platform_system_core/logd/LogStatistics.cpp
Mark Salyzyn 61e9ce6709 logd: add getEventTag command and service
Will register a new event tag by name and format, and return an
event-log-tags format response with the newly allocated tag.
If format is not specified, then nothing will be recorded, but
a pre-existing named entry will be listed. If name and format are
not specified, list all dynamic entries. If name=* list all
event log tag entries.

Stickiness through logd crash will be managed with the tmpfs file
/dev/event-log-tags and through a reboot with add_tag entries in
the pmsg last logcat event log. On debug builds we retain a
/data/misc/logd/event-log-tags file that aids stickiness and that
can be picked up by the bugreport.

If we detect truncation damage to /dev/event-log-tags, or to
/data/misc/logd/event-log-tags, rebuild file with a new first line
signature incorporating the time so mmap'd readers of the file can
detect the possible change in shape and order.

Manual testing:

Make sure nc (netcat) is built for the target platform on the host:
$ m nc

Then the following can be used to issue a request on the platform:
$ echo -n 'getEventTag name=<name> format="<format>"\0EXIT\0' |
> nc -U /dev/socket/logd

Test: gTest logd-unit-test --gtest_filter=getEventTag*
Bug: 31456426
Change-Id: I5dacc5f84a24d52dae09cca5ee1a3a9f9207f06d
2017-02-02 14:24:18 -08:00

643 lines
20 KiB
C++

/*
* Copyright (C) 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 <fcntl.h>
#include <pwd.h>
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <unistd.h>
#include <list>
#include <android/log.h>
#include "LogStatistics.h"
size_t LogStatistics::SizesTotal;
LogStatistics::LogStatistics() : enable(false) {
log_id_for_each(id) {
mSizes[id] = 0;
mElements[id] = 0;
mDroppedElements[id] = 0;
mSizesTotal[id] = 0;
mElementsTotal[id] = 0;
}
}
namespace android {
size_t sizesTotal() { return LogStatistics::sizesTotal(); }
// caller must own and free character string
char *pidToName(pid_t pid) {
char *retval = NULL;
if (pid == 0) { // special case from auditd/klogd for kernel
retval = strdup("logd");
} else {
char buffer[512];
snprintf(buffer, sizeof(buffer), "/proc/%u/cmdline", pid);
int fd = open(buffer, O_RDONLY);
if (fd >= 0) {
ssize_t ret = read(fd, buffer, sizeof(buffer));
if (ret > 0) {
buffer[sizeof(buffer)-1] = '\0';
// frameworks intermediate state
if (fastcmp<strcmp>(buffer, "<pre-initialized>")) {
retval = strdup(buffer);
}
}
close(fd);
}
}
return retval;
}
}
void LogStatistics::add(LogBufferElement *element) {
log_id_t log_id = element->getLogId();
unsigned short size = element->getMsgLen();
mSizes[log_id] += size;
++mElements[log_id];
if (element->getDropped()) {
++mDroppedElements[log_id];
} else {
// When caller adding a chatty entry, they will have already
// called add() and subtract() for each entry as they are
// evaluated and trimmed, thus recording size and number of
// elements, but we must recognize the manufactured dropped
// entry as not contributing to the lifetime totals.
