From 484641003cf727def0101f35c83d1ef135b93f54 Mon Sep 17 00:00:00 2001
From: Liam <byteslice@airmail.cc>
Date: Tue, 7 Mar 2023 19:18:06 -0500
Subject: [PATCH] kernel: clone fpu status on CreateThread
---
src/core/hle/kernel/k_thread.cpp | 24 +++++++++++++++++++++++-
src/core/hle/kernel/k_thread.h | 2 ++
src/core/hle/kernel/svc/svc_thread.cpp | 3 +++
3 files changed, 28 insertions(+), 1 deletion(-)
diff --git a/src/core/hle/kernel/k_thread.cpp b/src/core/hle/kernel/k_thread.cpp
index 8c403f5fdd..15ae652f9d 100644
--- a/src/core/hle/kernel/k_thread.cpp
+++ b/src/core/hle/kernel/k_thread.cpp
@@ -49,6 +49,7 @@ static void ResetThreadContext32(Core::ARM_Interface::ThreadContext32& context,
context.cpu_registers[0] = arg;
context.cpu_registers[15] = entry_point;
context.cpu_registers[13] = stack_top;
+ context.fpscr = 0;
}
static void ResetThreadContext64(Core::ARM_Interface::ThreadContext64& context, VAddr stack_top,
@@ -58,8 +59,8 @@ static void ResetThreadContext64(Core::ARM_Interface::ThreadContext64& context,
context.cpu_registers[18] = Kernel::KSystemControl::GenerateRandomU64() | 1;
context.pc = entry_point;
context.sp = stack_top;
- // TODO(merry): Perform a hardware test to determine the below value.
context.fpcr = 0;
+ context.fpsr = 0;
}
} // namespace
@@ -815,6 +816,27 @@ void KThread::Continue() {
KScheduler::OnThreadStateChanged(kernel, this, old_state);
}
+void KThread::CloneFpuStatus() {
+ // We shouldn't reach here when starting kernel threads.
+ ASSERT(this->GetOwnerProcess() != nullptr);
+ ASSERT(this->GetOwnerProcess() == GetCurrentProcessPointer(kernel));
+
+ if (this->GetOwnerProcess()->Is64BitProcess()) {
+ // Clone FPSR and FPCR.
+ ThreadContext64 cur_ctx{};
+ kernel.System().CurrentArmInterface().SaveContext(cur_ctx);
+
+ this->GetContext64().fpcr = cur_ctx.fpcr;
+ this->GetContext64().fpsr = cur_ctx.fpsr;
+ } else {
+ // Clone FPSCR.
+ ThreadContext32 cur_ctx{};
+ kernel.System().CurrentArmInterface().SaveContext(cur_ctx);
+
+ this->GetContext32().fpscr = cur_ctx.fpscr;
+ }
+}
+
Result KThread::SetActivity(Svc::ThreadActivity activity) {
// Lock ourselves.
KScopedLightLock lk(activity_pause_lock);
diff --git a/src/core/hle/kernel/k_thread.h b/src/core/hle/kernel/k_thread.h
index bd125f5f16..9423f08ca7 100644
--- a/src/core/hle/kernel/k_thread.h
+++ b/src/core/hle/kernel/k_thread.h
@@ -254,6 +254,8 @@ public:
thread_context_32.tpidr = static_cast<u32>(value);
}
+ void CloneFpuStatus();
+
[[nodiscard]] ThreadContext32& GetContext32() {
return thread_context_32;
}
diff --git a/src/core/hle/kernel/svc/svc_thread.cpp b/src/core/hle/kernel/svc/svc_thread.cpp
index b398078418..9bc1ebe74d 100644
--- a/src/core/hle/kernel/svc/svc_thread.cpp
+++ b/src/core/hle/kernel/svc/svc_thread.cpp
@@ -82,6 +82,9 @@ Result CreateThread(Core::System& system, Handle* out_handle, VAddr entry_point,
// Commit the thread reservation.
thread_reservation.Commit();
+ // Clone the current fpu status to the new thread.
+ thread->CloneFpuStatus();
+
// Register the new thread.
KThread::Register(kernel, thread);