All of lore.kernel.org
 help / color / mirror / Atom feed
From: Willy Tarreau <w@1wt.eu>
To: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
	Paul Gortmaker <paul.gortmaker@windriver.com>,
	Johannes Weiner <hannes@cmpxchg.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Antonio SJ Musumeci <trapexit@spawn.link>,
	Miklos Szeredi <miklos@szeredi.hu>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	stable <stable@vger.kernel.org>
Subject: Re: BUG_ON() in workingset_node_shadows_dec() triggers
Date: Fri, 7 Oct 2016 20:26:43 +0200	[thread overview]
Message-ID: <20161007182643.GA10538@1wt.eu> (raw)
In-Reply-To: <CAGXu5jKPA1-=LdnXZLxXpzUaFKKnMbfyNg89y_UryWd4V9hGnA@mail.gmail.com>

Hi Kees,

On Fri, Oct 07, 2016 at 10:33:33AM -0700, Kees Cook wrote:
> I'll quit debating how to change things, but I'll just try to point
> out that the "stop execution" logic, currently, is not an accident.
> Without CONFIG_BUG, BUG is defined as "do {} while (1)", and without
> CONFIG_HAVE_ARCH_BUG, BUG is defined as "printk(...); panic(...);".

I think we're all convinced about this *initial* intent. However among
the 3197 BUG() and 9594 BUG_ON() that are present in v4.8, how many
should *really* be of them ? I'm seeing that during 4.8 development
cycle alone, we managed to add 81 BUG() and 55 BUG_ON(). I doubt we
found so many valid reasons to kill the system. 38 of them were added
to drivers/. The problem is that this "style" has accumulated over the
years. We only had 1739 BUG() and 1801 BUG_ON() in 2.6.12. So we
roughly multiplied that by 4 in 11 years.

The current trend seems to actually be to remove some of them, 3 were
removed from lib/, 4 from include/, 29 removed from fs/, one removed
from mm/ but two added to kernel/ and 3 other ones to net/.

Maybe changing only kernel/ and mm/'s BUG() occurrences to something
like "I_KNOW_I_WILL_BE_BLAMED_FOR_THIS_BUG()" and letting them kill
until they're properly audited, and leaving the other ones non-fatal
could be a reasonable tradeoff to start with ?

Willy

  reply	other threads:[~2016-10-07 18:27 UTC|newest]

Thread overview: 37+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-10-04  4:00 BUG_ON() in workingset_node_shadows_dec() triggers Linus Torvalds
2016-10-04  4:07 ` Andrew Morton
2016-10-04  4:12   ` Linus Torvalds
2016-10-04  7:03     ` Raymond Jennings
2016-10-04 16:03       ` Linus Torvalds
2016-10-04  8:02 ` Greg KH
2016-10-04  9:32 ` Johannes Weiner
2016-10-05  1:21   ` Linus Torvalds
2016-10-05  9:25     ` Johannes Weiner
2016-10-05  9:31       ` Johannes Weiner
2016-10-05 10:40       ` Jan Kara
2016-10-05 16:10       ` Linus Torvalds
2016-10-05 17:00         ` [PATCH] checkpatch: extend BUG warning Joe Perches
2016-10-05 17:00           ` Joe Perches
2016-10-05 17:07           ` Linus Torvalds
2016-10-05  2:43 ` BUG_ON() in workingset_node_shadows_dec() triggers Paul Gortmaker
2016-10-05  3:29   ` Linus Torvalds
2016-10-05  5:44     ` Willy Tarreau
2016-10-05 15:52       ` Linus Torvalds
2016-10-05 19:06         ` Willy Tarreau
2016-10-05 19:18           ` Linus Torvalds
2016-10-05 21:09             ` Willy Tarreau
2016-10-05 21:14             ` Kees Cook
2016-10-05 21:46               ` Linus Torvalds
2016-10-05 22:17                 ` Kees Cook
2016-10-05 22:29                   ` Linus Torvalds
2016-10-06 22:07                     ` Kees Cook
2016-10-06 22:29                       ` Linus Torvalds
2016-10-06 23:05                         ` Kees Cook
2016-10-06 23:59                           ` Linus Torvalds
2016-10-07  5:48                             ` Willy Tarreau
2016-10-07 17:16                               ` Kees Cook
2016-10-07 17:21                                 ` Linus Torvalds
2016-10-07 17:33                                   ` Kees Cook
2016-10-07 18:26                                     ` Willy Tarreau [this message]
2016-10-06  1:59     ` Dave Chinner
2016-10-06  2:12       ` Linus Torvalds

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20161007182643.GA10538@1wt.eu \
    --to=w@1wt.eu \
    --cc=akpm@linux-foundation.org \
    --cc=hannes@cmpxchg.org \
    --cc=keescook@chromium.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=miklos@szeredi.hu \
    --cc=paul.gortmaker@windriver.com \
    --cc=stable@vger.kernel.org \
    --cc=torvalds@linux-foundation.org \
    --cc=trapexit@spawn.link \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.