linux-kernel - [PATCH v3] arm64: mm: Test for pmd_sect() in vmemmap_check

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250102074047.674156-1-quic_zhenhuah@quicinc.com>
Date: Thu, 2 Jan 2025 15:40:47 +0800
From: Zhenhua Huang <quic_zhenhuah@...cinc.com>
To: <anshuman.khandual@....com>, <catalin.marinas@....com>
CC: <will@...nel.org>, <ardb@...nel.org>, <ryan.roberts@....com>,
        <mark.rutland@....com>, <joey.gouly@....com>,
        <dave.hansen@...ux.intel.com>, <akpm@...ux-foundation.org>,
        <chenfeiyang@...ngson.cn>, <chenhuacai@...nel.org>,
        <linux-mm@...ck.org>, <linux-arm-kernel@...ts.infradead.org>,
        <linux-kernel@...r.kernel.org>, <quic_tingweiz@...cinc.com>,
        Zhenhua Huang <quic_zhenhuah@...cinc.com>
Subject: [PATCH v3] arm64: mm: Test for pmd_sect() in vmemmap_check_pmd()

Commit 2045a3b8911b ("mm/sparse-vmemmap: generalise vmemmap_populate_hugepages()")
introduces the vmemmap_check_pmd() while does not verify if the entry is a
section mapping, as is already done for Loongarch & X86.
The update includes a check for pmd_sect(). Only if pmd_sect() returns true,
further vmemmap population for the addr is skipped.

Signed-off-by: Zhenhua Huang <quic_zhenhuah@...cinc.com>
---
Separate the patch out based on the discussion:
https://lore.kernel.org/linux-arm-kernel/20241209094227.1529977-3-quic_zhenhuah@quicinc.com/T/#m41d49cd91b348ecfe2c37c4b3c0911180426934e
 
 arch/arm64/mm/mmu.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index 9afeb35673a3..50a22c63f450 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -1172,7 +1172,8 @@ int __meminit vmemmap_check_pmd(pmd_t *pmdp, int node,
 				unsigned long addr, unsigned long next)
 {
 	vmemmap_verify((pte_t *)pmdp, node, addr, next);
-	return 1;
+
+	return pmd_sect(READ_ONCE(*pmdp));
 }
 
 int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
-- 
2.25.1