From 5c89312cdfe484e7b8e4cf32427d7576aa4ba2ac Mon Sep 17 00:00:00 2001

From: Noriko Hosoi <nhosoi@redhat.com>

Date: Mon, 11 Jan 2016 15:53:28 -0800

Subject: [PATCH 373/375] Ticket #48406 - Avoid self deadlock by

 PR_Lock(conn->c_mutex)

Description:  Fixing ticket 48338 introduced a self deadlock.

To avoid the self deadlock, tried to remove PR_Lock(conn->c_mutex)

which looked harmless, but it introduced a crash by memory corruption.

This patch replaces PR_Lock/Unlock with PR_EnterMonitor/ExitMonitor,

respectively.

https://fedorahosted.org/389/ticket/48406

Reviewed by rmeggins@redhat.com, lkrispen@redhat.com, and wibrown@redhat.com.

Thank you, Rich, Ludwig and William!

(cherry picked from commit f25f804a8bce83b3790e7045dfc03230d7ece1af)

(cherry picked from commit 84da7d05ddc5a963b0d025df08f38a6ccd7d90d2)

(cherry picked from commit ad08d1fa7c258bb99cd64a4de570035d82e6a492)

(cherry picked from commit f69d19a351a34313c5f45499718c892a9bb3b42a)

---

 ldap/servers/slapd/abandon.c         |   4 +-

 ldap/servers/slapd/bind.c            |   4 +-

 ldap/servers/slapd/connection.c      |  88 +++++++++++++++---------------

 ldap/servers/slapd/conntable.c       |  19 +++----

 ldap/servers/slapd/daemon.c          |  14 ++---

 ldap/servers/slapd/extendop.c        |  10 ++--

 ldap/servers/slapd/opshared.c        |  18 +++----

 ldap/servers/slapd/pagedresults.c    | 100 +++++++++++++++++------------------

 ldap/servers/slapd/pblock.c          |  72 ++++++++++++-------------

 ldap/servers/slapd/psearch.c         |   8 +--

 ldap/servers/slapd/saslbind.c        |  26 ++++-----

 ldap/servers/slapd/slap.h            |   2 +-

 ldap/servers/slapd/start_tls_extop.c |  15 +++---

 ldap/servers/slapd/unbind.c          |   4 +-

 14 files changed, 192 insertions(+), 192 deletions(-)

diff --git a/ldap/servers/slapd/abandon.c b/ldap/servers/slapd/abandon.c

index 09da149..06a17e1 100644

--- a/ldap/servers/slapd/abandon.c

+++ b/ldap/servers/slapd/abandon.c

@@ -108,7 +108,7 @@ do_abandon( Slapi_PBlock *pb )

 	 * flag and abort the operation at a convenient time.

 	 */

-	PR_Lock( pb->pb_conn->c_mutex );

+	PR_EnterMonitor(pb->pb_conn->c_mutex);

 	for ( o = pb->pb_conn->c_ops; o != NULL; o = o->o_next ) {

 		if ( o->o_msgid == id && o != pb->pb_op)

 			break;

@@ -170,7 +170,7 @@ do_abandon( Slapi_PBlock *pb )

 	}

-	PR_Unlock( pb->pb_conn->c_mutex );

+	PR_ExitMonitor(pb->pb_conn->c_mutex);

 	/*

 	 * Wake up the persistent searches, so they

 	 * can notice if they've been abandoned.

diff --git a/ldap/servers/slapd/bind.c b/ldap/servers/slapd/bind.c

index 11ec22e..bc8040f 100644

--- a/ldap/servers/slapd/bind.c

+++ b/ldap/servers/slapd/bind.c

@@ -290,7 +290,7 @@ do_bind( Slapi_PBlock *pb )

         slapi_pblock_get (pb, SLAPI_PWPOLICY, &pw_response_requested);

     }

-    PR_Lock( pb->pb_conn->c_mutex );

+    PR_EnterMonitor(pb->pb_conn->c_mutex);

     bind_credentials_clear( pb->pb_conn, PR_FALSE, /* do not lock conn */

                             PR_FALSE /* do not clear external creds. */ );

@@ -323,7 +323,7 @@ do_bind( Slapi_PBlock *pb )

      * bound user can work properly

      */

     pb->pb_conn->c_needpw = 0;

-    PR_Unlock( pb->pb_conn->c_mutex );

