From: David Hildenbrand <david@redhat.com>
To: Vlastimil Babka <vbabka@suse.cz>,
Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Alexander Potapenko <glider@google.com>,
Kees Cook <keescook@chromium.org>,
Michal Hocko <mhocko@kernel.org>,
Mateusz Nosek <mateusznosek0@gmail.com>
Subject: Re: [PATCH 1/3] mm, page_alloc: do not rely on the order of page_poison and init_on_alloc/free parameters
Date: Tue, 27 Oct 2020 10:58:57 +0100 [thread overview]
Message-ID: <c14170b8-9705-f9ac-bcb0-aaa623de903d@redhat.com> (raw)
In-Reply-To: <9a2b88de-3c01-21d0-69ff-08643f7c4b68@suse.cz>
On 27.10.20 10:58, Vlastimil Babka wrote:
> On 10/27/20 10:03 AM, David Hildenbrand wrote:
>> On 26.10.20 18:33, Vlastimil Babka wrote:
>>> Enabling page_poison=1 together with init_on_alloc=1 or init_on_free=1 produces
>>> a warning in dmesg that page_poison takes precendence. However, as these
>>> warnings are printed in early_param handlers for init_on_alloc/free, they are
>>> not printed if page_poison is enabled later on the command line (handlers are
>>> called in the order of their parameters), or when init_on_alloc/free is always
>>> enabled by the respective config option - before the page_poison early param
>>> handler is called, it is not considered to be enabled. This is inconsistent.
>>>
>>> We can remove the dependency on order by making the init_on_* parameters only
>>> set a boolean variable, and postponing the evaluation after all early params
>>> have been processed. Introduce a new init_mem_debugging() function for that,
>>> and move the related debug_pagealloc processing there as well.
>>
>> init_mem_debugging() is somewhat sub-optimal - init_on_alloc=1 or
>> init_on_free=1 are rather security hardening mechanisms.
>
> Well yeah, init_mem_debugging_and_hardening()?
Would work for me.
--
Thanks,
David / dhildenb
next prev parent reply other threads:[~2020-10-27 10:00 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-26 17:33 [PATCH 0/3] optimize handling of memory debugging parameters Vlastimil Babka
2020-10-26 17:33 ` [PATCH 1/3] mm, page_alloc: do not rely on the order of page_poison and init_on_alloc/free parameters Vlastimil Babka
2020-10-27 9:03 ` David Hildenbrand
2020-10-27 9:58 ` Vlastimil Babka
2020-10-27 9:58 ` David Hildenbrand [this message]
2020-10-28 8:31 ` Mike Rapoport
2020-10-26 17:33 ` [PATCH 2/3] mm, page_poison: use static key more efficiently Vlastimil Babka
2020-10-27 9:07 ` David Hildenbrand
2020-10-30 16:27 ` Luis Chamberlain
2020-10-30 22:56 ` Vlastimil Babka
2020-11-11 13:29 ` Luis Chamberlain
2020-10-26 17:33 ` [PATCH 3/3] mm, page_alloc: reduce static keys in prep_new_page() Vlastimil Babka
2020-10-27 9:10 ` David Hildenbrand
2020-10-27 11:05 ` Vlastimil Babka
2020-10-27 13:32 ` Vlastimil Babka
2020-10-27 17:41 ` Vlastimil Babka
2020-10-28 8:38 ` David Hildenbrand
2020-10-29 17:37 ` Alexander Potapenko
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