[PATCH 1/3] powerpc/mm/radix: Refactor radix__mark_rodata_ro()

[Michael Ellerman]

Move the core logic into a helper, so we can use it for changing permissions
other than _PAGE_WRITE.

Signed-off-by: Michael Ellerman <m...@ellerman.id.au>
---
 arch/powerpc/mm/pgtable-radix.c | 20 +++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/arch/powerpc/mm/pgtable-radix.c b/arch/powerpc/mm/pgtable-radix.c
index 8c13e4282308..336e52ec652c 100644
--- a/arch/powerpc/mm/pgtable-radix.c
+++ b/arch/powerpc/mm/pgtable-radix.c
@@ -112,10 +112,9 @@ int radix__map_kernel_page(unsigned long ea, unsigned long 
pa,
 }
 
 #ifdef CONFIG_STRICT_KERNEL_RWX
-void radix__mark_rodata_ro(void)
+void radix__change_memory_range(unsigned long start, unsigned long end,
+                               unsigned long clear)
 {
-       unsigned long start = (unsigned long)_stext;
-       unsigned long end = (unsigned long)__init_begin;
        unsigned long idx;
        pgd_t *pgdp;
        pud_t *pudp;
@@ -125,7 +124,8 @@ void radix__mark_rodata_ro(void)
        start = ALIGN_DOWN(start, PAGE_SIZE);
        end = PAGE_ALIGN(end); // aligns up
 
-       pr_devel("marking ro start %lx, end %lx\n", start, end);
+       pr_debug("Changing flags on range %lx-%lx removing 0x%lx\n",
+                start, end, clear);
 
        for (idx = start; idx < end; idx += PAGE_SIZE) {
                pgdp = pgd_offset_k(idx);
@@ -147,11 +147,21 @@ void radix__mark_rodata_ro(void)
                if (!ptep)
                        continue;
 update_the_pte:
-               radix__pte_update(&init_mm, idx, ptep, _PAGE_WRITE, 0, 0);
+               radix__pte_update(&init_mm, idx, ptep, clear, 0, 0);
        }
 
        radix__flush_tlb_kernel_range(start, end);
 }
+
+void radix__mark_rodata_ro(void)
+{
+       unsigned long start, end;
+
+       start = (unsigned long)_stext;
+       end = (unsigned long)__init_begin;
+
+       radix__change_memory_range(start, end, _PAGE_WRITE);
+}
 #endif /* CONFIG_STRICT_KERNEL_RWX */
 
 static inline void __meminit print_mapping(unsigned long start,
-- 
2.7.4