+    PR_ExitMonitor(pb->pb_conn->c_mutex);

     log_bind_access(pb, dn?dn:"empty", method, version, saslmech, NULL);

diff --git a/ldap/servers/slapd/connection.c b/ldap/servers/slapd/connection.c

index c2ec4a7..d0387fc 100644

--- a/ldap/servers/slapd/connection.c

+++ b/ldap/servers/slapd/connection.c

@@ -111,7 +111,7 @@ connection_done(Connection *conn)

 	}

 	if (NULL != conn->c_mutex)

 	{

-		PR_DestroyLock(conn->c_mutex);

+		PR_DestroyMonitor(conn->c_mutex);

 	}

 	if (NULL != conn->c_pdumutex)

 	{

@@ -703,10 +703,10 @@ int connection_is_free (Connection *conn)

 {

     int rc;

-    PR_Lock(conn->c_mutex);

+    PR_EnterMonitor(conn->c_mutex);

     rc = conn->c_sd == SLAPD_INVALID_SOCKET && conn->c_refcnt == 0 &&

          !(conn->c_flags & CONN_FLAG_CLOSING);

-    PR_Unlock(conn->c_mutex);

+    PR_ExitMonitor(conn->c_mutex);

     return rc;

 }

@@ -748,17 +748,17 @@ static void inc_op_count(Connection* conn)

 static int connection_increment_reference(Connection *conn)

 {

 	int rc = 0;

-	PR_Lock( conn->c_mutex );

+	PR_EnterMonitor(conn->c_mutex);

 	rc = connection_acquire_nolock (conn);

-	PR_Unlock( conn->c_mutex );

+	PR_ExitMonitor(conn->c_mutex);

 	return rc;

 }

 static void connection_decrement_reference(Connection *conn)

 {

-	PR_Lock( conn->c_mutex );

+	PR_EnterMonitor(conn->c_mutex);

 	connection_release_nolock (conn);

-	PR_Unlock( conn->c_mutex );

+	PR_ExitMonitor(conn->c_mutex);

 }

 static void

@@ -990,29 +990,29 @@ done:

 	     * If not a persistent search, remove the operation

 	     * from this connection's list.

 	     */

-	    PR_Lock( conn->c_mutex );

+	    PR_EnterMonitor(conn->c_mutex);

 	    connection_remove_operation( conn, op );

-	    PR_Unlock( conn->c_mutex );

+	    PR_ExitMonitor(conn->c_mutex);

 		/* destroying the pblock will cause destruction of the operation

 		 * so this must happen before releasing the connection

 		 */

 	    slapi_pblock_destroy( pb );

-	    PR_Lock( conn->c_mutex );

+	    PR_EnterMonitor(conn->c_mutex);

         if (connection_release_nolock (conn) != 0)

 	    {

 			return_value = -1;

 		}

-	    PR_Unlock( conn->c_mutex );

+	    PR_ExitMonitor(conn->c_mutex);

 	} else { /* ps code acquires ref to conn - we need to release ours here */

-	    PR_Lock( conn->c_mutex );

+	    PR_EnterMonitor(conn->c_mutex);

         if (connection_release_nolock (conn) != 0)

 	    {

 			return_value = -1;

 		}

-	    PR_Unlock( conn->c_mutex );

+	    PR_ExitMonitor(conn->c_mutex);

 	}

 	return return_value;

 }

@@ -1075,19 +1075,19 @@ static int connection_operation_new(Connection *conn, Operation **ppOp)

 	Operation *temp_op = NULL;

 	int rc;

-	PR_Lock( conn->c_mutex );

+	PR_EnterMonitor(conn->c_mutex);

 	if (connection_is_active_nolock(conn) == 0) {

 	    LDAPDebug(LDAP_DEBUG_CONNS,

 		      "not creating a new operation when conn %" NSPRIu64 " closing\n",

 		      conn->c_connid,0,0);

-	    PR_Unlock( conn->c_mutex );

+	    PR_ExitMonitor(conn->c_mutex);

 	    return -1;

 	}

 	temp_op = operation_new( plugin_build_operation_action_bitmap( 0,

 			plugin_get_server_plg() ));

 	connection_add_operation( conn, temp_op);

 	rc = connection_acquire_nolock (conn); 

-	PR_Unlock( conn->c_mutex );

+	PR_ExitMonitor(conn->c_mutex);

 	/* Stash the op pointer in the connection structure for later use */

 	PR_ASSERT(NULL == conn->c_private->c_current_op);

 	conn->c_private->c_current_op = temp_op;

@@ -1173,21 +1173,21 @@ static int read_the_data(Connection *conn, int *process_op, int *defer_io, int *

