Kernel+LibC: Introduce new archctl syscall

This syscall will be used for architecture-specific operations.

Kernel/API/Syscall.h

@@ -50,6 +50,7 @@ enum class NeedsBigProcessLock {
     S(adjtime, NeedsBigProcessLock::No)                    \
     S(alarm, NeedsBigProcessLock::No)                      \
     S(allocate_tls, NeedsBigProcessLock::No)               \
+    S(archctl, NeedsBigProcessLock::No)                    \
     S(anon_create, NeedsBigProcessLock::No)                \
     S(annotate_mapping, NeedsBigProcessLock::No)           \
     S(bind, NeedsBigProcessLock::No)                       \

Kernel/API/archctl_numbers.h

@@ -0,0 +1,7 @@
+/*
+ * Copyright (c) 2024, Sönke Holz <sholz8530@gmail.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once

Kernel/Arch/aarch64/archctl.cpp

@@ -0,0 +1,20 @@
+/*
+ * Copyright (c) 2024, Sönke Holz <sholz8530@gmail.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <Kernel/Tasks/Process.h>
+
+namespace Kernel {
+
+ErrorOr<FlatPtr> Process::sys$archctl(int option, FlatPtr arg1)
+{
+    (void)option;
+    (void)arg1;
+
+    VERIFY_NO_PROCESS_BIG_LOCK(this);
+    return ENOSYS;
+}
+
+}

Kernel/Arch/riscv64/archctl.cpp

@@ -0,0 +1,20 @@
+/*
+ * Copyright (c) 2024, Sönke Holz <sholz8530@gmail.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <Kernel/Tasks/Process.h>
+
+namespace Kernel {
+
+ErrorOr<FlatPtr> Process::sys$archctl(int option, FlatPtr arg1)
+{
+    (void)option;
+    (void)arg1;
+
+    VERIFY_NO_PROCESS_BIG_LOCK(this);
+    return ENOSYS;
+}
+
+}

Kernel/Arch/x86_64/archctl.cpp

@@ -0,0 +1,20 @@
+/*
+ * Copyright (c) 2024, Sönke Holz <sholz8530@gmail.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <Kernel/Tasks/Process.h>
+
+namespace Kernel {
+
+ErrorOr<FlatPtr> Process::sys$archctl(int option, FlatPtr arg1)
+{
+    (void)option;
+    (void)arg1;
+
+    VERIFY_NO_PROCESS_BIG_LOCK(this);
+    return ENOSYS;
+}
+
+}

Kernel/CMakeLists.txt

@@ -386,6 +386,8 @@ if ("${SERENITY_ARCH}" STREQUAL "x86_64")
     set(KERNEL_SOURCES
         ${KERNEL_SOURCES}
 
+        Arch/x86_64/archctl.cpp
+
         Arch/x86_64/CMOS.cpp
         Arch/x86_64/DebugOutput.cpp
         Arch/x86_64/Delay.cpp
@@ -485,6 +487,7 @@ elseif("${SERENITY_ARCH}" STREQUAL "aarch64")
 
         Arch/aarch64/Firmware/ACPI/StaticParsing.cpp
 
+        Arch/aarch64/archctl.cpp
         Arch/aarch64/boot.S
         Arch/aarch64/BootPPMParser.cpp
         Arch/aarch64/CPUID.cpp
@@ -528,6 +531,7 @@ elseif("${SERENITY_ARCH}" STREQUAL "riscv64")
 
         Arch/riscv64/Firmware/ACPI/StaticParsing.cpp
 
+        Arch/riscv64/archctl.cpp
         Arch/riscv64/boot.S
         Arch/riscv64/CPU.cpp
         Arch/riscv64/CurrentTime.cpp

Kernel/Tasks/Process.h

@@ -482,6 +482,7 @@ public:
     ErrorOr<FlatPtr> sys$get_root_session_id(pid_t force_sid);
     ErrorOr<FlatPtr> sys$remount(Userspace<Syscall::SC_remount_params const*> user_params);
     ErrorOr<FlatPtr> sys$bindmount(Userspace<Syscall::SC_bindmount_params const*> user_params);
+    ErrorOr<FlatPtr> sys$archctl(int option, FlatPtr arg1);
 
     enum SockOrPeerName {
         SockName,

Userland/Libraries/LibC/CMakeLists.txt

@@ -52,6 +52,7 @@ set(LIBC_SOURCES
     string.cpp
     strings.cpp
     stubs.cpp
+    sys/archctl.cpp
     sys/auxv.cpp
     sys/file.cpp
     sys/mman.cpp

Userland/Libraries/LibC/sys/archctl.cpp

@@ -0,0 +1,26 @@
+/*
+ * Copyright (c) 2024, Sönke Holz <sholz8530@gmail.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <errno.h>
+#include <stdarg.h>
+#include <sys/archctl.h>
+#include <syscall.h>
+
+extern "C" {
+
+int archctl(int option, ...)
+{
+    va_list args;
+    va_start(args, option);
+
+    uintptr_t arg1 = va_arg(args, uintptr_t);
+
+    va_end(args);
+
+    int rc = syscall(SC_archctl, option, arg1);
+    __RETURN_WITH_ERRNO(rc, rc, -1);
+}
+}

Userland/Libraries/LibC/sys/archctl.h

@@ -0,0 +1,17 @@
+/*
+ * Copyright (c) 2024, Sönke Holz <sholz8530@gmail.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <Kernel/API/archctl_numbers.h>
+#include <sys/cdefs.h>
+#include <sys/types.h>
+
+__BEGIN_DECLS
+
+int archctl(int option, ...);
+
+__END_DECLS