Merge "logd: don't poll() before recvmsg()" am: bf3b47a031 am: de2a239467 (b123c2e1) · Commits · e / os / android_system_core

logd/LogListener.cpp

+33 −17

Original line number	Original line	Diff line number	Diff line
	@@ -22,6 +22,8 @@
	#include <sys/un.h>		#include <sys/un.h>
	#include <unistd.h>		#include <unistd.h>

			#include <thread>

	#include <cutils/sockets.h>		#include <cutils/sockets.h>
	#include <private/android_filesystem_config.h>		#include <private/android_filesystem_config.h>
	#include <private/android_logger.h>		#include <private/android_logger.h>
	@@ -31,17 +33,33 @@
	#include "LogUtils.h"		#include "LogUtils.h"

	LogListener::LogListener(LogBuffer* buf, LogReader* reader)		LogListener::LogListener(LogBuffer* buf, LogReader* reader)
	: SocketListener(getLogSocket(), false), logbuf(buf), reader(reader) {}		: socket_(GetLogSocket()), logbuf_(buf), reader_(reader) {}

			bool LogListener::StartListener() {
			if (socket_ <= 0) {
			return false;
			}
			auto thread = std::thread(&LogListener::ThreadFunction, this);
			thread.detach();
			return true;
			}

	bool LogListener::onDataAvailable(SocketClient* cli) {		void LogListener::ThreadFunction() {
	static bool name_set;		static bool name_set;
	if (!name_set) {		if (!name_set) {
	prctl(PR_SET_NAME, "logd.writer");		prctl(PR_SET_NAME, "logd.writer");
	name_set = true;		name_set = true;
	}		}

			while (true) {
			HandleData();
			}
			}

			void LogListener::HandleData() {
	// + 1 to ensure null terminator if MAX_PAYLOAD buffer is received		// + 1 to ensure null terminator if MAX_PAYLOAD buffer is received
	char buffer[sizeof(android_log_header_t) + LOGGER_ENTRY_MAX_PAYLOAD + 1];		__attribute__((uninitialized)) char
			buffer[sizeof(android_log_header_t) + LOGGER_ENTRY_MAX_PAYLOAD + 1];
	struct iovec iov = {buffer, sizeof(buffer) - 1};		struct iovec iov = {buffer, sizeof(buffer) - 1};

	alignas(4) char control[CMSG_SPACE(sizeof(struct ucred))];		alignas(4) char control[CMSG_SPACE(sizeof(struct ucred))];
	@@ -49,15 +67,13 @@ bool LogListener::onDataAvailable(SocketClient* cli) {
	nullptr, 0, &iov, 1, control, sizeof(control), 0,		nullptr, 0, &iov, 1, control, sizeof(control), 0,
	};		};

	int socket = cli->getSocket();

	// To clear the entire buffer is secure/safe, but this contributes to 1.68%		// To clear the entire buffer is secure/safe, but this contributes to 1.68%
	// overhead under logging load. We are safe because we check counts, but		// overhead under logging load. We are safe because we check counts, but
	// still need to clear null terminator		// still need to clear null terminator
	// memset(buffer, 0, sizeof(buffer));		// memset(buffer, 0, sizeof(buffer));
	ssize_t n = recvmsg(socket, &hdr, 0);		ssize_t n = recvmsg(socket_, &hdr, 0);
	if (n <= (ssize_t)(sizeof(android_log_header_t))) {		if (n <= (ssize_t)(sizeof(android_log_header_t))) {
	return false;		return;
	}		}

	buffer[n] = 0;		buffer[n] = 0;
	@@ -75,14 +91,14 @@ bool LogListener::onDataAvailable(SocketClient* cli) {
	}		}

	if (cred == nullptr) {		if (cred == nullptr) {
	return false;		return;
	}		}

	if (cred->uid == AID_LOGD) {		if (cred->uid == AID_LOGD) {
	// ignore log messages we send to ourself.		// ignore log messages we send to ourself.
	// Such log messages are often generated by libraries we depend on		// Such log messages are often generated by libraries we depend on
	// which use standard Android logging.		// which use standard Android logging.
	return false;		return;
	}		}

