From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sat, 16 Apr 2005 15:20:36 -0700 Subject: Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip! --- drivers/usb/mon/mon_main.c | 377 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 377 insertions(+) create mode 100644 drivers/usb/mon/mon_main.c (limited to 'drivers/usb/mon/mon_main.c') diff --git a/drivers/usb/mon/mon_main.c b/drivers/usb/mon/mon_main.c new file mode 100644 index 000000000000..aa9d00808e4e --- /dev/null +++ b/drivers/usb/mon/mon_main.c @@ -0,0 +1,377 @@ +/* + * The USB Monitor, inspired by Dave Harding's USBMon. + * + * mon_main.c: Main file, module initiation and exit, registrations, etc. + */ + +#include +#include +#include +#include +#include + +#include "usb_mon.h" +#include "../core/hcd.h" + +static void mon_submit(struct usb_bus *ubus, struct urb *urb); +static void mon_complete(struct usb_bus *ubus, struct urb *urb); +static void mon_stop(struct mon_bus *mbus); +static void mon_dissolve(struct mon_bus *mbus, struct usb_bus *ubus); +static void mon_bus_drop(struct kref *r); +static void mon_bus_init(struct dentry *mondir, struct usb_bus *ubus); + +DECLARE_MUTEX(mon_lock); + +static struct dentry *mon_dir; /* /dbg/usbmon */ +static LIST_HEAD(mon_buses); /* All buses we know: struct mon_bus */ + +/* + * Link a reader into the bus. + * + * This must be called with mon_lock taken because of mbus->ref. + */ +void mon_reader_add(struct mon_bus *mbus, struct mon_reader *r) +{ + unsigned long flags; + struct usb_bus *ubus; + + spin_lock_irqsave(&mbus->lock, flags); + if (mbus->nreaders == 0) { + ubus = mbus->u_bus; + if (ubus->monitored) { + /* + * Something is really broken, refuse to go on and + * possibly corrupt ops pointers or worse. + */ + printk(KERN_ERR TAG ": bus %d is already monitored\n", + ubus->busnum); + spin_unlock_irqrestore(&mbus->lock, flags); + return; + } + ubus->monitored = 1; + } + mbus->nreaders++; + list_add_tail(&r->r_link, &mbus->r_list); + spin_unlock_irqrestore(&mbus->lock, flags); + + kref_get(&mbus->ref); +} + +/* + * Unlink reader from the bus. + * + * This is called with mon_lock taken, so we can decrement mbus->ref. + */ +void mon_reader_del(struct mon_bus *mbus, struct mon_reader *r) +{ + unsigned long flags; + + spin_lock_irqsave(&mbus->lock, flags); + list_del(&r->r_link); + --mbus->nreaders; + if (mbus->nreaders == 0) + mon_stop(mbus); + spin_unlock_irqrestore(&mbus->lock, flags); + + kref_put(&mbus->ref, mon_bus_drop); +} + +/* + */ +static void mon_submit(struct usb_bus *ubus, struct urb *urb) +{ + struct mon_bus *mbus; + unsigned long flags; + struct list_head *pos; + struct mon_reader *r; + + mbus = ubus->mon_bus; + if (mbus == NULL) + goto out_unlocked; + + spin_lock_irqsave(&mbus->lock, flags); + if (mbus->nreaders == 0) + goto out_locked; + + list_for_each (pos, &mbus->r_list) { + r = list_entry(pos, struct mon_reader, r_link); + r->rnf_submit(r->r_data, urb); + } + + spin_unlock_irqrestore(&mbus->lock, flags); + return; + +out_locked: + spin_unlock_irqrestore(&mbus->lock, flags); +out_unlocked: + return; +} + +/* + */ +static void mon_submit_error(struct usb_bus *ubus, struct urb *urb, int err) +{ + struct mon_bus *mbus; + + mbus = ubus->mon_bus; + if (mbus == NULL) + goto out_unlocked; + + /* + * XXX Capture the error code and the 'E' event. + */ + + return; + +out_unlocked: + return; +} + +/* + */ +static void mon_complete(struct usb_bus *ubus, struct urb *urb) +{ + struct mon_bus *mbus; + unsigned long flags; + struct list_head *pos; + struct mon_reader *r; + + mbus = ubus->mon_bus; + if (mbus == NULL) { + /* + * This should not happen. + * At this point we do not even know the bus number... + */ + printk(KERN_ERR TAG ": Null mon bus in URB, pipe 0x%x\n", + urb->pipe); + return; + } + + spin_lock_irqsave(&mbus->lock, flags); + list_for_each (pos, &mbus->r_list) { + r = list_entry(pos, struct mon_reader, r_link); + r->rnf_complete(r->r_data, urb); + } + spin_unlock_irqrestore(&mbus->lock, flags); +} + +/* int (*unlink_urb) (struct urb *urb, int status); */ + +/* + * Stop monitoring. + * Obviously this must be well locked, so no need to play with mb's. + */ +static void mon_stop(struct mon_bus *mbus) +{ + struct usb_bus *ubus = mbus->u_bus; + + /* + * A stop can be called for a dissolved mon_bus in case of + * a reader staying across an rmmod foo_hcd. + */ + if (ubus != NULL) { + ubus->monitored = 0; + mb(); + } +} + +/* + * Add