ladybird/Kernel/Syscalls/umask.cpp
Andreas Kling 8ed06ad814 Kernel: Guard Process "protected data" with a spinlock
This ensures that both mutable and immutable access to the protected
data of a process is serialized.

Note that there may still be multiple TOCTOU issues around this, as we
have a bunch of convenience accessors that make it easy to introduce
them. We'll need to audit those as well.
2022-08-21 12:25:14 +02:00

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/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <Kernel/Process.h>
namespace Kernel {
ErrorOr<FlatPtr> Process::sys$umask(mode_t mask)
{
VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this);
TRY(require_promise(Pledge::stdio));
return with_mutable_protected_data([&](auto& protected_data) -> ErrorOr<FlatPtr> {
auto old_mask = protected_data.umask;
protected_data.umask = mask & 0777;
return old_mask;
});
}
}