[09/10] usb: Add USB subsystem notifications [ver #3]

Message ID	155981420247.17513.18371208824032389940.stgit@warthog.procyon.org.uk (mailing list archive)
State	New, archived
Headers	show Return-Path: <linux-security-module-owner@kernel.org> Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 Subject: [PATCH 09/10] usb: Add USB subsystem notifications [ver #3] From: David Howells <dhowells@redhat.com> To: viro@zeniv.linux.org.uk Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>, linux-usb@vger.kernel.org, dhowells@redhat.com, raven@themaw.net, linux-fsdevel@vger.kernel.org, linux-api@vger.kernel.org, linux-block@vger.kernel.org, keyrings@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org Date: Thu, 06 Jun 2019 10:43:22 +0100 Message-ID: <155981420247.17513.18371208824032389940.stgit@warthog.procyon.org.uk> In-Reply-To: <155981411940.17513.7137844619951358374.stgit@warthog.procyon.org.uk> References: <155981411940.17513.7137844619951358374.stgit@warthog.procyon.org.uk> User-Agent: StGit/unknown-version MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk
Series	Mount, FS, Block and Keyrings notifications [ver #3] \| expand [RFC,00/10] Mount, FS, Block and Keyrings notifications [ver #3] [01/10] security: Override creds in __fput() with last fputter's creds [ver #3] [02/10] General notification queue with user mmap()'able ring buffer [ver #3] [03/10] keys: Add a notification facility [ver #3] [04/10] vfs: Add a mount-notification facility [ver #3] [05/10] vfs: Add superblock notifications [ver #3] [06/10] fsinfo: Export superblock notification counter [ver #3] [07/10] Add a general, global device notification watch list [ver #3] [08/10] block: Add block layer notifications [ver #3] [09/10] usb: Add USB subsystem notifications [ver #3] [10/10] Add sample notification program [ver #3]

