From 388f9e6455519e92e1abb5f2d19b73cc7a471e56 Mon Sep 17 00:00:00 2001
From: Michael Scire <SciresM@gmail.com>
Date: Mon, 12 Oct 2020 01:05:30 -0700
Subject: [PATCH] kern: minor behavioral fixes to condvar/address arbiter

---
 .../source/kern_k_address_arbiter.cpp         | 67 +++++++++++++------
 .../source/kern_k_condition_variable.cpp      |  9 +--
 2 files changed, 50 insertions(+), 26 deletions(-)

diff --git a/libraries/libmesosphere/source/kern_k_address_arbiter.cpp b/libraries/libmesosphere/source/kern_k_address_arbiter.cpp
index dfcd40883..171fd6d33 100644
--- a/libraries/libmesosphere/source/kern_k_address_arbiter.cpp
+++ b/libraries/libmesosphere/source/kern_k_address_arbiter.cpp
@@ -73,15 +73,16 @@ namespace ams::kern {
         s32 num_waiters = 0;
         {
             KScopedSchedulerLock sl;
-            g_cv_arbiter_compare_thread.SetupForAddressArbiterCompare(addr, -1);
-
-            auto it = this->tree.nfind(g_cv_arbiter_compare_thread);
 
             /* Check the userspace value. */
             s32 user_value;
             R_UNLESS(UpdateIfEqual(std::addressof(user_value), addr, value, value + 1), svc::ResultInvalidCurrentMemory());
             R_UNLESS(user_value == value,                                               svc::ResultInvalidState());
 
+            g_cv_arbiter_compare_thread.SetupForAddressArbiterCompare(addr, -1);
+
+            auto it = this->tree.nfind(g_cv_arbiter_compare_thread);
+
             while ((it != this->tree.end()) && (count <= 0 || num_waiters < count) && (it->GetAddressArbiterKey() == addr)) {
                 KThread *target_thread = std::addressof(*it);
                 target_thread->SetSyncedObject(nullptr, ResultSuccess());
@@ -108,26 +109,54 @@ namespace ams::kern {
 
             /* Determine the updated value. */
             s32 new_value;
-            if (count <= 0) {
-                if ((it != this->tree.end()) && (it->GetAddressArbiterKey() == addr)) {
-                    new_value = value - 1;
+            if (GetTargetFirmware() >= TargetFirmware_7_0_0) {
+                if (count <= 0) {
+                    if ((it != this->tree.end()) && (it->GetAddressArbiterKey() == addr)) {
+                        new_value = value - 2;
+                    } else {
+                        new_value = value + 1;
+                    }
                 } else {
-                    new_value = value + 1;
+                    if ((it != this->tree.end()) && (it->GetAddressArbiterKey() == addr)) {
+                        auto tmp_it = it;
+                        s32 tmp_num_waiters = 0;
+                        while ((++tmp_it != this->tree.end()) && (tmp_it->GetAddressArbiterKey() == addr)) {
+                            if ((tmp_num_waiters++) >= count) {
+                                break;
+                            }
+                        }
+
+                        if (tmp_num_waiters < count) {
+                            new_value = value - 1;
+                        } else {
+                            new_value = value;
+                        }
+                    } else {
+                        new_value = value + 1;
+                    }
                 }
             } else {
-                auto tmp_it = it;
-                int tmp_num_waiters = 0;
-                while ((tmp_it != this->tree.end()) && (tmp_it->GetAddressArbiterKey() == addr) && (tmp_num_waiters < count + 1)) {
-                    ++tmp_num_waiters;
-                    ++tmp_it;
-                }
-
-                if (tmp_num_waiters == 0) {
-                    new_value = value + 1;
-                } else if (tmp_num_waiters <= count) {
-                    new_value = value - 1;
+                if (count <= 0) {
+                    if ((it != this->tree.end()) && (it->GetAddressArbiterKey() == addr)) {
+                        new_value = value - 1;
+                    } else {
+                        new_value = value + 1;
+                    }
                 } else {
-                    new_value = value;
+                    auto tmp_it = it;
+                    s32 tmp_num_waiters = 0;
+                    while ((tmp_it != this->tree.end()) && (tmp_it->GetAddressArbiterKey() == addr) && (tmp_num_waiters < count + 1)) {
+                        ++tmp_num_waiters;
+                        ++tmp_it;
+                    }
+
+                    if (tmp_num_waiters == 0) {
+                        new_value = value + 1;
+                    } else if (tmp_num_waiters <= count) {
+                        new_value = value - 1;
+                    } else {
+                        new_value = value;
+                    }
                 }
             }
 
diff --git a/libraries/libmesosphere/source/kern_k_condition_variable.cpp b/libraries/libmesosphere/source/kern_k_condition_variable.cpp
index 270c3c8ac..dc768e43c 100644
--- a/libraries/libmesosphere/source/kern_k_condition_variable.cpp
+++ b/libraries/libmesosphere/source/kern_k_condition_variable.cpp
@@ -205,13 +205,8 @@ namespace ams::kern {
         }
 
         /* Close threads in the list. */
-        if (num_waiters > MaxThreads) {
-            auto it = thread_list.begin();
-            while (it != thread_list.end()) {
-                KThread *thread = std::addressof(*it);
-                thread->Close();
-                it = thread_list.erase(it);
-            }
+        for (auto it = thread_list.begin(); it != thread_list.end(); it = thread_list.erase(it)) {
+            (*it).Close();
         }
     }