EXC_BAD_ACCESS（SIGSEGV）崩潰

Question

如何追蹤崩潰？

Process:   iAddressGrabber [253] 
Path:   /Users/egrabber/Library/Application Support/iPhone Simulator/User/Applications/DB3B2896-258C-4EC2-A490-802B1190A675/iAddressGrabber.app/iAddressGrabber 
Identifier:  iAddressGrabber 
Version:   ??? (???) 
Code Type:  X86 (Native) 
Parent Process: launchd [64] 

Interval Since Last Report:   34544 sec 
Crashes Since Last Report:   1 
Per-App Interval Since Last Report: 0 sec 
Per-App Crashes Since Last Report: 2 

Date/Time:  2009-11-14 10:17:50.058 +0530 
OS Version:  Mac OS X 10.5.8 (9L30) 
Report Version: 6 
Anonymous UUID: 3EC1BE31-C7B9-47B9-8056-879CC319BF57 

Exception Type: EXC_BAD_ACCESS (SIGSEGV) 
Exception Codes: KERN_INVALID_ADDRESS at 0x00000000c0000023 
Crashed Thread: 0 

Application Specific Information: 
iPhone Simulator 3.0 (138), iPhone OS 3.0 (7A341) 

Thread 0 Crashed: 
0 libobjc.A.dylib     0x910e0688 objc_msgSend + 24 
1 CFNetwork      0x006b4868 URLConnectionClient::_clientDidFinishLoading(URLConnectionClient::ClientConnectionEventQueue*) + 194 
2 CFNetwork      0x006b40c8 URLConnectionClient::ClientConnectionEventQueue::processAllEventsAndConsumePayload(XConnectionEventInfo<XClientEvent, XClientEventParams>*, long) + 306 
3 CFNetwork      0x006b4d4c URLConnectionClient::processEvents() + 100 
4 CFNetwork      0x00662b29 MultiplexerSource::perform() + 183 
5 CoreFoundation     0x302452c1 CFRunLoopRunSpecific + 3217 
6 CoreFoundation     0x30244628 CFRunLoopRunInMode + 88 
7 GraphicsServices    0x32044c31 GSEventRunModal + 217 
8 GraphicsServices    0x32044cf6 GSEventRun + 115 
9 UIKit       0x309021ee UIApplicationMain + 1157 
10 iAddressGrabber     0x00001efc main + 102 (main.m:14) 
11 iAddressGrabber     0x00001e6a start + 54 

Thread 1: 
0 libSystem.B.dylib    0x928da286 mach_msg_trap + 10 
1 libSystem.B.dylib    0x928e1a7c mach_msg + 72 
2 CoreFoundation     0x30244d62 CFRunLoopRunSpecific + 1842 
3 CoreFoundation     0x30244628 CFRunLoopRunInMode + 88 
4 WebCore       0x3588ea13 __ZL12RunWebThreadPv + 467 
5 libSystem.B.dylib    0x9290b155 _pthread_start + 321 
6 libSystem.B.dylib    0x9290b012 thread_start + 34 

Thread 2: 
0 libSystem.B.dylib    0x928da286 mach_msg_trap + 10 
1 libSystem.B.dylib    0x928e1a7c mach_msg + 72 
2 CoreFoundation     0x30244d62 CFRunLoopRunSpecific + 1842 
3 CoreFoundation     0x30244628 CFRunLoopRunInMode + 88 
4 Foundation      0x3056002e +[NSURLConnection(NSURLConnectionReallyInternal) _resourceLoadLoop:] + 318 
5 Foundation      0x3050a79d -[NSThread main] + 45 
6 Foundation      0x3050a338 __NSThread__main__ + 280 
7 libSystem.B.dylib    0x9290b155 _pthread_start + 321 
8 libSystem.B.dylib    0x9290b012 thread_start + 34 

Thread 3: 
0 libSystem.B.dylib    0x929296fa select$DARWIN_EXTSN + 10 
1 libSystem.B.dylib    0x9290b155 _pthread_start + 321 
2 libSystem.B.dylib    0x9290b012 thread_start + 34 

Thread 0 crashed with X86 Thread State (32-bit): 
    eax: 0x00f797f0 ebx: 0x305063d1 ecx: 0x9117c334 edx: 0xc0000003 
    edi: 0x00f7b3b0 esi: 0xbfffeaa4 ebp: 0xbfffea28 esp: 0xbfffe8a8 
    ss: 0x0000001f efl: 0x00010206 eip: 0x910e0688 cs: 0x00000017 
    ds: 0x0000001f es: 0x0000001f fs: 0x00000000 gs: 0x00000037 
    cr2: 0xc0000023 

Answer 1

啓用NSZombie - 它會告訴你哪個取消分配的對象objcMsgSend正試圖調用。

請參閱this earlier question。

Answer 2

下面的技術說明中包含處理此類垃圾場所需的全部信息：

Technical Note TN2124 - Mac OS X Debugging Magic

一個小提示：

1 CFNetwork      0x006b4868 URLConnectionClient::_clientDidFinishLoading(URLConnectionClient::ClientConnectionEventQueue*) + 194 

關注這一部分，EXC_BAD_ACCESS建議一個（ab）使用無效的內存指針。