linux-kernel - [PATCH v3 06/10] mm/kasan: Use pXd_leaf() in shadow

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Message-ID: <20240305043750.93762-7-peterx@redhat.com>
Date: Tue,  5 Mar 2024 12:37:46 +0800
From: peterx@...hat.com
To: linux-mm@...ck.org,
	linux-kernel@...r.kernel.org
Cc: Christophe Leroy <christophe.leroy@...roup.eu>,
	x86@...nel.org,
	"Kirill A . Shutemov" <kirill@...temov.name>,
	Jason Gunthorpe <jgg@...dia.com>,
	Yang Shi <shy828301@...il.com>,
	peterx@...hat.com,
	Andrew Morton <akpm@...ux-foundation.org>,
	linuxppc-dev@...ts.ozlabs.org,
	Muchun Song <muchun.song@...ux.dev>,
	Andrey Ryabinin <ryabinin.a.a@...il.com>,
	Alexander Potapenko <glider@...gle.com>,
	Andrey Konovalov <andreyknvl@...il.com>,
	Dmitry Vyukov <dvyukov@...gle.com>,
	Vincenzo Frascino <vincenzo.frascino@....com>,
	kasan-dev@...glegroups.com
Subject: [PATCH v3 06/10] mm/kasan: Use pXd_leaf() in shadow_mapped()

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

There is an old trick in shadow_mapped() to use pXd_bad() to detect huge
pages.  After commit 93fab1b22ef7 ("mm: add generic p?d_leaf() macros") we
have a global API for huge mappings.  Use that to replace the trick.

Cc: Andrey Ryabinin <ryabinin.a.a@...il.com>
Cc: Alexander Potapenko <glider@...gle.com>
Cc: Andrey Konovalov <andreyknvl@...il.com>
Cc: Dmitry Vyukov <dvyukov@...gle.com>
Cc: Vincenzo Frascino <vincenzo.frascino@....com>
Cc: kasan-dev@...glegroups.com
Signed-off-by: Peter Xu <peterx@...hat.com>
---
 mm/kasan/shadow.c | 11 ++---------
 1 file changed, 2 insertions(+), 9 deletions(-)

diff --git a/mm/kasan/shadow.c b/mm/kasan/shadow.c
index 9ef84f31833f..d6210ca48dda 100644
--- a/mm/kasan/shadow.c
+++ b/mm/kasan/shadow.c
@@ -199,19 +199,12 @@ static bool shadow_mapped(unsigned long addr)
 	pud = pud_offset(p4d, addr);
 	if (pud_none(*pud))
 		return false;
-
-	/*
-	 * We can't use pud_large() or pud_huge(), the first one is
-	 * arch-specific, the last one depends on HUGETLB_PAGE.  So let's abuse
-	 * pud_bad(), if pud is bad then it's bad because it's huge.
-	 */
-	if (pud_bad(*pud))
+	if (pud_leaf(*pud))
 		return true;
 	pmd = pmd_offset(pud, addr);
 	if (pmd_none(*pmd))
 		return false;
-
-	if (pmd_bad(*pmd))
+	if (pmd_leaf(*pmd))
 		return true;
 	pte = pte_offset_kernel(pmd, addr);
 	return !pte_none(ptep_get(pte));
-- 
2.44.0