[PATCH 5.15 052/124] arm64: mm: fix p?d_leaf()

Greg Kroah-Hartman
2022-04-26T09:07:53Z

From: Muchun Song <songmuchun@bytedance.com>

[ Upstream commit 23bc8f69f0eceecbb87c3801d2e48827d2dca92b ]

The pmd_leaf() is used to test a leaf mapped PMD, however, it misses
the PROT_NONE mapped PMD on arm64. Fix it. A real world issue [1]
caused by this was reported by Qian Cai. Also fix pud_leaf().

Link: https://patchwork.kernel.org/comment/24798260/ [1]
Fixes: 8aa82df3c123 ("arm64: mm: add p?d_leaf() definitions")
Reported-by: Qian Cai <quic_qiancai@quicinc.com>
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Link: https://lore.kernel.org/r/20220422060033.48711-1-songmuchun@bytedance.com
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/arm64/include/asm/pgtable.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 08363d3cc1da..ed57717cd004 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -535,7 +535,7 @@ extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
PMD_TYPE_TABLE)
#define pmd_sect(pmd) ((pmd_val(pmd) & PMD_TYPE_MASK) == \
PMD_TYPE_SECT)
-#define pmd_leaf(pmd) pmd_sect(pmd)
+#define pmd_leaf(pmd) (pmd_present(pmd) && !pmd_table(pmd))
#define pmd_bad(pmd) (!pmd_table(pmd))

#define pmd_leaf_size(pmd) (pmd_cont(pmd) ? CONT_PMD_SIZE : PMD_SIZE)
@@ -625,7 +625,7 @@ static inline unsigned long pmd_page_vaddr(pmd_t pmd)
#define pud_none(pud) (!pud_val(pud))
#define pud_bad(pud) (!pud_table(pud))
#define pud_present(pud) pte_present(pud_pte(pud))
-#define pud_leaf(pud) pud_sect(pud)
+#define pud_leaf(pud) (pud_present(pud) && !pud_table(pud))
#define pud_valid(pud) pte_valid(pud_pte(pud))

static inline void set_pud(pud_t *pudp, pud_t pud)
--
2.35.1