From 0b3144da31f855fce652303f588416a60991bdef Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Wed, 13 Nov 2024 07:49:22 +0100 Subject: USB: make single lock for all usb dynamic id lists There are a number of places where we accidentally pass in a constant structure to later cast it off to a dynamic one, and then attempt to grab a lock on it, which is not a good idea. To help resolve this, move the dynamic id lock out of the dynamic id structure for the driver and into one single lock for all USB dynamic ids. As this lock should never have any real contention (it's only every accessed when a device is added or removed, which is always serialized) there should not be any difference except for some memory savings. Note, this just converts the existing use of the dynamic id lock to the new static lock, there is one place that is accessing the dynamic id list without grabbing the lock, that will be fixed up in a follow-on change. Cc: Johan Hovold Cc: Herve Codina Cc: Rob Herring Cc: Alan Stern Cc: Grant Grundler Cc: Oliver Neukum Cc: Yajun Deng Cc: Douglas Anderson Cc: linux-usb@vger.kernel.org Link: https://lore.kernel.org/r/2024111322-kindly-finalist-d247@gregkh Signed-off-by: Greg Kroah-Hartman --- drivers/usb/common/common.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'drivers/usb/common/common.c') diff --git a/drivers/usb/common/common.c b/drivers/usb/common/common.c index b7bea1015d7c..871cf199b6bf 100644 --- a/drivers/usb/common/common.c +++ b/drivers/usb/common/common.c @@ -415,6 +415,9 @@ EXPORT_SYMBOL_GPL(usb_of_get_companion_dev); struct dentry *usb_debug_root; EXPORT_SYMBOL_GPL(usb_debug_root); +DEFINE_MUTEX(usb_dynids_lock); +EXPORT_SYMBOL_GPL(usb_dynids_lock); + static int __init usb_common_init(void) { usb_debug_root = debugfs_create_dir("usb", NULL); -- cgit v1.2.3