rcu: Update all rcu_read_lock() users to implement a dummy RCU read lock.

Signed-off-by: Keir Fraser <keir.fraser@citrix.com>

diff --git a/xen/arch/x86/hvm/vmsi.c b/xen/arch/x86/hvm/vmsi.c
index d9ec9fb0a4b0e06bdb5bc78727c85f078f7103fc..31ee9b7cfe208f6caf01a3d4eca4dfb5dc4428ae 100644 (file)
--- a/xen/arch/x86/hvm/vmsi.c
+++ b/xen/arch/x86/hvm/vmsi.c
@@ -162,6 +162,8 @@ struct msixtbl_entry
     struct rcu_head rcu;
 };
 
+static DEFINE_RCU_READ_LOCK(msixtbl_rcu_lock);
+
 static struct msixtbl_entry *msixtbl_find_entry(
     struct vcpu *v, unsigned long addr)
 {
@@ -207,7 +209,7 @@ static int msixtbl_read(
     void *virt;
     int r = X86EMUL_UNHANDLEABLE;
 
-    rcu_read_lock();
+    rcu_read_lock(&msixtbl_rcu_lock);
 
     if ( len != 4 )
         goto out;
@@ -225,7 +227,7 @@ static int msixtbl_read(
     r = X86EMUL_OKAY;
 
 out:
-    rcu_read_unlock();
+    rcu_read_unlock(&msixtbl_rcu_lock);
     return r;
 }
 
@@ -238,7 +240,7 @@ static int msixtbl_write(struct vcpu *v, unsigned long address,
     int nr_entry;
     int r = X86EMUL_UNHANDLEABLE;
 
-    rcu_read_lock();
+    rcu_read_lock(&msixtbl_rcu_lock);
 
     if ( len != 4 )
         goto out;
@@ -265,7 +267,7 @@ static int msixtbl_write(struct vcpu *v, unsigned long address,
     r = X86EMUL_OKAY;
 
 out:
-    rcu_read_unlock();
+    rcu_read_unlock(&msixtbl_rcu_lock);
     return r;
 }
 
@@ -274,12 +276,12 @@ static int msixtbl_range(struct vcpu *v, unsigned long addr)
     struct msixtbl_entry *entry;
     void *virt;
 
-    rcu_read_lock();
+    rcu_read_lock(&msixtbl_rcu_lock);
 
     entry = msixtbl_find_entry(v, addr);
     virt = msixtbl_addr_to_virt(entry, addr);
 
-    rcu_read_unlock();
+    rcu_read_unlock(&msixtbl_rcu_lock);
 
     return !!virt;
 }

diff --git a/xen/include/xen/rcupdate.h b/xen/include/xen/rcupdate.h
index 285e574e28d6a30b54b90b9c3b9d1b627d727da6..68f98acfda73947adb7059b11ed1cd8ca2939af9 100644 (file)
--- a/xen/include/xen/rcupdate.h
+++ b/xen/include/xen/rcupdate.h
@@ -145,14 +145,14 @@ typedef struct _rcu_read_lock rcu_read_lock_t;
  *
  * It is illegal to block while in an RCU read-side critical section.
  */
-#define rcu_read_lock(x)       do { } while (0)
+#define rcu_read_lock(x)       ((void)(x))
 
 /**
  * rcu_read_unlock - marks the end of an RCU read-side critical section.
  *
  * See rcu_read_lock() for more information.
  */
-#define rcu_read_unlock(x)     do { } while (0)
+#define rcu_read_unlock(x)     ((void)(x))
 
 /*
  * So where is rcu_write_lock()?  It does not exist, as there is no

diff --git a/xen/include/xen/sched.h b/xen/include/xen/sched.h
index 6e4a89854aebf1a56e0cf91627780e120257c7ab..ab92088fc1875e9c57bf07178131433d4304b1b4 100644 (file)
--- a/xen/include/xen/sched.h
+++ b/xen/include/xen/sched.h
@@ -344,6 +344,10 @@ struct domain_setup_info
     unsigned long symtab_len;
 };
 
+/* Protect updates/reads (resp.) of domain_list and domain_hash. */
+extern spinlock_t domlist_update_lock;
+extern rcu_read_lock_t domlist_read_lock;
+
 extern struct vcpu *idle_vcpu[NR_CPUS];
 #define IDLE_DOMAIN_ID   (0x7FFFU)
 #define is_idle_domain(d) ((d)->domain_id == IDLE_DOMAIN_ID)
@@ -533,10 +537,6 @@ unsigned long hypercall_create_continuation(
         local_events_need_delivery()            \
     ))
 
