Stephane wrote:
>
> I have a question about mmap and the close operation of a
> vm_area_struct.
> Is there a reason why in exit_mmap, when a process dies unexpectedly,
> the vm_ops->close is called before zap_page_range is called?
>
> The problem is that if you have allocated one or several kernel pages
> for a vm_area_struct, you can not free them in the vm_ops->close
> operation since the count field of the pages is not 0 because they are
> still mapped. The count will be cleared when zap_page_range is called.
>
> This means that exit_mmap calls vm_ops->close and zap_page_range in the
> reverse order of a normal execution of the process, that is when the
> process unmap the area before dying.
>
> It would be more deterministic and simple if vm_ops->close was always
> called when all the pages of the area was unmapped.
>
> PS: please can you CC'ed the answer to stephane.tessier@netinsight.se
> --
> Stephane Tessier
> Net Insight AB stephane.tessier@netinsight.se
> Västberga Allé 9 http://www.netinsight.se
> SE-126 30 Hägersten phone:+46-8-685 04 60
> Sweden fax: +46-8-685 04 20
-- Stephane Tessier Net Insight AB stephane.tessier@netinsight.se Västberga Allé 9 http://www.netinsight.se SE-126 30 Hägersten phone:+46-8-685 04 60 Sweden fax: +46-8-685 04 20 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/