Merge "init: simplify async restorecon"
diff --git a/init/property_service.cpp b/init/property_service.cpp
index 9766584..a1e9551 100644
--- a/init/property_service.cpp
+++ b/init/property_service.cpp
@@ -41,7 +41,9 @@
#include <map>
#include <memory>
+#include <mutex>
#include <queue>
+#include <thread>
#include <vector>
#include <android-base/chrono_utils.h>
@@ -83,6 +85,8 @@
namespace android {
namespace init {
+static constexpr const char kRestoreconProperty[] = "selinux.restorecon_recursive";
+
static bool persistent_properties_loaded = false;
static int property_set_fd = -1;
@@ -204,88 +208,51 @@
return PROP_SUCCESS;
}
-typedef int (*PropertyAsyncFunc)(const std::string&, const std::string&);
+class AsyncRestorecon {
+ public:
+ void TriggerRestorecon(const std::string& path) {
+ auto guard = std::lock_guard{mutex_};
+ paths_.emplace(path);
-struct PropertyChildInfo {
- pid_t pid;
- PropertyAsyncFunc func;
- std::string name;
- std::string value;
+ if (!thread_started_) {
+ thread_started_ = true;
+ std::thread{&AsyncRestorecon::ThreadFunction, this}.detach();
+ }
+ }
+
+ private:
+ void ThreadFunction() {
+ auto lock = std::unique_lock{mutex_};
+
+ while (!paths_.empty()) {
+ auto path = paths_.front();
+ paths_.pop();
+
+ lock.unlock();
+ if (selinux_android_restorecon(path.c_str(), SELINUX_ANDROID_RESTORECON_RECURSE) != 0) {
+ LOG(ERROR) << "Asynchronous restorecon of '" << path << "' failed'";
+ }
+ android::base::SetProperty(kRestoreconProperty, path);
+ lock.lock();
+ }
+
+ thread_started_ = false;
+ }
+
+ std::mutex mutex_;
+ std::queue<std::string> paths_;
+ bool thread_started_ = false;
};
-static std::queue<PropertyChildInfo> property_children;
-
-static void PropertyChildLaunch() {
- auto& info = property_children.front();
- pid_t pid = fork();
- if (pid < 0) {
- LOG(ERROR) << "Failed to fork for property_set_async";
- while (!property_children.empty()) {
- property_children.pop();
- }
- return;
- }
- if (pid != 0) {
- info.pid = pid;
- } else {
- if (info.func(info.name, info.value) != 0) {
- LOG(ERROR) << "property_set_async(\"" << info.name << "\", \"" << info.value
- << "\") failed";
- }
- _exit(0);
- }
-}
-
-bool PropertyChildReap(pid_t pid) {
- if (property_children.empty()) {
- return false;
- }
- auto& info = property_children.front();
- if (info.pid != pid) {
- return false;
- }
- std::string error;
- if (PropertySet(info.name, info.value, &error) != PROP_SUCCESS) {
- LOG(ERROR) << "Failed to set async property " << info.name << " to " << info.value << ": "
- << error;
- }
- property_children.pop();
- if (!property_children.empty()) {
- PropertyChildLaunch();
- }
- return true;
-}
-
-static uint32_t PropertySetAsync(const std::string& name, const std::string& value,
- PropertyAsyncFunc func, std::string* error) {
- if (value.empty()) {
- return PropertySet(name, value, error);
- }
-
- PropertyChildInfo info;
- info.func = func;
- info.name = name;
- info.value = value;
- property_children.push(info);
- if (property_children.size() == 1) {
- PropertyChildLaunch();
- }
- return PROP_SUCCESS;
-}
-
-static int RestoreconRecursiveAsync(const std::string& name, const std::string& value) {
- return selinux_android_restorecon(value.c_str(), SELINUX_ANDROID_RESTORECON_RECURSE);
-}
-
uint32_t InitPropertySet(const std::string& name, const std::string& value) {
if (StartsWith(name, "ctl.")) {
LOG(ERROR) << "InitPropertySet: Do not set ctl. properties from init; call the Service "
"functions directly";
return PROP_ERROR_INVALID_NAME;
}
- if (name == "selinux.restorecon_recursive") {
- LOG(ERROR) << "InitPropertySet: Do not set selinux.restorecon_recursive from init; use the "
- "restorecon builtin directly";
+ if (name == kRestoreconProperty) {
+ LOG(ERROR) << "InitPropertySet: Do not set '" << kRestoreconProperty
+ << "' from init; use the restorecon builtin directly";
return PROP_ERROR_INVALID_NAME;
}
@@ -525,8 +492,14 @@
<< process_log_string;
}
- if (name == "selinux.restorecon_recursive") {
- return PropertySetAsync(name, value, RestoreconRecursiveAsync, error);
+ // If a process other than init is writing a non-empty value, it means that process is
+ // requesting that init performs a restorecon operation on the path specified by 'value'.
+ // We use a thread to do this restorecon operation to prevent holding up init, as it may take
+ // a long time to complete.
+ if (name == kRestoreconProperty && cr.pid != 1 && !value.empty()) {
+ static AsyncRestorecon async_restorecon;
+ async_restorecon.TriggerRestorecon(value);
+ return PROP_SUCCESS;
}
return PropertySet(name, value, error);
@@ -692,7 +665,7 @@
}
if (StartsWith(key, "ctl.") || key == "sys.powerctl"s ||
- key == "selinux.restorecon_recursive"s) {
+ std::string{key} == kRestoreconProperty) {
LOG(ERROR) << "Ignoring disallowed property '" << key
<< "' with special meaning in prop file '" << filename << "'";
continue;
diff --git a/init/property_service.h b/init/property_service.h
index 207c03b..7f9f844 100644
--- a/init/property_service.h
+++ b/init/property_service.h
@@ -32,8 +32,6 @@
uint32_t HandlePropertySet(const std::string& name, const std::string& value,
const std::string& source_context, const ucred& cr, std::string* error);
-extern bool PropertyChildReap(pid_t pid);
-
void property_init();
void property_load_boot_defaults(bool load_debug_prop);
void load_persist_props();
diff --git a/init/sigchld_handler.cpp b/init/sigchld_handler.cpp
index 0b03324..987b2f9 100644
--- a/init/sigchld_handler.cpp
+++ b/init/sigchld_handler.cpp
@@ -29,7 +29,6 @@
#include <android-base/stringprintf.h>
#include "init.h"
-#include "property_service.h"
#include "service.h"
using android::base::StringPrintf;
@@ -61,9 +60,7 @@
std::string wait_string;
Service* service = nullptr;
- if (PropertyChildReap(pid)) {
- name = "Async property child";
- } else if (SubcontextChildReap(pid)) {
+ if (SubcontextChildReap(pid)) {
name = "Subcontext";
} else {
service = ServiceList::GetInstance().FindService(pid, &Service::pid);
