[lldb] [gdb-remote] Support getting siginfo via API

Add Thread::GetSiginfo() and SBThread::GetSiginfo() methods to retrieve
the siginfo value from server.

Differential Revision: https://reviews.llvm.org/D118055

diff --git a/lldb/bindings/interface/SBThread.i b/lldb/bindings/interface/SBThread.i
index d847d38..1e46bd6 100644 (file)
--- a/lldb/bindings/interface/SBThread.i
+++ b/lldb/bindings/interface/SBThread.i
@@ -405,6 +405,12 @@ public:
     bool
     SafeToCallFunctions ();
 
+    %feature("autodoc","
+    Retruns a SBValue object representing the siginfo for the current signal.
+    ") GetSiginfo;
+    lldb::SBValue
+    GetSiginfo();
+
     STRING_EXTENSION(SBThread)
 
 #ifdef SWIGPYTHON

diff --git a/lldb/include/lldb/API/SBThread.h b/lldb/include/lldb/API/SBThread.h
index ac1b840..924aae2 100644 (file)
--- a/lldb/include/lldb/API/SBThread.h
+++ b/lldb/include/lldb/API/SBThread.h
@@ -208,6 +208,8 @@ public:
 
   bool SafeToCallFunctions();
 
+  SBValue GetSiginfo();
+
 private:
   friend class SBBreakpoint;
   friend class SBBreakpointLocation;

diff --git a/lldb/include/lldb/Target/Thread.h b/lldb/include/lldb/Target/Thread.h
index 587b29e..2fd7d88 100644 (file)
--- a/lldb/include/lldb/Target/Thread.h
+++ b/lldb/include/lldb/Target/Thread.h
@@ -22,6 +22,7 @@
 #include "lldb/Utility/CompletionRequest.h"
 #include "lldb/Utility/Event.h"
 #include "lldb/Utility/StructuredData.h"
+#include "lldb/Utility/UnimplementedError.h"
 #include "lldb/Utility/UserID.h"
 #include "lldb/lldb-private.h"
 
@@ -1184,6 +1185,8 @@ public:
 
   lldb::ThreadSP GetCurrentExceptionBacktrace();
 
+  lldb::ValueObjectSP GetSiginfoValue();
+
 protected:
   friend class ThreadPlan;
   friend class ThreadList;
@@ -1233,6 +1236,11 @@ protected:
 
   void FrameSelectedCallback(lldb_private::StackFrame *frame);
 
+  virtual llvm::Expected<std::unique_ptr<llvm::MemoryBuffer>>
+  GetSiginfo(size_t max_size) const {
+    return llvm::make_error<UnimplementedError>();
+  }
+
   // Classes that inherit from Process can see and modify these
   lldb::ProcessWP m_process_wp;    ///< The process that owns this thread.
   lldb::StopInfoSP m_stop_info_sp; ///< The private stop reason for this thread

diff --git a/lldb/source/API/SBThread.cpp b/lldb/source/API/SBThread.cpp
index 46a6c27..a08cb74 100644 (file)
--- a/lldb/source/API/SBThread.cpp
+++ b/lldb/source/API/SBThread.cpp
@@ -1317,3 +1317,12 @@ lldb_private::Thread *SBThread::operator->() {
 lldb_private::Thread *SBThread::get() {
   return m_opaque_sp->GetThreadSP().get();
 }
+
+SBValue SBThread::GetSiginfo() {
+  LLDB_INSTRUMENT_VA(this);
+
+  ThreadSP thread_sp = m_opaque_sp->GetThreadSP();
+  if (!thread_sp)
+    return SBValue();
+  return thread_sp->GetSiginfoValue();
+}

diff --git a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp
index b5b1053..f6526d0 100644 (file)
--- a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp
+++ b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.cpp
@@ -173,6 +173,13 @@ bool GDBRemoteCommunicationClient::GetQXferMemoryMapReadSupported() {
   return m_supports_qXfer_memory_map_read == eLazyBoolYes;
 }
 
