Merge "init: Unify duplicated get_android_dt_dir with libfs_mgr" into main

fs_mgr/libfstab/boot_config.cpp

@@ -27,6 +27,33 @@
 #include "fstab_priv.h"
 #include "logging_macros.h"
 
+namespace android {
+namespace fs_mgr {
+
+const std::string& GetAndroidDtDir() {
+    // Set once and saves time for subsequent calls to this function
+    static const std::string kAndroidDtDir = [] {
+        std::string android_dt_dir;
+        if ((fs_mgr_get_boot_config_from_bootconfig_source("android_dt_dir", &android_dt_dir) ||
+             fs_mgr_get_boot_config_from_kernel_cmdline("android_dt_dir", &android_dt_dir)) &&
+            !android_dt_dir.empty()) {
+            // Ensure the returned path ends with a /
+            if (android_dt_dir.back() != '/') {
+                android_dt_dir.push_back('/');
+            }
+        } else {
+            // Fall back to the standard procfs-based path
+            android_dt_dir = "/proc/device-tree/firmware/android/";
+        }
+        LINFO << "Using Android DT directory " << android_dt_dir;
+        return android_dt_dir;
+    }();
+    return kAndroidDtDir;
+}
+
+}  // namespace fs_mgr
+}  // namespace android
+
 std::vector<std::pair<std::string, std::string>> fs_mgr_parse_cmdline(const std::string& cmdline) {
     static constexpr char quote = '"';
 
@@ -145,7 +172,7 @@ bool fs_mgr_get_boot_config(const std::string& key, std::string* out_val) {
 
     // firstly, check the device tree
     if (is_dt_compatible()) {
-        std::string file_name = get_android_dt_dir() + "/" + key;
+        std::string file_name = android::fs_mgr::GetAndroidDtDir() + key;
         if (android::base::ReadFileToString(file_name, out_val)) {
             if (!out_val->empty()) {
                 out_val->pop_back();  // Trims the trailing '\0' out.

fs_mgr/libfstab/fstab.cpp

@@ -51,7 +51,6 @@ namespace android {
 namespace fs_mgr {
 namespace {
 
-constexpr char kDefaultAndroidDtDir[] = "/proc/device-tree/firmware/android";
 constexpr char kProcMountsPath[] = "/proc/mounts";
 
 struct FlagList {
@@ -337,25 +336,14 @@ bool ParseFsMgrFlags(const std::string& flags, FstabEntry* entry) {
     return true;
 }
 
-std::string InitAndroidDtDir() {
-    std::string android_dt_dir;
-    // The platform may specify a custom Android DT path in kernel cmdline
-    if (!fs_mgr_get_boot_config_from_bootconfig_source("android_dt_dir", &android_dt_dir) &&
-        !fs_mgr_get_boot_config_from_kernel_cmdline("android_dt_dir", &android_dt_dir)) {
-        // Fall back to the standard procfs-based path
-        android_dt_dir = kDefaultAndroidDtDir;
-    }
-    return android_dt_dir;
-}
-
 bool IsDtFstabCompatible() {
     std::string dt_value;
-    std::string file_name = get_android_dt_dir() + "/fstab/compatible";
+    std::string file_name = GetAndroidDtDir() + "fstab/compatible";
 
     if (ReadDtFile(file_name, &dt_value) && dt_value == "android,fstab") {
         // If there's no status property or its set to "ok" or "okay", then we use the DT fstab.
         std::string status_value;
-        std::string status_file_name = get_android_dt_dir() + "/fstab/status";
+        std::string status_file_name = GetAndroidDtDir() + "fstab/status";
         return !ReadDtFile(status_file_name, &status_value) || status_value == "ok" ||
                status_value == "okay";
     }
@@ -368,7 +356,7 @@ std::string ReadFstabFromDt() {
         return {};
     }
 
-    std::string fstabdir_name = get_android_dt_dir() + "/fstab";
+    std::string fstabdir_name = GetAndroidDtDir() + "fstab";
     std::unique_ptr<DIR, int (*)(DIR*)> fstabdir(opendir(fstabdir_name.c_str()), closedir);
     if (!fstabdir) return {};
 
@@ -876,7 +864,7 @@ const FstabEntry* GetEntryForMountPoint(const Fstab* fstab, const std::string& p
 
 std::set<std::string> GetBootDevices() {
     // First check bootconfig, then kernel commandline, then the device tree
-    std::string dt_file_name = get_android_dt_dir() + "/boot_devices";
+    std::string dt_file_name = GetAndroidDtDir() + "boot_devices";
     std::string value;
     if (fs_mgr_get_boot_config_from_bootconfig_source("boot_devices", &value) ||
         fs_mgr_get_boot_config_from_bootconfig_source("boot_device", &value)) {
@@ -948,15 +936,8 @@ bool InRecovery() {
 }  // namespace fs_mgr
 }  // namespace android
 
-// FIXME: The same logic is duplicated in system/core/init/
-const std::string& get_android_dt_dir() {
-    // Set once and saves time for subsequent calls to this function
-    static const std::string kAndroidDtDir = android::fs_mgr::InitAndroidDtDir();
-    return kAndroidDtDir;
-}
-
 bool is_dt_compatible() {
-    std::string file_name = get_android_dt_dir() + "/compatible";
+    std::string file_name = android::fs_mgr::GetAndroidDtDir() + "compatible";
     std::string dt_value;
     if (android::fs_mgr::ReadDtFile(file_name, &dt_value)) {
         if (dt_value == "android,firmware") {

fs_mgr/libfstab/fstab_priv.h

@@ -36,7 +36,6 @@ bool fs_mgr_get_boot_config_from_bootconfig(const std::string& bootconfig, const
 bool fs_mgr_get_boot_config_from_bootconfig_source(const std::string& key, std::string* out_val);
 
 bool fs_mgr_update_for_slotselect(android::fs_mgr::Fstab* fstab);
-const std::string& get_android_dt_dir();
 bool is_dt_compatible();
 
 namespace android {

fs_mgr/libfstab/include/fstab/fstab.h

@@ -124,5 +124,9 @@ std::set<std::string> GetBootDevices();
 // expected name.
 std::string GetVerityDeviceName(const FstabEntry& entry);
 
