1195 lines
42 KiB
C++
1195 lines
42 KiB
C++
/*
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* Copyright (C) 2012-2014 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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// for manual checking of stale entries during LogBuffer::erase()
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//#define DEBUG_CHECK_FOR_STALE_ENTRIES
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#include <ctype.h>
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#include <endian.h>
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#include <errno.h>
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#include <stdio.h>
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#include <string.h>
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#include <sys/cdefs.h>
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#include <sys/user.h>
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#include <time.h>
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#include <unistd.h>
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#include <unordered_map>
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#include <cutils/properties.h>
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#include <private/android_logger.h>
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#include "LogBuffer.h"
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#include "LogKlog.h"
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#include "LogReader.h"
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#include "LogUtils.h"
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#ifndef __predict_false
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#define __predict_false(exp) __builtin_expect((exp) != 0, 0)
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#endif
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// Default
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#define log_buffer_size(id) mMaxSize[id]
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const log_time LogBuffer::pruneMargin(3, 0);
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void LogBuffer::init() {
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log_id_for_each(i) {
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mLastSet[i] = false;
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mLast[i] = mLogElements.begin();
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if (setSize(i, __android_logger_get_buffer_size(i))) {
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setSize(i, LOG_BUFFER_MIN_SIZE);
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}
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}
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bool lastMonotonic = monotonic;
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monotonic = android_log_clockid() == CLOCK_MONOTONIC;
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if (lastMonotonic != monotonic) {
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//
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// Fixup all timestamps, may not be 100% accurate, but better than
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// throwing what we have away when we get 'surprised' by a change.
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// In-place element fixup so no need to check reader-lock. Entries
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// should already be in timestamp order, but we could end up with a
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// few out-of-order entries if new monotonics come in before we
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// are notified of the reinit change in status. A Typical example would
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// be:
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// --------- beginning of system
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// 10.494082 184 201 D Cryptfs : Just triggered post_fs_data
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// --------- beginning of kernel
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// 0.000000 0 0 I : Initializing cgroup subsys
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// as the act of mounting /data would trigger persist.logd.timestamp to
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// be corrected. 1/30 corner case YMMV.
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//
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rdlock();
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LogBufferElementCollection::iterator it = mLogElements.begin();
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while ((it != mLogElements.end())) {
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LogBufferElement* e = *it;
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if (monotonic) {
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if (!android::isMonotonic(e->mRealTime)) {
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LogKlog::convertRealToMonotonic(e->mRealTime);
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}
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} else {
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if (android::isMonotonic(e->mRealTime)) {
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LogKlog::convertMonotonicToReal(e->mRealTime);
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}
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}
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++it;
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}
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unlock();
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}
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// We may have been triggered by a SIGHUP. Release any sleeping reader
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// threads to dump their current content.
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//
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// NB: this is _not_ performed in the context of a SIGHUP, it is
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// performed during startup, and in context of reinit administrative thread
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LogTimeEntry::wrlock();
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LastLogTimes::iterator times = mTimes.begin();
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while (times != mTimes.end()) {
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LogTimeEntry* entry = (*times);
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if (entry->owned_Locked()) {
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entry->triggerReader_Locked();
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}
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times++;
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}
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LogTimeEntry::unlock();
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}
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LogBuffer::LogBuffer(LastLogTimes* times)
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: monotonic(android_log_clockid() == CLOCK_MONOTONIC), mTimes(*times) {
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pthread_rwlock_init(&mLogElementsLock, nullptr);
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log_id_for_each(i) {
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lastLoggedElements[i] = nullptr;
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droppedElements[i] = nullptr;
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}
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init();
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}
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LogBuffer::~LogBuffer() {
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log_id_for_each(i) {
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delete lastLoggedElements[i];
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delete droppedElements[i];
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}
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}
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enum match_type { DIFFERENT, SAME, SAME_LIBLOG };
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static enum match_type identical(LogBufferElement* elem,
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LogBufferElement* last) {
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// is it mostly identical?
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// if (!elem) return DIFFERENT;
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ssize_t lenl = elem->getMsgLen();
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if (lenl <= 0) return DIFFERENT; // value if this represents a chatty elem
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// if (!last) return DIFFERENT;
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ssize_t lenr = last->getMsgLen();
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if (lenr <= 0) return DIFFERENT; // value if this represents a chatty elem
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// if (elem->getLogId() != last->getLogId()) return DIFFERENT;
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if (elem->getUid() != last->getUid()) return DIFFERENT;
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if (elem->getPid() != last->getPid()) return DIFFERENT;
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if (elem->getTid() != last->getTid()) return DIFFERENT;
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// last is more than a minute old, stop squashing identical messages
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if (elem->getRealTime().nsec() >
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(last->getRealTime().nsec() + 60 * NS_PER_SEC))
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return DIFFERENT;
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// Identical message
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const char* msgl = elem->getMsg();
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const char* msgr = last->getMsg();
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if (lenl == lenr) {
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if (!fastcmp<memcmp>(msgl, msgr, lenl)) return SAME;
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// liblog tagged messages (content gets summed)
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if ((elem->getLogId() == LOG_ID_EVENTS) &&
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(lenl == sizeof(android_log_event_int_t)) &&
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!fastcmp<memcmp>(msgl, msgr, sizeof(android_log_event_int_t) -
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sizeof(int32_t)) &&
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(elem->getTag() == LIBLOG_LOG_TAG)) {
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return SAME_LIBLOG;
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}
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}
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// audit message (except sequence number) identical?
