Disassembler realiability fixes (#2234)

* re-enable the failing tests

* add a fix

* translate only jump and call instruction addresses, allows for avoiding AV

Author: adamsitnik

src/BenchmarkDotNet/Disassemblers/Arm64Disassembler.cs

@@ -206,6 +206,8 @@ protected override IEnumerable<Asm> Decode(byte[] code, ulong startAddress, Stat
                             // is at an address one memory page higher than the code.
                             byte[] buffer = new byte[12];
 
+                            FlushCachedDataIfNeeded(state.Runtime.DataTarget.DataReader, address, buffer);
+
                             if (state.Runtime.DataTarget.DataReader.Read(address, buffer) == buffer.Length)
                             {
                                 if (buffer.SequenceEqual(callCountingStubTemplate))

src/BenchmarkDotNet/Disassemblers/ClrMdV2Disassembler.cs

@@ -7,12 +7,18 @@
 using System.IO;
 using System.Linq;
 using System.Text.RegularExpressions;
+using BenchmarkDotNet.Portability;
 
 namespace BenchmarkDotNet.Disassemblers
 {
     // This Disassembler uses ClrMd v2x. Please keep it in sync with ClrMdV1Disassembler (if possible).
     internal abstract class ClrMdV2Disassembler
     {
+        // Translating an address to a method can cause AV and a process crash (https://github.com/dotnet/BenchmarkDotNet/issues/2070).
+        // It was fixed in https://github.com/dotnet/runtime/pull/79846,
+        // and most likely will be backported to 7.0.2 very soon (https://github.com/dotnet/runtime/pull/79862).
+        protected static readonly bool IsVulnerableToAvInDac = !RuntimeInformation.IsWindows() && Environment.Version < new Version(7, 0, 2);
+
         internal DisassemblyResult AttachAndDisassemble(Settings settings)
         {
             using (var dataTarget = DataTarget.AttachToProcess(
@@ -270,7 +276,7 @@ protected void TryTranslateAddressToName(ulong address, bool isAddressPrecodeMD,
 
             if (method is null)
             {
-                if (isAddressPrecodeMD || this is not Arm64Disassembler)
+                if (isAddressPrecodeMD || !IsVulnerableToAvInDac)
                 {
                     var methodDescriptor = runtime.GetMethodByHandle(address);
                     if (!(methodDescriptor is null))
@@ -287,7 +293,7 @@ protected void TryTranslateAddressToName(ulong address, bool isAddressPrecodeMD,
                     }
                 }
 
-                if (this is not Arm64Disassembler)
+                if (!IsVulnerableToAvInDac)
                 {
                     var methodTableName = runtime.DacLibrary.SOSDacInterface.GetMethodTableName(address);
                     if (!string.IsNullOrEmpty(methodTableName))
@@ -311,6 +317,22 @@ protected void TryTranslateAddressToName(ulong address, bool isAddressPrecodeMD,
             state.AddressToNameMapping.Add(address, methodName);
         }
 
+        protected void FlushCachedDataIfNeeded(IDataReader dataTargetDataReader, ulong address, byte[] buffer)
+        {
+            if (!RuntimeInformation.IsWindows())
+            {
+                if (dataTargetDataReader.Read(address, buffer) <= 0)
+                {
+                    // We don't suspend the benchmark process for the time of disassembling,
+                    // as it would require sudo privileges.
+                    // Because of that, the Tiered JIT thread might still re-compile some methods
+                    // in the meantime when the host process it trying to disassemble the code.
+                    // In such case, Tiered JIT thread might create stubs which requires flushing of the cached data.
+                    dataTargetDataReader.FlushCachedData();
+                }
+            }
+        }
+
         // GetMethodByInstructionPointer sometimes returns wrong methods.
         // In case given address does not belong to the methods range, null is returned.
         private static ClrMethod WorkaroundGetMethodByInstructionPointerBug(ClrRuntime runtime, ClrMethod method, ulong newAddress)

src/BenchmarkDotNet/Disassemblers/IntelDisassembler.cs

@@ -51,6 +51,8 @@ protected override IEnumerable<Asm> Decode(byte[] code, ulong startAddress, Stat
                             // is at an address one memory page higher than the code.
                             byte[] buffer = new byte[10];
 
+                            FlushCachedDataIfNeeded(state.Runtime.DataTarget.DataReader, address, buffer);
+
                             if (state.Runtime.DataTarget.DataReader.Read(address, buffer) == buffer.Length && buffer.SequenceEqual(callCountingStubTemplate))
                             {
                                 const ulong TargetMethodAddressSlotOffset = 8;
@@ -82,7 +84,10 @@ protected override IEnumerable<Asm> Decode(byte[] code, ulong startAddress, Stat
 
                     if (address > ushort.MaxValue)
                     {
-                        TryTranslateAddressToName(address, isPrestubMD, state, isIndirect, depth, currentMethod);
+                        if (!IsVulnerableToAvInDac || IsCallOrJump(instruction))
+                        {
+                            TryTranslateAddressToName(address, isPrestubMD, state, isIndirect, depth, currentMethod);
+                        }
                     }
                 }
 
@@ -97,6 +102,17 @@ protected override IEnumerable<Asm> Decode(byte[] code, ulong startAddress, Stat
             }
         }
 
+        private static bool IsCallOrJump(Instruction instruction)
+            => instruction.FlowControl switch
+            {
+                FlowControl.Call => true,
+                FlowControl.IndirectCall => true,
+                FlowControl.ConditionalBranch => true,
+                FlowControl.IndirectBranch => true,
+                FlowControl.UnconditionalBranch => true,
+                _ => false
+            };
+
         private static bool TryGetReferencedAddress(Instruction instruction, uint pointerSize, out ulong referencedAddress)
         {
             for (int i = 0; i < instruction.OpCount; i++)

tests/BenchmarkDotNet.IntegrationTests/DisassemblyDiagnoserTests.cs

@@ -83,7 +83,6 @@ public void Recursive()
         public void CanDisassembleAllMethodCalls(Jit jit, Platform platform, Runtime runtime)
         {
             if (RuntimeInformation.IsMacOS()) return; // currently not supported
-            if (RuntimeInformation.IsLinux()) return; // https://github.com/dotnet/BenchmarkDotNet/issues/2223
 
             var disassemblyDiagnoser = new DisassemblyDiagnoser(
                 new DisassemblyDiagnoserConfig(printSource: true, maxDepth: 3));
@@ -150,7 +149,6 @@ [Benchmark] public void JustReturn() { }
         public void CanDisassembleInlinableBenchmarks(Jit jit, Platform platform, Runtime runtime)
         {
             if (RuntimeInformation.IsMacOS()) return; // currently not supported
-            if (RuntimeInformation.IsLinux()) return; // https://github.com/dotnet/BenchmarkDotNet/issues/2223
 
             var disassemblyDiagnoser = new DisassemblyDiagnoser(
                 new DisassemblyDiagnoserConfig(printSource: true, maxDepth: 3));