Eric Lee / smarc-ti-linux-kernel

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Commit 16ace91043bf5fa192bb6e42451524b3c6ad7bd7

Authored by Tahsin Erdogan
Committed by Greg Kroah-Hartman
1 parent 1771fc58a3
Exists in smarct4x-processor-sdk-04.01.00.06 and in 1 other branch smarct3x-processor-sdk-04.01.00.06

mm: do not call mem_cgroup_free() from within mem_cgroup_alloc() 

commit 40e952f9d687928b32db20226f085ae660a7237c upstream.

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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Showing 1 changed file with 8 additions and 3 deletions Side-by-side Diff

... ... @@ -4139,17 +4139,22 @@
4139 4139 kfree(memcg->nodeinfo[node]);
4140 4140 }
4141 4141  
4142   -static void mem_cgroup_free(struct mem_cgroup *memcg)
  4142 +static void __mem_cgroup_free(struct mem_cgroup *memcg)
4143 4143 {
4144 4144 int node;
4145 4145  
4146   - memcg_wb_domain_exit(memcg);
4147 4146 for_each_node(node)
4148 4147 free_mem_cgroup_per_node_info(memcg, node);
4149 4148 free_percpu(memcg->stat);
4150 4149 kfree(memcg);
4151 4150 }
4152 4151  
  4152 +static void mem_cgroup_free(struct mem_cgroup *memcg)
  4153 +{
  4154 + memcg_wb_domain_exit(memcg);
  4155 + __mem_cgroup_free(memcg);
  4156 +}
  4157 +
4153 4158 static struct mem_cgroup *mem_cgroup_alloc(void)
4154 4159 {
4155 4160 struct mem_cgroup *memcg;
... ... @@ -4200,7 +4205,7 @@
4200 4205 fail:
4201 4206 if (memcg->id.id > 0)
4202 4207 idr_remove(&mem_cgroup_idr, memcg->id.id);
4203   - mem_cgroup_free(memcg);
  4208 + __mem_cgroup_free(memcg);
4204 4209 return NULL;
4205 4210 }
4206 4211