[PATCH bpf-next v2] kallsyms: move module-related functions under correct configs

From: Viktor Malik
Date: Thu Mar 30 2023 - 06:21:08 EST


Functions for searching module kallsyms should have non-empty
definitions only if CONFIG_MODULES=y and CONFIG_KALLSYMS=y. Until now,
only CONFIG_MODULES check was used for many of these, which may have
caused complilation errors on some configs.

This patch moves all relevant functions under the correct configs.

Fixes: bd5314f8dd2d ("kallsyms, bpf: Move find_kallsyms_symbol_value out of internal header")
Signed-off-by: Viktor Malik <vmalik@xxxxxxxxxx>
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Link: https://lore.kernel.org/oe-kbuild-all/202303181535.RFDCnz3E-lkp@xxxxxxxxx/
---
v2:
- keep dereference_module_function_descriptor() in original place to
avoid compilation errors
- fix indentation
- add the "Fixes" tag

include/linux/module.h | 135 ++++++++++++++++++++++-------------------
1 file changed, 74 insertions(+), 61 deletions(-)

diff --git a/include/linux/module.h b/include/linux/module.h
index 41cfd3be57e5..886d24877c7c 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -608,16 +608,6 @@ static inline bool within_module(unsigned long addr, const struct module *mod)
/* Search for module by name: must be in a RCU-sched critical section. */
struct module *find_module(const char *name);

-/* Returns 0 and fills in value, defined and namebuf, or -ERANGE if
- symnum out of range. */
-int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
- char *name, char *module_name, int *exported);
-
-/* Look for this name: can be of form module:name. */
-unsigned long module_kallsyms_lookup_name(const char *name);
-
-unsigned long find_kallsyms_symbol_value(struct module *mod, const char *name);
-
extern void __noreturn __module_put_and_kthread_exit(struct module *mod,
long code);
#define module_put_and_kthread_exit(code) __module_put_and_kthread_exit(THIS_MODULE, code)
@@ -664,17 +654,6 @@ static inline void __module_get(struct module *module)
/* Dereference module function descriptor */
void *dereference_module_function_descriptor(struct module *mod, void *ptr);

-/* For kallsyms to ask for address resolution. namebuf should be at
- * least KSYM_NAME_LEN long: a pointer to namebuf is returned if
- * found, otherwise NULL. */
-const char *module_address_lookup(unsigned long addr,
- unsigned long *symbolsize,
- unsigned long *offset,
- char **modname, const unsigned char **modbuildid,
- char *namebuf);
-int lookup_module_symbol_name(unsigned long addr, char *symname);
-int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name);
-
int register_module_notifier(struct notifier_block *nb);
int unregister_module_notifier(struct notifier_block *nb);

@@ -765,45 +744,6 @@ static inline void module_put(struct module *module)

#define module_name(mod) "kernel"

-/* For kallsyms to ask for address resolution. NULL means not found. */
-static inline const char *module_address_lookup(unsigned long addr,
- unsigned long *symbolsize,
- unsigned long *offset,
- char **modname,
- const unsigned char **modbuildid,
- char *namebuf)
-{
- return NULL;
-}
-
-static inline int lookup_module_symbol_name(unsigned long addr, char *symname)
-{
- return -ERANGE;
-}
-
-static inline int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name)
-{
- return -ERANGE;
-}
-
-static inline int module_get_kallsym(unsigned int symnum, unsigned long *value,
- char *type, char *name,
- char *module_name, int *exported)
-{
- return -ERANGE;
-}
-
-static inline unsigned long module_kallsyms_lookup_name(const char *name)
-{
- return 0;
-}
-
-static inline unsigned long find_kallsyms_symbol_value(struct module *mod,
- const char *name)
-{
- return 0;
-}
-
static inline int register_module_notifier(struct notifier_block *nb)
{
/* no events will happen anyway, so this can always succeed */
@@ -899,7 +839,36 @@ int module_kallsyms_on_each_symbol(const char *modname,
int (*fn)(void *, const char *,
struct module *, unsigned long),
void *data);
-#else
+
+/* For kallsyms to ask for address resolution. namebuf should be at
+ * least KSYM_NAME_LEN long: a pointer to namebuf is returned if
+ * found, otherwise NULL.
+ */
+const char *module_address_lookup(unsigned long addr,
+ unsigned long *symbolsize,
+ unsigned long *offset,
+ char **modname, const unsigned char **modbuildid,
+ char *namebuf);
+int lookup_module_symbol_name(unsigned long addr, char *symname);
+int lookup_module_symbol_attrs(unsigned long addr,
+ unsigned long *size,
+ unsigned long *offset,
+ char *modname,
+ char *name);
+
+/* Returns 0 and fills in value, defined and namebuf, or -ERANGE if
+ * symnum out of range.
+ */
+int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
+ char *name, char *module_name, int *exported);
+
+/* Look for this name: can be of form module:name. */
+unsigned long module_kallsyms_lookup_name(const char *name);
+
+unsigned long find_kallsyms_symbol_value(struct module *mod, const char *name);
+
+#else /* CONFIG_MODULES && CONFIG_KALLSYMS */
+
static inline int module_kallsyms_on_each_symbol(const char *modname,
int (*fn)(void *, const char *,
struct module *, unsigned long),
@@ -907,6 +876,50 @@ static inline int module_kallsyms_on_each_symbol(const char *modname,
{
return -EOPNOTSUPP;
}
+
+/* For kallsyms to ask for address resolution. NULL means not found. */
+static inline const char *module_address_lookup(unsigned long addr,
+ unsigned long *symbolsize,
+ unsigned long *offset,
+ char **modname,
+ const unsigned char **modbuildid,
+ char *namebuf)
+{
+ return NULL;
+}
+
+static inline int lookup_module_symbol_name(unsigned long addr, char *symname)
+{
+ return -ERANGE;
+}
+
+static inline int lookup_module_symbol_attrs(unsigned long addr,
+ unsigned long *size,
+ unsigned long *offset,
+ char *modname,
+ char *name)
+{
+ return -ERANGE;
+}
+
+static inline int module_get_kallsym(unsigned int symnum, unsigned long *value,
+ char *type, char *name,
+ char *module_name, int *exported)
+{
+ return -ERANGE;
+}
+
+static inline unsigned long module_kallsyms_lookup_name(const char *name)
+{
+ return 0;
+}
+
+static inline unsigned long find_kallsyms_symbol_value(struct module *mod,
+ const char *name)
+{
+ return 0;
+}
+
#endif /* CONFIG_MODULES && CONFIG_KALLSYMS */

#endif /* _LINUX_MODULE_H */
--
2.39.2