 						"conn=%" NSPRIu64 " fd=%d The length of BER Element was too long.\n",

 						conn->c_connid, conn->c_sd );

 				}

-				PR_Lock( conn->c_mutex );

+				PR_EnterMonitor(conn->c_mutex);

 				connection_remove_operation( conn, op );

 				operation_free(&op, conn);

 				priv->c_current_op = NULL;

-				PR_Unlock( conn->c_mutex );

+				PR_ExitMonitor(conn->c_mutex);

 				return -1; /* Abandon Connection */

 			}

 		}

 		if (is_ber_too_big(conn,ber_len))

 		{

-			PR_Lock( conn->c_mutex );

+			PR_EnterMonitor(conn->c_mutex);

 			connection_remove_operation( conn, op );

 			operation_free(&op, conn);

 			priv->c_current_op = NULL;

-			PR_Unlock( conn->c_mutex );

+			PR_ExitMonitor(conn->c_mutex);

 			return -1; /* Abandon Connection */

 		}

@@ -1210,11 +1210,11 @@ static int read_the_data(Connection *conn, int *process_op, int *defer_io, int *

 					"conn=%" NSPRIu64 " received a non-LDAP message"

 					" (tag 0x%lx, expected 0x%lx)\n",

 					conn->c_connid, tag, LDAP_TAG_MESSAGE );

-				PR_Lock( conn->c_mutex );

+				PR_EnterMonitor(conn->c_mutex);

 				connection_remove_operation( conn, op );

 	     	    operation_free(&op, conn);

 				priv->c_current_op = NULL;

-				PR_Unlock( conn->c_mutex );

+				PR_ExitMonitor(conn->c_mutex);

 				return -1; /* Abandon Connection */

 			}

 		}

@@ -1891,10 +1891,10 @@ int connection_read_operation(Connection *conn, Operation *op, ber_tag_t *tag, i

 		if (ret <= 0) {

 			if (0 == ret) {

 				/* Connection is closed */

-				PR_Lock( conn->c_mutex );

+				PR_EnterMonitor(conn->c_mutex);

 				disconnect_server_nomutex( conn, conn->c_connid, -1, SLAPD_DISCONNECT_BAD_BER_TAG, 0 );

 				conn->c_gettingber = 0;

-				PR_Unlock( conn->c_mutex );

+				PR_ExitMonitor(conn->c_mutex);

 				signal_listner();

 				return CONN_DONE;

 			}

@@ -2024,9 +2024,9 @@ int connection_read_operation(Connection *conn, Operation *op, ber_tag_t *tag, i

 void connection_make_readable(Connection *conn)

 {

-	PR_Lock( conn->c_mutex );

+	PR_EnterMonitor(conn->c_mutex);

 	conn->c_gettingber = 0;

-	PR_Unlock( conn->c_mutex );

+	PR_ExitMonitor(conn->c_mutex);

 	signal_listner();

 }

@@ -2037,7 +2037,7 @@ void connection_check_activity_level(Connection *conn)

 {

 	int current_count = 0;

 	int delta_count = 0;

-	PR_Lock( conn->c_mutex );

+	PR_EnterMonitor(conn->c_mutex);

 	/* get the current op count */

 	current_count = conn->c_opscompleted;

 	/* compare to the previous op count */

@@ -2048,7 +2048,7 @@ void connection_check_activity_level(Connection *conn)

 	conn->c_private->previous_op_count = current_count;

 	/* update the last checked time */

 	conn->c_private->previous_count_check_time = current_time();

-	PR_Unlock( conn->c_mutex );

+	PR_ExitMonitor(conn->c_mutex);

 	LDAPDebug(LDAP_DEBUG_CONNS,"conn %" NSPRIu64 " activity level = %d\n",conn->c_connid,delta_count,0); 

 }

@@ -2092,7 +2092,7 @@ void connection_enter_leave_turbo(Connection *conn, int current_turbo_flag, int

 	int connection_count = 0;

 	int our_rank = 0;

 	int threshold_rank = 0;

-	PR_Lock(conn->c_mutex);

+	PR_EnterMonitor(conn->c_mutex);

 	/* We can already be in turbo mode, or not */

 	current_mode = current_turbo_flag;

 	if (pagedresults_in_use_nolock(conn)) {

@@ -2148,7 +2148,7 @@ void connection_enter_leave_turbo(Connection *conn, int current_turbo_flag, int

 		}

 	  }

 	}

-	PR_Unlock(conn->c_mutex);

