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From: Jared Kangas <jkangas@redhat.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: ryabinin.a.a@gmail.com, glider@google.com, andreyknvl@gmail.com,
	dvyukov@google.com, vincenzo.frascino@arm.com,
	kasan-dev@googlegroups.com, linux-mm@kvack.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] kasan: make report_lock a raw spinlock
Date: Fri, 22 Nov 2024 10:03:16 -0800	[thread overview]
Message-ID: <Z0DHZIEI5hobBUwn@jkangas-thinkpadp1gen3.rmtuswa.csb> (raw)
In-Reply-To: <20241121222809.4b53e070a943e100bb6f7ba0@linux-foundation.org>

On Thu, Nov 21, 2024 at 10:28:09PM -0800, Andrew Morton wrote:
> On Tue, 19 Nov 2024 13:02:34 -0800 Jared Kangas <jkangas@redhat.com> wrote:
> 
> > If PREEMPT_RT is enabled, report_lock is a sleeping spinlock and must
> > not be locked when IRQs are disabled. However, KASAN reports may be
> > triggered in such contexts. For example:
> > 
> >         char *s = kzalloc(1, GFP_KERNEL);
> >         kfree(s);
> >         local_irq_disable();
> >         char c = *s;  /* KASAN report here leads to spin_lock() */
> >         local_irq_enable();
> > 
> > Make report_spinlock a raw spinlock to prevent rescheduling when
> > PREEMPT_RT is enabled.
> 
> So I assume we want this backported into 6.12.x?

Sorry for missing that; I think a backport of the patch would be
appropriate.

> If so, please help us identify a suitable Fixes: commit.

Fixes: 342a93247e08 ("locking/spinlock: Provide RT variant header: <linux/spinlock_rt.h>")



      reply	other threads:[~2024-11-22 18:03 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-11-19 21:02 Jared Kangas
2024-11-22  6:28 ` Andrew Morton
2024-11-22 18:03   ` Jared Kangas [this message]

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