From ed2febb28990982624e5d41c5bccd5bf8f22af08 Mon Sep 17 00:00:00 2001
From: 4lDO2 <4lDO2@protonmail.com>
Date: Tue, 11 Jul 2023 16:18:20 +0200
Subject: [PATCH] Disable thread-local storage entirely.
---
linkers/i686.ld | 13 -------------
linkers/x86_64.ld | 11 -----------
src/arch/x86/gdt.rs | 27 +--------------------------
src/arch/x86_64/gdt.rs | 28 ++--------------------------
src/lib.rs | 2 +-
targets/x86_64-unknown-kernel.json | 3 +--
6 files changed, 5 insertions(+), 79 deletions(-)
diff --git a/linkers/i686.ld b/linkers/i686.ld
index 386ceff5..0405e100 100644
--- a/linkers/i686.ld
+++ b/linkers/i686.ld
@@ -33,19 +33,6 @@ SECTIONS {
. = ALIGN(4K);
}
- .tdata ALIGN(4K) : AT(ADDR(.tdata) - KERNEL_OFFSET) {
- __bss_end = .;
- __tdata_start = .;
- *(.tdata*)
- . = ALIGN(4K);
- __tdata_end = .;
- __tbss_start = .;
- *(.tbss*)
- . += 8;
- . = ALIGN(4K);
- __tbss_end = .;
- }
-
__end = .;
/DISCARD/ : {
diff --git a/linkers/x86_64.ld b/linkers/x86_64.ld
index fc8a626d..9f90acf8 100644
--- a/linkers/x86_64.ld
+++ b/linkers/x86_64.ld
@@ -32,17 +32,6 @@ SECTIONS {
*(.bss*)
}
- .tdata ALIGN(4K) : AT(ADDR(.tdata) - KERNEL_OFFSET) {
- __bss_end = .;
- __tdata_start = .;
- *(.tdata*)
- __tdata_end = .;
- __tbss_start = .;
- *(.tbss*)
- . = ALIGN(4K);
- __tbss_end = .;
- }
-
__end = .;
/DISCARD/ : {
diff --git a/src/arch/x86/gdt.rs b/src/arch/x86/gdt.rs
index b3dc9d5e..fb73e23a 100644
--- a/src/arch/x86/gdt.rs
+++ b/src/arch/x86/gdt.rs
@@ -74,10 +74,9 @@ const BASE_GDT: [GdtEntry; 9] = [
#[repr(C, align(4096))]
pub struct ProcessorControlRegion {
- pub tcb_end: usize,
+ pub self_ref: usize,
pub user_rsp_tmp: usize,
pub tss: TssWrapper,
- pub self_ref: usize,
pub gdt: [GdtEntry; 9],
percpu: crate::percpu::PercpuBlock,
}
@@ -138,8 +137,6 @@ pub unsafe fn init_paging(stack_offset: usize, cpu_id: usize) {
base: pcr.gdt.as_ptr() as *const SegmentDescriptor,
};
- pcr.tcb_end = init_percpu();
-
{
let tss = &pcr.tss.0 as *const _ as usize as u32;
@@ -172,28 +169,6 @@ pub unsafe fn init_paging(stack_offset: usize, cpu_id: usize) {
};
}
-// TODO: Share code with x86. Maybe even with aarch64?
