Crash in objc_end_catch when catching re-thrown exception on armeabi-v7a

[triplef]

Calling the following -test method on armeabi-v7a crashes with SEGV_MAPERR in objc_end_catch() (eh_personality.c:638) using the libc++ branch (#152) because td->caughtExceptions is NULL. Other ABIs (arm64, i386) are unaffected.

- (void)test
{
	@try {
		[self catchAndRethrowException];
	} @catch (NSException *e) {
		NSLog(@"ObjC exception 2: %@", e);
	}
}

- (void)catchAndRethrowException
{
	@try {
		[[NSException exceptionWithName:NSInternalInconsistencyException reason:@"Test ObjC Exception" userInfo:nil] raise];
	} @catch (NSException *e) {
		NSLog(@"ObjC exception 1: %@", e);
		[e raise];
	}
}

Unfortunately I’m not able to test this with the latest master as it doesn’t build for ARM. The latest EH changes seem to assume the Itanium ABI, as the private_1/private_2 fields don’t exist on ARM (please let me know if I should open a separate issue for this):

eh_personality.c:571:22: error: no member named 'private_1' in 'struct _Unwind_Exception'
                ex->cxx_exception->private_1 = exceptionObject->private_1;

[davidchisnall]

Does this still fail? The C++ exception interop tests fail in CI on 32-bit Arm, but I don't think that's related?

[hmelder]

Cannot reproduce this on Debian Unstable armhf (armv7l-unknown-linux-gnueabihf). Have to test this on Android with armeabi-v7a.

root@debian:~# clang-18 --version
Debian clang version 18.1.4 (1)
Target: arm-unknown-linux-gnueabihf
Thread model: posix
InstalledDir: /usr/bin

2024-04-27 15:00:16.895 a.out[11050:11050] ObjC exception 1: <NSException: 0x1e809a4> NAME:NSInternalInconsistencyException REASON:Test ObjC Exception INFO:(null)
2024-04-27 15:00:16.921 a.out[11050:11050] ObjC exception 2: <NSException: 0x1e809a4> NAME:NSInternalInconsistencyException REASON:Test ObjC Exception INFO:(null)

[hmelder]

Was able to reproduce this on armeabi-v7a Android 10 API29.

