Get TLS variables to work for minidump, add a test that the value is accessable correctly

Author: Jlalond

lldb/source/Core/DynamicLoader.cpp

@@ -355,7 +355,7 @@ int64_t DynamicLoader::ReadUnsignedIntWithSizeInBytes(addr_t addr,
     return (int64_t)value;
 }
 
-addr_t DynamicLoader::ReadPointer(addr_t addr) {
+addr_t DynamicLoader::  ReadPointer(addr_t addr) {
   Status error;
   addr_t value = m_process->ReadPointerFromMemory(addr, error);
   if (error.Fail())
@@ -369,4 +369,3 @@ void DynamicLoader::LoadOperatingSystemPlugin(bool flush)
     if (m_process)
         m_process->LoadOperatingSystemPlugin(flush);
 }
-

lldb/source/Plugins/DynamicLoader/POSIX-DYLD/DynamicLoaderPOSIXDYLD.cpp

@@ -118,7 +118,6 @@ void DynamicLoaderPOSIXDYLD::DidAttach() {
       addr_t load_addr = addr.GetLoadAddress(&target);
       if (load_addr != LLDB_INVALID_ADDRESS) {
         rebase_exec = false;
-        m_loaded_modules[executable_sp] = load_addr;
       } 
     }
   } else {
@@ -127,7 +126,7 @@ void DynamicLoaderPOSIXDYLD::DidAttach() {
   }
 
   // if the target executable should be re-based
-  if (rebase_exec) {
+  if (rebase_exec || IsCoreFile()) {
     ModuleList module_list;
 
     module_list.Append(executable_sp);

lldb/source/Plugins/Process/minidump/RegisterContextMinidump_x86_64.cpp

@@ -44,6 +44,17 @@ static void writeRegister(const void *reg_src, uint8_t *context,
   memcpy(reg_dest.data(), reg_src, reg_dest.size());
 }
 
+// TODO: Fix the registers in this file!
+// writeRegister checks x86_64 registers without base registers. This causes
+// an overlap in the register enum values. So we were truncating fs_base. 
+// We should standardize to the x86_64_with_base registers.
+static void writeBaseRegister(const void *reg_src, uint8_t *context,
+                              const RegisterInfo &reg) {
+  auto bytes = reg.mutable_data(context);
+  llvm::MutableArrayRef<uint8_t> reg_dest = bytes.take_front(8);
+  memcpy(reg_dest.data(), reg_src, reg_dest.size());
+}
+
 lldb::DataBufferSP lldb_private::minidump::ConvertMinidumpContext_x86_64(
     llvm::ArrayRef<uint8_t> source_data,
     RegisterInfoInterface *target_reg_interface) {
@@ -105,10 +116,11 @@ lldb::DataBufferSP lldb_private::minidump::ConvertMinidumpContext_x86_64(
     writeRegister(&context->r15, result_base, reg_info[lldb_r15_x86_64]);
   }
 
+  // See comment on base regsiter
   if ((context_flags & LLDBSpecificFlag) == LLDBSpecificFlag) {
-    writeRegister(&context->fs_base, result_base,
+    writeBaseRegister(&context->fs_base, result_base,
                   reg_info[x86_64_with_base::lldb_fs_base]);
-    writeRegister(&context->gs_base, result_base,
+    writeBaseRegister(&context->gs_base, result_base,
                   reg_info[x86_64_with_base::lldb_gs_base]);
   }
 

lldb/test/API/functionalities/process_save_core_minidump/TestProcessSaveCoreMinidump.py

@@ -548,6 +548,7 @@ def minidump_saves_fs_base_region(self):
 
             registers = thread.GetFrameAtIndex(0).GetRegisters()
             fs_base = registers.GetFirstValueByName("fs_base").GetValueAsUnsigned()
+            self.assertTrue(fs_base != 0)
             core_target = self.dbg.CreateTarget(None)
             core_proc = core_target.LoadCore(one_region_file)
             core_region_list = core_proc.GetMemoryRegions()
@@ -598,3 +599,34 @@ def minidump_deterministic_difference(self):
 
         finally:
             self.assertTrue(self.dbg.DeleteTarget(target))
+
+    @skipUnlessPlatform(["linux"])
+    @skipUnlessArch("x86_64")
+    def minidump_saves_fs_base_region(self):
+        self.build()
+        exe = self.getBuildArtifact("a.out")
+        try:
+            target = self.dbg.CreateTarget(exe)
+            process = target.LaunchSimple(
+                None, None, self.get_process_working_directory()
+            )
+            self.assertState(process.GetState(), lldb.eStateStopped)
+            thread = process.GetThreadAtIndex(0)
+            tls_file = self.getBuildArtifact("core.tls.dmp")
+            options = lldb.SBSaveCoreOptions()
+            options.SetOutputFile(lldb.SBFileSpec(tls_file))
+            options.SetPluginName("minidump")
+            options.SetStyle(lldb.eSaveCoreCustomOnly)
+            options.AddThread(thread)
+            error = process.SaveCore(options)
+            self.assertTrue(error.Success())
+            core_target = self.dbg.CreateTarget(None)
+            core_proc = core_target.LoadCore(tls_file)
+            frame = core_proc.GetThreadAtIndex(0).GetFrameAtIndex(0)
+            tls_val = frame.FindValue('lf')
+            self.assertEqual(tls_val.GetValueAsUnsigned(), 42)
+
+        except:
+            self.assertTrue(self.dbg.DeleteTarget(target))
+            if os.path.isfile(tls_file):
+                os.unlink(tls_file)

lldb/test/API/functionalities/process_save_core_minidump/main.cpp

@@ -1,6 +1,7 @@
 #include <cassert>
 #include <iostream>
 #include <thread>
+thread_local size_t lf = 42;
 
 void g() { assert(false); }
 
@@ -16,6 +17,7 @@ size_t h() {
   return sum;
 }
 
+
 int main() {
   std::thread t1(f);