linux-kernel - Re: [PATCH v2 01/10] dmaengine: idxd: Fix lockdep warnings when calling idxd_device

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <878qh3keyh.fsf@intel.com>
Date: Tue, 21 Oct 2025 16:33:26 -0700
From: Vinicius Costa Gomes <vinicius.gomes@...el.com>
To: Dave Hansen <dave.hansen@...el.com>, Dave Jiang <dave.jiang@...el.com>,
 Vinod Koul <vkoul@...nel.org>, Fenghua Yu <fenghua.yu@...el.com>, Dan
 Williams <dan.j.williams@...el.com>
Cc: dmaengine@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 01/10] dmaengine: idxd: Fix lockdep warnings when
 calling idxd_device_config()

Hi,

Dave Hansen <dave.hansen@...el.com> writes:

> On 8/21/25 15:59, Vinicius Costa Gomes wrote:
>> Move the check for IDXD_FLAG_CONFIGURABLE and the locking to "inside"
>> idxd_device_config(), as this is common to all callers, and the one
>> that wasn't holding the lock was an error (that was causing the
>> lockdep warning).
>
> What is "the lockdep error"? I don't see any details about an error in
> the changelog here or the cover letter?

I should have added the lockdep splat here, idxd_reset_done() is calling
idxd_device_config() without holding the lock, and the lockdep assert
inside idxd_device_config() complains about that.

I thought the commit message ("one wasn't holding") and the code would
be clear enough. In case of a another version the series, I will add the
information here.

Cheers,
-- 
Vinicius