linux-kernel - [PATCH] arm64/mm: Drop use_1G

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: <1644988012-25455-1-git-send-email-anshuman.khandual@arm.com>
Date:   Wed, 16 Feb 2022 10:36:52 +0530
From:   Anshuman Khandual <anshuman.khandual@....com>
To:     linux-arm-kernel@...ts.infradead.org
Cc:     Anshuman Khandual <anshuman.khandual@....com>,
        Catalin Marinas <catalin.marinas@....com>,
        Will Deacon <will@...nel.org>, linux-kernel@...r.kernel.org
Subject: [PATCH] arm64/mm: Drop use_1G_block()

pud_sect_supported() already checks for PUD level block mapping support i.e
on ARM64_4K_PAGES config. Hence pud_sect_supported(), along with some other
required alignment checks can help completely drop use_1G_block().

Cc: Catalin Marinas <catalin.marinas@....com>
Cc: Will Deacon <will@...nel.org>
Cc: linux-arm-kernel@...ts.infradead.org
Cc: linux-kernel@...r.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@....com>
---
This applies on v5.17-rc4

 arch/arm64/mm/mmu.c | 15 ++-------------
 1 file changed, 2 insertions(+), 13 deletions(-)

diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index acfae9b41cc8..5a7954c9e6ec 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -294,18 +294,6 @@ static void alloc_init_cont_pmd(pud_t *pudp, unsigned long addr,
 	} while (addr = next, addr != end);
 }
 
-static inline bool use_1G_block(unsigned long addr, unsigned long next,
-			unsigned long phys)
-{
-	if (PAGE_SHIFT != 12)
-		return false;
-
-	if (((addr | next | phys) & ~PUD_MASK) != 0)
-		return false;
-
-	return true;
-}
-
 static void alloc_init_pud(pgd_t *pgdp, unsigned long addr, unsigned long end,
 			   phys_addr_t phys, pgprot_t prot,
 			   phys_addr_t (*pgtable_alloc)(int),
@@ -338,7 +326,8 @@ static void alloc_init_pud(pgd_t *pgdp, unsigned long addr, unsigned long end,
 		/*
 		 * For 4K granule only, attempt to put down a 1GB block
 		 */
-		if (use_1G_block(addr, next, phys) &&
+		if (pud_sect_supported() &&
+		   ((addr | next | phys) & ~PUD_MASK) == 0 &&
 		    (flags & NO_BLOCK_MAPPINGS) == 0) {
 			pud_set_huge(pudp, phys, prot);
 
-- 
2.20.1