linux-kernel - [PATCH v4 05/13] mm/arch: Provide pud

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: <20240327152332.950956-6-peterx@redhat.com>
Date: Wed, 27 Mar 2024 11:23:24 -0400
From: peterx@...hat.com
To: linux-mm@...ck.org,
	linux-kernel@...r.kernel.org
Cc: Yang Shi <shy828301@...il.com>,
	"Kirill A . Shutemov" <kirill@...temov.name>,
	Mike Kravetz <mike.kravetz@...cle.com>,
	John Hubbard <jhubbard@...dia.com>,
	Michael Ellerman <mpe@...erman.id.au>,
	peterx@...hat.com,
	Andrew Jones <andrew.jones@...ux.dev>,
	Muchun Song <muchun.song@...ux.dev>,
	linux-riscv@...ts.infradead.org,
	linuxppc-dev@...ts.ozlabs.org,
	Christophe Leroy <christophe.leroy@...roup.eu>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Christoph Hellwig <hch@...radead.org>,
	Lorenzo Stoakes <lstoakes@...il.com>,
	Matthew Wilcox <willy@...radead.org>,
	Rik van Riel <riel@...riel.com>,
	linux-arm-kernel@...ts.infradead.org,
	Andrea Arcangeli <aarcange@...hat.com>,
	David Hildenbrand <david@...hat.com>,
	"Aneesh Kumar K . V" <aneesh.kumar@...nel.org>,
	Vlastimil Babka <vbabka@...e.cz>,
	James Houghton <jthoughton@...gle.com>,
	Jason Gunthorpe <jgg@...dia.com>,
	Mike Rapoport <rppt@...nel.org>,
	Axel Rasmussen <axelrasmussen@...gle.com>
Subject: [PATCH v4 05/13] mm/arch: Provide pud_pfn() fallback

From: Peter Xu <peterx@...hat.com>

The comment in the code explains the reasons.  We took a different approach
comparing to pmd_pfn() by providing a fallback function.

Another option is to provide some lower level config options (compare to
HUGETLB_PAGE or THP) to identify which layer an arch can support for such
huge mappings.  However that can be an overkill.

Cc: Mike Rapoport (IBM) <rppt@...nel.org>
Cc: Matthew Wilcox <willy@...radead.org>
Reviewed-by: Jason Gunthorpe <jgg@...dia.com>
Signed-off-by: Peter Xu <peterx@...hat.com>
---
 arch/riscv/include/asm/pgtable.h    |  1 +
 arch/s390/include/asm/pgtable.h     |  1 +
 arch/sparc/include/asm/pgtable_64.h |  1 +
 arch/x86/include/asm/pgtable.h      |  1 +
 include/linux/pgtable.h             | 10 ++++++++++
 5 files changed, 14 insertions(+)

diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index 20242402fc11..0ca28cc8e3fa 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -646,6 +646,7 @@ static inline unsigned long pmd_pfn(pmd_t pmd)
 
 #define __pud_to_phys(pud)  (__page_val_to_pfn(pud_val(pud)) << PAGE_SHIFT)
 
+#define pud_pfn pud_pfn
 static inline unsigned long pud_pfn(pud_t pud)
 {
 	return ((__pud_to_phys(pud) & PUD_MASK) >> PAGE_SHIFT);
diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
index 1a71cb19c089..6cbbe473f680 100644
--- a/arch/s390/include/asm/pgtable.h
+++ b/arch/s390/include/asm/pgtable.h
@@ -1414,6 +1414,7 @@ static inline unsigned long pud_deref(pud_t pud)
 	return (unsigned long)__va(pud_val(pud) & origin_mask);
 }
 
+#define pud_pfn pud_pfn
 static inline unsigned long pud_pfn(pud_t pud)
 {
 	return __pa(pud_deref(pud)) >> PAGE_SHIFT;
diff --git a/arch/sparc/include/asm/pgtable_64.h b/arch/sparc/include/asm/pgtable_64.h
index 4d1bafaba942..26efc9bb644a 100644
--- a/arch/sparc/include/asm/pgtable_64.h
+++ b/arch/sparc/include/asm/pgtable_64.h
@@ -875,6 +875,7 @@ static inline bool pud_leaf(pud_t pud)
 	return pte_val(pte) & _PAGE_PMD_HUGE;
 }
 
+#define pud_pfn pud_pfn
 static inline unsigned long pud_pfn(pud_t pud)
 {
 	pte_t pte = __pte(pud_val(pud));
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index cefc7a84f7a4..273f7557218c 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -234,6 +234,7 @@ static inline unsigned long pmd_pfn(pmd_t pmd)
 	return (pfn & pmd_pfn_mask(pmd)) >> PAGE_SHIFT;
 }
 
+#define pud_pfn pud_pfn
 static inline unsigned long pud_pfn(pud_t pud)
 {
 	phys_addr_t pfn = pud_val(pud);
diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
index 600e17d03659..75fe309a4e10 100644
--- a/include/linux/pgtable.h
+++ b/include/linux/pgtable.h
@@ -1817,6 +1817,16 @@ typedef unsigned int pgtbl_mod_mask;
 #define pte_leaf_size(x) PAGE_SIZE
 #endif
 
+/*
+ * We always define pmd_pfn for all archs as it's used in lots of generic
+ * code.  Now it happens too for pud_pfn (and can happen for larger
+ * mappings too in the future; we're not there yet).  Instead of defining
+ * it for all archs (like pmd_pfn), provide a fallback.
+ */
+#ifndef pud_pfn
+#define pud_pfn(x) ({ BUILD_BUG(); 0; })
+#endif
+
 /*
  * Some architectures have MMUs that are configurable or selectable at boot
  * time. These lead to variable PTRS_PER_x. For statically allocated arrays it
-- 
2.44.0