问题描述
我已经移植并创建了几个低级C库到Android，用于我的应用程序。我使用NDK交叉编译它们，然后使用System.loadLibrary（）链接到它们。在一段时间后，我的应用程序崩溃，似乎是由于库中的错误：
I have ported and created several low-level C-libraries to Android for my use in my application. I cross-compiled them using the NDK, and then link to them using System.loadLibrary(). After some amount of time, my application crashes, seemingly due to a bug in the library:
07-28 11:31:21.675: INFO/DEBUG(2880): *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
07-28 11:31:21.675: INFO/DEBUG(2880): Build fingerprint: 'verizon/voles/sholes/sholes:2.2.2/FRG83G/91102:user/release-keys'
07-28 11:31:21.675: INFO/DEBUG(2880): pid: 2893, tid: 2894 >>> com.gnychis.coexisyst <<<
07-28 11:31:21.675: INFO/DEBUG(2880): signal 11 (SIGSEGV), fault addr 2d4eedb4
07-28 11:31:21.675: INFO/DEBUG(2880): r0 2d4eeda4 r1 00000000 r2 00000024 r3 00000000
07-28 11:31:21.675: INFO/DEBUG(2880): r4 00d3e770 r5 00000000 r6 4184ff98 r7 4184ffa4
07-28 11:31:21.675: INFO/DEBUG(2880): r8 100ffad0 r9 4184ff9c 10 4184ff84 fp 100ffe30
07-28 11:31:21.675: INFO/DEBUG(2880): ip 85b7efec sp 100ffa88 lr 845d13f8 pc 845f8c38 cpsr 60000010
07-28 11:31:21.675: INFO/DEBUG(2880): d0 6472656767756265 d1 4472fb3844714069
07-28 11:31:21.675: INFO/DEBUG(2880): d2 4186eeec4186ee6e d3 4186ef544186ef74
07-28 11:31:21.675: INFO/DEBUG(2880): d4 4186ef544186ef20 d5 418998f84186ef88
07-28 11:31:21.675: INFO/DEBUG(2880): d6 418999604189992c d7 418999c841899994
07-28 11:31:21.675: INFO/DEBUG(2880): d8 0000000000000000 d9 0000000000000000
07-28 11:31:21.675: INFO/DEBUG(2880): d10 0000000000000000 d11 0000000000000000
07-28 11:31:21.675: INFO/DEBUG(2880): d12 0000000000000000 d13 0000000000000000
07-28 11:31:21.675: INFO/DEBUG(2880): d14 0000000000000000 d15 0000000000000000
07-28 11:31:21.675: INFO/DEBUG(2880): d16 0113580000000001 d17 3fe999999999999a
07-28 11:31:21.675: INFO/DEBUG(2880): d18 42eccefa43de3400 d19 3fe00000000000b4
07-28 11:31:21.675: INFO/DEBUG(2880): d20 4008000000000000 d21 3fd99a27ad32ddf5
07-28 11:31:21.675: INFO/DEBUG(2880): d22 3fd24998d6307188 d23 3fcc7288e957b53b
07-28 11:31:21.675: INFO/DEBUG(2880): d24 3fc74721cad6b0ed d25 3fc39a09d078c69f
07-28 11:31:21.675: INFO/DEBUG(2880): d26 0000000000000000 d27 0000000000000000
07-28 11:31:21.675: INFO/DEBUG(2880): d28 0000000000000000 d29 0000000000000000
07-28 11:31:21.675: INFO/DEBUG(2880): d30 0000000000000000 d31 0000000000000000
07-28 11:31:21.675: INFO/DEBUG(2880): scr 80000012
07-28 11:31:21.753: INFO/DEBUG(2880): #00 pc 005f0c38 /data/data/com.gnychis.coexisyst/lib/libtshark.so
07-28 11:31:21.761: INFO/DEBUG(2880): #01 pc 005c93f4 /data/data/com.gnychis.coexisyst/lib/libtshark.so
07-28 11:31:21.761: INFO/DEBUG(2880): #02 pc 00001dd2 /data/data/com.gnychis.coexisyst/lib/libwireshark_helper.so
