From 7211aab2881b0a8b6a002ec2eb341b2d3cb9f003 Mon Sep 17 00:00:00 2001
From: Alexandre Ghiti <alexandre.ghiti@canonical.com>
Date: Fri, 25 Feb 2022 13:39:49 +0100
Subject: [PATCH] riscv: Fix config KASAN && SPARSEMEM && !SPARSE_VMEMMAP
commit a3d328037846d013bb4c7f3777241e190e4c75e1 upstream.
In order to get the pfn of a struct page* when sparsemem is enabled
without vmemmap, the mem_section structures need to be initialized which
happens in sparse_init.
But kasan_early_init calls pfn_to_page way before sparse_init is called,
which then tries to dereference a null mem_section pointer.
Fix this by removing the usage of this function in kasan_early_init.
Fixes: 8ad8b72721d0 ("riscv: Add KASAN support")
Signed-off-by: Alexandre Ghiti <alexandre.ghiti@canonical.com>
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/riscv/mm/kasan_init.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/arch/riscv/mm/kasan_init.c b/arch/riscv/mm/kasan_init.c
index 883c3be43ea98..2db442701ee28 100644
--- a/arch/riscv/mm/kasan_init.c
+++ b/arch/riscv/mm/kasan_init.c
@@ -21,8 +21,7 @@ asmlinkage void __init kasan_early_init(void)
for (i = 0; i < PTRS_PER_PTE; ++i)
set_pte(kasan_early_shadow_pte + i,
- mk_pte(virt_to_page(kasan_early_shadow_page),
- PAGE_KERNEL));
+ pfn_pte(virt_to_pfn(kasan_early_shadow_page), PAGE_KERNEL));
for (i = 0; i < PTRS_PER_PMD; ++i)
set_pmd(kasan_early_shadow_pmd + i,
--
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