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Diffstat (limited to 'arch/x86/mm/init_32.c')
-rw-r--r--arch/x86/mm/init_32.c35
1 files changed, 32 insertions, 3 deletions
diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c
index db81e9a8556b..749559ed80f5 100644
--- a/arch/x86/mm/init_32.c
+++ b/arch/x86/mm/init_32.c
@@ -1054,17 +1054,47 @@ static noinline int do_test_wp_bit(void)
1054const int rodata_test_data = 0xC3; 1054const int rodata_test_data = 0xC3;
1055EXPORT_SYMBOL_GPL(rodata_test_data); 1055EXPORT_SYMBOL_GPL(rodata_test_data);
1056 1056
1057static int kernel_set_to_readonly;
1058
1059void set_kernel_text_rw(void)
1060{
1061 unsigned long start = PFN_ALIGN(_text);
1062 unsigned long size = PFN_ALIGN(_etext) - start;
1063
1064 if (!kernel_set_to_readonly)
1065 return;
1066
1067 pr_debug("Set kernel text: %lx - %lx for read write\n",
1068 start, start+size);
1069
1070 set_pages_rw(virt_to_page(start), size >> PAGE_SHIFT);
1071}
1072
1073void set_kernel_text_ro(void)
1074{
1075 unsigned long start = PFN_ALIGN(_text);
1076 unsigned long size = PFN_ALIGN(_etext) - start;
1077
1078 if (!kernel_set_to_readonly)
1079 return;
1080
1081 pr_debug("Set kernel text: %lx - %lx for read only\n",
1082 start, start+size);
1083
1084 set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
1085}
1086
1057void mark_rodata_ro(void) 1087void mark_rodata_ro(void)
1058{ 1088{
1059 unsigned long start = PFN_ALIGN(_text); 1089 unsigned long start = PFN_ALIGN(_text);
1060 unsigned long size = PFN_ALIGN(_etext) - start; 1090 unsigned long size = PFN_ALIGN(_etext) - start;
1061 1091
1062#ifndef CONFIG_DYNAMIC_FTRACE
1063 /* Dynamic tracing modifies the kernel text section */
1064 set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT); 1092 set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
1065 printk(KERN_INFO "Write protecting the kernel text: %luk\n", 1093 printk(KERN_INFO "Write protecting the kernel text: %luk\n",
1066 size >> 10); 1094 size >> 10);
1067 1095
1096 kernel_set_to_readonly = 1;
1097
1068#ifdef CONFIG_CPA_DEBUG 1098#ifdef CONFIG_CPA_DEBUG
1069 printk(KERN_INFO "Testing CPA: Reverting %lx-%lx\n", 1099 printk(KERN_INFO "Testing CPA: Reverting %lx-%lx\n",
1070 start, start+size); 1100 start, start+size);
@@ -1073,7 +1103,6 @@ void mark_rodata_ro(void)
1073 printk(KERN_INFO "Testing CPA: write protecting again\n"); 1103 printk(KERN_INFO "Testing CPA: write protecting again\n");
1074 set_pages_ro(virt_to_page(start), size>>PAGE_SHIFT); 1104 set_pages_ro(virt_to_page(start), size>>PAGE_SHIFT);
1075#endif 1105#endif
1076#endif /* CONFIG_DYNAMIC_FTRACE */
1077 1106
1078 start += size; 1107 start += size;
1079 size = (unsigned long)__end_rodata - start; 1108 size = (unsigned long)__end_rodata - start;