From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D04FBC433EF for ; Mon, 25 Jul 2022 13:46:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234461AbiGYNqt (ORCPT ); Mon, 25 Jul 2022 09:46:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60948 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229514AbiGYNqo (ORCPT ); Mon, 25 Jul 2022 09:46:44 -0400 Received: from smtp-out2.suse.de (smtp-out2.suse.de [IPv6:2001:67c:2178:6::1d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 92CDBF5B2; Mon, 25 Jul 2022 06:46:43 -0700 (PDT) Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out2.suse.de (Postfix) with ESMTP id 7039D2023D; Mon, 25 Jul 2022 13:46:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1658756801; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=ZWg1dNIhhKKeM/ZSg5hAzZXqdnTzD1UVa31cpsoSSq4=; b=SQ48r1r+JWht5928b2Ar6Uz5vJJzxMnT5Io/z7g4K7/llpT2wtqEjkWLgl/qApcQXugSXb ZeCxQr39rxPcodlVPHFW5c6fkxrFX2vzn3ADMX+fq5n9+SnB5V6Dd8HflMFh1w+P5iWxjR hGZAkDxxp8DlVFbF56tG7J2gB5tSqpk= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1658756801; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=ZWg1dNIhhKKeM/ZSg5hAzZXqdnTzD1UVa31cpsoSSq4=; b=gZVZBo+MfWbc2oWAcUgAhvJx8Z2uEwDGQXKQvGyBt5XvnZE/jyr4a4zmNx+b6335v6lK/Q FsDkk9BjosyslkAQ== Received: from hawking.suse.de (unknown [10.168.4.11]) by relay2.suse.de (Postfix) with ESMTP id 651FB2C153; Mon, 25 Jul 2022 13:46:40 +0000 (UTC) Received: by hawking.suse.de (Postfix, from userid 17005) id 48CD9444B2F; Mon, 25 Jul 2022 15:46:40 +0200 (CEST) From: Andreas Schwab To: Daniel Bristot de Oliveira Cc: Steven Rostedt , linux-trace-devel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] rtla: fix double free References: X-Yow: Th' PINK SOCK... soaking... soaking... soaking... Th' PINK SOCK... washing... washing... washing... Th' PINK SOCK... rinsing... rinsing... rinsing... Date: Mon, 25 Jul 2022 15:46:40 +0200 In-Reply-To: (Daniel Bristot de Oliveira's message of "Mon, 25 Jul 2022 15:34:56 +0200") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.1.90 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-trace-devel@vger.kernel.org On Jul 25 2022, Daniel Bristot de Oliveira wrote: > Hi Andreas > > On 7/25/22 15:10, Andreas Schwab wrote: >> Don't call trace_instance_destroy in trace_instance_init when it fails, >> this is done by the caller. > > Regarding the Subject, are you seeing a double-free error, or it is just an > optimization? A double free nowadays is almost always an error, due to better malloc checking. > AFAICS, trace_instance_destroy() checks the pointers before calling free(). That doesn't help when the pointer is not cleared afterwards. Do you prefer that? > Why am I asking? because if it is a double-free bug, we need to add the "Fixes:" > tag, It's the first time I tried running rtla, so I don't know whether it is a regression, but from looking at the history it appears to have been introduced already in commit 0605bf009f18 ("rtla: Add osnoise tool") -- Andreas Schwab, SUSE Labs, schwab@suse.de GPG Key fingerprint = 0196 BAD8 1CE9 1970 F4BE 1748 E4D4 88E3 0EEA B9D7 "And now for something completely different."