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-rw-r--r--init/init.cpp166
1 files changed, 94 insertions, 72 deletions
diff --git a/init/init.cpp b/init/init.cpp
index b29dfa3f6..a9d63013f 100644
--- a/init/init.cpp
+++ b/init/init.cpp
@@ -22,6 +22,7 @@
#include <signal.h>
#include <stdlib.h>
#include <string.h>
+#include <sys/eventfd.h>
#include <sys/mount.h>
#include <sys/signalfd.h>
#include <sys/types.h>
@@ -45,6 +46,7 @@
#include <android-base/properties.h>
#include <android-base/stringprintf.h>
#include <android-base/strings.h>
+#include <backtrace/Backtrace.h>
#include <fs_avb/fs_avb.h>
#include <fs_mgr_vendor_overlay.h>
#include <keyutils.h>
@@ -81,6 +83,7 @@ using namespace std::chrono_literals;
using namespace std::string_literals;
using android::base::boot_clock;
+using android::base::ConsumePrefix;
using android::base::GetProperty;
using android::base::ReadFileToString;
using android::base::SetProperty;
@@ -113,30 +116,26 @@ static std::queue<PendingControlMessage> pending_control_messages;
// to fill that socket and deadlock the system. Now we use locks to handle the property changes
// directly in the property thread, however we still must wake the epoll to inform init that there
// is a change to process, so we use this FD. It is non-blocking, since we do not care how many
-// times WakeEpoll() is called, only that the epoll will wake.
-static int wake_epoll_fd = -1;
+// times WakeMainInitThread() is called, only that the epoll will wake.
+static int wake_main_thread_fd = -1;
static void InstallInitNotifier(Epoll* epoll) {
- int sockets[2];
- if (socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK, 0, sockets) != 0) {
- PLOG(FATAL) << "Failed to socketpair() between property_service and init";
+ wake_main_thread_fd = eventfd(0, EFD_CLOEXEC);
+ if (wake_main_thread_fd == -1) {
+ PLOG(FATAL) << "Failed to create eventfd for waking init";
}
- int epoll_fd = sockets[0];
- wake_epoll_fd = sockets[1];
-
- auto drain_socket = [epoll_fd] {
- char buf[512];
- while (read(epoll_fd, buf, sizeof(buf)) > 0) {
- }
+ auto clear_eventfd = [] {
+ uint64_t counter;
+ TEMP_FAILURE_RETRY(read(wake_main_thread_fd, &counter, sizeof(counter)));
};
- if (auto result = epoll->RegisterHandler(epoll_fd, drain_socket); !result.ok()) {
+ if (auto result = epoll->RegisterHandler(wake_main_thread_fd, clear_eventfd); !result.ok()) {
LOG(FATAL) << result.error();
}
}
-static void WakeEpoll() {
- constexpr char value[] = "1";
- write(wake_epoll_fd, value, sizeof(value));
+static void WakeMainInitThread() {
+ uint64_t counter = 1;
+ TEMP_FAILURE_RETRY(write(wake_main_thread_fd, &counter, sizeof(counter)));
}
static class PropWaiterState {
@@ -180,7 +179,7 @@ static class PropWaiterState {
LOG(INFO) << "Wait for property '" << wait_prop_name_ << "=" << wait_prop_value_
<< "' took " << *waiting_for_prop_;
ResetWaitForPropLocked();
- WakeEpoll();
+ WakeMainInitThread();
}
}
}
@@ -217,6 +216,16 @@ void ResetWaitForProp() {
prop_waiter_state.ResetWaitForProp();
}
+static void UnwindMainThreadStack() {
+ std::unique_ptr<Backtrace> backtrace(Backtrace::Create(BACKTRACE_CURRENT_PROCESS, 1));
+ if (!backtrace->Unwind(0)) {
+ LOG(ERROR) << __FUNCTION__ << ": Failed to unwind callstack.";
+ }
+ for (size_t i = 0; i < backtrace->NumFrames(); i++) {
+ LOG(ERROR) << backtrace->FormatFrameData(i);
+ }
+}
+
static class ShutdownState {
public:
void TriggerShutdown(const std::string& command) {
@@ -228,7 +237,7 @@ static class ShutdownState {
auto lock = std::lock_guard{shutdown_command_lock_};
shutdown_command_ = command;
do_shutdown_ = true;
- WakeEpoll();
+ WakeMainInitThread();
}
std::optional<std::string> CheckShutdown() {
@@ -240,12 +249,27 @@ static class ShutdownState {
return {};
}
