Android ndk-stack tool
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Introduction:
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This document describes the 'ndk-stack' tool that is distributed with
the Android NDK, since release r6.
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Overview:
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'ndk-stack' is a simple tool that allows you to filter stack traces as they
appear in the output of 'adb logcat' and replace any address inside a shared
library with the corresponding <source-file>
:
<line-number>
?values.
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In a nutshell, it will translate something like:
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? ? I/DEBUG ? ( ? 31): *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
? ? I/DEBUG ? ( ? 31): Build fingerprint: 'generic/google_sdk/generic/:2.2/FRF91/43546:eng/test-keys'
? ? I/DEBUG ? ( ? 31): pid: 351, tid: 351 ?%gt;%gt;%gt; /data/local/ndk-tests/crasher <<<
? ? I/DEBUG ? ( ? 31): signal 11 (SIGSEGV), fault addr 0d9f00d8
? ? I/DEBUG ? ( ? 31): ?r0 0000af88 ?r1 0000a008 ?r2 baadf00d ?r3 0d9f00d8
? ? I/DEBUG ? ( ? 31): ?r4 00000004 ?r5 0000a008 ?r6 0000af88 ?r7 00013c44
? ? I/DEBUG ? ( ? 31): ?r8 00000000 ?r9 00000000 ?10 00000000 ?fp 00000000
? ? I/DEBUG ? ( ? 31): ?ip 0000959c ?sp be956cc8 ?lr 00008403 ?pc 0000841e ?cpsr 60000030
? ? I/DEBUG ? ( ? 31): ? ? ? ? ?#00 ?pc 0000841e ?/data/local/ndk-tests/crasher
? ? I/DEBUG ? ( ? 31): ? ? ? ? ?#01 ?pc 000083fe ?/data/local/ndk-tests/crasher
? ? I/DEBUG ? ( ? 31): ? ? ? ? ?#02 ?pc 000083f6 ?/data/local/ndk-tests/crasher
? ? I/DEBUG ? ( ? 31): ? ? ? ? ?#03 ?pc 000191ac ?/system/lib/libc.so
? ? I/DEBUG ? ( ? 31): ? ? ? ? ?#04 ?pc 000083ea ?/data/local/ndk-tests/crasher
? ? I/DEBUG ? ( ? 31): ? ? ? ? ?#05 ?pc 00008458 ?/data/local/ndk-tests/crasher
? ? I/DEBUG ? ( ? 31): ? ? ? ? ?#06 ?pc 0000d362 ?/system/lib/libc.so
? ? I/DEBUG ? ( ? 31):
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Into the more readable output:
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? ? ********** Crash dump: **********
? ? Build fingerprint: 'generic/google_sdk/generic/:2.2/FRF91/43546:eng/test-keys'
? ? pid: 351, tid: 351 ?>>> /data/local/ndk-tests/crasher <<<
? ? signal 11 (SIGSEGV), fault addr 0d9f00d8
? ? Stack frame #00 ?pc 0000841e ?/data/local/ndk-tests/crasher : Routine zoo in /tmp/foo/crasher/jni/zoo.c:13
? ? Stack frame #01 ?pc 000083fe ?/data/local/ndk-tests/crasher : Routine bar in /tmp/foo/crasher/jni/bar.c:5
? ? Stack frame #02 ?pc 000083f6 ?/data/local/ndk-tests/crasher : Routine my_comparison in /tmp/foo/crasher/jni/foo.c:9
? ? Stack frame #03 ?pc 000191ac ?/system/lib/libc.so
? ? Stack frame #04 ?pc 000083ea ?/data/local/ndk-tests/crasher : Routine foo in /tmp/foo/crasher/jni/foo.c:14
? ? Stack frame #05 ?pc 00008458 ?/data/local/ndk-tests/crasher : Routine main in /tmp/foo/crasher/jni/main.c:19
? ? Stack frame #06 ?pc 0000d362 ?/system/lib/libc.so
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Usage:
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To do this, you will first need a directory containing symbolic versions of your
application's shared libraries. If you use the NDK build system (i.e. ndk-build),
then these are always located under $PROJECT_PATH/obj/local/<ab>, where
<ab> stands for your device's ABI (i.e. 'armeabi' by default).
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You can feed the logcat text either as direct input to the program, e.g.:
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? ?adb logcat | $NDK/ndk-stack -sym $PROJECT_PATH/obj/local/armeabi
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Or you can use the -dump option to specify the logcat as an input file, e.g.:
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? ?adb logcat > /tmp/foo.txt
? ?$NDK/ndk-stack -sym $PROJECT_PATH/obj/local/armeabi -dump foo.txt
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** IMPORTANT **:
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? The tool looks for the initial line containing starts in the logcat output,
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? ? *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
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? When copy/pasting traces, don't forget this line from the traces, or
? ndk-stack won't work correctly.
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TODO:
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A future version of 'ndk-stack' will try to launch 'adb logcat' and select the
library path automatically. For now, you'll have to do these steps manually.
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As of now, ndk-stack doesn't handle libraries that don't have debug information
in them. It may be useful to try to detect the nearest function entry point to
a given PC address (e.g. as in the libc.so example above).