2021-04-29 15:11:31

by Geert Uytterhoeven

Subject: [PATCH] riscv: Consistify protect_kernel_linear_mapping_text_rodata() use

The various uses of protect_kernel_linear_mapping_text_rodata() are
not consistent:
- Its definition depends on "64BIT && !XIP_KERNEL",
- Its forward declaration depends on MMU,
- Its single caller depends on "STRICT_KERNEL_RWX && 64BIT && MMU &&
!XIP_KERNEL".

Fix this by settling on the dependencies of the caller, which can be
simplified as STRICT_KERNEL_RWX depends on "MMU && !XIP_KERNEL".
Provide a dummy definition, as the caller is protected by
"IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)" instead of "#ifdef
CONFIG_STRICT_KERNEL_RWX".

Signed-off-by: Geert Uytterhoeven <[email protected]>
---
Only tested on K210 (SiPeed MAIX BiT).
---
arch/riscv/include/asm/set_memory.h | 7 ++++++-
arch/riscv/kernel/setup.c | 2 --
arch/riscv/mm/init.c | 2 +-
3 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/arch/riscv/include/asm/set_memory.h b/arch/riscv/include/asm/set_memory.h
index a9c56776fa0e74d6..086f757e8ba3cc69 100644
--- a/arch/riscv/include/asm/set_memory.h
+++ b/arch/riscv/include/asm/set_memory.h
@@ -17,7 +17,6 @@ int set_memory_x(unsigned long addr, int numpages);
int set_memory_nx(unsigned long addr, int numpages);
int set_memory_rw_nx(unsigned long addr, int numpages);
void protect_kernel_text_data(void);
-void protect_kernel_linear_mapping_text_rodata(void);
#else
static inline int set_memory_ro(unsigned long addr, int numpages) { return 0; }
static inline int set_memory_rw(unsigned long addr, int numpages) { return 0; }
@@ -27,6 +26,12 @@ static inline void protect_kernel_text_data(void) {}
static inline int set_memory_rw_nx(unsigned long addr, int numpages) { return 0; }
#endif

+#if defined(CONFIG_64BIT) && defined(CONFIG_STRICT_KERNEL_RWX)
+void protect_kernel_linear_mapping_text_rodata(void);
+#else
+static inline void protect_kernel_linear_mapping_text_rodata(void) {}
+#endif
+
int set_direct_map_invalid_noflush(struct page *page);
int set_direct_map_default_noflush(struct page *page);
bool kernel_page_present(struct page *page);
diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
index 7b31779101f662e4..03901d3a8b027343 100644
--- a/arch/riscv/kernel/setup.c
+++ b/arch/riscv/kernel/setup.c
@@ -293,9 +293,7 @@ void __init setup_arch(char **cmdline_p)

if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)) {
protect_kernel_text_data();
-#if defined(CONFIG_64BIT) && defined(CONFIG_MMU) && !defined(CONFIG_XIP_KERNEL)
protect_kernel_linear_mapping_text_rodata();
-#endif
}

#ifdef CONFIG_SWIOTLB
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index 3ebc0f5d2b73b42b..6cc0421a5d0ef4a3 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -646,7 +646,7 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa)
#endif
}

-#if defined(CONFIG_64BIT) && !defined(CONFIG_XIP_KERNEL)
+#if defined(CONFIG_64BIT) && defined(CONFIG_STRICT_KERNEL_RWX)
void protect_kernel_linear_mapping_text_rodata(void)
{
unsigned long text_start = (unsigned long)lm_alias(_start);
--
2.25.1

2021-05-02 14:11:33

by Alexandre Ghiti

Subject: Re: [PATCH] riscv: Consistify protect_kernel_linear_mapping_text_rodata() use

