diff options
Diffstat (limited to 'drivers/usb/mon/mon_text.c')
| -rw-r--r-- | drivers/usb/mon/mon_text.c | 761 |
1 files changed, 761 insertions, 0 deletions
diff --git a/drivers/usb/mon/mon_text.c b/drivers/usb/mon/mon_text.c new file mode 100644 index 000000000..ad408251d --- /dev/null +++ b/drivers/usb/mon/mon_text.c @@ -0,0 +1,761 @@ +/* + * The USB Monitor, inspired by Dave Harding's USBMon. + * + * This is a text format reader. + */ + +#include <linux/kernel.h> +#include <linux/list.h> +#include <linux/usb.h> +#include <linux/slab.h> +#include <linux/time.h> +#include <linux/export.h> +#include <linux/mutex.h> +#include <linux/debugfs.h> +#include <linux/scatterlist.h> +#include <asm/uaccess.h> + +#include "usb_mon.h" + +/* + * No, we do not want arbitrarily long data strings. + * Use the binary interface if you want to capture bulk data! + */ +#define DATA_MAX 32 + +/* + * Defined by USB 2.0 clause 9.3, table 9.2. + */ +#define SETUP_MAX 8 + +/* + * This limit exists to prevent OOMs when the user process stops reading. + * If usbmon were available to unprivileged processes, it might be open + * to a local DoS. But we have to keep to root in order to prevent + * password sniffing from HID devices. + */ +#define EVENT_MAX (4*PAGE_SIZE / sizeof(struct mon_event_text)) + +/* + * Potentially unlimited number; we limit it for similar allocations. + * The usbfs limits this to 128, but we're not quite as generous. + */ +#define ISODESC_MAX 5 + +#define PRINTF_DFL 250 /* with 5 ISOs segs */ + +struct mon_iso_desc { + int status; + unsigned int offset; + unsigned int length; /* Unsigned here, signed in URB. Historic. */ +}; + +struct mon_event_text { + struct list_head e_link; + int type; /* submit, complete, etc. */ + unsigned long id; /* From pointer, most of the time */ + unsigned int tstamp; + int busnum; + char devnum; + char epnum; + char is_in; + char xfertype; + int length; /* Depends on type: xfer length or act length */ + int status; + int interval; + int start_frame; + int error_count; + char setup_flag; + char data_flag; + int numdesc; /* Full number */ + struct mon_iso_desc isodesc[ISODESC_MAX]; + unsigned char setup[SETUP_MAX]; + unsigned char data[DATA_MAX]; +}; + +#define SLAB_NAME_SZ 30 +struct mon_reader_text { + struct kmem_cache *e_slab; + int nevents; + struct list_head e_list; + struct mon_reader r; /* In C, parent class can be placed anywhere */ + + wait_queue_head_t wait; + int printf_size; + char *printf_buf; + struct mutex printf_lock; + + char slab_name[SLAB_NAME_SZ]; +}; + +static struct dentry *mon_dir; /* Usually /sys/kernel/debug/usbmon */ + +static void mon_text_ctor(void *); + +struct mon_text_ptr { + int cnt, limit; + char *pbuf; +}; + +static struct mon_event_text * + mon_text_read_wait(struct mon_reader_text *rp, struct file *file); +static void mon_text_read_head_t(struct mon_reader_text *rp, + struct mon_text_ptr *p, const struct mon_event_text *ep); +static void mon_text_read_head_u(struct mon_reader_text *rp, + struct mon_text_ptr *p, const struct mon_event_text *ep); +static void mon_text_read_statset(struct mon_reader_text *rp, + struct mon_text_ptr *p, const struct mon_event_text *ep); +static void mon_text_read_intstat(struct mon_reader_text *rp, + struct mon_text_ptr *p, const struct mon_event_text *ep); +static void mon_text_read_isostat(struct mon_reader_text *rp, + struct mon_text_ptr *p, const struct mon_event_text *ep); +static void mon_text_read_isodesc(struct mon_reader_text *rp, + struct mon_text_ptr *p, const struct mon_event_text *ep); +static void mon_text_read_data(struct mon_reader_text *rp, + struct mon_text_ptr *p, const struct mon_event_text *ep); + +/* + * mon_text_submit + * mon_text_complete + * + * May be called from an interrupt. + * + * This is called with the whole mon_bus locked, so no additional lock. + */ + +static inline char mon_text_get_setup(struct mon_event_text *ep, + struct urb *urb, char ev_type, struct mon_bus *mbus) +{ + + if (ep->xfertype != USB_ENDPOINT_XFER_CONTROL || ev_type != 'S') + return '-'; + + if (urb->setup_packet == NULL) + return 'Z'; /* '0' would be not as pretty. */ + + memcpy(ep->setup, urb->setup_packet, SETUP_MAX); + return 0; +} + +static inline char mon_text_get_data(struct mon_event_text *ep, struct urb *urb, + int len, char ev_type, struct mon_bus *mbus) +{ + void *src; + + if (len <= 0) + return 'L'; + if (len >= DATA_MAX) + len = DATA_MAX; + + if (ep->is_in) { + if (ev_type != 'C') + return '<'; + } else { + if (ev_type != 'S') + return '>'; + } + + if (urb->num_sgs == 0) { + src = urb->transfer_buffer; + if (src == NULL) + return 'Z'; /* '0' would be not as pretty. */ + } else { + struct scatterlist *sg = urb->sg; + + if (PageHighMem(sg_page(sg))) + return 'D'; + + /* For the text interface we copy only the first sg buffer */ + len = min_t(int, sg->length, len); + src = sg_virt(sg); + } + + memcpy(ep->data, src, len); + return 0; +} + +static inline unsigned int mon_get_timestamp(void) +{ + struct timeval tval; + unsigned int stamp; + + do_gettimeofday(&tval); + stamp = tval.tv_sec & 0xFFF; /* 2^32 = 4294967296. Limit to 4096s. */ + stamp = stamp * 1000000 + tval.tv_usec; + return stamp; +} + +static void mon_text_event(struct mon_reader_text *rp, struct urb *urb, + char ev_type, int status) +{ + struct mon_event_text *ep; + unsigned int stamp; + struct usb_iso_packet_descriptor *fp; + struct mon_iso_desc *dp; + int i, ndesc; + + stamp = mon_get_timestamp(); + + if (rp->nevents >= EVENT_MAX || + (ep = kmem_cache_alloc(rp->e_slab, GFP_ATOMIC)) == NULL) { + rp->r.m_bus->cnt_text_lost++; + return; + } + + ep->type = ev_type; + ep->id = (unsigned long) urb; + ep->busnum = urb->dev->bus->busnum; + ep->devnum = urb->dev->devnum; + ep->epnum = usb_endpoint_num(&urb->ep->desc); + ep->xfertype = usb_endpoint_type(&urb->ep->desc); + ep->is_in = usb_urb_dir_in(urb); + ep->tstamp = stamp; + ep->length = (ev_type == 'S') ? + urb->transfer_buffer_length : urb->actual_length; + /* Collecting status makes debugging sense for submits, too */ + ep->status = status; + + if (ep->xfertype == USB_ENDPOINT_XFER_INT) { + ep->interval = urb->interval; + } else if (ep->xfertype == USB_ENDPOINT_XFER_ISOC) { + ep->interval = urb->interval; + ep->start_frame = urb->start_frame; + ep->error_count = urb->error_count; + } + ep->numdesc = urb->number_of_packets; + if (ep->xfertype == USB_ENDPOINT_XFER_ISOC && + urb->number_of_packets > 0) { + if ((ndesc = urb->number_of_packets) > ISODESC_MAX) + ndesc = ISODESC_MAX; + fp = urb->iso_frame_desc; + dp = ep->isodesc; + for (i = 0; i < ndesc; i++) { + dp->status = fp->status; + dp->offset = fp->offset; + dp->length = (ev_type == 'S') ? + fp->length : fp->actual_length; + fp++; + dp++; + } + /* Wasteful, but simple to understand: ISO 'C' is