Fix inconsistent target arch when attaching to arm64 binaries on arm64e platforms.

[aprantl]

Summary

On arm64e-capable Apple platforms, the system libraries are always arm64e, but applications often are arm64. When a target is created from file, LLDB recognizes it as an arm64 target, but debugserver will still (technically correct) report the process as being arm64e. For consistency, set the target to arm64 here.

rdar://92248684

[mib]

lldb/include/lldb/Target/Target.h

1012

typo ?

[JDevlieghere]

lldb/source/Plugins/DynamicLoader/MacOSX-DYLD/DynamicLoaderDarwin.cpp

584

Why can't you set the target_arch to exe_module_sp->GetArchitecture().GetTriple()?

[aprantl]

lldb/source/Plugins/DynamicLoader/MacOSX-DYLD/DynamicLoaderDarwin.cpp

584

That would be shorter. I was worried that could undo any mac catalyst versus macos fixups we did in DynamicLinkerDarwin before.

[JDevlieghere]

lldb/source/Plugins/DynamicLoader/MacOSX-DYLD/DynamicLoaderDarwin.cpp

584

Fair enough. Can we at least take the architecture from the triple then and pass that instead of hardcoding arm64?

[aprantl]

Address feedback!

[JDevlieghere]

That test is not going to win any beauty pageants but it looks like it gets the job done. LGTM.

[rsmith]

Hi, the newly-added test, TestDynamicLoaderDarwin.py, fails under asan: https://gist.github.com/zygoloid/bf7b21f03d7db966e456b6c365c4635d

Please can you take a look?

[aprantl]

In D133069#3768088, @rsmith wrote:

Hi, the newly-added test, TestDynamicLoaderDarwin.py, fails under asan: https://gist.github.com/zygoloid/bf7b21f03d7db966e456b6c365c4635d

Thanks! Should be fixed in

commit 603d5a8d632164038a869c200818c4cc238bb85a (HEAD -> main)
Author: Adrian Prantl <[e-mail]>
Date:   Fri Sep 2 18:14:12 2022 -0700

    Fix out-of-bounds memory access in test

lldb/include/lldb/Target/Target.h

public:
   ///
   /// \param[in] set_platform
   ///     If \b true, then the platform will be adjusted if the currently
   ///     selected platform is not compatible with the architecture being set.
   ///     If \b false, then just the architecture will be set even if the
   ///     currently selected platform isn't compatible (in case it might be
   ///     manually set following this function call).
   ///
+  /// \param[in] merged
+  ///     If true, arch_spec is merged with the current
+  ///     architecture. Otherwise it's replaced.
+  ///
   /// \return
   ///     \b true if the architecture was successfully set, \b false otherwise.
-  bool SetArchitecture(const ArchSpec &arch_spec, bool set_platform = false);
+  bool SetArchitecture(const ArchSpec &arch_spec, bool set_platform = false,
+                       bool merge = true);
 
   bool MergeArchitecture(const ArchSpec &arch_spec);
 
   Architecture *GetArchitecturePlugin() const { return m_arch.GetPlugin(); }
 
   Debugger &GetDebugger() { return m_debugger; }
 
   size_t ReadMemoryFromFileCache(const Address &addr, void *dst, size_t dst_len,

lldb/packages/Python/lldbsuite/test/gdbclientutils.py

def respond(self, packet):
         if packet == "qOffsets":
             return self.qOffsets();
         if packet == "qProcessInfo":
             return self.qProcessInfo()
         if packet == "qsProcessInfo":
             return self.qsProcessInfo()
         if packet.startswith("qfProcessInfo"):
             return self.qfProcessInfo(packet)
+        if packet.startswith("jGetLoadedDynamicLibrariesInfos"):
+            return self.jGetLoadedDynamicLibrariesInfos(packet)
         if packet.startswith("qPathComplete:"):
             return self.qPathComplete()
         if packet.startswith("vFile:"):
             return self.vFile(packet)
         if packet.startswith("vRun;"):
             return self.vRun(packet)
         if packet.startswith("qLaunchSuccess"):
             return self.qLaunchSuccess()
def respond(self, packet):
         return self.other(packet)
 
     def qsProcessInfo(self):
         return "E04"
 
     def qfProcessInfo(self, packet):
         return "E04"
 
