From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm1-x336.google.com (mail-wm1-x336.google.com [IPv6:2a00:1450:4864:20::336]) by sourceware.org (Postfix) with ESMTPS id 6BB133894C21 for ; Sat, 17 Apr 2021 18:02:08 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 6BB133894C21 Received: by mail-wm1-x336.google.com with SMTP id w186so11411292wmg.3 for ; Sat, 17 Apr 2021 11:02:08 -0700 (PDT) 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=umgyAWENld3fVPgU6tBnHoTp2BOktYlZOjAqOjscN1U=; b=QdzOYzEoyfOX8jQYAgNEcqQ8AExxbmkRb6C0QEfrE6DiluRyw0pWfMUFgAUWbIXn+h MeH9solQePp5+rk8fjqSdMZAK/nJT7x1ovNuU5+0SKJxo+DFZOti0h87CqKTo8S6JTiG QmxxtNp35rz1rQDYVazuFKAr7FknzrNB6xmJwLyfvvDiqiikj62txTl/bthhCpDFv9TN M9UJJf7OfXwm2dziK2hIkoN26DCT40QASXndpr02nPIlsvfsKLTq8QoiJ0Z9jSMgVLhK 7Qr2OWUkdzecE2EDDZMklID8MREznDBgG8D61yFiFSl63QDPEjfeO2gX0h1LVdoitvGH P5Rw== X-Gm-Message-State: AOAM531rjrRPboT910eWwYsTEvoOZqhRGix+tSuBAxPVBGAxbzpgkMe0 PIoDgLZcoDpDI5oGsOFleSgj67dJqv+fpmzdmYYdjBqnC9ij3w== X-Google-Smtp-Source: ABdhPJwL97ETNNQP/8PD4RfFKCw4IiZyz3KmMm1Zn4X+OHoU0IyisNEu9HEcZbRF+U4VyDQqxZWNQmq2OLSdOgEmcY0= X-Received: by 2002:a1c:c246:: with SMTP id s67mr13255499wmf.86.1618682527050; Sat, 17 Apr 2021 11:02:07 -0700 (PDT) MIME-Version: 1.0 References: <20210417172258.2788076-1-vitalybuka@google.com> In-Reply-To: <20210417172258.2788076-1-vitalybuka@google.com> From: Paul Pluzhnikov Date: Sat, 17 Apr 2021 11:01:39 -0700 Message-ID: Subject: Re: [PATCH] stdlib: Fix data race in __run_exit_handlers To: Vitaly Buka Cc: GLIBC Devel Content-Type: text/plain; charset="UTF-8" X-Spam-Status: No, score=-25.5 required=5.0 tests=BAYES_00, DKIMWL_WL_MED, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, ENV_AND_HDR_SPF_MATCH, GIT_PATCH_0, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP, USER_IN_DEF_DKIM_WL, USER_IN_DEF_SPF_WL autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 17 Apr 2021 18:02:18 -0000 On Sat, Apr 17, 2021 at 10:23 AM Vitaly Buka via Libc-alpha wrote: > diff --git a/stdlib/test-cxa_atexit-race2.c b/stdlib/test-cxa_atexit-race2.c > + This test spawns multiple threads, and check the same desctructor is Typo. Suggest: This test spawns multiple threads, and checks that the same destructor is > + not called more then once. */ s/then/than/ > +static void *cb_arg = NULL; > +static void > +add_handlers (void) > +{ > + int n = 10; > + for (int i = 0; i < n; ++i) > + __cxa_atexit (&atexit_cb, ++cb_arg, 0); add_handlers() is called from many threads. This code appears to race on cb_arg. -- Paul Pluzhnikov