add a new list which link all usb_function at configfs layers,
it means that after link a function a configuration,
from configfs layer, we can still found all functions,
it will allow trace all functions from configfs.
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Signed-off-by: Linyu Yuan <quic_linyyuan@xxxxxxxxxxx>
---
v2: fix unused cfg variable warning
v3: add struct inside configfs.c
v4: no change
v5: lost v2 fix, add it again
drivers/usb/gadget/configfs.c | 55 ++++++++++++++++++++++++-------------------
1 file changed, 31 insertions(+), 24 deletions(-)
diff --git a/drivers/usb/gadget/configfs.c b/drivers/usb/gadget/configfs.c
index 477e72a..5b2e6f9 100644
--- a/drivers/usb/gadget/configfs.c
+++ b/drivers/usb/gadget/configfs.c
@@ -58,6 +58,11 @@ static inline struct gadget_info *to_gadget_info(struct config_item *item)
return container_of(to_config_group(item), struct gadget_info, group);
}
+struct config_usb_function {
+ struct list_head list;
+ struct usb_function *f;
+};
+
struct config_usb_cfg {
struct config_group group;
struct config_group strings_group;
@@ -420,7 +425,7 @@ static int config_usb_cfg_link(
struct usb_function_instance *fi = container_of(group,
struct usb_function_instance, group);
struct usb_function_instance *a_fi;
- struct usb_function *f;
+ struct config_usb_function *cf;
int ret;
mutex_lock(&gi->lock);
@@ -438,21 +443,29 @@ static int config_usb_cfg_link(
goto out;
}
- list_for_each_entry(f, &cfg->func_list, list) {
- if (f->fi == fi) {
+ list_for_each_entry(cf, &cfg->func_list, list) {
+ if (cf->f->fi == fi) {
ret = -EEXIST;
goto out;
}
}
- f = usb_get_function(fi);
- if (IS_ERR(f)) {
- ret = PTR_ERR(f);
+ cf = kzalloc(sizeof(*cf), GFP_KERNEL);
+ if (!cf) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ INIT_LIST_HEAD(&cf->list);
+
+ cf->f = usb_get_function(fi);
+ if (IS_ERR(cf->f)) {
+ ret = PTR_ERR(cf->f);
+ kfree(cf);
goto out;
}
/* stash the function until we bind it to the gadget */
- list_add_tail(&f->list, &cfg->func_list);
+ list_add_tail(&cf->list, &cfg->func_list);
ret = 0;
out:
mutex_unlock(&gi->lock);
@@ -470,7 +483,7 @@ static void config_usb_cfg_unlink(
struct config_group *group = to_config_group(usb_func_ci);
struct usb_function_instance *fi = container_of(group,
struct usb_function_instance, group);
- struct usb_function *f;
+ struct config_usb_function *cf;
/*
* ideally I would like to forbid to unlink functions while a gadget is
@@ -483,10 +496,11 @@ static void config_usb_cfg_unlink(
unregister_gadget(gi);
WARN_ON(gi->composite.gadget_driver.udc_name);
- list_for_each_entry(f, &cfg->func_list, list) {
- if (f->fi == fi) {
- list_del(&f->list);
- usb_put_function(f);
+ list_for_each_entry(cf, &cfg->func_list, list) {
+ if (cf->f->fi == fi) {
+ list_del(&cf->list);
+ usb_put_function(cf->f);
+ kfree(cf);
mutex_unlock(&gi->lock);
return;
}
@@ -1257,13 +1271,10 @@ static void purge_configs_funcs(struct gadget_info *gi)
list_for_each_entry(c, &gi->cdev.configs, list) {
struct usb_function *f, *tmp;
- struct config_usb_cfg *cfg;
-
- cfg = container_of(c, struct config_usb_cfg, c);
list_for_each_entry_safe_reverse(f, tmp, &c->functions, list) {
- list_move(&f->list, &cfg->func_list);
+ list_del(&f->list);
if (f->unbind) {
dev_dbg(&gi->cdev.gadget->dev,
"unbind function '%s'/%p\n",
@@ -1371,8 +1382,7 @@ static int configfs_composite_bind(struct usb_gadget *gadget,
/* Go through all configs, attach all functions */
list_for_each_entry(c, &gi->cdev.configs, list) {
struct config_usb_cfg *cfg;
- struct usb_function *f;
- struct usb_function *tmp;
+ struct config_usb_function *cf, *tmp;
struct gadget_config_name *cn;
if (gadget_is_otg(gadget))
@@ -1396,13 +1406,10 @@ static int configfs_composite_bind(struct usb_gadget *gadget,
c->iConfiguration = s[0].id;
}
- list_for_each_entry_safe(f, tmp, &cfg->func_list, list) {
- list_del(&f->list);
- ret = usb_add_function(c, f);
- if (ret) {
- list_add(&f->list, &cfg->func_list);
+ list_for_each_entry_safe(cf, tmp, &cfg->func_list, list) {
+ ret = usb_add_function(c, cf->f);
+ if (ret)
goto err_purge_funcs;
- }
}
ret = usb_gadget_check_config(cdev->gadget);
if (ret)
--
2.7.4
