create libmodprobe, integrate into first_stage_init
Modprobe functionality is required both within first stage init and also
as a standalone binary. Create a library for this using and extending
the logic in modalias_handler.cpp.
First stage init will attempt to load modules from /lib/modules.
Bug: 129780532
Change-Id: Ie3582358fd839c2f64e1b386b30ed551a86aef5d
diff --git a/libmodprobe/libmodprobe_ext.cpp b/libmodprobe/libmodprobe_ext.cpp
new file mode 100644
index 0000000..5f3a04d
--- /dev/null
+++ b/libmodprobe/libmodprobe_ext.cpp
@@ -0,0 +1,68 @@
+/*
+ * Copyright (C) 2018 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 <sys/stat.h>
+#include <sys/syscall.h>
+
+#include <android-base/logging.h>
+#include <android-base/unique_fd.h>
+
+#include <modprobe/modprobe.h>
+
+bool Modprobe::Insmod(const std::string& path_name) {
+ android::base::unique_fd fd(
+ TEMP_FAILURE_RETRY(open(path_name.c_str(), O_RDONLY | O_NOFOLLOW | O_CLOEXEC)));
+ if (fd == -1) {
+ LOG(ERROR) << "Could not open module '" << path_name << "'";
+ return false;
+ }
+
+ std::string options = "";
+ auto options_iter = module_options_.find(MakeCanonical(path_name));
+ if (options_iter != module_options_.end()) {
+ options = options_iter->second;
+ }
+
+ LOG(INFO) << "Loading module " << path_name << " with args \"" << options << "\"";
+ int ret = syscall(__NR_finit_module, fd.get(), options.c_str(), 0);
+ if (ret != 0) {
+ if (errno == EEXIST) {
+ // Module already loaded
+ return true;
+ }
+ LOG(ERROR) << "Failed to insmod '" << path_name << "' with args '" << options << "'";
+ return false;
+ }
+
+ LOG(INFO) << "Loaded kernel module " << path_name;
+ return true;
+}
+
+bool Modprobe::ModuleExists(const std::string& module_name) {
+ struct stat fileStat;
+ auto deps = GetDependencies(module_name);
+ if (deps.empty()) {
+ // missing deps can happen in the case of an alias
+ return false;
+ }
+ if (stat(deps.front().c_str(), &fileStat)) {
+ return false;
+ }
+ if (!S_ISREG(fileStat.st_mode)) {
+ return false;
+ }
+ return true;
+}