From 5398eff0450832aea68f91b796e3a2c873c60129 Mon Sep 17 00:00:00 2001
From: Billy Laws <blaws05@gmail.com>
Date: Sat, 6 Aug 2022 15:54:57 +0530
Subject: [PATCH] Fix `KProcess::MutexUnlock` PI CAS

The PI CAS in `MutexUnlock` ends up loading `basePriority` rather than `priority` which could lead to an infinite CAS loop when `basePriority` doesn't equal to `priority` and the `highestPriorityThread`'s priority is lower than `basePriority`.
---
 app/src/main/cpp/skyline/kernel/types/KProcess.cpp | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/app/src/main/cpp/skyline/kernel/types/KProcess.cpp b/app/src/main/cpp/skyline/kernel/types/KProcess.cpp
index 211796db..c76569a4 100644
--- a/app/src/main/cpp/skyline/kernel/types/KProcess.cpp
+++ b/app/src/main/cpp/skyline/kernel/types/KProcess.cpp
@@ -177,11 +177,10 @@ namespace skyline::kernel::type {
             if (!waiters.empty()) {
                 // If there are threads still waiting on us then try to inherit their priority
                 auto highestPriorityThread{waiters.front()};
-                i8 newPriority, basePriority;
+                i8 newPriority, currentPriority{state.thread->priority.load()};
                 do {
-                    basePriority = state.thread->basePriority.load();
-                    newPriority = std::min(basePriority, highestPriorityThread->priority.load());
-                } while (basePriority != newPriority && !state.thread->priority.compare_exchange_strong(basePriority, newPriority));
+                    newPriority = std::min(currentPriority, highestPriorityThread->priority.load());
+                } while (currentPriority != newPriority && !state.thread->priority.compare_exchange_strong(currentPriority, newPriority));
                 state.scheduler->UpdatePriority(state.thread);
             } else {
                 i8 priority, basePriority;