linux-kernel - [PATCH v2 16/46] hugetlb: make default arch_make_huge

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: <20230218002819.1486479-17-jthoughton@google.com>
Date:   Sat, 18 Feb 2023 00:27:49 +0000
From:   James Houghton <jthoughton@...gle.com>
To:     Mike Kravetz <mike.kravetz@...cle.com>,
        Muchun Song <songmuchun@...edance.com>,
        Peter Xu <peterx@...hat.com>,
        Andrew Morton <akpm@...ux-foundation.org>
Cc:     David Hildenbrand <david@...hat.com>,
        David Rientjes <rientjes@...gle.com>,
        Axel Rasmussen <axelrasmussen@...gle.com>,
        Mina Almasry <almasrymina@...gle.com>,
        "Zach O'Keefe" <zokeefe@...gle.com>,
        Manish Mishra <manish.mishra@...anix.com>,
        Naoya Horiguchi <naoya.horiguchi@....com>,
        "Dr . David Alan Gilbert" <dgilbert@...hat.com>,
        "Matthew Wilcox (Oracle)" <willy@...radead.org>,
        Vlastimil Babka <vbabka@...e.cz>,
        Baolin Wang <baolin.wang@...ux.alibaba.com>,
        Miaohe Lin <linmiaohe@...wei.com>,
        Yang Shi <shy828301@...il.com>,
        Frank van der Linden <fvdl@...gle.com>,
        Jiaqi Yan <jiaqiyan@...gle.com>, linux-mm@...ck.org,
        linux-kernel@...r.kernel.org,
        James Houghton <jthoughton@...gle.com>
Subject: [PATCH v2 16/46] hugetlb: make default arch_make_huge_pte understand
 small mappings

This is a simple change: don't create a "huge" PTE if we are making a
regular, PAGE_SIZE PTE. All architectures that want to implement HGM
likely need to be changed in a similar way if they implement their own
version of arch_make_huge_pte.

Signed-off-by: James Houghton <jthoughton@...gle.com>

diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 726d581158b1..b767b6889dea 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -899,7 +899,7 @@ static inline void arch_clear_hugepage_flags(struct page *page) { }
 static inline pte_t arch_make_huge_pte(pte_t entry, unsigned int shift,
 				       vm_flags_t flags)
 {
-	return pte_mkhuge(entry);
+	return shift > PAGE_SHIFT ? pte_mkhuge(entry) : entry;
 }
 #endif
 
-- 
2.39.2.637.g21b0678d19-goog