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if (last->isBinary()) {
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if (fastcmp<memcmp>(msgl, msgr, sizeof(android_log_event_string_t) -
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sizeof(int32_t))) {
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return DIFFERENT;
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}
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msgl += sizeof(android_log_event_string_t);
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lenl -= sizeof(android_log_event_string_t);
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msgr += sizeof(android_log_event_string_t);
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lenr -= sizeof(android_log_event_string_t);
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}
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static const char avc[] = "): avc: ";
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const char* avcl = android::strnstr(msgl, lenl, avc);
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if (!avcl) return DIFFERENT;
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lenl -= avcl - msgl;
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const char* avcr = android::strnstr(msgr, lenr, avc);
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if (!avcr) return DIFFERENT;
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lenr -= avcr - msgr;
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if (lenl != lenr) return DIFFERENT;
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if (fastcmp<memcmp>(avcl + strlen(avc), avcr + strlen(avc),
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lenl - strlen(avc))) {
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return DIFFERENT;
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}
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return SAME;
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}
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int LogBuffer::log(log_id_t log_id, log_time realtime, uid_t uid, pid_t pid,
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pid_t tid, const char* msg, unsigned short len) {
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if ((log_id >= LOG_ID_MAX) || (log_id < 0)) {
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return -EINVAL;
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}
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LogBufferElement* elem =
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new LogBufferElement(log_id, realtime, uid, pid, tid, msg, len);
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if (log_id != LOG_ID_SECURITY) {
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int prio = ANDROID_LOG_INFO;
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const char* tag = nullptr;
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if (log_id == LOG_ID_EVENTS) {
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tag = tagToName(elem->getTag());
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} else {
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prio = *msg;
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tag = msg + 1;
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}
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if (!__android_log_is_loggable(prio, tag, ANDROID_LOG_VERBOSE)) {
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// Log traffic received to total
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wrlock();
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stats.addTotal(elem);
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unlock();
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delete elem;
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return -EACCES;
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}
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}
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wrlock();
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LogBufferElement* currentLast = lastLoggedElements[log_id];
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if (currentLast) {
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LogBufferElement* dropped = droppedElements[log_id];
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unsigned short count = dropped ? dropped->getDropped() : 0;
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//
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// State Init
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// incoming:
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// dropped = nullptr
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// currentLast = nullptr;
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// elem = incoming message
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// outgoing:
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// dropped = nullptr -> State 0
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// currentLast = copy of elem
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// log elem
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// State 0
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// incoming:
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// count = 0
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// dropped = nullptr
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// currentLast = copy of last message
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// elem = incoming message
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// outgoing: if match != DIFFERENT
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// dropped = copy of first identical message -> State 1
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// currentLast = reference to elem
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// break: if match == DIFFERENT
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// dropped = nullptr -> State 0
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// delete copy of last message (incoming currentLast)
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// currentLast = copy of elem
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// log elem
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// State 1
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// incoming:
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// count = 0
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// dropped = copy of first identical message
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// currentLast = reference to last held-back incoming
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// message
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// elem = incoming message
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// outgoing: if match == SAME
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// delete copy of first identical message (dropped)
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// dropped = reference to last held-back incoming
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// message set to chatty count of 1 -> State 2
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// currentLast = reference to elem
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// outgoing: if match == SAME_LIBLOG
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// dropped = copy of first identical message -> State 1
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// take sum of currentLast and elem
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// if sum overflows:
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// log currentLast
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// currentLast = reference to elem
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// else
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// delete currentLast
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// currentLast = reference to elem, sum liblog.
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// break: if match == DIFFERENT
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// delete dropped
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// dropped = nullptr -> State 0
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// log reference to last held-back (currentLast)
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// currentLast = copy of elem
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// log elem
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// State 2
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// incoming:
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// count = chatty count
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// dropped = chatty message holding count
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// currentLast = reference to last held-back incoming
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// message.
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// dropped = chatty message holding count
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// elem = incoming message
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// outgoing: if match != DIFFERENT
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// delete chatty message holding count
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// dropped = reference to last held-back incoming
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// message, set to chatty count + 1
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// currentLast = reference to elem
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// break: if match == DIFFERENT
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// log dropped (chatty message)
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// dropped = nullptr -> State 0
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// log reference to last held-back (currentLast)
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// currentLast = copy of elem
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// log elem
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//
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enum match_type match = identical(elem, currentLast);
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if (match != DIFFERENT) {
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if (dropped) {
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// Sum up liblog tag messages?
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if ((count == 0) /* at Pass 1 */ && (match == SAME_LIBLOG)) {
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android_log_event_int_t* event =
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reinterpret_cast<android_log_event_int_t*>(
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const_cast<char*>(currentLast->getMsg()));
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//
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// To unit test, differentiate with something like:
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// event->header.tag = htole32(CHATTY_LOG_TAG);
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// here, then instead of delete currentLast below,
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// log(currentLast) to see the incremental sums form.
