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genode/repos/ports/src/noux/child.h

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/*
* \brief Noux child process
* \author Norman Feske
* \date 2011-02-17
*/
/*
* Copyright (C) 2011-2017 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.
*/
#ifndef _NOUX__CHILD_H_
#define _NOUX__CHILD_H_
/* Genode includes */
#include <base/attached_ram_dataspace.h>
#include <base/attached_rom_dataspace.h>
#include <vfs/dir_file_system.h>
/* Noux includes */
#include <file_descriptor_registry.h>
#include <noux_session/capability.h>
#include <args.h>
#include <environment.h>
#include <cpu_session_component.h>
#include <pd_session_component.h>
#include <child_policy.h>
#include <io_receptor_registry.h>
#include <destruct_queue.h>
#include <interrupt_handler.h>
#include <kill_broadcaster.h>
#include <parent_execve.h>
#include <empty_rom_service.h>
#include <local_rom_service.h>
#include <verbose.h>
#include <user_info.h>
#include <armed_timeout.h>
namespace Noux {
class Pid_allocator;
/**
* Return singleton instance of Io_receptor_registry
*/
Io_receptor_registry *io_receptor_registry();
/*
* Return lock for protecting the signal queue
*/
Genode::Lock &signal_lock();
class Child_config;
class Child;
/**
* Return true is child is the init process
*/
bool init_process(Child *child);
void init_process_exited(int);
}
/**
* Allocator for process IDs
*/
class Noux::Pid_allocator
{
private:
Lock _lock { };
int _num_pids { 0 };
public:
int alloc()
{
Lock::Guard guard(_lock);
return _num_pids++;
}
};
struct Noux::Child_config : Attached_ram_dataspace
{
enum { CONFIG_DS_SIZE = 4096 };
Child_config(Ram_allocator &ram, Region_map &local_rm, Verbose const &verbose)
:
Attached_ram_dataspace(ram, local_rm, CONFIG_DS_SIZE)
{
Xml_generator xml(local_addr<char>(), CONFIG_DS_SIZE, "config", [&] ()
{
if (verbose.ld())
xml.attribute("ld_verbose", "yes");
xml.node("ld", [&] () {
xml.node("library", [&] () {
xml.attribute("rom", "libc_noux.lib.so"); }); });
});
}
};
class Noux::Child : public Rpc_object<Session>,
public File_descriptor_registry,
public Family_member,
public Destruct_queue::Element<Child>,
public Interrupt_handler
{
private:
/*
* Noncopyable
*/
Child(Child const &);
Child &operator = (Child const &);
Child_policy::Name const _name;
Verbose const &_verbose;
User_info const &_user_info;
Parent_exit *_parent_exit;
Kill_broadcaster &_kill_broadcaster;
Timer::Connection &_timer_connection;
Parent_execve &_parent_execve;
Pid_allocator &_pid_allocator;
Env &_env;
Vfs::File_system &_root_dir;
Vfs_io_waiter_registry &_vfs_io_waiter_registry;
Vfs_handle_context _vfs_handle_context { };
Destruct_queue &_destruct_queue;
void _handle_destruct() { _destruct_queue.insert(this); }
Signal_handler<Child> _destruct_handler {
_env.ep(), *this, &Child::_handle_destruct };
Allocator &_heap;
/**
* Entrypoint used to serve the RPC interfaces of the
* locally-provided services
*/
enum { STACK_SIZE = 64*1024 };
Rpc_entrypoint _ep { &_env.pd(), STACK_SIZE, "noux_process", false };
Pd_session &_ref_pd;
Pd_session_capability const _ref_pd_cap;
/**
* Registry of dataspaces owned by the Noux process
*/
Dataspace_registry _ds_registry { _heap };
/**
* Locally-provided PD service
*/
typedef Local_service<Pd_session_component> Pd_service;
Pd_session_component _pd { _heap, _env, _ep, _name, _ds_registry };
Pd_service::Single_session_factory _pd_factory { _pd };
Pd_service _pd_service { _pd_factory };
/**
* Locally-provided CPU service
*/
typedef Local_service<Cpu_session_component> Cpu_service;
Cpu_session_component _cpu { _env, _ep, _name, false, _ds_registry };
Cpu_service::Single_session_factory _cpu_factory { _cpu };
Cpu_service _cpu_service { _cpu_factory };
/*
* Locally-provided Noux service
*/
Capability_guard _cap_guard { _ep, *this };
typedef Local_service<Rpc_object<Session> > Noux_service;
Noux_service::Single_session_factory _noux_factory { *this };
Noux_service _noux_service { _noux_factory };
/*
* Locally-provided ROM service
*/
Empty_rom_factory _empty_rom_factory { _heap, _ep };
Empty_rom_service _empty_rom_service { _empty_rom_factory };
Local_rom_factory _rom_factory { _heap, _env, _ep, _root_dir,
_vfs_io_waiter_registry, _ds_registry };
Local_rom_service _rom_service { _rom_factory };
/**
* Command line arguments
*/
