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[Kernel] Make KeEnter/LeaveCriticalRegion only affect the caller thread

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Adds a new X_KTHREAD::apc_disable_count field at 0xB0 into X_KTHREAD based on where 360 kernel seems to store it, and made CriticalRegion funcs act on that, instead of locking things between all threads, and changes DeliverAPCs to check that field before running the APCs.

XThread::LockApc/UnlockApc were also updated too as those previously called into EnterCrit/LeaveCrit to work, but AFAIK the code that uses LockApc/UnlockApc does have an actual need for locking between threads, so changed them to work on XThread::global_critical_region_ directly instead.
This commit is contained in:
emoose
2021-05-24 04:01:35 +01:00
committed by Rick Gibbed
parent 0d3ef65dcd
commit 052ce3d389
3 changed files with 19 additions and 12 deletions
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15
src/xenia/kernel/xthread.cc
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@@ -578,11 +578,15 @@ void XThread::Reenter(uint32_t address) {
}
void XThread::EnterCriticalRegion() {
xe::global_critical_region::mutex().lock();
guest_object<X_KTHREAD>()->apc_disable_count--;
}
void XThread::LeaveCriticalRegion() {
xe::global_critical_region::mutex().unlock();
auto kthread = guest_object<X_KTHREAD>();
auto apc_disable_count = ++kthread->apc_disable_count;
if (apc_disable_count == 0) {
CheckApcs();
}
}
uint32_t XThread::RaiseIrql(uint32_t new_irql) {
@@ -593,11 +597,11 @@ void XThread::LowerIrql(uint32_t new_irql) { irql_ = new_irql; }
void XThread::CheckApcs() { DeliverAPCs(); }
void XThread::LockApc() { EnterCriticalRegion(); }
void XThread::LockApc() { global_critical_region_.mutex().lock(); }
void XThread::UnlockApc(bool queue_delivery) {
bool needs_apc = apc_list_.HasPending();
LeaveCriticalRegion();
global_critical_region_.mutex().unlock();
if (needs_apc && queue_delivery) {
thread_->QueueUserCallback([this]() { DeliverAPCs(); });
}
@@ -632,7 +636,8 @@ void XThread::DeliverAPCs() {
// https://www.drdobbs.com/inside-nts-asynchronous-procedure-call/184416590?pgno=7
auto processor = kernel_state()->processor();
LockApc();
while (apc_list_.HasPending()) {
auto kthread = guest_object<X_KTHREAD>();
while (apc_list_.HasPending() && kthread->apc_disable_count == 0) {
// Get APC entry (offset for LIST_ENTRY offset) and cache what we need.
// Calling the routine may delete the memory/overwrite it.
uint32_t apc_ptr = apc_list_.Shift() - 8;