From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752093AbdKHSJu (ORCPT ); Wed, 8 Nov 2017 13:09:50 -0500 Received: from mailout1.samsung.com ([203.254.224.24]:26724 "EHLO mailout1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751600AbdKHSJr (ORCPT ); Wed, 8 Nov 2017 13:09:47 -0500 DKIM-Filter: OpenDKIM Filter v2.11.0 mailout1.samsung.com 20171108180945epoutp01fa7a212c5ac639afa07e8125ba96a102~1LrCOmY9F0232102321epoutp011 X-AuditID: b6c32a37-ef3ff70000001049-76-5a034869c323 From: Bartlomiej Zolnierkiewicz To: Fengguang Wu Cc: linux-ide@vger.kernel.org, Borislav Petkov , "David S. Miller" , Linus Torvalds , Jens Axboe , Bart Van Assche , linux-kernel@vger.kernel.org Subject: Re: [cdrom_check_status] BUG: unable to handle kernel NULL pointer dereference at 000001c0 Date: Wed, 08 Nov 2017 19:09:42 +0100 Message-id: <4286386.v3LAhFsTvW@amdc3058> User-Agent: KMail/4.13.3 (Linux/3.13.0-96-generic; KDE/4.13.3; x86_64; ; ) In-reply-to: <7885793.0mqNGdeUvE@amdc3058> MIME-version: 1.0 Content-transfer-encoding: 7Bit Content-type: text/plain; charset="us-ascii" X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFupgleLIzCtJLcpLzFFi42LZdlhTVzfTgznKYNEUbovVd/vZLA7+bGO0 +LzhH5vFnPMtLBbvn69ntji24xGTxeVdc9gsHvW9ZXfg8Pje2sfisWXlTSaPxXteMnlcPlvq cWLGbxaPaWvOM3l83iQXwB7FZZOSmpNZllqkb5fAlfHlxVzGggncFS0dKxgbGJs5uxg5OCQE TCRurjDuYuTiEBLYwShx7PZDZgjnO6NE98WHbF2MnGBFF081MkEkdjNKrN77ihHC+coocfzL arAqNgEriYntqxhBbBEBTYm3hzazgNjMAm1MEsuWsoPYwgKpEm17T7KC2CwCqhIXT24A6+UF qu+f9p0ZxBYV8JLYsq+dCcTmFNCSuLz4KAtEjaDEj8n3oGbKS+zbP5UVwtaROHtsHdhBEgKX 2SSmt5+EOttFYs/elcwQtrDEq+Nb2CF+lpa4dNQWIjydUWL7bwmI3s2MEqt2T2CHSFhLHD5+ EWoBn8S7rz2sEL28Eh1tQhAlHhIzZ71ghbAdJVY3bgD7HRyOk35bTGCUnYXk7FlIzp6F5OwF jMyrGMVSC4pz01OLDQuM9YoTc4tL89L1kvNzNzGC04eW+Q7GDed8DjEKcDAq8fBekGOKEmJN LCuuzD3EKMHBrCTC26vPHCXEm5JYWZValB9fVJqTWnyIUZqDRUmcV2z9tQghgfTEktTs1NSC 1CKYLBMHp1QDo672zLVVDjdlvdZU5uc//M0mqHLkRs4fnSSHLaInItlauXb0Wv1/vtp6Ut8B uVsLFvoyCbz37zasX5+98XHaMyGb819E0hYwxWyuL0ydnO+Z96mU8d2R059iX9oau+24wOO9 3ZbzdtE7Fp47l9uPNP05ci1jz8wnWy8t3hxRcP7P/nW3rPUFeZRYijMSDbWYi4oTAer4l4Eb AwAA X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFnrILMWRmVeSWpSXmKPExsVy+t9jAd0MD+Yog6ObdC1W3+1nszj4s43R 4vOGf2wWc863sFi8f76e2eLYjkdMFpd3zWGzeNT3lt2Bw+N7ax+Lx5aVN5k8Fu95yeRx+Wyp x4kZv1k8pq05z+TxeZNcAHsUl01Kak5mWWqRvl0CV8aXF3MZCyZwV7R0rGBsYGzm7GLk5JAQ MJG4eKqRqYuRi0NIYCejxMG99xkhnK+MEkvW/WMBqWITsJKY2L6KEcQWEdCUeHtoM1icWaCN SWLiQw0QW1ggVaJt70lWEJtFQFXi4skNbCA2L1B9/7TvzCC2qICXxJZ97UwgNqeAlsTlxUeB 5nAALUuR2PycGaJcUOLH5HtQ4+Ul9u2fygpha0ms33mcaQIj/ywkZbOQlM1CUraAkXkVo2Rq QXFuem6xUYFhXmq5XnFibnFpXrpecn7uJkZgwG87rNW3g/H+kvhDjAIcjEo8vBfkmKKEWBPL iitzDzFKcDArifD26jNHCfGmJFZWpRblxxeV5qQWH2KU5mBREue9nXcsUkggPbEkNTs1tSC1 CCbLxMEp1cDo5ru7vHit5NTEGQ9aMldVfFlwMTToR/CHNRtcNmustlq++9vRK0IlnSFX2Uuk fi7IY0y6waH6fjNLSGGrh0Xqoextk5XEFrPpXhFr3NDywNQ00JD1cWZ81yq+lmcyzDxfuU/E xP9pc+CtWy6xeyr/oTAuKYOQza+eb5zK6cSnJJXKy3rKJU6JpTgj0VCLuag4EQD0gSmxdAIA AA== X-CMS-MailID: 20171108180944epcas1p18bb9337cb4cfb5c7e9bd5f6eccfa33f4 X-Msg-Generator: CA CMS-TYPE: 101P X-CMS-RootMailID: 20171108180944epcas1p18bb9337cb4cfb5c7e9bd5f6eccfa33f4 X-RootMTR: 20171108180944epcas1p18bb9337cb4cfb5c7e9bd5f6eccfa33f4 References: <20171107102538.mzbfdxll3fpf2kqg@wfg-t540p.sh.intel.com> <7885793.0mqNGdeUvE@amdc3058> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wednesday, November 08, 2017 05:28:16 PM Bartlomiej Zolnierkiewicz wrote: > Something is very wrong here as pci_request_selected_regions() in > drivers/ide/setup-pci.c:ide_pci_enable() should allocate PCI resources > so the second probe attempt should not happen. Also interface/device > names reuse should be prevented by ide_find_port_slot().. OK, I see now what is going on here: ... CONFIG_DEBUG_TEST_DRIVER_REMOVE=y ... config DEBUG_TEST_DRIVER_REMOVE bool "Test driver remove calls during probe (UNSTABLE)" depends on DEBUG_KERNEL help Say Y here if you want the Driver core to test driver remove functions by calling probe, remove, probe. This tests the remove path without having to unbind the driver or unload the driver module. This option is expected to find errors and may render your system unusable. You should say N here unless you are explicitly looking to test this functionality. We actually see race on ->remove inside IDE's ide-cd.c driver related to disk_check_events() handling.. It is not worth to continue with fixing IDE but from the quick look SCSI sr.c may have similar problem - it may be worth to try to reproduce it using libata's piix driver (disable CONFIG_IDE and enable CONFIG_BLK_DEV_SR, CONFIG_ATA_PIIX is already enabled). Best regards, -- Bartlomiej Zolnierkiewicz Samsung R&D Institute Poland Samsung Electronics