linux/drivers/usb/mon/mon_main.c

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/*
* 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 cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 16:04:11 +08:00
#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;
if ((mbus = ubus->mon_bus) != 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;
if ((mbus = ubus->mon_bus) != 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;
if ((mbus = ubus->mon_bus) != 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 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;
if ((mbus = kzalloc(sizeof(struct mon_bus), GFP_KERNEL)) == 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;
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_list_lock);
list_for_each_entry (ubus, &usb_bus_list, bus_list) {
mon_bus_init(ubus);
}
usb_register_notify(&mon_nb);
mutex_unlock(&usb_bus_list_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);
atomic_set(&mbus->ref.refcount, 2); /* 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");