LibAFL_QEMU: Don't require extra_tokens. (#2576)

Co-authored-by: Romain Malmain <romain.malmain@pm.me>

fuzzers/binary_only/qemu_launcher/src/client.rs

@@ -153,8 +153,6 @@ impl<'a> Client<'a> {
                 }
             });
 
-        let extra_tokens = injection_module.as_ref().map(|h| h.tokens.clone());
-
         qemu.entry_break(start_pc);
 
         let ret_addr: GuestAddr = qemu
@@ -169,7 +167,12 @@ impl<'a> Client<'a> {
             .address_filter(self.coverage_filter(&qemu)?)
             .build();
 
-        let instance = Instance::builder()
+        let extra_tokens = injection_module
+            .as_ref()
+            .map(|h| h.tokens.clone())
+            .unwrap_or_default();
+
+        let instance_builder = Instance::builder()
             .options(self.options)
             .qemu(&qemu)
             .mgr(mgr)
@@ -178,7 +181,7 @@ impl<'a> Client<'a> {
 
         if is_asan && is_cmplog {
             if let Some(injection_module) = injection_module {
-                instance.build().run(
+                instance_builder.build().run(
                     tuple_list!(
                         edge_coverage_module,
                         CmpLogModule::default(),
@@ -188,7 +191,7 @@ impl<'a> Client<'a> {
                     state,
                 )
             } else {
-                instance.build().run(
+                instance_builder.build().run(
                     tuple_list!(
                         edge_coverage_module,
                         CmpLogModule::default(),
@@ -199,7 +202,7 @@ impl<'a> Client<'a> {
             }
         } else if is_asan_guest && is_cmplog {
             if let Some(injection_module) = injection_module {
-                instance.build().run(
+                instance_builder.build().run(
                     tuple_list!(
                         edge_coverage_module,
                         CmpLogModule::default(),
@@ -209,7 +212,7 @@ impl<'a> Client<'a> {
                     state,
                 )
             } else {
-                instance.build().run(
+                instance_builder.build().run(
                     tuple_list!(
                         edge_coverage_module,
                         CmpLogModule::default(),
@@ -220,7 +223,7 @@ impl<'a> Client<'a> {
             }
         } else if is_asan {
             if let Some(injection_module) = injection_module {
-                instance.build().run(
+                instance_builder.build().run(
                     tuple_list!(
                         edge_coverage_module,
                         AsanModule::default(asan.take().unwrap()),
@@ -229,7 +232,7 @@ impl<'a> Client<'a> {
                     state,
                 )
             } else {
-                instance.build().run(
+                instance_builder.build().run(
                     tuple_list!(
                         edge_coverage_module,
                         AsanModule::default(asan.take().unwrap()),
@@ -242,10 +245,10 @@ impl<'a> Client<'a> {
                 edge_coverage_module,
                 AsanGuestModule::default(&qemu, asan_lib.take().unwrap())
             );
-            instance.build().run(modules, state)
+            instance_builder.build().run(modules, state)
         } else if is_cmplog {
             if let Some(injection_module) = injection_module {
-                instance.build().run(
+                instance_builder.build().run(
                     tuple_list!(
                         edge_coverage_module,
                         CmpLogModule::default(),
@@ -254,17 +257,17 @@ impl<'a> Client<'a> {
                     state,
                 )
             } else {
-                instance.build().run(
+                instance_builder.build().run(
                     tuple_list!(edge_coverage_module, CmpLogModule::default()),
                     state,
                 )
             }
         } else if let Some(injection_module) = injection_module {
-            instance
+            instance_builder
                 .build()
                 .run(tuple_list!(edge_coverage_module, injection_module), state)
         } else {
-            instance
+            instance_builder
                 .build()
                 .run(tuple_list!(edge_coverage_module), state)
         }

fuzzers/binary_only/qemu_launcher/src/instance.rs

@@ -64,7 +64,8 @@ pub struct Instance<'a, M: Monitor> {
     qemu: &'a Qemu,
     mgr: ClientMgr<M>,
     core_id: CoreId,
-    extra_tokens: Option<Vec<String>>,
+    #[builder(default)]
+    extra_tokens: Vec<String>,
     #[builder(default=PhantomData)]
     phantom: PhantomData<M>,
 }
@@ -134,12 +135,10 @@ impl<'a, M: Monitor> Instance<'a, M> {
 
         let mut tokens = Tokens::new();
 
-        if let Some(extra_tokens) = &self.extra_tokens {
-            for token in extra_tokens {
+        for token in &self.extra_tokens {
             let bytes = token.as_bytes().to_vec();
             let _ = tokens.add_token(&bytes);
         }
-        }
 
         if let Some(tokenfile) = &self.options.tokens {
             tokens.add_from_file(tokenfile)?;

libafl_qemu/src/modules/edges.rs

@@ -357,6 +357,8 @@ pub struct EdgeCoverageModuleBuilder<AF, PF, V> {
 pub struct EdgeCoverageModule<AF, PF, V> {
     variant: V,
     address_filter: AF,
+    // we only use it in system mode at the moment.
+    #[cfg_attr(not(emulation_mode = "systemmode"), allow(dead_code))]
     page_filter: PF,
     use_hitcounts: bool,
     use_jit: bool,