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Update stub decoding for .NET 8 for disassemblers #2416

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Merged
adamsitnik merged 2 commits into from
Aug 25, 2023
Merged

Update stub decoding for .NET 8 for disassemblers #2416

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Update stub decoding for .NET 8 for disassemblers
janvorli Aug 24, 2023
6f699e9
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janvorli Aug 25, 2023
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@janvorli
janvorli committed Aug 25, 2023
commit 6f699e916601bd720b686beafd7f2ef2d59dfa1f
20 changes: 10 additions & 10 deletions src/BenchmarkDotNet/Disassemblers/Arm64Disassembler.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -147,28 +147,28 @@ internal sealed class RuntimeSpecificData
// ldr x9, DATA_SLOT(CallCountingStub, RemainingCallCountCell)
// ldrh w10, [x9]
// subs w10, w10, #0x1
internal byte[] callCountingStubTemplate = new byte[12] { 0x09, 0x00, 0x00, 0x58, 0x2a, 0x01, 0x40, 0x79, 0x4a, 0x05, 0x00, 0x71 };
internal readonly byte[] callCountingStubTemplate = new byte[12] { 0x09, 0x00, 0x00, 0x58, 0x2a, 0x01, 0x40, 0x79, 0x4a, 0x05, 0x00, 0x71 };
// ldr x10, DATA_SLOT(StubPrecode, Target)
// ldr x12, DATA_SLOT(StubPrecode, MethodDesc)
// br x10
internal byte[] stubPrecodeTemplate = new byte[12] { 0x4a, 0x00, 0x00, 0x58, 0xec, 0x00, 0x00, 0x58, 0x40, 0x01, 0x1f, 0xd6 };
internal readonly byte[] stubPrecodeTemplate = new byte[12] { 0x4a, 0x00, 0x00, 0x58, 0xec, 0x00, 0x00, 0x58, 0x40, 0x01, 0x1f, 0xd6 };
// ldr x11, DATA_SLOT(FixupPrecode, Target)
// br x11
// ldr x12, DATA_SLOT(FixupPrecode, MethodDesc)
internal byte[] fixupPrecodeTemplate = new byte[12] { 0x0b, 0x00, 0x00, 0x58, 0x60, 0x01, 0x1f, 0xd6, 0x0c, 0x00, 0x00, 0x58 };
internal int stubPageSize;
internal readonly byte[] fixupPrecodeTemplate = new byte[12] { 0x0b, 0x00, 0x00, 0x58, 0x60, 0x01, 0x1f, 0xd6, 0x0c, 0x00, 0x00, 0x58 };
internal readonly ulong stubPageSize;

internal RuntimeSpecificData(State state)
{
stubPageSize = Environment.SystemPageSize;
stubPageSize = (ulong)Environment.SystemPageSize;
if (state.RuntimeVersion.Major >= 8)
{
// In .NET 8, the stub page size was changed to min 16kB
stubPageSize = Math.Max(Environment.SystemPageSize, 16384);
stubPageSize = Math.Max(stubPageSize, 16384);
}

