Re: [paulmck-rcu:dev.2024.04.04a 17/74] mm/memcontrol.c:1200:31: sparse: sparse: incorrect type in argument 2 (different base types)

From: Paul E. McKenney
Date: Tue Apr 09 2024 - 21:09:24 EST


On Wed, Apr 10, 2024 at 08:08:14AM +0800, kernel test robot wrote:
> tree: https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git dev.2024.04.04a
> head: e2a520f3f3921cb5d3c9631917fccf8c215991ce
> commit: 27011e7159ef6e100e9ae1debb01a8e180ee94bf [17/74] riscv: Emulate one-byte cmpxchg
> config: riscv-randconfig-r122-20240409 (https://download.01.org/0day-ci/archive/20240410/202404100829.OchVjDmF-lkp@xxxxxxxxx/config)
> compiler: riscv64-linux-gcc (GCC) 13.2.0
> reproduce: (https://download.01.org/0day-ci/archive/20240410/202404100829.OchVjDmF-lkp@xxxxxxxxx/reproduce)
>
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@xxxxxxxxx>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202404100829.OchVjDmF-lkp@xxxxxxxxx/

I believe these to be fixed by the addition of casts by this new
version of the above commit:

4d5c72a34948 ("riscv: Emulate one-byte cmpxchg")

As always, please let me know if I am missing something.

Thanx, Paul

> sparse warnings: (new ones prefixed by >>)
> >> mm/memcontrol.c:1200:31: sparse: sparse: incorrect type in argument 2 (different base types) @@ expected unsigned long [usertype] old @@ got struct mem_cgroup *__old @@
> mm/memcontrol.c:1200:31: sparse: expected unsigned long [usertype] old
> mm/memcontrol.c:1200:31: sparse: got struct mem_cgroup *__old
> >> mm/memcontrol.c:1200:31: sparse: sparse: incorrect type in argument 3 (different base types) @@ expected unsigned long [usertype] new @@ got struct mem_cgroup *__new @@
> mm/memcontrol.c:1200:31: sparse: expected unsigned long [usertype] new
> mm/memcontrol.c:1200:31: sparse: got struct mem_cgroup *__new
> mm/memcontrol.c:1240:23: sparse: sparse: incorrect type in argument 2 (different base types) @@ expected unsigned long [usertype] old @@ got struct mem_cgroup *__old @@
> mm/memcontrol.c:1240:23: sparse: expected unsigned long [usertype] old
> mm/memcontrol.c:1240:23: sparse: got struct mem_cgroup *__old
> mm/memcontrol.c:1240:23: sparse: sparse: incorrect type in argument 3 (different base types) @@ expected unsigned long [usertype] new @@ got struct mem_cgroup *__new @@
> mm/memcontrol.c:1240:23: sparse: expected unsigned long [usertype] new
> mm/memcontrol.c:1240:23: sparse: got struct mem_cgroup *__new
> mm/memcontrol.c:1281:17: sparse: sparse: incorrect type in argument 2 (different base types) @@ expected unsigned long [usertype] old @@ got struct mem_cgroup *__old @@
> mm/memcontrol.c:1281:17: sparse: expected unsigned long [usertype] old
> mm/memcontrol.c:1281:17: sparse: got struct mem_cgroup *__old
> mm/memcontrol.c:1281:17: sparse: sparse: incorrect type in argument 3 (different base types) @@ expected unsigned long [usertype] new @@ got struct mem_cgroup *__new @@
> mm/memcontrol.c:1281:17: sparse: expected unsigned long [usertype] new
> mm/memcontrol.c:1281:17: sparse: got struct mem_cgroup *__new
> >> mm/memcontrol.c:3184:19: sparse: sparse: incorrect type in argument 2 (different base types) @@ expected unsigned long [usertype] old @@ got struct obj_cgroup *__old @@
> mm/memcontrol.c:3184:19: sparse: expected unsigned long [usertype] old
> mm/memcontrol.c:3184:19: sparse: got struct obj_cgroup *__old
> >> mm/memcontrol.c:3184:19: sparse: sparse: incorrect type in argument 3 (different base types) @@ expected unsigned long [usertype] new @@ got struct obj_cgroup *__new @@
> mm/memcontrol.c:3184:19: sparse: expected unsigned long [usertype] new
> mm/memcontrol.c:3184:19: sparse: got struct obj_cgroup *__new
> mm/memcontrol.c:4408:21: sparse: sparse: incompatible types in comparison expression (different address spaces):
