Fix memory allocating inside signal handler (MI)

[ki.stfu]

Summary

This patch fixes a memory allocating inside signal handler.

This bug was found by @vharron:

Hi all,

I noticed these thread sanitizer warnings while running lldb-mi tests on
Linux.

WARNING: ThreadSanitizer: signal-unsafe call inside of a signal (pid=39721)

#0 operator new(unsigned long) <null>:0 (lldb-mi-3.7.0+0x000000092b9d)

#1 std::string::_Rep::_S_create(unsigned long, unsigned long,

std::allocator<char> const&) <null>:0 (libstdc++.so.6+0x0000000ba3b8)

#2 CMICmnResources::GetStringFromResource(unsigned int, CMIUtilString&)

const
/usr/local/google/home/vharron/ll/tot/llvm/tools/lldb/tools/lldb-mi/MICmnResources.cpp:434
(lldb-mi-3.7.0+0x00000014ddd8)

#3 CMICmnResources::GetString(unsigned int) const

/usr/local/google/home/vharron/ll/tot/llvm/tools/lldb/tools/lldb-mi/MICmnResources.cpp:371
(lldb-mi-3.7.0+0x00000014db81)

#4 sigwinch_handler(int)

/usr/local/google/home/vharron/ll/tot/llvm/tools/lldb/tools/lldb-mi/MIDriverMain.cpp:99
(lldb-mi-3.7.0+0x0000001589ff)

#5 __tsan::CallUserSignalHandler(__tsan::ThreadState*, bool, bool, int,

my_siginfo_t*, void*) tsan_interceptors.o:0 (lldb-mi-3.7.0+0x00000009f25f)

#6 void std::this_thread::sleep_for<long, std::ratio<1l, 1000l>

(std::chrono::duration<long, std::ratio<1l, 1000l> > const&)

/usr/bin/../lib/gcc/x86_64-linux-gnu/4.8/../../../../include/c++/4.8/thread:279
(lldb-mi-3.7.0+0x00000013243e)

#7 CMIDriver::ReadStdinLineQueue()

/usr/local/google/home/vharron/ll/tot/llvm/tools/lldb/tools/lldb-mi/MIDriver.cpp:710
(lldb-mi-3.7.0+0x000000155e62)

#8 CMIDriver::DoMainLoop()

/usr/local/google/home/vharron/ll/tot/llvm/tools/lldb/tools/lldb-mi/MIDriver.cpp:631
(lldb-mi-3.7.0+0x000000155d37)

#9 non-virtual thunk to CMIDriver::DoMainLoop()

/usr/local/google/home/vharron/ll/tot/llvm/tools/lldb/tools/lldb-mi/MIDriver.cpp:648
(lldb-mi-3.7.0+0x000000155fbd)

#10 CMIDriverMgr::DriverMainLoop()

/usr/local/google/home/vharron/ll/tot/llvm/tools/lldb/tools/lldb-mi/MIDriverMgr.cpp:340
(lldb-mi-3.7.0+0x000000159ee6)

#11 main

/usr/local/google/home/vharron/ll/tot/llvm/tools/lldb/tools/lldb-mi/MIDriverMain.cpp:364
(lldb-mi-3.7.0+0x000000158f60)

[abidh]

I think best will be to remove that logging from the signal handler. The signal handler in the lldb does not log anything too. Moving forward, I think lldb-mi should only handle the MI mode. I dont see the reason why it also tries to be a normal driver. If someone wants command line driver, he can just call lldb. When that happens, we can just remove handler for sigwinch as it is not really useful for lldb-mi.

[ki.stfu]

Let's wait for Vince's review.

[vharron]

If you can reproduce the error without the patch and then it goes away with Thread Sanitizer, then I approve.

Here is how I build with Thread Sanitizer

cmake -GNinja \
-DCMAKE_C_COMPILER=clang-3.5 \
-DCMAKE_CXX_COMPILER=clang++-3.5 \
-DCMAKE_BUILD_TYPE=Debug ../../llvm \
-DLLVM_USE_SANITIZER=Thread && \
ninja

(run your test)

[ki.stfu]

Revert CMICmnResources; Remove logging from signal handlers

[ki.stfu]

Remove unused IDS_PROCESS_SIGNAL_RECEIVED from CMICmnResources

[ki.stfu]

Please, take a look again.

[abidh]

Looks ok.

tools/lldb-mi/MICmnResources.h

enum
     IDS_CMDFACTORY_ERR_INVALID_CMD_NAME,
     IDS_CMDFACTORY_ERR_INVALID_CMD_CR8FN,
     IDS_CMDFACTORY_ERR_CMD_NOT_REGISTERED,
     IDS_CMDFACTORY_ERR_CMD_ALREADY_REGED,
 
     IDS_CMDMGR_ERR_CMD_FAILED_CREATE,
     IDS_CMDMGR_ERR_CMD_INVOKER,
 
-    IDS_PROCESS_SIGNAL_RECEIVED,
-
     IDS_MI_INIT_ERR_LOG,
     IDS_MI_INIT_ERR_RESOURCES,
     IDS_MI_INIT_ERR_INIT,
     IDS_MI_INIT_ERR_STREAMSTDIN,
     IDS_MI_INIT_ERR_STREAMSTDIN_OSHANDLER,
     IDS_MI_INIT_ERR_OS_STDIN_HANDLER,
     IDS_MI_INIT_ERR_STREAMSTDOUT,
     IDS_MI_INIT_ERR_STREAMSTDERR,

tools/lldb-mi/MICmnResources.cpp

const CMICmnResources::SRsrcTextData CMICmnResources::ms_pResourceId2TextData[] = {
     {IDS_FALLTHRU_DRIVER_CMD_RECEIVED, "Fall Thru Driver. Received command '%s'. Is was %shandled"},
     {IDS_CMDFACTORY_ERR_INVALID_CMD_NAME, "Command factory. MI command name '%s' is invalid"},
     {IDS_CMDFACTORY_ERR_INVALID_CMD_CR8FN,
      "Command factory. Command creation function invalid for command '%s'. Does function exist? Pointer assigned to it?"},
     {IDS_CMDFACTORY_ERR_CMD_NOT_REGISTERED, "Command factory. Command '%s' not registered"},
     {IDS_CMDFACTORY_ERR_CMD_ALREADY_REGED, "Command factory. Command '%s' by that name already registered"},
     {IDS_CMDMGR_ERR_CMD_FAILED_CREATE, "Command manager. Command creation failed. %s"},
     {IDS_CMDMGR_ERR_CMD_INVOKER, "Command manager. %s "},
-    {IDS_PROCESS_SIGNAL_RECEIVED, "Process signal. Application received signal '%s' (%d)"},
     {IDS_MI_INIT_ERR_LOG, "Log. Error occurred during initialisation %s"},
     {IDS_MI_INIT_ERR_RESOURCES, "Resources. Error occurred during initialisation %s"},
     {IDS_MI_INIT_ERR_INIT, "Driver. Error occurred during initialisation %s"},
     {IDS_MI_INIT_ERR_STREAMSTDIN, "Stdin. Error occurred during initialisation %s"},
     {IDS_MI_INIT_ERR_STREAMSTDIN_OSHANDLER, "Stdin. The OS specific stdin stream handler has not been specified for this OS"},
     {IDS_MI_INIT_ERR_OS_STDIN_HANDLER, "Stdin handler. Error occurred during initialisation %s"},
     {IDS_MI_INIT_ERR_STREAMSTDOUT, "Stdout. Error occurred during initialisation %s"},
     {IDS_MI_INIT_ERR_STREAMSTDERR, "Stderr. Error occurred during initialisation %s"},

tools/lldb-mi/MIDriverMain.cpp

 #include "MICmnConfig.h"
 #include "Platform.h" // Define signals - CODETAG_IOR_SIGNALS
 #include "Driver.h"
 #include "MIDriverMgr.h"
 #include "MIDriver.h"
 #include "MICmnResources.h"
 #include "MICmnStreamStdin.h"
 #include "MIUtilDebug.h"
-#include "MICmnLog.h"
 
