[PATCH bpf-next] kallsyms: move find_kallsyms_symbol_value out of internal header

From: Viktor Malik
Date: Fri Mar 17 2023 - 05:57:26 EST


Moving find_kallsyms_symbol_value from kernel/module/internal.h to
include/linux/module.h. The reason is that internal.h is not prepared to
be included when CONFIG_MODULES=n. find_kallsyms_symbol_value is used by
kernel/bpf/verifier.c and including internal.h from it (without modules)
leads into a compilation error:

In file included from ../include/linux/container_of.h:5,
from ../include/linux/list.h:5,
from ../include/linux/timer.h:5,
from ../include/linux/workqueue.h:9,
from ../include/linux/bpf.h:10,
from ../include/linux/bpf-cgroup.h:5,
from ../kernel/bpf/verifier.c:7:
../kernel/bpf/../module/internal.h: In function 'mod_find':
../include/linux/container_of.h:20:54: error: invalid use of undefined type 'struct module'
20 | static_assert(__same_type(*(ptr), ((type *)0)->member) || \
| ^~
[...]

This patch fixes the above error.

Signed-off-by: Viktor Malik <vmalik@xxxxxxxxxx>
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Link: https://lore.kernel.org/oe-kbuild-all/202303161404.OrmfCy09-lkp@xxxxxxxxx/
---
include/linux/module.h | 8 ++++++++
kernel/bpf/verifier.c | 2 +-
kernel/module/internal.h | 6 ------
3 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/include/linux/module.h b/include/linux/module.h
index 4435ad9439ab..41cfd3be57e5 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -616,6 +616,8 @@ 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);

+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)
@@ -796,6 +798,12 @@ 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 */
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index d62b7127ff2a..99394a2f7ee4 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -24,7 +24,7 @@
#include <linux/bpf_lsm.h>
#include <linux/btf_ids.h>
#include <linux/poison.h>
-#include "../module/internal.h"
+#include <linux/module.h>

#include "disasm.h"

diff --git a/kernel/module/internal.h b/kernel/module/internal.h
index 5c9170f9135c..1c877561a7d2 100644
--- a/kernel/module/internal.h
+++ b/kernel/module/internal.h
@@ -246,7 +246,6 @@ static inline void kmemleak_load_module(const struct module *mod,
void init_build_id(struct module *mod, const struct load_info *info);
void layout_symtab(struct module *mod, struct load_info *info);
void add_kallsyms(struct module *mod, const struct load_info *info);
-unsigned long find_kallsyms_symbol_value(struct module *mod, const char *name);

static inline bool sect_empty(const Elf_Shdr *sect)
{
@@ -256,11 +255,6 @@ static inline bool sect_empty(const Elf_Shdr *sect)
static inline void init_build_id(struct module *mod, const struct load_info *info) { }
static inline void layout_symtab(struct module *mod, struct load_info *info) { }
static inline void add_kallsyms(struct module *mod, const struct load_info *info) { }
-static inline unsigned long find_kallsyms_symbol_value(struct module *mod,
- const char *name)
-{
- return 0;
-}
#endif /* CONFIG_KALLSYMS */

#ifdef CONFIG_SYSFS
--
2.39.2