v4.19.13 snapshot.
diff --git a/drivers/usb/mon/mon_text.c b/drivers/usb/mon/mon_text.c
new file mode 100644
index 0000000..bc5ecd5
--- /dev/null
+++ b/drivers/usb/mon/mon_text.c
@@ -0,0 +1,773 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * 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/sched/signal.h>
+#include <linux/time.h>
+#include <linux/ktime.h>
+#include <linux/export.h>
+#include <linux/mutex.h>
+#include <linux/debugfs.h>
+#include <linux/scatterlist.h>
+#include <linux/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;
+ size_t printf_offset;
+ size_t printf_togo;
+ 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 timespec64 now;
+ unsigned int stamp;
+
+ ktime_get_ts64(&now);
+ stamp = now.tv_sec & 0xFFF; /* 2^32 = 4294967296. Limit to 4096s. */
+ stamp = stamp * USEC_PER_SEC + now.tv_nsec / NSEC_PER_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;
+}
+
+static ssize_t mon_text_copy_to_user(struct mon_reader_text *rp,
+ char __user * const buf, const size_t nbytes)
+{
+ const size_t togo = min(nbytes, rp->printf_togo);
+
+ if (copy_to_user(buf, &rp->printf_buf[rp->printf_offset], togo))
+ return -EFAULT;
+ rp->printf_togo -= togo;
+ rp->printf_offset += togo;
+ return togo;
+}
+
+/* ppos is not advanced since the llseek operation is not permitted. */
+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;
+ ssize_t ret;
+
+ mutex_lock(&rp->printf_lock);
+
+ if (rp->printf_togo == 0) {
+
+ ep = mon_text_read_wait(rp, file);
+ if (IS_ERR(ep)) {
+ mutex_unlock(&rp->printf_lock);
+ return PTR_ERR(ep);
+ }
+ 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);
+
+ rp->printf_togo = ptr.cnt;
+ rp->printf_offset = 0;
+
+ kmem_cache_free(rp->e_slab, ep);
+ }
+
+ ret = mon_text_copy_to_user(rp, buf, nbytes);
+ mutex_unlock(&rp->printf_lock);
+ return ret;
+}
+
+/* ppos is not advanced since the llseek operation is not permitted. */
+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;
+ ssize_t ret;
+
+ mutex_lock(&rp->printf_lock);
+
+ if (rp->printf_togo == 0) {
+
+ ep = mon_text_read_wait(rp, file);
+ if (IS_ERR(ep)) {
+ mutex_unlock(&rp->printf_lock);
+ return PTR_ERR(ep);
+ }
+ 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);
+
+ rp->printf_togo = ptr.cnt;
+ rp->printf_offset = 0;
+
+ kmem_cache_free(rp->e_slab, ep);
+ }
+
+ ret = mon_text_copy_to_user(rp, buf, nbytes);
+ mutex_unlock(&rp->printf_lock);
+ return ret;
+}
+
+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)
+{
+ 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;
+ mbus->dent_t = debugfs_create_file(name, 0600, mon_dir, mbus,
+ &mon_fops_text_t);
+ }
+
+ rc = snprintf(name, NAMESZ, "%du", busnum);
+ if (rc <= 0 || rc >= NAMESZ)
+ goto err_print_u;
+ mbus->dent_u = debugfs_create_file(name, 0600, mon_dir, mbus,
+ &mon_fops_text_u);
+
+ rc = snprintf(name, NAMESZ, "%ds", busnum);
+ if (rc <= 0 || rc >= NAMESZ)
+ goto err_print_s;
+ mbus->dent_s = debugfs_create_file(name, 0600, mon_dir, mbus,
+ &mon_fops_stat);
+
+ return 1;
+
+err_print_s:
+ debugfs_remove(mbus->dent_u);
+ mbus->dent_u = NULL;
+err_print_u:
+ if (ubus != NULL) {
+ debugfs_remove(mbus->dent_t);
+ mbus->dent_t = NULL;
+ }
+err_print_t:
+ return 0;
+}
+
+void mon_text_del(struct mon_bus *mbus)
+{
+ debugfs_remove(mbus->dent_u);
+ 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)
+{
+ mon_dir = debugfs_create_dir("usbmon", usb_debug_root);
+ return 0;
+}
+
+void mon_text_exit(void)
+{
+ debugfs_remove(mon_dir);
+}