From 42c5533b06fba095d24b75a58863f635385209cc Mon Sep 17 00:00:00 2001
From: slipher <slipher@protonmail.com>
Date: Sat, 7 Nov 2026 19:32:31 -0600
Subject: [PATCH 1/2] VirtualMachine: Remove broken armhf->box64 fallback code

On arm64 Linux there is a half-attempt to fall back to box64 if the
armhf loader can't start. This was merged by mistake; it depends on the
double bootstrap loader which does not exist in the final version of
https://github.com/DaemonEngine/Daemon/pull/2018. The process exit code
detection junk which depended on that must be removed.

I will add a working version of armhf->box64 fallback later.
---
 src/engine/framework/VirtualMachine.cpp | 149 ++----------------------
 1 file changed, 7 insertions(+), 142 deletions(-)

diff --git a/src/engine/framework/VirtualMachine.cpp b/src/engine/framework/VirtualMachine.cpp
index 76e9ac9dc3..5139284af0 100644
--- a/src/engine/framework/VirtualMachine.cpp
+++ b/src/engine/framework/VirtualMachine.cpp
@@ -358,86 +358,6 @@ static std::pair<Sys::OSHandle, IPC::Socket> InternalLoadModule(std::pair<IPC::S
 #endif
 }
 
-#if defined(DAEMON_NACL_RUNTIME_LINUX) && defined(YOKAI_ARCH_ARM64)
-enum class ExeSupport
-{
-	Supported,
-	Unsupported,
-	Unknown,
-};
-
-static void SilenceOutput()
-{
-	int devnull = open("/dev/null", O_WRONLY);
-
-	if (devnull < 0) {
-		_exit(200);
-	}
-
-	dup2(devnull, STDOUT_FILENO);
-	dup2(devnull, STDERR_FILENO);
-
-	close(devnull);
-}
-
-static ExeSupport CheckExeSupport(Str::StringRef probe)
-{
-	pid_t pid = fork();
-	if (pid < 0) {
-		return ExeSupport::Unknown;
-	}
-
-	if (pid == 0) {
-		SilenceOutput();
-
-		char *const argv[] = {
-			const_cast<char *>(probe.data()),
-			nullptr,
-		};
-
-		execve(probe.data(), argv, environ);
-
-		switch (errno)
-		{
-			case ENOEXEC:
-				// The kernel cannot execute the probe.
-				_exit(100);
-
-			case ENOENT:
-			case EACCES:
-				// Missing or inaccessible probe.
-				_exit(101);
-
-			default:
-				_exit(102);
-		}
-	}
-
-	int status;
-	if (waitpid(pid, &status, 0) < 0) {
-		return ExeSupport::Unknown;
-	}
-
-	if (!WIFEXITED(status)) {
-		return ExeSupport::Unknown;
-	}
-
-	switch (WEXITSTATUS(status))
-	{
-		case 100:
-			return ExeSupport::Unsupported;
-
-		case 101:
-		case 102:
-			return ExeSupport::Unknown;
-
-		default:
-			// The probe has been executed properly.
-			return ExeSupport::Supported;
-	}
-}
-#endif // defined(DAEMON_NACL_RUNTIME_LINUX) && defined(NACL_ARCH_ARM64)
-
 #if defined(DAEMON_NACL_RUNTIME_ENABLED)
 static std::pair<Sys::OSHandle, IPC::Socket> CreateNaClVM(std::pair<IPC::Socket, IPC::Socket> pair, Str::StringRef name, bool debug, bool extract, int debugLoader) {
 	const std::string& libPath = FS::GetLibPath();
@@ -462,12 +382,6 @@ static std::pair<Sys::OSHandle, IPC::Socket> CreateNaClVM(std::pair<IPC::Socket,
 	bool i686ForceAmd64 = systemInfo.wProcessorArchitecture == PROCESSOR_ARCHITECTURE_AMD64;
 #endif // !( !defined(_WIN32) || defined(_WIN64) )
 
-#if defined(DAEMON_NACL_RUNTIME_LINUX) && defined(YOKAI_ARCH_ARM64)
-	constexpr bool hasMultiarch = true;
-#else
-	constexpr bool hasMultiarch = false;
-#endif
-
 	std::string bootstrapPath;
 
