diff mbox series

[2/8] riscv: add ARCH_HAS_SET_DIRECT_MAP support

Message ID 20200217083223.2011-3-zong.li@sifive.com (mailing list archive)
State New, archived
Headers show
Series Support strict kernel memory permissions for security | expand

Commit Message

Zong Li Feb. 17, 2020, 8:32 a.m. UTC 
Add set_direct_map_*() functions for setting the direct map alias for
the page to its default permissions and to an invalid state that cannot
be cached in a TLB. (See d253ca0c ("x86/mm/cpa: Add set_direct_map_*()
functions")) Add a similar implementation for RISC-V.

Signed-off-by: Zong Li <zong.li@sifive.com>
---
 arch/riscv/Kconfig                  |  1 +
 arch/riscv/include/asm/set_memory.h |  3 +++
 arch/riscv/mm/pageattr.c            | 24 ++++++++++++++++++++++++
 3 files changed, 28 insertions(+)

Comments

Palmer Dabbelt March 5, 2020, 12:57 a.m. UTC | #1 
On Mon, 17 Feb 2020 00:32:17 PST (-0800), zong.li@sifive.com wrote:
> Add set_direct_map_*() functions for setting the direct map alias for
> the page to its default permissions and to an invalid state that cannot
> be cached in a TLB. (See d253ca0c ("x86/mm/cpa: Add set_direct_map_*()
> functions")) Add a similar implementation for RISC-V.
>
> Signed-off-by: Zong Li <zong.li@sifive.com>
> ---
>  arch/riscv/Kconfig                  |  1 +
>  arch/riscv/include/asm/set_memory.h |  3 +++
>  arch/riscv/mm/pageattr.c            | 24 ++++++++++++++++++++++++
>  3 files changed, 28 insertions(+)
>
> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
> index 76ed36543b3a..07bf1a7c0dd2 100644
> --- a/arch/riscv/Kconfig
> +++ b/arch/riscv/Kconfig
> @@ -60,6 +60,7 @@ config RISCV
>  	select HAVE_EBPF_JIT if 64BIT
>  	select EDAC_SUPPORT
>  	select ARCH_HAS_GIGANTIC_PAGE
> +	select ARCH_HAS_SET_DIRECT_MAP
>  	select ARCH_HAS_SET_MEMORY
>  	select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
>  	select SPARSEMEM_STATIC if 32BIT
> diff --git a/arch/riscv/include/asm/set_memory.h b/arch/riscv/include/asm/set_memory.h
> index 936f08063566..a9783a878dca 100644
> --- a/arch/riscv/include/asm/set_memory.h
> +++ b/arch/riscv/include/asm/set_memory.h
> @@ -14,4 +14,7 @@ int set_memory_rw(unsigned long addr, int numpages);
>  int set_memory_x(unsigned long addr, int numpages);
>  int set_memory_nx(unsigned long addr, int numpages);
>
> +int set_direct_map_invalid_noflush(struct page *page);
> +int set_direct_map_default_noflush(struct page *page);
> +
>  #endif /* _ASM_RISCV_SET_MEMORY_H */
> diff --git a/arch/riscv/mm/pageattr.c b/arch/riscv/mm/pageattr.c
> index fcd59ef2835b..7be6cd67e2ef 100644
> --- a/arch/riscv/mm/pageattr.c
> +++ b/arch/riscv/mm/pageattr.c
> @@ -148,3 +148,27 @@ int set_memory_nx(unsigned long addr, int numpages)
>  {
>  	return __set_memory(addr, numpages, __pgprot(0), __pgprot(_PAGE_EXEC));
>  }
> +
> +int set_direct_map_invalid_noflush(struct page *page)
> +{
> +	unsigned long start = (unsigned long)page_address(page);
> +	unsigned long end = start + PAGE_SIZE;
> +	struct pageattr_masks masks = {
> +		.set_mask = __pgprot(0),
> +		.clear_mask = __pgprot(_PAGE_PRESENT)
> +	};
> +
> +	return walk_page_range(&init_mm, start, end, &pageattr_ops, &masks);
> +}
> +
> +int set_direct_map_default_noflush(struct page *page)
> +{
> +	unsigned long start = (unsigned long)page_address(page);
> +	unsigned long end = start + PAGE_SIZE;
> +	struct pageattr_masks masks = {
> +		.set_mask = PAGE_KERNEL,
> +		.clear_mask = __pgprot(0)
> +	};
> +
> +	return walk_page_range(&init_mm, start, end, &pageattr_ops, &masks);
> +}

Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
diff mbox series

Patch

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 76ed36543b3a..07bf1a7c0dd2 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -60,6 +60,7 @@  config RISCV
 	select HAVE_EBPF_JIT if 64BIT
 	select EDAC_SUPPORT
 	select ARCH_HAS_GIGANTIC_PAGE
+	select ARCH_HAS_SET_DIRECT_MAP
 	select ARCH_HAS_SET_MEMORY
 	select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
 	select SPARSEMEM_STATIC if 32BIT
diff --git a/arch/riscv/include/asm/set_memory.h b/arch/riscv/include/asm/set_memory.h
index 936f08063566..a9783a878dca 100644
--- a/arch/riscv/include/asm/set_memory.h
+++ b/arch/riscv/include/asm/set_memory.h
@@ -14,4 +14,7 @@  int set_memory_rw(unsigned long addr, int numpages);
 int set_memory_x(unsigned long addr, int numpages);
 int set_memory_nx(unsigned long addr, int numpages);
 
+int set_direct_map_invalid_noflush(struct page *page);
+int set_direct_map_default_noflush(struct page *page);
+
 #endif /* _ASM_RISCV_SET_MEMORY_H */
diff --git a/arch/riscv/mm/pageattr.c b/arch/riscv/mm/pageattr.c
index fcd59ef2835b..7be6cd67e2ef 100644
--- a/arch/riscv/mm/pageattr.c
+++ b/arch/riscv/mm/pageattr.c
@@ -148,3 +148,27 @@  int set_memory_nx(unsigned long addr, int numpages)
 {
 	return __set_memory(addr, numpages, __pgprot(0), __pgprot(_PAGE_EXEC));
 }
+
+int set_direct_map_invalid_noflush(struct page *page)
+{
+	unsigned long start = (unsigned long)page_address(page);
+	unsigned long end = start + PAGE_SIZE;
+	struct pageattr_masks masks = {
+		.set_mask = __pgprot(0),
+		.clear_mask = __pgprot(_PAGE_PRESENT)
+	};
+
+	return walk_page_range(&init_mm, start, end, &pageattr_ops, &masks);
+}
+
+int set_direct_map_default_noflush(struct page *page)
+{
+	unsigned long start = (unsigned long)page_address(page);
+	unsigned long end = start + PAGE_SIZE;
+	struct pageattr_masks masks = {
+		.set_mask = PAGE_KERNEL,
+		.clear_mask = __pgprot(0)
+	};
+
+	return walk_page_range(&init_mm, start, end, &pageattr_ops, &masks);
+}