+bool GDBRemoteCommunicationClient::GetQXferSigInfoReadSupported() {
+  if (m_supports_qXfer_siginfo_read == eLazyBoolCalculate) {
+    GetRemoteQSupported();
+  }
+  return m_supports_qXfer_siginfo_read == eLazyBoolYes;
+}
+
 uint64_t GDBRemoteCommunicationClient::GetRemoteMaxPacketSize() {
   if (m_max_packet_size == 0) {
     GetRemoteQSupported();
@@ -273,6 +280,7 @@ void GDBRemoteCommunicationClient::ResetDiscoverableSettings(bool did_exec) {
     m_supports_qXfer_libraries_svr4_read = eLazyBoolCalculate;
     m_supports_qXfer_features_read = eLazyBoolCalculate;
     m_supports_qXfer_memory_map_read = eLazyBoolCalculate;
+    m_supports_qXfer_siginfo_read = eLazyBoolCalculate;
     m_supports_augmented_libraries_svr4_read = eLazyBoolCalculate;
     m_uses_native_signals = eLazyBoolCalculate;
     m_supports_qProcessInfoPID = true;
@@ -320,6 +328,7 @@ void GDBRemoteCommunicationClient::GetRemoteQSupported() {
   m_supports_augmented_libraries_svr4_read = eLazyBoolNo;
   m_supports_qXfer_features_read = eLazyBoolNo;
   m_supports_qXfer_memory_map_read = eLazyBoolNo;
+  m_supports_qXfer_siginfo_read = eLazyBoolNo;
   m_supports_multiprocess = eLazyBoolNo;
   m_supports_qEcho = eLazyBoolNo;
   m_supports_QPassSignals = eLazyBoolNo;
@@ -362,6 +371,8 @@ void GDBRemoteCommunicationClient::GetRemoteQSupported() {
         m_supports_qXfer_features_read = eLazyBoolYes;
       else if (x == "qXfer:memory-map:read+")
         m_supports_qXfer_memory_map_read = eLazyBoolYes;
+      else if (x == "qXfer:siginfo:read+")
+        m_supports_qXfer_siginfo_read = eLazyBoolYes;
       else if (x == "qEcho")
         m_supports_qEcho = eLazyBoolYes;
       else if (x == "QPassSignals+")

diff --git a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.h b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.h
index c69c33b..58ed221 100644 (file)
--- a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.h
+++ b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.h
@@ -337,6 +337,8 @@ public:
 
   bool GetQXferMemoryMapReadSupported();
 
+  bool GetQXferSigInfoReadSupported();
+
   LazyBool SupportsAllocDeallocMemory() // const
   {
     // Uncomment this to have lldb pretend the debug server doesn't respond to
@@ -551,6 +553,7 @@ protected:
   LazyBool m_supports_qXfer_libraries_svr4_read = eLazyBoolCalculate;
   LazyBool m_supports_qXfer_features_read = eLazyBoolCalculate;
   LazyBool m_supports_qXfer_memory_map_read = eLazyBoolCalculate;
+  LazyBool m_supports_qXfer_siginfo_read = eLazyBoolCalculate;
   LazyBool m_supports_augmented_libraries_svr4_read = eLazyBoolCalculate;
   LazyBool m_supports_jThreadExtendedInfo = eLazyBoolCalculate;
   LazyBool m_supports_jLoadedDynamicLibrariesInfos = eLazyBoolCalculate;

diff --git a/lldb/source/Plugins/Process/gdb-remote/ThreadGDBRemote.cpp b/lldb/source/Plugins/Process/gdb-remote/ThreadGDBRemote.cpp
index ba73115..3d23c07 100644 (file)
--- a/lldb/source/Plugins/Process/gdb-remote/ThreadGDBRemote.cpp
+++ b/lldb/source/Plugins/Process/gdb-remote/ThreadGDBRemote.cpp
@@ -346,3 +346,23 @@ bool ThreadGDBRemote::CalculateStopInfo() {
         ->CalculateThreadStopInfo(this);
   return false;
 }
+
+llvm::Expected<std::unique_ptr<llvm::MemoryBuffer>>
+ThreadGDBRemote::GetSiginfo(size_t max_size) const {
+  ProcessSP process_sp(GetProcess());
+  if (!process_sp)
+    return llvm::createStringError(llvm::inconvertibleErrorCode(),
+                                   "no process");
+  ProcessGDBRemote *gdb_process =
+      static_cast<ProcessGDBRemote *>(process_sp.get());
+  if (!gdb_process->m_gdb_comm.GetQXferSigInfoReadSupported())
+    return llvm::createStringError(llvm::inconvertibleErrorCode(),
+                                   "qXfer:siginfo:read not supported");
+
+  llvm::Expected<std::string> response =
+      gdb_process->m_gdb_comm.ReadExtFeature("siginfo", "");
+  if (!response)
+    return response.takeError();
+
+  return llvm::MemoryBuffer::getMemBufferCopy(response.get());
+}

