From owner-svn-src-all@freebsd.org Wed Dec 20 17:33:34 2017 Return-Path: Delivered-To: svn-src-all@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id C0EC3E98188; Wed, 20 Dec 2017 17:33:34 +0000 (UTC) (envelope-from jhb@freebsd.org) Received: from mail.baldwin.cx (bigwig.baldwin.cx [IPv6:2001:470:1f11:75::1]) (using TLSv1 with cipher DHE-RSA-CAMELLIA256-SHA (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 975D578D22; Wed, 20 Dec 2017 17:33:34 +0000 (UTC) (envelope-from jhb@freebsd.org) Received: from ralph.baldwin.cx (astound-66-234-202-155.ca.astound.net [66.234.202.155]) by mail.baldwin.cx (Postfix) with ESMTPSA id 38E6910AF2A; Wed, 20 Dec 2017 12:33:33 -0500 (EST) From: John Baldwin To: David Chisnall Cc: Eugene Grosbein , Konstantin Belousov , Conrad Meyer , src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: Re: svn commit: r326758 - in head/sys/i386: conf include Date: Wed, 20 Dec 2017 09:14:07 -0800 Message-ID: <1839614.eNG2DjLqvF@ralph.baldwin.cx> User-Agent: KMail/4.14.10 (FreeBSD/11.1-STABLE; KDE/4.14.30; amd64; ; ) In-Reply-To: <68FECEF0-014E-4741-BE96-680E9338557B@FreeBSD.org> References: <201712110432.vBB4WbnE021090@repo.freebsd.org> <1705b795-46ca-bb27-6ba7-fab4eeed0aba@FreeBSD.org> <68FECEF0-014E-4741-BE96-680E9338557B@FreeBSD.org> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.4.3 (mail.baldwin.cx); Wed, 20 Dec 2017 12:33:33 -0500 (EST) X-Virus-Scanned: clamav-milter 0.99.2 at mail.baldwin.cx X-Virus-Status: Clean X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.25 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 20 Dec 2017 17:33:34 -0000 On Wednesday, December 20, 2017 09:59:26 AM David Chisnall wrote: > On 16 Dec 2017, at 18:05, John Baldwin wrote: > >=20 > > When I build a FreeBSD/mips64 kernel with clang, > > _any_ simple NFS op triggers a kernel stack overflow. Kernels comp= iled > > with GCC do not. >=20 > That is not my experience. I haven=E2=80=99t tried a MIPS64 kernel b= uilt with clang, but with in-tree gcc I get kernel panics as soon as I = try to use NFS, unless I use Stacey=E2=80=99s patches that increase the= kernel stack size. I have primarily been using modern GCC for GCC once that was working, b= ut at least when running a MALTA64 kernel under qemu I was not triggering pan= ics even with old GCC. With the in-tree clang 5.0 or with CHERI clang, jus= t doing an 'ls' of a NFS directory or even a tab-complete of a path that is on NFS reliably triggers a kernel stack overflow for MALTA64 in qemu= . With Stacey's kstack pages, a clang kernel does survive, but those are = not in stock FreeBSD which is where I have been testing this. --=20 John Baldwin