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Kernel: Remove big lock from sys$accept4

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The only thing we needed to check is whether `socket.accept()` returns
a socket, and if not, we go back to blocking again.
This commit is contained in:
Jelle Raaijmakers 2022-04-09 17:28:31 +02:00 committed by Andreas Kling
parent 14fc05e912
commit cc411b328c
2 changed files with 12 additions and 13 deletions
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2
Kernel/API/Syscall.h
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@ -40,7 +40,7 @@ enum class NeedsBigProcessLock {
// - VERIFY_NO_PROCESS_BIG_LOCK(this)
//
#define ENUMERATE_SYSCALLS(S) \
S(accept4, NeedsBigProcessLock::Yes) \
S(accept4, NeedsBigProcessLock::No) \
S(access, NeedsBigProcessLock::Yes) \
S(adjtime, NeedsBigProcessLock::No) \
S(alarm, NeedsBigProcessLock::Yes) \

23
Kernel/Syscalls/socket.cpp
View file

@ -78,7 +78,7 @@ ErrorOr<FlatPtr> Process::sys$listen(int sockfd, int backlog)
ErrorOr<FlatPtr> Process::sys$accept4(Userspace<Syscall::SC_accept4_params const*> user_params)
{
VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this)
VERIFY_NO_PROCESS_BIG_LOCK(this)
TRY(require_promise(Pledge::accept));
auto params = TRY(copy_typed_from_user(user_params));
@ -88,9 +88,8 @@ ErrorOr<FlatPtr> Process::sys$accept4(Userspace<Syscall::SC_accept4_params const
int flags = params.flags;
socklen_t address_size = 0;
if (user_address) {
if (user_address)
TRY(copy_from_user(&address_size, static_ptr_cast<socklen_t const*>(user_address_size)));
}
ScopedDescriptionAllocation fd_allocation;
RefPtr<OpenFileDescription> accepting_socket_description;
@ -104,17 +103,17 @@ ErrorOr<FlatPtr> Process::sys$accept4(Userspace<Syscall::SC_accept4_params const
return ENOTSOCK;
auto& socket = *accepting_socket_description->socket();
if (!socket.can_accept()) {
if (accepting_socket_description->is_blocking()) {
auto unblock_flags = Thread::FileBlocker::BlockFlags::None;
if (Thread::current()->block<Thread::AcceptBlocker>({}, *accepting_socket_description, unblock_flags).was_interrupted())
return EINTR;
} else {
RefPtr<Socket> accepted_socket;
for (;;) {
accepted_socket = socket.accept();
if (accepted_socket)
break;
if (!accepting_socket_description->is_blocking())
return EAGAIN;
}
auto unblock_flags = Thread::FileBlocker::BlockFlags::None;
if (Thread::current()->block<Thread::AcceptBlocker>({}, *accepting_socket_description, unblock_flags).was_interrupted())
return EINTR;
}
auto accepted_socket = socket.accept();
VERIFY(accepted_socket);
if (user_address) {
sockaddr_un address_buffer {};