4 files changed, 63 insertions, 18 deletions

diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
index 8541f18694a4..46b4e67d2372 100644
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -402,6 +402,7 @@ void __init mem_init(void)
 void free_initmem(void)
 {
         ppc_md.progress = ppc_printk_progress;
+        mark_initmem_nx();
         free_initmem_default(POISON_FREE_INITMEM);
 }
 
diff --git a/arch/powerpc/mm/pgtable-hash64.c b/arch/powerpc/mm/pgtable-hash64.c
index 188b4107584d..443a2c66a304 100644
--- a/arch/powerpc/mm/pgtable-hash64.c
+++ b/arch/powerpc/mm/pgtable-hash64.c
@@ -425,33 +425,51 @@ int hash__has_transparent_hugepage(void)
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 
 #ifdef CONFIG_STRICT_KERNEL_RWX
-void hash__mark_rodata_ro(void)
+static bool hash__change_memory_range(unsigned long start, unsigned long end,
+                                      unsigned long newpp)
 {
-        unsigned long start = (unsigned long)_stext;
-        unsigned long end = (unsigned long)__init_begin;
         unsigned long idx;
         unsigned int step, shift;
-        unsigned long newpp = PP_RXXX;
 
         shift = mmu_psize_defs[mmu_linear_psize].shift;
         step = 1 << shift;
 
-        start = ((start + step - 1) >> shift) << shift;
-        end = (end >> shift) << shift;
+        start = ALIGN_DOWN(start, step);
+        end = ALIGN(end, step); // aligns up
 
-        pr_devel("marking ro start %lx, end %lx, step %x\n",
-                        start, end, step);
+        if (start >= end)
+                return false;
 
-        if (start == end) {
-                pr_warn("could not set rodata ro, relocate the start"
-                        " of the kernel to a 0x%x boundary\n", step);
-                return;
-        }
+        pr_debug("Changing page protection on range 0x%lx-0x%lx, to 0x%lx, step 0x%x\n",
+                 start, end, newpp, step);
 
         for (idx = start; idx < end; idx += step)
                 /* Not sure if we can do much with the return value */
                 mmu_hash_ops.hpte_updateboltedpp(newpp, idx, mmu_linear_psize,
                                                         mmu_kernel_ssize);
 
+        return true;
+}
+
+void hash__mark_rodata_ro(void)
+{
+        unsigned long start, end;
+
+        start = (unsigned long)_stext;
+        end = (unsigned long)__init_begin;
+
+        WARN_ON(!hash__change_memory_range(start, end, PP_RXXX));
+}
+
+void hash__mark_initmem_nx(void)
+{
+        unsigned long start, end, pp;
+
+        start = (unsigned long)__init_begin;
+        end = (unsigned long)__init_end;
+
+        pp = htab_convert_pte_flags(pgprot_val(PAGE_KERNEL));
+
+        WARN_ON(!hash__change_memory_range(start, end, pp));
 }
 #endif
diff --git a/arch/powerpc/mm/pgtable-radix.c b/arch/powerpc/mm/pgtable-radix.c
index 8c13e4282308..5cc50d47ce3f 100644
--- a/arch/powerpc/mm/pgtable-radix.c
+++ b/arch/powerpc/mm/pgtable-radix.c
@@ -112,10 +112,9 @@ set_the_pte:
 }
 
 #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 +147,29 @@ 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);
+}
+
+void radix__mark_initmem_nx(void)
+{
+        unsigned long start = (unsigned long)__init_begin;
+        unsigned long end = (unsigned long)__init_end;
+
+        radix__change_memory_range(start, end, _PAGE_EXEC);
+}
 #endif /* CONFIG_STRICT_KERNEL_RWX */
 
 static inline void __meminit print_mapping(unsigned long start,
diff --git a/arch/powerpc/mm/pgtable_64.c b/arch/powerpc/mm/pgtable_64.c
index 5c0b795d656c..0736e94c7615 100644
--- a/arch/powerpc/mm/pgtable_64.c
+++ b/arch/powerpc/mm/pgtable_64.c
@@ -505,4 +505,12 @@ void mark_rodata_ro(void)
         else
                 hash__mark_rodata_ro();
 }
+
+void mark_initmem_nx(void)
+{
+        if (radix_enabled())
+                radix__mark_initmem_nx();
+        else
+                hash__mark_initmem_nx();
+}
 #endif