Propagate process labels to PD sessions

On Linux, we use the session label for naming the corresponding Linux
process. When looking up the processes via 'ps', the Genode process
hierarchy becomes immediately visible.

base-linux/include/linux_pd_session/client.h

@@ -35,8 +35,8 @@ namespace Genode {
 		 * Linux-specific extension **
 		 *****************************/
 
-		void start(Capability<Dataspace> binary, Name const &name) {
+		void start(Capability<Dataspace> binary) {
-			call<Rpc_start>(binary, name); }
+			call<Rpc_start>(binary); }
 	};
 }
 

base-linux/include/linux_pd_session/linux_pd_session.h

@@ -21,16 +21,14 @@ namespace Genode {
 
 	struct Linux_pd_session : Pd_session
 	{
-		typedef Rpc_in_buffer<64> Name;
+		void start(Capability<Dataspace> binary);
-
-		void start(Capability<Dataspace> binary, Name const &name);
 
 
 		/*********************
 		 ** RPC declaration **
 		 *********************/
 
-		GENODE_RPC(Rpc_start, void, start, Capability<Dataspace>, Name const &);
+		GENODE_RPC(Rpc_start, void, start, Capability<Dataspace>);
 		GENODE_RPC_INTERFACE_INHERIT(Pd_session, Rpc_start);
 	};
 }

base-linux/src/base/process/process.cc

@@ -57,9 +57,10 @@ Process::Process(Dataspace_capability   elf_data_ds_cap,
                  Cpu_session_capability cpu_session_cap,
                  Rm_session_capability  rm_session_cap,
                  Parent_capability      parent_cap,
-                 const char            *name,
+                 char const            *name,
                  char *const            argv[])
 :
+	_pd(name),
 	_cpu_session_client(Cpu_session_capability()),
 	_rm_session_client(Rm_session_capability())
 {
@@ -75,7 +76,7 @@ Process::Process(Dataspace_capability   elf_data_ds_cap,
 	Linux_pd_session_client lx_pd(static_cap_cast<Linux_pd_session>(_pd.cap()));
 
 	lx_pd.assign_parent(parent_cap);
-	lx_pd.start(elf_data_ds_cap, name);
+	lx_pd.start(elf_data_ds_cap);
 }
 
 

base-linux/src/core/include/pd_session_component.h

@@ -27,7 +27,10 @@ namespace Genode {
 	{
 		private:
 
+			enum { LABEL_MAX_LEN = 1024 };
+
 			unsigned long      _pid;
+			char               _label[LABEL_MAX_LEN];
 			Parent_capability  _parent;
 			Rpc_entrypoint    *_ds_ep;
 
@@ -55,7 +58,7 @@ namespace Genode {
 			 ** Linux-specific extension **
 			 ******************************/
 
-			void start(Capability<Dataspace> binary, Name const &name);
+			void start(Capability<Dataspace> binary);
 	};
 }
 

base-linux/src/core/pd_session_component.cc

@@ -12,6 +12,7 @@
  */
 
 /* Genode includes */
+#include <util/arg_string.h>
 #include <base/printf.h>
 #include <base/snprintf.h>
 
@@ -78,8 +79,13 @@ static const char *get_env(const char *key)
  ** PD session interface **
  **************************/
 
-Pd_session_component::Pd_session_component(Rpc_entrypoint *ds_ep, const char *)
+Pd_session_component::Pd_session_component(Rpc_entrypoint *ep, const char *args)
-: _pid(0), _ds_ep(ds_ep) { }
+:
+	_pid(0), _ds_ep(ep)
+{
+	Arg_string::find_arg(args, "label").string(_label, sizeof(_label),
+	                                           "<unlabeled>");
+}
 
 
 Pd_session_component::~Pd_session_component()
@@ -100,10 +106,11 @@ int Pd_session_component::assign_parent(Parent_capability parent)
 }
 
 
-void Pd_session_component::start(Capability<Dataspace> binary, Name const &name)
+void Pd_session_component::start(Capability<Dataspace> binary)
 {
 	/* lookup binary dataspace */
-	Dataspace_component *ds = reinterpret_cast<Dataspace_component *>(_ds_ep->obj_by_cap(binary));
+	Dataspace_component *ds =
+		reinterpret_cast<Dataspace_component *>(_ds_ep->obj_by_cap(binary));
 
 	if (!ds) {
 		PERR("could not lookup binary, aborted PD startup");
@@ -128,8 +135,9 @@ void Pd_session_component::start(Capability<Dataspace> binary, Name const &name)
 	                &envbuf[3][0], &envbuf[4][0], 0 };
 
 	/* prefix name of Linux program (helps killing some zombies) */
-	char pname_buf[9 + Linux_dataspace::FNAME_LEN];
+	char const *prefix = "[Genode] ";
-	snprintf(pname_buf, sizeof(pname_buf), "[Genode] %s", name.string());
+	char pname_buf[sizeof(_label) + sizeof(prefix)];
+	snprintf(pname_buf, sizeof(pname_buf), "%s%s", prefix, _label);
 	char *argv_buf[2];
 	argv_buf[0] = pname_buf;
 	argv_buf[1] = 0;

base-okl4/include/okl4_pd_session/connection.h

@@ -21,18 +21,9 @@ namespace Genode {
 
 	struct Pd_connection : Connection<Pd_session>, Okl4_pd_session_client
 	{
-		/**
+		Pd_connection()
-		 * Constructor
-		 *
-		 * \param args  additional session arguments
-		 */
-		Pd_connection(const char *args = 0)
 		:
-			Connection<Pd_session>(
+			Connection<Pd_session>(session("ram_quota=4K")),
-				session("ram_quota=4K%s%s",
-				        args ? ", " : "",
-				        args ? args : "")),
-
 			Okl4_pd_session_client(cap())
 		{ }
 	};

base/include/pd_session/connection.h

@@ -24,15 +24,11 @@ namespace Genode {
 		/**
 		 * Constructor
 		 *
-		 * \param args  additional session arguments
+		 * \param label  session label
 		 */
-		Pd_connection(const char *args = 0)
+		Pd_connection(const char *label = "")
 		:
-			Connection<Pd_session>(
+			Connection<Pd_session>(session("ram_quota=4K, label=\"%s\"", label)),
-				session("ram_quota=4K%s%s",
-				        args ? ", " : "",
-				        args ? args : "")),
-
 			Pd_session_client(cap())
 		{ }
 	};

base/src/base/process/process.cc

@@ -174,9 +174,10 @@ Process::Process(Dataspace_capability    elf_ds_cap,
                  Cpu_session_capability  cpu_session_cap,
                  Rm_session_capability   rm_session_cap,
                  Parent_capability       parent_cap,
-                 const char             *name,
+                 char const             *name,
                  char *const             argv[])
 :
+	_pd(name),
 	_cpu_session_client(cpu_session_cap),
 	_rm_session_client(rm_session_cap)
 {