+	PR_ExitMonitor(conn->c_mutex);

 	if (current_mode != new_mode) {

 		if (current_mode) {

 			LDAPDebug(LDAP_DEBUG_CONNS,"conn %" NSPRIu64 " leaving turbo mode\n",conn->c_connid,0,0); 

@@ -2244,13 +2244,13 @@ connection_threadmain()

 			*/

 			PR_Sleep(PR_INTERVAL_NO_WAIT);

-			PR_Lock(conn->c_mutex);

+			PR_EnterMonitor(conn->c_mutex);

 			/* Make our own pb in turbo mode */

 			connection_make_new_pb(&pb,conn);

 			if (connection_call_io_layer_callbacks(conn)) {

 				LDAPDebug0Args( LDAP_DEBUG_ANY, "Error: could not add/remove IO layers from connection\n" );

 			}

-			PR_Unlock(conn->c_mutex);

+			PR_ExitMonitor(conn->c_mutex);

 			if (! config_check_referral_mode()) {

 			  slapi_counter_increment(ops_initiated);

 			  slapi_counter_increment(g_get_global_snmp_vars()->ops_tbl.dsInOps); 

@@ -2374,7 +2374,7 @@ done:

 		/* If this op isn't a persistent search, remove it */

 		if ( !( pb->pb_op->o_flags & OP_FLAG_PS )) {

 		    /* delete from connection operation queue & decr refcnt */

-		    PR_Lock( conn->c_mutex );

+		    PR_EnterMonitor(conn->c_mutex);

 		    connection_remove_operation( conn, op );

 			/* destroying the pblock will cause destruction of the operation

 			 * so this must happend before releasing the connection

@@ -2386,11 +2386,11 @@ done:

 		    if (!thread_turbo_flag && !more_data) {

 				connection_release_nolock (conn);

 			}

-		    PR_Unlock( conn->c_mutex );

+		    PR_ExitMonitor(conn->c_mutex);

 		} else { /* the ps code acquires a ref to the conn - we need to release ours here */

-		    PR_Lock( conn->c_mutex );

+		    PR_EnterMonitor(conn->c_mutex);

 			connection_release_nolock (conn);

-		    PR_Unlock( conn->c_mutex );

+		    PR_ExitMonitor(conn->c_mutex);

 		}

 		/* Since we didn't do so earlier, we need to make a replication connection readable again here */

 		if ( ((1 == is_timedout) || (replication_connection && !thread_turbo_flag)) && !more_data)

@@ -2401,7 +2401,7 @@ done:

 		}

 		if (!thread_turbo_flag && !more_data) { /* Don't do this in turbo mode */

-			PR_Lock( conn->c_mutex );

+			PR_EnterMonitor(conn->c_mutex);

 			/* if the threadnumber of now below the maximum, wakeup

 			 * the listener thread so that we start polling on this 

 			 * connection again

@@ -2412,7 +2412,7 @@ done:

 			else

 				need_wakeup = 0;

 			conn->c_threadnumber--;

-			PR_Unlock( conn->c_mutex );

+			PR_ExitMonitor(conn->c_mutex);

 			if (need_wakeup)

 				signal_listner();

@@ -2647,7 +2647,7 @@ op_copy_identity(Connection *conn, Operation *op)

     size_t dnlen;

     size_t typelen;

-	PR_Lock( conn->c_mutex );

+	PR_EnterMonitor(conn->c_mutex);

 	dnlen= conn->c_dn ? strlen (conn->c_dn) : 0;

 	typelen= conn->c_authtype ? strlen (conn->c_authtype) : 0;

@@ -2679,14 +2679,14 @@ op_copy_identity(Connection *conn, Operation *op)

         op->o_ssf = conn->c_local_ssf;

     }

-    PR_Unlock( conn->c_mutex );

+    PR_ExitMonitor(conn->c_mutex);

 }

 /* Sets the SSL SSF in the connection struct. */

 static void

 connection_set_ssl_ssf(Connection *conn)

 {

-	PR_Lock( conn->c_mutex );

+	PR_EnterMonitor(conn->c_mutex);

 	if (conn->c_flags & CONN_FLAG_SSL) {

 		SSL_SecurityStatus(conn->c_prfd, NULL, NULL, NULL, &(conn->c_ssl_ssf), NULL, NULL);

@@ -2694,7 +2694,7 @@ connection_set_ssl_ssf(Connection *conn)

 		conn->c_ssl_ssf = 0;

 	}

-	PR_Unlock( conn->c_mutex );

+	PR_ExitMonitor(conn->c_mutex);

