From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755776Ab0CETwr (ORCPT ); Fri, 5 Mar 2010 14:52:47 -0500 Received: from hera.kernel.org ([140.211.167.34]:54549 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755691Ab0CETwq (ORCPT ); Fri, 5 Mar 2010 14:52:46 -0500 Message-ID: <4B9160BF.3060104@kernel.org> Date: Fri, 05 Mar 2010 11:51:27 -0800 From: Yinghai Lu User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.5) Gecko/20091130 SUSE/3.0.0-1.1.1 Thunderbird/3.0 MIME-Version: 1.0 To: Ian Campbell , "H. Peter Anvin" , Thomas Gleixner CC: linux-kernel@vger.kernel.org, Peter Zijlstra , Ingo Molnar Subject: Re: [PATCH] x86: do not free zero sized per cpu areas References: <4B914A61.20409@kernel.org> <1267818583-5627-1-git-send-email-ian.campbell@citrix.com> In-Reply-To: <1267818583-5627-1-git-send-email-ian.campbell@citrix.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/05/2010 11:49 AM, Ian Campbell wrote: > This avoids an infinite loop in free_early_partial(). > > Add a warning to free_early_partial to catch future problems. > > Signed-off-by: Ian Campbell > Cc: Yinghai Lu > Cc: Peter Zijlstra > Cc: Ingo Molnar > --- > arch/x86/kernel/setup_percpu.c | 3 ++- > kernel/early_res.c | 5 +++++ > 2 files changed, 7 insertions(+), 1 deletions(-) > > diff --git a/arch/x86/kernel/setup_percpu.c b/arch/x86/kernel/setup_percpu.c > index ef6370b..89a3205 100644 > --- a/arch/x86/kernel/setup_percpu.c > +++ b/arch/x86/kernel/setup_percpu.c > @@ -140,7 +140,8 @@ static void __init pcpu_fc_free(void *ptr, size_t size) > #ifdef CONFIG_NO_BOOTMEM > u64 start = __pa(ptr); > u64 end = start + size; > - free_early_partial(start, end); > + if (start < end) > + free_early_partial(start, end); > #else > free_bootmem(__pa(ptr), size); > #endif > diff --git a/kernel/early_res.c b/kernel/early_res.c > index 3cb2c66..f3a861b 100644 > --- a/kernel/early_res.c > +++ b/kernel/early_res.c > @@ -333,6 +333,11 @@ void __init free_early_partial(u64 start, u64 end) > struct early_res *r; > int i; > > + if (WARN_ONCE(start >= end, > + "free_early_partial got wrong start/end %#llx/%#llx\n", > + start, end)) > + return; > + > try_next: > i = find_overlapped_early(start, end); > if (i >= max_early_res) Acked-by: Yinghai Lu