Remove SandboxRuntimeConfig

Each field moves to the place that already owns its data:

* debug_info and guest_core_dump are read from SandboxConfiguration.
* The crashdump entry point is read from the memory manager, which
  restore already updates.
* The guest binary path is dropped. Core dumps report <unknown>
  as the process name for every sandbox, as snapshot sandboxes
  already did.

Sandbox setup and restore no longer need crashdump or gdb plumbing.

Signed-off-by: Ludvig Liljenberg <4257730+ludfjig@users.noreply.github.com>

Author: ludfjig

CHANGELOG.md

@@ -7,6 +7,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 ### Added
 
 ### Changed
+* Core dumps no longer record the guest binary path. The process name and command line are always `<unknown>`, as they already were for sandboxes created from snapshots by @ludfjig
 
 ### Removed
 

docs/how-to-debug-a-hyperlight-guest.md

@@ -267,7 +267,7 @@ After the core dump has been created, to inspect the state of the guest, load th
 
 #### Using gdb
 
-Load the core dump alongside the guest binary that was running when the crash occurred:
+Load the core dump alongside the guest binary that was running when the crash occurred. Core dumps do not record which guest binary that was, so keep track of the guest each sandbox runs:
 
 ```bash
 gdb <guest-binary> -c <core-dump-file>

src/hyperlight_host/src/hypervisor/crashdump.rs

@@ -30,6 +30,10 @@ const CORE_DUMP_PID: i32 = 1;
 /// The page size of the core dump
 const CORE_DUMP_PAGE_SIZE: usize = 0x1000;
 
+/// Process name and command line in the core dump. Sandboxes do not
+/// record which guest binary they run.
+const UNKNOWN_PROCESS: &str = "<unknown>";
+
 /// Structure to hold the crash dump context
 /// This structure contains the information needed to create a core dump
 #[derive(Debug)]
@@ -38,7 +42,6 @@ pub(crate) struct CrashDumpContext {
     regs: [u64; 27],
     xsave: Vec<u8>,
     entry: u64,
-    binary: Option<PathBuf>,
 }
 
 impl CrashDumpContext {
@@ -47,14 +50,12 @@ impl CrashDumpContext {
         regs: [u64; 27],
         xsave: Vec<u8>,
         entry: u64,
-        binary: Option<PathBuf>,
     ) -> Self {
         Self {
             regions,
             regs,
             xsave,
             entry,
-            binary,
         }
     }
 }
@@ -88,21 +89,6 @@ impl GuestView {
             })
             .collect();
 
-        let filename = ctx
-            .binary
-            .as_deref()
-            .and_then(|path| path.file_name())
-            .map_or("<unknown>".to_string(), |name| {
-                name.to_string_lossy().into_owned()
-            });
-
-        let cmd = ctx
-            .binary
-            .as_deref()
-            .map_or("<unknown>".to_string(), |path| {
-                path.to_string_lossy().into_owned()
-            });
-
         // The xsave state is checked as it can be empty
         let mut components = vec![];
         if !ctx.xsave.is_empty() {
@@ -122,7 +108,7 @@ impl GuestView {
             tid: 1,
             uid: 0, // User ID
             gid: 0, // Group ID
-            comm: filename,
+            comm: UNKNOWN_PROCESS.to_string(),
             ppid: 0,    // Parent PID
             pgrp: 0,    // Process group ID
             nice: 0,    // Nice value
@@ -135,7 +121,7 @@ impl GuestView {
             session: 0, // Session ID of the process
             sighold: 0, // Blocked signal
             sigpend: 0, // Pending signal
-            cmd_line: cmd,
+            cmd_line: UNKNOWN_PROCESS.to_string(),
 
             arch_state: Box::new(ArchState {
                 gpr_state: ctx.regs.to_vec(),
