linux/drivers/usb/usbip/vhci_tx.c
Andrew Goodbody 21619792d1 usb: usbip: Fix possible deadlocks reported by lockdep
Change spin_lock calls to spin_lock_irqsave to prevent
attmpted recursive lock taking in interrupt context.

This patch fixes Bug 109351
  https://bugzilla.kernel.org/show_bug.cgi?id=109351

Signed-off-by: Andrew Goodbody <andrew.goodbody@cambrionix.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-03 13:52:10 -08:00

227 lines
5.7 KiB
C

/*
* Copyright (C) 2003-2008 Takahiro Hirofuchi
*
* This 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 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.
*/
#include <linux/kthread.h>
#include <linux/slab.h>
#include "usbip_common.h"
#include "vhci.h"
static void setup_cmd_submit_pdu(struct usbip_header *pdup, struct urb *urb)
{
struct vhci_priv *priv = ((struct vhci_priv *)urb->hcpriv);
struct vhci_device *vdev = priv->vdev;
usbip_dbg_vhci_tx("URB, local devnum %u, remote devid %u\n",
usb_pipedevice(urb->pipe), vdev->devid);
pdup->base.command = USBIP_CMD_SUBMIT;
pdup->base.seqnum = priv->seqnum;
pdup->base.devid = vdev->devid;
pdup->base.direction = usb_pipein(urb->pipe) ?
USBIP_DIR_IN : USBIP_DIR_OUT;
pdup->base.ep = usb_pipeendpoint(urb->pipe);
usbip_pack_pdu(pdup, urb, USBIP_CMD_SUBMIT, 1);
if (urb->setup_packet)
memcpy(pdup->u.cmd_submit.setup, urb->setup_packet, 8);
}
static struct vhci_priv *dequeue_from_priv_tx(struct vhci_device *vdev)
{
struct vhci_priv *priv, *tmp;
unsigned long flags;
spin_lock_irqsave(&vdev->priv_lock, flags);
list_for_each_entry_safe(priv, tmp, &vdev->priv_tx, list) {
list_move_tail(&priv->list, &vdev->priv_rx);
spin_unlock_irqrestore(&vdev->priv_lock, flags);
return priv;
}
spin_unlock_irqrestore(&vdev->priv_lock, flags);
return NULL;
}
static int vhci_send_cmd_submit(struct vhci_device *vdev)
{
struct vhci_priv *priv = NULL;
struct msghdr msg;
struct kvec iov[3];
size_t txsize;
size_t total_size = 0;
while ((priv = dequeue_from_priv_tx(vdev)) != NULL) {
int ret;
struct urb *urb = priv->urb;
struct usbip_header pdu_header;
struct usbip_iso_packet_descriptor *iso_buffer = NULL;
txsize = 0;
memset(&pdu_header, 0, sizeof(pdu_header));
memset(&msg, 0, sizeof(msg));
memset(&iov, 0, sizeof(iov));
usbip_dbg_vhci_tx("setup txdata urb %p\n", urb);
/* 1. setup usbip_header */
setup_cmd_submit_pdu(&pdu_header, urb);
usbip_header_correct_endian(&pdu_header, 1);
iov[0].iov_base = &pdu_header;
iov[0].iov_len = sizeof(pdu_header);
txsize += sizeof(pdu_header);
/* 2. setup transfer buffer */
if (!usb_pipein(urb->pipe) && urb->transfer_buffer_length > 0) {
iov[1].iov_base = urb->transfer_buffer;
iov[1].iov_len = urb->transfer_buffer_length;
txsize += urb->transfer_buffer_length;
}
/* 3. setup iso_packet_descriptor */
if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) {
ssize_t len = 0;
iso_buffer = usbip_alloc_iso_desc_pdu(urb, &len);
if (!iso_buffer) {
usbip_event_add(&vdev->ud,
SDEV_EVENT_ERROR_MALLOC);
return -1;
}
iov[2].iov_base = iso_buffer;
iov[2].iov_len = len;
txsize += len;
}
ret = kernel_sendmsg(vdev->ud.tcp_socket, &msg, iov, 3, txsize);
if (ret != txsize) {
pr_err("sendmsg failed!, ret=%d for %zd\n", ret,
txsize);
kfree(iso_buffer);
usbip_event_add(&vdev->ud, VDEV_EVENT_ERROR_TCP);
return -1;
}
kfree(iso_buffer);
usbip_dbg_vhci_tx("send txdata\n");
total_size += txsize;
}
return total_size;
}
static struct vhci_unlink *dequeue_from_unlink_tx(struct vhci_device *vdev)
{
struct vhci_unlink *unlink, *tmp;
unsigned long flags;
spin_lock_irqsave(&vdev->priv_lock, flags);
list_for_each_entry_safe(unlink, tmp, &vdev->unlink_tx, list) {
list_move_tail(&unlink->list, &vdev->unlink_rx);
spin_unlock_irqrestore(&vdev->priv_lock, flags);
return unlink;
}
spin_unlock_irqrestore(&vdev->priv_lock, flags);
return NULL;
}
static int vhci_send_cmd_unlink(struct vhci_device *vdev)
{
struct vhci_unlink *unlink = NULL;
struct msghdr msg;
struct kvec iov[3];
size_t txsize;
size_t total_size = 0;
while ((unlink = dequeue_from_unlink_tx(vdev)) != NULL) {
int ret;
struct usbip_header pdu_header;
txsize = 0;
memset(&pdu_header, 0, sizeof(pdu_header));
memset(&msg, 0, sizeof(msg));
memset(&iov, 0, sizeof(iov));
usbip_dbg_vhci_tx("setup cmd unlink, %lu\n", unlink->seqnum);
/* 1. setup usbip_header */
pdu_header.base.command = USBIP_CMD_UNLINK;
pdu_header.base.seqnum = unlink->seqnum;
pdu_header.base.devid = vdev->devid;
pdu_header.base.ep = 0;
pdu_header.u.cmd_unlink.seqnum = unlink->unlink_seqnum;
usbip_header_correct_endian(&pdu_header, 1);
iov[0].iov_base = &pdu_header;
iov[0].iov_len = sizeof(pdu_header);
txsize += sizeof(pdu_header);
ret = kernel_sendmsg(vdev->ud.tcp_socket, &msg, iov, 1, txsize);
if (ret != txsize) {
pr_err("sendmsg failed!, ret=%d for %zd\n", ret,
txsize);
usbip_event_add(&vdev->ud, VDEV_EVENT_ERROR_TCP);
return -1;
}
usbip_dbg_vhci_tx("send txdata\n");
total_size += txsize;
}
return total_size;
}
int vhci_tx_loop(void *data)
{
struct usbip_device *ud = data;
struct vhci_device *vdev = container_of(ud, struct vhci_device, ud);
while (!kthread_should_stop()) {
if (vhci_send_cmd_submit(vdev) < 0)
break;
if (vhci_send_cmd_unlink(vdev) < 0)
break;
wait_event_interruptible(vdev->waitq_tx,
(!list_empty(&vdev->priv_tx) ||
!list_empty(&vdev->unlink_tx) ||
kthread_should_stop()));
usbip_dbg_vhci_tx("pending urbs ?, now wake up\n");
}
return 0;
}