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Commit ab0dcf68 authored by Mark Salyzyn's avatar Mark Salyzyn
Browse files

logd: annotate worst-UID pruned entries 

- internal dropped entries are associated by prune by worst UID
  and are applied by UID and by PID
- track dropped entries by rewriting them in place
- merge similar dropped entries together for same UID(implied),
  PID and TID so that blame can more clearly be placed
- allow aging of dropped entries by the general backgound pruning
- report individual dropped entries formatted to reader
- add statistics to track dropped entries by UID, the combination
  of statistics and dropped logging can track over-the-top Chattiest
  clients.

Bug: 19608965
Change-Id: Ibc68480df0c69c55703270cd70c6b26aea165853
parent 65937e9b

logd/Android.mk

+2 −1
Original line number Diff line number Diff line
@@ -32,8 +32,9 @@ LOCAL_SHARED_LIBRARIES := \ 
#        "s/^\([0-9]*\)[ \t]*$1[ \t].*/-D`echo $1 | tr a-z A-Z`_LOG_TAG=\1/p" \

#        $(LOCAL_PATH)/$2/event.logtags)

#  event_flag := $(call event_logtags,auditd)

#  event_flag += $(call event_logtags,logd)

# so make sure we do not regret hard-coding it as follows:

event_flag := -DAUDITD_LOG_TAG=1003

event_flag := -DAUDITD_LOG_TAG=1003 -DLOGD_LOG_TAG=1004



LOCAL_CFLAGS := -Werror $(event_flag)

logd/LogBuffer.cpp

+72 −9
Original line number Diff line number Diff line
@@ -297,6 +297,8 @@ void LogBuffer::prune(log_id_t id, unsigned long pruneRows, uid_t caller_uid) { 
        }



        bool kick = false;

        bool leading = true;

        LogBufferElement *last = NULL;

        for(it = mLogElements.begin(); it != mLogElements.end();) {

            LogBufferElement *e = *it;
@@ -309,26 +311,87 @@ void LogBuffer::prune(log_id_t id, unsigned long pruneRows, uid_t caller_uid) { 
                continue;

            }



            uid_t uid = e->getUid();

            unsigned short dropped = e->getDropped();



            // !Worst and !BlackListed?

            if ((uid != worst) && (!hasBlacklist || !mPrune.naughty(e))) {

                ++it;

            // remove any leading drops

            if (leading && dropped) {

                it = erase(it);

                continue;

            }



            unsigned short len = e->getMsgLen();

            pid_t pid = e->getPid();



            // merge any drops

            if (last && dropped

             && ((dropped + last->getDropped()) < USHRT_MAX)

             && (last->getPid() == pid)

             && (last->getTid() == e->getTid())) {

                it = mLogElements.erase(it);

                stats.erase(e);

                delete e;

                last->setDropped(dropped + last->getDropped());

                continue;

            }



            leading = false;



            if (hasBlacklist && mPrune.naughty(e)) {

                last = NULL;

                it = erase(it);

                if (dropped) {

                    continue;

                }



                pruneRows--;

                if (pruneRows == 0) {

                    break;

                }



            if (uid != worst) {

                if (e->getUid() == worst) {

                    kick = true;

                    if (worst_sizes < second_worst_sizes) {

                        break;

                    }

                    worst_sizes -= e->getMsgLen();

                }

                continue;

            }



            if (dropped) {

                last = e;

                ++it;

                continue;

            }



            if (e->getUid() != worst) {

                last = NULL;

                ++it;

                continue;

            }



            pruneRows--;

            if (pruneRows == 0) {

                break;

            }



            kick = true;



            unsigned short len = e->getMsgLen();

            stats.drop(e);

            e->setDropped(1);

            // merge any drops

            if (last

             && (last->getDropped() < (USHRT_MAX - 1))

             && (last->getPid() == pid)

             && (last->getTid() == e->getTid())) {

                it = mLogElements.erase(it);

                stats.erase(e);

                delete e;

                last->setDropped(last->getDropped() + 1);

            } else {

                last = e;

                ++it;

            }

            if (worst_sizes < second_worst_sizes) {

                break;

            }

logd/LogBufferElement.cpp

+72 −6
Original line number Diff line number Diff line
@@ -14,14 +14,17 @@ 
 * limitations under the License.