Le 4/29/21 ? 11:10 AM, Geert Uytterhoeven a ?crit?:
> The various uses of protect_kernel_linear_mapping_text_rodata() are
> not consistent:
> - Its definition depends on "64BIT && !XIP_KERNEL",
> - Its forward declaration depends on MMU,
> - Its single caller depends on "STRICT_KERNEL_RWX && 64BIT && MMU &&
> !XIP_KERNEL".
>
> Fix this by settling on the dependencies of the caller, which can be
> simplified as STRICT_KERNEL_RWX depends on "MMU && !XIP_KERNEL".
> Provide a dummy definition, as the caller is protected by
> "IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)" instead of "#ifdef
> CONFIG_STRICT_KERNEL_RWX".
>
> Signed-off-by: Geert Uytterhoeven <[email protected]>
> ---
> Only tested on K210 (SiPeed MAIX BiT).
> ---
> arch/riscv/include/asm/set_memory.h | 7 ++++++-
> arch/riscv/kernel/setup.c | 2 --
> arch/riscv/mm/init.c | 2 +-
> 3 files changed, 7 insertions(+), 4 deletions(-)
>
> diff --git a/arch/riscv/include/asm/set_memory.h b/arch/riscv/include/asm/set_memory.h
> index a9c56776fa0e74d6..086f757e8ba3cc69 100644
> --- a/arch/riscv/include/asm/set_memory.h
> +++ b/arch/riscv/include/asm/set_memory.h
> @@ -17,7 +17,6 @@ int set_memory_x(unsigned long addr, int numpages);
> int set_memory_nx(unsigned long addr, int numpages);
> int set_memory_rw_nx(unsigned long addr, int numpages);
> void protect_kernel_text_data(void);
> -void protect_kernel_linear_mapping_text_rodata(void);
> #else
> static inline int set_memory_ro(unsigned long addr, int numpages) { return 0; }
> static inline int set_memory_rw(unsigned long addr, int numpages) { return 0; }
> @@ -27,6 +26,12 @@ static inline void protect_kernel_text_data(void) {}
> static inline int set_memory_rw_nx(unsigned long addr, int numpages) { return 0; }
> #endif
>
> +#if defined(CONFIG_64BIT) && defined(CONFIG_STRICT_KERNEL_RWX)
> +void protect_kernel_linear_mapping_text_rodata(void);
> +#else
> +static inline void protect_kernel_linear_mapping_text_rodata(void) {}
> +#endif
> +
> int set_direct_map_invalid_noflush(struct page *page);
> int set_direct_map_default_noflush(struct page *page);
> bool kernel_page_present(struct page *page);
> diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
> index 7b31779101f662e4..03901d3a8b027343 100644
> --- a/arch/riscv/kernel/setup.c
> +++ b/arch/riscv/kernel/setup.c
> @@ -293,9 +293,7 @@ void __init setup_arch(char **cmdline_p)
>
> if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)) {
> protect_kernel_text_data();
> -#if defined(CONFIG_64BIT) && defined(CONFIG_MMU) && !defined(CONFIG_XIP_KERNEL)
> protect_kernel_linear_mapping_text_rodata();
> -#endif
> }
>
> #ifdef CONFIG_SWIOTLB
> diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
> index 3ebc0f5d2b73b42b..6cc0421a5d0ef4a3 100644
> --- a/arch/riscv/mm/init.c
> +++ b/arch/riscv/mm/init.c
> @@ -646,7 +646,7 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa)
> #endif
> }
>
> -#if defined(CONFIG_64BIT) && !defined(CONFIG_XIP_KERNEL)
> +#if defined(CONFIG_64BIT) && defined(CONFIG_STRICT_KERNEL_RWX)
> void protect_kernel_linear_mapping_text_rodata(void)
> {
> unsigned long text_start = (unsigned long)lm_alias(_start);
>

I tested this on the following configs:

- rv32_defconfig (build and valid on qemu)
- defconfig (with and without CONFIG_STRICT_KERNEL_RWX) (build and valid
on qemu)
- xip kernel (build and valid on qemu)
- nommu_k210_defconfig (build only)

so you can add:

Tested-by: Alexandre Ghiti <[email protected]>

Thank you for the cleanup!