mSizesTotal[log_id] += size;
SizesTotal += size;
++mElementsTotal[log_id];
}
if (log_id == LOG_ID_KERNEL) {
return;
}
uidTable[log_id].add(element->getUid(), element);
if (element->getUid() == AID_SYSTEM) {
pidSystemTable[log_id].add(element->getPid(), element);
}
if (!enable) {
return;
}
pidTable.add(element->getPid(), element);
tidTable.add(element->getTid(), element);
uint32_t tag = element->getTag();
if (tag) {
if (log_id == LOG_ID_SECURITY) {
securityTagTable.add(tag, element);
} else {
tagTable.add(tag, element);
}
}
}
void LogStatistics::subtract(LogBufferElement *element) {
log_id_t log_id = element->getLogId();
unsigned short size = element->getMsgLen();
mSizes[log_id] -= size;
--mElements[log_id];
if (element->getDropped()) {
--mDroppedElements[log_id];
}
if (log_id == LOG_ID_KERNEL) {
return;
}
uidTable[log_id].subtract(element->getUid(), element);
if (element->getUid() == AID_SYSTEM) {
pidSystemTable[log_id].subtract(element->getPid(), element);
}
if (!enable) {
return;
}
pidTable.subtract(element->getPid(), element);
tidTable.subtract(element->getTid(), element);
uint32_t tag = element->getTag();
if (tag) {
if (log_id == LOG_ID_SECURITY) {
securityTagTable.subtract(tag, element);
} else {
tagTable.subtract(tag, element);
}
}
}
// Atomically set an entry to drop
// entry->setDropped(1) must follow this call, caller should do this explicitly.
void LogStatistics::drop(LogBufferElement *element) {
log_id_t log_id = element->getLogId();
unsigned short size = element->getMsgLen();
mSizes[log_id] -= size;
++mDroppedElements[log_id];
uidTable[log_id].drop(element->getUid(), element);
if (element->getUid() == AID_SYSTEM) {
pidSystemTable[log_id].drop(element->getPid(), element);
}
if (!enable) {
return;
}
pidTable.drop(element->getPid(), element);
tidTable.drop(element->getTid(), element);
uint32_t tag = element->getTag();
if (tag) {
if (log_id == LOG_ID_SECURITY) {
securityTagTable.drop(tag, element);
} else {
tagTable.drop(tag, element);
}
}
}
// caller must own and free character string
const char *LogStatistics::uidToName(uid_t uid) const {
// Local hard coded favourites
if (uid == AID_LOGD) {
return strdup("auditd");
}
// Android system
if (uid < AID_APP) {
// in bionic, thread safe as long as we copy the results
struct passwd *pwd = getpwuid(uid);
if (pwd) {
return strdup(pwd->pw_name);
}
}
// Parse /data/system/packages.list
uid_t userId = uid % AID_USER_OFFSET;
const char *name = android::uidToName(userId);
if (!name && (userId > (AID_SHARED_GID_START - AID_APP))) {
name = android::uidToName(userId - (AID_SHARED_GID_START - AID_APP));
}
if (name) {
return name;
}
// Android application
if (uid >= AID_APP) {
struct passwd *pwd = getpwuid(uid);
if (pwd) {
return strdup(pwd->pw_name);
}
}
// report uid -> pid(s) -> pidToName if unique
for(pidTable_t::const_iterator it = pidTable.begin(); it != pidTable.end(); ++it) {
const PidEntry &entry = it->second;
if (entry.getUid() == uid) {
const char *nameTmp = entry.getName();
if (nameTmp) {
if (!name) {
name = strdup(nameTmp);
} else if (fastcmp<strcmp>(name, nameTmp)) {
free(const_cast<char *>(name));
name = NULL;
break;
}
}
}
}
// No one
return name;
}
std::string UidEntry::formatHeader(const std::string &name, log_id_t id) const {
bool isprune = worstUidEnabledForLogid(id);
return formatLine(android::base::StringPrintf(
name.c_str(), android_log_id_to_name(id)),
std::string("Size"),
std::string(isprune ? "+/- Pruned" : ""))
+ formatLine(std::string("UID PACKAGE"),
std::string("BYTES"),
std::string(isprune ? "NUM" : ""));
}
std::string UidEntry::format(const LogStatistics &stat, log_id_t id) const {
uid_t uid = getUid();
std::string name = android::base::StringPrintf("%u", uid);
const char *nameTmp = stat.uidToName(uid);
if (nameTmp) {
name += android::base::StringPrintf(
"%*s%s", (int)std::max(6 - name.length(), (size_t)1),
"", nameTmp);
free(const_cast<char *>(nameTmp));
}
std::string size = android::base::StringPrintf("%zu", getSizes());
std::string pruned = "";
if (worstUidEnabledForLogid(id)) {
size_t totalDropped = 0;
for (LogStatistics::uidTable_t::const_iterator it = stat.uidTable[id].begin();
it != stat.uidTable[id].end(); ++it) {
totalDropped += it->second.getDropped();
}
size_t sizes = stat.sizes(id);
size_t totalSize = stat.sizesTotal(id);
size_t totalElements = stat.elementsTotal(id);
float totalVirtualSize = (float)sizes + (float)totalDropped * totalSize
/ totalElements;
size_t entrySize = getSizes();
float virtualEntrySize = entrySize;
int realPermille = virtualEntrySize * 1000.0 / sizes;
size_t dropped = getDropped();
if (dropped) {
pruned = android::base::StringPrintf("%zu", dropped);
virtualEntrySize += (float)dropped * totalSize / totalElements;
}
int virtualPermille = virtualEntrySize * 1000.0 / totalVirtualSize;
int permille = (realPermille - virtualPermille) * 1000L
/ (virtualPermille ?: 1);
if ((permille < -1) || (1 < permille)) {
std::string change;
const char *units = "%";
const char *prefix = (permille > 0) ? "+" : "";
if (permille > 999) {
permille = (permille + 1000) / 100; // Now tenths fold
units = "X";
prefix = "";
}
if ((-99 < permille) && (permille < 99)) {
change = android::base::StringPrintf("%s%d.%u%s",
prefix,
permille / 10,
((permille < 0) ? (-permille % 10) : (permille % 10)),
units);
} else {
change = android::base::StringPrintf("%s%d%s",
prefix,
(permille + 5) / 10, units);
}
ssize_t spaces = EntryBaseConstants::pruned_len
- 2 - pruned.length() - change.length();
if ((spaces <= 0) && pruned.length()) {
spaces = 1;
}
if (spaces > 0) {
change += android::base::StringPrintf("%*s", (int)spaces, "");
}
pruned = change + pruned;
}
}
std::string output = formatLine(name, size, pruned);
if (uid != AID_SYSTEM) {
return output;
}
static const size_t maximum_sorted_entries = 32;
std::unique_ptr<const PidEntry *[]> sorted
= stat.pidSystemTable[id].sort(uid, (pid_t)0, maximum_sorted_entries);
if (!sorted.get()) {
return output;
}
std::string byPid;
size_t index;
bool hasDropped = false;
for (index = 0; index < maximum_sorted_entries; ++index) {
const PidEntry *entry = sorted[index];
if (!entry) {
break;
}
if (entry->getSizes() <= (getSizes() / 100)) {
break;
}
if (entry->getDropped()) {
hasDropped = true;
}
byPid += entry->format(stat, id);
}
if (index > 1) { // print this only if interesting
std::string ditto("\" ");
output += formatLine(std::string(" PID/UID COMMAND LINE"),
ditto, hasDropped ? ditto : std::string(""));
output += byPid;
}
return output;
}
std::string PidEntry::formatHeader(const std::string &name, log_id_t /* id */) const {
return formatLine(name,
std::string("Size"),
std::string("Pruned"))
+ formatLine(std::string(" PID/UID COMMAND LINE"),
std::string("BYTES"),
std::string("NUM"));
}
std::string PidEntry::format(const LogStatistics &stat, log_id_t /* id */) const {
uid_t uid = getUid();
pid_t pid = getPid();
std::string name = android::base::StringPrintf("%5u/%u", pid, uid);
const char *nameTmp = getName();
if (nameTmp) {
name += android::base::StringPrintf(
"%*s%s", (int)std::max(12 - name.length(), (size_t)1),
"", nameTmp);
} else if ((nameTmp = stat.uidToName(uid))) {
name += android::base::StringPrintf(
"%*s%s", (int)std::max(12 - name.length(), (size_t)1),
"", nameTmp);
free(const_cast<char *>(nameTmp));
}
std::string size = android::base::StringPrintf("%zu",
getSizes());
std::string pruned = "";
size_t dropped = getDropped();
if (dropped) {
pruned = android::base::StringPrintf("%zu", dropped);
}
return formatLine(name, size, pruned);
}
std::string TidEntry::formatHeader(const std::string &name, log_id_t /* id */) const {
return formatLine(name,
std::string("Size"),
std::string("Pruned"))
+ formatLine(std::string(" TID/UID COMM"),
std::string("BYTES"),
std::string("NUM"));
}
std::string TidEntry::format(const LogStatistics &stat, log_id_t /* id */) const {
uid_t uid = getUid();
std::string name = android::base::StringPrintf("%5u/%u",
getTid(), uid);
const char *nameTmp = getName();
if (nameTmp) {
name += android::base::StringPrintf(
"%*s%s", (int)std::max(12 - name.length(), (size_t)1),
"", nameTmp);
} else if ((nameTmp = stat.uidToName(uid))) {
// if we do not have a PID name, lets punt to try UID name?
