Show a MIPS stack trace on crash screen (#17211)

* Print simple stack traces to log on crashes.

* Display stack traces on crash screen

* Show the in-function offset in the printed callstacks.

* Libretro buildfix attempt

Core/ControlMapper.cpp

@@ -151,7 +151,6 @@ void ControlMapper::Update() {
 	}
 }
 
-
 inline bool IsAnalogStickKey(int key) {
 	switch (key) {
 	case VIRTKEY_AXIS_X_MIN:

Core/Core.cpp

@@ -37,6 +37,7 @@
 #include "Core/MemMap.h"
 #include "Core/SaveState.h"
 #include "Core/System.h"
+#include "Core/MemFault.h"
 #include "Core/Debugger/Breakpoints.h"
 #include "Core/HW/Display.h"
 #include "Core/MIPS/MIPS.h"
@@ -443,6 +444,11 @@ void Core_MemoryException(u32 address, u32 accessSize, u32 pc, MemoryExceptionTy
 	}
 
 	if (!g_Config.bIgnoreBadMemAccess) {
+		// Try to fetch a call stack, to start with.
+		std::vector<MIPSStackWalk::StackFrame> stackFrames = WalkCurrentStack(-1);
+		std::string stackTrace = FormatStackTrace(stackFrames);
+		WARN_LOG(MEMMAP, "\n%s", stackTrace.c_str());
+
 		ExceptionInfo &e = g_exceptionInfo;
 		e = {};
 		e.type = ExceptionType::MEMORY;
@@ -450,6 +456,7 @@ void Core_MemoryException(u32 address, u32 accessSize, u32 pc, MemoryExceptionTy
 		e.memory_type = type;
 		e.address = address;
 		e.accessSize = accessSize;
+		e.stackTrace = stackTrace;
 		e.pc = pc;
 		Core_EnableStepping(true, "memory.exception", address);
 	}
@@ -465,12 +472,18 @@ void Core_MemoryExceptionInfo(u32 address, u32 pc, u32 accessSize, MemoryExcepti
 	}
 
 	if (!g_Config.bIgnoreBadMemAccess || forceReport) {
+		// Try to fetch a call stack, to start with.
+		std::vector<MIPSStackWalk::StackFrame> stackFrames = WalkCurrentStack(-1);
+		std::string stackTrace = FormatStackTrace(stackFrames);
+		WARN_LOG(MEMMAP, "\n%s", stackTrace.c_str());
+
 		ExceptionInfo &e = g_exceptionInfo;
 		e = {};
 		e.type = ExceptionType::MEMORY;
 		e.info = additionalInfo;
 		e.memory_type = type;
 		e.address = address;
+		e.stackTrace = stackTrace;
 		e.pc = pc;
 		Core_EnableStepping(true, "memory.exception", address);
 	}

Core/Core.h

@@ -122,6 +122,7 @@ enum class ExceptionType {
 struct ExceptionInfo {
 	ExceptionType type;
 	std::string info;
+	std::string stackTrace;  // if available.
 
 	// Memory exception info
 	MemoryExceptionType memory_type;

Core/HLE/sceKernel.cpp

@@ -306,8 +306,7 @@ bool __KernelIsRunning() {
 }
 
 std::string __KernelStateSummary() {
-	std::string threadSummary = __KernelThreadingSummary();
+	return __KernelThreadingSummary();
-	return StringFromFormat("%s", threadSummary.c_str());
 }
 
 

Core/MIPS/MIPSStackWalk.cpp

@@ -185,4 +185,6 @@ namespace MIPSStackWalk {
 
 		return frames;
 	}
+
+
 };

Core/MemFault.cpp

@@ -20,7 +20,9 @@
 #include <cstdint>
 #include <unordered_set>
 #include <mutex>
+#include <sstream>
 
+#include "Common/StringUtils.h"
 #include "Common/MachineContext.h"
 
 #if PPSSPP_ARCH(AMD64) || PPSSPP_ARCH(X86)
@@ -38,6 +40,12 @@
 #include "Core/MemFault.h"
 #include "Core/MemMap.h"
 #include "Core/MIPS/JitCommon/JitCommon.h"
+#include "Core/Debugger/SymbolMap.h"
+
+// Stack walking stuff
+#include "Core/MIPS/MIPSStackWalk.h"
+#include "Core/MIPS/MIPSDebugInterface.h"
+#include "Core/HLE/sceKernelThread.h"
 
 namespace Memory {
 
@@ -132,8 +140,7 @@ bool HandleFault(uintptr_t hostAddress, void *ctx) {
 		}
 	}
 