 */



#include <endian.h>

#include <stdio.h>

#include <string.h>

#include <time.h>

#include <unistd.h>



#include <log/logger.h>

#include <private/android_logger.h>



#include "LogBufferElement.h"

#include "LogCommand.h"

#include "LogReader.h"



const uint64_t LogBufferElement::FLUSH_ERROR(0);
@@ -45,11 +48,59 @@ LogBufferElement::~LogBufferElement() { 
    delete [] mMsg;

}



// assumption: mMsg == NULL

size_t LogBufferElement::populateDroppedMessage(char *&buffer, bool privileged) {

    static const char format_uid[] = "uid=%u dropped=%u";

    static const size_t unprivileged_offset = 7;

    static const char tag[] = "logd";



    size_t len;

    if (privileged) {

        len = snprintf(NULL, 0, format_uid, mUid, mDropped);

    } else {

        len = snprintf(NULL, 0, format_uid + unprivileged_offset, mDropped);

    }



    size_t hdrLen;

    if (mLogId == LOG_ID_EVENTS) {

        hdrLen = sizeof(android_log_event_string_t);

    } else {

        hdrLen = 1 + sizeof(tag);

    }



    buffer = static_cast<char *>(calloc(1, hdrLen + len + 1));

    if (!buffer) {

        return 0;

    }



    size_t retval = hdrLen + len;

    if (mLogId == LOG_ID_EVENTS) {

        android_log_event_string_t *e = reinterpret_cast<android_log_event_string_t *>(buffer);



        e->header.tag = htole32(LOGD_LOG_TAG);

        e->type = EVENT_TYPE_STRING;

        e->length = htole32(len);

    } else {

        ++retval;

        buffer[0] = ANDROID_LOG_INFO;

        strcpy(buffer + 1, tag);

    }



    if (privileged) {

        snprintf(buffer + hdrLen, len + 1, format_uid, mUid, mDropped);

    } else {

        snprintf(buffer + hdrLen, len + 1, format_uid + unprivileged_offset, mDropped);

    }



    return retval;

}



uint64_t LogBufferElement::flushTo(SocketClient *reader) {

    struct logger_entry_v3 entry;



    memset(&entry, 0, sizeof(struct logger_entry_v3));



    entry.hdr_size = sizeof(struct logger_entry_v3);

    entry.len = mMsgLen;

    entry.lid = mLogId;

    entry.pid = mPid;

    entry.tid = mTid;
@@ -59,11 +110,26 @@ uint64_t LogBufferElement::flushTo(SocketClient *reader) { 
    struct iovec iovec[2];

    iovec[0].iov_base = &entry;

    iovec[0].iov_len = sizeof(struct logger_entry_v3);



    char *buffer = NULL;



    if (!mMsg) {

        entry.len = populateDroppedMessage(buffer, clientHasLogCredentials(reader));

        if (!entry.len) {

            return mSequence;

        }

        iovec[1].iov_base = buffer;

    } else {

        entry.len = mMsgLen;

        iovec[1].iov_base = mMsg;

    iovec[1].iov_len = mMsgLen;

    if (reader->sendDatav(iovec, 2)) {

        return FLUSH_ERROR;

    }

    iovec[1].iov_len = entry.len;



    return mSequence;

    uint64_t retval = reader->sendDatav(iovec, 2) ? FLUSH_ERROR : mSequence;



    if (buffer) {

        free(buffer);

    }



    return retval;

}

logd/LogBufferElement.h

+17 −2
Original line number Diff line number Diff line
@@ -18,6 +18,7 @@ 
#define _LOGD_LOG_BUFFER_ELEMENT_H__



