From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 71D35C33CB2 for ; Tue, 14 Jan 2020 18:26:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4E87A222C3 for ; Tue, 14 Jan 2020 18:26:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=mev.co.uk header.i=@mev.co.uk header.b="EH4oqtkS" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726839AbgANS0A (ORCPT ); Tue, 14 Jan 2020 13:26:00 -0500 Received: from smtp104.ord1c.emailsrvr.com ([108.166.43.104]:51913 "EHLO smtp104.ord1c.emailsrvr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728909AbgANSZ7 (ORCPT ); Tue, 14 Jan 2020 13:25:59 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=mev.co.uk; s=20190130-41we5z8j; t=1579026358; bh=x97t4sVCLec0AUkyNkrph7ut/gSYCSeAr+g7v3AiIVs=; h=From:To:Subject:Date:From; b=EH4oqtkSvIzVRUoYf9m/iInrr7YCBCTkZgHOPMDyXTpDEBvjCpoIjT5RlDVylKj+M Bdl5aCHZeA7AsP7NNbm3bZR3yBXgzvTVJBBcjzbcmT5xKoCok1r2rK/xBiXDTXSEWC KdPu3BBfoT2yW+FZ0IeWW3dZAZv8hjSlBEDmZLl4= X-Auth-ID: abbotti@mev.co.uk Received: by smtp6.relay.ord1c.emailsrvr.com (Authenticated sender: abbotti-AT-mev.co.uk) with ESMTPSA id 06F8FA0108; Tue, 14 Jan 2020 13:25:56 -0500 (EST) X-Sender-Id: abbotti@mev.co.uk Received: from ian-deb.inside.mev.co.uk (remote.quintadena.com [81.133.34.160]) (using TLSv1.2 with cipher DHE-RSA-AES128-GCM-SHA256) by 0.0.0.0:465 (trex/5.7.12); Tue, 14 Jan 2020 13:25:58 -0500 From: Ian Abbott To: devel@driverdev.osuosl.org Cc: Greg Kroah-Hartman , Ian Abbott , H Hartley Sweeten , linux-kernel@vger.kernel.org, stable@vger.kernel.org, "Spencer E . Olson" Subject: [PATCH 2/2] staging: comedi: ni_routes: allow partial routing information Date: Tue, 14 Jan 2020 18:25:32 +0000 Message-Id: <20200114182532.132058-3-abbotti@mev.co.uk> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200114182532.132058-1-abbotti@mev.co.uk> References: <20200114182532.132058-1-abbotti@mev.co.uk> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org This patch fixes a regression on setting up asynchronous commands to use external trigger sources when board-specific routing information is missing. `ni_find_device_routes()` (called via `ni_assign_device_routes()`) finds the table of register values for the device family and the set of valid routes for the specific board. If both are found, `tables->route_values` is set to point to the table of register values for the device family and `tables->valid_routes` is set to point to the list of valid routes for the specific board. If either is not found, both `tables->route_values` and `tables->valid_routes` are left set at their initial null values (initialized by `ni_assign_device_routes()`) and the function returns `-ENODATA`. Returning an error results in some routing functionality being disabled. Unfortunately, leaving `table->route_values` set to `NULL` also breaks the setting up of asynchronous commands that are configured to use external trigger sources. Calls to `ni_check_trigger_arg()` or `ni_check_trigger_arg_roffs()` while checking the asynchronous command set-up would result in a null pointer dereference if `table->route_values` is `NULL`. The null pointer dereference is fixed in another patch, but it now results in failure to set up the asynchronous command. That is a regression from the behavior prior to commit 347e244884c3 ("staging: comedi: tio: implement global tio/ctr routing") and commit 56d0b826d39f ("staging: comedi: ni_mio_common: implement new routing for TRIG_EXT"). Change `ni_find_device_routes()` to set `tables->route_values` and/or `tables->valid_routes` to valid information even if the other one can only be set to `NULL` due to missing information. The function will still return an error in that case. This should result in `tables->valid_routes` being valid for all currently supported device families even if the board-specific routing information is missing. That should be enough to fix the regression on setting up asynchronous commands to use external triggers for boards with missing routing information. Fixes: 347e244884c3 ("staging: comedi: tio: implement global tio/ctr routing") Fixes: 56d0b826d39f ("staging: comedi: ni_mio_common: implement new routing for TRIG_EXT"). Cc: # 4.20+ Cc: Spencer E. Olson Signed-off-by: Ian Abbott --- drivers/staging/comedi/drivers/ni_routes.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) diff --git a/drivers/staging/comedi/drivers/ni_routes.c b/drivers/staging/comedi/drivers/ni_routes.c index 9627bd1d2a78..8f398b30f5bf 100644 --- a/drivers/staging/comedi/drivers/ni_routes.c +++ b/drivers/staging/comedi/drivers/ni_routes.c @@ -72,9 +72,6 @@ static int ni_find_device_routes(const char *device_family, } } - if (!rv) - return -ENODATA; - /* Second, find the set of routes valid for this device. */ for (i = 0; ni_device_routes_list[i]; ++i) { if (memcmp(ni_device_routes_list[i]->device, board_name, @@ -84,12 +81,12 @@ static int ni_find_device_routes(const char *device_family, } } - if (!dr) - return -ENODATA; - tables->route_values = rv; tables->valid_routes = dr; + if (!rv || !dr) + return -ENODATA; + return 0; } -- 2.24.1