x86: make sure initmem is writable

When we free initmem, various rodata and CPA checks may have left
memory read only.. this patch ensures that the memory is writable
before we free it.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c
index 0d3369b900e967ba999a2add81e95fbc6e827c4a..4d115654519442babfa3e0d2a3f4d4fc3749a9b6 100644 (file)
--- a/arch/x86/mm/init_32.c
+++ b/arch/x86/mm/init_32.c
@@ -780,6 +780,13 @@ void free_init_pages(char *what, unsigned long begin, unsigned long end)
 {
        unsigned long addr;
 
+       /*
+        * We just marked the kernel text read only above, now that
+        * we are going to free part of that, we need to make that
+        * writeable first.
+        */
+       set_memory_rw(begin, (end - begin) >> PAGE_SHIFT);
+
        for (addr = begin; addr < end; addr += PAGE_SIZE) {
                ClearPageReserved(virt_to_page(addr));
                init_page_count(virt_to_page(addr));

diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index 9b69fa54a831fd84e1c8114728a6ad9ea0dec9e5..f97ace7a55e5a15bca02fe015ac0f4ff73e8749a 100644 (file)
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -570,6 +570,7 @@ void free_init_pages(char *what, unsigned long begin, unsigned long end)
         * 2Mb kernel mapping just for this debug feature.
         */
        if (begin >= __START_KERNEL_map) {
+               set_memory_rw(begin, (end - begin)/PAGE_SIZE);
                set_memory_np(begin, (end - begin)/PAGE_SIZE);
                set_memory_nx(begin, (end - begin)/PAGE_SIZE);
        }