> mm/memcontrol.c:4408:21: sparse: struct mem_cgroup_threshold_ary [noderef] __rcu *
> mm/memcontrol.c:4408:21: sparse: struct mem_cgroup_threshold_ary *
> mm/memcontrol.c:4410:21: sparse: sparse: incompatible types in comparison expression (different address spaces):
> mm/memcontrol.c:4410:21: sparse: struct mem_cgroup_threshold_ary [noderef] __rcu *
> mm/memcontrol.c:4410:21: sparse: struct mem_cgroup_threshold_ary *
> mm/memcontrol.c:4566:9: sparse: sparse: incompatible types in comparison expression (different address spaces):
> mm/memcontrol.c:4566:9: sparse: struct mem_cgroup_threshold_ary [noderef] __rcu *
> mm/memcontrol.c:4566:9: sparse: struct mem_cgroup_threshold_ary *
> mm/memcontrol.c:4660:9: sparse: sparse: incompatible types in comparison expression (different address spaces):
> mm/memcontrol.c:4660:9: sparse: struct mem_cgroup_threshold_ary [noderef] __rcu *
> mm/memcontrol.c:4660:9: sparse: struct mem_cgroup_threshold_ary *
> mm/memcontrol.c: note: in included file:
> include/linux/memcontrol.h:761:9: sparse: sparse: context imbalance in 'folio_lruvec_lock' - wrong count at exit
> include/linux/memcontrol.h:761:9: sparse: sparse: context imbalance in 'folio_lruvec_lock_irq' - wrong count at exit
> include/linux/memcontrol.h:761:9: sparse: sparse: context imbalance in 'folio_lruvec_lock_irqsave' - wrong count at exit
> mm/memcontrol.c:2185:6: sparse: sparse: context imbalance in 'folio_memcg_lock' - wrong count at exit
> mm/memcontrol.c:2232:17: sparse: sparse: context imbalance in '__folio_memcg_unlock' - unexpected unlock
> --
> >> fs/fs-writeback.c:291:13: sparse: sparse: incorrect type in argument 2 (different base types) @@ expected unsigned long [usertype] old @@ got struct bdi_writeback *__old @@
> fs/fs-writeback.c:291:13: sparse: expected unsigned long [usertype] old
> fs/fs-writeback.c:291:13: sparse: got struct bdi_writeback *__old
> >> fs/fs-writeback.c:291:13: sparse: sparse: incorrect type in argument 3 (different base types) @@ expected unsigned long [usertype] new @@ got struct bdi_writeback *__new @@
> fs/fs-writeback.c:291:13: sparse: expected unsigned long [usertype] new
> fs/fs-writeback.c:291:13: sparse: got struct bdi_writeback *__new
> fs/fs-writeback.c:753:15: sparse: sparse: context imbalance in 'wbc_attach_and_unlock_inode' - unexpected unlock
> fs/fs-writeback.c:1804:20: sparse: sparse: context imbalance in 'writeback_single_inode' - different lock contexts for basic block
> fs/fs-writeback.c:1990:9: sparse: sparse: context imbalance in 'writeback_sb_inodes' - different lock contexts for basic block
> fs/fs-writeback.c:2580:20: sparse: sparse: context imbalance in '__mark_inode_dirty' - unexpected unlock
> --
> fs/bcachefs/btree_cache.c: note: in included file:
> fs/bcachefs/bcachefs.h:1023:9: sparse: sparse: array of flexible structures
> >> fs/bcachefs/btree_cache.c:534:15: sparse: sparse: incorrect type in argument 2 (different base types) @@ expected unsigned long [usertype] old @@ got struct task_struct *__old @@
> fs/bcachefs/btree_cache.c:534:15: sparse: expected unsigned long [usertype] old
> fs/bcachefs/btree_cache.c:534:15: sparse: got struct task_struct *__old
> >> fs/bcachefs/btree_cache.c:534:15: sparse: sparse: incorrect type in argument 3 (different base types) @@ expected unsigned long [usertype] new @@ got struct task_struct *__new @@
> fs/bcachefs/btree_cache.c:534:15: sparse: expected unsigned long [usertype] new
> fs/bcachefs/btree_cache.c:534:15: sparse: got struct task_struct *__new
> fs/bcachefs/btree_cache.c:546:15: sparse: sparse: incorrect type in argument 2 (different base types) @@ expected unsigned long [usertype] old @@ got struct task_struct *__old @@