diff --git a/lldb/source/Plugins/Process/gdb-remote/ThreadGDBRemote.h b/lldb/source/Plugins/Process/gdb-remote/ThreadGDBRemote.h
index b7d7502..5bc90a3 100644 (file)
--- a/lldb/source/Plugins/Process/gdb-remote/ThreadGDBRemote.h
+++ b/lldb/source/Plugins/Process/gdb-remote/ThreadGDBRemote.h
@@ -115,6 +115,9 @@ protected:
   void SetStopInfoFromPacket(StringExtractor &stop_packet, uint32_t stop_id);
 
   bool CalculateStopInfo() override;
+
+  llvm::Expected<std::unique_ptr<llvm::MemoryBuffer>>
+  GetSiginfo(size_t max_size) const override;
 };
 
 } // namespace process_gdb_remote

diff --git a/lldb/source/Target/Thread.cpp b/lldb/source/Target/Thread.cpp
index c5f16b4..bde6dad 100644 (file)
--- a/lldb/source/Target/Thread.cpp
+++ b/lldb/source/Target/Thread.cpp
@@ -13,6 +13,7 @@
 #include "lldb/Core/Module.h"
 #include "lldb/Core/StructuredDataImpl.h"
 #include "lldb/Core/ValueObject.h"
+#include "lldb/Core/ValueObjectConstResult.h"
 #include "lldb/Host/Host.h"
 #include "lldb/Interpreter/OptionValueFileSpecList.h"
 #include "lldb/Interpreter/OptionValueProperties.h"
@@ -2005,3 +2006,26 @@ ThreadSP Thread::GetCurrentExceptionBacktrace() {
 
   return ThreadSP();
 }
+
+lldb::ValueObjectSP Thread::GetSiginfoValue() {
+  ProcessSP process_sp = GetProcess();
+  assert(process_sp);
+  Target &target = process_sp->GetTarget();
+  PlatformSP platform_sp = target.GetPlatform();
+  assert(platform_sp);
+  ArchSpec arch = target.GetArchitecture();
+
+  CompilerType type = platform_sp->GetSiginfoType(arch.GetTriple());
+  if (!type.IsValid())
+    return ValueObjectConstResult::Create(&target, Status("no siginfo_t for the platform"));
+
+  llvm::Optional<uint64_t> type_size = type.GetByteSize(nullptr);
+  assert(type_size);
+  llvm::Expected<std::unique_ptr<llvm::MemoryBuffer>> data = GetSiginfo(type_size.getValue());
+  if (!data)
+    return ValueObjectConstResult::Create(&target, Status(data.takeError()));
+
+  DataExtractor data_extractor{data.get()->getBufferStart(), data.get()->getBufferSize(),
+    process_sp->GetByteOrder(), arch.GetAddressByteSize()};
+  return ValueObjectConstResult::Create(&target, type, ConstString("__lldb_siginfo"), data_extractor);
+}

