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Fix issues about cancelling USB transfers in LibUSB when the USB device has

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been detached. When a USB device has been detached the kernel file handle
stops responding to commands. USB applications which continue to run after
the USB device has been detached, depend on LibUSB generated events to tear
down its pending USB transfers. Add code to handle the needed cleanup when
processing the USB transfer(s) fails and prevent new USB transfer(s) from
being submitted.

Found by:		Ludovic Rousseau <ludovic.rousseau+freebsd@gmail.com>
PR:			231076
MFC after:		1 week
Approved by:		re (gjb)
Sponsored by:		Mellanox Technologies
This commit is contained in:
Hans Petter Selasky 2018-09-12 15:06:30 +00:00
parent a8a8a8a808
commit 540c72297d
3 changed files with 91 additions and 43 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

99
lib/libusb/libusb10.c
View File

@ -114,6 +114,19 @@ libusb_set_nonblocking(int f)
fcntl(f, F_SETFL, flags);
}
static void
libusb10_wakeup_event_loop(libusb_context *ctx)
{
uint8_t dummy = 0;
int err;
err = write(ctx->ctrl_pipe[1], &dummy, sizeof(dummy));
if (err < (int)sizeof(dummy)) {
/* ignore error, if any */
DPRINTF(ctx, LIBUSB_DEBUG_FUNCTION, "Waking up event loop failed!");
}
}
int
libusb_init(libusb_context **context)
{
@ -484,7 +497,6 @@ libusb_open(libusb_device *dev, libusb_device_handle **devh)
{
libusb_context *ctx = dev->ctx;
struct libusb20_device *pdev = dev->os_priv;
uint8_t dummy;
int err;
if (devh == NULL)
@ -506,12 +518,8 @@ libusb_open(libusb_device *dev, libusb_device_handle **devh)
POLLOUT | POLLRDNORM | POLLWRNORM);
/* make sure our event loop detects the new device */
dummy = 0;
err = write(ctx->ctrl_pipe[1], &dummy, sizeof(dummy));
if (err < (int)sizeof(dummy)) {
/* ignore error, if any */
DPRINTF(ctx, LIBUSB_DEBUG_FUNCTION, "libusb_open write failed!");
}
libusb10_wakeup_event_loop(ctx);
*devh = pdev;
return (0);
@ -564,8 +572,6 @@ libusb_close(struct libusb20_device *pdev)
{
libusb_context *ctx;
struct libusb_device *dev;
uint8_t dummy;
int err;
if (pdev == NULL)
return; /* be NULL safe */
@ -581,12 +587,7 @@ libusb_close(struct libusb20_device *pdev)
libusb_unref_device(dev);
/* make sure our event loop detects the closed device */
dummy = 0;
err = write(ctx->ctrl_pipe[1], &dummy, sizeof(dummy));
if (err < (int)sizeof(dummy)) {
/* ignore error, if any */
DPRINTF(ctx, LIBUSB_DEBUG_FUNCTION, "libusb_close write failed!");
}
libusb10_wakeup_event_loop(ctx);
}
libusb_device *
@ -1314,7 +1315,6 @@ libusb10_submit_transfer_sub(struct libusb20_device *pdev, uint8_t endpoint)
int buffsize;
int maxframe;
int temp;
uint8_t dummy;
dev = libusb_get_device(pdev);
@ -1415,10 +1415,8 @@ libusb10_submit_transfer_sub(struct libusb20_device *pdev, uint8_t endpoint)
failure:
libusb10_complete_transfer(pxfer0, sxfer, LIBUSB_TRANSFER_ERROR);
/* make sure our event loop spins the done handler */
dummy = 0;
err = write(dev->ctx->ctrl_pipe[1], &dummy, sizeof(dummy));
libusb10_wakeup_event_loop(dev->ctx);
}
/* The following function must be called unlocked */
@ -1459,6 +1457,8 @@ libusb_submit_transfer(struct libusb_transfer *uxfer)
(libusb20_tr_get_priv_sc1(pxfer0) == sxfer) ||
(libusb20_tr_get_priv_sc1(pxfer1) == sxfer)) {
err = LIBUSB_ERROR_BUSY;
} else if (dev->device_is_gone != 0) {
err = LIBUSB_ERROR_NO_DEVICE;
} else {
/* set pending state */
@ -1490,6 +1490,7 @@ libusb_cancel_transfer(struct libusb_transfer *uxfer)
struct libusb20_transfer *pxfer1;
struct libusb_super_transfer *sxfer;
struct libusb_device *dev;
struct libusb_device_handle *devh;
uint8_t endpoint;
int retval;
@ -1497,12 +1498,12 @@ libusb_cancel_transfer(struct libusb_transfer *uxfer)
return (LIBUSB_ERROR_INVALID_PARAM);
/* check if not initialised */
if (uxfer->dev_handle == NULL)
if ((devh = uxfer->dev_handle) == NULL)
return (LIBUSB_ERROR_NOT_FOUND);
endpoint = uxfer->endpoint;
dev = libusb_get_device(uxfer->dev_handle);
dev = libusb_get_device(devh);
DPRINTF(dev->ctx, LIBUSB_DEBUG_FUNCTION, "libusb_cancel_transfer enter");
@ -1513,8 +1514,8 @@ libusb_cancel_transfer(struct libusb_transfer *uxfer)
CTX_LOCK(dev->ctx);
pxfer0 = libusb10_get_transfer(uxfer->dev_handle, endpoint, 0);
pxfer1 = libusb10_get_transfer(uxfer->dev_handle, endpoint, 1);
pxfer0 = libusb10_get_transfer(devh, endpoint, 0);
pxfer1 = libusb10_get_transfer(devh, endpoint, 1);
if (sxfer->state != LIBUSB_SUPER_XFER_ST_PEND) {
/* only update the transfer status */
@ -1526,23 +1527,38 @@ libusb_cancel_transfer(struct libusb_transfer *uxfer)
sxfer->entry.tqe_prev = NULL;
libusb10_complete_transfer(NULL,
sxfer, LIBUSB_TRANSFER_CANCELLED);
/* make sure our event loop spins the done handler */
libusb10_wakeup_event_loop(dev->ctx);
} else if (pxfer0 == NULL || pxfer1 == NULL) {
/* not started */
retval = LIBUSB_ERROR_NOT_FOUND;
} else if (libusb20_tr_get_priv_sc1(pxfer0) == sxfer) {
libusb10_complete_transfer(pxfer0,
sxfer, LIBUSB_TRANSFER_CANCELLED);
if (dev->device_is_gone != 0) {
/* clear transfer pointer */
libusb20_tr_set_priv_sc1(pxfer0, NULL);
/* make sure our event loop spins the done handler */
libusb10_wakeup_event_loop(dev->ctx);
} else {
libusb20_tr_stop(pxfer0);
/* make sure the queue doesn't stall */
libusb10_submit_transfer_sub(
uxfer->dev_handle, endpoint);
libusb10_submit_transfer_sub(devh, endpoint);
}
} else if (libusb20_tr_get_priv_sc1(pxfer1) == sxfer) {
libusb10_complete_transfer(pxfer1,
sxfer, LIBUSB_TRANSFER_CANCELLED);
/* check if handle is still active */
if (dev->device_is_gone != 0) {
/* clear transfer pointer */
libusb20_tr_set_priv_sc1(pxfer1, NULL);
/* make sure our event loop spins the done handler */
libusb10_wakeup_event_loop(dev->ctx);
} else {
libusb20_tr_stop(pxfer1);
/* make sure the queue doesn't stall */
libusb10_submit_transfer_sub(
uxfer->dev_handle, endpoint);
libusb10_submit_transfer_sub(devh, endpoint);
}
} else {
/* not started */
retval = LIBUSB_ERROR_NOT_FOUND;
@ -1571,6 +1587,35 @@ libusb10_cancel_all_transfer(libusb_device *dev)
}
}
UNEXPORTED void
libusb10_cancel_all_transfer_locked(struct libusb20_device *pdev, struct libusb_device *dev)
{
struct libusb_super_transfer *sxfer;
unsigned x;
for (x = 0; x != LIBUSB_NUM_SW_ENDPOINTS; x++) {
struct libusb20_transfer *xfer;
xfer = libusb20_tr_get_pointer(pdev, x);
if (xfer == NULL)
continue;
if (libusb20_tr_pending(xfer) == 0)
continue;
sxfer = libusb20_tr_get_priv_sc1(xfer);
if (sxfer == NULL)
continue;
/* complete pending transfer */
libusb10_complete_transfer(xfer, sxfer, LIBUSB_TRANSFER_ERROR);
}
while ((sxfer = TAILQ_FIRST(&dev->tr_head))) {
TAILQ_REMOVE(&dev->tr_head, sxfer, entry);
/* complete pending transfer */
libusb10_complete_transfer(NULL, sxfer, LIBUSB_TRANSFER_ERROR);
}
}
uint16_t
libusb_cpu_to_le16(uint16_t x)
{

