base-linux: do not copy dataspace components

Dataspace components inherit from RPC objects which are non-copyable from now
on. Therefore, the Rom_session_component's constructor had to be modified
to not construct a dataspace component on the stack and assign it in the
following.

Ref #1704

repos/base-linux/src/core/dataspace_component.cc

@@ -0,0 +1,62 @@
+/*
+ * \brief  Linux-specific core implementation of the dataspace component
+ * \author Stefan Kalkowski
+ * \date   2015-09-25
+ *
+ * The Linux version of ROM session component does not use the
+ * Rom_fs as provided as constructor argument. Instead, we map
+ * rom modules directly to files of the host file system.
+ */
+
+/*
+ * Copyright (C) 2015 Genode Labs GmbH
+ *
+ * This file is part of the Genode OS framework, which is distributed
+ * under the terms of the GNU General Public License version 2.
+ */
+
+/* Linux includes */
+#include <core_linux_syscalls.h>
+#include <sys/fcntl.h>
+
+/* Genode includes */
+#include <linux_dataspace/linux_dataspace.h>
+#include <util/arg_string.h>
+#include <root/root.h>
+
+/* local includes */
+#include "dataspace_component.h"
+
+using namespace Genode;
+
+
+Linux_dataspace::Filename Dataspace_component::_file_name(const char *args)
+{
+	Filename fname;
+	Arg_string::find_arg(args, "filename").string(fname.buf,
+	                                              sizeof(fname.buf), "");
+	
+	/* only files inside the current working directory are allowed */
+	for (const char *c = fname.buf; *c; c++)
+		if (*c == '/') throw Root::Invalid_args();
+
+	return fname;
+}
+
+
+Genode::size_t Dataspace_component::_file_size()
+{
+	struct stat64 s;
+	if (lx_stat(_fname.buf, &s) < 0) throw Root::Invalid_args();
+
+	return s.st_size;
+}
+
+
+Dataspace_component::Dataspace_component(const char *args)
+: _fname(_file_name(args)),
+  _size(_file_size()),
+  _addr(0),
+  _fd(lx_open(_fname.buf, O_RDONLY | LX_O_CLOEXEC, S_IRUSR | S_IXUSR)),
+  _writable(false),
+  _owner(0) { }

repos/base-linux/src/core/include/dataspace_component.h

@@ -36,9 +36,9 @@ namespace Genode {
 	{
 		private:
 
+			Filename       _fname;              /* filename for mmap          */
 			size_t         _size;               /* size of dataspace in bytes */
 			addr_t         _addr;               /* meaningless on linux       */
-			Filename       _fname;              /* filename for mmap          */
 			int            _fd;                 /* file descriptor            */
 			bool           _writable;           /* false if read-only         */
 
@@ -46,6 +46,9 @@ namespace Genode {
 			 * others is necessary on the dataspace, otherwise it is 0 */
 			Dataspace_owner * _owner;
 
+			static Filename _file_name(const char *args);
+			size_t _file_size();
+
 		public:
 
 			/**
@@ -78,12 +81,11 @@ namespace Genode {
 			}
 
 			/**
-			 * Define corresponding filename of dataspace
+			 * This constructor is especially used for ROM dataspaces
 			 *
-			 * The file name is only relevant for ROM dataspaces that should
-			 * be executed via execve.
+			 * \param args  session parameters containing 'filename' key/value
 			 */
-			void fname(const char *fname) { strncpy(_fname.buf, fname, sizeof(_fname.buf)); }
+			Dataspace_component(const char *args);
 
 			/**
 			 * Assign file descriptor to dataspace

repos/base-linux/src/core/rom_session_component.cc

@@ -30,45 +30,11 @@
 using namespace Genode;
 
 
-static Genode::size_t file_size(const char *path)
-{
-	struct stat64 s;
-	if (lx_stat(path, &s) < 0)
-		return 0;
-	else
-		return s.st_size;
-}
-
-
 Rom_session_component::Rom_session_component(Rom_fs         *rom_fs,
                                              Rpc_entrypoint *ds_ep,
                                              const char     *args)
-: _ds_ep(ds_ep)
+: _ds(args), _ds_ep(ds_ep)
 {
-	/* extract filename from session arguments */
-	char fname[Linux_dataspace::FNAME_LEN];
-	Arg_string::find_arg(args, "filename").string(fname, sizeof(fname), "");
-
-	/* only files inside the current working directory are allowed */
-	for (const char *c = fname; *c; c++)
-		if (*c == '/')
-			throw Root::Invalid_args();
-
-	Genode::size_t const fsize = file_size(fname);
-
-	/* use invalid capability as default value */
-	_ds_cap = Rom_dataspace_capability();
-
-	/* ROM module not found */
-	if (fsize == 0)
-		throw Root::Invalid_args();
-
-	int const fd = lx_open(fname, O_RDONLY | LX_O_CLOEXEC, S_IRUSR | S_IXUSR);
-
-	_ds = Dataspace_component(fsize, 0, CACHED, false, 0);
-	_ds.fd(fd);
-	_ds.fname(fname);
-
 	Dataspace_capability ds_cap = _ds_ep->manage(&_ds);
 	_ds_cap = static_cap_cast<Rom_dataspace>(ds_cap);
 }

repos/base-linux/src/core/target.mk

@@ -15,6 +15,7 @@ SRC_CC        = main.cc \
                 cpu_session_component.cc \
                 cpu_session_extension.cc \
                 cpu_session_support.cc \
+                dataspace_component.cc \
                 pd_session_component.cc \
                 io_mem_session_component.cc \
                 signal_session_component.cc \