From: Johannes Berg <johannes@sipsolutions.net>
To: David Gow <davidgow@google.com>,
Vincent Whitchurch <vincent.whitchurch@axis.com>,
Patricia Alfonso <trishalfonso@google.com>,
Jeff Dike <jdike@addtoit.com>,
Richard Weinberger <richard@nod.at>,
anton.ivanov@cambridgegreys.com,
Dmitry Vyukov <dvyukov@google.com>,
Brendan Higgins <brendanhiggins@google.com>,
Andrew Morton <akpm@linux-foundation.org>,
Andrey Konovalov <andreyknvl@gmail.com>,
Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: kasan-dev <kasan-dev@googlegroups.com>,
linux-um@lists.infradead.org, LKML <linux-kernel@vger.kernel.org>,
Daniel Latypov <dlatypov@google.com>,
linux-mm@kvack.org
Subject: Re: [PATCH v2 2/2] UML: add support for KASAN under x86_64
Date: Sun, 29 May 2022 19:04:08 +0200 [thread overview]
Message-ID: <1a4e51a4d2ed51e7ae1ff55bd4da6a47fad7c0bf.camel@sipsolutions.net> (raw)
In-Reply-To: <20220527185600.1236769-2-davidgow@google.com>
On Fri, 2022-05-27 at 11:56 -0700, David Gow wrote:
>
> The UML-specific KASAN initializer uses mmap to map the roughly 2.25TB
You say 2.25TB here, and
> +config KASAN_SHADOW_OFFSET
> + hex
> + depends on KASAN
> + default 0x100000000000
> + help
> + This is the offset at which the ~2.25TB of shadow memory is
here too, of course.
But I notice that I get ~16TB address space use when running,
> +/* used in kasan_mem_to_shadow to divide by 8 */
> +#define KASAN_SHADOW_SCALE_SHIFT 3
> +
> +#ifdef CONFIG_X86_64
> +#define KASAN_HOST_USER_SPACE_END_ADDR 0x00007fffffffffffUL
> +/* KASAN_SHADOW_SIZE is the size of total address space divided by 8 */
> +#define KASAN_SHADOW_SIZE ((KASAN_HOST_USER_SPACE_END_ADDR + 1) >> \
> + KASAN_SHADOW_SCALE_SHIFT)
because this ends up being 0x100000000000, i.e. 16 TiB.
Is that intentional? Was something missed? Maybe
KASAN_HOST_USER_SPACE_END_ADDR was too big?
It doesn't really matter, but I guess then the documentation should be
updated.
johannes
next prev parent reply other threads:[~2022-05-29 17:04 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-27 18:55 [PATCH v2 1/2] mm: Add PAGE_ALIGN_DOWN macro David Gow
2022-05-27 18:56 ` [PATCH v2 2/2] UML: add support for KASAN under x86_64 David Gow
2022-05-27 20:14 ` Johannes Berg
2022-05-29 17:55 ` Johannes Berg
2022-06-30 7:53 ` David Gow
2022-05-29 17:04 ` Johannes Berg [this message]
2022-06-30 7:53 ` David Gow
2022-05-30 18:03 ` Andrey Konovalov
2022-06-30 7:54 ` David Gow
2022-05-30 0:06 ` [PATCH v2 1/2] mm: Add PAGE_ALIGN_DOWN macro Andrew Morton
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=1a4e51a4d2ed51e7ae1ff55bd4da6a47fad7c0bf.camel@sipsolutions.net \
--to=johannes@sipsolutions.net \
--cc=akpm@linux-foundation.org \
--cc=andreyknvl@gmail.com \
--cc=anton.ivanov@cambridgegreys.com \
--cc=brendanhiggins@google.com \
--cc=davidgow@google.com \
--cc=dlatypov@google.com \
--cc=dvyukov@google.com \
--cc=jdike@addtoit.com \
--cc=kasan-dev@googlegroups.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linux-um@lists.infradead.org \
--cc=richard@nod.at \
--cc=ryabinin.a.a@gmail.com \
--cc=trishalfonso@google.com \
--cc=vincent.whitchurch@axis.com \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).