3
lib/libusb/libusb10.h
View File

@ -116,6 +116,8 @@ struct libusb_context {
struct libusb_device {
int refcnt;
int device_is_gone;
uint32_t claimed_interfaces;
struct libusb_super_pollfd dev_poll;
@ -134,5 +136,6 @@ extern struct libusb_context *usbi_default_context;
void libusb10_add_pollfd(libusb_context *ctx, struct libusb_super_pollfd *pollfd, struct libusb20_device *pdev, int fd, short events);
void libusb10_remove_pollfd(libusb_context *ctx, struct libusb_super_pollfd *pollfd);
void libusb10_cancel_all_transfer(libusb_device *dev);
void libusb10_cancel_all_transfer_locked(struct libusb20_device *pdev, struct libusb_device *dev);
#endif /* __LIBUSB10_H__ */

18
lib/libusb/libusb10_io.c
View File

@ -161,17 +161,19 @@ libusb10_handle_events_sub(struct libusb_context *ctx, struct timeval *tv)
if (ppdev[i] != NULL) {
dev = libusb_get_device(ppdev[i]);
if (fds[i].revents == 0)
err = 0; /* nothing to do */
else
if (fds[i].revents != 0) {
err = libusb20_dev_process(ppdev[i]);
if (err) {
/* cancel all transfers - device is gone */
libusb10_cancel_all_transfer(dev);
/* set device is gone */
dev->device_is_gone = 1;
/* remove USB device from polling loop */
libusb10_remove_pollfd(dev->ctx, &dev->dev_poll);
/* cancel all pending transfers */
libusb10_cancel_all_transfer_locked(ppdev[i], dev);
}
}
CTX_UNLOCK(ctx);
libusb_unref_device(dev);
@ -180,10 +182,8 @@ libusb10_handle_events_sub(struct libusb_context *ctx, struct timeval *tv)
} else {
uint8_t dummy;
while (1) {
if (read(fds[i].fd, &dummy, 1) != 1)
break;
}
while (read(fds[i].fd, &dummy, 1) == 1)
;
}
}