In lustre/obdclass/lprocfs_status.c ,and in the function "lprocfs_alloc_stats",
when alloc percpu pointers for all possible cpu slots,the corresponding code:
LIBCFS_ALLOC(stats, offsetof(typeof(*stats), ls_percpu[num_entry]));
In fact ,this code didn't alloc space for its member struct lprocfs_counter lp_cntr[0],
but in other operations like funcion：
lprocfs_counter_init which call lprocfs_stats_counter_get
the code in fuction lprocfs_stats_counter_get such as
stats->ls_percpu[cpuid]->lp_cntr[index]
may access memory that not belong to var stats itself,
it's not safe and may lead to Segmentation fault.especially when there is not enough memory.