Race conditions on tracing globals in jit-tracing mode in ZTS

Description

While testing opcache.jit=tracing with a threading extension and valgrind --tool=drd, a good number of my extension's tests started detecting race conditions in zend_jit_trace_hot_root and some other places.

I'm seeing races in the following places:
https://github.com/php/php-src/blob/PHP-8.3.13/ext/opcache/jit/zend_jit_trace.c#L7231
https://github.com/php/php-src/blob/PHP-8.3.13/ext/opcache/jit/zend_jit_trace.c#L7701
https://github.com/php/php-src/blob/PHP-8.3.13/ext/opcache/jit/zend_jit_trace.c#L7731
https://github.com/php/php-src/blob/PHP-8.3.13/ext/opcache/jit/zend_jit_trace.c#L8033
https://github.com/php/php-src/blob/PHP-8.3.13/ext/opcache/jit/zend_jit_trace.c#L8051

https://github.com/php/php-src/blob/PHP-8.3.13/ext/opcache/jit/zend_jit.c#L5096

https://github.com/php/php-src/blob/PHP-8.3.13/ext/opcache/jit/zend_jit_vm_helpers.c#L899

and a few other places

Vast majority seem to have zend_jit_trace_hot_root() in the stack traces

I have a whole bunch of test outputs from my CI if these are any help. Unfortunately the traces are a bit jumbled up in some cases for whatever reason.

Basically it looks like races may occur if two threads try to perform tracing JIT at the same time.

test-results-8.3.13-valgrind-drd-opcache-jit-tracing.zip
from
https://github.com/pmmp/ext-pmmpthread/actions/runs/11915925430/job/33207393626

PHP Version

8.3.13

Operating System

ubuntu-20.04 (GitHub Actions)

まず、ext/opcache/jit/zend_jit_trace.c、zend_jit.c、zend_jit_vm_helpers.c の該当箇所を確認し、zend_jit_trace_hot_root と並行 tracing に注目してください。リンクされているテスト結果をコンテキストとして使用し、opcache.jit=tracing と valgrind --tool=drd で報告を再現してください。複数のスレッドが tracing JIT を実行したときに、報告された race が発生しなくなれば完了です。