Linux-2.6.12-rc2v2.6.12-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!

1 files changed, 377 insertions, 0 deletions

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 <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/usb.h>
+#include <linux/debugfs.h>
+#include <linux/smp_lock.h>
+
+#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");