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 X-Spam-Level: X-Spam-Status: No, score=-11.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 D8C9CC433E0 for ; Tue, 11 Aug 2020 17:29:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B5AB120781 for ; Tue, 11 Aug 2020 17:29:42 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="IqDuLgB6" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729320AbgHKR3g (ORCPT ); Tue, 11 Aug 2020 13:29:36 -0400 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:45999 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1729218AbgHKR3f (ORCPT ); Tue, 11 Aug 2020 13:29:35 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1597166974; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=/kCCiP1A994GEPhfTMliHq1uK+Sv/vNDYIXMua8VMzw=; b=IqDuLgB6JJNeR0UFLOWa+giGAEu2+7S1ZRnVivBFGZEbewfUjRrQAnRG12cJjwF7TFt6Eu wHQ1do3sBMR1J6aD/tuz9H6GlecmHeebI2mFspeJrPQpmssjLMiK/UgxIhjcFQ6HgUVLaz bsatkcLL428CRS2XQa0/Q/SBxS92AGQ= Received: from mail-qk1-f198.google.com (mail-qk1-f198.google.com [209.85.222.198]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-503-TVFwQiL0M2y6yYcg3WB2Lg-1; Tue, 11 Aug 2020 13:29:32 -0400 X-MC-Unique: TVFwQiL0M2y6yYcg3WB2Lg-1 Received: by mail-qk1-f198.google.com with SMTP id a186so9834581qke.1 for ; Tue, 11 Aug 2020 10:29:32 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-transfer-encoding :content-language; bh=/kCCiP1A994GEPhfTMliHq1uK+Sv/vNDYIXMua8VMzw=; b=nfBPO+zEeNH/o2JrdQPSBgfi/oyJmkXDSABOUzS7ZB0p7LavHIYrryJtvIRs2OO8XX /mgGeMXS/8mzKfHFDjF70MQcLAN4+y0joKVTFvG5ES4N9VztWmk2yiU3xKW2G1XcOQ7/ JSdvwdHHGvf3tXOhh0T21ck6JmqpCWaI5V6LcMqWhPM032NRzECTfnBME371A92s2MVq WJWcJAXAhoX1GLRGy312Hl0vBVwx3qPDNvtV5/06GbyoQjRCGgQiEfsYbvm77y/hfP3K uHOvpIgkPhH5EQplzyXeVijcqHRfY5O9HOC3bWJ/X0AuKXF2T7bi7+sdnh5KuJxeXDWo vWsw== X-Gm-Message-State: AOAM531o4rLDn2upkIxLcSKtiJaOFHmrBNYkEbpS/vObhk8U+ddLQQQ6 0yDColjtg2jR5zO8BqcZjcNacFmRZr9jI5PxFVoGLLLzEaftl8hoqnPh34Em7VsiCJvCSvI0Rnz wxJKuPn7DsCw80l04n8RjYsmt X-Received: by 2002:ac8:6e87:: with SMTP id c7mr2347338qtv.62.1597166971941; Tue, 11 Aug 2020 10:29:31 -0700 (PDT) X-Google-Smtp-Source: ABdhPJyL8bEYELl1qXi1MXs8Z4bGDTdMzjg5IXgTDDjBowuqwx+PFGWiyKTQTphCbSqHo0N18EI7IQ== X-Received: by 2002:ac8:6e87:: with SMTP id c7mr2347311qtv.62.1597166971642; Tue, 11 Aug 2020 10:29:31 -0700 (PDT) Received: from trix.remote.csb (075-142-250-213.res.spectrum.com. [75.142.250.213]) by smtp.gmail.com with ESMTPSA id g55sm20376876qta.94.2020.08.11.10.29.30 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 11 Aug 2020 10:29:31 -0700 (PDT) Subject: Re: [PATCH] USB: realtek_cr: fix return check for dma functions To: Alan Stern Cc: gregkh@linuxfoundation.org, acozzette@cs.hmc.edu, linux-usb@vger.kernel.org, usb-storage@lists.one-eyed-alien.net, linux-kernel@vger.kernel.org References: <20200811151505.12222-1-trix@redhat.com> <20200811160348.GD335280@rowland.harvard.edu> From: Tom Rix Message-ID: <1f7d5a64-f264-4fed-bf90-b64e2693652d@redhat.com> Date: Tue, 11 Aug 2020 10:29:29 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.6.0 MIME-Version: 1.0 In-Reply-To: <20200811160348.GD335280@rowland.harvard.edu> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 8/11/20 9:03 AM, Alan Stern wrote: > On Tue, Aug 11, 2020 at 08:15:05AM -0700, trix@redhat.com wrote: >> From: Tom Rix >> >> clang static analysis reports this representative problem >> >> realtek_cr.c:639:3: warning: The left expression of the compound >> assignment is an uninitialized value. The computed value will >> also be garbage >> SET_BIT(value, 2); >> ^~~~~~~~~~~~~~~~~ >> >> value is set by a successful call to rts51x_read_mem() >> >> retval = rts51x_read_mem(us, 0xFE77, &value, 1); >> if (retval < 0) >> return -EIO; >> >> A successful call to rts51x_read_mem returns 0, failure can >> return positive and negative values. This check is wrong >> for a number of functions. Fix the retval check. >> >> Fixes: 065e60964e29 ("ums_realtek: do not use stack memory for DMA") >> Signed-off-by: Tom Rix >> --- >> drivers/usb/storage/realtek_cr.c | 36 ++++++++++++++++---------------- >> 1 file changed, 18 insertions(+), 18 deletions(-) >> >> diff --git a/drivers/usb/storage/realtek_cr.c b/drivers/usb/storage/realtek_cr.c >> index 3789698d9d3c..b983753e2368 100644 >> --- a/drivers/usb/storage/realtek_cr.c >> +++ b/drivers/usb/storage/realtek_cr.c >> @@ -481,16 +481,16 @@ static int enable_oscillator(struct us_data *us) >> u8 value; >> >> retval = rts51x_read_mem(us, 0xFE77, &value, 1); >> - if (retval < 0) >> + if (retval != STATUS_SUCCESS) >> return -EIO; > Instead of changing all these call sites, wouldn't it be a lot easier > just to change rts51x_read_mem() to make it always return a negative > value (such as -EIO) when there's an error? > > Alan Stern I thought about that but there was already existing (retval != STATUS_SUCCESS) checks for these calls. Tom >