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Commit c9ea2114 authored by Jeff Vander Stoep's avatar Jeff Vander Stoep Committed by Jeffrey Vander Stoep
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mediacodec: add seccomp filter for arm/arm64 

mediacodec always runs in 32 bit mode so the arm seccomp filter is also
used on arm64 devices.

Tests: mediaserver CTS for bullhead, volantis and shamu

Add policy to log blocked syscalls to syslog and allow debuggerd attach
on mediacodec crash.

Bug: 27066802, 27064966
Change-Id: I4bdbba25b8847afa98d89b4b4ca863829fa19754
parent fc958a08

services/mediacodec/Android.mk

+5 −2
Original line number Diff line number Diff line
@@ -14,8 +14,10 @@ include $(BUILD_SHARED_LIBRARY) 


# service executable

include $(CLEAR_VARS)

LOCAL_SRC_FILES := main_codecservice.cpp

LOCAL_SHARED_LIBRARIES := libmedia libmediacodecservice libbinder libutils liblog

LOCAL_REQUIRED_MODULES_arm := mediacodec-seccomp.policy

LOCAL_SRC_FILES := main_codecservice.cpp minijail/minijail.cpp

LOCAL_SHARED_LIBRARIES := libmedia libmediacodecservice libbinder libutils \

	liblog libminijail

LOCAL_C_INCLUDES := \

    $(TOP)/frameworks/av/media/libstagefright \

    $(TOP)/frameworks/native/include/media/openmax
@@ -24,4 +26,5 @@ LOCAL_32_BIT_ONLY := true 
LOCAL_INIT_RC := mediacodec.rc

include $(BUILD_EXECUTABLE)



include $(call all-makefiles-under, $(LOCAL_PATH))

services/mediacodec/main_codecservice.cpp

+3 −1
Original line number Diff line number Diff line 
/*

**

** Copyright 2015, The Android Open Source Project

** Copyright 2016, 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.
@@ -28,6 +28,7 @@ 


// from LOCAL_C_INCLUDES

#include "MediaCodecService.h"

#include "minijail/minijail.h"



using namespace android;
@@ -35,6 +36,7 @@ int main(int argc __unused, char** argv) 
{

    ALOGI("@@@ mediacodecservice starting");

    signal(SIGPIPE, SIG_IGN);

    MiniJail();



    strcpy(argv[0], "media.codec");

    sp<ProcessState> proc(ProcessState::self());

services/mediacodec/minijail/Android.mk

0 → 100644
+28 −0
Original line number Diff line number Diff line 
LOCAL_PATH := $(call my-dir)



ifeq ($(TARGET_ARCH), $(filter $(TARGET_ARCH), arm arm64))

include $(CLEAR_VARS)

LOCAL_MODULE := mediacodec-seccomp.policy

LOCAL_MODULE_CLASS := ETC

LOCAL_MODULE_PATH := $(TARGET_OUT)/etc/seccomp_policy



# mediacodec runs in 32-bit combatibility mode. For 64 bit architectures,

# use the 32 bit policy

ifdef TARGET_2ND_ARCH

    LOCAL_SRC_FILES := $(LOCAL_PATH)/seccomp_policy/mediacodec-seccomp-$(TARGET_2ND_ARCH).policy

else

    LOCAL_SRC_FILES := $(LOCAL_PATH)/seccomp_policy/mediacodec-seccomp-$(TARGET_ARCH).policy

endif



# allow device specific additions to the syscall whitelist

ifneq (,$(wildcard $(BOARD_SECCOMP_POLICY)/mediacodec-seccomp.policy))

    LOCAL_SRC_FILES += $(BOARD_SECCOMP_POLICY)/mediacodec-seccomp.policy

endif



include $(BUILD_SYSTEM)/base_rules.mk



$(LOCAL_BUILT_MODULE): $(LOCAL_SRC_FILES)

	@mkdir -p $(dir $@)

	$(hide) cat > $@ $^



endif

services/mediacodec/minijail/minijail.cpp

0 → 100644
+50 −0
Original line number Diff line number Diff line 
/*

**

** Copyright 2016, 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 <cutils/log.h>

#include <libminijail.h>



#include "minijail.h"



namespace android {



/* Must match location in Android.mk */

static const char kSeccompFilePath[] = "/system/etc/seccomp_policy/mediacodec-seccomp.policy";



int MiniJail()

{

    /* no seccomp policy for this architecture */

    if (access(kSeccompFilePath, R_OK) == -1) {

        ALOGW("No seccomp filter defined for this architecture.");

        return 0;

    }



    struct minijail *jail = minijail_new();

    if (jail == NULL) {

        ALOGW("Failed to create minijail.");

        return -1;

    }



    minijail_no_new_privs(jail);

    minijail_log_seccomp_filter_failures(jail);

    minijail_use_seccomp_filter(jail);

    minijail_parse_seccomp_filters(jail, kSeccompFilePath);

    minijail_enter(jail);

    minijail_destroy(jail);

    return 0;

}

}

services/mediacodec/minijail/minijail.h

0 → 100644
+20 −0
Original line number Diff line number Diff line 
/*

**

** Copyright 2016, 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.

*/



namespace android {

int MiniJail();

}