diff --git a/lldb/test/API/functionalities/gdb_remote_client/TestGDBRemoteClient.py b/lldb/test/API/functionalities/gdb_remote_client/TestGDBRemoteClient.py
index 16cf4b4..8d12bd7 100644 (file)
--- a/lldb/test/API/functionalities/gdb_remote_client/TestGDBRemoteClient.py
+++ b/lldb/test/API/functionalities/gdb_remote_client/TestGDBRemoteClient.py
@@ -490,3 +490,98 @@ class TestGDBRemoteClient(GDBRemoteTestBase):
                          lldb.eStopReasonSignal)
         self.assertEqual(process.threads[0].GetStopDescription(100),
                          'signal SIGUSR1')
+
+    def do_siginfo_test(self, platform, target_yaml, raw_data, expected):
+        class MyResponder(MockGDBServerResponder):
+            def qSupported(self, client_supported):
+                return "PacketSize=3fff;QStartNoAckMode+;qXfer:siginfo:read+"
+
+            def qXferRead(self, obj, annex, offset, length):
+                if obj == "siginfo":
+                    return raw_data, False
+                else:
+                    return None, False
+
+            def haltReason(self):
+                return "T02"
+
+            def cont(self):
+                return self.haltReason()
+
+        self.server.responder = MyResponder()
+
+        self.runCmd("platform select " + platform)
+        target = self.createTarget(target_yaml)
+        process = self.connect(target)
+
+        siginfo = process.threads[0].GetSiginfo()
+        self.assertTrue(siginfo.GetError().Success(), siginfo.GetError())
+
+        for key, value in expected.items():
+            self.assertEqual(siginfo.GetValueForExpressionPath("." + key)
+                             .GetValueAsUnsigned(),
+                             value)
+
+
+    def test_siginfo_linux_amd64(self):
+        data = (
+          # si_signo         si_errno        si_code
+            "\x11\x00\x00\x00\x00\x00\x00\x00\x01\x00\x00\x00"
+          # __pad0           si_pid          si_uid
+            "\x00\x00\x00\x00\xbf\xf7\x0b\x00\xe8\x03\x00\x00"
+          # si_status
+            "\x0c\x00\x00\x00" + "\x00" * 100)
+        expected = {
+            "si_signo": 17,  # SIGCHLD
+            "si_errno": 0,
+            "si_code": 1,  # CLD_EXITED
+            "_sifields._sigchld.si_pid": 784319,
+            "_sifields._sigchld.si_uid": 1000,
+            "_sifields._sigchld.si_status": 12,
+            "_sifields._sigchld.si_utime": 0,
+            "_sifields._sigchld.si_stime": 0,
+        }
+        self.do_siginfo_test("remote-linux", "basic_eh_frame.yaml",
+                             data, expected)
+
+    def test_siginfo_linux_i386(self):
+        data = (
+          # si_signo         si_errno        si_code
+            "\x11\x00\x00\x00\x00\x00\x00\x00\x01\x00\x00\x00"
+          # si_pid           si_uid          si_status
+            "\x49\x43\x07\x00\xe8\x03\x00\x00\x0c\x00\x00\x00"
+            + "\x00" * 104)
+        expected = {
+            "si_signo": 17,  # SIGCHLD
+            "si_errno": 0,
+            "si_code": 1,  # CLD_EXITED
+            "_sifields._sigchld.si_pid": 475977,
+            "_sifields._sigchld.si_uid": 1000,
+            "_sifields._sigchld.si_status": 12,
+            "_sifields._sigchld.si_utime": 0,
+            "_sifields._sigchld.si_stime": 0,
+        }
+        self.do_siginfo_test("remote-linux", "basic_eh_frame-i386.yaml",
+                             data, expected)
+
+    def test_siginfo_freebsd_amd64(self):
+        data = (
+          # si_signo         si_errno        si_code
+            "\x0b\x00\x00\x00\x00\x00\x00\x00\x01\x00\x00\x00"
+          # si_pid           si_uid          si_status
+            "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
+          # si_addr
+            "\x76\x98\xba\xdc\xfe\x00\x00\x00"
+          # si_status                        si_trapno
+            "\x00\x00\x00\x00\x00\x00\x00\x00\x0c\x00\x00\x00"
+            + "\x00" * 36)
+
+        expected = {
+            "si_signo": 11,  # SIGSEGV
+            "si_errno": 0,
+            "si_code": 1,  # SEGV_MAPERR
+            "si_addr": 0xfedcba9876,
+            "_reason._fault._trapno": 12,
+        }
+        self.do_siginfo_test("remote-freebsd", "basic_eh_frame.yaml",
+                             data, expected)