diff --git a/repos/dde_rump/lib/mk/rump_base.inc b/repos/dde_rump/lib/mk/rump_base.inc
index 45bd84779..b70e54794 100644
--- a/repos/dde_rump/lib/mk/rump_base.inc
+++ b/repos/dde_rump/lib/mk/rump_base.inc
@@ -28,8 +28,8 @@ SOURCE = $(addprefix $(REP_DIR)/src/lib/rump/,$(SRC_CC))
 BUILD_CMD = BUILD_CC=cc BUILD_AR=ar BUILD_NM=nm BUILD_OBJCOPY=objcopy \
             AR=$(AR) NM=$(NM) OBJCOPY=$(OBJCOPY) CC_TARGET=$(shell basename $(CC)) \
             $(RUMP_CONTRIB_DIR)/buildrump.sh -k -V'MAKEVERBOSE=$(VERBOSE_LEVEL)' \
-            -V'NOGCCERROR=1' $(RUMP_OPT) -s $(RUMP_SRC) -T $(RUMP_TOOLS) \
-            -o $(RUMP_OBJ) -d $(RUMP_BASE)
+            -V'NOGCCERROR=1' $(RUMP_OPT) -V'RUMP_LOCKS_UP=yes' \
+            -s $(RUMP_SRC) -T $(RUMP_TOOLS) -o $(RUMP_OBJ) -d $(RUMP_BASE)
 
 #
 # Linkage
diff --git a/repos/dde_rump/src/lib/rump/hypercall.cc b/repos/dde_rump/src/lib/rump/hypercall.cc
index 0891ee6f6..2624dddac 100644
--- a/repos/dde_rump/src/lib/rump/hypercall.cc
+++ b/repos/dde_rump/src/lib/rump/hypercall.cc
@@ -230,11 +230,11 @@ int rumpuser_malloc(size_t len, int alignment, void **memp)
 {
 	Genode::Lock::Guard guard(_alloc_lock);
 
-	int align = Genode::log2(alignment);
+	int align = alignment ? Genode::log2(alignment) : 0;
 	*memp     = allocator()->alloc(len, align);
 
 	if (verbose)
-		PWRN("ALLOC: p: %p, s: %zx, a: %d", *memp, len, align);
+		PWRN("ALLOC: p: %p, s: %zx, a: %d %d", *memp, len, align, alignment);
 
 
 	return *memp ? 0 : -1;
diff --git a/repos/dde_rump/src/lib/rump/io.cc b/repos/dde_rump/src/lib/rump/io.cc
index e1f02a71c..22b4bfde6 100644
--- a/repos/dde_rump/src/lib/rump/io.cc
+++ b/repos/dde_rump/src/lib/rump/io.cc
@@ -309,15 +309,13 @@ void rumpuser_bio(int fd, int op, void *data, size_t dlen, int64_t off,
                   rump_biodone_fn biodone, void *donearg)
 {
 	int nlocks;
-	
-	rumpkern_unsched(&nlocks, 0);
 
+	rumpkern_unsched(&nlocks, 0);
 	Packet *p = backend()->alloc();
 
-#if 0
-	PDBG("fd: %d op: %d len: %zu off: %lx p %p bio %p sync %u", fd, op, dlen, off,
-	     p, donearg, !!(op & RUMPUSER_BIO_SYNC));
-#endif
+	if (verbose)
+		PDBG("fd: %d op: %d len: %zu off: %lx p %p bio %p sync %u", fd, op, dlen, off,
+		     p, donearg, !!(op & RUMPUSER_BIO_SYNC));
 
 	p->opcode= op & RUMPUSER_BIO_WRITE ? Block::Packet_descriptor::WRITE :
 	                                     Block::Packet_descriptor::READ;
diff --git a/repos/dde_rump/src/lib/rump/sync.cc b/repos/dde_rump/src/lib/rump/sync.cc
index 805af7e64..d1c8cc555 100644
--- a/repos/dde_rump/src/lib/rump/sync.cc
+++ b/repos/dde_rump/src/lib/rump/sync.cc
@@ -35,18 +35,19 @@ struct rumpuser_mtx
 
 	bool down(bool try_lock = false)
 	{
-		counter_lock.lock();
+		Genode::Lock::Guard guard(counter_lock);
 
 		if (sem.cnt() > 1)
-			PERR("SEM cnt > 1");
+			PERR("%p: SEM cnt > 1 (%d) %p", rumpuser_curlwp(), sem.cnt(), this);
 
 		bool locked = sem.cnt() <= 0;
 
-		counter_lock.unlock();
-
 		if (locked && try_lock)
 			return false;
 
+		if (!try_lock)
+			counter_lock.unlock();
+
 		sem.down();
 		set_owner();
 
@@ -56,6 +57,10 @@ struct rumpuser_mtx
 	void up()
 	{
 		Genode::Lock::Guard guard(counter_lock);
+
+		if (sem.cnt() >= 1)
+			return;
+
 		clear_owner();
 		sem.up();
 	}
@@ -453,10 +458,26 @@ void rumpuser_rw_init(struct rumpuser_rw **rw)
 
 void rumpuser_rw_enter(int enum_rumprwlock, struct rumpuser_rw *rw)
 {
-	if (enum_rumprwlock == RUMPUSER_RW_WRITER)
-		rw->rw.lock(false);
-	else
-		rw->rw.read_lock(false);
+	int nlocks;
+	bool try_lock = true;
+	bool locked   = false;
+
+
+	while (!locked) {
+
+		if (!try_lock)
+			rumpkern_unsched(&nlocks, 0);
+
+		if (enum_rumprwlock == RUMPUSER_RW_WRITER)
+			locked = rw->rw.lock(try_lock);
+		else
+			locked = rw->rw.read_lock(try_lock);
+
+		if (!try_lock)
+			rumpkern_sched(nlocks, 0);
+
+		try_lock = false;
+	}
 }