	android_log_header_t* header =		android_log_header_t* header =
	@@ -90,13 +106,13 @@ bool LogListener::onDataAvailable(SocketClient* cli) {
	log_id_t logId = static_cast<log_id_t>(header->id);		log_id_t logId = static_cast<log_id_t>(header->id);
	if (/* logId < LOG_ID_MIN \|\| */ logId >= LOG_ID_MAX \|\|		if (/* logId < LOG_ID_MIN \|\| */ logId >= LOG_ID_MAX \|\|
	logId == LOG_ID_KERNEL) {		logId == LOG_ID_KERNEL) {
	return false;		return;
	}		}

	if ((logId == LOG_ID_SECURITY) &&		if ((logId == LOG_ID_SECURITY) &&
	(!__android_log_security() \|\|		(!__android_log_security() \|\|
	!clientHasLogCredentials(cred->uid, cred->gid, cred->pid))) {		!clientHasLogCredentials(cred->uid, cred->gid, cred->pid))) {
	return false;		return;
	}		}

	char* msg = ((char*)buffer) + sizeof(android_log_header_t);		char* msg = ((char*)buffer) + sizeof(android_log_header_t);
	@@ -105,16 +121,16 @@ bool LogListener::onDataAvailable(SocketClient* cli) {
	// NB: hdr.msg_flags & MSG_TRUNC is not tested, silently passing a		// NB: hdr.msg_flags & MSG_TRUNC is not tested, silently passing a
	// truncated message to the logs.		// truncated message to the logs.

	int res = logbuf->log(logId, header->realtime, cred->uid, cred->pid, header->tid, msg,		int res = logbuf_->log(logId, header->realtime, cred->uid, cred->pid, header->tid, msg,
	((size_t)n <= UINT16_MAX) ? (uint16_t)n : UINT16_MAX);		((size_t)n <= UINT16_MAX) ? (uint16_t)n : UINT16_MAX);
	if (res > 0) {		if (res > 0) {
	reader->notifyNewLog(static_cast<unsigned int>(1 << logId));		reader_->notifyNewLog(static_cast<unsigned int>(1 << logId));
	}		}

	return true;		return;
	}		}

	int LogListener::getLogSocket() {		int LogListener::GetLogSocket() {
	static const char socketName[] = "logdw";		static const char socketName[] = "logdw";
	int sock = android_get_control_socket(socketName);		int sock = android_get_control_socket(socketName);

logd/LogListener.h

+13 −15

Original line number	Original line	Diff line number	Diff line
	@@ -14,24 +14,22 @@
	* limitations under the License.		* limitations under the License.
	*/		*/

	#ifndef _LOGD_LOG_LISTENER_H__		#pragma once
	#define _LOGD_LOG_LISTENER_H__

	#include <sysutils/SocketListener.h>		#include "LogBuffer.h"
	#include "LogReader.h"		#include "LogReader.h"

	class LogListener : public SocketListener {		class LogListener {
	LogBuffer* logbuf;
	LogReader* reader;

	public:		public:
	LogListener(LogBuffer* buf, LogReader* reader);		LogListener(LogBuffer* buf, LogReader* reader);
			bool StartListener();
	protected:
	virtual bool onDataAvailable(SocketClient* cli);

	private:		private:
	static int getLogSocket();		void ThreadFunction();
	};		void HandleData();
			static int GetLogSocket();

	#endif		int socket_;
			LogBuffer* logbuf_;
			LogReader* reader_;
			};

logd/main.cpp

+1 −2

Original line number	Original line	Diff line number	Diff line
	@@ -304,8 +304,7 @@ int main(int argc, char* argv[]) {
	// and LogReader is notified to send updates to connected clients.		// and LogReader is notified to send updates to connected clients.

	LogListener* swl = new LogListener(logBuf, reader);		LogListener* swl = new LogListener(logBuf, reader);
	// Backlog and /proc/sys/net/unix/max_dgram_qlen set to large value		if (!swl->StartListener()) {
	if (swl->startListener(600)) {
	return EXIT_FAILURE;		return EXIT_FAILURE;
	}		}