kallsyms: only build {,module_}kallsyms_on_each_symbol when required

kallsyms_on_each_symbol and module_kallsyms_on_each_symbol are only used
by the livepatching code, so don't build them if livepatching is not
enabled.

Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jessica Yu <jeyu@kernel.org>

diff --git a/include/linux/kallsyms.h b/include/linux/kallsyms.h
index 481273f..465060a 100644 (file)
--- a/include/linux/kallsyms.h
+++ b/include/linux/kallsyms.h
@@ -71,15 +71,14 @@ static inline void *dereference_symbol_descriptor(void *ptr)
        return ptr;
 }
 
-#ifdef CONFIG_KALLSYMS
-/* Lookup the address for a symbol. Returns 0 if not found. */
-unsigned long kallsyms_lookup_name(const char *name);
-
-/* Call a function on each kallsyms symbol in the core kernel */
 int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *,
                                      unsigned long),
                            void *data);
 
+#ifdef CONFIG_KALLSYMS
+/* Lookup the address for a symbol. Returns 0 if not found. */
+unsigned long kallsyms_lookup_name(const char *name);
+
 extern int kallsyms_lookup_size_offset(unsigned long addr,
                                  unsigned long *symbolsize,
                                  unsigned long *offset);
@@ -108,14 +107,6 @@ static inline unsigned long kallsyms_lookup_name(const char *name)
        return 0;
 }
 
-static inline int kallsyms_on_each_symbol(int (*fn)(void *, const char *,
-                                                   struct module *,
-                                                   unsigned long),
-                                         void *data)
-{
-       return 0;
-}
-
 static inline int kallsyms_lookup_size_offset(unsigned long addr,
                                              unsigned long *symbolsize,
                                              unsigned long *offset)

diff --git a/include/linux/module.h b/include/linux/module.h
index a64aa84..3ea4ffa 100644 (file)
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -608,10 +608,6 @@ int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
 /* Look for this name: can be of form module:name. */
 unsigned long module_kallsyms_lookup_name(const char *name);
 
-int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
-                                            struct module *, unsigned long),
-                                  void *data);
-
 extern void __noreturn __module_put_and_exit(struct module *mod,
                        long code);
 #define module_put_and_exit(code) __module_put_and_exit(THIS_MODULE, code)
@@ -795,14 +791,6 @@ static inline unsigned long module_kallsyms_lookup_name(const char *name)
        return 0;
 }
 
-static inline int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
-                                                          struct module *,
-                                                          unsigned long),
-                                                void *data)
-{
-       return 0;
-}
-
 static inline int register_module_notifier(struct notifier_block *nb)
 {
        /* no events will happen anyway, so this can always succeed */
@@ -891,4 +879,8 @@ static inline bool module_sig_ok(struct module *module)
 }
 #endif /* CONFIG_MODULE_SIG */
 
+int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
+                                            struct module *, unsigned long),
+                                  void *data);
+
 #endif /* _LINUX_MODULE_H */

diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c
index a0d3f08..8043a90 100644 (file)
--- a/kernel/kallsyms.c
+++ b/kernel/kallsyms.c
@@ -177,6 +177,7 @@ unsigned long kallsyms_lookup_name(const char *name)
        return module_kallsyms_lookup_name(name);
 }
 
+#ifdef CONFIG_LIVEPATCH
 /*
  * Iterate over all symbols in vmlinux.  For symbols from modules use
  * module_kallsyms_on_each_symbol instead.
@@ -198,6 +199,7 @@ int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *,
        }
        return 0;
 }
+#endif /* CONFIG_LIVEPATCH */
 
 static unsigned long get_symbol_pos(unsigned long addr,
                                    unsigned long *symbolsize,

diff --git a/kernel/module.c b/kernel/module.c
index 481eb34..06155c4 100644 (file)
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -4488,6 +4488,7 @@ unsigned long module_kallsyms_lookup_name(const char *name)
        return ret;
 }
 
+#ifdef CONFIG_LIVEPATCH
 int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
                                             struct module *, unsigned long),
                                   void *data)
@@ -4518,6 +4519,7 @@ int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
        mutex_unlock(&module_mutex);
        return ret;
 }
+#endif /* CONFIG_LIVEPATCH */
 #endif /* CONFIG_KALLSYMS */
 
 /* Maximum number of characters written by module_flags() */