Merge ../torvalds-2.6/

2 files changed, 45 insertions, 6 deletions

diff --git a/arch/i386/mm/init.c b/arch/i386/mm/init.c
index 06e26f006238..7df494b51a5b 100644
--- a/arch/i386/mm/init.c
+++ b/arch/i386/mm/init.c
@@ -735,6 +735,30 @@ void free_initmem(void)
         printk (KERN_INFO "Freeing unused kernel memory: %dk freed\n", (__init_end - __init_begin) >> 10);
 }
 
+#ifdef CONFIG_DEBUG_RODATA
+
+extern char __start_rodata, __end_rodata;
+void mark_rodata_ro(void)
+{
+        unsigned long addr = (unsigned long)&__start_rodata;
+
+        for (; addr < (unsigned long)&__end_rodata; addr += PAGE_SIZE)
+                change_page_attr(virt_to_page(addr), 1, PAGE_KERNEL_RO);
+
+        printk ("Write protecting the kernel read-only data: %luk\n",
+                        (unsigned long)(&__end_rodata - &__start_rodata) >> 10);
+
+        /*
+         * change_page_attr() requires a global_flush_tlb() call after it.
+         * We do this after the printk so that if something went wrong in the
+         * change, the printk gets out at least to give a better debug hint
+         * of who is the culprit.
+         */
+        global_flush_tlb();
+}
+#endif
+
+
 #ifdef CONFIG_BLK_DEV_INITRD
 void free_initrd_mem(unsigned long start, unsigned long end)
 {
diff --git a/arch/i386/mm/pageattr.c b/arch/i386/mm/pageattr.c
index f600fc244f02..c30a16df6440 100644
--- a/arch/i386/mm/pageattr.c
+++ b/arch/i386/mm/pageattr.c
@@ -13,6 +13,7 @@
 #include <asm/processor.h>
 #include <asm/tlbflush.h>
 #include <asm/pgalloc.h>
+#include <asm/sections.h>
 
 static DEFINE_SPINLOCK(cpa_lock);
 static struct list_head df_list = LIST_HEAD_INIT(df_list);
@@ -36,7 +37,8 @@ pte_t *lookup_address(unsigned long address)
         return pte_offset_kernel(pmd, address);
 } 
 
-static struct page *split_large_page(unsigned long address, pgprot_t prot)
+static struct page *split_large_page(unsigned long address, pgprot_t prot,
+                                        pgprot_t ref_prot)
 { 
         int i; 
         unsigned long addr;
@@ -54,7 +56,7 @@ static struct page *split_large_page(unsigned long address, pgprot_t prot)
         pbase = (pte_t *)page_address(base);
         for (i = 0; i < PTRS_PER_PTE; i++, addr += PAGE_SIZE) {
                set_pte(&pbase[i], pfn_pte(addr >> PAGE_SHIFT,
-                                          addr == address ? prot : PAGE_KERNEL));
+                                          addr == address ? prot : ref_prot));
         }
         return base;
 } 
@@ -98,11 +100,18 @@ static void set_pmd_pte(pte_t *kpte, unsigned long address, pte_t pte)
  */
 static inline void revert_page(struct page *kpte_page, unsigned long address)
 {
-        pte_t *linear = (pte_t *) 
+        pgprot_t ref_prot;
+        pte_t *linear;
+
+        ref_prot =
+        ((address & LARGE_PAGE_MASK) < (unsigned long)&_etext)
+                ? PAGE_KERNEL_LARGE_EXEC : PAGE_KERNEL_LARGE;
+
+        linear = (pte_t *)
                 pmd_offset(pud_offset(pgd_offset_k(address), address), address);
         set_pmd_pte(linear,  address,
                     pfn_pte((__pa(address) & LARGE_PAGE_MASK) >> PAGE_SHIFT,
-                            PAGE_KERNEL_LARGE));
+                            ref_prot));
 }
 
 static int
@@ -123,10 +132,16 @@ __change_page_attr(struct page *page, pgprot_t prot)
                 if ((pte_val(*kpte) & _PAGE_PSE) == 0) { 
                         set_pte_atomic(kpte, mk_pte(page, prot)); 
                 } else {
-                        struct page *split = split_large_page(address, prot); 
+                        pgprot_t ref_prot;
+                        struct page *split;
+
+                        ref_prot =
+                        ((address & LARGE_PAGE_MASK) < (unsigned long)&_etext)
+                                ? PAGE_KERNEL_EXEC : PAGE_KERNEL;
+                        split = split_large_page(address, prot, ref_prot);
                         if (!split)
                                 return -ENOMEM;
-                        set_pmd_pte(kpte,address,mk_pte(split, PAGE_KERNEL));
+                        set_pmd_pte(kpte,address,mk_pte(split, ref_prot));
                         kpte_page = split;
                 }       
                 get_page(kpte_page);