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Fix: Recover from null pointer execution crashes

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Add proper recovery mechanism for null pointer execution (PC < 0x1000)
by returning from invalid function calls using the Link Register instead
of blindly continuing execution.

Fixes infinite crash loop in games like Little Nightmares III.

Signed-off-by: Zephyron <zephyron@citron-emu.org>
This commit is contained in:
Zephyron
2025-10-11 17:02:28 +10:00
parent 3c16d8330b
commit fbb4f5c015
2 changed files with 43 additions and 4 deletions
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36
src/core/hle/kernel/physical_core.cpp
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@@ -125,10 +125,38 @@ void PhysicalCore::RunThread(Kernel::KThread* thread) {
if (prefetch_abort) {
LOG_WARNING(Core_ARM, "Prefetch abort detected - checking if recoverable...");
// For Nintendo SDK crashes, try to continue execution
// This is especially important for games like Phoenix Switch
should_continue = true;
LOG_INFO(Core_ARM, "Attempting to continue execution after Nintendo SDK crash");
// Get the current PC to check if we're in a null pointer execution loop
Kernel::Svc::ThreadContext ctx;
interface->GetContext(ctx);
u64 current_pc = ctx.pc;
// Detect null pointer execution loop (PC in very low memory addresses)
if (current_pc < 0x1000) {
LOG_WARNING(Core_ARM, "Null pointer execution detected at PC={:016X}", current_pc);
LOG_WARNING(Core_ARM, "Attempting to recover by returning from invalid function call");
// Try to recover by returning from the function using LR (X30)
// This simulates a function return
u64 return_address = ctx.lr;
if (return_address != 0 && return_address >= 0x1000) {
LOG_INFO(Core_ARM, "Recovering: Setting PC to return address {:016X}", return_address);
ctx.pc = return_address;
// Set return value to 0 in X0
ctx.r[0] = 0;
interface->SetContext(ctx);
should_continue = true;
} else {
LOG_ERROR(Core_ARM, "Cannot recover: Invalid return address {:016X}", return_address);
LOG_ERROR(Core_ARM, "Thread will be suspended due to unrecoverable crash");
should_continue = false;
}
} else {
// For Nintendo SDK crashes at valid addresses, try to continue execution
// This is especially important for games like Phoenix Switch
should_continue = true;
LOG_INFO(Core_ARM, "Attempting to continue execution after Nintendo SDK crash");
}
}
} else {
system.GetDebugger().NotifyThreadStopped(thread);