From c59b94d1021a9c7c9a41bb073b77b1a03a6b258f Mon Sep 17 00:00:00 2001
From: Jeremy Soller <jackpot51@gmail.com>
Date: Thu, 25 Aug 2022 19:03:49 -0600
Subject: [PATCH] Hacks to support aarch64 static TLS
---
src/ld_so/tcb.rs | 64 +++++++++++++++++++++++++-----------------------
1 file changed, 33 insertions(+), 31 deletions(-)
diff --git a/src/ld_so/tcb.rs b/src/ld_so/tcb.rs
index 404c84784..7b7f1f230 100644
--- a/src/ld_so/tcb.rs
+++ b/src/ld_so/tcb.rs
@@ -55,7 +55,7 @@ impl Tcb {
/// Create a new TCB
pub unsafe fn new(size: usize) -> Result<&'static mut Self> {
let page_size = Sys::getpagesize();
- let (tls, tcb_page) = Self::os_new(round_up(size, page_size))?;
+ let (abi_page, tls, tcb_page) = Self::os_new(round_up(size, page_size))?;
let tcb_ptr = tcb_page.as_mut_ptr() as *mut Self;
trace!("New TCB: {:p}", tcb_ptr);
@@ -123,8 +123,14 @@ impl Tcb {
.filter(|m| m.len > 0)
.enumerate()
{
- let range =
- self.tls_len - master.offset..self.tls_len - master.offset + master.len;
+ let range = if cfg!(any(target_arch = "x86", target_arch = "x86_64")) {
+ // x86 TLS layout is backwards
+ self.tls_len - master.offset..self.tls_len - master.offset + master.len
+ } else {
+ //TODO: fix aarch64 TLS layout when there is more than one master
+ assert_eq!(i, 0, "aarch64 TLS layout only supports one master");
+ 0..master.len
+ };
if let Some(tls_data) = tls.get_mut(range) {
let data = master.data();
trace!(
@@ -165,7 +171,7 @@ impl Tcb {
/// Activate TLS
pub unsafe fn activate(&mut self) {
- Self::os_arch_activate(self.tcb_ptr as usize);
+ Self::os_arch_activate(self.tls_end as usize, self.tls_len);
}
/// Mapping with correct flags for TCB and TLS
@@ -189,23 +195,26 @@ impl Tcb {
/// OS specific code to create a new TLS and TCB - Linux and Redox
#[cfg(any(target_os = "linux", target_os = "redox"))]
- unsafe fn os_new(size: usize) -> Result<(&'static mut [u8], &'static mut [u8])> {
+ unsafe fn os_new(size: usize) -> Result<(&'static mut [u8], &'static mut [u8], &'static mut [u8])> {
let page_size = Sys::getpagesize();
- let tls_tcb = Self::map(size + page_size)?;
- Ok(tls_tcb.split_at_mut(size))
+ let abi_tls_tcb = Self::map(page_size + size + page_size)?;
+ let (abi, tls_tcb) = abi_tls_tcb.split_at_mut(page_size);
+ let (tls, tcb) = tls_tcb.split_at_mut(size);
+ Ok((abi, tls, tcb))
}
/// Architecture specific code to read a usize from the TCB - aarch64
#[inline(always)]
#[cfg(target_arch = "aarch64")]
unsafe fn arch_read(offset: usize) -> usize {
- let tp: usize;
+ let abi_ptr: usize;
asm!(
"mrs {}, tpidr_el0",
- out(reg) tp,
+ out(reg) abi_ptr,
);
- *((tp + offset) as *const usize)
+ let tcb_ptr = *(abi_ptr as *const usize);
+ *((tcb_ptr + offset) as *const usize)
}
/// Architecture specific code to read a usize from the TCB - x86
@@ -240,33 +249,26 @@ impl Tcb {
/// OS and architecture specific code to activate TLS - Linux x86_64
#[cfg(all(target_os = "linux", target_arch = "x86_64"))]
- unsafe fn os_arch_activate(tp: usize) {
+ unsafe fn os_arch_activate(tls_end: usize, _tls_len: usize) {
const ARCH_SET_FS: usize = 0x1002;
- syscall!(ARCH_PRCTL, ARCH_SET_FS, tp);
+ syscall!(ARCH_PRCTL, ARCH_SET_FS, tls_end);
}
/// OS and architecture specific code to activate TLS - Redox aarch64
#[cfg(all(target_os = "redox", target_arch = "aarch64"))]
- unsafe fn os_arch_activate(tp: usize) {
- let mut env = syscall::EnvRegisters::default();
-
- let file = syscall::open("thisproc:current/regs/env", syscall::O_CLOEXEC | syscall::O_RDWR)
- .expect_notls("failed to open handle for process registers");
-
- let _ = syscall::read(file, &mut env)
- .expect_notls("failed to read thread pointer");
-
- env.tpidr_el0 = tp;
-
- let _ = syscall::write(file, &env)
- .expect_notls("failed to write thread pointer");
-
- let _ = syscall::close(file);
+ unsafe fn os_arch_activate(tls_end: usize, tls_len: usize) {
+ // Uses ABI page
+ let abi_ptr = tls_end - tls_len - 16;
+ ptr::write(abi_ptr as *mut usize, tls_end);
+ asm!(
+ "msr tpidr_el0, {}",
+ in(reg) abi_ptr,
+ );
}
/// OS and architecture specific code to activate TLS - Redox x86
#[cfg(all(target_os = "redox", target_arch = "x86"))]
- unsafe fn os_arch_activate(tp: usize) {
+ unsafe fn os_arch_activate(tls_end: usize, _tls_len: usize) {
let mut env = syscall::EnvRegisters::default();
let file = syscall::open("thisproc:current/regs/env", syscall::O_CLOEXEC | syscall::O_RDWR)
@@ -275,7 +277,7 @@ impl Tcb {
let _ = syscall::read(file, &mut env)
.expect_notls("failed to read gsbase");
- env.gsbase = tp as u32;
+ env.gsbase = tls_end as u32;
let _ = syscall::write(file, &env)
.expect_notls("failed to write gsbase");
@@ -285,7 +287,7 @@ impl Tcb {
/// OS and architecture specific code to activate TLS - Redox x86_64
#[cfg(all(target_os = "redox", target_arch = "x86_64"))]
- unsafe fn os_arch_activate(tp: usize) {
+ unsafe fn os_arch_activate(tls_end: usize, _tls_len: usize) {
let mut env = syscall::EnvRegisters::default();
let file = syscall::open("thisproc:current/regs/env", syscall::O_CLOEXEC | syscall::O_RDWR)
@@ -294,7 +296,7 @@ impl Tcb {
let _ = syscall::read(file, &mut env)
.expect_notls("failed to read fsbase");
- env.fsbase = tp as u64;
+ env.fsbase = tls_end as u64;
let _ = syscall::write(file, &env)
.expect_notls("failed to write fsbase");
--
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