-
+	// OK, a guest executable did a bad access. Let's handle it.
-	// OK, a guest executable did a bad access. Take care of it.
 
 	uint32_t guestAddress = invalidHostAddress ? 0xFFFFFFFFUL : (uint32_t)(hostAddress - baseAddress);
 
@@ -317,3 +324,31 @@ bool HandleFault(uintptr_t hostAddress, void *ctx) {
 #endif
 
 }  // namespace Memory
+
+std::vector<MIPSStackWalk::StackFrame> WalkCurrentStack(int threadID) {
+	DebugInterface *cpuDebug = currentDebugMIPS;
+
+	auto threads = GetThreadsInfo();
+	uint32_t entry = cpuDebug->GetPC();
+	uint32_t stackTop = 0;
+	for (const DebugThreadInfo &th : threads) {
+		if ((threadID == -1 && th.isCurrent) || th.id == threadID) {
+			entry = th.entrypoint;
+			stackTop = th.initialStack;
+			break;
+		}
+	}
+
+	uint32_t ra = cpuDebug->GetRegValue(0, MIPS_REG_RA);
+	uint32_t sp = cpuDebug->GetRegValue(0, MIPS_REG_SP);
+	return MIPSStackWalk::Walk(cpuDebug->GetPC(), ra, sp, entry, stackTop);
+}
+
+std::string FormatStackTrace(const std::vector<MIPSStackWalk::StackFrame> &frames) {
+	std::stringstream str;
+	for (const auto &frame : frames) {
+		std::string desc = g_symbolMap->GetDescription(frame.entry);
+		str << StringFromFormat("%s (%08x+%03x, pc: %08x sp: %08x)\n", desc.c_str(), frame.entry, frame.pc - frame.entry, frame.pc, frame.sp);
+	}
+	return str.str();
+}

Core/MemFault.h

@@ -2,6 +2,8 @@
 
 #include <cstdint>
 
+#include "Core/MIPS/MIPSStackWalk.h"
+
 namespace Memory {
 
 void MemFault_Init();
@@ -19,3 +21,10 @@ void MemFault_IgnoreLastCrash();
 bool HandleFault(uintptr_t hostAddress, void *context);
 
 }
+
+// Stack walk utility function, walks from the current state. Useful in the debugger and crash report screens etc.
+// Doesn't exactly belong here maybe, but can think of worse locations.
+// threadID can be -1 for current.
+std::vector<MIPSStackWalk::StackFrame> WalkCurrentStack(int threadID);
+
+std::string FormatStackTrace(const std::vector<MIPSStackWalk::StackFrame> &frames);

UI/EmuScreen.cpp

@@ -1201,7 +1201,7 @@ static void DrawCrashDump(UIContext *ctx, const Path &gamePath) {
 
 	ctx->PushScissor(Bounds(x, y, columnWidth, height));
 
-	INFO_LOG(SYSTEM, "DrawCrashDump (%d %d %d %d)", x, y, columnWidth, height);
+	// INFO_LOG(SYSTEM, "DrawCrashDump (%d %d %d %d)", x, y, columnWidth, height);
 
 	snprintf(statbuf, sizeof(statbuf), R"(%s
 %s (%s)
@@ -1262,6 +1262,14 @@ Invalid / Unknown (%d)
 
 	ctx->Draw()->DrawTextShadow(ubuntu24, kernelState.c_str(), x, y, 0xFFFFFFFF);
 
+	y += 40;
+
+	ctx->Draw()->SetFontScale(.5f, .5f);
+
+	ctx->Draw()->DrawTextShadow(ubuntu24, info.stackTrace.c_str(), x, y, 0xFFFFFFFF);
+
+	ctx->Draw()->SetFontScale(.7f, .7f);
+
 	ctx->PopScissor();
 
 	// Draw some additional stuff to the right.

libretro/Makefile.common

@@ -650,6 +650,7 @@ SOURCES_CXX += \
 	       $(COREDIR)/MIPS/MIPSInt.cpp \
 	       $(COREDIR)/MIPS/MIPSIntVFPU.cpp \
 	       $(COREDIR)/MIPS/MIPSTables.cpp \
+	       $(COREDIR)/MIPS/MIPSStackWalk.cpp \
 	       $(COREDIR)/MIPS/MIPSVFPUUtils.cpp \
 	       $(COREDIR)/MemFault.cpp \
 	       $(COREDIR)/MemMap.cpp \