Avoid confusion between pte_t* and pte_t data types by appending pointer
type variables by p. No functional change.
Signed-off-by: Dev Jain <dev.jain@arm.com>
---
mm/mremap.c | 28 ++++++++++++++--------------
1 file changed, 14 insertions(+), 14 deletions(-)
diff --git a/mm/mremap.c b/mm/mremap.c
index 7db9da609c84..1a08a7c3b92f 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -176,7 +176,7 @@ 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;
pmd_t dummy_pmdval;
spinlock_t *old_ptl, *new_ptl;
bool force_flush = false;
@@ -211,8 +211,8 @@ 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;
goto out;
}
@@ -223,10 +223,10 @@ static int move_ptes(struct pagetable_move_control *pmc,
* mmap_lock, so this new_pte page is stable, so there is no need to get
* pmdval and do pmd_same() check.
*/
- new_pte = pte_offset_map_rw_nolock(mm, new_pmd, new_addr, &dummy_pmdval,
+ new_ptep = pte_offset_map_rw_nolock(mm, new_pmd, new_addr, &dummy_pmdval,
&new_ptl);
- if (!new_pte) {
- pte_unmap_unlock(old_pte, old_ptl);
+ if (!new_ptep) {
+ pte_unmap_unlock(old_ptep, old_ptl);
err = -EAGAIN;
goto out;
}
@@ -235,12 +235,12 @@ static int move_ptes(struct pagetable_move_control *pmc,
flush_tlb_batched_pending(vma->vm_mm);
arch_enter_lazy_mmu_mode();
- for (; old_addr < old_end; old_pte++, old_addr += PAGE_SIZE,
- new_pte++, new_addr += PAGE_SIZE) {
- if (pte_none(ptep_get(old_pte)))
+ for (; old_addr < old_end; old_ptep++, old_addr += PAGE_SIZE,
+ new_ptep++, new_addr += PAGE_SIZE) {
+ if (pte_none(ptep_get(old_ptep)))
continue;
- pte = ptep_get_and_clear(mm, old_addr, old_pte);
+ pte = ptep_get_and_clear(mm, old_addr, old_ptep);
/*
* If we are remapping a valid PTE, make sure
* to flush TLB before we drop the PTL for the
@@ -258,7 +258,7 @@ static int move_ptes(struct pagetable_move_control *pmc,
pte = move_soft_dirty_pte(pte);
if (need_clear_uffd_wp && pte_marker_uffd_wp(pte))
- pte_clear(mm, new_addr, new_pte);
+ pte_clear(mm, new_addr, new_ptep);
else {
if (need_clear_uffd_wp) {
if (pte_present(pte))
@@ -266,7 +266,7 @@ static int move_ptes(struct pagetable_move_control *pmc,
else if (is_swap_pte(pte))
pte = pte_swp_clear_uffd_wp(pte);
}
- set_pte_at(mm, new_addr, new_pte, pte);
+ set_pte_at(mm, new_addr, new_ptep, pte);
}
}
@@ -275,8 +275,8 @@ static int move_ptes(struct pagetable_move_control *pmc,
flush_tlb_range(vma, old_end - len, old_end);
if (new_ptl != old_ptl)
spin_unlock(new_ptl);
- pte_unmap(new_pte - 1);
- pte_unmap_unlock(old_pte - 1, old_ptl);
+ pte_unmap(new_ptep - 1);
+ pte_unmap_unlock(old_ptep - 1, old_ptl);
out:
if (pmc->need_rmap_locks)
drop_rmap_locks(vma);
--
2.30.2On Tue, May 06, 2025 at 10:30:54AM +0530, Dev Jain wrote:
> Avoid confusion between pte_t* and pte_t data types by appending pointer
> type variables by p. No functional change.
NIT: 'appending'->'suffixing' and 'by p' -> with p'.
>
> Signed-off-by: Dev Jain <dev.jain@arm.com>
This looks generally fine, could you fix the nit below however... sorry to
be a pain!
Thanks!