-/* Protect updates/reads (resp.) of domain_list and domain_hash. */
-extern spinlock_t domlist_update_lock;
-extern rcu_read_lock_t domlist_read_lock;
-
 extern struct domain *domain_list;
 
 /* Caller must hold the domlist_read_lock or domlist_update_lock. */

diff --git a/xen/xsm/flask/avc.c b/xen/xsm/flask/avc.c
index 57b1657d619f01ab8d972b4df6e272f895598433..60efc62458a58d8101125ac3cf748e021d2285cb 100644 (file)
--- a/xen/xsm/flask/avc.c
+++ b/xen/xsm/flask/avc.c
@@ -124,6 +124,8 @@ DEFINE_PER_CPU(struct avc_cache_stats, avc_cache_stats);
 static struct avc_cache avc_cache;
 static struct avc_callback_node *avc_callbacks;
 
+static DEFINE_RCU_READ_LOCK(avc_rcu_lock);
+
 static inline int avc_hash(u32 ssid, u32 tsid, u16 tclass)
 {
     return (ssid ^ (tsid<<2) ^ (tclass<<4)) & (AVC_CACHE_SLOTS - 1);
@@ -255,7 +257,7 @@ int avc_get_hash_stats(char *buf, uint32_t size)
     struct avc_node *node;
     struct hlist_head *head;
 
-    rcu_read_lock();
+    rcu_read_lock(&avc_rcu_lock);
 
     slots_used = 0;
     max_chain_len = 0;
@@ -275,7 +277,7 @@ int avc_get_hash_stats(char *buf, uint32_t size)
         }
     }
 
-    rcu_read_unlock();
+    rcu_read_unlock(&avc_rcu_lock);
     
     return snprintf(buf, size, "entries: %d\nbuckets used: %d/%d\n"
                                 "longest chain: %d\n",
@@ -328,7 +330,7 @@ static inline int avc_reclaim_node(void)
         lock = &avc_cache.slots_lock[hvalue];
 
         spin_lock_irqsave(&avc_cache.slots_lock[hvalue], flags);
-        rcu_read_lock();
+        rcu_read_lock(&avc_rcu_lock);
         hlist_for_each_entry(node, next, head, list)
         {
                 avc_node_delete(node);
@@ -336,12 +338,12 @@ static inline int avc_reclaim_node(void)
                 ecx++;
                 if ( ecx >= AVC_CACHE_RECLAIM )
                 {
-                 rcu_read_unlock();
+                 rcu_read_unlock(&avc_rcu_lock);
                  spin_unlock_irqrestore(lock, flags);
                  goto out;
                 }
         }
-        rcu_read_unlock();
+        rcu_read_unlock(&avc_rcu_lock);
         spin_unlock_irqrestore(lock, flags);
     }    
 out:
@@ -727,10 +729,10 @@ int avc_ss_reset(u32 seqno)
         lock = &avc_cache.slots_lock[i];
 
         spin_lock_irqsave(lock, flag);
-        rcu_read_lock();
+        rcu_read_lock(&avc_rcu_lock);
         hlist_for_each_entry(node, next, head, list)
             avc_node_delete(node);
-        rcu_read_unlock();
+        rcu_read_unlock(&avc_rcu_lock);
         spin_unlock_irqrestore(lock, flag);
     }
     
@@ -780,12 +782,12 @@ int avc_has_perm_noaudit(u32 ssid, u32 tsid, u16 tclass, u32 requested,
 
     BUG_ON(!requested);
 
-    rcu_read_lock();
+    rcu_read_lock(&avc_rcu_lock);
 
     node = avc_lookup(ssid, tsid, tclass);
     if ( !node )
     {
-        rcu_read_unlock();
+        rcu_read_unlock(&avc_rcu_lock);
 
         if ( in_avd )
             avd = in_avd;
@@ -795,7 +797,7 @@ int avc_has_perm_noaudit(u32 ssid, u32 tsid, u16 tclass, u32 requested,
         rc = security_compute_av(ssid,tsid,tclass,requested,avd);
         if ( rc )
             goto out;
-        rcu_read_lock();
+        rcu_read_lock(&avc_rcu_lock);
         node = avc_insert(ssid,tsid,tclass,avd);
     } else {
         if ( in_avd )
@@ -814,7 +816,7 @@ int avc_has_perm_noaudit(u32 ssid, u32 tsid, u16 tclass, u32 requested,
             rc = -EACCES;
     }
 
-    rcu_read_unlock();
+    rcu_read_unlock(&avc_rcu_lock);
 out:
     return rc;
 }