linux_dsm_epyc7002/drivers/usb/core/devices.c
Oliver Neukum 6957e1ac9c USB: fix needless failure under certain conditions
in devices.c we have a piece of code for dealing with losing in a race.
If we indeed lose the race we don't care whether our own memory allocation
worked. The check for that is so early that we return early even if we
don't have to.

Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-02-16 15:32:17 -08:00

683 lines
18 KiB
C

/*
* devices.c
* (C) Copyright 1999 Randy Dunlap.
* (C) Copyright 1999,2000 Thomas Sailer <sailer@ife.ee.ethz.ch>. (proc file per device)
* (C) Copyright 1999 Deti Fliegl (new USB architecture)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*************************************************************
*
* <mountpoint>/devices contains USB topology, device, config, class,
* interface, & endpoint data.
*
* I considered using /proc/bus/usb/devices/device# for each device
* as it is attached or detached, but I didn't like this for some
* reason -- maybe it's just too deep of a directory structure.
* I also don't like looking in multiple places to gather and view
* the data. Having only one file for ./devices also prevents race
* conditions that could arise if a program was reading device info
* for devices that are being removed (unplugged). (That is, the
* program may find a directory for devnum_12 then try to open it,
* but it was just unplugged, so the directory is now deleted.
* But programs would just have to be prepared for situations like
* this in any plug-and-play environment.)
*
* 1999-12-16: Thomas Sailer <sailer@ife.ee.ethz.ch>
* Converted the whole proc stuff to real
* read methods. Now not the whole device list needs to fit
* into one page, only the device list for one bus.
* Added a poll method to /proc/bus/usb/devices, to wake
* up an eventual usbd
* 2000-01-04: Thomas Sailer <sailer@ife.ee.ethz.ch>
* Turned into its own filesystem
* 2000-07-05: Ashley Montanaro <ashley@compsoc.man.ac.uk>
* Converted file reading routine to dump to buffer once
* per device, not per bus
*
* $Id: devices.c,v 1.5 2000/01/11 13:58:21 tom Exp $
*/
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/poll.h>
#include <linux/usb.h>
#include <linux/smp_lock.h>
#include <linux/usbdevice_fs.h>
#include <linux/mutex.h>
#include <asm/uaccess.h>
#include "usb.h"
#include "hcd.h"
#define MAX_TOPO_LEVEL 6
/* Define ALLOW_SERIAL_NUMBER if you want to see the serial number of devices */
#define ALLOW_SERIAL_NUMBER
static const char *format_topo =
/* T: Bus=dd Lev=dd Prnt=dd Port=dd Cnt=dd Dev#=ddd Spd=ddd MxCh=dd */
"\nT: Bus=%2.2d Lev=%2.2d Prnt=%2.2d Port=%2.2d Cnt=%2.2d Dev#=%3d Spd=%3s MxCh=%2d\n";
static const char *format_string_manufacturer =
/* S: Manufacturer=xxxx */
"S: Manufacturer=%.100s\n";
static const char *format_string_product =
/* S: Product=xxxx */
"S: Product=%.100s\n";
#ifdef ALLOW_SERIAL_NUMBER
static const char *format_string_serialnumber =
/* S: SerialNumber=xxxx */
"S: SerialNumber=%.100s\n";
#endif
static const char *format_bandwidth =
/* B: Alloc=ddd/ddd us (xx%), #Int=ddd, #Iso=ddd */
"B: Alloc=%3d/%3d us (%2d%%), #Int=%3d, #Iso=%3d\n";
static const char *format_device1 =
/* D: Ver=xx.xx Cls=xx(sssss) Sub=xx Prot=xx MxPS=dd #Cfgs=dd */
"D: Ver=%2x.%02x Cls=%02x(%-5s) Sub=%02x Prot=%02x MxPS=%2d #Cfgs=%3d\n";
static const char *format_device2 =
/* P: Vendor=xxxx ProdID=xxxx Rev=xx.xx */
"P: Vendor=%04x ProdID=%04x Rev=%2x.%02x\n";
static const char *format_config =
/* C: #Ifs=dd Cfg#=dd Atr=xx MPwr=dddmA */
"C:%c #Ifs=%2d Cfg#=%2d Atr=%02x MxPwr=%3dmA\n";
static const char *format_iface =
/* I: If#=dd Alt=dd #EPs=dd Cls=xx(sssss) Sub=xx Prot=xx Driver=xxxx*/
"I:%c If#=%2d Alt=%2d #EPs=%2d Cls=%02x(%-5s) Sub=%02x Prot=%02x Driver=%s\n";
static const char *format_endpt =
/* E: Ad=xx(s) Atr=xx(ssss) MxPS=dddd Ivl=D?s */
"E: Ad=%02x(%c) Atr=%02x(%-4s) MxPS=%4d Ivl=%d%cs\n";
/*
* Need access to the driver and USB bus lists.
