From owner-freebsd-current@freebsd.org Sat Aug 4 13:57:21 2018 Return-Path: Delivered-To: freebsd-current@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 5E34D106C26A for ; Sat, 4 Aug 2018 13:57:21 +0000 (UTC) (envelope-from kevans@freebsd.org) Received: from smtp.freebsd.org (smtp.freebsd.org [IPv6:2610:1c1:1:606c::24b:4]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "smtp.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 10F8778161; Sat, 4 Aug 2018 13:57:21 +0000 (UTC) (envelope-from kevans@freebsd.org) Received: from mail-lf1-f49.google.com (mail-lf1-f49.google.com [209.85.167.49]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G3" (verified OK)) (Authenticated sender: kevans) by smtp.freebsd.org (Postfix) with ESMTPSA id A2DE6186EA; Sat, 4 Aug 2018 13:57:20 +0000 (UTC) (envelope-from kevans@freebsd.org) Received: by mail-lf1-f49.google.com with SMTP id u202-v6so6035137lff.9; Sat, 04 Aug 2018 06:57:20 -0700 (PDT) X-Gm-Message-State: AOUpUlENxlRgYV/a0wMU4mOMC/hgYG/C6EaU3hL7voSQhE6indwng0dn nO3IRZwY7jHMavxqvYqGeScRq3yaEBWbTNmQ/O8= X-Google-Smtp-Source: AAOMgpd8zji5Okmh9PcfRU8Dvx5yZZwriJJ47LoNZrXswruXqqMaT24Uu1LR8FNPcdfkQfGA5VBTHRRvlq0jYyhmx20= X-Received: by 2002:a19:9481:: with SMTP id o1-v6mr7559745lfk.38.1533391039254; Sat, 04 Aug 2018 06:57:19 -0700 (PDT) MIME-Version: 1.0 Received: by 2002:a2e:5742:0:0:0:0:0 with HTTP; Sat, 4 Aug 2018 06:56:58 -0700 (PDT) In-Reply-To: <20180804131352.GL6049@kib.kiev.ua> References: <20180804083720.GJ6049@kib.kiev.ua> <20180804131352.GL6049@kib.kiev.ua> From: Kyle Evans Date: Sat, 4 Aug 2018 08:56:58 -0500 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: panic: mutex pmap not owned at ... efirt_machdep.c:255 To: Konstantin Belousov Cc: freebsd-current Current , Eitan Adler Content-Type: text/plain; charset="UTF-8" X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.27 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 04 Aug 2018 13:57:21 -0000 On Sat, Aug 4, 2018 at 8:13 AM, Konstantin Belousov wrote: > On Sat, Aug 04, 2018 at 08:05:24AM -0500, Kyle Evans wrote: >> On Sat, Aug 4, 2018 at 3:37 AM, Konstantin Belousov wrote: >> > On Fri, Aug 03, 2018 at 11:27:02PM -0500, Kyle Evans wrote: >> >> >> >> This seems odd- pmap lock is acquired at [1], then asserted shortly >> >> later at [2]... I avoid some of this stuff as well as I can, but is it >> >> actually possible for PCPU_GET(...) acquired curpmap to not match >> >> curthread->td_proc->p_vmspace->vm_pmap in this context? >> >> >> >> [1] https://svnweb.freebsd.org/base/head/sys/dev/efidev/efirt.c?view=markup#l260 >> >> [2] https://svnweb.freebsd.org/base/head/sys/amd64/amd64/efirt_machdep.c?view=markup#l254 >> > There could be that curpcpu not yet synced with proc0 pmap. It could be >> > fixed. >> > >> > But it is not clear to me why efi_arch_enter() is called there. I see >> > the check for GetTime belonging to the range described by a map descriptor. >> > I do not see why do you need an enter into the EFI context for comparing >> > integers. >> >> This probably could have been documented better, but efi_runtime >> pointer may (always?) point into runtime service memory that isn't >> valid/available at that point, so we get a fault and panic when >> dereferencing it to grab rt_gettime address. We ran into this wall >> when adding the check originally. > Wouldn't it be enough to access it by translating physical address into > DMAP ? Ah, sure, sure. [1] is proper form, yeah? [1] https://people.freebsd.org/~kevans/efi-dmap.diff