_tr, rt, r);
+                        if (rc) {
+                                kfree(rt);
+                                kfree(r);
                                 goto bad;
                         }
-                        lrt = rt;
                 }
+                rangetr_hash_eval(p->range_tr);
         }
 
         p->type_attr_map = kmalloc(p->p_types.nprim*sizeof(struct ebitmap), GFP_KERNEL);
diff --git a/security/selinux/ss/policydb.h b/security/selinux/ss/policydb.h
index cdcc5700946f..26d9adf8542b 100644
--- a/security/selinux/ss/policydb.h
+++ b/security/selinux/ss/policydb.h
@@ -27,6 +27,8 @@
 #include "symtab.h"
 #include "avtab.h"
 #include "sidtab.h"
+#include "ebitmap.h"
+#include "mls_types.h"
 #include "context.h"
 #include "constraint.h"
 
@@ -113,8 +115,6 @@ struct range_trans {
         u32 source_type;
         u32 target_type;
         u32 target_class;
-        struct mls_range target_range;
-        struct range_trans *next;
 };
 
 /* Boolean data type */
@@ -187,6 +187,8 @@ struct genfs {
 
 /* The policy database */
 struct policydb {
+        int mls_enabled;
+
         /* symbol tables */
         struct symtab symtab[SYM_NUM];
 #define p_commons symtab[SYM_COMMONS]
@@ -240,8 +242,8 @@ struct policydb {
            fixed labeling behavior. */
         struct genfs *genfs;
 
-        /* range transitions */
-        struct range_trans *range_tr;
+        /* range transitions table (range_trans_key -> mls_range) */
+        struct hashtab *range_tr;
 
         /* type -> attribute reverse mapping */
         struct ebitmap *type_attr_map;
diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
index b3efae204ac7..cf27b3ee1a95 100644
--- a/security/selinux/ss/services.c
+++ b/security/selinux/ss/services.c
@@ -26,6 +26,10 @@
  *
  *  Added support for bounds domain and audit messaged on masked permissions
  *
+ * Updated: Guido Trentalancia <guido@trentalancia.com>
+ *
+ *  Added support for runtime switching of the policy type
+ *
  * Copyright (C) 2008, 2009 NEC Corporation
  * Copyright (C) 2006, 2007 Hewlett-Packard Development Company, L.P.
  * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc.
@@ -87,11 +91,10 @@ static u32 latest_granting;
 static int context_struct_to_string(struct context *context, char **scontext,
                                     u32 *scontext_len);
 
-static int context_struct_compute_av(struct context *scontext,
-                                     struct context *tcontext,
-                                     u16 tclass,
-                                     u32 requested,
-                                     struct av_decision *avd);
+static void context_struct_compute_av(struct context *scontext,
+                                      struct context *tcontext,
+                                      u16 tclass,
+                                      struct av_decision *avd);
 
 struct selinux_mapping {
         u16 value; /* policy value */
@@ -196,23 +199,6 @@ static u16 unmap_class(u16 tclass)
         return tclass;
 }
 
-static u32 unmap_perm(u16 tclass, u32 tperm)
-{
-        if (tclass < current_mapping_size) {
-                unsigned i;
-                u32 kperm = 0;
-
-                for (i = 0; i < current_mapping[tclass].num_perms; i++)
-                        if (tperm & (1<<i)) {
-                                kperm |= current_mapping[tclass].perms[i];
-                                tperm &= ~(1<<i);
-                        }
-                return kperm;
-        }
-
-        return tperm;
-}
-
 static void map_decision(u16 tclass, struct av_decision *avd,
                          int allow_unknown)
 {
@@ -250,6 +236,10 @@ static void map_decision(u16 tclass, struct av_decision *avd,
         }
 }
 
