research: add ptrace compatibility results for Copilot coding-agent environment

[Copilot]

Motivation

Verify that ptrace (attach, word I/O, process_vm_*, mmap injection via PTRACE_CONT) works correctly in the Copilot Coding Agent execution environment, and document the findings for the inject_demo / fspy development context.

Changes

• research/copilot-coding-agent-ptrace-current-results.md — new report containing:
  • Commit SHA and source grep verification (required-summary, ptrace-word-io, ptrace::cont, patch_syscall_and_trap; confirmed no ptrace::step)
  • Full environment snapshot: kernel 6.17.0-1022-azure, Ubuntu 24.04.4, Azure VM (systemd-detect-virt: microsoft), uid=1001, CapEff=0, NoNewPrivs=0, Seccomp=0, Yama scope=1, no container
  • ptrace-environment-probe compile (exit 0) and run results: required-summary PASS, exit 0; ptrace-word-io PASS; process-vm-* PASS (tracked separately); three expected Yama-scope-1 relationship failures documented
  • rustup target add x86_64-unknown-none (the one permitted setup action; target was absent)
  • cargo run --locked -p inject_demo full output and exit 0; confirms PTRACE_CONT + syscall+trap patch path, not SINGLESTEP; payload mapped, SIGSYS interception active, child /bin/cat exited 0

Conclusion: ptrace is fully functional in this environment. All required checks pass.

Original prompt

Run a second, self-contained direct ptrace compatibility experiment in this GitHub Copilot coding-agent environment. The earlier attempt's injector build exited 101 only because the Rust target component was absent. This task explicitly permits the single ephemeral build-dependency action "rustup target add x86_64-unknown-none" if rustup target list --installed does not already show it. Do not use sudo or apt, install anything else, add capabilities, change seccomp/Yama, create credentials, or launch GitHub Actions. Do not edit product code or workflows.\n\nUse the ordinary agent user. Report git rev-parse HEAD and verify current source:\ngrep -nE 'required-summary|ptrace-word-io' research/ptrace-environment-probe.c\ngrep -nE 'ptrace::(cont|step)|patch_syscall_and_trap' crates/inject_demo/src/main.rs\nAbort if remote_mmap uses ptrace::step.\n\nCapture uname -a, /etc/os-release, id, CapEff/NoNewPrivs/Seccomp/Seccomp_filters, Yama value/read failure, both cgroup files, container marker presence, and systemd-detect-virt output/exit.\n\nCompile and run:\ngcc -O2 -Wall -Wextra -Werror research/ptrace-environment-probe.c -o /tmp/ptrace-environment-probe\nCapture compile exit, full output, and exact run exit. Required success needs both required-summary PASS and exit 0. Keep process_vm_* separate from required ptrace-word-io and distinguish expected relationship failures.\n\nBefore the injector, print rustup target list --installed. Only if missing, run:\nrustup target add x86_64-unknown-none\nCapture exact exit. Then run:\ncargo run --locked -p inject_demo\nCapture complete stdout/stderr and exact exit. Confirm this is PTRACE_CONT plus syscall+trap, not SINGLESTEP.\n\nWrite only research/copilot-coding-agent-ptrace-current-results.md with exact commands, relevant exact outputs/exits, commit SHA, direct Copilot execution identity, and the allowed one-component setup. Commit only that report. Preserve any blocker exactly and do not infer ptrace failure from build/setup errors.

[wan9chi]

Experiment captured in the consolidated local research note; closing the temporary Copilot task PR. The shared strict base branch remains for reproduction.