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Kernel: Move syscall implementations out of Process.cpp

This is something I've been meaning to do for a long time, and here we
finally go. This patch moves all sys$foo functions out of Process.cpp
and into files in Kernel/Syscalls/.

It's not exactly one syscall per file (although it could be, but I got
a bit tired of the repetitive work here..)

This makes hacking on individual syscalls a lot less painful since you
don't have to rebuild nearly as much code every time. I'm also hopeful
that this makes it easier to understand individual syscalls. :^)
This commit is contained in:
Andreas Kling 2020-07-30 23:38:15 +02:00
parent 027c450d6d
commit 949aef4aef
73 changed files with 6774 additions and 4485 deletions

113
Kernel/Syscalls/futex.cpp Normal file
View file

@ -0,0 +1,113 @@
/*
* 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/Time.h>
#include <Kernel/Process.h>
namespace Kernel {
void compute_relative_timeout_from_absolute(const timeval& absolute_time, timeval& relative_time)
{
// Convert absolute time to relative time of day.
timeval_sub(absolute_time, kgettimeofday(), relative_time);
}
void compute_relative_timeout_from_absolute(const timespec& absolute_time, timeval& relative_time)
{
timeval tv_absolute_time;
timespec_to_timeval(absolute_time, tv_absolute_time);
compute_relative_timeout_from_absolute(tv_absolute_time, relative_time);
}
WaitQueue& Process::futex_queue(i32* userspace_address)
{
auto& queue = m_futex_queues.ensure((FlatPtr)userspace_address);
if (!queue)
queue = make<WaitQueue>();
return *queue;
}
int Process::sys$futex(const Syscall::SC_futex_params* user_params)
{
REQUIRE_PROMISE(thread);
Syscall::SC_futex_params params;
if (!validate_read_and_copy_typed(&params, user_params))
return -EFAULT;
i32* userspace_address = params.userspace_address;
int futex_op = params.futex_op;
i32 value = params.val;
const timespec* user_timeout = params.timeout;
if (!validate_read_typed(userspace_address))
return -EFAULT;
if (user_timeout && !validate_read_typed(user_timeout))
return -EFAULT;
switch (futex_op) {
case FUTEX_WAIT: {
i32 user_value;
copy_from_user(&user_value, userspace_address);
if (user_value != value)
return -EAGAIN;
timespec ts_abstimeout { 0, 0 };
if (user_timeout && !validate_read_and_copy_typed(&ts_abstimeout, user_timeout))
return -EFAULT;
WaitQueue& wait_queue = futex_queue(userspace_address);
timeval* optional_timeout = nullptr;
timeval relative_timeout { 0, 0 };
if (user_timeout) {
compute_relative_timeout_from_absolute(ts_abstimeout, relative_timeout);
optional_timeout = &relative_timeout;
}
// FIXME: This is supposed to be interruptible by a signal, but right now WaitQueue cannot be interrupted.
Thread::BlockResult result = Thread::current()->wait_on(wait_queue, "Futex", optional_timeout);
if (result == Thread::BlockResult::InterruptedByTimeout) {
return -ETIMEDOUT;
}
break;
}
case FUTEX_WAKE:
if (value == 0)
return 0;
if (value == 1) {
futex_queue(userspace_address).wake_one();
} else {
futex_queue(userspace_address).wake_n(value);
}
break;
}
return 0;
}
}