* extern struct list_head usb_bus_list;
* However, these will come from functions that return ptrs to each of them.
*/
static DECLARE_WAIT_QUEUE_HEAD(deviceconndiscwq);
static unsigned int conndiscevcnt = 0;
/* this struct stores the poll state for <mountpoint>/devices pollers */
struct usb_device_status {
unsigned int lastev;
};
struct class_info {
int class;
char *class_name;
};
static const struct class_info clas_info[] =
{ /* max. 5 chars. per name string */
{USB_CLASS_PER_INTERFACE, ">ifc"},
{USB_CLASS_AUDIO, "audio"},
{USB_CLASS_COMM, "comm."},
{USB_CLASS_HID, "HID"},
{USB_CLASS_HUB, "hub"},
{USB_CLASS_PHYSICAL, "PID"},
{USB_CLASS_PRINTER, "print"},
{USB_CLASS_MASS_STORAGE, "stor."},
{USB_CLASS_CDC_DATA, "data"},
{USB_CLASS_APP_SPEC, "app."},
{USB_CLASS_VENDOR_SPEC, "vend."},
{USB_CLASS_STILL_IMAGE, "still"},
{USB_CLASS_CSCID, "scard"},
{USB_CLASS_CONTENT_SEC, "c-sec"},
{-1, "unk."} /* leave as last */
};
/*****************************************************************/
void usbfs_conn_disc_event(void)
{
conndiscevcnt++;
wake_up(&deviceconndiscwq);
}
static const char *class_decode(const int class)
{
int ix;
for (ix = 0; clas_info[ix].class != -1; ix++)
if (clas_info[ix].class == class)
break;
return clas_info[ix].class_name;
}
static char *usb_dump_endpoint_descriptor(
int speed,
char *start,
char *end,
const struct usb_endpoint_descriptor *desc
)
{
char dir, unit, *type;
unsigned interval, bandwidth = 1;
if (start > end)
return start;
dir = usb_endpoint_dir_in(desc) ? 'I' : 'O';
if (speed == USB_SPEED_HIGH) {
switch (le16_to_cpu(desc->wMaxPacketSize) & (0x03 << 11)) {
case 1 << 11: bandwidth = 2; break;
case 2 << 11: bandwidth = 3; break;
}
}
/* this isn't checking for illegal values */
switch (desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) {
case USB_ENDPOINT_XFER_CONTROL:
type = "Ctrl";
if (speed == USB_SPEED_HIGH) /* uframes per NAK */
interval = desc->bInterval;
else
interval = 0;
dir = 'B'; /* ctrl is bidirectional */
break;
case USB_ENDPOINT_XFER_ISOC:
type = "Isoc";
interval = 1 << (desc->bInterval - 1);
break;
case USB_ENDPOINT_XFER_BULK:
type = "Bulk";
if (speed == USB_SPEED_HIGH && dir == 'O') /* uframes per NAK */
interval = desc->bInterval;
else
interval = 0;
break;
case USB_ENDPOINT_XFER_INT:
type = "Int.";
if (speed == USB_SPEED_HIGH)
interval = 1 << (desc->bInterval - 1);
else
interval = desc->bInterval;
break;
default: /* "can't happen" */
return start;
}
interval *= (speed == USB_SPEED_HIGH) ? 125 : 1000;
if (interval % 1000)
unit = 'u';
else {
unit = 'm';
interval /= 1000;
}
start += sprintf(start, format_endpt, desc->bEndpointAddress, dir,
desc->bmAttributes, type,
(le16_to_cpu(desc->wMaxPacketSize) & 0x07ff) * bandwidth,
interval, unit);
return start;
}
static char *usb_dump_interface_descriptor(char *start, char *end,
const struct usb_interface_cache *intfc,
const struct usb_interface *iface,
int setno)
{
const struct usb_interface_descriptor *desc = &intfc->altsetting[setno].desc;
