proof of concept syscall-hook tcb tracer

fuzzers/wcet_qemu_sys/.gitignore

@@ -0,0 +1,5 @@
+*.axf
+*.qcow2
+demo
+*.ron
+*.bsp

fuzzers/wcet_qemu_sys/src/freertos.rs

@@ -1,3 +1,4 @@
+use serde::{Deserialize, Serialize};
 // Manual Types
 use libafl_qemu::Emulator;
 
@@ -20,7 +21,7 @@ pub type StackType_t = u32;
 pub type UBaseType_t = ::std::os::raw::c_uint;
 pub type TickType_t = u32;
 #[repr(C)]
-#[derive(Debug, Copy, Clone)]
+#[derive(Debug, Copy, Clone, Default, Serialize, Deserialize)]
 pub struct xLIST_ITEM {
     pub xItemValue: TickType_t,
     pub pxNext: xLIST_ITEM_ptr,
@@ -93,7 +94,7 @@ fn bindgen_test_layout_xLIST_ITEM() {
 }
 pub type ListItem_t = xLIST_ITEM;
 #[repr(C)]
-#[derive(Debug, Copy, Clone)]
+#[derive(Debug, Copy, Clone, Default, Serialize, Deserialize)]
 pub struct xMINI_LIST_ITEM {
     pub xItemValue: TickType_t,
     pub pxNext: xLIST_ITEM_ptr,
@@ -144,7 +145,7 @@ fn bindgen_test_layout_xMINI_LIST_ITEM() {
 }
 pub type MiniListItem_t = xMINI_LIST_ITEM;
 #[repr(C)]
-#[derive(Debug, Copy, Clone)]
+#[derive(Debug, Copy, Clone, Default)]
 pub struct xLIST {
     pub uxNumberOfItems: UBaseType_t,
     pub pxIndex: ListItem_t_ptr,
@@ -194,7 +195,7 @@ fn bindgen_test_layout_xLIST() {
     );
 }
 pub type List_t = xLIST;
-pub type TaskHandle_t = *mut tskTaskControlBlock;
+pub type TaskHandle_t = ::std::os::raw::c_uint;
 pub const eTaskState_eRunning: eTaskState = 0;
 pub const eTaskState_eReady: eTaskState = 1;
 pub const eTaskState_eBlocked: eTaskState = 2;
@@ -203,7 +204,7 @@ pub const eTaskState_eDeleted: eTaskState = 4;
 pub const eTaskState_eInvalid: eTaskState = 5;
 pub type eTaskState = ::std::os::raw::c_uint;
 #[repr(C)]
-#[derive(Debug, Copy, Clone)]
+#[derive(Debug, Copy, Clone, Serialize, Deserialize)]
 pub struct xTASK_STATUS {
     pub xHandle: TaskHandle_t,
     pub pcTaskName: char_ptr,
@@ -322,14 +323,14 @@ fn bindgen_test_layout_xTASK_STATUS() {
 }
 pub type TaskStatus_t = xTASK_STATUS;
 #[repr(C)]
-#[derive(Debug, Copy, Clone)]
+#[derive(Debug, Copy, Clone, Default, Serialize, Deserialize)]
 pub struct tskTaskControlBlock {
     pub pxTopOfStack: StackType_t_ptr,
     pub xStateListItem: ListItem_t,
     pub xEventListItem: ListItem_t,
     pub uxPriority: UBaseType_t,
     pub pxStack: StackType_t_ptr,
-    pub pcTaskName: [::std::os::raw::c_char; 10usize],
+    pub pcTaskName: [::std::os::raw::c_uchar; 10usize],
     pub uxBasePriority: UBaseType_t,
     pub uxMutexesHeld: UBaseType_t,
     pub ulNotifiedValue: [u32; 1usize],

fuzzers/wcet_qemu_sys/src/main.rs

@@ -3,6 +3,7 @@ pub mod fuzzer;
 pub mod showmap;
 pub mod worst;
 pub mod freertos;
+pub mod system_trace;
 use libafl_qemu::{
     edges,
     edges::QemuEdgeCoverageHelper,

fuzzers/wcet_qemu_sys/src/showmap.rs

@@ -1,5 +1,6 @@
 //! A singlethreaded QEMU fuzzer that can auto-restart.
 
