From: Dave Hansen <dave.hansen@intel.com>
To: Marco Elver <elver@google.com>,
glider@google.com, akpm@linux-foundation.org,
catalin.marinas@arm.com, cl@linux.com, rientjes@google.com,
iamjoonsoo.kim@lge.com, mark.rutland@arm.com, penberg@kernel.org
Cc: hpa@zytor.com, paulmck@kernel.org, andreyknvl@google.com,
aryabinin@virtuozzo.com, luto@kernel.org, bp@alien8.de,
dave.hansen@linux.intel.com, dvyukov@google.com,
edumazet@google.com, gregkh@linuxfoundation.org,
mingo@redhat.com, jannh@google.com, corbet@lwn.net,
keescook@chromium.org, peterz@infradead.org, cai@lca.pw,
tglx@linutronix.de, will@kernel.org, x86@kernel.org,
linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
kasan-dev@googlegroups.com, linux-arm-kernel@lists.infradead.org,
linux-mm@kvack.org
Subject: Re: [PATCH RFC 09/10] kfence, Documentation: add KFENCE documentation
Date: Tue, 8 Sep 2020 08:54:36 -0700 [thread overview]
Message-ID: <3e87490e-3145-da2e-4190-176017d0e099@intel.com> (raw)
In-Reply-To: <20200907134055.2878499-10-elver@google.com>
On 9/7/20 6:40 AM, Marco Elver wrote:
> +The most important parameter is KFENCE's sample interval, which can be set via
> +the kernel boot parameter ``kfence.sample_interval`` in milliseconds. The
> +sample interval determines the frequency with which heap allocations will be
> +guarded by KFENCE. The default is configurable via the Kconfig option
> +``CONFIG_KFENCE_SAMPLE_INTERVAL``. Setting ``kfence.sample_interval=0``
> +disables KFENCE.
> +
> +With the Kconfig option ``CONFIG_KFENCE_NUM_OBJECTS`` (default 255), the number
> +of available guarded objects can be controlled. Each object requires 2 pages,
> +one for the object itself and the other one used as a guard page; object pages
> +are interleaved with guard pages, and every object page is therefore surrounded
> +by two guard pages.
Is it hard to make these both tunable at runtime?
It would be nice if I hit a KFENCE error on a system to bump up the
number of objects and turn up the frequency of guarded objects to try to
hit it again. That would be a really nice feature for development
environments.
It would also be nice to have a counter somewhere (/proc/vmstat?) to
explicitly say how many pages are currently being used.
I didn't mention it elsewhere, but this work looks really nice. It has
very little impact on the core kernel and looks like a very nice tool to
have in the toolbox. I don't see any major reasons we wouldn't want to
merge after our typical bikeshedding. :)
next prev parent reply other threads:[~2020-09-08 15:54 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-07 13:40 [PATCH RFC 00/10] KFENCE: A low-overhead sampling-based memory safety error detector Marco Elver
2020-09-07 13:40 ` [PATCH RFC 01/10] mm: add Kernel Electric-Fence infrastructure Marco Elver
2020-09-07 15:41 ` Jonathan Cameron
2020-09-07 16:38 ` Marco Elver
2020-09-10 14:57 ` Dmitry Vyukov
2020-09-10 15:06 ` Marco Elver
2020-09-10 15:48 ` Dmitry Vyukov
2020-09-10 16:22 ` Marco Elver
2020-09-10 15:42 ` Dmitry Vyukov
2020-09-10 16:19 ` Alexander Potapenko
2020-09-10 17:11 ` Dmitry Vyukov
2020-09-10 17:41 ` Marco Elver
2020-09-10 20:25 ` Paul E. McKenney
2020-09-15 13:57 ` SeongJae Park
2020-09-15 14:14 ` Marco Elver
2020-09-15 14:26 ` SeongJae Park
2020-09-07 13:40 ` [PATCH RFC 02/10] x86, kfence: enable KFENCE for x86 Marco Elver
2020-09-07 13:40 ` [PATCH RFC 03/10] arm64, kfence: enable KFENCE for ARM64 Marco Elver
2020-09-09 15:13 ` Marco Elver
2020-09-07 13:40 ` [PATCH RFC 04/10] mm, kfence: insert KFENCE hooks for SLAB Marco Elver
2020-09-11 7:17 ` Dmitry Vyukov
2020-09-11 12:24 ` Marco Elver
2020-09-11 13:03 ` Dmitry Vyukov
2020-09-07 13:40 ` [PATCH RFC 05/10] mm, kfence: insert KFENCE hooks for SLUB Marco Elver
2020-09-07 13:40 ` [PATCH RFC 06/10] kfence, kasan: make KFENCE compatible with KASAN Marco Elver
2020-09-11 7:04 ` Dmitry Vyukov
2020-09-11 13:00 ` Marco Elver
2020-09-07 13:40 ` [PATCH RFC 07/10] kfence, kmemleak: make KFENCE compatible with KMEMLEAK Marco Elver
2020-09-08 11:53 ` Catalin Marinas
2020-09-08 12:29 ` Alexander Potapenko
2020-09-07 13:40 ` [PATCH RFC 08/10] kfence, lockdep: make KFENCE compatible with lockdep Marco Elver
2020-09-07 13:40 ` [PATCH RFC 09/10] kfence, Documentation: add KFENCE documentation Marco Elver
2020-09-07 15:33 ` Andrey Konovalov
2020-09-07 16:33 ` Marco Elver
2020-09-07 17:55 ` Andrey Konovalov
2020-09-07 18:16 ` Marco Elver
2020-09-08 15:54 ` Dave Hansen [this message]
2020-09-08 16:14 ` Marco Elver
2020-09-11 7:14 ` Dmitry Vyukov
2020-09-11 7:46 ` Marco Elver
2020-09-07 13:40 ` [PATCH RFC 10/10] kfence: add test suite Marco Elver
2020-09-08 11:48 ` [PATCH RFC 00/10] KFENCE: A low-overhead sampling-based memory safety error detector Vlastimil Babka
2020-09-08 12:16 ` Alexander Potapenko
2020-09-08 14:40 ` Vlastimil Babka
2020-09-08 15:21 ` Marco Elver
2020-09-08 14:52 ` Dave Hansen
2020-09-08 15:31 ` Marco Elver
2020-09-08 15:36 ` Vlastimil Babka
2020-09-08 15:56 ` Marco Elver
2020-09-11 7:35 ` Dmitry Vyukov
2020-09-11 12:03 ` Marco Elver
2020-09-11 13:09 ` Dmitry Vyukov
2020-09-11 13:33 ` Marco Elver
2020-09-11 16:33 ` Marco Elver
2020-09-08 15:37 ` Dave Hansen
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