From c459f19a0ca505ccaca534579e3b45e6ff0c4c06 Mon Sep 17 00:00:00 2001
From: Stefan Lankes <slankes@eonerc.rwth-aachen.de>
Date: Tue, 19 Nov 2024 15:59:35 +0100
Subject: [PATCH] zeroed stack during the initialization

- the stack initialization with dummy values isn't longer necessary
- initialization with 0 reduce the number of "memset" calls
---
 src/arch/aarch64/kernel/scheduler.rs | 4 +---
 src/arch/riscv64/kernel/scheduler.rs | 4 +---
 src/arch/x86_64/kernel/scheduler.rs  | 4 +---
 3 files changed, 3 insertions(+), 9 deletions(-)

diff --git a/src/arch/aarch64/kernel/scheduler.rs b/src/arch/aarch64/kernel/scheduler.rs
index c640ee92f3..0f1c6e8821 100644
--- a/src/arch/aarch64/kernel/scheduler.rs
+++ b/src/arch/aarch64/kernel/scheduler.rs
@@ -161,7 +161,7 @@ impl TaskStacks {
 		unsafe {
 			ptr::write_bytes(
 				(virt_addr + DEFAULT_STACK_SIZE + 2 * BasePageSize::SIZE).as_mut_ptr::<u8>(),
-				0xAC,
+				0,
 				user_stack_size,
 			);
 		}
@@ -360,8 +360,6 @@ impl TaskFrame for Task {
 			stack -= mem::size_of::<State>();
 
 			let state = stack.as_mut_ptr::<State>();
-			ptr::write_bytes(stack.as_mut_ptr::<u8>(), 0, mem::size_of::<State>());
-
 			if let Some(tls) = &self.tls {
 				(*state).tpidr_el0 = tls.thread_ptr() as u64;
 			}
diff --git a/src/arch/riscv64/kernel/scheduler.rs b/src/arch/riscv64/kernel/scheduler.rs
index 4a1e96d4c6..c748e84ab3 100644
--- a/src/arch/riscv64/kernel/scheduler.rs
+++ b/src/arch/riscv64/kernel/scheduler.rs
@@ -161,7 +161,7 @@ impl TaskStacks {
 				(virt_addr + KERNEL_STACK_SIZE + DEFAULT_STACK_SIZE + 3 * BasePageSize::SIZE)
 					//(virt_addr + KERNEL_STACK_SIZE + DEFAULT_STACK_SIZE)
 					.as_mut_ptr::<u8>(),
-				0xAC,
+				0,
 				user_stack_size,
 			);
 		}
@@ -391,8 +391,6 @@ impl TaskFrame for Task {
 			stack -= mem::size_of::<State>();
 
 			let state = stack.as_mut_ptr::<State>();
-			ptr::write_bytes(stack.as_mut_ptr::<u8>(), 0, mem::size_of::<State>());
-
 			if let Some(tls) = &self.tls {
 				(*state).tp = tls.tp().as_usize();
 			}
diff --git a/src/arch/x86_64/kernel/scheduler.rs b/src/arch/x86_64/kernel/scheduler.rs
index fe24e38290..803e349c03 100644
--- a/src/arch/x86_64/kernel/scheduler.rs
+++ b/src/arch/x86_64/kernel/scheduler.rs
@@ -147,7 +147,7 @@ impl TaskStacks {
 			ptr::write_bytes(
 				(virt_addr + IST_SIZE + DEFAULT_STACK_SIZE + 3 * BasePageSize::SIZE)
 					.as_mut_ptr::<u8>(),
-				0xAC,
+				0,
 				user_stack_size,
 			);
 		}
@@ -358,8 +358,6 @@ impl TaskFrame for Task {
 			stack -= mem::size_of::<State>();
 
 			let state = stack.as_mut_ptr::<State>();
-			ptr::write_bytes(stack.as_mut_ptr::<u8>(), 0, mem::size_of::<State>());
-
 			#[cfg(not(feature = "common-os"))]
 			if let Some(tls) = &self.tls {
 				(*state).fs = tls.thread_ptr().addr() as u64;