Re: [PATCH v2 04/23] coresight: trbe: Check the buffer association before IRQ validation

[James Clark <james.clark@linaro.org>]

On 16/10/2026 17:55, Leo Yan wrote:
> is_perf_trbe() obtains the sink buffer from the output handle and
> dereferences buf->cpudata before validating either pointer. A live AUX
> transaction does not guarantee that the selected buffer has a CPU
> association.
> 
> Reject a missing buffer or CPU association before reading CPU driver
> data or checking the hardware buffer addresses. Treat these configurations
> as an invalid perf TRBE session.
> 
> Signed-off-by: Leo Yan <leo.yan@arm.com>
> ---
>   drivers/hwtracing/coresight/coresight-trbe.c | 10 ++++++++--
>   1 file changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/hwtracing/coresight/coresight-trbe.c b/drivers/hwtracing/coresight/coresight-trbe.c
> index 8ec0b4c4987f25d10ee0b2f80c27e10f76357387..91fbdbad3676ffae399df0b4d4ddcd603a40e86c 100644
> --- a/drivers/hwtracing/coresight/coresight-trbe.c
> +++ b/drivers/hwtracing/coresight/coresight-trbe.c
> @@ -1111,10 +1111,16 @@ static int trbe_handle_overflow(struct perf_output_handle *handle)
>   static bool is_perf_trbe(struct perf_output_handle *handle)
>   {
>   	struct trbe_buf *buf = etm_perf_sink_config(handle);
> -	struct trbe_cpudata *cpudata = buf->cpudata;
> -	struct trbe_drvdata *drvdata = cpudata->drvdata;
> +	struct trbe_cpudata *cpudata;
> +	struct trbe_drvdata *drvdata;
>   	int cpu = smp_processor_id();
>   
> +	if (!buf || !buf->cpudata)
> +		return false;
> +
> +	cpudata = buf->cpudata;
> +	drvdata = cpudata->drvdata;
> +
>   	WARN_ON(buf->trbe_hw_base != get_trbe_base_pointer());
>   	WARN_ON(buf->trbe_limit != get_trbe_limit_pointer());
>   
> 

Reviewed-by: James Clark <james.clark@linaro.org>