Received: by 2002:ad5:474a:0:0:0:0:0 with SMTP id i10csp3592067imu; Mon, 10 Dec 2018 04:54:51 -0800 (PST) X-Google-Smtp-Source: AFSGD/X0Q7a6VBCYWufRVnq5njpf5GIj+b35CW6pAeDimeWBHSrJQt5VYWpJ1XnXQf2BdFNVz2tw X-Received: by 2002:a62:4714:: with SMTP id u20mr12109308pfa.144.1544446491807; Mon, 10 Dec 2018 04:54:51 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1544446491; cv=none; d=google.com; s=arc-20160816; b=ktwzv2Jl2t8xQrIsnzn7ABOXzF2xGW50spsjHEbOUYkdLVt9rWqsYG6EUaYte5NjJo KFJDrSWEgWD6Nt5BHCLlfq2iRY7xsbw7yzwpCpWl4/Pesi/rYufVA8uPI47RsUUribvB TGnctgFSBcuO3BlOkrOFyERlLfKwwrf+NjFDK0iPQAjtlW85SVcuaPNaToJ3k9BMZgRg 2/sgAL/QE2qIxbb4RivSJD+NT+WgE4mSqhG4NDVqPkkLeUh7ChMlks5ItGsCFmPrQRz7 ADKEG2bzBWrh/9t6wtpltpEgJRSES7WAEdL8XaM3qKOasmhsH4hOUbpiZaxUR8xK2wGs Vtrw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:user-agent:in-reply-to :content-disposition:mime-version:references:message-id:subject:cc :to:from:date; bh=TemvrqTzANXtagLGPonCX0B6nkxV36rNz+MflC1tRdI=; b=Msk1LHSSlGCpALKeDJj4M+204XF4C9ihX3snFuGE+5b+O8H1kAzXw7t9MbTevtSThW 4Oe7dDadQY5wmWiA3Qkp8PGrY0HIlnYa6w0QAvC/qDXJO8qOY2uOnfoP57Lk+CKYJTUw r7xB6NubR7/usiZs74Qxn+VlvSn7/3mzXpKUywZTO29NGTiWc7rgAM00QE5y02u07s12 nHl8DNvCMR/aae8UobqYNQzKpmDxMS0A3ha0dyigIhx+yVAgwQPP5mfgzmjKBIdHe96+ JqBVs0eM74E1oyFxDbXCrUls9/ZH76ISBTpMHntxEeatQcJUuBHhoYPvdLqa+LzbsG1l z/dg== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id h5si10762574plk.373.2018.12.10.04.54.36; Mon, 10 Dec 2018 04:54:51 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726985AbeLJMra (ORCPT + 99 others); Mon, 10 Dec 2018 07:47:30 -0500 Received: from Chamillionaire.breakpoint.cc ([146.0.238.67]:57730 "EHLO Chamillionaire.breakpoint.cc" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726664AbeLJMra (ORCPT ); Mon, 10 Dec 2018 07:47:30 -0500 Received: from fw by Chamillionaire.breakpoint.cc with local (Exim 4.89) (envelope-from ) id 1gWKy4-0007kE-6g; Mon, 10 Dec 2018 13:47:24 +0100 Date: Mon, 10 Dec 2018 13:47:24 +0100 From: Florian Westphal To: syzbot Cc: davem@davemloft.net, herbert@gondor.apana.org.au, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, steffen.klassert@secunet.com, syzkaller-bugs@googlegroups.com Subject: Re: INFO: rcu detected stall in xfrm_hash_rebuild Message-ID: <20181210124724.iuver2va3yjdsokf@breakpoint.cc> References: <00000000000075fe86057ca6367e@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <00000000000075fe86057ca6367e@google.com> User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org syzbot wrote: > Hello, > > syzbot found the following crash on: [..] > Workqueue: events xfrm_hash_rebuild Ignoring this report for a second -- I think it makes sense to see if we can just remove the entire hash table rebuild/resize code. After recent tree conversion, we could probably make the exact policies part of the 'inexact tree' (which would be renamed to 'policy tree' or some such). Special-casing the exact policies made a lot of sense when we had a single list for the inexact policies (to keep its length down). But now I think we could try to unify all of this and only maintain the existing tree-based storage. Would also remove the need to do lookups in two different data structures (bydst-hash-then-inexact-tree). What do you think?