Newsgroups: php.internals Path: news.php.net Xref: news.php.net php.internals:108317 Return-Path: Delivered-To: mailing list internals@lists.php.net Received: (qmail 98783 invoked from network); 29 Jan 2020 12:48:54 -0000 Received: from unknown (HELO php-smtp4.php.net) (45.112.84.5) by pb1.pair.com with SMTP; 29 Jan 2020 12:48:54 -0000 Received: from php-smtp4.php.net (localhost [127.0.0.1]) by php-smtp4.php.net (Postfix) with ESMTP id E14F71804D1 for ; Wed, 29 Jan 2020 02:59:32 -0800 (PST) X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on php-smtp4.php.net X-Spam-Level: X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM,HTML_MESSAGE, RCVD_IN_DNSWL_NONE,RCVD_IN_MSPIKE_H2,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.2 X-Spam-ASN: AS15169 209.85.128.0/17 X-Spam-Virus: No X-Envelope-From: Received: from mail-lj1-f182.google.com (mail-lj1-f182.google.com [209.85.208.182]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by php-smtp4.php.net (Postfix) with ESMTPS for ; Wed, 29 Jan 2020 02:59:32 -0800 (PST) Received: by mail-lj1-f182.google.com with SMTP id n18so17929664ljo.7 for ; Wed, 29 Jan 2020 02:59:32 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=eXvSqJNsFjaw1FYfXCrTM4dwqfz1gg7AnqXUNba5PLE=; b=QdOdscgeAkatVQ/ncIE+sCQlt+XOOu26plJkGMUgKnaor9k89ZDXHr9rcmrgyngXaw c3TVpDpevvoUFNmVdLU7tVagOaERBaSDYYUzZG4/idSCRX0B/gaN4gI9oBbs3T0Czh6p XVxzweoQmns+1LcraK7d3+jtvR6FERI1GuQYrhQUfhTjs+xiFQEnDt0SzYfEUk6HV1xF x8Ue1wfmwaKOmTb/4pTFoc92opO5Sq/+vz6uBeuu8o6fL9g6YZe7kiqsgSYKS4f+lYcF fNhklQ4JqOd/HWRXBxc1meB6dsjBLrmrd9ykzXYzqVJJDoKkwqbpp4HRWzvoRQIHUpZy Qjtg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=eXvSqJNsFjaw1FYfXCrTM4dwqfz1gg7AnqXUNba5PLE=; b=GtKGtXtM1xgll4FvmDhuZncffwjksMXEW1qxT877uZD1tuLfProcszycJeo5jmQSb6 lzVbkp2NKZuHqq4YgU2b3ZNghFw8LzNTWi+Z8MvAvkkocOE2BcEJNWK+hL8kxk61Vd7F RvcFEcmTR+VfxklWSUNScKSKysdFuxfJsDRv9L1um6FG7fJzrdLLqwYvFYqyTclzrCz8 phPu+lsS3xEi/AkEpnyHtDnY+RruYeOVjT6B8GGB75gH8bZQvkeydlAXl4h5Q4LHmYZ7 KuvfTGYRU9lhy7fbzLx8VPgHEIgiz7odGleR6kKUyIYcETh9G9hKIpU0VZmX+iV/IUZU sJag== X-Gm-Message-State: APjAAAVKOWEh9G0h6k3NMICDUtthTHw20UDAPgbVxTeLWAXEuPaqBKnx IiooOlXF+Na84DfJdFfnmv+beIQN0su2FTC1ZGvcDtcvqnI= X-Google-Smtp-Source: APXvYqzrrLeryPWvz/j9eCIiM9ld21JBdZQHPNg531PKSV4Z6Ib/Ofu9n1tXfgAwjkiK3vjcm28YFVrwRBcT80P//ZM= X-Received: by 2002:a2e:2e11:: with SMTP id u17mr15631158lju.117.1580295571017; Wed, 29 Jan 2020 02:59:31 -0800 (PST) MIME-Version: 1.0 References: In-Reply-To: Date: Wed, 29 Jan 2020 11:59:15 +0100 Message-ID: To: Benjamin Morel Cc: PHP Internals Content-Type: multipart/alternative; boundary="000000000000269164059d453c96" Subject: Re: [PHP-DEV] How to debug a segmentation fault? From: nikita.ppv@gmail.com (Nikita Popov) --000000000000269164059d453c96 Content-Type: text/plain; charset="UTF-8" On Tue, Jan 28, 2020 at 5:29 PM Benjamin Morel wrote: > Hi internals, > > I'm encountering a SIGSEGV in PHP-FPM on PHP 7.4.2 in a Symfony app. The > bug seems to happen during the rendering of a Twig template; this makes it > hard for me to pinpoint the code that triggers the segfault. > > Could you please tell me what the procedure to collect information is, so > that I can file a useful bug report? > As the first step, I would always suggest to reproduce this issue with the CLI binary (this includes the builtin server under -S localhost:8000 -t public). That way you don't have to deal with multi-process FPM. Once that is done, the easiest way to get some useful debugging information is to run PHP under valgrind, this is done using "USE_ZEND_ALLOC=0 valgrind php ...". Nikita --000000000000269164059d453c96--