Android: Numerous fixes

* GetSerialNumber in ISystemSettingsServer

* Bionic qualifiers

* Revert application pool size to 3285 MB for 4 GB DRAM

* Fix PPTC recompilation if mod or patch is applied

src/Ryujinx.Cpu/AddressTable.cs

@@ -181,7 +181,7 @@ namespace ARMeilleure.Common
         public static AddressTable<TEntry> CreateForArm(bool for64Bits, MemoryManagerType type)
         {
             // Assume software memory means that we don't want to use any signal handlers.
-            bool sparse = type != MemoryManagerType.SoftwareMmu && type != MemoryManagerType.SoftwarePageTable;
+            bool sparse = type != MemoryManagerType.SoftwareMmu && type != MemoryManagerType.SoftwarePageTable && PlatformInfo.IsBionic != true;
 
             return new AddressTable<TEntry>(AddressTablePresets.GetArmPreset(for64Bits, sparse), sparse);
         }

src/Ryujinx.Cpu/MemoryEhMeilleure.cs

@@ -55,6 +55,24 @@ namespace Ryujinx.Cpu
             }
         }
 
+        public MemoryEhMeilleure(ulong asSize, MemoryTracking tracking)
+        {
+            _tracking = tracking;
+            _baseAddress = 0UL;
+            ulong endAddress = asSize;
+
+            _trackingEvent = VirtualMemoryEvent;
+
+            _pageSize = MemoryBlock.GetPageSize();
+
+            bool added = NativeSignalHandler.AddTrackedRegion((nuint)_baseAddress, (nuint)endAddress, Marshal.GetFunctionPointerForDelegate(_trackingEvent));
+
+            if (!added)
+            {
+                throw new InvalidOperationException("Number of allowed tracked regions exceeded.");
+            }
+        }
+
         private ulong VirtualMemoryEvent(ulong address, ulong size, bool write)
         {
             ulong pageSize = _pageSize;

src/Ryujinx.Cpu/Signal/NativeSignalHandler.cs

@@ -89,10 +89,16 @@ namespace Ryujinx.Cpu.Signal
 
                 ref SignalHandlerConfig config = ref GetConfigRef();
 
-                if (OperatingSystem.IsLinux() || OperatingSystem.IsMacOS())
+                if (OperatingSystem.IsLinux() || OperatingSystem.IsMacOS() || PlatformInfo.IsBionic)
                 {
                     _signalHandlerPtr = MapCode(NativeSignalHandlerGenerator.GenerateUnixSignalHandler(_handlerConfig, rangeStructSize));
 
+                    if (PlatformInfo.IsBionic)
+                    {
+                        config.StructAddressOffset = 16; // si_addr
+                        config.StructWriteOffset = 8; // si_code
+                    }
+
                     if (customSignalHandlerFactory != null)
                     {
                         _signalHandlerPtr = customSignalHandlerFactory(UnixSignalHandlerRegistration.GetSegfaultExceptionHandler().sa_handler, _signalHandlerPtr);
@@ -122,6 +128,21 @@ namespace Ryujinx.Cpu.Signal
             }
         }
 
+        public static void InstallUnixAlternateStackForCurrentThread(IntPtr stackPtr, ulong stackSize)
+        {
+            UnixSignalHandlerRegistration.RegisterAlternateStack(stackPtr, stackSize);
+        }
+
+        public static void UninstallUnixAlternateStackForCurrentThread()
+        {
+            UnixSignalHandlerRegistration.UnregisterAlternateStack();
+        }
+
+        public static void InstallUnixSignalHandler(int sigNum, IntPtr action)
+        {
+            UnixSignalHandlerRegistration.RegisterExceptionHandler(sigNum, action);
+        }
+
         private static IntPtr MapCode(ReadOnlySpan<byte> code)
         {
             Debug.Assert(_codeBlock == null);

src/Ryujinx.Cpu/Signal/UnixSignalHandlerRegistration.cs

@@ -1,5 +1,7 @@
+using Ryujinx.Common;
 using System;
 using System.Runtime.InteropServices;
+using System.Runtime.Versioning;
 
 namespace Ryujinx.Cpu.Signal
 {
@@ -20,26 +22,73 @@ namespace Ryujinx.Cpu.Signal
             public IntPtr sa_restorer;
         }
 