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//
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uint32_t swab = event->payload.data;
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unsigned long long total = htole32(swab);
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event = reinterpret_cast<android_log_event_int_t*>(
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const_cast<char*>(elem->getMsg()));
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swab = event->payload.data;
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lastLoggedElements[LOG_ID_EVENTS] = elem;
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total += htole32(swab);
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// check for overflow
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if (total >= UINT32_MAX) {
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log(currentLast);
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unlock();
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return len;
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}
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stats.addTotal(currentLast);
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delete currentLast;
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swab = total;
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event->payload.data = htole32(swab);
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unlock();
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return len;
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}
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if (count == USHRT_MAX) {
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log(dropped);
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count = 1;
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} else {
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delete dropped;
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++count;
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}
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}
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if (count) {
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stats.addTotal(currentLast);
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currentLast->setDropped(count);
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}
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droppedElements[log_id] = currentLast;
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lastLoggedElements[log_id] = elem;
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unlock();
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return len;
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}
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if (dropped) { // State 1 or 2
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if (count) { // State 2
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log(dropped); // report chatty
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} else { // State 1
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delete dropped;
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}
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droppedElements[log_id] = nullptr;
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log(currentLast); // report last message in the series
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} else { // State 0
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delete currentLast;
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}
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}
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lastLoggedElements[log_id] = new LogBufferElement(*elem);
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log(elem);
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unlock();
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return len;
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}
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// assumes LogBuffer::wrlock() held, owns elem, look after garbage collection
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void LogBuffer::log(LogBufferElement* elem) {
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// cap on how far back we will sort in-place, otherwise append
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static uint32_t too_far_back = 5; // five seconds
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// Insert elements in time sorted order if possible
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// NB: if end is region locked, place element at end of list
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LogBufferElementCollection::iterator it = mLogElements.end();
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LogBufferElementCollection::iterator last = it;
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if (__predict_true(it != mLogElements.begin())) --it;
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if (__predict_false(it == mLogElements.begin()) ||
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__predict_true((*it)->getRealTime() <= elem->getRealTime()) ||
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__predict_false((((*it)->getRealTime().tv_sec - too_far_back) >
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elem->getRealTime().tv_sec) &&
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(elem->getLogId() != LOG_ID_KERNEL) &&
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((*it)->getLogId() != LOG_ID_KERNEL))) {
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mLogElements.push_back(elem);
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} else {
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log_time end = log_time::EPOCH;
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bool end_set = false;
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bool end_always = false;
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LogTimeEntry::rdlock();
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LastLogTimes::iterator times = mTimes.begin();
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while (times != mTimes.end()) {
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LogTimeEntry* entry = (*times);
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if (entry->owned_Locked()) {
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if (!entry->mNonBlock) {
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end_always = true;
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break;
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}
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// it passing mEnd is blocked by the following checks.
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if (!end_set || (end <= entry->mEnd)) {
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end = entry->mEnd;
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end_set = true;
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}
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}
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times++;
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}
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if (end_always || (end_set && (end > (*it)->getRealTime()))) {
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mLogElements.push_back(elem);
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} else {
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// should be short as timestamps are localized near end()
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do {
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last = it;
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if (__predict_false(it == mLogElements.begin())) {
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break;
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}
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--it;
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} while (((*it)->getRealTime() > elem->getRealTime()) &&
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(!end_set || (end <= (*it)->getRealTime())));
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mLogElements.insert(last, elem);
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}
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LogTimeEntry::unlock();
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}
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stats.add(elem);
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maybePrune(elem->getLogId());
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}
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// Prune at most 10% of the log entries or maxPrune, whichever is less.
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//
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// LogBuffer::wrlock() must be held when this function is called.
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void LogBuffer::maybePrune(log_id_t id) {
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size_t sizes = stats.sizes(id);
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unsigned long maxSize = log_buffer_size(id);
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if (sizes > maxSize) {
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size_t sizeOver = sizes - ((maxSize * 9) / 10);
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size_t elements = stats.realElements(id);
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size_t minElements = elements / 100;
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if (minElements < minPrune) {
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minElements = minPrune;
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}
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unsigned long pruneRows = elements * sizeOver / sizes;
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if (pruneRows < minElements) {
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pruneRows = minElements;
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}
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if (pruneRows > maxPrune) {
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pruneRows = maxPrune;
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}
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prune(id, pruneRows);
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}
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}
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LogBufferElementCollection::iterator LogBuffer::erase(
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LogBufferElementCollection::iterator it, bool coalesce) {
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LogBufferElement* element = *it;
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log_id_t id = element->getLogId();
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// Remove iterator references in the various lists that will become stale
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// after the element is erased from the main logging list.
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{ // start of scope for found iterator
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int key = ((id == LOG_ID_EVENTS) || (id == LOG_ID_SECURITY))
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? element->getTag()
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: element->getUid();
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LogBufferIteratorMap::iterator found = mLastWorst[id].find(key);
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if ((found != mLastWorst[id].end()) && (it == found->second)) {
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mLastWorst[id].erase(found);
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}
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}
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{ // start of scope for pid found iterator
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// element->getUid() may not be AID_SYSTEM for next-best-watermark.
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// will not assume id != LOG_ID_EVENTS or LOG_ID_SECURITY for KISS and
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// long term code stability, find() check should be fast for those ids.
