[<prev] [next>] [<thread-prev] [day] [month] [year] [list]
Message-ID: <ZMMyWmyC8EvFIL/G@casper.infradead.org>
Date: Fri, 28 Jul 2023 04:13:30 +0100
From: Matthew Wilcox <willy@...radead.org>
To: Stephen Rothwell <sfr@...b.auug.org.au>
Cc: Andrew Morton <akpm@...ux-foundation.org>,
Jann Horn <jannh@...gle.com>,
Linus Torvalds <torvalds@...ux-foundation.org>,
Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
Linux Next Mailing List <linux-next@...r.kernel.org>,
Suren Baghdasaryan <surenb@...gle.com>
Subject: Re: linux-next: manual merge of the mm tree with Linus' tree
On Fri, Jul 28, 2023 at 10:00:47AM +1000, Stephen Rothwell wrote:
> I have gone with below. Again, please check.
LGTM
> diff --cc mm/memory.c
> index ca632b58f792,271982fab2b8..000000000000
> --- a/mm/memory.c
> +++ b/mm/memory.c
> @@@ -5392,32 -5597,18 +5597,21 @@@ retry
> if (!vma)
> goto inval;
>
> - /* Only anonymous and tcp vmas are supported for now */
> - if (!vma_is_anonymous(vma) && !vma_is_tcp(vma))
> - /* find_mergeable_anon_vma uses adjacent vmas which are not locked */
> - if (vma_is_anonymous(vma) && !vma->anon_vma)
> -- goto inval;
> --
> if (!vma_start_read(vma))
> goto inval;
>
> + /*
> + * find_mergeable_anon_vma uses adjacent vmas which are not locked.
> + * This check must happen after vma_start_read(); otherwise, a
> + * concurrent mremap() with MREMAP_DONTUNMAP could dissociate the VMA
> + * from its anon_vma.
> + */
> - if (unlikely(!vma->anon_vma && !vma_is_tcp(vma)))
> - goto inval_end_read;
> -
> - /*
> - * Due to the possibility of userfault handler dropping mmap_lock, avoid
> - * it for now and fall back to page fault handling under mmap_lock.
> - */
> - if (userfaultfd_armed(vma))
> ++ if (unlikely(vma_is_anonymous(vma) && !vma->anon_vma))
> + goto inval_end_read;
> +
> /* Check since vm_start/vm_end might change before we lock the VMA */
> - if (unlikely(address < vma->vm_start || address >= vma->vm_end)) {
> - vma_end_read(vma);
> - goto inval;
> - }
> + if (unlikely(address < vma->vm_start || address >= vma->vm_end))
> + goto inval_end_read;
>
> /* Check if the VMA got isolated after we found it */
> if (vma->detached) {
If Andrew wants to rebase on Linus' tree, I'll be happy to respin
on top of that.
Powered by blists - more mailing lists