2019-10-16 12:16:12

by Greentime Hu

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

From: Greentime Hu <[email protected]>

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 <[email protected]>
---
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


2019-10-16 12:40:49

by Anup Patel

[permalink] [raw]
Subject: Re: [PATCH] RISC-V: fix virtual address overlapped in FIXADDR_START and VMEMMAP_START

On Wed, Oct 16, 2019 at 1:04 PM <[email protected]> wrote:
>
> From: Greentime Hu <[email protected]>
>
> 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 <[email protected]>
> ---
> 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
>

Looks good to me.

Reviewed-by: Anup Patel <[email protected]>

Regards,
Anup

2019-10-16 12:45:16

by Andreas Schwab

[permalink] [raw]
Subject: Re: [PATCH] RISC-V: fix virtual address overlapped in FIXADDR_START and VMEMMAP_START

On Okt 16 2019, [email protected] wrote:

> From: Greentime Hu <[email protected]>
>
> 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.

s/be existed/exist/
s/be overlapped/overlap/

Andreas.

--
Andreas Schwab, SUSE Labs, [email protected]
GPG Key fingerprint = 0196 BAD8 1CE9 1970 F4BE 1748 E4D4 88E3 0EEA B9D7
"And now for something completely different."

2019-10-16 17:07:26

by Paul Walmsley

[permalink] [raw]
Subject: Re: [PATCH] RISC-V: fix virtual address overlapped in FIXADDR_START and VMEMMAP_START

On Wed, 16 Oct 2019, [email protected] wrote:

> From: Greentime Hu <[email protected]>
>
> 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 <[email protected]>

Thanks, here's what's been queued for v5.4-rc.


- Paul

From: Greentime Hu <[email protected]>
Date: Tue, 8 Oct 2019 14:45:24 +0800
Subject: [PATCH] RISC-V: fix virtual address overlapped in FIXADDR_START and
VMEMMAP_START

This patch fixes the virtual address layout in pgtable.h. The virtual
address of FIXADDR_START and VMEMMAP_START should not be overlapped.

Fixes: d95f1a542c3d ("RISC-V: Implement sparsemem")
Signed-off-by: Greentime Hu <[email protected]>
Reviewed-by: Anup Patel <[email protected]>
[[email protected]: fixed patch description]
Signed-off-by: Paul Walmsley <[email protected]>
---
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 7255f2d8395b..42292d99cc74 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.
--
2.23.0