fix(fspy): avoid recursive syscall initialization

[fengmk2]

Motivation

Concurrent calls to syscall can make tracked Linux programs, such as pnpm dlx, abort with a stack overflow. LazyLock waits through futex, which calls the same syscall hook before its initialization completes.

The hook now sends system calls directly to the kernel and preserves libc return values and errno.

Fixes the stack overflow in the Vite+ create job.

[github-actions]

fspy benchmark

linux

dynamic/launch             change  +0.68%  [ -9.21% ..  +9.67%]  overhead   +49.67%
dynamic/access             change  -0.57%  [-17.30% ..  +6.38%]  overhead   +13.20%
dynamic/access-relative    change  -1.14%  [-15.54% .. +10.52%]  overhead   +58.38%
dynamic/access-contended   change  +0.32%  [-11.93% .. +13.57%]  overhead   +22.39%
static/launch              change  +0.02%  [ -4.23% ..  +5.78%]  overhead  +180.02%
static/access              change  +0.25%  [ -1.73% ..  +1.99%]  overhead  +810.50%
static/access-relative     change  +0.89%  [ -2.60% ..  +5.00%]  overhead +1343.52%
static/access-contended    change  +0.06%  [ -3.21% ..  +2.05%]  overhead +3237.29%

macos

dynamic/launch             change  +0.32%  [ -1.60% ..  +2.81%]  overhead  +223.27%
dynamic/access             change  +0.48%  [ -1.89% ..  +2.69%]  overhead    +4.53%
dynamic/access-relative    change  +0.00%  [ -1.83% ..  +2.84%]  overhead  +244.26%
dynamic/access-contended   change  +1.30%  [ -0.74% ..  +3.08%]  overhead    +0.62%

windows

dynamic/launch             change  -0.65%  [-12.26% .. +11.68%]  overhead   +32.21%
dynamic/access             change  +0.21%  [ -2.23% ..  +3.79%]  overhead    +2.59%
dynamic/access-relative    change  +0.00%  [ -2.64% ..  +1.64%]  overhead    +1.68%
dynamic/access-contended   change  +1.00%  [ -3.14% .. +23.48%]  overhead    +1.84%

[fengmk2]

@codex review

[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-10-14T13:29:53.795031Z	a63dea0	Manual request

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[chatgpt-codex-connector]

Codex Review: Didn't find any major issues. Bravo.

Reviewed commit: a63dea0e36

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