+        [SupportedOSPlatform("android"), StructLayout(LayoutKind.Sequential, Pack = 8)]
+        public struct SigActionBionic
+        {
+            public int sa_flags;
+            public IntPtr sa_handler;
+            public SigSet sa_mask;
+            public IntPtr sa_restorer;
+        }
+
+        [StructLayout(LayoutKind.Sequential, Pack = 8)]
+        public struct Stack
+        {
+            public IntPtr ss_sp;
+            public int ss_flags;
+            public IntPtr ss_size;
+        }
+
         private const int SIGSEGV = 11;
         private const int SIGBUS = 10;
         private const int SA_SIGINFO = 0x00000004;
+        private const int SA_ONSTACK = 0x08000000;
+        private const int SS_DISABLE = 2;
+        private const int SS_AUTODISARM = 1 << 31;
 
         [LibraryImport("libc", SetLastError = true)]
         private static partial int sigaction(int signum, ref SigAction sigAction, out SigAction oldAction);
 
+        [SupportedOSPlatform("android"), LibraryImport("libc", SetLastError = true)]
+        private static partial int sigaction(int signum, ref SigActionBionic sigAction, out SigActionBionic oldAction);
+
         [LibraryImport("libc", SetLastError = true)]
         private static partial int sigaction(int signum, IntPtr sigAction, out SigAction oldAction);
 
+        [SupportedOSPlatform("android"), LibraryImport("libc", SetLastError = true)]
+        private static partial int sigaction(int signum, IntPtr sigAction, out SigActionBionic oldAction);
+
         [LibraryImport("libc", SetLastError = true)]
         private static partial int sigemptyset(ref SigSet set);
 
+        [LibraryImport("libc", SetLastError = true)]
+        private static partial int sigaltstack(ref Stack ss, out Stack oldSs);
+
         public static SigAction GetSegfaultExceptionHandler()
         {
-            int result = sigaction(SIGSEGV, IntPtr.Zero, out SigAction old);
+            int result;
+            SigAction old;
+
+            if (PlatformInfo.IsBionic)
+            {
+                result = sigaction(SIGSEGV, IntPtr.Zero, out SigActionBionic tmp);
+
+                old = new SigAction
+                {
+                    sa_handler = tmp.sa_handler,
+                    sa_mask = tmp.sa_mask,
+                    sa_flags = tmp.sa_flags,
+                    sa_restorer = tmp.sa_restorer
+                };
+            }
+            else
+            {
+                result = sigaction(SIGSEGV, IntPtr.Zero, out old);
+            }
 
             if (result != 0)
             {
-                throw new InvalidOperationException($"Could not get SIGSEGV sigaction. Error: {result}");
+                throw new SystemException($"Could not get SIGSEGV sigaction. Error: {Marshal.GetLastPInvokeErrorMessage()}");
             }
 
             return old;
@@ -47,37 +96,167 @@ namespace Ryujinx.Cpu.Signal
 
         public static SigAction RegisterExceptionHandler(IntPtr action)
         {
-            SigAction sig = new()
+            int result;
+            SigAction old;
+
+            if (PlatformInfo.IsBionic)
             {
-                sa_handler = action,
-                sa_flags = SA_SIGINFO,
-            };
+                SigActionBionic sig = new()
+                {
+                    sa_handler = action,
+                    sa_flags = SA_SIGINFO | SA_ONSTACK,
+                };
 
-            sigemptyset(ref sig.sa_mask);
+                sigemptyset(ref sig.sa_mask);
 
-            int result = sigaction(SIGSEGV, ref sig, out SigAction old);
+                result = sigaction(SIGSEGV, ref sig, out SigActionBionic tmp);
 
-            if (result != 0)
-            {
-                throw new InvalidOperationException($"Could not register SIGSEGV sigaction. Error: {result}");
+                old = new SigAction
+                {
+                    sa_handler = tmp.sa_handler,
+                    sa_mask = tmp.sa_mask,
+                    sa_flags = tmp.sa_flags,
+                    sa_restorer = tmp.sa_restorer
+                };
             }
-
-            if (OperatingSystem.IsMacOS())
+            else
             {
-                result = sigaction(SIGBUS, ref sig, out _);
+                SigAction sig = new SigAction
+                {
+                    sa_handler = action,
+                    sa_flags = SA_SIGINFO | SA_ONSTACK,
+                };
+
+                sigemptyset(ref sig.sa_mask);
+
+                result = sigaction(SIGSEGV, ref sig, out old);
 