+int security_mls_enabled(void)
+{
+        return policydb.mls_enabled;
+}
 
 /*
  * Return the boolean value of a constraint expression
@@ -465,7 +455,8 @@ static void security_dump_masked_av(struct context *scontext,
         char *scontext_name = NULL;
         char *tcontext_name = NULL;
         char *permission_names[32];
-        int index, length;
+        int index;
+        u32 length;
         bool need_comma = false;
 
         if (!permissions)
@@ -532,7 +523,6 @@ out:
 static void type_attribute_bounds_av(struct context *scontext,
                                      struct context *tcontext,
                                      u16 tclass,
-                                     u32 requested,
                                      struct av_decision *avd)
 {
         struct context lo_scontext;
@@ -553,7 +543,6 @@ static void type_attribute_bounds_av(struct context *scontext,
                 context_struct_compute_av(&lo_scontext,
                                           tcontext,
                                           tclass,
-                                          requested,
                                           &lo_avd);
                 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
                         return;         /* no masked permission */
@@ -569,7 +558,6 @@ static void type_attribute_bounds_av(struct context *scontext,
                 context_struct_compute_av(scontext,
                                           &lo_tcontext,
                                           tclass,
-                                          requested,
                                           &lo_avd);
                 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
                         return;         /* no masked permission */
@@ -586,7 +574,6 @@ static void type_attribute_bounds_av(struct context *scontext,
                 context_struct_compute_av(&lo_scontext,
                                           &lo_tcontext,
                                           tclass,
-                                          requested,
                                           &lo_avd);
                 if ((lo_avd.allowed & avd->allowed) == avd->allowed)
                         return;         /* no masked permission */
@@ -607,11 +594,10 @@ static void type_attribute_bounds_av(struct context *scontext,
  * Compute access vectors based on a context structure pair for
  * the permissions in a particular class.
  */
-static int context_struct_compute_av(struct context *scontext,
-                                     struct context *tcontext,
-                                     u16 tclass,
-                                     u32 requested,
-                                     struct av_decision *avd)
+static void context_struct_compute_av(struct context *scontext,
+                                      struct context *tcontext,
+                                      u16 tclass,
+                                      struct av_decision *avd)
 {
         struct constraint_node *constraint;
         struct role_allow *ra;
@@ -622,19 +608,14 @@ static int context_struct_compute_av(struct context *scontext,
         struct ebitmap_node *snode, *tnode;
         unsigned int i, j;
 
-        /*
-         * Initialize the access vectors to the default values.
-         */
         avd->allowed = 0;
         avd->auditallow = 0;
         avd->auditdeny = 0xffffffff;
-        avd->seqno = latest_granting;
-        avd->flags = 0;
 
         if (unlikely(!tclass || tclass > policydb.p_classes.nprim)) {
                 if (printk_ratelimit())
                         printk(KERN_WARNING "SELinux:  Invalid class %hu\n", tclass);
-                return -EINVAL;
+                return;
         }
 
         tclass_datum = policydb.class_val_to_struct[tclass - 1];
@@ -705,9 +686,7 @@ static int context_struct_compute_av(struct context *scontext,
          * permission and notice it to userspace via audit.
          */
         type_attribute_bounds_av(scontext, tcontext,
-                                 tclass, requested, avd);
-
-        return 0;
+                                 tclass, avd);
 }
 
 static int security_validtrans_handle_fail(struct context *ocontext,
@@ -864,7 +843,7 @@ int security_bounded_transition(u32 old_sid, u32 new_sid)
         if (rc) {
                 char *old_name = NULL;
                 char *new_name = NULL;
-                int length;
+                u32 length;
 
                 if (!context_struct_to_string(old_context,
                                               &old_name, &length) &&
@@ -886,110 +865,116 @@ out:
         return rc;
 }
 
-
-static int security_compute_av_core(u32 ssid,
-                                    u32 tsid,
-                                    u16 tclass,
-                                    u32 requested,
-                                    struct av_decision *avd)
+static void avd_init(struct av_decision *avd)
 {
-        struct context *scontext = NULL, *tcontext = NULL;
-        int rc = 0;
-
-        scontext = sidtab_search(&sidtab, ssid);
-        if (!scontext) {
-                printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
-                       __func__, ssid);
-                return -EINVAL;
-        }
-        tcontext = sidtab_search(&sidtab, tsid);
-        if (!tcontext) {
-                printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
-                       __func__, tsid);
-                return -EINVAL;
-        }
-
-        rc = context_struct_compute_av(scontext, tcontext, tclass,
-                                       requested, avd);
-
-        /* permissive domain? */
-        if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
-                avd->flags |= AVD_FLAGS_PERMISSIVE;
-
-        return rc;
+        avd->allowed = 0;
+        avd->auditallow = 0;
+        avd->auditdeny = 0xffffffff;
+        avd->seqno = latest_granting;
+        avd->flags = 0;
 }
 
