From patchwork Tue Mar 6 15:47:22 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jarkko Nikula X-Patchwork-Id: 10262165 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 801016016D for ; Tue, 6 Mar 2018 15:47:31 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 704B21FF41 for ; Tue, 6 Mar 2018 15:47:31 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 620E028C42; Tue, 6 Mar 2018 15:47:31 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id CFC991FF41 for ; Tue, 6 Mar 2018 15:47:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752784AbeCFPra (ORCPT ); Tue, 6 Mar 2018 10:47:30 -0500 Received: from mga01.intel.com ([192.55.52.88]:60332 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750797AbeCFPr3 (ORCPT ); Tue, 6 Mar 2018 10:47:29 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga101.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 06 Mar 2018 07:47:29 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.47,432,1515484800"; d="scan'208";a="32831547" Received: from mylly.fi.intel.com (HELO mylly.fi.intel.com.) ([10.237.72.56]) by orsmga003.jf.intel.com with ESMTP; 06 Mar 2018 07:47:27 -0800 From: Jarkko Nikula To: linux-spi@vger.kernel.org Cc: Mark Brown , Suniel Mahesh , Jarkko Nikula , stable@vger.kernel.org Subject: [PATCH] spi: Fix unregistration of controller with fixed SPI bus number Date: Tue, 6 Mar 2018 17:47:22 +0200 Message-Id: <20180306154722.8813-1-jarkko.nikula@linux.intel.com> X-Mailer: git-send-email 2.16.1 Sender: linux-spi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Commit 9b61e302210e (spi: Pick spi bus number from Linux idr or spi alias) ceased to unregister SPI buses with fixed bus numbers. Moreover this is visible only if CONFIG_SPI_DEBUG=y is set or when trying to re-register the same SPI controller. rmmod spi_pxa2xx_platform (with CONFIG_SPI_DEBUG=y): [ 26.788362] spi_master spi1: attempting to delete unregistered controller [spi1] modprobe spi_pxa2xx_platform: [ 37.883137] sysfs: cannot create duplicate filename '/devices/pci0000:00/0000:00:19.0/pxa2xx-spi.12/spi_master/spi1' [ 37.894984] CPU: 1 PID: 1467 Comm: modprobe Not tainted 4.16.0-rc4+ #21 [ 37.902384] Call Trace: ... [ 38.122680] kobject_add_internal failed for spi1 with -EEXIST, don't try to register things with the same name in the same directory. [ 38.136154] WARNING: CPU: 1 PID: 1467 at lib/kobject.c:238 kobject_add_internal+0x2a5/0x2f0 ... [ 38.513817] pxa2xx-spi pxa2xx-spi.12: problem registering spi master [ 38.521036] pxa2xx-spi: probe of pxa2xx-spi.12 failed with error -17 Fix this by not returning immediately from spi_unregister_controller() if idr_find() doesn't find controller with given ID/bus number. It finds only those controllers that were registered with dynamic SPI bus numbers. Only conditional cleanup between dynamic and fixed bus numbers is to remove allocated IDR. Fixes: 9b61e302210e (spi: Pick spi bus number from Linux idr or spi alias) Cc: stable@vger.kernel.org Signed-off-by: Jarkko Nikula --- This doesn't apply to v4.14 without commit 67f7b2781faf ("spi: fix use-after-free at controller deregistration"). --- drivers/spi/spi.c | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-) diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index b33a727a0158..e90fd442b3f0 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -2254,12 +2254,6 @@ void spi_unregister_controller(struct spi_controller *ctlr) mutex_lock(&board_lock); found = idr_find(&spi_master_idr, id); mutex_unlock(&board_lock); - if (found != ctlr) { - dev_dbg(&ctlr->dev, - "attempting to delete unregistered controller [%s]\n", - dev_name(&ctlr->dev)); - return; - } if (ctlr->queued) { if (spi_destroy_queue(ctlr)) dev_err(&ctlr->dev, "queue remove failed\n"); @@ -2272,7 +2266,8 @@ void spi_unregister_controller(struct spi_controller *ctlr) device_unregister(&ctlr->dev); /* free bus id */ mutex_lock(&board_lock); - idr_remove(&spi_master_idr, id); + if (found == ctlr) + idr_remove(&spi_master_idr, id); mutex_unlock(&board_lock); } EXPORT_SYMBOL_GPL(spi_unregister_controller);