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/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <Kernel/FileSystem/FIFO.h>
#include <Kernel/Process.h>
namespace Kernel {
ErrorOr<FlatPtr> Process::sys$pipe(int pipefd[2], int flags)
{
VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this)
TRY(require_promise(Pledge::stdio));
auto open_count = fds().with_shared([](auto& fds) { return fds.open_count(); });
if (open_count + 2 > OpenFileDescriptions::max_open())
return EMFILE;
// Reject flags other than O_CLOEXEC, O_NONBLOCK
if ((flags & (O_CLOEXEC | O_NONBLOCK)) != flags)
return EINVAL;
u32 fd_flags = (flags & O_CLOEXEC) ? FD_CLOEXEC : 0;
auto fifo = TRY(FIFO::try_create(uid()));
ScopedDescriptionAllocation reader_fd_allocation;
ScopedDescriptionAllocation writer_fd_allocation;
TRY(m_fds.with_exclusive([&](auto& fds) -> ErrorOr<void> {
reader_fd_allocation = TRY(fds.allocate());
writer_fd_allocation = TRY(fds.allocate());
return {};
}));
auto reader_description = TRY(fifo->open_direction(FIFO::Direction::Reader));
auto writer_description = TRY(fifo->open_direction(FIFO::Direction::Writer));
reader_description->set_readable(true);
writer_description->set_writable(true);
if (flags & O_NONBLOCK) {
reader_description->set_blocking(false);
writer_description->set_blocking(false);
}
TRY(m_fds.with_exclusive([&](auto& fds) -> ErrorOr<void> {
fds[reader_fd_allocation.fd].set(move(reader_description), fd_flags);
fds[writer_fd_allocation.fd].set(move(writer_description), fd_flags);
return {};
}));
TRY(copy_to_user(&pipefd[0], &reader_fd_allocation.fd));
TRY(copy_to_user(&pipefd[1], &writer_fd_allocation.fd));
return 0;
}
}
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