RTDECL(void) RTSpinlockAcquire(RTSPINLOCK Spinlock)
{
PRTSPINLOCKINTERNAL pThis = (PRTSPINLOCKINTERNAL)Spinlock;
AssertMsg(pThis && pThis->u32Magic == RTSPINLOCK_MAGIC, ("magic=%#x\n", pThis->u32Magic));
KIRQL SavedIrql;
if (pThis->fFlags & RTSPINLOCK_FLAGS_INTERRUPT_SAFE)
{
#ifndef RTSPINLOCK_NT_HACK_NOIRQ
RTCCUINTREG fIntSaved = ASMGetFlags();
ASMIntDisable();
KeAcquireSpinLock(&pThis->Spinlock, &SavedIrql);
#else
SavedIrql = KeGetCurrentIrql();
if (SavedIrql < DISPATCH_LEVEL)
{
KeRaiseIrql(DISPATCH_LEVEL, &SavedIrql);
Assert(SavedIrql < DISPATCH_LEVEL);
}
RTCCUINTREG fIntSaved = ASMGetFlags();
ASMIntDisable();
if (!ASMAtomicCmpXchgU32(&pThis->u32Hack, RTSPINLOCK_NT_HACK_NOIRQ_TAKEN, RTSPINLOCK_NT_HACK_NOIRQ_FREE))
{
while (!ASMAtomicCmpXchgU32(&pThis->u32Hack, RTSPINLOCK_NT_HACK_NOIRQ_TAKEN, RTSPINLOCK_NT_HACK_NOIRQ_FREE))
ASMNopPause();
}
pThis->fIntSaved = fIntSaved;
#endif
}
else
KeAcquireSpinLock(&pThis->Spinlock, &SavedIrql);
pThis->SavedIrql = SavedIrql;
}
RTDECL(void) RTSpinlockAcquire(RTSPINLOCK Spinlock)
{
PRTSPINLOCKINTERNAL pThis = (PRTSPINLOCKINTERNAL)Spinlock;
AssertPtr(pThis);
Assert(pThis->u32Magic == RTSPINLOCK_MAGIC);
if (pThis->fFlags & RTSPINLOCK_FLAGS_INTERRUPT_SAFE)
{
uint32_t fIntSaved = ASMGetFlags();
ASMIntDisable();
lck_spin_lock(pThis->pSpinLock);
pThis->fIntSaved = fIntSaved;
}
else
lck_spin_lock(pThis->pSpinLock);
}
/**
* Hook function for the thread-preempting event.
*
* @param pPreemptNotifier Pointer to the preempt_notifier struct.
* @param pNext Pointer to the task that is preempting the
* current thread.
*
* @remarks Called with the rq (runqueue) lock held and with preemption and
* interrupts disabled!
*/
static void rtThreadCtxHooksLnxSchedOut(struct preempt_notifier *pPreemptNotifier, struct task_struct *pNext)
{
PRTTHREADCTXINT pThis = RT_FROM_MEMBER(pPreemptNotifier, RTTHREADCTXINT, hPreemptNotifier);
#if defined(RT_ARCH_AMD64) || defined(RT_ARCH_X86)
RTCCUINTREG fSavedEFlags = ASMGetFlags();
stac();
#endif
AssertPtr(pThis);
AssertPtr(pThis->pfnThreadCtxHook);
Assert(pThis->fRegistered);
Assert(!RTThreadPreemptIsEnabled(NIL_RTTHREAD));
pThis->pfnThreadCtxHook(RTTHREADCTXEVENT_PREEMPTING, pThis->pvUser);
#if defined(RT_ARCH_AMD64) || defined(RT_ARCH_X86)
ASMSetFlags(fSavedEFlags);
# if LINUX_VERSION_CODE >= KERNEL_VERSION(3, 1, 19) && defined(RT_ARCH_AMD64)
pThis->fSavedRFlags = fSavedEFlags;
# endif
#endif
}
/**
* Hook function for the thread-resumed event.
*
* @param pPreemptNotifier Pointer to the preempt_notifier struct.
* @param iCpu The CPU this thread is scheduled on.
*
* @remarks Called without holding the rq (runqueue) lock and with preemption
* enabled!
*/
static void rtThreadCtxHooksLnxSchedIn(struct preempt_notifier *pPreemptNotifier, int iCpu)
{
PRTTHREADCTXINT pThis = RT_FROM_MEMBER(pPreemptNotifier, RTTHREADCTXINT, hPreemptNotifier);
#if defined(RT_ARCH_AMD64) || defined(RT_ARCH_X86)
RTCCUINTREG fSavedEFlags = ASMGetFlags();
stac();
#endif
AssertPtr(pThis);
AssertPtr(pThis->pfnThreadCtxHook);
Assert(pThis->fRegistered);
pThis->pfnThreadCtxHook(RTTHREADCTXEVENT_RESUMED, pThis->pvUser);
#if defined(RT_ARCH_AMD64) || defined(RT_ARCH_X86)
# if LINUX_VERSION_CODE >= KERNEL_VERSION(3, 1, 19) && defined(RT_ARCH_AMD64)
fSavedEFlags &= ~RT_BIT_64(18) /*X86_EFL_AC*/;
fSavedEFlags |= pThis->fSavedRFlags & RT_BIT_64(18) /*X86_EFL_AC*/;
# endif
ASMSetFlags(fSavedEFlags);
#endif
}
RTDECL(void) RTSpinlockAcquire(RTSPINLOCK Spinlock)
{
PRTSPINLOCKINTERNAL pThis = (PRTSPINLOCKINTERNAL)Spinlock;
AssertMsg(pThis && pThis->u32Magic == RTSPINLOCK_GEN_MAGIC,
("pThis=%p u32Magic=%08x\n", pThis, pThis ? (int)pThis->u32Magic : 0));
if (pThis->fFlags & RTSPINLOCK_FLAGS_INTERRUPT_SAFE)
{
#if defined(RT_ARCH_AMD64) || defined(RT_ARCH_X86)
uint32_t fIntSaved = ASMGetFlags();
#endif
#if RT_CFG_SPINLOCK_GENERIC_DO_SLEEP
for (;;)
{
#if defined(RT_ARCH_AMD64) || defined(RT_ARCH_X86)
ASMIntDisable();
#endif
for (int c = RT_CFG_SPINLOCK_GENERIC_DO_SLEEP; c > 0; c--)
{
if (ASMAtomicCmpXchgU32(&pThis->fLocked, 1, 0))
{
# if defined(RT_ARCH_AMD64) || defined(RT_ARCH_X86)
pThis->fIntSaved = fIntSaved;
# endif
return;
}
ASMNopPause();
}
#if defined(RT_ARCH_AMD64) || defined(RT_ARCH_X86)
ASMSetFlags(fIntSaved);
#endif
RTThreadYield();
}
#else
for (;;)
{
#if defined(RT_ARCH_AMD64) || defined(RT_ARCH_X86)
ASMIntDisable();
#endif
if (ASMAtomicCmpXchgU32(&pThis->fLocked, 1, 0))
{
# if defined(RT_ARCH_AMD64) || defined(RT_ARCH_X86)
pThis->fIntSaved = fIntSaved;
# endif
return;
}
#if defined(RT_ARCH_AMD64) || defined(RT_ARCH_X86)
ASMSetFlags(fIntSaved);
#endif
ASMNopPause();
}
#endif
}
else
{
#if RT_CFG_SPINLOCK_GENERIC_DO_SLEEP
for (;;)
{
for (int c = RT_CFG_SPINLOCK_GENERIC_DO_SLEEP; c > 0; c--)
{
if (ASMAtomicCmpXchgU32(&pThis->fLocked, 1, 0))
return;
ASMNopPause();
}
RTThreadYield();
}
#else
while (!ASMAtomicCmpXchgU32(&pThis->fLocked, 1, 0))
ASMNopPause();
#endif
}
}
static int VBoxDrvLinuxIOCtl(struct inode *pInode, struct file *pFilp, unsigned int uCmd, unsigned long ulArg)
#endif
{
PSUPDRVSESSION pSession = (PSUPDRVSESSION)pFilp->private_data;
int rc;
#if defined(VBOX_STRICT) || defined(VBOX_WITH_EFLAGS_AC_SET_IN_VBOXDRV)
RTCCUINTREG fSavedEfl;
/*
* Refuse all I/O control calls if we've ever detected EFLAGS.AC being cleared.
*
* This isn't a problem, as there is absolutely nothing in the kernel context that
* depend on user context triggering cleanups. That would be pretty wild, right?
*/
if (RT_UNLIKELY(g_DevExt.cBadContextCalls > 0))
{
SUPR0Printf("VBoxDrvLinuxIOCtl: EFLAGS.AC=0 detected %u times, refusing all I/O controls!\n", g_DevExt.cBadContextCalls);
return ESPIPE;
}
fSavedEfl = ASMAddFlags(X86_EFL_AC);
# else
stac();
# endif
/*
* Deal with the two high-speed IOCtl that takes it's arguments from
* the session and iCmd, and only returns a VBox status code.
*/
#ifdef HAVE_UNLOCKED_IOCTL
if (RT_LIKELY( ( uCmd == SUP_IOCTL_FAST_DO_RAW_RUN
|| uCmd == SUP_IOCTL_FAST_DO_HM_RUN
|| uCmd == SUP_IOCTL_FAST_DO_NOP)
&& pSession->fUnrestricted == true))
rc = supdrvIOCtlFast(uCmd, ulArg, &g_DevExt, pSession);
else
rc = VBoxDrvLinuxIOCtlSlow(pFilp, uCmd, ulArg, pSession);
#else /* !HAVE_UNLOCKED_IOCTL */
unlock_kernel();
if (RT_LIKELY( ( uCmd == SUP_IOCTL_FAST_DO_RAW_RUN
|| uCmd == SUP_IOCTL_FAST_DO_HM_RUN
|| uCmd == SUP_IOCTL_FAST_DO_NOP)
&& pSession->fUnrestricted == true))
rc = supdrvIOCtlFast(uCmd, ulArg, &g_DevExt, pSession);
else
rc = VBoxDrvLinuxIOCtlSlow(pFilp, uCmd, ulArg, pSession);
lock_kernel();
#endif /* !HAVE_UNLOCKED_IOCTL */
#if defined(VBOX_STRICT) || defined(VBOX_WITH_EFLAGS_AC_SET_IN_VBOXDRV)
/*
* Before we restore AC and the rest of EFLAGS, check if the IOCtl handler code
* accidentially modified it or some other important flag.
*/
if (RT_UNLIKELY( (ASMGetFlags() & (X86_EFL_AC | X86_EFL_IF | X86_EFL_DF | X86_EFL_IOPL))
!= ((fSavedEfl & (X86_EFL_AC | X86_EFL_IF | X86_EFL_DF | X86_EFL_IOPL)) | X86_EFL_AC) ))
{
char szTmp[48];
RTStrPrintf(szTmp, sizeof(szTmp), "uCmd=%#x: %#x->%#x!", _IOC_NR(uCmd), (uint32_t)fSavedEfl, (uint32_t)ASMGetFlags());
supdrvBadContext(&g_DevExt, "SUPDrv-linux.c", __LINE__, szTmp);
}
ASMSetFlags(fSavedEfl);
#else
clac();
#endif
return rc;
}
