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Commit 81211143 authored by Glenn Kasten's avatar Glenn Kasten
Browse files

Factor out and speed up permission-checking code 

Use the caching permission check for dump to save IPC.

Cache getpid() to save kernel call for other permission checks.

The C runtime library getpid() can't cache due to a fork
race condition, but we know that mediaserver doesn't fork.

Don't construct String16 on the stack.

Change-Id: I6be6161dae5155d39ba6ed6228e7683e67be34ed
parent f96901f8

services/audioflinger/Android.mk

+2 −1
Original line number Diff line number Diff line
@@ -6,7 +6,8 @@ LOCAL_SRC_FILES:= \ 
    AudioFlinger.cpp            \

    AudioMixer.cpp.arm          \

    AudioResampler.cpp.arm      \

    AudioPolicyService.cpp

    AudioPolicyService.cpp      \

    ServiceUtilities.cpp

#   AudioResamplerSinc.cpp.arm

#   AudioResamplerCubic.cpp.arm

services/audioflinger/AudioFlinger.cpp

+6 −19
Original line number Diff line number Diff line
@@ -48,6 +48,7 @@ 


#include "AudioMixer.h"

#include "AudioFlinger.h"

#include "ServiceUtilities.h"



#include <media/EffectsFactoryApi.h>

#include <audio_effects/effect_visualizer.h>
@@ -101,20 +102,6 @@ static const uint32_t kMaxThreadSleepTimeShift = 2; 


// ----------------------------------------------------------------------------



static bool recordingAllowed() {

    if (getpid() == IPCThreadState::self()->getCallingPid()) return true;

    bool ok = checkCallingPermission(String16("android.permission.RECORD_AUDIO"));

    if (!ok) ALOGE("Request requires android.permission.RECORD_AUDIO");

    return ok;

}



static bool settingsAllowed() {

    if (getpid() == IPCThreadState::self()->getCallingPid()) return true;

    bool ok = checkCallingPermission(String16("android.permission.MODIFY_AUDIO_SETTINGS"));

    if (!ok) ALOGE("Request requires android.permission.MODIFY_AUDIO_SETTINGS");

    return ok;

}



// To collect the amplifier usage

static void addBatteryData(uint32_t params) {

    sp<IMediaPlayerService> service = IMediaDeathNotifier::getMediaPlayerService();
@@ -321,7 +308,7 @@ static bool tryLock(Mutex& mutex) 


status_t AudioFlinger::dump(int fd, const Vector<String16>& args)

{

    if (!checkCallingPermission(String16("android.permission.DUMP"))) {

    if (!dumpAllowed()) {

        dumpPermissionDenial(fd, args);

    } else {

        // get state of hardware lock
@@ -3436,7 +3423,7 @@ void AudioFlinger::PlaybackThread::Track::dump(char* buffer, size_t size) 
    uint32_t vlr = mCblk->getVolumeLR();

    snprintf(buffer, size, "   %05d %05d %03u %03u 0x%08x %05u   %04u %1d %1d %1d %05u %05u %05u  0x%08x 0x%08x 0x%08x 0x%08x\n",

            mName - AudioMixer::TRACK0,

            (mClient == 0) ? getpid() : mClient->pid(),

            (mClient == 0) ? getpid_cached : mClient->pid(),

            mStreamType,

            mFormat,

            mChannelMask,
@@ -3757,7 +3744,7 @@ void AudioFlinger::RecordThread::RecordTrack::stop() 
void AudioFlinger::RecordThread::RecordTrack::dump(char* buffer, size_t size)

{

    snprintf(buffer, size, "   %05d %03u 0x%08x %05d   %04u %01d %05u  %08x %08x\n",

            (mClient == 0) ? getpid() : mClient->pid(),

            (mClient == 0) ? getpid_cached : mClient->pid(),

            mFormat,

            mChannelMask,

            mSessionId,
@@ -5404,7 +5391,7 @@ sp<IEffect> AudioFlinger::createEffect(pid_t pid, 


    // Session AUDIO_SESSION_OUTPUT_STAGE is reserved for output stage effects

    // that can only be created by audio policy manager (running in same process)

    if (sessionId == AUDIO_SESSION_OUTPUT_STAGE && getpid() != pid) {

    if (sessionId == AUDIO_SESSION_OUTPUT_STAGE && getpid_cached != pid) {

        lStatus = PERMISSION_DENIED;

        goto Exit;

    }
@@ -7022,7 +7009,7 @@ void AudioFlinger::EffectHandle::dump(char* buffer, size_t size) 
    bool locked = mCblk != NULL && tryLock(mCblk->lock);



    snprintf(buffer, size, "\t\t\t%05d %05d    %01u    %01u      %05u  %05u\n",

            (mClient == 0) ? getpid() : mClient->pid(),

            (mClient == 0) ? getpid_cached : mClient->pid(),

            mPriority,

            mHasControl,

            !locked,

services/audioflinger/AudioPolicyService.cpp

+7 −13
Original line number Diff line number Diff line
@@ -30,6 +30,7 @@ 
#include <utils/String16.h>

#include <utils/threads.h>

#include "AudioPolicyService.h"

#include "ServiceUtilities.h"