07-28 11:31:21.761: INFO/DEBUG(2880): #03 pc 00001d9a /data/data/com.gnychis.coexisyst/lib/libwireshark_helper.so
07-28 11:31:21.761: INFO/DEBUG(2880): #04 pc 00016e34 /system/lib/libdvm.so
07-28 11:31:21.761: INFO/DEBUG(2880): #05 pc 000452c4 /system/lib/libdvm.so
07-28 11:31:21.761: INFO/DEBUG(2880): #06 pc 0001bd98 /system/lib/libdvm.so
07-28 11:31:21.761: INFO/DEBUG(2880): #07 pc 00022794 /system/lib/libdvm.so
07-28 11:31:21.761: INFO/DEBUG(2880): #08 pc 00021634 /system/lib/libdvm.so
07-28 11:31:21.761: INFO/DEBUG(2880): #09 pc 0005c5cc /system/lib/libdvm.so
07-28 11:31:21.761: INFO/DEBUG(2880): #10 pc 0005c7fc /system/lib/libdvm.so
07-28 11:31:21.761: INFO/DEBUG(2880): #11 pc 0005203e /system/lib/libdvm.so
07-28 11:31:21.761: INFO/DEBUG(2880): #12 pc 000520ca /system/lib/libdvm.so
07-28 11:31:21.761: INFO/DEBUG(2880): #13 pc 000525a0 /system/lib/libdvm.so
07-28 11:31:21.769: INFO/DEBUG(2880): #14 pc 0004f9ec /system/lib/libdvm.so
07-28 11:31:21.769: INFO/DEBUG(2880): #15 pc 00010ed4 /system/lib/libc.so
07-28 11:31:21.769: INFO/DEBUG(2880): #16 pc 000109c0 /system/lib/libc.so
07-28 11:31:21.769: INFO/DEBUG(2880): code around pc:
07-28 11:31:21.769: INFO/DEBUG(2880): 845f8c18 ebfda8d5 eaffffdf e5950014 e3500000
07-28 11:31:21.769: INFO/DEBUG(2880): 845f8c28 0affffdc ebfdc232 eaffffda e92d4070
07-28 11:31:21.769: INFO/DEBUG(2880): 845f8c38 e5904010 e1a05000 e3540000 0a000004
07-28 11:31:21.769: INFO/DEBUG(2880): 845f8c48 e5940000 ebfdac25 e5944004 e3540000
07-28 11:31:21.769: INFO/DEBUG(2880): 845f8c58 1afffffa e1a00005 e8bd4070 eafdd2ef
07-28 11:31:21.769: INFO/DEBUG(2880): code around lr:
07-28 11:31:21.769: INFO/DEBUG(2880): 845d13d8 e1a01003 eafe72bb e92d4010 e1a04000
07-28 11:31:21.769: INFO/DEBUG(2880): 845d13e8 e2800008 ebfe4c98 e5940000 ebfe4a3b
07-28 11:31:21.769: INFO/DEBUG(2880): 845d13f8 e5940004 e3500000 0a000001 e8bd4010
07-28 11:31:21.769: INFO/DEBUG(2880): 845d1408 eafe7322 e8bd8010 e92d4010 e1a04000
07-28 11:31:21.769: INFO/DEBUG(2880): 845d1418 ebfe690a e1a00004 e8bd4010 eafe46d2
07-28 11:31:21.769: INFO/DEBUG(2880): stack:
07-28 11:31:21.769: INFO/DEBUG(2880): 100ffa48 afd43724 /system/lib/libc.so
07-28 11:31:21.769: INFO/DEBUG(2880): 100ffa4c 00000004
07-28 11:31:21.769: INFO/DEBUG(2880): 100ffa50 00d417e0 [heap]
07-28 11:31:21.769: INFO/DEBUG(2880): 100ffa54 00000008
07-28 11:31:21.769: INFO/DEBUG(2880): 100ffa58 00000000
07-28 11:31:21.769: INFO/DEBUG(2880): 100ffa5c afd10280 /system/lib/libc.so
07-28 11:31:21.769: INFO/DEBUG(2880): 100ffa60 00d417e0 [heap]
07-28 11:31:21.769: INFO/DEBUG(2880): 100ffa64 00000000
07-28 11:31:21.769: INFO/DEBUG(2880): 100ffa68 0024a330 [heap]
07-28 11:31:21.769: INFO/DEBUG(2880): 100ffa64 00000000
07-28 11:31:21.769: INFO/DEBUG(2880): 100ffa68 0024a330 [heap]
