Re: [RESEND PATCH v5 1/6] perf: Introduce ioctl to communicate driver configuration to kernel

[Greg KH]

On Mon, Dec 17, 2018 at 10:21:41AM -0700, Mathieu Poirier wrote:
> Adding a new IOCTL command to communicate PMU specific configuration to
> PMU kernel drivers.  This can be anything a PMU might need for
> configuration that doesn't fit in the perf_event_attr structure, such
> as the CoreSight sink to use for a session.
> 
> Signed-off-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
> ---
>  include/uapi/linux/perf_event.h       | 1 +
>  tools/include/uapi/linux/perf_event.h | 1 +
>  2 files changed, 2 insertions(+)
> 
> diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h
> index 9de8780ac8d9..a39d8dc2e7a9 100644
> --- a/include/uapi/linux/perf_event.h
> +++ b/include/uapi/linux/perf_event.h
> @@ -462,6 +462,7 @@ struct perf_event_query_bpf {
>  #define PERF_EVENT_IOC_PAUSE_OUTPUT		_IOW('$', 9, __u32)
>  #define PERF_EVENT_IOC_QUERY_BPF		_IOWR('$', 10, struct perf_event_query_bpf *)
>  #define PERF_EVENT_IOC_MODIFY_ATTRIBUTES	_IOW('$', 11, struct perf_event_attr *)
> +#define PERF_EVENT_IOC_SET_DRV_CONFIG		_IOW('$', 12, __u64 *)
>  
>  enum perf_event_ioc_flags {
>  	PERF_IOC_FLAG_GROUP		= 1U << 0,
> diff --git a/tools/include/uapi/linux/perf_event.h b/tools/include/uapi/linux/perf_event.h
> index 9de8780ac8d9..a39d8dc2e7a9 100644
> --- a/tools/include/uapi/linux/perf_event.h
> +++ b/tools/include/uapi/linux/perf_event.h
> @@ -462,6 +462,7 @@ struct perf_event_query_bpf {
>  #define PERF_EVENT_IOC_PAUSE_OUTPUT		_IOW('$', 9, __u32)
>  #define PERF_EVENT_IOC_QUERY_BPF		_IOWR('$', 10, struct perf_event_query_bpf *)
>  #define PERF_EVENT_IOC_MODIFY_ATTRIBUTES	_IOW('$', 11, struct perf_event_attr *)
> +#define PERF_EVENT_IOC_SET_DRV_CONFIG		_IOW('$', 12, __u64 *)

A pointer to an unknown structure?  That's just asking for abuse :(