Re: linux-next: build failure after merge of the hmm tree

From: Stephen Rothwell
Date: Mon Jul 08 2019 - 20:21:44 EST


Hi all,

On Mon, 1 Jul 2019 21:08:53 +1000 Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx> wrote:
>
> After merging the hmm tree, today's linux-next build (x86_64 allmodconfig)
> failed like this:
>
> mm/hmm.c: In function 'hmm_get_or_create':
> mm/hmm.c:50:2: error: implicit declaration of function 'lockdep_assert_held_exclusive'; did you mean 'lockdep_assert_held_once'? [-Werror=implicit-function-declaration]
> lockdep_assert_held_exclusive(&mm->mmap_sem);
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> lockdep_assert_held_once
>
> Caused by commit
>
> 8a9320b7ec5d ("mm/hmm: Simplify hmm_get_or_create and make it reliable")
>
> interacting with commit
>
> 9ffbe8ac05db ("locking/lockdep: Rename lockdep_assert_held_exclusive() -> lockdep_assert_held_write()")
>
> from the tip tree.
>
> I have added the following merge fix.
>
> From: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>
> Date: Mon, 1 Jul 2019 21:05:59 +1000
> Subject: [PATCH] mm/hmm: fixup for "locking/lockdep: Rename
> lockdep_assert_held_exclusive() -> lockdep_assert_held_write()"
>
> Signed-off-by: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>
> ---
> mm/hmm.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/mm/hmm.c b/mm/hmm.c
> index c1bdcef403ee..2ddbd589b207 100644
> --- a/mm/hmm.c
> +++ b/mm/hmm.c
> @@ -47,7 +47,7 @@ static struct hmm *hmm_get_or_create(struct mm_struct *mm)
> {
> struct hmm *hmm;
>
> - lockdep_assert_held_exclusive(&mm->mmap_sem);
> + lockdep_assert_held_write(&mm->mmap_sem);
>
> /* Abuse the page_table_lock to also protect mm->hmm. */
> spin_lock(&mm->page_table_lock);
> @@ -248,7 +248,7 @@ static const struct mmu_notifier_ops hmm_mmu_notifier_ops = {
> */
> int hmm_mirror_register(struct hmm_mirror *mirror, struct mm_struct *mm)
> {
> - lockdep_assert_held_exclusive(&mm->mmap_sem);
> + lockdep_assert_held_write(&mm->mmap_sem);
>
> /* Sanity check */
> if (!mm || !mirror || !mirror->ops)

I am still getting this conflict (the commit ids may have changed).
Just a reminder in case you think Linus may need to know.

--
Cheers,
Stephen Rothwell

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