AAssetManager_fromJava crash when enabling proguard obfuscation

ol...@illusionlabs.se

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May 28, 2014, 10:18:09 AM5/28/14

to andro...@googlegroups.com

I'm using AAssetManager_fromJava in my JNI code.

This works perfectly.

Until I enable proguard, then the call to AAssetManager_fromJava crashes.

I'm assuming I need to add something to my proguard config, but what?

I tried add -keep class android.content.res.* but that is not enough.

Anyone know what to add? Have tried searching the documentation and google but couldn't find any information about it.

Cheers,

Olof

Here is the crash:

05-28 16:02:04.752 23051 23051 F libc : Fatal signal 11 (SIGSEGV) at 0x0000002c (code=1), thread 23051 (llusionlabs.bmx)

05-28 16:02:04.853 123 123 I DEBUG : *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***

05-28 16:02:04.853 123 123 I DEBUG : Build fingerprint: 'Amazon/soho/soho:4.2.2/JDQ39/11.3.2.2_user_322095420:user/release-keys'

05-28 16:02:04.853 123 123 I DEBUG : Revision: '1'

05-28 16:02:04.853 123 123 I DEBUG : pid: 23051, tid: 23051, name: llusionlabs.bmx >>> se.illusionlabs.bmx <<<

05-28 16:02:04.853 123 123 I DEBUG : signal 11 (SIGSEGV), code 1 (SEGV_MAPERR), fault addr 0000002c

05-28 16:02:04.931 123 123 I DEBUG : r0 00000000 r1 00000000 r2 40e8d950 r3 40929c88

05-28 16:02:04.931 123 123 I DEBUG : r4 00000000 r5 5c4ffa3d r6 40e8d950 r7 5c4ffa45

05-28 16:02:04.931 123 123 I DEBUG : r8 be9654d8 r9 40defc4c sl 40e8fe20 fp be9654a8

05-28 16:02:04.931 123 123 I DEBUG : ip 00000000 sp be965360 lr 408cb6f1 pc 408cb6f0 cpsr 60000030

05-28 16:02:04.931 123 123 I DEBUG : d0 6d41797469766961 d1 6341584d422f787a

05-28 16:02:04.931 123 123 I DEBUG : d2 65746e6f635f646f d3 415f7365725f746e

05-28 16:02:04.931 123 123 I DEBUG : d4 0000000000000000 d5 3ff0000000000000

05-28 16:02:04.931 123 123 I DEBUG : d6 42c8000000000963 d7 0000000000000000

05-28 16:02:04.931 123 123 I DEBUG : d8 0000000000000000 d9 0000000000000000

05-28 16:02:04.931 123 123 I DEBUG : d10 0000000000000000 d11 0000000000000000

05-28 16:02:04.931 123 123 I DEBUG : d12 0000000000000000 d13 0000000000000000

05-28 16:02:04.931 123 123 I DEBUG : d14 0000000000000000 d15 0000000000000000

05-28 16:02:04.931 123 123 I DEBUG : d16 0000000000000017 d17 0000000000000000

05-28 16:02:04.931 123 123 I DEBUG : d18 0000000000000000 d19 0000000000000000

05-28 16:02:04.931 123 123 I DEBUG : d20 3fc554e7eb0eb47c d21 3e66376972bea4d0

05-28 16:02:04.931 123 123 I DEBUG : d22 3f4de16b9c24a98f d23 3fb0f4a31edab38b

05-28 16:02:04.931 123 123 I DEBUG : d24 3fede16b9c24a98f d25 3fe55559ee5e69f9

05-28 16:02:04.931 123 123 I DEBUG : d26 0000000000000000 d27 0000000000000000

05-28 16:02:04.931 123 123 I DEBUG : d28 0000000000000005 d29 0000000000000000

05-28 16:02:04.931 123 123 I DEBUG : d30 0000000000000000 d31 0000000000000000

05-28 16:02:04.931 123 123 I DEBUG : scr 80000090

05-28 16:02:04.931 123 123 I DEBUG :

05-28 16:02:04.931 123 123 I DEBUG : backtrace:

05-28 16:02:04.931 123 123 I DEBUG : #00 pc 0004b6f0 /system/lib/libdvm.so

05-28 16:02:04.931 123 123 I DEBUG : #01 pc 00008add /system/lib/libandroid.so (AAssetManager_fromJava+52)

05-28 16:02:04.931 123 123 I DEBUG : #02 pc 0011f82c /data/app-lib/se.illusionlabs.bmx-1/libcommon.so (ILFile_InitAssetManager(_JNIEnv*, _jobject*, char const*)+72)

05-28 16:02:04.931 123 123 I DEBUG : #03 pc 002003b8 /data/app-lib/se.illusionlabs.bmx-1/libbmx.so (Java_se_illusionlabs_bmx_BMXJNILib_setup+140)

05-28 16:02:04.931 123 123 I DEBUG : #04 pc 0001e390 /system/lib/libdvm.so (dvmPlatformInvoke+112)

05-28 16:02:04.931 123 123 I DEBUG : #05 pc 0004d319 /system/lib/libdvm.so (dvmCallJNIMethod(unsigned int const*, JValue*, Method const*, Thread*)+396)

05-28 16:02:04.931 123 123 I DEBUG : #06 pc 0004f477 /system/lib/libdvm.so (dvmResolveNativeMethod(unsigned int const*, JValue*, Method const*, Thread*)+174)

05-28 16:02:04.931 123 123 I DEBUG : #07 pc 000277a0 /system/lib/libdvm.so

05-28 16:02:04.931 123 123 I DEBUG : #08 pc 0002b488 /system/lib/libdvm.so (dvmInterpret(Thread*, Method const*, JValue*)+184)

