From 44e18bb63daa932ed844591de4d2dbb3777d63f7 Mon Sep 17 00:00:00 2001
From: Anton Kling <anton@kling.gg>
Date: Wed, 1 May 2024 18:27:52 +0200
Subject: Bug: Kernel/MMU: Initialize memory after allocation

The memory not being zeroed caused certain flags to be set(presumably
no-cache flag) and resulted in the OS being unusually for only certain
operations and only in certain cases.
---
 kernel/arch/i386/mmu.c | 3 +++
 1 file changed, 3 insertions(+)

(limited to 'kernel/arch')

diff --git a/kernel/arch/i386/mmu.c b/kernel/arch/i386/mmu.c
index bf0d514..9802142 100644
--- a/kernel/arch/i386/mmu.c
+++ b/kernel/arch/i386/mmu.c
@@ -70,6 +70,7 @@ void *ksbrk(size_t s) {
                                          (data_end - (uintptr_t)rc))) {
     return (void *)-1;
   }
+  get_fast_insecure_random(rc, s);
   assert(((uintptr_t)rc % PAGE_SIZE) == 0);
   return (void *)rc;
 }
@@ -182,6 +183,7 @@ PageTable *clone_table(u32 src_index, PageDirectory *src_directory,
                        u32 *physical_address) {
   PageTable *new_table =
       kmalloc_align(sizeof(PageTable), (void **)physical_address);
+  memset(new_table, 0, sizeof(PageTable));
   if (!new_table) {
     return NULL;
   }
@@ -251,6 +253,7 @@ PageDirectory *clone_directory(PageDirectory *original) {
   u32 physical_address;
   PageDirectory *new_directory =
       kmalloc_align(sizeof(PageDirectory), (void **)&physical_address);
+  memset(new_directory, 0, sizeof(PageDirectory));
   if (!new_directory) {
     return NULL;
   }
-- 
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