Re: [PATCH 1/2] mm: page_isolation: check pfn validity before access

[Weijie Yang]

On Wed, Nov 12, 2014 at 6:23 AM, Andrew Morton
<akpm@xxxxxxxxxxxxxxxxxxxx> wrote:
> On Thu, 06 Nov 2014 16:08:02 +0800 Weijie Yang <weijie.yang@xxxxxxxxxxx> wrote:
>
>> In the undo path of start_isolate_page_range(), we need to check
>> the pfn validity before access its page, or it will trigger an
>> addressing exception if there is hole in the zone.
>>
>
> There is not enough information in the chagnelog for me to decide how
> to handle the patch.  3.19?  3.18? 3.18+stable?
>
> When fixing bugs, please remember to fully explain the end-user impact
> of the bug.  Under what circumstances does it occur?

I'm sorry to disturb you. This issue is found by code-review not a test-trigger.
In "CONFIG_HOLES_IN_ZONE" environment, there is a certain chance that
it would casue an addressing exception when start_isolate_page_range() fails,
this could affect CMA, hugepage and memory-hotplug function.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/