[lldb-dev] Remote debugging ARM target from x86 host

Wed Aug 23 10:45:18 PDT 2017

Port zero should never be returned as a valid port. We do bind to port zero just so we don't try and pick a port at random just to find it is being used. When we bind to port 9, we must find the actual port we bound to and return that. Seems something has gone wrong with the code that discovers the port that was actually bound and is not reporting that back correctly. 

Should be straight forward to do by debugging the function GDBRemoteCommunicationServerPlatform::Handle_qLaunchGDBServer(...) in GDBRemoteCommunicationServerPlatform.cpp and see what is going on and why it is returning 0 as the port.

Greg

> On Aug 23, 2017, at 9:44 AM, Hans Wennborg via lldb-dev <lldb-dev at lists.llvm.org> wrote:
> 
> This was marked as an lldb 5.0.0 release blocker since it's a
> regression from 4.0.1: https://bugs.llvm.org/show_bug.cgi?id=34183
> 
> lldb-dev: Is there any interest in fixing this bug?
> 
> On Fri, Aug 4, 2017 at 10:13 PM, Ramana via lldb-dev
> <lldb-dev at lists.llvm.org> wrote:
>> Hi,
>> 
>> I am trying to remote debug ARM (linux) target from x86 (linux) host
>> and I am getting the following error while trying to launch a process.
>> The local debugging on ARM works.
>> 
>> error: connect remote failed (invalid host:port specification: '10.10.2.3')
>> error: process launch failed: invalid host:port specification: '10.10.2.3'
>> 
>> It appears the above error is because the gdb-remote is returning the
>> communication port as zero.
>> 
>> <  36> send packet: $qLaunchGDBServer;host:svrlin249;#bb
>> <  19> read packet: $pid:298;port:0;#bf
>> 
>> What are the possible reasons for the above behavior from gdb-remote
>> and how I could resolve this?
>> 
>> If it helps, below is the full log.
>> 
>> (lldb) log enable lldb comm
>> (lldb) log enable gdb-remote packets
>> (lldb) platform select remote-linux
>>  Platform: remote-linux
>> Connected: no
>> (lldb) platform connect connect://10.10.2.3:500
>> 0x915bd78 Communication::Communication (name = gdb-remote.client)
>> 0x915bd78 Communication::Disconnect ()
>> 0x915bd78 Communication::Disconnect ()
>> 0x915bd78 Communication::Connect (url = connect://10.10.2.3:500)
>> Socket::TcpConnect (host/port = 10.10.2.3:500)
>> TCPSocket::Connect (host/port = 10.10.2.3:500)
>> 0x915bd78 Communication::Write (src = 0xbfcb7433, src_len = 1)
>> connection = 0x915f578
>> 0x915f608 Socket::Write() (socket = 7, src = 0xbfcb7433, src_len = 1,
>> flags = 0) => 1 (error = (null))
>> <   1> send packet: +
>> this = 0x0915BD78, dst = 0xBFCB53EC, dst_len = 8192, timeout = 10000
>> us, connection = 0x0915F578
>> 0x915bd78 Communication::Write (src = 0x916022c, src_len = 19)
>> connection = 0x915f578
>> 0x915f608 Socket::Write() (socket = 7, src = 0x916022c, src_len = 19,
>> flags = 0) => 19 (error = (null))
>> history[1] tid=0x7cbf <   1> send packet: +
>> <  19> send packet: $QStartNoAckMode#b0
>> this = 0x0915BD78, dst = 0xBFCB51AC, dst_len = 8192, timeout = 6000000
