linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: Ryan Roberts <ryan.roberts@arm.com>
To: Andrew Morton <akpm@linux-foundation.org>,
	Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>,
	linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: [PATCH v1] mm: use ptep_get() instead of directly dereferencing pte_t*
Date: Mon, 10 Mar 2025 14:04:17 +0000	[thread overview]
Message-ID: <20250310140418.1737409-1-ryan.roberts@arm.com> (raw)

It is best practice for all pte accesses to go via the arch helpers, to
ensure non-torn values and to allow the arch to intervene where needed
(contpte for arm64 for example). While in this case it was probably safe
to directly dereference, let's tidy it up for consistency.

Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
---
 mm/migrate.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/migrate.c b/mm/migrate.c
index 22e270f727ed..33a22c2d6b20 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -202,7 +202,7 @@ static bool try_to_map_unused_to_zeropage(struct page_vma_mapped_walk *pvmw,
 		return false;
 	VM_BUG_ON_PAGE(!PageAnon(page), page);
 	VM_BUG_ON_PAGE(!PageLocked(page), page);
-	VM_BUG_ON_PAGE(pte_present(*pvmw->pte), page);
+	VM_BUG_ON_PAGE(pte_present(ptep_get(pvmw->pte)), page);

 	if (folio_test_mlocked(folio) || (pvmw->vma->vm_flags & VM_LOCKED) ||
 	    mm_forbids_zeropage(pvmw->vma->vm_mm))
--
2.43.0



             reply	other threads:[~2025-03-10 14:04 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-03-10 14:04 Ryan Roberts [this message]
2025-03-10 14:10 ` Lorenzo Stoakes
2025-03-10 15:51 ` Qi Zheng
2025-03-10 16:31   ` Ryan Roberts
2025-03-11  3:14     ` Qi Zheng
2025-03-11  5:28 ` Anshuman Khandual
2025-03-11  6:03 ` Dev Jain

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=20250310140418.1737409-1-ryan.roberts@arm.com \
    --to=ryan.roberts@arm.com \
    --cc=akpm@linux-foundation.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=lorenzo.stoakes@oracle.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