[php-src] Issue #7817: JIT segmentation fault in PHP 8.1

Issue: https://github.com/php/php-src/issues/7817 Comment Author: kvas-damian We had a similar problem after upgrade to PHP 8.1.3 - before we used PHP 8.0.3 without problems. In our case, Laravel8 app based on PHP-FPM is hosted in Kubernetes. K8s cluster is based on N2D instances with 3rd Gen AMD EPYC processors. Dockerfile which started the problem for us is following: ``` FROM composer:2.1.12 AS php-composer FROM php:8.1.3-fpm-alpine3.15 USER root RUN apk --no-cache add --virtual .build-deps \ build-base \ && apk --no-cache add libpng-dev libzip-dev libjpeg-turbo-dev freetype-dev \ && docker-php-ext-configure gd \ --with-freetype \ --with-jpeg \ && docker-php-ext-install -j$(nproc) bcmath gd zip mysqli pdo_mysql sockets \ && docker-php-ext-enable opcache \ && echo $'zend_extension=opcache\n\ [opcache]\n\ opcache.enable=1\n\ opcache.enable_cli=1\n\ opcache.validate_timestamps=0\n\ opcache.max_accelerated_files=10000\n\ opcache.memory_consumption=128\n\ opcache.max_wasted_percentage=10\n\ opcache.interned_strings_buffer=16\n\ opcache.fast_shutdown=1\n\ opcache.jit_buffer_size=100M' > /usr/local/etc/php/conf.d/docker-php-ext-opcache.ini \ && apk del .build-deps # copy composer from the first stage COPY --from=php-composer /usr/bin/composer /usr/bin RUN composer --ansi --version --no-interaction; php -v; php -m; php -r 'var_export(gd_info()); echo PHP_EOL; var_export(opcache_get_status());' ``` **From ~20 identical pods, only 2 were segfaulting, for all requests**. We found following entries in our logs: ``` [4539894.358435] php-fpm[3056477]: segfault at 8 ip 0000000048d82054 sp 00007ffe99621df0 error 4 in zero (deleted)[48d19000+6400000]\r\n WARNING: [pool www] child 792 exited on signal 11 (SIGSEGV) after 15.030120 seconds from start ``` Change from JIT tracing to function (opcache.jit=1205) solved the problem. I hope it helps you find the root cause.