[PATCH] RISC-V: fix virtual address overlapped in FIXADDR_START and VMEMMAP_START

greentime.hu
2019-10-16T07:34:21Z

From: Greentime Hu <greentime.hu@sifive.com>

This patch fixes the virtual address layout in pgtable.h.
The virtual address of FIXADDR_START and VMEMMAP_START should not be overlapped.
These addresses will be existed at the same time in Linux kernel that they can't
be overlapped.

Fixes: d95f1a542c3d ("RISC-V: Implement sparsemem")
Signed-off-by: Greentime Hu <greentime.hu@sifive.com>
---
arch/riscv/include/asm/pgtable.h | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index 4f4162d90586..b927fb4ecf1c 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -87,14 +87,6 @@ extern pgd_t swapper_pg_dir[];
#define VMALLOC_END (PAGE_OFFSET - 1)
#define VMALLOC_START (PAGE_OFFSET - VMALLOC_SIZE)

-#define FIXADDR_TOP VMALLOC_START
-#ifdef CONFIG_64BIT
-#define FIXADDR_SIZE PMD_SIZE
-#else
-#define FIXADDR_SIZE PGDIR_SIZE
-#endif
-#define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE)
-
/*
* Roughly size the vmemmap space to be large enough to fit enough
* struct pages to map half the virtual address space. Then
@@ -108,6 +100,14 @@ extern pgd_t swapper_pg_dir[];

#define vmemmap ((struct page *)VMEMMAP_START)

+#define FIXADDR_TOP (VMEMMAP_START)
+#ifdef CONFIG_64BIT
+#define FIXADDR_SIZE PMD_SIZE
+#else
+#define FIXADDR_SIZE PGDIR_SIZE
+#endif
+#define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE)
+
/*
* ZERO_PAGE is a global shared page that is always zero,
* used for zero-mapped memory areas, etc.
--
2.17.1