[LLDB][MIPS] Add LinuxSignals for mips64 and change trap opcode for mips64el.

[slthakur]

Summary

• Added LinuxSignals for MIPS64.
• Changed software trap opcode for mips64el.

[emaste]

lldb reviews should have the lldb list as a subscriber instead of llvm
this could do with an explanation of why MIPS needs special signal handling

[tberghammer]

Looks good

source/Plugins/Process/Utility/MipsLinuxSignals.cpp

1

(nit: line length)

source/Plugins/Process/Utility/MipsLinuxSignals.h

1

(nit: line length)

[slthakur]

Hi @emaste,

this could do with an explanation of why MIPS needs special signal handling

MIPS needs special signal handling because the signal numbers defined in asm/signal.h in kernel headers for mips are different from signal numbers defined in x86 kernel headers.
Therefore while remote debugging, the remote server(mips64) sends T packets with signals numbers that are defined for mips in signal.h, which is interpreted incorrectly by the client side(x86_64).

[clayborg]

Looks good.

[flackr]

This seems to have broken the xcode build for me - confirmed that reverting fixes the build failure:

Ld DerivedData/lldb/Build/Products/Debug/LLDB.framework/Versions/A/LLDB normal x86_64

cd /Users/flackr/projects/ll/lldb
export MACOSX_DEPLOYMENT_TARGET=10.8
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang++ -arch x86_64 -dynamiclib -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.10.sdk -L/Users/flackr/projects/ll/lldb/DerivedData/lldb/Build/Products/Debug -L/Users/flackr/projects/ll/lldb/llvm-build/Release+Asserts/x86_64 -F/Users/flackr/projects/ll/lldb/DerivedData/lldb/Build/Products/Debug -F/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.10.sdk/System/Library/PrivateFrameworks -F/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.10.sdk/System/Library/Frameworks/CoreServices.framework/Frameworks -filelist /Users/flackr/projects/ll/lldb/DerivedData/lldb/Build/Intermediates/lldb.build/Debug/LLDB.build/Objects-normal/x86_64/LLDB.LinkFileList -exported_symbols_list resources/lldb-framework-exports -install_name @rpath/LLDB.framework/LLDB -mmacosx-version-min=10.8 -L/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/config -lpython2.7 -lllvmclang -framework Foundation -framework DebugSymbols -framework Security -framework CoreServices -framework ApplicationServices -stdlib=libc++ -lpanel -lncurses -ledit -lxml2 /Users/flackr/projects/ll/lldb/DerivedData/lldb/Build/Products/Debug/liblldb-core.a -lz -framework CoreFoundation -lobjc -framework Security -single_module -compatibility_version 1 -current_version 340.99.0 -Xlinker -dependency_info -Xlinker /Users/flackr/projects/ll/lldb/DerivedData/lldb/Build/Intermediates/lldb.build/Debug/LLDB.build/Objects-normal/x86_64/LLDB_dependency_info.dat -o /Users/flackr/projects/ll/lldb/DerivedData/lldb/Build/Products/Debug/LLDB.framework/Versions/A/LLDB

Undefined symbols for architecture x86_64:

"lldb_private::process_linux::MipsLinuxSignals::MipsLinuxSignals()", referenced from:
    lldb_private::process_gdb_remote::ProcessGDBRemote::DoConnectRemote(lldb_private::Stream*, char const*) in liblldb-core.a(ProcessGDBRemote.o)

ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

• BUILD FAILED **

The following build commands failed:

Ld DerivedData/lldb/Build/Products/Debug/LLDB.framework/Versions/A/LLDB normal x86_64

(1 failure)

[clayborg]

Fixed the Xcode build with:

% svn commit !$
svn commit lldb.xcodeproj/project.pbxproj
Sending lldb.xcodeproj/project.pbxproj
Transmitting file data .
Committed revision 234500.

source/Plugins/Platform/Linux/PlatformLinux.cpp

case llvm::Triple::arm:
             else
             {
                 trap_opcode = g_arm_breakpoint_opcode;
                 trap_opcode_size = sizeof(g_arm_breakpoint_opcode);
             }
         }
         break;
     case llvm::Triple::mips64:
-    case llvm::Triple::mips64el:
         {
             static const uint8_t g_hex_opcode[] = { 0x00, 0x00, 0x00, 0x0d };
             trap_opcode = g_hex_opcode;
             trap_opcode_size = sizeof(g_hex_opcode);
         }
         break;
+    case llvm::Triple::mips64el:
+        {
+            static const uint8_t g_hex_opcode[] = { 0x0d, 0x00, 0x00, 0x00 };
+            trap_opcode = g_hex_opcode;
+            trap_opcode_size = sizeof(g_hex_opcode);
+        }
+        break;
     }
 
     if (bp_site->SetTrapOpcode(trap_opcode, trap_opcode_size))
         return trap_opcode_size;
     return 0;
 }
 