a USB bus (usually by a modprobe foo-hcd) + * + * This does not return an error code because the core cannot care less + * if monitoring is not established. + */ +static void mon_bus_add(struct usb_bus *ubus) +{ + mon_bus_init(mon_dir, ubus); +} + +/* + * Remove a USB bus (either from rmmod foo-hcd or from a hot-remove event). + */ +static void mon_bus_remove(struct usb_bus *ubus) +{ + struct mon_bus *mbus = ubus->mon_bus; + + down(&mon_lock); + list_del(&mbus->bus_link); + debugfs_remove(mbus->dent_t); + debugfs_remove(mbus->dent_s); + + mon_dissolve(mbus, ubus); + kref_put(&mbus->ref, mon_bus_drop); + up(&mon_lock); +} + +/* + * Ops + */ +static struct usb_mon_operations mon_ops_0 = { + .urb_submit = mon_submit, + .urb_submit_error = mon_submit_error, + .urb_complete = mon_complete, + .bus_add = mon_bus_add, + .bus_remove = mon_bus_remove, +}; + +/* + * Tear usb_bus and mon_bus apart. + */ +static void mon_dissolve(struct mon_bus *mbus, struct usb_bus *ubus) +{ + + /* + * Never happens, but... + */ + if (ubus->monitored) { + printk(KERN_ERR TAG ": bus %d is dissolved while monitored\n", + ubus->busnum); + ubus->monitored = 0; + mb(); + } + + ubus->mon_bus = NULL; + mbus->u_bus = NULL; + mb(); + // usb_bus_put(ubus); +} + +/* + */ +static void mon_bus_drop(struct kref *r) +{ + struct mon_bus *mbus = container_of(r, struct mon_bus, ref); + kfree(mbus); +} + +/* + * Initialize a bus for us: + * - allocate mon_bus + * - refcount USB bus struct + * - link + */ +static void mon_bus_init(struct dentry *mondir, struct usb_bus *ubus) +{ + struct dentry *d; + struct mon_bus *mbus; + enum { NAMESZ = 10 }; + char name[NAMESZ]; + int rc; + + if ((mbus = kmalloc(sizeof(struct mon_bus), GFP_KERNEL)) == NULL) + goto err_alloc; + memset(mbus, 0, sizeof(struct mon_bus)); + kref_init(&mbus->ref); + spin_lock_init(&mbus->lock); + INIT_LIST_HEAD(&mbus->r_list); + + /* + * This usb_bus_get here is superfluous, because we receive + * a notification if usb_bus is about to be removed. + */ + // usb_bus_get(ubus); + mbus->u_bus = ubus; + ubus->mon_bus = mbus; + + rc = snprintf(name, NAMESZ, "%dt", ubus->busnum); + if (rc <= 0 || rc >= NAMESZ) + goto err_print_t; + d = debugfs_create_file(name, 0600, mondir, mbus, &mon_fops_text); + if (d == NULL) + goto err_create_t; + mbus->dent_t = d; + + rc = snprintf(name, NAMESZ, "%ds", ubus->busnum); + if (rc <= 0 || rc >= NAMESZ) + goto err_print_s; + d = debugfs_create_file(name, 0600, mondir, mbus, &mon_fops_stat); + if (d == NULL) + goto err_create_s; + mbus->dent_s = d; + + down(&mon_lock); + list_add_tail(&mbus->bus_link, &mon_buses); + up(&mon_lock); + return; + +err_create_s: +err_print_s: + debugfs_remove(mbus->dent_t); +err_create_t: +err_print_t: + kfree(mbus); +err_alloc: + return; +} + +static int __init mon_init(void) +{ + struct usb_bus *ubus; + struct dentry *mondir; + + mondir = debugfs_create_dir("usbmon", NULL); + if (IS_ERR(mondir)) { + printk(KERN_NOTICE TAG ": debugs is not available\n"); + return -ENODEV; + } + if (mondir == NULL) { + printk(KERN_NOTICE TAG ": unable to create usbmon directory\n"); + return -ENODEV; + } + mon_dir = mondir; + + if (usb_mon_register(&mon_ops_0) != 0) { + printk(KERN_NOTICE TAG ": unable to register with the core\n"); + debugfs_remove(mondir); + return -ENODEV; + } + // MOD_INC_USE_COUNT(which_module?); + + down(&usb_bus_list_lock); + list_for_each_entry (ubus, &usb_bus_list, bus_list) { + mon_bus_init(mondir, ubus); + } + up(&usb_bus_list_lock); + return 0; +} + +static void __exit mon_exit(void) +{ + struct mon_bus *mbus; + struct list_head *p; + + usb_mon_deregister(); + + down(&mon_lock); + while (!list_empty(&mon_buses)) { + p = mon_buses.next; + mbus = list_entry(p, struct mon_bus, bus_link); + list_del(p); + + debugfs_remove(mbus->dent_t); + debugfs_remove(mbus->dent_s); + + /* + * This never happens, because the open/close paths in + * file level maintain module use counters and so rmmod fails + * before reaching here. However, better be safe... + */ + if (mbus->nreaders) { + printk(KERN_ERR TAG + ": Outstanding opens (%d) on usb%d, leaking...\n", + mbus->nreaders, mbus->u_bus->busnum); + atomic_set(&mbus->ref.refcount, 2); /* Force leak */ + } + + mon_dissolve(mbus, mbus->u_bus); + kref_put(&mbus->ref, mon_bus_drop); + } + up(&mon_lock); + + debugfs_remove(mon_dir); +} + +module_init(mon_init); +module_exit(mon_exit); + +MODULE_LICENSE("GPL"); -- cgit v1.2.3