name += android::base::StringPrintf(
"%*s%s", (int)std::max(12 - name.length(), (size_t)1),
"", nameTmp);
free(const_cast<char *>(nameTmp));
// We tried, better to not have a name at all, we still
// have TID/UID by number to report in any case.
}
std::string size = android::base::StringPrintf("%zu",
getSizes());
std::string pruned = "";
size_t dropped = getDropped();
if (dropped) {
pruned = android::base::StringPrintf("%zu", dropped);
}
return formatLine(name, size, pruned);
}
std::string TagEntry::formatHeader(const std::string &name, log_id_t id) const {
bool isprune = worstUidEnabledForLogid(id);
return formatLine(name,
std::string("Size"),
std::string(isprune ? "Prune" : ""))
+ formatLine(std::string(" TAG/UID TAGNAME"),
std::string("BYTES"),
std::string(isprune ? "NUM" : ""));
}
std::string TagEntry::format(const LogStatistics & /* stat */, log_id_t /* id */) const {
std::string name;
uid_t uid = getUid();
if (uid == (uid_t)-1) {
name = android::base::StringPrintf("%7u",
getKey());
} else {
name = android::base::StringPrintf("%7u/%u",
getKey(), uid);
}
const char *nameTmp = getName();
if (nameTmp) {
name += android::base::StringPrintf(
"%*s%s", (int)std::max(14 - name.length(), (size_t)1),
"", nameTmp);
}
std::string size = android::base::StringPrintf("%zu",
getSizes());
std::string pruned = "";
size_t dropped = getDropped();
if (dropped) {
pruned = android::base::StringPrintf("%zu", dropped);
}
return formatLine(name, size, pruned);
}
std::string LogStatistics::format(uid_t uid, pid_t pid,
unsigned int logMask) const {
static const unsigned short spaces_total = 19;
// Report on total logging, current and for all time
std::string output = "size/num";
size_t oldLength;
short spaces = 1;
log_id_for_each(id) {
if (!(logMask & (1 << id))) continue;
oldLength = output.length();
if (spaces < 0) spaces = 0;
output += android::base::StringPrintf("%*s%s", spaces, "",
android_log_id_to_name(id));
spaces += spaces_total + oldLength - output.length();
}
if (spaces < 0) spaces = 0;
output += android::base::StringPrintf("%*sTotal", spaces, "");
static const char TotalStr[] = "\nTotal";
spaces = 10 - strlen(TotalStr);
output += TotalStr;
size_t totalSize = 0;
size_t totalEls = 0;
log_id_for_each(id) {
if (!(logMask & (1 << id))) continue;
oldLength = output.length();
if (spaces < 0) spaces = 0;
size_t szs = sizesTotal(id);
totalSize += szs;
size_t els = elementsTotal(id);
totalEls += els;
output += android::base::StringPrintf("%*s%zu/%zu", spaces, "", szs, els);
spaces += spaces_total + oldLength - output.length();
}
if (spaces < 0) spaces = 0;
output += android::base::StringPrintf("%*s%zu/%zu", spaces, "", totalSize, totalEls);
static const char NowStr[] = "\nNow";
spaces = 10 - strlen(NowStr);
output += NowStr;
totalSize = 0;
totalEls = 0;
log_id_for_each(id) {
if (!(logMask & (1 << id))) continue;
size_t els = elements(id);
if (els) {
oldLength = output.length();
if (spaces < 0) spaces = 0;
size_t szs = sizes(id);
totalSize += szs;
totalEls += els;
output += android::base::StringPrintf("%*s%zu/%zu", spaces, "", szs, els);
spaces -= output.length() - oldLength;
}
spaces += spaces_total;
}
if (spaces < 0) spaces = 0;
output += android::base::StringPrintf("%*s%zu/%zu", spaces, "", totalSize, totalEls);
static const char OverheadStr[] = "\nOverhead";
spaces = 10 - strlen(OverheadStr);
output += OverheadStr;
totalSize = 0;
log_id_for_each(id) {
if (!(logMask & (1 << id))) continue;
size_t els = elements(id);
if (els) {
oldLength = output.length();
if (spaces < 0) spaces = 0;
// estimate the std::list overhead.