#include <stdatomic.h>

#include <stdlib.h>

#include <sys/types.h>



#include <sysutils/SocketClient.h>
@@ -38,11 +39,17 @@ class LogBufferElement { 
    const pid_t mPid;

    const pid_t mTid;

    char *mMsg;

    const unsigned short mMsgLen;

    union {

        const unsigned short mMsgLen; // mMSg != NULL

        unsigned short mDropped;      // mMsg == NULL

    };

    const uint64_t mSequence;

    const log_time mRealTime;

    static atomic_int_fast64_t sequence;



    // assumption: mMsg == NULL

    size_t populateDroppedMessage(char *&buffer, bool privileged);



public:

    LogBufferElement(log_id_t log_id, log_time realtime,

                     uid_t uid, pid_t pid, pid_t tid,
@@ -53,7 +60,15 @@ public: 
    uid_t getUid(void) const { return mUid; }

    pid_t getPid(void) const { return mPid; }

    pid_t getTid(void) const { return mTid; }

    unsigned short getMsgLen() const { return mMsgLen; }

    unsigned short getDropped(void) const { return mMsg ? 0 : mDropped; }

    unsigned short setDropped(unsigned short value) {

        if (mMsg) {

            free(mMsg);

            mMsg = NULL;

        }

        return mDropped = value;

    }

    unsigned short getMsgLen() const { return mMsg ? mMsgLen : 0; }

    uint64_t getSequence(void) const { return mSequence; }

    static uint64_t getCurrentSequence(void) { return sequence.load(memory_order_relaxed); }

    log_time getRealTime(void) const { return mRealTime; }

logd/LogStatistics.cpp

+78 −14
Original line number Diff line number Diff line
@@ -71,16 +71,19 @@ void LogStatistics::add(LogBufferElement *e) { 
    ++mElements[log_id];



    uid_t uid = e->getUid();

    unsigned short dropped = e->getDropped();

    android::hash_t hash = android::hash_type(uid);

    uidTable_t &table = uidTable[log_id];

    ssize_t index = table.find(-1, hash, uid);

    if (index == -1) {

        UidEntry initEntry(uid);

        initEntry.add(size);

        initEntry.add_dropped(dropped);

        table.add(hash, initEntry);

    } else {

        UidEntry &entry = table.editEntryAt(index);

        entry.add(size);

        entry.add_dropped(dropped);

    }



    mSizesTotal[log_id] += size;
@@ -96,6 +99,7 @@ void LogStatistics::add(LogBufferElement *e) { 
    if (index == -1) {

        PidEntry initEntry(pid, uid, android::pidToName(pid));

        initEntry.add(size);

        initEntry.add_dropped(dropped);

        pidTable.add(hash, initEntry);

    } else {

        PidEntry &entry = pidTable.editEntryAt(index);
@@ -109,6 +113,7 @@ void LogStatistics::add(LogBufferElement *e) { 
            }

        }

        entry.add(size);

        entry.add_dropped(dropped);

    }

}
@@ -119,12 +124,13 @@ void LogStatistics::subtract(LogBufferElement *e) { 
    --mElements[log_id];



    uid_t uid = e->getUid();

    unsigned short dropped = e->getDropped();

    android::hash_t hash = android::hash_type(uid);

    uidTable_t &table = uidTable[log_id];

    ssize_t index = table.find(-1, hash, uid);

    if (index != -1) {

        UidEntry &entry = table.editEntryAt(index);

        if (entry.subtract(size)) {

        if (entry.subtract(size) || entry.subtract_dropped(dropped)) {

            table.removeAt(index);

        }

    }
@@ -138,12 +144,43 @@ void LogStatistics::subtract(LogBufferElement *e) { 
    index = pidTable.find(-1, hash, pid);

    if (index != -1) {

        PidEntry &entry = pidTable.editEntryAt(index);

        if (entry.subtract(size)) {

        if (entry.subtract(size) || entry.subtract_dropped(dropped)) {

            pidTable.removeAt(index);

        }

    }

}



// Atomically set an entry to drop

// entry->setDropped(1) must follow this call, caller should do this explicitly.

