Re: [PATCH] Revert "x86/mm: implement free pmd/pte page interfaces"

[Kani, Toshi]

On Thu, 2018-04-26 at 17:14 +0200, Joerg Roedel wrote:
> From: Joerg Roedel <jroedel@xxxxxxx>
> 
> This reverts commit 28ee90fe6048fa7b7ceaeb8831c0e4e454a4cf89.
> 
> This commit is broken for x86, as it unmaps the PTE and PMD
> pages and immediatly frees them without doing a TLB flush.
> 
> Further this lacks synchronization with other page-tables in
> the system when the PMD pages are not shared between
> mm_structs.
> 
> On x86-32 with PAE and PTI patches on-top this patch
> triggers the BUG_ON in vmalloc_sync_one() because the kernel
> and the process page-table were not synchronized.
> 
> Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>

I do not agree with the comments and this revert.  Let's discuss further
on the original thread.

Thanks,
-Toshi