Merge current mainline tree into linux-omap tree
[pandora-kernel.git] / security / selinux / avc.c
index 187964e..114b4b4 100644 (file)
@@ -2,16 +2,16 @@
  * Implementation of the kernel access vector cache (AVC).
  *
  * Authors:  Stephen Smalley, <sds@epoch.ncsc.mil>
- *           James Morris <jmorris@redhat.com>
+ *          James Morris <jmorris@redhat.com>
  *
  * Update:   KaiGai, Kohei <kaigai@ak.jp.nec.com>
- *     Replaced the avc_lock spinlock by RCU.
+ *     Replaced the avc_lock spinlock by RCU.
  *
  * 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 version 2,
- *      as published by the Free Software Foundation.
+ *     as published by the Free Software Foundation.
  */
 #include <linux/types.h>
 #include <linux/stddef.h>
@@ -44,7 +44,7 @@ static const char *class_to_string[] = {
 #undef S_
 };
 
-#define TB_(s) static const char * s [] = {
+#define TB_(s) static const char *s[] = {
 #define TE_(s) };
 #define S_(s) s,
 #include "common_perm_to_string.h"
@@ -72,7 +72,7 @@ const struct selinux_class_perm selinux_class_perm = {
 #define AVC_CACHE_RECLAIM              16
 
 #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
-#define avc_cache_stats_incr(field)                            \
+#define avc_cache_stats_incr(field)                            \
 do {                                                           \
        per_cpu(avc_cache_stats, get_cpu()).field++;            \
        put_cpu();                                              \
@@ -92,7 +92,7 @@ struct avc_entry {
 struct avc_node {
        struct avc_entry        ae;
        struct list_head        list;
-       struct rcu_head         rhead;
+       struct rcu_head         rhead;
 };
 
 struct avc_cache {
@@ -105,8 +105,8 @@ struct avc_cache {
 
 struct avc_callback_node {
        int (*callback) (u32 event, u32 ssid, u32 tsid,
-                        u16 tclass, u32 perms,
-                        u32 *out_retained);
+                        u16 tclass, u32 perms,
+                        u32 *out_retained);
        u32 events;
        u32 ssid;
        u32 tsid;
@@ -202,7 +202,7 @@ static void avc_dump_query(struct audit_buffer *ab, u32 ssid, u32 tsid, u16 tcla
        char *scontext;
        u32 scontext_len;
 
-       rc = security_sid_to_context(ssid, &scontext, &scontext_len);
+       rc = security_sid_to_context(ssid, &scontext, &scontext_len);
        if (rc)
                audit_log_format(ab, "ssid=%d", ssid);
        else {
@@ -306,12 +306,13 @@ static inline int avc_reclaim_node(void)
        int hvalue, try, ecx;
        unsigned long flags;
 
-       for (try = 0, ecx = 0; try < AVC_CACHE_SLOTS; try++ ) {
+       for (try = 0, ecx = 0; try < AVC_CACHE_SLOTS; try++) {
                hvalue = atomic_inc_return(&avc_cache.lru_hint) & (AVC_CACHE_SLOTS - 1);
 
                if (!spin_trylock_irqsave(&avc_cache.slots_lock[hvalue], flags))
                        continue;
 
+               rcu_read_lock();
                list_for_each_entry(node, &avc_cache.slots[hvalue], list) {
                        if (atomic_dec_and_test(&node->ae.used)) {
                                /* Recently Unused */
@@ -319,11 +320,13 @@ static inline int avc_reclaim_node(void)
                                avc_cache_stats_incr(reclaims);
                                ecx++;
                                if (ecx >= AVC_CACHE_RECLAIM) {
+                                       rcu_read_unlock();
                                        spin_unlock_irqrestore(&avc_cache.slots_lock[hvalue], flags);
                                        goto out;
                                }
                        }
                }
+               rcu_read_unlock();
                spin_unlock_irqrestore(&avc_cache.slots_lock[hvalue], flags);
        }
 out:
@@ -426,7 +429,7 @@ static int avc_latest_notif_update(int seqno, int is_insert)
        spin_lock_irqsave(&notif_lock, flag);
        if (is_insert) {
                if (seqno < avc_cache.latest_notif) {
-                       printk(KERN_WARNING "avc:  seqno %d < latest_notif %d\n",
+                       printk(KERN_WARNING "SELinux: avc:  seqno %d < latest_notif %d\n",
                               seqno, avc_cache.latest_notif);
                        ret = -EAGAIN;
                }
@@ -475,7 +478,7 @@ static struct avc_node *avc_insert(u32 ssid, u32 tsid, u16 tclass, struct avc_en
                        if (pos->ae.ssid == ssid &&
                            pos->ae.tsid == tsid &&
                            pos->ae.tclass == tclass) {
-                               avc_node_replace(node, pos);
+                               avc_node_replace(node, pos);
                                goto found;
                        }
                }
@@ -526,8 +529,8 @@ static inline void avc_print_ipv4_addr(struct audit_buffer *ab, __be32 addr,
  * before calling the auditing code.
  */
 void avc_audit(u32 ssid, u32 tsid,
-               u16 tclass, u32 requested,
-               struct av_decision *avd, int result, struct avc_audit_data *a)
+              u16 tclass, u32 requested,
+              struct av_decision *avd, int result, struct avc_audit_data *a)
 {
        struct task_struct *tsk = current;
        struct inode *inode = NULL;
@@ -541,7 +544,7 @@ void avc_audit(u32 ssid, u32 tsid,
                        return;
        } else if (result) {
                audited = denied = requested;
-        } else {
+       } else {
                audited = requested;
                if (!(audited & avd->auditallow))
                        return;
@@ -551,7 +554,7 @@ void avc_audit(u32 ssid, u32 tsid,
        if (!ab)
                return;         /* audit_panic has been called */
        audit_log_format(ab, "avc:  %s ", denied ? "denied" : "granted");
-       avc_dump_av(ab, tclass,audited);
+       avc_dump_av(ab, tclass, audited);
        audit_log_format(ab, " for ");
        if (a && a->tsk)
                tsk = a->tsk;
@@ -643,11 +646,11 @@ void avc_audit(u32 ssid, u32 tsid,
                                        if (*p)
                                                audit_log_untrustedstring(ab, p);
                                        else
-                                               audit_log_hex(ab, p, len);
+                                               audit_log_n_hex(ab, p, len);
                                        break;
                                }
                        }
-                       
+
                        switch (a->u.net.family) {
                        case AF_INET:
                                avc_print_ipv4_addr(ab, a->u.net.v4info.saddr,
@@ -702,10 +705,10 @@ void avc_audit(u32 ssid, u32 tsid,
  * -%ENOMEM if insufficient memory exists to add the callback.
  */
 int avc_add_callback(int (*callback)(u32 event, u32 ssid, u32 tsid,
-                                     u16 tclass, u32 perms,
-                                     u32 *out_retained),
-                     u32 events, u32 ssid, u32 tsid,
-                     u16 tclass, u32 perms)
+                                    u16 tclass, u32 perms,
+                                    u32 *out_retained),
+                    u32 events, u32 ssid, u32 tsid,
+                    u16 tclass, u32 perms)
 {
        struct avc_callback_node *c;
        int rc = 0;
@@ -759,10 +762,10 @@ static int avc_update_node(u32 event, u32 perms, u32 ssid, u32 tsid, u16 tclass)
        hvalue = avc_hash(ssid, tsid, tclass);
        spin_lock_irqsave(&avc_cache.slots_lock[hvalue], flag);
 
