From owner-freebsd-current@FreeBSD.ORG Thu Nov 8 14:33:25 2012 Return-Path: Delivered-To: current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 582033BD; Thu, 8 Nov 2012 14:33:25 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from kib.kiev.ua (kib.kiev.ua [IPv6:2001:470:d5e7:1::1]) by mx1.freebsd.org (Postfix) with ESMTP id E59D38FC0C; Thu, 8 Nov 2012 14:33:24 +0000 (UTC) Received: from tom.home (localhost [127.0.0.1]) by kib.kiev.ua (8.14.5/8.14.5) with ESMTP id qA8EXKwk000467; Thu, 8 Nov 2012 16:33:20 +0200 (EET) (envelope-from kostikbel@gmail.com) X-DKIM: OpenDKIM Filter v2.5.2 kib.kiev.ua qA8EXKwk000467 Received: (from kostik@localhost) by tom.home (8.14.5/8.14.5/Submit) id qA8EXKg7000466; Thu, 8 Nov 2012 16:33:20 +0200 (EET) (envelope-from kostikbel@gmail.com) X-Authentication-Warning: tom.home: kostik set sender to kostikbel@gmail.com using -f Date: Thu, 8 Nov 2012 16:33:20 +0200 From: Konstantin Belousov To: Joel Dahl Subject: Re: Reboot during startup with recent head Message-ID: <20121108143320.GV73505@kib.kiev.ua> References: <20121108084523.GW1092@jd.benders.se> <509B8F9E.9040502@FreeBSD.org> <20121108122313.GB91783@jd.benders.se> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="aObFJ3I/fcifeQec" Content-Disposition: inline In-Reply-To: <20121108122313.GB91783@jd.benders.se> User-Agent: Mutt/1.5.21 (2010-09-15) X-Spam-Status: No, score=0.2 required=5.0 tests=ALL_TRUSTED, DKIM_ADSP_CUSTOM_MED,FREEMAIL_FROM,NML_ADSP_CUSTOM_MED autolearn=no version=3.3.2 X-Spam-Checker-Version: SpamAssassin 3.3.2 (2011-06-06) on tom.home Cc: current@freebsd.org, Andriy Gapon X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.14 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: Thu, 08 Nov 2012 14:33:25 -0000 --aObFJ3I/fcifeQec Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Nov 08, 2012 at 01:23:13PM +0100, Joel Dahl wrote: > On 08-11-2012 12:55, Andriy Gapon wrote: > > on 08/11/2012 10:45 Joel Dahl said the following: > > > Hi, > > >=20 > > > I rebuilt head (r242605) in a VMware virtual machine a couple of days= ago, and > > > now it won't boot anymore. The loader menu appears, the countdown sta= rts, and boom, > > > reboot. I tried a fresh head (r242700) but the problem remains. > > >=20 > > > Going back to r242205 solves the problem, so this was introduced some= where > > > between r242205 and r242605. > > >=20 > > > I managed to record the entire thing with my phone before I had to le= ave for > > > work today. You can see it here: > > >=20 > > > http://mirror.vnode.se/upload/head-reboots.mov > > >=20 > > > Any ideas? Any specific revision I should try to back out? > > >=20 > >=20 > > Rather wild guess - try to back out the recent SMEP commit. >=20 > Well, it was a good guess. :-) I backed out revision 242433, rebuilt the = kernel, > and now it boots again. The following patch should allow you to boot. Please show me the verbose dm= esg of the boot with the patch applied. diff --git a/sys/amd64/amd64/pmap.c b/sys/amd64/amd64/pmap.c index 06b45b2..7846194 100644 --- a/sys/amd64/amd64/pmap.c +++ b/sys/amd64/amd64/pmap.c @@ -598,6 +598,7 @@ pmap_bootstrap(vm_paddr_t *firstaddr) { vm_offset_t va; pt_entry_t *pte, *unused; + int smep_enable; =20 /* * Create an initial set of page tables to run the kernel in. @@ -613,8 +614,16 @@ pmap_bootstrap(vm_paddr_t *firstaddr) /* XXX do %cr0 as well */ load_cr4(rcr4() | CR4_PGE | CR4_PSE); load_cr3(KPML4phys); - if (cpu_stdext_feature & CPUID_STDEXT_SMEP) - load_cr4(rcr4() | CR4_SMEP); + if (cpu_stdext_feature & CPUID_STDEXT_SMEP) { + smep_enable =3D 0; + TUNABLE_INT_FETCH("hw.smep_enable", &smep_enable); + if (smep_enable) + load_cr4(rcr4() | CR4_SMEP); + else { + cpu_stdext_feature &=3D ~CPUID_STDEXT_SMEP; + printf("SMEP: disabled\n"); + } + } =20 /* * Initialize the kernel pmap (which is statically allocated). --aObFJ3I/fcifeQec Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.19 (FreeBSD) iEYEARECAAYFAlCbwrAACgkQC3+MBN1Mb4io7QCg2deFNfZAtY3kwHCMAyYru9cr 1CAAnAkrgJ+frvdHcxlLowezhNG4o4Dt =QuUk -----END PGP SIGNATURE----- --aObFJ3I/fcifeQec--