From patchwork Sat Jul 14 12:32:12 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nicholas Mc Guire X-Patchwork-Id: 10524711 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 6ECF2601C2 for ; Sat, 14 Jul 2018 12:49:21 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 524B828C17 for ; Sat, 14 Jul 2018 12:49:21 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4656928C28; Sat, 14 Jul 2018 12:49:21 +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=-5.2 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 0742328C17 for ; Sat, 14 Jul 2018 12:49:20 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id E86296E2D2; Sat, 14 Jul 2018 12:49:17 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org X-Greylist: delayed 775 seconds by postgrey-1.36 at gabe; Sat, 14 Jul 2018 12:49:15 UTC Received: from www.osadl.org (www.osadl.org [62.245.132.105]) by gabe.freedesktop.org (Postfix) with ESMTPS id D0B3F6E2D2 for ; Sat, 14 Jul 2018 12:49:15 +0000 (UTC) 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 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 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: David Airlie , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, Nicholas Mc Guire MIME-Version: 1.0 Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" X-Virus-Scanned: ClamAV using ClamSMTP 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;