From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757143Ab0IXRLR (ORCPT ); Fri, 24 Sep 2010 13:11:17 -0400 Received: from out01.mta.xmission.com ([166.70.13.231]:41695 "EHLO out01.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754151Ab0IXRLP (ORCPT ); Fri, 24 Sep 2010 13:11:15 -0400 From: ebiederm@xmission.com (Eric W. Biederman) To: "Hans J. Koch" Cc: Greg Kroah-Hartman , linux-kernel@vger.kernel.org, Thomas Gleixner References: <20100917205946.GF2522@local> <20100924105555.GD1819@silverbox.local> Date: Fri, 24 Sep 2010 10:11:09 -0700 In-Reply-To: <20100924105555.GD1819@silverbox.local> (Hans J. Koch's message of "Fri, 24 Sep 2010 12:55:56 +0200") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-XM-SPF: eid=;;;mid=;;;hst=in01.mta.xmission.com;;;ip=98.207.157.188;;;frm=ebiederm@xmission.com;;;spf=neutral X-SA-Exim-Connect-IP: 98.207.157.188 X-SA-Exim-Mail-From: ebiederm@xmission.com X-Spam-Report: * -1.0 ALL_TRUSTED Passed through trusted hosts only via SMTP * 1.5 XMNoVowels Alpha-numberic number with no vowels * 0.0 T_TM2_M_HEADER_IN_MSG BODY: T_TM2_M_HEADER_IN_MSG * -3.0 BAYES_00 BODY: Bayes spam probability is 0 to 1% * [score: 0.0000] * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa02 1397; Body=1 Fuz1=1 Fuz2=1] * 0.0 T_TooManySym_01 4+ unique symbols in subject * 0.4 UNTRUSTED_Relay Comes from a non-trusted relay X-Spam-DCC: XMission; sa02 1397; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: ;"Hans J. Koch" X-Spam-Relay-Country: Subject: Re: [PATCH 5/5] uio: Implement hotunplug support, using libunload X-Spam-Flag: No X-SA-Exim-Version: 4.2.1 (built Fri, 06 Aug 2010 16:31:04 -0600) X-SA-Exim-Scanned: Yes (on in01.mta.xmission.com) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org "Hans J. Koch" writes: > On Mon, Sep 20, 2010 at 12:24:19AM -0700, Eric W. Biederman wrote: >> >> } >> >> static ssize_t uio_read(struct file *filep, char __user *buf, >> size_t count, loff_t *ppos) >> { >> struct uio_listener *listener = filep->private_data; >> - struct uio_device *idev = listener->dev; >> + struct uio_device *idev = listener_idev(listener); >> DECLARE_WAITQUEUE(wait, current); >> ssize_t retval; >> s32 event_count; >> >> - if (!idev->info->irq) >> + if (!unload_trylock(&idev->unload)) >> return -EIO; >> >> + retval = -EIO; >> + if (!idev->info->irq) >> + goto out; >> + >> + retval = -EIO; >> if (count != sizeof(s32)) >> - return -EINVAL; >> + goto out; > > No. uio_read() should return -EINVAL if count != sizeof(s32). This is > simply wrong userspace code that passes in an illegal value, so it's > not an IO error but an invalid parameter. > BTW, you use -EINVAL in the same situation in uio_write()... Apologies. That was a typo. It was my intention to preserve the existing return codes. Eric