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/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <AK/String.h>
#include <AK/StringBuilder.h>
#include <AK/StringView.h>
#include <Kernel/Process.h>
#include <Kernel/VM/MemoryManager.h>
#include <Kernel/VM/PageDirectory.h>
namespace Kernel {
int Process::sys$create_thread(void* (*entry)(void*), Userspace<const Syscall::SC_create_thread_params*> user_params)
{
REQUIRE_PROMISE(thread);
Syscall::SC_create_thread_params params;
if (!copy_from_user(¶ms, user_params))
return -EFAULT;
unsigned detach_state = params.m_detach_state;
int schedule_priority = params.m_schedule_priority;
unsigned stack_size = params.m_stack_size;
auto user_stack_address = (u8*)params.m_stack_location + stack_size;
if (!MM.validate_user_stack(*this, VirtualAddress(user_stack_address - 4)))
return -EFAULT;
// FIXME: return EAGAIN if Thread::all_threads().size() is greater than PTHREAD_THREADS_MAX
int requested_thread_priority = schedule_priority;
if (requested_thread_priority < THREAD_PRIORITY_MIN || requested_thread_priority > THREAD_PRIORITY_MAX)
return -EINVAL;
bool is_thread_joinable = (0 == detach_state);
// FIXME: Do something with guard pages?
auto* thread = new Thread(*this);
// We know this thread is not the main_thread,
// So give it a unique name until the user calls $set_thread_name on it
// length + 4 to give space for our extra junk at the end
StringBuilder builder(m_name.length() + 4);
builder.append(m_name);
builder.appendf("[%d]", thread->tid().value());
thread->set_name(builder.to_string());
thread->set_priority(requested_thread_priority);
thread->set_joinable(is_thread_joinable);
auto& tss = thread->tss();
tss.eip = (FlatPtr)entry;
tss.eflags = 0x0202;
tss.cr3 = page_directory().cr3();
tss.esp = (u32)user_stack_address;
auto tsr_result = thread->make_thread_specific_region({});
if (tsr_result.is_error())
return tsr_result.error();
thread->set_state(Thread::State::Runnable);
return thread->tid().value();
}
void Process::sys$exit_thread(Userspace<void*> exit_value)
{
REQUIRE_PROMISE(thread);
cli();
auto current_thread = Thread::current();
current_thread->m_exit_value = reinterpret_cast<void*>(exit_value.ptr());
current_thread->set_should_die();
big_lock().force_unlock_if_locked();
current_thread->die_if_needed();
ASSERT_NOT_REACHED();
}
int Process::sys$detach_thread(pid_t tid)
{
REQUIRE_PROMISE(thread);
InterruptDisabler disabler;
auto* thread = Thread::from_tid(tid);
if (!thread || thread->pid() != pid())
return -ESRCH;
if (!thread->is_joinable())
return -EINVAL;
thread->set_joinable(false);
return 0;
}
int Process::sys$join_thread(pid_t tid, Userspace<void**> exit_value)
{
REQUIRE_PROMISE(thread);
InterruptDisabler disabler;
auto* thread = Thread::from_tid(tid);
if (!thread || thread->pid() != pid())
return -ESRCH;
auto current_thread = Thread::current();
if (thread == current_thread)
return -EDEADLK;
if (thread->m_joinee == current_thread)
return -EDEADLK;
ASSERT(thread->m_joiner != current_thread);
if (thread->m_joiner)
return -EINVAL;
if (!thread->is_joinable())
return -EINVAL;
void* joinee_exit_value = nullptr;
// NOTE: pthread_join() cannot be interrupted by signals. Only by death.
for (;;) {
auto result = current_thread->block<Thread::JoinBlocker>(nullptr, *thread, joinee_exit_value);
if (result == Thread::BlockResult::InterruptedByDeath) {
// NOTE: This cleans things up so that Thread::finalize() won't
// get confused about a missing joiner when finalizing the joinee.
InterruptDisabler disabler_t;
if (current_thread->m_joinee) {
current_thread->m_joinee->m_joiner = nullptr;
current_thread->m_joinee = nullptr;
}
break;
}
}
// NOTE: 'thread' is very possibly deleted at this point. Clear it just to be safe.
thread = nullptr;
if (exit_value && !copy_to_user(exit_value, &joinee_exit_value))
return -EFAULT;
return 0;
}
int Process::sys$set_thread_name(pid_t tid, Userspace<const char*> user_name, size_t user_name_length)
{
REQUIRE_PROMISE(thread);
auto name = copy_string_from_user(user_name, user_name_length);
if (name.is_null())
return -EFAULT;
const size_t max_thread_name_size = 64;
if (name.length() > max_thread_name_size)
return -EINVAL;
InterruptDisabler disabler;
auto* thread = Thread::from_tid(tid);
if (!thread || thread->pid() != pid())
return -ESRCH;
thread->set_name(move(name));
return 0;
}
int Process::sys$get_thread_name(pid_t tid, Userspace<char*> buffer, size_t buffer_size)
{
REQUIRE_PROMISE(thread);
if (buffer_size == 0)
return -EINVAL;
InterruptDisabler disabler;
auto* thread = Thread::from_tid(tid);
if (!thread || thread->pid() != pid())
return -ESRCH;
if (thread->name().length() + 1 > (size_t)buffer_size)
return -ENAMETOOLONG;
if (!copy_to_user(buffer, thread->name().characters(), thread->name().length() + 1))
return -EFAULT;
return 0;
}
int Process::sys$gettid()
{
REQUIRE_PROMISE(stdio);
return Thread::current()->tid().value();
}
}
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