                 if (result != 0)
                 {
-                    throw new InvalidOperationException($"Could not register SIGBUS sigaction. Error: {result}");
+                    throw new SystemException($"Could not register SIGSEGV sigaction. Error: {Marshal.GetLastPInvokeErrorMessage()}");
+                }
+
+                if (OperatingSystem.IsMacOS() || OperatingSystem.IsIOS())
+                {
+                    result = sigaction(SIGBUS, ref sig, out _);
+
+                    if (result != 0)
+                    {
+                        throw new SystemException($"Could not register SIGBUS sigaction. Error: {Marshal.GetLastPInvokeErrorMessage()}");
+                    }
                 }
             }
 
             return old;
         }
 
+        public static void RegisterAlternateStack(IntPtr stackPtr, ulong stackSize)
+        {
+            Stack stack = new()
+            {
+                ss_sp = stackPtr,
+                ss_flags = SS_AUTODISARM,
+                ss_size = (IntPtr)stackSize
+            };
+
+            int result = sigaltstack(ref stack, out _);
+
+            if (result != 0)
+            {
+                throw new SystemException($"Could not set alternate stack. Error: {Marshal.GetLastPInvokeErrorMessage()}");
+            }
+        }
+
+        public static void UnregisterAlternateStack()
+        {
+            Stack stack = new()
+            {
+                ss_flags = SS_DISABLE
+            };
+
+            int result = sigaltstack(ref stack, out _);
+
+            if (result != 0)
+            {
+                throw new SystemException($"Could not remove alternate stack. Error: {Marshal.GetLastPInvokeErrorMessage()}");
+            }
+        }
+
+        public static void RegisterExceptionHandler(int sigNum, IntPtr action)
+        {
+            int result;
+
+            if (PlatformInfo.IsBionic)
+            {
+                SigActionBionic sig = new()
+                {
+                    sa_handler = action,
+                    sa_flags = SA_SIGINFO | SA_ONSTACK
+                };
+
+                sigemptyset(ref sig.sa_mask);
+
+                result = sigaction(sigNum, ref sig, out SigActionBionic oldu);
+
+                if (oldu.sa_handler != IntPtr.Zero)
+                {
+                    throw new InvalidOperationException($"SIG{sigNum} is already in use.");
+                }
+
+                if (result != 0)
+                {
+                    throw new SystemException($"Could not register SIG{sigNum} sigaction. Error: {Marshal.GetLastPInvokeErrorMessage()}");
+                }
+            }
+            else
+            {
+                SigAction sig = new()
+                {
+                    sa_handler = action,
+                    sa_flags = SA_SIGINFO | SA_ONSTACK,
+                };
+
+                sigemptyset(ref sig.sa_mask);
+
+                result = sigaction(sigNum, ref sig, out SigAction oldu);
+
+                if (oldu.sa_handler != IntPtr.Zero)
+                {
+                    throw new InvalidOperationException($"SIG{sigNum} is already in use.");
+                }
+
+                if (result != 0)
+                {
+                    throw new SystemException($"Could not register SIG{sigNum} sigaction. Error: {Marshal.GetLastPInvokeErrorMessage()}");
+                }
+            }
+        }
+
         public static bool RestoreExceptionHandler(SigAction oldAction)
         {
-            return sigaction(SIGSEGV, ref oldAction, out SigAction _) == 0 && (!OperatingSystem.IsMacOS() || sigaction(SIGBUS, ref oldAction, out SigAction _) == 0);
+            if (PlatformInfo.IsBionic)
+            {
+                SigActionBionic tmp = new SigActionBionic
+                {
+                    sa_handler = oldAction.sa_handler,
+                    sa_mask = oldAction.sa_mask,
+                    sa_flags = oldAction.sa_flags,
+                    sa_restorer = oldAction.sa_restorer
+                };
+
+                return sigaction(SIGSEGV, ref tmp, out SigActionBionic _) == 0;
+            }
+            else
+            {
+                bool success = sigaction(SIGSEGV, ref oldAction, out SigAction _) == 0;
+
+                if (success && (OperatingSystem.IsMacOS() || OperatingSystem.IsIOS()))
+                {
+                    success = sigaction(SIGBUS, ref oldAction, out SigAction _) == 0;
+                }
+
+                return success;
+            }
         }
     }
 }