sparse. */ + if (ev_type == 'C') + ep->length = urb->transfer_buffer_length; + } + + ep->setup_flag = mon_text_get_setup(ep, urb, ev_type, rp->r.m_bus); + ep->data_flag = mon_text_get_data(ep, urb, ep->length, ev_type, + rp->r.m_bus); + + rp->nevents++; + list_add_tail(&ep->e_link, &rp->e_list); + wake_up(&rp->wait); +} + +static void mon_text_submit(void *data, struct urb *urb) +{ + struct mon_reader_text *rp = data; + mon_text_event(rp, urb, 'S', -EINPROGRESS); +} + +static void mon_text_complete(void *data, struct urb *urb, int status) +{ + struct mon_reader_text *rp = data; + mon_text_event(rp, urb, 'C', status); +} + +static void mon_text_error(void *data, struct urb *urb, int error) +{ + struct mon_reader_text *rp = data; + struct mon_event_text *ep; + + if (rp->nevents >= EVENT_MAX || + (ep = kmem_cache_alloc(rp->e_slab, GFP_ATOMIC)) == NULL) { + rp->r.m_bus->cnt_text_lost++; + return; + } + + ep->type = 'E'; + ep->id = (unsigned long) urb; + ep->busnum = urb->dev->bus->busnum; + ep->devnum = urb->dev->devnum; + ep->epnum = usb_endpoint_num(&urb->ep->desc); + ep->xfertype = usb_endpoint_type(&urb->ep->desc); + ep->is_in = usb_urb_dir_in(urb); + ep->tstamp = mon_get_timestamp(); + ep->length = 0; + ep->status = error; + + ep->setup_flag = '-'; + ep->data_flag = 'E'; + + rp->nevents++; + list_add_tail(&ep->e_link, &rp->e_list); + wake_up(&rp->wait); +} + +/* + * Fetch next event from the circular buffer. + */ +static struct mon_event_text *mon_text_fetch(struct mon_reader_text *rp, + struct mon_bus *mbus) +{ + struct list_head *p; + unsigned long flags; + + spin_lock_irqsave(&mbus->lock, flags); + if (list_empty(&rp->e_list)) { + spin_unlock_irqrestore(&mbus->lock, flags); + return NULL; + } + p = rp->e_list.next; + list_del(p); + --rp->nevents; + spin_unlock_irqrestore(&mbus->lock, flags); + return list_entry(p, struct mon_event_text, e_link); +} + +/* + */ +static int mon_text_open(struct inode *inode, struct file *file) +{ + struct mon_bus *mbus; + struct mon_reader_text *rp; + int rc; + + mutex_lock(&mon_lock); + mbus = inode->i_private; + + rp = kzalloc(sizeof(struct mon_reader_text), GFP_KERNEL); + if (rp == NULL) { + rc = -ENOMEM; + goto err_alloc; + } + INIT_LIST_HEAD(&rp->e_list); + init_waitqueue_head(&rp->wait); + mutex_init(&rp->printf_lock); + + rp->printf_size = PRINTF_DFL; + rp->printf_buf = kmalloc(rp->printf_size, GFP_KERNEL); + if (rp->printf_buf == NULL) { + rc = -ENOMEM; + goto err_alloc_pr; + } + + rp->r.m_bus = mbus; + rp->r.r_data = rp; + rp->r.rnf_submit = mon_text_submit; + rp->r.rnf_error = mon_text_error; + rp->r.rnf_complete = mon_text_complete; + + snprintf(rp->slab_name, SLAB_NAME_SZ, "mon_text_%p", rp); + rp->e_slab = kmem_cache_create(rp->slab_name, + sizeof(struct mon_event_text), sizeof(long), 0, + mon_text_ctor); + if (rp->e_slab == NULL) { + rc = -ENOMEM; + goto err_slab; + } + + mon_reader_add(mbus, &rp->r); + + file->private_data = rp; + mutex_unlock(&mon_lock); + return 0; + +// err_busy: +// kmem_cache_destroy(rp->e_slab); +err_slab: + kfree(rp->printf_buf); +err_alloc_pr: + kfree(rp); +err_alloc: + mutex_unlock(&mon_lock); + return rc; +} + +/* + * For simplicity, we read one record in one system call and throw out + * what does not fit. This means that the following does not work: + * dd if=/dbg/usbmon/0t bs=10 + * Also, we do not allow seeks and do not bother advancing the