Re: [PATCH 17/26] perf tools: Synthesize kernel with mmap3

[Arnaldo Carvalho de Melo]

Em Sun, Sep 13, 2020 at 11:03:04PM +0200, Jiri Olsa escreveu:
> Synthesizing kernel with mmap3 events so we can
> get build id data for kernel map as well.

Ditto as for 15/26
 
> Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
> ---
>  tools/perf/util/synthetic-events.c | 23 ++++++++++++++---------
>  1 file changed, 14 insertions(+), 9 deletions(-)
> 
> diff --git a/tools/perf/util/synthetic-events.c b/tools/perf/util/synthetic-events.c
> index 6bd2423ce2f3..844ca87b6e97 100644
> --- a/tools/perf/util/synthetic-events.c
> +++ b/tools/perf/util/synthetic-events.c
> @@ -1029,7 +1029,7 @@ static int __perf_event__synthesize_kernel_mmap(struct perf_tool *tool,
>  	 * available use this, and after it is use this as a fallback for older
>  	 * kernels.
>  	 */
> -	event = zalloc((sizeof(event->mmap) + machine->id_hdr_size));
> +	event = zalloc((sizeof(event->mmap3) + machine->id_hdr_size));
>  	if (event == NULL) {
>  		pr_debug("Not enough memory synthesizing mmap event "
>  			 "for kernel modules\n");
> @@ -1046,16 +1046,21 @@ static int __perf_event__synthesize_kernel_mmap(struct perf_tool *tool,
>  		event->header.misc = PERF_RECORD_MISC_GUEST_KERNEL;
>  	}
>  
> -	size = snprintf(event->mmap.filename, sizeof(event->mmap.filename),
> +	size = snprintf(event->mmap3.filename, sizeof(event->mmap3.filename),
>  			"%s%s", machine->mmap_name, kmap->ref_reloc_sym->name) + 1;
>  	size = PERF_ALIGN(size, sizeof(u64));
> -	event->mmap.header.type = PERF_RECORD_MMAP;
> -	event->mmap.header.size = (sizeof(event->mmap) -
> -			(sizeof(event->mmap.filename) - size) + machine->id_hdr_size);
> -	event->mmap.pgoff = kmap->ref_reloc_sym->addr;
> -	event->mmap.start = map->start;
> -	event->mmap.len   = map->end - event->mmap.start;
> -	event->mmap.pid   = machine->pid;
> +	event->mmap3.header.type = PERF_RECORD_MMAP3;
> +	event->mmap3.header.size = (sizeof(event->mmap3) -
> +			(sizeof(event->mmap3.filename) - size) + machine->id_hdr_size);
> +	event->mmap3.pgoff = kmap->ref_reloc_sym->addr;
> +	event->mmap3.start = map->start;
> +	event->mmap3.len   = map->end - event->mmap3.start;
> +	event->mmap3.pid   = machine->pid;
> +
> +	err = sysfs__read_build_id("/sys/kernel/notes", event->mmap3.buildid,
> +				   BUILD_ID_SIZE);
> +	if (err)
> +		pr_err("Failed to read kernel build ID\n");
>  
>  	err = perf_tool__process_synth_event(tool, event, machine, process);
>  	free(event);
> -- 
> 2.26.2
> 

-- 

- Arnaldo