Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

7 files changed, 2796 insertions, 0 deletions

diff --git a/drivers/usb/mon/Kconfig b/drivers/usb/mon/Kconfig
new file mode 100644
index 000000000..ffc7cd422
--- /dev/null
+++ b/drivers/usb/mon/Kconfig
@@ -0,0 +1,13 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# USB Monitor configuration
+#
+
+config USB_MON
+	tristate "USB Monitor"
+	help
+	  If you select this option, a component which captures the USB traffic
+	  between peripheral-specific drivers and HC drivers will be built.
+	  For more information, see <file:Documentation/usb/usbmon.rst>.
+
+	  If unsure, say Y, if allowed, otherwise M.
diff --git a/drivers/usb/mon/Makefile b/drivers/usb/mon/Makefile
new file mode 100644
index 000000000..09f43e896
--- /dev/null
+++ b/drivers/usb/mon/Makefile
@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for USB monitor
+#
+
+usbmon-y := mon_main.o mon_stat.o mon_text.o mon_bin.o
+
+obj-$(CONFIG_USB_MON)	+= usbmon.o
diff --git a/drivers/usb/mon/mon_bin.c b/drivers/usb/mon/mon_bin.c
new file mode 100644
index 000000000..35483217b
--- /dev/null
+++ b/drivers/usb/mon/mon_bin.c
@@ -0,0 +1,1420 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * The USB Monitor, inspired by Dave Harding's USBMon.
+ *
+ * This is a binary format reader.
+ *
+ * Copyright (C) 2006 Paolo Abeni (paolo.abeni@email.it)
+ * Copyright (C) 2006,2007 Pete Zaitcev (zaitcev@redhat.com)
+ */
+
+#include <linux/kernel.h>
+#include <linux/sched/signal.h>
+#include <linux/types.h>
+#include <linux/fs.h>
+#include <linux/cdev.h>
+#include <linux/export.h>
+#include <linux/usb.h>
+#include <linux/poll.h>
+#include <linux/compat.h>
+#include <linux/mm.h>
+#include <linux/scatterlist.h>
+#include <linux/slab.h>
+#include <linux/time64.h>
+
+#include <linux/uaccess.h>
+
+#include "usb_mon.h"
+
+/*
+ * Defined by USB 2.0 clause 9.3, table 9.2.
+ */
+#define SETUP_LEN  8
+
+/* ioctl macros */
+#define MON_IOC_MAGIC 0x92
+
+#define MON_IOCQ_URB_LEN _IO(MON_IOC_MAGIC, 1)
+/* #2 used to be MON_IOCX_URB, removed before it got into Linus tree */
+#define MON_IOCG_STATS _IOR(MON_IOC_MAGIC, 3, struct mon_bin_stats)
+#define MON_IOCT_RING_SIZE _IO(MON_IOC_MAGIC, 4)
+#define MON_IOCQ_RING_SIZE _IO(MON_IOC_MAGIC, 5)
+#define MON_IOCX_GET   _IOW(MON_IOC_MAGIC, 6, struct mon_bin_get)
+#define MON_IOCX_MFETCH _IOWR(MON_IOC_MAGIC, 7, struct mon_bin_mfetch)
+#define MON_IOCH_MFLUSH _IO(MON_IOC_MAGIC, 8)
+/* #9 was MON_IOCT_SETAPI */
+#define MON_IOCX_GETX   _IOW(MON_IOC_MAGIC, 10, struct mon_bin_get)
+
+#ifdef CONFIG_COMPAT
+#define MON_IOCX_GET32 _IOW(MON_IOC_MAGIC, 6, struct mon_bin_get32)
+#define MON_IOCX_MFETCH32 _IOWR(MON_IOC_MAGIC, 7, struct mon_bin_mfetch32)
+#define MON_IOCX_GETX32   _IOW(MON_IOC_MAGIC, 10, struct mon_bin_get32)
+#endif
+
+/*
+ * Some architectures have enormous basic pages (16KB for ia64, 64KB for ppc).
+ * But it's all right. Just use a simple way to make sure the chunk is never
+ * smaller than a page.
+ *
+ * N.B. An application does not know our chunk size.
+ *
+ * Woops, get_zeroed_page() returns a single page. I guess we're stuck with
+ * page-sized chunks for the time being.
+ */
+#define CHUNK_SIZE   PAGE_SIZE
+#define CHUNK_ALIGN(x)   (((x)+CHUNK_SIZE-1) & ~(CHUNK_SIZE-1))
+
+/*
+ * The magic limit was calculated so that it allows the monitoring
+ * application to pick data once in two ticks. This way, another application,
+ * which presumably drives the bus, gets to hog CPU, yet we collect our data.
+ * If HZ is 100, a 480 mbit/s bus drives 614 KB every jiffy. USB has an
+ * enormous overhead built into the bus protocol, so we need about 1000 KB.
+ *
+ * This is still too much for most cases, where we just snoop a few
+ * descriptor fetches for enumeration. So, the default is a "reasonable"
+ * amount for systems with HZ=250 and incomplete bus saturation.
+ *
+ * XXX What about multi-megabyte URBs which take minutes to transfer?
+ */
+#define BUFF_MAX  CHUNK_ALIGN(1200*1024)
+#define BUFF_DFL   CHUNK_ALIGN(300*1024)
+#define BUFF_MIN     CHUNK_ALIGN(8*1024)
+
+/*
+ * The per-event API header (2 per URB).
+ *
+ * This structure is seen in userland as defined by the documentation.
+ */
+struct mon_bin_hdr {
+	u64 id;			/* URB ID - from submission to callback */
+	unsigned char type;	/* Same as in text API; extensible. */
+	unsigned char xfer_type;	/* ISO, Intr, Control, Bulk */
+	unsigned char epnum;	/* Endpoint number and transfer direction */
+	unsigned char devnum;	/* Device address */
+	unsigned short busnum;	/* Bus number */
+	char flag_setup;
+	char flag_data;
+	s64 ts_sec;		/* ktime_get_real_ts64 */
+	s32 ts_usec;		/* ktime_get_real_ts64 */
+	int status;
+	unsigned int len_urb;	/* Length of data (submitted or actual) */
+	unsigned int len_cap;	/* Delivered length */
+	union {
+		unsigned char setup[SETUP_LEN];	/* Only for Control S-type */
+		struct iso_rec {
+			int error_count;
+			int numdesc;
+		} iso;
+	} s;
+	int interval;
+	int start_frame;
+	unsigned int xfer_flags;
+	unsigned int ndesc;	/* Actual number of ISO descriptors */
+};
+
+/*
+ * ISO vector, packed into the head of data stream.
+ * This has to take 16 bytes to make sure that the end of buffer
+ * wrap is not happening in the middle of a descriptor.
+ */
+struct mon_bin_isodesc {
+	int          iso_status;
+	unsigned int iso_off;
+	unsigned int iso_len;
+	u32 _pad;
+};
+
+/* per file statistic */
+struct mon_bin_stats {
+	u32 queued;
+	u32 dropped;
+};
+
+struct mon_bin_get {
+	struct mon_bin_hdr __user *hdr;	/* Can be 48 bytes or 64. */
+	void __user *data;
+	size_t alloc;		/* Length of data (can be zero) */
+};
+
+struct mon_bin_mfetch {
+	u32 __user *offvec;	/* Vector of events fetched */
+	u32 nfetch;		/* Number of events to fetch (out: fetched) */
+	u32 nflush;		/* Number of events to flush */
+};
+
+#ifdef CONFIG_COMPAT
+struct mon_bin_get32 {
+	u32 hdr32;
+	u32 data32;
+	u32 alloc32;
+};
+
+struct mon_bin_mfetch32 {
+        u32 offvec32;
+        u32 nfetch32;
+        u32 nflush32;
+};
+#endif
+
+/* Having these two values same prevents wrapping of the mon_bin_hdr */
+#define PKT_ALIGN   64
+#define PKT_SIZE    64
+
+#define PKT_SZ_API0 48	/* API 0 (2.6.20) size */
+#define PKT_SZ_API1 64	/* API 1 size: extra fields */
+
+#define ISODESC_MAX   128	/* Same number as usbfs allows, 2048 bytes. */
+
+/* max number of USB bus supported */
+#define MON_BIN_MAX_MINOR 128
+
+/*
+ * The buffer: map of used pages.
+ */
+struct mon_pgmap {
+	struct page *pg;
+	unsigned char *ptr;	/* XXX just use page_to_virt everywhere? */
+};
+
+/*
+ * This gets associated with an open file struct.