 int32_t

source/Plugins/Process/Linux/NativeProcessLinux.cpp

 Error
 NativeProcessLinux::GetSoftwareBreakpointTrapOpcode (size_t trap_opcode_size_hint, size_t &actual_opcode_size, const uint8_t *&trap_opcode_bytes)
 {
     // FIXME put this behind a breakpoint protocol class that can be
     // set per architecture.  Need ARM, MIPS support here.
     static const uint8_t g_aarch64_opcode[] = { 0x00, 0x00, 0x20, 0xd4 };
     static const uint8_t g_i386_opcode [] = { 0xCC };
     static const uint8_t g_mips64_opcode[] = { 0x00, 0x00, 0x00, 0x0d };
+    static const uint8_t g_mips64el_opcode[] = { 0x0d, 0x00, 0x00, 0x00 };
 
     switch (m_arch.GetMachine ())
     {
     case llvm::Triple::aarch64:
         trap_opcode_bytes = g_aarch64_opcode;
         actual_opcode_size = sizeof(g_aarch64_opcode);
         return Error ();
 
     case llvm::Triple::x86:
     case llvm::Triple::x86_64:
         trap_opcode_bytes = g_i386_opcode;
         actual_opcode_size = sizeof(g_i386_opcode);
         return Error ();
 
     case llvm::Triple::mips64:
-    case llvm::Triple::mips64el:
         trap_opcode_bytes = g_mips64_opcode;
         actual_opcode_size = sizeof(g_mips64_opcode);
         return Error ();
 
+    case llvm::Triple::mips64el:
+        trap_opcode_bytes = g_mips64el_opcode;
+        actual_opcode_size = sizeof(g_mips64el_opcode);
+        return Error ();
+
     default:
         assert(false && "CPU type not supported!");
         return Error ("CPU type not supported");
     }
 }
 
 #if 0
 ProcessMessage::CrashReason

source/Plugins/Process/Utility/CMakeLists.txt

 include_directories(../../../Utility/)
 
 set(LLVM_NO_RTTI 1)
 
 add_lldb_library(lldbPluginProcessUtility
   DynamicRegisterInfo.cpp
   FreeBSDSignals.cpp
   HistoryThread.cpp
   HistoryUnwind.cpp
   InferiorCallPOSIX.cpp
   LinuxSignals.cpp
+  MipsLinuxSignals.cpp
   RegisterContextDarwin_arm.cpp
   RegisterContextDarwin_arm64.cpp
   RegisterContextDarwin_i386.cpp
   RegisterContextDarwin_x86_64.cpp
   RegisterContextDummy.cpp
   RegisterContextFreeBSD_arm64.cpp
   RegisterContextFreeBSD_i386.cpp
   RegisterContextFreeBSD_mips64.cpp

source/Plugins/Process/Utility/MipsLinuxSignals.h

+//===-- MipsLinuxSignals.h ------------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef liblldb_MipsLinuxSignals_H_
+#define liblldb_MipsLinuxSignals_H_
+
+// C Includes
+// C++ Includes
+// Other libraries and framework includes
+// Project includes
+#include "lldb/Target/UnixSignals.h"
+
+namespace lldb_private {
+namespace process_linux {
+
+    /// Linux specific set of Unix signals.
+    class MipsLinuxSignals
+        : public lldb_private::UnixSignals
+    {
+    public:
+        MipsLinuxSignals();
+
+    private:
+        void
+        Reset();
+    };
+
+} // namespace lldb_private
+} // namespace process_linux
+
+#endif

