[v2,6/7] arm64: map linear region as non-executable

Commit Message

Ard Biesheuvel Sept. 23, 2015, 12:37 a.m. UTC

Now that we moved the kernel text out of the linear region, there
is no longer a reason to map the linear region as executable. This
also allows us to completely get rid of the __map_mem() variant that
only maps some of it executable if CONFIG_DEBUG_RODATA is selected.

Signed-off-by: Ard Biesheuvel <[e-mail]>
---
 arch/arm64/mm/mmu.c | 41 +-------------------
 1 file changed, 2 insertions(+), 39 deletions(-)

Patch

diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index 91a619482cc2..4a1c9d0769f2 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -302,47 +302,10 @@  static void create_mapping_late(phys_addr_t phys, unsigned long virt,
 				phys, virt, size, prot, late_alloc);
 }
 
-#ifdef CONFIG_DEBUG_RODATA
 static void __init __map_memblock(phys_addr_t start, phys_addr_t end)
 {
-	/*
-	 * Set up the executable regions using the existing section mappings
-	 * for now. This will get more fine grained later once all memory
-	 * is mapped
-	 */
-	unsigned long kernel_x_start = round_down(__pa(_stext), SECTION_SIZE);
-	unsigned long kernel_x_end = round_up(__pa(__init_end), SECTION_SIZE);
-
-	if (end < kernel_x_start) {
-		create_mapping(start, __phys_to_virt(start),
-			end - start, PAGE_KERNEL);
-	} else if (start >= kernel_x_end) {
-		create_mapping(start, __phys_to_virt(start),
-			end - start, PAGE_KERNEL);
-	} else {
-		if (start < kernel_x_start)
-			create_mapping(start, __phys_to_virt(start),
-				kernel_x_start - start,
-				PAGE_KERNEL);
-		create_mapping(kernel_x_start,
-				__phys_to_virt(kernel_x_start),
-				kernel_x_end - kernel_x_start,
-				PAGE_KERNEL_EXEC);
-		if (kernel_x_end < end)
-			create_mapping(kernel_x_end,
-				__phys_to_virt(kernel_x_end),
-				end - kernel_x_end,
-				PAGE_KERNEL);
-	}
-
-}
-#else
-static void __init __map_memblock(phys_addr_t start, phys_addr_t end)
-{
-	create_mapping(start, __phys_to_virt(start), end - start,
-			PAGE_KERNEL_EXEC);
+	create_mapping(start, __phys_to_virt(start), end - start, PAGE_KERNEL);
 }
-#endif
 
 struct bootstrap_pgtables {
 	pte_t	pte[PTRS_PER_PTE];
@@ -427,7 +390,7 @@  static unsigned long __init bootstrap_region(struct bootstrap_pgtables *reg,
 #endif
 
 		create_mapping(__pa(vstart - va_offset), vstart, vend - vstart,
-			       PAGE_KERNEL_EXEC);
+			       PAGE_KERNEL);
 
 		return vend;
 	}