crash log

12-31 04:07:10.321 503 503 F DEBUG 12-31 04:07:10.321 503 503 F DEBUG 12-31 04:07:10.321 503 503 F DEBUG 12-31 04:07:10.321 503 503 F DEBUG 12-31 04:07:10.321 503 503 F DEBUG 12-31 04:07:10.321 503 503 F DEBUG 12-31 04:07:10.363 503 503 F DEBUG 12-31 04:07:10.363 503 503 F DEBUG : 12-31 04:07:10.363 503 503 F DEBUG : 12-31 04:07:10.363 503 503 F DEBUG : 12-31 04:07:10.363 503 503 F DEBUG : 12-31 04:07:10.363 503 503 F DEBUG : 12-31 04:07:10.363 503 503 F DEBUG : 12-31 04:07:10.363 503 503 F DEBUG : 12-31 04:07:10.363 503 503 F DEBUG : 12-31 04:07:10.363 503 503 F DEBUG : 12-31 04:07:10.385 503 503 F DEBUG 12-31 04:07:10.385 503 503 F DEBUG 12-31 04:07:10.385 503 503 F DEBUG : 12-31 04:07:10.385 503 503 F DEBUG : 12-31 04:07:10.385 503 503 F DEBUG : 12-31 04:07:10.385 503 503 F DEBUG : 12-31 04:07:10.385 503 503 F DEBUG : 12-31 04:07:10.385 503 503 F DEBUG : 12-31 04:07:10.385 503 503 F DEBUG : 12-31 04:07:10.385 503 503 F DEBUG : 12-31 04:07:10.385 503 503 F DEBUG : 12-31 04:07:10.385 503 503 F DEBUG : 12-31 04:07:10.385 503 503 F DEBUG : 12-31 04:07:10.386 503 503 F DEBUG : : *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
: Build fingerprint: 'Xiaomi/nikel/nikel:6.0/MRA58K/9.3.21:user/release-keys'
: Revision: '0'
: ABI: 'arm64'
: pid: 13405, tid: 13405, name: com.mytest >>> com.mytest <<<
: signal 6 (SIGABRT), code 0 (SI_USER), fault addr --------
: Abort message: 'art/runtime/java_vm_ext.cc:440] JNI DETECTED ERROR IN APPLICATION: JNI CallVoidMethodV called with pending exception java.lang.NullPointerException: Attempt to invoke virtual method 'void android.hardware.Camera.stopFaceDetection()' on a null object reference'
x0 0000000000000000 x1 000000000000345d x2 0000000000000006 x3 0000000000000000
x4 0000000000000000 x5 0000000000000001 x6 0000000000000000 x7 0000000000000000
x8 0000000000000083 x9 000000000000f540 x10 00000002f1290dc0 x11 00000002f1290f00
x12 0000000000000000 x13 0000007f9d45e000 x14 0000000000000000 x15 0000000000000000
x16 0000007f9d450570 x17 0000007f9d3e1b1c x18 0000007f9d461f50 x19 0000007f9d868380
x20 0000007f9d8682c0 x21 000000000000000b x22 0000000000000006 x23 0000007f999fc400
x24 0000007f49f0f540 x25 0000000000000000 x26 0000007f997a9000 x27 0000000000000000
x28 0000007f999fc400 x29 0000007ff3b2fec0 x30 0000007f9d3df2b8
sp 0000007ff3b2fec0 pc 0000007f9d3e1b24 pstate 0000000020000000
:
: backtrace:
#00 pc 000000000006ab24 /system/lib64/libc.so (tgkill+8)
#01 pc 00000000000682b4 /system/lib64/libc.so (pthread_kill+68)
#02 pc 0000000000023ae4 /system/lib64/libc.so (raise+28)
#03 pc 000000000001e284 /system/lib64/libc.so (abort+60)
#04 pc 00000000004347c4 /system/lib64/libart.so (_ZN3art7Runtime5AbortEv+324)
#05 pc 00000000001365b0 /system/lib64/libart.so (_ZN3art10LogMessageD2Ev+3136)
#06 pc 0000000000311568 /system/lib64/libart.so (ZN3art9JavaVMExt8JniAbortEPKcS2+2288)
#07 pc 0000000000311a18 /system/lib64/libart.so (_ZN3art9JavaVMExt9JniAbortVEPKcS2_St9__va_list+116)
#08 pc 0000000000142414 /system/lib64/libart.so (_ZN3art11ScopedCheck6AbortFEPKcz+144)
#09 pc 00000000001492c4 /system/lib64/libart.so (_ZN3art11ScopedCheck5CheckERNS_18ScopedObjectAccessEbPKcPNS_12JniValueTypeE.constprop.116+6088)
#10 pc 000000000015bec8 /system/lib64/libart.so (_ZN3art8CheckJNI11CallMethodVEPKcP7_JNIEnvP8_jobjectP7_jclassP10_jmethodIDSt9__va_listNS_9Primitive4TypeENS_10InvokeTypeE+684)
#11 pc 000000000015e190 /system/lib64/libart.so (_ZN3art8CheckJNI15CallVoidMethodVEP7_JNIEnvP8_jobjectP10_jmethodIDSt9__va_list+68)

分析

signal 6 (SIGABRT), code 0 (SI_USER)、Abort message
这几个信息说明是用户层程序调用abort()造成的。
JNI CallVoidMethodV called with pending exception java.lang.NullPointerException
出错的地方是JNI调用CallVoidMethodV，但是后面有个重要的信息“pending exception”，说明在这之前有一个没有解决的exception。所以这个时候native通过JNI调用java，虚拟机直接会abort()。
所以，这个问题的根源是找到java程序的NullPointerException，和native的程序无关。
backtrace
后面的堆栈信息有abort()、_ZN3art7Runtime5AbortEv，验证了我们的分析，即虚拟机（libart.so）主动调用abort()退出。