From 31c8b6f83e4eb3480442f2541fe4ae10ae253078 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alexander=20Mei=C3=9Fner?= <AlexanderMeissner@gmx.net>
Date: Sat, 30 Sep 2023 16:13:13 +0200
Subject: [PATCH] Adds a reference to the loader in the VM. (#533)

---
 cli/src/main.rs       |  2 +-
 src/jit.rs            |  2 +-
 src/vm.rs             | 16 ++++++++++------
 test_utils/src/lib.rs |  2 +-
 4 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/cli/src/main.rs b/cli/src/main.rs
index 905028a1..30c8e2ca 100644
--- a/cli/src/main.rs
+++ b/cli/src/main.rs
@@ -171,7 +171,7 @@ fn main() {
     let memory_mapping = MemoryMapping::new(regions, config, sbpf_version).unwrap();
 
     let mut vm = EbpfVm::new(
-        executable.get_config(),
+        executable.get_loader().clone(),
         executable.get_sbpf_version(),
         &mut context_object,
         memory_mapping,
diff --git a/src/jit.rs b/src/jit.rs
index 8f9a4653..ae555132 100644
--- a/src/jit.rs
+++ b/src/jit.rs
@@ -1628,7 +1628,7 @@ mod tests {
         let executable = create_mockup_executable(&[]);
         let mut context_object = TestContextObject::new(0);
         let env = EbpfVm::new(
-            executable.get_config(),
+            executable.get_loader().clone(),
             executable.get_sbpf_version(),
             &mut context_object,
             MemoryMapping::new_identity(),
diff --git a/src/vm.rs b/src/vm.rs
index 7b677d12..365239a2 100644
--- a/src/vm.rs
+++ b/src/vm.rs
@@ -319,13 +319,12 @@ pub struct CallFrame {
 ///
 /// let loader = std::sync::Arc::new(BuiltinProgram::new_mock());
 /// let function_registry = FunctionRegistry::default();
-/// let mut executable = Executable::<TestContextObject>::from_text_bytes(prog, loader, SBPFVersion::V2, function_registry).unwrap();
+/// let mut executable = Executable::<TestContextObject>::from_text_bytes(prog, loader.clone(), SBPFVersion::V2, function_registry).unwrap();
 /// executable.verify::<RequisiteVerifier>().unwrap();
 /// let mut context_object = TestContextObject::new(1);
-/// let config = executable.get_config();
 /// let sbpf_version = executable.get_sbpf_version();
 ///
-/// let mut stack = AlignedMemory::<{ebpf::HOST_ALIGN}>::zero_filled(config.stack_size());
+/// let mut stack = AlignedMemory::<{ebpf::HOST_ALIGN}>::zero_filled(executable.get_config().stack_size());
 /// let stack_len = stack.len();
 /// let mut heap = AlignedMemory::<{ebpf::HOST_ALIGN}>::with_capacity(0);
 ///
@@ -339,9 +338,9 @@ pub struct CallFrame {
 ///     MemoryRegion::new_writable(mem, ebpf::MM_INPUT_START),
 /// ];
 ///
-/// let memory_mapping = MemoryMapping::new(regions, config, sbpf_version).unwrap();
+/// let memory_mapping = MemoryMapping::new(regions, executable.get_config(), sbpf_version).unwrap();
 ///
-/// let mut vm = EbpfVm::new(config, sbpf_version, &mut context_object, memory_mapping, stack_len);
+/// let mut vm = EbpfVm::new(loader, sbpf_version, &mut context_object, memory_mapping, stack_len);
 ///
 /// let (instruction_count, result) = vm.execute_program(&executable, true);
 /// assert_eq!(instruction_count, 1);
@@ -379,6 +378,8 @@ pub struct EbpfVm<'a, C: ContextObject> {
     pub memory_mapping: MemoryMapping<'a>,
     /// Stack of CallFrames used by the Interpreter
     pub call_frames: Vec<CallFrame>,
+    /// Loader built-in program
+    pub loader: Arc<BuiltinProgram<C>>,
     /// TCP port for the debugger interface
     #[cfg(feature = "debugger")]
     pub debug_port: Option<u16>,
@@ -387,12 +388,13 @@ pub struct EbpfVm<'a, C: ContextObject> {
 impl<'a, C: ContextObject> EbpfVm<'a, C> {
     /// Creates a new virtual machine instance.
     pub fn new(
-        config: &Config,
+        loader: Arc<BuiltinProgram<C>>,
         sbpf_version: &SBPFVersion,
         context_object: &'a mut C,
         mut memory_mapping: MemoryMapping<'a>,
         stack_len: usize,
     ) -> Self {
+        let config = loader.get_config();
         let stack_pointer =
             ebpf::MM_STACK_START.saturating_add(if sbpf_version.dynamic_stack_frames() {
                 // the stack is fully descending, frames start as empty and change size anytime r11 is modified
@@ -416,6 +418,7 @@ impl<'a, C: ContextObject> EbpfVm<'a, C> {
             program_result: ProgramResult::Ok(0),
             memory_mapping,
             call_frames: vec![CallFrame::default(); config.max_call_depth],
+            loader,
             #[cfg(feature = "debugger")]
             debug_port: None,
         }
@@ -429,6 +432,7 @@ impl<'a, C: ContextObject> EbpfVm<'a, C> {
         executable: &Executable<C>,
         interpreted: bool,
     ) -> (u64, ProgramResult) {
+        debug_assert!(Arc::ptr_eq(&self.loader, executable.get_loader()));
         // R1 points to beginning of input memory, R10 to the stack of the first frame, R11 is the pc (hidden)
         self.registers[1] = ebpf::MM_INPUT_START;
         self.registers[ebpf::FRAME_PTR_REG] = self.stack_pointer;
diff --git a/test_utils/src/lib.rs b/test_utils/src/lib.rs
index d173dd94..7c56eb57 100644
--- a/test_utils/src/lib.rs
+++ b/test_utils/src/lib.rs
@@ -208,7 +208,7 @@ macro_rules! create_vm {
         )
         .unwrap();
         let mut $vm_name = solana_rbpf::vm::EbpfVm::new(
-            $verified_executable.get_config(),
+            $verified_executable.get_loader().clone(),
             $verified_executable.get_sbpf_version(),
             $context_object,
             memory_mapping,