Revert "ueventd: remove PlatformDeviceList"
Bug: 62864413
This reverts commit f51657ccef9d49b3dc037aae5a072bce795fcf99.
Change-Id: I1397ca2de716395782139688542c69848a31d62f
diff --git a/init/devices.cpp b/init/devices.cpp
index 2943fb7..c52d8f8 100644
--- a/init/devices.cpp
+++ b/init/devices.cpp
@@ -147,34 +147,21 @@
}
}
-// Given a path that may start with a platform device, find the parent platform device by finding a
-// parent directory with a 'subsystem' symlink that points to the platform bus.
-// If it doesn't start with a platform device, return false
-bool DeviceHandler::FindPlatformDevice(std::string path, std::string* platform_device_path) const {
- platform_device_path->clear();
-
- // Uevents don't contain the mount point, so we need to add it here.
- path.insert(0, sysfs_mount_point_);
-
- std::string directory = android::base::Dirname(path);
-
- while (directory != "/" && directory != ".") {
- std::string subsystem_link_path;
- if (android::base::Realpath(directory + "/subsystem", &subsystem_link_path) &&
- subsystem_link_path == sysfs_mount_point_ + "/bus/platform") {
- // We need to remove the mount point that we added above before returning.
- directory.erase(0, sysfs_mount_point_.size());
- *platform_device_path = directory;
+// Given a path that may start with a platform device, find the length of the
+// platform device prefix. If it doesn't start with a platform device, return false
+bool PlatformDeviceList::Find(const std::string& path, std::string* out_path) const {
+ out_path->clear();
+ // platform_devices is searched backwards, since parents are added before their children,
+ // and we want to match as deep of a child as we can.
+ for (auto it = platform_devices_.crbegin(); it != platform_devices_.crend(); ++it) {
+ auto platform_device_path_length = it->length();
+ if (platform_device_path_length < path.length() &&
+ path[platform_device_path_length] == '/' &&
+ android::base::StartsWith(path, it->c_str())) {
+ *out_path = *it;
return true;
}
-
- auto last_slash = path.rfind('/');
- if (last_slash == std::string::npos) return false;
-
- path.erase(last_slash);
- directory = android::base::Dirname(path);
}
-
return false;
}
@@ -271,7 +258,7 @@
std::vector<std::string> DeviceHandler::GetCharacterDeviceSymlinks(const Uevent& uevent) const {
std::string parent_device;
- if (!FindPlatformDevice(uevent.path, &parent_device)) return {};
+ if (!platform_devices_.Find(uevent.path, &parent_device)) return {};
// skip path to the parent driver
std::string path = uevent.path.substr(parent_device.length());
@@ -329,7 +316,7 @@
std::string device;
std::string type;
- if (FindPlatformDevice(uevent.path, &device)) {
+ if (platform_devices_.Find(uevent.path, &device)) {
// Skip /devices/platform or /devices/ if present
static const std::string devices_platform_prefix = "/devices/platform/";
static const std::string devices_prefix = "/devices/";
@@ -401,6 +388,14 @@
}
}
+void DeviceHandler::HandlePlatformDeviceEvent(const Uevent& uevent) {
+ if (uevent.action == "add") {
+ platform_devices_.Add(uevent.path);
+ } else if (uevent.action == "remove") {
+ platform_devices_.Remove(uevent.path);
+ }
+}
+
void DeviceHandler::HandleBlockDeviceEvent(const Uevent& uevent) const {
// if it's not a /dev device, nothing to do
if (uevent.major < 0 || uevent.minor < 0) return;
@@ -463,6 +458,8 @@
if (uevent.subsystem == "block") {
HandleBlockDeviceEvent(uevent);
+ } else if (uevent.subsystem == "platform") {
+ HandlePlatformDeviceEvent(uevent);
} else {
HandleGenericDeviceEvent(uevent);
}
@@ -475,8 +472,7 @@
sysfs_permissions_(std::move(sysfs_permissions)),
subsystems_(std::move(subsystems)),
sehandle_(selinux_android_file_context_handle()),