> ---
> mm/mremap.c | 28 ++++++++++++++--------------
> 1 file changed, 14 insertions(+), 14 deletions(-)
>
> diff --git a/mm/mremap.c b/mm/mremap.c
> index 7db9da609c84..1a08a7c3b92f 100644
> --- a/mm/mremap.c
> +++ b/mm/mremap.c
> @@ -176,7 +176,7 @@ 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;
While we're at it, can we please move the pte decl to a new line? Mixing
pointers and non-pointers is not great (I refactored it but mremap still
has a bunch of less-than-ideal stuff in it :)
> pmd_t dummy_pmdval;
> spinlock_t *old_ptl, *new_ptl;
> bool force_flush = false;
> @@ -211,8 +211,8 @@ 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;
> goto out;
> }
> @@ -223,10 +223,10 @@ static int move_ptes(struct pagetable_move_control *pmc,
> * mmap_lock, so this new_pte page is stable, so there is no need to get
> * pmdval and do pmd_same() check.
> */
> - new_pte = pte_offset_map_rw_nolock(mm, new_pmd, new_addr, &dummy_pmdval,
> + new_ptep = pte_offset_map_rw_nolock(mm, new_pmd, new_addr, &dummy_pmdval,
> &new_ptl);
> - if (!new_pte) {
> - pte_unmap_unlock(old_pte, old_ptl);
> + if (!new_ptep) {
> + pte_unmap_unlock(old_ptep, old_ptl);
> err = -EAGAIN;
> goto out;
> }
> @@ -235,12 +235,12 @@ static int move_ptes(struct pagetable_move_control *pmc,
> flush_tlb_batched_pending(vma->vm_mm);
> arch_enter_lazy_mmu_mode();
>
> - for (; old_addr < old_end; old_pte++, old_addr += PAGE_SIZE,
> - new_pte++, new_addr += PAGE_SIZE) {
> - if (pte_none(ptep_get(old_pte)))
> + for (; old_addr < old_end; old_ptep++, old_addr += PAGE_SIZE,
> + new_ptep++, new_addr += PAGE_SIZE) {
> + if (pte_none(ptep_get(old_ptep)))
> continue;
>
> - pte = ptep_get_and_clear(mm, old_addr, old_pte);
> + pte = ptep_get_and_clear(mm, old_addr, old_ptep);
> /*
> * If we are remapping a valid PTE, make sure
> * to flush TLB before we drop the PTL for the
> @@ -258,7 +258,7 @@ static int move_ptes(struct pagetable_move_control *pmc,
> pte = move_soft_dirty_pte(pte);
>
> if (need_clear_uffd_wp && pte_marker_uffd_wp(pte))
> - pte_clear(mm, new_addr, new_pte);
> + pte_clear(mm, new_addr, new_ptep);
> else {
> if (need_clear_uffd_wp) {
> if (pte_present(pte))
> @@ -266,7 +266,7 @@ static int move_ptes(struct pagetable_move_control *pmc,
> else if (is_swap_pte(pte))
> pte = pte_swp_clear_uffd_wp(pte);
> }
> - set_pte_at(mm, new_addr, new_pte, pte);
> + set_pte_at(mm, new_addr, new_ptep, pte);
> }
> }
>
> @@ -275,8 +275,8 @@ static int move_ptes(struct pagetable_move_control *pmc,
> flush_tlb_range(vma, old_end - len, old_end);
> if (new_ptl != old_ptl)
> spin_unlock(new_ptl);
> - pte_unmap(new_pte - 1);
> - pte_unmap_unlock(old_pte - 1, old_ptl);
> + pte_unmap(new_ptep - 1);
> + pte_unmap_unlock(old_ptep - 1, old_ptl);
> out:
> if (pmc->need_rmap_locks)
> drop_rmap_locks(vma);
> --
> 2.30.2
>
On 06/05/25 4:22 pm, Lorenzo Stoakes wrote:
> On Tue, May 06, 2025 at 10:30:54AM +0530, Dev Jain wrote:
>> Avoid confusion between pte_t* and pte_t data types by appending pointer
>> type variables by p. No functional change.
>
> NIT: 'appending'->'suffixing' and 'by p' -> with p'.
Thanks.
>
>>
>> Signed-off-by: Dev Jain <dev.jain@arm.com>
>
> This looks generally fine, could you fix the nit below however... sorry to
> be a pain!
>
> Thanks!
