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authorStephen Smalley <sds@tycho.nsa.gov>2010-01-07 15:55:16 -0500
committerJames Morris <jmorris@namei.org>2010-01-25 08:29:05 +1100
commit2f3e82d694d3d7a2db019db1bb63385fbc1066f3 (patch)
tree9d99a883eb2ab097a3ff1ee4e1c9bf2fa851d832 /security
parent2457552d1e6f3183cd93f81c49a8da5fe8bb0e42 (diff)
downloadlinux-2f3e82d694d3d7a2db019db1bb63385fbc1066f3.tar.bz2
selinux: convert range transition list to a hashtab
Per https://bugzilla.redhat.com/show_bug.cgi?id=548145 there are sufficient range transition rules in modern (Fedora) policy to make mls_compute_sid a significant factor on the shmem file setup path due to the length of the range_tr list. Replace the simple range_tr list with a hashtab inside the security server to help mitigate this problem. Signed-off-by: Stephen D. Smalley <sds@tycho.nsa.gov> Signed-off-by: James Morris <jmorris@namei.org>
Diffstat (limited to 'security')
-rw-r--r--security/selinux/ss/mls.c18
-rw-r--r--security/selinux/ss/policydb.c103
-rw-r--r--security/selinux/ss/policydb.h6
3 files changed, 86 insertions, 41 deletions
diff --git a/security/selinux/ss/mls.c b/security/selinux/ss/mls.c
index e6654b543aed..443ae7370144 100644
--- a/security/selinux/ss/mls.c
+++ b/security/selinux/ss/mls.c
@@ -513,7 +513,8 @@ 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)
return 0;
@@ -521,15 +522,12 @@ int mls_compute_sid(struct context *scontext,
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)
diff --git a/security/selinux/ss/policydb.c b/security/selinux/ss/policydb.c
index f03667213ea8..5b92c0219207 100644
--- a/security/selinux/ss/policydb.c
+++ b/security/selinux/ss/policydb.c
@@ -177,6 +177,21 @@ 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 +219,10 @@ 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 +427,20 @@ 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
/*
@@ -612,6 +645,17 @@ 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 +676,6 @@ 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 +736,8 @@ 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++)
@@ -1689,7 +1720,8 @@ int policydb_read(struct policydb *p, void *fp)
u32 len, len2, config, nprim, nel, nel2;
char *policydb_str;
struct policydb_compat_info *info;
- struct range_trans *rt, *lrt;
+ struct range_trans *rt;
+ struct mls_range *r;
config = 0;
@@ -2122,44 +2154,61 @@ 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..193736b64de8 100644
--- a/security/selinux/ss/policydb.h
+++ b/security/selinux/ss/policydb.h
@@ -113,8 +113,6 @@ struct range_trans {
u32 source_type;
u32 target_type;
u32 target_class;
- struct mls_range target_range;
- struct range_trans *next;
};
/* Boolean data type */
@@ -240,8 +238,8 @@ 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;