Re: [PATCH 04/15] perf tools: Add map_groups to 'struct addr_location'

[Jiri Olsa <jolsa@redhat.com>]

On Tue, Nov 12, 2019 at 03:37:46PM -0300, Arnaldo Carvalho de Melo wrote:
> From: Arnaldo Carvalho de Melo <acme@redhat.com>
> 
> From there we can get al->mg->machine, so replace that field with the
> more useful 'struct map_groups' that for now we're obtaining from
> al->map->groups, and that is one thing getting into the way of maps
> being fully shareable.
> 
> Cc: Adrian Hunter <adrian.hunter@intel.com>
> Cc: Andi Kleen <ak@linux.intel.com>
> Cc: Jiri Olsa <jolsa@kernel.org>
> Cc: Namhyung Kim <namhyung@kernel.org>
> Link: https://lkml.kernel.org/n/tip-4qdducrm32tgrjupcp0kjh1e@git.kernel.org
> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
> ---
>  tools/perf/util/callchain.c                          |  6 +++---
>  tools/perf/util/db-export.c                          | 12 ++++++------
>  tools/perf/util/event.c                              |  6 +++---
>  .../perf/util/scripting-engines/trace-event-python.c |  2 +-
>  tools/perf/util/symbol.h                             |  2 +-
>  5 files changed, 14 insertions(+), 14 deletions(-)
> 
> diff --git a/tools/perf/util/callchain.c b/tools/perf/util/callchain.c
> index 9a9b56ed3f0a..89faa644b0bc 100644
> --- a/tools/perf/util/callchain.c
> +++ b/tools/perf/util/callchain.c
> @@ -1119,8 +1119,8 @@ int fill_callchain_info(struct addr_location *al, struct callchain_cursor_node *
>  			goto out;
>  	}
>  
> -	if (al->map->groups == &al->machine->kmaps) {
> -		if (machine__is_host(al->machine)) {
> +	if (al->mg == &al->mg->machine->kmaps) {

heya, I'm getting segfault because of this change

perf record --call-graph dwarf ./ex

	(gdb) r report --stdio
	Program received signal SIGSEGV, Segmentation fault.
	fill_callchain_info (al=0x7fffffffa1b0, node=0xcd2bd0, hide_unresolved=false) at util/callchain.c:1122
	1122            if (al->maps == &al->maps->machine->kmaps) {
	(gdb) p al->maps
	$1 = (struct maps *) 0x0

I wish all those map changes would go through some review,
I have no idea how the code works now ;-)

thanks,
jirka