Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756318AbcCBAp7 (ORCPT ); Tue, 1 Mar 2016 19:45:59 -0500 Received: from mail333.us4.mandrillapp.com ([205.201.137.77]:58676 "EHLO mail333.us4.mandrillapp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756057AbcCAX4s (ORCPT ); Tue, 1 Mar 2016 18:56:48 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; q=dns; s=mandrill; d=linuxfoundation.org; b=T9CixOEKjXvKVcU1xCZ/4S1a05g+LoD/KqqZ3McB/jUSeIyJnWdgD58Pu+GkyQDaEB7rE2gQLmzW 4XHqplQ9mX1hztF5WmYDaAD3sLDTQvxNKprREVqHLN7Q75cTUcBPAocOoqFM/Pt3Hh+yppBHAm2E R/L+EGUhW4JU5hZ21ts=; From: Greg Kroah-Hartman Subject: [PATCH 4.4 130/342] posix-clock: Fix return code on the poll methods error path X-Mailer: git-send-email 2.7.2 To: Cc: Greg Kroah-Hartman , , Markus Elfring , John Stultz , Julia Lawall , Thomas Gleixner Message-Id: <20160301234532.145570684@linuxfoundation.org> In-Reply-To: <20160301234527.990448862@linuxfoundation.org> References: <20160301234527.990448862@linuxfoundation.org> X-Report-Abuse: Please forward a copy of this message, including all headers, to abuse@mandrill.com X-Report-Abuse: You can also report abuse here: http://mandrillapp.com/contact/abuse?id=30481620.b321d4982ed942f7b76157d7df74b4b2 X-Mandrill-User: md_30481620 Date: Tue, 01 Mar 2016 23:54:39 +0000 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1785 Lines: 49 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Richard Cochran commit 1b9f23727abb92c5e58f139e7d180befcaa06fe0 upstream. The posix_clock_poll function is supposed to return a bit mask of POLLxxx values. However, in case the hardware has disappeared (due to hot plugging for example) this code returns -ENODEV in a futile attempt to throw an error at the file descriptor level. The kernel's file_operations interface does not accept such error codes from the poll method. Instead, this function aught to return POLLERR. The value -ENODEV does, in fact, contain the POLLERR bit (and almost all the other POLLxxx bits as well), but only by chance. This patch fixes code to return a proper bit mask. Credit goes to Markus Elfring for pointing out the suspicious signed/unsigned mismatch. Reported-by: Markus Elfring igned-off-by: Richard Cochran Cc: John Stultz Cc: Julia Lawall Link: http://lkml.kernel.org/r/1450819198-17420-1-git-send-email-richardcochran@gmail.com Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman --- kernel/time/posix-clock.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/kernel/time/posix-clock.c +++ b/kernel/time/posix-clock.c @@ -69,10 +69,10 @@ static ssize_t posix_clock_read(struct f static unsigned int posix_clock_poll(struct file *fp, poll_table *wait) { struct posix_clock *clk = get_posix_clock(fp); - int result = 0; + unsigned int result = 0; if (!clk) - return -ENODEV; + return POLLERR; if (clk->ops.poll) result = clk->ops.poll(clk, fp, wait);