// The stubs code depends on the current OS memory page size, so we need to update the templates to reflect that
int pageSizeShifted = stubPageSize / 32;
ulong pageSizeShifted = stubPageSize / 32;
// Calculate the ldr x9, #offset instruction with offset based on the page size
callCountingStubTemplate[1] = (byte)(pageSizeShifted & 0xff);
callCountingStubTemplate[2] = (byte)(pageSizeShifted >> 8);
Expand Down Expand Up @@ -231,18 +231,18 @@ protected override IEnumerable<Asm> Decode(byte[] code, ulong startAddress, Stat
if (buffer.SequenceEqual(data.callCountingStubTemplate))
{
const ulong TargetMethodAddressSlotOffset = 8;
address = state.Runtime.DataTarget.DataReader.ReadPointer(address + (ulong)data.stubPageSize + TargetMethodAddressSlotOffset);
address = state.Runtime.DataTarget.DataReader.ReadPointer(address + data.stubPageSize + TargetMethodAddressSlotOffset);
}
else if (buffer.SequenceEqual(data.stubPrecodeTemplate))
{
const ulong MethodDescSlotOffset = 0;
address = state.Runtime.DataTarget.DataReader.ReadPointer(address + (ulong)data.stubPageSize + MethodDescSlotOffset);
address = state.Runtime.DataTarget.DataReader.ReadPointer(address + data.stubPageSize + MethodDescSlotOffset);
isPrestubMD = true;
}
else if (buffer.SequenceEqual(data.fixupPrecodeTemplate))
{
const ulong MethodDescSlotOffset = 8;
address = state.Runtime.DataTarget.DataReader.ReadPointer(address + (ulong)data.stubPageSize + MethodDescSlotOffset);
address = state.Runtime.DataTarget.DataReader.ReadPointer(address + data.stubPageSize + MethodDescSlotOffset);
isPrestubMD = true;
}
}
Expand Down
16 changes: 8 additions & 8 deletions src/BenchmarkDotNet/Disassemblers/IntelDisassembler.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -18,19 +18,19 @@ internal sealed class RuntimeSpecificData
// jmp QWORD PTR [rip + DATA_SLOT(CallCountingStub, TargetForMethod)]
// LOCAL_LABEL(CountReachedZero):
// jmp QWORD PTR [rip + DATA_SLOT(CallCountingStub, TargetForThresholdReached)]
internal byte[] callCountingStubTemplate = new byte[10] { 0x48, 0x8b, 0x05, 0xf9, 0x0f, 0x00, 0x00, 0x66, 0xff, 0x08 };
internal readonly byte[] callCountingStubTemplate = new byte[10] { 0x48, 0x8b, 0x05, 0xf9, 0x0f, 0x00, 0x00, 0x66, 0xff, 0x08 };
// mov r10, [rip + DATA_SLOT(StubPrecode, MethodDesc)]
// jmp [rip + DATA_SLOT(StubPrecode, Target)]
internal byte[] stubPrecodeTemplate = new byte[13] { 0x4c, 0x8b, 0x15, 0xf9, 0x0f, 0x00, 0x00, 0xff, 0x25, 0xfb, 0x0f, 0x00, 0x00 };
internal readonly byte[] stubPrecodeTemplate = new byte[13] { 0x4c, 0x8b, 0x15, 0xf9, 0x0f, 0x00, 0x00, 0xff, 0x25, 0xfb, 0x0f, 0x00, 0x00 };
// jmp [rip + DATA_SLOT(FixupPrecode, Target)]
// mov r10, [rip + DATA_SLOT(FixupPrecode, MethodDesc)]
// jmp [rip + DATA_SLOT(FixupPrecode, PrecodeFixupThunk)]
internal byte[] fixupPrecodeTemplate = new byte[19] { 0xff, 0x25, 0xfa, 0x0f, 0x00, 0x00, 0x4c, 0x8b, 0x15, 0xfb, 0x0f, 0x00, 0x00, 0xff, 0x25, 0xfd, 0x0f, 0x00, 0x00 };
internal int stubPageSize;
internal readonly byte[] fixupPrecodeTemplate = new byte[19] { 0xff, 0x25, 0xfa, 0x0f, 0x00, 0x00, 0x4c, 0x8b, 0x15, 0xfb, 0x0f, 0x00, 0x00, 0xff, 0x25, 0xfd, 0x0f, 0x00, 0x00 };
internal readonly ulong stubPageSize;

internal RuntimeSpecificData(State state)
{
stubPageSize = Environment.SystemPageSize;
stubPageSize = (ulong)Environment.SystemPageSize;
if (state.RuntimeVersion.Major >= 8)
{
// In .NET 8, the stub page size was changed to 16kB
Expand Down Expand Up @@ -84,15 +84,15 @@ protected override IEnumerable<Asm> Decode(byte[] code, ulong startAddress, Stat
if (state.Runtime.DataTarget.DataReader.Read(address, buffer) == buffer.Length && buffer.SequenceEqual(data.callCountingStubTemplate))
{
const ulong TargetMethodAddressSlotOffset = 8;
address = state.Runtime.DataTarget.DataReader.ReadPointer(address + (ulong)data.stubPageSize + TargetMethodAddressSlotOffset);
address = state.Runtime.DataTarget.DataReader.ReadPointer(address + data.stubPageSize + TargetMethodAddressSlotOffset);
}
else
{
buffer = new byte[13];
if (state.Runtime.DataTarget.DataReader.Read(address, buffer) == buffer.Length && buffer.SequenceEqual(data.stubPrecodeTemplate))
{
const ulong MethodDescSlotOffset = 0;
address = state.Runtime.DataTarget.DataReader.ReadPointer(address + (ulong)data.stubPageSize + MethodDescSlotOffset);
address = state.Runtime.DataTarget.DataReader.ReadPointer(address + data.stubPageSize + MethodDescSlotOffset);
isPrestubMD = true;
}
else
Expand All @@ -101,7 +101,7 @@ protected override IEnumerable<Asm> Decode(byte[] code, ulong startAddress, Stat
if (state.Runtime.DataTarget.DataReader.Read(address, buffer) == buffer.Length && buffer.SequenceEqual(data.fixupPrecodeTemplate))
{
const ulong MethodDescSlotOffset = 8;
address = state.Runtime.DataTarget.DataReader.ReadPointer(address + (ulong)data.stubPageSize + MethodDescSlotOffset);
address = state.Runtime.DataTarget.DataReader.ReadPointer(address + data.stubPageSize + MethodDescSlotOffset);
isPrestubMD = true;
}

Expand Down