@@ -435,13 +421,7 @@ mod test {
     #[test]
     fn test_crashdump_write_fails_when_no_regions() {
         // Create a dummy context
-        let ctx = CrashDumpContext::new(
-            vec![],
-            [0; 27],
-            vec![],
-            0,
-            Some(PathBuf::from("dummy_binary")),
-        );
+        let ctx = CrashDumpContext::new(vec![], [0; 27], vec![], 0);
 
         let get_writer = || Ok(Box::new(std::io::empty()) as Box<dyn Write>);
 
@@ -466,13 +446,7 @@ mod test {
             region_type: crate::mem::memory_region::MemoryRegionType::Code,
         }];
         // Create a dummy context
-        let ctx = CrashDumpContext::new(
-            regions,
-            [0; 27],
-            vec![],
-            0x1000,
-            Some(PathBuf::from("dummy_binary")),
-        );
+        let ctx = CrashDumpContext::new(regions, [0; 27], vec![], 0x1000);
 
         let get_writer = || Ok(Box::new(std::io::empty()) as Box<dyn Write>);
 

src/hyperlight_host/src/hypervisor/hyperlight_vm/aarch64.rs

@@ -37,8 +37,6 @@ use crate::sandbox::host_funcs::FunctionRegistry;
 use crate::sandbox::snapshot::NextAction;
 #[cfg(feature = "mem_profile")]
 use crate::sandbox::trace::MemTraceInfo;
-#[cfg(crashdump)]
-use crate::sandbox::uninitialized::SandboxRuntimeConfig;
 
 impl HyperlightVm {
     #[allow(clippy::too_many_arguments)]
@@ -52,7 +50,6 @@ impl HyperlightVm {
         page_size: usize,
         #[cfg_attr(target_os = "windows", allow(unused_variables))] config: &SandboxConfiguration,
         #[cfg(gdb)] _gdb_conn: Option<DebugCommChannel<DebugResponse, DebugMsg>>,
-        #[cfg(crashdump)] _rt_cfg: SandboxRuntimeConfig,
         #[cfg(feature = "mem_profile")] _trace_info: MemTraceInfo,
     ) -> std::result::Result<Self, CreateHyperlightVmError> {
         // TODO: support gdb on aarch64

src/hyperlight_host/src/hypervisor/hyperlight_vm/mod.rs

@@ -44,8 +44,6 @@ use crate::sandbox::outb::{HandleOutbError, handle_outb};
 use crate::sandbox::snapshot::NextAction;
 #[cfg(feature = "mem_profile")]
 use crate::sandbox::trace::MemTraceInfo;
-#[cfg(crashdump)]
-use crate::sandbox::uninitialized::SandboxRuntimeConfig;
 
 /// Get the logging level filter to pass to the guest entrypoint
 ///
@@ -399,7 +397,7 @@ pub(crate) struct HyperlightVm {
     #[cfg(feature = "mem_profile")]
     pub(super) trace_info: MemTraceInfo,
     #[cfg(crashdump)]
-    pub(super) rt_cfg: SandboxRuntimeConfig,
+    pub(super) guest_core_dump: bool,
     /// MSRs restored on snapshot restore.
     #[cfg(target_arch = "x86_64")]
     pub(super) msr_reset: crate::hypervisor::regs::MsrResetState,
@@ -576,18 +574,6 @@ impl HyperlightVm {
         self.next_action = next_action
     }
 
-    /// Set the guest ELF entry point used to fill `AT_ENTRY` in
-    /// crashdumps.
-    #[cfg(crashdump)]
-    pub(crate) fn set_crashdump_entry_point(&mut self, entry_point: u64) {
-        self.rt_cfg.entry_point = Some(entry_point);
-    }
-
-    #[cfg(crashdump)]
-    pub(crate) fn clear_crashdump_binary_path(&mut self) {
-        self.rt_cfg.binary_path = None;
-    }
-
     pub(crate) fn interrupt_handle(&self) -> Arc<dyn InterruptHandle> {
         self.interrupt_handle.clone()
     }
@@ -786,7 +772,7 @@ impl HyperlightVm {
             }
             Err(e) => {
                 #[cfg(crashdump)]
-                if self.rt_cfg.guest_core_dump {
+                if self.guest_core_dump {
                     crate::hypervisor::crashdump::generate_crashdump(self, mem_mgr, None)
                         .map_err(|e| RunVmError::CrashdumpGeneration(Box::new(e)))?;
                 }

