From patchwork Tue Mar 18 15:54:19 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tvrtko Ursulin X-Patchwork-Id: 14021198 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 C5602C282EC for ; Tue, 18 Mar 2025 15:54:48 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 345C510E4AB; Tue, 18 Mar 2025 15:54:48 +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="GptJIt4P"; dkim-atps=neutral Received: from fanzine2.igalia.com (fanzine.igalia.com [178.60.130.6]) by gabe.freedesktop.org (Postfix) with ESMTPS id 1E74C10E223 for ; Tue, 18 Mar 2025 15:54:30 +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=PAt9yeccigKpqHuLr9PM6lHeWkKthPLmxUbcJcP1XTI=; b=GptJIt4Ps1oCVwATW1LfKM0jl3 NF9w/NgzJlqyElmeAPKaV8rGUp2jLrZDpRs4xiRyEfG74L9bxQUcXyM3QBfBLNCLJPaNJ4BRu5Zue nGVa4MJkMzsgkUJpZZEFC6QgBAn1CNi9GSqWl2xplRv8r6zAYQXEu4FOzmDte0nxns9izUDICqIiw KkSJDlYGQz3f63YrjzRIbuvVF6W+KZNQGonOsxIWZVmvwN0swHhJr/Ad6GK8ZLjUoFlsPzNUidwbb QipDLJzzerjarILAfy88xsARFr0IXcrT5jOlvyfY2TyvmTY3Dwpo+Va4hL2ao+yIBtADmVoiTCN+1 KQWsSIJA==; 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 1tuZGu-002ngf-Cw; Tue, 18 Mar 2025 16:54:28 +0100 From: Tvrtko Ursulin To: dri-devel@lists.freedesktop.org Cc: kernel-dev@igalia.com, Tvrtko Ursulin Subject: [PATCH 3/7] drm/syncobj: Avoid one temporary allocation in drm_syncobj_array_find Date: Tue, 18 Mar 2025 15:54:19 +0000 Message-ID: <20250318155424.78552-4-tvrtko.ursulin@igalia.com> X-Mailer: git-send-email 2.48.0 In-Reply-To: <20250318155424.78552-1-tvrtko.ursulin@igalia.com> References: <20250318155424.78552-1-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 --- drivers/gpu/drm/drm_syncobj.c | 44 +++++++++++++++++------------------ 1 file changed, 21 insertions(+), 23 deletions(-) diff --git a/drivers/gpu/drm/drm_syncobj.c b/drivers/gpu/drm/drm_syncobj.c index fd5ba6c89666..cdda2df06bec 100644 --- a/drivers/gpu/drm/drm_syncobj.c +++ b/drivers/gpu/drm/drm_syncobj.c @@ -1213,48 +1213,46 @@ 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++) { + u64 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; + syncobjs[i] = NULL; + 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; err_put_syncobjs: - while (i-- > 0) - drm_syncobj_put(syncobjs[i]); + while (i > 0) { + if (syncobjs[i]) + drm_syncobj_put(syncobjs[i]); + i--; + } kfree(syncobjs); -err_free_handles: - kfree(handles); return ret; }