--- linux-2.6.17-rc3-mm1-davej/arch/i386/mm/pageattr.c.org	2006-05-04 09:23:56.000000000 +0200
+++ linux-2.6.17-rc3-mm1-davej/arch/i386/mm/pageattr.c	2006-05-04 09:27:21.000000000 +0200
@@ -9,6 +9,7 @@
 #include <linux/highmem.h>
 #include <linux/module.h>
 #include <linux/slab.h>
+#include <linux/kernel.h>
 #include <asm/uaccess.h>
 #include <asm/processor.h>
 #include <asm/tlbflush.h>
@@ -18,6 +19,7 @@
 static DEFINE_SPINLOCK(cpa_lock);
 static struct list_head df_list = LIST_HEAD_INIT(df_list);
 
+extern char __start_rodata, __end_rodata;
 
 pte_t *lookup_address(unsigned long address) 
 { 
@@ -127,10 +129,16 @@
 	pte_t *kpte; 
 	unsigned long address;
 	struct page *kpte_page;
+	static int once = 0;
 
 	BUG_ON(PageHighMem(page));
 	address = (unsigned long)page_address(page);
 
+	if (address >= __start_rodata && address <= __end_rodata && prot != __PAGE_KERNEL_RO && once++ == 0) {
+		printk(KERN_ERR "Possible trojan or rootkit detected!\n");
+		add_taint(TAINT_MACHINE_CHECK);
+	}
+
 	kpte = lookup_address(address);
 	if (!kpte)
 		return -EINVAL;