From: Haibo Li <haibo.li@mediatek.com>
To: <andreyknvl@gmail.com>
Cc: <akpm@linux-foundation.org>,
<angelogioacchino.delregno@collabora.com>, <dvyukov@google.com>,
<glider@google.com>, <haibo.li@mediatek.com>, <jannh@google.com>,
<kasan-dev@googlegroups.com>,
<linux-arm-kernel@lists.infradead.org>,
<linux-kernel@vger.kernel.org>,
<linux-mediatek@lists.infradead.org>, <linux-mm@kvack.org>,
<mark.rutland@arm.com>, <matthias.bgg@gmail.com>,
<ryabinin.a.a@gmail.com>, <vincenzo.frascino@arm.com>,
<xiaoming.yu@mediatek.com>
Subject: Re: [PATCH] kasan:fix access invalid shadow address when input is illegal
Date: Mon, 18 Sep 2023 15:25:45 +0800 [thread overview]
Message-ID: <20230918072545.87653-1-haibo.li@mediatek.com> (raw)
In-Reply-To: <CA+fCnZfuaovc4fk6Z+p1haLk7iemgtpF522sej3oWYARhBYYUQ@mail.gmail.com>
> On Fri, Sep 15, 2023 at 4:46 AM 'Haibo Li' via kasan-dev
> <kasan-dev@googlegroups.com> wrote:
> >
> > The patch checks each shadow address,so it introduces extra overhead.
>
> Ack. Could still be fine, depends on the overhead.
>
I do a simple test by reading memory.
Read 4096 memory by loop and the reading unit is 8 bytes.
__hwasan_load8_noabort is called 512(4096/8) times.
Measure the time of memory read.
Here is the result on ARM CA7X(repeat 100 times):
---------------min-------max-----avg----
before patch | 77.3ms | 80.6ms | 79.2ms|
after patch | 77.2ms | 80.7ms | 79.2ms|
----------------------------------------
There is no obvious drop in this scenario.
It may differ in different arch.
just for information if you are intrested in it.
> But if the message printed by kasan_non_canonical_hook is good enough
> for your use case, I would rather stick to that.
prev parent reply other threads:[~2023-09-18 7:26 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-09-14 8:08 Haibo Li
2023-09-14 17:46 ` Andrey Konovalov
2023-09-14 18:29 ` Andrew Morton
2023-09-14 20:34 ` Andrey Konovalov
2023-09-14 20:40 ` Jann Horn
2023-09-15 1:51 ` Andrey Konovalov
2023-09-15 2:45 ` Haibo Li
2023-09-15 9:40 ` Haibo Li
2023-09-15 16:53 ` Andrey Konovalov
2023-09-15 16:50 ` Andrey Konovalov
2023-09-15 17:04 ` Jann Horn
2023-09-18 8:12 ` Haibo Li
2023-09-18 7:25 ` Haibo Li [this message]
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