 #if defined(DAEMON_NACL_BOOSTRAP_ENABLED)
@@ -477,65 +391,21 @@ static std::pair<Sys::OSHandle, IPC::Socket> CreateNaClVM(std::pair<IPC::Socket,
 	Q_UNUSED(bootstrapPath);
 #endif // !defined(DAEMON_NACL_BOOSTRAP_ENABLED)
 
-	std::string box64Path;
-
 #if defined(DAEMON_NACL_BOX64_EMULATION)
-	constexpr bool hasBox64 = true;
-#else // !defined(DAEMON_NACL_BOX64_EMULATION)
-	constexpr bool hasBox64 = false;
-	Q_UNUSED(box64Path);
+	std::string box64Path;
 #endif // !defined(DAEMON_NACL_BOX64_EMULATION)
 
-#if defined(DAEMON_NACL_RUNTIME_LINUX)
-#if defined(YOKAI_ARCH_ARM64)
-	/* We later turn this boolean off when we detect armhf support is not
-	provided on arm64. */
-	bool hasArmhf = true;
-#elif defined(YOKAI_ARCH_ARMHF)
-	constexpr bool hasArmhf = false;
-#endif // !defined(YOKAI_ARCH_ARMHF)
-#endif // !defined(DAEMON_NACL_RUNTIME_LINUX)
-
-	bool useMultiarch = hasMultiarch;
-	bool useBox64 = hasBox64;
-
 #if defined(DAEMON_NACL_RUNTIME_LINUX) && defined(YOKAI_ARCH_ARM64)
 	const std::string libs_linux_armhf = "lib-armhf";
 	const std::string libld_linux_armhf = "ld-linux-armhf";
 
 	std::string libsDirPath = FS::Path::Build(libPath, libs_linux_armhf);
 	std::string libLoaderPath = FS::Path::Build(libsDirPath, libld_linux_armhf);
-
-	switch (CheckExeSupport(libLoaderPath))
-	{
-		case ExeSupport::Supported:
-			Log::Notice("Working multiarch support.");
-			break;
-
-		case ExeSupport::Unsupported:
-			Log::Notice("Unsupported multiarch.");
-			hasArmhf = false;
-			break;
-
-		case ExeSupport::Unknown:
-			Log::Warn("Cannot determine multiarch support.");
-			hasArmhf = false;
-			break;
-	}
-
-	if (!hasArmhf) {
-		useMultiarch = false;
-	}
 #endif // defined(DAEMON_NACL_RUNTIME_LINUX) && defined(YOKAI_ARCH_ARM64)
 
-	if (useMultiarch && useBox64) {
-		Log::Notice("Preferring multiarch over Box64 emulation.");
-		useBox64 = false;
-	}
-
-	bool useBootstrap = hasBootstrap && !useBox64;
+	bool useBootstrap = hasBootstrap;
 
-	std::string arch = (useBox64 || i686ForceAmd64) ? "amd64" : DAEMON_NACL_ARCH_STRING;
+	std::string arch = i686ForceAmd64 ? "amd64" : DAEMON_NACL_ARCH_STRING;
 
 	std::string moduleName = Str::Format("%s-%s.nexe", name, arch);
 	std::string irt = FS::Path::Build(naclPath, Str::Format("irt_core-%s.nexe", arch));
@@ -592,12 +462,10 @@ static std::pair<Sys::OSHandle, IPC::Socket> CreateNaClVM(std::pair<IPC::Socket,
 		}
 
 #if defined(DAEMON_NACL_BOX64_EMULATION)
-		if (useBox64) {
-			box64Path = ResolveBox64Path(naclPath);
-			Log::Notice("Using Box64 emulator: %s", box64Path);
-			args.push_back(box64Path.c_str());
-			inheritEnvironment = true;
-		}
+		box64Path = ResolveBox64Path(naclPath);
+		Log::Notice("Using Box64 emulator: %s", box64Path);
+		args.push_back(box64Path.c_str());
+		inheritEnvironment = true;
 #endif
 	}
 
