From: Andrey Ryabinin <aryabinin@virtuozzo.com>
To: Arnd Bergmann <arnd@arndb.de>, Andrew Morton <akpm@linux-foundation.org>
Cc: Alexander Potapenko <glider@google.com>,
Dmitry Vyukov <dvyukov@google.com>,
kasan-dev@googlegroups.com, linux-mm@kvack.org,
Andrey Konovalov <andreyknvl@google.com>,
Will Deacon <will.deacon@arm.com>,
Christoph Lameter <cl@linux.com>,
Mark Rutland <mark.rutland@arm.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] [v2] page flags: prioritize kasan bits over last-cpuid
Date: Tue, 18 Jun 2019 17:30:02 +0300 [thread overview]
Message-ID: <5ac26e68-8b75-1b06-eecd-950987550451@virtuozzo.com> (raw)
In-Reply-To: <20190618095347.3850490-1-arnd@arndb.de>
On 6/18/19 12:53 PM, Arnd Bergmann wrote:
> ARM64 randdconfig builds regularly run into a build error, especially
> when NUMA_BALANCING and SPARSEMEM are enabled but not SPARSEMEM_VMEMMAP:
>
> #error "KASAN: not enough bits in page flags for tag"
>
> The last-cpuid bits are already contitional on the available space,
> so the result of the calculation is a bit random on whether they
> were already left out or not.
>
> Adding the kasan tag bits before last-cpuid makes it much more likely
> to end up with a successful build here, and should be reliable for
> randconfig at least, as long as that does not randomize NR_CPUS
> or NODES_SHIFT but uses the defaults.
>
> In order for the modified check to not trigger in the x86 vdso32 code
> where all constants are wrong (building with -m32), enclose all the
> definitions with an #ifdef.
>
Why not keep "#error "KASAN: not enough bits in page flags for tag"" under "#ifdef CONFIG_KASAN_SW_TAGS" ?
next prev parent reply other threads:[~2019-06-18 14:29 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-18 9:53 [PATCH] [v2] page flags: prioritize kasan bits over last-cpuid Arnd Bergmann
2019-06-18 14:30 ` Andrey Ryabinin [this message]
2019-06-18 15:30 ` Arnd Bergmann
2019-06-18 16:28 ` Andrey Ryabinin
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=5ac26e68-8b75-1b06-eecd-950987550451@virtuozzo.com \
--to=aryabinin@virtuozzo.com \
--cc=akpm@linux-foundation.org \
--cc=andreyknvl@google.com \
--cc=arnd@arndb.de \
--cc=cl@linux.com \
--cc=dvyukov@google.com \
--cc=glider@google.com \
--cc=kasan-dev@googlegroups.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mark.rutland@arm.com \
--cc=torvalds@linux-foundation.org \
--cc=will.deacon@arm.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).