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Commit 984bb80d authored by Arjan van de Ven's avatar Arjan van de Ven Committed by Ingo Molnar
Browse files

x86: mark the .rodata section also NX 



The .rodata section shouldn't just be read-only,
but also non-executable. This is free since we've broken
up the 2MB page already anyway.

also update test_nx to check for this.

Signed-off-by: default avatarArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent a57dae3a

arch/x86/kernel/test_nx.c

+1 −1
Original line number Diff line number Diff line
@@ -139,7 +139,6 @@ static int test_NX(void) 
	 * Until then, don't run them to avoid too many people getting scared

	 * by the error message

	 */

#if 0



#ifdef CONFIG_DEBUG_RODATA

	/* Test 3: Check if the .rodata section is executable */
@@ -152,6 +151,7 @@ static int test_NX(void) 
	}

#endif



#if 0

	/* Test 4: Check if the .data section of a module is executable */

	if (test_address(&test_data)) {

		printk(KERN_ERR "test_nx: .data section is executable\n");

arch/x86/mm/init_64.c

+8 −1
Original line number Diff line number Diff line
@@ -591,10 +591,17 @@ void mark_rodata_ro(void) 
	if (end <= start)

		return;



	set_memory_ro(start, (end - start) >> PAGE_SHIFT);



	printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",

	       (end - start) >> 10);

	set_memory_ro(start, (end - start) >> PAGE_SHIFT);



	/*

	 * The rodata section (but not the kernel text!) should also be

	 * not-executable.

	 */

	start = ((unsigned long)__start_rodata + PAGE_SIZE - 1) & PAGE_MASK;

	set_memory_nx(start, (end - start) >> PAGE_SHIFT);



	rodata_test();