On 09/11/2014 01:46 AM, Qiaowei Ren wrote: > +static int allocate_bt(long __user *bd_entry) > +{ > + unsigned long bt_addr, old_val = 0; > + int ret = 0; > + > + bt_addr = mpx_mmap(MPX_BT_SIZE_BYTES); > + if (IS_ERR((void *)bt_addr)) > + return bt_addr; > + bt_addr = (bt_addr & MPX_BT_ADDR_MASK) | MPX_BD_ENTRY_VALID_FLAG; Qiaowei, why do we need the "& MPX_BT_ADDR_MASK" here? -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>