From 413238a0a65dc03b9964843523ddd96ffc29276f Mon Sep 17 00:00:00 2001
From: Jeremy Soller <jackpot51@gmail.com>
Date: Mon, 7 Feb 2022 16:36:05 -0700
Subject: [PATCH] Prevent re-use of real mode areas, adjust areas instead of
panic
---
src/arch/x86_64/rmm.rs | 36 ++++++++++++++++++++++++++++--------
1 file changed, 28 insertions(+), 8 deletions(-)
diff --git a/src/arch/x86_64/rmm.rs b/src/arch/x86_64/rmm.rs
index e043fc73..d36d9632 100644
--- a/src/arch/x86_64/rmm.rs
+++ b/src/arch/x86_64/rmm.rs
@@ -1,3 +1,4 @@
+use core::cmp;
use rmm::{
KILOBYTE,
MEGABYTE,
@@ -223,21 +224,21 @@ pub unsafe fn init(
) {
type A = RmmA;
+ let real_base = 0;
+ let real_size = 0x100000;
+ let real_end = real_base + real_size;
+
let kernel_size_aligned = ((kernel_size + (A::PAGE_SIZE - 1))/A::PAGE_SIZE) * A::PAGE_SIZE;
let kernel_end = kernel_base + kernel_size_aligned;
- println!("kernel_end: {:X}", kernel_end);
let stack_size_aligned = ((stack_size + (A::PAGE_SIZE - 1))/A::PAGE_SIZE) * A::PAGE_SIZE;
let stack_end = stack_base + stack_size_aligned;
- println!("stack_end: {:X}", stack_end);
let env_size_aligned = ((env_size + (A::PAGE_SIZE - 1))/A::PAGE_SIZE) * A::PAGE_SIZE;
let env_end = env_base + env_size_aligned;
- println!("env_end: {:X}", env_end);
let acpi_size_aligned = ((acpi_size + (A::PAGE_SIZE - 1))/A::PAGE_SIZE) * A::PAGE_SIZE;
let acpi_end = acpi_base + acpi_size_aligned;
- println!("acpi_end: {:X}", acpi_end);
// Copy memory map from bootloader location, and page align it
let mut area_i = 0;
@@ -266,24 +267,43 @@ pub unsafe fn init(
size &= !A::PAGE_OFFSET_MASK;
println!(" => {:X}:{:X}", base, size);
+ let mut new_base = base;
+
+ // Ensure real-mode areas are not used
+ if base < real_end && base + size > real_base {
+ println!("{:X}:{:X} overlaps with real mode {:X}:{:X}", base, size, real_base, real_size);
+ new_base = cmp::max(new_base, real_end);
+ }
+
// Ensure kernel areas are not used
if base < kernel_end && base + size > kernel_base {
- panic!("{:X}:{:X} overlaps with kernel {:X}:{:X}", base, size, kernel_base, kernel_size);
+ println!("{:X}:{:X} overlaps with kernel {:X}:{:X}", base, size, kernel_base, kernel_size);
+ new_base = cmp::max(new_base, kernel_end);
}
// Ensure stack areas are not used
if base < stack_end && base + size > stack_base {
- panic!("{:X}:{:X} overlaps with stack {:X}:{:X}", base, size, stack_base, stack_size);
+ println!("{:X}:{:X} overlaps with stack {:X}:{:X}", base, size, stack_base, stack_size);
+ new_base = cmp::max(new_base, stack_end);
}
// Ensure env areas are not used
if base < env_end && base + size > env_base {
- panic!("{:X}:{:X} overlaps with env {:X}:{:X}", base, size, env_base, env_size);
+ println!("{:X}:{:X} overlaps with env {:X}:{:X}", base, size, env_base, env_size);
+ new_base = cmp::max(new_base, env_end);
}
// Ensure acpi areas are not used
if base < acpi_end && base + size > acpi_base {
- panic!("{:X}:{:X} overlaps with acpi {:X}:{:X}", base, size, acpi_base, acpi_size);
+ println!("{:X}:{:X} overlaps with acpi {:X}:{:X}", base, size, acpi_base, acpi_size);
+ new_base = cmp::max(new_base, acpi_end);
+ }
+
+ if new_base != base {
+ let end = base + size;
+ base = new_base;
+ size = end.checked_sub(base).unwrap_or(0);
+ println!("moved to {:X}:{:X}", base, size);
}
if size == 0 {
--
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