From b2971b48ed8f86857878f0fc0e1a744c4bc9d766 Mon Sep 17 00:00:00 2001
From: bunnei <bunneidev@gmail.com>
Date: Wed, 9 Jun 2021 21:37:11 -0700
Subject: [PATCH 1/4] hle: kernel: KServerSession: Fix client disconnected.

- Prevents a cloned session's handler from being overwritten by another disconnected session.
- Fixes session handler nullptr asserts with Pokemon Sword & Shield.
---
 src/core/hle/kernel/hle_ipc.cpp        |  4 ++--
 src/core/hle/kernel/k_server_session.h | 11 +++++------
 src/core/hle/service/service.h         |  2 +-
 3 files changed, 8 insertions(+), 9 deletions(-)

diff --git a/src/core/hle/kernel/hle_ipc.cpp b/src/core/hle/kernel/hle_ipc.cpp
index 45aced99fd..28ed6265ac 100644
--- a/src/core/hle/kernel/hle_ipc.cpp
+++ b/src/core/hle/kernel/hle_ipc.cpp
@@ -57,11 +57,11 @@ bool SessionRequestManager::HasSessionRequestHandler(const HLERequestContext& co
 }
 
 void SessionRequestHandler::ClientConnected(KServerSession* session) {
-    session->SetSessionHandler(shared_from_this());
+    session->ClientConnected(shared_from_this());
 }
 
 void SessionRequestHandler::ClientDisconnected(KServerSession* session) {
-    session->SetSessionHandler(nullptr);
+    session->ClientDisconnected();
 }
 
 HLERequestContext::HLERequestContext(KernelCore& kernel_, Core::Memory::Memory& memory_,
diff --git a/src/core/hle/kernel/k_server_session.h b/src/core/hle/kernel/k_server_session.h
index 9efd400bc7..d44bc9d4f4 100644
--- a/src/core/hle/kernel/k_server_session.h
+++ b/src/core/hle/kernel/k_server_session.h
@@ -62,15 +62,14 @@ public:
 
     void OnClientClosed();
 
-    /**
-     * Sets the HLE handler for the session. This handler will be called to service IPC requests
-     * instead of the regular IPC machinery. (The regular IPC machinery is currently not
-     * implemented.)
-     */
-    void SetSessionHandler(SessionRequestHandlerPtr handler) {
+    void ClientConnected(SessionRequestHandlerPtr handler) {
         manager->SetSessionHandler(std::move(handler));
     }
 
+    void ClientDisconnected() {
+        manager = nullptr;
+    }
+
     /**
      * Handle a sync request from the emulated application.
      *
diff --git a/src/core/hle/service/service.h b/src/core/hle/service/service.h
index 7f133a7cb8..78afd7c731 100644
--- a/src/core/hle/service/service.h
+++ b/src/core/hle/service/service.h
@@ -42,7 +42,7 @@ class ServiceManager;
 
 static const int kMaxPortSize = 8; ///< Maximum size of a port name (8 characters)
 /// Arbitrary default number of maximum connections to an HLE service.
-static const u32 DefaultMaxSessions = 0x10000;
+static const u32 DefaultMaxSessions = 0x100;
 
 /**
  * This is an non-templated base of ServiceFramework to reduce code bloat and compilation times, it

From 2aa6a8d889e91cf999a9e95d18d06f455c337288 Mon Sep 17 00:00:00 2001
From: bunnei <bunneidev@gmail.com>
Date: Wed, 9 Jun 2021 22:04:36 -0700
Subject: [PATCH 2/4] hle: service: Use correct size for ServerSessionCountMax.

---
 src/core/hle/service/service.h | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/src/core/hle/service/service.h b/src/core/hle/service/service.h
index 78afd7c731..e078ac1765 100644
--- a/src/core/hle/service/service.h
+++ b/src/core/hle/service/service.h
@@ -40,9 +40,11 @@ namespace SM {
 class ServiceManager;
 }
 
-static const int kMaxPortSize = 8; ///< Maximum size of a port name (8 characters)
-/// Arbitrary default number of maximum connections to an HLE service.
-static const u32 DefaultMaxSessions = 0x100;
+/// Default number of maximum connections to a server session.
+static constexpr u32 ServerSessionCountMax = 0x40;
+static_assert(ServerSessionCountMax == 0x40,
+              "ServerSessionCountMax isn't 0x40 somehow, this assert is a reminder that this will "
+              "break lots of things");
 
