Fix UUID decoding from minidump files

This patch fixes:

UUIDs now don't include the age field from a PDB70 when the age is zero. Prior to this they would incorrectly contain the zero age which stopped us from being able to match up the UUID with real files.
UUIDs for Apple targets get the first 32 bit value and next two 16 bit values swapped. Breakpad incorrectly swaps these values when it creates darwin minidump files, so this must be undone so we can match up symbol files with the minidump modules.
UUIDs that are all zeroes are treated as invalid UUIDs. Breakpad will always save out a UUID, even if one wasn't available. This caused all files that have UUID values of zero to be uniqued to the first module that had a zero UUID. We now don't fill in the UUID if it is all zeroes.
Added tests for PDB70 and ELF build ID based CvRecords.

Differential Revision: https://reviews.llvm.org/D59433

llvm-svn: 356573

lldb/packages/Python/lldbsuite/test/functionalities/postmortem/minidump-new/TestMiniDumpUUID.py

@@ -0,0 +1,121 @@
+"""
+Test basics of Minidump debugging.
+"""
+
+from __future__ import print_function
+from six import iteritems
+
+import shutil
+
+import lldb
+from lldbsuite.test.decorators import *
+from lldbsuite.test.lldbtest import *
+from lldbsuite.test import lldbutil
+
+
+class MiniDumpUUIDTestCase(TestBase):
+
+    mydir = TestBase.compute_mydir(__file__)
+
+    NO_DEBUG_INFO_TESTCASE = True
+
+    def setUp(self):
+        super(MiniDumpUUIDTestCase, self).setUp()
+        self._initial_platform = lldb.DBG.GetSelectedPlatform()
+
+    def tearDown(self):
+        lldb.DBG.SetSelectedPlatform(self._initial_platform)
+        super(MiniDumpUUIDTestCase, self).tearDown()
+
+    def verify_module(self, module, verify_path, verify_uuid):
+        uuid = module.GetUUIDString()
+        self.assertEqual(verify_path, module.GetFileSpec().fullpath)
+        self.assertEqual(verify_uuid, uuid)
+
+    def test_zero_uuid_modules(self):
+        """
+            Test multiple modules having a MINIDUMP_MODULE.CvRecord that is valid,
+            but contains a PDB70 value whose age is zero and whose UUID values are 
+            all zero. Prior to a fix all such modules would be duplicated to the
+            first one since the UUIDs claimed to be valid and all zeroes. Now we
+            ensure that the UUID is not valid for each module and that we have
+            each of the modules in the target after loading the core
+        """
+        self.dbg.CreateTarget(None)
+        self.target = self.dbg.GetSelectedTarget()
+        self.process = self.target.LoadCore("linux-arm-zero-uuids.dmp")
+        modules = self.target.modules
+        self.assertEqual(2, len(modules))
+        self.verify_module(modules[0], "/file/does/not/exist/a", None)
+        self.verify_module(modules[1], "/file/does/not/exist/b", None)
+
+    def test_uuid_modules_no_age(self):
+        """
+            Test multiple modules having a MINIDUMP_MODULE.CvRecord that is valid,
+            and contains a PDB70 value whose age is zero and whose UUID values are 
+            valid. Ensure we decode the UUID and don't include the age field in the UUID.
+        """
+        self.dbg.CreateTarget(None)
+        self.target = self.dbg.GetSelectedTarget()
+        self.process = self.target.LoadCore("linux-arm-uuids-no-age.dmp")
+        modules = self.target.modules
+        self.assertEqual(2, len(modules))
+        self.verify_module(modules[0], "/tmp/a", "01020304-0506-0708-090A-0B0C0D0E0F10")
+        self.verify_module(modules[1], "/tmp/b", "0A141E28-323C-4650-5A64-6E78828C96A0")
+
+    def test_uuid_modules_no_age_apple(self):
+        """
+            Test multiple modules having a MINIDUMP_MODULE.CvRecord that is valid,
+            and contains a PDB70 value whose age is zero and whose UUID values are 
+            valid. Ensure we decode the UUID and don't include the age field in the UUID.
+            Also ensure that the first uint32_t is byte swapped, along with the next
+            two uint16_t values. Breakpad incorrectly byte swaps these values when it
+            saves Darwin minidump files.
+        """
+        self.dbg.CreateTarget(None)
+        self.target = self.dbg.GetSelectedTarget()
+        self.process = self.target.LoadCore("macos-arm-uuids-no-age.dmp")
+        modules = self.target.modules
+        self.assertEqual(2, len(modules))
+        self.verify_module(modules[0], "/tmp/a", "04030201-0605-0807-090A-0B0C0D0E0F10")
+        self.verify_module(modules[1], "/tmp/b", "281E140A-3C32-5046-5A64-6E78828C96A0")
+
+    def test_uuid_modules_with_age(self):
+        """
+            Test multiple modules having a MINIDUMP_MODULE.CvRecord that is valid,
+            and contains a PDB70 value whose age is valid and whose UUID values are 
+            valid. Ensure we decode the UUID and include the age field in the UUID.
+        """
+        self.dbg.CreateTarget(None)
+        self.target = self.dbg.GetSelectedTarget()
+        self.process = self.target.LoadCore("linux-arm-uuids-with-age.dmp")
+        modules = self.target.modules
+        self.assertEqual(2, len(modules))
+        self.verify_module(modules[0], "/tmp/a", "01020304-0506-0708-090A-0B0C0D0E0F10-10101010")
+        self.verify_module(modules[1], "/tmp/b", "0A141E28-323C-4650-5A64-6E78828C96A0-20202020")
+
+    def test_uuid_modules_elf_build_id_16(self):
+        """
+            Test multiple modules having a MINIDUMP_MODULE.CvRecord that is valid,
+            and contains a ELF build ID whose value is valid and is 16 bytes long.
+        """
+        self.dbg.CreateTarget(None)
+        self.target = self.dbg.GetSelectedTarget()
+        self.process = self.target.LoadCore("linux-arm-uuids-elf-build-id-16.dmp")
+        modules = self.target.modules
+        self.assertEqual(2, len(modules))
+        self.verify_module(modules[0], "/tmp/a", "01020304-0506-0708-090A-0B0C0D0E0F10")
+        self.verify_module(modules[1], "/tmp/b", "0A141E28-323C-4650-5A64-6E78828C96A0")
+
+    def test_uuid_modules_elf_build_id_20(self):
+        """
+            Test multiple modules having a MINIDUMP_MODULE.CvRecord that is valid,
+            and contains a ELF build ID whose value is valid and is 20 bytes long.
+        """
+        self.dbg.CreateTarget(None)
+        self.target = self.dbg.GetSelectedTarget()
+        self.process = self.target.LoadCore("linux-arm-uuids-elf-build-id-20.dmp")
+        modules = self.target.modules
+        self.assertEqual(2, len(modules))
+        self.verify_module(modules[0], "/tmp/a", "01020304-0506-0708-090A-0B0C0D0E0F10-11121314")
+        self.verify_module(modules[1], "/tmp/b", "0A141E28-323C-4650-5A64-6E78828C96A0-AAB4BEC8")

