From 3cb5fd8ebc817af35c6b23698caf15b185c6be14 Mon Sep 17 00:00:00 2001
From: Eladash <elad3356p@gmail.com>
Date: Sat, 7 Nov 2020 18:12:52 +0200
Subject: [PATCH] Debugger: Implement SPU callstack, fix PPU callstack

---
 rpcs3/Emu/Cell/PPUThread.cpp | 32 ++++++++++++++++---
 rpcs3/Emu/Cell/SPUThread.cpp | 60 ++++++++++++++++++++++++++++++++++--
 rpcs3/Emu/Cell/SPUThread.h   |  2 +-
 3 files changed, 86 insertions(+), 8 deletions(-)

diff --git a/rpcs3/Emu/Cell/PPUThread.cpp b/rpcs3/Emu/Cell/PPUThread.cpp
index 8cb5998314..3de988ecf8 100644
--- a/rpcs3/Emu/Cell/PPUThread.cpp
+++ b/rpcs3/Emu/Cell/PPUThread.cpp
@@ -538,7 +538,7 @@ std::string ppu_thread::dump_callstack() const
 	for (const auto& sp : dump_callstack_list())
 	{
 		// TODO: function addresses too
-		fmt::append(ret, "> from 0x%08x (r1=0x%08x)\n", sp.first, sp.second);
+		fmt::append(ret, "> from 0x%08x (sp=0x%08x)\n", sp.first, sp.second);
 	}
 
 	return ret;
@@ -579,17 +579,39 @@ std::vector<std::pair<u32, u32>> ppu_thread::dump_callstack_list() const
 
 	std::vector<std::pair<u32, u32>> call_stack_list;
 
+	bool first = true;
+
 	for (
-		u64 sp = *vm::get_super_ptr<u64>(stack_ptr);
+		u64 sp = r1;
 		sp % 0x10 == 0u && sp >= stack_min && sp <= stack_max - ppu_stack_start_offset;
 		sp = *vm::get_super_ptr<u64>(static_cast<u32>(sp))
 		)
 	{
-		const u64 addr = *vm::get_super_ptr<u64>(static_cast<u32>(sp + 16));
+		u64 addr = *vm::get_super_ptr<u64>(static_cast<u32>(sp + 16));
 
-		if (addr > UINT32_MAX || addr % 4 || !vm::check_addr(static_cast<u32>(addr), 1, vm::page_executable))
+		auto is_invalid = [](u64 addr)
 		{
-			break;
+			return (addr > UINT32_MAX || addr % 4 || !vm::check_addr(static_cast<u32>(addr), 1, vm::page_executable));
+		};
+
+		if (is_invalid(addr))
+		{
+			if (std::exchange(first, false))
+			{
+				// Function hasn't saved LR, could be because it's a leaf function
+				// Use LR directly instead
+				addr = lr;
+
+				if (is_invalid(addr))
+				{
+					// Skip it, workaround
+					continue;
+				}
+			}
+			else
+			{
+				break;
+			}
 		}
 
 		// TODO: function addresses too
diff --git a/rpcs3/Emu/Cell/SPUThread.cpp b/rpcs3/Emu/Cell/SPUThread.cpp
index 05e7faa3b2..84ad06c519 100644
--- a/rpcs3/Emu/Cell/SPUThread.cpp
+++ b/rpcs3/Emu/Cell/SPUThread.cpp
@@ -1245,12 +1245,68 @@ std::string spu_thread::dump_regs() const
 
 std::string spu_thread::dump_callstack() const
 {
-	return {};
+	std::string ret;
+
+	fmt::append(ret, "Call stack:\n=========\n0x%08x (0x0) called\n", pc);
+
+	for (const auto& sp : dump_callstack_list())
+	{
+		// TODO: function addresses too
+		fmt::append(ret, "> from 0x%08x (sp=0x%08x)\n", sp.first, sp.second);
+	}
+
+	return ret;
 }
 
 std::vector<std::pair<u32, u32>> spu_thread::dump_callstack_list() const
 {
-	return {};
+	std::vector<std::pair<u32, u32>> call_stack_list;
+
+	bool first = true;
+
+	// Declare first 128-bytes as invalid for stack (common values such as 0 do not make sense here)
+	for (u32 sp = gpr[1]._u32[3]; (sp & ~0x3FFF0) == 0u && sp >= 0x80u; sp = _ref<u32>(sp))
+	{
+		v128 lr = _ref<v128>(sp + 16);
+
+		auto is_invalid = [](v128 v)
+		{
+			const u32 addr = v._u32[3];
+
+			if (v != v128::from32r(addr))
+			{
+				// Non-zero lower words are invalid (because BRSL-like instructions generate only zeroes)
+				return true;
+			}
+
+			return !!(addr & ~0x3FFFC);
+		};
+
+		if (is_invalid(lr))
+		{
+			if (std::exchange(first, false))
+			{
+				// Function hasn't saved LR, could be because it's a leaf function
+				// Use LR directly instead
+				lr = gpr[0];
+
+				if (is_invalid(lr))
+				{
+					// Skip it, workaround
+					continue;
+				}
+			}
+			else
+			{
+				break;
+			}
+		}
+
+		// TODO: function addresses too
+		call_stack_list.emplace_back(lr._u32[3], sp);
+	}
+
+	return call_stack_list;
 }
 
 std::string spu_thread::dump_misc() const
diff --git a/rpcs3/Emu/Cell/SPUThread.h b/rpcs3/Emu/Cell/SPUThread.h
index a5fae796cd..cf694ec1d5 100644
--- a/rpcs3/Emu/Cell/SPUThread.h
+++ b/rpcs3/Emu/Cell/SPUThread.h
@@ -792,7 +792,7 @@ public:
 	template<typename T>
 	to_be_t<T>* _ptr(u32 lsa) const
 	{
-		return reinterpret_cast<to_be_t<T>*>(ls + lsa);
+		return reinterpret_cast<to_be_t<T>*>(ls + (lsa % SPU_LS_SIZE));
 	}
 
 	// Convert specified SPU LS address to a reference of specified (possibly converted to BE) type