From owner-freebsd-current@freebsd.org Thu Sep 26 17:29:32 2019 Return-Path: Delivered-To: freebsd-current@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 5D5EF12E3EF for ; Thu, 26 Sep 2019 17:29:32 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from kib.kiev.ua (kib.kiev.ua [IPv6:2001:470:d5e7:1::1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) server-signature RSA-PSS (4096 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 46fMP80FjGz4Zmq; Thu, 26 Sep 2019 17:29:31 +0000 (UTC) (envelope-from kostikbel@gmail.com) Received: from tom.home (kib@localhost [127.0.0.1]) by kib.kiev.ua (8.15.2/8.15.2) with ESMTPS id x8QHTOM8030541 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NO); Thu, 26 Sep 2019 20:29:27 +0300 (EEST) (envelope-from kostikbel@gmail.com) DKIM-Filter: OpenDKIM Filter v2.10.3 kib.kiev.ua x8QHTOM8030541 Received: (from kostik@localhost) by tom.home (8.15.2/8.15.2/Submit) id x8QHTO2Y030540; Thu, 26 Sep 2019 20:29:24 +0300 (EEST) (envelope-from kostikbel@gmail.com) X-Authentication-Warning: tom.home: kostik set sender to kostikbel@gmail.com using -f Date: Thu, 26 Sep 2019 20:29:24 +0300 From: Konstantin Belousov To: Alan Somers Cc: FreeBSD CURRENT Subject: Re: panic: Unregistered use of FPU in kernel Message-ID: <20190926172924.GH44691@kib.kiev.ua> References: <20190926170241.GG44691@kib.kiev.ua> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.12.2 (2019-09-21) X-Spam-Status: No, score=-1.0 required=5.0 tests=ALL_TRUSTED,BAYES_00, DKIM_ADSP_CUSTOM_MED,FORGED_GMAIL_RCVD,FREEMAIL_FROM, NML_ADSP_CUSTOM_MED autolearn=no autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on tom.home X-Rspamd-Queue-Id: 46fMP80FjGz4Zmq X-Spamd-Bar: ----- Authentication-Results: mx1.freebsd.org; none X-Spamd-Result: default: False [-5.99 / 15.00]; NEURAL_HAM_MEDIUM(-0.99)[-0.989,0]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; REPLY(-4.00)[] X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.29 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, 26 Sep 2019 17:29:32 -0000 On Thu, Sep 26, 2019 at 11:20:51AM -0600, Alan Somers wrote: > On Thu, Sep 26, 2019 at 11:02 AM Konstantin Belousov > wrote: > > > On Thu, Sep 26, 2019 at 09:45:43AM -0600, Alan Somers wrote: > > > The latest VM snapshot > > (FreeBSD-13.0-CURRENT-amd64-20190920-r352544.qcow2) > > > instapanics on boot: > > > > > > panic: Unregistered use of FPU in kernel > > > > > > stack trace: > > > ... > > > sse42_crc32c > > > readsuper > > > ffs_sbget > > > g_label_ufs_taste_common > > > g_label_taste > > > g_new_provider_event > > > g_run_events > > > fork_exit > > > ... > > > > > > Has anybody touched this area recently? I'll try to narrow down the > > commit > > > range. > > > > Start with disassembling the faulting instruction. I suspect that somehow > > vital compiler switches like -mno-sse got omitted in the build. > > > > No problem with compiler switches here. The C file uses inline assembly to > generate a crc32q instruction, in crc32_sse42.c:257. But why would that > generate a floating point exception? The instruction doesn't appear to be > using any floating point registers. This is on a Kaby Lake CPU. > > crc32q %rsi, %rbx No idea, this instruction does not generate #NP at all. Provide exact script of the panic and backtrace, together with the disassembly of the function which contained the faulted instruction. Do disassemble from ddb, in case text was corrupted.