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LogBufferPidIteratorMap::iterator found =
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mLastWorstPidOfSystem[id].find(element->getPid());
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if ((found != mLastWorstPidOfSystem[id].end()) &&
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(it == found->second)) {
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mLastWorstPidOfSystem[id].erase(found);
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}
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}
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|
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bool setLast[LOG_ID_MAX];
|
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bool doSetLast = false;
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log_id_for_each(i) {
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doSetLast |= setLast[i] = mLastSet[i] && (it == mLast[i]);
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}
|
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#ifdef DEBUG_CHECK_FOR_STALE_ENTRIES
|
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LogBufferElementCollection::iterator bad = it;
|
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int key = ((id == LOG_ID_EVENTS) || (id == LOG_ID_SECURITY))
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? element->getTag()
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: element->getUid();
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#endif
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it = mLogElements.erase(it);
|
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if (doSetLast) {
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log_id_for_each(i) {
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if (setLast[i]) {
|
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if (__predict_false(it == mLogElements.end())) { // impossible
|
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mLastSet[i] = false;
|
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mLast[i] = mLogElements.begin();
|
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} else {
|
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mLast[i] = it; // push down the road as next-best-watermark
|
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}
|
|
}
|
|
}
|
|
}
|
|
#ifdef DEBUG_CHECK_FOR_STALE_ENTRIES
|
|
log_id_for_each(i) {
|
|
for (auto b : mLastWorst[i]) {
|
|
if (bad == b.second) {
|
|
android::prdebug("stale mLastWorst[%d] key=%d mykey=%d\n", i,
|
|
b.first, key);
|
|
}
|
|
}
|
|
for (auto b : mLastWorstPidOfSystem[i]) {
|
|
if (bad == b.second) {
|
|
android::prdebug("stale mLastWorstPidOfSystem[%d] pid=%d\n", i,
|
|
b.first);
|
|
}
|
|
}
|
|
if (mLastSet[i] && (bad == mLast[i])) {
|
|
android::prdebug("stale mLast[%d]\n", i);
|
|
mLastSet[i] = false;
|
|
mLast[i] = mLogElements.begin();
|
|
}
|
|
}
|
|
#endif
|
|
if (coalesce) {
|
|
stats.erase(element);
|
|
} else {
|
|
stats.subtract(element);
|
|
}
|
|
delete element;
|
|
|
|
return it;
|
|
}
|
|
|
|
// Define a temporary mechanism to report the last LogBufferElement pointer
|
|
// for the specified uid, pid and tid. Used below to help merge-sort when
|
|
// pruning for worst UID.
|
|
class LogBufferElementKey {
|
|
const union {
|
|
struct {
|
|
uint32_t uid;
|
|
uint16_t pid;
|
|
uint16_t tid;
|
|
} __packed;
|
|
uint64_t value;
|
|
} __packed;
|
|
|
|
public:
|
|
LogBufferElementKey(uid_t uid, pid_t pid, pid_t tid)
|
|
: uid(uid), pid(pid), tid(tid) {
|
|
}
|
|
explicit LogBufferElementKey(uint64_t key) : value(key) {
|
|
}
|
|
|
|
uint64_t getKey() {
|
|
return value;
|
|
}
|
|
};
|
|
|
|
class LogBufferElementLast {
|
|
typedef std::unordered_map<uint64_t, LogBufferElement*> LogBufferElementMap;
|
|
LogBufferElementMap map;
|
|
|
|
public:
|
|
bool coalesce(LogBufferElement* element, unsigned short dropped) {
|
|
LogBufferElementKey key(element->getUid(), element->getPid(),
|
|
element->getTid());
|
|
LogBufferElementMap::iterator it = map.find(key.getKey());
|
|
if (it != map.end()) {
|
|
LogBufferElement* found = it->second;
|
|
unsigned short moreDropped = found->getDropped();
|
|
if ((dropped + moreDropped) > USHRT_MAX) {
|
|
map.erase(it);
|
|
} else {
|
|
found->setDropped(dropped + moreDropped);
|
|
return true;
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
void add(LogBufferElement* element) {
|
|
LogBufferElementKey key(element->getUid(), element->getPid(),
|
|
element->getTid());
|
|
map[key.getKey()] = element;
|
|
}
|
|
|
|
inline void clear() {
|
|
map.clear();
|
|
}
|
|
|
|
void clear(LogBufferElement* element) {
|
|
log_time current =
|
|
element->getRealTime() - log_time(EXPIRE_RATELIMIT, 0);
|
|
for (LogBufferElementMap::iterator it = map.begin(); it != map.end();) {
|
|
LogBufferElement* mapElement = it->second;
|
|
if ((mapElement->getDropped() >= EXPIRE_THRESHOLD) &&
|
|
(current > mapElement->getRealTime())) {
|
|
it = map.erase(it);
|
|
} else {
|
|
++it;
|
|
}
|
|
}
|
|
}
|
|
};
|
|
|
|
// Determine if watermark is within pruneMargin + 1s from the end of the list,
|
|
// the caller will use this result to set an internal busy flag indicating
|
|
// the prune operation could not be completed because a reader is blocking
|
|
// the request.
|
|
bool LogBuffer::isBusy(log_time watermark) {
|
|
LogBufferElementCollection::iterator ei = mLogElements.end();
|
|
--ei;
|
|
return watermark < ((*ei)->getRealTime() - pruneMargin - log_time(1, 0));
|
|
}
|
|
|
|
// If the selected reader is blocking our pruning progress, decide on
|
|
// what kind of mitigation is necessary to unblock the situation.
|
|
void LogBuffer::kickMe(LogTimeEntry* me, log_id_t id, unsigned long pruneRows) {
|
|
if (stats.sizes(id) > (2 * log_buffer_size(id))) { // +100%
|
|
// A misbehaving or slow reader has its connection
|
|
// dropped if we hit too much memory pressure.
|
|
me->release_Locked();
|
|
} else if (me->mTimeout.tv_sec || me->mTimeout.tv_nsec) {
|
|
// Allow a blocked WRAP timeout reader to
|
|
// trigger and start reporting the log data.
|
|
me->triggerReader_Locked();
|
|
} else {
|
|
// tell slow reader to skip entries to catch up
|
|
me->triggerSkip_Locked(id, pruneRows);
|
|
}
|
|
}
|
|
|
|
// prune "pruneRows" of type "id" from the buffer.
