From patchwork Wed May 12 14:48:30 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 437177 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A0478C43460 for ; Wed, 12 May 2021 15:02:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6F6D361625 for ; Wed, 12 May 2021 15:02:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232632AbhELPDo (ORCPT ); Wed, 12 May 2021 11:03:44 -0400 Received: from mail.kernel.org ([198.145.29.99]:59262 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232963AbhELPC2 (ORCPT ); Wed, 12 May 2021 11:02:28 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id B3BAC6142F; Wed, 12 May 2021 14:58:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1620831488; bh=q1/IcQVgXlUD0gUcHUY67siCIkWUFeOim6tCP7jKEA4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LthpfIuX39jM89rLEGjpLGo1dDNTUSsUDyW6xj/YTT25wU9KqVnTTEbZ8P7fVBYMv LU170ydCnvl2BUMo3FYQFm6yqaHmoON/G2102OwIV3+uM06mxlz6ZIvkRRfLKmnZZD yZykTja0IRonyLQmwXpsk81jgB2W6Gk8/3K9AY18= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dan Carpenter , Joel Stanley , Patrick Venture , Arnd Bergmann , Sasha Levin Subject: [PATCH 5.4 139/244] soc: aspeed: fix a ternary sign expansion bug Date: Wed, 12 May 2021 16:48:30 +0200 Message-Id: <20210512144747.462916994@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210512144743.039977287@linuxfoundation.org> References: <20210512144743.039977287@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Dan Carpenter [ Upstream commit 5ffa828534036348fa90fb3079ccc0972d202c4a ] The intent here was to return negative error codes but it actually returns positive values. The problem is that type promotion with ternary operations is quite complicated. "ret" is an int. "copied" is a u32. And the snoop_file_read() function returns long. What happens is that "ret" is cast to u32 and becomes positive then it's cast to long and it's still positive. Fix this by removing the ternary so that "ret" is type promoted directly to long. Fixes: 3772e5da4454 ("drivers/misc: Aspeed LPC snoop output using misc chardev") Signed-off-by: Dan Carpenter Signed-off-by: Joel Stanley Reviewed-by: Patrick Venture Link: https://lore.kernel.org/r/YIE90PSXsMTa2Y8n@mwanda Link: https://lore.kernel.org/r/20210423000919.1249474-1-joel@jms.id.au' Signed-off-by: Arnd Bergmann Signed-off-by: Sasha Levin --- drivers/soc/aspeed/aspeed-lpc-snoop.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/soc/aspeed/aspeed-lpc-snoop.c b/drivers/soc/aspeed/aspeed-lpc-snoop.c index dbe5325a324d..538d7aab8db5 100644 --- a/drivers/soc/aspeed/aspeed-lpc-snoop.c +++ b/drivers/soc/aspeed/aspeed-lpc-snoop.c @@ -95,8 +95,10 @@ static ssize_t snoop_file_read(struct file *file, char __user *buffer, return -EINTR; } ret = kfifo_to_user(&chan->fifo, buffer, count, &copied); + if (ret) + return ret; - return ret ? ret : copied; + return copied; } static __poll_t snoop_file_poll(struct file *file,