feat: overhaul userspace heap and virtual memory

kernel/src/Hal/IDT.cpp

@@ -13,6 +13,7 @@
 #include <Memory/PageFrameAllocator.hpp>
 #include <Sched/Scheduler.hpp>
 #include <Sched/CrashReport.hpp>
+#include <Api/Heap.hpp>
 #include <Hal/SmpBoot.hpp>
 #include <Timekeeping/ApicTimer.hpp>
 
@@ -201,10 +202,12 @@ namespace Hal {
         // pushes past the mapped stack and kernel accesses to not-yet-grown
         // user stack buffers passed into syscalls.
         if ((errorCode & 1) == 0 && cpu != nullptr && cpu->currentSlot >= 0
-            && Sched::GetCurrentPid() >= 0
-            && Sched::TryGrowUserStack(cr2)) {
-            if (fromUser) asm volatile("swapgs");
-            return;
+            && Sched::GetCurrentPid() >= 0) {
+            if (montauk::abi::TryHandleAnonymousPageFault(cr2, errorCode) ||
+                Sched::TryGrowUserStack(cr2)) {
+                if (fromUser) asm volatile("swapgs");
+                return;
+            }
         }
 
         // Not a growable fault. Hand the RAW frame (error code at offset 0)

kernel/src/Hal/SmpBoot.cpp

@@ -188,7 +188,7 @@ namespace Smp {
 
         // --- Program SYSCALL MSRs ---
         uint64_t efer = Hal::ReadMSR(Hal::IA32_EFER);
-        efer |= 1;  // SCE
+        efer |= 1 | (1ULL << 11);  // SCE | NXE
         Hal::WriteMSR(Hal::IA32_EFER, efer);
 
         uint64_t star = (0x0010ULL << 48) | (0x0008ULL << 32);