usbmon: bus zero
Add the "bus zero" feature to the usbmon. If a user process specifies bus
with number zero, it receives events from all buses. This is useful when
we wish to see initial enumeration when a bus is created, typically after
a modprobe. Until now, an application had to loop until a new bus could
be open, then start capturing on it. This procedure was cumbersome and
could lose initial events. Also, often it's too bothersome to find exactly
to which bus a specific device is attached.
Paolo Albeni provided the original concept implementation. I added the
handling of "bus->monitored" flag and generally fixed it up.
Signed-off-by: Pete Zaitcev <zaitcev@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/mon/mon_bin.c b/drivers/usb/mon/mon_bin.c
index b2bedd9..0af11a6 100644
--- a/drivers/usb/mon/mon_bin.c
+++ b/drivers/usb/mon/mon_bin.c
@@ -356,8 +356,10 @@
if (!usb_pipecontrol(urb->pipe) || ev_type != 'S')
return '-';
- if (urb->transfer_flags & URB_NO_SETUP_DMA_MAP)
+ if (urb->dev->bus->uses_dma &&
+ (urb->transfer_flags & URB_NO_SETUP_DMA_MAP)) {
return mon_dmapeek(setupb, urb->setup_dma, SETUP_LEN);
+ }
if (urb->setup_packet == NULL)
return 'Z';
@@ -369,7 +371,8 @@
unsigned int offset, struct urb *urb, unsigned int length)
{
- if (urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP) {
+ if (urb->dev->bus->uses_dma &&
+ (urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)) {
mon_dmapeek_vec(rp, offset, urb->transfer_dma, length);
return 0;
}
@@ -440,7 +443,7 @@
/* We use the fact that usb_pipein() returns 0x80 */
ep->epnum = usb_pipeendpoint(urb->pipe) | usb_pipein(urb->pipe);
ep->devnum = usb_pipedevice(urb->pipe);
- ep->busnum = rp->r.m_bus->u_bus->busnum;
+ ep->busnum = urb->dev->bus->busnum;
ep->id = (unsigned long) urb;
ep->ts_sec = ts.tv_sec;
ep->ts_usec = ts.tv_usec;
@@ -500,7 +503,7 @@
/* We use the fact that usb_pipein() returns 0x80 */
ep->epnum = usb_pipeendpoint(urb->pipe) | usb_pipein(urb->pipe);
ep->devnum = usb_pipedevice(urb->pipe);
- ep->busnum = rp->r.m_bus->u_bus->busnum;
+ ep->busnum = urb->dev->bus->busnum;
ep->id = (unsigned long) urb;
ep->status = error;
@@ -515,7 +518,6 @@
static int mon_bin_open(struct inode *inode, struct file *file)
{
struct mon_bus *mbus;
- struct usb_bus *ubus;
struct mon_reader_bin *rp;
size_t size;
int rc;
@@ -525,7 +527,7 @@
mutex_unlock(&mon_lock);
return -ENODEV;
}
- if ((ubus = mbus->u_bus) == NULL) {
+ if (mbus != &mon_bus0 && mbus->u_bus == NULL) {
printk(KERN_ERR TAG ": consistency error on open\n");
mutex_unlock(&mon_lock);
return -ENODEV;
diff --git a/drivers/usb/mon/mon_main.c b/drivers/usb/mon/mon_main.c
index c9739e7..8a1df2c 100644
--- a/drivers/usb/mon/mon_main.c
+++ b/drivers/usb/mon/mon_main.c
@@ -16,8 +16,6 @@
#include "usb_mon.h"
#include "../core/hcd.h"
-static void mon_submit(struct usb_bus *ubus, struct urb *urb);
-static void mon_complete(struct usb_bus *ubus, struct urb *urb);
static void mon_stop(struct mon_bus *mbus);
static void mon_dissolve(struct mon_bus *mbus, struct usb_bus *ubus);
static void mon_bus_drop(struct kref *r);
@@ -25,6 +23,7 @@
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 */
/*
@@ -35,22 +34,19 @@
void mon_reader_add(struct mon_bus *mbus, struct mon_reader *r)
{
unsigned long flags;
- struct usb_bus *ubus;
+ struct list_head *p;
spin_lock_irqsave(&mbus->lock, flags);
if (mbus->nreaders == 0) {
- ubus = mbus->u_bus;
- if (ubus->monitored) {
- /*
- * Something is really broken, refuse to go on and
- * possibly corrupt ops pointers or worse.
