linux-kernel - Re: [PATCH -tip 00/12] locking/atomics: Add and use inc,dec calls for FETCH-OP flavors

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20160624193536.GA26017@linux-80c1.suse>
Date:	Fri, 24 Jun 2016 12:35:36 -0700
From:	Davidlohr Bueso <dave@...olabs.net>
To:	KY Srinivasan <kys@...rosoft.com>
Cc:	James Bottomley <James.Bottomley@...senPartnership.com>,
	"peterz@...radead.org" <peterz@...radead.org>,
	"mingo@...nel.org" <mingo@...nel.org>,
	"davem@...emloft.net" <davem@...emloft.net>,
	"cw00.choi@...sung.com" <cw00.choi@...sung.com>,
	"dougthompson@...ssion.com" <dougthompson@...ssion.com>,
	"bp@...en8.de" <bp@...en8.de>,
	"mchehab@....samsung.com" <mchehab@....samsung.com>,
	"gregkh@...uxfoundation.org" <gregkh@...uxfoundation.org>,
	"pfg@....com" <pfg@....com>, "jikos@...nel.org" <jikos@...nel.org>,
	"hans.verkuil@...co.com" <hans.verkuil@...co.com>,
	"awalls@...metrocast.net" <awalls@...metrocast.net>,
	"dledford@...hat.com" <dledford@...hat.com>,
	"sean.hefty@...el.com" <sean.hefty@...el.com>,
	"heiko.carstens@...ibm.com" <heiko.carstens@...ibm.com>,
	"sumit.semwal@...aro.org" <sumit.semwal@...aro.org>,
	"schwidefsky@...ibm.com" <schwidefsky@...ibm.com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH -tip 00/12] locking/atomics: Add and use inc,dec calls
 for FETCH-OP flavors

On Fri, 24 Jun 2016, KY Srinivasan wrote:

>How so? Can you expand on the racy part. The subtraction is done on a local copy of
>the value.

Yeah, you're right. I took a look at the generated code and I was unnecessarily worried
about the window between the return value and the subtraction.

Thanks,
Davidlohr