[3/8] riscv: add ARCH_SUPPORTS_DEBUG_PAGEALLOC support
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Message ID 20200217083223.2011-4-zong.li@sifive.com
State Superseded
Headers show
Series
  • Support strict kernel memory permissions for security
Related show

Commit Message

Zong Li Feb. 17, 2020, 8:32 a.m. UTC
ARCH_SUPPORTS_DEBUG_PAGEALLOC provides a hook to map and unmap
pages for debugging purposes. Implement the __kernel_map_pages
functions to fill the poison pattern.

Signed-off-by: Zong Li <zong.li@sifive.com>
---
 arch/riscv/Kconfig       |  3 +++
 arch/riscv/mm/pageattr.c | 13 +++++++++++++
 2 files changed, 16 insertions(+)

Comments

Palmer Dabbelt March 5, 2020, 12:57 a.m. UTC | #1
On Mon, 17 Feb 2020 00:32:18 PST (-0800), zong.li@sifive.com wrote:
> ARCH_SUPPORTS_DEBUG_PAGEALLOC provides a hook to map and unmap
> pages for debugging purposes. Implement the __kernel_map_pages
> functions to fill the poison pattern.
>
> Signed-off-by: Zong Li <zong.li@sifive.com>
> ---
>  arch/riscv/Kconfig       |  3 +++
>  arch/riscv/mm/pageattr.c | 13 +++++++++++++
>  2 files changed, 16 insertions(+)
>
> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
> index 07bf1a7c0dd2..f524d7e60648 100644
> --- a/arch/riscv/Kconfig
> +++ b/arch/riscv/Kconfig
> @@ -132,6 +132,9 @@ config ARCH_SELECT_MEMORY_MODEL
>  config ARCH_WANT_GENERAL_HUGETLB
>  	def_bool y
>
> +config ARCH_SUPPORTS_DEBUG_PAGEALLOC
> +	def_bool y
> +
>  config SYS_SUPPORTS_HUGETLBFS
>  	def_bool y
>
> diff --git a/arch/riscv/mm/pageattr.c b/arch/riscv/mm/pageattr.c
> index 7be6cd67e2ef..728759eb530a 100644
> --- a/arch/riscv/mm/pageattr.c
> +++ b/arch/riscv/mm/pageattr.c
> @@ -172,3 +172,16 @@ int set_direct_map_default_noflush(struct page *page)
>
>  	return walk_page_range(&init_mm, start, end, &pageattr_ops, &masks);
>  }
> +
> +void __kernel_map_pages(struct page *page, int numpages, int enable)
> +{
> +	if (!debug_pagealloc_enabled())
> +		return;
> +
> +	if (enable)
> +		__set_memory((unsigned long)page_address(page), numpages,
> +			     __pgprot(_PAGE_PRESENT), __pgprot(0));
> +	else
> +		__set_memory((unsigned long)page_address(page), numpages,
> +			     __pgprot(0), __pgprot(_PAGE_PRESENT));
> +}

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

Patch
diff mbox series

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 07bf1a7c0dd2..f524d7e60648 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -132,6 +132,9 @@  config ARCH_SELECT_MEMORY_MODEL
 config ARCH_WANT_GENERAL_HUGETLB
 	def_bool y
 
+config ARCH_SUPPORTS_DEBUG_PAGEALLOC
+	def_bool y
+
 config SYS_SUPPORTS_HUGETLBFS
 	def_bool y
 
diff --git a/arch/riscv/mm/pageattr.c b/arch/riscv/mm/pageattr.c
index 7be6cd67e2ef..728759eb530a 100644
--- a/arch/riscv/mm/pageattr.c
+++ b/arch/riscv/mm/pageattr.c
@@ -172,3 +172,16 @@  int set_direct_map_default_noflush(struct page *page)
 
 	return walk_page_range(&init_mm, start, end, &pageattr_ops, &masks);
 }
+
+void __kernel_map_pages(struct page *page, int numpages, int enable)
+{
+	if (!debug_pagealloc_enabled())
+		return;
+
+	if (enable)
+		__set_memory((unsigned long)page_address(page), numpages,
+			     __pgprot(_PAGE_PRESENT), __pgprot(0));
+	else
+		__set_memory((unsigned long)page_address(page), numpages,
+			     __pgprot(0), __pgprot(_PAGE_PRESENT));
+}