From 83f89912e0f9e9e2b62743b1a3d9080ada280a52 Mon Sep 17 00:00:00 2001
From: Jeremy Soller <jeremy@system76.com>
Date: Sat, 20 Apr 2019 10:36:18 -0600
Subject: [PATCH] Do not copy kernel-allocated TLS
---
src/ld_so/tcb.rs | 13 +++++++------
src/platform/pte.rs | 14 +++++++++-----
2 files changed, 16 insertions(+), 11 deletions(-)
diff --git a/src/ld_so/tcb.rs b/src/ld_so/tcb.rs
index 643e5122..662ef4c5 100644
--- a/src/ld_so/tcb.rs
+++ b/src/ld_so/tcb.rs
@@ -55,6 +55,7 @@ impl Tcb {
let (tls, tcb_page) = Self::os_new(size)?;
let tcb_ptr = tcb_page.as_mut_ptr() as *mut Self;
+ // println!("New TCB: {:p}", tcb_ptr);
ptr::write(tcb_ptr, Self {
tls_end: tls.as_mut_ptr().add(tls.len()),
tls_len: tls.len(),
@@ -111,12 +112,12 @@ impl Tcb {
let range = master.range();
let data = master.data();
if let Some(tls_data) = tls.get_mut(range) {
- println!(
- "tls master {}: {:p}, {:#x}: {:p}, {:#x}",
- i,
- data.as_ptr(), data.len(),
- tls_data.as_mut_ptr(), tls_data.len()
- );
+ // println!(
+ // "tls master {}: {:p}, {:#x}: {:p}, {:#x}",
+ // i,
+ // data.as_ptr(), data.len(),
+ // tls_data.as_mut_ptr(), tls_data.len()
+ // );
tls_data.copy_from_slice(data);
} else {
diff --git a/src/platform/pte.rs b/src/platform/pte.rs
index 2a4bf5e9..2948f76d 100644
--- a/src/platform/pte.rs
+++ b/src/platform/pte.rs
@@ -68,11 +68,15 @@ unsafe extern "C" fn pte_osThreadShim(
tls_masters_ptr: *mut Master,
tls_masters_len: usize
) {
- let mut tcb = Tcb::new(tls_size).unwrap();
- tcb.masters_ptr = tls_masters_ptr;
- tcb.masters_len = tls_masters_len;
- tcb.copy_masters().unwrap();
- tcb.activate();
+ // The kernel allocated TLS does not have masters set, so do not attempt to copy it.
+ // It will be copied by the kernel.
+ if ! tls_masters_ptr.is_null() {
+ let mut tcb = Tcb::new(tls_size).unwrap();
+ tcb.masters_ptr = tls_masters_ptr;
+ tcb.masters_len = tls_masters_len;
+ tcb.copy_masters().unwrap();
+ tcb.activate();
+ }
// Wait until pte_osThreadStart
pte_osMutexLock(mutex);
--
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