genode/repos/base-linux/src/lib/base/child_process.cc
Norman Feske 4d442bca30 Streamline exception types
This patch reduces the number of exception types by facilitating
globally defined exceptions for common usage patterns shared by most
services. In particular, RPC functions that demand a session-resource
upgrade not longer reflect this condition via a session-specific
exception but via the 'Out_of_ram' or 'Out_of_caps' types.

Furthermore, the 'Parent::Service_denied', 'Parent::Unavailable',
'Root::Invalid_args', 'Root::Unavailable', 'Service::Invalid_args',
'Service::Unavailable', and 'Local_service::Factory::Denied' types have
been replaced by the single 'Service_denied' exception type defined in
'session/session.h'.

This consolidation eases the error handling (there are fewer exceptions
to handle), alleviates the need to convert exceptions along the
session-creation call chain, and avoids possible aliasing problems
(catching the wrong type with the same name but living in a different
scope).
2017-05-31 13:16:07 +02:00

118 lines
3.2 KiB
C++

/*
* \brief Implementation of process creation for Linux
* \author Norman Feske
* \date 2006-07-06
*/
/*
* Copyright (C) 2006-2017 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/env.h>
#include <base/child.h>
#include <base/log.h>
#include <linux_native_pd/client.h>
/* base-internal includes */
#include <linux_syscalls.h>
#include <base/internal/elf.h>
using namespace Genode;
/*
* Register main thread at core
*
* At this point in time, we do not yet know the TID and PID of the new
* thread. Those information will be provided to core by the constructor of
* the 'Platform_env' of the new process.
*/
Child::Initial_thread::Initial_thread(Cpu_session &cpu,
Pd_session_capability pd,
Name const &name)
:
_cpu(cpu),
_cap(cpu.create_thread(pd, name, Affinity::Location(), Cpu_session::Weight()))
{ }
Child::Initial_thread::~Initial_thread() { }
void Child::Initial_thread::start(addr_t) { }
/*
* On Linux, the ELF loading is performed by the kernel
*/
Child::Process::Loaded_executable::Loaded_executable(Dataspace_capability,
Dataspace_capability,
Ram_session &,
Region_map &,
Region_map &,
Parent_capability) { }
Child::Process::Process(Dataspace_capability elf_ds,
Dataspace_capability ldso_ds,
Pd_session_capability pd_cap,
Pd_session &pd,
Ram_session &ram,
Initial_thread_base &,
Region_map &local_rm,
Region_map &remote_rm,
Parent_capability parent_cap)
:
loaded_executable(elf_ds, ldso_ds, ram, local_rm, remote_rm, parent_cap)
{
/* skip loading when called during fork */
if (!elf_ds.valid())
return;
/* attach ELF locally */
addr_t elf_addr;
try { elf_addr = local_rm.attach(elf_ds); }
catch (Region_map::Invalid_dataspace) {
error("local attach of ELF executable failed (Invalid_dataspace)"); throw; }
catch (Region_map::Region_conflict) {
error("local attach of ELF executable failed (Region_conflict)"); throw; }
/* setup ELF object and read program entry pointer */
Elf_binary elf(elf_addr);
if (!elf.valid())
throw Invalid_executable();
bool const dynamically_linked = elf.dynamically_linked();
local_rm.detach(elf_addr);
/*
* If the specified executable is a dynamically linked program, we load
* the dynamic linker instead.
*/
if (dynamically_linked) {
if (!ldso_ds.valid()) {
error("attempt to start dynamic executable without dynamic linker");
throw Missing_dynamic_linker();
}
elf_ds = ldso_ds;
}
pd.assign_parent(parent_cap);
Linux_native_pd_client
lx_pd(static_cap_cast<Linux_native_pd>(pd.native_pd()));
lx_pd.start(elf_ds);
}
Child::Process::~Process() { }