Author: Pavel Labath Date: 2022-06-14T08:49:02+02:00 New Revision: 926a7ecdc8b21f01b06a1db78bdd81f1dacaad61
URL: https://github.com/llvm/llvm-project/commit/926a7ecdc8b21f01b06a1db78bdd81f1dacaad61 DIFF: https://github.com/llvm/llvm-project/commit/926a7ecdc8b21f01b06a1db78bdd81f1dacaad61.diff LOG: [lldb] Fix TCPSocket::Connect when getaddrinfo returns multiple addrs TCPSocket::Connect() calls SocketAddress::GetAddressInfo() and tries to connect any of them (in a for loop). This used to work before commit 4f6d3a376c9f("[LLDB] Fix setting of success in Socket::Close()") https://reviews.llvm.org/D116768. As a side effect of that commit, TCPSocket can only connect to the first address returned by SocketAddress::GetAddressInfo(). 1. If the attempt to connect to the first address fails, TCPSocket::Connect(), calls CLOSE_SOCKET(GetNativeSocket()), which closes the fd, but DOES NOT set m_socket to kInvalidSocketValue. 2. On the second attempt, TCPSocket::CreateSocket() calls Socket::Close(). 3. Socket::Close() proceeds, because IsValid() is true (m_socket was not reset on step 1). 4. Socket::Close() calls ::close(m_socket), which fails 5. Since commit 4f6d3a376c9f("[LLDB] Fix setting of success in Socket::Close()"), this is error is detected. Socket::Close() returns an error. 6. TCPSocket::CreateSocket() therefore returns an error. 7. TCPSocket::Connect() detects the error and continues, skipping the second (and the third, fourth...) address. This commit fixes the problem by changing step 1: by calling Socket::Close, instead of directly calling close(m_socket), m_socket is also se to kInvalidSocketValue. On step 3, Socket::Close() is going to return immediately and, on step 6, TCPSocket::CreateSocket() does not fail. How to reproduce this problem: On my system, getaddrinfo() resolves "localhost" to "::1" (first) and to "127.0.0.1" (second). Start a gdbserver that only listens on 127.0.0.1: ``` gdbserver 127.0.0.1:2159 /bin/cat Process /bin/cat created; pid = 2146709 Listening on port 2159 ``` Start lldb and make it connect to "localhost:2159" ``` ./bin/lldb (lldb) gdb-remote localhost:2159 ``` Before 4f6d3a376c9f("[LLDB] Fix setting of success in Socket::Close()"), this used to work. After that commit, it stopped working. This commit fixes the problem. Reviewed By: labath Differential Revision: https://reviews.llvm.org/D126702 Added: Modified: lldb/source/Host/common/TCPSocket.cpp Removed: ################################################################################ diff --git a/lldb/source/Host/common/TCPSocket.cpp b/lldb/source/Host/common/TCPSocket.cpp index 46d97ad470e4f..eabc9fef8a661 100644 --- a/lldb/source/Host/common/TCPSocket.cpp +++ b/lldb/source/Host/common/TCPSocket.cpp @@ -170,7 +170,7 @@ Status TCPSocket::Connect(llvm::StringRef name) { if (-1 == llvm::sys::RetryAfterSignal(-1, ::connect, GetNativeSocket(), &address.sockaddr(), address.GetLength())) { - CLOSE_SOCKET(GetNativeSocket()); + Close(); continue; } _______________________________________________ lldb-commits mailing list lldb-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits