Adding upstream version 6.0.4-dfsg.upstream/6.0.4-dfsgupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 421 insertions, 0 deletions

diff --git a/src/VBox/Runtime/r0drv/linux/semmutex-r0drv-linux.c b/src/VBox/Runtime/r0drv/linux/semmutex-r0drv-linux.c
new file mode 100644
index 00000000..5a0a0ef5
--- /dev/null
+++ b/src/VBox/Runtime/r0drv/linux/semmutex-r0drv-linux.c
@@ -0,0 +1,421 @@
+/* $Id: semmutex-r0drv-linux.c $ */
+/** @file
+ * IPRT - Mutex Semaphores, Ring-0 Driver, Linux.
+ */
+
+/*
+ * Copyright (C) 2006-2019 Oracle Corporation
+ *
+ * This file is part of VirtualBox Open Source Edition (OSE), as
+ * available from http://www.virtualbox.org. This file is free software;
+ * you can redistribute it and/or modify it under the terms of the GNU
+ * General Public License (GPL) as published by the Free Software
+ * Foundation, in version 2 as it comes in the "COPYING" file of the
+ * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
+ * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
+ *
+ * The contents of this file may alternatively be used under the terms
+ * of the Common Development and Distribution License Version 1.0
+ * (CDDL) only, as it comes in the "COPYING.CDDL" file of the
+ * VirtualBox OSE distribution, in which case the provisions of the
+ * CDDL are applicable instead of those of the GPL.
+ *
+ * You may elect to license modified versions of this file under the
+ * terms and conditions of either the GPL or the CDDL or both.
+ */
+
+
+/*********************************************************************************************************************************
+*   Header Files                                                                                                                 *
+*********************************************************************************************************************************/
+#define RTSEMMUTEX_WITHOUT_REMAPPING
+#include "the-linux-kernel.h"
+#include "internal/iprt.h"
+#include <iprt/semaphore.h>
+
+#include <iprt/assert.h>
+#include <iprt/asm.h>
+#include <iprt/mem.h>
+#include <iprt/err.h>
+#include <iprt/list.h>
+
+#include "internal/magics.h"
+
+
+/*********************************************************************************************************************************
+*   Structures and Typedefs                                                                                                      *
+*********************************************************************************************************************************/
+typedef struct RTSEMMUTEXLNXWAITER
+{
+    /** The list entry. */
+    RTLISTNODE                  ListEntry;
+    /** The waiting task. */
+    struct task_struct         *pTask;
+    /** Why did we wake up? */
+    enum
+    {
+        /** Wakeup to take the semaphore. */
+        RTSEMMUTEXLNXWAITER_WAKEUP,
+        /** Mutex is being destroyed. */
+        RTSEMMUTEXLNXWAITER_DESTROYED,
+        /** Some other reason. */
+        RTSEMMUTEXLNXWAITER_OTHER
+    } volatile                  enmReason;
+} RTSEMMUTEXLNXWAITER, *PRTSEMMUTEXLNXWAITER;
+
+/**
+ * Wrapper for the linux semaphore structure.
+ */
+typedef struct RTSEMMUTEXINTERNAL
+{
+    /** Magic value (RTSEMMUTEX_MAGIC). */
+    uint32_t                    u32Magic;
+    /** The number of recursions. */
+    uint32_t                    cRecursions;
+    /** The list of waiting threads. */
+    RTLISTANCHOR                WaiterList;
+    /** The current owner, NULL if none. */
+    struct task_struct         *pOwnerTask;
+    /** The number of references to this piece of memory.  This is used to
+     *  prevent it from being kicked from underneath us while waiting. */
+    uint32_t volatile           cRefs;
+    /** The spinlock protecting the members and falling asleep. */
+    spinlock_t                  Spinlock;
+} RTSEMMUTEXINTERNAL, *PRTSEMMUTEXINTERNAL;
+
+
+RTDECL(int) RTSemMutexCreate(PRTSEMMUTEX phMtx)
+{
+    int rc = VINF_SUCCESS;
+    IPRT_LINUX_SAVE_EFL_AC();
+
+    /*
+     * Allocate.
+     */
+    PRTSEMMUTEXINTERNAL pThis;
+    pThis = (PRTSEMMUTEXINTERNAL)RTMemAlloc(sizeof(*pThis));
+    if (pThis)
+    {
+        /*
+         * Initialize.
+         */
+        pThis->u32Magic     = RTSEMMUTEX_MAGIC;
+        pThis->cRecursions  = 0;
+        pThis->pOwnerTask   = NULL;
+        pThis->cRefs        = 1;
+        RTListInit(&pThis->WaiterList);
+        spin_lock_init(&pThis->Spinlock);
+
+        *phMtx = pThis;
+    }
+    else
+        rc = VERR_NO_MEMORY;
+
+    IPRT_LINUX_RESTORE_EFL_AC();
+    return rc;
+}
+RT_EXPORT_SYMBOL(RTSemMutexCreate);
+
+
+RTDECL(int) RTSemMutexDestroy(RTSEMMUTEX hMtx)
+{
+    PRTSEMMUTEXINTERNAL     pThis = hMtx;
+    PRTSEMMUTEXLNXWAITER    pCur;
+    unsigned long           fSavedIrq;
+
+    /*
+     * Validate.
+     */
+    if (pThis == NIL_RTSEMMUTEX)
+        return VINF_SUCCESS;
+    AssertPtrReturn(pThis, VERR_INVALID_HANDLE);
+    AssertMsgReturn(pThis->u32Magic == RTSEMMUTEX_MAGIC, ("u32Magic=%RX32 pThis=%p\n", pThis->u32Magic, pThis), VERR_INVALID_HANDLE);
+
+    /*
+     * Kill it, kick waiters and release it.
+     */
+    AssertReturn(ASMAtomicCmpXchgU32(&pThis->u32Magic, RTSEMMUTEX_MAGIC_DEAD, RTSEMMUTEX_MAGIC), VERR_INVALID_HANDLE);
+
+    IPRT_LINUX_SAVE_EFL_AC();
+
+    spin_lock_irqsave(&pThis->Spinlock, fSavedIrq);
+    RTListForEach(&pThis->WaiterList, pCur, RTSEMMUTEXLNXWAITER, ListEntry)
+    {
+        pCur->enmReason = RTSEMMUTEXLNXWAITER_DESTROYED;
+        wake_up_process(pCur->pTask);
+    }
+
+    if (ASMAtomicDecU32(&pThis->cRefs) != 0)
+        spin_unlock_irqrestore(&pThis->Spinlock, fSavedIrq);
+    else
+    {
+        spin_unlock_irqrestore(&pThis->Spinlock, fSavedIrq);
+        RTMemFree(pThis);
+    }
+
+    IPRT_LINUX_RESTORE_EFL_AC();
+
+    return VINF_SUCCESS;
+}
+RT_EXPORT_SYMBOL(RTSemMutexDestroy);
+
+
+/**
+ * Worker for rtSemMutexLinuxRequest that handles the case where we go to sleep.
+ *
+ * @returns VINF_SUCCESS, VERR_INTERRUPTED, VERR_TIMEOUT or VERR_SEM_DESTROYED.
+ *          Returns without owning the spinlock.
+ * @param   pThis           The mutex instance.
+ * @param   cMillies        The timeout.
+ * @param   fInterruptible  The wait type.
+ * @param   fSavedIrq       The saved IRQ flags.
+ */
+static int rtSemMutexLinuxRequestSleep(PRTSEMMUTEXINTERNAL pThis, RTMSINTERVAL cMillies,
+                                       bool fInterruptible, unsigned long fSavedIrq)
+{
+    struct task_struct *pSelf    = current;
+    int                 rc       = VERR_TIMEOUT;
+    long                lTimeout = cMillies == RT_INDEFINITE_WAIT ? MAX_SCHEDULE_TIMEOUT : msecs_to_jiffies(cMillies);
+    RTSEMMUTEXLNXWAITER Waiter;
+
+    IPRT_DEBUG_SEMS_STATE(pThis, 'm');
+
+    /*
+     * Grab a reference to the mutex and add ourselves to the waiter list.
+     */
+    ASMAtomicIncU32(&pThis->cRefs);
+
+    Waiter.pTask     = pSelf;
+    Waiter.enmReason = RTSEMMUTEXLNXWAITER_OTHER;
+    RTListAppend(&pThis->WaiterList, &Waiter.ListEntry);
+
+    /*
+     * Do the waiting.
+     */
+    for (;;)
+    {
+        /* Check signal and timeout conditions. */
+        if (    fInterruptible
+            &&  signal_pending(pSelf))
+        {
+            rc = VERR_INTERRUPTED;
+            break;
+        }
+
+        if (!lTimeout)
+            break;
+
+        /* Go to sleep. */
+        set_current_state(fInterruptible ? TASK_INTERRUPTIBLE : TASK_UNINTERRUPTIBLE);
+        spin_unlock_irq(&pThis->Spinlock);
+
+        lTimeout = schedule_timeout(lTimeout);
+
+        spin_lock_irq(&pThis->Spinlock);
+        set_current_state(TASK_RUNNING);
+
+        /* Did someone wake us up? */
+        if (Waiter.enmReason == RTSEMMUTEXLNXWAITER_WAKEUP)
+        {
+            Assert(pThis->cRecursions == 0);
+            pThis->cRecursions = 1;
+            pThis->pOwnerTask  = pSelf;
+            rc = VINF_SUCCESS;
+            break;
+        }
+
+        /* Is the mutex being destroyed? */
+        if (RT_UNLIKELY(   Waiter.enmReason == RTSEMMUTEXLNXWAITER_DESTROYED
+                        || pThis->u32Magic != RTSEMMUTEX_MAGIC))
+        {
+            rc = VERR_SEM_DESTROYED;
+            break;
+        }
+    }
+
+    /*
+     * Unlink ourself from the waiter list, dereference the mutex and exit the
+     * lock.  We might have to free the mutex if it was the destroyed.
+     */
+    RTListNodeRemove(&Waiter.ListEntry);
+    IPRT_DEBUG_SEMS_STATE_RC(pThis, 'M', rc);
+
+    if (RT_LIKELY(ASMAtomicDecU32(&pThis->cRefs) != 0))
+        spin_unlock_irqrestore(&pThis->Spinlock, fSavedIrq);
+    else
+    {
+        Assert(RT_FAILURE_NP(rc));
+        spin_unlock_irqrestore(&pThis->Spinlock, fSavedIrq);
+        RTMemFree(pThis);
+    }
+    return rc;
+}
+
+
+/**
+ * Internal worker.
+ */
+DECLINLINE(int) rtSemMutexLinuxRequest(RTSEMMUTEX hMutexSem, RTMSINTERVAL cMillies, bool fInterruptible)
+{
+    PRTSEMMUTEXINTERNAL pThis = hMutexSem;
+    struct task_struct *pSelf = current;
+    unsigned long       fSavedIrq;
+    int                 rc;
+    IPRT_LINUX_SAVE_EFL_AC();
+
+    /*
+     * Validate.
+     */
+    AssertPtrReturn(pThis, VERR_INVALID_HANDLE);
+    AssertMsgReturn(pThis->u32Magic == RTSEMMUTEX_MAGIC, ("u32Magic=%RX32 pThis=%p\n", pThis->u32Magic, pThis), VERR_INVALID_HANDLE);
+    Assert(pThis->cRefs >= 1);
+
+    /*
+     * Lock it and check if it's a recursion.
+     */
+    spin_lock_irqsave(&pThis->Spinlock, fSavedIrq);
+    if (pThis->pOwnerTask == pSelf)
+    {
+        pThis->cRecursions++;
+        Assert(pThis->cRecursions > 1);
+        Assert(pThis->cRecursions < 256);
+        rc = VINF_SUCCESS;
+    }
+    /*
+     * Not a recursion, maybe it's not owned by anyone then?
+     */
+    else if (   pThis->pOwnerTask == NULL
+             && RTListIsEmpty(&pThis->WaiterList))
+    {
+        Assert(pThis->cRecursions == 0);
+        pThis->cRecursions = 1;
+        pThis->pOwnerTask  = pSelf;
+        rc = VINF_SUCCESS;
+    }
+    /*
+     * Was it a polling call?
+     */
+    else if (cMillies == 0)
+        rc = VERR_TIMEOUT;
+    /*
+     * No, so go to sleep.
+     */
+    else
+    {
+        rc = rtSemMutexLinuxRequestSleep(pThis, cMillies, fInterruptible, fSavedIrq);
+        IPRT_LINUX_RESTORE_EFL_ONLY_AC();
+        return rc;
+    }
+
+    IPRT_DEBUG_SEMS_STATE_RC(pThis, 'M', rc);
+    spin_unlock_irqrestore(&pThis->Spinlock, fSavedIrq);
+    IPRT_LINUX_RESTORE_EFL_ONLY_AC();
+    return rc;
+}
+
+
+RTDECL(int) RTSemMutexRequest(RTSEMMUTEX hMutexSem, RTMSINTERVAL cMillies)
+{
+    return rtSemMutexLinuxRequest(hMutexSem, cMillies, false /*fInterruptible*/);
+}
+RT_EXPORT_SYMBOL(RTSemMutexRequest);
+
+
+RTDECL(int) RTSemMutexRequestDebug(RTSEMMUTEX hMutexSem, RTMSINTERVAL cMillies, RTHCUINTPTR uId, RT_SRC_POS_DECL)
+{
+    RT_NOREF_PV(uId); RT_SRC_POS_NOREF();
+    return RTSemMutexRequest(hMutexSem, cMillies);
+}
+RT_EXPORT_SYMBOL(RTSemMutexRequestDebug);
+
+
+RTDECL(int) RTSemMutexRequestNoResume(RTSEMMUTEX hMutexSem, RTMSINTERVAL cMillies)
+{
+    return rtSemMutexLinuxRequest(hMutexSem, cMillies, true /*fInterruptible*/);
+}
+RT_EXPORT_SYMBOL(RTSemMutexRequestNoResume);
+
+
+RTDECL(int) RTSemMutexRequestNoResumeDebug(RTSEMMUTEX hMutexSem, RTMSINTERVAL cMillies, RTHCUINTPTR uId, RT_SRC_POS_DECL)
+{
+    RT_NOREF_PV(uId); RT_SRC_POS_NOREF();
+    return RTSemMutexRequestNoResume(hMutexSem, cMillies);
+}
+RT_EXPORT_SYMBOL(RTSemMutexRequestNoResumeDebug);
+
+
+RTDECL(int) RTSemMutexRelease(RTSEMMUTEX hMtx)
+{
+    PRTSEMMUTEXINTERNAL pThis = hMtx;
+    struct task_struct *pSelf = current;
+    unsigned long       fSavedIrq;
+    int                 rc;
+    IPRT_LINUX_SAVE_EFL_AC();
+
+    /*
+     * Validate.
+     */
+    AssertPtrReturn(pThis, VERR_INVALID_HANDLE);
+    AssertMsgReturn(pThis->u32Magic == RTSEMMUTEX_MAGIC, ("u32Magic=%RX32 pThis=%p\n", pThis->u32Magic, pThis), VERR_INVALID_HANDLE);
+    Assert(pThis->cRefs >= 1);
+
+    /*
+     * Take the lock and release one recursion.
+     */
+    spin_lock_irqsave(&pThis->Spinlock, fSavedIrq);
+    if (pThis->pOwnerTask == pSelf)
+    {
+        Assert(pThis->cRecursions > 0);
+        if (--pThis->cRecursions == 0)
+        {
+            pThis->pOwnerTask = NULL;
+
+            /* anyone to wake up? */
+            if (!RTListIsEmpty(&pThis->WaiterList))
+            {
+                PRTSEMMUTEXLNXWAITER pWaiter = RTListGetFirst(&pThis->WaiterList, RTSEMMUTEXLNXWAITER, ListEntry);
+                pWaiter->enmReason = RTSEMMUTEXLNXWAITER_WAKEUP;
+                wake_up_process(pWaiter->pTask);
+            }
+            IPRT_DEBUG_SEMS_STATE(pThis, 'u');
+        }
+        rc = VINF_SUCCESS;
+    }
+    else
+        rc = VERR_NOT_OWNER;
+    spin_unlock_irqrestore(&pThis->Spinlock, fSavedIrq);
+
+    AssertRC(rc);
+    IPRT_LINUX_RESTORE_EFL_AC();
+    return rc;
+}
+RT_EXPORT_SYMBOL(RTSemMutexRelease);
+
+
+RTDECL(bool) RTSemMutexIsOwned(RTSEMMUTEX hMutexSem)
+{
+    PRTSEMMUTEXINTERNAL pThis = hMutexSem;
+    unsigned long       fSavedIrq;
+    bool                fOwned;
+    IPRT_LINUX_SAVE_EFL_AC();
+
+    /*
+     * Validate.
+     */
+    AssertPtrReturn(pThis, false);
+    AssertMsgReturn(pThis->u32Magic == RTSEMMUTEX_MAGIC, ("u32Magic=%RX32 pThis=%p\n", pThis->u32Magic, pThis), false);
+    Assert(pThis->cRefs >= 1);
+
+    /*
+     * Take the lock and release one recursion.
+     */
+    spin_lock_irqsave(&pThis->Spinlock, fSavedIrq);
+    fOwned = pThis->pOwnerTask != NULL;
+    spin_unlock_irqrestore(&pThis->Spinlock, fSavedIrq);
+
+    IPRT_LINUX_RESTORE_EFL_AC();
+    return fOwned;
+
+}
+RT_EXPORT_SYMBOL(RTSemMutexIsOwned);
+