07-28 11:31:21.769: INFO/DEBUG(2880): 100ffa6c 00000001
07-28 11:31:21.769: INFO/DEBUG(2880): 100ffa70 00000008
07-28 11:31:21.769: INFO/DEBUG(2880): 100ffa74 00000000
07-28 11:31:21.769: INFO/DEBUG(2880): 100ffa78 00d3e778 [heap]
07-28 11:31:21.769: INFO/DEBUG(2880): 100ffa7c 8063b4af /system/lib/libglib-2.0.so
07-28 11:31:21.769: INFO/DEBUG(2880): 100ffa80 df002777
07-28 11:31:21.769: INFO/DEBUG(2880): 100ffa84 e3a070ad
07-28 11:31:21.769: INFO/DEBUG(2880): #00 100ffa88 00d3e770 [heap]
07-28 11:31:21.769: INFO/DEBUG(2880): 100ffa8c 00000000
07-28 11:31:21.769: INFO/DEBUG(2880): 100ffa90 4184ff98
07-28 11:31:21.769: INFO/DEBUG(2880): 100ffa94 845d13f8 /data/data/com.gnychis.coexisyst/lib/libtshark.so
07-28 11:31:21.769: INFO/DEBUG(2880): #01 100ffa98 100ffaf0
07-28 11:31:21.769: INFO/DEBUG(2880): 100ffa9c 80d01dd5 /data/data/com.gnychis.coexisyst/lib/libwireshark_helper.so
首先，我不完全确定如何正确解释它，并且如果任何内存地址对我来说实际上是有用的。例如，我可以拿一个内存地址来确定哪个功能发生在哪里？基于堆栈，哪个库是发生故障的库？
First off, I'm not entirely sure how to properly interpret it, and if any of the memory addresses are actually useful for me. For example, can I take a memory address and determine which function the fault happened in? Based on the stack, which library was the one where the fault occurred?
故障需要一些时间才能发生，所以逐步通过代码似乎有点棘手。有没有办法获得核心转储或任何东西？我尝试使用本地代码的日志消息，但日志消息对我来说没有足够的帮助来缩小问题。
The fault takes some time to happen, so stepping through code seems a little tricky. Is there a way to get a core dump or anything? I have attempted using log messages from the native code, but the log messages are not helpful enough for me to narrow the problem.
推荐答案
如果您的应用程序真正崩溃本机代码，我强烈推荐以下内容：
If your application is truly crashing in native code, I highly recommend the following:
- 设置一个java断点，将在您的本地库已经加载，但在开始执行之前。
- 转到终端并启动ndk的gdb版本（称为ndk-gdb）。最初，只需键入c继续。
- 回到java，继续执行。
- 一旦您的应用程序崩溃，gdb将暂停，您可以通过本机代码检查堆栈的完整性bt命令（backtrace）。
- Set a java breakpoint that will be hit after your native library has been loaded but before it starts executing.
- Go to the terminal and launch the ndk's version of gdb (it's called "ndk-gdb"). Initially, just type "c" to continue.
- Back in java, continue execution.
- Once your app crashes, gdb will pause and you can examine the integrity of the stack in native code via the "bt" command (backtrace).
无论如何，您应该能够完全调试本机代码并通过ndk捕获问题-gdb。您可以在本地安装的ndk中找到ndk版本的gdb的具体文档（例如，在我的机器上）：
At any rate, you should be able to fully debug native code and catch problems via ndk-gdb. You can find specific documentation on the ndk's version of gdb in your local installation of the ndk (for example, on my machine it's here):
android-ndk-r6 / document.html
android-ndk-r6/documentation.html
最后，这是gdb基础教程：
Finally, here's a basic tutorial on gdb:
希望这有帮助！
这篇关于在Android应用程序链接的本地库中调试崩溃的最简单的方法？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！