Alex

2021-05-06 09:19:21

by Palmer Dabbelt

Subject: Re: [PATCH] riscv: Consistify protect_kernel_linear_mapping_text_rodata() use

On Thu, 29 Apr 2021 08:10:04 PDT (-0700), [email protected] wrote:
> The various uses of protect_kernel_linear_mapping_text_rodata() are
> not consistent:
> - Its definition depends on "64BIT && !XIP_KERNEL",
> - Its forward declaration depends on MMU,
> - Its single caller depends on "STRICT_KERNEL_RWX && 64BIT && MMU &&
> !XIP_KERNEL".
>
> Fix this by settling on the dependencies of the caller, which can be
> simplified as STRICT_KERNEL_RWX depends on "MMU && !XIP_KERNEL".
> Provide a dummy definition, as the caller is protected by
> "IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)" instead of "#ifdef
> CONFIG_STRICT_KERNEL_RWX".
>
> Signed-off-by: Geert Uytterhoeven <[email protected]>
> ---
> Only tested on K210 (SiPeed MAIX BiT).
> ---
> arch/riscv/include/asm/set_memory.h | 7 ++++++-
> arch/riscv/kernel/setup.c | 2 --
> arch/riscv/mm/init.c | 2 +-
> 3 files changed, 7 insertions(+), 4 deletions(-)
>
> diff --git a/arch/riscv/include/asm/set_memory.h b/arch/riscv/include/asm/set_memory.h
> index a9c56776fa0e74d6..086f757e8ba3cc69 100644
> --- a/arch/riscv/include/asm/set_memory.h
> +++ b/arch/riscv/include/asm/set_memory.h
> @@ -17,7 +17,6 @@ int set_memory_x(unsigned long addr, int numpages);
> int set_memory_nx(unsigned long addr, int numpages);
> int set_memory_rw_nx(unsigned long addr, int numpages);
> void protect_kernel_text_data(void);
> -void protect_kernel_linear_mapping_text_rodata(void);
> #else
> static inline int set_memory_ro(unsigned long addr, int numpages) { return 0; }
> static inline int set_memory_rw(unsigned long addr, int numpages) { return 0; }
> @@ -27,6 +26,12 @@ static inline void protect_kernel_text_data(void) {}
> static inline int set_memory_rw_nx(unsigned long addr, int numpages) { return 0; }
> #endif
>
> +#if defined(CONFIG_64BIT) && defined(CONFIG_STRICT_KERNEL_RWX)
> +void protect_kernel_linear_mapping_text_rodata(void);
> +#else
> +static inline void protect_kernel_linear_mapping_text_rodata(void) {}
> +#endif
> +
> int set_direct_map_invalid_noflush(struct page *page);
> int set_direct_map_default_noflush(struct page *page);
> bool kernel_page_present(struct page *page);
> diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
> index 7b31779101f662e4..03901d3a8b027343 100644
> --- a/arch/riscv/kernel/setup.c
> +++ b/arch/riscv/kernel/setup.c
> @@ -293,9 +293,7 @@ void __init setup_arch(char **cmdline_p)
>
> if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)) {
> protect_kernel_text_data();
> -#if defined(CONFIG_64BIT) && defined(CONFIG_MMU) && !defined(CONFIG_XIP_KERNEL)
> protect_kernel_linear_mapping_text_rodata();
> -#endif
> }
>
> #ifdef CONFIG_SWIOTLB
> diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
> index 3ebc0f5d2b73b42b..6cc0421a5d0ef4a3 100644
> --- a/arch/riscv/mm/init.c
> +++ b/arch/riscv/mm/init.c
> @@ -646,7 +646,7 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa)
> #endif
> }
>
> -#if defined(CONFIG_64BIT) && !defined(CONFIG_XIP_KERNEL)
> +#if defined(CONFIG_64BIT) && defined(CONFIG_STRICT_KERNEL_RWX)
> void protect_kernel_linear_mapping_text_rodata(void)
> {
> unsigned long text_start = (unsigned long)lm_alias(_start);

Thanks, this is on for-next.