static const size_t overhead =
((sizeof(LogBufferElement) + sizeof(uint64_t) - 1) &
-sizeof(uint64_t)) +
sizeof(std::list<LogBufferElement*>);
size_t szs = sizes(id) + els * overhead;
totalSize += szs;
output += android::base::StringPrintf("%*s%zu", spaces, "", szs);
spaces -= output.length() - oldLength;
}
spaces += spaces_total;
}
totalSize += sizeOf();
if (spaces < 0) spaces = 0;
output += android::base::StringPrintf("%*s%zu", spaces, "", totalSize);
// Report on Chattiest
std::string name;
// Chattiest by application (UID)
log_id_for_each(id) {
if (!(logMask & (1 << id))) continue;
name = (uid == AID_ROOT)
? "Chattiest UIDs in %s log buffer:"
: "Logging for your UID in %s log buffer:";
output += uidTable[id].format(*this, uid, pid, name, id);
}
if (enable) {
name = ((uid == AID_ROOT) && !pid)
? "Chattiest PIDs:"
: "Logging for this PID:";
output += pidTable.format(*this, uid, pid, name);
name = "Chattiest TIDs";
if (pid) name += android::base::StringPrintf(" for PID %d", pid);
name += ":";
output += tidTable.format(*this, uid, pid, name);
}
if (enable && (logMask & (1 << LOG_ID_EVENTS))) {
name = "Chattiest events log buffer TAGs";
if (pid) name += android::base::StringPrintf(" for PID %d", pid);
name += ":";
output += tagTable.format(*this, uid, pid, name, LOG_ID_EVENTS);
}
if (enable && (logMask & (1 << LOG_ID_SECURITY))) {
name = "Chattiest security log buffer TAGs";
if (pid) name += android::base::StringPrintf(" for PID %d", pid);
name += ":";
output += securityTagTable.format(*this, uid, pid, name, LOG_ID_SECURITY);
}
return output;
}
namespace android {
uid_t pidToUid(pid_t pid) {
char buffer[512];
snprintf(buffer, sizeof(buffer), "/proc/%u/status", pid);
FILE *fp = fopen(buffer, "r");
if (fp) {
while (fgets(buffer, sizeof(buffer), fp)) {
int uid;
if (sscanf(buffer, "Uid: %d", &uid) == 1) {
fclose(fp);
return uid;
}
}
fclose(fp);
}
return AID_LOGD; // associate this with the logger
}
}
uid_t LogStatistics::pidToUid(pid_t pid) {
return pidTable.add(pid)->second.getUid();
}
// caller must free character string
const char *LogStatistics::pidToName(pid_t pid) const {
// An inconvenient truth ... getName() can alter the object
pidTable_t &writablePidTable = const_cast<pidTable_t &>(pidTable);
const char *name = writablePidTable.add(pid)->second.getName();
if (!name) {
return NULL;
}
return strdup(name);
}