- */
- printk(KERN_ERR TAG ": bus %d is already monitored\n",
- ubus->busnum);
- spin_unlock_irqrestore(&mbus->lock, flags);
- return;
+ 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;
}
- ubus->monitored = 1;
}
mbus->nreaders++;
list_add_tail(&r->r_link, &mbus->r_list);
@@ -80,77 +76,79 @@
/*
*/
-static void mon_submit(struct usb_bus *ubus, struct urb *urb)
+static void mon_bus_submit(struct mon_bus *mbus, struct urb *urb)
{
- struct mon_bus *mbus;
unsigned long flags;
struct list_head *pos;
struct mon_reader *r;
- mbus = ubus->mon_bus;
- if (mbus == NULL)
- goto out_unlocked;
-
spin_lock_irqsave(&mbus->lock, flags);
- if (mbus->nreaders == 0)
- goto out_locked;
-
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);
return;
+}
-out_locked:
- spin_unlock_irqrestore(&mbus->lock, flags);
-out_unlocked:
- return;
+static void mon_submit(struct usb_bus *ubus, struct urb *urb)
+{
+ struct mon_bus *mbus;
+
+ if ((mbus = ubus->mon_bus) != NULL)
+ mon_bus_submit(mbus, urb);
+ mon_bus_submit(&mon_bus0, urb);
}
/*
*/
-static void mon_submit_error(struct usb_bus *ubus, struct urb *urb, int error)
+static void mon_bus_submit_error(struct mon_bus *mbus, struct urb *urb, int error)
{
- struct mon_bus *mbus;
unsigned long flags;
struct list_head *pos;
struct mon_reader *r;
- mbus = ubus->mon_bus;
- if (mbus == NULL)
- goto out_unlocked;
-
spin_lock_irqsave(&mbus->lock, flags);
- if (mbus->nreaders == 0)
- goto out_locked;
-
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);
return;
+}
-out_locked:
- spin_unlock_irqrestore(&mbus->lock, flags);
-out_unlocked:
- return;
+static void mon_submit_error(struct usb_bus *ubus, struct urb *urb, int error)
+{
+ struct mon_bus *mbus;
+
+ if ((mbus = ubus->mon_bus) != NULL)
+ mon_bus_submit_error(mbus, urb, error);
+ mon_bus_submit_error(&mon_bus0, urb, error);
}
/*
*/
-static void mon_complete(struct usb_bus *ubus, struct urb *urb)
+static void mon_bus_complete(struct mon_bus *mbus, struct urb *urb)
{
- struct mon_bus *mbus;
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);
+ }
+ spin_unlock_irqrestore(&mbus->lock, flags);
+}
+
+static void mon_complete(struct usb_bus *ubus, struct urb *urb)
+{
+ struct mon_bus *mbus;
+
mbus = ubus->mon_bus;
if (mbus == NULL) {
/*
@@ -162,13 +160,8 @@
return;
}
- 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);
- }
- spin_unlock_irqrestore(&mbus->lock, flags);
+ mon_bus_complete(mbus, urb);
+ mon_bus_complete(&mon_bus0, urb);
}
/* int (*unlink_urb) (struct urb *urb, int status); */
@@ -179,14 +172,26 @@
static void mon_stop(struct mon_bus *mbus)
{
struct usb_bus *ubus = mbus->u_bus;
+ struct list_head *p;
- /*
- * A stop can be called for a dissolved mon_bus in case of
- * a reader staying across an rmmod foo_hcd.
- */
- if (ubus != NULL) {
- ubus->monitored = 0;
- mb();
+ 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();
+ }
}
}
@@ -199,6 +204,10 @@
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);
}
/*
@@ -250,12 +259,7 @@
static void mon_dissolve(struct mon_bus *mbus, struct usb_bus *ubus)
{
- /*
- * Never happens, but...
- */
if (ubus->monitored) {
- printk(KERN_ERR TAG ": bus %d is dissolved while monitored\n",
- ubus->busnum);
ubus->monitored = 0;
mb();
}
@@ -263,6 +267,8 @@
ubus->mon_bus = NULL;
mbus->u_bus = NULL;
mb();
+
+ /* We want synchronize_irq() here, but that needs an argument. */
}
/*
@@ -295,9 +301,8 @@
*/
mbus->u_bus = ubus;
ubus->mon_bus = mbus;
- mbus->uses_dma = ubus->uses_dma;
- mbus->text_inited = mon_text_add(mbus, ubus);
+ mbus->text_inited = mon_text_add(mbus, ubus->busnum);
// mon_bin_add(...)
mutex_lock(&mon_lock);
@@ -309,6 +314,18 @@
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, 0);
+ // mbus->bin_inited = mon_bin_add(mbus, 0);
+}
+
/*
* Search a USB bus by number. Notice that USB bus numbers start from one,
* which we may later use to identify "all" with zero.