2024-05-07 09:24:40.653 18735-18735 com.exampl...pplication com.example.myapplication            E  [thread:2579433444] Testing Objective-C Exceptions
2024-05-07 09:24:40.657 18735-18735 libc                    com.example.myapplication            A  Fatal signal 11 (SIGSEGV), code 1 (SEGV_MAPERR), fault addr 0x0 in tid 18735 (e.myapplication), pid 18735 (e.myapplication)
2024-05-07 09:24:40.797 18828-18828 DEBUG                   pid-18828                            A  pid: 18735, tid: 18735, name: e.myapplication  >>> com.example.myapplication <<<
2024-05-07 09:24:41.623 18828-18828 DEBUG                   crash_dump32                         A        #01 pc 00086d55  /data/app/com.example.myapplication-bvkfI6_5gXWTYAVnmUw2pA==/base.apk!libc++_shared.so (offset 0x6c8000) (BuildId: 02d0aa8c4dc8332a9dad132ede6ba1a9e24cee0b)
2024-05-07 09:24:41.623 18828-18828 DEBUG                   crash_dump32                         A        #02 pc 00087209  /data/app/com.example.myapplication-bvkfI6_5gXWTYAVnmUw2pA==/base.apk!libc++_shared.so (offset 0x6c8000) (BuildId: 02d0aa8c4dc8332a9dad132ede6ba1a9e24cee0b)
2024-05-07 09:24:41.623 18828-18828 DEBUG                   crash_dump32                         A        #03 pc 000871a5  /data/app/com.example.myapplication-bvkfI6_5gXWTYAVnmUw2pA==/base.apk!libc++_shared.so (offset 0x6c8000) (BuildId: 02d0aa8c4dc8332a9dad132ede6ba1a9e24cee0b)
2024-05-07 09:24:41.623 18828-18828 DEBUG                   crash_dump32                         A        #04 pc 00086e6b  /data/app/com.example.myapplication-bvkfI6_5gXWTYAVnmUw2pA==/base.apk!libc++_shared.so (offset 0x6c8000) (__gxx_personality_v0+174) (BuildId: 02d0aa8c4dc8332a9dad132ede6ba1a9e24cee0b)
2024-05-07 09:24:41.623 18828-18828 DEBUG                   crash_dump32                         A        #05 pc 00011e35  /data/app/com.example.myapplication-bvkfI6_5gXWTYAVnmUw2pA==/base.apk!libobjc.so (offset 0x610000) (__gnustep_objcxx_personality_v0+216) (BuildId: a7d7a17ffe869b89ba802b0dc285ce588a0aa629)
2024-05-07 09:24:41.623 18828-18828 DEBUG                   crash_dump32                         A        #06 pc 0001c278  /data/app/com.example.myapplication-bvkfI6_5gXWTYAVnmUw2pA==/base.apk!libobjc.so (offset 0x610000) (BuildId: a7d7a17ffe869b89ba802b0dc285ce588a0aa629)
2024-05-07 09:24:41.623 18828-18828 DEBUG                   crash_dump32                         A        #07 pc 0001c1b0  /data/app/com.example.myapplication-bvkfI6_5gXWTYAVnmUw2pA==/base.apk!libobjc.so (offset 0x610000) (BuildId: a7d7a17ffe869b89ba802b0dc285ce588a0aa629)
2024-05-07 09:24:41.623 18828-18828 DEBUG                   crash_dump32                         A        #08 pc 000118a7  /data/app/com.example.myapplication-bvkfI6_5gXWTYAVnmUw2pA==/base.apk!libobjc.so (offset 0x610000) (objc_exception_throw+146) (BuildId: a7d7a17ffe869b89ba802b0dc285ce588a0aa629)
2024-05-07 09:24:41.623 18828-18828 DEBUG                   crash_dump32                         A        #09 pc 0029df6b  /data/app/com.example.myapplication-bvkfI6_5gXWTYAVnmUw2pA==/base.apk!libgnustep-base.so (offset 0x290c000) (BuildId: c5457c2c730de792682f69f84d2ed999b74595cd)
2024-05-07 09:24:41.623 18828-18828 DEBUG                   crash_dump32                         A        #10 pc 00001e87  /data/app/com.example.myapplication-bvkfI6_5gXWTYAVnmUw2pA==/base.apk!libnative-lib.so (offset 0x3544000) (BuildId: e589f4513c32bb10cca8e9a2ce75df50c81abc7f)
2024-05-07 09:24:41.624 18828-18828 DEBUG                   crash_dump32                         A        #11 pc 00001dbf  /data/app/com.example.myapplication-bvkfI6_5gXWTYAVnmUw2pA==/base.apk!libnative-lib.so (offset 0x3544000) (BuildId: e589f4513c32bb10cca8e9a2ce75df50c81abc7f)
2024-05-07 09:24:41.624 18828-18828 DEBUG                   crash_dump32                         A        #12 pc 00001f6d  /data/app/com.example.myapplication-bvkfI6_5gXWTYAVnmUw2pA==/base.apk!libnative-lib.so (offset 0x3544000) (Java_com_example_myapplication_MainActivity_blockOperation+52) (BuildId: e589f4513c32bb10cca8e9a2ce75df50c81abc7f)
2024-05-07 09:24:41.625 18828-18828 DEBUG                   crash_dump32                         A        #21 pc 00000354  [anon:dalvik-classes4.dex extracted in memory from /data/app/com.example.myapplication-bvkfI6_5gXWTYAVnmUw2pA==/base.apk!classes4.dex] (com.example.myapplication.MainActivity.onCreate+32)