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

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 06/02/2011 01:10 AM, Hiroyuki Kamezawa wrote:
pc = list_entry(list->prev, struct page_cgroup, lru);
Hmm, I disagree your patch is a fix for mainline. At least, a cgroup
before completion of
create() is not populated to userland and you never be able to rmdir()
it because you can't
find it.


  >26:   e8 7d 12 30 00          call   0x3012a8
  >2b:*  8b 73 08                mov    0x8(%ebx),%esi<-- trapping
instruction
  >2e:   8b 7c 24 24             mov    0x24(%esp),%edi
  >32:   8b 07                   mov    (%edi),%eax

Hm, what is the call 0x3012a8 ?

                pc = list_entry(list->prev, struct page_cgroup, lru);
                if (busy == pc) {
                        list_move(&pc->lru, list);
                        busy = 0;
                        spin_unlock_irqrestore(&zone->lru_lock, flags);
                        continue;
                }
spin_unlock_irqrestore(&zone->lru_lock, flags); <---- is call 0x3012a8
                ret = mem_cgroup_move_parent(pc, mem, GFP_KERNEL);

and  mov 0x8(%ebx),%esi
is dereferencing of 'pc' in inlined mem_cgroup_move_parent

I've looked at vmcore once more and indeed there isn't any parallel task
that touches cgroups code path.
Will investigate if it is xen to blame for incorrect data in place.

Thanks very much for your opinion.
Thanks,
-Kame

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxxx  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>


[Index of Archives]     [Linux ARM Kernel]     [Linux ARM]     [Linux Omap]     [Fedora ARM]     [IETF Annouce]     [Bugtraq]     [Linux]     [Linux OMAP]     [Linux MIPS]     [ECOS]     [Asterisk Internet PBX]     [Linux API]