From patchwork Thu Mar 27 08:42:10 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Tvrtko Ursulin X-Patchwork-Id: 14030862 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 E85FAC36012 for ; Thu, 27 Mar 2025 08:42:36 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 8030F10E87D; Thu, 27 Mar 2025 08:42:30 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=igalia.com header.i=@igalia.com header.b="Qp9N2DGC"; dkim-atps=neutral Received: from fanzine2.igalia.com (fanzine.igalia.com [178.60.130.6]) by gabe.freedesktop.org (Postfix) with ESMTPS id 59A2110E882 for ; Thu, 27 Mar 2025 08:42:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=igalia.com; s=20170329; h=Content-Transfer-Encoding:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:Cc:To:From:Sender:Reply-To:Content-Type:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=LpH3h5639y/WJq18Up1M67BswU21entH/+d9ra7bVa8=; b=Qp9N2DGC4gbNVHZ66TswRMgDZD xcqL3De7k4pLpNszIZXCn974FrF3hqiAmMr0EMxKO0DCg/TmOeRBay4QayYz3Iz94xwx6kt+hw2kO sDjdnZ2yU+WA3Xd5nzU2s7XwJSHPYoA69tvw/r7ohzZS1XobCBefskdNqkPRDipwiXVUg2YWFGCNV UpfFPA+tKvagBSgkPMSco/ZyxKQsg0DrUw1u41esjRX3Pq/OcmtCFqWvGA9TxZ3gu+Dqj8mhXL/Nf HJ0iMgv+YclKovEDVVBe9QmV6wp1D3SxxxxRMt57gRZN/VoyRkW904dgeBDlzBLiEetXNweChXAZi KNr2CoTw==; Received: from [90.241.98.187] (helo=localhost) by fanzine2.igalia.com with esmtpsa (Cipher TLS1.3:ECDHE_SECP256R1__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim) id 1txiof-0078l1-QB; Thu, 27 Mar 2025 09:42:21 +0100 From: Tvrtko Ursulin To: dri-devel@lists.freedesktop.org Cc: kernel-dev@igalia.com, =?utf-8?q?Ma=C3=ADra_Canal?= , Tvrtko Ursulin Subject: [PATCH v2 3/7] drm/syncobj: Avoid one temporary allocation in drm_syncobj_array_find Date: Thu, 27 Mar 2025 08:42:10 +0000 Message-ID: <20250327084215.26662-4-tvrtko.ursulin@igalia.com> X-Mailer: git-send-email 2.48.0 In-Reply-To: <20250327084215.26662-1-tvrtko.ursulin@igalia.com> References: <20250327084215.26662-1-tvrtko.ursulin@igalia.com> MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Drm_syncobj_array_find() helper is used from many userspace ioctl entry points with the task of looking up userspace handles to internal objects. We can easily avoid one temporary allocation by making it read the handles as it is looking them up. Signed-off-by: Tvrtko Ursulin Reviewed-by: Maíra Canal --- v2: * Fix handle type. * Undo pointless unwind change. --- drivers/gpu/drm/drm_syncobj.c | 36 +++++++++++++++-------------------- 1 file changed, 15 insertions(+), 21 deletions(-) diff --git a/drivers/gpu/drm/drm_syncobj.c b/drivers/gpu/drm/drm_syncobj.c index 28081cf74052..cd36c888f112 100644 --- a/drivers/gpu/drm/drm_syncobj.c +++ b/drivers/gpu/drm/drm_syncobj.c @@ -1213,39 +1213,35 @@ signed long drm_timeout_abs_to_jiffies(int64_t timeout_nsec) EXPORT_SYMBOL(drm_timeout_abs_to_jiffies); static int drm_syncobj_array_find(struct drm_file *file_private, - void __user *user_handles, - uint32_t count_handles, + u32 __user *handles, + uint32_t count, struct drm_syncobj ***syncobjs_out) { - uint32_t i, *handles; struct drm_syncobj **syncobjs; + uint32_t i; int ret; - handles = kmalloc_array(count_handles, sizeof(*handles), GFP_KERNEL); - if (handles == NULL) + if (!access_ok(handles, count * sizeof(*handles))) + return -EFAULT; + + syncobjs = kmalloc_array(count, sizeof(*syncobjs), GFP_KERNEL); + if (!syncobjs) return -ENOMEM; - if (copy_from_user(handles, user_handles, - sizeof(uint32_t) * count_handles)) { - ret = -EFAULT; - goto err_free_handles; - } + for (i = 0; i < count; i++) { + u32 handle; - syncobjs = kmalloc_array(count_handles, sizeof(*syncobjs), GFP_KERNEL); - if (syncobjs == NULL) { - ret = -ENOMEM; - goto err_free_handles; - } - - for (i = 0; i < count_handles; i++) { - syncobjs[i] = drm_syncobj_find(file_private, handles[i]); + if (__get_user(handle, handles++)) { + ret = -EFAULT; + goto err_put_syncobjs; + } + syncobjs[i] = drm_syncobj_find(file_private, handle); if (!syncobjs[i]) { ret = -ENOENT; goto err_put_syncobjs; } } - kfree(handles); *syncobjs_out = syncobjs; return 0; @@ -1253,8 +1249,6 @@ static int drm_syncobj_array_find(struct drm_file *file_private, while (i-- > 0) drm_syncobj_put(syncobjs[i]); kfree(syncobjs); -err_free_handles: - kfree(handles); return ret; }