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 2600A296BD2 for ; Fri, 6 Mar 2026 00:31:31 +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=1772757092; cv=none; b=B6swgzgwhOqrLZgsZth67ok1hvMl9Kvf9/mcB+TYdpqbUAFHfDeIt4EYGAo/tUJOfxpLolSvf1RjePCjIpTFSSXdUQgOmq/hgo5DOUlH6CVjV/iDCyQeAv6NYryYcKt3mkn9FimDVgEBrOREubUOGTkDEXyKc+CoZjytc1qJI+Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772757092; c=relaxed/simple; bh=v8js3b8R7MoYBLwXO5S8I3wY8kupCiwhoGBJuJeMUfs=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=QM4e3AbdAfA8Smej7HzOgolR+4BS7m0p9AO1On0kNlqgGVnP93h4IJ4L6tX1YrYExxZC6KlkhuDtq10kJRUqjDrA0rBsXxMw6krvD3+gqVWyB1A7PRitxhr7IpPC1Xc0INbNDMQmnx+5I+EdIDAlD7EgJ5z9aB97eYR7hmVL6Vs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ixAdbykG; 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="ixAdbykG" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CCC18C116C6; Fri, 6 Mar 2026 00:31:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772757091; bh=v8js3b8R7MoYBLwXO5S8I3wY8kupCiwhoGBJuJeMUfs=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=ixAdbykG0cBE4K5uL1ctY7iQoFhA67SgWGBfUwbzCJqgGkevQXT53OUFvnwSQpup1 e+EnYY/CLyKotJJKv32WpPba8xhdRq0d2H9+iCJAl2J7tNR6uRr9CXpSiUeQ5EkqMd tGwzt+kYfV1MLSqFpzKAKHjlZAPStjjCOcCZ2rhNzih0FhcUfK6NxtAEVPLX1wO+cN iH9gRIw8ZebXCq0t9afPdOx2TNOA3NXAWnEytFCguRY19qwI5aD9ApP3Raai7JO3HT 4J6YWiELSE+N98wS75Uxug0bumQRQ3CMbmUzC5E6+/V7uLVgjXYS/dMjcLiWx7jMTH hYB2gAyCWtOzw== Date: Fri, 6 Mar 2026 09:31:29 +0900 From: Masami Hiramatsu (Google) To: Sasha Levin Cc: Matthieu Baerts , "Masami Hiramatsu (Google)" , Andrew Morton , Carlos Llamas , Luca Ceresoli , linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] decode_stacktrace: Support caller address decoding Message-Id: <20260306093129.fa5a93ce9cd0b1a8ece0d532@kernel.org> In-Reply-To: References: <177272956276.1018623.6026552620206046640.stgit@mhiramat.tok.corp.google.com> <7f47295b-803b-4d17-900f-8e19f2931407@kernel.org> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) 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-Transfer-Encoding: 7bit On Thu, 5 Mar 2026 15:47:23 -0500 Sasha Levin wrote: > On Thu, Mar 05, 2026 at 06:05:59PM +0100, Matthieu Baerts wrote: > >Hi Masami, > > > >Thank you for the new version, and your previous reply! > > > >On 05/03/2026 17:52, Masami Hiramatsu (Google) wrote: > >> Add -c option to decodecall address instead of the return address. > >> With this option, it decodes the line info 1byte before the return > >> address which will be the call(branch) instruction address. > >> If the return address is a symbol address, it falls back to > >> decoding the return address. > > > >From what I got from Sasha, this "addr-1" trick seems quite common. Why > >not using this new feature by default, and having an option to disable it? > > +1 OK, let's make it the default behavior. > > >Or no option if someone can validate the new behaviour on architectures > >which have these delay slots you mentioned? > > I didn't think that delay slots were an issue because architectures with delay > slots handle their stack unwinding and return address adjustment in their own > arch-specific code before it ever reaches the script. OK. In case this is an issue, I'll add an option to decode the return address. Thank you, > > -- > Thanks, > Sasha -- Masami Hiramatsu (Google)