 }

 static int

@@ -2741,9 +2741,9 @@ log_ber_too_big_error(const Connection *conn, ber_len_t ber_len,

 void

 disconnect_server( Connection *conn, PRUint64 opconnid, int opid, PRErrorCode reason, PRInt32 error )

 {

-	PR_Lock( conn->c_mutex );

+	PR_EnterMonitor(conn->c_mutex);

 	disconnect_server_nomutex( conn, opconnid, opid, reason, error );

-	PR_Unlock( conn->c_mutex );

+	PR_ExitMonitor(conn->c_mutex);

 }

 static ps_wakeup_all_fn_ptr ps_wakeup_all_fn = NULL;

diff --git a/ldap/servers/slapd/conntable.c b/ldap/servers/slapd/conntable.c

index 7cf9f31..5917401 100644

--- a/ldap/servers/slapd/conntable.c

+++ b/ldap/servers/slapd/conntable.c

@@ -141,11 +141,11 @@ connection_table_abandon_all_operations(Connection_Table *ct)

 	int	i;

 	for ( i = 0; i < ct->size; i++ )

 	{

-		if ( ct->c[i].c_mutex != NULL )

+		if ( ct->c[i].c_mutex )

 		{

-			PR_Lock( ct->c[i].c_mutex );

+			PR_EnterMonitor(ct->c[i].c_mutex);

 			connection_abandon_operations( &ct->c[i] );

-			PR_Unlock( ct->c[i].c_mutex );

+			PR_ExitMonitor(ct->c[i].c_mutex);

 		}

 	}

 }

@@ -195,7 +195,7 @@ connection_table_get_connection(Connection_Table *ct, int sd)

 		if ( c->c_mutex == NULL )

 		{

 			PR_Lock( ct->table_mutex );

-			c->c_mutex = PR_NewLock();

+			c->c_mutex = PR_NewMonitor();

 			c->c_pdumutex = PR_NewLock();

 			PR_Unlock( ct->table_mutex );

 			if ( c->c_mutex == NULL || c->c_pdumutex == NULL )

@@ -399,7 +399,7 @@ connection_table_as_entry(Connection_Table *ct, Slapi_Entry *e)

 		/* Can't take c_mutex if holding table_mutex; temporarily unlock */ 

 		PR_Unlock( ct->table_mutex );

-		PR_Lock( ct->c[i].c_mutex );

+		PR_EnterMonitor(ct->c[i].c_mutex);

 		if ( ct->c[i].c_sd != SLAPD_INVALID_SOCKET )

 		{

 			char buf2[20];

@@ -446,7 +446,7 @@ connection_table_as_entry(Connection_Table *ct, Slapi_Entry *e)

 			attrlist_merge( &e->e_attrs, "connection", vals );

 			slapi_ch_free_string(&newbuf);

 		}

-		PR_Unlock( ct->c[i].c_mutex );

+		PR_ExitMonitor(ct->c[i].c_mutex);

 	}

 	PR_snprintf( buf, sizeof(buf), "%d", nconns );

@@ -474,14 +474,15 @@ void

 connection_table_dump_activity_to_errors_log(Connection_Table *ct)

 {

 	int i;

+

 	for ( i = 0; i < ct->size; i++ )

 	{

 		Connection *c= &(ct->c[i]);

-		if ( c->c_mutex != NULL )

+		if ( c->c_mutex )

 		{

 			/* Find the connection we are referring to */

 			int j= c->c_fdi;

-			PR_Lock( c->c_mutex );

+			PR_EnterMonitor(c->c_mutex);

 			if ( (c->c_sd != SLAPD_INVALID_SOCKET) && 

 			     (j >= 0) && (c->c_prfd == ct->fd[j].fd) )

 			{

@@ -491,7 +492,7 @@ connection_table_dump_activity_to_errors_log(Connection_Table *ct)

 					LDAPDebug( LDAP_DEBUG_CONNS,"activity on %d%s\n", i, r ? "r" : "",0 );

 				}

 			}

-			PR_Unlock( c->c_mutex );

+			PR_ExitMonitor(c->c_mutex);

 		}

 	}

 }

diff --git a/ldap/servers/slapd/daemon.c b/ldap/servers/slapd/daemon.c

index 9a362c7..b34358d 100644

--- a/ldap/servers/slapd/daemon.c

+++ b/ldap/servers/slapd/daemon.c

@@ -1678,7 +1678,7 @@ setup_pr_read_pds(Connection_Table *ct, PRFileDesc **n_tcps, PRFileDesc **s_tcps