+ */
+struct mon_reader_bin {
+	/* The buffer: one per open. */
+	spinlock_t b_lock;		/* Protect b_cnt, b_in */
+	unsigned int b_size;		/* Current size of the buffer - bytes */
+	unsigned int b_cnt;		/* Bytes used */
+	unsigned int b_in, b_out;	/* Offsets into buffer - bytes */
+	unsigned int b_read;		/* Amount of read data in curr. pkt. */
+	struct mon_pgmap *b_vec;	/* The map array */
+	wait_queue_head_t b_wait;	/* Wait for data here */
+
+	struct mutex fetch_lock;	/* Protect b_read, b_out */
+	int mmap_active;
+
+	/* A list of these is needed for "bus 0". Some time later. */
+	struct mon_reader r;
+
+	/* Stats */
+	unsigned int cnt_lost;
+};
+
+static inline struct mon_bin_hdr *MON_OFF2HDR(const struct mon_reader_bin *rp,
+    unsigned int offset)
+{
+	return (struct mon_bin_hdr *)
+	    (rp->b_vec[offset / CHUNK_SIZE].ptr + offset % CHUNK_SIZE);
+}
+
+#define MON_RING_EMPTY(rp)	((rp)->b_cnt == 0)
+
+static unsigned char xfer_to_pipe[4] = {
+	PIPE_CONTROL, PIPE_ISOCHRONOUS, PIPE_BULK, PIPE_INTERRUPT
+};
+
+static struct class *mon_bin_class;
+static dev_t mon_bin_dev0;
+static struct cdev mon_bin_cdev;
+
+static void mon_buff_area_fill(const struct mon_reader_bin *rp,
+    unsigned int offset, unsigned int size);
+static int mon_bin_wait_event(struct file *file, struct mon_reader_bin *rp);
+static int mon_alloc_buff(struct mon_pgmap *map, int npages);
+static void mon_free_buff(struct mon_pgmap *map, int npages);
+
+/*
+ * This is a "chunked memcpy". It does not manipulate any counters.
+ */
+static unsigned int mon_copy_to_buff(const struct mon_reader_bin *this,
+    unsigned int off, const unsigned char *from, unsigned int length)
+{
+	unsigned int step_len;
+	unsigned char *buf;
+	unsigned int in_page;
+
+	while (length) {
+		/*
+		 * Determine step_len.
+		 */
+		step_len = length;
+		in_page = CHUNK_SIZE - (off & (CHUNK_SIZE-1));
+		if (in_page < step_len)
+			step_len = in_page;
+
+		/*
+		 * Copy data and advance pointers.
+		 */
+		buf = this->b_vec[off / CHUNK_SIZE].ptr + off % CHUNK_SIZE;
+		memcpy(buf, from, step_len);
+		if ((off += step_len) >= this->b_size) off = 0;
+		from += step_len;
+		length -= step_len;
+	}
+	return off;
+}
+
+/*
+ * This is a little worse than the above because it's "chunked copy_to_user".
+ * The return value is an error code, not an offset.
+ */
+static int copy_from_buf(const struct mon_reader_bin *this, unsigned int off,
+    char __user *to, int length)
+{
+	unsigned int step_len;
+	unsigned char *buf;
+	unsigned int in_page;
+
+	while (length) {
+		/*
+		 * Determine step_len.
+		 */
+		step_len = length;
+		in_page = CHUNK_SIZE - (off & (CHUNK_SIZE-1));
+		if (in_page < step_len)
+			step_len = in_page;
+
+		/*
+		 * Copy data and advance pointers.
+		 */
+		buf = this->b_vec[off / CHUNK_SIZE].ptr + off % CHUNK_SIZE;
+		if (copy_to_user(to, buf, step_len))
+			return -EINVAL;
+		if ((off += step_len) >= this->b_size) off = 0;
+		to += step_len;
+		length -= step_len;
+	}
+	return 0;
+}
+
+/*
+ * Allocate an (aligned) area in the buffer.
+ * This is called under b_lock.
+ * Returns ~0 on failure.
+ */
+static unsigned int mon_buff_area_alloc(struct mon_reader_bin *rp,
+    unsigned int size)
+{
+	unsigned int offset;
+
+	size = (size + PKT_ALIGN-1) & ~(PKT_ALIGN-1);
+	if (rp->b_cnt + size > rp->b_size)
+		return ~0;
+	offset = rp->b_in;
+	rp->b_cnt += size;
+	if ((rp->b_in += size) >= rp->b_size)
+		rp->b_in -= rp->b_size;
+	return offset;
+}
+
+/*
+ * This is the same thing as mon_buff_area_alloc, only it does not allow
+ * buffers to wrap. This is needed by applications which pass references
+ * into mmap-ed buffers up their stacks (libpcap can do that).
+ *
+ * Currently, we always have the header stuck with the data, although
+ * it is not strictly speaking necessary.
+ *
+ * When a buffer would wrap, we place a filler packet to mark the space.
+ */
+static unsigned int mon_buff_area_alloc_contiguous(struct mon_reader_bin *rp,
+    unsigned int size)
+{
+	unsigned int offset;
+	unsigned int fill_size;
+
+	size = (size + PKT_ALIGN-1) & ~(PKT_ALIGN-1);
+	if (rp->b_cnt + size > rp->b_size)
+		return ~0;
+	if (rp->b_in + size > rp->b_size) {
+		/*
+		 * This would wrap. Find if we still have space after
+		 * skipping to the end of the buffer. If we do, place
+		 * a filler packet and allocate a new packet.
+		 */
+		fill_size = rp->b_size - rp->b_in;
+		if (rp->b_cnt + size + fill_size > rp->b_size)
+			return ~0;
+		mon_buff_area_fill(rp, rp->b_in, fill_size);
+
+		offset = 0;
+		rp->b_in = size;
+		rp->b_cnt += size + fill_size;
+	} else if (rp->b_in + size == rp->b_size) {
+		offset = rp->b_in;
+		rp->b_in = 0;
+		rp->b_cnt += size;
+	} else {
+		offset = rp->b_in;
+		rp->b_in += size;
+		rp->b_cnt += size;
+	}
+	return offset;
+}
+
+/*
+ * Return a few (kilo-)bytes to the head of the buffer.
+ * This is used if a data fetch fails.
+ */
+static void mon_buff_area_shrink(struct mon_reader_bin *rp, unsigned int size)
+{
+
+	/* size &= ~(PKT_ALIGN-1);  -- we're called with aligned size */
+	rp->b_cnt -= size;
+	if (rp->b_in < size)
+		rp->b_in += rp->b_size;
+	rp->b_in -= size;
+}
+
+/*
+ * This has to be called under both b_lock and fetch_lock, because
+ * it accesses both b_cnt and b_out.
+ */
+static void mon_buff_area_free(struct mon_reader_bin *rp, unsigned int size)
+{
+
+	size = (size + PKT_ALIGN-1) & ~(PKT_ALIGN-1);
+	rp->b_cnt -= size;
+	if ((rp->b_out += size) >= rp->b_size)
+		rp->b_out -= rp->b_size;
+}
+
+static void mon_buff_area_fill(const struct mon_reader_bin *rp,
+    unsigned int offset, unsigned int size)
+{
+	struct mon_bin_hdr *ep;
+
+	ep = MON_OFF2HDR(rp, offset);
+	memset(ep, 0, PKT_SIZE);
+	ep->type = '@';
+	ep->len_cap = size - PKT_SIZE;
+}
+
+static inline char mon_bin_get_setup(unsigned char *setupb,
+    const struct urb *urb, char ev_type)
+{
+
+	if (urb->setup_packet == NULL)
+		return 'Z';
+	memcpy(setupb, urb->setup_packet, SETUP_LEN);
+	return 0;
+}
+
+static unsigned int mon_bin_get_data(const struct mon_reader_bin *rp,
+    unsigned int offset, struct urb *urb, unsigned int length,
+    char *flag)
+{
+	int i;
+	struct scatterlist *sg;
+	unsigned int this_len;
+
+	*flag = 0;
+	if (urb->num_sgs == 0) {
+		if (urb->transfer_buffer == NULL) {
+			*flag = 'Z';
+			return length;
+		}
+		mon_copy_to_buff(rp, offset, urb->transfer_buffer, length);
+		length = 0;
+
+	} else {
+		/* If IOMMU coalescing occurred, we cannot trust sg_page */
+		if (urb->transfer_flags & URB_DMA_SG_COMBINED) {
+			*flag = 'D';
+			return length;
+		}
+
+		/* Copy up to the first non-addressable segment */
+		for_each_sg(urb->sg, sg, urb->num_sgs, i) {
+			if (length == 0 || PageHighMem(sg_page(sg)))
+				break;
+			this_len = min_t(unsigned int, sg->length, length);
+			offset = mon_copy_to_buff(rp, offset, sg_virt(sg),
+					this_len);
+			length -= this_len;
+		}
+		if (i == 0)
+			*flag = 'D';
+	}
+
+	return length;
+}
+
+/*
+ * This is the look-ahead pass in case of 'C Zi', when actual_length cannot
+ * be used to determine the length of the whole contiguous buffer.
