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=-2.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,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 35111ECDFAA for ; Sat, 14 Jul 2018 12:43:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 80CE72086B for ; Sat, 14 Jul 2018 12:43:41 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 80CE72086B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=osadl.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726971AbeGNM4U (ORCPT ); Sat, 14 Jul 2018 08:56:20 -0400 Received: from www.osadl.org ([62.245.132.105]:36844 "EHLO www.osadl.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725981AbeGNM4U (ORCPT ); Sat, 14 Jul 2018 08:56:20 -0400 Received: from debian01.hofrr.at (178.115.242.59.static.drei.at [178.115.242.59] (may be forged)) by www.osadl.org (8.13.8/8.13.8/OSADL-2007092901) with ESMTP id w6ECWu8X023927; Sat, 14 Jul 2018 14:32:56 +0200 From: Nicholas Mc Guire To: Gustavo Padovan Cc: Maarten Lankhorst , Sean Paul , David Airlie , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Nicholas Mc Guire Subject: [PATCH] drm: re-enable error handling Date: Sat, 14 Jul 2018 14:32:12 +0200 Message-Id: <1531571532-22733-1-git-send-email-hofrat@osadl.org> X-Mailer: git-send-email 2.1.4 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org drm_legacy_ctxbitmap_next() returns idr_alloc() which can return -ENOMEM, -EINVAL or -ENOSPC none of which are -1 . but the call sites of drm_legacy_ctxbitmap_next() seem to be assuming that the error case would be -1 (original return of drm_ctxbitmap_next() prior to 2.6.23 was actually -1). Thus reenable error handling by checking for < 0. Signed-off-by: Nicholas Mc Guire Fixes: 62968144e673 ("drm: convert drm context code to use Linux idr") --- Problem located with experimental coccinelle script The noted Fixes tag is one of the commits that removed the -1 return value in 2.6.23 in drm_ctxbitmap_next() but thats not the only change that must have taken place to invalidate the error check. Patch was compile tested with: x86_64_defconfig Patch is against 4.18-rc4 (localversion-next is next-20180713) drivers/gpu/drm/drm_context.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/drm_context.c b/drivers/gpu/drm/drm_context.c index 3c4000f..f973d28 100644 --- a/drivers/gpu/drm/drm_context.c +++ b/drivers/gpu/drm/drm_context.c @@ -372,7 +372,7 @@ int drm_legacy_addctx(struct drm_device *dev, void *data, ctx->handle = drm_legacy_ctxbitmap_next(dev); } DRM_DEBUG("%d\n", ctx->handle); - if (ctx->handle == -1) { + if (ctx->handle < 0) { DRM_DEBUG("Not enough free contexts.\n"); /* Should this return -EBUSY instead? */ return -ENOMEM; -- 2.1.4