From: Thomas Gleixner <tglx@kernel.org>
To: "Thomas Weißschuh" <thomas.weissschuh@linutronix.de>,
"Andy Lutomirski" <luto@kernel.org>,
"Vincenzo Frascino" <vincenzo.frascino@arm.com>,
"Christophe Leroy (CS GROUP)" <chleroy@kernel.org>
Cc: linux-kernel@vger.kernel.org
Subject: Re: [PATCH] vdso/datastore: Zero out newly allocated datastore pages
Date: Thu, 09 Apr 2026 22:21:36 +0200 [thread overview]
Message-ID: <87ik9z28bz.ffs@tglx> (raw)
In-Reply-To: <20260409131620-8b31cf24-e2da-4650-a3f6-97a35fdaeb36@linutronix.de>
On Thu, Apr 09 2026 at 13:17, Thomas Weißschuh wrote:
>> The data pages need to be zeroed initially, as garbage data can break
>> the vDSO userspace logic.
>>
>> Fixes: 05988dba1179 ("vdso/datastore: Allocate data pages dynamically")
>> Link: https://lore.kernel.org/lkml/aQjJNmwniQwwjeBR@finisterre.sirena.org.uk/
>> Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
>> ---
>> I messed up and dropped __GFP_ZERO again when switching from folio_alloc() to
>> alloc_pages() in v6 of "sparc64: vdso: Switch to the generic vDSO library"
>> Previously the missing __GFP_ZERO triggered boot-failures in -next, but
>> apparently with alloc_pages() we got "lucky" so far.
>
> ... I panicked a bit after looking at the code again and not seeing the
> explicit zeroing. The actually works fine, as the memcpy() from the static
> vdso_initdata will do the zeroing.
>
> Sorry for the noise.
Happens to all of us. Better safe than sorry six weeks down the road.
prev parent reply other threads:[~2026-04-09 20:21 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-04-09 11:14 [PATCH] vdso/datastore: Zero out newly allocated datastore pages Thomas Weißschuh
2026-04-09 11:17 ` Thomas Weißschuh
2026-04-09 20:21 ` Thomas Gleixner [this message]
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=87ik9z28bz.ffs@tglx \
--to=tglx@kernel.org \
--cc=chleroy@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=luto@kernel.org \
--cc=thomas.weissschuh@linutronix.de \
--cc=vincenzo.frascino@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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.