Files
codex/codex-rs/shell-escalation
Michael Bolin 1265df0ec2 refactor: narrow async lock guard lifetimes (#18211)
Follow-up to https://github.com/openai/codex/pull/18178, where we called
out enabling the await-holding lint as a follow-up.

The long-term goal is to enable Clippy coverage for async guards held
across awaits. This PR is intentionally only the first, low-risk cleanup
pass: it narrows obvious lock guard lifetimes and leaves
`codex-rs/Cargo.toml` unchanged so the lint is not enabled until the
remaining cases are fixed or explicitly justified. It intentionally
leaves the active-turn/turn-state locking pattern alone because those
checks and mutations need to stay atomic.

## Common fixes used here

These are the main patterns reviewers should expect in this PR, and they
are also the patterns to reach for when fixing future `await_holding_*`
findings:

- **Scope the guard to the synchronous work.** If the code only needs
data from a locked value, move the lock into a small block, clone or
compute the needed values, and do the later `.await` after the block.
- **Use direct one-line mutations when there is no later await.** Cases
like `map.lock().await.remove(&id)` are acceptable when the guard is
only needed for that single mutation and the statement ends before any
async work.
- **Drain or clone work out of the lock before notifying or awaiting.**
For example, the JS REPL drains pending exec senders into a local vector
and the websocket writer clones buffered envelopes before it serializes
or sends them.
- **Use a `Semaphore` only when serialization is intentional across
async work.** The test serialization guards intentionally span awaited
setup or execution, so using a semaphore communicates "one at a time"
without holding a mutex guard.
- **Remove the mutex when there is only one owner.** The PTY stdin
writer task owns `stdin` directly; the old `Arc<Mutex<_>>` did not
protect shared access because nothing else had access to the writer.
- **Do not split locks that protect an atomic invariant.** This PR
deliberately leaves active-turn/turn-state paths alone because those
checks and mutations need to stay atomic. Those cases should be fixed
separately with a design change or documented with `#[expect]`.

## What changed

- Narrow scoped async mutex guards in app-server, JS REPL, network
approval, remote-control websocket, and the RMCP test server.
- Replace test-only async mutex serialization guards with semaphores
where the guard intentionally lives across async work.
- Let the PTY pipe writer task own stdin directly instead of wrapping it
in an async mutex.

## Verification

- `just fix -p codex-core -p codex-app-server -p codex-rmcp-client -p
codex-shell-escalation -p codex-utils-pty -p codex-utils-readiness`
- `just clippy -p codex-core`
- `cargo test -p codex-core -p codex-app-server -p codex-rmcp-client -p
codex-shell-escalation -p codex-utils-pty -p codex-utils-readiness` was
run; the app-server suite passed, and `codex-core` failed in the local
sandbox on six otel approval tests plus
`suite::user_shell_cmd::user_shell_command_does_not_set_network_sandbox_env_var`,
which appear to depend on local command approval/default rules and
`CODEX_SANDBOX_NETWORK_DISABLED=1` in this environment.
2026-04-17 14:06:50 -07:00
..

codex-shell-escalation

This crate contains the Unix shell-escalation protocol implementation and the codex-execve-wrapper executable.

codex-execve-wrapper receives the arguments to an intercepted execve(2) call and delegates the decision to the shell-escalation protocol over a shared file descriptor (specified by the CODEX_ESCALATE_SOCKET environment variable). The server on the other side replies with one of:

  • Run: codex-execve-wrapper should invoke execve(2) on itself to run the original command within the sandboxed shell.
  • Escalate: forward the file descriptors of the current process so the command can be run faithfully outside the sandbox. When the process completes, the server forwards the exit code back to codex-execve-wrapper.
  • Deny: the server has declared the proposed command to be forbidden, so codex-execve-wrapper prints an error to stderr and exits with 1.

Patched zsh

We carry a small patch to Src/exec.c (see patches/zsh-exec-wrapper.patch) that adds support for EXEC_WRAPPER. The patch applies to 77045ef899e53b9598bebc5a41db93a548a40ca6 from https://git.code.sf.net/p/zsh/code. To rebuild manually:

git clone https://git.code.sf.net/p/zsh/code
git checkout 77045ef899e53b9598bebc5a41db93a548a40ca6
git apply /path/to/patches/zsh-exec-wrapper.patch
./Util/preconfig
./configure
make -j"$(nproc)"