From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752917AbbL2Kir (ORCPT ); Tue, 29 Dec 2015 05:38:47 -0500 Received: from terminus.zytor.com ([198.137.202.10]:56941 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751646AbbL2Kip (ORCPT ); Tue, 29 Dec 2015 05:38:45 -0500 Date: Tue, 29 Dec 2015 02:36:43 -0800 From: tip-bot for Richard Cochran Message-ID: Cc: julia.lawall@lip6.fr, mingo@kernel.org, linux-kernel@vger.kernel.org, richardcochran@gmail.com, john.stultz@linaro.org, hpa@zytor.com, elfring@users.sourceforge.net, tglx@linutronix.de Reply-To: julia.lawall@lip6.fr, mingo@kernel.org, linux-kernel@vger.kernel.org, richardcochran@gmail.com, john.stultz@linaro.org, elfring@users.sourceforge.net, hpa@zytor.com, tglx@linutronix.de In-Reply-To: <1450819198-17420-1-git-send-email-richardcochran@gmail.com> References: <1450819198-17420-1-git-send-email-richardcochran@gmail.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:timers/urgent] posix-clock: Fix return code on the poll method's error path Git-Commit-ID: 1b9f23727abb92c5e58f139e7d180befcaa06fe0 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 1b9f23727abb92c5e58f139e7d180befcaa06fe0 Gitweb: http://git.kernel.org/tip/1b9f23727abb92c5e58f139e7d180befcaa06fe0 Author: Richard Cochran AuthorDate: Tue, 22 Dec 2015 22:19:58 +0100 Committer: Thomas Gleixner CommitDate: Tue, 29 Dec 2015 11:33:06 +0100 posix-clock: Fix return code on the poll method's error path 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 Cc: stable@vger.kernel.org Signed-off-by: Thomas Gleixner --- kernel/time/posix-clock.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/time/posix-clock.c b/kernel/time/posix-clock.c index ce033c7..9cff0ab 100644 --- a/kernel/time/posix-clock.c +++ b/kernel/time/posix-clock.c @@ -69,10 +69,10 @@ static ssize_t posix_clock_read(struct file *fp, char __user *buf, 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);