ports: add 'gdb_support'

Fixes #5163

repos/ports/recipes/pkg/gdb_x86/archives

@@ -1,8 +1,10 @@
 _/raw/gdb_x86
 _/src/init
+_/src/chroot
 _/src/cached_fs_rom
 _/src/vfs
 _/src/expat
+_/src/gdb_support
 _/src/gdb_x86
 _/src/gmp
 _/src/libc

repos/ports/recipes/pkg/gdb_x86/runtime

@@ -1,15 +1,19 @@
-<runtime ram="76M" caps="1000" binary="init" config="gdb.config">
+<runtime ram="128M" caps="1000" binary="init" config="gdb.config">
 
 	<requires>
 		<timer/>
 		<terminal label="monitor"/>
 		<terminal label="ui"/>
-		<file_system label="target"/>
+		<file_system label="system_config" writeable="no"/>
+		<file_system label="used" writeable="no"/>
+		<rom label="build_info"/>
 		<rm/>
 	</requires>
 
 	<content>
+		<rom label="chroot"/>
 		<rom label="gdb.config"/>
+		<rom label="gdb_support"/>
 		<rom label="init"/>
 		<rom label="vfs"/>
 		<rom label="cached_fs_rom"/>

repos/ports/recipes/raw/gdb_x86/gdb.config

@@ -14,16 +14,62 @@
 
 	<default caps="100"/>
 
+	<start name="depot_ro">
+		<binary name="chroot"/>
+		<resource name="RAM" quantum="2M" />
+		<provides> <service name="File_system"/> </provides>
+		<config>
+			<default-policy path="/depot" writeable="no"/>
+		</config>
+		<route>
+			<service name="File_system">
+				<parent label="used"/>
+			</service>
+			<any-service> <parent/> </any-service>
+		</route>
+	</start>
+
 	<start name="vfs" caps="150">
 		<resource name="RAM" quantum="12M"/>
 		<provides><service name="File_system"/></provides>
 		<config>
 			<vfs>
+				<dir name="depot"> <fs label="depot"/> </dir>
+				<dir name="debug"> <ram/> </dir>
 				<tar name="gdb.tar"/>
 			</vfs>
 			<policy label_prefix="vfs_rom" root="/"/>
-			<default-policy root="/" writeable="yes"/>
+			<policy label_prefix="gdb_support -> debug" root="/debug" writeable="yes"/>
+			<default-policy root="/" writeable="no"/>
 		</config>
+		<route>
+			<service name="File_system" label="depot">
+				<child name="depot_ro"/>
+			</service>
+			<any-service> <parent/> </any-service>
+		</route>
+	</start>
+
+	<start name="gdb_support">
+		<resource name="RAM" quantum="16M"/>
+		<config>
+			<vfs>
+				<dir name="config"> <fs label="config"/> </dir>
+				<dir name="debug"> <fs label="debug"/> </dir>
+			</vfs>
+		</config>
+		<route>
+			<service name="File_system" label="config">
+				<parent label="system_config"/>
+			</service>
+			<service name="File_system" label="debug">
+				<child name="vfs"/>
+			</service>
+			<service name="ROM" label="build_info">
+				<parent label="build_info"/>
+			</service>
+			<any-service> <parent/> </any-service>
+		</route>
 	</start>
 
 	<start name="vfs_rom">
@@ -39,7 +85,7 @@
 
 	<start name="gdb" caps="200">
 		<binary name="/bin/genode-x86-gdb"/>
-		<resource name="RAM" quantum="28M" />
+		<resource name="RAM" quantum="64M" />
 		<config>
 			<vfs>
 				<dir name="dev">
@@ -49,7 +95,6 @@
 					<terminal name="tty" label="ui"/>
 				</dir>
 				<dir name="pipe"> <pipe/> </dir>
-				<dir name="target"> <fs label="target"/> </dir>
 				<fs/>
 			</vfs>
 			<libc stdin="/dev/tty"
@@ -62,9 +107,6 @@
 			<arg value="-ex"/> <arg value="target extended-remote /dev/monitor"/>
 		</config>
 		<route>
-			<service name="File_system" label="target">
-				<parent label="target"/>
-			</service>
 			<service name="File_system">
 				<child name="vfs"/>
 			</service>

