[host/{hypervisor/{*drivers,crashdump},sandbox/builder}] re-added crashdump feature

Crashdump feature used the old MemoryRegion API. Updated it to use the new SandboxMemorySections API (causing
changes in all drivers) and added a test in sandbox_builder for the feature.

Signed-off-by: danbugs <[email protected]>

Author: danbugs

src/hyperlight_host/src/hypervisor/crashdump.rs

@@ -16,15 +16,15 @@ pub(crate) fn crashdump_to_tempfile(hv: &dyn Hypervisor) -> Result<()> {
     temp_file.write_all(b"================ MEMORY DUMP =================\n")?;
 
     // write the raw memory dump for each memory region
-    for region in hv.get_memory_regions() {
-        if region.host_region.start == 0 || region.host_region.is_empty() {
+    for (_, region) in hv.get_memory_sections().iter() {
+        if region.page_aligned_guest_offset == 0 {
             continue;
         }
         // SAFETY: we got this memory region from the hypervisor so should never be invalid
         let region_slice = unsafe {
             std::slice::from_raw_parts(
-                region.host_region.start as *const u8,
-                region.host_region.len(),
+                region.host_address.ok_or("Failed to get host address")? as *const u8,
+                region.page_aligned_size,
             )
         };
         temp_file.write_all(region_slice)?;

src/hyperlight_host/src/hypervisor/hyperv_linux.rs

@@ -658,11 +658,10 @@ impl Hypervisor for HypervLinuxDriver {
         self as &mut dyn Hypervisor
     }
 
-    // TODO(danbugs:297): bring back
-    // #[cfg(crashdump)]
-    // fn get_memory_regions(&self) -> &[MemoryRegion] {
-    //     &self.mem_sections
-    // }
+    #[cfg(crashdump)]
+    fn get_memory_sections(&self) -> &SandboxMemorySections {
+        &self.mem_sections
+    }
 
     #[cfg(gdb)]
     fn handle_debug(

src/hyperlight_host/src/hypervisor/hyperv_windows.rs

@@ -488,7 +488,7 @@ impl Hypervisor for HypervWindowsDriver {
     }
 
     #[cfg(crashdump)]
-    fn get_memory_regions(&self) -> &[MemoryRegion] {
+    fn get_memory_sections(&self) -> &SandboxMemorySections {
         &self.mem_sections
     }
 }

src/hyperlight_host/src/hypervisor/inprocess.rs

@@ -22,9 +22,9 @@ use log::LevelFilter;
 #[cfg(gdb)]
 use super::handlers::DbgMemAccessHandlerWrapper;
 use super::{HyperlightExit, Hypervisor};
-#[cfg(crashdump)]
-use crate::mem::memory_region::MemoryRegion;
 use crate::sandbox::leaked_outb::LeakedOutBWrapper;
+#[cfg(crashdump)]
+use crate::sandbox::sandbox_builder::SandboxMemorySections;
 use crate::Result;
 
 /// Arguments passed to inprocess driver
@@ -128,7 +128,7 @@ impl<'a> Hypervisor for InprocessDriver<'a> {
     }
 
     #[cfg(crashdump)]
-    fn get_memory_regions(&self) -> &[MemoryRegion] {
-        unimplemented!("get_memory_regions is not supported since we are in in-process mode")
+    fn get_memory_sections(&self) -> &SandboxMemorySections {
+        unimplemented!("get_memory_sections is not supported since we are in in-process mode")
     }
 }

src/hyperlight_host/src/hypervisor/kvm.rs

@@ -583,11 +583,10 @@ impl Hypervisor for KVMDriver {
         self as &mut dyn Hypervisor
     }
 
-    // TODO(danbugs:297): bring back
-    // #[cfg(crashdump)]
-    // fn get_memory_regions(&self) -> &[MemoryRegion] {
-    //     &self.mem_sections
-    // }
+    #[cfg(crashdump)]
+    fn get_memory_sections(&self) -> &SandboxMemorySections {
+        &self.mem_sections
+    }
 
     #[cfg(gdb)]
     fn handle_debug(

src/hyperlight_host/src/hypervisor/mod.rs

@@ -235,9 +235,8 @@ pub(crate) trait Hypervisor: Debug + Sync + Send {
     #[cfg(target_os = "windows")]
     fn get_partition_handle(&self) -> windows::Win32::System::Hypervisor::WHV_PARTITION_HANDLE;
 
-    // TODO(danbugs:297): bring back
-    // #[cfg(crashdump)]
-    // fn get_memory_regions(&self) -> &[MemoryRegion];
+    #[cfg(crashdump)]
+    fn get_memory_sections(&self) -> &SandboxMemorySections;
 
     #[cfg(gdb)]
     /// handles the cases when the vCPU stops due to a Debug event

src/hyperlight_host/src/sandbox/sandbox_builder.rs

@@ -957,4 +957,67 @@ mod tests {
 
         Ok(())
     }
+
+    #[test]
+    #[cfg(crashdump)]
+    fn test_sandbox_builder_crashdump() -> Result<()> {
+        // Capture list of files in /tmp before the test
+        let tmp_dir = Path::new("/tmp");
+        let before_files: std::collections::HashSet<_> = std::fs::read_dir(tmp_dir)
+            .expect("Failed to read /tmp directory")
+            .map(|e| e.unwrap().file_name())
+            .collect();
+
+        // Setup guest sandbox
+        let sandbox_builder =
+            SandboxBuilder::new(GuestBinary::FilePath(simple_guest_as_string()?))?;
+
+        let mut uninitialized_sandbox = sandbox_builder.build()?;
+
+        // Register host function
+        fn add(a: i32, b: i32) -> Result<i32> {
+            Ok(a + b)
+        }
+        let host_function = Arc::new(Mutex::new(add));
+        host_function.register(&mut uninitialized_sandbox, "HostAdd")?;
+
+        // Evolve to multi-use sandbox
+        let mut multi_use_sandbox = uninitialized_sandbox.evolve(Noop::default())?;
+
+        // Call the guest function expected to crash
+        let result = multi_use_sandbox.call_guest_function_by_name(
+            "StackOverflow",
+            ReturnType::Void,
+            Some(vec![ParameterValue::Int(512)]),
+        );
+
+        assert!(result.is_err());
+
+        // Capture list of files in /tmp after the crash
+        let after_files: std::collections::HashSet<_> = std::fs::read_dir(tmp_dir)
+            .expect("Failed to read /tmp directory")
+            .map(|e| e.unwrap().file_name())
+            .collect();
+
+        // Find the new files created
+        let new_files: Vec<_> = after_files
+            .difference(&before_files)
+            .filter(|f| f.to_string_lossy().ends_with(".dmp"))
+            .collect();
+
+        assert!(!new_files.is_empty(), "No crashdump file was created.");
+
+        // Check the crashdump file(s)
+        for file_name in new_files {
+            let file_path = tmp_dir.join(file_name);
+            let metadata = std::fs::metadata(&file_path)?;
+            assert!(
+                metadata.len() > 0,
+                "Crashdump file is empty: {:?}",
+                file_path
+            );
+        }
+
+        Ok(())
+    }
 }