+
 /**
  * security_compute_av - Compute access vector decisions.
  * @ssid: source security identifier
  * @tsid: target security identifier
  * @tclass: target security class
- * @requested: requested permissions
  * @avd: access vector decisions
  *
  * Compute a set of access vector decisions based on the
  * SID pair (@ssid, @tsid) for the permissions in @tclass.
- * Return -%EINVAL if any of the parameters are invalid or %0
- * if the access vector decisions were computed successfully.
  */
-int security_compute_av(u32 ssid,
-                        u32 tsid,
-                        u16 orig_tclass,
-                        u32 orig_requested,
-                        struct av_decision *avd)
+void security_compute_av(u32 ssid,
+                         u32 tsid,
+                         u16 orig_tclass,
+                         struct av_decision *avd)
 {
         u16 tclass;
-        u32 requested;
-        int rc;
+        struct context *scontext = NULL, *tcontext = NULL;
 
         read_lock(&policy_rwlock);
-
+        avd_init(avd);
         if (!ss_initialized)
                 goto allow;
 
-        requested = unmap_perm(orig_tclass, orig_requested);
+        scontext = sidtab_search(&sidtab, ssid);
+        if (!scontext) {
+                printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
+                       __func__, ssid);
+                goto out;
+        }
+
+        /* permissive domain? */
+        if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
+                avd->flags |= AVD_FLAGS_PERMISSIVE;
+
+        tcontext = sidtab_search(&sidtab, tsid);
+        if (!tcontext) {
+                printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
+                       __func__, tsid);
+                goto out;
+        }
+
         tclass = unmap_class(orig_tclass);
         if (unlikely(orig_tclass && !tclass)) {
                 if (policydb.allow_unknown)
                         goto allow;
-                rc = -EINVAL;
                 goto out;
         }
-        rc = security_compute_av_core(ssid, tsid, tclass, requested, avd);
+        context_struct_compute_av(scontext, tcontext, tclass, avd);
         map_decision(orig_tclass, avd, policydb.allow_unknown);
 out:
         read_unlock(&policy_rwlock);
-        return rc;
+        return;
 allow:
         avd->allowed = 0xffffffff;
-        avd->auditallow = 0;
-        avd->auditdeny = 0xffffffff;
-        avd->seqno = latest_granting;
-        avd->flags = 0;
-        rc = 0;
         goto out;
 }
 
-int security_compute_av_user(u32 ssid,
-                             u32 tsid,
-                             u16 tclass,
-                             u32 requested,
-                             struct av_decision *avd)
+void security_compute_av_user(u32 ssid,
+                              u32 tsid,
+                              u16 tclass,
+                              struct av_decision *avd)
 {
-        int rc;
+        struct context *scontext = NULL, *tcontext = NULL;
 
-        if (!ss_initialized) {
-                avd->allowed = 0xffffffff;
-                avd->auditallow = 0;
-                avd->auditdeny = 0xffffffff;
-                avd->seqno = latest_granting;
-                return 0;
+        read_lock(&policy_rwlock);
+        avd_init(avd);
+        if (!ss_initialized)
+                goto allow;
+
+        scontext = sidtab_search(&sidtab, ssid);
+        if (!scontext) {
+                printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
+                       __func__, ssid);
+                goto out;
         }
 
-        read_lock(&policy_rwlock);
-        rc = security_compute_av_core(ssid, tsid, tclass, requested, avd);
+        /* permissive domain? */
+        if (ebitmap_get_bit(&policydb.permissive_map, scontext->type))
+                avd->flags |= AVD_FLAGS_PERMISSIVE;
+
+        tcontext = sidtab_search(&sidtab, tsid);
+        if (!tcontext) {
+                printk(KERN_ERR "SELinux: %s:  unrecognized SID %d\n",
+                       __func__, tsid);
+                goto out;
+        }
+
+        if (unlikely(!tclass)) {
+                if (policydb.allow_unknown)
+                        goto allow;
+                goto out;
+        }
+
+        context_struct_compute_av(scontext, tcontext, tclass, avd);
+ out:
         read_unlock(&policy_rwlock);
-        return rc;
+        return;
+allow:
+        avd->allowed = 0xffffffff;
+        goto out;
 }
 
 /*
@@ -1565,7 +1550,10 @@ static int clone_sid(u32 sid,
 {
         struct sidtab *s = arg;
 
