diff options
Diffstat (limited to 'lldb/source/Plugins/Process/gdb-remote')
6 files changed, 137 insertions, 13 deletions
diff --git a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.cpp b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.cpp index 38942ec2d17..652af4bdb7a 100644 --- a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.cpp +++ b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.cpp @@ -18,6 +18,7 @@ // C++ Includes // Other libraries and framework includes #include "lldb/Core/Log.h" +#include "lldb/Core/RegularExpression.h" #include "lldb/Core/StreamFile.h" #include "lldb/Core/StreamString.h" #include "lldb/Host/ConnectionFileDescriptor.h" @@ -150,6 +151,8 @@ GDBRemoteCommunication::GDBRemoteCommunication(const char *comm_name, #else m_packet_timeout (1), #endif + m_echo_number(0), + m_supports_qEcho (eLazyBoolCalculate), m_sequence_mutex (Mutex::eMutexTypeRecursive), m_public_is_running (false), m_private_is_running (false), @@ -292,7 +295,7 @@ GDBRemoteCommunication::PacketResult GDBRemoteCommunication::GetAck () { StringExtractorGDBRemote packet; - PacketResult result = WaitForPacketWithTimeoutMicroSecondsNoLock (packet, GetPacketTimeoutInMicroSeconds ()); + PacketResult result = WaitForPacketWithTimeoutMicroSecondsNoLock (packet, GetPacketTimeoutInMicroSeconds (), false); if (result == PacketResult::Success) { if (packet.GetResponseType() == StringExtractorGDBRemote::ResponseType::eAck) @@ -321,7 +324,7 @@ GDBRemoteCommunication::WaitForNotRunningPrivate (const TimeValue *timeout_ptr) } GDBRemoteCommunication::PacketResult -GDBRemoteCommunication::WaitForPacketWithTimeoutMicroSecondsNoLock (StringExtractorGDBRemote &packet, uint32_t timeout_usec) +GDBRemoteCommunication::WaitForPacketWithTimeoutMicroSecondsNoLock (StringExtractorGDBRemote &packet, uint32_t timeout_usec, bool sync_on_timeout) { uint8_t buffer[8192]; Error error; @@ -358,6 +361,104 @@ GDBRemoteCommunication::WaitForPacketWithTimeoutMicroSecondsNoLock (StringExtrac { case eConnectionStatusTimedOut: case eConnectionStatusInterrupted: + if (sync_on_timeout) + { + //------------------------------------------------------------------ + /// Sync the remote GDB server and make sure we get a response that + /// corresponds to what we send. + /// + /// Sends a "qEcho" packet and makes sure it gets the exact packet + /// echoed back. If the qEcho packet isn't supported, we send a qC + /// packet and make sure we get a valid thread ID back. We use the + /// "qC" packet since its response if very unique: is responds with + /// "QC%x" where %x is the thread ID of the current thread. This + /// makes the response unique enough from other packet responses to + /// ensure we are back on track. + /// + /// This packet is needed after we time out sending a packet so we + /// can ensure that we are getting the response for the packet we + /// are sending. There are no sequence IDs in the GDB remote + /// protocol (there used to be, but they are not supported anymore) + /// so if you timeout sending packet "abc", you might then send + /// packet "cde" and get the response for the previous "abc" packet. + /// Many responses are "OK" or "" (unsupported) or "EXX" (error) so + /// many responses for packets can look like responses for other + /// packets. So if we timeout, we need to ensure that we can get + /// back on track. If we can't get back on track, we must + /// disconnect. + //------------------------------------------------------------------ + bool sync_success = false; + bool got_actual_response = false; + // We timed out, we need to sync back up with the + char echo_packet[32]; + int echo_packet_len = 0; + RegularExpression response_regex; + + if (m_supports_qEcho == eLazyBoolYes) + { + echo_packet_len = ::snprintf (echo_packet, sizeof(echo_packet), "qEcho:%u", ++m_echo_number); + std::string regex_str = "^"; + regex_str += echo_packet; + regex_str += "$"; + response_regex.Compile(regex_str.c_str()); + } + else + { + echo_packet_len = ::snprintf (echo_packet, sizeof(echo_packet), "qC"); + response_regex.Compile("^QC[0-9A-Fa-f]+$"); + } + + PacketResult echo_packet_result = SendPacketNoLock (echo_packet, echo_packet_len); + if (echo_packet_result == PacketResult::Success) + { + const uint32_t max_retries = 3; + uint32_t successful_responses = 0; + for (uint32_t i=0; i<max_retries; ++i) + { + StringExtractorGDBRemote echo_response; + echo_packet_result = WaitForPacketWithTimeoutMicroSecondsNoLock (echo_response, timeout_usec, false); + if (echo_packet_result == PacketResult::Success) + { + ++successful_responses; + if (response_regex.Execute(echo_response.GetStringRef().c_str())) + { + sync_success = true; + break; + } + else if (successful_responses == 1) + { + // We got something else back as the first successful response, it probably is + // the response to the packet we actually wanted, so copy it over if this + // is the first success and continue to try to get the qEcho response + packet = echo_response; + got_actual_response = true; + } + } + else if (echo_packet_result == PacketResult::ErrorReplyTimeout) + continue; // Packet timed out, continue waiting for a response + else + break; // Something else went wrong getting the packet back, we failed and are done trying + } + } + + // We weren't able to sync back up with the server, we must abort otherwise + // all responses might not be from the right packets... + if (sync_success) + { + // We timed out, but were able to recover + if (got_actual_response) + { + // We initially timed out, but we did get a response that came in before the successful + // reply to our qEcho packet, so lets say everything is fine... + return PacketResult::Success; + } + } + else + { + disconnected = true; + Disconnect(); + } + } timed_out = true; break; case eConnectionStatusSuccess: diff --git a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.h b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.h index 6fd1b854d8a..011adec9e4e 100644 --- a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.h +++ b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunication.h @@ -281,7 +281,8 @@ protected: PacketResult WaitForPacketWithTimeoutMicroSecondsNoLock (StringExtractorGDBRemote &response, - uint32_t timeout_usec); + uint32_t timeout_usec, + bool sync_on_timeout); bool WaitForNotRunningPrivate (const TimeValue *timeout_ptr); @@ -290,6 +291,8 @@ protected: // Classes that inherit from GDBRemoteCommunication can see and modify these //------------------------------------------------------------------ uint32_t m_packet_timeout; + uint32_t m_echo_number; + LazyBool m_supports_qEcho; #ifdef ENABLE_MUTEX_ERROR_CHECKING TrackingMutex m_sequence_mutex; #else diff --git a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp index a452ae95b07..3e9278853a7 100644 --- a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp +++ b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp @@ -145,7 +145,7 @@ GDBRemoteCommunicationClient::HandshakeWithServer (Error *error_ptr) PacketResult packet_result = PacketResult::Success; const uint32_t timeout_usec = 10 * 1000; // Wait for 10 ms for a response while (packet_result == PacketResult::Success) - packet_result = WaitForPacketWithTimeoutMicroSecondsNoLock (response, timeout_usec); + packet_result = WaitForPacketWithTimeoutMicroSecondsNoLock (response, timeout_usec, false); // The return value from QueryNoAckModeSupported() is true if the packet // was sent and _any_ response (including UNIMPLEMENTED) was received), @@ -170,13 +170,24 @@ GDBRemoteCommunicationClient::HandshakeWithServer (Error *error_ptr) } bool +GDBRemoteCommunicationClient::GetEchoSupported () +{ + if (m_supports_qEcho == eLazyBoolCalculate) + { + GetRemoteQSupported(); + } + return m_supports_qEcho == eLazyBoolYes; +} + + +bool GDBRemoteCommunicationClient::GetAugmentedLibrariesSVR4ReadSupported () { if (m_supports_augmented_libraries_svr4_read == eLazyBoolCalculate) { GetRemoteQSupported(); } - return (m_supports_augmented_libraries_svr4_read == eLazyBoolYes); + return m_supports_augmented_libraries_svr4_read == eLazyBoolYes; } bool @@ -186,7 +197,7 @@ GDBRemoteCommunicationClient::GetQXferLibrariesSVR4ReadSupported () { GetRemoteQSupported(); } - return (m_supports_qXfer_libraries_svr4_read == eLazyBoolYes); + return m_supports_qXfer_libraries_svr4_read == eLazyBoolYes; } bool @@ -196,7 +207,7 @@ GDBRemoteCommunicationClient::GetQXferLibrariesReadSupported () { GetRemoteQSupported(); } - return (m_supports_qXfer_libraries_read == eLazyBoolYes); + return m_supports_qXfer_libraries_read == eLazyBoolYes; } bool @@ -206,7 +217,7 @@ GDBRemoteCommunicationClient::GetQXferAuxvReadSupported () { GetRemoteQSupported(); } - return (m_supports_qXfer_auxv_read == eLazyBoolYes); + return m_supports_qXfer_auxv_read == eLazyBoolYes; } bool @@ -216,7 +227,7 @@ GDBRemoteCommunicationClient::GetQXferFeaturesReadSupported () { GetRemoteQSupported(); } - return (m_supports_qXfer_features_read == eLazyBoolYes); + return m_supports_qXfer_features_read == eLazyBoolYes; } uint64_t @@ -412,6 +423,11 @@ GDBRemoteCommunicationClient::GetRemoteQSupported () if (::strstr (response_cstr, "qXfer:features:read+")) m_supports_qXfer_features_read = eLazyBoolYes; + if (::strstr (response_cstr, "qEcho")) + m_supports_qEcho = eLazyBoolYes; + else + m_supports_qEcho = eLazyBoolNo; + const char *packet_size_str = ::strstr (response_cstr, "PacketSize="); if (packet_size_str) { @@ -638,7 +654,7 @@ GDBRemoteCommunicationClient::SendPacketAndWaitForResponseNoLock (const char *pa { PacketResult packet_result = SendPacketNoLock (payload, payload_length); if (packet_result == PacketResult::Success) - packet_result = WaitForPacketWithTimeoutMicroSecondsNoLock (response, GetPacketTimeoutInMicroSeconds ()); + packet_result = WaitForPacketWithTimeoutMicroSecondsNoLock (response, GetPacketTimeoutInMicroSeconds (), true); return packet_result; } @@ -888,7 +904,7 @@ GDBRemoteCommunicationClient::SendContinuePacketAndWaitForResponse if (log) log->Printf ("GDBRemoteCommunicationClient::%s () WaitForPacket(%s)", __FUNCTION__, continue_packet.c_str()); - if (WaitForPacketWithTimeoutMicroSecondsNoLock(response, UINT32_MAX) == PacketResult::Success) + if (WaitForPacketWithTimeoutMicroSecondsNoLock(response, UINT32_MAX, false) == PacketResult::Success) { if (response.Empty()) state = eStateInvalid; @@ -945,7 +961,7 @@ GDBRemoteCommunicationClient::SendContinuePacketAndWaitForResponse // packet to make sure it doesn't get in the way StringExtractorGDBRemote extra_stop_reply_packet; uint32_t timeout_usec = 1000; - if (WaitForPacketWithTimeoutMicroSecondsNoLock (extra_stop_reply_packet, timeout_usec) == PacketResult::Success) + if (WaitForPacketWithTimeoutMicroSecondsNoLock (extra_stop_reply_packet, timeout_usec, false) == PacketResult::Success) { switch (extra_stop_reply_packet.GetChar()) { diff --git a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.h b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.h index 517eb3d0f17..23b5d382a0c 100644 --- a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.h +++ b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.h @@ -430,6 +430,9 @@ public: GetRemoteMaxPacketSize(); bool + GetEchoSupported (); + + bool GetAugmentedLibrariesSVR4ReadSupported (); bool diff --git a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServer.cpp b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServer.cpp index 409efdfa2f7..13ce9b2dc5c 100644 --- a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServer.cpp +++ b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServer.cpp @@ -51,7 +51,7 @@ GDBRemoteCommunicationServer::GetPacketAndSendResponse (uint32_t timeout_usec, { StringExtractorGDBRemote packet; - PacketResult packet_result = WaitForPacketWithTimeoutMicroSecondsNoLock (packet, timeout_usec); + PacketResult packet_result = WaitForPacketWithTimeoutMicroSecondsNoLock (packet, timeout_usec, false); if (packet_result == PacketResult::Success) { const StringExtractorGDBRemote::ServerPacketType packet_type = packet.GetServerPacketType (); diff --git a/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp b/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp index 8f2efa2cf73..61cc89dc71b 100644 --- a/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp +++ b/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp @@ -1170,6 +1170,7 @@ ProcessGDBRemote::ConnectToDebugserver (const char *connect_url) if (GetTarget().GetNonStopModeEnabled()) m_gdb_comm.SetNonStopMode(true); + m_gdb_comm.GetEchoSupported (); m_gdb_comm.GetThreadSuffixSupported (); m_gdb_comm.GetListThreadsInStopReplySupported (); m_gdb_comm.GetHostInfo (); |
