From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 4B2351F8AD9; Tue, 17 Dec 2024 19:43:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734464617; cv=none; b=QUAoKkJqK/MzRmG3lKgnqDlgHZFnFAkZRA/ZZk1/dPdMEd47/XsMJRQZBNBa+9OztNz5hIngE/YBWX2c5tGmJ4SOQ/X8oQ/xCH2JHr8Y+fcDqGlHcUM+yg4kvtPgWhN3nji/qN6kov3Dg1EzJYe9LGDvYTtaGG4cpahYEoE0vUU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734464617; c=relaxed/simple; bh=/2JWy7XyRJojOLT9csZ59o7qdtHc70xuhWajqM8UXVY=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=E9XyGXG8JUG9KaL65CGPD53qet/nO0OaiAotLkgGDkuCzMid/M9Jecseg8v+adUiGxMgAlVbnRYaPl96z1ca5neTurXr1lOYj3I0Rwa5VZ3lBNoOpEybjoG+qiIKhtlbxsetYFdDFzIsHUnPFmgXgdKfKixSybOsOyxF5ROCNcw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 Received: by smtp.kernel.org (Postfix) with ESMTPSA id D2730C4CED3; Tue, 17 Dec 2024 19:43:35 +0000 (UTC) Date: Tue, 17 Dec 2024 14:44:11 -0500 From: Steven Rostedt To: Linus Torvalds Cc: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers , Andrew Morton , stable@vger.kernel.org Subject: Re: [PATCH 1/3] ring-buffer: Add uname to match criteria for persistent ring buffer Message-ID: <20241217144411.2165f73b@gandalf.local.home> In-Reply-To: References: <20241217173237.836878448@goodmis.org> <20241217173520.314190793@goodmis.org> <20241217130454.5bb593e8@gandalf.local.home> <20241217133318.06f849c9@gandalf.local.home> <20241217140153.22ac28b0@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 On Tue, 17 Dec 2024 11:38:00 -0800 Linus Torvalds wrote: > On Tue, 17 Dec 2024 at 11:01, Steven Rostedt wrote: > > > > But instead, I'll replace the text/data_deltas with a kaslr offset (it will > > only be exported if the trace contains data from a previous kernel so not > > to export the current kaslr offset). > > Right - never export the KASRL offset for the *current* kernel, but > the same interface that exports the "previous kernel trace data" can > certainly export the KASLR for that previous case. But this will be future work and not something for this merge window, as it's more of a feature. The only fix is to add that print_field() code, and the patch series that removes trace_check_vprintf() (which fixes a different bug). > > > Then, on our production systems, we'll save the meta data of the events we > > enable (this can include module events as well as dynamic events) and after > > a crash, we'll extract the data along with the saved data stored on disk, > > and be able to recreate the entire trace. > > Yes. And if you save the module names and load addresses, you can now > hopefully sort out things like %s (and %pS) from modules too. > > Although maybe they don't happen that often? Actually, they do appear a bit. As the kmalloc trace event records the call sites that do allocation and many of them are in module code. -- Steve