linux-kernel - [PATCH v2 02/12] x86: pgtable: Always use pte_free

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

Message-ID: <20250408095222.860601-3-kevin.brodsky@arm.com>
Date: Tue,  8 Apr 2025 10:52:12 +0100
From: Kevin Brodsky <kevin.brodsky@....com>
To: linux-mm@...ck.org
Cc: linux-kernel@...r.kernel.org,
	Kevin Brodsky <kevin.brodsky@....com>,
	Albert Ou <aou@...s.berkeley.edu>,
	Andreas Larsson <andreas@...sler.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Catalin Marinas <catalin.marinas@....com>,
	Dave Hansen <dave.hansen@...ux.intel.com>,
	"David S. Miller" <davem@...emloft.net>,
	Geert Uytterhoeven <geert@...ux-m68k.org>,
	Linus Walleij <linus.walleij@...aro.org>,
	Madhavan Srinivasan <maddy@...ux.ibm.com>,
	Mark Rutland <mark.rutland@....com>,
	Matthew Wilcox <willy@...radead.org>,
	Michael Ellerman <mpe@...erman.id.au>,
	"Mike Rapoport (IBM)" <rppt@...nel.org>,
	Palmer Dabbelt <palmer@...belt.com>,
	Paul Walmsley <paul.walmsley@...ive.com>,
	Peter Zijlstra <peterz@...radead.org>,
	Qi Zheng <zhengqi.arch@...edance.com>,
	Ryan Roberts <ryan.roberts@....com>,
	Will Deacon <will@...nel.org>,
	Yang Shi <yang@...amperecomputing.com>,
	linux-arch@...r.kernel.org,
	linux-arm-kernel@...ts.infradead.org,
	linux-csky@...r.kernel.org,
	linux-m68k@...ts.linux-m68k.org,
	linux-openrisc@...r.kernel.org,
	linux-riscv@...ts.infradead.org,
	linux-s390@...r.kernel.org,
	linuxppc-dev@...ts.ozlabs.org,
	sparclinux@...r.kernel.org,
	x86@...nel.org
Subject: [PATCH v2 02/12] x86: pgtable: Always use pte_free_kernel()

Page table pages are normally freed using the appropriate helper for
the given page table level. On x86, pud_free_pmd_page() and
pmd_free_pte_page() are an exception to the rule: they call
free_page() directly.

Constructor/destructor calls are about to be introduced for kernel
PTEs. To avoid missing dtor calls in those helpers, free the PTE
pages using pte_free_kernel() instead of free_page().

While at it also use pmd_free() instead of calling pagetable_dtor()
explicitly at the PMD level.

Signed-off-by: Kevin Brodsky <kevin.brodsky@....com>
---
 arch/x86/mm/pgtable.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c
index 7930f234c5f6..1dee9bdbeea5 100644
--- a/arch/x86/mm/pgtable.c
+++ b/arch/x86/mm/pgtable.c
@@ -809,14 +809,13 @@ int pud_free_pmd_page(pud_t *pud, unsigned long addr)
 	for (i = 0; i < PTRS_PER_PMD; i++) {
 		if (!pmd_none(pmd_sv[i])) {
 			pte = (pte_t *)pmd_page_vaddr(pmd_sv[i]);
-			free_page((unsigned long)pte);
+			pte_free_kernel(&init_mm, pte);
 		}
 	}
 
 	free_page((unsigned long)pmd_sv);
 
-	pagetable_dtor(virt_to_ptdesc(pmd));
-	free_page((unsigned long)pmd);
+	pmd_free(&init_mm, pmd);
 
 	return 1;
 }
@@ -839,7 +838,7 @@ int pmd_free_pte_page(pmd_t *pmd, unsigned long addr)
 	/* INVLPG to clear all paging-structure caches */
 	flush_tlb_kernel_range(addr, addr + PAGE_SIZE-1);
 
-	free_page((unsigned long)pte);
+	pte_free_kernel(&init_mm, pte);
 
 	return 1;
 }
-- 
2.47.0