From d396da5f3c4dca3b60332565d1f001611a1299fb Mon Sep 17 00:00:00 2001
From: Erin <erin@erindesu.cz>
Date: Wed, 15 Nov 2023 19:37:52 +0100
Subject: [PATCH] Stack grows downwards, baka.

---
 kernel/src/holeybytes/mod.rs | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/kernel/src/holeybytes/mod.rs b/kernel/src/holeybytes/mod.rs
index fa3bb72d..cbf56f72 100644
--- a/kernel/src/holeybytes/mod.rs
+++ b/kernel/src/holeybytes/mod.rs
@@ -1,12 +1,10 @@
-use core::ptr::NonNull;
-
 mod ecah;
 mod mem;
 
 use {
     crate::{arch, ipc::buffer::IpcBuffer, kmain::IPC_BUFFERS},
     alloc::boxed::Box,
-    core::{default, future::Future, marker::PhantomData, task::Poll},
+    core::{default, future::Future, marker::PhantomData, ptr::NonNull, task::Poll},
     hbvm::{
         mem::{
             softpaging::{icache::ICache, HandlePageFault, SoftPagedMem},
@@ -17,6 +15,7 @@ use {
     log::{debug, error, info, trace, warn},
 };
 
+const STACK_SIZE: usize = 1024 * 1024;
 const TIMER_QUOTIENT: usize = 100;
 type Vm = hbvm::Vm<mem::Memory, TIMER_QUOTIENT>;
 
@@ -41,7 +40,7 @@ impl<'p> ExecThread<'p> {
             )
         };
 
-        let stack_top = allocate_stack().as_ptr();
+        let stack_top = unsafe { allocate_stack().as_ptr().add(STACK_SIZE - 1) };
         vm.write_reg(254, stack_top as u64);
 
         ExecThread {
@@ -54,7 +53,7 @@ impl<'p> ExecThread<'p> {
 
 impl<'p> Drop for ExecThread<'p> {
     fn drop(&mut self) {
-        unsafe { alloc::alloc::dealloc(self.stack_top, stack_layout()) };
+        unsafe { alloc::alloc::dealloc(self.stack_top.sub(STACK_SIZE - 1), stack_layout()) };
     }
 }
 
@@ -111,7 +110,7 @@ impl HandlePageFault for PageFaultHandler {
 }
 
 const fn stack_layout() -> core::alloc::Layout {
-    unsafe { alloc::alloc::Layout::from_size_align_unchecked(1024 * 1024, 4096) }
+    unsafe { alloc::alloc::Layout::from_size_align_unchecked(STACK_SIZE, 4096) }
 }
 
 fn allocate_stack() -> NonNull<u8> {