From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Robinson Subject: Re: [offlist] Re: Crash in netlink/sk_filter_trim_cap on ARMv7 on 4.18rc1 Date: Fri, 17 Aug 2018 13:25:44 +0100 Message-ID: References: <7ff516fd-1d01-4d7a-1d5d-b58932c0c69d@gmail.com> <20180816203515.GA7688@torres.zugschlus.de> <20180816225844.GW30658@n2100.armlinux.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Cc: Marc Haber , linux-arm-kernel@lists.infradead.org, netdev@vger.kernel.org, labbott@redhat.com, Eric Dumazet , Daniel Borkmann To: Russell King - ARM Linux Return-path: Received: from mail-wm0-f66.google.com ([74.125.82.66]:52485 "EHLO mail-wm0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727102AbeHQP3A (ORCPT ); Fri, 17 Aug 2018 11:29:00 -0400 Received: by mail-wm0-f66.google.com with SMTP id o11-v6so7376449wmh.2 for ; Fri, 17 Aug 2018 05:25:45 -0700 (PDT) In-Reply-To: <20180816225844.GW30658@n2100.armlinux.org.uk> Sender: netdev-owner@vger.kernel.org List-ID: On Thu, Aug 16, 2018 at 11:58 PM, Russell King - ARM Linux wrote: > On Thu, Aug 16, 2018 at 10:35:16PM +0200, Marc Haber wrote: >> On Mon, Jun 25, 2018 at 05:41:27PM +0100, Peter Robinson wrote: >> > So with that and the other fix there was no improvement, with those >> > and the BPF JIT disabled it works, I'm not sure if the two patches >> > have any effect with the JIT disabled though. >> >> I can confirm the crash with the released 4.18.1 on Banana Pi, and I can >> also confirm that disabling BPF JIT makes the Banana Pi work again., > > Hi, > > I'm afraid that the information in the crash dumps is insufficient > to be able to work very much out about these crashes. > > We need a recipe (kernel configuration and what userspace is doing) > so that it's possible to recreate the crash, or we need responses > to requests for information - I requested the disassembly of > sk_filter_trim_cap and the BPF code dump via setting a sysctl back > in early July. Without this, as I say, I don't see how this problem > can be progressed. I can provide a kernel config [1] but I've not had enough time to sit down and get the rest of the stuff and debug it due to a combination of travel and other priorities. > If the problem is at boot, one way to set the sysctl would be to > hack the kernel and explicitly initialise the sysctl to '2', or > boot with init=/bin/sh, then manually mount /proc, set the sysctl, > and then "exec /sbin/init" from that shell. (Remember there's no > job control in that shell, so ^z, ^c, etc do not work.) It starts to happen in the early kernel boot long before we get to any userspace across a number of ARMv7 devices (RPi2/3, BeagleBone and AllWinner H3 based devices at least). [1] https://pbrobinson.fedorapeople.org/kernel-armv7hl.config From mboxrd@z Thu Jan 1 00:00:00 1970 From: pbrobinson@gmail.com (Peter Robinson) Date: Fri, 17 Aug 2018 13:25:44 +0100 Subject: [offlist] Re: Crash in netlink/sk_filter_trim_cap on ARMv7 on 4.18rc1 In-Reply-To: <20180816225844.GW30658@n2100.armlinux.org.uk> References: <7ff516fd-1d01-4d7a-1d5d-b58932c0c69d@gmail.com> <20180816203515.GA7688@torres.zugschlus.de> <20180816225844.GW30658@n2100.armlinux.org.uk> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thu, Aug 16, 2018 at 11:58 PM, Russell King - ARM Linux wrote: > On Thu, Aug 16, 2018 at 10:35:16PM +0200, Marc Haber wrote: >> On Mon, Jun 25, 2018 at 05:41:27PM +0100, Peter Robinson wrote: >> > So with that and the other fix there was no improvement, with those >> > and the BPF JIT disabled it works, I'm not sure if the two patches >> > have any effect with the JIT disabled though. >> >> I can confirm the crash with the released 4.18.1 on Banana Pi, and I can >> also confirm that disabling BPF JIT makes the Banana Pi work again., > > Hi, > > I'm afraid that the information in the crash dumps is insufficient > to be able to work very much out about these crashes. > > We need a recipe (kernel configuration and what userspace is doing) > so that it's possible to recreate the crash, or we need responses > to requests for information - I requested the disassembly of > sk_filter_trim_cap and the BPF code dump via setting a sysctl back > in early July. Without this, as I say, I don't see how this problem > can be progressed. I can provide a kernel config [1] but I've not had enough time to sit down and get the rest of the stuff and debug it due to a combination of travel and other priorities. > If the problem is at boot, one way to set the sysctl would be to > hack the kernel and explicitly initialise the sysctl to '2', or > boot with init=/bin/sh, then manually mount /proc, set the sysctl, > and then "exec /sbin/init" from that shell. (Remember there's no > job control in that shell, so ^z, ^c, etc do not work.) It starts to happen in the early kernel boot long before we get to any userspace across a number of ARMv7 devices (RPi2/3, BeagleBone and AllWinner H3 based devices at least). [1] https://pbrobinson.fedorapeople.org/kernel-armv7hl.config