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usbmon: bus zero
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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>
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Pete Zaitcev authored and Greg Kroah-Hartman committed Apr 27, 2007
1 parent 35d07fd commit ecb658d
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Showing 4 changed files with 116 additions and 84 deletions.
14 changes: 8 additions & 6 deletions drivers/usb/mon/mon_bin.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -356,8 +356,10 @@ static inline char mon_bin_get_setup(unsigned char *setupb,
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';

Expand All @@ -369,7 +371,8 @@ static char mon_bin_get_data(const struct mon_reader_bin *rp,
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;
}
Expand Down Expand Up @@ -440,7 +443,7 @@ static void mon_bin_event(struct mon_reader_bin *rp, struct urb *urb,
/* 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;
Expand Down Expand Up @@ -500,7 +503,7 @@ static void mon_bin_error(void *data, struct urb *urb, int error)
/* 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;

Expand All @@ -515,7 +518,6 @@ static void mon_bin_error(void *data, struct urb *urb, int error)
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;
Expand All @@ -525,7 +527,7 @@ static int mon_bin_open(struct inode *inode, struct file *file)
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;
Expand Down
158 changes: 93 additions & 65 deletions drivers/usb/mon/mon_main.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -16,15 +16,14 @@
#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);
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 */

/*
Expand All @@ -35,22 +34,19 @@ static LIST_HEAD(mon_buses); /* All buses we know: struct mon_bus */
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);
Expand Down Expand Up @@ -80,77 +76,79 @@ void mon_reader_del(struct mon_bus *mbus, struct mon_reader *r)

/*
*/
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) {
/*
Expand All @@ -162,13 +160,8 @@ static void mon_complete(struct usb_bus *ubus, struct urb *urb)
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); */
Expand All @@ -179,14 +172,26 @@ static void mon_complete(struct usb_bus *ubus, struct urb *urb)
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();
}
}
}

Expand All @@ -199,6 +204,10 @@ static void mon_stop(struct mon_bus *mbus)
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);
}

/*
Expand Down Expand Up @@ -250,19 +259,16 @@ static struct usb_mon_operations mon_ops_0 = {
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();
}

ubus->mon_bus = NULL;
mbus->u_bus = NULL;
mb();

/* We want synchronize_irq() here, but that needs an argument. */
}

/*
Expand Down Expand Up @@ -295,9 +301,8 @@ static void mon_bus_init(struct usb_bus *ubus)
*/
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);
Expand All @@ -309,6 +314,18 @@ static void mon_bus_init(struct usb_bus *ubus)
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.
Expand All @@ -322,6 +339,9 @@ 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) {
Expand All @@ -341,6 +361,8 @@ static int __init mon_init(void)
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;
Expand Down Expand Up @@ -374,6 +396,7 @@ static void __exit mon_exit(void)
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);
Expand All @@ -397,6 +420,11 @@ static void __exit mon_exit(void)
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();
Expand Down
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