patches/old/x86-remove-custom-definition-of-mk_pte.patch

From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Subject: x86: remove custom definition of mk_pte()
Date: Wed, 2 Apr 2025 19:16:58 +0100

Move the shadow stack check to pfn_pte() which lets us use the common
definition of mk_pte().

Link: https://lkml.kernel.org/r/20250402181709.2386022-5-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Richard Weinberger <richard@nod.at>
Cc: <x86@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 arch/x86/include/asm/pgtable.h |   19 +++----------------
 1 file changed, 3 insertions(+), 16 deletions(-)

--- a/arch/x86/include/asm/pgtable.h~x86-remove-custom-definition-of-mk_pte
+++ a/arch/x86/include/asm/pgtable.h
@@ -784,6 +784,9 @@ static inline pgprotval_t check_pgprot(p
 static inline pte_t pfn_pte(unsigned long page_nr, pgprot_t pgprot)
 {
 	phys_addr_t pfn = (phys_addr_t)page_nr << PAGE_SHIFT;
+	/* This bit combination is used to mark shadow stacks */
+	WARN_ON_ONCE((pgprot_val(pgprot) & (_PAGE_DIRTY | _PAGE_RW)) ==
+			_PAGE_DIRTY);
 	pfn ^= protnone_mask(pgprot_val(pgprot));
 	pfn &= PTE_PFN_MASK;
 	return __pte(pfn | check_pgprot(pgprot));
@@ -1080,22 +1083,6 @@ static inline unsigned long pmd_page_vad
  */
 #define pmd_page(pmd)	pfn_to_page(pmd_pfn(pmd))
 
-/*
- * Conversion functions: convert a page and protection to a page entry,
- * and a page entry and page directory to the page they refer to.
- *
- * (Currently stuck as a macro because of indirect forward reference
- * to linux/mm.h:page_to_nid())
- */
-#define mk_pte(page, pgprot)						  \
-({									  \
-	pgprot_t __pgprot = pgprot;					  \
-									  \
-	WARN_ON_ONCE((pgprot_val(__pgprot) & (_PAGE_DIRTY | _PAGE_RW)) == \
-		    _PAGE_DIRTY);					  \
-	pfn_pte(page_to_pfn(page), __pgprot);				  \
-})
-
 static inline int pmd_bad(pmd_t pmd)
 {
 	return (pmd_flags(pmd) & ~(_PAGE_USER | _PAGE_ACCESSED)) !=
_