Re: [PATCH 12/24] perf tools: Store build id from mmap2 events

[Arnaldo Carvalho de Melo]

Em Tue, Nov 17, 2020 at 12:00:41PM +0100, Jiri Olsa escreveu:
> When processing mmap2 event, check on the build id
> misc bit: PERF_RECORD_MISC_BUILD_ID and if it's set,
> store the build id in mmap's dso object.
> 
> Also adding the build id data arts to struct
> perf_record_mmap2 event definition.
> 
> Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
> ---
>  kernel/events/core.c                |  4 ++++
>  tools/lib/perf/include/perf/event.h | 18 ++++++++++++++----
>  tools/perf/util/machine.c           | 24 +++++++++++++++++++-----
>  tools/perf/util/map.c               |  8 ++++++--
>  tools/perf/util/map.h               |  3 ++-
>  5 files changed, 45 insertions(+), 12 deletions(-)

You mixed up kernel changes with tools/ changes, can you please split
this up?

Also there is an indentation problem in the kernel changes, which, I
think, is just debugging cruft that you forgot to excise? :-)

- Arnaldo
 
> diff --git a/kernel/events/core.c b/kernel/events/core.c
> index 5841b5bca68d..fa7f392c6c0c 100644
> --- a/kernel/events/core.c
> +++ b/kernel/events/core.c
> @@ -8017,6 +8017,10 @@ static void perf_event_mmap_output(struct perf_event *event,
>  
>  			__output_copy(&handle, size, 4);
>  			__output_copy(&handle, mmap_event->build_id, BUILD_ID_SIZE);
> +
> +if (mmap_event->build_id_size > 20)
> +	trace_printk("build_id_size %u %s\n", mmap_event->build_id_size, mmap_event->file_name);
> +
>  		} else {
>  			perf_output_put(&handle, mmap_event->maj);
>  			perf_output_put(&handle, mmap_event->min);
> diff --git a/tools/lib/perf/include/perf/event.h b/tools/lib/perf/include/perf/event.h
> index 988c539bedb6..d82054225fcc 100644
> --- a/tools/lib/perf/include/perf/event.h
> +++ b/tools/lib/perf/include/perf/event.h
> @@ -23,10 +23,20 @@ struct perf_record_mmap2 {
>  	__u64			 start;
>  	__u64			 len;
>  	__u64			 pgoff;
> -	__u32			 maj;
> -	__u32			 min;
> -	__u64			 ino;
> -	__u64			 ino_generation;
> +	union {
> +		struct {
> +			__u32	 maj;
> +			__u32	 min;
> +			__u64	 ino;
> +			__u64	 ino_generation;
> +		};
> +		struct {
> +			__u8	 build_id_size;
> +			__u8	 __reserved_1;
> +			__u16	 __reserved_2;
> +			__u8	 build_id[20];
> +		};
> +	};
>  	__u32			 prot;
>  	__u32			 flags;
>  	char			 filename[PATH_MAX];
> diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
> index 1ae32a81639c..1edb7d10b042 100644
> --- a/tools/perf/util/machine.c
> +++ b/tools/perf/util/machine.c
> @@ -1599,7 +1599,8 @@ static int machine__process_extra_kernel_map(struct machine *machine,
>  }
>  
>  static int machine__process_kernel_mmap_event(struct machine *machine,
> -					      struct extra_kernel_map *xm)
> +					      struct extra_kernel_map *xm,
> +					      struct build_id *bid)
>  {
>  	struct map *map;
>  	enum dso_space_type dso_space;
> @@ -1624,6 +1625,10 @@ static int machine__process_kernel_mmap_event(struct machine *machine,
>  			goto out_problem;
>  
>  		map->end = map->start + xm->end - xm->start;
> +
> +		if (build_id__is_defined(bid))
> +			dso__set_build_id(map->dso, bid);
> +
>  	} else if (is_kernel_mmap) {
>  		const char *symbol_name = (xm->name + strlen(machine->mmap_name));
>  		/*
> @@ -1681,6 +1686,9 @@ static int machine__process_kernel_mmap_event(struct machine *machine,
>  
>  		machine__update_kernel_mmap(machine, xm->start, xm->end);
>  
> +		if (build_id__is_defined(bid))
> +			dso__set_build_id(kernel, bid);
> +
>  		/*
>  		 * Avoid using a zero address (kptr_restrict) for the ref reloc
>  		 * symbol. Effectively having zero here means that at record
