From 3289b2a3aad71c4b157e0211a82dcffa94a4337c Mon Sep 17 00:00:00 2001
From: Luke Street <luke.street@encounterpc.com>
Date: Mon, 10 Jun 2024 00:40:37 -0600
Subject: [PATCH] Ignore invalid instructions

This could be a bad idea, but
it's unclear how to properly
handle these cases.

Resolves #55
---
 src/analysis/slices.rs  |  9 +++++++--
 src/analysis/tracker.rs | 15 +++++++++------
 2 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/src/analysis/slices.rs b/src/analysis/slices.rs
index ce121fa..685ce90 100644
--- a/src/analysis/slices.rs
+++ b/src/analysis/slices.rs
@@ -266,8 +266,13 @@ impl FunctionSlices {
                 }
             }
             StepResult::Illegal => {
-                log::debug!("Illegal instruction @ {:#010X}", ins_addr);
-                Ok(ExecCbResult::End(false))
+                if ins.code == 0 {
+                    log::debug!("Hit zeroed padding @ {:#010X}", ins_addr);
+                    Ok(ExecCbResult::End(false))
+                } else {
+                    log::debug!("Illegal instruction @ {:#010X}", ins_addr);
+                    Ok(ExecCbResult::Continue)
+                }
             }
             StepResult::Jump(target) => match target {
                 BranchTarget::Unknown
diff --git a/src/analysis/tracker.rs b/src/analysis/tracker.rs
index 24bb321..af4cc5f 100644
--- a/src/analysis/tracker.rs
+++ b/src/analysis/tracker.rs
@@ -348,12 +348,15 @@ impl Tracker {
                 }
                 Ok(ExecCbResult::Continue)
             }
-            StepResult::Illegal => bail!(
-                "Illegal instruction hit @ {:#010X} (function {:#010X}-{:#010X})",
-                ins_addr,
-                function_start,
-                function_end
-            ),
+            StepResult::Illegal => {
+                log::debug!(
+                    "Illegal instruction hit @ {:#010X} (function {:#010X}-{:#010X})",
+                    ins_addr,
+                    function_start,
+                    function_end
+                );
+                Ok(ExecCbResult::Continue)
+            }
             StepResult::Jump(target) => match target {
                 BranchTarget::Unknown
                 | BranchTarget::Return