- skip_restorecon_(skip_restorecon),
- sysfs_mount_point_("/sys") {}
+ skip_restorecon_(skip_restorecon) {}
DeviceHandler::DeviceHandler()
: DeviceHandler(std::vector<Permissions>{}, std::vector<SysfsPermissions>{},
diff --git a/init/devices.h b/init/devices.h
index 362c38c..09a0ce3 100644
--- a/init/devices.h
+++ b/init/devices.h
@@ -93,6 +93,20 @@
DevnameSource devname_source_;
};
+class PlatformDeviceList {
+ public:
+ void Add(const std::string& path) { platform_devices_.emplace_back(path); }
+ void Remove(const std::string& path) {
+ auto it = std::find(platform_devices_.begin(), platform_devices_.end(), path);
+ if (it != platform_devices_.end()) platform_devices_.erase(it);
+ }
+ bool Find(const std::string& path, std::string* out_path) const;
+ auto size() const { return platform_devices_.size(); }
+
+ private:
+ std::vector<std::string> platform_devices_;
+};
+
class DeviceHandler {
public:
friend class DeviceHandlerTester;
@@ -105,11 +119,16 @@
void HandleDeviceEvent(const Uevent& uevent);
+ void FixupSysPermissions(const std::string& upath, const std::string& subsystem) const;
+
+ void HandlePlatformDeviceEvent(const Uevent& uevent);
+ void HandleBlockDeviceEvent(const Uevent& uevent) const;
+ void HandleGenericDeviceEvent(const Uevent& uevent) const;
+
std::vector<std::string> GetBlockDeviceSymlinks(const Uevent& uevent) const;
void set_skip_restorecon(bool value) { skip_restorecon_ = value; }
private:
- bool FindPlatformDevice(std::string path, std::string* platform_device_path) const;
std::tuple<mode_t, uid_t, gid_t> GetDevicePermissions(
const std::string& path, const std::vector<std::string>& links) const;
void MakeDevice(const std::string& path, int block, int major, int minor,
@@ -117,17 +136,13 @@
std::vector<std::string> GetCharacterDeviceSymlinks(const Uevent& uevent) const;
void HandleDevice(const std::string& action, const std::string& devpath, int block, int major,
int minor, const std::vector<std::string>& links) const;
- void FixupSysPermissions(const std::string& upath, const std::string& subsystem) const;
-
- void HandleBlockDeviceEvent(const Uevent& uevent) const;
- void HandleGenericDeviceEvent(const Uevent& uevent) const;
std::vector<Permissions> dev_permissions_;
std::vector<SysfsPermissions> sysfs_permissions_;
std::vector<Subsystem> subsystems_;
+ PlatformDeviceList platform_devices_;
selabel_handle* sehandle_;
bool skip_restorecon_;
- std::string sysfs_mount_point_;
};
// Exposed for testing
diff --git a/init/devices_test.cpp b/init/devices_test.cpp
index e1e4e49..41b101b 100644
--- a/init/devices_test.cpp
+++ b/init/devices_test.cpp
@@ -16,29 +16,33 @@
#include "devices.h"
+#include <string>
+#include <vector>
+
#include <android-base/scopeguard.h>
-#include <android-base/test_utils.h>
#include <gtest/gtest.h>
-#include "util.h"
-
-using namespace std::string_literals;
-
class DeviceHandlerTester {
public:
- void TestGetSymlinks(const std::string& platform_device, const Uevent& uevent,
+ void AddPlatformDevice(const std::string& path) {
+ Uevent uevent = {
+ .action = "add", .subsystem = "platform", .path = path,
+ };
+ device_handler_.HandlePlatformDeviceEvent(uevent);
+ }
+
+ void RemovePlatformDevice(const std::string& path) {
+ Uevent uevent = {
+ .action = "remove", .subsystem = "platform", .path = path,
+ };
+ device_handler_.HandlePlatformDeviceEvent(uevent);
+ }
+
+ void TestGetSymlinks(const std::string& platform_device_name, const Uevent& uevent,
const std::vector<std::string> expected_links, bool block) {
- TemporaryDir fake_sys_root;
- device_handler_.sysfs_mount_point_ = fake_sys_root.path;
-
- std::string platform_device_dir = fake_sys_root.path + platform_device;
