blob: b6b6124689bbbf64fbacf1bae34389f7f4d04662 [file] [log] [blame]
/*
* Copyright (C) 2012-2014 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <ctype.h>
#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <sys/user.h>
#include <time.h>
#include <unistd.h>
#include <cutils/properties.h>
#include <log/logger.h>
#include "LogBuffer.h"
#include "LogReader.h"
// Default
#define LOG_BUFFER_SIZE (256 * 1024) // Tuned on a per-platform basis here?
#define log_buffer_size(id) mMaxSize[id]
#define LOG_BUFFER_MIN_SIZE (64 * 1024UL)
#define LOG_BUFFER_MAX_SIZE (256 * 1024 * 1024UL)
static bool valid_size(unsigned long value) {
if ((value < LOG_BUFFER_MIN_SIZE) || (LOG_BUFFER_MAX_SIZE < value)) {
return false;
}
long pages = sysconf(_SC_PHYS_PAGES);
if (pages < 1) {
return true;
}
long pagesize = sysconf(_SC_PAGESIZE);
if (pagesize <= 1) {
pagesize = PAGE_SIZE;
}
// maximum memory impact a somewhat arbitrary ~3%
pages = (pages + 31) / 32;
unsigned long maximum = pages * pagesize;
if ((maximum < LOG_BUFFER_MIN_SIZE) || (LOG_BUFFER_MAX_SIZE < maximum)) {
return true;
}
return value <= maximum;
}
static unsigned long property_get_size(const char *key) {
char property[PROPERTY_VALUE_MAX];
property_get(key, property, "");
char *cp;
unsigned long value = strtoul(property, &cp, 10);
switch(*cp) {
case 'm':
case 'M':
value *= 1024;
/* FALLTHRU */
case 'k':
case 'K':
value *= 1024;
/* FALLTHRU */
case '\0':
break;
default:
value = 0;
}
if (!valid_size(value)) {
value = 0;
}
return value;
}
void LogBuffer::init() {
static const char global_tuneable[] = "persist.logd.size"; // Settings App
static const char global_default[] = "ro.logd.size"; // BoardConfig.mk
unsigned long default_size = property_get_size(global_tuneable);
if (!default_size) {
default_size = property_get_size(global_default);
}
log_id_for_each(i) {
char key[PROP_NAME_MAX];
snprintf(key, sizeof(key), "%s.%s",
global_tuneable, android_log_id_to_name(i));
unsigned long property_size = property_get_size(key);
if (!property_size) {
snprintf(key, sizeof(key), "%s.%s",
global_default, android_log_id_to_name(i));
property_size = property_get_size(key);
}
if (!property_size) {
property_size = default_size;
}
if (!property_size) {
property_size = LOG_BUFFER_SIZE;
}
if (setSize(i, property_size)) {
setSize(i, LOG_BUFFER_MIN_SIZE);
}
}
}
LogBuffer::LogBuffer(LastLogTimes *times)
: mTimes(*times) {
pthread_mutex_init(&mLogElementsLock, NULL);
init();
}
int LogBuffer::log(log_id_t log_id, log_time realtime,
uid_t uid, pid_t pid, pid_t tid,
const char *msg, unsigned short len) {
if ((log_id >= LOG_ID_MAX) || (log_id < 0)) {
return -EINVAL;
}
LogBufferElement *elem = new LogBufferElement(log_id, realtime,
uid, pid, tid, msg, len);
pthread_mutex_lock(&mLogElementsLock);
// Insert elements in time sorted order if possible
// NB: if end is region locked, place element at end of list
LogBufferElementCollection::iterator it = mLogElements.end();
LogBufferElementCollection::iterator last = it;
while (last != mLogElements.begin()) {
--it;
if ((*it)->getRealTime() <= realtime) {
break;
}
last = it;
}
if (last == mLogElements.end()) {
mLogElements.push_back(elem);
} else {
uint64_t end = 1;
bool end_set = false;
bool end_always = false;
LogTimeEntry::lock();
LastLogTimes::iterator t = mTimes.begin();
while(t != mTimes.end()) {
LogTimeEntry *entry = (*t);
if (entry->owned_Locked()) {
if (!entry->mNonBlock) {
end_always = true;
break;
}
if (!end_set || (end <= entry->mEnd)) {
end = entry->mEnd;
end_set = true;
}
}
t++;
}
if (end_always
|| (end_set && (end >= (*last)->getSequence()))) {
mLogElements.push_back(elem);
} else {
mLogElements.insert(last,elem);
}
LogTimeEntry::unlock();
}
stats.add(elem);
maybePrune(log_id);
pthread_mutex_unlock(&mLogElementsLock);
return len;
}
// If we're using more than 256K of memory for log entries, prune
// at least 10% of the log entries.
