internal static unsafe void ReturnStackSegmentRawCommon(ref ThreadContext context,
bool kernelAllocation,
bool initialStack)
{
UIntPtr begin = context.stackBegin;
UIntPtr limit = context.stackLimit;
StackHead *head = (StackHead *)(begin - sizeof(StackHead));
#if DO_TRACE_STACKS
Kernel.Waypoint(669);
#endif
UIntPtr addr = limit - SafetyBufferSize;
UIntPtr size = begin - limit + SafetyBufferSize;
#if DEBUG_STACK_VERBOSE
fixed(ThreadContext *ptr = &context)
{
Tracing.Log(Tracing.Debug,
"ReturnStackSegmentRaw(ctx={0:x8}) [{1:x8}..{2:x8}]\n",
(UIntPtr)ptr, context.stackLimit, context.stackBegin);
}
#endif
#if !PAGING
context.stackBegin = head->prevBegin;
context.stackLimit = head->prevLimit;
#else
//context.stackBegin = head->prevBegin;
//context.stackLimit = head->prevLimit;
// Moved below, because of the following scenario:
// - call UnlinkStack
// - UnlinkStack switches to the scheduler stack
// - UnlinkStack calls ReturnStackSegmentRaw, which calls
// various other methods
// - one of the other methods invokes write barrier code
// - the write barrier code performs a stack link check
// - If context.stackLimit is already set to head->prevLimit,
// then it may appear that we're out of stack space,
// even if we're really not, so we jump to LinkStack
// - LinkStack overwrites the scheduler stack
// TODO: really fix this.
UIntPtr stackBegin = head->prevBegin;
UIntPtr stackLimit = head->prevLimit;
#endif
Process owner = Process.GetProcessByID(context.processId);
//
//// See note above in GetStackSegmentRaw
//if ((owner != Process.kernelProcess) &&
//(addr >= BootInfo.KERNEL_BOUNDARY)) {
//MemoryManager.UserFree(addr, MemoryManager.PagesFromBytes(size), owner);
//}
//else {
//MemoryManager.KernelFree(addr, MemoryManager.PagesFromBytes(size), owner);
//}
//
MemoryManager.StackFree(addr, MemoryManager.PagesFromBytes(size), owner, kernelAllocation, initialStack);
#if PAGING
// See comments above.
context.stackBegin = stackBegin;
context.stackLimit = stackLimit;
#endif
#if DEBUG_STACK_VERBOSE
Tracing.Log(Tracing.Debug,
"ReturnStackSegment({0:x8}, {1:x8}) [{2:x8}..{3:x8}]\n",
addr, size, context.stackLimit, context.stackBegin);
#endif
}