-       list_for_each_entry(pos, &avc_cache.slots[hvalue], list){
-               if ( ssid==pos->ae.ssid &&
-                    tsid==pos->ae.tsid &&
-                    tclass==pos->ae.tclass ){
+       list_for_each_entry(pos, &avc_cache.slots[hvalue], list) {
+               if (ssid == pos->ae.ssid &&
+                   tsid == pos->ae.tsid &&
+                   tclass == pos->ae.tclass){
                        orig = pos;
                        break;
                }
@@ -821,15 +824,21 @@ int avc_ss_reset(u32 seqno)
 
        for (i = 0; i < AVC_CACHE_SLOTS; i++) {
                spin_lock_irqsave(&avc_cache.slots_lock[i], flag);
+               /*
+                * With preemptable RCU, the outer spinlock does not
+                * prevent RCU grace periods from ending.
+                */
+               rcu_read_lock();
                list_for_each_entry(node, &avc_cache.slots[i], list)
                        avc_node_delete(node);
+               rcu_read_unlock();
                spin_unlock_irqrestore(&avc_cache.slots_lock[i], flag);
        }
 
        for (c = avc_callbacks; c; c = c->next) {
                if (c->events & AVC_CALLBACK_RESET) {
                        tmprc = c->callback(AVC_CALLBACK_RESET,
-                                           0, 0, 0, 0, NULL);
+                                           0, 0, 0, 0, NULL);
                        /* save the first error encountered for the return
                           value and continue processing the callbacks */
                        if (!rc)
@@ -871,16 +880,18 @@ int avc_has_perm_noaudit(u32 ssid, u32 tsid,
        int rc = 0;
        u32 denied;
 
+       BUG_ON(!requested);
+
        rcu_read_lock();
 
        node = avc_lookup(ssid, tsid, tclass, requested);
        if (!node) {
                rcu_read_unlock();
-               rc = security_compute_av(ssid,tsid,tclass,requested,&entry.avd);
+               rc = security_compute_av(ssid, tsid, tclass, requested, &entry.avd);
                if (rc)
                        goto out;
                rcu_read_lock();
-               node = avc_insert(ssid,tsid,tclass,&entry);
+               node = avc_insert(ssid, tsid, tclass, &entry);
        }
 
        p_ae = node ? &node->ae : &entry;
@@ -890,13 +901,14 @@ int avc_has_perm_noaudit(u32 ssid, u32 tsid,
 
        denied = requested & ~(p_ae->avd.allowed);
 
-       if (!requested || denied) {
-               if (selinux_enforcing || (flags & AVC_STRICT))
+       if (denied) {
+               if (flags & AVC_STRICT)
                        rc = -EACCES;
+               else if (!selinux_enforcing || security_permissive_sid(ssid))
+                       avc_update_node(AVC_CALLBACK_GRANT, requested, ssid,
+                                       tsid, tclass);
                else
-                       if (node)
-                               avc_update_node(AVC_CALLBACK_GRANT,requested,
-                                               ssid,tsid,tclass);
+                       rc = -EACCES;
        }
 
        rcu_read_unlock();
@@ -921,7 +933,7 @@ out:
  * another -errno upon other errors.
  */
 int avc_has_perm(u32 ssid, u32 tsid, u16 tclass,
-                 u32 requested, struct avc_audit_data *auditdata)
+                u32 requested, struct avc_audit_data *auditdata)
 {
        struct av_decision avd;
        int rc;