mirror of
https://github.com/LadybirdBrowser/ladybird.git
synced 2024-09-11 13:36:13 +03:00
3e30d9bc99
This closes two race windows: - ProcessGroup removed itself from the "all process groups" list in its destructor. It was possible to walk the list between the last unref() and the destructor invocation, and grab a pointer to a ProcessGroup that was about to get deleted. - sys$setsid() could end up creating a process group that already existed, as there was a race window between checking if the PGID is used, and actually creating a ProcessGroup with that PGID.
60 lines
1.8 KiB
C++
60 lines
1.8 KiB
C++
/*
|
|
* Copyright (c) 2020, the SerenityOS developers.
|
|
* Copyright (c) 2021-2023, Andreas Kling <kling@serenityos.org>
|
|
*
|
|
* SPDX-License-Identifier: BSD-2-Clause
|
|
*/
|
|
|
|
#include <AK/Singleton.h>
|
|
#include <Kernel/ProcessGroup.h>
|
|
|
|
namespace Kernel {
|
|
|
|
static Singleton<SpinlockProtected<ProcessGroup::AllInstancesList, LockRank::None>> s_all_instances;
|
|
|
|
SpinlockProtected<ProcessGroup::AllInstancesList, LockRank::None>& ProcessGroup::all_instances()
|
|
{
|
|
return s_all_instances;
|
|
}
|
|
|
|
ProcessGroup::~ProcessGroup() = default;
|
|
|
|
ErrorOr<NonnullRefPtr<ProcessGroup>> ProcessGroup::create_if_unused_pgid(ProcessGroupID pgid)
|
|
{
|
|
return all_instances().with([&](auto& all_instances) -> ErrorOr<NonnullRefPtr<ProcessGroup>> {
|
|
for (auto& process_group : all_instances) {
|
|
if (process_group.pgid() == pgid)
|
|
return EPERM;
|
|
}
|
|
auto process_group = TRY(adopt_nonnull_ref_or_enomem(new (nothrow) ProcessGroup(pgid)));
|
|
all_instances.prepend(*process_group);
|
|
return process_group;
|
|
});
|
|
}
|
|
|
|
ErrorOr<NonnullRefPtr<ProcessGroup>> ProcessGroup::find_or_create(ProcessGroupID pgid)
|
|
{
|
|
return all_instances().with([&](auto& all_instances) -> ErrorOr<NonnullRefPtr<ProcessGroup>> {
|
|
for (auto& group : all_instances) {
|
|
if (group.pgid() == pgid)
|
|
return group;
|
|
}
|
|
auto process_group = TRY(adopt_nonnull_ref_or_enomem(new (nothrow) ProcessGroup(pgid)));
|
|
all_instances.prepend(*process_group);
|
|
return process_group;
|
|
});
|
|
}
|
|
|
|
RefPtr<ProcessGroup> ProcessGroup::from_pgid(ProcessGroupID pgid)
|
|
{
|
|
return all_instances().with([&](auto& groups) -> RefPtr<ProcessGroup> {
|
|
for (auto& group : groups) {
|
|
if (group.pgid() == pgid)
|
|
return &group;
|
|
}
|
|
return nullptr;
|
|
});
|
|
}
|
|
|
|
}
|