|
|
//
|
|
// This garbage collection task is used to expire log entries. It is called to
|
|
// remove all logs (clear), all UID logs (unprivileged clear), or every
|
|
// 256 or 10% of the total logs (whichever is less) to prune the logs.
|
|
//
|
|
// First there is a prep phase where we discover the reader region lock that
|
|
// acts as a backstop to any pruning activity to stop there and go no further.
|
|
//
|
|
// There are three major pruning loops that follow. All expire from the oldest
|
|
// entries. Since there are multiple log buffers, the Android logging facility
|
|
// will appear to drop entries 'in the middle' when looking at multiple log
|
|
// sources and buffers. This effect is slightly more prominent when we prune
|
|
// the worst offender by logging source. Thus the logs slowly loose content
|
|
// and value as you move back in time. This is preferred since chatty sources
|
|
// invariably move the logs value down faster as less chatty sources would be
|
|
// expired in the noise.
|
|
//
|
|
// The first loop performs blacklisting and worst offender pruning. Falling
|
|
// through when there are no notable worst offenders and have not hit the
|
|
// region lock preventing further worst offender pruning. This loop also looks
|
|
// after managing the chatty log entries and merging to help provide
|
|
// statistical basis for blame. The chatty entries are not a notification of
|
|
// how much logs you may have, but instead represent how much logs you would
|
|
// have had in a virtual log buffer that is extended to cover all the in-memory
|
|
// logs without loss. They last much longer than the represented pruned logs
|
|
// since they get multiplied by the gains in the non-chatty log sources.
|
|
//
|
|
// The second loop get complicated because an algorithm of watermarks and
|
|
// history is maintained to reduce the order and keep processing time
|
|
// down to a minimum at scale. These algorithms can be costly in the face
|
|
// of larger log buffers, or severly limited processing time granted to a
|
|
// background task at lowest priority.
|
|
//
|
|
// This second loop does straight-up expiration from the end of the logs
|
|
// (again, remember for the specified log buffer id) but does some whitelist
|
|
// preservation. Thus whitelist is a Hail Mary low priority, blacklists and
|
|
// spam filtration all take priority. This second loop also checks if a region
|
|
// lock is causing us to buffer too much in the logs to help the reader(s),
|
|
// and will tell the slowest reader thread to skip log entries, and if
|
|
// persistent and hits a further threshold, kill the reader thread.
|
|
//
|
|
// The third thread is optional, and only gets hit if there was a whitelist
|
|
// and more needs to be pruned against the backstop of the region lock.
|
|
//
|
|
// LogBuffer::wrlock() must be held when this function is called.
|
|
//
|
|
bool LogBuffer::prune(log_id_t id, unsigned long pruneRows, uid_t caller_uid) {
|
|
LogTimeEntry* oldest = nullptr;
|
|
bool busy = false;
|
|
bool clearAll = pruneRows == ULONG_MAX;
|
|
|
|
LogTimeEntry::rdlock();
|
|
|
|
// Region locked?
|
|
LastLogTimes::iterator times = mTimes.begin();
|
|
while (times != mTimes.end()) {
|
|
LogTimeEntry* entry = (*times);
|
|
if (entry->owned_Locked() && entry->isWatching(id) &&
|
|
(!oldest || (oldest->mStart > entry->mStart) ||
|
|
((oldest->mStart == entry->mStart) &&
|
|
(entry->mTimeout.tv_sec || entry->mTimeout.tv_nsec)))) {
|
|
oldest = entry;
|
|
}
|
|
times++;
|
|
}
|
|
log_time watermark(log_time::tv_sec_max, log_time::tv_nsec_max);
|
|
if (oldest) watermark = oldest->mStart - pruneMargin;
|
|
|
|
LogBufferElementCollection::iterator it;
|
|
|
|
if (__predict_false(caller_uid != AID_ROOT)) { // unlikely
|
|
// Only here if clear all request from non system source, so chatty
|
|
// filter logistics is not required.
