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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 57487C433EF for ; Tue, 7 Jun 2022 10:53:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242079AbiFGKxG (ORCPT ); Tue, 7 Jun 2022 06:53:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42776 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242359AbiFGKuN (ORCPT ); Tue, 7 Jun 2022 06:50:13 -0400 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BC52F92713; Tue, 7 Jun 2022 03:49:58 -0700 (PDT) Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out1.suse.de (Postfix) with ESMTP id F27C621B94; Tue, 7 Jun 2022 10:49:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1654598996; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=XqOqmzhUBo2wSHvuFRli3HBY7pXAt9x2omkwDPctFWs=; b=UwAKwJJNX4qilhKp/JymHxO1waEh4pYphLeHstRXxd1B7b4tad2BY+4kCKJyzqhndHm3Jp jnV7Jp8KqhIBuy/ki4F/zVhgipCGrH4YsytoOonpzRGXnkgv83+kRqJTZ0O1WmrIwMuPU2 26sVgPC5laKIN4VrFL1U6XrcxL2HV6E= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1654598996; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=XqOqmzhUBo2wSHvuFRli3HBY7pXAt9x2omkwDPctFWs=; b=SjwBOjnWfAmtsJXSBBsZfqN8T9wd+xjAsMRkgHEiYqrpxVm/F9b2h6Xm3VW0xzva4R1yCV Aa278ZTOT+y40BCw== Received: from localhost.localdomain (unknown [10.100.201.122]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by relay2.suse.de (Postfix) with ESMTPS id C9AAA2C143; Tue, 7 Jun 2022 10:49:56 +0000 (UTC) From: Jiri Slaby To: gregkh@linuxfoundation.org Cc: linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, Jiri Slaby Subject: [PATCH 36/36] tty/vt: consolemap: walk the buffer only once in con_set_trans_old() Date: Tue, 7 Jun 2022 12:49:46 +0200 Message-Id: <20220607104946.18710-36-jslaby@suse.cz> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220607104946.18710-1-jslaby@suse.cz> References: <20220607104946.18710-1-jslaby@suse.cz> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Fetch the user data one by one (by get_user()) and fill in the local buffer simultaneously. I.e. we no longer require to walk two buffers and save thus 256 B from stack (whole ubuf). Signed-off-by: Jiri Slaby --- drivers/tty/vt/consolemap.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/drivers/tty/vt/consolemap.c b/drivers/tty/vt/consolemap.c index f97f7ee6268b..fff97ae87e00 100644 --- a/drivers/tty/vt/consolemap.c +++ b/drivers/tty/vt/consolemap.c @@ -343,15 +343,15 @@ static void update_user_maps(void) */ int con_set_trans_old(unsigned char __user * arg) { - int i; unsigned short inbuf[E_TABSZ]; - unsigned char ubuf[E_TABSZ]; - - if (copy_from_user(ubuf, arg, E_TABSZ)) - return -EFAULT; + unsigned int i; + unsigned char ch; - for (i = 0; i < E_TABSZ ; i++) - inbuf[i] = UNI_DIRECT_BASE | ubuf[i]; + for (i = 0; i < ARRAY_SIZE(inbuf); i++) { + if (get_user(ch, &arg[i])) + return -EFAULT; + inbuf[i] = UNI_DIRECT_BASE | ch; + } console_lock(); memcpy(translations[USER_MAP], inbuf, sizeof(inbuf)); -- 2.36.1