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Diffstat (limited to 'en/devices/tech/debug/native-crash.html')
| -rw-r--r-- | en/devices/tech/debug/native-crash.html | 59 |
1 files changed, 31 insertions, 28 deletions
diff --git a/en/devices/tech/debug/native-crash.html b/en/devices/tech/debug/native-crash.html index 00f72cd0..686af070 100644 --- a/en/devices/tech/debug/native-crash.html +++ b/en/devices/tech/debug/native-crash.html @@ -49,15 +49,40 @@ plus SIGABRT are the things to look for in the <code>debuggerd</code> output to recognize this case.</p> <p> -As mentioned above, there may be an explicit "abort message" line. But you +As mentioned above, there may be an explicit "abort message" line. You should also look in the <code>logcat</code> output to see what this thread logged before -deliberately killing itself, because the basic abort primitive doesn't accept a -message. +deliberately killing itself, because unlike assert(3) or high level fatal logging +facilities, abort(3) doesn't accept a message. </p> + +<p> +Current versions of Android inline the <code><a +href="http://man7.org/linux/man-pages/man2/tgkill.2.html">tgkill(2)</a></code> +system call, so their stacks are the easiest to read, with the call to abort(3) +at the very top: +</p> +<pre class="devsite-click-to-copy"> +pid: 4637, tid: 4637, name: crasher >>> crasher <<< +signal 6 (<i style="color:Orange">SIGABRT</i>), code -6 (SI_TKILL), fault addr -------- +<i style="color:Orange">Abort message</i>: 'some_file.c:123: some_function: assertion "false" failed' + r0 00000000 r1 0000121d r2 00000006 r3 00000008 + r4 0000121d r5 0000121d r6 ffb44a1c r7 0000010c + r8 00000000 r9 00000000 r10 00000000 r11 00000000 + ip ffb44c20 sp ffb44a08 lr eace2b0b pc eace2b16 +backtrace: + #00 pc 0001cb16 /system/lib/<i style="color:Orange">libc.so</i> (<i style="color:Orange">abort</i>+57) + #01 pc 0001cd8f /system/lib/libc.so (__assert2+22) + #02 pc 00001531 /system/bin/crasher (do_action+764) + #03 pc 00002301 /system/bin/crasher (main+68) + #04 pc 0008a809 /system/lib/libc.so (__libc_init+48) + #05 pc 00001097 /system/bin/crasher (_start_main+38) +</pre> + <p> -Older versions of Android (especially on 32-bit ARM) followed a convoluted path -between the original abort call (frame 4 here) and the actual sending of the -signal (frame 0 here): +Older versions of Android followed a convoluted path between the original abort call (frame 4 here) +and the actual sending of the signal (frame 0 here). This was especially true on 32-bit ARM, +which added <code>__libc_android_abort</code> (frame 3 here) to the other platforms' sequence of +<code>raise</code>/<code>pthread_kill</code>/<code>tgkill</code>: </p> <pre class="devsite-click-to-copy"> pid: 1656, tid: 1656, name: crasher >>> crasher <<< @@ -80,28 +105,6 @@ backtrace: #09 pc 00000abc /system/xbin/crasher </pre> <p> -More recent versions call <code><a -href="http://man7.org/linux/man-pages/man2/tgkill.2.html">tgkill(2)</a></code> -directly from <code>abort</code>, so there are fewer stack frames for you to -skip over before you get to the interesting frames:</p> - -<pre class="devsite-click-to-copy"> -pid: 25301, tid: 25301, name: crasher >>> crasher <<< -signal 6 (SIGABRT), code -6 (SI_TKILL), fault addr -------- - r0 00000000 r1 000062d5 r2 00000006 r3 00000008 - r4 ffa09dd8 r5 000062d5 r6 000062d5 r7 0000010c - r8 00000000 r9 00000000 sl 00000000 fp ffa09f0c - ip 00000000 sp ffa09dc8 lr eac63ce3 pc eac93f0c cpsr 000d0010 -backtrace: - #00 pc 00049f0c /system/lib/libc.so (tgkill+12) - #01 pc 00019cdf /system/lib/libc.so (abort+50) - #02 pc 000012db /system/xbin/crasher (maybe_abort+26) - #03 pc 000015b7 /system/xbin/crasher (do_action+414) - #04 pc 000020d5 /system/xbin/crasher (main+100) - #05 pc 000177a1 /system/lib/libc.so (__libc_init+48) - #06 pc 000010e4 /system/xbin/crasher (_start+96) -</pre> -<p> You can reproduce an instance of this type of crash using: <code>crasher abort</code> </p> |