Add the addr info when appropriate for NIX' crash signals

Author: Jlalond

lldb/source/Plugins/Process/elf-core/ProcessElfCore.cpp

@@ -931,6 +931,7 @@ llvm::Error ProcessElfCore::parseLinuxNotes(llvm::ArrayRef<CoreNote> notes) {
         return status.ToError();
       thread_data.signo = siginfo.si_signo;
       thread_data.code = siginfo.si_code;
+      thread_data.description = siginfo.GetDescription();
       break;
     }
     case ELF::NT_FILE: {

lldb/source/Plugins/Process/elf-core/ThreadElfCore.cpp

@@ -6,9 +6,11 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "Plugins/Process/POSIX/CrashReason.h"
 #include "lldb/Target/RegisterContext.h"
 #include "lldb/Target/StopInfo.h"
 #include "lldb/Target/Target.h"
+#include "lldb/Target/UnixSignals.h"
 #include "lldb/Target/Unwind.h"
 #include "lldb/Utility/DataExtractor.h"
 #include "lldb/Utility/LLDBLog.h"
@@ -41,6 +43,7 @@
 #include "RegisterContextPOSIXCore_x86_64.h"
 #include "ThreadElfCore.h"
 
+#include "bits/types/siginfo_t.h"
 #include <memory>
 
 using namespace lldb;
@@ -49,8 +52,8 @@ using namespace lldb_private;
 // Construct a Thread object with given data
 ThreadElfCore::ThreadElfCore(Process &process, const ThreadData &td)
     : Thread(process, td.tid), m_thread_name(td.name), m_thread_reg_ctx_sp(),
-      m_signo(td.signo), m_code(td.code), m_gpregset_data(td.gpregset),
-      m_notes(td.notes) {}
+      m_signo(td.signo), m_code(td.code), m_sig_description(td.description),
+      m_gpregset_data(td.gpregset), m_notes(td.notes) {}
 
 ThreadElfCore::~ThreadElfCore() { DestroyThread(); }
 
@@ -241,7 +244,7 @@ bool ThreadElfCore::CalculateStopInfo() {
     return false;
 
   SetStopInfo(StopInfo::CreateStopReasonWithSignal(
-      *this, m_signo, /*description=*/nullptr, m_code));
+      *this, m_signo, m_sig_description.c_str(), m_code));
   return true;
 }
 
@@ -543,7 +546,8 @@ size_t ELFLinuxSigInfo::GetSize(const lldb_private::ArchSpec &arch) {
 
 Status ELFLinuxSigInfo::Parse(const DataExtractor &data, const ArchSpec &arch) {
   Status error;
-  if (GetSize(arch) > data.GetByteSize()) {
+  uint64_t size = GetSize(arch);
+  if (size > data.GetByteSize()) {
     error = Status::FromErrorStringWithFormat(
         "NT_SIGINFO size should be %zu, but the remaining bytes are: %" PRIu64,
         GetSize(arch), data.GetByteSize());
@@ -556,6 +560,36 @@ Status ELFLinuxSigInfo::Parse(const DataExtractor &data, const ArchSpec &arch) {
   si_signo = data.GetU32(&offset);
   si_errno = data.GetU32(&offset);
   si_code = data.GetU32(&offset);
+  // 64b ELF have a 4 byte pad.
+  if (data.GetAddressByteSize() == 8)
+    offset += 4;
+  switch (si_signo) {
+    case SIGFPE:
+    case SIGILL:
+    case SIGSEGV:
+    case SIGBUS:
+    case SIGTRAP:
+      addr = (void*)data.GetAddress(&offset);
+      addr_lsb = data.GetU16(&offset);
+      return error;
+    default:
+      return error;
+  }
+}
 
