From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Borkmann Subject: Re: [PATCH net-next 01/13] ARM: net: bpf: enumerate the JIT scratch stack layout Date: Tue, 10 Jul 2018 20:30:04 +0200 Message-ID: <41b5fc68-e15f-56f9-c55b-4f6deb61c54c@iogearbox.net> References: <20180710123340.GK17271@n2100.armlinux.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, linux-arm-kernel@lists.infradead.org To: Russell King Return-path: Received: from www62.your-server.de ([213.133.104.62]:36787 "EHLO www62.your-server.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732565AbeGJSaR (ORCPT ); Tue, 10 Jul 2018 14:30:17 -0400 In-Reply-To: Content-Language: en-US Sender: netdev-owner@vger.kernel.org List-ID: Hi Russell, thanks a lot for your work on the arm32 JIT! On 07/10/2018 02:36 PM, Russell King wrote: > Enumerate the contents of the JIT scratch stack layout used for storing > some of the JITs 64-bit registers, tail call counter and AX register. > > XXX: what about the skb_copy_bits buffer - this appears to overlap with > the first word of the JITs accessible stack. Could you elaborate on that case? Unless I'm missing something there should be no use of the skb_copy_bits buffer anymore (aka former SKB_BUFFER at STACK_VAR(SCRATCH_SIZE) offset), but aside from that it's not supposed to overlap either. Thanks, Daniel