Re: [PATCH] memcg: do not expose uninitialized mem_cgroup_per_node to world

[Igor Mammedov <imammedo@redhat.com>]

On 06/01/2011 03:41 PM, Michal Hocko wrote:
> [Let's CC some cgroup people]
>
> On Wed 01-06-11 15:07:40, Igor Mammedov wrote:
>> Yes I've seen it (RHBZ#700565).
> I am not subscribed so I will not get there.
>
Sorry, I've not realized that BZ wasn't public, just fixed it.
It is public now.

OOPS backtrace looks like this:

Stopping cgconfig service: BUG: unable to handle kernel paging request at fffffffc
IP: [<c05235b3>] mem_cgroup_force_empty+0x123/0x4a0
*pdpt = 00000000016a0001 *pde = 000000000000a067 *pte = 0000000000000000
Oops: 0000 [#1] SMP
last sysfs file: /sys/module/nf_conntrack/refcnt
Modules linked in: xt_CHECKSUM tun bridge stp llc autofs4 sunrpc ipt_REJECT ip6t_REJECT ipv6 dm_mirror dm_region_hash dm_log uinput microcode xen_netfront sg i2c_piix4 i2c_core ext4 mbcache jbd2 sr_mod cdrom xen_blkfront ata_generic pata_acpi ata_piix dm_mod [last unloaded: nf_conntrack]

Pid: 2300, comm: cgclear Not tainted (2.6.32-131.0.10.el6.i686 #1) HVM domU
EIP: 0060:[<c05235b3>] EFLAGS: 00010206 CPU: 0
EIP is at mem_cgroup_force_empty+0x123/0x4a0
EAX: 00000206 EBX: fffffff4 ECX: c0a3f1e0 EDX: 00000206
ESI: 00000206 EDI: 00000000 EBP: f343ca00 ESP: f34e7e84
  DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
Process cgclear (pid: 2300, ti=f34e6000 task=f35baab0 task.ti=f34e6000)
Stack:
  ffffffff 00000001 00000000 f34e7eb8 00000100 00000000 c0a3f1e0 c05a5af5
<0>  f343ca00 f343cc00 00000000 00000000 00000000 00000000 00000000 00000000
<0>  c0a3e7c0 f35172c0 00000005 00000000 f35172d0 f35baab0 00000000 f35172c0
Call Trace:
  [<c05a5af5>] ? may_link+0xc5/0x130
  [<c049b246>] ? cgroup_rmdir+0x96/0x3f0
  [<c0473f20>] ? autoremove_wake_function+0x0/0x40
  [<c05339ce>] ? vfs_rmdir+0x9e/0xd0
  [<c0536806>] ? do_rmdir+0xc6/0xe0
  [<c0506702>] ? do_munmap+0x1f2/0x2c0
  [<c04adecc>] ? audit_syscall_entry+0x21c/0x240
  [<c04adbe6>] ? audit_syscall_exit+0x216/0x240
  [<c0409adf>] ? sysenter_do_call+0x12/0x28
Code: 89 7c 24 20 8b 54 95 08 31 ff 89 44 24 14 81 c2 00 01 00 00 89 54 24 10 e9 83 00 00 00 8d 76 00 8b 44 24 18 89 f2 e8 7d 12 30 00<8b>  73 08 8b 7c 24 24 8b 07 8b 40 18 85 c0 89 44 24 08 0f 84 c5
EIP: [<c05235b3>] mem_cgroup_force_empty+0x123/0x4a0 SS:ESP 0068:f34e7e84
CR2: 00000000fffffffc
---[ end trace 5700dda23f74f94a ]---