linux-kernel - Re: [PATCH v4 06/10] coresight: etm-perf: Update to activate selected configuration

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: <20210225215122.GC3567106@xps15>
Date:   Thu, 25 Feb 2021 14:51:22 -0700
From:   Mathieu Poirier <mathieu.poirier@...aro.org>
To:     Mike Leach <mike.leach@...aro.org>
Cc:     linux-arm-kernel@...ts.infradead.org, coresight@...ts.linaro.org,
        linux-doc@...r.kernel.org, suzuki.poulose@....com,
        yabinc@...gle.com, corbet@....net, leo.yan@...aro.org,
        alexander.shishkin@...ux.intel.com, tingwei@...eaurora.org,
        gregkh@...uxfoundation.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v4 06/10] coresight: etm-perf: Update to activate
 selected configuration

On Thu, Jan 28, 2021 at 05:09:32PM +0000, Mike Leach wrote:
> Add calls to activate the selected configuration as perf starts
> and stops the tracing session.
> 
> Signed-off-by: Mike Leach <mike.leach@...aro.org>
> ---
>  drivers/hwtracing/coresight/coresight-etm-perf.c | 14 +++++++++++++-
>  drivers/hwtracing/coresight/coresight-etm-perf.h |  2 ++
>  2 files changed, 15 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c
> index e270bb1e0f7d..5c1aeddabc59 100644
> --- a/drivers/hwtracing/coresight/coresight-etm-perf.c
> +++ b/drivers/hwtracing/coresight/coresight-etm-perf.c
> @@ -178,6 +178,10 @@ static void free_event_data(struct work_struct *work)
>  	/* Free the sink buffers, if there are any */
>  	free_sink_buffer(event_data);
>  
> +	/* clear any configuration we were using */
> +	if (event_data->config_id_hash)
> +		cscfg_deactivate_config(event_data->config_id_hash);
> +
>  	for_each_cpu(cpu, mask) {
>  		struct list_head **ppath;
>  
> @@ -236,7 +240,7 @@ static void etm_free_aux(void *data)
>  static void *etm_setup_aux(struct perf_event *event, void **pages,
>  			   int nr_pages, bool overwrite)
>  {
> -	u32 id;
> +	u32 id, config_id;

config_id, cfg_hash, id_hash...

>  	int cpu = event->cpu;
>  	cpumask_t *mask;
>  	struct coresight_device *sink = NULL;
> @@ -253,6 +257,14 @@ static void *etm_setup_aux(struct perf_event *event, void **pages,
>  		sink = coresight_get_sink_by_id(id);
>  	}
>  
> +	/* check if user wants a coresight configuration selected */
> +	config_id = (u32)((event->attr.config2 & GENMASK_ULL(63, 32)) >> 32);
> +	if (config_id) {
> +		if (cscfg_activate_config(config_id))
> +			goto err;
> +		event_data->config_id_hash = config_id;
> +	}
> +
>  	mask = &event_data->mask;
>  
>  	/*
> diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.h b/drivers/hwtracing/coresight/coresight-etm-perf.h
> index 3646a3837a0b..751d768939d8 100644
> --- a/drivers/hwtracing/coresight/coresight-etm-perf.h
> +++ b/drivers/hwtracing/coresight/coresight-etm-perf.h
> @@ -49,12 +49,14 @@ struct etm_filters {
>   * @work:		Handle to free allocated memory outside IRQ context.
>   * @mask:		Hold the CPU(s) this event was set for.
>   * @snk_config:		The sink configuration.
> + * @config_id_hash:	The id of any coresight config selected.
>   * @path:		An array of path, each slot for one CPU.
>   */
>  struct etm_event_data {
>  	struct work_struct work;
>  	cpumask_t mask;
>  	void *snk_config;
> +	u32 config_id_hash;

Please align this with the naming convention you will be using above and
throughout.

More comments tomorrow.

Thanks,
Mathieu

>  	struct list_head * __percpu *path;
>  };
>  
> -- 
> 2.17.1
>