cleanup

arch/x86_64/archctl.c

@@ -1,19 +1,32 @@
 #include <zinnia/errno.h>
+#include <zinnia/syscall.h>
 #include <arch/archctl.h>
+#include <arch/mem.h>
 #include <uapi/archctl.h>
 #include <x86_64/asm.h>
 #include <x86_64/defs.h>
 
-errno_t arch_archctl(uintptr_t op, uintptr_t arg) {
+struct syscall_ret arch_archctl(uintptr_t op, uintptr_t arg) {
+    struct syscall_ret ret = {};
+
     switch (op) {
     case __ARCHCTL_SET_FSBASE:
+        if (!arch_mem_addr_is_user(arg)) {
+            ret.errno = EINVAL;
+            return ret;
+        }
         asm_wrmsr(MSR_FS_BASE, arg);
-        return 0;
+        return ret;
     case __ARCHCTL_SET_GSBASE:
+        if (!arch_mem_addr_is_user(arg)) {
+            ret.errno = EINVAL;
+            return ret;
+        }
         // Update the inactive GSBASE MSR, not ours.
         asm_wrmsr(MSR_KERNEL_GS_BASE, arg);
-        return 0;
+        return ret;
     default:
-        return EINVAL;
+        ret.errno = EINVAL;
+        return ret;
     }
 }