@@ -322,6 +339,9 @@
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) {
@@ -341,6 +361,8 @@
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;
@@ -374,6 +396,7 @@
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);
@@ -397,6 +420,11 @@
mon_dissolve(mbus, mbus->u_bus);
kref_put(&mbus->ref, mon_bus_drop);
}
+
+ mbus = &mon_bus0;
+ if (mbus->text_inited)
+ mon_text_del(mbus);
+
mutex_unlock(&mon_lock);
mon_text_exit();
diff --git a/drivers/usb/mon/mon_text.c b/drivers/usb/mon/mon_text.c
index bbf5439..ec0cc51 100644
--- a/drivers/usb/mon/mon_text.c
+++ b/drivers/usb/mon/mon_text.c
@@ -124,8 +124,10 @@
if (!usb_pipecontrol(urb->pipe) || ev_type != 'S')
return '-';
- if (mbus->uses_dma && (urb->transfer_flags & URB_NO_SETUP_DMA_MAP))
+ if (urb->dev->bus->uses_dma &&
+ (urb->transfer_flags & URB_NO_SETUP_DMA_MAP)) {
return mon_dmapeek(ep->setup, urb->setup_dma, SETUP_MAX);
+ }
if (urb->setup_packet == NULL)
return 'Z'; /* '0' would be not as pretty. */
@@ -160,8 +162,10 @@
* contain non-NULL garbage in case the upper level promised to
* set DMA for the HCD.
*/
- if (mbus->uses_dma && (urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP))
+ if (urb->dev->bus->uses_dma &&
+ (urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)) {
return mon_dmapeek(ep->data, urb->transfer_dma, len);
+ }
if (urb->transfer_buffer == NULL)
return 'Z'; /* '0' would be not as pretty. */
@@ -201,7 +205,7 @@
ep->type = ev_type;
ep->pipe = urb->pipe;
ep->id = (unsigned long) urb;
- ep->busnum = rp->r.m_bus->u_bus->busnum;
+ ep->busnum = urb->dev->bus->busnum;
ep->tstamp = stamp;
ep->length = (ev_type == 'S') ?
urb->transfer_buffer_length : urb->actual_length;
@@ -305,13 +309,11 @@
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;
mutex_lock(&mon_lock);
mbus = inode->i_private;
- ubus = mbus->u_bus;
rp = kzalloc(sizeof(struct mon_reader_text), GFP_KERNEL);
if (rp == NULL) {
@@ -335,8 +337,7 @@
rp->r.rnf_error = mon_text_error;
rp->r.rnf_complete = mon_text_complete;
- snprintf(rp->slab_name, SLAB_NAME_SZ, "mon%dt_%lx", ubus->busnum,
- (long)rp);
+ 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, NULL);
@@ -654,14 +655,14 @@
.release = mon_text_release,
};
-int mon_text_add(struct mon_bus *mbus, const struct usb_bus *ubus)
+int mon_text_add(struct mon_bus *mbus, int busnum)
{
struct dentry *d;
enum { NAMESZ = 10 };
char name[NAMESZ];
int rc;
- rc = snprintf(name, NAMESZ, "%dt", ubus->busnum);
+ rc = snprintf(name, NAMESZ, "%dt", busnum);
if (rc <= 0 || rc >= NAMESZ)
goto err_print_t;
d = debugfs_create_file(name, 0600, mon_dir, mbus, &mon_fops_text_t);
@@ -669,7 +670,7 @@
goto err_create_t;
mbus->dent_t = d;
- rc = snprintf(name, NAMESZ, "%du", ubus->busnum);
+ rc = snprintf(name, NAMESZ, "%du", busnum);
if (rc <= 0 || rc >= NAMESZ)
goto err_print_u;
d = debugfs_create_file(name, 0600, mon_dir, mbus, &mon_fops_text_u);
@@ -677,7 +678,7 @@
goto err_create_u;
mbus->dent_u = d;
- rc = snprintf(name, NAMESZ, "%ds", ubus->busnum);
+ rc = snprintf(name, NAMESZ, "%ds", busnum);
if (rc <= 0 || rc >= NAMESZ)
goto err_print_s;
d = debugfs_create_file(name, 0600, mon_dir, mbus, &mon_fops_stat);
diff --git a/drivers/usb/mon/usb_mon.h b/drivers/usb/mon/usb_mon.h
index a1e2b8e..13d6325 100644
--- a/drivers/usb/mon/usb_mon.h
+++ b/drivers/usb/mon/usb_mon.h
@@ -23,7 +23,6 @@
struct dentry *dent_s; /* Debugging file */
struct dentry *dent_t; /* Text interface file */
struct dentry *dent_u; /* Second text interface file */
- int uses_dma;
/* Ref */
int nreaders; /* Under mon_lock AND mbus->lock */
@@ -53,7 +52,7 @@
struct mon_bus *mon_bus_lookup(unsigned int num);
-int /*bool*/ mon_text_add(struct mon_bus *mbus, const struct usb_bus *ubus);
+int /*bool*/ mon_text_add(struct mon_bus *mbus, int busnum);
void mon_text_del(struct mon_bus *mbus);
// void mon_bin_add(struct mon_bus *);
@@ -82,4 +81,6 @@
extern const struct file_operations mon_fops_stat;
+extern struct mon_bus mon_bus0; /* Only for redundant checks */
+
#endif /* __USB_MON_H */