[tip: perf/urgent] perf machine: Fill map_symbol->maps in append_inlines() to fix segfault

[tip-bot2 for Arnaldo Carvalho de Melo]

The following commit has been merged into the perf/urgent branch of tip:

Commit-ID:     77b91c1a525d84cb560a4baef6f5f548b5c23f80
Gitweb:        https://git.kernel.org/tip/77b91c1a525d84cb560a4baef6f5f548b5c23f80
Author:        Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
AuthorDate:    Fri, 29 Nov 2019 15:47:51 -03:00
Committer:     Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitterDate: Fri, 29 Nov 2019 16:11:06 -03:00

perf machine: Fill map_symbol->maps in append_inlines() to fix segfault

I forgot to fill in the map_symbol->maps field in append_inlines() which
then makes code down the line segfault when trying to deref it.

It doesn't make any sense to have an addr_location with its 'map' member
not NULL while its 'maps' is NULL, after all al->maps is where al->map
is in.

It is done that way so that we don't have to have in each 'struct map' a
pointer to the 'struct maps' it is in, as we had in the past when we
would have 'map->mg', before 'struct maps' was combined with 'struct
map_groups', because there was always a one-to-one relationship for
these structs.

This fixes a segfault when processing DWARF callgraphs in 'perf report'.

Reported-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Fixes: 08f6680e627e ("perf tools: Add a 'struct map_groups' pointer to 'struct map_symbol'")
Link: http://lore.kernel.org/lkml/20191129160631.GD26963@xxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
 tools/perf/util/machine.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index 416d174..c8c5410 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -2446,6 +2446,7 @@ static int append_inlines(struct callchain_cursor *cursor, struct map_symbol *ms
 
 	list_for_each_entry(ilist, &inline_node->val, list) {
 		struct map_symbol ilist_ms = {
+			.maps = ms->maps,
 			.map = map,
 			.sym = ilist->symbol,
 		};