From patchwork Tue Sep 11 12:50:22 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chris Wilson X-Patchwork-Id: 10595643 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 06BEC109C for ; Tue, 11 Sep 2018 12:50:41 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EAE1F293DB for ; Tue, 11 Sep 2018 12:50:40 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id DF3B2293E5; Tue, 11 Sep 2018 12:50:40 +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 6E670293DB for ; Tue, 11 Sep 2018 12:50:40 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 373E66E386; Tue, 11 Sep 2018 12:50:39 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from fireflyinternet.com (mail.fireflyinternet.com [109.228.58.192]) by gabe.freedesktop.org (Postfix) with ESMTPS id 1513E6E386 for ; Tue, 11 Sep 2018 12:50:36 +0000 (UTC) X-Default-Received-SPF: pass (skip=forwardok (res=PASS)) x-ip-name=78.156.65.138; Received: from haswell.alporthouse.com (unverified [78.156.65.138]) by fireflyinternet.com (Firefly Internet (M1)) with ESMTP id 13731867-1500050 for multiple; Tue, 11 Sep 2018 13:50:20 +0100 From: Chris Wilson To: intel-gfx@lists.freedesktop.org Date: Tue, 11 Sep 2018 13:50:22 +0100 Message-Id: <20180911125022.2555-1-chris@chris-wilson.co.uk> X-Mailer: git-send-email 2.19.0.rc2 MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH] drm/i915: Nuke struct_mutex from context_setparam X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" X-Virus-Scanned: ClamAV using ClamSMTP Userspace should be free to race against itself and shoot itself in the foot if it so desires to adjust a parameter at the same time as submitting a batch to that context. As such, the struct_mutex in context setparam is only being used to serialise userspace against itself and not for any protection of internal structs and so is superfluous. Signed-off-by: Chris Wilson Cc: Tvrtko Ursulin --- drivers/gpu/drm/i915/i915_gem_context.c | 8 +------- 1 file changed, 1 insertion(+), 7 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c index 747b8170a15a..10fd742b591d 100644 --- a/drivers/gpu/drm/i915/i915_gem_context.c +++ b/drivers/gpu/drm/i915/i915_gem_context.c @@ -896,16 +896,12 @@ int i915_gem_context_setparam_ioctl(struct drm_device *dev, void *data, struct drm_i915_file_private *file_priv = file->driver_priv; struct drm_i915_gem_context_param *args = data; struct i915_gem_context *ctx; - int ret; + int ret = 0; ctx = i915_gem_context_lookup(file_priv, args->ctx_id); if (!ctx) return -ENOENT; - ret = i915_mutex_lock_interruptible(dev); - if (ret) - goto out; - switch (args->param) { case I915_CONTEXT_PARAM_BAN_PERIOD: ret = -EINVAL; @@ -960,9 +956,7 @@ int i915_gem_context_setparam_ioctl(struct drm_device *dev, void *data, ret = -EINVAL; break; } - mutex_unlock(&dev->struct_mutex); -out: i915_gem_context_put(ctx); return ret; }