 		}

 		else

 		{

-			PR_Lock( c->c_mutex );

+			PR_EnterMonitor(c->c_mutex);

 			if (c->c_flags & CONN_FLAG_CLOSING)

 			{

 				/* A worker thread has marked that this connection

@@ -1724,7 +1724,7 @@ setup_pr_read_pds(Connection_Table *ct, PRFileDesc **n_tcps, PRFileDesc **s_tcps

 					c->c_fdi = SLAPD_INVALID_SOCKET_INDEX;

 				}

 			}

-			PR_Unlock( c->c_mutex );

+			PR_ExitMonitor(c->c_mutex);

 		}

 		c = next;

 	}

@@ -1743,7 +1743,7 @@ handle_timeout( void )

 	time_t curtime = current_time();

 	if (0 == prevtime) {

-		prevtime = time (&housekeeping_fire_time);		

+		prevtime = time (&housekeeping_fire_time);

 	}

 	if ( difftime(curtime, prevtime) >= 

@@ -1979,7 +1979,7 @@ handle_pr_read_ready(Connection_Table *ct, PRIntn num_poll)

 	{

 		if ( c->c_mutex != NULL )

 		{

-			PR_Lock( c->c_mutex );

+			PR_EnterMonitor(c->c_mutex);

 			if ( connection_is_active_nolock (c) && c->c_gettingber == 0 )

 			{

 			    PRInt16 out_flags;

@@ -2036,7 +2036,7 @@ handle_pr_read_ready(Connection_Table *ct, PRIntn num_poll)

 								   SLAPD_DISCONNECT_IDLE_TIMEOUT, EAGAIN );

 				}

 			}

-			PR_Unlock( c->c_mutex );

+			PR_ExitMonitor(c->c_mutex);

 		}

 	}

 #endif

@@ -2611,7 +2611,7 @@ handle_new_connection(Connection_Table *ct, int tcps, PRFileDesc *pr_acceptfd, i

 		PR_Close(pr_acceptfd);

 		return -1;

 	}

-	PR_Lock( conn->c_mutex );

+	PR_EnterMonitor(conn->c_mutex);

 	/*

 	 * Set the default idletimeout and the handle.  We'll update c_idletimeout

@@ -2721,7 +2721,7 @@ handle_new_connection(Connection_Table *ct, int tcps, PRFileDesc *pr_acceptfd, i

 		connection_table_move_connection_on_to_active_list(the_connection_table,conn);

 	}

-	PR_Unlock( conn->c_mutex );

+	PR_ExitMonitor(conn->c_mutex);

 	g_increment_current_conn_count();

diff --git a/ldap/servers/slapd/extendop.c b/ldap/servers/slapd/extendop.c

index 8f25b27..0a0615c 100644

--- a/ldap/servers/slapd/extendop.c

+++ b/ldap/servers/slapd/extendop.c

@@ -90,7 +90,7 @@ static void extop_handle_import_start(Slapi_PBlock *pb, char *extoid,

         send_ldap_result(pb, LDAP_OPERATIONS_ERROR, NULL, NULL, 0, NULL);

         return;

     }

-	suffix = slapi_sdn_get_dn(sdn);

+    suffix = slapi_sdn_get_dn(sdn);

     /*    be = slapi_be_select(sdn); */

     be = slapi_mapping_tree_find_backend_for_sdn(sdn);

     if (be == NULL || be == defbackend_get_backend()) {

@@ -164,10 +164,10 @@ static void extop_handle_import_start(Slapi_PBlock *pb, char *extoid,

     /* okay, the import is starting now -- save the backend in the

      * connection block & mark this connection as belonging to a bulk import

      */

-    PR_Lock(pb->pb_conn->c_mutex);

+    PR_EnterMonitor(pb->pb_conn->c_mutex);

     pb->pb_conn->c_flags |= CONN_FLAG_IMPORT;

     pb->pb_conn->c_bi_backend = be;

-    PR_Unlock(pb->pb_conn->c_mutex);

+    PR_ExitMonitor(pb->pb_conn->c_mutex);

     slapi_pblock_set(pb, SLAPI_EXT_OP_RET_OID, EXTOP_BULK_IMPORT_START_OID);

     bv.bv_val = NULL;

@@ -189,11 +189,11 @@ static void extop_handle_import_done(Slapi_PBlock *pb, char *extoid,

     struct berval bv;

     int ret;

-    PR_Lock(pb->pb_conn->c_mutex);

