linux-kernel - Re: [PATCH v4 7/7] mm/mm_init: Use for_each_valid_pfn() in init_unavailable

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: <20250425163813.58b72a3aa2d3ebbd96d1929e@linux-foundation.org>
Date: Fri, 25 Apr 2025 16:38:13 -0700
From: Andrew Morton <akpm@...ux-foundation.org>
To: Lorenzo Stoakes <lorenzo.stoakes@...cle.com>
Cc: David Woodhouse <dwmw2@...radead.org>, Mike Rapoport <rppt@...nel.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: Re: [PATCH v4 7/7] mm/mm_init: Use for_each_valid_pfn() in
 init_unavailable_range()

On Fri, 25 Apr 2025 17:11:10 +0100 Lorenzo Stoakes <lorenzo.stoakes@...cle.com> wrote:

> Andrew - can we drop this from mm-new? It's breaking it.

I almost did, but David seems to have a fix.

--- a/include/linux/mmzone.h~mm-mm_init-use-for_each_valid_pfn-in-init_unavailable_range-fix
+++ a/include/linux/mmzone.h
@@ -2190,10 +2190,10 @@ static inline unsigned long next_valid_p
 	/*
 	 * Either every PFN within the section (or subsection for VMEMMAP) is
 	 * valid, or none of them are. So there's no point repeating the check
-	 * for every PFN; only call first_valid_pfn() the first time, and when
-	 * crossing a (sub)section boundary (i.e. !(pfn & ~PFN_VALID_MASK)).
+	 * for every PFN; only call first_valid_pfn() again when crossing a
+	 * (sub)section boundary (i.e. !(pfn & ~PAGE_{SUB,}SECTION_MASK)).
 	 */
-	if (pfn & (IS_ENABLED(CONFIG_SPARSEMEM_VMEMMAP) ?
+	if (pfn & ~(IS_ENABLED(CONFIG_SPARSEMEM_VMEMMAP) ?
 		   PAGE_SUBSECTION_MASK : PAGE_SECTION_MASK))
 		return pfn;
 
_