enum { ARGS_DS_SIZE = sizeof(Sysio::Args) };
Args_dataspace _args;
/**
* Environment variables
*/
Environment _sysio_env;
/*
* Child configuration
*/
Child_config _config { _ref_pd, _env.rm(), _verbose };
enum { PAGE_SIZE = 4096, PAGE_MASK = ~(PAGE_SIZE - 1) };
enum { SYSIO_DS_SIZE = PAGE_MASK & (sizeof(Sysio) + PAGE_SIZE - 1) };
Attached_ram_dataspace _sysio_ds { _ref_pd, _env.rm(), SYSIO_DS_SIZE };
Sysio &_sysio = *_sysio_ds.local_addr<Sysio>();
typedef Ring_buffer<enum Sysio::Signal, Sysio::SIGNAL_QUEUE_SIZE>
Signal_queue;
Signal_queue _pending_signals { };
Parent_services &_parent_services;
Static_dataspace_info _sysio_ds_info;
Static_dataspace_info _args_ds_info;
Static_dataspace_info _sysio_env_ds_info;
Static_dataspace_info _config_ds_info;
Child_policy _child_policy;
Genode::Child _child;
/**
* Exception type for failed file-descriptor lookup
*/
class Invalid_fd { };
Shared_pointer<Io_channel> _lookup_channel(int fd) const
{
Shared_pointer<Io_channel> channel = io_channel_by_fd(fd);
if (channel)
return channel;
throw Invalid_fd();
}
/**
* Let specified child inherit our file descriptors
*/
void _assign_io_channels_to(Child *child, bool skip_when_close_on_execve_set)
{
for (int fd = 0; fd < MAX_FILE_DESCRIPTORS; fd++)
if (fd_in_use(fd)) {
if (skip_when_close_on_execve_set && close_fd_on_execve(fd))
continue;
child->add_io_channel(io_channel_by_fd(fd), fd);
child->close_fd_on_execve(fd, close_fd_on_execve(fd));
}
}
/**
* Block until the IO channel is ready for reading or writing or an
* exception occured.
*
* \param io the IO channel
* \param rd check for data available for reading
* \param wr check for readiness for writing
* \param ex check for exceptions
*/
void _block_for_io_channel(Shared_pointer<Io_channel> &io,
bool rd, bool wr, bool ex)
{
/* reset the blocker lock to the 'locked' state */
_blocker.unlock();
_blocker.lock();
Wake_up_notifier notifier(&_blocker);
io->register_wake_up_notifier(&notifier);
for (;;) {
if (io->check_unblock(rd, wr, ex) ||
!_pending_signals.empty())
break;
/* block (unless the lock got unlocked in the meantime) */
_blocker.lock();
}
io->unregister_wake_up_notifier(&notifier);
}
void _destruct()
{
_ep.dissolve(this);
if (init_process(this))
init_process_exited(_child_policy.exit_value());
}
public:
struct Insufficient_memory : Exception { };
/**
* Constructor
*
* \param forked false if the child is spawned directly from
* an executable binary (i.e., the init process,
* or children created via execve, or
* true if the child is a fork from another child
*
* \throw Insufficent_memory if the child could not be started by
* the parent
*/
Child(Child_policy::Name const &name,
Verbose const &verbose,
User_info const &user_info,
Parent_exit *parent_exit,
Kill_broadcaster &kill_broadcaster,
Timer::Connection &timer_connection,
Parent_execve &parent_execve,
Pid_allocator &pid_allocator,
int pid,
Env &env,
Vfs::File_system &root_dir,
Vfs_io_waiter_registry &vfs_io_waiter_registry,
Args const &args,
Sysio::Env const &sysio_env,
Allocator &heap,
Pd_session &ref_pd,
Pd_session_capability ref_pd_cap,
Parent_services &parent_services,
bool forked,
Destruct_queue &destruct_queue)
:
Family_member(pid),
Destruct_queue::Element<Child>(heap),
_name(name),
_verbose(verbose),
_user_info(user_info),
_parent_exit(parent_exit),
_kill_broadcaster(kill_broadcaster),
_timer_connection(timer_connection),
_parent_execve(parent_execve),
_pid_allocator(pid_allocator),
_env(env),
_root_dir(root_dir),
_vfs_io_waiter_registry(vfs_io_waiter_registry),
_destruct_queue(destruct_queue),
_heap(heap),
_ref_pd (ref_pd), _ref_pd_cap (ref_pd_cap),
_args(ref_pd, _env.rm(), ARGS_DS_SIZE, args),
_sysio_env(_ref_pd, _env.rm(), sysio_env),
_parent_services(parent_services),
_sysio_ds_info(_ds_registry, _sysio_ds.cap()),
_args_ds_info(_ds_registry, _args.cap()),
_sysio_env_ds_info(_ds_registry, _sysio_env.cap()),
_config_ds_info(_ds_registry, _config.cap()),
_child_policy(name, forked,
_args.cap(), _sysio_env.cap(), _config.cap(),
_ep, _pd_service, _cpu_service,
_noux_service, _empty_rom_service,
_rom_service, _parent_services,
*this, parent_exit, *this, _destruct_handler,
ref_pd, ref_pd_cap,
_verbose.enabled()),
_child(_env.rm(), _ep, _child_policy)
{
if (_verbose.enabled())
_args.dump();
if (!_child.main_thread_cap().valid()) {
_destruct();
throw Insufficient_memory();
