Re: [PATCH RFC 11/19] perf tools: Synthesize and process mmap events for x86_64 KPTI entry trampolines

[Jiri Olsa]

On Wed, May 09, 2018 at 02:43:40PM +0300, Adrian Hunter wrote:
> Like the kernel text, the location of x86_64 KPTI entry trampolines must be
> recorded in the perf.data file. Like the kernel, synthesize a mmap event
> for that, and add processing for it.
> 
> Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
> ---
>  tools/perf/util/event.c   | 90 +++++++++++++++++++++++++++++++++++++++++++++--
>  tools/perf/util/machine.c | 28 +++++++++++++++
>  2 files changed, 115 insertions(+), 3 deletions(-)
> 
> diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
> index aafa9878465f..d810ff8488b1 100644
> --- a/tools/perf/util/event.c
> +++ b/tools/perf/util/event.c
> @@ -888,9 +888,80 @@ int kallsyms__get_function_start(const char *kallsyms_filename,
>  	return 0;
>  }
>  
> -int perf_event__synthesize_kernel_mmap(struct perf_tool *tool,
> -				       perf_event__handler_t process,
> -				       struct machine *machine)
> +#if defined(__x86_64__)

also this could go under arch/x86/

jirka

> +
> +static int perf_event__synthesize_special_kmaps(struct perf_tool *tool,
> +						perf_event__handler_t process,
> +						struct machine *machine)
> +{
> +	int rc = 0;
> +	struct map *pos;
> +	struct map_groups *kmaps = &machine->kmaps;
> +	struct maps *maps = &kmaps->maps;
> +	union perf_event *event = zalloc(sizeof(event->mmap) +
> +					 machine->id_hdr_size);
> +
> +	if (!event) {
> +		pr_debug("Not enough memory synthesizing mmap event "
> +			 "for special kernel maps\n");
> +		return -1;
> +	}
> +

SNIP