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

@@ -165,21 +165,44 @@ UUID MinidumpParser::GetModuleUUID(const MinidumpModule *module) {
       static_cast<CvSignature>(static_cast<uint32_t>(*signature));
 
   if (cv_signature == CvSignature::Pdb70) {
-    // PDB70 record
     const CvRecordPdb70 *pdb70_uuid = nullptr;
     Status error = consumeObject(cv_record, pdb70_uuid);
-    if (!error.Fail()) {
-      auto arch = GetArchitecture();
-      // For Apple targets we only need a 16 byte UUID so that we can match
-      // the UUID in the Module to actual UUIDs from the built binaries. The
-      // "Age" field is zero in breakpad minidump files for Apple targets, so
-      // we restrict the UUID to the "Uuid" field so we have a UUID we can use
-      // to match.
-      if (arch.GetTriple().getVendor() == llvm::Triple::Apple)
-        return UUID::fromData(pdb70_uuid->Uuid, sizeof(pdb70_uuid->Uuid));
-      else
-        return UUID::fromData(pdb70_uuid, sizeof(*pdb70_uuid));
+    if (error.Fail())
+      return UUID();
+    // If the age field is not zero, then include the entire pdb70_uuid struct
+    if (pdb70_uuid->Age != 0)
+      return UUID::fromData(pdb70_uuid, sizeof(*pdb70_uuid));
+
+    // Many times UUIDs are all zeroes. This can cause more than one module
+    // to claim it has a valid UUID of all zeroes and causes the files to all
+    // merge into the first module that claims this valid zero UUID.
+    bool all_zeroes = true;
+    for (size_t i = 0; all_zeroes && i < sizeof(pdb70_uuid->Uuid); ++i)
+      all_zeroes = pdb70_uuid->Uuid[i] == 0;
+    if (all_zeroes)
+      return UUID();
+    
+    if (GetArchitecture().GetTriple().getVendor() == llvm::Triple::Apple) {
+      // Breakpad incorrectly byte swaps the first 32 bit and next 2 16 bit
+      // values in the UUID field. Undo this so we can match things up
+      // with our symbol files
+      uint8_t apple_uuid[16];
+      // Byte swap the first 32 bits
+      apple_uuid[0] = pdb70_uuid->Uuid[3];
+      apple_uuid[1] = pdb70_uuid->Uuid[2];
+      apple_uuid[2] = pdb70_uuid->Uuid[1];
+      apple_uuid[3] = pdb70_uuid->Uuid[0];
+      // Byte swap the next 16 bit value
+      apple_uuid[4] = pdb70_uuid->Uuid[5];
+      apple_uuid[5] = pdb70_uuid->Uuid[4];
+      // Byte swap the next 16 bit value
+      apple_uuid[6] = pdb70_uuid->Uuid[7];
+      apple_uuid[7] = pdb70_uuid->Uuid[6];
+      for (size_t i = 8; i < sizeof(pdb70_uuid->Uuid); ++i)
+        apple_uuid[i] = pdb70_uuid->Uuid[i];
+      return UUID::fromData(apple_uuid, sizeof(apple_uuid));
     }
+    return UUID::fromData(pdb70_uuid->Uuid, sizeof(pdb70_uuid->Uuid));
   } else if (cv_signature == CvSignature::ElfBuildId)
     return UUID::fromData(cv_record);