+ */
+static unsigned int mon_bin_collate_isodesc(const struct mon_reader_bin *rp,
+    struct urb *urb, unsigned int ndesc)
+{
+	struct usb_iso_packet_descriptor *fp;
+	unsigned int length;
+
+	length = 0;
+	fp = urb->iso_frame_desc;
+	while (ndesc-- != 0) {
+		if (fp->actual_length != 0) {
+			if (fp->offset + fp->actual_length > length)
+				length = fp->offset + fp->actual_length;
+		}
+		fp++;
+	}
+	return length;
+}
+
+static void mon_bin_get_isodesc(const struct mon_reader_bin *rp,
+    unsigned int offset, struct urb *urb, char ev_type, unsigned int ndesc)
+{
+	struct mon_bin_isodesc *dp;
+	struct usb_iso_packet_descriptor *fp;
+
+	fp = urb->iso_frame_desc;
+	while (ndesc-- != 0) {
+		dp = (struct mon_bin_isodesc *)
+		    (rp->b_vec[offset / CHUNK_SIZE].ptr + offset % CHUNK_SIZE);
+		dp->iso_status = fp->status;
+		dp->iso_off = fp->offset;
+		dp->iso_len = (ev_type == 'S') ? fp->length : fp->actual_length;
+		dp->_pad = 0;
+		if ((offset += sizeof(struct mon_bin_isodesc)) >= rp->b_size)
+			offset = 0;
+		fp++;
+	}
+}
+
+static void mon_bin_event(struct mon_reader_bin *rp, struct urb *urb,
+    char ev_type, int status)
+{
+	const struct usb_endpoint_descriptor *epd = &urb->ep->desc;
+	struct timespec64 ts;
+	unsigned long flags;
+	unsigned int urb_length;
+	unsigned int offset;
+	unsigned int length;
+	unsigned int delta;
+	unsigned int ndesc, lendesc;
+	unsigned char dir;
+	struct mon_bin_hdr *ep;
+	char data_tag = 0;
+
+	ktime_get_real_ts64(&ts);
+
+	spin_lock_irqsave(&rp->b_lock, flags);
+
+	/*
+	 * Find the maximum allowable length, then allocate space.
+	 */
+	urb_length = (ev_type == 'S') ?
+	    urb->transfer_buffer_length : urb->actual_length;
+	length = urb_length;
+
+	if (usb_endpoint_xfer_isoc(epd)) {
+		if (urb->number_of_packets < 0) {
+			ndesc = 0;
+		} else if (urb->number_of_packets >= ISODESC_MAX) {
+			ndesc = ISODESC_MAX;
+		} else {
+			ndesc = urb->number_of_packets;
+		}
+		if (ev_type == 'C' && usb_urb_dir_in(urb))
+			length = mon_bin_collate_isodesc(rp, urb, ndesc);
+	} else {
+		ndesc = 0;
+	}
+	lendesc = ndesc*sizeof(struct mon_bin_isodesc);
+
+	/* not an issue unless there's a subtle bug in a HCD somewhere */
+	if (length >= urb->transfer_buffer_length)
+		length = urb->transfer_buffer_length;
+
+	if (length >= rp->b_size/5)
+		length = rp->b_size/5;
+
+	if (usb_urb_dir_in(urb)) {
+		if (ev_type == 'S') {
+			length = 0;
+			data_tag = '<';
+		}
+		/* Cannot rely on endpoint number in case of control ep.0 */
+		dir = USB_DIR_IN;
+	} else {
+		if (ev_type == 'C') {
+			length = 0;
+			data_tag = '>';
+		}
+		dir = 0;
+	}
+
+	if (rp->mmap_active) {
+		offset = mon_buff_area_alloc_contiguous(rp,
+						 length + PKT_SIZE + lendesc);
+	} else {
+		offset = mon_buff_area_alloc(rp, length + PKT_SIZE + lendesc);
+	}
+	if (offset == ~0) {
+		rp->cnt_lost++;
+		spin_unlock_irqrestore(&rp->b_lock, flags);
+		return;
+	}
+
+	ep = MON_OFF2HDR(rp, offset);
+	if ((offset += PKT_SIZE) >= rp->b_size) offset = 0;
+
+	/*
+	 * Fill the allocated area.
+	 */
+	memset(ep, 0, PKT_SIZE);
+	ep->type = ev_type;
+	ep->xfer_type = xfer_to_pipe[usb_endpoint_type(epd)];
+	ep->epnum = dir | usb_endpoint_num(epd);
+	ep->devnum = urb->dev->devnum;
+	ep->busnum = urb->dev->bus->busnum;
+	ep->id = (unsigned long) urb;
+	ep->ts_sec = ts.tv_sec;
+	ep->ts_usec = ts.tv_nsec / NSEC_PER_USEC;
+	ep->status = status;
+	ep->len_urb = urb_length;
+	ep->len_cap = length + lendesc;
+	ep->xfer_flags = urb->transfer_flags;
+
+	if (usb_endpoint_xfer_int(epd)) {
+		ep->interval = urb->interval;
+	} else if (usb_endpoint_xfer_isoc(epd)) {
+		ep->interval = urb->interval;
+		ep->start_frame = urb->start_frame;
+		ep->s.iso.error_count = urb->error_count;
+		ep->s.iso.numdesc = urb->number_of_packets;
+	}
+
+	if (usb_endpoint_xfer_control(epd) && ev_type == 'S') {
+		ep->flag_setup = mon_bin_get_setup(ep->s.setup, urb, ev_type);
+	} else {
+		ep->flag_setup = '-';
+	}
+
+	if (ndesc != 0) {
+		ep->ndesc = ndesc;
+		mon_bin_get_isodesc(rp, offset, urb, ev_type, ndesc);
+		if ((offset += lendesc) >= rp->b_size)
+			offset -= rp->b_size;
+	}
+
+	if (length != 0) {
+		length = mon_bin_get_data(rp, offset, urb, length,
+				&ep->flag_data);
+		if (length > 0) {
+			delta = (ep->len_cap + PKT_ALIGN-1) & ~(PKT_ALIGN-1);
+			ep->len_cap -= length;
+			delta -= (ep->len_cap + PKT_ALIGN-1) & ~(PKT_ALIGN-1);
+			mon_buff_area_shrink(rp, delta);
+		}
+	} else {
+		ep->flag_data = data_tag;
+	}
+
+	spin_unlock_irqrestore(&rp->b_lock, flags);
+
+	wake_up(&rp->b_wait);
+}
+
+static void mon_bin_submit(void *data, struct urb *urb)
+{
+	struct mon_reader_bin *rp = data;
+	mon_bin_event(rp, urb, 'S', -EINPROGRESS);
+}
+
+static void mon_bin_complete(void *data, struct urb *urb, int status)
+{
+	struct mon_reader_bin *rp = data;
+	mon_bin_event(rp, urb, 'C', status);
+}
+
+static void mon_bin_error(void *data, struct urb *urb, int error)
+{
+	struct mon_reader_bin *rp = data;
+	struct timespec64 ts;
+	unsigned long flags;
+	unsigned int offset;
+	struct mon_bin_hdr *ep;
+
+	ktime_get_real_ts64(&ts);
+
+	spin_lock_irqsave(&rp->b_lock, flags);
+
+	offset = mon_buff_area_alloc(rp, PKT_SIZE);
+	if (offset == ~0) {
+		/* Not incrementing cnt_lost. Just because. */
+		spin_unlock_irqrestore(&rp->b_lock, flags);
+		return;
+	}
+
+	ep = MON_OFF2HDR(rp, offset);
+
+	memset(ep, 0, PKT_SIZE);
+	ep->type = 'E';
+	ep->xfer_type = xfer_to_pipe[usb_endpoint_type(&urb->ep->desc)];
+	ep->epnum = usb_urb_dir_in(urb) ? USB_DIR_IN : 0;
+	ep->epnum |= usb_endpoint_num(&urb->ep->desc);
+	ep->devnum = urb->dev->devnum;
+	ep->busnum = urb->dev->bus->busnum;
+	ep->id = (unsigned long) urb;
+	ep->ts_sec = ts.tv_sec;
+	ep->ts_usec = ts.tv_nsec / NSEC_PER_USEC;
+	ep->status = error;
+
+	ep->flag_setup = '-';
+	ep->flag_data = 'E';
+
+	spin_unlock_irqrestore(&rp->b_lock, flags);
+
+	wake_up(&rp->b_wait);
+}
+
+static int mon_bin_open(struct inode *inode, struct file *file)
+{
+	struct mon_bus *mbus;
+	struct mon_reader_bin *rp;
+	size_t size;
+	int rc;
+
+	mutex_lock(&mon_lock);
+	mbus = mon_bus_lookup(iminor(inode));
+	if (mbus == NULL) {
+		mutex_unlock(&mon_lock);
+		return -ENODEV;
+	}
+	if (mbus != &mon_bus0 && mbus->u_bus == NULL) {
+		printk(KERN_ERR TAG ": consistency error on open\n");
+		mutex_unlock(&mon_lock);
+		return -ENODEV;
+	}
+
+	rp = kzalloc(sizeof(struct mon_reader_bin), GFP_KERNEL);
+	if (rp == NULL) {
+		rc = -ENOMEM;
+		goto err_alloc;
+	}
+	spin_lock_init(&rp->b_lock);
+	init_waitqueue_head(&rp->b_wait);
+	mutex_init(&rp->fetch_lock);
+	rp->b_size = BUFF_DFL;
+
+	size = sizeof(struct mon_pgmap) * (rp->b_size/CHUNK_SIZE);
+	if ((rp->b_vec = kzalloc(size, GFP_KERNEL)) == NULL) {
+		rc = -ENOMEM;
+		goto err_allocvec;
+	}
+
+	if ((rc = mon_alloc_buff(rp->b_vec, rp->b_size/CHUNK_SIZE)) < 0)
+		goto err_allocbuff;
+
+	rp->r.m_bus = mbus;
+	rp->r.r_data = rp;
+	rp->r.rnf_submit = mon_bin_submit;
+	rp->r.rnf_error = mon_bin_error;
+	rp->r.rnf_complete = mon_bin_complete;
+
+	mon_reader_add(mbus, &rp->r);
+
+	file->private_data = rp;
+	mutex_unlock(&mon_lock);
+	return 0;
+
+err_allocbuff:
+	kfree(rp->b_vec);
+err_allocvec:
+	kfree(rp);
+err_alloc:
+	mutex_unlock(&mon_lock);
+	return rc;
+}
+
+/*
+ * Extract an event from buffer and copy it to user space.
