Re: [PATCH 6.18 000/552] 6.18.50-rc1 review

Re: [PATCH 6.18 000/552] 6.18.50-rc1 review

[Miguel Ojeda]

On Fri, 04 Sep 2026 06:52:37 +0200 Greg Kroah-Hartman <gregkh@linuxfoundation.org> wrote:
>
> This is the start of the stable review cycle for the 6.18.50 release.
> There are 552 patches in this series, all will be posted as a response
> to this one.  If anyone has any issues with these being applied, please
> let me know.
>
> Responses should be made by Sun, 06 Sep 2026 04:56:59 +0000.
> Anything received after that time might be too late.

Boot-tested under QEMU for Rust x86_64, arm64 and riscv64; built-tested
for loongarch64 and arm32:

Tested-by: Miguel Ojeda <ojeda@kernel.org>

I see the same arm32 build issue:

    mm/page_vma_mapped.c:110:11: error: call to undeclared function 'huge_ptep_get'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
      110 |                 ptent = huge_ptep_get(pvmw->vma->vm_mm, pvmw->address,
          |                         ^

In addition, in UML (x86_64) there is also nearby:

    mm/page_vma_mapped.c:110:9: error: assigning to 'pte_t' from incompatible type 'int'
      110 |                 ptent = huge_ptep_get(pvmw->vma->vm_mm, pvmw->address,
          |                       ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      111 |                                       pvmw->pte);
          |                                       ~~~~~~~~~~

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Harry Yoo <harry@kernel.org>
Cc: Jann Horn <jannh@google.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: linux-mm@kvack.org

Cc: Russell King <linux@armlinux.org.uk>
Cc: linux-arm-kernel@lists.infradead.org

Cc: Richard Weinberger <richard@nod.at>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: linux-um@lists.infradead.org

Thanks!

Cheers,
Miguel

Re: [PATCH 6.18 000/552] 6.18.50-rc1 review

[Dominique Martinet]

Miguel Ojeda wrote on Sat, Sep 05, 2026 at 01:41:11PM +0200:
> I see the same arm32 build issue:
> 
>     mm/page_vma_mapped.c:110:11: error: call to undeclared function 'huge_ptep_get'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
>       110 |                 ptent = huge_ptep_get(pvmw->vma->vm_mm, pvmw->address,
>           |                         ^
> 
> In addition, in UML (x86_64) there is also nearby:
> 
>     mm/page_vma_mapped.c:110:9: error: assigning to 'pte_t' from incompatible type 'int'
>       110 |                 ptent = huge_ptep_get(pvmw->vma->vm_mm, pvmw->address,
>           |                       ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>       111 |                                       pvmw->pte);
>           |                                       ~~~~~~~~~~

See this 6.12 thread[1] for this build failure (I didn't check but
assume it is the same, that missing commit only made it 7.3-rc1 but was
also backported to the 7.2 tree, which also explains 7.2 didn't build
fail)
---
This builds on master because this commit:
f5407e9b697c ("mm/rmap: use huge_ptep_get() in try_to_unmap_one()")
added a function declaration in linux/hugetlb.h !CONFIG_HUGETLB_PAGE
code:
```
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 817b8b4223fa..95b1b6ee1f96 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -1270,6 +1270,8 @@ static inline void hugetlb_count_sub(long l, struct mm_struct *mm)
 {
 }
 
+pte_t huge_ptep_get(struct mm_struct *mm, unsigned long addr, pte_t *ptep);
+
 static inline pte_t huge_ptep_clear_flush(struct vm_area_struct *vma,
 					 unsigned long addr, pte_t *ptep)
 {
```

The rest of that commit isn't applicable, so we either need to roll that
change in 'mm/migrate: use huge_ptep_get() in remove_migration_pte()' or
add it separately (or drop that commit)
---

[1] https://lore.kernel.org/r/apq_s8mFJJPzoIdo@codewreck.org

-- 
Dominique

Re: [PATCH 6.18 000/552] 6.18.50-rc1 review

[Greg KH]

On Sat, Sep 05, 2026 at 08:49:04PM +0900, Dominique Martinet wrote:
> Miguel Ojeda wrote on Sat, Sep 05, 2026 at 01:41:11PM +0200:
> > I see the same arm32 build issue:
> > 
> >     mm/page_vma_mapped.c:110:11: error: call to undeclared function 'huge_ptep_get'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
> >       110 |                 ptent = huge_ptep_get(pvmw->vma->vm_mm, pvmw->address,
> >           |                         ^
> > 
> > In addition, in UML (x86_64) there is also nearby:
> > 
> >     mm/page_vma_mapped.c:110:9: error: assigning to 'pte_t' from incompatible type 'int'
> >       110 |                 ptent = huge_ptep_get(pvmw->vma->vm_mm, pvmw->address,
> >           |                       ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> >       111 |                                       pvmw->pte);
> >           |                                       ~~~~~~~~~~
> 
> See this 6.12 thread[1] for this build failure (I didn't check but
> assume it is the same, that missing commit only made it 7.3-rc1 but was
> also backported to the 7.2 tree, which also explains 7.2 didn't build
> fail)

I should have this fixed up now, will push out a -rc2 so that you all
can test it as I'm away from my big build box at the moment :(

thanks,

greg k-h