On Mon, Sep 17, 2018 at 12:33:47PM -0700, Hugh Dickins wrote:
On Mon, 17 Sep 2018, gregkh@linuxfoundation.org wrote:
This is a note to let you know that I've just added the patch titled
x86/kexec: Allocate 8k PGDs for PTIto the 3.18-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: x86-kexec-allocate-8k-pgds-for-pti.patch and it can be found in the queue-3.18 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
I believe this commit is an example of the auto-selector being too eager, and this should not be in *any* of the stable trees. As the commit message indicates, it's a fix by Joerg for his PTI-x86-32 implementation - which has not been backported to any of the stable trees (yet), has it?
In several of the recent stable trees, I think this will not do any actual harm; but it looks as if it will prevent relevant x86-32 configs from building on 3.18 (I see no definition of PGD_ALLOCATION_ORDER in linux-3.18.y - you preferred not to have any PTI in that tree), and I haven't checked whether its definition in older backports will build correctly here or not.
Ah, you are right, I just got a build failure report from the 4.4.y tree with this exact error.
Thanks for letting me know, I'll go drop this from all of the stable tree queues right now.
greg k-h