>> us, connection = 0x0915F578
>> 0x915f608 Socket::Read() (socket = 7, src = 0xbfcb51ac, src_len = 7,
>> flags = 0) => 7 (error = (null))
>> <   1> read packet: +
>> <   6> read packet: $OK#9a
>> 0x915bd78 Communication::Write (src = 0xbfcb50f3, src_len = 1)
>> connection = 0x915f578
>> 0x915f608 Socket::Write() (socket = 7, src = 0xbfcb50f3, src_len = 1,
>> flags = 0) => 1 (error = (null))
>> <   1> send packet: +
>> 0x915bd78 Communication::Write (src = 0x9161ff4, src_len = 13)
>> connection = 0x915f578
>> 0x915f608 Socket::Write() (socket = 7, src = 0x9161ff4, src_len = 13,
>> flags = 0) => 13 (error = (null))
>> <  13> send packet: $qHostInfo#9b
>> this = 0x0915BD78, dst = 0xBFCB510C, dst_len = 8192, timeout = 1000000
>> us, connection = 0x0915F578
>> 0x915f608 Socket::Read() (socket = 7, src = 0xbfcb510c, src_len = 316,
>> flags = 0) => 316 (error = (null))
>> < 316> read packet:
>> $triple:61726d2d2d6c696e75782d676e75656162696866;ptrsize:4;watchpoint_exceptions_received:before;endian:little;os_version:3.10.31;os_build:332e31302e33312d6c7473692d30323836312d6738303161343066;os_kernel:233520534d5020467269204d61792031332031353a35383a3232204953542032303136;hostname:736f
>> 63667067615f617272696135;#0a
>> 0x915bd78 Communication::Write (src = 0x915fe9c, src_len = 18)
>> connection = 0x915f578
>> 0x915f608 Socket::Write() (socket = 7, src = 0x915fe9c, src_len = 18,
>> flags = 0) => 18 (error = (null))
>> <  18> send packet: $qGetWorkingDir#91
>> this = 0x0915BD78, dst = 0xBFCB50FC, dst_len = 8192, timeout = 1000000
>> us, connection = 0x0915F578
>> 0x915f608 Socket::Read() (socket = 7, src = 0xbfcb50fc, src_len = 24,
>> flags = 0) => 24 (error = (null))
>> <  24> read packet: $2f686f6d652f726f6f74#4b
>> 0x915bd78 Communication::Write (src = 0x915fe9c, src_len = 19)
>> connection = 0x915f578
>> 0x915f608 Socket::Write() (socket = 7, src = 0x915fe9c, src_len = 19,
>> flags = 0) => 19 (error = (null))
>> <  19> send packet: $qQueryGDBServer#cb
>> this = 0x0915BD78, dst = 0xBFCB531C, dst_len = 8192, timeout = 1000000
>> us, connection = 0x0915F578
>> 0x915f608 Socket::Read() (socket = 7, src = 0xbfcb531c, src_len = 7,
>> flags = 0) => 7 (error = (null))
>> <   7> read packet: $E04#a9
>>  Platform: remote-linux
>>    Triple: arm-*-linux-gnueabihf
>> OS Version: 3.10.31 (3.10.31-ltsi-02861-g801a40f)
>>    Kernel: #5 SMP Fri May 13 15:58:22 IST 2016
>>  Hostname: socfpga_arria5
>> Connected: yes
>> WorkingDir: /home/root
>> (lldb) file main
>> 0x915bd78 Communication::Write (src = 0x91638fc, src_len = 137)
>> connection = 0x915f578
>> 0x915f608 Socket::Write() (socket = 7, src = 0x91638fc, src_len = 137,
>> flags = 0) => 137 (error = (null))
>> < 137> send packet:
>> $qModuleInfo:2f686f6d652f72616d616e616e2f776f726b5f726f6f742f546f545f6c6c64622f74657374732f6d61696e;61726d2d2d6c696e75782d656162696866#f1
>> this = 0x0915BD78, dst = 0xBFCB172C, dst_len = 8192, timeout = 1000000
>> us, connection = 0x0915F578
>> 0x915f608 Socket::Read() (socket = 7, src = 0xbfcb172c, src_len = 7,
