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Diffstat (limited to 'arch/x86/mm/init_64.c')
-rw-r--r--arch/x86/mm/init_64.c37
1 files changed, 32 insertions, 5 deletions
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index 54efa57d1c03..1753e8020df6 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -734,21 +734,48 @@ void __init mem_init(void)
734const int rodata_test_data = 0xC3; 734const int rodata_test_data = 0xC3;
735EXPORT_SYMBOL_GPL(rodata_test_data); 735EXPORT_SYMBOL_GPL(rodata_test_data);
736 736
737static int kernel_set_to_readonly;
738
739void set_kernel_text_rw(void)
740{
741 unsigned long start = PFN_ALIGN(_stext);
742 unsigned long end = PFN_ALIGN(__start_rodata);
743
744 if (!kernel_set_to_readonly)
745 return;
746
747 pr_debug("Set kernel text: %lx - %lx for read write\n",
748 start, end);
749
750 set_memory_rw(start, (end - start) >> PAGE_SHIFT);
751}
752
753void set_kernel_text_ro(void)
754{
755 unsigned long start = PFN_ALIGN(_stext);
756 unsigned long end = PFN_ALIGN(__start_rodata);
757
758 if (!kernel_set_to_readonly)
759 return;
760
761 pr_debug("Set kernel text: %lx - %lx for read only\n",
762 start, end);
763
764 set_memory_ro(start, (end - start) >> PAGE_SHIFT);
765}
766
737void mark_rodata_ro(void) 767void mark_rodata_ro(void)
738{ 768{
739 unsigned long start = PFN_ALIGN(_stext), end = PFN_ALIGN(__end_rodata); 769 unsigned long start = PFN_ALIGN(_stext), end = PFN_ALIGN(__end_rodata);
740 unsigned long rodata_start = 770 unsigned long rodata_start =
741 ((unsigned long)__start_rodata + PAGE_SIZE - 1) & PAGE_MASK; 771 ((unsigned long)__start_rodata + PAGE_SIZE - 1) & PAGE_MASK;
742 772
743#ifdef CONFIG_DYNAMIC_FTRACE
744 /* Dynamic tracing modifies the kernel text section */
745 start = rodata_start;
746#endif
747
748 printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n", 773 printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
749 (end - start) >> 10); 774 (end - start) >> 10);
750 set_memory_ro(start, (end - start) >> PAGE_SHIFT); 775 set_memory_ro(start, (end - start) >> PAGE_SHIFT);
751 776
777 kernel_set_to_readonly = 1;
778
752 /* 779 /*
753 * The rodata section (but not the kernel text!) should also be 780 * The rodata section (but not the kernel text!) should also be
754 * not-executable. 781 * not-executable.