void LogStatistics::drop(LogBufferElement *e) {

    log_id_t log_id = e->getLogId();

    unsigned short size = e->getMsgLen();

    mSizes[log_id] -= size;



    uid_t uid = e->getUid();

    android::hash_t hash = android::hash_type(uid);

    typeof uidTable[0] &table = uidTable[log_id];

    ssize_t index = table.find(-1, hash, uid);

    if (index != -1) {

        UidEntry &entry = table.editEntryAt(index);

        entry.subtract(size);

        entry.add_dropped(1);

    }



    if (!enable) {

        return;

    }



    pid_t pid = e->getPid();

    hash = android::hash_type(pid);

    index = pidTable.find(-1, hash, pid);

    if (index != -1) {

        PidEntry &entry = pidTable.editEntryAt(index);

        entry.subtract(size);

        entry.add_dropped(1);

    }

}



// caller must own and free character string

char *LogStatistics::uidToName(uid_t uid) {

    // Local hard coded favourites
@@ -191,12 +228,22 @@ char *LogStatistics::uidToName(uid_t uid) { 
}



static void format_line(android::String8 &output,

        android::String8 &name, android::String8 &size) {

    static const size_t total_len = 70;



        android::String8 &name, android::String8 &size, android::String8 &pruned) {

    static const size_t pruned_len = 6;

    static const size_t total_len = 70 + pruned_len;



    ssize_t drop_len = std::max(pruned.length() + 1, pruned_len);

    ssize_t size_len = std::max(size.length() + 1,

                                total_len - name.length() - drop_len - 1);



    if (pruned.length()) {

        output.appendFormat("%s%*s%*s\n", name.string(),

                                          (int)size_len, size.string(),

                                          (int)drop_len, pruned.string());

    } else {

        output.appendFormat("%s%*s\n", name.string(),

        (int)std::max(total_len - name.length() - 1, size.length() + 1),

        size.string());

                                       (int)size_len, size.string());

    }

}



void LogStatistics::format(char **buf, uid_t uid, unsigned int logMask) {
@@ -285,14 +332,18 @@ void LogStatistics::format(char **buf, uid_t uid, unsigned int logMask) { 
                    output.appendFormat(

                        "\n\nChattiest UIDs in %s:\n",

                        android_log_id_to_name(id));

                    android::String8 name("UID");

                    android::String8 size("Size");

                    format_line(output, name, size);

                } else {

                    output.appendFormat(

                        "\n\nLogging for your UID in %s:\n",

                        android_log_id_to_name(id));

                }

                android::String8 name("UID");

                android::String8 size("Size");

                android::String8 pruned("Pruned");

                if (id == LOG_ID_CRASH) {

                    pruned.setTo("");

                }

                format_line(output, name, size, pruned);

                headerPrinted = true;

            }
@@ -307,7 +358,13 @@ void LogStatistics::format(char **buf, uid_t uid, unsigned int logMask) { 
            android::String8 size("");

            size.appendFormat("%zu", entry->getSizes());



            format_line(output, name, size);

            android::String8 pruned("");

            size_t dropped = entry->getDropped();

            if (dropped) {

                pruned.appendFormat("%zu", dropped);

            }



            format_line(output, name, size, pruned);

        }

    }
@@ -330,7 +387,8 @@ void LogStatistics::format(char **buf, uid_t uid, unsigned int logMask) { 
                }

                android::String8 name("  PID/UID");

                android::String8 size("Size");

                format_line(output, name, size);

                android::String8 pruned("Pruned");

                format_line(output, name, size, pruned);

                headerPrinted = true;

            }
@@ -350,7 +408,13 @@ void LogStatistics::format(char **buf, uid_t uid, unsigned int logMask) { 
            android::String8 size("");

            size.appendFormat("%zu", entry->getSizes());



            format_line(output, name, size);

            android::String8 pruned("");

            size_t dropped = entry->getDropped();

            if (dropped) {

                pruned.appendFormat("%zu", dropped);

            }



            format_line(output, name, size, pruned);

        }

    }