From 9b8228d76f36833d2150a1f073a316982f503d9a Mon Sep 17 00:00:00 2001
From: Christian Prochaska <christian.prochaska@genode-labs.com>
Date: Fri, 8 Sep 2017 13:08:58 +0200
Subject: [PATCH] Noux: fix race condition on Vfs_io_channel destruction

Fixes #2518
---
 repos/ports/src/noux/child.h          |  1 +
 repos/ports/src/noux/main.cc          | 12 ++++++++----
 repos/ports/src/noux/syscall.cc       |  2 +-
 repos/ports/src/noux/vfs_io_channel.h |  8 +++++---
 4 files changed, 15 insertions(+), 8 deletions(-)

diff --git a/repos/ports/src/noux/child.h b/repos/ports/src/noux/child.h
index 4ada464fc..5c024056f 100644
--- a/repos/ports/src/noux/child.h
+++ b/repos/ports/src/noux/child.h
@@ -127,6 +127,7 @@ class Noux::Child : public Rpc_object<Session>,
 		Vfs::Dir_file_system &_root_dir;
 
 		Vfs_io_waiter_registry &_vfs_io_waiter_registry;
+		Vfs_handle_context      _vfs_handle_context;
 
 		Destruct_queue &_destruct_queue;
 
diff --git a/repos/ports/src/noux/main.cc b/repos/ports/src/noux/main.cc
index 82da53a43..81bb48bc1 100644
--- a/repos/ports/src/noux/main.cc
+++ b/repos/ports/src/noux/main.cc
@@ -97,6 +97,7 @@ connect_stdio(Genode::Env                                 &env,
               Genode::Constructible<Terminal::Connection> &terminal,
               Genode::Xml_node                             config,
               Vfs::Dir_file_system                        &root,
+              Noux::Vfs_handle_context                    &vfs_handle_context,
               Noux::Vfs_io_waiter_registry                &vfs_io_waiter_registry,
               Noux::Terminal_io_channel::Type              type,
               Genode::Allocator                           &alloc)
@@ -143,7 +144,8 @@ connect_stdio(Genode::Env                                 &env,
 
 	return *new (alloc)
 		Vfs_io_channel(path.string(), root.leaf_path(path.string()), &root,
-		               vfs_handle, vfs_io_waiter_registry, env.ep());
+		               vfs_handle, vfs_handle_context,
+		               vfs_io_waiter_registry, env.ep());
 }
 
 
@@ -237,6 +239,8 @@ struct Noux::Main
 	                                 _io_response_handler,
 	                                 _global_file_system_factory };
 
+	Vfs_handle_context _vfs_handle_context;
+
 	Pid_allocator _pid_allocator;
 
 	Timeout_scheduler _timeout_scheduler { _env };
@@ -301,13 +305,13 @@ struct Noux::Main
 
 	Shared_pointer<Io_channel>
 		_channel_0 { &connect_stdio(_env, _terminal, _config.xml(), _root_dir,
-		             _io_response_handler.io_waiter_registry,
+		             _vfs_handle_context, _io_response_handler.io_waiter_registry,
 		             Tio::STDIN,  _heap), _heap },
 		_channel_1 { &connect_stdio(_env, _terminal, _config.xml(), _root_dir,
-		            _io_response_handler.io_waiter_registry,
+		            _vfs_handle_context, _io_response_handler.io_waiter_registry,
 		             Tio::STDOUT, _heap), _heap },
 		_channel_2 { &connect_stdio(_env, _terminal, _config.xml(), _root_dir,
-		             _io_response_handler.io_waiter_registry,
+		             _vfs_handle_context, _io_response_handler.io_waiter_registry,
 		             Tio::STDERR, _heap), _heap };
 
 	Main(Env &env) : _env(env)
diff --git a/repos/ports/src/noux/syscall.cc b/repos/ports/src/noux/syscall.cc
index 822fd4016..1d508c769 100644
--- a/repos/ports/src/noux/syscall.cc
+++ b/repos/ports/src/noux/syscall.cc
@@ -240,7 +240,7 @@ bool Noux::Child::syscall(Noux::Session::Syscall sc)
 				Shared_pointer<Io_channel>
 					channel(new (_heap) Vfs_io_channel(_sysio.open_in.path,
 					                                   leaf_path, &_root_dir,
-					                                   vfs_handle,
+					                                   vfs_handle, _vfs_handle_context,
 					                                   _vfs_io_waiter_registry,
 					                                   _env.ep()),
 					                                   _heap);
diff --git a/repos/ports/src/noux/vfs_io_channel.h b/repos/ports/src/noux/vfs_io_channel.h
index ff33d2615..876af82f9 100644
--- a/repos/ports/src/noux/vfs_io_channel.h
+++ b/repos/ports/src/noux/vfs_io_channel.h
@@ -62,20 +62,22 @@ struct Noux::Vfs_io_channel : Io_channel
 
 	Vfs::Vfs_handle *_fh;
 
+	Vfs_handle_context &_context;
+
 	Vfs_io_waiter_registry &_vfs_io_waiter_registry;
 
 	Absolute_path _path;
 	Absolute_path _leaf_path;
 
-	Vfs_handle_context _context;
-
 	Vfs_io_channel(char const *path, char const *leaf_path,
 	               Vfs::Dir_file_system *root_dir, Vfs::Vfs_handle *vfs_handle,
+	               Vfs_handle_context &vfs_handle_context,
 	               Vfs_io_waiter_registry &vfs_io_waiter_registry,
 	               Entrypoint &ep)
 	:
 		_read_avail_handler(ep, *this, &Vfs_io_channel::_handle_read_avail),
-		_fh(vfs_handle), _vfs_io_waiter_registry(vfs_io_waiter_registry),
+		_fh(vfs_handle), _context(vfs_handle_context),
+		_vfs_io_waiter_registry(vfs_io_waiter_registry),
 		_path(path), _leaf_path(leaf_path)
 	{
 		_fh->context = &_context;