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Diffstat (limited to 'drivers/usb/mon/mon_text.c')
-rw-r--r--drivers/usb/mon/mon_text.c405
1 files changed, 405 insertions, 0 deletions
diff --git a/drivers/usb/mon/mon_text.c b/drivers/usb/mon/mon_text.c
new file mode 100644
index 000000000000..755a4570477f
--- /dev/null
+++ b/drivers/usb/mon/mon_text.c
@@ -0,0 +1,405 @@
+/*
+ * 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/time.h>
+#include <asm/uaccess.h>
+
+#include "usb_mon.h"
+
+/*
+ * No, we do not want arbitrarily long data strings.
+ * Use the binary interface if you want to capture bulk data!
+ */
+#define DATA_MAX 32
+
+/*
+ * This limit exists to prevent OOMs when the user process stops reading.
+ */
+#define EVENT_MAX 25
+
+#define PRINTF_DFL 120
+
+struct mon_event_text {
+ struct list_head e_link;
+ int type; /* submit, complete, etc. */
+ unsigned int pipe; /* Pipe */
+ unsigned long id; /* From pointer, most of the time */
+ unsigned int tstamp;
+ int length; /* Depends on type: xfer length or act length */
+ int status;
+ char data_flag;
+ unsigned char data[DATA_MAX];
+};
+
+#define SLAB_NAME_SZ 30
+struct mon_reader_text {
+ kmem_cache_t *e_slab;
+ int nevents;
+ struct list_head e_list;
+ struct mon_reader r; /* In C, parent class can be placed anywhere */
+
+ wait_queue_head_t wait;
+ int printf_size;
+ char *printf_buf;
+ struct semaphore printf_lock;
+
+ char slab_name[SLAB_NAME_SZ];
+};
+
+static void mon_text_ctor(void *, kmem_cache_t *, unsigned long);
+static void mon_text_dtor(void *, kmem_cache_t *, unsigned long);
+
+/*
+ * 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_data(struct mon_event_text *ep, struct urb *urb,
+ int len, char ev_type)
+{
+ int pipe = urb->pipe;
+ unsigned char *data;
+
+ /*
+ * The check to see if it's safe to poke at data has an enormous
+ * number of corner cases, but it seems that the following is
+ * more or less safe.
+ *
+ * We do not even try to look transfer_buffer, because it can
+ * contain non-NULL garbage in case the upper level promised to
+ * set DMA for the HCD.
+ */
+ if (urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)
+ return 'D';
+
+ if (len <= 0)
+ return 'L';
+
+ if ((data = urb->transfer_buffer) == NULL)
+ return 'Z'; /* '0' would be not as pretty. */
+
+ /*
+ * Bulk is easy to shortcut reliably.
+ * XXX Control needs setup packet taken.
+ * XXX Other pipe types need consideration. Currently, we overdo it
+ * and collect garbage for them: better more than less.
+ */
+ if (usb_pipebulk(pipe) || usb_pipecontrol(pipe)) {
+ if (usb_pipein(pipe)) {
+ if (ev_type == 'S')
+ return '<';
+ } else {
+ if (ev_type == 'C')
+ return '>';
+ }
+ }
+
+ if (len >= DATA_MAX)
+ len = DATA_MAX;
+ memcpy(ep->data, urb->transfer_buffer, len);
+ return 0;
+}
+
+static inline unsigned int mon_get_timestamp(void)
+{
+ struct timeval tval;
+ unsigned int stamp;
+
+ do_gettimeofday(&tval);
+ stamp = tval.tv_sec & 0xFFFF; /* 2^32 = 4294967296. Limit to 4096s. */
+ stamp = stamp * 1000000 + tval.tv_usec;
+ return stamp;
+}
+
+static void mon_text_event(struct mon_reader_text *rp, struct urb *urb,
+ char ev_type)
+{
+ struct mon_event_text *ep;
+ unsigned int stamp;
+
+ stamp = mon_get_timestamp();
+
+ if (rp->nevents >= EVENT_MAX ||
+ (ep = kmem_cache_alloc(rp->e_slab, SLAB_ATOMIC)) == NULL) {
+ rp->r.m_bus->cnt_text_lost++;
+ return;
+ }
+
+ ep->type = ev_type;
+ ep->pipe = urb->pipe;
+ ep->id = (unsigned long) 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 = urb->status;
+
+ ep->data_flag = mon_text_get_data(ep, urb, ep->length, ev_type);
+
+ 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');
+}
+
+static void mon_text_complete(void *data, struct urb *urb)
+{
+ struct mon_reader_text *rp = data;
+ mon_text_event(rp, urb, 'C');
+}
+
+/*
+ * 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 usb_bus *ubus;
+ struct mon_reader_text *rp;
+ int rc;
+
+ down(&mon_lock);
+ mbus = inode->u.generic_ip;
+ ubus = mbus->u_bus;
+
+ rp = kmalloc(sizeof(struct mon_reader_text), GFP_KERNEL);
+ if (rp == NULL) {
+ rc = -ENOMEM;
+ goto err_alloc;
+ }
+ memset(rp, 0, sizeof(struct mon_reader_text));
+ INIT_LIST_HEAD(&rp->e_list);
+ init_waitqueue_head(&rp->wait);
+ init_MUTEX(&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_complete = mon_text_complete;
+
+ snprintf(rp->slab_name, SLAB_NAME_SZ, "mon%dt_%lx", ubus->busnum,
+ (long)rp);
+ rp->e_slab = kmem_cache_create(rp->slab_name,
+ sizeof(struct mon_event_text), sizeof(long), 0,
+ mon_text_ctor, mon_text_dtor);
+ if (rp->e_slab == NULL) {
+ rc = -ENOMEM;
+ goto err_slab;
+ }
+
+ mon_reader_add(mbus, &rp->r);
+
+ file->private_data = rp;
+ up(&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:
+ up(&mon_lock);
+ return rc;
+}
+
+/*
+ * For simplicity, we read one record in one system call and throw out
+ * what does not fit. This means that the following does not work:
+ * dd if=/dbg/usbmon/0t bs=10
+ * Also, we do not allow seeks and do not bother advancing the offset.