>> flags = 0) => 7 (error = (null))
>> <   7> read packet: $E03#a8
>> Current executable set to 'main' (arm).
>> (lldb) b main
>> Breakpoint 1: where = main`main + 4 at main.c:4, address = 0x000104a0
>> (lldb) run
>> 0x915bd78 Communication::Write (src = 0x917bae4, src_len = 36)
>> connection = 0x915f578
>> 0x915f608 Socket::Write() (socket = 7, src = 0x917bae4, src_len = 36,
>> flags = 0) => 36 (error = (null))
>> <  36> send packet: $qLaunchGDBServer;host:svrlin249;#bb
>> this = 0x0915BD78, dst = 0xBFCB4FDC, dst_len = 8192, timeout =
>> 10000000 us, connection = 0x0915F578
>> 0x915f608 Socket::Read() (socket = 7, src = 0xbfcb4fdc, src_len = 19,
>> flags = 0) => 19 (error = (null))
>> <  19> read packet: $pid:298;port:0;#bf
>> 0x92b0a84 Communication::Communication (name = process.stdio)
>> 0x92b0d78 Communication::Communication (name = gdb-remote.client)
>> 0x92b0a84 Communication::Disconnect ()
>> Socket::TcpConnect (host/port = 10.10.2.3)
>> TCPSocket::Connect (host/port = 10.10.2.3)
>> Socket::TcpConnect (host/port = 10.10.2.3)
>> TCPSocket::Connect (host/port = 10.10.2.3)
>> Socket::TcpConnect (host/port = 10.10.2.3)
>> TCPSocket::Connect (host/port = 10.10.2.3)
>> Socket::TcpConnect (host/port = 10.10.2.3)
>> TCPSocket::Connect (host/port = 10.10.2.3)
>> Socket::TcpConnect (host/port = 10.10.2.3)
>> TCPSocket::Connect (host/port = 10.10.2.3)
>> Socket::TcpConnect (host/port = 10.10.2.3)
>> TCPSocket::Connect (host/port = 10.10.2.3)
>> Socket::TcpConnect (host/port = 10.10.2.3)
>> TCPSocket::Connect (host/port = 10.10.2.3)
>> Socket::TcpConnect (host/port = 10.10.2.3)
>> ..................
>> ..................
>> ..................
>> TCPSocket::Connect (host/port = 10.10.2.3)
>> Socket::TcpConnect (host/port = 10.10.2.3)
>> TCPSocket::Connect (host/port = 10.10.2.3)
>> Socket::TcpConnect (host/port = 10.10.2.3)
>> TCPSocket::Connect (host/port = 10.10.2.3)
>> Socket::TcpConnect (host/port = 10.10.2.3)
>> TCPSocket::Connect (host/port = 10.10.2.3)
>> Socket::TcpConnect (host/port = 10.10.2.3)
>> TCPSocket::Connect (host/port = 10.10.2.3)
>> Socket::TcpConnect (host/port = 10.10.2.3)
>> TCPSocket::Connect (host/port = 10.10.2.3)
>> error: connect remote failed (invalid host:port specification: '10.10.2.3')
>> 0x915bd78 Communication::Write (src = 0x92b38c4, src_len = 27)
>> connection = 0x915f578
>> 0x915f608 Socket::Write() (socket = 7, src = 0x92b38c4, src_len = 27,
>> flags = 0) => 27 (error = (null))
>> <  27> send packet: $qKillSpawnedProcess:298#8b
>> this = 0x0915BD78, dst = 0xBFCB509C, dst_len = 8192, timeout = 1000000
>> us, connection = 0x0915F578
>> 0x915f608 Socket::Read() (socket = 7, src = 0xbfcb509c, src_len = 7,
>> flags = 0) => 7 (error = (null))
>> <   7> read packet: $E0a#d6
>> error: process launch failed: invalid host:port specification: '10.10.2.3'
>> (lldb)
>> 
>> 
>> Regards,
>> Ramana
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>> lldb-dev at lists.llvm.org
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