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 4D42023B0; Fri, 24 Jan 2025 17:09:23 +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=1737738564; cv=none; b=Rh7wTpBX3tttDOGKvFf40n4ZcFfKDBLThYIkb1MX8h4TCGUfcF/yVXrzv5Xu/6YGEoTB4eDx2z7qiCjtmACrvT81k6Vad4stuVrUHJhu2tYORVeVfl19D8SaZL0yLZZPfXVqwXdh+RPwcVFlRWcGwdbzGENF1JpQpEMBGWSutD0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737738564; c=relaxed/simple; bh=iNmuXDwZuK0qZxAFbFwroLVFsePi12ssQU51ekJzrAM=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=NHqiktcr7EwbpY+a3e/iIzVjczO5jt7JaRhfk2X8zj34VqK/Mg7uzs04yyNSCQuY6C14L2ajhthumRk15jBEwF3C+Dtd/dny1AUDUX+9MbLjhPjuWb/4uL/8FWg8Ib32EJPJvPrP4FFmNWwp1aSI7Yye/zttQv8DznuVISYEfWI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ieZqMWOi; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ieZqMWOi" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B889AC4CED2; Fri, 24 Jan 2025 17:09:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1737738563; bh=iNmuXDwZuK0qZxAFbFwroLVFsePi12ssQU51ekJzrAM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ieZqMWOik2QkTKqrv1o7nfD+wo7NGHLoI3b0VQAW+vvtcyVC06eCIz8slOdgZonem dck36YfNx3GJKfpBhfdPpC0CPjzGKJl3Ij5kiRZvyORM4fmgWRJGjqB2+zd9dmnRZ3 qwzRJL+km6U80fulA27dopXG4K6xLq55C360hYOQk6rw4INZT4/cHLoxKhyuKZod3I boxSS74tPsbxyh6lhuR6jRBpV+qj7cdtASwVMDGkIUU3DhGVduSwoYDpcNMmgT0EVa X7DcyyNXFWy+RHf/Cn8eTe7g0bVM2D70+yqw+pqnY0mdgxOBdNw2mLdwzq3x1YHwEx QWiXlUNc0YiHg== Date: Fri, 24 Jan 2025 09:09:21 -0800 From: Josh Poimboeuf To: Jens Remus Cc: x86@kernel.org, Peter Zijlstra , Steven Rostedt , Ingo Molnar , Arnaldo Carvalho de Melo , linux-kernel@vger.kernel.org, Indu Bhagat , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Ian Rogers , Adrian Hunter , linux-perf-users@vger.kernel.org, Mark Brown , linux-toolchains@vger.kernel.org, Jordan Rome , Sam James , linux-trace-kernel@vger.kernel.org, Andrii Nakryiko , Mathieu Desnoyers , Florian Weimer , Andy Lutomirski , Masami Hiramatsu , Weinan Liu , Heiko Carstens , Vasily Gorbik Subject: Re: [PATCH v4 11/39] unwind_user: Add user space unwinding API Message-ID: <20250124170921.oa5etcxie3axy6jk@jpoimboe> References: 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=utf-8 Content-Disposition: inline In-Reply-To: On Fri, Jan 24, 2025 at 05:41:29PM +0100, Jens Remus wrote: > On 22.01.2025 03:31, Josh Poimboeuf wrote: > > +int unwind_user_next(struct unwind_user_state *state) > > +{ > > + struct unwind_user_frame _frame; > > + struct unwind_user_frame *frame = &_frame; > > + unsigned long cfa = 0, fp, ra = 0; > > Why are cfa and ra initialized to zero? Where is that important in > subsequent patches? > > "[PATCH v4 12/39] unwind_user: Add frame pointer support" does either > unconditionally set both cfa and ra or bail out. Right, probably leftovers from some previous iteration. I drop those. -- Josh