 /**
  * This is an non-templated base of ServiceFramework to reduce code bloat and compilation times, it
@@ -178,7 +180,7 @@ protected:
      *                      connected to this service at the same time.
      */
     explicit ServiceFramework(Core::System& system_, const char* service_name_,
-                              u32 max_sessions_ = DefaultMaxSessions)
+                              u32 max_sessions_ = ServerSessionCountMax)
         : ServiceFrameworkBase(system_, service_name_, max_sessions_, Invoker) {}
 
     /// Registers handlers in the service.

From ec5674a6ad89ec705e835d2b711dca18f4ef1616 Mon Sep 17 00:00:00 2001
From: bunnei <bunneidev@gmail.com>
Date: Wed, 9 Jun 2021 22:29:18 -0700
Subject: [PATCH 3/4] hle: service: sm: Fix GetService setup of session & port.

---
 src/core/hle/kernel/k_client_port.cpp | 2 +-
 src/core/hle/service/sm/sm.cpp        | 8 ++++----
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/src/core/hle/kernel/k_client_port.cpp b/src/core/hle/kernel/k_client_port.cpp
index 50606bd917..bcb884e8a9 100644
--- a/src/core/hle/kernel/k_client_port.cpp
+++ b/src/core/hle/kernel/k_client_port.cpp
@@ -66,7 +66,7 @@ ResultCode KClientPort::CreateSession(KClientSession** out,
     // Update the session counts.
     {
         // Atomically increment the number of sessions.
-        s32 new_sessions;
+        s32 new_sessions{};
         {
             const auto max = max_sessions;
             auto cur_sessions = num_sessions.load(std::memory_order_acquire);
diff --git a/src/core/hle/service/sm/sm.cpp b/src/core/hle/service/sm/sm.cpp
index bffa9ffcb9..a1e1a7d76d 100644
--- a/src/core/hle/service/sm/sm.cpp
+++ b/src/core/hle/service/sm/sm.cpp
@@ -164,18 +164,18 @@ ResultVal<Kernel::KClientSession*> SM::GetServiceImpl(Kernel::HLERequestContext&
     R_UNLESS(session_reservation.Succeeded(), Kernel::ResultLimitReached);
 
     // Create a new session.
-    auto* session = Kernel::KSession::Create(kernel);
-    session->Initialize(&port->GetClientPort(), std::move(name));
+    Kernel::KClientSession* session{};
+    port->GetClientPort().CreateSession(std::addressof(session));
 
     // Commit the session reservation.
     session_reservation.Commit();
 
     // Enqueue the session with the named port.
-    port->EnqueueSession(&session->GetServerSession());
+    port->EnqueueSession(&session->GetParent()->GetServerSession());
 
     LOG_DEBUG(Service_SM, "called service={} -> session={}", name, session->GetId());
 
-    return MakeResult(&session->GetClientSession());
+    return MakeResult(session);
 }
 
 void SM::RegisterService(Kernel::HLERequestContext& ctx) {

From b259e95c09f231571c6a1c66046ff859019b1733 Mon Sep 17 00:00:00 2001
From: bunnei <bunneidev@gmail.com>
Date: Wed, 9 Jun 2021 22:36:42 -0700
Subject: [PATCH 4/4] hle: kernel: KClientPort: Add an assert for session
 count.

- Prevents us from over decrementing num_sessions.
---
 src/core/hle/kernel/k_client_port.cpp | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/core/hle/kernel/k_client_port.cpp b/src/core/hle/kernel/k_client_port.cpp
index bcb884e8a9..ef168fe87a 100644
--- a/src/core/hle/kernel/k_client_port.cpp
+++ b/src/core/hle/kernel/k_client_port.cpp
@@ -28,6 +28,9 @@ void KClientPort::Initialize(KPort* parent_port_, s32 max_sessions_, std::string
 void KClientPort::OnSessionFinalized() {
     KScopedSchedulerLock sl{kernel};
 
+    // This might happen if a session was improperly used with this port.
+    ASSERT_MSG(num_sessions > 0, "num_sessions is invalid");
+
     const auto prev = num_sessions--;
     if (prev == max_sessions) {
         this->NotifyAvailable();