linux-kernel - Re: [PATCH] padata: use smp_mb in padata_reorder to avoid orphaned padata jobs

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: <20190713050321.c5wq7a7jrb6q2pxn@gondor.apana.org.au>
Date:   Sat, 13 Jul 2019 13:03:21 +0800
From:   Herbert Xu <herbert@...dor.apana.org.au>
To:     Daniel Jordan <daniel.m.jordan@...cle.com>
Cc:     Steffen Klassert <steffen.klassert@...unet.com>,
        andrea.parri@...rulasolutions.com, boqun.feng@...il.com,
        paulmck@...ux.ibm.com, peterz@...radead.org,
        linux-arch@...r.kernel.org, linux-crypto@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH] padata: use smp_mb in padata_reorder to avoid orphaned
 padata jobs

On Fri, Jul 12, 2019 at 12:07:37PM -0400, Daniel Jordan wrote:
>
> modprobe (CPU2)               kworker/21:1-293 (CPU21)                              kworker/5:2-276 (CPU5)
> --------------------------    ------------------------                              ----------------------
> <submit job, seq_nr=16581>
> ...
>   padata_do_parallel
>     queue_work_on(21, ...)
> <sleeps>
>                               padata_parallel_worker
>                                 pcrypt_aead_dec
>                                   padata_do_serial
>                                     padata_reorder

This can't happen because if the job started on CPU2 then it must
go back to CPU2 for completion.  IOW padata_do_serial should be
punting this to a work queue for CPU2 rather than calling
padata_reorder on CPU21.

Cheers,
-- 
Email: Herbert Xu <herbert@...dor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt