[sos] clrstack might show the wrong value for ushort

[dacheng-gao]

Description

With the test code:

// integers in different size:
// 1-byte: sbyte, byte
// 2-byte: short, ushort
// 4-byte: int, uint
// 8-byte: long, ulong

namespace Vars01;

class Program
{
    static void Main(string[] args)
    {
        sbyte b1 = SByte.MaxValue;
        byte b2 = Byte.MaxValue;

        Console.WriteLine("signed byte and unsigned byte:");
        Console.Write(b1);
        Console.Write(',');
        Console.WriteLine(b2);

        short short1 = Int16.MaxValue;
        ushort short2 = UInt16.MaxValue;

        Console.WriteLine("signed short and unsigned short:");
        Console.Write(short1);
        Console.Write(',');
        Console.WriteLine(short2);

        int int1 = Int32.MaxValue;
        uint int2 = UInt32.MaxValue;

        Console.WriteLine("signed int and unsigned int:");
        Console.Write(int1);
        Console.Write(',');
        Console.WriteLine(int2);

        long long1 = Int64.MaxValue;
        ulong long2 = UInt64.MaxValue;

        Console.WriteLine("signed long and unsigned long:");
        Console.Write(long1);
        Console.Write(',');
        Console.WriteLine(long2);
    }
}

When I try to view the internal details through lldb + sos with clrstack command, I found it might be showing the wrong value for ushort, the key command and output is below:

(lldb) clrstack -l
OS Thread Id: 0xaf9d14 (1)
        Child SP               IP Call Site
000000016B6A26E0 0000000108981E94 Vars01.Program.Main(System.String[]) [/Users/gdc/Repos/dotnet-examples/vars/Vars01/Program.cs @ 43]
    LOCALS:
        0x000000016B6A2704 = 0x000000000000007f
        0x000000016B6A2700 = 0x00000000000000ff
        0x000000016B6A26FC = 0x0000000000007fff
        0x000000016B6A26F8 = 0xffffffffffffffff
        0x000000016B6A26F4 = 0x000000007fffffff
        0x000000016B6A26F0 = 0x00000000ffffffff
        0x000000016B6A26E8 = 0x7fffffffffffffff
        0x000000016B6A26E0 = 0xffffffffffffffff
(lldb) memory read 0x000000016B6A26E0 -c 0x30
0x16b6a26e0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff 7f  ................
0x16b6a26f0: ff ff ff ff ff ff ff 7f ff ff 00 00 ff 7f 00 00  ................
0x16b6a2700: ff 00 00 00 7f 00 00 00 f0 cf 00 40 01 00 00 00  ...........@....
(lldb) memory read -c 1 0x000000016B6A2704
0x16b6a2704: 7f                                               .
(lldb) memory read -c 1 0x000000016B6A2700
0x16b6a2700: ff                                               .
(lldb) memory read -c 2 0x000000016B6A26FC
0x16b6a26fc: ff 7f                                            ..
(lldb) memory read -c 2 0x000000016B6A26F8
0x16b6a26f8: ff ff                                            ..
(lldb) memory read -c 4 0x000000016B6A26F4
0x16b6a26f4: ff ff ff 7f                                      ....
(lldb) memory read -c 4 0x000000016B6A26F0
0x16b6a26f0: ff ff ff ff                                      ....
(lldb) memory read -c 8 0x000000016B6A26E8
0x16b6a26e8: ff ff ff ff ff ff ff 7f                          ........
(lldb) memory read -c 8 0x000000016B6A26E0
0x16b6a26e0: ff ff ff ff ff ff ff ff                          ........        

The value for variable short2 at address 0x000000016B6A26F8 showing as 0xffffffffffffffff, it should be 0x000000000000ffff.

Configuration

sh vars $ dotnet --info
.NET SDK:
 Version:           9.0.100
 Commit:            59db016f11
 Workload version:  9.0.100-manifests.3068a692
 MSBuild version:   17.12.7+5b8665660

Runtime Environment:
 OS Name:     Mac OS X
 OS Version:  15.2
 OS Platform: Darwin
 RID:         osx-arm64
 Base Path:   /Users/gdc/dotnet/sdk/9.0.100/

.NET workloads installed:
There are no installed workloads to display.
Configured to use loose manifests when installing new manifests.

Host:
  Version:      9.0.0
  Architecture: arm64
  Commit:       9d5a6a9aa4

.NET SDKs installed:
  8.0.403 [/Users/gdc/dotnet/sdk]
  8.0.404 [/Users/gdc/dotnet/sdk]
  9.0.100 [/Users/gdc/dotnet/sdk]

.NET runtimes installed:
  Microsoft.AspNetCore.App 8.0.10 [/Users/gdc/dotnet/shared/Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 8.0.11 [/Users/gdc/dotnet/shared/Microsoft.AspNetCore.App]
  Microsoft.AspNetCore.App 9.0.0 [/Users/gdc/dotnet/shared/Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 8.0.10 [/Users/gdc/dotnet/shared/Microsoft.NETCore.App]
  Microsoft.NETCore.App 8.0.11 [/Users/gdc/dotnet/shared/Microsoft.NETCore.App]
  Microsoft.NETCore.App 9.0.0 [/Users/gdc/dotnet/shared/Microsoft.NETCore.App]

Other architectures found:
  None

Environment variables:
  DOTNET_ROOT       [/Users/gdc/dotnet]

global.json file:
  Not found

Learn more:
  https://aka.ms/dotnet/info

Download .NET:
  https://aka.ms/dotnet/download
sh vars $ lldb -v
lldb version 16.0.6
sh vars $ which lldb
/opt/homebrew/bin/lldb

Regression?

Not sure.

Other information