+ arm64-mm-use-ptep_clear-instead-of-pte_clear-in-clear_flush.patch added to mm-unstable branch

+ arm64-mm-use-ptep_clear-instead-of-pte_clear-in-clear_flush.patch added to mm-unstable branch

[Andrew Morton]

The patch titled
     Subject: arm64: mm: use ptep_clear() instead of pte_clear() in clear_flush()
has been added to the -mm mm-unstable branch.  Its filename is
     arm64-mm-use-ptep_clear-instead-of-pte_clear-in-clear_flush.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/arm64-mm-use-ptep_clear-instead-of-pte_clear-in-clear_flush.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days

------------------------------------------------------
From: Qi Zheng <qi.zheng@linux.dev>
Subject: arm64: mm: use ptep_clear() instead of pte_clear() in clear_flush()
Date: Thu, 10 Aug 2023 09:32:41 +0000


In clear_flush(), the original pte may be a present entry, so we should
use ptep_clear() to let page_table_check track the pte clearing operation,
otherwise it may cause false positive in subsequent set_pte_at().

Link: https://lkml.kernel.org/r/20230810093241.1181142-1-qi.zheng@linux.dev
Fixes: 42b2547137f5 ("arm64/mm: enable ARCH_SUPPORTS_PAGE_TABLE_CHECK")
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 arch/arm64/mm/hugetlbpage.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/arm64/mm/hugetlbpage.c~arm64-mm-use-ptep_clear-instead-of-pte_clear-in-clear_flush
+++ a/arch/arm64/mm/hugetlbpage.c
@@ -236,7 +236,7 @@ static void clear_flush(struct mm_struct
 	unsigned long i, saddr = addr;
 
 	for (i = 0; i < ncontig; i++, addr += pgsize, ptep++)
-		pte_clear(mm, addr, ptep);
+		ptep_clear(mm, addr, ptep);
 
 	flush_tlb_range(&vma, saddr, addr);
 }
_

Patches currently in -mm which might be from qi.zheng@linux.dev are

arm64-mm-use-ptep_clear-instead-of-pte_clear-in-clear_flush.patch