From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752378AbbCCG1H (ORCPT ); Tue, 3 Mar 2015 01:27:07 -0500 Received: from terminus.zytor.com ([198.137.202.10]:49366 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752292AbbCCG1E (ORCPT ); Tue, 3 Mar 2015 01:27:04 -0500 Date: Mon, 2 Mar 2015 22:26:46 -0800 From: tip-bot for Kan Liang Message-ID: Cc: ak@linux.intel.com, acme@redhat.com, a.p.zijlstra@chello.nl, kan.liang@intel.com, hpa@zytor.com, mingo@kernel.org, tglx@linutronix.de, linux-kernel@vger.kernel.org, xiakaixu@huawei.com Reply-To: hpa@zytor.com, ak@linux.intel.com, acme@redhat.com, kan.liang@intel.com, a.p.zijlstra@chello.nl, linux-kernel@vger.kernel.org, xiakaixu@huawei.com, mingo@kernel.org, tglx@linutronix.de In-Reply-To: <1425280466-7830-1-git-send-email-kan.liang@intel.com> References: <1425280466-7830-1-git-send-email-kan.liang@intel.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/core] Revert "perf: Remove the extra validity check on nr_pages" Git-Commit-ID: 2ed11312eb19506c027e7cac039994ad42a9cb2c 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: 2ed11312eb19506c027e7cac039994ad42a9cb2c Gitweb: http://git.kernel.org/tip/2ed11312eb19506c027e7cac039994ad42a9cb2c Author: Kan Liang AuthorDate: Mon, 2 Mar 2015 02:14:26 -0500 Committer: Arnaldo Carvalho de Melo CommitDate: Mon, 2 Mar 2015 18:25:38 -0300 Revert "perf: Remove the extra validity check on nr_pages" This reverts commit 74390aa55678 ("perf: Remove the extra validity check on nr_pages") nr_pages equals to number of pages - 1 in perf_mmap. So nr_pages = 0 is valid. So the nr_pages != 0 && !is_power_of_2(nr_pages) are all needed for checking. Otherwise, for example, perf test 6 failed. # perf test 6 6: x86 rdpmc test :Error: mmap() syscall returned with (Invalid argument) FAILED! Signed-off-by: Kan Liang Cc: Andi Kleen Cc: Kaixu Xia Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1425280466-7830-1-git-send-email-kan.liang@intel.com Signed-off-by: Arnaldo Carvalho de Melo --- kernel/events/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/events/core.c b/kernel/events/core.c index af924bc..8bb20cc 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -4446,7 +4446,7 @@ static int perf_mmap(struct file *file, struct vm_area_struct *vma) * If we have rb pages ensure they're a power-of-two number, so we * can do bitmasks instead of modulo. */ - if (!is_power_of_2(nr_pages)) + if (nr_pages != 0 && !is_power_of_2(nr_pages)) return -EINVAL; if (vma_size != PAGE_SIZE * (1 + nr_pages))