repos/ports/recipes/src/gdb_support/content.mk

@@ -0,0 +1,2 @@
+SRC_DIR = src/app/gdb_support
+include $(GENODE_DIR)/repos/base/recipes/src/content.inc

repos/ports/recipes/src/gdb_support/hash

@@ -0,0 +1 @@
+2023-10-14 cb73462763634ec8a2581206e7b4cf3f58a1eecb

repos/ports/recipes/src/gdb_support/used_apis

@@ -0,0 +1,3 @@
+base
+os
+vfs

repos/ports/src/app/gdb_support/main.cc

@@ -0,0 +1,224 @@
+/*
+ * \brief  Component which creates symlinks to depot binaries and
+ *         debug info files based on the current runtime/monitor
+ *         configuration
+ * \author Christian Prochaska
+ * \date   2023-10-13
+ */
+
+/*
+ * Copyright (C) 2023-2024 Genode Labs GmbH
+ *
+ * This file is part of the Genode OS framework, which is distributed
+ * under the terms of the GNU Affero General Public License version 3.
+ */
+
+/* Genode includes */
+#include <base/attached_rom_dataspace.h>
+#include <base/component.h>
+#include <base/heap.h>
+#include <base/log.h>
+#include <os/vfs.h>
+
+using namespace Genode;
+
+struct Main
+{
+	Genode::Env &_env;
+	Heap         _heap { _env.ram(), _env.rm() };
+
+	Attached_rom_dataspace _config     { _env, "config" };
+	Attached_rom_dataspace _build_info { _env, "build_info" };
+
+	Session_label _base_archive { };
+
+	Root_directory _root_dir { _env, _heap, _config.xml().sub_node("vfs") };
+
+	static constexpr char const *_runtime_config_path { "/config/managed/runtime" };
+
+	Directory _debug_dir { _root_dir, "/debug" };
+
+	Watch_handler<Main> _runtime_config_watch_handler {
+		_env.ep(), _root_dir, _runtime_config_path,
+		*this, &Main::_handle_runtime_config_update };
+
+
+	void _remove_outdated_debug_directories(Xml_node const &monitor)
+	{
+		bool dir_removed = false;
+
+		do {
+
+			dir_removed = false;
+
+			_debug_dir.for_each_entry([&] (Directory::Entry &component_entry) {
+
+				/*
+				 * 'for_each_entry()' must be restarted when a
+				 * directory has been removed from within.
+				 */
+				if (dir_removed)
+					return;
+
+				bool found_in_config = false;
+
+				monitor.for_each_sub_node("policy", [&] (Xml_node const &policy) {
+					Session_label policy_label {
+						policy.attribute_value("label",
+								               Session_label::String()) };
+					if (policy_label == component_entry.name())
+						found_in_config = true;
+				});
+
+				if (!found_in_config) {
+					Directory component_dir { _debug_dir, component_entry.name() };
+					component_dir.for_each_entry([&] (Directory::Entry &file_entry) {
+						component_dir.unlink(file_entry.name()); });
+
+					_debug_dir.unlink(component_entry.name());
+					dir_removed = true;
+				}
+			});
+		} while (dir_removed);
+	}
+
+
+	void _process_monitor_config(Xml_node const &config, Xml_node const &monitor)
+	{
+		monitor.for_each_sub_node("policy", [&] (Xml_node const &policy) {
+
+			Session_label policy_label {
+				policy.attribute_value("label", Session_label::String()) };
+
+			if (_debug_dir.directory_exists(policy_label))
+				return;
+
+			_debug_dir.create_sub_directory(policy_label);
+
+			Directory component_dir { _debug_dir, policy_label };
+
+			config.for_each_sub_node("start", [&] (Xml_node const &start) {
+
+				if (start.attribute_value("name", Session_label::String()) !=
+				    policy_label)
+					return;
+
+				start.with_sub_node("route", [&] (Xml_node const &route) {
+
+					route.for_each_sub_node("service", [&] (Xml_node const &service) {
+
+						if (service.attribute_value("name", String<8>()) != "ROM")