>
>> ---
>> mm/mremap.c | 28 ++++++++++++++--------------
>> 1 file changed, 14 insertions(+), 14 deletions(-)
>>
>> diff --git a/mm/mremap.c b/mm/mremap.c
>> index 7db9da609c84..1a08a7c3b92f 100644
>> --- a/mm/mremap.c
>> +++ b/mm/mremap.c
>> @@ -176,7 +176,7 @@ 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;
>
> While we're at it, can we please move the pte decl to a new line? Mixing
> pointers and non-pointers is not great (I refactored it but mremap still
> has a bunch of less-than-ideal stuff in it :)
Sure.
>
>> pmd_t dummy_pmdval;
>> spinlock_t *old_ptl, *new_ptl;
>> bool force_flush = false;
>> @@ -211,8 +211,8 @@ 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;
>> goto out;
>> }
>> @@ -223,10 +223,10 @@ static int move_ptes(struct pagetable_move_control *pmc,
>> * mmap_lock, so this new_pte page is stable, so there is no need to get
>> * pmdval and do pmd_same() check.
>> */
>> - new_pte = pte_offset_map_rw_nolock(mm, new_pmd, new_addr, &dummy_pmdval,
>> + new_ptep = pte_offset_map_rw_nolock(mm, new_pmd, new_addr, &dummy_pmdval,
>> &new_ptl);
>> - if (!new_pte) {
>> - pte_unmap_unlock(old_pte, old_ptl);
>> + if (!new_ptep) {
>> + pte_unmap_unlock(old_ptep, old_ptl);
>> err = -EAGAIN;
>> goto out;
>> }
>> @@ -235,12 +235,12 @@ static int move_ptes(struct pagetable_move_control *pmc,
>> flush_tlb_batched_pending(vma->vm_mm);
>> arch_enter_lazy_mmu_mode();
>>
>> - for (; old_addr < old_end; old_pte++, old_addr += PAGE_SIZE,
>> - new_pte++, new_addr += PAGE_SIZE) {
>> - if (pte_none(ptep_get(old_pte)))
>> + for (; old_addr < old_end; old_ptep++, old_addr += PAGE_SIZE,
>> + new_ptep++, new_addr += PAGE_SIZE) {
>> + if (pte_none(ptep_get(old_ptep)))
>> continue;
>>
>> - pte = ptep_get_and_clear(mm, old_addr, old_pte);
>> + pte = ptep_get_and_clear(mm, old_addr, old_ptep);
>> /*
>> * If we are remapping a valid PTE, make sure
>> * to flush TLB before we drop the PTL for the
>> @@ -258,7 +258,7 @@ static int move_ptes(struct pagetable_move_control *pmc,
>> pte = move_soft_dirty_pte(pte);
>>
>> if (need_clear_uffd_wp && pte_marker_uffd_wp(pte))
>> - pte_clear(mm, new_addr, new_pte);
>> + pte_clear(mm, new_addr, new_ptep);
>> else {
>> if (need_clear_uffd_wp) {
>> if (pte_present(pte))
>> @@ -266,7 +266,7 @@ static int move_ptes(struct pagetable_move_control *pmc,
>> else if (is_swap_pte(pte))
>> pte = pte_swp_clear_uffd_wp(pte);
>> }
>> - set_pte_at(mm, new_addr, new_pte, pte);
>> + set_pte_at(mm, new_addr, new_ptep, pte);
>> }
>> }
>>
>> @@ -275,8 +275,8 @@ static int move_ptes(struct pagetable_move_control *pmc,
>> flush_tlb_range(vma, old_end - len, old_end);
>> if (new_ptl != old_ptl)
>> spin_unlock(new_ptl);
>> - pte_unmap(new_pte - 1);
>> - pte_unmap_unlock(old_pte - 1, old_ptl);
>> + pte_unmap(new_ptep - 1);
>> + pte_unmap_unlock(old_ptep - 1, old_ptl);
>> out:
>> if (pmc->need_rmap_locks)
>> drop_rmap_locks(vma);
>> --
>> 2.30.2
>>
On 5/6/25 10:30, Dev Jain wrote:
> Avoid confusion between pte_t* and pte_t data types by appending pointer
> type variables by p. No functional change.