src/hyperlight_host/src/hypervisor/hyperlight_vm/x86_64.rs

@@ -44,8 +44,6 @@ use crate::sandbox::host_funcs::FunctionRegistry;
 use crate::sandbox::snapshot::NextAction;
 #[cfg(feature = "mem_profile")]
 use crate::sandbox::trace::MemTraceInfo;
-#[cfg(crashdump)]
-use crate::sandbox::uninitialized::SandboxRuntimeConfig;
 
 #[cfg(gdb)]
 type BoxedVm = Box<dyn DebuggableVm>;
@@ -65,7 +63,6 @@ impl HyperlightVm {
         page_size: usize,
         #[cfg_attr(target_os = "windows", allow(unused_variables))] config: &SandboxConfiguration,
         #[cfg(gdb)] gdb_conn: Option<DebugCommChannel<DebugResponse, DebugMsg>>,
-        #[cfg(crashdump)] rt_cfg: SandboxRuntimeConfig,
         #[cfg(feature = "mem_profile")] trace_info: MemTraceInfo,
     ) -> std::result::Result<Self, CreateHyperlightVmError> {
         let mut vm: BoxedVm = match get_available_hypervisor() {
@@ -136,7 +133,7 @@ impl HyperlightVm {
             #[cfg(feature = "mem_profile")]
             trace_info,
             #[cfg(crashdump)]
-            rt_cfg,
+            guest_core_dump: config.get_guest_core_dump(),
             msr_reset,
         };
 
@@ -521,7 +518,7 @@ impl HyperlightVm {
         mem_mgr: &mut SandboxMemoryManager<HostSharedMemory>,
     ) -> std::result::Result<Option<crate::hypervisor::crashdump::CrashDumpContext>, CrashDumpError>
     {
-        if self.rt_cfg.guest_core_dump {
+        if self.guest_core_dump {
             let mut regs = [0; 27];
 
             let vcpu_regs = self.vm.regs()?;
@@ -557,17 +554,12 @@ impl HyperlightVm {
             regs[25] = sregs.fs.selector as u64; // fs
             regs[26] = sregs.gs.selector as u64; // gs
 
-            // Use the stored entry point address from the runtime config.
-            // This is the original entry point (load_addr + ELF entry offset)
-            // which GDB needs for AT_ENTRY to compute the PIE load offset.
-            // We cannot use self.next_action here because it transitions from
-            // Initialise(addr) to Call(dispatch_addr) after guest init.
-            let initialise = self.rt_cfg.entry_point.unwrap_or_else(|| {
-                tracing::warn!(
-                    "entry_point was never set in SandboxRuntimeConfig; AT_ENTRY will be 0"
-                );
-                0
-            });
+            // GDB derives the PIE load offset from AT_ENTRY. `next_action`
+            // holds the dispatch address after init, so use the ELF entry.
+            let entry = mem_mgr.original_entrypoint;
+            if entry == 0 {
+                tracing::warn!("Guest entry point is unknown; AT_ENTRY will be 0");
+            }
             let mmap_regions: Vec<MemoryRegion> = self.get_mapped_regions().cloned().collect();
             let root_pt = self.get_root_pt()?;
 
@@ -579,8 +571,7 @@ impl HyperlightVm {
                 regions,
                 regs,
                 xsave.to_vec(),
-                initialise,
-                self.rt_cfg.binary_path.clone(),
+                entry,
             )))
         } else {
             Ok(None)
@@ -880,8 +871,6 @@ mod tests {
     use crate::mem::shared_mem::{ExclusiveSharedMemory, ReadonlySharedMemory};
     use crate::sandbox::SandboxConfiguration;
     use crate::sandbox::host_funcs::FunctionRegistry;
-    #[cfg(any(crashdump, gdb))]
-    use crate::sandbox::uninitialized::SandboxRuntimeConfig;
     use crate::sandbox::uninitialized_evolve::set_up_hypervisor_partition;
 
     /// Test context holding an initialized VM with memory manager.
@@ -1472,8 +1461,6 @@ mod tests {
     /// both `hyperlight_vm()` and `create_test_vm_context()`.
     fn create_test_vm_context(code: &[u8]) -> TestVmContext {