offset. + */ +static ssize_t mon_text_read_t(struct file *file, char __user *buf, + size_t nbytes, loff_t *ppos) +{ + struct mon_reader_text *rp = file->private_data; + struct mon_event_text *ep; + struct mon_text_ptr ptr; + + if (IS_ERR(ep = mon_text_read_wait(rp, file))) + return PTR_ERR(ep); + mutex_lock(&rp->printf_lock); + ptr.cnt = 0; + ptr.pbuf = rp->printf_buf; + ptr.limit = rp->printf_size; + + mon_text_read_head_t(rp, &ptr, ep); + mon_text_read_statset(rp, &ptr, ep); + ptr.cnt += snprintf(ptr.pbuf + ptr.cnt, ptr.limit - ptr.cnt, + " %d", ep->length); + mon_text_read_data(rp, &ptr, ep); + + if (copy_to_user(buf, rp->printf_buf, ptr.cnt)) + ptr.cnt = -EFAULT; + mutex_unlock(&rp->printf_lock); + kmem_cache_free(rp->e_slab, ep); + return ptr.cnt; +} + +static ssize_t mon_text_read_u(struct file *file, char __user *buf, + size_t nbytes, loff_t *ppos) +{ + struct mon_reader_text *rp = file->private_data; + struct mon_event_text *ep; + struct mon_text_ptr ptr; + + if (IS_ERR(ep = mon_text_read_wait(rp, file))) + return PTR_ERR(ep); + mutex_lock(&rp->printf_lock); + ptr.cnt = 0; + ptr.pbuf = rp->printf_buf; + ptr.limit = rp->printf_size; + + mon_text_read_head_u(rp, &ptr, ep); + if (ep->type == 'E') { + mon_text_read_statset(rp, &ptr, ep); + } else if (ep->xfertype == USB_ENDPOINT_XFER_ISOC) { + mon_text_read_isostat(rp, &ptr, ep); + mon_text_read_isodesc(rp, &ptr, ep); + } else if (ep->xfertype == USB_ENDPOINT_XFER_INT) { + mon_text_read_intstat(rp, &ptr, ep); + } else { + mon_text_read_statset(rp, &ptr, ep); + } + ptr.cnt += snprintf(ptr.pbuf + ptr.cnt, ptr.limit - ptr.cnt, + " %d", ep->length); + mon_text_read_data(rp, &ptr, ep); + + if (copy_to_user(buf, rp->printf_buf, ptr.cnt)) + ptr.cnt = -EFAULT; + mutex_unlock(&rp->printf_lock); + kmem_cache_free(rp->e_slab, ep); + return ptr.cnt; +} + +static struct mon_event_text *mon_text_read_wait(struct mon_reader_text *rp, + struct file *file) +{ + struct mon_bus *mbus = rp->r.m_bus; + DECLARE_WAITQUEUE(waita, current); + struct mon_event_text *ep; + + add_wait_queue(&rp->wait, &waita); + set_current_state(TASK_INTERRUPTIBLE); + while ((ep = mon_text_fetch(rp, mbus)) == NULL) { + if (file->f_flags & O_NONBLOCK) { + set_current_state(TASK_RUNNING); + remove_wait_queue(&rp->wait, &waita); + return ERR_PTR(-EWOULDBLOCK); + } + /* + * We do not count nwaiters, because ->release is supposed + * to be called when all openers are gone only. + */ + schedule(); + if (signal_pending(current)) { + remove_wait_queue(&rp->wait, &waita); + return ERR_PTR(-EINTR); + } + set_current_state(TASK_INTERRUPTIBLE); + } + set_current_state(TASK_RUNNING); + remove_wait_queue(&rp->wait, &waita); + return ep; +} + +static void mon_text_read_head_t(struct mon_reader_text *rp, + struct mon_text_ptr *p, const struct mon_event_text *ep) +{ + char udir, utype; + + udir = (ep->is_in ? 'i' : 'o'); + switch (ep->xfertype) { + case USB_ENDPOINT_XFER_ISOC: utype = 'Z'; break; + case USB_ENDPOINT_XFER_INT: utype = 'I'; break; + case USB_ENDPOINT_XFER_CONTROL: utype = 'C'; break; + default: /* PIPE_BULK */ utype = 'B'; + } + p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, + "%lx %u %c %c%c:%03u:%02u", + ep->id, ep->tstamp, ep->type, + utype, udir, ep->devnum, ep->epnum); +} + +static void mon_text_read_head_u(struct mon_reader_text *rp, + struct mon_text_ptr *p, const struct mon_event_text *ep) +{ + char udir, utype; + + udir = (ep->is_in ? 