From: Jann Horn <jannh@google.com>
To: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: linux-mm@kvack.org, Arjun Roy <arjunroy@google.com>,
Eric Dumazet <edumazet@google.com>,
Suren Baghdasaryan <surenb@google.com>,
linux-fsdevel@vger.kernel.org,
Punit Agrawal <punit.agrawal@bytedance.com>
Subject: Re: [PATCH v2 5/9] mm: Move FAULT_FLAG_VMA_LOCK check down in handle_pte_fault()
Date: Mon, 24 Jul 2023 17:46:21 +0200 [thread overview]
Message-ID: <CAG48ez2iccdvgjUh+tTpthJT8rHwd9eJwjgxBFMCWpa+imkQ7w@mail.gmail.com> (raw)
In-Reply-To: <20230711202047.3818697-6-willy@infradead.org>
On Tue, Jul 11, 2023 at 10:20 PM Matthew Wilcox (Oracle)
<willy@infradead.org> wrote:
> Call do_pte_missing() under the VMA lock ... then immediately retry
> in do_fault().
>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
> ---
[...]
> @@ -4961,6 +4961,11 @@ static vm_fault_t handle_pte_fault(struct vm_fault *vmf)
> if (!vmf->pte)
> return do_pte_missing(vmf);
>
> + if ((vmf->flags & FAULT_FLAG_VMA_LOCK) && !vma_is_anonymous(vmf->vma)) {
> + vma_end_read(vmf->vma);
> + return VM_FAULT_RETRY;
> + }
At this point we can have vmf->pte mapped, right? Does this mean this
bailout leaks a kmap_local() on CONFIG_HIGHPTE?
> if (!pte_present(vmf->orig_pte))
> return do_swap_page(vmf);
next prev parent reply other threads:[~2023-07-24 15:47 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-11 20:20 [PATCH v2 0/9] Avoid the mmap lock for fault-around Matthew Wilcox (Oracle)
2023-07-11 20:20 ` [PATCH v2 1/9] Revert "tcp: Use per-vma locking for receive zerocopy" Matthew Wilcox (Oracle)
2023-07-14 3:02 ` Suren Baghdasaryan
2023-07-14 3:34 ` Matthew Wilcox
2023-07-24 14:49 ` Jann Horn
2023-07-24 15:06 ` Matthew Wilcox
2023-07-24 21:42 ` Jakub Kicinski
2023-07-11 20:20 ` [PATCH v2 2/9] mm: Allow per-VMA locks on file-backed VMAs Matthew Wilcox (Oracle)
2023-07-14 3:03 ` Suren Baghdasaryan
2023-07-11 20:20 ` [PATCH v2 3/9] mm: Move FAULT_FLAG_VMA_LOCK check from handle_mm_fault() Matthew Wilcox (Oracle)
2023-07-14 3:04 ` Suren Baghdasaryan
2023-07-11 20:20 ` [PATCH v2 4/9] mm: Move FAULT_FLAG_VMA_LOCK check into handle_pte_fault() Matthew Wilcox (Oracle)
2023-07-14 3:17 ` Suren Baghdasaryan
2023-07-24 15:46 ` Jann Horn
2023-07-24 16:37 ` Matthew Wilcox
2023-07-11 20:20 ` [PATCH v2 5/9] mm: Move FAULT_FLAG_VMA_LOCK check down in handle_pte_fault() Matthew Wilcox (Oracle)
2023-07-14 3:26 ` Suren Baghdasaryan
2023-07-24 15:46 ` Jann Horn [this message]
2023-07-24 17:45 ` Matthew Wilcox
2023-07-11 20:20 ` [PATCH v2 6/9] mm: Move the FAULT_FLAG_VMA_LOCK check down from do_fault() Matthew Wilcox (Oracle)
2023-07-14 3:27 ` Suren Baghdasaryan
2023-07-11 20:20 ` [PATCH v2 7/9] mm: Run the fault-around code under the VMA lock Matthew Wilcox (Oracle)
2023-07-14 3:32 ` Suren Baghdasaryan
2023-07-24 17:38 ` Matthew Wilcox
2023-07-11 20:20 ` [PATCH v2 8/9] mm: Remove CONFIG_PER_VMA_LOCK ifdefs Matthew Wilcox (Oracle)
2023-07-14 3:34 ` Suren Baghdasaryan
2023-07-11 20:20 ` [PATCH v2 9/9] tcp: Use per-vma locking for receive zerocopy Matthew Wilcox (Oracle)
2023-07-14 3:40 ` Suren Baghdasaryan
2023-07-21 18:48 ` Matthew Wilcox
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=CAG48ez2iccdvgjUh+tTpthJT8rHwd9eJwjgxBFMCWpa+imkQ7w@mail.gmail.com \
--to=jannh@google.com \
--cc=arjunroy@google.com \
--cc=edumazet@google.com \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=punit.agrawal@bytedance.com \
--cc=surenb@google.com \
--cc=willy@infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox