From 5351ccf03820155a2b866fa8fde0d3024d3b4ae6 Mon Sep 17 00:00:00 2001
From: Mark Poliakov <mark@alnyan.me>
Date: Fri, 15 Sep 2023 00:09:26 +0300
Subject: [PATCH] x86-64: fix some loop {}s

---
 src/arch/x86_64/mem/mod.rs | 16 +++++++++-------
 src/arch/x86_64/mod.rs     |  9 ++++++---
 2 files changed, 15 insertions(+), 10 deletions(-)

diff --git a/src/arch/x86_64/mem/mod.rs b/src/arch/x86_64/mem/mod.rs
index 177bf25d..7aabcd9c 100644
--- a/src/arch/x86_64/mem/mod.rs
+++ b/src/arch/x86_64/mem/mod.rs
@@ -15,7 +15,7 @@ use crate::{
     mem::{
         address::{FromRaw, IntoRaw, KernelImageObject},
         device::RawDeviceMemoryMapping,
-        table::{EntryLevel, KernelAddressSpace, MapAttributes},
+        table::EntryLevel,
         PhysicalAddress, KERNEL_VIRT_OFFSET,
     },
 };
@@ -96,12 +96,12 @@ unsafe fn map_early_pages(physical: PhysicalAddress, count: usize) -> Result<usi
         return Ok(EARLY_MAPPING_OFFSET + l3i * L3::SIZE);
     }
 
-    loop {}
+    Err(Error::OutOfMemory)
 }
 
 unsafe fn unmap_early_page(address: usize) {
     if address < EARLY_MAPPING_OFFSET || address >= EARLY_MAPPING_OFFSET + L2::SIZE {
-        loop {}
+        panic!("Tried to unmap invalid early mapping: {:#x}", address);
     }
 
     let l3i = L3::index(address - EARLY_MAPPING_OFFSET);
@@ -135,7 +135,8 @@ unsafe fn map_device_memory_l3(base: PhysicalAddress, count: usize) -> Result<us
 
         return Ok(DEVICE_MAPPING_OFFSET + i * L3::SIZE);
     }
-    loop {}
+
+    Err(Error::OutOfMemory)
 }
 
 unsafe fn map_device_memory_l2(base: PhysicalAddress, count: usize) -> Result<usize, Error> {
@@ -159,7 +160,8 @@ unsafe fn map_device_memory_l2(base: PhysicalAddress, count: usize) -> Result<us
         );
         return Ok(DEVICE_MAPPING_OFFSET + i * L2::SIZE);
     }
-    loop {}
+
+    Err(Error::OutOfMemory)
 }
 
 pub(super) unsafe fn map_device_memory(
@@ -226,12 +228,12 @@ pub(super) unsafe fn unmap_device_memory(map: &RawDeviceMemoryMapping) {
 
 pub(super) unsafe fn map_heap_block(index: usize, page: PhysicalAddress) {
     if L2::page_offset(page.into_raw()) != 0 {
-        loop {}
+        panic!("Attempted to map a misaligned 2MiB page");
     }
     assert!(index < 512);
 
     if HEAP_MAPPING_L2[index].is_present() {
-        loop {}
+        panic!("Page is already mappged: {:#x}", page);
     }
 
     // TODO NX
diff --git a/src/arch/x86_64/mod.rs b/src/arch/x86_64/mod.rs
index e417b8f2..41ea60f0 100644
--- a/src/arch/x86_64/mod.rs
+++ b/src/arch/x86_64/mod.rs
@@ -173,7 +173,10 @@ impl Architecture for X86_64 {
         let end_l1i = (IntoRaw::<usize>::into_raw(memory_end) + (1 << 30) - 1) >> 30;
 
         if end_l1i > 512 {
-            loop {}
+            todo!(
+                "Cannot handle {}GiB of RAM",
+                end_l1i * L1::SIZE / (1024 * 1024 * 1024)
+            );
         }
 
         MEMORY_LIMIT.init(memory_end.into_raw());
@@ -196,7 +199,7 @@ impl Architecture for X86_64 {
 
             Ok(())
         } else {
-            loop {}
+            todo!();
         }
     }
 
@@ -235,7 +238,7 @@ impl Architecture for X86_64 {
 
 impl X86_64 {
     unsafe fn handle_ipi(&self, msg: CpuMessage) {
-        loop {}
+        todo!()
     }
 
     fn set_boot_data(&self, data: BootData) {