+ */
+static ssize_t mon_text_read(struct file *file, char __user *buf,
+ size_t nbytes, loff_t *ppos)
+{
+ struct mon_reader_text *rp = file->private_data;
+ struct mon_bus *mbus = rp->r.m_bus;
+ DECLARE_WAITQUEUE(waita, current);
+ struct mon_event_text *ep;
+ int cnt, limit;
+ char *pbuf;
+ char udir, utype;
+ int data_len, i;
+
+ 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 -EWOULDBLOCK; /* Same as EAGAIN in Linux */
+ }
+ /*
+ * 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 -EINTR;
+ }
+ set_current_state(TASK_INTERRUPTIBLE);
+ }
+ set_current_state(TASK_RUNNING);
+ remove_wait_queue(&rp->wait, &waita);
+
+ down(&rp->printf_lock);
+ cnt = 0;
+ pbuf = rp->printf_buf;
+ limit = rp->printf_size;
+
+ udir = usb_pipein(ep->pipe) ? 'i' : 'o';
+ switch (usb_pipetype(ep->pipe)) {
+ case PIPE_ISOCHRONOUS: utype = 'Z'; break;
+ case PIPE_INTERRUPT: utype = 'I'; break;
+ case PIPE_CONTROL: utype = 'C'; break;
+ default: /* PIPE_BULK */ utype = 'B';
+ }
+ cnt += snprintf(pbuf + cnt, limit - cnt,
+ "%lx %u %c %c%c:%03u:%02u %d %d",
+ ep->id, ep->tstamp, ep->type,
+ utype, udir, usb_pipedevice(ep->pipe), usb_pipeendpoint(ep->pipe),
+ ep->status, ep->length);
+
+ if ((data_len = ep->length) > 0) {
+ if (ep->data_flag == 0) {
+ cnt += snprintf(pbuf + cnt, limit - cnt, " =");
+ if (data_len >= DATA_MAX)
+ data_len = DATA_MAX;
+ for (i = 0; i < data_len; i++) {
+ if (i % 4 == 0) {
+ cnt += snprintf(pbuf + cnt, limit - cnt,
+ " ");
+ }
+ cnt += snprintf(pbuf + cnt, limit - cnt,
+ "%02x", ep->data[i]);
+ }
+ cnt += snprintf(pbuf + cnt, limit - cnt, "\n");
+ } else {
+ cnt += snprintf(pbuf + cnt, limit - cnt,
+ " %c\n", ep->data_flag);
+ }
+ } else {
+ cnt += snprintf(pbuf + cnt, limit - cnt, "\n");
+ }
+
+ if (copy_to_user(buf, rp->printf_buf, cnt))
+ cnt = -EFAULT;
+ up(&rp->printf_lock);
+ kmem_cache_free(rp->e_slab, ep);
+ return cnt;
+}
+
+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;
+
+ down(&mon_lock);
+ mbus = inode->u.generic_ip;
+
+ if (mbus->nreaders <= 0) {
+ printk(KERN_ERR TAG ": consistency error on close\n");
+ up(&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);
+
+ up(&mon_lock);
+ return 0;
+}
+
+struct file_operations mon_fops_text = {
+ .owner = THIS_MODULE,
+ .open = mon_text_open,
+ .llseek = no_llseek,
+ .read = mon_text_read,
+ /* .write = mon_text_write, */
+ /* .poll = mon_text_poll, */
+ /* .ioctl = mon_text_ioctl, */
+ .release = mon_text_release,
+};
+
+/*
+ * Slab interface: constructor.
+ */
+static void mon_text_ctor(void *mem, kmem_cache_t *slab, unsigned long sflags)
+{
+ /*
+ * Nothing to initialize. No, really!
+ * So, we fill it with garbage to emulate a reused object.
+ */
+ memset(mem, 0xe5, sizeof(struct mon_event_text));
+}
+
+static void mon_text_dtor(void *mem, kmem_cache_t *slab, unsigned long sflags)
+{
+ ;
+}