const char *driver_name = "";
int active = 0;
if (start > end)
return start;
down_read(&usb_bus_type.subsys.rwsem);
if (iface) {
driver_name = (iface->dev.driver
? iface->dev.driver->name
: "(none)");
active = (desc == &iface->cur_altsetting->desc);
}
start += sprintf(start, format_iface,
active ? '*' : ' ', /* mark active altsetting */
desc->bInterfaceNumber,
desc->bAlternateSetting,
desc->bNumEndpoints,
desc->bInterfaceClass,
class_decode(desc->bInterfaceClass),
desc->bInterfaceSubClass,
desc->bInterfaceProtocol,
driver_name);
up_read(&usb_bus_type.subsys.rwsem);
return start;
}
static char *usb_dump_interface(
int speed,
char *start,
char *end,
const struct usb_interface_cache *intfc,
const struct usb_interface *iface,
int setno
) {
const struct usb_host_interface *desc = &intfc->altsetting[setno];
int i;
start = usb_dump_interface_descriptor(start, end, intfc, iface, setno);
for (i = 0; i < desc->desc.bNumEndpoints; i++) {
if (start > end)
return start;
start = usb_dump_endpoint_descriptor(speed,
start, end, &desc->endpoint[i].desc);
}
return start;
}
/* TBD:
* 0. TBDs
* 1. marking active interface altsettings (code lists all, but should mark
* which ones are active, if any)
*/
static char *usb_dump_config_descriptor(char *start, char *end, const struct usb_config_descriptor *desc, int active)
{
if (start > end)
return start;
start += sprintf(start, format_config,
active ? '*' : ' ', /* mark active/actual/current cfg. */
desc->bNumInterfaces,
desc->bConfigurationValue,
desc->bmAttributes,
desc->bMaxPower * 2);
return start;
}
static char *usb_dump_config (
int speed,
char *start,
char *end,
const struct usb_host_config *config,
int active
)
{
int i, j;
struct usb_interface_cache *intfc;
struct usb_interface *interface;
if (start > end)
return start;
if (!config) /* getting these some in 2.3.7; none in 2.3.6 */
return start + sprintf(start, "(null Cfg. desc.)\n");
start = usb_dump_config_descriptor(start, end, &config->desc, active);
for (i = 0; i < config->desc.bNumInterfaces; i++) {
intfc = config->intf_cache[i];
interface = config->interface[i];
for (j = 0; j < intfc->num_altsetting; j++) {
if (start > end)
return start;
start = usb_dump_interface(speed,
start, end, intfc, interface, j);
}
}
return start;
}
/*
* Dump the different USB descriptors.
*/
static char *usb_dump_device_descriptor(char *start, char *end, const struct usb_device_descriptor *desc)
{
u16 bcdUSB = le16_to_cpu(desc->bcdUSB);
u16 bcdDevice = le16_to_cpu(desc->bcdDevice);
if (start > end)
return start;
start += sprintf(start, format_device1,
bcdUSB >> 8, bcdUSB & 0xff,
desc->bDeviceClass,
class_decode (desc->bDeviceClass),
desc->bDeviceSubClass,
desc->bDeviceProtocol,
desc->bMaxPacketSize0,
desc->bNumConfigurations);
if (start > end)
return start;
start += sprintf(start, format_device2,
le16_to_cpu(desc->idVendor),
le16_to_cpu(desc->idProduct),
bcdDevice >> 8, bcdDevice & 0xff);
return start;
}
/*
* Dump the different strings that this device holds.