@@ -616,8 +484,6 @@ static std::pair<Sys::OSHandle, IPC::Socket> CreateNaClVM(std::pair<IPC::Socket,
 
 #if defined(DAEMON_NACL_RUNTIME_LINUX) && (defined(YOKAI_ARCH_ARM64) || defined(YOKAI_ARCH_ARMHF))
 	if (enableQualification
-	&& hasArmhf
-	&& !useBox64
 	&& workaround_naclArchitecture_arm64_disableQualification.Get()) {
 		/* This is required to run armhf NaCl loader on arm64 kernel
 		otherwise nexe loading fails with this message:
@@ -643,7 +509,6 @@ static std::pair<Sys::OSHandle, IPC::Socket> CreateNaClVM(std::pair<IPC::Socket,
 
 #if defined(DAEMON_NACL_BOX64_EMULATION)
 	if (enableQualification
-	&& useBox64
 	&& workaround_box64_disableQualification.Get()) {
 		/* When running the amd64 NaCl loader under Box64, the loader's
 		platform qualification will fail because the CPU is not actually x86_64.

From e9133de4cb964a27259fd8d997b53f8abeed5ded Mon Sep 17 00:00:00 2001
From: slipher <slipher@protonmail.com>
Date: Sat, 7 Nov 2026 19:32:31 -0600
Subject: [PATCH 2/2] Clean up bootstrap handling for NaCl VMs

Handle all setup of the NaCl bootstrap loader in a single block of code,
instead of spraying little pieces and ifdefs all over the place.

This was supposed to be merged as part of the "Don't use
nacl_helper_bootstrap with x86-64 loader" commit in
https://github.com/DaemonEngine/Daemon/pull/2001.
---
 src/engine/framework/VirtualMachine.cpp | 64 +++++++++----------------
 1 file changed, 23 insertions(+), 41 deletions(-)

diff --git a/src/engine/framework/VirtualMachine.cpp b/src/engine/framework/VirtualMachine.cpp
index 5139284af0..b4db6a1995 100644
--- a/src/engine/framework/VirtualMachine.cpp
+++ b/src/engine/framework/VirtualMachine.cpp
@@ -79,9 +79,6 @@ static Cvar::Cvar<bool> workaround_naclSystem_freebsd_disableQualification(
 // Many BSDs have a Linuxulator, for now we only tested one.
 #if defined(__linux__) || defined(__FreeBSD__)
 #define DAEMON_NACL_RUNTIME_LINUX
-#if YOKAI_ARCH_I686 || YOKAI_ARCH_ARM64 || YOKAI_ARCH_ARMHF
-#define DAEMON_NACL_BOOSTRAP_ENABLED
-#endif // !(YOKAI_ARCH_I686 || YOKAI_ARCH_ARM64 || YOKAI_ARCH_ARMHF)
 #endif // defined(__linux__) || defined(DAEMON_LINUXULATOR)
 #endif // defined(DAEMON_NACL_RUNTIME_ENABLED)
 
@@ -182,6 +179,7 @@ static Cvar::Cvar<bool> vm_nacl_qualification(
 
 namespace VM {
 
+#if defined(DAEMON_NACL_RUNTIME_LINUX)
 // https://github.com/Unvanquished/Unvanquished/issues/944#issuecomment-744454772
 static void CheckMinAddressSysctlTooLarge()
 {
@@ -206,6 +204,7 @@ static void CheckMinAddressSysctlTooLarge()
 	}
 #endif // __linux__
 }
+#endif // DAEMON_NACL_RUNTIME_LINUX
 
 #if defined(DAEMON_NACL_RUNTIME_LINUX) && (defined(YOKAI_ARCH_ARM64) || defined(YOKAI_ARCH_ARMHF))
 static bool OnArm64()
@@ -382,19 +381,6 @@ static std::pair<Sys::OSHandle, IPC::Socket> CreateNaClVM(std::pair<IPC::Socket,
 	bool i686ForceAmd64 = systemInfo.wProcessorArchitecture == PROCESSOR_ARCHITECTURE_AMD64;
 #endif // !( !defined(_WIN32) || defined(_WIN64) )
 
