All of lore.kernel.org
 help / color / mirror / Atom feed
From: David Rientjes <rientjes@google.com>
To: Marco Elver <elver@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	Christoph Lameter <cl@linux.com>,
	Pekka Enberg <penberg@kernel.org>,
	Joonsoo Kim <iamjoonsoo.kim@lge.com>,
	Vlastimil Babka <vbabka@suse.cz>,
	linux-mm@kvack.org, linux-kernel@vger.kernel.org,
	Dmitry Vyukov <dvyukov@google.com>,
	Alexander Potapenko <glider@google.com>,
	kasan-dev@googlegroups.com, Ingo Molnar <mingo@redhat.com>
Subject: Re: [PATCH] mm/slab_common: use WARN() if cache still has objects on destroy
Date: Tue, 9 Nov 2021 17:49:14 -0800 (PST)	[thread overview]
Message-ID: <146e59b4-76c-69e4-969-ce8a75ccfe5d@google.com> (raw)
In-Reply-To: <20211102170733.648216-1-elver@google.com>

On Tue, 2 Nov 2021, Marco Elver wrote:

> Calling kmem_cache_destroy() while the cache still has objects allocated
> is a kernel bug, and will usually result in the entire cache being
> leaked. While the message in kmem_cache_destroy() resembles a warning,
> it is currently not implemented using a real WARN().
> 
> This is problematic for infrastructure testing the kernel, all of which
> rely on the specific format of WARN()s to pick up on bugs.
> 
> Some 13 years ago this used to be a simple WARN_ON() in slub, but
> d629d8195793 ("slub: improve kmem_cache_destroy() error message")
> changed it into an open-coded warning to avoid confusion with a bug in
> slub itself.
> 
> Instead, turn the open-coded warning into a real WARN() with the message
> preserved, so that test systems can actually identify these issues, and
> we get all the other benefits of using a normal WARN(). The warning
> message is extended with "when called from <caller-ip>" to make it even
> clearer where the fault lies.
> 
> For most configurations this is only a cosmetic change, however, note
> that WARN() here will now also respect panic_on_warn.
> 
> Signed-off-by: Marco Elver <elver@google.com>

Acked-by: David Rientjes <rientjes@google.com>

Thanks Marco!

      parent reply	other threads:[~2021-11-10  1:49 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-11-02 17:07 [PATCH] mm/slab_common: use WARN() if cache still has objects on destroy Marco Elver
2021-11-03  7:23 ` Vlastimil Babka
2021-11-10  1:49 ` David Rientjes [this message]

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=146e59b4-76c-69e4-969-ce8a75ccfe5d@google.com \
    --to=rientjes@google.com \
    --cc=akpm@linux-foundation.org \
    --cc=cl@linux.com \
    --cc=dvyukov@google.com \
    --cc=elver@google.com \
    --cc=glider@google.com \
    --cc=iamjoonsoo.kim@lge.com \
    --cc=kasan-dev@googlegroups.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=mingo@redhat.com \
    --cc=penberg@kernel.org \
    --cc=vbabka@suse.cz \
    /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.