'i' : 'o'); + switch (ep->xfertype) { + case USB_ENDPOINT_XFER_ISOC: utype = 'Z'; break; + case USB_ENDPOINT_XFER_INT: utype = 'I'; break; + case USB_ENDPOINT_XFER_CONTROL: utype = 'C'; break; + default: /* PIPE_BULK */ utype = 'B'; + } + p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, + "%lx %u %c %c%c:%d:%03u:%u", + ep->id, ep->tstamp, ep->type, + utype, udir, ep->busnum, ep->devnum, ep->epnum); +} + +static void mon_text_read_statset(struct mon_reader_text *rp, + struct mon_text_ptr *p, const struct mon_event_text *ep) +{ + + if (ep->setup_flag == 0) { /* Setup packet is present and captured */ + p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, + " s %02x %02x %04x %04x %04x", + ep->setup[0], + ep->setup[1], + (ep->setup[3] << 8) | ep->setup[2], + (ep->setup[5] << 8) | ep->setup[4], + (ep->setup[7] << 8) | ep->setup[6]); + } else if (ep->setup_flag != '-') { /* Unable to capture setup packet */ + p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, + " %c __ __ ____ ____ ____", ep->setup_flag); + } else { /* No setup for this kind of URB */ + p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, + " %d", ep->status); + } +} + +static void mon_text_read_intstat(struct mon_reader_text *rp, + struct mon_text_ptr *p, const struct mon_event_text *ep) +{ + p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, + " %d:%d", ep->status, ep->interval); +} + +static void mon_text_read_isostat(struct mon_reader_text *rp, + struct mon_text_ptr *p, const struct mon_event_text *ep) +{ + if (ep->type == 'S') { + p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, + " %d:%d:%d", ep->status, ep->interval, ep->start_frame); + } else { + p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, + " %d:%d:%d:%d", + ep->status, ep->interval, ep->start_frame, ep->error_count); + } +} + +static void mon_text_read_isodesc(struct mon_reader_text *rp, + struct mon_text_ptr *p, const struct mon_event_text *ep) +{ + int ndesc; /* Display this many */ + int i; + const struct mon_iso_desc *dp; + + p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, + " %d", ep->numdesc); + ndesc = ep->numdesc; + if (ndesc > ISODESC_MAX) + ndesc = ISODESC_MAX; + if (ndesc < 0) + ndesc = 0; + dp = ep->isodesc; + for (i = 0; i < ndesc; i++) { + p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, + " %d:%u:%u", dp->status, dp->offset, dp->length); + dp++; + } +} + +static void mon_text_read_data(struct mon_reader_text *rp, + struct mon_text_ptr *p, const struct mon_event_text *ep) +{ + int data_len, i; + + if ((data_len = ep->length) > 0) { + if (ep->data_flag == 0) { + p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, + " ="); + if (data_len >= DATA_MAX) + data_len = DATA_MAX; + for (i = 0; i < data_len; i++) { + if (i % 4 == 0) { + p->cnt += snprintf(p->pbuf + p->cnt, + p->limit - p->cnt, + " "); + } + p->cnt += snprintf(p->pbuf + p->cnt, + p->limit - p->cnt, + "%02x", ep->data[i]); + } + p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, + "\n"); + } else { + p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, + " %c\n", ep->data_flag); + } + } else { + p->cnt += snprintf(p->pbuf + p->cnt, p->limit - p->cnt, "\n"); + } +} + +static int mon_text_release(struct inode *inode, struct file *file) +{ + struct mon_reader_text *rp = file->private_data; + struct mon_bus *mbus; + /* unsigned long flags; */ + struct list_head *p; + struct mon_event_text *ep; + + mutex_lock(&mon_lock); + mbus = inode->i_private; + + if (mbus->nreaders <= 0) { + printk(KERN_ERR TAG ": consistency error on close\n"); + mutex_unlock(&mon_lock); + return 0; + } + mon_reader_del(mbus, &rp->r); + + /* + * In theory, e_list is protected by mbus->lock. However, + * after mon_reader_del has finished, the following is the case: + * - we are not on reader list anymore, so new events won't be added; + * - whole mbus may be dropped if it was orphaned. + * So, we better not touch mbus. + */ + /* spin_lock_irqsave(&mbus->lock, flags); */ + while (!list_empty(&rp->e_list)) { + p = rp->e_list.next; + ep = list_entry(p, struct mon_event_text, e_link); + list_del(p); + --rp->nevents; + kmem_cache_free(rp->e_slab, ep); + } + /* spin_unlock_irqrestore(&mbus->lock, flags); */ + + kmem_cache_destroy(rp->e_slab); + kfree(rp->printf_buf); + kfree(rp); + + mutex_unlock(&mon_lock); + return 0; +} + +static const struct file_operations mon_fops_text_t = { + .owner = THIS_MODULE, + .open = mon_text_open, + .llseek = no_llseek, + .read = mon_text_read_t, + .release = mon_text_release, +}; + +static const struct file_operations mon_fops_text_u = { + .owner = THIS_MODULE, + .open = mon_text_open, + .llseek = no_llseek, + .read = mon_text_read_u, + .release = mon_text_release, +}; + +int mon_text_add(struct mon_bus *mbus, const struct usb_bus *ubus) +{ + struct dentry *d; + enum { NAMESZ = 10 }; + char name[NAMESZ]; + int busnum = ubus? ubus->busnum: 0; + int rc; + + if (mon_dir == NULL) + return 0; + + if (ubus != NULL) { + rc = snprintf(name, NAMESZ, "%dt", busnum); + if (rc <= 0 || rc >= NAMESZ) + goto err_print_t; + d = debugfs_create_file(name, 0600, mon_dir, mbus, + &mon_fops_text_t); + if (d == NULL) + goto err_create_t; + mbus->dent_t = d; + } + + rc = snprintf(name, NAMESZ, "%du", busnum); + if (rc <= 0 || rc >= NAMESZ) + goto err_print_u; + d = debugfs_create_file(name, 0600, mon_dir, mbus, &mon_fops_text_u); + if (d == NULL) + goto err_create_u; + mbus->dent_u = d; + + rc = snprintf(name, NAMESZ, "%ds", busnum); + if (rc <= 0 || rc >= NAMESZ) + goto err_print_s; + d = debugfs_create_file(name, 0600, mon_dir, mbus, &mon_fops_stat); + if (d == NULL) + goto err_create_s; + mbus->dent_s = d; + + return 1; + +err_create_s: +err_print_s: + debugfs_remove(mbus->dent_u); + mbus->dent_u = NULL; +err_create_u: +err_print_u: + if (ubus != NULL) { + debugfs_remove(mbus->dent_t); + mbus->dent_t = NULL; + } +err_create_t: +err_print_t: + return 0; +} + +void mon_text_del(struct mon_bus *mbus) +{ + debugfs_remove(mbus->dent_u); + if (mbus->dent_t != NULL) + debugfs_remove(mbus->dent_t); + debugfs_remove(mbus->dent_s); +} + +/* + * Slab interface: constructor. + */ +static void mon_text_ctor(void *mem) +{ + /* + * Nothing to initialize. No, really! + * So, we fill it with garbage to emulate a reused object. + */ + memset(mem, 0xe5, sizeof(struct mon_event_text)); +} + +int __init mon_text_init(void) +{ + struct dentry *mondir; + + mondir = debugfs_create_dir("usbmon", usb_debug_root); + if (IS_ERR(mondir)) { + /* debugfs not available, but we can use usbmon without it */ + return 0; + } + if (mondir == NULL) { + printk(KERN_NOTICE TAG ": unable to create usbmon directory\n"); + return -ENOMEM; + } + mon_dir = mondir; + return 0; +} + +void mon_text_exit(void) +{ + debugfs_remove(mon_dir); +} |