*/
static char *usb_dump_device_strings(char *start, char *end, struct usb_device *dev)
{
if (start > end)
return start;
if (dev->manufacturer)
start += sprintf(start, format_string_manufacturer, dev->manufacturer);
if (start > end)
goto out;
if (dev->product)
start += sprintf(start, format_string_product, dev->product);
if (start > end)
goto out;
#ifdef ALLOW_SERIAL_NUMBER
if (dev->serial)
start += sprintf(start, format_string_serialnumber, dev->serial);
#endif
out:
return start;
}
static char *usb_dump_desc(char *start, char *end, struct usb_device *dev)
{
int i;
if (start > end)
return start;
start = usb_dump_device_descriptor(start, end, &dev->descriptor);
if (start > end)
return start;
start = usb_dump_device_strings(start, end, dev);
for (i = 0; i < dev->descriptor.bNumConfigurations; i++) {
if (start > end)
return start;
start = usb_dump_config(dev->speed,
start, end, dev->config + i,
/* active ? */
(dev->config + i) == dev->actconfig);
}
return start;
}
#ifdef PROC_EXTRA /* TBD: may want to add this code later */
static char *usb_dump_hub_descriptor(char *start, char *end, const struct usb_hub_descriptor * desc)
{
int leng = USB_DT_HUB_NONVAR_SIZE;
unsigned char *ptr = (unsigned char *)desc;
if (start > end)
return start;
start += sprintf(start, "Interface:");
while (leng && start <= end) {
start += sprintf(start, " %02x", *ptr);
ptr++; leng--;
}
*start++ = '\n';
return start;
}
static char *usb_dump_string(char *start, char *end, const struct usb_device *dev, char *id, int index)
{
if (start > end)
return start;
start += sprintf(start, "Interface:");
if (index <= dev->maxstring && dev->stringindex && dev->stringindex[index])
start += sprintf(start, "%s: %.100s ", id, dev->stringindex[index]);
return start;
}
#endif /* PROC_EXTRA */
/*****************************************************************/
/* This is a recursive function. Parameters:
* buffer - the user-space buffer to write data into
* nbytes - the maximum number of bytes to write
* skip_bytes - the number of bytes to skip before writing anything
* file_offset - the offset into the devices file on completion
* The caller must own the device lock.
*/
static ssize_t usb_device_dump(char __user **buffer, size_t *nbytes, loff_t *skip_bytes, loff_t *file_offset,
struct usb_device *usbdev, struct usb_bus *bus, int level, int index, int count)
{
int chix;
int ret, cnt = 0;
int parent_devnum = 0;
char *pages_start, *data_end, *speed;
unsigned int length;
ssize_t total_written = 0;
/* don't bother with anything else if we're not writing any data */
if (*nbytes <= 0)
return 0;
if (level > MAX_TOPO_LEVEL)
return 0;
/* allocate 2^1 pages = 8K (on i386); should be more than enough for one device */
if (!(pages_start = (char*) __get_free_pages(GFP_KERNEL,1)))
return -ENOMEM;
if (usbdev->parent && usbdev->parent->devnum != -1)
parent_devnum = usbdev->parent->devnum;
/*
* So the root hub's parent is 0 and any device that is
* plugged into the root hub has a parent of 0.
*/
switch (usbdev->speed) {
case USB_SPEED_LOW:
speed = "1.5"; break;
case USB_SPEED_UNKNOWN: /* usb 1.1 root hub code */
case USB_SPEED_FULL:
speed = "12 "; break;
case USB_SPEED_HIGH:
speed = "480"; break;
default:
speed = "?? ";
}
data_end = pages_start + sprintf(pages_start, format_topo,
bus->busnum, level, parent_devnum,
index, count, usbdev->devnum,
speed, usbdev->maxchild);
/*
* level = topology-tier level;
* parent_devnum = parent device number;
* index = parent's connector number;
* count = device count at this level
*/
/* If this is the root hub, display the bandwidth information */
if (level == 0) {
int max;
/* high speed reserves 80%, full/low reserves 90% */
if (usbdev->speed == USB_SPEED_HIGH)
max = 800;
else
max = FRAME_TIME_MAX_USECS_ALLOC;
/* report "average" periodic allocation over a microsecond.
* the schedules are actually bursty, HCDs need to deal with
* that and just compute/report this average.