}
}
~Child() { _destruct(); }
void start() { _ep.activate(); }
void start_forked_main_thread(addr_t ip, addr_t sp, addr_t parent_cap_addr)
{
/* poke parent_cap_addr into child's address space */
Capability<Parent>::Raw const raw = _child.parent_cap().raw();
_pd.poke(_env.rm(), parent_cap_addr, (char *)&raw, sizeof(raw));
/* start execution of new main thread at supplied trampoline */
_cpu.start_main_thread(ip, sp);
}
void submit_exit_signal()
{
if (init_process(this)) {
log("init process exited");
/* trigger exit of main event loop */
init_process_exited(_child_policy.exit_value());
} else {
Signal_transmitter(_destruct_handler).submit();
}
}
Pd_session_component &pd() { return _pd; }
Dataspace_registry &ds_registry() { return _ds_registry; }
/****************************
** Noux session interface **
****************************/
Dataspace_capability sysio_dataspace() override
{
return _sysio_ds.cap();
}
Capability<Region_map> lookup_region_map(addr_t const addr) override
{
return _pd.lookup_region_map(addr);
}
bool syscall(Syscall sc) override;
int next_open_fd(int start_fd) override
{
if (start_fd >= 0)
for (int fd = start_fd; fd < MAX_FILE_DESCRIPTORS; fd++)
if (fd_in_use(fd))
return fd;
return -1;
}
/****************************************
** File_descriptor_registry overrides **
****************************************/
/**
* Find out if the IO channel associated with 'fd' has more file
* descriptors associated with it
*/
bool _is_the_only_fd_for_io_channel(int fd,
Shared_pointer<Io_channel> io_channel)
{
for (int f = 0; f < MAX_FILE_DESCRIPTORS; f++) {
if ((f != fd) &&
fd_in_use(f) &&
(io_channel_by_fd(f) == io_channel))
return false;
}
return true;
}
int add_io_channel(Shared_pointer<Io_channel> io_channel, int fd = -1) override
{
fd = File_descriptor_registry::add_io_channel(io_channel, fd);
/* Register the interrupt handler only once per IO channel */
if (_is_the_only_fd_for_io_channel(fd, io_channel)) {
Io_channel_listener *l = new (_heap) Io_channel_listener(this);
io_channel->register_interrupt_handler(l);
}
return fd;
}
void remove_io_channel(int fd) override
{
Shared_pointer<Io_channel> io_channel = _lookup_channel(fd);
/*
* Unregister the interrupt handler only if there are no other
* file descriptors associated with the IO channel.
*/
if (_is_the_only_fd_for_io_channel(fd, io_channel)) {
Io_channel_listener *l = io_channel->lookup_io_channel_listener(this);
io_channel->unregister_interrupt_handler(l);
Genode::destroy(_heap, l);
}
File_descriptor_registry::remove_io_channel(fd);
}
void flush() override
{
for (int fd = 0; fd < MAX_FILE_DESCRIPTORS; fd++)
try {
remove_io_channel(fd);
} catch (Invalid_fd) { }
}
/*****************************
** Family_member interface **
*****************************/
void submit_signal(Noux::Sysio::Signal sig) override
{
try {
_pending_signals.add(sig);
} catch (Signal_queue::Overflow) {
error("signal queue is full - signal dropped");
}
_blocker.unlock();
}
Family_member *do_execve(const char *filename,
Args const &args,
Sysio::Env const &env) override
{
Lock::Guard signal_lock_guard(signal_lock());
Child *child = new (_heap) Child(filename,
_verbose,
_user_info,
_parent_exit,
_kill_broadcaster,
_timer_connection,
_parent_execve,
_pid_allocator,
pid(),
_env,
_root_dir,
_vfs_io_waiter_registry,
args,
env,
_heap,
_ref_pd, _ref_pd_cap,
_parent_services,
false,
_destruct_queue);
_assign_io_channels_to(child, true);
/* move the signal queue */
while (!_pending_signals.empty())
child->_pending_signals.add(_pending_signals.get());
/*
* Close all open files.
*
* This action is not part of the child destructor,
* because in the case that a child exits itself,
* it may need to close all files to unblock the
* parent (which might be reading from a pipe) before
* the parent can destroy the child object.
*/
flush();
/* signal main thread to remove ourself */
Signal_transmitter(_destruct_handler).submit();
/* start executing the new process */
child->start();
/* this child will be removed by the execve_finalization_dispatcher */
return child;
}
/*********************************
** Interrupt_handler interface **
*********************************/
void handle_interrupt(Sysio::Signal signal) override
{
submit_signal(signal);
}
};
#endif /* _NOUX__CHILD_H_ */
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