linux-kernel - Re: [PATCH v5 04/13] coresight: Hide unused ETMv3 format attributes

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: <CAJ9a7Vgj2P=PM2iFwSfL=GiDWtReCFn+QHUHXpkAg9y2vkocqw@mail.gmail.com>
Date: Thu, 20 Nov 2025 11:21:45 +0000
From: Mike Leach <mike.leach@...aro.org>
To: James Clark <james.clark@...aro.org>
Cc: Suzuki K Poulose <suzuki.poulose@....com>, 
	Alexander Shishkin <alexander.shishkin@...ux.intel.com>, Jonathan Corbet <corbet@....net>, 
	Leo Yan <leo.yan@....com>, Randy Dunlap <rdunlap@...radead.org>, coresight@...ts.linaro.org, 
	linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org, 
	linux-doc@...r.kernel.org
Subject: Re: [PATCH v5 04/13] coresight: Hide unused ETMv3 format attributes

On Tue, 18 Nov 2025 at 16:28, James Clark <james.clark@...aro.org> wrote:
>
> ETMv3 only has a few attributes, and setting unused ones results in an
> error, so hide them to begin with.
>
> Signed-off-by: James Clark <james.clark@...aro.org>
> ---
>  drivers/hwtracing/coresight/coresight-etm-perf.c | 22 ++++++++++++++++++++++
>  1 file changed, 22 insertions(+)
>
> diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c
> index 17afa0f4cdee..faebd7822a77 100644
> --- a/drivers/hwtracing/coresight/coresight-etm-perf.c
> +++ b/drivers/hwtracing/coresight/coresight-etm-perf.c
> @@ -106,8 +106,30 @@ static struct attribute *etm_config_formats_attr[] = {
>         NULL,
>  };
>
> +static umode_t etm_format_attr_is_visible(struct kobject *kobj,
> +                                         struct attribute *attr, int unused)
> +{
> +       /* ETM4 has all attributes */
> +       if (IS_ENABLED(CONFIG_CORESIGHT_SOURCE_ETM4X))
> +               return attr->mode;
> +
> +       /*
> +        * ETM3 only uses these attributes for programming itself (see
> +        * ETM3X_SUPPORTED_OPTIONS). Sink ID is also supported for selecting a
> +        * sink, but not used for configuring the ETM.
> +        */
> +       if (attr == &format_attr_cycacc.attr ||
> +           attr == &format_attr_timestamp.attr ||
> +           attr == &format_attr_retstack.attr ||
> +           attr == &format_attr_sinkid.attr)
> +               return attr->mode;
> +
> +       return 0;
> +}
> +
>  static const struct attribute_group etm_pmu_format_group = {
>         .name   = "format",
> +       .is_visible = etm_format_attr_is_visible,
>         .attrs  = etm_config_formats_attr,
>  };
>
>
> --
> 2.34.1
>
Reviewed-by: Mike Leach <mike.leach@...aro.org>


--
Mike Leach
Principal Engineer, ARM Ltd.
Manchester Design Centre. UK