#include <cutils/properties.h>

#include <hardware_legacy/power.h>

#include <media/AudioEffect.h>
@@ -49,13 +50,6 @@ static const char kCmdDeadlockedString[] = "AudioPolicyService command thread ma 
static const int kDumpLockRetries = 50;

static const int kDumpLockSleepUs = 20000;



static bool checkPermission() {

    if (getpid() == IPCThreadState::self()->getCallingPid()) return true;

    bool ok = checkCallingPermission(String16("android.permission.MODIFY_AUDIO_SETTINGS"));

    if (!ok) ALOGE("Request requires android.permission.MODIFY_AUDIO_SETTINGS");

    return ok;

}



namespace {

    extern struct audio_policy_service_ops aps_ops;

};
@@ -157,7 +151,7 @@ status_t AudioPolicyService::setDeviceConnectionState(audio_devices_t device, 
    if (mpAudioPolicy == NULL) {

        return NO_INIT;

    }

    if (!checkPermission()) {

    if (!settingsAllowed()) {

        return PERMISSION_DENIED;

    }

    if (!audio_is_output_device(device) && !audio_is_input_device(device)) {
@@ -190,7 +184,7 @@ status_t AudioPolicyService::setPhoneState(audio_mode_t state) 
    if (mpAudioPolicy == NULL) {

        return NO_INIT;

    }

    if (!checkPermission()) {

    if (!settingsAllowed()) {

        return PERMISSION_DENIED;

    }

    if (uint32_t(state) >= AUDIO_MODE_CNT) {
@@ -213,7 +207,7 @@ status_t AudioPolicyService::setForceUse(audio_policy_force_use_t usage, 
    if (mpAudioPolicy == NULL) {

        return NO_INIT;

    }

    if (!checkPermission()) {

    if (!settingsAllowed()) {

        return PERMISSION_DENIED;

    }

    if (usage < 0 || usage >= AUDIO_POLICY_FORCE_USE_CNT) {
@@ -388,7 +382,7 @@ status_t AudioPolicyService::initStreamVolume(audio_stream_type_t stream, 
    if (mpAudioPolicy == NULL) {

        return NO_INIT;

    }

    if (!checkPermission()) {

    if (!settingsAllowed()) {

        return PERMISSION_DENIED;

    }

    if (uint32_t(stream) >= AUDIO_STREAM_CNT) {
@@ -405,7 +399,7 @@ status_t AudioPolicyService::setStreamVolumeIndex(audio_stream_type_t stream, 
    if (mpAudioPolicy == NULL) {

        return NO_INIT;

    }

    if (!checkPermission()) {

    if (!settingsAllowed()) {

        return PERMISSION_DENIED;

    }

    if (uint32_t(stream) >= AUDIO_STREAM_CNT) {
@@ -578,7 +572,7 @@ status_t AudioPolicyService::dumpInternals(int fd) 


status_t AudioPolicyService::dump(int fd, const Vector<String16>& args)

{

    if (!checkCallingPermission(String16("android.permission.DUMP"))) {

    if (!dumpAllowed()) {

        dumpPermissionDenial(fd);

    } else {

        bool locked = tryLock(mLock);

services/audioflinger/ServiceUtilities.cpp

0 → 100644
+55 −0
Original line number Diff line number Diff line 
/*

 * Copyright (C) 2012 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 <binder/IPCThreadState.h>

#include <binder/IServiceManager.h>

#include <binder/PermissionCache.h>

#include "ServiceUtilities.h"



namespace android {



// This optimization assumes mediaserver process doesn't fork, which it doesn't

const pid_t getpid_cached = getpid();



bool recordingAllowed() {

    if (getpid_cached == IPCThreadState::self()->getCallingPid()) return true;

    static const String16 sRecordAudio("android.permission.RECORD_AUDIO");

    // don't use PermissionCache; this is not a system permission

    bool ok = checkCallingPermission(sRecordAudio);

    if (!ok) ALOGE("Request requires android.permission.RECORD_AUDIO");

    return ok;

}



bool settingsAllowed() {

    if (getpid_cached == IPCThreadState::self()->getCallingPid()) return true;

    static const String16 sAudioSettings("android.permission.MODIFY_AUDIO_SETTINGS");

    // don't use PermissionCache; this is not a system permission

    bool ok = checkCallingPermission(sAudioSettings);

    if (!ok) ALOGE("Request requires android.permission.MODIFY_AUDIO_SETTINGS");

    return ok;

}



bool dumpAllowed() {

    // don't optimize for same pid, since mediaserver never dumps itself

    static const String16 sDump("android.permission.DUMP");

    // OK to use PermissionCache; this is a system permission

    bool ok = PermissionCache::checkCallingPermission(sDump);

    // convention is for caller to dump an error message to fd instead of logging here

    //if (!ok) ALOGE("Request requires android.permission.DUMP");

    return ok;

}



} // namespace android

services/audioflinger/ServiceUtilities.h

0 → 100644
+27 −0
Original line number Diff line number Diff line 
/*

 * Copyright (C) 2012 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 <unistd.h>



namespace android {



extern const pid_t getpid_cached;



bool recordingAllowed();

bool settingsAllowed();

bool dumpAllowed();



}