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POiOS crash log, backtrace not available
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  1. POiOS crash log, backtrace not available
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    copied!<h2>Summary</h2> <p>Since the last update of our app was released, many users started complaining about the app not starting anymore. We received a crash log and console log from 2 different users, as well as a video from the crash. </p> <p>Our app does not crash on every device, but when it does it crashes every single time within a second of tapping the icon (the video shows this as well as the phone of a friend).</p> <p>The crash log is very weird, for it does not contain a backtrace and the frame pointer (R7) is 0x00000000. We didn't change much for this update and nothing we changed could corrupt the stack like this. Furthermore, reinstalling the app fixes the issue. This leads us to believe the error is not in our code, but in the binary which might have become corrupted somewhere.</p> <h2>Details</h2> <p>According to some users our app crashes on startup since the last update. We are unable to reproduce this issue but received crash logs from one the users. The log comes from the harddrive of the user (~/Library/Logs/CrashReporter/MobileDevice/). I've seen the same thing directly from the phone of a friend who experiences the same issue.</p> <p>This crash appears to occur as soon as our app receives control from iOS (see update). However, the crash logs contains no backtrace and states an error occurred on an unknown thread. I tried symbolicating the log, but obviously there is nothing to symbolicate.</p> <p>It appears to be some kind of nullpointer error, but why no backtrace? What could cause this type of error and what can I do to reproduce/solve it?</p> <pre><code>Incident Identifier: 984C8208-F4B4-4325-90B3-C9BE371E1A12 CrashReporter Key: c512972e5cd00e75d8d7a6ddb59ff9a08946fd7b Hardware Model: iPad3,3 Process: MyApp [3224] Path: /var/mobile/Applications/A0AEAA1D-7E5D-4BDC-8C9F-EA5FF4595059/MyApp.app/MyApp Identifier: MyApp Version: ??? (???) Code Type: ARM (Native) Parent Process: launchd [1] Date/Time: 2012-10-18 09:27:06.158 +0200 OS Version: iOS 6.0 (10A403) Report Version: 104 Exception Type: EXC_BAD_ACCESS (SIGSEGV) Exception Codes: KERN_INVALID_ADDRESS at 0x00000000 Highlighted Thread: 0 Backtrace not available Unknown thread crashed with ARM Thread State (32-bit): r0: 0x000e64e0 r1: 0x7f8940c0 r2: 0x00000000 r3: 0x3c56cb88 r4: 0x2fd1bd34 r5: 0x00000000 r6: 0x00000000 r7: 0x00000000 r8: 0x2fd1bd3c r9: 0x3c5688a8 r10: 0x00000000 r11: 0x00000000 ip: 0x80000028 sp: 0x2fd1bd40 lr: 0x2fe9a8d7 pc: 0x000e64e0 cpsr: 0x60000010 Binary Images: 0xe5000 - 0x170fff +MyApp armv7 &lt;15fd2c3131d03790bcd321411a241390&gt; /var/mobile/Applications/A0AEAA1D-7E5D-4BDC-8C9F-EA5FF4595059/MyApp.app/MyApp 0x2fe96000 - 0x2feb6fff dyld armv7 &lt;75594988728831d98e1f7c4c7b7ca29d&gt; /usr/lib/dyld [...] </code></pre> <h2>Update</h2> <p>A video sent to me by the same user indicates the app crashes even <em>before</em> the intro animation starts. So before the app is actually running (or one of the first lines of code our app runs).</p> <p>In ARMv6/7 architecture, the R7 register holds the frame pointer. It should point to the previous stack frame, but is 0x00000000 in our case. A lot of registers are null actually. What could possibly cause this? </p> <p>Also, the crashing is very consistent; it crashes <em>every time</em> within a second of tapping the icon. At least for this particular user. We've had more, but less specific, reports of the app "not starting". Re-installing the app fixes any problem the user had.</p> <p>The console log doesn't show much either, just this:</p> <p>It's starting to sound very much like updating through the App Store corrupts the binary, but only on updating:</p> <p><a href="http://www.pcworld.com/article/258827/updated_apps_crashing_heres_what_you_need_to_know.html" rel="nofollow">http://www.pcworld.com/article/258827/updated_apps_crashing_heres_what_you_need_to_know.html</a></p> <p><a href="http://www.marco.org/2012/07/04/app-store-corrupt-binaries" rel="nofollow">http://www.marco.org/2012/07/04/app-store-corrupt-binaries</a></p> <p>I've sent a request to Apple's technical service to help out on this. I'll report back here.</p> <h2>Apple Technical Service update</h2> <p>I've posted a bug report, they requested a console log of the time of crash. I've supplied them one, which to my understanding doesn't contain much of use. Except:</p> <pre><code>2012-10-23 09:14:18 +0000 backboardd Application 'UIKitApplication:com.company.myapp[0xdd31]' exited abnormally with signal 11: Segmentation fault: 11 </code></pre> <p>The technical department doesn't know what to do about this issue either, but advised us NOT to upload a new binary without any code changes. There is no way to test if the issues goes away (wtf) and if it doesn't work it will upset users even more.</p> <p>Still waiting for the answer to my bug report...</p>
 

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