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

[John Hubbard]

On 2020-05-25 05:17, Stephen Rothwell wrote:
> Hi all,
>
> After merging the akpm tree, today's linux-next build (x86_64
> allmodconfig) failed like this:
>
> In file included from include/linux/kernel.h:14,
>                   from mm/gup.c:2:
> mm/gup.c: In function 'internal_get_user_pages_fast':
> mm/gup.c:2732:33: error: 'struct mm_struct' has no member named 'mmap_sem'; did you mean 'mmap_base'?
>   2732 |   might_lock_read(&current->mm->mmap_sem);
>        |                                 ^~~~~~~~
>
> Caused by commit
>
>    64fe66e8a95e ("mmap locking API: rename mmap_sem to mmap_lock")
>
> fron the akpm tree interacting with commit
>
>    b1fc8b5ddb4e ("mm/gup: might_lock_read(mmap_sem) in get_user_pages_fast()")
>
> from the akpm-current tree.
>
> I added the following patch for today.
>
> From: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>
> Date: Mon, 25 May 2020 22:11:51 +1000
> Subject: [PATCH] mm/gup: update for mmap_sem rename
>
> Signed-off-by: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>
> ---
>   mm/gup.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/mm/gup.c b/mm/gup.c
> index 8977e5fe9843..f4bca3de0b4b 100644
> --- a/mm/gup.c
> +++ b/mm/gup.c
> @@ -2729,7 +2729,7 @@ static int internal_get_user_pages_fast(unsigned long start, int nr_pages,
>   		return -EINVAL;
>   
>   	if (!(gup_flags & FOLL_FAST_ONLY))
> -		might_lock_read(&current->mm->mmap_sem);
> +		might_lock_read(&current->mm->mmap_lock);
>   
>   	start = untagged_addr(start) & PAGE_MASK;
>   	addr = start;

Yes, looks good. And in fact, Andrew has the same fix-up in the mmotm branch of
linux-next.git, as

    commit a76c281a8ddd ("mmap-locking-api-rename-mmap_sem-to-mmap_lock-fix").


thanks,
--
John Hubbard
NVIDIA