Re: [PATCH perf] perf tools: fix synthesized PERF_RECORD_KSYMBOL/BPF_EVENT

[Arnaldo Carvalho de Melo]

Em Tue, Jan 22, 2019 at 01:02:18PM -0800, Song Liu escreveu:
> Added missing machine->id_hdr_size to event->header.size. Also fixed size
> of PERF_RECORD_KSYMBOL by removing extra bytes for name.

Ok, noticed this now, thanks,

- Arnaldo
 
> Fixes: 7b612e291a5a ("perf tools: Synthesize PERF_RECORD_* for loaded BPF programs")
> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
> Suggested-by: Jiri Olsa <jolsa@xxxxxxxxxx>
> Signed-off-by: Song Liu <songliubraving@xxxxxx>
> ---
>  tools/perf/util/bpf-event.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/perf/util/bpf-event.c b/tools/perf/util/bpf-event.c
> index 01e1dc1bb7fb..f610872812ef 100644
> --- a/tools/perf/util/bpf-event.c
> +++ b/tools/perf/util/bpf-event.c
> @@ -7,6 +7,7 @@
>  #include "bpf-event.h"
>  #include "debug.h"
>  #include "symbol.h"
> +#include "machine.h"
>  
>  #define ptr_to_u64(ptr)    ((__u64)(unsigned long)(ptr))
>  
> @@ -149,7 +150,7 @@ static int perf_event__synthesize_one_bpf_prog(struct perf_tool *tool,
>  		*ksymbol_event = (struct ksymbol_event){
>  			.header = {
>  				.type = PERF_RECORD_KSYMBOL,
> -				.size = sizeof(struct ksymbol_event),
> +				.size = offsetof(struct ksymbol_event, name),
>  			},
>  			.addr = prog_addrs[i],
>  			.len = prog_lens[i],
> @@ -178,6 +179,9 @@ static int perf_event__synthesize_one_bpf_prog(struct perf_tool *tool,
>  
>  		ksymbol_event->header.size += PERF_ALIGN(name_len + 1,
>  							 sizeof(u64));
> +
> +		memset(event + event->header.size, 0, machine->id_hdr_size);
> +		event->header.size += machine->id_hdr_size;
>  		err = perf_tool__process_synth_event(tool, event,
>  						     machine, process);
>  	}
> @@ -194,6 +198,8 @@ static int perf_event__synthesize_one_bpf_prog(struct perf_tool *tool,
>  			.id = info.id,
>  		};
>  		memcpy(bpf_event->tag, prog_tags[i], BPF_TAG_SIZE);
> +		memset(event + event->header.size, 0, machine->id_hdr_size);
> +		event->header.size += machine->id_hdr_size;
>  		err = perf_tool__process_synth_event(tool, event,
>  						     machine, process);
>  	}
> -- 
> 2.17.1

-- 

- Arnaldo