         let config: SandboxConfiguration = Default::default();
-        #[cfg(any(crashdump, gdb))]
-        let rt_cfg: SandboxRuntimeConfig = Default::default();
 
         let (layout, pt_bytes) = create_test_layout(code.len());
 
@@ -1506,8 +1493,6 @@ mod tests {
             &config,
             stack_top_gva,
             page_size::get(),
-            #[cfg(any(crashdump, gdb))]
-            rt_cfg,
             crate::mem::exe::LoadInfo::dummy(),
         )
         .unwrap();

src/hyperlight_host/src/hypervisor/mod.rs

@@ -470,8 +470,6 @@ pub(crate) mod tests {
     use hyperlight_testing::dummy_guest_as_pathbuf;
 
     use crate::sandbox::uninitialized::GuestBinary;
-    #[cfg(any(crashdump, gdb))]
-    use crate::sandbox::uninitialized::SandboxRuntimeConfig;
     use crate::sandbox::uninitialized_evolve::set_up_hypervisor_partition;
     use crate::sandbox::{SandboxConfiguration, UninitializedSandbox};
     use crate::{Result, is_hypervisor_present};
@@ -489,8 +487,6 @@ pub(crate) mod tests {
         let filename = dummy_guest_as_pathbuf();
 
         let config: SandboxConfiguration = Default::default();
-        #[cfg(any(crashdump, gdb))]
-        let rt_cfg: SandboxRuntimeConfig = Default::default();
         let sandbox =
             UninitializedSandbox::new(GuestBinary::FilePath(filename.clone()), Some(config))?;
         let (mut mem_mgr, gshm) = sandbox.mgr.build().unwrap();
@@ -502,8 +498,6 @@ pub(crate) mod tests {
             &config,
             exn_stack_top_gva,
             page_size::get(),
-            #[cfg(any(crashdump, gdb))]
-            rt_cfg,
             sandbox.load_info,
         )?;
 

src/hyperlight_host/src/sandbox/initialized.rs

@@ -287,32 +287,8 @@ impl Sandbox {
         #[cfg(target_os = "linux")]
         crate::signal_handlers::setup_signal_handlers(&config)?;
 
-        // Runtime config for the restored sandbox. `guest_core_dump`
-        // (crashdump) and `guest_debug_info` (gdb) come from the caller's
-        // config. `binary_path` stays `None`. `set_up_hypervisor_partition`
-        // fills `entry_point` from the manager's entry point so crashdumps
-        // carry the correct `AT_ENTRY`.
-        #[cfg(any(crashdump, gdb))]
-        let rt_cfg = crate::sandbox::uninitialized::SandboxRuntimeConfig {
-            #[cfg(crashdump)]
-            binary_path: None,
-            #[cfg(gdb)]
-            debug_info: config.get_guest_debug_info(),
-            #[cfg(crashdump)]
-            guest_core_dump: config.get_guest_core_dump(),
-            #[cfg(crashdump)]
-            entry_point: None,
-        };
-
-        let mut vm = set_up_hypervisor_partition(
-            gshm,
-            &config,
-            stack_top_gva,
-            page_size,
-            #[cfg(any(crashdump, gdb))]
-            rt_cfg,
-            load_info,
-        )?;
+        let mut vm =
+            set_up_hypervisor_partition(gshm, &config, stack_top_gva, page_size, load_info)?;
 
         let seed = {
             let mut rng = rand::rng();
@@ -670,14 +646,6 @@ impl Sandbox {
 
         self.vm.set_stack_top(snapshot.stack_top_gva());
         self.vm.set_next_action(snapshot.next_action());
-        // Carry the guest ELF entry point across restore so a later
-        // crashdump fills `AT_ENTRY` from the restored image.
-        #[cfg(crashdump)]
-        {
-            self.vm
-                .set_crashdump_entry_point(snapshot.original_entrypoint());
-            self.vm.clear_crashdump_binary_path();
-        }
 
         self.mem_mgr
             .request_libc_rng_reseed(rand::random::<u32>())?;