> fs/bcachefs/btree_cache.c:546:15: sparse: expected unsigned long [usertype] old
> fs/bcachefs/btree_cache.c:546:15: sparse: got struct task_struct *__old
> fs/bcachefs/btree_cache.c:546:15: sparse: sparse: incorrect type in argument 3 (different base types) @@ expected unsigned long [usertype] new @@ got struct task_struct *__new @@
> fs/bcachefs/btree_cache.c:546:15: sparse: expected unsigned long [usertype] new
> fs/bcachefs/btree_cache.c:546:15: sparse: got struct task_struct *__new
>
> vim +1200 mm/memcontrol.c
>
> 4b569387c0d566 Nhat Pham 2023-10-06 1138
> 5660048ccac873 Johannes Weiner 2012-01-12 1139 /**
> 5660048ccac873 Johannes Weiner 2012-01-12 1140 * mem_cgroup_iter - iterate over memory cgroup hierarchy
> 5660048ccac873 Johannes Weiner 2012-01-12 1141 * @root: hierarchy root
> 5660048ccac873 Johannes Weiner 2012-01-12 1142 * @prev: previously returned memcg, NULL on first invocation
> 5660048ccac873 Johannes Weiner 2012-01-12 1143 * @reclaim: cookie for shared reclaim walks, NULL for full walks
> 5660048ccac873 Johannes Weiner 2012-01-12 1144 *
> 5660048ccac873 Johannes Weiner 2012-01-12 1145 * Returns references to children of the hierarchy below @root, or
> 5660048ccac873 Johannes Weiner 2012-01-12 1146 * @root itself, or %NULL after a full round-trip.
> 5660048ccac873 Johannes Weiner 2012-01-12 1147 *
> 5660048ccac873 Johannes Weiner 2012-01-12 1148 * Caller must pass the return value in @prev on subsequent
> 5660048ccac873 Johannes Weiner 2012-01-12 1149 * invocations for reference counting, or use mem_cgroup_iter_break()
> 5660048ccac873 Johannes Weiner 2012-01-12 1150 * to cancel a hierarchy walk before the round-trip is complete.
> 5660048ccac873 Johannes Weiner 2012-01-12 1151 *
> 05bdc520b3ad39 Miaohe Lin 2020-10-13 1152 * Reclaimers can specify a node in @reclaim to divide up the memcgs
> 05bdc520b3ad39 Miaohe Lin 2020-10-13 1153 * in the hierarchy among all concurrent reclaimers operating on the
> 05bdc520b3ad39 Miaohe Lin 2020-10-13 1154 * same node.
> 5660048ccac873 Johannes Weiner 2012-01-12 1155 */
> 694fbc0fe78518 Andrew Morton 2013-09-24 1156 struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root,
> 9f3a0d0933de07 Johannes Weiner 2012-01-12 1157 struct mem_cgroup *prev,
> 694fbc0fe78518 Andrew Morton 2013-09-24 1158 struct mem_cgroup_reclaim_cookie *reclaim)
> 7d74b06f240f1b KAMEZAWA Hiroyuki 2010-10-27 1159 {
> 3f649ab728cda8 Kees Cook 2020-06-03 1160 struct mem_cgroup_reclaim_iter *iter;
> 5ac8fb31ad2ebd Johannes Weiner 2014-12-10 1161 struct cgroup_subsys_state *css = NULL;
> 9f3a0d0933de07 Johannes Weiner 2012-01-12 1162 struct mem_cgroup *memcg = NULL;
> 5ac8fb31ad2ebd Johannes Weiner 2014-12-10 1163 struct mem_cgroup *pos = NULL;
> 711d3d2c9bc3fb KAMEZAWA Hiroyuki 2010-10-27 1164
> 694fbc0fe78518 Andrew Morton 2013-09-24 1165 if (mem_cgroup_disabled())
> 694fbc0fe78518 Andrew Morton 2013-09-24 1166 return NULL;
> 5660048ccac873 Johannes Weiner 2012-01-12 1167
> 9f3a0d0933de07 Johannes Weiner 2012-01-12 1168 if (!root)
> 9f3a0d0933de07 Johannes Weiner 2012-01-12 1169 root = root_mem_cgroup;
> 9f3a0d0933de07 Johannes Weiner 2012-01-12 1170
> 542f85f9ae4acd Michal Hocko 2013-04-29 1171 rcu_read_lock();
> 14067bb3e24b96 KAMEZAWA Hiroyuki 2009-04-02 1172
> 527a5ec9a53471 Johannes Weiner 2012-01-12 1173 if (reclaim) {
> ef8f2327996b5c Mel Gorman 2016-07-28 1174 struct mem_cgroup_per_node *mz;
> 527a5ec9a53471 Johannes Weiner 2012-01-12 1175
> a3747b53b1771a Johannes Weiner 2021-04-29 1176 mz = root->nodeinfo[reclaim->pgdat->node_id];
> 9da83f3fc74b80 Yafang Shao 2019-11-30 1177 iter = &mz->iter;
> 5ac8fb31ad2ebd Johannes Weiner 2014-12-10 1178
> a9320aae68a1cd Wei Yang 2022-04-28 1179 /*
> a9320aae68a1cd Wei Yang 2022-04-28 1180 * On start, join the current reclaim iteration cycle.
