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-rw-r--r--arch/riscv/include/asm/kasan.h22
1 files changed, 19 insertions, 3 deletions
diff --git a/arch/riscv/include/asm/kasan.h b/arch/riscv/include/asm/kasan.h
index b04028c6218c..a2b3d9cdbc86 100644
--- a/arch/riscv/include/asm/kasan.h
+++ b/arch/riscv/include/asm/kasan.h
@@ -8,12 +8,28 @@
#ifdef CONFIG_KASAN
+/*
+ * The following comment was copied from arm64:
+ * KASAN_SHADOW_START: beginning of the kernel virtual addresses.
+ * KASAN_SHADOW_END: KASAN_SHADOW_START + 1/N of kernel virtual addresses,
+ * where N = (1 << KASAN_SHADOW_SCALE_SHIFT).
+ *
+ * KASAN_SHADOW_OFFSET:
+ * This value is used to map an address to the corresponding shadow
+ * address by the following formula:
+ * shadow_addr = (address >> KASAN_SHADOW_SCALE_SHIFT) + KASAN_SHADOW_OFFSET
+ *
+ * (1 << (64 - KASAN_SHADOW_SCALE_SHIFT)) shadow addresses that lie in range
+ * [KASAN_SHADOW_OFFSET, KASAN_SHADOW_END) cover all 64-bits of virtual
+ * addresses. So KASAN_SHADOW_OFFSET should satisfy the following equation:
+ * KASAN_SHADOW_OFFSET = KASAN_SHADOW_END -
+ * (1ULL << (64 - KASAN_SHADOW_SCALE_SHIFT))
+ */
#define KASAN_SHADOW_SCALE_SHIFT 3
-#define KASAN_SHADOW_SIZE (UL(1) << (38 - KASAN_SHADOW_SCALE_SHIFT))
-#define KASAN_SHADOW_START KERN_VIRT_START /* 2^64 - 2^38 */
+#define KASAN_SHADOW_SIZE (UL(1) << ((CONFIG_VA_BITS - 1) - KASAN_SHADOW_SCALE_SHIFT))
+#define KASAN_SHADOW_START KERN_VIRT_START
#define KASAN_SHADOW_END (KASAN_SHADOW_START + KASAN_SHADOW_SIZE)
-
#define KASAN_SHADOW_OFFSET (KASAN_SHADOW_END - (1ULL << \
(64 - KASAN_SHADOW_SCALE_SHIFT)))