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authorTahsin Erdogan <tahsin@google.com>2017-03-09 16:17:26 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2017-03-09 17:01:10 -0800
commit40e952f9d687928b32db20226f085ae660a7237c (patch)
treee1ba402f9b997cca4cf23ed4b18c720dbc9d118c
parent6ebb4a1b848fe75323135f93e72c78f8780fd268 (diff)
mm: do not call mem_cgroup_free() from within mem_cgroup_alloc()
mem_cgroup_free() indirectly calls wb_domain_exit() which is not prepared to deal with a struct wb_domain object that hasn't executed wb_domain_init(). For instance, the following warning message is printed by lockdep if alloc_percpu() fails in mem_cgroup_alloc(): INFO: trying to register non-static key. the code is fine but needs lockdep annotation. turning off the locking correctness validator. CPU: 1 PID: 1950 Comm: mkdir Not tainted 4.10.0+ #151 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: dump_stack+0x67/0x99 register_lock_class+0x36d/0x540 __lock_acquire+0x7f/0x1a30 lock_acquire+0xcc/0x200 del_timer_sync+0x3c/0xc0 wb_domain_exit+0x14/0x20 mem_cgroup_free+0x14/0x40 mem_cgroup_css_alloc+0x3f9/0x620 cgroup_apply_control_enable+0x190/0x390 cgroup_mkdir+0x290/0x3d0 kernfs_iop_mkdir+0x58/0x80 vfs_mkdir+0x10e/0x1a0 SyS_mkdirat+0xa8/0xd0 SyS_mkdir+0x14/0x20 entry_SYSCALL_64_fastpath+0x18/0xad Add __mem_cgroup_free() which skips wb_domain_exit(). This is used by both mem_cgroup_free() and mem_cgroup_alloc() clean up. Fixes: 0b8f73e104285 ("mm: memcontrol: clean up alloc, online, offline, free functions") Link: http://lkml.kernel.org/r/20170306192122.24262-1-tahsin@google.com Signed-off-by: Tahsin Erdogan <tahsin@google.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--mm/memcontrol.c11
1 files changed, 8 insertions, 3 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 76f513cc1b0e..2bd7541d7c11 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -4138,17 +4138,22 @@ static void free_mem_cgroup_per_node_info(struct mem_cgroup *memcg, int node)
kfree(memcg->nodeinfo[node]);
}
-static void mem_cgroup_free(struct mem_cgroup *memcg)
+static void __mem_cgroup_free(struct mem_cgroup *memcg)
{
int node;
- memcg_wb_domain_exit(memcg);
for_each_node(node)
free_mem_cgroup_per_node_info(memcg, node);
free_percpu(memcg->stat);
kfree(memcg);
}
+static void mem_cgroup_free(struct mem_cgroup *memcg)
+{
+ memcg_wb_domain_exit(memcg);
+ __mem_cgroup_free(memcg);
+}
+
static struct mem_cgroup *mem_cgroup_alloc(void)
{
struct mem_cgroup *memcg;
@@ -4199,7 +4204,7 @@ static struct mem_cgroup *mem_cgroup_alloc(void)
fail:
if (memcg->id.id > 0)
idr_remove(&mem_cgroup_idr, memcg->id.id);
- mem_cgroup_free(memcg);
+ __mem_cgroup_free(memcg);
return NULL;
}

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