Hi Vlastimil, Thanks for comment! On 2017/10/31 16:34, Vlastimil Babka wrote: > On 10/27/2017 12:14 PM, Yisheng Xie wrote: >> It appears there is a nodemask miscalculation in the get_nodes() >> function in mm/mempolicy.c. This bug has two effects: >> >> 1. It is impossible to specify a length 1 nodemask. >> 2. It is impossible to specify a nodemask containing the last node. > > This should be more specific, which syscalls are you talking about? > I assume it's set_mempolicy() and mbind() and it's the same issue that > was discussed at https://marc.info/?l=linux-mm&m=150732591909576&w=2 ? I just missed this thread, sorry about that. Not only set_mempolicy() and mbind(), but migrate_pages() also suffers this problem. Maybe related manpage should documented this as your mentioned below. Thanks Yisheng Xie > >> Brent have submmit a patch before v2.6.12, however, Andi revert his >> changed for ABI problem. I just resent this patch as RFC, for do not >> clear about what's the problem Andi have met. > > You should have CC'd Andi. As was discussed in the other thread, this > would make existing programs potentially unsafe, so we can't change it. > Instead it should be documented. > >> As manpage of set_mempolicy, If the value of maxnode is zero, the >> nodemask argument is ignored. but we should not ignore the nodemask >> when maxnode is 1. >> -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
