[PATCH 5.2 378/413] mm/memcontrol: fix wrong statistics in memory.stat

From: Greg Kroah-Hartman
Date: Wed Jul 24 2019 - 16:24:33 EST


From: Yafang Shao <laoar.shao@xxxxxxxxx>

commit dd9239900e12db84c198855b262ae7796db1123b upstream.

When we calculate total statistics for memcg1_stats and memcg1_events,
we use the the index 'i' in the for loop as the events index. Actually
we should use memcg1_stats[i] and memcg1_events[i] as the events index.

Link: http://lkml.kernel.org/r/1562116978-19539-1-git-send-email-laoar.shao@xxxxxxxxx
Fixes: 42a300353577 ("mm: memcontrol: fix recursive statistics correctness & scalabilty").
Signed-off-by: Yafang Shao <laoar.shao@xxxxxxxxx
Reviewed-by: Shakeel Butt <shakeelb@xxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Yafang Shao <shaoyafang@xxxxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
mm/memcontrol.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3530,12 +3530,13 @@ static int memcg_stat_show(struct seq_fi
if (memcg1_stats[i] == MEMCG_SWAP && !do_memsw_account())
continue;
seq_printf(m, "total_%s %llu\n", memcg1_stat_names[i],
- (u64)memcg_page_state(memcg, i) * PAGE_SIZE);
+ (u64)memcg_page_state(memcg, memcg1_stats[i]) *
+ PAGE_SIZE);
}

for (i = 0; i < ARRAY_SIZE(memcg1_events); i++)
seq_printf(m, "total_%s %llu\n", memcg1_event_names[i],
- (u64)memcg_events(memcg, i));
+ (u64)memcg_events(memcg, memcg1_events[i]));

for (i = 0; i < NR_LRU_LISTS; i++)
seq_printf(m, "total_%s %llu\n", mem_cgroup_lru_names[i],