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From: "David Hildenbrand (Arm)" <david@kernel.org>
To: Ameer Hamza <ameer.hamza@truenas.com>,
	ljs@kernel.org, rppt@kernel.org, peterz@infradead.org
Cc: akpm@linux-foundation.org, mingo@redhat.com, acme@kernel.org,
	namhyung@kernel.org, linux-mm@kvack.org,
	linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org,
	regressions@lists.linux.dev, stable@vger.kernel.org,
	4ncienth@gmail.com, sashal@kernel.org,
	alexander.motin@truenas.com, caleb.stjohn@truenas.com
Subject: Re: [REGRESSION] secretmem: SIGBUS on memfd_secret() pages while perf record runs
Date: Sat, 3 Oct 2026 16:14:49 +0200	[thread overview]
Message-ID: <3c5b9d1e-5ed4-4bd1-b532-39f2d4612965@kernel.org> (raw)
In-Reply-To: <20261002175651.811343-1-ameer.hamza@truenas.com>

On 10/2/26 19:56, Ameer Hamza wrote:
> Hi,
> 

Hi!

> Since commit 97d34aa65c29 ("mm/secretmem: properly account locked
> pages"), in v7.3-rc2 and the 6.18.52 and 7.2.5 backports, touching a
> memfd_secret() page for the first time fails with SIGBUS while the
> same user is running perf record, and read() into such a page fails
> with EFAULT. This happens for root as well as for an unprivileged
> user running its own perf record. It reproduces on v7.3-rc4 and
> 6.18.52, and the same test passes without the recording or with the
> commit reverted.

Thanks for the report!

May I know whether this problem was found by

(a) A real workload

(b) A test case

(c) Complains by some tooling

I am asking, because so far I was under the assumption that secretmem isn't
heavily used in the wild.

-- 
Cheers,

David

  parent reply	other threads:[~2026-10-03 14:15 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-10-02 17:56 Ameer Hamza
2026-10-03  1:30 ` Sasha Levin
2026-10-03  9:18   ` Lorenzo Stoakes (ARM)
2026-10-03 14:30     ` Sasha Levin
2026-10-03 16:23       ` Lorenzo Stoakes (ARM)
2026-10-03 22:34         ` Sasha Levin
2026-10-03 14:14 ` David Hildenbrand (Arm) [this message]
2026-10-03 17:05   ` Ameer Hamza
2026-10-03 15:56 ` Lorenzo Stoakes (ARM)
2026-10-03 16:31   ` Lorenzo Stoakes (ARM)
2026-10-03 18:02   ` Ameer Hamza

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