//
// mLogElementsLock must be held when this function is called.
void LogBuffer::maybePrune(log_id_t id) {
size_t sizes = stats.sizes(id);
if (sizes > log_buffer_size(id)) {
size_t sizeOver90Percent = sizes - ((log_buffer_size(id) * 9) / 10);
size_t elements = stats.elements(id);
unsigned long pruneRows = elements * sizeOver90Percent / sizes;
elements /= 10;
if (pruneRows <= elements) {
pruneRows = elements;
}
prune(id, pruneRows);
}
}
LogBufferElementCollection::iterator LogBuffer::erase(LogBufferElementCollection::iterator it) {
LogBufferElement *e = *it;
it = mLogElements.erase(it);
stats.subtract(e);
delete e;
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 {
uint16_t uid;
uint16_t pid;
uint16_t tid;
uint16_t padding;
} __packed;
uint64_t value;
} __packed;
public:
LogBufferElementKey(uid_t u, pid_t p, pid_t t):uid(u),pid(p),tid(t),padding(0) { }
LogBufferElementKey(uint64_t k):value(k) { }
uint64_t getKey() { return value; }
};
class LogBufferElementEntry {
const uint64_t key;
LogBufferElement *last;
public:
LogBufferElementEntry(const uint64_t &k, LogBufferElement *e):key(k),last(e) { }
const uint64_t&getKey() const { return key; }
LogBufferElement *getLast() { return last; }
};
class LogBufferElementLast : public android::BasicHashtable<uint64_t, LogBufferElementEntry> {
public:
bool merge(LogBufferElement *e, unsigned short dropped) {
LogBufferElementKey key(e->getUid(), e->getPid(), e->getTid());
android::hash_t hash = android::hash_type(key.getKey());
ssize_t index = find(-1, hash, key.getKey());
if (index != -1) {
LogBufferElementEntry &entry = editEntryAt(index);
LogBufferElement *l = entry.getLast();
unsigned short d = l->getDropped();
if ((dropped + d) > USHRT_MAX) {
removeAt(index);
} else {
l->setDropped(dropped + d);
return true;
}
}
return false;
}
size_t add(LogBufferElement *e) {
LogBufferElementKey key(e->getUid(), e->getPid(), e->getTid());
android::hash_t hash = android::hash_type(key.getKey());
return android::BasicHashtable<uint64_t, LogBufferElementEntry>::
add(hash, LogBufferElementEntry(key.getKey(), e));
}
inline void clear() {
android::BasicHashtable<uint64_t, LogBufferElementEntry>::clear();
}
void clear(LogBufferElement *e) {
uint64_t current = e->getRealTime().nsec() - NS_PER_SEC;
ssize_t index = -1;
while((index = next(index)) >= 0) {
LogBufferElement *l = editEntryAt(index).getLast();
if ((l->getDropped() >= 4) && (current > l->getRealTime().nsec())) {
removeAt(index);
index = -1;
}
}
}
};
// prune "pruneRows" of type "id" from the buffer.
//
// mLogElementsLock must be held when this function is called.
void LogBuffer::prune(log_id_t id, unsigned long pruneRows, uid_t caller_uid) {
LogTimeEntry *oldest = NULL;
LogTimeEntry::lock();
// Region locked?
LastLogTimes::iterator t = mTimes.begin();
while(t != mTimes.end()) {
LogTimeEntry *entry = (*t);
if (entry->owned_Locked() && entry->isWatching(id)
&& (!oldest || (oldest->mStart > entry->mStart))) {
oldest = entry;
}
t++;
}
LogBufferElementCollection::iterator it;
if (caller_uid != AID_ROOT) {
for(it = mLogElements.begin(); it != mLogElements.end();) {
LogBufferElement *e = *it;
if (oldest && (oldest->mStart <= e->getSequence())) {
break;
}
if (e->getLogId() != id) {
++it;
continue;
}
if (e->getUid() == caller_uid) {
it = erase(it);
pruneRows--;
if (pruneRows == 0) {
break;
}
} else {
++it;
}
}
LogTimeEntry::unlock();
return;
}
// prune by worst offender by uid
bool hasBlacklist = mPrune.naughty();
while (pruneRows > 0) {
// recalculate the worst offender on every batched pass
uid_t worst = (uid_t) -1;
size_t worst_sizes = 0;
size_t second_worst_sizes = 0;
if (worstUidEnabledForLogid(id) && mPrune.worstUidEnabled()) {
std::unique_ptr<const UidEntry *[]> sorted = stats.sort(2, id);
if (sorted.get()) {
if (sorted[0] && sorted[1]) {
worst_sizes = sorted[0]->getSizes();
// Calculate threshold as 12.5% of available storage
size_t threshold = log_buffer_size(id) / 8;
if (worst_sizes > threshold) {
worst = sorted[0]->getKey();
second_worst_sizes = sorted[1]->getSizes();
if (second_worst_sizes < threshold) {
second_worst_sizes = threshold;
}
}
}
}
}
// skip if we have neither worst nor naughty filters
if ((worst == (uid_t) -1) && !hasBlacklist) {
break;
}
bool kick = false;
bool leading = true;
LogBufferElementLast last;
for(it = mLogElements.begin(); it != mLogElements.end();) {
LogBufferElement *e = *it;
if (oldest && (oldest->mStart <= e->getSequence())) {
break;
}