+ * Wait if there is no event ready.
+ * Returns zero or error.
+ */
+static int mon_bin_get_event(struct file *file, struct mon_reader_bin *rp,
+    struct mon_bin_hdr __user *hdr, unsigned int hdrbytes,
+    void __user *data, unsigned int nbytes)
+{
+	unsigned long flags;
+	struct mon_bin_hdr *ep;
+	size_t step_len;
+	unsigned int offset;
+	int rc;
+
+	mutex_lock(&rp->fetch_lock);
+
+	if ((rc = mon_bin_wait_event(file, rp)) < 0) {
+		mutex_unlock(&rp->fetch_lock);
+		return rc;
+	}
+
+	ep = MON_OFF2HDR(rp, rp->b_out);
+
+	if (copy_to_user(hdr, ep, hdrbytes)) {
+		mutex_unlock(&rp->fetch_lock);
+		return -EFAULT;
+	}
+
+	step_len = min(ep->len_cap, nbytes);
+	if ((offset = rp->b_out + PKT_SIZE) >= rp->b_size) offset = 0;
+
+	if (copy_from_buf(rp, offset, data, step_len)) {
+		mutex_unlock(&rp->fetch_lock);
+		return -EFAULT;
+	}
+
+	spin_lock_irqsave(&rp->b_lock, flags);
+	mon_buff_area_free(rp, PKT_SIZE + ep->len_cap);
+	spin_unlock_irqrestore(&rp->b_lock, flags);
+	rp->b_read = 0;
+
+	mutex_unlock(&rp->fetch_lock);
+	return 0;
+}
+
+static int mon_bin_release(struct inode *inode, struct file *file)
+{
+	struct mon_reader_bin *rp = file->private_data;
+	struct mon_bus* mbus = rp->r.m_bus;
+
+	mutex_lock(&mon_lock);
+
+	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);
+
+	mon_free_buff(rp->b_vec, rp->b_size/CHUNK_SIZE);
+	kfree(rp->b_vec);
+	kfree(rp);
+
+	mutex_unlock(&mon_lock);
+	return 0;
+}
+
+static ssize_t mon_bin_read(struct file *file, char __user *buf,
+    size_t nbytes, loff_t *ppos)
+{
+	struct mon_reader_bin *rp = file->private_data;
+	unsigned int hdrbytes = PKT_SZ_API0;
+	unsigned long flags;
+	struct mon_bin_hdr *ep;
+	unsigned int offset;
+	size_t step_len;
+	char *ptr;
+	ssize_t done = 0;
+	int rc;
+
+	mutex_lock(&rp->fetch_lock);
+
+	if ((rc = mon_bin_wait_event(file, rp)) < 0) {
+		mutex_unlock(&rp->fetch_lock);
+		return rc;
+	}
+
+	ep = MON_OFF2HDR(rp, rp->b_out);
+
+	if (rp->b_read < hdrbytes) {
+		step_len = min(nbytes, (size_t)(hdrbytes - rp->b_read));
+		ptr = ((char *)ep) + rp->b_read;
+		if (step_len && copy_to_user(buf, ptr, step_len)) {
+			mutex_unlock(&rp->fetch_lock);
+			return -EFAULT;
+		}
+		nbytes -= step_len;
+		buf += step_len;
+		rp->b_read += step_len;
+		done += step_len;
+	}
+
+	if (rp->b_read >= hdrbytes) {
+		step_len = ep->len_cap;
+		step_len -= rp->b_read - hdrbytes;
+		if (step_len > nbytes)
+			step_len = nbytes;
+		offset = rp->b_out + PKT_SIZE;
+		offset += rp->b_read - hdrbytes;
+		if (offset >= rp->b_size)
+			offset -= rp->b_size;
+		if (copy_from_buf(rp, offset, buf, step_len)) {
+			mutex_unlock(&rp->fetch_lock);
+			return -EFAULT;
+		}
+		nbytes -= step_len;
+		buf += step_len;
+		rp->b_read += step_len;
+		done += step_len;
+	}
+
+	/*
+	 * Check if whole packet was read, and if so, jump to the next one.
+	 */
+	if (rp->b_read >= hdrbytes + ep->len_cap) {
+		spin_lock_irqsave(&rp->b_lock, flags);
+		mon_buff_area_free(rp, PKT_SIZE + ep->len_cap);
+		spin_unlock_irqrestore(&rp->b_lock, flags);
+		rp->b_read = 0;
+	}
+
+	mutex_unlock(&rp->fetch_lock);
+	return done;
+}
+
+/*
+ * Remove at most nevents from chunked buffer.
+ * Returns the number of removed events.
+ */
+static int mon_bin_flush(struct mon_reader_bin *rp, unsigned nevents)
+{
+	unsigned long flags;
+	struct mon_bin_hdr *ep;
+	int i;
+
+	mutex_lock(&rp->fetch_lock);
+	spin_lock_irqsave(&rp->b_lock, flags);
+	for (i = 0; i < nevents; ++i) {
+		if (MON_RING_EMPTY(rp))
+			break;
+
+		ep = MON_OFF2HDR(rp, rp->b_out);
+		mon_buff_area_free(rp, PKT_SIZE + ep->len_cap);
+	}
+	spin_unlock_irqrestore(&rp->b_lock, flags);
+	rp->b_read = 0;
+	mutex_unlock(&rp->fetch_lock);
+	return i;
+}
+
+/*
+ * Fetch at most max event offsets into the buffer and put them into vec.
+ * The events are usually freed later with mon_bin_flush.
+ * Return the effective number of events fetched.
+ */
+static int mon_bin_fetch(struct file *file, struct mon_reader_bin *rp,
+    u32 __user *vec, unsigned int max)
+{
+	unsigned int cur_out;
+	unsigned int bytes, avail;
+	unsigned int size;
+	unsigned int nevents;
+	struct mon_bin_hdr *ep;
+	unsigned long flags;
+	int rc;
+
+	mutex_lock(&rp->fetch_lock);
+
+	if ((rc = mon_bin_wait_event(file, rp)) < 0) {
+		mutex_unlock(&rp->fetch_lock);
+		return rc;
+	}
+
+	spin_lock_irqsave(&rp->b_lock, flags);
+	avail = rp->b_cnt;
+	spin_unlock_irqrestore(&rp->b_lock, flags);
+
+	cur_out = rp->b_out;
+	nevents = 0;
+	bytes = 0;
+	while (bytes < avail) {
+		if (nevents >= max)
+			break;
+
+		ep = MON_OFF2HDR(rp, cur_out);
+		if (put_user(cur_out, &vec[nevents])) {
+			mutex_unlock(&rp->fetch_lock);
+			return -EFAULT;
+		}
+
+		nevents++;
+		size = ep->len_cap + PKT_SIZE;
+		size = (size + PKT_ALIGN-1) & ~(PKT_ALIGN-1);
+		if ((cur_out += size) >= rp->b_size)
+			cur_out -= rp->b_size;
+		bytes += size;
+	}
+
+	mutex_unlock(&rp->fetch_lock);
+	return nevents;
+}
+
+/*
+ * Count events. This is almost the same as the above mon_bin_fetch,
+ * only we do not store offsets into user vector, and we have no limit.
+ */
+static int mon_bin_queued(struct mon_reader_bin *rp)
+{
+	unsigned int cur_out;
+	unsigned int bytes, avail;
+	unsigned int size;
+	unsigned int nevents;
+	struct mon_bin_hdr *ep;
+	unsigned long flags;
+
+	mutex_lock(&rp->fetch_lock);
+
+	spin_lock_irqsave(&rp->b_lock, flags);
+	avail = rp->b_cnt;
+	spin_unlock_irqrestore(&rp->b_lock, flags);
+
+	cur_out = rp->b_out;
+	nevents = 0;
+	bytes = 0;
+	while (bytes < avail) {
+		ep = MON_OFF2HDR(rp, cur_out);
+
+		nevents++;
+		size = ep->len_cap + PKT_SIZE;
+		size = (size + PKT_ALIGN-1) & ~(PKT_ALIGN-1);
+		if ((cur_out += size) >= rp->b_size)
+			cur_out -= rp->b_size;
+		bytes += size;
+	}
+
+	mutex_unlock(&rp->fetch_lock);
+	return nevents;
+}
+
+/*
+ */
+static long mon_bin_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	struct mon_reader_bin *rp = file->private_data;
+	// struct mon_bus* mbus = rp->r.m_bus;
+	int ret = 0;
+	struct mon_bin_hdr *ep;
+	unsigned long flags;
+
+	switch (cmd) {
+
+	case MON_IOCQ_URB_LEN:
+		/*
+		 * N.B. This only returns the size of data, without the header.
+		 */
+		spin_lock_irqsave(&rp->b_lock, flags);
+		if (!MON_RING_EMPTY(rp)) {
+			ep = MON_OFF2HDR(rp, rp->b_out);
+			ret = ep->len_cap;
+		}
+		spin_unlock_irqrestore(&rp->b_lock, flags);
+		break;
+
+	case MON_IOCQ_RING_SIZE:
+		mutex_lock(&rp->fetch_lock);
+		ret = rp->b_size;
+		mutex_unlock(&rp->fetch_lock);
+		break;
+
+	case MON_IOCT_RING_SIZE:
+		/*
+		 * Changing the buffer size will flush it's contents; the new
+		 * buffer is allocated before releasing the old one to be sure
+		 * the device will stay functional also in case of memory
+		 * pressure.
+		 */
+		{
+		int size;
+		struct mon_pgmap *vec;
+
+		if (arg < BUFF_MIN || arg > BUFF_MAX)
+			return -EINVAL;
+
+		size = CHUNK_ALIGN(arg);
+		vec = kcalloc(size / CHUNK_SIZE, sizeof(struct mon_pgmap),
+			      GFP_KERNEL);
+		if (vec == NULL) {
+			ret = -ENOMEM;
+			break;
+		}
+
+		ret = mon_alloc_buff(vec, size/CHUNK_SIZE);
+		if (ret < 0) {
+			kfree(vec);
+			break;
+		}
+
+		mutex_lock(&rp->fetch_lock);
+		spin_lock_irqsave(&rp->b_lock, flags);
+		if (rp->mmap_active) {
+			mon_free_buff(vec, size/CHUNK_SIZE);
+			kfree(vec);
+			ret = -EBUSY;
+		} else {
+			mon_free_buff(rp->b_vec, rp->b_size/CHUNK_SIZE);
+			kfree(rp->b_vec);
+			rp->b_vec  = vec;
+			rp->b_size = size;
+			rp->b_read = rp->b_in = rp->b_out = rp->b_cnt = 0;
+			rp->cnt_lost = 0;
+		}
+		spin_unlock_irqrestore(&rp->b_lock, flags);
+		mutex_unlock(&rp->fetch_lock);
+		}
+		break;
+
+	case MON_IOCH_MFLUSH:
+		ret = mon_bin_flush(rp, arg);
+		break;
+
+	case MON_IOCX_GET:
+	case MON_IOCX_GETX:
+		{
+		struct mon_bin_get getb;
+
+		if (copy_from_user(&getb, (void __user *)arg,
+					    sizeof(struct mon_bin_get)))
+			return -EFAULT;
+
+		if (getb.alloc > 0x10000000)	/* Want to cast to u32 */
+			return -EINVAL;
+		ret = mon_bin_get_event(file, rp, getb.hdr,
+		    (cmd == MON_IOCX_GET)? PKT_SZ_API0: PKT_SZ_API1,
+		    getb.data, (unsigned int)getb.alloc);
+		}
+		break;
+
+	case MON_IOCX_MFETCH:
+		{
+		struct mon_bin_mfetch mfetch;
+		struct mon_bin_mfetch __user *uptr;
+
+		uptr = (struct mon_bin_mfetch __user *)arg;
+
+		if (copy_from_user(&mfetch, uptr, sizeof(mfetch)))
+			return -EFAULT;
+
+		if (mfetch.nflush) {
+			ret = mon_bin_flush(rp, mfetch.nflush);
+			if (ret < 0)
+				return ret;
+			if (put_user(ret, &uptr->nflush))
+				return -EFAULT;
+		}
+		ret = mon_bin_fetch(file, rp, mfetch.offvec, mfetch.nfetch);
+		if (ret < 0)
+			return ret;
+		if (put_user(ret, &uptr->nfetch))
+			return -EFAULT;
+		ret = 0;
+		}
+		break;
+
+	case MON_IOCG_STATS: {
+		struct mon_bin_stats __user *sp;
+		unsigned int nevents;
+		unsigned int ndropped;
+
+		spin_lock_irqsave(&rp->b_lock, flags);
+		ndropped = rp->cnt_lost;
+		rp->cnt_lost = 0;
+		spin_unlock_irqrestore(&rp->b_lock, flags);
+		nevents = mon_bin_queued(rp);
+
+		sp = (struct mon_bin_stats __user *)arg;
+		if (put_user(ndropped, &sp->dropped))
+			return -EFAULT;
+		if (put_user(nevents, &sp->queued))
+			return -EFAULT;
+
+		}
+		break;
+
+	default:
+		return -ENOTTY;
+	}
+
+	return ret;
+}
+
+#ifdef CONFIG_COMPAT
+static long mon_bin_compat_ioctl(struct file *file,
+    unsigned int cmd, unsigned long arg)
+{
+	struct mon_reader_bin *rp = file->private_data;
+	int ret;
+
+	switch (cmd) {
+
+	case MON_IOCX_GET32:
+	case MON_IOCX_GETX32:
+		{
+		struct mon_bin_get32 getb;
+
+		if (copy_from_user(&getb, (void __user *)arg,
+					    sizeof(struct mon_bin_get32)))
+			return -EFAULT;
+
+		ret = mon_bin_get_event(file, rp, compat_ptr(getb.hdr32),
+		    (cmd == MON_IOCX_GET32)? PKT_SZ_API0: PKT_SZ_API1,
+		    compat_ptr(getb.data32), getb.alloc32);
+		if (ret < 0)
+			return ret;
+		}
+		return 0;
+
+	case MON_IOCX_MFETCH32:
+		{
+		struct mon_bin_mfetch32 mfetch;
+		struct mon_bin_mfetch32 __user *uptr;
+
+		uptr = (struct mon_bin_mfetch32 __user *) compat_ptr(arg);
+
+		if (copy_from_user(&mfetch, uptr, sizeof(mfetch)))
+			return -EFAULT;
+
+		if (mfetch.nflush32) {
+			ret = mon_bin_flush(rp, mfetch.nflush32);
+			if (ret < 0)
+				return ret;
+			if (put_user(ret, &uptr->nflush32))
+				return -EFAULT;
+		}
+		ret = mon_bin_fetch(file, rp, compat_ptr(mfetch.offvec32),
+		    mfetch.nfetch32);
+		if (ret < 0)
+			return ret;
+		if (put_user(ret, &uptr->nfetch32))
+			return -EFAULT;
+		}
+		return 0;
+
+	case MON_IOCG_STATS:
+		return mon_bin_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
+
+	case MON_IOCQ_URB_LEN:
+	case MON_IOCQ_RING_SIZE:
+	case MON_IOCT_RING_SIZE:
+	case MON_IOCH_MFLUSH:
+		return mon_bin_ioctl(file, cmd, arg);
+
+	default:
+		;
+	}
+	return -ENOTTY;
+}
+#endif /* CONFIG_COMPAT */
+
+static __poll_t
+mon_bin_poll(struct file *file, struct poll_table_struct *wait)
+{
+	struct mon_reader_bin *rp = file->private_data;
+	__poll_t mask = 0;
+	unsigned long flags;
+
+	if (file->f_mode & FMODE_READ)
+		poll_wait(file, &rp->b_wait, wait);
+
+	spin_lock_irqsave(&rp->b_lock, flags);
+	if (!MON_RING_EMPTY(rp))
+		mask |= EPOLLIN | EPOLLRDNORM;    /* readable */
+	spin_unlock_irqrestore(&rp->b_lock, flags);
+	return mask;
+}
+
+/*
+ * open and close: just keep track of how many times the device is
+ * mapped, to use the proper memory allocation function.
