EXC_BAD_ACCESS 在设备上，但在模拟器上很好 [英] EXC_BAD_ACCESS on device, but fine on Simulator

问题描述

我有一个在模拟器上运行良好的滚动视图应用程序，但是，当我安装在设备上时，当我尝试滚动一页时，它会给我一个 EXC_BAD_ACCESS.我已经通过具有分配和泄漏的仪器运行它，但没有任何泄漏，也没有僵尸消息...我只是好奇是什么可能导致模拟器与设备之间的这种差异?任何调试方法，因为我的符号化崩溃日志(部分如下)，似乎不是很符号化.

I have a scroll view app which runs fine on the simulator, however, when installed on the device, it gives me an EXC_BAD_ACCESS, when i attempt to scroll one page. I have ran it through Instruments with Allocations and Leaks, but nothing is leaked and no zombies are messaged... i'm just curious what could cause such a difference in simulator vs device? Any ways to debug this, since my symbolicated crash log (partial below), doesn't seem to be very symbolicated.

异常类型:EXC_BAD_ACCESS (SIGBUS)
异常代码:0x0000000f 处的 KERN_PROTECTION_FAILURE
崩溃的线程:0

Exception Type: EXC_BAD_ACCESS (SIGBUS)
Exception Codes: KERN_PROTECTION_FAILURE at 0x0000000f
Crashed Thread: 0

线程 0 崩溃:
0 libobjc.A.dylib          0x0000286e objc_msgSend + 18
1 我的应用程序                 0x00004fee 0x1000 + 16366
2 UIKit                   0x000668f4 -[UIViewController 视图] + 104
3 我的应用程序                0x00009716 0x1000 + 34582
4 我的应用程序               0x0000960c 0x1000 + 34316
5 UIKit                   0x0001426c -[UIScrollView setContentOffset:] + 344

Thread 0 Crashed:
0 libobjc.A.dylib            0x0000286e objc_msgSend + 18
1 MyApp                       0x00004fee 0x1000 + 16366
2 UIKit                         0x000668f4 -[UIViewController view] + 104
3 MyApp                     0x00009716 0x1000 + 34582
4 MyApp                     0x0000960c 0x1000 + 34316
5 UIKit                         0x0001426c -[UIScrollView setContentOffset:] + 344

谢谢

推荐答案

您在模拟器中的代码可能有错误，但不会触发 EXC_BAD_ACCESS 只是因为您取消引用的指针不在未映射的内存中.一个指针可能是坏的，可以访问，但没有被检测到——它仍然是一个错误.

Your code in the simulator could have the bug, but isn't triggering EXC_BAD_ACCESS by just the luck that a pointer that you dereference is not in unmapped memory. A pointer could be bad, and accessed, but not detected -- it's still a bug.

你已经检查了没有僵尸消息，这本来是我的第一个建议.

You have already checked to see that no Zombies are messaged, which would have been my first suggestion.

接下来要做的是启用 Guard Malloc -- 然后阅读本文

The next thing to do is Enable Guard Malloc -- and then read this

http://developer.apple.com/iphone/library/documentation/Performance/Conceptual/ManagingMemory/Articles/MallocDebug.html

您只能在模拟器中执行此操作——您的目标是使用超敏感堆使错误在模拟器中抛出 EXC_BAD_ACCESS.

You can only do this in the simulator -- your goal is to use the extra-sensitive heap to make the bug throw EXC_BAD_ACCESS in the simulator.

在文章中:

1. 看看如何在GDB中设置变量
2. 阅读检测堆损坏"部分

这篇关于EXC_BAD_ACCESS 在设备上，但在模拟器上很好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IT屋！