From 27600805e62f800bacf990354632eae4e487d34c Mon Sep 17 00:00:00 2001 From: Yazen Ghannam Date: Thu, 3 Sep 2026 10:43:25 -0500 Subject: x86/amd_node: Fix PCI device reference counting in amd_smn_init() The local "root" pointer is a temporary variable used during the device search. Therefore, refcount related to the search iterators should be cleaned up after the search is complete. Use the __free() cleanup macro to ensure the refcount is decremented when the temporary pointer goes out of scope. Additionally, increment the refcount when caching a root pointer. This ensures the in-use refcount is separate from the temporary search refcounting. Finally, drop the redundant "root = NULL" before the second search loop. The pci_get_class() iterator always decrements the refcount of its "from" argument, so the first loop can only fall through with "root" already NULL. Fixes: 0a4b61d9c2e4 ("x86/amd_node: Fix AMD root device caching") Closes: https://sashiko.dev/#/patchset/20260806160159.230453-1-jason.andryuk%40amd.com Reported-by: Sashiko Assisted-by: LLM Signed-off-by: Yazen Ghannam Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Mario Limonciello (AMD) Cc: Link: https://patch.msgid.link/20260903154325.74343-1-yazen.ghannam@amd.com --- drivers/usb/gadget/functions.c | 117 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 117 insertions(+) create mode 100644 drivers/usb/gadget/functions.c (limited to 'drivers/usb/gadget/functions.c') diff --git a/drivers/usb/gadget/functions.c b/drivers/usb/gadget/functions.c new file mode 100644 index 000000000..203361a64 --- /dev/null +++ b/drivers/usb/gadget/functions.c @@ -0,0 +1,117 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include + +#include + +static LIST_HEAD(func_list); +static DEFINE_MUTEX(func_lock); + +static struct usb_function_instance *try_get_usb_function_instance(const char *name) +{ + struct usb_function_driver *fd; + struct usb_function_instance *fi; + + fi = ERR_PTR(-ENOENT); + mutex_lock(&func_lock); + list_for_each_entry(fd, &func_list, list) { + + if (strcmp(name, fd->name)) + continue; + + if (!try_module_get(fd->mod)) { + fi = ERR_PTR(-EBUSY); + break; + } + fi = fd->alloc_inst(); + if (IS_ERR(fi)) + module_put(fd->mod); + else + fi->fd = fd; + break; + } + mutex_unlock(&func_lock); + return fi; +} + +struct usb_function_instance *usb_get_function_instance(const char *name) +{ + struct usb_function_instance *fi; + int ret; + + fi = try_get_usb_function_instance(name); + if (!IS_ERR(fi)) + return fi; + ret = PTR_ERR(fi); + if (ret != -ENOENT) + return fi; + ret = request_module("usbfunc:%s", name); + if (ret < 0) + return ERR_PTR(ret); + return try_get_usb_function_instance(name); +} +EXPORT_SYMBOL_GPL(usb_get_function_instance); + +struct usb_function *usb_get_function(struct usb_function_instance *fi) +{ + struct usb_function *f; + + f = fi->fd->alloc_func(fi); + if (IS_ERR(f)) + return f; + f->fi = fi; + return f; +} +EXPORT_SYMBOL_GPL(usb_get_function); + +void usb_put_function_instance(struct usb_function_instance *fi) +{ + struct module *mod; + + if (!fi) + return; + + mod = fi->fd->mod; + fi->free_func_inst(fi); + module_put(mod); +} +EXPORT_SYMBOL_GPL(usb_put_function_instance); + +void usb_put_function(struct usb_function *f) +{ + if (!f) + return; + + f->free_func(f); +} +EXPORT_SYMBOL_GPL(usb_put_function); + +int usb_function_register(struct usb_function_driver *newf) +{ + struct usb_function_driver *fd; + int ret; + + ret = -EEXIST; + + mutex_lock(&func_lock); + list_for_each_entry(fd, &func_list, list) { + if (!strcmp(fd->name, newf->name)) + goto out; + } + ret = 0; + list_add_tail(&newf->list, &func_list); +out: + mutex_unlock(&func_lock); + return ret; +} +EXPORT_SYMBOL_GPL(usb_function_register); + +void usb_function_unregister(struct usb_function_driver *fd) +{ + mutex_lock(&func_lock); + list_del(&fd->list); + mutex_unlock(&func_lock); +} +EXPORT_SYMBOL_GPL(usb_function_unregister); -- cgit v1.3.1