+ */
+static void mon_bin_vma_open(struct vm_area_struct *vma)
+{
+	struct mon_reader_bin *rp = vma->vm_private_data;
+	unsigned long flags;
+
+	spin_lock_irqsave(&rp->b_lock, flags);
+	rp->mmap_active++;
+	spin_unlock_irqrestore(&rp->b_lock, flags);
+}
+
+static void mon_bin_vma_close(struct vm_area_struct *vma)
+{
+	unsigned long flags;
+
+	struct mon_reader_bin *rp = vma->vm_private_data;
+	spin_lock_irqsave(&rp->b_lock, flags);
+	rp->mmap_active--;
+	spin_unlock_irqrestore(&rp->b_lock, flags);
+}
+
+/*
+ * Map ring pages to user space.
+ */
+static vm_fault_t mon_bin_vma_fault(struct vm_fault *vmf)
+{
+	struct mon_reader_bin *rp = vmf->vma->vm_private_data;
+	unsigned long offset, chunk_idx;
+	struct page *pageptr;
+	unsigned long flags;
+
+	spin_lock_irqsave(&rp->b_lock, flags);
+	offset = vmf->pgoff << PAGE_SHIFT;
+	if (offset >= rp->b_size) {
+		spin_unlock_irqrestore(&rp->b_lock, flags);
+		return VM_FAULT_SIGBUS;
+	}
+	chunk_idx = offset / CHUNK_SIZE;
+	pageptr = rp->b_vec[chunk_idx].pg;
+	get_page(pageptr);
+	vmf->page = pageptr;
+	spin_unlock_irqrestore(&rp->b_lock, flags);
+	return 0;
+}
+
+static const struct vm_operations_struct mon_bin_vm_ops = {
+	.open =     mon_bin_vma_open,
+	.close =    mon_bin_vma_close,
+	.fault =    mon_bin_vma_fault,
+};
+
+static int mon_bin_mmap(struct file *filp, struct vm_area_struct *vma)
+{
+	/* don't do anything here: "fault" will set up page table entries */
+	vma->vm_ops = &mon_bin_vm_ops;
+
+	if (vma->vm_flags & VM_WRITE)
+		return -EPERM;
+
+	vma->vm_flags &= ~VM_MAYWRITE;
+	vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
+	vma->vm_private_data = filp->private_data;
+	mon_bin_vma_open(vma);
+	return 0;
+}
+
+static const struct file_operations mon_fops_binary = {
+	.owner =	THIS_MODULE,
+	.open =		mon_bin_open,
+	.llseek =	no_llseek,
+	.read =		mon_bin_read,
+	/* .write =	mon_text_write, */
+	.poll =		mon_bin_poll,
+	.unlocked_ioctl = mon_bin_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl =	mon_bin_compat_ioctl,
+#endif
+	.release =	mon_bin_release,
+	.mmap =		mon_bin_mmap,
+};
+
+static int mon_bin_wait_event(struct file *file, struct mon_reader_bin *rp)
+{
+	DECLARE_WAITQUEUE(waita, current);
+	unsigned long flags;
+
+	add_wait_queue(&rp->b_wait, &waita);
+	set_current_state(TASK_INTERRUPTIBLE);
+
+	spin_lock_irqsave(&rp->b_lock, flags);
+	while (MON_RING_EMPTY(rp)) {
+		spin_unlock_irqrestore(&rp->b_lock, flags);
+
+		if (file->f_flags & O_NONBLOCK) {
+			set_current_state(TASK_RUNNING);
+			remove_wait_queue(&rp->b_wait, &waita);
+			return -EWOULDBLOCK; /* Same as EAGAIN in Linux */
+		}
+		schedule();
+		if (signal_pending(current)) {
+			remove_wait_queue(&rp->b_wait, &waita);
+			return -EINTR;
+		}
+		set_current_state(TASK_INTERRUPTIBLE);
+
+		spin_lock_irqsave(&rp->b_lock, flags);
+	}
+	spin_unlock_irqrestore(&rp->b_lock, flags);
+
+	set_current_state(TASK_RUNNING);
+	remove_wait_queue(&rp->b_wait, &waita);
+	return 0;
+}
+
+static int mon_alloc_buff(struct mon_pgmap *map, int npages)
+{
+	int n;
+	unsigned long vaddr;
+
+	for (n = 0; n < npages; n++) {
+		vaddr = get_zeroed_page(GFP_KERNEL);
+		if (vaddr == 0) {
+			while (n-- != 0)
+				free_page((unsigned long) map[n].ptr);
+			return -ENOMEM;
+		}
+		map[n].ptr = (unsigned char *) vaddr;
+		map[n].pg = virt_to_page((void *) vaddr);
+	}
+	return 0;
+}
+
+static void mon_free_buff(struct mon_pgmap *map, int npages)
+{
+	int n;
+
+	for (n = 0; n < npages; n++)
+		free_page((unsigned long) map[n].ptr);
+}
+
+int mon_bin_add(struct mon_bus *mbus, const struct usb_bus *ubus)
+{
+	struct device *dev;
+	unsigned minor = ubus? ubus->busnum: 0;
+
+	if (minor >= MON_BIN_MAX_MINOR)
+		return 0;
+
+	dev = device_create(mon_bin_class, ubus ? ubus->controller : NULL,
+			    MKDEV(MAJOR(mon_bin_dev0), minor), NULL,
+			    "usbmon%d", minor);
+	if (IS_ERR(dev))
+		return 0;
+
+	mbus->classdev = dev;
+	return 1;
+}
+
+void mon_bin_del(struct mon_bus *mbus)
+{
+	device_destroy(mon_bin_class, mbus->classdev->devt);
+}
+
+int __init mon_bin_init(void)
+{
+	int rc;
+
+	mon_bin_class = class_create(THIS_MODULE, "usbmon");
+	if (IS_ERR(mon_bin_class)) {
+		rc = PTR_ERR(mon_bin_class);
+		goto err_class;
+	}
+
+	rc = alloc_chrdev_region(&mon_bin_dev0, 0, MON_BIN_MAX_MINOR, "usbmon");
+	if (rc < 0)
+		goto err_dev;
+
+	cdev_init(&mon_bin_cdev, &mon_fops_binary);
+	mon_bin_cdev.owner = THIS_MODULE;
+
+	rc = cdev_add(&mon_bin_cdev, mon_bin_dev0, MON_BIN_MAX_MINOR);
+	if (rc < 0)
+		goto err_add;
+
+	return 0;
+
+err_add:
+	unregister_chrdev_region(mon_bin_dev0, MON_BIN_MAX_MINOR);
+err_dev:
+	class_destroy(mon_bin_class);
+err_class:
+	return rc;
+}
+
+void mon_bin_exit(void)
+{
+	cdev_del(&mon_bin_cdev);
+	unregister_chrdev_region(mon_bin_dev0, MON_BIN_MAX_MINOR);
+	class_destroy(mon_bin_class);
+}
diff --git a/drivers/usb/mon/mon_main.c b/drivers/usb/mon/mon_main.c
new file mode 100644
index 000000000..9812d102a
--- /dev/null
+++ b/drivers/usb/mon/mon_main.c
@@ -0,0 +1,435 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * The USB Monitor, inspired by Dave Harding's USBMon.
