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		cbaa3465a8
		
	
	
	
	
		
			
			We should consider whether the selected Thread is within the same jail or not. Therefore let's make it clear to callers with jail semantics if a called method checks if the desired Thread object is within the same jail. As for Thread::for_each_* methods, currently nothing in the kernel codebase needs iteration with consideration for jails, so the old Thread::for_each* were simply renamed to include "ignoring_jails" suffix in their names.
		
			
				
	
	
		
			117 lines
		
	
	
	
		
			3.9 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			117 lines
		
	
	
	
		
			3.9 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
| /*
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|  * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
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|  * Copyright (c) 2022, kleines Filmröllchen <filmroellchen@serenityos.org>
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|  *
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|  * SPDX-License-Identifier: BSD-2-Clause
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|  */
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| 
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| #include <Kernel/API/Syscall.h>
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| #include <Kernel/Tasks/Process.h>
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| #include <Kernel/Tasks/Scheduler.h>
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| 
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| namespace Kernel {
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| 
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| ErrorOr<FlatPtr> Process::sys$yield()
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| {
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|     VERIFY_NO_PROCESS_BIG_LOCK(this);
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|     TRY(require_promise(Pledge::stdio));
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|     Thread::current()->yield_without_releasing_big_lock();
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|     return 0;
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| }
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| 
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| ErrorOr<NonnullRefPtr<Thread>> Process::get_thread_from_pid_or_tid(pid_t pid_or_tid, Syscall::SchedulerParametersMode mode)
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| {
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|     VERIFY(g_scheduler_lock.is_locked_by_current_processor());
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|     Thread* peer;
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|     switch (mode) {
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|     case Syscall::SchedulerParametersMode::Thread: {
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|         peer = Thread::current();
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|         if (pid_or_tid != 0)
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|             peer = Thread::from_tid_in_same_jail(pid_or_tid);
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| 
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|         // Only superuser can access other processes' threads.
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|         if (!credentials()->is_superuser() && peer && &peer->process() != this)
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|             return EPERM;
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| 
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|         break;
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|     }
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|     case Syscall::SchedulerParametersMode::Process: {
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|         auto* searched_process = this;
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|         if (pid_or_tid != 0)
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|             searched_process = Process::from_pid_in_same_jail(pid_or_tid);
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| 
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|         if (searched_process == nullptr)
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|             return ESRCH;
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|         auto pid = searched_process->pid().value();
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|         // Main thread has tid == pid
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|         this->thread_list().for_each([&](auto& thread) {
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|             if (thread.tid().value() == pid)
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|                 peer = &thread;
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|         });
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|         break;
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|     }
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|     default:
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|         VERIFY_NOT_REACHED();
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|     }
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|     if (!peer)
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|         return ESRCH;
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|     return NonnullRefPtr<Thread> { *peer };
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| }
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| 
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| ErrorOr<FlatPtr> Process::sys$scheduler_set_parameters(Userspace<Syscall::SC_scheduler_parameters_params const*> user_param)
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| {
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|     VERIFY_NO_PROCESS_BIG_LOCK(this);
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|     TRY(require_promise(Pledge::proc));
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|     auto parameters = TRY(copy_typed_from_user(user_param));
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| 
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|     if (parameters.parameters.sched_priority < THREAD_PRIORITY_MIN || parameters.parameters.sched_priority > THREAD_PRIORITY_MAX)
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|         return EINVAL;
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| 
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|     SpinlockLocker lock(g_scheduler_lock);
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|     auto peer = TRY(get_thread_from_pid_or_tid(parameters.pid_or_tid, parameters.mode));
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| 
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|     auto credentials = this->credentials();
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|     auto peer_credentials = peer->process().credentials();
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|     if (!credentials->is_superuser() && credentials->euid() != peer_credentials->uid() && credentials->uid() != peer_credentials->uid())
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|         return EPERM;
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| 
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|     peer->set_priority((u32)parameters.parameters.sched_priority);
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|     // POSIX says that process scheduling parameters have precedence over thread scheduling parameters.
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|     // We don't track them separately, so overwrite the thread scheduling settings manually for now.
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|     if (parameters.mode == Syscall::SchedulerParametersMode::Process) {
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|         peer->process().for_each_thread([&](auto& thread) {
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|             thread.set_priority((u32)parameters.parameters.sched_priority);
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|         });
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|     }
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| 
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|     return 0;
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| }
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| 
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| ErrorOr<FlatPtr> Process::sys$scheduler_get_parameters(Userspace<Syscall::SC_scheduler_parameters_params*> user_param)
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| {
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|     VERIFY_NO_PROCESS_BIG_LOCK(this);
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|     TRY(require_promise(Pledge::proc));
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| 
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|     Syscall::SC_scheduler_parameters_params parameters;
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|     TRY(copy_from_user(¶meters, user_param));
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| 
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|     int priority;
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|     {
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|         SpinlockLocker lock(g_scheduler_lock);
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|         auto peer = TRY(get_thread_from_pid_or_tid(parameters.pid_or_tid, parameters.mode));
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| 
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|         auto credentials = this->credentials();
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|         auto peer_credentials = peer->process().credentials();
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|         if (!credentials->is_superuser() && credentials->euid() != peer_credentials->uid() && credentials->uid() != peer_credentials->uid())
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|             return EPERM;
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| 
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|         priority = (int)peer->priority();
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|     }
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| 
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|     parameters.parameters.sched_priority = priority;
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| 
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|     TRY(copy_to_user(user_param, ¶meters));
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|     return 0;
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| }
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| 
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| }
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