+use crate::system_trace::QemuSystemStateHelper;
 use libafl::feedbacks::CrashFeedback;
 use std::path::Path;
 use libafl_qemu::QemuExecutor;
@@ -208,6 +209,21 @@ fn fuzz(
         .expect("Symbol pxReadyTasksLists not found");
     // let task_queue_addr = virt2phys(task_queue_addr,&elf.goblin());
     println!("Task Queue at {:#x}", task_queue_addr);
+    let shv = elf
+        .resolve_symbol("xPortSysTickHandler", 0)
+        .expect("Symbol xPortSysTickHandler not found");
+    let shv = virt2phys(shv,&elf.goblin());
+    println!("SysTick at {:#x}", shv);
+    let shv = elf
+        .resolve_symbol("vPortSVCHandler", 0)
+        .expect("Symbol vPortSVCHandler not found");
+    let shv = virt2phys(shv,&elf.goblin());
+    println!("SVChandle at {:#x}", shv);
+    let shv = elf
+        .resolve_symbol("xPortPendSVHandler", 0)
+        .expect("Symbol xPortPendSVHandler not found");
+    let shv = virt2phys(shv,&elf.goblin());
+    println!("PendHandle at {:#x}", shv);
 
 
 
@@ -274,12 +290,12 @@ fn fuzz(
 
             emu.run();
             //====== experiment inspecting the current tcb
-            let curr_tcb_addr : freertos::void_ptr = freertos::emu_lookup::lookup(&emu, curr_tcb_pointer.try_into().unwrap());
-            println!("Current TCB addr: {:x}",curr_tcb_addr);
-            let current_tcb : freertos::TCB_t = freertos::emu_lookup::lookup(&emu,curr_tcb_addr);
-            println!("Current TCB: {:?}",current_tcb);
-            let ready_queue : freertos::List_t = freertos::emu_lookup::lookup(&emu,task_queue_addr.try_into().unwrap());
-            println!("Ready Queue: {:?}",ready_queue);
+            // let curr_tcb_addr : freertos::void_ptr = freertos::emu_lookup::lookup(&emu, curr_tcb_pointer.try_into().unwrap());
+            // println!("Current TCB addr: {:x}",curr_tcb_addr);
+            // let current_tcb : freertos::TCB_t = freertos::emu_lookup::lookup(&emu,curr_tcb_addr);
+            // println!("Current TCB: {:?}",current_tcb);
+            // let ready_queue : freertos::List_t = freertos::emu_lookup::lookup(&emu,task_queue_addr.try_into().unwrap());
+            // println!("Ready Queue: {:?}",ready_queue);
         }
 
         ExitKind::Ok
@@ -293,7 +309,8 @@ fn fuzz(
             QemuEdgeCoverageHelper::new(),
             // QemuCmpLogHelper::new(),
             // QemuAsanHelper::new(),
-            QemuSysSnapshotHelper::new()
+            QemuSysSnapshotHelper::new(),
+            QemuSystemStateHelper::new()
         ),
         tuple_list!(edges_observer),
         &mut fuzzer,
@@ -305,17 +322,6 @@ fn fuzz(
         false => seed_dir.clone()
     };
     fuzzer.evaluate_input(&mut state, &mut executor, &mut mgr, Input::from_file(&firstinput).expect("Could not load file")).expect("Evaluation failed");
-    // fuzzer.evaluate_input(&mut state, &mut executor, &mut mgr, Input::from_file(&firstinput).expect("Could not load file")).expect("Evaluation failed");
-    // let mutator = StdScheduledMutator::new(havoc_mutations().merge(tokens_mutations()));
-    // let mut stages = tuple_list!(StdMutationalStage::new(mutator));
-    // if state.corpus().count() < 1 {
-    //     state
-    //         .load_initial_inputs(&mut fuzzer, &mut executor, &mut mgr, &[seed_dir.clone()])
-    //         .expect("Failed to load initial corpus");
-    //     println!("We imported {} inputs from disk.", state.corpus().count());
-    // }
-    // fuzzer.fuzz_loop(&mut stages, &mut executor, &mut state, &mut mgr)
-    //     .expect("Error in the fuzzing loop");
     return Ok(());
 }
 