|
|
it = mLastSet[id] ? mLast[id] : mLogElements.begin();
|
|
while (it != mLogElements.end()) {
|
|
LogBufferElement* element = *it;
|
|
|
|
if ((element->getLogId() != id) ||
|
|
(element->getUid() != caller_uid)) {
|
|
++it;
|
|
continue;
|
|
}
|
|
|
|
if (!mLastSet[id] || ((*mLast[id])->getLogId() != id)) {
|
|
mLast[id] = it;
|
|
mLastSet[id] = true;
|
|
}
|
|
|
|
if (oldest && (watermark <= element->getRealTime())) {
|
|
busy = isBusy(watermark);
|
|
if (busy) kickMe(oldest, id, pruneRows);
|
|
break;
|
|
}
|
|
|
|
it = erase(it);
|
|
if (--pruneRows == 0) {
|
|
break;
|
|
}
|
|
}
|
|
LogTimeEntry::unlock();
|
|
return busy;
|
|
}
|
|
|
|
// prune by worst offenders; by blacklist, UID, and by PID of system UID
|
|
bool hasBlacklist = (id != LOG_ID_SECURITY) && mPrune.naughty();
|
|
while (!clearAll && (pruneRows > 0)) {
|
|
// recalculate the worst offender on every batched pass
|
|
int worst = -1; // not valid for getUid() or getKey()
|
|
size_t worst_sizes = 0;
|
|
size_t second_worst_sizes = 0;
|
|
pid_t worstPid = 0; // POSIX guarantees PID != 0
|
|
|
|
if (worstUidEnabledForLogid(id) && mPrune.worstUidEnabled()) {
|
|
// Calculate threshold as 12.5% of available storage
|
|
size_t threshold = log_buffer_size(id) / 8;
|
|
|
|
if ((id == LOG_ID_EVENTS) || (id == LOG_ID_SECURITY)) {
|
|
stats.sortTags(AID_ROOT, (pid_t)0, 2, id)
|
|
.findWorst(worst, worst_sizes, second_worst_sizes,
|
|
threshold);
|
|
// per-pid filter for AID_SYSTEM sources is too complex
|
|
} else {
|
|
stats.sort(AID_ROOT, (pid_t)0, 2, id)
|
|
.findWorst(worst, worst_sizes, second_worst_sizes,
|
|
threshold);
|
|
|
|
if ((worst == AID_SYSTEM) && mPrune.worstPidOfSystemEnabled()) {
|
|
stats.sortPids(worst, (pid_t)0, 2, id)
|
|
.findWorst(worstPid, worst_sizes, second_worst_sizes);
|
|
}
|
|
}
|
|
}
|
|
|
|
// skip if we have neither worst nor naughty filters
|
|
if ((worst == -1) && !hasBlacklist) {
|
|
break;
|
|
}
|
|
|
|
bool kick = false;
|
|
bool leading = true;
|
|
it = mLastSet[id] ? mLast[id] : mLogElements.begin();
|
|
// Perform at least one mandatory garbage collection cycle in following
|
|
// - clear leading chatty tags
|
|
// - coalesce chatty tags
|
|
// - check age-out of preserved logs
|
|
bool gc = pruneRows <= 1;
|
|
if (!gc && (worst != -1)) {
|
|
{ // begin scope for worst found iterator
|
|
LogBufferIteratorMap::iterator found =
|
|
mLastWorst[id].find(worst);
|
|
if ((found != mLastWorst[id].end()) &&
|
|
(found->second != mLogElements.end())) {
|
|
leading = false;
|
|
it = found->second;
|
|
}
|
|
}
|
|
if (worstPid) { // begin scope for pid worst found iterator
|
|
// FYI: worstPid only set if !LOG_ID_EVENTS and
|
|
// !LOG_ID_SECURITY, not going to make that assumption ...
|
|
LogBufferPidIteratorMap::iterator found =
|
|
mLastWorstPidOfSystem[id].find(worstPid);
|
|
if ((found != mLastWorstPidOfSystem[id].end()) &&
|
|
(found->second != mLogElements.end())) {
|
|
leading = false;
|
|
it = found->second;
|
|
}
|
|
}
|
|
}
|
|
static const timespec too_old = { EXPIRE_HOUR_THRESHOLD * 60 * 60, 0 };
|
|
LogBufferElementCollection::iterator lastt;
|
|
lastt = mLogElements.end();
|
|
--lastt;
|
|
LogBufferElementLast last;
|
|
while (it != mLogElements.end()) {
|
|
LogBufferElement* element = *it;
|
|
|
|
if (oldest && (watermark <= element->getRealTime())) {
|
|
busy = isBusy(watermark);
|
|
// Do not let chatty eliding trigger any reader mitigation
|
|
break;
|
|
}
|
|
|
|
if (element->getLogId() != id) {
|
|
++it;
|
|
continue;
|
|
}
|
|
// below this point element->getLogId() == id
|
|
|
|
if (leading && (!mLastSet[id] || ((*mLast[id])->getLogId() != id))) {
|
|
mLast[id] = it;
|
|
mLastSet[id] = true;
|
|
}
|
|
|
|
unsigned short dropped = element->getDropped();
|
|
|
|
// remove any leading drops
|
|
if (leading && dropped) {
|
|
it = erase(it);
|
|
continue;
|
|
}
|
|
|
|
if (dropped && last.coalesce(element, dropped)) {
|
|
it = erase(it, true);
|
|
continue;
|
|
}
|
|
|
|
int key = ((id == LOG_ID_EVENTS) || (id == LOG_ID_SECURITY))
|
|
? element->getTag()
|
|
: element->getUid();
|
|
|
|
if (hasBlacklist && mPrune.naughty(element)) {
|
|
last.clear(element);
|
|
it = erase(it);
|
|
if (dropped) {
|
|
continue;
|
|
}
|
|
|
|
pruneRows--;
|
|
if (pruneRows == 0) {
|
|
break;
|
|
}
|
|
|
|
if (key == worst) {
|
|
kick = true;
|
|
if (worst_sizes < second_worst_sizes) {
|
|
break;
|
|
}
|
|
worst_sizes -= element->getMsgLen();
|
|
}
|
|
continue;
|
|
}
|
|
|
|
if ((element->getRealTime() < ((*lastt)->getRealTime() - too_old)) ||
|
|
(element->getRealTime() > (*lastt)->getRealTime())) {
|
|
break;
|
|
}
|
|
|
|
if (dropped) {
|
|
last.add(element);
|
|
if (worstPid &&
|
|
((!gc && (element->getPid() == worstPid)) ||
|
|
(mLastWorstPidOfSystem[id].find(element->getPid()) ==
|
|
mLastWorstPidOfSystem[id].end()))) {
|
|
// element->getUid() may not be AID_SYSTEM, next best
|
|
// watermark if current one empty. id is not LOG_ID_EVENTS
|
|
// or LOG_ID_SECURITY because of worstPid check.
