linux-kernel - Re: [PATCH v4 1/2] mm: Call pointers to ptes as ptep

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <5d1a561b-cf29-4527-b695-90ae9e5bd696@lucifer.local>
Date: Wed, 11 Jun 2025 14:29:15 +0100
From: Lorenzo Stoakes <lorenzo.stoakes@...cle.com>
To: Dev Jain <dev.jain@....com>
Cc: David Hildenbrand <david@...hat.com>, akpm@...ux-foundation.org,
        Liam.Howlett@...cle.com, vbabka@...e.cz, jannh@...gle.com,
        pfalcato@...e.de, linux-mm@...ck.org, linux-kernel@...r.kernel.org,
        peterx@...hat.com, ryan.roberts@....com, mingo@...nel.org,
        libang.li@...group.com, maobibo@...ngson.cn,
        zhengqi.arch@...edance.com, baohua@...nel.org,
        anshuman.khandual@....com, willy@...radead.org, ioworker0@...il.com,
        yang@...amperecomputing.com, baolin.wang@...ux.alibaba.com,
        ziy@...dia.com, hughd@...gle.com
Subject: Re: [PATCH v4 1/2] mm: Call pointers to ptes as ptep

On Wed, Jun 11, 2025 at 06:55:28PM +0530, Dev Jain wrote:
>
> On 11/06/25 6:53 pm, David Hildenbrand wrote:
> > On 10.06.25 05:50, Dev Jain wrote:
> > > Avoid confusion between pte_t* and pte_t data types by suffixing pointer
> > > type variables with p. No functional change.
> > >
> > > Reviewed-by: Barry Song <baohua@...nel.org>
> > > Reviewed-by: Anshuman Khandual <anshuman.khandual@....com>
> > > Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@...cle.com>
> > > Signed-off-by: Dev Jain <dev.jain@....com>
> > > ---
> > >   mm/mremap.c | 31 ++++++++++++++++---------------
> > >   1 file changed, 16 insertions(+), 15 deletions(-)
> > >
> > > diff --git a/mm/mremap.c b/mm/mremap.c
> > > index 60f6b8d0d5f0..180b12225368 100644
> > > --- a/mm/mremap.c
> > > +++ b/mm/mremap.c
> > > @@ -176,7 +176,8 @@ static int move_ptes(struct
> > > pagetable_move_control *pmc,
> > >       struct vm_area_struct *vma = pmc->old;
> > >       bool need_clear_uffd_wp = vma_has_uffd_without_event_remap(vma);
> > >       struct mm_struct *mm = vma->vm_mm;
> > > -    pte_t *old_pte, *new_pte, pte;
> > > +    pte_t *old_ptep, *new_ptep;
> > > +    pte_t pte;
> >
> > Could have left that on the same line ...
>
> AFAIR Lorenzo had insisted on moving that to a new line.

Yeah, not a fan of having pointer and non-pointer types declared on same line.
>
>
> >
> > >       pmd_t dummy_pmdval;
> > >       spinlock_t *old_ptl, *new_ptl;
> > >       bool force_flush = false;
> > > @@ -211,8 +212,8 @@ static int move_ptes(struct
> > > pagetable_move_control *pmc,
> > >        * We don't have to worry about the ordering of src and dst
> > >        * pte locks because exclusive mmap_lock prevents deadlock.
> > >        */
> > > -    old_pte = pte_offset_map_lock(mm, old_pmd, old_addr, &old_ptl);
> > > -    if (!old_pte) {
> > > +    old_ptep = pte_offset_map_lock(mm, old_pmd, old_addr, &old_ptl);
> > > +    if (!old_ptep) {
> > >           err = -EAGAIN;
> >
> > One of those things that's completely inconsistent all over the place.
> >
> > But yeah, I agree that ptep is much better for a PTE pointer.
> >
> > Acked-by: David Hildenbrand <david@...hat.com>
> >