diff --git a/Documentation/watch_queue.rst b/Documentation/watch_queue.rst index c2954e191989..7ce5d4147fa9 100644 --- a/Documentation/watch_queue.rst +++ b/Documentation/watch_queue.rst @@ -15,6 +15,8 @@ receive notifications from the kernel. This can be used in conjunction with:: * Block layer event notifications + * USB subsystem event notifications + The notifications buffers can be enabled by: @@ -344,6 +346,13 @@ Any particular buffer can be fed from multiple sources. Sources include: or temporary link loss. Watchpoints of this type are set on the global device watch list. + * WATCH_TYPE_USB_NOTIFY + + Notifications of this type indicate USB subsystem events, such as + attachment, removal, reset and I/O errors. Separate events are generated + for buses and devices. Watchpoints of this type are set on the global + device watch list. + Event Filtering =============== diff --git a/drivers/usb/core/Kconfig b/drivers/usb/core/Kconfig index bdb6bd0b63a6..4be88368ab6b 100644 --- a/drivers/usb/core/Kconfig +++ b/drivers/usb/core/Kconfig @@ -103,3 +103,13 @@ config USB_AUTOSUSPEND_DELAY The default value Linux has always had is 2 seconds. Change this value if you want a different delay and cannot modify the command line or module parameter. + +config USB_NOTIFICATIONS + bool "Provide USB hardware event notifications" + depends on USB + select DEVICE_NOTIFICATIONS + help + This option provides support for getting hardware event notifications + on USB devices and interfaces. This makes use of the + /dev/watch_queue misc device to handle the notification buffer. + device_notify(2) is used to set/remove watches. diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c index fa783531ee88..af7f339c35c5 100644 --- a/drivers/usb/core/devio.c +++ b/drivers/usb/core/devio.c @@ -41,6 +41,7 @@ #include <linux/dma-mapping.h> #include <asm/byteorder.h> #include <linux/moduleparam.h> +#include <linux/watch_queue.h> #include "usb.h" @@ -2633,13 +2634,67 @@ static void usbdev_remove(struct usb_device *udev) } } +#ifdef CONFIG_USB_NOTIFICATIONS +static noinline void post_usb_notification(const char *devname, + enum usb_notification_type subtype, + u32 error) +{ + unsigned int name_len, n_len; + u64 id = 0; /* Might want to put a dev# here. */ + + struct { + struct usb_notification n; + char more_name[USB_NOTIFICATION_MAX_NAME_LEN - + (sizeof(struct usb_notification) - + offsetof(struct usb_notification, name))]; + } n; + + name_len = strlen(devname); + name_len = min_t(size_t, name_len, USB_NOTIFICATION_MAX_NAME_LEN); + n_len = round_up(offsetof(struct usb_notification, name) + name_len, + sizeof(__u64)); + + memset(&n, 0, sizeof(n)); + memcpy(n.n.name, devname, n_len); + + n.n.watch.type = WATCH_TYPE_USB_NOTIFY; + n.n.watch.subtype = subtype; + n.n.watch.info = n_len; + n.n.error = error; + n.n.name_len = name_len; + + post_device_notification(&n.n.watch, id); +} + +void post_usb_device_notification(const struct usb_device *udev, + enum usb_notification_type subtype, u32 error) +{ + post_usb_notification(dev_name(&udev->dev), subtype, error); +} + +void post_usb_bus_notification(const struct usb_bus *ubus, + enum usb_notification_type subtype, u32 error) +{ + post_usb_notification(ubus->bus_name, subtype, error); +} +#endif + static int usbdev_notify(struct notifier_block *self, unsigned long action, void *dev) { switch (action) { case USB_DEVICE_ADD: + post_usb_device_notification(dev, NOTIFY_USB_DEVICE_ADD, 0); break; case USB_DEVICE_REMOVE: + post_usb_device_notification(dev, NOTIFY_USB_DEVICE_REMOVE, 0); + usbdev_remove(dev); + break; + case USB_BUS_ADD: + post_usb_bus_notification(dev, NOTIFY_USB_BUS_ADD, 0); + break; + case USB_BUS_REMOVE: + post_usb_bus_notification(dev, NOTIFY_USB_BUS_REMOVE, 0); usbdev_remove(dev); break; } diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 2f94568ba385..722013d8142c 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -4596,6 +4596,9 @@ hub_port_init(struct usb_hub *hub, struct usb_device *udev, int port1, (udev->config) ? "reset" : "new", speed, devnum, driver_name); + if (udev->config) + post_usb_device_notification(udev, NOTIFY_USB_DEVICE_RESET, 0); + /* Set up TT records, if needed */ if (hdev->tt) { udev->tt = hdev->tt; diff --git a/include/linux/usb.h b/include/linux/usb.h index ae82d9d1112b..12687b55811d 100644 --- a/include/linux/usb.h +++ b/include/linux/usb.h @@ -2008,6 +2008,25 @@ extern void usb_led_activity(enum usb_led_event ev); static inline void usb_led_activity(enum usb_led_event ev) {} #endif +/* + * Notification functions. + */ +#ifdef CONFIG_USB_NOTIFICATIONS +extern void post_usb_device_notification(const struct usb_device *udev, + enum usb_notification_type subtype, + u32 error); +extern void post_usb_bus_notification(const struct usb_bus *ubus, + enum usb_notification_type subtype, + u32 error); +#else +static inline void post_usb_device_notification(const struct usb_device *udev, + enum usb_notification_type subtype, + u32 error) {} +static inline void post_usb_bus_notification(const struct usb_bus *ubus, + enum usb_notification_type subtype, + u32 error) {} +#endif + #endif /* __KERNEL__ */ #endif diff --git a/include/uapi/linux/watch_queue.h b/include/uapi/linux/watch_queue.h index 22e3326b83a6..d596ac5a61e4 100644 --- a/include/uapi/linux/watch_queue.h +++ b/include/uapi/linux/watch_queue.h @@ -14,7 +14,8 @@ enum watch_notification_type { WATCH_TYPE_SB_NOTIFY = 2, /* Superblock notification */ WATCH_TYPE_KEY_NOTIFY = 3, /* Key/keyring change notification */ WATCH_TYPE_BLOCK_NOTIFY = 4, /* Block layer notifications */ -#define WATCH_TYPE___NR 5 + WATCH_TYPE_USB_NOTIFY = 5, /* USB subsystem notifications */ +#define WATCH_TYPE___NR 6 }; enum watch_meta_notification_subtype { @@ -182,4 +183,31 @@ struct block_notification { __u64 sector; /* Affected sector */ }; +/* + * Type of USB layer notification. + */ +enum usb_notification_type { + NOTIFY_USB_DEVICE_ADD = 0, /* USB device added */ + NOTIFY_USB_DEVICE_REMOVE = 1, /* USB device removed */ + NOTIFY_USB_BUS_ADD = 2, /* USB bus added */ + NOTIFY_USB_BUS_REMOVE = 3, /* USB bus removed */ + NOTIFY_USB_DEVICE_RESET = 4, /* USB device reset */ + NOTIFY_USB_DEVICE_ERROR = 5, /* USB device error */ +}; + +/* + * USB subsystem notification record. + * - watch.type = WATCH_TYPE_USB_NOTIFY + * - watch.subtype = enum usb_notification_type + */ +struct usb_notification { + struct watch_notification watch; /* WATCH_TYPE_USB_NOTIFY */ + __u32 error; + __u32 reserved; + __u8 name_len; /* Length of device name */ + __u8 name[0]; /* Device name (padded to __u64, truncated at 63 chars) */ +}; + +#define USB_NOTIFICATION_MAX_NAME_LEN 63 + #endif /* _UAPI_LINUX_WATCH_QUEUE_H */

[09/10] usb: Add USB subsystem notifications [ver #3]

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