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: <20220218060926.GA26206@X58A-UD3R>
Date:   Fri, 18 Feb 2022 15:09:26 +0900
From:   Byungchul Park <byungchul.park@....com>
To:     Steven Rostedt <rostedt@...dmis.org>
Cc:     torvalds@...ux-foundation.org, damien.lemoal@...nsource.wdc.com,
        linux-ide@...r.kernel.org, adilger.kernel@...ger.ca,
        linux-ext4@...r.kernel.org, mingo@...hat.com,
        linux-kernel@...r.kernel.org, peterz@...radead.org,
        will@...nel.org, tglx@...utronix.de, joel@...lfernandes.org,
        sashal@...nel.org, daniel.vetter@...ll.ch,
        chris@...is-wilson.co.uk, duyuyang@...il.com,
        johannes.berg@...el.com, tj@...nel.org, tytso@....edu,
        willy@...radead.org, david@...morbit.com, amir73il@...il.com,
        bfields@...ldses.org, gregkh@...uxfoundation.org,
        kernel-team@....com, linux-mm@...ck.org, akpm@...ux-foundation.org,
        mhocko@...nel.org, minchan@...nel.org, hannes@...xchg.org,
        vdavydov.dev@...il.com, sj@...nel.org, jglisse@...hat.com,
        dennis@...nel.org, cl@...ux.com, penberg@...nel.org,
        rientjes@...gle.com, vbabka@...e.cz, ngupta@...are.org,
        linux-block@...r.kernel.org, axboe@...nel.dk,
        paolo.valente@...aro.org, josef@...icpanda.com,
        linux-fsdevel@...r.kernel.org, viro@...iv.linux.org.uk,
        jack@...e.cz, jack@...e.com, jlayton@...nel.org,
        dan.j.williams@...el.com, hch@...radead.org, djwong@...nel.org,
        dri-devel@...ts.freedesktop.org, airlied@...ux.ie,
        rodrigosiqueiramelo@...il.com, melissa.srw@...il.com,
        hamohammed.sa@...il.com
Subject: Re: [PATCH 02/16] dept: Implement Dept(Dependency Tracker)

On Thu, Feb 17, 2022 at 12:36:56PM -0500, Steven Rostedt wrote:
> > +struct dept_ecxt;
> > +struct dept_iecxt {
> > +	struct dept_ecxt *ecxt;
> > +	int enirq;
> > +	bool staled; /* for preventing to add a new ecxt */
> > +};
> > +
> > +struct dept_wait;
> > +struct dept_iwait {
> > +	struct dept_wait *wait;
> > +	int irq;
> > +	bool staled; /* for preventing to add a new wait */
> > +	bool touched;
> > +};
> 
> Nit. It makes it easier to read (and then review) if structures are spaced
> where their fields are all lined up:
> 
> struct dept_iecxt {
> 	struct dept_ecxt		*ecxt;
> 	int				enirq;
> 	bool				staled;
> };
> 
> struct dept_iwait {
> 	struct dept_wait		*wait;
> 	int				irq;
> 	bool				staled;
> 	bool				touched;
> };
> 
> See, the fields stand out, and is nicer on the eyes. Especially for those
> of us that are getting up in age, and our eyes do not work as well as they
> use to ;-)

Sure! I will apply this.

> > + * ---
> > + * This program is free software; you can redistribute it and/or modify
> > + * it under the terms of the GNU General Public License as published by
> > + * the Free Software Foundation; either version 2 of the License, or
> > + * (at your ootion) any later version.
> > + *
> > + * This program is distributed in the hope that it will be useful, but
> > + * WITHOUT ANY WARRANTY; without even the implied warranty of
> > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> > + * General Public License for more details.
> > + *
> > + * You should have received a copy of the GNU General Public License
> > + * along with this program; if not, you can access it online at
> > + * http://www.gnu.org/licenses/gpl-2.0.html.
> 
> The SPDX at the top of the file is all that is needed. Please remove this
> boiler plate. We do not use GPL boiler plates in the kernel anymore. The
> SPDX code supersedes that.

Thank you for informing it!

> > +/*
> > + * Can use llist no matter whether CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG is
> > + * enabled because DEPT never race with NMI by nesting control.
> 
>                          "never races with"

Good eyes!

> Although, I'm confused by what you mean with "by nesting control".

I should've expressed it more clearly. It meant NMI and other contexts
never run inside of Dept concurrently in the same CPU by preventing
reentrance.

> > +static void initialize_class(struct dept_class *c)
> > +{
> > +	int i;
> > +
> > +	for (i = 0; i < DEPT_IRQS_NR; i++) {
> > +		struct dept_iecxt *ie = &c->iecxt[i];
> > +		struct dept_iwait *iw = &c->iwait[i];
> > +
> > +		ie->ecxt = NULL;
> > +		ie->enirq = i;
> > +		ie->staled = false;
> > +
> > +		iw->wait = NULL;
> > +		iw->irq = i;
> > +		iw->staled = false;
> > +		iw->touched = false;
> > +	}
> > +	c->bfs_gen = 0U;
> 
> Is the U really necessary?

I was just wondering if it's really harmful? I want to leave this if
it's harmless because U let us guess the data type of ->bfs_gen correctly
at a glance. Or am I missing some reason why I should fix this?

Thank you very much, Steven.

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