Android dalvik removal utility may crash?

Question

Android dalvik removal utility may crash?

We are working on a project for Android jelly bean. Our platform is hand-based, and the kernel version is 3.1.10. In our development process, we found that there was a very low probability that the application crashed in dalwick. Based on the following backtrace log, an accident occurred during garbage collection. After using addr2line to analyze the pc address, we found that obj-> clazz became an address violation when a problem occurred.

Code stream: (dvmHeapScanMarkedObjects → processMarkStack-> scanObject → (IS_CLASS_FLAG_SET (obj-> clazz, CLASS_ISARRAY)))

Now we are stuck here and cannot find a way to solve it. Therefore, we need more suggestions and help.

Does anyone know this problem or how to check it?

Backtrace log as below:

F/libc ( 912): Fatal signal 11 (SIGSEGV) at 0x00000025 (code=1), thread 912 (zygote) I/DEBUG ( 910): *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***I/DEBUG ( 910): Revision: '32' I/DEBUG ( 910): pid: 912, tid: 912, name: zygote >>> zygote <<< I/DEBUG ( 910): signal 11 (SIGSEGV), code 1 (SEGV_MAPERR), fault addr 00000025 I/DEBUG ( 910): r0 00000005 r1 41246df0 r2 44208890 r3 412471e8 I/DEBUG ( 910): r4 40e3c1b8 r5 412569c0 r6 40e3c1b8 r7 41246df0 I/DEBUG ( 910): r8 0000154c r9 00000000 sl 000798e4 fp 7fffffff I/DEBUG ( 910): ip 51b2c044 sp bee580c0 lr 40dc5b88 pc 40dc598c cpsr 80000010 I/DEBUG ( 910): d0 6e69737275636567 d1 6f7268540000fa2e I/DEBUG ( 910): d2 573752085737512e d3 573752785737522e I/DEBUG ( 910): d4 5737527857375240 d5 573841a0573752b0 I/DEBUG ( 910): d6 00010000573841d8 d7 000000614ac3ff00 I/DEBUG ( 910): d8 0000000000000000 d9 0000000000000000 I/DEBUG ( 910): d10 0000000000000000 d11 0000000000000000 I/DEBUG ( 910): d12 0000000000000000 d13 0000000000000000 I/DEBUG ( 910): d14 0000000000000000 d15 0000000000000000 I/DEBUG ( 910): d16 0000000000019a5c d17 0000000000019a5c I/DEBUG ( 910): d18 0000000000000000 d19 3fe8000000000000 I/DEBUG ( 910): d20 0000000000000000 d21 0000000000000000 I/DEBUG ( 910): d22 0000000000000000 d23 0000000000000000 I/DEBUG ( 910): d24 0000000000000000 d25 0000000000000000 I/DEBUG ( 910): d26 0000000000000000 d27 0000000000000000 I/DEBUG ( 910): d28 0000000000000000 d29 0000000000000000 I/DEBUG ( 910): d30 0000000000000000 d31 0000000000000000 I/DEBUG ( 910): scr 60000010 I/DEBUG ( 910): I/DEBUG ( 910): backtrace: I/DEBUG ( 910): #00 pc 0003798c /system/lib/libdvm.so I/DEBUG ( 910): #01 pc 00037b84 /system/lib/libdvm.so I/DEBUG ( 910): #02 pc 000298c0 /system/lib/libdvm.so (dvmCollectGarbageInternal(GcSpec const*)+196) I/DEBUG ( 910): #03 pc 0002a0bc /system/lib/libdvm.so (dvmMalloc(unsigned int, int)+152) I/DEBUG ( 910): #04 pc 00054f57 /system/lib/libdvm.so (dvmAllocObject+6) I/DEBUG ( 910): #05 pc 0001ecb0 /system/lib/libdvm.so I/DEBUG ( 910): #06 pc 0002b754 /system/lib/libdvm.so (dvmInterpret(Thread*, Method const*, JValue*)+184) I/DEBUG ( 910): #07 pc 0005fe09 /system/lib/libdvm.so (dvmCallMethodV(Thread*, Method const*, Object*, bool, JValue*, std::__va_list)+272) I/DEBUG ( 910): #08 pc 0005fe33 /system/lib/libdvm.so (dvmCallMethod(Thread*, Method const*, Object*, JValue*, ...)+20) I/DEBUG ( 910): #09 pc 000539c9 /system/lib/libdvm.so (dvmPrepMainThread()+188) I/DEBUG ( 910): #10 pc 00047c65 /system/lib/libdvm.so (dvmStartup(int, char const* const*, bool, _JNIEnv*)+1108) I/DEBUG ( 910): #11 pc 0004dd8d /system/lib/libdvm.so (JNI_CreateJavaVM+544) I/DEBUG ( 910): #12 pc 00047227 /system/lib/libandroid_runtime.so (android::AndroidRuntime::startVm(_JavaVM**, _JNIEnv**)+1626) I/DEBUG ( 910): #13 pc 000476bd /system/lib/libandroid_runtime.so (android::AndroidRuntime::start(char const*, char const*)+176) I/DEBUG ( 910): #14 pc 00000db7 /system/bin/app_process I/DEBUG ( 910): I/DEBUG ( 910): stack: I/DEBUG ( 910): bee58080 00000000 I/DEBUG ( 910): bee58084 40dc599c /system/lib/libdvm.so I/DEBUG ( 910): bee58088 41247f38 /dev/ashmem/dalvik-heap (deleted) I/DEBUG ( 910): bee5808c 000003f0 I/DEBUG ( 910): bee58090 000000fd I/DEBUG ( 910): bee58094 00000000 I/DEBUG ( 910): bee58098 41246ebc [heap] I/DEBUG ( 910): bee5809c 40db7578 /system/lib/libdvm.so (dvmHeapBitmapScanWalk(HeapBitmap*, void (*)(Object*, void*, void*), void*)+128) I/DEBUG ( 910): bee580a0 40dc5b9c /system/lib/libdvm.so I/DEBUG ( 910): bee580a4 41247f38 /dev/ashmem/dalvik-heap (deleted) I/DEBUG ( 910): bee580a8 40e3c1b8 /system/lib/libdvm.so I/DEBUG ( 910): bee580ac 412569a0 /dev/ashmem/dalvik-heap (deleted) I/DEBUG ( 910): bee580b0 40e3c1b8 /system/lib/libdvm.so I/DEBUG ( 910): bee580b4 41246df0 [heap] I/DEBUG ( 910): bee580b8 df0027ad I/DEBUG ( 910): bee580bc 00000000 I/DEBUG ( 910): #00 bee580c0 51b2c048 /dev/ashmem/dalvik-mark-stack (deleted) I/DEBUG ( 910): bee580c4 41246df0 [heap] I/DEBUG ( 910): bee580c8 41246dd8 [heap] I/DEBUG ( 910): bee580cc 40e3c1b8 /system/lib/libdvm.so I/DEBUG ( 910): bee580d0 00000001 I/DEBUG ( 910): bee580d4 40dc5b88 /system/lib/libdvm.so I/DEBUG ( 910): #01 bee580d8 40e34aa8 /system/lib/libdvm.so I/DEBUG ( 910): bee580dc 40db78c4 /system/lib/libdvm.so (dvmCollectGarbageInternal(GcSpec const*)+200) I/DEBUG ( 910): #02 bee580e0 bee58124 [stack] I/DEBUG ( 910): bee580e4 40df9095 /system/lib/libdvm.so I/DEBUG ( 910): bee580e8 5855879e /data/dalvik-cache/ system@framework @ core.jar@classes.dex I/DEBUG ( 910): bee580ec 40087010 I/DEBUG ( 910): bee580f0 5855879e /data/dalvik-cache/ system@framework @ core.jar@classes.dex I/DEBUG ( 910): bee580f4 410be000 /dev/ashmem/dalvik-aux-structure (deleted) I/DEBUG ( 910): bee580f8 00000000 I/DEBUG ( 910): bee580fc 00000000 I/DEBUG ( 910): bee58100 000006db I/DEBUG ( 910): bee58104 410be000 /dev/ashmem/dalvik-aux-structure (deleted) I/DEBUG ( 910): bee58108 00000000 I/DEBUG ( 910): bee5810c 410f55cc /dev/ashmem/dalvik-aux-structure (deleted) I/DEBUG ( 910): bee58110 412569d8 /dev/ashmem/dalvik-heap (deleted) I/DEBUG ( 910): bee58114 41248338 /dev/ashmem/dalvik-heap (deleted) I/DEBUG ( 910): bee58118 41248338 /dev/ashmem/dalvik-heap (deleted) I/DEBUG ( 910): bee5811c 40e3c1b8 /system/lib/libdvm.so I/DEBUG ( 910): ........ ........