+ bool do_shutdown() const { return do_shutdown_; }
+
private:
std::mutex shutdown_command_lock_;
std::string shutdown_command_;
bool do_shutdown_ = false;
} shutdown_state;
+void DebugRebootLogging() {
+ LOG(INFO) << "do_shutdown: " << shutdown_state.do_shutdown()
+ << " IsShuttingDown: " << IsShuttingDown();
+ if (shutdown_state.do_shutdown()) {
+ LOG(ERROR) << "sys.powerctl set while a previous shutdown command has not been handled";
+ UnwindMainThreadStack();
+ }
+ if (IsShuttingDown()) {
+ LOG(ERROR) << "sys.powerctl set while init is already shutting down";
+ UnwindMainThreadStack();
+ }
+}
+
void DumpState() {
ServiceList::GetInstance().DumpState();
ActionManager::GetInstance().DumpState();
@@ -312,7 +336,7 @@ void PropertyChanged(const std::string& name, const std::string& value) {
if (property_triggers_enabled) {
ActionManager::GetInstance().QueuePropertyChange(name, value);
- WakeEpoll();
+ WakeMainInitThread();
}
prop_waiter_state.CheckAndResetWait(name, value);
@@ -367,40 +391,27 @@ enum class ControlTarget {
INTERFACE, // action gets called for every service that holds this interface
};
-struct ControlMessageFunction {
- ControlTarget target;
- std::function<Result<void>(Service*)> action;
-};
+using ControlMessageFunction = std::function<Result<void>(Service*)>;
-static const std::map<std::string, ControlMessageFunction>& get_control_message_map() {
+static const std::map<std::string, ControlMessageFunction, std::less<>>& GetControlMessageMap() {
// clang-format off
- static const std::map<std::string, ControlMessageFunction> control_message_functions = {
- {"sigstop_on", {ControlTarget::SERVICE,
- [](auto* service) { service->set_sigstop(true); return Result<void>{}; }}},
- {"sigstop_off", {ControlTarget::SERVICE,
- [](auto* service) { service->set_sigstop(false); return Result<void>{}; }}},
- {"start", {ControlTarget::SERVICE, DoControlStart}},
- {"stop", {ControlTarget::SERVICE, DoControlStop}},
- {"restart", {ControlTarget::SERVICE, DoControlRestart}},
- {"interface_start", {ControlTarget::INTERFACE, DoControlStart}},
- {"interface_stop", {ControlTarget::INTERFACE, DoControlStop}},
- {"interface_restart", {ControlTarget::INTERFACE, DoControlRestart}},
+ static const std::map<std::string, ControlMessageFunction, std::less<>> control_message_functions = {
+ {"sigstop_on", [](auto* service) { service->set_sigstop(true); return Result<void>{}; }},
+ {"sigstop_off", [](auto* service) { service->set_sigstop(false); return Result<void>{}; }},
+ {"oneshot_on", [](auto* service) { service->set_oneshot(true); return Result<void>{}; }},
+ {"oneshot_off", [](auto* service) { service->set_oneshot(false); return Result<void>{}; }},
+ {"start", DoControlStart},
+ {"stop", DoControlStop},
+ {"restart", DoControlRestart},
};
// clang-format on
return control_message_functions;
}
-bool HandleControlMessage(const std::string& msg, const std::string& name, pid_t pid) {
- const auto& map = get_control_message_map();
- const auto it = map.find(msg);
-
- if (it == map.end()) {
- LOG(ERROR) << "Unknown control msg '" << msg << "'";
- return false;
- }
-
- std::string cmdline_path = StringPrintf("proc/%d/cmdline", pid);
+static bool HandleControlMessage(std::string_view message, const std::string& name,
+ pid_t from_pid) {
+ std::string cmdline_path = StringPrintf("proc/%d/cmdline", from_pid);
std::string process_cmdline;
if (ReadFileToString(cmdline_path, &process_cmdline)) {
std::replace(process_cmdline.begin(), process_cmdline.end(), '\0', ' ');
@@ -409,37 +420,37 @@ bool HandleControlMessage(const std::string& msg, const std::string& name, pid_t
process_cmdline = "unknown process";
}
- const ControlMessageFunction& function = it->second;
-
- Service* svc = nullptr;
+ Service* service = nullptr;
