If usb_add_function() fails then the currently processed function is already not in the list in struct config_usb_cfg, and neither is it in the list in struct usb_configuration. At the err_purge_funcs label the purge_config_funcs() is called, which iterates over all configurations, and in each configuration it iterates over all _successfully_ added functions, and moves them back from the list in struct usb_configuration to the list in struct config_usb_cfg. BUT the function which has just failed adding and caused the unwind process is not taken care of and is effectively lost.
This patch modifies the configfs_composite_bind() function so that if the usb_add_function() fails, then the currently processed function is returned to the list in struct config_usb_cfg. It would be tempting to delay the list_del() in question after usb_add_function() invocation, but a struct list_head (&f->list) cannot be stored in more than one list at the same time, so the list_del() must be called before usb_add_function(). Hence, the solution is to list_add() after usb_add_function() in case of error. Signed-off-by: Andrzej Pietrasiewicz <[email protected]> Signed-off-by: Kyungmin Park <[email protected]> --- drivers/usb/gadget/configfs.c | 4 +++- 1 files changed, 3 insertions(+), 1 deletions(-) diff --git a/drivers/usb/gadget/configfs.c b/drivers/usb/gadget/configfs.c index c5d8f81..8cb5006 100644 --- a/drivers/usb/gadget/configfs.c +++ b/drivers/usb/gadget/configfs.c @@ -866,8 +866,10 @@ static int configfs_composite_bind(struct usb_gadget *gadget, list_for_each_entry_safe(f, tmp, &cfg->func_list, list) { list_del(&f->list); ret = usb_add_function(c, f); - if (ret) + if (ret) { + list_add(&f->list, &cfg->func_list); goto err_purge_funcs; + } } usb_ep_autoconfig_reset(cdev->gadget); } -- 1.7.0.4 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
