From: Matthew Wilcox <willy@infradead.org>
To: Yin Fengwei <fengwei.yin@intel.com>
Cc: david@redhat.com, linux-mm@kvack.org, dave.hansen@intel.com,
tim.c.chen@intel.com, ying.huang@intel.com
Subject: Re: [RFC PATCH 4/5] mm: add do_set_pte_entry()
Date: Mon, 30 Jan 2023 13:53:12 +0000 [thread overview]
Message-ID: <Y9fLyKPL/gQSsv7h@casper.infradead.org> (raw)
In-Reply-To: <20230130125504.2509710-5-fengwei.yin@intel.com>
On Mon, Jan 30, 2023 at 08:55:03PM +0800, Yin Fengwei wrote:
> +++ b/include/linux/mm.h
> @@ -1061,6 +1061,8 @@ static inline pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma)
>
> vm_fault_t do_set_pmd(struct vm_fault *vmf, struct page *page);
> void do_set_pte(struct vm_fault *vmf, struct page *page, unsigned long addr);
> +void do_set_pte_entry(struct vm_fault *vmf, struct page *page,
> + unsigned long addr);
indentation
> -void do_set_pte(struct vm_fault *vmf, struct page *page, unsigned long addr)
> +void do_set_pte_entry(struct vm_fault *vmf, struct page *page,
> + unsigned long addr)
ditto
> {
> struct vm_area_struct *vma = vmf->vma;
> bool uffd_wp = pte_marker_uffd_wp(vmf->orig_pte);
> @@ -4276,6 +4277,16 @@ void do_set_pte(struct vm_fault *vmf, struct page *page, unsigned long addr)
> entry = maybe_mkwrite(pte_mkdirty(entry), vma);
> if (unlikely(uffd_wp))
> entry = pte_mkuffd_wp(entry);
> + set_pte_at(vma->vm_mm, addr, vmf->pte, entry);
I'm not sure this is safe. As soon as you call set_pte_at(), the page
can be found by GUP. If it is, and it doesn't have rmap set up, aren't
things going to go horribly wrong?
next prev parent reply other threads:[~2023-01-30 13:53 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-30 12:54 [RFC PATCH 0/5] folio based filemap_map_pages() Yin Fengwei
2023-01-30 12:55 ` [RFC PATCH 1/5] mm: Enable fault around for shared file page fault Yin Fengwei
2023-01-30 13:21 ` Matthew Wilcox
2023-01-31 0:59 ` Yin, Fengwei
2023-01-30 12:55 ` [RFC PATCH 2/5] filemap: do file page mapping with folio granularity Yin Fengwei
2023-01-30 13:35 ` Matthew Wilcox
2023-01-31 1:03 ` Yin, Fengwei
2023-01-31 3:34 ` Huang, Ying
2023-01-31 6:32 ` Yin, Fengwei
2023-01-30 12:55 ` [RFC PATCH 3/5] rmap: add page_add_file_rmap_range() Yin Fengwei
2023-01-30 13:50 ` Matthew Wilcox
2023-01-31 7:24 ` Huang, Ying
2023-01-31 7:48 ` Yin, Fengwei
2023-01-30 12:55 ` [RFC PATCH 4/5] mm: add do_set_pte_entry() Yin Fengwei
2023-01-30 13:53 ` Matthew Wilcox [this message]
2023-01-31 1:06 ` Yin, Fengwei
2023-01-30 12:55 ` [RFC PATCH 5/5] filemap: batched update mm counter,rmap when map file folio Yin Fengwei
2023-01-30 14:14 ` Matthew Wilcox
2023-01-31 1:11 ` Yin, Fengwei
2023-01-30 12:58 ` [RFC PATCH 0/5] folio based filemap_map_pages() Yin, Fengwei
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=Y9fLyKPL/gQSsv7h@casper.infradead.org \
--to=willy@infradead.org \
--cc=dave.hansen@intel.com \
--cc=david@redhat.com \
--cc=fengwei.yin@intel.com \
--cc=linux-mm@kvack.org \
--cc=tim.c.chen@intel.com \
--cc=ying.huang@intel.com \
/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