> @@ -1718,11 +1726,17 @@ int machine__process_mmap2_event(struct machine *machine,
>  		.ino = event->mmap2.ino,
>  		.ino_generation = event->mmap2.ino_generation,
>  	};
> +	struct build_id __bid, *bid = NULL;
>  	int ret = 0;
>  
>  	if (dump_trace)
>  		perf_event__fprintf_mmap2(event, stdout);
>  
> +	if (event->header.misc & PERF_RECORD_MISC_MMAP_BUILD_ID) {
> +		bid = &__bid;
> +		build_id__init(bid, event->mmap2.build_id, event->mmap2.build_id_size);
> +	}
> +
>  	if (sample->cpumode == PERF_RECORD_MISC_GUEST_KERNEL ||
>  	    sample->cpumode == PERF_RECORD_MISC_KERNEL) {
>  		struct extra_kernel_map xm = {
> @@ -1732,7 +1746,7 @@ int machine__process_mmap2_event(struct machine *machine,
>  		};
>  
>  		strlcpy(xm.name, event->mmap2.filename, KMAP_NAME_LEN);
> -		ret = machine__process_kernel_mmap_event(machine, &xm);
> +		ret = machine__process_kernel_mmap_event(machine, &xm, bid);
>  		if (ret < 0)
>  			goto out_problem;
>  		return 0;
> @@ -1746,7 +1760,7 @@ int machine__process_mmap2_event(struct machine *machine,
>  	map = map__new(machine, event->mmap2.start,
>  			event->mmap2.len, event->mmap2.pgoff,
>  			&dso_id, event->mmap2.prot,
> -			event->mmap2.flags,
> +			event->mmap2.flags, bid,
>  			event->mmap2.filename, thread);
>  
>  	if (map == NULL)
> @@ -1789,7 +1803,7 @@ int machine__process_mmap_event(struct machine *machine, union perf_event *event
>  		};
>  
>  		strlcpy(xm.name, event->mmap.filename, KMAP_NAME_LEN);
> -		ret = machine__process_kernel_mmap_event(machine, &xm);
> +		ret = machine__process_kernel_mmap_event(machine, &xm, NULL);
>  		if (ret < 0)
>  			goto out_problem;
>  		return 0;
> @@ -1805,7 +1819,7 @@ int machine__process_mmap_event(struct machine *machine, union perf_event *event
>  
>  	map = map__new(machine, event->mmap.start,
>  			event->mmap.len, event->mmap.pgoff,
> -			NULL, prot, 0, event->mmap.filename, thread);
> +			NULL, prot, 0, NULL, event->mmap.filename, thread);
>  
>  	if (map == NULL)
>  		goto out_problem_map;
> diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
> index f44ede437dc7..692e56dc832e 100644
> --- a/tools/perf/util/map.c
> +++ b/tools/perf/util/map.c
> @@ -130,8 +130,8 @@ void map__init(struct map *map, u64 start, u64 end, u64 pgoff, struct dso *dso)
>  
>  struct map *map__new(struct machine *machine, u64 start, u64 len,
>  		     u64 pgoff, struct dso_id *id,
> -		     u32 prot, u32 flags, char *filename,
> -		     struct thread *thread)
> +		     u32 prot, u32 flags, struct build_id *bid,
> +		     char *filename, struct thread *thread)
>  {
>  	struct map *map = malloc(sizeof(*map));
>  	struct nsinfo *nsi = NULL;
> @@ -194,6 +194,10 @@ struct map *map__new(struct machine *machine, u64 start, u64 len,
>  				dso__set_loaded(dso);
>  		}
>  		dso->nsinfo = nsi;
> +
> +		if (build_id__is_defined(bid))
> +			dso__set_build_id(dso, bid);
> +
>  		dso__put(dso);
>  	}
>  	return map;
> diff --git a/tools/perf/util/map.h b/tools/perf/util/map.h
> index b1c0686db1b7..9f32825c98d8 100644
> --- a/tools/perf/util/map.h
> +++ b/tools/perf/util/map.h
> @@ -104,10 +104,11 @@ void map__init(struct map *map,
>  	       u64 start, u64 end, u64 pgoff, struct dso *dso);
>  
>  struct dso_id;
> +struct build_id;
>  
>  struct map *map__new(struct machine *machine, u64 start, u64 len,
>  		     u64 pgoff, struct dso_id *id, u32 prot, u32 flags,
> -		     char *filename, struct thread *thread);
> +		     struct build_id *bid, char *filename, struct thread *thread);
>  struct map *map__new2(u64 start, struct dso *dso);
>  void map__delete(struct map *map);
>  struct map *map__clone(struct map *map);
> -- 
> 2.26.2
> 

-- 

- Arnaldo