-	std::string bootstrapPath;
-
-#if defined(DAEMON_NACL_BOOSTRAP_ENABLED)
-	bool hasBootstrap = true;
-#else // !defined(DAEMON_NACL_BOOSTRAP_ENABLED)
-	constexpr bool hasBootstrap = false;
-	Q_UNUSED(bootstrapPath);
-#endif // !defined(DAEMON_NACL_BOOSTRAP_ENABLED)
-
-#if defined(DAEMON_NACL_BOX64_EMULATION)
-	std::string box64Path;
-#endif // !defined(DAEMON_NACL_BOX64_EMULATION)
-
 #if defined(DAEMON_NACL_RUNTIME_LINUX) && defined(YOKAI_ARCH_ARM64)
 	const std::string libs_linux_armhf = "lib-armhf";
 	const std::string libld_linux_armhf = "ld-linux-armhf";
@@ -403,8 +389,6 @@ static std::pair<Sys::OSHandle, IPC::Socket> CreateNaClVM(std::pair<IPC::Socket,
 	std::string libLoaderPath = FS::Path::Build(libsDirPath, libld_linux_armhf);
 #endif // defined(DAEMON_NACL_RUNTIME_LINUX) && defined(YOKAI_ARCH_ARM64)
 
-	bool useBootstrap = hasBootstrap;
-
 	std::string arch = i686ForceAmd64 ? "amd64" : DAEMON_NACL_ARCH_STRING;
 
 	std::string moduleName = Str::Format("%s-%s.nexe", name, arch);
@@ -444,37 +428,35 @@ static std::pair<Sys::OSHandle, IPC::Socket> CreateNaClVM(std::pair<IPC::Socket,
 		Sys::Error("NaCl integrated runtime not found: %s", irt);
 	}
 
-	if (useBootstrap) {
-		CheckMinAddressSysctlTooLarge();
-
-		bootstrapPath = FS::Path::Build(naclPath, Str::Format("nacl_helper_bootstrap-%s", arch));
-
-		if (FS::RawPath::FileExists(bootstrapPath)) {
-			args.push_back(bootstrapPath.c_str());
-		} else {
-			Log::Warn("NaCl bootstrap helper not found: %s", bootstrapPath);
-			useBootstrap = false;
-		}
-	}
-	else {
-		if (hasBootstrap) {
-			Log::Notice("Not using NaCl bootstrap helper.");
-		}
-
 #if defined(DAEMON_NACL_BOX64_EMULATION)
-		box64Path = ResolveBox64Path(naclPath);
-		Log::Notice("Using Box64 emulator: %s", box64Path);
-		args.push_back(box64Path.c_str());
-		inheritEnvironment = true;
+	std::string box64Path = ResolveBox64Path(naclPath);
+	Log::Notice("Using Box64 emulator: %s", box64Path);
+	args.push_back(box64Path.c_str());
+	inheritEnvironment = true;
 #endif
-	}
 
-	args.push_back(nacl_loader.c_str());
+#if defined(DAEMON_NACL_RUNTIME_LINUX)
+	std::string bootstrapPath;
+	// Mutually exclusive with box64 since the NaCl arch is amd64 there.
+	bool useBootstrap = arch != "amd64";
 
 	if (useBootstrap) {
+		CheckMinAddressSysctlTooLarge();
+
+		bootstrapPath = FS::Path::Build(naclPath, Str::Format("nacl_helper_bootstrap-%s", arch));
+		if (!FS::RawPath::FileExists(bootstrapPath)) {
+			Sys::Error("NaCl bootstrap helper not found: %s", bootstrapPath);
+		}
+		args.push_back(bootstrapPath.c_str());
+		args.push_back(nacl_loader.c_str());
 		args.push_back("--r_debug=0xXXXXXXXXXXXXXXXX");
 		args.push_back("--reserved_at_zero=0xXXXXXXXXXXXXXXXX");
+	} else {
+		args.push_back(nacl_loader.c_str());
 	}
+#else
+	args.push_back(nacl_loader.c_str());
+#endif
 
 	bool enableQualification = vm_nacl_qualification.Get();