From patchwork Mon Jan 6 10:55:17 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tvrtko Ursulin X-Patchwork-Id: 13927190 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 3FA92E77188 for ; Mon, 6 Jan 2025 10:55:34 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id A1C7010E61B; Mon, 6 Jan 2025 10:55:28 +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="NY6mnIIB"; dkim-atps=neutral Received: from fanzine2.igalia.com (fanzine.igalia.com [178.60.130.6]) by gabe.freedesktop.org (Postfix) with ESMTPS id 82A5810E61A for ; Mon, 6 Jan 2025 10:55:27 +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=hU/69p/jwGJXm8YfbQxFGn4pO8R2zhm2nIn9RhkewnA=; b=NY6mnIIBtKl8FfZlmJjsLY3OkG Ig4MxZQMh6pU2Rb2KSCpq+x2RYfaLyQNfv/6mCswGHICHv92HK0PCPLswusvw25bTg0pk7i6IqeUo FpeVt/3RxeSEeXXhbCDRsMpYCFT5E8DzqNdRjcquzDW9utitwVf20bRcDYSY0nNyLuLvMMgipJuX4 iN7cYmqeTLWzXwTFIhi3t/YKMJQLWoW4oyhNERlhzAU4NTwgw9XsOD6xhTUucNXAsf77AzV+xrjj9 N3AxVcXyaghnBoiDw39ZRnGtDUM7lx4v/5OKqd0PO6uO91XdnkNC+1hjsdOoSa4DGfnC9koAN+tTP UGy3VTQA==; 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 1tUklZ-00CESA-Q0; Mon, 06 Jan 2025 11:55:25 +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: Mon, 6 Jan 2025 10:55:17 +0000 Message-ID: <20250106105521.53149-4-tursulin@igalia.com> X-Mailer: git-send-email 2.47.1 In-Reply-To: <20250106105521.53149-1-tursulin@igalia.com> References: <20250106105521.53149-1-tursulin@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" From: Tvrtko Ursulin 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; }