From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (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 D7A5225C711 for ; Fri, 24 Oct 2025 13:40:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.92.199 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761313233; cv=none; b=fi9cnK57G+t7GqH875/2nNRC//sQQfM6eYd+WHGl7bFMwULGkQfJxHlo4dhF4D4rrAaqPzlKkhtNn67qT+f7FmODp+3OUagoT3EhA/UdKgt/PA1GIbLo6/myBGwJNp5kZTmjd97vAMFmIhaEt8V/4hbht+qSLT4waNM2E7J29xs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761313233; c=relaxed/simple; bh=iRGB7KwxF+heWMfqHG+AJZi2NLuLRS3ljgXoZCP1T7s=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=m+g/6hWmQTY02PhJIWqdmkQ1LcYb9WzTrcBYmGGCHF1mz2aKFQvhvluS2IK+3FnMg5fllQ1g5dFsVo9GsJxOHRZTKRGodD2VxS10y7DLBcNCJzNRFgIKh3S+74x9QCMC2VGL1/GP3joqCwUV84rOIruAg7ZssarEWElhgM1zTmA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=YOjznXwF; arc=none smtp.client-ip=90.155.92.199 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="YOjznXwF" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=eqIlbFIS1NrExPF+0T4MGwSwd18ATnESRaBZ3QjiXDA=; b=YOjznXwFR1FWIfwQXVIcQR6/xc nGUFkoP8jUkymiGrc3rvJqH13WH40TDTz0+L7GSw/DFAR944I+zpLoxV6eI1GXdT7lu3H88CH6Luk I+71rIVwOYvARtm/DarVu4j5nYSHKMUn0qqfMtYvXKFGwORZj9JavN9PYhzVDd9dIqvuGNvoNZ8Dj vl+T+7wSImpU1pLx2DiuKtH7Lk0KseI+2ltaEejCpBv9S4YpFsG6eWvIW7lEgAsf9jfn+OHXETrqM 0w74y5HKTeFrgeF+cVd8X9qfpWOwM1EdehXWb9o4SmuD86BvL7IuyJ90ka8W4V6IwzHZShlOrnqxp /CN9KGJQ==; Received: from 77-249-17-252.cable.dynamic.v4.ziggo.nl ([77.249.17.252] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.98.2 #2 (Red Hat Linux)) id 1vCHAC-00000002Irx-1TNu; Fri, 24 Oct 2025 12:45:01 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id D126E300323; Fri, 24 Oct 2025 15:40:24 +0200 (CEST) Date: Fri, 24 Oct 2025 15:40:24 +0200 From: Peter Zijlstra To: Jens Remus Cc: jpoimboe@kernel.org, rostedt@kernel.org, Indu Bhagat , linux-kernel@vger.kernel.org, Heiko Carstens , Vasily Gorbik Subject: Re: [PATCH 11/12] unwind: Implement compat fp unwind Message-ID: <20251024134024.GT4067720@noisy.programming.kicks-ass.net> References: <20250924075948.579302904@infradead.org> <20250924080119.613695709@infradead.org> <20251020103940.GP3419281@noisy.programming.kicks-ass.net> <5bdb1c91-8862-44b1-9f12-c5afa9e1806c@linux.ibm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5bdb1c91-8862-44b1-9f12-c5afa9e1806c@linux.ibm.com> On Wed, Oct 22, 2025 at 04:55:01PM +0200, Jens Remus wrote: > Hello Peter! > > On 10/20/2025 12:39 PM, Peter Zijlstra wrote: > > On Mon, Oct 20, 2025 at 11:16:45AM +0200, Jens Remus wrote: > >> On 10/17/2025 5:47 PM, Jens Remus wrote: > > >>> In SFrame the CFA, FP, and RA offsets are unscaled. Would it be ok, if > >>> unwind user sframe would factor state->ws from those offset values? What > >>> if they were not aligned? unwind user sframe would then have to fail. > >> > >> Sorry that I did not immediately think about the most obvious solution > >> tho above issues: to not factor out the word size from the frame CFA, > >> FP, and RA offsets. What do you think about making the following > >> changes to this and giyour subsequent patch? That would work nicely > >> with unwind user sframe. > > > > > > Yes, this should do nicely. I've made the changes, I'll do a test build > > and then push out to the robots. > > Thanks! Looking at your following updated patch I found that your > change from "pointer to const struct unwind_user_frame" to > "const struct unwind_user_frame" (done for obvious reasons) will require > unwind user sframe to undo this when refactoring unwind_user_next_fp() > into unwind_user_next_common(). Would that be the usual procedure or > could you leave it as "pointer to const struct unwind_user_frame" for > now? Ah, I see, that is here: https://lkml.kernel.org/r/20251022144326.4082059-9-jremus@linux.ibm.com Yeah, just change it there. It is a bit weird to have this indirection at this point.