Re: [PATCH v2 10/15] s390: pgtable: also move pagetable_dtor() of PxD to __tlb_remove_table()

[Alexander Gordeev]

On Wed, Dec 18, 2024 at 09:04:46PM +0800, Qi Zheng wrote:
> In s390, the pagetable_dtor() of PTE has long been moved to
> __tlb_remove_table().

Well, not pagetable_dtor(), but rather pagetable_pte_dtor() and
not to __tlb_remove_table(), but to pagetable_pte_dtor_free() ;)

> So similarly, also move the pagetable_dtor() of
> PMD|PUD|P4D to __tlb_remove_table(). This prevents the use-after-free
> problem where the ptlock is freed immediately but the page table pages
> is freed later via RCU.
> 
> By the way, rename pagetable_pte_dtor_free() to pagetable_dtor_free().

This is not just a random rename, but rather a result of unifying
PxD and PTE TLB free paths.

Could you please come up with a better wording concerning the above?

> Signed-off-by: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>
> Suggested-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
> Cc: linux-s390@xxxxxxxxxxxxxxx
> ---
>  arch/s390/include/asm/tlb.h |  3 ---
>  arch/s390/mm/pgalloc.c      | 14 ++++----------
>  2 files changed, 4 insertions(+), 13 deletions(-)

You also did not CC linux-s390@xxxxxxxxxxxxxxx for other patches
that affect s390 sources. Just CC the whole series, please.

Thanks!