+    def jGetLoadedDynamicLibrariesInfos(self, packet):
+        return ""
+
     def qGetWorkingDir(self):
         return "2f"
 
     def qOffsets(self):
         return ""
 
     def qProcessInfo(self):
         return ""

lldb/source/Plugins/DynamicLoader/MacOSX-DYLD/DynamicLoaderDarwin.cpp

if (exe_idx != UINT32_MAX && !target.GetExecutableModule()) {
     const bool can_create = true;
     ModuleSP exe_module_sp(FindTargetModuleForImageInfo(image_infos[exe_idx],
                                                         can_create, nullptr));
     if (exe_module_sp) {
       LLDB_LOGF(log, "Found executable module: %s",
                 exe_module_sp->GetFileSpec().GetPath().c_str());
       target.GetImages().AppendIfNeeded(exe_module_sp);
       UpdateImageLoadAddress(exe_module_sp.get(), image_infos[exe_idx]);
-      if (exe_module_sp.get() != target.GetExecutableModulePointer()) {
+      if (exe_module_sp.get() != target.GetExecutableModulePointer())
         target.SetExecutableModule(exe_module_sp, eLoadDependentsNo);
+
+      // Update the target executable's arch if necessary.
+      auto exe_triple = exe_module_sp->GetArchitecture().GetTriple();
+      if (target_arch.GetTriple().isArm64e() &&
+          exe_triple.getArch() == llvm::Triple::aarch64 &&
+          !exe_triple.isArm64e()) {
+        // On arm64e-capable Apple platforms, the system libraries are
+        // always arm64e, but applications often are arm64. When a
+        // target is created from a file, LLDB recognizes it as an
+        // arm64 target, but debugserver will still (technically
+        // correct) report the process as being arm64e. For
+        // consistency, set the target to arm64 here, so attaching to
+        // a live process behaves the same as creating a process from
+        // file.
+        auto triple = target_arch.GetTriple();
+        triple.setArchName(exe_triple.getArchName());
+        target_arch.SetTriple(triple);
+        target.SetArchitecture(target_arch, /*set_platform=*/false,
+                               /*merge=*/false);
       }
     }
   }
 
   if (dyld_idx != UINT32_MAX) {
     const bool can_create = true;
     ModuleSP dyld_sp = FindTargetModuleForImageInfo(image_infos[dyld_idx],
                                                     can_create, nullptr);

lldb/source/Target/Target.cpp

if (executable_objfile && load_dependents) {
             objfile->GetDependentModules(dependent_files);
         }
       }
       ModulesDidLoad(added_modules);
     }
   }
 }
 
-bool Target::SetArchitecture(const ArchSpec &arch_spec, bool set_platform) {
+bool Target::SetArchitecture(const ArchSpec &arch_spec, bool set_platform,
+                             bool merge) {
   Log *log = GetLog(LLDBLog::Target);
   bool missing_local_arch = !m_arch.GetSpec().IsValid();
   bool replace_local_arch = true;
   bool compatible_local_arch = false;
   ArchSpec other(arch_spec);
 
   // Changing the architecture might mean that the currently selected platform
   // isn't compatible. Set the platform correctly if we are asked to do so,
if (other.IsValid()) {
           if (platform_arch.IsValid())
             other = platform_arch;
         }
       }
     }
   }
 
   if (!missing_local_arch) {
-    if (m_arch.GetSpec().IsCompatibleMatch(arch_spec)) {
+    if (merge && m_arch.GetSpec().IsCompatibleMatch(arch_spec)) {
       other.MergeFrom(m_arch.GetSpec());
 
       if (m_arch.GetSpec().IsCompatibleMatch(other)) {
         compatible_local_arch = true;
         bool arch_changed, vendor_changed, os_changed, os_ver_changed,
             env_changed;
 
