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https://github.com/edk2-porting/linux-next.git
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21619792d1
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>
130 lines
2.9 KiB
C
130 lines
2.9 KiB
C
/*
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* Copyright (C) 2003-2008 Takahiro Hirofuchi
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*
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* This is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
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* USA.
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*/
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#include <linux/kthread.h>
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#include <linux/export.h>
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#include "usbip_common.h"
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static int event_handler(struct usbip_device *ud)
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{
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usbip_dbg_eh("enter\n");
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/*
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* Events are handled by only this thread.
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*/
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while (usbip_event_happened(ud)) {
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usbip_dbg_eh("pending event %lx\n", ud->event);
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/*
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* NOTE: shutdown must come first.
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* Shutdown the device.
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*/
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if (ud->event & USBIP_EH_SHUTDOWN) {
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ud->eh_ops.shutdown(ud);
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ud->event &= ~USBIP_EH_SHUTDOWN;
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}
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/* Reset the device. */
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if (ud->event & USBIP_EH_RESET) {
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ud->eh_ops.reset(ud);
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ud->event &= ~USBIP_EH_RESET;
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}
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/* Mark the device as unusable. */
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if (ud->event & USBIP_EH_UNUSABLE) {
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ud->eh_ops.unusable(ud);
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ud->event &= ~USBIP_EH_UNUSABLE;
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}
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/* Stop the error handler. */
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if (ud->event & USBIP_EH_BYE)
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return -1;
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}
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return 0;
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}
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static int event_handler_loop(void *data)
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{
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struct usbip_device *ud = data;
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while (!kthread_should_stop()) {
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wait_event_interruptible(ud->eh_waitq,
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usbip_event_happened(ud) ||
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kthread_should_stop());
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usbip_dbg_eh("wakeup\n");
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if (event_handler(ud) < 0)
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break;
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}
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return 0;
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}
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int usbip_start_eh(struct usbip_device *ud)
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{
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init_waitqueue_head(&ud->eh_waitq);
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ud->event = 0;
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ud->eh = kthread_run(event_handler_loop, ud, "usbip_eh");
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if (IS_ERR(ud->eh)) {
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pr_warn("Unable to start control thread\n");
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return PTR_ERR(ud->eh);
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}
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return 0;
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}
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EXPORT_SYMBOL_GPL(usbip_start_eh);
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void usbip_stop_eh(struct usbip_device *ud)
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{
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if (ud->eh == current)
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return; /* do not wait for myself */
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kthread_stop(ud->eh);
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usbip_dbg_eh("usbip_eh has finished\n");
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}
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EXPORT_SYMBOL_GPL(usbip_stop_eh);
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void usbip_event_add(struct usbip_device *ud, unsigned long event)
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{
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unsigned long flags;
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spin_lock_irqsave(&ud->lock, flags);
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ud->event |= event;
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wake_up(&ud->eh_waitq);
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spin_unlock_irqrestore(&ud->lock, flags);
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}
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EXPORT_SYMBOL_GPL(usbip_event_add);
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int usbip_event_happened(struct usbip_device *ud)
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{
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int happened = 0;
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unsigned long flags;
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spin_lock_irqsave(&ud->lock, flags);
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if (ud->event != 0)
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happened = 1;
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spin_unlock_irqrestore(&ud->lock, flags);
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return happened;
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}
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EXPORT_SYMBOL_GPL(usbip_event_happened);
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