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https://github.com/torvalds/linux
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85d2b0aa17
The sysfs_create_link() return code is marked as __must_check, but the module_add_driver() function tries hard to not care, by assigning the return code to a variable. When building with 'make W=1', gcc still warns because this variable is only assigned but not used: drivers/base/module.c: In function 'module_add_driver': drivers/base/module.c:36:6: warning: variable 'no_warn' set but not used [-Wunused-but-set-variable] Rework the code to properly unwind and return the error code to the caller. My reading of the original code was that it tries to not fail when the links already exist, so keep ignoring -EEXIST errors. Fixes:e17e0f51ae("Driver core: show drivers in /sys/module/") See-also:4a7fb6363f("add __must_check to device management code") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Link: https://lore.kernel.org/r/20240408080616.3911573-1-arnd@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
114 lines
2.2 KiB
C
114 lines
2.2 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* module.c - module sysfs fun for drivers
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*/
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#include <linux/device.h>
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#include <linux/module.h>
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#include <linux/errno.h>
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#include <linux/slab.h>
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#include <linux/string.h>
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#include "base.h"
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static char *make_driver_name(struct device_driver *drv)
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{
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char *driver_name;
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driver_name = kasprintf(GFP_KERNEL, "%s:%s", drv->bus->name, drv->name);
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if (!driver_name)
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return NULL;
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return driver_name;
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}
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static void module_create_drivers_dir(struct module_kobject *mk)
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{
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static DEFINE_MUTEX(drivers_dir_mutex);
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mutex_lock(&drivers_dir_mutex);
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if (mk && !mk->drivers_dir)
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mk->drivers_dir = kobject_create_and_add("drivers", &mk->kobj);
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mutex_unlock(&drivers_dir_mutex);
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}
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int module_add_driver(struct module *mod, struct device_driver *drv)
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{
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char *driver_name;
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struct module_kobject *mk = NULL;
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int ret;
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if (!drv)
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return 0;
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if (mod)
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mk = &mod->mkobj;
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else if (drv->mod_name) {
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struct kobject *mkobj;
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/* Lookup built-in module entry in /sys/modules */
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mkobj = kset_find_obj(module_kset, drv->mod_name);
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if (mkobj) {
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mk = container_of(mkobj, struct module_kobject, kobj);
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/* remember our module structure */
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drv->p->mkobj = mk;
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/* kset_find_obj took a reference */
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kobject_put(mkobj);
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}
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}
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if (!mk)
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return 0;
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ret = sysfs_create_link(&drv->p->kobj, &mk->kobj, "module");
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if (ret)
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return ret;
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driver_name = make_driver_name(drv);
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if (!driver_name) {
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ret = -ENOMEM;
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goto out;
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}
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module_create_drivers_dir(mk);
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if (!mk->drivers_dir) {
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ret = -EINVAL;
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goto out;
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}
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ret = sysfs_create_link(mk->drivers_dir, &drv->p->kobj, driver_name);
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if (ret)
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goto out;
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kfree(driver_name);
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return 0;
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out:
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sysfs_remove_link(&drv->p->kobj, "module");
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sysfs_remove_link(mk->drivers_dir, driver_name);
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kfree(driver_name);
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return ret;
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}
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void module_remove_driver(struct device_driver *drv)
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{
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struct module_kobject *mk = NULL;
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char *driver_name;
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if (!drv)
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return;
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sysfs_remove_link(&drv->p->kobj, "module");
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if (drv->owner)
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mk = &drv->owner->mkobj;
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else if (drv->p->mkobj)
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mk = drv->p->mkobj;
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if (mk && mk->drivers_dir) {
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driver_name = make_driver_name(drv);
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if (driver_name) {
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sysfs_remove_link(mk->drivers_dir, driver_name);
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kfree(driver_name);
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}
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}
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}
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