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 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 45C4CC77B7E for ; Thu, 25 May 2023 08:16:28 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 1B49610E7F5; Thu, 25 May 2023 08:16:28 +0000 (UTC) Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by gabe.freedesktop.org (Postfix) with ESMTPS id 24F4F10E7F5 for ; Thu, 25 May 2023 08:16:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1685002587; x=1716538587; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=o4n8Yvc9ITGjxW66pjEXgifAkzmd+L/dEydea9oBS1I=; b=dA+Uk3aUi0apR2Qb1who1a062R2HzS+bnLwJHnt4cTFmjK9FzexDUUVQ uvfxr/4oXMRMhhb/QYcNSbmAtYkO+ePkXKut0Z3U76c4m6lgTiFak6vTj 3sbd6wQptoWZQHJHBVipso4BPsNqCQe84/sAcuq6lXi1fGyGPR+p6FnFG lOG4IeHjWRBi7VKDNPRqjrSWGjkR1d1bTKuBlpS9lAvx8Dze0waU2mQwd fIPbAw2LEnffDq6JreZ4Y+vbIZ5xp+V4JAluVeQZPfGxy1wNSqrOdCOJo E3rb7hiqk4X+Dk2Vc3YE5qFRugUF/SxgBtppjY6Xpm9uXSoKGiXuvEYfO Q==; X-IronPort-AV: E=McAfee;i="6600,9927,10720"; a="351333884" X-IronPort-AV: E=Sophos;i="6.00,190,1681196400"; d="scan'208";a="351333884" Received: from orsmga004.jf.intel.com ([10.7.209.38]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 May 2023 01:16:25 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10720"; a="828944166" X-IronPort-AV: E=Sophos;i="6.00,190,1681196400"; d="scan'208";a="828944166" Received: from lsilistr-mobl.ger.corp.intel.com (HELO thellstr-mobl1.intel.com) ([10.249.254.226]) by orsmga004-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 May 2023 01:16:24 -0700 From: =?UTF-8?q?Thomas=20Hellstr=C3=B6m?= To: intel-xe@lists.freedesktop.org Date: Thu, 25 May 2023 10:16:15 +0200 Message-Id: <20230525081615.179819-1-thomas.hellstrom@linux.intel.com> X-Mailer: git-send-email 2.39.2 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Subject: [Intel-xe] [PATCH] drm/xe: Fix engine lookup refcount race X-BeenThere: intel-xe@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel Xe graphics driver List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-xe-bounces@lists.freedesktop.org Sender: "Intel-xe" Fix a race where the engine could disappear between lookup unlock and xe_engine_get(). Signed-off-by: Thomas Hellström --- drivers/gpu/drm/xe/xe_engine.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/gpu/drm/xe/xe_engine.c b/drivers/gpu/drm/xe/xe_engine.c index 094ec17d3004..3a400a546dfe 100644 --- a/drivers/gpu/drm/xe/xe_engine.c +++ b/drivers/gpu/drm/xe/xe_engine.c @@ -161,10 +161,9 @@ struct xe_engine *xe_engine_lookup(struct xe_file *xef, u32 id) mutex_lock(&xef->engine.lock); e = xa_load(&xef->engine.xa, id); - mutex_unlock(&xef->engine.lock); - if (e) xe_engine_get(e); + mutex_unlock(&xef->engine.lock); return e; } -- 2.39.2