Add tombstone_handler for crashes in Microdroid

This changes the crash export mechanism in Microdroid. For this, we
create module tombstone_handler which exports methods very similar to
tombstoned.h

For Microdroid (detected using prop: ro.hardware): It calls newly
introduces microdroid specific methods to connect/notify completion of
crash.

Individual methods:
connect -> For Android, it would connect to
tombstoned which would send it the fd corresponding to newly created
file on /data/tombstone_ . For Microdroid, we connect to tombstone
server on host via vsock & populate these sockets as the output fd.
crash_dump, in the later case, would directly write on the socket(s).

notify_completion: For Microdroid, it would simply shutdown the vsock
connections.

Note when OS is not Microdroid: It calls corresponding methods of
tombstoned_client, essentially serving as a proxy.

Detailed design: go/vm-tombstone
Test: atest MicrodroidHostTests#testTombstonesAreGeneratedUponUserspaceCrash
Bug: 243494912

Change-Id: I68537b967f2ee48c1647f0f923aa79e8bcc66942

debuggerd/Android.bp

@@ -368,6 +368,7 @@ cc_binary {
     name: "crash_dump",
     srcs: [
         "crash_dump.cpp",
+        "tombstone_handler.cpp",
         "util.cpp",
     ],
     defaults: ["debuggerd_defaults"],

debuggerd/TEST_MAPPING

@@ -5,6 +5,9 @@
     },
     {
       "name": "libtombstoned_client_rust_test"
+    },
+    {
+      "name": "MicrodroidHostTestCases"
     }
   ],
   "hwasan-presubmit": [

debuggerd/crash_dump.cpp

@@ -59,7 +59,7 @@
 #include "libdebuggerd/utility.h"
 
 #include "debuggerd/handler.h"
-#include "tombstoned/tombstoned.h"
+#include "tombstone_handler.h"
 
 #include "protocol.h"
 #include "util.h"
@@ -215,8 +215,8 @@ static void Initialize(char** argv) {
     // If we abort before we get an output fd, contact tombstoned to let any
     // potential listeners know that we failed.
     if (!g_tombstoned_connected) {
-      if (!tombstoned_connect(g_target_thread, &g_tombstoned_socket, &g_output_fd, &g_proto_fd,
-                              kDebuggerdAnyIntercept)) {
+      if (!connect_tombstone_server(g_target_thread, &g_tombstoned_socket, &g_output_fd,
+                                    &g_proto_fd, kDebuggerdAnyIntercept)) {
         // We failed to connect, not much we can do.
         LOG(ERROR) << "failed to connected to tombstoned to report failure";
         _exit(1);
@@ -589,8 +589,8 @@ int main(int argc, char** argv) {
   {
     ATRACE_NAME("tombstoned_connect");
     LOG(INFO) << "obtaining output fd from tombstoned, type: " << dump_type;
-    g_tombstoned_connected = tombstoned_connect(g_target_thread, &g_tombstoned_socket, &g_output_fd,
-                                                &g_proto_fd, dump_type);
+    g_tombstoned_connected = connect_tombstone_server(g_target_thread, &g_tombstoned_socket,
+                                                      &g_output_fd, &g_proto_fd, dump_type);
   }
 
   if (g_tombstoned_connected) {
@@ -673,7 +673,8 @@ int main(int argc, char** argv) {
 
   // Close stdout before we notify tombstoned of completion.
   close(STDOUT_FILENO);
-  if (g_tombstoned_connected && !tombstoned_notify_completion(g_tombstoned_socket.get())) {
+  if (g_tombstoned_connected &&
+      !notify_completion(g_tombstoned_socket.get(), g_output_fd.get(), g_proto_fd.get())) {
     LOG(ERROR) << "failed to notify tombstoned of completion";
   }
 

