From cf534f514989e0d2e52df208818a39aa5eead7c0 Mon Sep 17 00:00:00 2001
From: Liam <byteslice@airmail.cc>
Date: Tue, 21 Nov 2023 23:23:48 -0500
Subject: [PATCH] arm_nce: skip data aborts for crash handling parity
---
src/core/arm/nce/arm_nce.cpp | 14 +++++++++++---
1 file changed, 11 insertions(+), 3 deletions(-)
diff --git a/src/core/arm/nce/arm_nce.cpp b/src/core/arm/nce/arm_nce.cpp
index bb1f6d2e65..6eb6299cc9 100644
--- a/src/core/arm/nce/arm_nce.cpp
+++ b/src/core/arm/nce/arm_nce.cpp
@@ -116,10 +116,18 @@ bool ARM_NCE::HandleGuestFault(GuestContext* guest_ctx, void* raw_info, void* ra
return true;
}
- // We can't handle the access, so trigger an exception.
+ // We can't handle the access, so determine why we crashed.
const bool is_prefetch_abort = host_ctx.pc == reinterpret_cast<u64>(info->si_addr);
- guest_ctx->esr_el1.fetch_or(
- static_cast<u64>(is_prefetch_abort ? HaltReason::PrefetchAbort : HaltReason::DataAbort));
+
+ // For data aborts, skip the instruction and return to guest code.
+ // This will allow games to continue in many scenarios where they would otherwise crash.
+ if (!is_prefetch_abort) {
+ host_ctx.pc += 4;
+ return true;
+ }
+
+ // This is a prefetch abort.
+ guest_ctx->esr_el1.fetch_or(static_cast<u64>(HaltReason::PrefetchAbort));
// Forcibly mark the context as locked. We are still running.
// We may race with SignalInterrupt here: