[PATCH 1/6] perf maps: Introduce map__set_kmap() for kernel maps

[Arnaldo Carvalho de Melo]

From: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>

We need to set it in other places than __maps__insert(), so that we can
have access to the 'struct kmap' from a kernel 'struct map'.

When building perf with 'DEBUG=1' we can notice it failing a consistency
check done in the check_invariants() function:

  root@number:~# perf record -- perf test -w offcpu
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.040 MB perf.data (23 samples) ]
  perf: util/maps.c:95: check_invariants: Assertion `map__end(prev) <= map__end(map)' failed.
  Aborted (core dumped)
  root@number:~#

The investigation on that was happening bisected to 876e80cf83d10585
("perf tools: Fixup end address of modules"), and the following patches
will plug the problems found, this patch is just legwork on that
direction.

Acked-by: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Ian Rogers <irogers@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: James Clark <james.clark@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
Link: https://lore.kernel.org/lkml/Z74V0hZXrTLM6VIJ@x1
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
 tools/perf/util/maps.c | 29 +++++++++++++++++++++--------
 1 file changed, 21 insertions(+), 8 deletions(-)

diff --git a/tools/perf/util/maps.c b/tools/perf/util/maps.c
index 09c9cc326c08d435..e21d29f5df01c6f7 100644
--- a/tools/perf/util/maps.c
+++ b/tools/perf/util/maps.c
@@ -428,11 +428,29 @@ static unsigned int maps__by_name_index(const struct maps *maps, const struct ma
 	return -1;
 }
 
+static void map__set_kmap(struct map *map, struct maps *maps)
+{
+	struct dso *dso;
+
+	if (map == NULL)
+		return;
+
+	dso = map__dso(map);
+
+	if (dso && dso__kernel(dso)) {
+                struct kmap *kmap = map__kmap(map);
+
+                if (kmap)
+                        kmap->kmaps = maps;
+                else
+                        pr_err("Internal error: kernel dso with non kernel map\n");
+        }
+}
+
 static int __maps__insert(struct maps *maps, struct map *new)
 {
 	struct map **maps_by_address = maps__maps_by_address(maps);
 	struct map **maps_by_name = maps__maps_by_name(maps);
-	const struct dso *dso = map__dso(new);
 	unsigned int nr_maps = maps__nr_maps(maps);
 	unsigned int nr_allocate = RC_CHK_ACCESS(maps)->nr_maps_allocated;
 
@@ -483,14 +501,9 @@ static int __maps__insert(struct maps *maps, struct map *new)
 	}
 	if (map__end(new) < map__start(new))
 		RC_CHK_ACCESS(maps)->ends_broken = true;
-	if (dso && dso__kernel(dso)) {
-		struct kmap *kmap = map__kmap(new);
 
-		if (kmap)
-			kmap->kmaps = maps;
-		else
-			pr_err("Internal error: kernel dso with non kernel map\n");
-	}
+	map__set_kmap(new, maps);
+
 	return 0;
 }
 
-- 
2.47.0