+							return;
+
+						if (!service.has_attribute("label_last"))
+							return;
+
+						Session_label rom_session_label;
+
+						if (service.attribute_value("label_last", Session_label::String()) ==
+						    "ld.lib.so") {
+
+							rom_session_label = { _base_archive, "/ld.lib.so" };
+
+						} else {
+
+							service.with_sub_node("child", [&] (Xml_node const &child) {
+
+								if (child.attribute_value("name", String<16>()) !=
+								    "depot_rom")
+									return;
+
+								rom_session_label =
+									child.attribute_value("label", Session_label::String());
+
+							}, [&] () {
+								Genode::warning("<child> XML node not found");
+								return;
+							});
+						}
+
+						Vfs::Absolute_path rom_session_label_path { rom_session_label };
+
+						Vfs::Absolute_path depot_user_path { rom_session_label_path };
+						while (!depot_user_path.has_single_element())
+							depot_user_path.strip_last_element();
+
+						Vfs::Absolute_path depot_type_path { rom_session_label_path };
+						depot_type_path.strip_prefix(depot_user_path.string());
+						while (!depot_type_path.has_single_element())
+							depot_type_path.strip_last_element();
+						if (depot_type_path != "/bin")
+							return;
+
+						Vfs::Absolute_path depot_component_path { rom_session_label_path };
+						depot_component_path.strip_prefix(
+							Directory::join(depot_user_path, depot_type_path).string());
+
+						/* create symlink to binary */
+
+						Vfs::Absolute_path depot_bin_path { "/depot" };
+						depot_bin_path.append(depot_user_path.string());
+						depot_bin_path.append("/bin");
+						depot_bin_path.append(depot_component_path.string());
+						Vfs::Absolute_path bin_file_path { depot_component_path };
+						bin_file_path.keep_only_last_element();
+
+						component_dir.create_symlink(bin_file_path, depot_bin_path);
+
+						/* create symlink to debug info file */
+
+						Vfs::Absolute_path depot_dbg_path { "/depot" };
+						depot_dbg_path.append(depot_user_path.string());
+						depot_dbg_path.append("/dbg");
+						depot_dbg_path.append(depot_component_path.string());
+						depot_dbg_path.append(".debug");
+						Vfs::Absolute_path debug_file_path { depot_dbg_path };
+						debug_file_path.keep_only_last_element();
+
+						component_dir.create_symlink(debug_file_path, depot_dbg_path);
+					});
+				}, [&] () {
+					Genode::error("<route> XML node not found");
+				});
+			});
+		});
+
+		_remove_outdated_debug_directories(monitor);
+	}
+
+
+	void _handle_runtime_config_update()
+	{
+		try {
+			File_content const runtime_config {
+				_heap, _root_dir, _runtime_config_path,
+				File_content::Limit(512*1024)
+			};
+
+			runtime_config.xml([&] (Xml_node const config) {
+				config.with_sub_node("monitor", [&] (Xml_node const &monitor) {
+					_process_monitor_config(config, monitor);
+				}, [&] () {
+					Genode::error("<monitor> XML node not found");
+				});
+			});
+		} catch (File_content::Truncated_during_read) {
+			Genode::error("Could not read ", _runtime_config_path);
+		}
+	}
+
+
+	Main(Genode::Env &env)
+	: _env(env)
+	{
+		_base_archive = _build_info.xml().attribute_value("base",
+		                                                  Session_label::String());
+		_handle_runtime_config_update();
+	}
+};
+
+
+void Component::construct(Genode::Env &env)
+{
+	static Main main(env);
+}

repos/ports/src/app/gdb_support/target.mk

@@ -0,0 +1,3 @@
+TARGET = gdb_support
+SRC_CC = main.cc
+LIBS   = base vfs