Merge "Fix potential miscellaneous debuggerd issues." into main

debuggerd/debuggerd_test.cpp

@@ -2264,10 +2264,14 @@ TEST_F(CrasherTest, fault_address_after_last_map) {
 
   ASSERT_MATCH(result, R"(\nmemory map \(.*\): \(fault address prefixed with --->)\n)");
 
-  // Assumes that the open files section comes after the map section.
+  // Verifies that the fault address error message is at the end of the
-  // If that assumption changes, the regex below needs to change.
+  // maps section. To do this, the check below looks for the start of the
+  // open files section or the start of the log file section. It's possible
+  // for either of these sections to be present after the maps section right
+  // now.
+  // If the sections move around, this check might need to be modified.
   match_str = android::base::StringPrintf(
-      R"(\n--->Fault address falls at %s after any mapped regions\n\nopen files:)",
+      R"(\n--->Fault address falls at %s after any mapped regions\n(---------|\nopen files:))",
       format_pointer(crash_uptr).c_str());
   ASSERT_MATCH(result, match_str);
 }

debuggerd/libdebuggerd/tombstone_proto.cpp

@@ -493,27 +493,48 @@ static void dump_mappings(Tombstone* tombstone, unwindstack::Maps* maps,
   }
 }
 
+// This creates a fake log message that indicates an error occurred when
+// reading the log.
+static void add_error_log_msg(Tombstone* tombstone, const std::string&& error_msg) {
+  LogBuffer buffer;
+  buffer.set_name("ERROR");
+
+  LogMessage* log_msg = buffer.add_logs();
+  log_msg->set_timestamp("00-00 00:00:00.000");
+  log_msg->set_pid(0);
+  log_msg->set_tid(0);
+  log_msg->set_priority(ANDROID_LOG_ERROR);
+  log_msg->set_tag("");
+  log_msg->set_message(error_msg);
+
+  *tombstone->add_log_buffers() = std::move(buffer);
+
+  async_safe_format_log(ANDROID_LOG_ERROR, LOG_TAG, "%s", error_msg.c_str());
+}
+
 static void dump_log_file(Tombstone* tombstone, const char* logger, pid_t pid) {
   logger_list* logger_list = android_logger_list_open(android_name_to_log_id(logger),
                                                       ANDROID_LOG_NONBLOCK, kMaxLogMessages, pid);
+  if (logger_list == nullptr) {
+    add_error_log_msg(tombstone, android::base::StringPrintf("Cannot open log file %s", logger));
+    return;
+  }
 
   LogBuffer buffer;
-
   while (true) {
     log_msg log_entry;
     ssize_t actual = android_logger_list_read(logger_list, &log_entry);
-
     if (actual < 0) {
       if (actual == -EINTR) {
         // interrupted by signal, retry
         continue;
       }
-      if (actual == -EAGAIN) {
+      // Don't consider EAGAIN an error since this is a non-blocking call.
-        // non-blocking EOF; we're done
+      if (actual != -EAGAIN) {
-        break;
+        add_error_log_msg(tombstone, android::base::StringPrintf("reading log %s failed (%s)",
-      } else {
+                                                                 logger, strerror(-actual)));
-        break;
       }
+      break;
     } else if (actual == 0) {
       break;
     }

debuggerd/libdebuggerd/tombstone_proto_to_text.cpp

@@ -81,6 +81,8 @@ static void print_thread_header(CallbackType callback, const Tombstone& tombston
   if (!tombstone.command_line().empty()) {
     process_name = tombstone.command_line()[0].c_str();
     CB(should_log, "Cmdline: %s", android::base::Join(tombstone.command_line(), " ").c_str());
+  } else {
+    CB(should_log, "Cmdline: <unknown>");
   }
   CB(should_log, "pid: %d, tid: %d, name: %s  >>> %s <<<", tombstone.pid(), thread.id(),
      thread.name().c_str(), process_name);