+    PR_EnterMonitor(pb->pb_conn->c_mutex);

     pb->pb_conn->c_flags &= ~CONN_FLAG_IMPORT;

     be = pb->pb_conn->c_bi_backend;

     pb->pb_conn->c_bi_backend = NULL;

-    PR_Unlock(pb->pb_conn->c_mutex);

+    PR_ExitMonitor(pb->pb_conn->c_mutex);

     if ((be == NULL) || (be->be_wire_import == NULL)) {

         /* can this even happen? */

diff --git a/ldap/servers/slapd/opshared.c b/ldap/servers/slapd/opshared.c

index e73ac6e..6ddbc91 100644

--- a/ldap/servers/slapd/opshared.c

+++ b/ldap/servers/slapd/opshared.c

@@ -700,7 +700,7 @@ op_shared_search (Slapi_PBlock *pb, int send_result)

        * In async paged result case, the search result might be released

        * by other theads.  We need to double check it in the locked region.

        */

-      PR_Lock(pb->pb_conn->c_mutex);

+      PR_EnterMonitor(pb->pb_conn->c_mutex);

       pr_search_result = pagedresults_get_search_result(pb->pb_conn, operation, 1/*locked*/, pr_idx);

       if (pr_search_result) {

         if (pagedresults_is_abandoned_or_notavailable(pb->pb_conn, 1/*locked*/, pr_idx)) {

@@ -708,7 +708,7 @@ op_shared_search (Slapi_PBlock *pb, int send_result)

           /* Previous operation was abandoned and the simplepaged object is not in use. */

           send_ldap_result(pb, 0, NULL, "Simple Paged Results Search abandoned", 0, NULL);

           rc = LDAP_SUCCESS;

-          PR_Unlock(pb->pb_conn->c_mutex);

+          PR_ExitMonitor(pb->pb_conn->c_mutex);

           goto free_and_return;

         } else {

           slapi_pblock_set( pb, SLAPI_SEARCH_RESULT_SET, pr_search_result );

@@ -717,7 +717,7 @@ op_shared_search (Slapi_PBlock *pb, int send_result)

           /* search result could be reset in the backend/dse */

           slapi_pblock_get(pb, SLAPI_SEARCH_RESULT_SET, &sr);

           pagedresults_set_search_result(pb->pb_conn, operation, sr, 1/*locked*/, pr_idx);

-          PR_Unlock(pb->pb_conn->c_mutex);

+          PR_ExitMonitor(pb->pb_conn->c_mutex);

         }

       } else {

         pr_stat = PAGEDRESULTS_SEARCH_END;

@@ -851,10 +851,10 @@ op_shared_search (Slapi_PBlock *pb, int send_result)

         /* PAGED RESULTS */

         if (op_is_pagedresults(operation)) {

             /* cleanup the slot */

-            PR_Lock(pb->pb_conn->c_mutex);

+            PR_EnterMonitor(pb->pb_conn->c_mutex);

             pagedresults_set_search_result(pb->pb_conn, operation, NULL, 1, pr_idx);

             rc = pagedresults_set_current_be(pb->pb_conn, NULL, pr_idx, 1);

-            PR_Unlock(pb->pb_conn->c_mutex);

+            PR_ExitMonitor(pb->pb_conn->c_mutex);

         }

         if (1 == flag_no_such_object) {

             break;

@@ -896,11 +896,11 @@ op_shared_search (Slapi_PBlock *pb, int send_result)

             slapi_pblock_get(pb, SLAPI_SEARCH_RESULT_SET, &sr);

             if (PAGEDRESULTS_SEARCH_END == pr_stat) {

               /* no more entries, but at least another backend */

-              PR_Lock(pb->pb_conn->c_mutex);

+              PR_EnterMonitor(pb->pb_conn->c_mutex);

               pagedresults_set_search_result(pb->pb_conn, operation, NULL, 1, pr_idx);

               be->be_search_results_release(&sr);

               rc = pagedresults_set_current_be(pb->pb_conn, next_be, pr_idx, 1);

-              PR_Unlock(pb->pb_conn->c_mutex);

+              PR_ExitMonitor(pb->pb_conn->c_mutex);

               if (NULL == next_be) {

                   /* no more entries && no more backends */

                   curr_search_count = -1;

@@ -925,9 +925,9 @@ op_shared_search (Slapi_PBlock *pb, int send_result)

             next_be = NULL; /* to break the loop */

             if (operation->o_status & SLAPI_OP_STATUS_ABANDONED) {

                 /* It turned out this search was abandoned. */

-                PR_Lock(pb->pb_conn->c_mutex);

