From e0f44e5ff5e0ead71cd08eb666b1e5499621e1dd Mon Sep 17 00:00:00 2001
From: 4lDO2 <4lDO2@protonmail.com>
Date: Thu, 11 Sep 2025 13:40:11 +0200
Subject: [PATCH] Correct chdir comment.

---
 src/platform/redox/path.rs | 12 +++---------
 1 file changed, 3 insertions(+), 9 deletions(-)

diff --git a/src/platform/redox/path.rs b/src/platform/redox/path.rs
index 9eb20eaec1..65a4fbdc5f 100644
--- a/src/platform/redox/path.rs
+++ b/src/platform/redox/path.rs
@@ -15,15 +15,8 @@ pub use redox_path::{canonicalize_using_cwd, RedoxPath};
 // TODO: Define in syscall
 const PATH_MAX: usize = 4096;
 
-// XXX: chdir is not marked thread-safe (MT-safe) by POSIX. But on Linux it is simply run as a
-// syscall and is therefore atomic, which is presumably why Rust's libstd doesn't synchronize
-// access to this.
-//
-// https://internals.rust-lang.org/t/synchronized-ffi-access-to-posix-environment-variable-functions/15475
-//
-// chdir is however signal-safe, forbidding the use of locks. We therefore call sigprocmask before
-// and after acquiring the locks. (TODO: ArcSwap? That will need to be ported to no_std first,
-// though).
+// POSIX states chdir is both thread-safe and signal-safe. Thus we need to synchronize access to CWD, but at the
+// same time forbid signal handlers from running in the meantime, to avoid reentrant deadlock.
 pub fn chdir(path: &str) -> Result<()> {
     let _siglock = tmp_disable_signals();
     let mut cwd_guard = CWD.lock();
@@ -43,6 +36,7 @@ pub fn chdir(path: &str) -> Result<()> {
     Ok(())
 }
 
+// getcwd is similarly both thread-safe and signal-safe.
 // TODO: MaybeUninit
 pub fn getcwd(buf: &mut [u8]) -> Option<usize> {
     let _siglock = tmp_disable_signals();