perf tools: Preserve eBPF maps when loading kcore (fb5a88d4) · Commits · 戴 / test

tools/perf/util/symbol.c

+93 −4

Original line number	Diff line number	Diff line
		@@ -1166,6 +1166,85 @@ static int kcore_mapfn(u64 start, u64 len, u64 pgoff, void *data)
		return 0;
		}

		/*
		* Merges map into map_groups by splitting the new map
		* within the existing map regions.
		*/
		static int map_groups__merge_in(struct map_groups kmaps, struct map new_map)
		{
		struct map *old_map;
		LIST_HEAD(merged);

		for (old_map = map_groups__first(kmaps); old_map;
		old_map = map_groups__next(old_map)) {

		/* no overload with this one */
		if (new_map->end < old_map->start \|\|
		new_map->start >= old_map->end)
		continue;

		if (new_map->start < old_map->start) {
		/*
		* \|new......
		* \|old....
		*/
		if (new_map->end < old_map->end) {
		/*
		* \|new......\| -> \|new..\|
		* \|old....\| -> \|old....\|
		*/
		new_map->end = old_map->start;
		} else {
		/*
		* \|new.............\| -> \|new..\| \|new..\|
		* \|old....\| -> \|old....\|
		*/
		struct map *m = map__clone(new_map);

		if (!m)
		return -ENOMEM;

		m->end = old_map->start;
		list_add_tail(&m->node, &merged);
		new_map->start = old_map->end;
		}
		} else {
		/*
		* \|new......
		* \|old....
		*/
		if (new_map->end < old_map->end) {
		/*
		* \|new..\| -> x
		* \|old.........\| -> \|old.........\|
		*/
		map__put(new_map);
		new_map = NULL;
		break;
		} else {
		/*
		* \|new......\| -> \|new...\|
		* \|old....\| -> \|old....\|
		*/
		new_map->start = old_map->end;
		}
		}
		}

		while (!list_empty(&merged)) {
		old_map = list_entry(merged.next, struct map, node);
		list_del_init(&old_map->node);
		map_groups__insert(kmaps, old_map);
		map__put(old_map);
		}

		if (new_map) {
		map_groups__insert(kmaps, new_map);
		map__put(new_map);
		}
		return 0;
		}

		static int dso__load_kcore(struct dso dso, struct map map,
		const char *kallsyms_filename)
		{
		@@ -1222,7 +1301,12 @@ static int dso__load_kcore(struct dso dso, struct map map,
		while (old_map) {
		struct map *next = map_groups__next(old_map);

		if (old_map != map)
		/*
		* We need to preserve eBPF maps even if they are
		* covered by kcore, because we need to access
		* eBPF dso for source data.
		*/
		if (old_map != map && !__map__is_bpf_prog(old_map))
		map_groups__remove(kmaps, old_map);
		old_map = next;
		}
		@@ -1256,11 +1340,16 @@ static int dso__load_kcore(struct dso dso, struct map map,
		map_groups__remove(kmaps, map);
		map_groups__insert(kmaps, map);
		map__put(map);
		map__put(new_map);
		} else {
		map_groups__insert(kmaps, new_map);
		/*
		* Merge kcore map into existing maps,
		* and ensure that current maps (eBPF)
		* stay intact.
		*/
		if (map_groups__merge_in(kmaps, new_map))
		goto out_err;
		}

		map__put(new_map);
		}

		if (machine__is(machine, "x86_64")) {

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