Sometimes, device drivers are bound using indirect references, which is not visible when looking at /proc/modules or lsmod.
Add a function to allow setting up module references for such cases.
Reviewed-by: Dan Williams dan.j.williams@intel.com Signed-off-by: Mauro Carvalho Chehab mchehab@kernel.org ---
See [PATCH 0/2] at: https://lore.kernel.org/all/cover.1651212016.git.mchehab@kernel.org/
include/linux/module.h | 7 +++++++ kernel/module/main.c | 31 +++++++++++++++++++++++++++++++ 2 files changed, 38 insertions(+)
diff --git a/include/linux/module.h b/include/linux/module.h index 46d4d5f2516e..be74f807e41d 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -596,6 +596,8 @@ 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);
+int module_add_named_dependency(const char *name, struct module *this); + /* 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, @@ -772,6 +774,11 @@ static inline int lookup_module_symbol_attrs(unsigned long addr, unsigned long * return -ERANGE; }
+static inline int module_add_named_dependency(const char *name, struct module *this) +{ + return 0; +} + static inline int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type, char *name, char *module_name, int *exported) diff --git a/kernel/module/main.c b/kernel/module/main.c index 05a42d8fcd7a..dbd577ccc38c 100644 --- a/kernel/module/main.c +++ b/kernel/module/main.c @@ -631,6 +631,37 @@ static int ref_module(struct module *a, struct module *b) return 0; }
+int module_add_named_dependency(const char *name, struct module *this) +{ + struct module *mod; + int ret; + + if (!name || !this || !this->name) { + return -EINVAL; + } + + mutex_lock(&module_mutex); + mod = find_module(name); + if (!mod) { + ret = -EINVAL; + goto ret; + } + + ret = ref_module(this, mod); + if (ret) + goto ret; + +#ifdef CONFIG_MODULE_UNLOAD + ret = sysfs_create_link(mod->holders_dir, + &this->mkobj.kobj, this->name); +#endif + +ret: + mutex_unlock(&module_mutex); + return ret; +} +EXPORT_SYMBOL_GPL(module_add_named_dependency); + /* Clear the unload stuff of the module. */ static void module_unload_free(struct module *mod) {