Trying to open a pseudo-tty throws an exception on 5.13+ Linux kernels #21203
Description
This was already reported and fixed in #20218, but Linux kernel changes have rendered the fix there insufficient.
Note: Ubuntu seems to have included this patch in their 5.4.0-75 kernels for Focal, so this is probably happening to you even if your mainline kernel version is <5.13 (it was my case).
Steps to Reproduce
On a Linux system:
- Compile the following code
using System.IO.Ports;
public class Test
{
public static void Main(string[] args)
{
SerialPort port;
port = new SerialPort();
port.PortName="/tmp/ttyA";
port.Open();
}
}
- Use
socatto open a PTY
socat PTY,rawer,link=/tmp/ttyA STDIO
- Run the testcase
Current Behavior
An exception is thrown.
Unhandled Exception:
System.IO.IOException: Inappropriate ioctl for device
at System.IO.Ports.SerialPortStream.ThrowIOException () [0x0000f] in <7024908a7fd94b32a39c17e950046899>:0
at System.IO.Ports.SerialPortStream.SetSignal (System.IO.Ports.SerialSignal signal, System.Boolean value) [0x00030] in <7024908a7fd94b32a39c17e950046899>:0
at (wrapper remoting-invoke-with-check) System.IO.Ports.SerialPortStream.SetSignal(System.IO.Ports.SerialSignal,bool)
at System.IO.Ports.SerialPortStream..ctor (System.String portName, System.Int32 baudRate, System.Int32 dataBits, System.IO.Ports.Parity parity, System.IO.Ports.StopBits stopBits, System.Boolean dtrEnable, System.Boolean rtsEnable, System.IO.Ports.Handshake handshake, System.Int32 readTimeout, System.Int32 writeTimeout, System.Int32 readBufferSize, System.Int32 writeBufferSize) [0x00051] in <7024908a7fd94b32a39c17e950046899>:0
at (wrapper remoting-invoke-with-check) System.IO.Ports.SerialPortStream..ctor(string,int,int,System.IO.Ports.Parity,System.IO.Ports.StopBits,bool,bool,System.IO.Ports.Handshake,int,int,int,int)
at System.IO.Ports.SerialPort.Open () [0x0006f] in <7024908a7fd94b32a39c17e950046899>:0
at (wrapper remoting-invoke-with-check) System.IO.Ports.SerialPort.Open()
at Test.Main (System.String[] args) [0x00011] in <51bd885d7d6f450eb7e9eb1425cc99f2>:0
[ERROR] FATAL UNHANDLED EXCEPTION: System.IO.IOException: Inappropriate ioctl for device
at System.IO.Ports.SerialPortStream.ThrowIOException () [0x0000f] in <7024908a7fd94b32a39c17e950046899>:0
at System.IO.Ports.SerialPortStream.SetSignal (System.IO.Ports.SerialSignal signal, System.Boolean value) [0x00030] in <7024908a7fd94b32a39c17e950046899>:0
at (wrapper remoting-invoke-with-check) System.IO.Ports.SerialPortStream.SetSignal(System.IO.Ports.SerialSignal,bool)
at System.IO.Ports.SerialPortStream..ctor (System.String portName, System.Int32 baudRate, System.Int32 dataBits, System.IO.Ports.Parity parity, System.IO.Ports.StopBits stopBits, System.Boolean dtrEnable, System.Boolean rtsEnable, System.IO.Ports.Handshake handshake, System.Int32 readTimeout, System.Int32 writeTimeout, System.Int32 readBufferSize, System.Int32 writeBufferSize) [0x00051] in <7024908a7fd94b32a39c17e950046899>:0
at (wrapper remoting-invoke-with-check) System.IO.Ports.SerialPortStream..ctor(string,int,int,System.IO.Ports.Parity,System.IO.Ports.StopBits,bool,bool,System.IO.Ports.Handshake,int,int,int,int)
at System.IO.Ports.SerialPort.Open () [0x0006f] in <7024908a7fd94b32a39c17e950046899>:0
at (wrapper remoting-invoke-with-check) System.IO.Ports.SerialPort.Open()
at Test.Main (System.String[] args) [0x00011] in <51bd885d7d6f450eb7e9eb1425cc99f2>:0
Expected Behavior
Program ending without errors.
On which platforms did you notice this
[ ] macOS
[X ] Linux
[ ] Windows
Version Used:
Mono JIT compiler version 6.13.0 (main/1bdb6cc55c3 mié 25 ago 2021 07:42:55 UTC)
Copyright (C) Novell, Inc, Xamarin Inc and Contributors. www.mono-project.com
TLS: __thread
SIGSEGV: altstack
Notifications: epoll
Architecture: amd64
Disabled: none
Misc: softdebug
Interpreter: yes
LLVM: supported, not enabled.
Suspend: hybrid
GC: sgen (concurrent by default)