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Merge "Revert "ueventd: remove PlatformDeviceList""

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am: 9c5f614945

Change-Id: Id20400ea7f34fb202219da3b998d81302edc05df
This commit is contained in:
Tom Cherry 2017-06-21 18:57:43 +00:00 committed by android-build-merger
commit b0350407f0
5 changed files with 114 additions and 53 deletions
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54
init/devices.cpp
View file

@ -147,34 +147,21 @@ void SysfsPermissions::SetPermissions(const std::string& path) const {
}
}
// 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 @@ out:
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::vector<std::string> DeviceHandler::GetBlockDeviceSymlinks(const Uevent& uev
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::HandleDevice(const std::string& action, const std::string& d
}
}
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 @@ void DeviceHandler::HandleDeviceEvent(const Uevent& uevent) {
if (uevent.subsystem == "block") {
HandleBlockDeviceEvent(uevent);
} else if (uevent.subsystem == "platform") {
HandlePlatformDeviceEvent(uevent);
} else {
HandleGenericDeviceEvent(uevent);
}
@ -475,8 +472,7 @@ DeviceHandler::DeviceHandler(std::vector<Permissions> dev_permissions,
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>{},

27
init/devices.h
View file

@ -93,6 +93,20 @@ class Subsystem {
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 @@ class DeviceHandler {
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 @@ class DeviceHandler {
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

62
init/devices_test.cpp
View file

@ -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 @@ class DeviceHandlerTester {
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 = {

6
init/init_first_stage.cpp
View file

@ -181,6 +181,12 @@ void FirstStageMount::InitRequiredDevices() {
}
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;

18
init/ueventd.cpp
View file

@ -128,7 +128,15 @@ class ColdBoot {
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 @@ void ColdBoot::RegenerateUevents() {
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;
});