ladybird/Kernel/Syscalls/setpgid.cpp
Timon Kruiper 9827c11d8b Kernel: Move InterruptDisabler out of Arch directory
The code in this file is not architecture specific, so it can be moved
to the base Kernel directory.
2022-10-17 20:11:31 +02:00

127 lines
3.9 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <Kernel/InterruptDisabler.h>
#include <Kernel/Process.h>
#include <Kernel/TTY/TTY.h>
namespace Kernel {
ErrorOr<FlatPtr> Process::sys$getsid(pid_t pid)
{
VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this);
TRY(require_promise(Pledge::stdio));
if (pid == 0)
return sid().value();
auto process = Process::from_pid(pid);
if (!process)
return ESRCH;
if (sid() != process->sid())
return EPERM;
return process->sid().value();
}
ErrorOr<FlatPtr> Process::sys$setsid()
{
VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this);
TRY(require_promise(Pledge::proc));
InterruptDisabler disabler;
bool found_process_with_same_pgid_as_my_pid = false;
Process::for_each_in_pgrp(pid().value(), [&](auto&) {
found_process_with_same_pgid_as_my_pid = true;
return IterationDecision::Break;
});
if (found_process_with_same_pgid_as_my_pid)
return EPERM;
// Create a new Session and a new ProcessGroup.
m_pg = TRY(ProcessGroup::try_create(ProcessGroupID(pid().value())));
m_tty = nullptr;
return with_mutable_protected_data([&](auto& protected_data) -> ErrorOr<FlatPtr> {
protected_data.sid = pid().value();
return protected_data.sid.value();
});
}
ErrorOr<FlatPtr> Process::sys$getpgid(pid_t pid)
{
VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this);
TRY(require_promise(Pledge::stdio));
if (pid == 0)
return pgid().value();
auto process = Process::from_pid(pid);
if (!process)
return ESRCH;
return process->pgid().value();
}
ErrorOr<FlatPtr> Process::sys$getpgrp()
{
VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this);
TRY(require_promise(Pledge::stdio));
return pgid().value();
}
SessionID Process::get_sid_from_pgid(ProcessGroupID pgid)
{
// FIXME: This xor sys$setsid() uses the wrong locking mechanism.
SessionID sid { -1 };
Process::for_each_in_pgrp(pgid, [&](auto& process) {
sid = process.sid();
return IterationDecision::Break;
});
return sid;
}
ErrorOr<FlatPtr> Process::sys$setpgid(pid_t specified_pid, pid_t specified_pgid)
{
VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this);
TRY(require_promise(Pledge::proc));
ProcessID pid = specified_pid ? ProcessID(specified_pid) : this->pid();
if (specified_pgid < 0) {
// The value of the pgid argument is less than 0, or is not a value supported by the implementation.
return EINVAL;
}
auto process = Process::from_pid(pid);
if (!process)
return ESRCH;
if (process != this && process->ppid() != this->pid()) {
// The value of the pid argument does not match the process ID
// of the calling process or of a child process of the calling process.
return ESRCH;
}
if (process->is_session_leader()) {
// The process indicated by the pid argument is a session leader.
return EPERM;
}
if (process->ppid() == this->pid() && process->sid() != sid()) {
// The value of the pid argument matches the process ID of a child
// process of the calling process and the child process is not in
// the same session as the calling process.
return EPERM;
}
ProcessGroupID new_pgid = specified_pgid ? ProcessGroupID(specified_pgid) : process->pid().value();
SessionID current_sid = sid();
SessionID new_sid = get_sid_from_pgid(new_pgid);
if (new_sid != -1 && current_sid != new_sid) {
// Can't move a process between sessions.
return EPERM;
}
if (new_sid == -1 && new_pgid != process->pid().value()) {
// The value of the pgid argument is valid, but is not
// the calling pid, and is not an existing process group.
return EPERM;
}
// FIXME: There are more EPERM conditions to check for here..
process->m_pg = TRY(ProcessGroup::try_find_or_create(new_pgid));
return 0;
}
}