debuggerd/tombstone_handler.cpp

@@ -0,0 +1,113 @@
+/*
+ * Copyright 2023, The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "tombstoned/tombstoned.h"
+
+#include <unistd.h>
+
+#include <android-base/logging.h>
+#include <android-base/properties.h>
+#include <android-base/unique_fd.h>
+#include <cutils/sockets.h>
+#include <linux/vm_sockets.h>
+#include "util.h"
+
+using android::base::unique_fd;
+
+/*
+  Port number that VirtualMachineService listens on connections from the guest VMs.
+  Kep in sync with IVirtualMachineService.aidl
+*/
+const unsigned int VM_TOMBSTONES_SERVICE_PORT = 2000;
+
+static bool is_microdroid() {
+  return android::base::GetProperty("ro.hardware", "") == "microdroid";
+}
+
+static bool connect_tombstone_server_microdroid(unique_fd* text_output_fd,
+                                                unique_fd* proto_output_fd,
+                                                DebuggerdDumpType dump_type) {
+  // We do not wait for the property to be set, the default behaviour is not export tombstones.
+  if (!android::base::GetBoolProperty("microdroid_manager.export_tombstones.enabled", false)) {
+    LOG(WARNING) << "exporting tombstones is not enabled";
+    return false;
+  }
+
+  // Microdroid supports handling requests originating from crash_dump which
+  // supports limited dump types. Java traces and incept management are not supported.
+  switch (dump_type) {
+    case kDebuggerdNativeBacktrace:
+    case kDebuggerdTombstone:
+    case kDebuggerdTombstoneProto:
+      break;
+
+    default:
+      LOG(WARNING) << "Requested dump type: " << dump_type << " "
+                   << "not supported";
+  }
+
+  int fd1 = TEMP_FAILURE_RETRY(socket(AF_VSOCK, SOCK_STREAM, 0));
+  int fd2 = TEMP_FAILURE_RETRY(socket(AF_VSOCK, SOCK_STREAM, 0));
+  if (fd1 < 0 || fd2 < 0) {
+    LOG(WARNING) << "Unable to create virtual socket for writing tombstones";
+    return false;
+  }
+
+  unique_fd vsock_output_fd(fd1), vsock_proto_fd(fd2);
+
+  struct sockaddr_vm sa = (struct sockaddr_vm){
+      .svm_family = AF_VSOCK,
+      .svm_port = VM_TOMBSTONES_SERVICE_PORT,
+      .svm_cid = VMADDR_CID_HOST,
+  };
+
+  if (TEMP_FAILURE_RETRY(connect(vsock_output_fd, (struct sockaddr*)&sa, sizeof(sa))) < 0) {
+    PLOG(WARNING) << "Unable to connect to tombstone service in host";
+    return false;
+  }
+
+  if (dump_type == kDebuggerdTombstoneProto) {
+    if (TEMP_FAILURE_RETRY(connect(vsock_proto_fd, (struct sockaddr*)&sa, sizeof(sa))) < 0) {
+      PLOG(WARNING) << "Unable to connect to tombstone service in host";
+      return false;
+    }
+  }
+
+  *text_output_fd = std::move(vsock_output_fd);
+  if (proto_output_fd) {
+    *proto_output_fd = std::move(vsock_proto_fd);
+  }
+  return true;
+}
+
+static bool notify_completion_microdroid(int vsock_out, int vsock_proto) {
+  if (shutdown(vsock_out, SHUT_WR) || shutdown(vsock_proto, SHUT_WR)) return false;
+  return true;
+}
+bool connect_tombstone_server(pid_t pid, unique_fd* tombstoned_socket, unique_fd* text_output_fd,
+                              unique_fd* proto_output_fd, DebuggerdDumpType dump_type) {
+  if (is_microdroid()) {
+    return connect_tombstone_server_microdroid(text_output_fd, proto_output_fd, dump_type);
+  }
+  return tombstoned_connect(pid, tombstoned_socket, text_output_fd, proto_output_fd, dump_type);
+}
+
+bool notify_completion(int tombstoned_socket, int vsock_out, int vsock_proto) {
+  if (is_microdroid()) {
+    return notify_completion_microdroid(vsock_out, vsock_proto);
+  }
+  return tombstoned_notify_completion(tombstoned_socket);
+}

debuggerd/tombstone_handler.h

@@ -0,0 +1,25 @@
+/*
+ * Copyright 2023, The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <android-base/unique_fd.h>
+#include "dump_type.h"
+
+bool connect_tombstone_server(pid_t pid, android::base::unique_fd* tombstoned_socket,
+                              android::base::unique_fd* text_output_fd,
+                              android::base::unique_fd* proto_output_fd,
+                              DebuggerdDumpType dump_type);
+
+bool notify_completion(int tombstoned_socket, int vsock_out, int vsock_proto);