From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0439BC433EF for ; Thu, 28 Oct 2021 06:40:27 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id C230C60D07 for ; Thu, 28 Oct 2021 06:40:25 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org C230C60D07 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ellerman.id.au Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=lists.ozlabs.org Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4Hfwsz72Lhz3c6f for ; Thu, 28 Oct 2021 17:40:23 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=ellerman.id.au header.i=@ellerman.id.au header.a=rsa-sha256 header.s=201909 header.b=Z3LRTgxV; dkim-atps=neutral Received: from gandalf.ozlabs.org (gandalf.ozlabs.org [IPv6:2404:9400:2:0:216:3eff:fee2:21ea]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4HfwsK2GPgz2xZg for ; Thu, 28 Oct 2021 17:39:49 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=ellerman.id.au header.i=@ellerman.id.au header.a=rsa-sha256 header.s=201909 header.b=Z3LRTgxV; dkim-atps=neutral Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mail.ozlabs.org (Postfix) with ESMTPSA id 4HfwsJ1CPpz4xbG; Thu, 28 Oct 2021 17:39:47 +1100 (AEDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ellerman.id.au; s=201909; t=1635403188; bh=6wVz/A4J4PFhe61AUA4JLJUcmjUln4No7uxrAJbBELU=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=Z3LRTgxV5/PH+lUIDnttJZibcEngUOLHJBMRa/mq/M1UaUgXXex8b2gJEZJPdrI0l 4ns/b1U5D9iVoGSIfoM9Gtb1hK2dzIxNMIQi0ylm7YiwtxvapwlVpYa0qqlnei+6U8 k/1qpta/A9vubDJ9p1BrGXId6iZTlac+cnrAWaOzhtfYQOpMKD83wU7QkeVHivme+N 0O5KvBQ1vfe4MPSqVTvvLPT/O4W9YjrMnhsxI5TMbnbVmGkXD+bMQTdE7l3lPphos0 jFhphwFsm4lE9/YZL/EEtTdPES4KxWnQT9malQIsM596jseL1tZGb/B3ck6FHFi40U WeIZnItbIJCyA== From: Michael Ellerman To: John Paul Adrian Glaubitz Subject: Re: Linux kernel: powerpc: KVM guest can trigger host crash on Power8 In-Reply-To: References: <87pmrtbbdt.fsf@mpe.ellerman.id.au> <05b88724-90b6-a38a-bb3b-7392f85c1934@physik.fu-berlin.de> <878ryfavaz.fsf@mpe.ellerman.id.au> <04864fe5-fdd0-74b2-2bad-0303e4c2b15a@physik.fu-berlin.de> <874k92bubv.fsf@mpe.ellerman.id.au> Date: Thu, 28 Oct 2021 17:39:46 +1100 Message-ID: <878rydac0d.fsf@mpe.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "debian-powerpc@lists.debian.org" , linuxppc-dev@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" [ Dropping oss-security from Cc] John Paul Adrian Glaubitz writes: > On 10/27/21 13:06, Michael Ellerman wrote: >> John Paul Adrian Glaubitz writes: >>> On 10/27/21 07:30, Michael Ellerman wrote: >>>> I did test the repro case you gave me before (in the bugzilla), which >>>> was building glibc, that passes for me with a patched host. >>> >>> Did you manage to crash the unpatched host? >> >> Yes, the parallel builds of glibc you described crashed the unpatched >> host 100% reliably for me. > > OK, that is very good news! > >> I also have a standalone reproducer I'll send you. > > Thanks, that would be helpful! > >>> Also, I'll try a kernel from git with Debian's config. >>> >>>> I guess we have yet another bug. >>>> >>>> I tried the following in a debian BE VM and it completed fine: >>>> >>>> $ dget -u http://ftp.debian.org/debian/pool/main/g/git/git_2.33.1-1.dsc >>>> $ sbuild -d sid --arch=powerpc --no-arch-all git_2.33.1-1.dsc >>>> >>>> Same for ppc64. >>>> >>>> And I also tried both at once, repeatedly in a loop. >>> >>> Did you try building gcc-11 for powerpc and ppc64 both at once? >> >> No, I will try that now. That completed fine on my BE VM here. I ran these in two tmux windows: $ sbuild -d sid --arch=powerpc --no-arch-all gcc-11_11.2.0-10.dsc $ sbuild -d sid --arch=ppc64 --no-arch-all gcc-11_11.2.0-10.dsc The VM has 32 CPUs, with 4 threads per core: $ ppc64_cpu --info Core 0: 0* 1* 2* 3* Core 1: 4* 5* 6* 7* Core 2: 8* 9* 10* 11* Core 3: 12* 13* 14* 15* Core 4: 16* 17* 18* 19* Core 5: 20* 21* 22* 23* Core 6: 24* 25* 26* 27* Core 7: 28* 29* 30* 31* cheers