 #if MICONFIG_COMPILE_MIDRIVER_VERSION
 
 #if defined(_MSC_VER)
 #pragma warning(once : 4530) // Warning C4530: C++ exception handler used, but unwind semantics are not enabled. Specify /EHsc
 #endif                       // _MSC_VER
 
 // ToDo: Reevaluate if this function needs to be implemented like the UNIX equivalent
#endif
     if (::isatty(STDIN_FILENO) && ::ioctl(STDIN_FILENO, TIOCGWINSZ, &window_size) == 0)
     {
         CMIDriverMgr &rDriverMgr = CMIDriverMgr::Instance();
         if (window_size.ws_col > 0)
         {
             rDriverMgr.DriverResizeWindow((uint32_t)window_size.ws_col);
         }
     }
-
-    CMICmnLog::Instance().WriteLog(CMIUtilString::Format(MIRSRC(IDS_PROCESS_SIGNAL_RECEIVED), "SIGWINCH", vSigno));
 }
 
 // CODETAG_IOR_SIGNALS
 //++ ------------------------------------------------------------------------------------
 // Details: The SIGINT signal is sent to a process by its controlling terminal when a
 //          user wishes to interrupt the process. This is typically initiated by pressing
 //          Control-C, but on some systems, the "delete" character or "break" key can be
 //          used.
if (pDebugger != nullptr)
         if (!g_interrupt_sent)
         {
             g_interrupt_sent = true;
             pDebugger->DispatchInputInterrupt();
             g_interrupt_sent = false;
         }
     }
 
-    CMICmnLog::Instance().WriteLog(CMIUtilString::Format(MIRSRC(IDS_PROCESS_SIGNAL_RECEIVED), "SIGINT", vSigno));
-
     // Send signal to driver so that it can take suitable action
     rDriverMgr.DeliverSignal (vSigno);
 }
 
 // ToDo: Reevaluate if this function needs to be implemented like the UNIX equivalent
 // CODETAG_IOR_SIGNALS
 //++ ------------------------------------------------------------------------------------
 // Details: The SIGTSTP signal is sent to a process by its controlling terminal to

 #endif
     CMIDriverMgr &rDriverMgr = CMIDriverMgr::Instance();
     lldb::SBDebugger *pDebugger = rDriverMgr.DriverGetTheDebugger();
     if (pDebugger != nullptr)
     {
         pDebugger->SaveInputTerminalState();
     }
 
-    CMICmnLog::Instance().WriteLog(CMIUtilString::Format(MIRSRC(IDS_PROCESS_SIGNAL_RECEIVED), "SIGTSTP", vSigno));
-
     // Send signal to driver so that it can take suitable action
     rDriverMgr.DeliverSignal (vSigno);
 }
 
 // ToDo: Reevaluate if this function needs to be implemented like the UNIX equivalent
 // CODETAG_IOR_SIGNALS
 //++ ------------------------------------------------------------------------------------
 // Details: The SIGCONT signal instructs the operating system to continue (restart) a

 #endif
     CMIDriverMgr &rDriverMgr = CMIDriverMgr::Instance();
     lldb::SBDebugger *pDebugger = rDriverMgr.DriverGetTheDebugger();
     if (pDebugger != nullptr)
     {
         pDebugger->RestoreInputTerminalState();
     }
 
-    CMICmnLog::Instance().WriteLog(CMIUtilString::Format(MIRSRC(IDS_PROCESS_SIGNAL_RECEIVED), "SIGCONT", vSigno));
-
     // Send signal to driver so that it can take suitable action
     rDriverMgr.DeliverSignal (vSigno);
 }
 
 //++ ------------------------------------------------------------------------------------
 // Details: Init the MI driver system. Initialize the whole driver system which includes
 //          both the original LLDB driver and the MI driver.
 // Type:    Function.