>
> Signed-off-by: Dev Jain <dev.jain@arm.com>
> ---
> mm/mremap.c | 28 ++++++++++++++--------------
> 1 file changed, 14 insertions(+), 14 deletions(-)
>
> diff --git a/mm/mremap.c b/mm/mremap.c
> index 7db9da609c84..1a08a7c3b92f 100644
> --- a/mm/mremap.c
> +++ b/mm/mremap.c
> @@ -176,7 +176,7 @@ 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;
> pmd_t dummy_pmdval;
> spinlock_t *old_ptl, *new_ptl;
> bool force_flush = false;
> @@ -211,8 +211,8 @@ 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;
> goto out;
> }
> @@ -223,10 +223,10 @@ static int move_ptes(struct pagetable_move_control *pmc,
> * mmap_lock, so this new_pte page is stable, so there is no need to get
> * pmdval and do pmd_same() check.
> */
> - new_pte = pte_offset_map_rw_nolock(mm, new_pmd, new_addr, &dummy_pmdval,
> + new_ptep = pte_offset_map_rw_nolock(mm, new_pmd, new_addr, &dummy_pmdval,
> &new_ptl);
> - if (!new_pte) {
> - pte_unmap_unlock(old_pte, old_ptl);
> + if (!new_ptep) {
> + pte_unmap_unlock(old_ptep, old_ptl);
> err = -EAGAIN;
> goto out;
> }
> @@ -235,12 +235,12 @@ static int move_ptes(struct pagetable_move_control *pmc,
> flush_tlb_batched_pending(vma->vm_mm);
> arch_enter_lazy_mmu_mode();
>
> - for (; old_addr < old_end; old_pte++, old_addr += PAGE_SIZE,
> - new_pte++, new_addr += PAGE_SIZE) {
> - if (pte_none(ptep_get(old_pte)))
> + for (; old_addr < old_end; old_ptep++, old_addr += PAGE_SIZE,
> + new_ptep++, new_addr += PAGE_SIZE) {
> + if (pte_none(ptep_get(old_ptep)))
> continue;
>
> - pte = ptep_get_and_clear(mm, old_addr, old_pte);
> + pte = ptep_get_and_clear(mm, old_addr, old_ptep);
> /*
> * If we are remapping a valid PTE, make sure
> * to flush TLB before we drop the PTL for the
> @@ -258,7 +258,7 @@ static int move_ptes(struct pagetable_move_control *pmc,
> pte = move_soft_dirty_pte(pte);
>
> if (need_clear_uffd_wp && pte_marker_uffd_wp(pte))
> - pte_clear(mm, new_addr, new_pte);
> + pte_clear(mm, new_addr, new_ptep);
> else {
> if (need_clear_uffd_wp) {
> if (pte_present(pte))
> @@ -266,7 +266,7 @@ static int move_ptes(struct pagetable_move_control *pmc,
> else if (is_swap_pte(pte))
> pte = pte_swp_clear_uffd_wp(pte);
> }
> - set_pte_at(mm, new_addr, new_pte, pte);
> + set_pte_at(mm, new_addr, new_ptep, pte);
> }
> }
>
> @@ -275,8 +275,8 @@ static int move_ptes(struct pagetable_move_control *pmc,
> flush_tlb_range(vma, old_end - len, old_end);
> if (new_ptl != old_ptl)
> spin_unlock(new_ptl);
> - pte_unmap(new_pte - 1);
> - pte_unmap_unlock(old_pte - 1, old_ptl);
> + pte_unmap(new_ptep - 1);
> + pte_unmap_unlock(old_ptep - 1, old_ptl);
> out:
> if (pmc->need_rmap_locks)
> drop_rmap_locks(vma);
Although this makes sense, mm/mremap.c might not be the only place with such
naming confusions regarding page table entry and page table pointers. Rather
than fixing this in just a single file, I guess generic MM wide change will
be better.
On Tue, May 06, 2025 at 02:20:01PM +0530, Anshuman Khandual wrote: > On 5/6/25 10:30, Dev Jain wrote: > > Avoid confusion between pte_t* and pte_t data types by appending pointer > > type variables by p. No functional change. > > > > Signed-off-by: Dev Jain <dev.jain@arm.com> > > --- [snip] > Although this makes sense, mm/mremap.c might not be the only place with such > naming confusions regarding page table entry and page table pointers. Rather > than fixing this in just a single file, I guess generic MM wide change will > be better. No, let's not please. that will be a ton of churn. This confusion literally already exists all over the place so it's not egregious. I am sympathetic to this kind of change (I really _hate_ this as an issue), and since I recently refactored all of mremap I am likely to be ok with this here, but let's do any such change iteratively, please.
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