+                PR_EnterMonitor(pb->pb_conn->c_mutex);

                 pagedresults_free_one_msgid_nolock( pb->pb_conn, operation->o_msgid);

-                PR_Unlock(pb->pb_conn->c_mutex);

+                PR_ExitMonitor(pb->pb_conn->c_mutex);

                 /* paged-results-request was abandoned; making an empty cookie. */

                 pagedresults_set_response_control(pb, 0, estimate, -1, pr_idx);

                 send_ldap_result(pb, 0, NULL, "Simple Paged Results Search abandoned", 0, NULL);

diff --git a/ldap/servers/slapd/pagedresults.c b/ldap/servers/slapd/pagedresults.c

index c1947f1..d10edd0 100644

--- a/ldap/servers/slapd/pagedresults.c

+++ b/ldap/servers/slapd/pagedresults.c

@@ -119,7 +119,7 @@ pagedresults_parse_control_value( Slapi_PBlock *pb,

         return LDAP_PROTOCOL_ERROR;

     }

-    PR_Lock(conn->c_mutex);

+    PR_EnterMonitor(conn->c_mutex);

     /* the ber encoding is no longer needed */

     ber_free(ber, 1);

     if ( cookie.bv_len <= 0 ) {

@@ -217,7 +217,7 @@ bail:

             }

         }

     }

-    PR_Unlock(conn->c_mutex);

+    PR_ExitMonitor(conn->c_mutex);

     LDAPDebug1Arg(LDAP_DEBUG_TRACE,

                   "<-- pagedresults_parse_control_value: idx %d\n", *index);

@@ -314,7 +314,7 @@ pagedresults_free_one( Connection *conn, Operation *op, int index )

     LDAPDebug1Arg(LDAP_DEBUG_TRACE,

                   "--> pagedresults_free_one: idx=%d\n", index);

     if (conn && (index > -1)) {

-        PR_Lock(conn->c_mutex);

+        PR_EnterMonitor(conn->c_mutex);

         if (conn->c_pagedresults.prl_count <= 0) {

             LDAPDebug2Args(LDAP_DEBUG_TRACE, "pagedresults_free_one: "

                            "conn=%d paged requests list count is %d\n",

@@ -325,7 +325,7 @@ pagedresults_free_one( Connection *conn, Operation *op, int index )

             conn->c_pagedresults.prl_count--;

             rc = 0;

         }

-        PR_Unlock(conn->c_mutex);

+        PR_ExitMonitor(conn->c_mutex);

     }

     LDAPDebug1Arg(LDAP_DEBUG_TRACE, "<-- pagedresults_free_one: %d\n", rc);

@@ -377,11 +377,11 @@ pagedresults_get_current_be(Connection *conn, int index)

     LDAPDebug1Arg(LDAP_DEBUG_TRACE,

                   "--> pagedresults_get_current_be: idx=%d\n", index);

     if (conn && (index > -1)) {

-        PR_Lock(conn->c_mutex);

+        PR_EnterMonitor(conn->c_mutex);

         if (index < conn->c_pagedresults.prl_maxlen) {

             be = conn->c_pagedresults.prl_list[index].pr_current_be;

         }

-        PR_Unlock(conn->c_mutex);

+        PR_ExitMonitor(conn->c_mutex);

     }

     LDAPDebug1Arg(LDAP_DEBUG_TRACE,

                   "<-- pagedresults_get_current_be: %p\n", be);

@@ -395,12 +395,12 @@ pagedresults_set_current_be(Connection *conn, Slapi_Backend *be, int index, int

     LDAPDebug1Arg(LDAP_DEBUG_TRACE,

                   "--> pagedresults_set_current_be: idx=%d\n", index);

     if (conn && (index > -1)) {

-        if (!nolock) PR_Lock(conn->c_mutex);

+        if (!nolock) PR_EnterMonitor(conn->c_mutex);

         if (index < conn->c_pagedresults.prl_maxlen) {

             conn->c_pagedresults.prl_list[index].pr_current_be = be;

         }

         rc = 0;

-        if (!nolock) PR_Unlock(conn->c_mutex);

+        if (!nolock) PR_ExitMonitor(conn->c_mutex);

     }

     LDAPDebug1Arg(LDAP_DEBUG_TRACE,

                   "<-- pagedresults_set_current_be: %d\n", rc);

@@ -419,13 +419,13 @@ pagedresults_get_search_result(Connection *conn, Operation *op, int locked, int

                    locked?"locked":"not locked", index);

     if (conn && (index > -1)) {

         if (!locked) {