*/
data_end += sprintf(data_end, format_bandwidth,
bus->bandwidth_allocated, max,
(100 * bus->bandwidth_allocated + max / 2)
/ max,
bus->bandwidth_int_reqs,
bus->bandwidth_isoc_reqs);
}
data_end = usb_dump_desc(data_end, pages_start + (2 * PAGE_SIZE) - 256, usbdev);
if (data_end > (pages_start + (2 * PAGE_SIZE) - 256))
data_end += sprintf(data_end, "(truncated)\n");
length = data_end - pages_start;
/* if we can start copying some data to the user */
if (length > *skip_bytes) {
length -= *skip_bytes;
if (length > *nbytes)
length = *nbytes;
if (copy_to_user(*buffer, pages_start + *skip_bytes, length)) {
free_pages((unsigned long)pages_start, 1);
return -EFAULT;
}
*nbytes -= length;
*file_offset += length;
total_written += length;
*buffer += length;
*skip_bytes = 0;
} else
*skip_bytes -= length;
free_pages((unsigned long)pages_start, 1);
/* Now look at all of this device's children. */
for (chix = 0; chix < usbdev->maxchild; chix++) {
struct usb_device *childdev = usbdev->children[chix];
if (childdev) {
usb_lock_device(childdev);
ret = usb_device_dump(buffer, nbytes, skip_bytes, file_offset, childdev,
bus, level + 1, chix, ++cnt);
usb_unlock_device(childdev);
if (ret == -EFAULT)
return total_written;
total_written += ret;
}
}
return total_written;
}
static ssize_t usb_device_read(struct file *file, char __user *buf, size_t nbytes, loff_t *ppos)
{
struct usb_bus *bus;
ssize_t ret, total_written = 0;
loff_t skip_bytes = *ppos;
if (*ppos < 0)
return -EINVAL;
if (nbytes <= 0)
return 0;
if (!access_ok(VERIFY_WRITE, buf, nbytes))
return -EFAULT;
mutex_lock(&usb_bus_list_lock);
/* print devices for all busses */
list_for_each_entry(bus, &usb_bus_list, bus_list) {
/* recurse through all children of the root hub */
if (!bus->root_hub)
continue;
usb_lock_device(bus->root_hub);
ret = usb_device_dump(&buf, &nbytes, &skip_bytes, ppos, bus->root_hub, bus, 0, 0, 0);
usb_unlock_device(bus->root_hub);
if (ret < 0) {
mutex_unlock(&usb_bus_list_lock);
return ret;
}
total_written += ret;
}
mutex_unlock(&usb_bus_list_lock);
return total_written;
}
/* Kernel lock for "lastev" protection */
static unsigned int usb_device_poll(struct file *file, struct poll_table_struct *wait)
{
struct usb_device_status *st = file->private_data;
unsigned int mask = 0;
lock_kernel();
if (!st) {
st = kmalloc(sizeof(struct usb_device_status), GFP_KERNEL);
/* we may have dropped BKL - need to check for having lost the race */
if (file->private_data) {
kfree(st);
st = file->private_data;
goto lost_race;
}
/* we haven't lost - check for allocation failure now */
if (!st) {
unlock_kernel();
return POLLIN;
}
/*
* need to prevent the module from being unloaded, since
* proc_unregister does not call the release method and
* we would have a memory leak
*/
st->lastev = conndiscevcnt;
file->private_data = st;
mask = POLLIN;
}
lost_race:
if (file->f_mode & FMODE_READ)
poll_wait(file, &deviceconndiscwq, wait);
if (st->lastev != conndiscevcnt)
mask |= POLLIN;
st->lastev = conndiscevcnt;
unlock_kernel();
return mask;
}
static int usb_device_open(struct inode *inode, struct file *file)
{
file->private_data = NULL;
return 0;
}
static int usb_device_release(struct inode *inode, struct file *file)
{
kfree(file->private_data);
file->private_data = NULL;
return 0;
}
static loff_t usb_device_lseek(struct file * file, loff_t offset, int orig)
{
loff_t ret;
lock_kernel();
switch (orig) {
case 0:
file->f_pos = offset;
ret = file->f_pos;
break;
case 1:
file->f_pos += offset;
ret = file->f_pos;
break;
case 2:
default:
ret = -EINVAL;
}
unlock_kernel();
return ret;
}
const struct file_operations usbfs_devices_fops = {
.llseek = usb_device_lseek,
.read = usb_device_read,
.poll = usb_device_poll,
.open = usb_device_open,
.release = usb_device_release,
};