source/Plugins/Process/Utility/MipsLinuxSignals.cpp

+//===-- MipsLinuxSignals.cpp ----------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// C++ Includes
+// Other libraries and framework includes
+// Project includes
+#include "MipsLinuxSignals.h"
+
+using namespace lldb_private::process_linux;
+
+MipsLinuxSignals::MipsLinuxSignals()
+    : UnixSignals()
+{
+    Reset();
+}
+
+void
+MipsLinuxSignals::Reset()
+{
+    m_signals.clear();
+
+    AddSignal (1,    "SIGHUP",    "HUP",     false,   true , true , "hangup");
+    AddSignal (2,    "SIGINT",    "INT",     true ,   true , true , "interrupt");
+    AddSignal (3,    "SIGQUIT",   "QUIT",    false,   true , true , "quit");
+    AddSignal (4,    "SIGILL",    "ILL",     false,   true , true , "illegal instruction");
+    AddSignal (5,    "SIGTRAP",   "TRAP",    true ,   true , true , "trace trap (not reset when caught)");
+    AddSignal (6,    "SIGABRT",   "ABRT",    false,   true , true , "abort()");
+    AddSignal (6,    "SIGIOT",    "IOT",     false,   true , true , "IOT trap");
+    AddSignal (7,    "SIGEMT",    "EMT",     false,   true , true , "terminate process with core dump");
+    AddSignal (8,    "SIGFPE",    "FPE",     false,   true , true , "floating point exception");
+    AddSignal (9,    "SIGKILL",   "KILL",    false,   true , true , "kill");
+    AddSignal (10,   "SIGBUS",    "BUS",     false,   true , true , "bus error");
+    AddSignal (11,   "SIGSEGV",   "SEGV",    false,   true , true , "segmentation violation");
+    AddSignal (12,   "SIGSYS",    "SYS",     false,   true , true , "invalid system call");
+    AddSignal (13,   "SIGPIPE",   "PIPE",    false,   true , true , "write to pipe with reading end closed");
+    AddSignal (14,   "SIGALRM",   "ALRM",    false,   false, false, "alarm");
+    AddSignal (15,   "SIGTERM",   "TERM",    false,   true , true , "termination requested");
+    AddSignal (16,   "SIGUSR1",   "USR1",    false,   true , true , "user defined signal 1");
+    AddSignal (17,   "SIGUSR2",   "USR2",    false,   true , true , "user defined signal 2");
+    AddSignal (18,   "SIGCLD",    "CLD",     false,   false, true , "same as SIGCHLD");
+    AddSignal (18,   "SIGCHLD",   "CHLD",    false,   false, true , "child status has changed");
+    AddSignal (19,   "SIGPWR",    "PWR",     false,   true , true , "power failure");
+    AddSignal (20,   "SIGWINCH",  "WINCH",   false,   true , true , "window size changes");
+    AddSignal (21,   "SIGURG",    "URG",     false,   true , true , "urgent data on socket");
+    AddSignal (22,   "SIGIO",     "IO",      false,   true , true , "input/output ready");
+    AddSignal (22,   "SIGPOLL",   "POLL",    false,   true , true , "pollable event");
+    AddSignal (23,   "SIGSTOP",   "STOP",    true ,   true , true , "process stop");
+    AddSignal (24,   "SIGTSTP",   "TSTP",    false,   true , true , "tty stop");
+    AddSignal (25,   "SIGCONT",   "CONT",    false,   true , true , "process continue");
+    AddSignal (26,   "SIGTTIN",   "TTIN",    false,   true , true , "background tty read");
+    AddSignal (27,   "SIGTTOU",   "TTOU",    false,   true , true , "background tty write");
+    AddSignal (28,   "SIGVTALRM", "VTALRM",  false,   true , true , "virtual time alarm");
+    AddSignal (29,   "SIGPROF",   "PROF",    false,   false, false, "profiling time alarm");
+    AddSignal (30,   "SIGXCPU",   "XCPU",    false,   true , true , "CPU resource exceeded");
+    AddSignal (31,   "SIGXFSZ",   "XFSZ",    false,   true , true , "file size limit exceeded");
+}

source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp

 #include "lldb/Target/SystemRuntime.h"
 #include "lldb/Utility/PseudoTerminal.h"
 
 // Project includes
 #include "lldb/Host/Host.h"
 #include "Plugins/Process/Utility/FreeBSDSignals.h"
 #include "Plugins/Process/Utility/InferiorCallPOSIX.h"
 #include "Plugins/Process/Utility/LinuxSignals.h"
+#include "Plugins/Process/Utility/MipsLinuxSignals.h"
 #include "Plugins/Process/Utility/StopInfoMachException.h"
 #include "Plugins/Platform/MacOSX/PlatformRemoteiOS.h"
 #include "Utility/StringExtractorGDBRemote.h"
 #include "GDBRemoteRegisterContext.h"
 #include "ProcessGDBRemote.h"
 #include "ProcessGDBRemoteLog.h"
 #include "ThreadGDBRemote.h"
 
if (error.Success ())
         if (arch_spec.IsValid ())
         {
             if (log)
                 log->Printf ("ProcessGDBRemote::%s pid %" PRIu64 ": determining unix signals type based on architecture %s, triple %s", __FUNCTION__, GetID (), arch_spec.GetArchitectureName () ? arch_spec.GetArchitectureName () : "<null>", arch_spec.GetTriple ().getTriple ().c_str ());
 
             switch (arch_spec.GetTriple ().getOS ())
             {
             case llvm::Triple::Linux:
+                if (arch_spec.GetTriple ().getArch () == llvm::Triple::mips64 || arch_spec.GetTriple ().getArch () == llvm::Triple::mips64el)
+                    SetUnixSignals (UnixSignalsSP (new process_linux::MipsLinuxSignals ()));
+                else
                     SetUnixSignals (UnixSignalsSP (new process_linux::LinuxSignals ()));
                 if (log)
                     log->Printf ("ProcessGDBRemote::%s using Linux unix signals type for pid %" PRIu64, __FUNCTION__, GetID ());
                 break;
             case llvm::Triple::OpenBSD:
             case llvm::Triple::FreeBSD:
             case llvm::Triple::NetBSD:
                 SetUnixSignals (UnixSignalsSP (new FreeBSDSignals ()));
                 if (log)