* [PATCH] mm/hugetlb: Fix build with !ARCH_WANT_HUGE_PMD_SHARE
@ 2021-03-10 18:53 Peter Xu
2021-03-10 19:21 ` Mike Kravetz
0 siblings, 1 reply; 3+ messages in thread
From: Peter Xu @ 2021-03-10 18:53 UTC (permalink / raw)
To: linux-kernel, linux-mm
Cc: peterx, Andrew Morton, Mike Kravetz, Axel Rasmussen, Naresh Kamboju
want_pmd_share() is undefined with !ARCH_WANT_HUGE_PMD_SHARE since it's put
by accident into a "#ifdef ARCH_WANT_HUGE_PMD_SHARE" block. Moving it out
won't work either since vma_shareable() is only defined within the block.
Define it for !ARCH_WANT_HUGE_PMD_SHARE instead.
Fixes: 5b109cc1cdcc ("hugetlb/userfaultfd: forbid huge pmd sharing when uffd enabled")
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Peter Xu <peterx@redhat.com>
---
mm/hugetlb.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index d58f1456fe27..8dda7e034477 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -5469,9 +5469,6 @@ static bool vma_shareable(struct vm_area_struct *vma, unsigned long addr)
bool want_pmd_share(struct vm_area_struct *vma, unsigned long addr)
{
-#ifndef CONFIG_ARCH_WANT_HUGE_PMD_SHARE
- return false;
-#endif
#ifdef CONFIG_USERFAULTFD
if (uffd_disable_huge_pmd_share(vma))
return false;
@@ -5616,6 +5613,11 @@ void adjust_range_if_pmd_sharing_possible(struct vm_area_struct *vma,
unsigned long *start, unsigned long *end)
{
}
+
+bool want_pmd_share(struct vm_area_struct *vma, unsigned long addr)
+{
+ return false;
+}
#endif /* CONFIG_ARCH_WANT_HUGE_PMD_SHARE */
#ifdef CONFIG_ARCH_WANT_GENERAL_HUGETLB
--
2.26.2
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] mm/hugetlb: Fix build with !ARCH_WANT_HUGE_PMD_SHARE
2021-03-10 18:53 [PATCH] mm/hugetlb: Fix build with !ARCH_WANT_HUGE_PMD_SHARE Peter Xu
@ 2021-03-10 19:21 ` Mike Kravetz
2021-03-10 19:40 ` Peter Xu
0 siblings, 1 reply; 3+ messages in thread
From: Mike Kravetz @ 2021-03-10 19:21 UTC (permalink / raw)
To: Peter Xu, linux-kernel, linux-mm
Cc: Andrew Morton, Axel Rasmussen, Naresh Kamboju
On 3/10/21 10:53 AM, Peter Xu wrote:
> want_pmd_share() is undefined with !ARCH_WANT_HUGE_PMD_SHARE since it's put
> by accident into a "#ifdef ARCH_WANT_HUGE_PMD_SHARE" block. Moving it out
> won't work either since vma_shareable() is only defined within the block.
> Define it for !ARCH_WANT_HUGE_PMD_SHARE instead.
>
> Fixes: 5b109cc1cdcc ("hugetlb/userfaultfd: forbid huge pmd sharing when uffd enabled")
That commit id is from Andrew's tree and I don't think it is stable.
There is a different id in the next tree. Not exactly sure how this is
supposed to be handled.
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Mike Kravetz <mike.kravetz@oracle.com>
> Cc: Axel Rasmussen <axelrasmussen@google.com>
> Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
> Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
> Signed-off-by: Peter Xu <peterx@redhat.com>
> ---
> mm/hugetlb.c | 8 +++++---
> 1 file changed, 5 insertions(+), 3 deletions(-)
Thanks Peter,
Not your fault, but that header file is a bit of a mess.
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
--
Mike Kravetz
>
> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> index d58f1456fe27..8dda7e034477 100644
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -5469,9 +5469,6 @@ static bool vma_shareable(struct vm_area_struct *vma, unsigned long addr)
>
> bool want_pmd_share(struct vm_area_struct *vma, unsigned long addr)
> {
> -#ifndef CONFIG_ARCH_WANT_HUGE_PMD_SHARE
> - return false;
> -#endif
> #ifdef CONFIG_USERFAULTFD
> if (uffd_disable_huge_pmd_share(vma))
> return false;
> @@ -5616,6 +5613,11 @@ void adjust_range_if_pmd_sharing_possible(struct vm_area_struct *vma,
> unsigned long *start, unsigned long *end)
> {
> }
> +
> +bool want_pmd_share(struct vm_area_struct *vma, unsigned long addr)
> +{
> + return false;
> +}
> #endif /* CONFIG_ARCH_WANT_HUGE_PMD_SHARE */
>
> #ifdef CONFIG_ARCH_WANT_GENERAL_HUGETLB
>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] mm/hugetlb: Fix build with !ARCH_WANT_HUGE_PMD_SHARE
2021-03-10 19:21 ` Mike Kravetz
@ 2021-03-10 19:40 ` Peter Xu
0 siblings, 0 replies; 3+ messages in thread
From: Peter Xu @ 2021-03-10 19:40 UTC (permalink / raw)
To: Mike Kravetz
Cc: linux-kernel, linux-mm, Andrew Morton, Axel Rasmussen, Naresh Kamboju
On Wed, Mar 10, 2021 at 11:21:50AM -0800, Mike Kravetz wrote:
> On 3/10/21 10:53 AM, Peter Xu wrote:
> > want_pmd_share() is undefined with !ARCH_WANT_HUGE_PMD_SHARE since it's put
> > by accident into a "#ifdef ARCH_WANT_HUGE_PMD_SHARE" block. Moving it out
> > won't work either since vma_shareable() is only defined within the block.
> > Define it for !ARCH_WANT_HUGE_PMD_SHARE instead.
> >
> > Fixes: 5b109cc1cdcc ("hugetlb/userfaultfd: forbid huge pmd sharing when uffd enabled")
>
> That commit id is from Andrew's tree and I don't think it is stable.
> There is a different id in the next tree. Not exactly sure how this is
> supposed to be handled.
I see - it'll be even better if this patch can be squashed into it.
>
> > Cc: Andrew Morton <akpm@linux-foundation.org>
> > Cc: Mike Kravetz <mike.kravetz@oracle.com>
> > Cc: Axel Rasmussen <axelrasmussen@google.com>
> > Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
> > Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
> > Signed-off-by: Peter Xu <peterx@redhat.com>
> > ---
> > mm/hugetlb.c | 8 +++++---
> > 1 file changed, 5 insertions(+), 3 deletions(-)
>
> Thanks Peter,
> Not your fault, but that header file is a bit of a mess.
>
> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
I'm still guilty on not noticing this before since I still could.. I think it
gives me some more clue to make less such mistake in the future.
Thanks for taking a quick look, Mike!
--
Peter Xu
^ permalink raw reply [flat|nested] 3+ messages in thread
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2021-03-10 18:53 [PATCH] mm/hugetlb: Fix build with !ARCH_WANT_HUGE_PMD_SHARE Peter Xu
2021-03-10 19:21 ` Mike Kravetz
2021-03-10 19:40 ` Peter Xu
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