+ *
+ * mon_main.c: Main file, module initiation and exit, registrations, etc.
+ *
+ * Copyright (C) 2005 Pete Zaitcev (zaitcev@redhat.com)
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/usb.h>
+#include <linux/usb/hcd.h>
+#include <linux/slab.h>
+#include <linux/notifier.h>
+#include <linux/mutex.h>
+
+#include "usb_mon.h"
+
+
+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 usb_bus *ubus);
+
+DEFINE_MUTEX(mon_lock);
+
+struct mon_bus mon_bus0;		/* Pseudo bus meaning "all buses" */
+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 list_head *p;
+
+	spin_lock_irqsave(&mbus->lock, flags);
+	if (mbus->nreaders == 0) {
+		if (mbus == &mon_bus0) {
+			list_for_each (p, &mon_buses) {
+				struct mon_bus *m1;
+				m1 = list_entry(p, struct mon_bus, bus_link);
+				m1->u_bus->monitored = 1;
+			}
+		} else {
+			mbus->u_bus->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_bus_submit(struct mon_bus *mbus, struct urb *urb)
+{
+	unsigned long flags;
+	struct list_head *pos;
+	struct mon_reader *r;
+
+	spin_lock_irqsave(&mbus->lock, flags);
+	mbus->cnt_events++;
+	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);
+}
+
+static void mon_submit(struct usb_bus *ubus, struct urb *urb)
+{
+	struct mon_bus *mbus;
+
+	mbus = ubus->mon_bus;
+	if (mbus != NULL)
+		mon_bus_submit(mbus, urb);
+	mon_bus_submit(&mon_bus0, urb);
+}
+
+/*
+ */
+static void mon_bus_submit_error(struct mon_bus *mbus, struct urb *urb, int error)
+{
+	unsigned long flags;
+	struct list_head *pos;
+	struct mon_reader *r;
+
+	spin_lock_irqsave(&mbus->lock, flags);
+	mbus->cnt_events++;
+	list_for_each (pos, &mbus->r_list) {
+		r = list_entry(pos, struct mon_reader, r_link);
+		r->rnf_error(r->r_data, urb, error);
+	}
+	spin_unlock_irqrestore(&mbus->lock, flags);
+}
+
+static void mon_submit_error(struct usb_bus *ubus, struct urb *urb, int error)
+{
+	struct mon_bus *mbus;
+
+	mbus = ubus->mon_bus;
+	if (mbus != NULL)
+		mon_bus_submit_error(mbus, urb, error);
+	mon_bus_submit_error(&mon_bus0, urb, error);
+}
+
+/*
+ */
+static void mon_bus_complete(struct mon_bus *mbus, struct urb *urb, int status)
+{
+	unsigned long flags;
+	struct list_head *pos;
+	struct mon_reader *r;
+
+	spin_lock_irqsave(&mbus->lock, flags);
+	mbus->cnt_events++;
+	list_for_each (pos, &mbus->r_list) {
+		r = list_entry(pos, struct mon_reader, r_link);
+		r->rnf_complete(r->r_data, urb, status);
+	}
+	spin_unlock_irqrestore(&mbus->lock, flags);
+}
+
+static void mon_complete(struct usb_bus *ubus, struct urb *urb, int status)
+{
+	struct mon_bus *mbus;
+
+	mbus = ubus->mon_bus;
+	if (mbus != NULL)
+		mon_bus_complete(mbus, urb, status);
+	mon_bus_complete(&mon_bus0, urb, status);
+}
+
+/* int (*unlink_urb) (struct urb *urb, int status); */
+
+/*
+ * Stop monitoring.
+ */
+static void mon_stop(struct mon_bus *mbus)
+{
+	struct usb_bus *ubus;
+	struct list_head *p;
+
+	if (mbus == &mon_bus0) {
+		list_for_each (p, &mon_buses) {
+			mbus = list_entry(p, struct mon_bus, bus_link);
+			/*
+			 * We do not change nreaders here, so rely on mon_lock.
+			 */
+			if (mbus->nreaders == 0 && (ubus = mbus->u_bus) != NULL)
+				ubus->monitored = 0;
+		}
+	} else {
+		/*
+		 * A stop can be called for a dissolved mon_bus in case of
+		 * a reader staying across an rmmod foo_hcd, so test ->u_bus.
+		 */
+		if (mon_bus0.nreaders == 0 && (ubus = mbus->u_bus) != 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(ubus);
+	mutex_lock(&mon_lock);
+	if (mon_bus0.nreaders != 0)
+		ubus->monitored = 1;
+	mutex_unlock(&mon_lock);
+}
+
+/*
+ * 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;
+
+	mutex_lock(&mon_lock);
+	list_del(&mbus->bus_link);
+	if (mbus->text_inited)
+		mon_text_del(mbus);
+	if (mbus->bin_inited)
+		mon_bin_del(mbus);
+
+	mon_dissolve(mbus, ubus);
+	kref_put(&mbus->ref, mon_bus_drop);
+	mutex_unlock(&mon_lock);
+}
+
+static int mon_notify(struct notifier_block *self, unsigned long action,
+		      void *dev)
+{
+	switch (action) {
+	case USB_BUS_ADD:
+		mon_bus_add(dev);
+		break;
+	case USB_BUS_REMOVE:
+		mon_bus_remove(dev);
+	}
+	return NOTIFY_OK;
+}
+
+static struct notifier_block mon_nb = {
+	.notifier_call = 	mon_notify,
+};
+
+/*
+ * Ops
+ */
+static const struct usb_mon_operations mon_ops_0 = {
+	.urb_submit =	mon_submit,
+	.urb_submit_error = mon_submit_error,
+	.urb_complete =	mon_complete,
+};
+
+/*
+ * Tear usb_bus and mon_bus apart.
+ */
+static void mon_dissolve(struct mon_bus *mbus, struct usb_bus *ubus)
+{
+
+	if (ubus->monitored) {
+		ubus->monitored = 0;
+		mb();
+	}
+
+	ubus->mon_bus = NULL;
+	mbus->u_bus = NULL;
+	mb();
+
+	/* We want synchronize_irq() here, but that needs an argument. */
+}
+
+/*
+ */
+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 usb_bus *ubus)
+{
+	struct mon_bus *mbus;
+
+	mbus = kzalloc(sizeof(struct mon_bus), GFP_KERNEL);
+	if (mbus == NULL)
+		goto err_alloc;
+	kref_init(&mbus->ref);
+	spin_lock_init(&mbus->lock);
+	INIT_LIST_HEAD(&mbus->r_list);
+
+	/*
+	 * We don't need to take a reference to ubus, because we receive
+	 * a notification if the bus is about to be removed.
+	 */
+	mbus->u_bus = ubus;
+	ubus->mon_bus = mbus;
+
+	mbus->text_inited = mon_text_add(mbus, ubus);
+	mbus->bin_inited = mon_bin_add(mbus, ubus);
+
+	mutex_lock(&mon_lock);
+	list_add_tail(&mbus->bus_link, &mon_buses);
+	mutex_unlock(&mon_lock);
+	return;
+
+err_alloc:
+	return;
+}
+
+static void mon_bus0_init(void)
+{
+	struct mon_bus *mbus = &mon_bus0;
+
+	kref_init(&mbus->ref);
+	spin_lock_init(&mbus->lock);
+	INIT_LIST_HEAD(&mbus->r_list);
+
+	mbus->text_inited = mon_text_add(mbus, NULL);
+	mbus->bin_inited = mon_bin_add(mbus, NULL);
+}
+
+/*
+ * Search a USB bus by number. Notice that USB bus numbers start from one,
+ * which we may later use to identify "all" with zero.
+ *
+ * This function must be called with mon_lock held.
+ *
+ * This is obviously inefficient and may be revised in the future.