05-28 16:02:04.931 123 123 I DEBUG : #09 pc 0005ff23 /system/lib/libdvm.so (dvmInvokeMethod(Object*, Method const*, ArrayObject*, ArrayObject*, ClassObject*, bool)+374)

05-28 16:02:04.931 123 123 I DEBUG : #10 pc 0006783d /system/lib/libdvm.so

05-28 16:02:04.931 123 123 I DEBUG : #11 pc 000277a0 /system/lib/libdvm.so

05-28 16:02:04.931 123 123 I DEBUG : #12 pc 0002b488 /system/lib/libdvm.so (dvmInterpret(Thread*, Method const*, JValue*)+184)

05-28 16:02:04.939 123 123 I DEBUG : #13 pc 0005fc4d /system/lib/libdvm.so (dvmCallMethodV(Thread*, Method const*, Object*, bool, JValue*, std::__va_list)+272)

05-28 16:02:04.939 123 123 I DEBUG : #14 pc 00049903 /system/lib/libdvm.so

05-28 16:02:04.939 123 123 I DEBUG : #15 pc 0004bc59 /system/lib/libandroid_runtime.so

05-28 16:02:04.939 123 123 I DEBUG : #16 pc 0004c903 /system/lib/libandroid_runtime.so (android::AndroidRuntime::start(char const*, char const*)+390)

05-28 16:02:04.939 123 123 I DEBUG : #17 pc 00000db7 /system/bin/app_process

05-28 16:02:04.939 123 123 I DEBUG : #18 pc 0001279f /system/lib/libc.so (__libc_init+38)

05-28 16:02:04.939 123 123 I DEBUG : #19 pc 00000ae8 /system/bin/app_process

And here is my proguard config:

# To enable ProGuard in your project, edit project.properties

# to define the proguard.config property as described in that file.

#

# Add project specific ProGuard rules here.

# By default, the flags in this file are appended to flags specified

# in ${sdk.dir}/tools/proguard/proguard-android.txt

# You can edit the include path and order by changing the ProGuard

# include property in project.properties.

#

# For more details, see

# http://developer.android.com/guide/developing/tools/proguard.html

# Add any project specific keep options here:

# If your project uses WebView with JS, uncomment the following

# and specify the fully qualified class name to the JavaScript interface

# class:

#-keepclassmembers class fqcn.of.javascript.interface.for.webview {

# public *;

#}

-dontwarn com.amazon.**

-keep class com.amazon.** {*;}

-keepattributes *Annotation*

-keep class se.illusionlabs.bmx.BMXJNILib

-keepclassmembers public class se.illusionlabs.bmx.BMXActivity {

public void startMusic();

public void stopMusic();

public void lockRotation();

public void unlockRotation();

}

-keepclassmembers public class se.illusionlabs.bmx.BMXActivityAmazon {

public void setupIAP();

public void buyItem(String);

public void addItem(String);

}

ol...@illusionlabs.se

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May 28, 2014, 10:59:20 AM5/28/14

to andro...@googlegroups.com

Ok, I've found the implementation of the AAssetManager_fromJava function;

It looks like this:

/**
0070  * Asset Manager functionality
0071  */
0072 AAssetManager* AAssetManager_fromJava(JNIEnv* env, jobject assetManager)
0073 {
0074     {
0075         Mutex::Autolock _l(gMutex);
0076 
0077         if (gJNIConfigured == false) {
0078             jclass amClass = env->FindClass("android/content/res/AssetManager");
0079             gAssetManagerOffsets.mObject = env->GetFieldID(amClass, "mObject", "I");
0080             gJNIConfigured = true;
0081         }
0082     }
0083 
0084     return (AAssetManager*) env->GetIntField(assetManager, gAssetManagerOffsets.mObject);
0085 }

So now I doubt my problem is rules in proguard config....

Only thing referenced is android.content.res.AssetManager so my rule should work right?

Anyone have any other ideas why enabling proguard would make a JNI method crash?

If I disable proguard and no other change, everything works fine.

Cheers,

Olof

Phill Djonov

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May 28, 2014, 8:12:54 PM5/28/14

to andro...@googlegroups.com

In your config, you need to make sure you not only have proguard keep the AssetManager class, but also its mObject field (which is what it might be renaming on you).

ol...@illusionlabs.se

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May 29, 2014, 4:49:43 AM5/29/14

to andro...@googlegroups.com

Thanks for helping out!

I still can't get it to work though... Could you possibly advise on exactly how the rules should look?

I'm a bit noob on using proguard.

Shouldn't "-keep class android.content.res.AssetManager" keep both the class and it's members?

I've tried a lot of different options, but I can't get anything to work. At the moment my rules look like this:

-keep class android.content.res.AssetManager

-keepclassmembers public class android.content.res.AssetManager {

<fields>;

}

Still the same crash.

Cheers,

Olof

ol...@illusionlabs.se

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May 29, 2014, 5:52:55 AM5/29/14

to andro...@googlegroups.com

Ok, I've solved it now.

Turns out it had nothing to do with AAssetManager_fromJava....

My code looks like this:

char* package_name = JNI_readString(env, c, bmxactivity, "PACKAGE_NAME");

LOGI("Package name: %s",package_name);

ILFile_InitAssetManager(env,assManager,package_name);

and I had forgot to keep the "PACKAGE_NAME" field.

I have no idea why the callstack would show the crash within AAssetManager_fromJava which is called from InitAssetManager....

package_name is null, but it's not used until after calling AAssetManager_fromJava.

Seems you do not need any rules for AAssetManager to work with proguard, I've removed them now and everything works fine.