-  return error;
+std::string ELFLinuxSigInfo::GetDescription() {
+  switch (si_signo) {
+    case SIGFPE:
+    case SIGILL:
+    case SIGSEGV:
+    case SIGBUS:
+    case SIGTRAP:
+      return lldb_private::UnixSignals::CreateForHost()->GetSignalDescription(
+        si_signo, si_code,
+        reinterpret_cast<uintptr_t>(addr));
+    default:
+      return lldb_private::UnixSignals::CreateForHost()->GetSignalDescription(
+        si_signo, si_code
+      );
+  }
 }

lldb/source/Plugins/Process/elf-core/ThreadElfCore.h

@@ -75,16 +75,25 @@ struct ELFLinuxPrStatus {
 static_assert(sizeof(ELFLinuxPrStatus) == 112,
               "sizeof ELFLinuxPrStatus is not correct!");
 
+union ELFSigval { 
+  int sival_int; 
+  void *sival_ptr; 
+};
+
 struct ELFLinuxSigInfo {
-  int32_t si_signo;
-  int32_t si_code;
+  int32_t si_signo; // Order matters for the first 3.
   int32_t si_errno;
+  int32_t si_code;
+  void *addr;         /* faulting insn/memory ref. */
+  int32_t addr_lsb; /* Valid LSB of the reported address.  */
 
   ELFLinuxSigInfo();
 
   lldb_private::Status Parse(const lldb_private::DataExtractor &data,
                              const lldb_private::ArchSpec &arch);
 
+  std::string GetDescription();
+
   // Return the bytesize of the structure
   // 64 bit - just sizeof
   // 32 bit - hardcoded because we are reusing the struct, but some of the
@@ -93,7 +102,7 @@ struct ELFLinuxSigInfo {
   static size_t GetSize(const lldb_private::ArchSpec &arch);
 };
 
-static_assert(sizeof(ELFLinuxSigInfo) == 12,
+static_assert(sizeof(ELFLinuxSigInfo) == 32,
               "sizeof ELFLinuxSigInfo is not correct!");
 
 // PRPSINFO structure's size differs based on architecture.
@@ -144,7 +153,9 @@ struct ThreadData {
   lldb::tid_t tid;
   int signo = 0;
   int code = 0;
+  void* sigaddr = nullptr;
   int prstatus_sig = 0;
+  std::string description;
   std::string name;
 };
 
@@ -183,6 +194,7 @@ class ThreadElfCore : public lldb_private::Thread {
 
   int m_signo;
   int m_code;
+  std::string m_sig_description;
 
   lldb_private::DataExtractor m_gpregset_data;
   std::vector<lldb_private::CoreNote> m_notes;

lldb/test/API/functionalities/postmortem/elf-core/TestLinuxCore.py

@@ -10,6 +10,7 @@
 from lldbsuite.test.decorators import *
 from lldbsuite.test.lldbtest import *
 from lldbsuite.test import lldbutil
+from fblldb import fbvscode
 
 
 class LinuxCoreTestCase(TestBase):
@@ -833,6 +834,22 @@ def test_riscv64_regs_gpr_only(self):
             substrs=["registers were unavailable"],
         )
 
+    def test_sigsev_stopreason(self):
+        """
+        Test that the address is included in the stop reason for a SIGSEV
+        """
+        src = self.getSourcePath("linux-x64-sigsev.yaml")
+        obj_file = self.getBuildArtifact("sigsev.out")
+        fbvscode.set_trace()
+        self.yaml2obj(src, obj_file)
+        target = self.dbg.CreateTarget(None)
+        process = target.LoadCore(obj_file)
+        self.assertTrue(process, PROCESS_IS_VALID)
+        stop_reason = process.GetThreadAtIndex(0).GetStopDescription(128)
+        self.assertEqual(process.GetNumThreads(), 1)
+        self.assertIn("SIGSEGV: address not mapped to object (fault address: 0x1000)", stop_reason)
+
+
     def test_get_core_file_api(self):
         """
         Test SBProcess::GetCoreFile() API can successfully get the core file.

lldb/test/API/functionalities/postmortem/elf-core/linux-x86_64-sigsev.yaml

@@ -0,0 +1,8 @@
+--- !ELF
+FileHeader:
+  Class:           ELFCLASS64
+  Data:            ELFDATA2LSB
+  OSABI:           ELFOSABI_FREEBSD
+  Type:            ET_EXEC
+  Machine:         EM_X86_64
+  Entry:           0xFFFFFFFF8037C000