mm: memcontrol: correct the nr_pages parameter type of mem_cgroup_update_lru_size()

The nr_pages parameter of mem_cgroup_update_lru_size() represents a page
count.  During the reparenting of LRU folios, the value passed to it can
potentially exceed the maximum value of a 32-bit integer.  It should be
declared as long instead of int to match the types used in lruvec size
accounting and to prevent possible overflow.

Update the parameter type to long to ensure correctness.

Link: https://lore.kernel.org/fd4140de44fa0a3978e4e2426731187fe8625f0b.1774604356.git.zhengqi.arch@bytedance.com
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
Reviewed-by: Harry Yoo (Oracle) <harry@kernel.org>
Cc: Allen Pais <apais@linux.microsoft.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Hamza Mahfooz <hamzamahfooz@linux.microsoft.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Imran Khan <imran.f.khan@oracle.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kamalesh Babulal <kamalesh.babulal@oracle.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Usama Arif <usamaarif642@gmail.com>
Cc: Wei Xu <weixugc@google.com>
Cc: Yuanchu Xie <yuanchu@google.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 0861589695298fbfcf7c49ff86f890c1cf69e5e1..dc3fa687759b45748b2acee6d7f43da325eb50c1 100644 (file)
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -878,7 +878,7 @@ static inline bool mem_cgroup_online(struct mem_cgroup *memcg)
 }
 
 void mem_cgroup_update_lru_size(struct lruvec *lruvec, enum lru_list lru,
-               int zid, int nr_pages);
+               int zid, long nr_pages);
 
 static inline
 unsigned long mem_cgroup_get_zone_lru_size(struct lruvec *lruvec,

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 685e6dd48ce575132f55a1214ad89de6c69ffcd3..c3d98ab41f1f1b6e5716bcdd3fd88bb529326e42 100644 (file)
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1472,7 +1472,7 @@ retry:
  * to or just after a page is removed from an lru list.
  */
 void mem_cgroup_update_lru_size(struct lruvec *lruvec, enum lru_list lru,
-                               int zid, int nr_pages)
+                               int zid, long nr_pages)
 {
        struct mem_cgroup_per_node *mz;
        unsigned long *lru_size;
@@ -1489,7 +1489,7 @@ void mem_cgroup_update_lru_size(struct lruvec *lruvec, enum lru_list lru,
 
        size = *lru_size;
        if (WARN_ONCE(size < 0,
-               "%s(%p, %d, %d): lru_size %ld\n",
+               "%s(%p, %d, %ld): lru_size %ld\n",
                __func__, lruvec, lru, nr_pages, size)) {
                VM_BUG_ON(1);
                *lru_size = 0;