Merge "Load crashkernel using kexec"

microdroid/kdump/Android.bp

@@ -4,9 +4,10 @@ package {
 
 cc_binary {
     name: "microdroid_kexec",
-    stem: "kexec",
+    stem: "kexec_load",
     srcs: ["kexec.c"],
     installable: false,
+    static_executable: true, // required because this runs before linkerconfig
     compile_multilib: "64",
 }
 

microdroid_manager/src/main.rs

@@ -166,6 +166,8 @@ fn try_main() -> Result<()> {
     let _ = kernlog::init();
     info!("started.");
 
+    load_crashkernel_if_supported().context("Failed to load crashkernel")?;
+
     let service = get_vms_rpc_binder()
         .context("cannot connect to VirtualMachineService")
         .map_err(|e| MicrodroidError::FailedToConnectToVirtualizationService(e.to_string()))?;
@@ -610,6 +612,20 @@ fn load_config(path: &Path) -> Result<VmPayloadConfig> {
     Ok(serde_json::from_reader(file)?)
 }
 
+/// Loads the crashkernel into memory using kexec if the VM is loaded with `crashkernel=' parameter
+/// in the cmdline.
+fn load_crashkernel_if_supported() -> Result<()> {
+    let supported = std::fs::read_to_string("/proc/cmdline")?.contains(" crashkernel=");
+    info!("ramdump supported: {}", supported);
+    if supported {
+        let status = Command::new("/system/bin/kexec_load").status()?;
+        if !status.success() {
+            return Err(anyhow!("Failed to load crashkernel: {:?}", status));
+        }
+    }
+    Ok(())
+}
+
 /// Executes the given task. Stdout of the task is piped into the vsock stream to the
 /// virtualizationservice in the host side.
 fn exec_task(task: &Task, service: &Strong<dyn IVirtualMachineService>) -> Result<i32> {