- mkdir_recursive(platform_device_dir, 0777, nullptr);
-
- std::string platform_bus = fake_sys_root.path + "/bus/platform"s;
- mkdir_recursive(platform_bus, 0777, nullptr);
- symlink(platform_bus.c_str(), (platform_device_dir + "/subsystem").c_str());
-
- mkdir_recursive(android::base::Dirname(fake_sys_root.path + uevent.path), 0777, nullptr);
+ AddPlatformDevice(platform_device_name);
+ auto platform_device_remover = android::base::make_scope_guard(
+ [this, &platform_device_name]() { RemovePlatformDevice(platform_device_name); });
std::vector<std::string> result;
if (block) {
@@ -61,6 +65,30 @@
DeviceHandler device_handler_;
};
+TEST(device_handler, PlatformDeviceList) {
+ PlatformDeviceList platform_device_list;
+
+ platform_device_list.Add("/devices/platform/some_device_name");
+ platform_device_list.Add("/devices/platform/some_device_name/longer");
+ platform_device_list.Add("/devices/platform/other_device_name");
+ EXPECT_EQ(3U, platform_device_list.size());
+
+ std::string out_path;
+ EXPECT_FALSE(platform_device_list.Find("/devices/platform/not_found", &out_path));
+ EXPECT_EQ("", out_path);
+
+ EXPECT_FALSE(platform_device_list.Find("/devices/platform/some_device_name_with_same_prefix",
+ &out_path));
+
+ EXPECT_TRUE(platform_device_list.Find("/devices/platform/some_device_name/longer/longer_child",
+ &out_path));
+ EXPECT_EQ("/devices/platform/some_device_name/longer", out_path);
+
+ EXPECT_TRUE(
+ platform_device_list.Find("/devices/platform/some_device_name/other_child", &out_path));
+ EXPECT_EQ("/devices/platform/some_device_name", out_path);
+}
+
TEST(device_handler, get_character_device_symlinks_success) {
const char* platform_device = "/devices/platform/some_device_name";
Uevent uevent = {
diff --git a/init/init_first_stage.cpp b/init/init_first_stage.cpp
index ebbe1cd..0f2b1f3 100644
--- a/init/init_first_stage.cpp
+++ b/init/init_first_stage.cpp
@@ -181,6 +181,12 @@
}
RegenerationAction FirstStageMount::UeventCallback(const Uevent& uevent) {
+ // We need platform devices to create symlinks.
+ if (uevent.subsystem == "platform") {
+ device_handler_.HandleDeviceEvent(uevent);
+ return RegenerationAction::kContinue;
+ }
+
// Ignores everything that is not a block device.
if (uevent.subsystem != "block") {
return RegenerationAction::kContinue;
diff --git a/init/ueventd.cpp b/init/ueventd.cpp
index 8cf9326..31e4106 100644
--- a/init/ueventd.cpp
+++ b/init/ueventd.cpp
@@ -128,7 +128,15 @@
void ColdBoot::UeventHandlerMain(unsigned int process_num, unsigned int total_processes) {
for (unsigned int i = process_num; i < uevent_queue_.size(); i += total_processes) {
auto& uevent = uevent_queue_[i];
- device_handler_.HandleDeviceEvent(uevent);
+ if (uevent.action == "add" || uevent.action == "change" || uevent.action == "online") {
+ device_handler_.FixupSysPermissions(uevent.path, uevent.subsystem);
+ }
+
+ if (uevent.subsystem == "block") {
+ device_handler_.HandleBlockDeviceEvent(uevent);
+ } else {
+ device_handler_.HandleGenericDeviceEvent(uevent);
+ }
}
_exit(EXIT_SUCCESS);
}
@@ -137,6 +145,14 @@
uevent_listener_.RegenerateUevents([this](const Uevent& uevent) {
HandleFirmwareEvent(uevent);
+ // This is the one mutable part of DeviceHandler, in which platform devices are
+ // added to a vector for later reference. Since there is no communication after
+ // fork()'ing subprocess handlers, all platform devices must be in the vector before
+ // we fork, and therefore they must be handled in this loop.
+ if (uevent.subsystem == "platform") {
+ device_handler_.HandlePlatformDeviceEvent(uevent);
+ }
+
uevent_queue_.emplace_back(std::move(uevent));
return RegenerationAction::kContinue;
});