netdev - Re: [PATCH v2 2/2] selftests: ptp: treat unsupported PHC operations as skip

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

Message-ID: <aXjwJ-p47nn1GfYO@horms.kernel.org>
Date: Tue, 27 Jan 2026 17:04:39 +0000
From: Simon Horman <horms@...nel.org>
To: Junjie Cao <junjie.cao@...el.com>
Cc: Shuah Khan <shuah@...nel.org>,
	Richard Cochran <richardcochran@...il.com>,
	linux-kselftest@...r.kernel.org, netdev@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 2/2] selftests: ptp: treat unsupported PHC operations
 as skip

On Mon, Jan 26, 2026 at 02:15:32PM +0800, Junjie Cao wrote:
> Some PTP hardware clock (PHC) devices may return -EOPNOTSUPP for
> operations like settime, adjtime, or adjfreq. This commonly occurs
> with timestamp-only PHC implementations that don't support full clock
> control.
> 
> For background, syzbot previously exposed a crash risk when PTP clock
> drivers lacked required callbacks[1]. Subsequent work[2] made callback
> presence a registration requirement. As a result, some drivers (like
> iwlwifi MVM/MLD[3]) now provide stub callbacks that return -EOPNOTSUPP
> for unsupported operations.
> 
> When phc_ctl encounters such devices, the "Operation not supported"
> error should be treated as a skip (device limitation) rather than a
> test failure. This patch:
> - Adds [SKIP] output handling in log_test()
> - Detects "Operation not supported" from phc_ctl and returns ksft_skip
> - Returns ksft_skip if all tests are skipped, preventing false-positive
>   results when testing timestamp-only PHC implementations
> 
> Link: https://lore.kernel.org/netdev/20251028043216.1971292-1-junjie.cao@intel.com/ [1]
> Link: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=dfb073d32cac [2]
> Link: https://lore.kernel.org/netdev/20251204123204.9316-1-ziyao@disroot.org/ [3]
> Signed-off-by: Junjie Cao <junjie.cao@...el.com>


Reviewed-by: Simon Horman <horms@...nel.org>