+// Returns the Android Device Tree directory as specified in the kernel bootconfig or cmdline.
+// If the platform does not configure a custom DT path, returns the standard one (based in procfs).
+const std::string& GetAndroidDtDir();
+
 }  // namespace fs_mgr
 }  // namespace android

init/Android.bp

@@ -539,6 +539,7 @@ cc_defaults {
         "libprotobuf-cpp-lite",
     ],
     static_libs: [
+        "libfs_mgr",
         "libhidl-gen-utils",
     ],
 }

init/property_service.cpp

@@ -57,6 +57,7 @@
 #include <android-base/result.h>
 #include <android-base/stringprintf.h>
 #include <android-base/strings.h>
+#include <fs_mgr.h>
 #include <property_info_parser/property_info_parser.h>
 #include <property_info_serializer/property_info_serializer.h>
 #include <selinux/android.h>
@@ -1317,7 +1318,8 @@ static void ProcessKernelDt() {
         return;
     }
 
-    std::unique_ptr<DIR, int (*)(DIR*)> dir(opendir(get_android_dt_dir().c_str()), closedir);
+    std::unique_ptr<DIR, int (*)(DIR*)> dir(opendir(android::fs_mgr::GetAndroidDtDir().c_str()),
+                                            closedir);
     if (!dir) return;
 
     std::string dt_file;
@@ -1328,7 +1330,7 @@ static void ProcessKernelDt() {
             continue;
         }
 
-        std::string file_name = get_android_dt_dir() + dp->d_name;
+        std::string file_name = android::fs_mgr::GetAndroidDtDir() + dp->d_name;
 
         android::base::ReadFileToString(file_name, &dt_file);
         std::replace(dt_file.begin(), dt_file.end(), ',', '.');

init/util.cpp

@@ -42,6 +42,10 @@
 #include <cutils/sockets.h>
 #include <selinux/android.h>
 
+#if defined(__ANDROID__)
+#include <fs_mgr.h>
+#endif
+
 #ifdef INIT_FULL_SOURCES
 #include <android/api-level.h>
 #include <sys/system_properties.h>
@@ -60,8 +64,6 @@ using namespace std::literals::string_literals;
 namespace android {
 namespace init {
 
-const std::string kDefaultAndroidDtDir("/proc/device-tree/firmware/android/");
-
 const std::string kDataDirPrefix("/data/");
 
 void (*trigger_shutdown)(const std::string& command) = nullptr;
@@ -375,45 +377,18 @@ Result<std::string> ExpandProps(const std::string& src) {
     return dst;
 }
 
-static std::string init_android_dt_dir() {
-    // Use the standard procfs-based path by default
-    std::string android_dt_dir = kDefaultAndroidDtDir;
-    // The platform may specify a custom Android DT path in kernel cmdline
-    ImportKernelCmdline([&](const std::string& key, const std::string& value) {
-        if (key == "androidboot.android_dt_dir") {
-            android_dt_dir = value;
-        }
-    });
-    // ..Or bootconfig
-    if (android_dt_dir == kDefaultAndroidDtDir) {
-        ImportBootconfig([&](const std::string& key, const std::string& value) {
-            if (key == "androidboot.android_dt_dir") {
-                android_dt_dir = value;
-            }
-        });
-    }
-
-    LOG(INFO) << "Using Android DT directory " << android_dt_dir;
-    return android_dt_dir;
-}
-
-// FIXME: The same logic is duplicated in system/core/fs_mgr/
-const std::string& get_android_dt_dir() {
-    // Set once and saves time for subsequent calls to this function
-    static const std::string kAndroidDtDir = init_android_dt_dir();
-    return kAndroidDtDir;
-}
-
 // Reads the content of device tree file under the platform's Android DT directory.
 // Returns true if the read is success, false otherwise.
 bool read_android_dt_file(const std::string& sub_path, std::string* dt_content) {
-    const std::string file_name = get_android_dt_dir() + sub_path;
+#if defined(__ANDROID__)
+    const std::string file_name = android::fs_mgr::GetAndroidDtDir() + sub_path;
     if (android::base::ReadFileToString(file_name, dt_content)) {
         if (!dt_content->empty()) {
             dt_content->pop_back();  // Trims the trailing '\0' out.
             return true;
         }
     }
+#endif
     return false;
 }
 

init/util.h

@@ -60,9 +60,6 @@ bool make_dir(const std::string& path, mode_t mode);
 bool is_dir(const char* pathname);
 Result<std::string> ExpandProps(const std::string& src);
 
-// Returns the platform's Android DT directory as specified in the kernel cmdline.
-// If the platform does not configure a custom DT path, returns the standard one (based in procfs).
-const std::string& get_android_dt_dir();
 // Reads or compares the content of device tree file under the platform's Android DT directory.
 bool read_android_dt_file(const std::string& sub_path, std::string* dt_content);
 bool is_android_dt_value_expected(const std::string& sub_path, const std::string& expected_content);