-        return sidtab_insert(s, sid, context);
+        if (sid > SECINITSID_NUM)
+                return sidtab_insert(s, sid, context);
+        else
+                return 0;
 }
 
 static inline int convert_context_handle_invalid_context(struct context *context)
@@ -1606,12 +1594,17 @@ static int convert_context(u32 key,
 {
         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;
+        int rc = 0;
+
+        if (key <= SECINITSID_NUM)
+                goto out;
 
         args = p;
 
@@ -1673,9 +1666,39 @@ static int convert_context(u32 key,
                 goto bad;
         c->type = typdatum->value;
 
-        rc = mls_convert_context(args->oldp, args->newp, c);
-        if (rc)
-                goto bad;
+        /* 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);
+                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:
+                 * ensure that the MLS fields of the context for all
+                 * existing entries in the sidtab are filled in with a
+                 * suitable default value, likely taken from one of the
+                 * initial SIDs.
+                 */
+                oc = args->newp->ocontexts[OCON_ISID];
+                while (oc && oc->sid[0] != SECINITSID_UNLABELED)
+                        oc = oc->next;
+                if (!oc) {
+                        printk(KERN_ERR "SELinux:  unable to look up"
+                                " the initial SIDs list\n");
+                        goto bad;
+                }
+                range = &oc->context[0].range;
+                rc = mls_range_set(c, range);
+                if (rc)
+                        goto bad;
+        }
 
         /* Check the validity of the new context. */
         if (!policydb_context_isvalid(args->newp, c)) {
@@ -1771,9 +1794,17 @@ int security_load_policy(void *data, size_t len)
         if (policydb_read(&newpolicydb, fp))
                 return -EINVAL;
 
-        if (sidtab_init(&newsidtab)) {
+        /* If switching between different policy types, log MLS status */
+        if (policydb.mls_enabled && !newpolicydb.mls_enabled)
+                printk(KERN_INFO "SELinux: Disabling MLS support...\n");
+        else if (!policydb.mls_enabled && newpolicydb.mls_enabled)
+                printk(KERN_INFO "SELinux: Enabling MLS support...\n");
+
+        rc = policydb_load_isids(&newpolicydb, &newsidtab);
+        if (rc) {
+                printk(KERN_ERR "SELinux:  unable to load the initial SIDs\n");
                 policydb_destroy(&newpolicydb);
-                return -ENOMEM;
+                return rc;
         }
 
         if (selinux_set_mapping(&newpolicydb, secclass_map,
@@ -1800,8 +1831,12 @@ int security_load_policy(void *data, size_t len)
         args.oldp = &policydb;
         args.newp = &newpolicydb;
         rc = sidtab_map(&newsidtab, convert_context, &args);
-        if (rc)
+        if (rc) {
+                printk(KERN_ERR "SELinux:  unable to convert the internal"
+                        " representation of contexts in the new SID"
+                        " table\n");
                 goto err;
+        }
 
         /* Save the old policydb and SID table to free later. */
         memcpy(&oldpolicydb, &policydb, sizeof policydb);
@@ -2397,7 +2432,7 @@ int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid)
         u32 len;
         int rc = 0;
 
-        if (!ss_initialized || !selinux_mls_enabled) {
+        if (!ss_initialized || !policydb.mls_enabled) {
                 *new_sid = sid;
                 goto out;
         }
@@ -2498,7 +2533,7 @@ int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type,
         /* we don't need to check ss_initialized here since the only way both
          * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
          * security server was initialized and ss_initialized was true */
-        if (!selinux_mls_enabled) {
+        if (!policydb.mls_enabled) {
                 *peer_sid = SECSID_NULL;
                 return 0;
         }
@@ -2555,7 +2590,7 @@ int security_get_classes(char ***classes, int *nclasses)
         read_lock(&policy_rwlock);
 
         *nclasses = policydb.p_classes.nprim;
-        *classes = kcalloc(*nclasses, sizeof(*classes), GFP_ATOMIC);
+        *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC);
         if (!*classes)
                 goto out;
 
@@ -2602,7 +2637,7 @@ int security_get_permissions(char *class, char ***perms, int *nperms)
         }
 
         *nperms = match->permissions.nprim;
-        *perms = kcalloc(*nperms, sizeof(*perms), GFP_ATOMIC);
+        *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC);
         if (!*perms)
                 goto out;