Move most of signal handling to Ryujinx.Cpu project (#6128)

* Move most of signal handling to Ryujinx.Cpu project

* Format whitespace

* Remove unused member

* Format whitespace

* This does not need to be public anymore

1 files changed, 83 insertions, 0 deletions

diff --git a/src/Ryujinx.Cpu/Signal/UnixSignalHandlerRegistration.cs b/src/Ryujinx.Cpu/Signal/UnixSignalHandlerRegistration.cs
new file mode 100644
index 00000000..e88a6c0f
--- /dev/null
+++ b/src/Ryujinx.Cpu/Signal/UnixSignalHandlerRegistration.cs
@@ -0,0 +1,83 @@
+using System;
+using System.Runtime.InteropServices;
+
+namespace Ryujinx.Cpu.Signal
+{
+    static partial class UnixSignalHandlerRegistration
+    {
+        [StructLayout(LayoutKind.Sequential, Pack = 1)]
+        public unsafe struct SigSet
+        {
+            fixed long sa_mask[16];
+        }
+
+        [StructLayout(LayoutKind.Sequential, Pack = 1)]
+        public struct SigAction
+        {
+            public IntPtr sa_handler;
+            public SigSet sa_mask;
+            public int sa_flags;
+            public IntPtr sa_restorer;
+        }
+
+        private const int SIGSEGV = 11;
+        private const int SIGBUS = 10;
+        private const int SA_SIGINFO = 0x00000004;
+
+        [LibraryImport("libc", SetLastError = true)]
+        private static partial int sigaction(int signum, ref SigAction sigAction, out SigAction oldAction);
+
+        [LibraryImport("libc", SetLastError = true)]
+        private static partial int sigaction(int signum, IntPtr sigAction, out SigAction oldAction);
+
+        [LibraryImport("libc", SetLastError = true)]
+        private static partial int sigemptyset(ref SigSet set);
+
+        public static SigAction GetSegfaultExceptionHandler()
+        {
+            int result = sigaction(SIGSEGV, IntPtr.Zero, out SigAction old);
+
+            if (result != 0)
+            {
+                throw new InvalidOperationException($"Could not get SIGSEGV sigaction. Error: {result}");
+            }
+
+            return old;
+        }
+
+        public static SigAction RegisterExceptionHandler(IntPtr action)
+        {
+            SigAction sig = new()
+            {
+                sa_handler = action,
+                sa_flags = SA_SIGINFO,
+            };
+
+            sigemptyset(ref sig.sa_mask);
+
+            int result = sigaction(SIGSEGV, ref sig, out SigAction old);
+
+            if (result != 0)
+            {
+                throw new InvalidOperationException($"Could not register SIGSEGV sigaction. Error: {result}");
+            }
+
+            if (OperatingSystem.IsMacOS())
+            {
+                result = sigaction(SIGBUS, ref sig, out _);
+
+                if (result != 0)
+                {
+                    throw new InvalidOperationException($"Could not register SIGBUS sigaction. Error: {result}");
+                }
+            }
+
+            return old;
+        }
+
+        public static bool RestoreExceptionHandler(SigAction oldAction)
+        {
+            return sigaction(SIGSEGV, ref oldAction, out SigAction _) == 0 && (!OperatingSystem.IsMacOS() || sigaction(SIGBUS, ref oldAction, out SigAction _) == 0);
+        }
+    }
+}