+6

android dalvik

建翰陳 Feb 25 '13 at 15:01

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2 answers

Imposter · Answer 1 · 2013-02-26T10:57:33+0000

It took me quite a while to analyze the situation for me with a similar problem. Hope my analysis helps you.

With my problem, the problem is with memory reordering by the compiler. In dalwick, several threads share ASHMEM memory. This ASHMEM could be corrupted due to memory reordering by the compiler for optimization. To avoid reordering memory at a specific location, implement a memory barrier (AKA membar). Check out this link to perform membar

Just place the ANDROID_MEMBAR_BARRIER() memory barrier before allocating the object and freeing the object in the Garbage data collector (for example, dalvik / vm / alloc / alloc.cpp) and in the .cpp, array.cpp and proxy.cpp classes in the dalvik source directory android This should solve the problem.

For more information about pls memory pls check the following links

memory barrier

example

white paper on hardware view memory barriers

建翰陳 · Answer 2 · 2013-02-26T13:38:25+0000

You mean putting ANDROID_MEMBAR_FULL () for the whole dvmMalloc, like the code in the following? And where is the free memory function in the garbage collection stream? thanks

 static bool createInitialClasses() { /* * Initialize the class Class. This has to be done specially, particularly * because it is an instance of itself. */ ClassObject* clazz = (ClassObject*) dvmMalloc(classObjectSize(CLASS_SFIELD_SLOTS), ALLOC_NON_MOVING); ANDROID_MEMBAR_FULL();

Android dalvik removal utility may crash?

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