> a9320aae68a1cd Wei Yang 2022-04-28 1181 * Exit when a concurrent walker completes it.
> a9320aae68a1cd Wei Yang 2022-04-28 1182 */
> a9320aae68a1cd Wei Yang 2022-04-28 1183 if (!prev)
> a9320aae68a1cd Wei Yang 2022-04-28 1184 reclaim->generation = iter->generation;
> a9320aae68a1cd Wei Yang 2022-04-28 1185 else if (reclaim->generation != iter->generation)
> 542f85f9ae4acd Michal Hocko 2013-04-29 1186 goto out_unlock;
> 5ac8fb31ad2ebd Johannes Weiner 2014-12-10 1187
> 6df38689e0e9a0 Vladimir Davydov 2015-12-29 1188 while (1) {
> 4db0c3c2983cc6 Jason Low 2015-04-15 1189 pos = READ_ONCE(iter->position);
> 6df38689e0e9a0 Vladimir Davydov 2015-12-29 1190 if (!pos || css_tryget(&pos->css))
> 6df38689e0e9a0 Vladimir Davydov 2015-12-29 1191 break;
> 5ac8fb31ad2ebd Johannes Weiner 2014-12-10 1192 /*
> 6df38689e0e9a0 Vladimir Davydov 2015-12-29 1193 * css reference reached zero, so iter->position will
> 6df38689e0e9a0 Vladimir Davydov 2015-12-29 1194 * be cleared by ->css_released. However, we should not
> 6df38689e0e9a0 Vladimir Davydov 2015-12-29 1195 * rely on this happening soon, because ->css_released
> 6df38689e0e9a0 Vladimir Davydov 2015-12-29 1196 * is called from a work queue, and by busy-waiting we
> 6df38689e0e9a0 Vladimir Davydov 2015-12-29 1197 * might block it. So we clear iter->position right
> 6df38689e0e9a0 Vladimir Davydov 2015-12-29 1198 * away.
> 5ac8fb31ad2ebd Johannes Weiner 2014-12-10 1199 */
> 6df38689e0e9a0 Vladimir Davydov 2015-12-29 @1200 (void)cmpxchg(&iter->position, pos, NULL);
> 6df38689e0e9a0 Vladimir Davydov 2015-12-29 1201 }
> 89d8330ccf2ad4 Wei Yang 2022-04-28 1202 } else if (prev) {
> 89d8330ccf2ad4 Wei Yang 2022-04-28 1203 pos = prev;
> 5ac8fb31ad2ebd Johannes Weiner 2014-12-10 1204 }
> 5ac8fb31ad2ebd Johannes Weiner 2014-12-10 1205
> 5ac8fb31ad2ebd Johannes Weiner 2014-12-10 1206 if (pos)
> 5ac8fb31ad2ebd Johannes Weiner 2014-12-10 1207 css = &pos->css;
> 5ac8fb31ad2ebd Johannes Weiner 2014-12-10 1208
> 5ac8fb31ad2ebd Johannes Weiner 2014-12-10 1209 for (;;) {
> 5ac8fb31ad2ebd Johannes Weiner 2014-12-10 1210 css = css_next_descendant_pre(css, &root->css);
> 5ac8fb31ad2ebd Johannes Weiner 2014-12-10 1211 if (!css) {
> 5ac8fb31ad2ebd Johannes Weiner 2014-12-10 1212 /*
> 5ac8fb31ad2ebd Johannes Weiner 2014-12-10 1213 * Reclaimers share the hierarchy walk, and a
> 5ac8fb31ad2ebd Johannes Weiner 2014-12-10 1214 * new one might jump in right at the end of
> 5ac8fb31ad2ebd Johannes Weiner 2014-12-10 1215 * the hierarchy - make sure they see at least
> 5ac8fb31ad2ebd Johannes Weiner 2014-12-10 1216 * one group and restart from the beginning.