         m_arch.GetSpec().PiecewiseTripleCompare(other, arch_changed,

lldb/test/API/functionalities/gdb_remote_client/TestDynamicLoaderDarwin.py

+import lldb
+from lldbsuite.test.lldbtest import *
+from lldbsuite.test.decorators import *
+from lldbsuite.test.gdbclientutils import *
+from lldbsuite.test.lldbgdbclient import *
+
+images = """
+{"images":[
+    {"load_address":4370792448,
+     "mod_date":0,
+     "pathname":"/usr/lib/dyld",
+     "uuid":"75627683-A780-32AD-AE34-CF86DD23A26B",
+     "min_version_os_name":"macosx",
+     "min_version_os_sdk":"12.5",
+     "mach_header":{
+         "magic":4277009103,
+         "cputype":16777228,
+         "cpusubtype":2,
+         "filetype":7,
+         "flags":133},
+    "segments":[
+        {"name":"__TEXT",
+         "vmaddr":0,
+         "vmsize":393216,
+         "fileoff":0,
+         "filesize":393216,
+         "maxprot":5},
+        {"name":"__DATA_CONST",
+         "vmaddr":393216,
+         "vmsize":98304,
+         "fileoff":393216,
+         "filesize":98304,
+         "maxprot":3},
+        {"name":"__DATA",
+         "vmaddr":491520,
+         "vmsize":16384,
+         "fileoff":491520,
+         "filesize":16384,
+         "maxprot":3},
+        {"name":"__LINKEDIT",
+         "vmaddr":507904,
+         "vmsize":229376,
+         "fileoff":507904,
+         "filesize":227520,
+         "maxprot":1}
+    ]
+    },
+    {"load_address":4369842176,
+     "mod_date":0,
+     "pathname":"/tmp/a.out",
+     "uuid":"536A0A09-792A-377C-BEBA-FFB00A787C38",
+     "min_version_os_name":"macosx",
+     "min_version_os_sdk":"12.0",
+     "mach_header":{
+         "magic":4277009103,
+         "cputype":16777228,
+         "cpusubtype":%s,
+         "filetype":2,
+         "flags":2097285
+     },
+     "segments":[
+         {"name":"__PAGEZERO",
+          "vmaddr":0,
+          "vmsize":4294967296,
+          "fileoff":0,
+          "filesize":0,
+          "maxprot":0},
+         {"name":"__TEXT",
+          "vmaddr":4294967296,
+          "vmsize":16384,
+          "fileoff":0,
+          "filesize":16384,
+          "maxprot":5},
+         {"name":"__DATA_CONST",
+          "vmaddr":4294983680,
+          "vmsize":16384,
+          "fileoff":16384,
+          "filesize":16384,
+          "maxprot":3},
+         {"name":"__LINKEDIT",
+          "vmaddr":4295000064,
+          "vmsize":32768,
+          "fileoff":32768,
+          "filesize":19488,
+          "maxprot":1}]
+    }
+]
+}
+"""
+
+arm64_binary = "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" + '0'*16384
+
+class TestDynamicLoaderDarwin(GDBRemoteTestBase):
+
+    NO_DEBUG_INFO_TESTCASE = True
+    class MyResponder(MockGDBServerResponder):
+
+        def __init__(self, cpusubtype):
+            self.cpusubtype = cpusubtype
+            MockGDBServerResponder.__init__(self)
+
+        def respond(self, packet):
+            if packet == "qProcessInfo":
+                return self.qProcessInfo()
+            return MockGDBServerResponder.respond(self, packet)
+
+        def qHostInfo(self):
+            return "cputype:16777223;cpusubtype:2;ostype:macosx;vendor:apple;os_version:10.15.4;maccatalyst_version:13.4;endian:little;ptrsize:8;"
+
+        def qProcessInfo(self):
+            return "pid:a860;parent-pid:d2a0;real-uid:1f5;real-gid:14;effective-uid:1f5;effective-gid:14;cputype:100000c;cpusubtype:2;ptrsize:8;ostype:macosx;vendor:apple;endian:little;"
+
+        def jGetLoadedDynamicLibrariesInfos(self, packet):
+            if 'fetch_all_solibs' in packet:
+                return escape_binary(images%self.cpusubtype)
+            return "OK"
+
+        def vCont(self):
+            return "vCont;"
+
+        def readMemory(self, addr, length):
+            return arm64_binary[addr-4369842176:length]
+
+        def setBreakpoint(self, packet):
+            return ""
+
+    @skipIfRemote
+    def test(self):
+        """Test that when attaching to an arm64 binary on an arm64e
+        host, the target's arch is set to arm64, even though
+        debugserver reports the process as being arm64e.
+        """
+        subtype_arm64e = 2
+        self.server.responder = self.MyResponder(subtype_arm64e)
+        if self.TraceOn():
+            self.runCmd("log enable gdb-remote packets")
+            self.addTearDownHook(
+                lambda: self.runCmd("log disable gdb-remote packets"))
+
+        target = self.dbg.CreateTargetWithFileAndArch(None, None)
+        process = self.connect(target)
+
+        self.assertEqual(target.GetTriple(), "arm64-apple-macosx-")