From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Eric Biggers <ebiggers@kernel.org>,
linux-crypto@vger.kernel.org,
"David S. Miller" <davem@davemloft.net>,
Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH] crypto: x86/aes-gcm: Disable FPU around skcipher_walk_done().
Date: Mon, 5 Aug 2024 10:21:19 +0200 [thread overview]
Message-ID: <20240805082119.n252N8l8@linutronix.de> (raw)
In-Reply-To: <Zq16_XsbZrmfnc4q@gondor.apana.org.au>
On 2024-08-03 08:34:05 [+0800], Herbert Xu wrote:
> On Fri, Aug 02, 2024 at 09:28:32AM -0700, Eric Biggers wrote:
> >
> > Note that kfree() lacks a might_sleep(), and its kerneldoc does not say that it
> > can sleep. Have you checked for other instances of this same problem? It seems
> > it would be quite common kernel-wide. Is it really necessary that kfree() takes
> > a sleepable lock on PREEMPT_RT?
>
> Agreed. kfree() gets called in all sorts of places under softirq
> context in the network stack which would presumably have the same
> issue.
>
> Please give a bit of context of when kfree started doing this.
I added "under PREEMPT_RT" in the patch description. The softirq under
PREEMPT_RT does not disable preemption so it is fully preemptible.
The other accelerated versions drop exclusive FPU access/ enable
preemption during these operations even on ARM/ ARM64.
> Cheers,
Sebastian
next prev parent reply other threads:[~2024-08-05 8:21 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-08-02 10:23 [PATCH] crypto: x86/aes-gcm: Disable FPU around skcipher_walk_done() Sebastian Andrzej Siewior
2024-08-02 16:28 ` Eric Biggers
2024-08-02 16:49 ` Eric Biggers
2024-08-05 9:02 ` Herbert Xu
2024-08-05 9:56 ` Sebastian Andrzej Siewior
2024-08-03 0:34 ` Herbert Xu
2024-08-05 8:21 ` Sebastian Andrzej Siewior [this message]
2024-08-05 8:41 ` Sebastian Andrzej Siewior
2024-08-05 17:38 ` Eric Biggers
2024-08-06 7:46 ` Sebastian Andrzej Siewior
2024-08-03 0:37 ` Herbert Xu
2024-08-05 9:34 ` Sebastian Andrzej Siewior
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=20240805082119.n252N8l8@linutronix.de \
--to=bigeasy@linutronix.de \
--cc=davem@davemloft.net \
--cc=ebiggers@kernel.org \
--cc=herbert@gondor.apana.org.au \
--cc=linux-crypto@vger.kernel.org \
--cc=tglx@linutronix.de \
/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.