-/// Copy tdata, clear tbss, calculate TCB end pointer
-#[cold]
-unsafe fn init_percpu() -> usize {
- use crate::kernel_executable_offsets::*;
-
- let size = __tbss_end() - __tdata_start();
- assert_eq!(size % PAGE_SIZE, 0);
-
- let tbss_offset = __tbss_start() - __tdata_start();
-
- let base_frame = crate::memory::allocate_frames(size / PAGE_SIZE).expect("failed to allocate percpu memory");
- let base = RmmA::phys_to_virt(base_frame.start_address());
-
- let tls_end = base.data() + size;
-
- core::ptr::copy_nonoverlapping(__tdata_start() as *const u8, base.data() as *mut u8, tbss_offset);
- core::ptr::write_bytes((base.data() + tbss_offset) as *mut u8, 0, size - tbss_offset);
-
- tls_end
-}
-
#[derive(Copy, Clone, Debug)]
#[repr(packed)]
pub struct GdtEntry {
diff --git a/src/arch/x86_64/gdt.rs b/src/arch/x86_64/gdt.rs
index 411386e8..5add48cb 100644
--- a/src/arch/x86_64/gdt.rs
+++ b/src/arch/x86_64/gdt.rs
@@ -3,7 +3,7 @@
use core::convert::TryInto;
use core::mem;
-use crate::paging::{PAGE_SIZE, RmmA, RmmArch};
+use crate::paging::{RmmA, RmmArch};
use crate::percpu::PercpuBlock;
use x86::bits64::task::TaskStateSegment;
@@ -74,12 +74,11 @@ const BASE_GDT: [GdtEntry; 8] = [
pub struct ProcessorControlRegion {
// TODO: When both KASLR and KPTI are implemented, the PCR may need to be split into two pages,
// such that "secret" kernel addresses are only stored in the protected half.
+ pub self_ref: usize,
- pub tcb_end: usize,
pub user_rsp_tmp: usize,
// TODO: The I/O permissions bitmap can require more than 8192 bytes of space.
pub tss: TaskStateSegment,
- pub self_ref: usize,
// The GDT *must* be stored in the PCR! The paranoid interrupt handler, lacking a reliable way
// to correctly obtain GSBASE, uses SGDT to calculate the PCR offset.
pub gdt: [GdtEntry; 8],
@@ -164,8 +163,6 @@ pub unsafe fn init_paging(stack_offset: usize, cpu_id: usize) {
base,
};
- pcr.tcb_end = init_percpu();
-
{
pcr.tss.iomap_base = 0xFFFF;
@@ -220,27 +217,6 @@ pub unsafe fn init_paging(stack_offset: usize, cpu_id: usize) {
};
}
-/// Copy tdata, clear tbss, calculate TCB end pointer
-#[cold]
-unsafe fn init_percpu() -> usize {
- use crate::kernel_executable_offsets::*;
-
- let size = __tbss_end() - __tdata_start();
- assert_eq!(size % PAGE_SIZE, 0);
-
- let tbss_offset = __tbss_start() - __tdata_start();
-
- let base_frame = crate::memory::allocate_frames(size / PAGE_SIZE).expect("failed to allocate percpu memory");
- let base = RmmA::phys_to_virt(base_frame.start_address());
-
- let tls_end = base.data() + size;
-
- core::ptr::copy_nonoverlapping(__tdata_start() as *const u8, base.data() as *mut u8, tbss_offset);
- core::ptr::write_bytes((base.data() + tbss_offset) as *mut u8, 0, size - tbss_offset);
-
- tls_end
-}
-
#[derive(Copy, Clone, Debug)]
#[repr(packed)]
pub struct GdtEntry {
diff --git a/src/lib.rs b/src/lib.rs
index e4fcae03..e743be86 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -282,5 +282,5 @@ macro_rules! linker_offsets(
}
);
pub mod kernel_executable_offsets {
- linker_offsets!(__text_start, __text_end, __rodata_start, __rodata_end, __data_start, __data_end, __bss_start, __bss_end, __tdata_start, __tdata_end, __tbss_start, __tbss_end, __usercopy_start, __usercopy_end);
+ linker_offsets!(__text_start, __text_end, __rodata_start, __rodata_end, __data_start, __data_end, __bss_start, __bss_end, __usercopy_start, __usercopy_end);
}
diff --git a/targets/x86_64-unknown-kernel.json b/targets/x86_64-unknown-kernel.json
index 1ab209b0..db03c07d 100644
--- a/targets/x86_64-unknown-kernel.json
+++ b/targets/x86_64-unknown-kernel.json
@@ -23,6 +23,5 @@
"exe-suffix": "",
"has-rpath": false,
"no-default-libraries": true,
- "position-independent-executables": false,
- "tls-model": "global-dynamic"
+ "position-independent-executables": false
}
--
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