+ auto action = message;
+ if (ConsumePrefix(&action, "interface_")) {
+ service = ServiceList::GetInstance().FindInterface(name);
+ } else {
+ service = ServiceList::GetInstance().FindService(name);
+ }
- switch (function.target) {
- case ControlTarget::SERVICE:
- svc = ServiceList::GetInstance().FindService(name);
- break;
- case ControlTarget::INTERFACE:
- svc = ServiceList::GetInstance().FindInterface(name);
- break;
- default:
- LOG(ERROR) << "Invalid function target from static map key ctl." << msg << ": "
- << static_cast<std::underlying_type<ControlTarget>::type>(function.target);
- return false;
+ if (service == nullptr) {
+ LOG(ERROR) << "Control message: Could not find '" << name << "' for ctl." << message
+ << " from pid: " << from_pid << " (" << process_cmdline << ")";
+ return false;
}
- if (svc == nullptr) {
- LOG(ERROR) << "Control message: Could not find '" << name << "' for ctl." << msg
- << " from pid: " << pid << " (" << process_cmdline << ")";
+ const auto& map = GetControlMessageMap();
+ const auto it = map.find(action);
+ if (it == map.end()) {
+ LOG(ERROR) << "Unknown control msg '" << message << "'";
return false;
}
+ const auto& function = it->second;
- if (auto result = function.action(svc); !result.ok()) {
- LOG(ERROR) << "Control message: Could not ctl." << msg << " for '" << name
- << "' from pid: " << pid << " (" << process_cmdline << "): " << result.error();
+ if (auto result = function(service); !result.ok()) {
+ LOG(ERROR) << "Control message: Could not ctl." << message << " for '" << name
+ << "' from pid: " << from_pid << " (" << process_cmdline
+ << "): " << result.error();
return false;
}
- LOG(INFO) << "Control message: Processed ctl." << msg << " for '" << name
- << "' from pid: " << pid << " (" << process_cmdline << ")";
+ LOG(INFO) << "Control message: Processed ctl." << message << " for '" << name
+ << "' from pid: " << from_pid << " (" << process_cmdline << ")";
return true;
}
@@ -451,7 +462,7 @@ bool QueueControlMessage(const std::string& message, const std::string& name, pi
return false;
}
pending_control_messages.push({message, name, pid, fd});
- WakeEpoll();
+ WakeMainInitThread();
return true;
}
@@ -477,7 +488,7 @@ static void HandleControlMessages() {
}
// If we still have items to process, make sure we wake back up to do so.
if (!pending_control_messages.empty()) {
- WakeEpoll();
+ WakeMainInitThread();
}
}
@@ -713,8 +724,15 @@ int SecondStageMain(int argc, char** argv) {
InitKernelLogging(argv);
LOG(INFO) << "init second stage started!";
- // Will handle EPIPE at the time of write by checking the errno
- signal(SIGPIPE, SIG_IGN);
+ // Init should not crash because of a dependence on any other process, therefore we ignore
+ // SIGPIPE and handle EPIPE at the call site directly. Note that setting a signal to SIG_IGN
+ // is inherited across exec, but custom signal handlers are not. Since we do not want to
+ // ignore SIGPIPE for child processes, we set a no-op function for the signal handler instead.
+ {
+ struct sigaction action = {.sa_flags = SA_RESTART};
+ action.sa_handler = [](int) {};
+ sigaction(SIGPIPE, &action, nullptr);
+ }
// Set init and its forked children's oom_adj.
if (auto result =
@@ -853,6 +871,8 @@ int SecondStageMain(int argc, char** argv) {
auto shutdown_command = shutdown_state.CheckShutdown();
if (shutdown_command) {
+ LOG(INFO) << "Got shutdown_command '" << *shutdown_command
+ << "' Calling HandlePowerctlMessage()";
HandlePowerctlMessage(*shutdown_command);
}
@@ -887,7 +907,9 @@ int SecondStageMain(int argc, char** argv) {
(*function)();
}
}
- HandleControlMessages();
+ if (!IsShuttingDown()) {
+ HandleControlMessages();
+ }
}
return 0;
generated by cgit v1.2.3 (git 2.25.1) at 2025-10-04 01:38:22 +0000