linux-kernel - Re: [PATCH RFC tools/lkmm 10/12] tools/memory-model: Add a S lock-based external-view litmus test

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: <Pine.LNX.4.44L0.1802211334560.2032-100000@iolanthe.rowland.org>
Date:   Wed, 21 Feb 2018 13:38:35 -0500 (EST)
From:   Alan Stern <stern@...land.harvard.edu>
To:     "Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>
cc:     linux-kernel@...r.kernel.org, <linux-arch@...r.kernel.org>,
        <mingo@...nel.org>, <parri.andrea@...il.com>,
        <will.deacon@....com>, <peterz@...radead.org>,
        <boqun.feng@...il.com>, <npiggin@...il.com>, <dhowells@...hat.com>,
        <j.alglave@....ac.uk>, <luc.maranget@...ia.fr>, <akiyks@...il.com>,
        <nborisov@...e.com>
Subject: Re: [PATCH RFC tools/lkmm 10/12] tools/memory-model: Add a S lock-based
 external-view litmus test

On Wed, 21 Feb 2018, Paul E. McKenney wrote:

> On Wed, Feb 21, 2018 at 11:50:31AM -0500, Alan Stern wrote:
> > On Wed, 21 Feb 2018, Paul E. McKenney wrote:
> > 
> > > On Wed, Feb 21, 2018 at 10:09:00AM -0500, Alan Stern wrote:
> > > > On Tue, 20 Feb 2018, Paul E. McKenney wrote:
> > > > 
> > > > > From: Alan Stern <stern@...land.harvard.edu>
> > > > > 
> > > > > This commit adds a litmus test in which P0() and P1() form a lock-based S
> > > > > litmus test, with the addition of P2(), which observes P0()'s and P1()'s
> > > > 
> > > > Why do you call this an "S" litmus test?  Isn't ISA2 a better 
> > > > description?
> > > 
> > > Indeed, the name of the test is in fact ISA2.
> > 
> > Sure; and the Changelog entry should reflect this.
> 
> No argument.

> ------------------------------------------------------------------------
> 
> commit e6658d1d7fcc6391f3d00beaadc484243123a893
> Author: Paul E. McKenney <paulmck@...ux.vnet.ibm.com>
> Date:   Wed Feb 21 09:49:01 2018 -0800
> 
>     tools/memory-order: Add documentation of new litmus test
>     
>     The litmus-tests/README file lacked any mention of then litmus test

s/lacked/lacks/
s/then/the new/

>     named ISA2+pooncelock+pooncelock+pombonce.litmus.  This commit therefore

s/named //

>     adds this test.

It adds a description of the test, not the test itself.

>     
>     Reported-by: Alan Stern <stern@...land.harvard.edu>
>     Signed-off-by: Paul E. McKenney <paulmck@...ux.vnet.ibm.com>
> 
> diff --git a/tools/memory-model/litmus-tests/README b/tools/memory-model/litmus-tests/README
> index dca7d823ad57..aff3eb90e067 100644
> --- a/tools/memory-model/litmus-tests/README
> +++ b/tools/memory-model/litmus-tests/README
> @@ -32,6 +32,11 @@ IRIW+poonceonces+OnceOnce.litmus
>  	order of a pair of writes, where each write is to a different
>  	variable by a different process?
>  
> +ISA2+pooncelock+pooncelock+pombonce.litmus
> +	Tests whether the ordering provided by a lock-protected S litmus

Call it an ISA2 litmus test, not an S litmus test!

> +	test is visible to an external process whose accesses are
> +	separated by smp_mb().
> +
>  ISA2+poonceonces.litmus
>  	As below, but with store-release replaced with WRITE_ONCE()
>  	and load-acquire replaced with READ_ONCE().

Alan