riscv: Introduce set_kernel_memory helper

This helper should be used for setting permissions to the kernel mapping as it takes pointers as arguments and then avoids explicit cast to unsigned long needed for the set_memory_* API. Suggested-by: Christoph Hellwig <[email protected]> Signed-off-by: Alexandre Ghiti <[email protected]>
AlexGhiti · Jun 3, 2021 · 181921d · 181921d
1 parent 0a9416f
commit 181921d
Show file tree

Hide file tree

Showing 2 changed files with 15 additions and 0 deletions.
diff --git a/arch/riscv/include/asm/set_memory.h b/arch/riscv/include/asm/set_memory.h
@@ -16,6 +16,7 @@ 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_memory_rw_nx(unsigned long addr, int numpages);
+int set_kernel_memory(char *start, char *end, int (*set_memory)(unsigned long, int));
 void protect_kernel_text_data(void);
 #else
 static inline int set_memory_ro(unsigned long addr, int numpages) { return 0; }
@@ -24,6 +25,10 @@ static inline int set_memory_x(unsigned long addr, int numpages) { return 0; }
 static inline int set_memory_nx(unsigned long addr, int numpages) { return 0; }
 static inline void protect_kernel_text_data(void) {}
 static inline int set_memory_rw_nx(unsigned long addr, int numpages) { return 0; }
+static inline int set_kernel_memory(char *start, char *end, int (*set_memory)(unsigned long, int))
+{
+	return 0;
+}
 #endif
 
 #if defined(CONFIG_64BIT) && defined(CONFIG_STRICT_KERNEL_RWX)

diff --git a/arch/riscv/mm/pageattr.c b/arch/riscv/mm/pageattr.c
@@ -156,6 +156,16 @@ int set_memory_nx(unsigned long addr, int numpages)
 	return __set_memory(addr, numpages, __pgprot(0), __pgprot(_PAGE_EXEC));
 }
 
+int set_kernel_memory(char *startp, char *endp,
+		      int (*set_memory)(unsigned long start, int num_pages))
+{
+	unsigned long start = (unsigned long)startp;
+	unsigned long end = (unsigned long)endp;
+	int num_pages = PAGE_ALIGN(end - start) >> PAGE_SHIFT;
+
+	return set_memory(start, num_pages);
+}
+
 int set_direct_map_invalid_noflush(struct page *page)
 {
 	int ret;