|
|
mLastWorstPidOfSystem[id][element->getPid()] = it;
|
|
}
|
|
if ((!gc && !worstPid && (key == worst)) ||
|
|
(mLastWorst[id].find(key) == mLastWorst[id].end())) {
|
|
mLastWorst[id][key] = it;
|
|
}
|
|
++it;
|
|
continue;
|
|
}
|
|
|
|
if ((key != worst) ||
|
|
(worstPid && (element->getPid() != worstPid))) {
|
|
leading = false;
|
|
last.clear(element);
|
|
++it;
|
|
continue;
|
|
}
|
|
// key == worst below here
|
|
// If worstPid set, then element->getPid() == worstPid below here
|
|
|
|
pruneRows--;
|
|
if (pruneRows == 0) {
|
|
break;
|
|
}
|
|
|
|
kick = true;
|
|
|
|
unsigned short len = element->getMsgLen();
|
|
|
|
// do not create any leading drops
|
|
if (leading) {
|
|
it = erase(it);
|
|
} else {
|
|
stats.drop(element);
|
|
element->setDropped(1);
|
|
if (last.coalesce(element, 1)) {
|
|
it = erase(it, true);
|
|
} else {
|
|
last.add(element);
|
|
if (worstPid &&
|
|
(!gc || (mLastWorstPidOfSystem[id].find(worstPid) ==
|
|
mLastWorstPidOfSystem[id].end()))) {
|
|
// element->getUid() may not be AID_SYSTEM, next best
|
|
// watermark if current one empty. id is not
|
|
// LOG_ID_EVENTS or LOG_ID_SECURITY because of worstPid.
|
|
mLastWorstPidOfSystem[id][worstPid] = it;
|
|
}
|
|
if ((!gc && !worstPid) ||
|
|
(mLastWorst[id].find(worst) == mLastWorst[id].end())) {
|
|
mLastWorst[id][worst] = it;
|
|
}
|
|
++it;
|
|
}
|
|
}
|
|
if (worst_sizes < second_worst_sizes) {
|
|
break;
|
|
}
|
|
worst_sizes -= len;
|
|
}
|
|
last.clear();
|
|
|
|
if (!kick || !mPrune.worstUidEnabled()) {
|
|
break; // the following loop will ask bad clients to skip/drop
|
|
}
|
|
}
|
|
|
|
bool whitelist = false;
|
|
bool hasWhitelist = (id != LOG_ID_SECURITY) && mPrune.nice() && !clearAll;
|
|
it = mLastSet[id] ? mLast[id] : mLogElements.begin();
|
|
while ((pruneRows > 0) && (it != mLogElements.end())) {
|
|
LogBufferElement* element = *it;
|
|
|
|
if (element->getLogId() != id) {
|
|
it++;
|
|
continue;
|
|
}
|
|
|
|
if (!mLastSet[id] || ((*mLast[id])->getLogId() != id)) {
|
|
mLast[id] = it;
|
|
mLastSet[id] = true;
|
|
}
|
|
|
|
if (oldest && (watermark <= element->getRealTime())) {
|
|
busy = isBusy(watermark);
|
|
if (!whitelist && busy) kickMe(oldest, id, pruneRows);
|
|
break;
|
|
}
|
|
|
|
if (hasWhitelist && !element->getDropped() && mPrune.nice(element)) {
|
|
// WhiteListed
|
|
whitelist = true;
|
|
it++;
|
|
continue;
|
|
}
|
|
|
|
it = erase(it);
|
|
pruneRows--;
|
|
}
|
|
|
|
// Do not save the whitelist if we are reader range limited
|
|
if (whitelist && (pruneRows > 0)) {
|
|
it = mLastSet[id] ? mLast[id] : mLogElements.begin();
|
|
while ((it != mLogElements.end()) && (pruneRows > 0)) {
|
|
LogBufferElement* element = *it;
|
|
|
|
if (element->getLogId() != id) {
|
|
++it;
|
|
continue;
|
|
}
|
|
|
|
if (!mLastSet[id] || ((*mLast[id])->getLogId() != id)) {
|
|
mLast[id] = it;
|
|
mLastSet[id] = true;
|
|
}
|
|
|
|
if (oldest && (watermark <= element->getRealTime())) {
|
|
busy = isBusy(watermark);
|
|
if (busy) kickMe(oldest, id, pruneRows);
|
|
break;
|
|
}
|
|
|
|
it = erase(it);
|
|
pruneRows--;
|
|
}
|
|
}
|
|
|
|
LogTimeEntry::unlock();
|
|
|
|
return (pruneRows > 0) && busy;
|
|
}
|
|
|
|
// clear all rows of type "id" from the buffer.
|
|
bool LogBuffer::clear(log_id_t id, uid_t uid) {
|
|
bool busy = true;
|
|
// If it takes more than 4 tries (seconds) to clear, then kill reader(s)
|
|
for (int retry = 4;;) {
|
|
if (retry == 1) { // last pass
|
|
// Check if it is still busy after the sleep, we say prune
|
|
// one entry, not another clear run, so we are looking for
|
|
// the quick side effect of the return value to tell us if
|
|
// we have a _blocked_ reader.
|
|
wrlock();
|
|
busy = prune(id, 1, uid);
|
|
unlock();
|
|
// It is still busy, blocked reader(s), lets kill them all!
|
|
// otherwise, lets be a good citizen and preserve the slow
|
|
// readers and let the clear run (below) deal with determining
|
|
// if we are still blocked and return an error code to caller.
