From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AB70A397352 for ; Wed, 26 Aug 2026 18:30:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=216.40.44.16 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787769056; cv=none; b=SjyiXpmAWM11QAkvQG4Ri0qhQFgfUokkBfv6lRzc63ehMg41O5U7yG/ZZ0xCXc/Ij2Nh4cWRiE4DEu7F8/VDAnU2tx5RTB4hkc53sfaqF55ckgvCzGrS8/9d4T0Xrxmqe3R+ZLYTl2nws7fDAfi535++d3/XLdqVDzI1y/Jk0vc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787769056; c=relaxed/simple; bh=IiJ6o9p4RdhW/e+YbM46z7SC+oyYsBTOEyeha9FqVlU=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=SZpGN2hajwyLCWYgEMgbkd8946P3EanL02YrNnsizzqwobHcs9k8dP+XnbYQAaBPkPeCiVTYeM5EezDJBrebTTU/1EdP7xZTP9KXNSKUzOKtixGe27ExpstqOk0iw9EoqniXHvrvLNKB5cpjpTo0l8yZNI6OVxJKnMrcQ22TcWI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=goodmis.org; spf=pass smtp.mailfrom=goodmis.org; dkim=pass (1024-bit key) header.d=goodmis.org header.i=@goodmis.org header.b=J1/Yr6f1; arc=none smtp.client-ip=216.40.44.16 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=goodmis.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=goodmis.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=goodmis.org header.i=@goodmis.org header.b="J1/Yr6f1" Received: from omf09.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 5623EC01D4; Wed, 26 Aug 2026 18:30:39 +0000 (UTC) Received: from [HIDDEN] (Authenticated sender: rostedt@goodmis.org) by omf09.hostedemail.com (Postfix) with ESMTPA id B847D20025; Wed, 26 Aug 2026 18:30:37 +0000 (UTC) Date: Wed, 26 Aug 2026 14:31:23 -0400 From: Steven Rostedt To: Vincent Donnefort Cc: sashiko-bot@kernel.org, sashiko-reviews@lists.linux.dev, linux-trace-kernel@vger.kernel.org Subject: Re: [PATCH v8 1/3] tracing: Fix subbuf resize races with trace_pipe_raw readers Message-ID: <20260826143123.1b3e3854@gandalf.local.home> In-Reply-To: References: <20260826094528.3738023-1-vdonnefort@google.com> <20260826094528.3738023-2-vdonnefort@google.com> <20260826095947.4FF8B1F000E9@smtp.kernel.org> <20260826103736.2b55b464@gandalf.local.home> X-Mailer: Claws Mail 3.20.0git84 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Stat-Signature: 9arpc6uhcx1uaw3q5wr7uxxjdfp5ge4u X-Rspamd-Server: rspamout06 X-Rspamd-Queue-Id: B847D20025 X-Session-Marker: 726F737465647440676F6F646D69732E6F7267 X-Session-ID: U2FsdGVkX18XxAdD1sfi8kUlzNUzj98ULs5E5VPo0Mw= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=goodmis.org; h=date:from:to:cc:subject:message-id:in-reply-to:references:mime-version:content-type:content-transfer-encoding; s=dkim1; bh=2MXGXKcjH51S/C76vlkXxPmKewipWiV9ccLaJ+mi+vE=; b=J1/Yr6f1+J5Rv8jfzxDTn4UeyErGMH3/Nr2uZ9alYACah5lcl4mmfg3MV86YEKt5A6RHZ7bpkyfgSuKaojTsINpiYCdFOzznk8t5l6yxBBQXVyMenkbSpE1hpMEX90SJoQLgJ6IvZk8TYeAKOzrBfuhny7RAuNmNkdAw5FJrrJ0= X-HE-Tag: 1787769037-13725 X-HE-Meta: U2FsdGVkX19vRzPEJka9ItcAL7AUiglo++gXaRZHmOQvgj3FGI+yZMrXH3+cZclO2C2iGwMFk+tjxY+vOq6jJhWI9Y2ST6teaSvUKOpAjM+u2iaUz+OmfoiwRzm6+c4idUjszeh9cf1E9uL/linc1xq34hyXF6CIbRUQh55ko65rWjBz7owrABefdKNt2aSWA7E5sjDmfGrW1TKgxLlbKtxOci4vZ918UPdWmfT828vvCLXWIswVdJH37O5MbbcyRkTQahNS52C/3cTY9v3yY71MT8uScLIpjiVitFpaL7JfR0ndDNoiUPTg2vIGnb27r0B44vT6AILh7KoO/FpWYqwxp7vKsDo5 On Wed, 26 Aug 2026 17:24:35 +0100 Vincent Donnefort wrote: > > This is a legitimate concern. But with an easy solution. Perhaps just add: > > > > if (full && > > (!read || (len < (size - read)) || > > - cpu_buffer->reader_page == cpu_buffer->commit_page)) > > + cpu_buffer->reader_page == cpu_buffer->commit_page) && > > + data_page->order == buffer->subbuf_order) > > return -1; > > > > If the user is changing the buffer size at the same time as reading raw > > pages, they get what they deserve! I just don't want to let the kernel go > > into an infinite loop. > > > > -- Steve > > > > Sounds good. Do you prefer to get a v9 or you fold this into the existing commit? > Please send a v9. It makes the patchwork flow much better. If I modify a patch, it makes patchwork not be able to automate the status updates as it moves around git trees. Thanks, -- Steve