linux-kernel - [PATCH v4 5/7] mm, x86: Use for_each_valid_pfn() from __ioremap_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-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250423133821.789413-6-dwmw2@infradead.org>
Date: Wed, 23 Apr 2025 14:33:41 +0100
From: David Woodhouse <dwmw2@...radead.org>
To: Mike Rapoport <rppt@...nel.org>
Cc: Andrew Morton <akpm@...ux-foundation.org>,
	"Sauerwein, David" <dssauerw@...zon.de>,
	Anshuman Khandual <anshuman.khandual@....com>,
	Ard Biesheuvel <ardb@...nel.org>,
	Catalin Marinas <catalin.marinas@....com>,
	David Hildenbrand <david@...hat.com>,
	Marc Zyngier <maz@...nel.org>,
	Mark Rutland <mark.rutland@....com>,
	Mike Rapoport <rppt@...ux.ibm.com>,
	Will Deacon <will@...nel.org>,
	linux-arm-kernel@...ts.infradead.org,
	linux-kernel@...r.kernel.org,
	linux-mm@...ck.org,
	Ruihan Li <lrh2000@....edu.cn>
Subject: [PATCH v4 5/7] mm, x86: Use for_each_valid_pfn() from __ioremap_check_ram()

From: David Woodhouse <dwmw@...zon.co.uk>

Instead of calling pfn_valid() separately for every single PFN in the
range, use for_each_valid_pfn() and only look at the ones which are.

Signed-off-by: David Woodhouse <dwmw@...zon.co.uk>
Acked-by: Mike Rapoport (Microsoft) <rppt@...nel.org>
---
 arch/x86/mm/ioremap.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index 331e101bf801..12c8180ca1ba 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -71,7 +71,7 @@ int ioremap_change_attr(unsigned long vaddr, unsigned long size,
 static unsigned int __ioremap_check_ram(struct resource *res)
 {
 	unsigned long start_pfn, stop_pfn;
-	unsigned long i;
+	unsigned long pfn;
 
 	if ((res->flags & IORESOURCE_SYSTEM_RAM) != IORESOURCE_SYSTEM_RAM)
 		return 0;
@@ -79,9 +79,8 @@ static unsigned int __ioremap_check_ram(struct resource *res)
 	start_pfn = (res->start + PAGE_SIZE - 1) >> PAGE_SHIFT;
 	stop_pfn = (res->end + 1) >> PAGE_SHIFT;
 	if (stop_pfn > start_pfn) {
-		for (i = 0; i < (stop_pfn - start_pfn); ++i)
-			if (pfn_valid(start_pfn + i) &&
-			    !PageReserved(pfn_to_page(start_pfn + i)))
+		for_each_valid_pfn(pfn, start_pfn, stop_pfn)
+			if (!PageReserved(pfn_to_page(pfn)))
 				return IORES_MAP_SYSTEM_RAM;
 	}
 
-- 
2.49.0