> 5ac8fb31ad2ebd Johannes Weiner 2014-12-10 1217 */
> 5ac8fb31ad2ebd Johannes Weiner 2014-12-10 1218 if (!prev)
> 5ac8fb31ad2ebd Johannes Weiner 2014-12-10 1219 continue;
> 5ac8fb31ad2ebd Johannes Weiner 2014-12-10 1220 break;
> 542f85f9ae4acd Michal Hocko 2013-04-29 1221 }
> 5f578161971863 Michal Hocko 2013-04-29 1222
> 5ac8fb31ad2ebd Johannes Weiner 2014-12-10 1223 /*
> 5ac8fb31ad2ebd Johannes Weiner 2014-12-10 1224 * Verify the css and acquire a reference. The root
> 5ac8fb31ad2ebd Johannes Weiner 2014-12-10 1225 * is provided by the caller, so we know it's alive
> 5ac8fb31ad2ebd Johannes Weiner 2014-12-10 1226 * and kicking, and don't take an extra reference.
> 5ac8fb31ad2ebd Johannes Weiner 2014-12-10 1227 */
> 41555dadbff8d2 Wei Yang 2022-04-28 1228 if (css == &root->css || css_tryget(css)) {
> 5ac8fb31ad2ebd Johannes Weiner 2014-12-10 1229 memcg = mem_cgroup_from_css(css);
> 5ac8fb31ad2ebd Johannes Weiner 2014-12-10 1230 break;
> 41555dadbff8d2 Wei Yang 2022-04-28 1231 }
> 5ac8fb31ad2ebd Johannes Weiner 2014-12-10 1232 }
> 9f3a0d0933de07 Johannes Weiner 2012-01-12 1233
> 527a5ec9a53471 Johannes Weiner 2012-01-12 1234 if (reclaim) {
> 5ac8fb31ad2ebd Johannes Weiner 2014-12-10 1235 /*
> 6df38689e0e9a0 Vladimir Davydov 2015-12-29 1236 * The position could have already been updated by a competing
> 6df38689e0e9a0 Vladimir Davydov 2015-12-29 1237 * thread, so check that the value hasn't changed since we read
> 6df38689e0e9a0 Vladimir Davydov 2015-12-29 1238 * it to avoid reclaiming from the same cgroup twice.
> 5ac8fb31ad2ebd Johannes Weiner 2014-12-10 1239 */
> 6df38689e0e9a0 Vladimir Davydov 2015-12-29 1240 (void)cmpxchg(&iter->position, pos, memcg);
> 6df38689e0e9a0 Vladimir Davydov 2015-12-29 1241
> 5ac8fb31ad2ebd Johannes Weiner 2014-12-10 1242 if (pos)
> 5ac8fb31ad2ebd Johannes Weiner 2014-12-10 1243 css_put(&pos->css);
> 542f85f9ae4acd Michal Hocko 2013-04-29 1244
> 19f39402864ea3 Michal Hocko 2013-04-29 1245 if (!memcg)
> 527a5ec9a53471 Johannes Weiner 2012-01-12 1246 iter->generation++;
> 527a5ec9a53471 Johannes Weiner 2012-01-12 1247 }
> 14067bb3e24b96 KAMEZAWA Hiroyuki 2009-04-02 1248
> 542f85f9ae4acd Michal Hocko 2013-04-29 1249 out_unlock:
> 542f85f9ae4acd Michal Hocko 2013-04-29 1250 rcu_read_unlock();
> c40046f3ad5e87 Michal Hocko 2013-04-29 1251 if (prev && prev != root)
> c40046f3ad5e87 Michal Hocko 2013-04-29 1252 css_put(&prev->css);
> c40046f3ad5e87 Michal Hocko 2013-04-29 1253
> 9f3a0d0933de07 Johannes Weiner 2012-01-12 1254 return memcg;
> 9f3a0d0933de07 Johannes Weiner 2012-01-12 1255 }
> 14067bb3e24b96 KAMEZAWA Hiroyuki 2009-04-02 1256
>
> :::::: The code at line 1200 was first introduced by commit
> :::::: 6df38689e0e9a07ff4f42c06b302e203b33667e9 mm: memcontrol: fix possible memcg leak due to interrupted reclaim
>
> :::::: TO: Vladimir Davydov <vdavydov@xxxxxxxxxxxxx>
> :::::: CC: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
>
> --
> 0-DAY CI Kernel Test Service
> https://github.com/intel/lkp-tests/wiki