linux-kernel - Re: [PATCH 1/2 v2] bcachefs: do not use PF_MEMALLOC

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: <citv2v6f33hoidq75xd2spaqxf7nl5wbmmzma4wgmrwpoqidhj@k453tmq7vdrk>
Date: Mon, 2 Sep 2024 05:51:00 -0400
From: Kent Overstreet <kent.overstreet@...ux.dev>
To: Michal Hocko <mhocko@...e.com>
Cc: Dave Chinner <david@...morbit.com>, 
	Andrew Morton <akpm@...ux-foundation.org>, Christoph Hellwig <hch@....de>, 
	Yafang Shao <laoar.shao@...il.com>, jack@...e.cz, Christian Brauner <brauner@...nel.org>, 
	Alexander Viro <viro@...iv.linux.org.uk>, Paul Moore <paul@...l-moore.com>, 
	James Morris <jmorris@...ei.org>, "Serge E. Hallyn" <serge@...lyn.com>, 
	linux-fsdevel@...r.kernel.org, linux-mm@...ck.org, linux-bcachefs@...r.kernel.org, 
	linux-security-module@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 1/2 v2] bcachefs: do not use PF_MEMALLOC_NORECLAIM

On Mon, Sep 02, 2024 at 11:39:41AM GMT, Michal Hocko wrote:
> On Mon 02-09-24 04:52:49, Kent Overstreet wrote:
> > On Mon, Sep 02, 2024 at 10:41:31AM GMT, Michal Hocko wrote:
> > > On Sun 01-09-24 21:35:30, Kent Overstreet wrote:
> > > [...]
> > > > But I am saying that kmalloc(__GFP_NOFAIL) _should_ fail and return NULL
> > > > in the case of bugs, because that's going to be an improvement w.r.t.
> > > > system robustness, in exactly the same way we don't use BUG_ON() if it's
> > > > something that we can't guarantee won't happen in the wild - we WARN()
> > > > and try to handle the error as best we can.
> > > 
> > > We have discussed that in a different email thread. And I have to say
> > > that I am not convinced that returning NULL makes a broken code much
> > > better. Why? Because we can expect that broken NOFAIL users will not have a
> > > error checking path. Even valid NOFAIL users will not have one because
> > > they _know_ they do not have a different than retry for ever recovery
> > > path. 
> > 
> > You mean where I asked you for a link to the discussion and rationale
> > you claimed had happened? Still waiting on that
> 
> I am not your assistent to be tasked and search through lore archives.
> Find one if you need that.
> 
> Anyway, if you read the email and even tried to understand what is
> written there rather than immediately started shouting a response then
> you would have noticed I have put actual arguments here. You are free to
> disagree with them and lay down your arguments. You have decided to
> 
> [...]
> 
> > Yeah, enough of this insanity.
> 
> so I do not think you are able to do that. Again...

Michal, if you think crashing processes is an acceptable alternative to
error handling _you have no business writing kernel code_.

You have been stridently arguing for one bad idea after another, and
it's an insult to those of us who do give a shit about writing reliable
software.

You're arguing against basic precepts of kernel programming.

Get your head examined. And get the fuck out of here with this shit.