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| author | Tahsin Erdogan <tahsin@google.com> | 2017-03-09 16:17:26 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-03-09 17:01:10 -0800 |
| commit | 40e952f9d687928b32db20226f085ae660a7237c (patch) | |
| tree | e1ba402f9b997cca4cf23ed4b18c720dbc9d118c /mm | |
| parent | 6ebb4a1b848fe75323135f93e72c78f8780fd268 (diff) | |
| download | linux-40e952f9d687928b32db20226f085ae660a7237c.tar.gz linux-40e952f9d687928b32db20226f085ae660a7237c.tar.bz2 linux-40e952f9d687928b32db20226f085ae660a7237c.zip | |
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>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/memcontrol.c | 11 |
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; } |