|
|
if (busy) {
|
|
LogTimeEntry::wrlock();
|
|
LastLogTimes::iterator times = mTimes.begin();
|
|
while (times != mTimes.end()) {
|
|
LogTimeEntry* entry = (*times);
|
|
// Killer punch
|
|
if (entry->owned_Locked() && entry->isWatching(id)) {
|
|
entry->release_Locked();
|
|
}
|
|
times++;
|
|
}
|
|
LogTimeEntry::unlock();
|
|
}
|
|
}
|
|
wrlock();
|
|
busy = prune(id, ULONG_MAX, uid);
|
|
unlock();
|
|
if (!busy || !--retry) {
|
|
break;
|
|
}
|
|
sleep(1); // Let reader(s) catch up after notification
|
|
}
|
|
return busy;
|
|
}
|
|
|
|
// get the used space associated with "id".
|
|
unsigned long LogBuffer::getSizeUsed(log_id_t id) {
|
|
rdlock();
|
|
size_t retval = stats.sizes(id);
|
|
unlock();
|
|
return retval;
|
|
}
|
|
|
|
// set the total space allocated to "id"
|
|
int LogBuffer::setSize(log_id_t id, unsigned long size) {
|
|
// Reasonable limits ...
|
|
if (!__android_logger_valid_buffer_size(size)) {
|
|
return -1;
|
|
}
|
|
wrlock();
|
|
log_buffer_size(id) = size;
|
|
unlock();
|
|
return 0;
|
|
}
|
|
|
|
// get the total space allocated to "id"
|
|
unsigned long LogBuffer::getSize(log_id_t id) {
|
|
rdlock();
|
|
size_t retval = log_buffer_size(id);
|
|
unlock();
|
|
return retval;
|
|
}
|
|
|
|
log_time LogBuffer::flushTo(SocketClient* reader, const log_time& start,
|
|
pid_t* lastTid, bool privileged, bool security,
|
|
int (*filter)(const LogBufferElement* element,
|
|
void* arg),
|
|
void* arg) {
|
|
LogBufferElementCollection::iterator it;
|
|
uid_t uid = reader->getUid();
|
|
|
|
rdlock();
|
|
|
|
if (start == log_time::EPOCH) {
|
|
// client wants to start from the beginning
|
|
it = mLogElements.begin();
|
|
} else {
|
|
// 3 second limit to continue search for out-of-order entries.
|
|
log_time min = start - pruneMargin;
|
|
|
|
// Cap to 300 iterations we look back for out-of-order entries.
|
|
size_t count = 300;
|
|
|
|
// Client wants to start from some specified time. Chances are
|
|
// we are better off starting from the end of the time sorted list.
|
|
LogBufferElementCollection::iterator last;
|
|
for (last = it = mLogElements.end(); it != mLogElements.begin();
|
|
/* do nothing */) {
|
|
--it;
|
|
LogBufferElement* element = *it;
|
|
if (element->getRealTime() > start) {
|
|
last = it;
|
|
} else if (!--count || (element->getRealTime() < min)) {
|
|
break;
|
|
}
|
|
}
|
|
it = last;
|
|
}
|
|
|
|
log_time max = start;
|
|
|
|
LogBufferElement* lastElement = nullptr; // iterator corruption paranoia
|
|
static const size_t maxSkip = 4194304; // maximum entries to skip
|
|
size_t skip = maxSkip;
|
|
for (; it != mLogElements.end(); ++it) {
|
|
LogBufferElement* element = *it;
|
|
|
|
if (!--skip) {
|
|
android::prdebug("reader.per: too many elements skipped");
|
|
break;
|
|
}
|
|
if (element == lastElement) {
|
|
android::prdebug("reader.per: identical elements");
|
|
break;
|
|
}
|
|
lastElement = element;
|
|
|
|
if (!privileged && (element->getUid() != uid)) {
|
|
continue;
|
|
}
|
|
|
|
if (!security && (element->getLogId() == LOG_ID_SECURITY)) {
|
|
continue;
|
|
}
|
|
|
|
// NB: calling out to another object with wrlock() held (safe)
|
|
if (filter) {
|
|
int ret = (*filter)(element, arg);
|
|
if (ret == false) {
|
|
continue;
|
|
}
|
|
if (ret != true) {
|
|
break;
|
|
}
|
|
}
|
|
|
|
bool sameTid = false;
|
|
if (lastTid) {
|
|
sameTid = lastTid[element->getLogId()] == element->getTid();
|
|
// Dropped (chatty) immediately following a valid log from the
|
|
// same source in the same log buffer indicates we have a
|
|
// multiple identical squash. chatty that differs source
|
|
// is due to spam filter. chatty to chatty of different
|
|
// source is also due to spam filter.
|
|
lastTid[element->getLogId()] =
|
|
(element->getDropped() && !sameTid) ? 0 : element->getTid();
|
|
}
|
|
|
|
unlock();
|
|
|
|
// range locking in LastLogTimes looks after us
|
|
log_time next = element->flushTo(reader, this, privileged, sameTid);
|
|
|
|
if (next == element->FLUSH_ERROR) return next;
|
|
if (next > max) max = next;
|
|
|
|
skip = maxSkip;
|
|
rdlock();
|
|
}
|
|
unlock();
|
|
|
|
return max;
|
|
}
|
|
|
|
std::string LogBuffer::formatStatistics(uid_t uid, pid_t pid,
|
|
unsigned int logMask) {
|
|
wrlock();
|
|
|
|
std::string ret = stats.format(uid, pid, logMask);
|
|
|
|
unlock();
|
|
|
|
return ret;
|
|
}
|