if (e->getLogId() != id) {
++it;
continue;
}
unsigned short dropped = e->getDropped();
// remove any leading drops
if (leading && dropped) {
it = erase(it);
continue;
}
// merge any drops
if (dropped && last.merge(e, dropped)) {
it = mLogElements.erase(it);
stats.erase(e);
delete e;
continue;
}
leading = false;
if (hasBlacklist && mPrune.naughty(e)) {
last.clear(e);
it = erase(it);
if (dropped) {
continue;
}
pruneRows--;
if (pruneRows == 0) {
break;
}
if (e->getUid() == worst) {
kick = true;
if (worst_sizes < second_worst_sizes) {
break;
}
worst_sizes -= e->getMsgLen();
}
continue;
}
if (dropped) {
last.add(e);
++it;
continue;
}
if (e->getUid() != worst) {
last.clear(e);
++it;
continue;
}
pruneRows--;
if (pruneRows == 0) {
break;
}
kick = true;
unsigned short len = e->getMsgLen();
stats.drop(e);
e->setDropped(1);
if (last.merge(e, 1)) {
it = mLogElements.erase(it);
stats.erase(e);
delete e;
} else {
last.add(e);
++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 = mPrune.nice();
it = mLogElements.begin();
while((pruneRows > 0) && (it != mLogElements.end())) {
LogBufferElement *e = *it;
if (e->getLogId() != id) {
it++;
continue;
}
if (oldest && (oldest->mStart <= e->getSequence())) {
if (whitelist) {
break;
}
if (stats.sizes(id) > (2 * log_buffer_size(id))) {
// kick a misbehaving log reader client off the island
oldest->release_Locked();
} else {
oldest->triggerSkip_Locked(id, pruneRows);
}
break;
}
if (hasWhitelist && mPrune.nice(e)) { // 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 = mLogElements.begin();
while((it != mLogElements.end()) && (pruneRows > 0)) {
LogBufferElement *e = *it;
if (e->getLogId() != id) {
++it;
continue;
}
if (oldest && (oldest->mStart <= e->getSequence())) {
if (stats.sizes(id) > (2 * log_buffer_size(id))) {
// kick a misbehaving log reader client off the island
oldest->release_Locked();
} else {
oldest->triggerSkip_Locked(id, pruneRows);
}
break;
}
it = erase(it);
pruneRows--;
}
}
LogTimeEntry::unlock();
}
// clear all rows of type "id" from the buffer.
void LogBuffer::clear(log_id_t id, uid_t uid) {
pthread_mutex_lock(&mLogElementsLock);
prune(id, ULONG_MAX, uid);
pthread_mutex_unlock(&mLogElementsLock);
}
// get the used space associated with "id".
unsigned long LogBuffer::getSizeUsed(log_id_t id) {
pthread_mutex_lock(&mLogElementsLock);
size_t retval = stats.sizes(id);
pthread_mutex_unlock(&mLogElementsLock);
return retval;
}
// set the total space allocated to "id"
int LogBuffer::setSize(log_id_t id, unsigned long size) {
// Reasonable limits ...
if (!valid_size(size)) {
return -1;
}
pthread_mutex_lock(&mLogElementsLock);
log_buffer_size(id) = size;
pthread_mutex_unlock(&mLogElementsLock);
return 0;
}
// get the total space allocated to "id"
unsigned long LogBuffer::getSize(log_id_t id) {
pthread_mutex_lock(&mLogElementsLock);
size_t retval = log_buffer_size(id);
pthread_mutex_unlock(&mLogElementsLock);
return retval;
}
uint64_t LogBuffer::flushTo(
SocketClient *reader, const uint64_t start, bool privileged,
int (*filter)(const LogBufferElement *element, void *arg), void *arg) {
LogBufferElementCollection::iterator it;
uint64_t max = start;
uid_t uid = reader->getUid();
pthread_mutex_lock(&mLogElementsLock);
if (start <= 1) {
// client wants to start from the beginning
it = mLogElements.begin();
} else {
// Client wants to start from some specified time. Chances are
// we are better off starting from the end of the time sorted list.
for (it = mLogElements.end(); it != mLogElements.begin(); /* do nothing */) {
--it;
LogBufferElement *element = *it;
if (element->getSequence() <= start) {
it++;
break;
}
}
}
for (; it != mLogElements.end(); ++it) {
LogBufferElement *element = *it;
if (!privileged && (element->getUid() != uid)) {
continue;
}
if (element->getSequence() <= start) {
continue;
}
// NB: calling out to another object with mLogElementsLock held (safe)
if (filter) {
int ret = (*filter)(element, arg);
if (ret == false) {
continue;
}
if (ret != true) {
break;
}
}
pthread_mutex_unlock(&mLogElementsLock);
// range locking in LastLogTimes looks after us
max = element->flushTo(reader, this);
if (max == element->FLUSH_ERROR) {
return max;
}
pthread_mutex_lock(&mLogElementsLock);
}
pthread_mutex_unlock(&mLogElementsLock);
return max;
}
void LogBuffer::formatStatistics(char **strp, uid_t uid, unsigned int logMask) {
pthread_mutex_lock(&mLogElementsLock);
stats.format(strp, uid, logMask);
pthread_mutex_unlock(&mLogElementsLock);
}