2 files changed, 21 insertions, 0 deletions

diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h
index 69b74a7b877f..ac80b7d70014 100644
--- a/arch/x86/include/asm/alternative.h
+++ b/arch/x86/include/asm/alternative.h
@@ -65,12 +65,17 @@ extern void alternatives_smp_module_add(struct module *mod, char *name,
                                         void *text, void *text_end);
 extern void alternatives_smp_module_del(struct module *mod);
 extern void alternatives_smp_switch(int smp);
+extern int alternatives_text_reserved(void *start, void *end);
 #else
 static inline void alternatives_smp_module_add(struct module *mod, char *name,
                                                void *locks, void *locks_end,
                                                void *text, void *text_end) {}
 static inline void alternatives_smp_module_del(struct module *mod) {}
 static inline void alternatives_smp_switch(int smp) {}
+static inline int alternatives_text_reserved(void *start, void *end)
+{
+        return 0;
+}
 #endif  /* CONFIG_SMP */
 
 /* alternative assembly primitive: */
diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index de7353c0ce9c..3c13284ff86d 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -390,6 +390,22 @@ void alternatives_smp_switch(int smp)
         mutex_unlock(&smp_alt);
 }
 
+/* Return 1 if the address range is reserved for smp-alternatives */
+int alternatives_text_reserved(void *start, void *end)
+{
+        struct smp_alt_module *mod;
+        u8 **ptr;
+
+        list_for_each_entry(mod, &smp_alt_modules, next) {
+                if (mod->text > end || mod->text_end < start)
+                        continue;
+                for (ptr = mod->locks; ptr < mod->locks_end; ptr++)
+                        if (start <= *ptr && end >= *ptr)
+                                return 1;
+        }
+
+        return 0;
+}
 #endif
 
 #ifdef CONFIG_PARAVIRT