ladybird/Userland/Libraries/LibC/sched.cpp
Andreas Kling e87eac9273 Userland: Add LibSystem and funnel all syscalls through it
This achieves two things:

- Programs can now intentionally perform arbitrary syscalls by calling
  syscall(). This allows us to work on things like syscall fuzzing.

- It restricts the ability of userspace to make syscalls to a single
  4KB page of code. In order to call the kernel directly, an attacker
  must now locate this page and call through it.
2021-02-05 12:23:39 +01:00

61 lines
2.0 KiB
C++

/*
* 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 <errno.h>
#include <sched.h>
#include <syscall.h>
extern "C" {
int sched_yield()
{
int rc = syscall(SC_yield);
__RETURN_WITH_ERRNO(rc, rc, -1);
}
int sched_get_priority_min([[maybe_unused]] int policy)
{
return 0; // Idle
}
int sched_get_priority_max([[maybe_unused]] int policy)
{
return 3; // High
}
int sched_setparam(pid_t pid, const struct sched_param* param)
{
int rc = syscall(SC_sched_setparam, pid, param);
__RETURN_WITH_ERRNO(rc, rc, -1);
}
int sched_getparam(pid_t pid, struct sched_param* param)
{
int rc = syscall(SC_sched_getparam, pid, param);
__RETURN_WITH_ERRNO(rc, rc, -1);
}
}