+ */
+struct mon_bus *mon_bus_lookup(unsigned int num)
+{
+	struct list_head *p;
+	struct mon_bus *mbus;
+
+	if (num == 0) {
+		return &mon_bus0;
+	}
+	list_for_each (p, &mon_buses) {
+		mbus = list_entry(p, struct mon_bus, bus_link);
+		if (mbus->u_bus->busnum == num) {
+			return mbus;
+		}
+	}
+	return NULL;
+}
+
+static int __init mon_init(void)
+{
+	struct usb_bus *ubus;
+	int rc, id;
+
+	if ((rc = mon_text_init()) != 0)
+		goto err_text;
+	if ((rc = mon_bin_init()) != 0)
+		goto err_bin;
+
+	mon_bus0_init();
+
+	if (usb_mon_register(&mon_ops_0) != 0) {
+		printk(KERN_NOTICE TAG ": unable to register with the core\n");
+		rc = -ENODEV;
+		goto err_reg;
+	}
+	// MOD_INC_USE_COUNT(which_module?);
+
+	mutex_lock(&usb_bus_idr_lock);
+	idr_for_each_entry(&usb_bus_idr, ubus, id)
+		mon_bus_init(ubus);
+	usb_register_notify(&mon_nb);
+	mutex_unlock(&usb_bus_idr_lock);
+	return 0;
+
+err_reg:
+	mon_bin_exit();
+err_bin:
+	mon_text_exit();
+err_text:
+	return rc;
+}
+
+static void __exit mon_exit(void)
+{
+	struct mon_bus *mbus;
+	struct list_head *p;
+
+	usb_unregister_notify(&mon_nb);
+	usb_mon_deregister();
+
+	mutex_lock(&mon_lock);
+
+	while (!list_empty(&mon_buses)) {
+		p = mon_buses.next;
+		mbus = list_entry(p, struct mon_bus, bus_link);
+		list_del(p);
+
+		if (mbus->text_inited)
+			mon_text_del(mbus);
+		if (mbus->bin_inited)
+			mon_bin_del(mbus);
+
+		/*
+		 * 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);
+			kref_get(&mbus->ref); /* Force leak */
+		}
+
+		mon_dissolve(mbus, mbus->u_bus);
+		kref_put(&mbus->ref, mon_bus_drop);
+	}
+
+	mbus = &mon_bus0;
+	if (mbus->text_inited)
+		mon_text_del(mbus);
+	if (mbus->bin_inited)
+		mon_bin_del(mbus);
+
+	mutex_unlock(&mon_lock);
+
+	mon_text_exit();
+	mon_bin_exit();
+}
+
+module_init(mon_init);
+module_exit(mon_exit);
+
+MODULE_LICENSE("GPL");
diff --git a/drivers/usb/mon/mon_stat.c b/drivers/usb/mon/mon_stat.c
new file mode 100644
index 000000000..98ab0cc47
--- /dev/null
+++ b/drivers/usb/mon/mon_stat.c
@@ -0,0 +1,71 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * The USB Monitor, inspired by Dave Harding's USBMon.
+ *
+ * This is the 's' or 'stat' reader which debugs usbmon itself.
+ * Note that this code blows through locks, so make sure that
+ * /dbg/usbmon/0s is well protected from non-root users.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/export.h>
+#include <linux/usb.h>
+#include <linux/fs.h>
+#include <linux/uaccess.h>
+
+#include "usb_mon.h"
+
+#define STAT_BUF_SIZE  80
+
+struct snap {
+	int slen;
+	char str[STAT_BUF_SIZE];
+};
+
+static int mon_stat_open(struct inode *inode, struct file *file)
+{
+	struct mon_bus *mbus;
+	struct snap *sp;
+
+	sp = kmalloc(sizeof(struct snap), GFP_KERNEL);
+	if (sp == NULL)
+		return -ENOMEM;
+
+	mbus = inode->i_private;
+
+	sp->slen = snprintf(sp->str, STAT_BUF_SIZE,
+	    "nreaders %d events %u text_lost %u\n",
+	    mbus->nreaders, mbus->cnt_events, mbus->cnt_text_lost);
+
+	file->private_data = sp;
+	return 0;
+}
+
+static ssize_t mon_stat_read(struct file *file, char __user *buf,
+				size_t nbytes, loff_t *ppos)
+{
+	struct snap *sp = file->private_data;
+
+	return simple_read_from_buffer(buf, nbytes, ppos, sp->str, sp->slen);
+}
+
+static int mon_stat_release(struct inode *inode, struct file *file)
+{
+	struct snap *sp = file->private_data;
+	file->private_data = NULL;
+	kfree(sp);
+	return 0;
+}
+
+const struct file_operations mon_fops_stat = {
+	.owner =	THIS_MODULE,
+	.open =		mon_stat_open,
+	.llseek =	no_llseek,
+	.read =		mon_stat_read,
+	/* .write =	mon_stat_write, */
+	/* .poll =		mon_stat_poll, */
+	/* .unlocked_ioctl =	mon_stat_ioctl, */
+	.release =	mon_stat_release,
+};
diff --git a/drivers/usb/mon/mon_text.c b/drivers/usb/mon/mon_text.c
new file mode 100644
index 000000000..39cb14164
--- /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 += scnprintf(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 += scnprintf(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 += scnprintf(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 += scnprintf(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 += scnprintf(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 += scnprintf(p->pbuf + p->cnt, p->limit - p->cnt,
+		    " %c __ __ ____ ____ ____", ep->setup_flag);
+	} else {                     /* No setup for this kind of URB */
+		p->cnt += scnprintf(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 += scnprintf(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 += scnprintf(p->pbuf + p->cnt, p->limit - p->cnt,
+		    " %d:%d:%d", ep->status, ep->interval, ep->start_frame);
+	} else {
+		p->cnt += scnprintf(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 += scnprintf(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 += scnprintf(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 += scnprintf(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 += scnprintf(p->pbuf + p->cnt,
+					    p->limit - p->cnt,
+					    " ");
+				}
+				p->cnt += scnprintf(p->pbuf + p->cnt,
+				    p->limit - p->cnt,
+				    "%02x", ep->data[i]);
+			}
+			p->cnt += scnprintf(p->pbuf + p->cnt, p->limit - p->cnt,
+			    "\n");
+		} else {
+			p->cnt += scnprintf(p->pbuf + p->cnt, p->limit - p->cnt,
+			    " %c\n", ep->data_flag);
+		}
+	} else {
+		p->cnt += scnprintf(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);
+}
diff --git a/drivers/usb/mon/usb_mon.h b/drivers/usb/mon/usb_mon.h
new file mode 100644
index 000000000..aa64efaba
--- /dev/null
+++ b/drivers/usb/mon/usb_mon.h
@@ -0,0 +1,76 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * The USB Monitor, inspired by Dave Harding's USBMon.
+ *
+ * Copyright (C) 2005 Pete Zaitcev (zaitcev@redhat.com)
+ */
+
+#ifndef __USB_MON_H
+#define __USB_MON_H
+
+#include <linux/list.h>
+#include <linux/slab.h>
+#include <linux/kref.h>
+/* #include <linux/usb.h> */	/* We use struct pointers only in this header */
+
+#define TAG "usbmon"
+
+struct mon_bus {
+	struct list_head bus_link;
+	spinlock_t lock;
+	struct usb_bus *u_bus;
+
+	int text_inited;
+	int bin_inited;
+	struct dentry *dent_s;		/* Debugging file */
+	struct dentry *dent_t;		/* Text interface file */
+	struct dentry *dent_u;		/* Second text interface file */
+	struct device *classdev;	/* Device in usbmon class */
+
+	/* Ref */
+	int nreaders;			/* Under mon_lock AND mbus->lock */
+	struct list_head r_list;	/* Chain of readers (usually one) */
+	struct kref ref;		/* Under mon_lock */
+
+	/* Stats */
+	unsigned int cnt_events;
+	unsigned int cnt_text_lost;
+};
+
+/*
+ * An instance of a process which opened a file (but can fork later)
+ */
+struct mon_reader {
+	struct list_head r_link;
+	struct mon_bus *m_bus;
+	void *r_data;		/* Use container_of instead? */
+
+	void (*rnf_submit)(void *data, struct urb *urb);
+	void (*rnf_error)(void *data, struct urb *urb, int error);
+	void (*rnf_complete)(void *data, struct urb *urb, int status);
+};
+
+void mon_reader_add(struct mon_bus *mbus, struct mon_reader *r);
+void mon_reader_del(struct mon_bus *mbus, struct mon_reader *r);
+
+struct mon_bus *mon_bus_lookup(unsigned int num);
+
+int /*bool*/ mon_text_add(struct mon_bus *mbus, const struct usb_bus *ubus);
+void mon_text_del(struct mon_bus *mbus);
+int /*bool*/ mon_bin_add(struct mon_bus *mbus, const struct usb_bus *ubus);
+void mon_bin_del(struct mon_bus *mbus);
+
+int __init mon_text_init(void);
+void mon_text_exit(void);
+int __init mon_bin_init(void);
+void mon_bin_exit(void);
+
+/*
+ */
+extern struct mutex mon_lock;
+
+extern const struct file_operations mon_fops_stat;
+
+extern struct mon_bus mon_bus0;		/* Only for redundant checks */
+
+#endif /* __USB_MON_H */