fuzzers/wcet_qemu_sys/src/system_trace.rs

@@ -0,0 +1,110 @@
+use crate::freertos;
+use hashbrown::HashMap;
+use libafl::{executors::ExitKind, inputs::Input, observers::ObserversTuple, state::HasMetadata};
+use serde::{Deserialize, Serialize};
+
+use libafl_qemu::{
+    emu::Emulator,
+    executor::QemuExecutor,
+    helper::{QemuHelper, QemuHelperTuple, QemuInstrumentationFilter},
+};
+
+#[derive(Debug, Default, Serialize, Deserialize)]
+pub struct QemuSystemStateMetadata {
+    pub tcbs: Vec<freertos::TCB_t>,
+    // pub map: HashMap<u64, u64>,
+    // pub current_id: u64,
+}
+
+impl QemuSystemStateMetadata {
+    #[must_use]
+    pub fn new() -> Self {
+        Self {
+            tcbs: Vec::new(),
+            // map: HashMap::new(),
+            // current_id: 0,
+        }
+    }
+}
+
+libafl::impl_serdeany!(QemuSystemStateMetadata);
+
+#[derive(Debug)]
+pub struct QemuSystemStateHelper {
+    filter: QemuInstrumentationFilter,
+}
+
+impl QemuSystemStateHelper {
+    #[must_use]
+    pub fn new() -> Self {
+        Self {
+            filter: QemuInstrumentationFilter::None,
+        }
+    }
+
+    #[must_use]
+    pub fn with_instrumentation_filter(filter: QemuInstrumentationFilter) -> Self {
+        Self { filter }
+    }
+
+    #[must_use]
+    pub fn must_instrument(&self, addr: u64) -> bool {
+        self.filter.allowed(addr)
+    }
+}
+
+impl Default for QemuSystemStateHelper {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl<I, S> QemuHelper<I, S> for QemuSystemStateHelper
+where
+    I: Input,
+    S: HasMetadata,
+{
+    fn init<'a, H, OT, QT>(&self, executor: &QemuExecutor<'a, H, I, OT, QT, S>)
+    where
+        H: FnMut(&I) -> ExitKind,
+        OT: ObserversTuple<I, S>,
+        QT: QemuHelperTuple<I, S>,
+    {
+        executor.hook_block_execution(exec_syscall_hook::<I, QT, S>);
+    }
+}
+
+pub fn exec_syscall_hook<I, QT, S>(
+    emulator: &Emulator,
+    helpers: &mut QT,
+    state: &mut S,
+    pc: u64,
+)
+where
+    S: HasMetadata,
+    I: Input,
+    QT: QemuHelperTuple<I, S>,
+{
+    // if pc == 0x2e8 {    //vPortSVCHandler
+    // if pc == 0x3c4 {    //SystemTick
+    if pc == 0x37c {    //xPortPendSVHandler
+        if let Some(h) = helpers.match_first_type::<QemuSystemStateHelper>() {
+            if !h.must_instrument(pc) {
+                return;
+            }
+        }
+        if state.metadata().get::<QemuSystemStateMetadata>().is_none() {
+            state.add_metadata(QemuSystemStateMetadata::new());
+        }
+        let meta = state
+            .metadata_mut()
+            .get_mut::<QemuSystemStateMetadata>()
+            .unwrap();
+        let curr_tcb_addr : freertos::void_ptr = freertos::emu_lookup::lookup(emulator, 0x20006ff0.try_into().unwrap());
+        // println!("Current TCB addr: {:x}",curr_tcb_addr);
+        let current_tcb : freertos::TCB_t = freertos::emu_lookup::lookup(emulator,curr_tcb_addr);
+        println!("{}", std::str::from_utf8(&current_tcb.pcTaskName).unwrap());
+        meta.tcbs.push(current_tcb);
+        let id = meta.tcbs.len();
+    }
+}