ios - Segfault from NSLog? -

i'm seeing segfault using nslog , specifically, on 64 bit device, segv_accerr. i'm new ios, i'm little confused.

here's stack trace:

exception type:  sigsegv exception codes: segv_accerr @ 0x108074000 crashed thread:  0  thread 0 crashed: 0   libsystem_platform.dylib             0x00000001826ea31c _platform_memmove + 300 1   libsystem_asl.dylib                  0x00000001825289a4 asl_string_append_no_encoding_len + 92 2   libsystem_asl.dylib                  0x0000000182522fc8 asl_string_new + 108 3   libsystem_asl.dylib                  0x0000000182522df4 asl_msg_to_string_raw + 68 4   libsystem_asl.dylib                  0x00000001825228dc _asl_send_message + 828 5   libsystem_asl.dylib                  0x00000001825224fc asl_send + 8 6   corefoundation                       0x0000000182a6fa1c __cflogcstring + 568 7   corefoundation                       0x0000000182a6f7ac _cflogvex2 + 300 8   corefoundation                       0x0000000182a6fc14 _cflogvex3 + 152 9   foundation                           0x0000000183435dd8 _nslogv + 128 10  foundation                           0x000000018336ae04 nslog + 28 

here code calls this:

    nsstring *truncated = [nsstring stringwithutf8string:buffer];     // using original nslog print.     #undef nslog             nslog(@"%@", truncated); 

and crashes nslog call.

where buffer char buffer.

my questions are:

1. is possible crash using apple's provided nslog? or stack trace wrong?
2. what seg_accerr mean in context?
3. how go finding if caused bad memory issue or not?
4. is blowing asl file under multiple threads?
5. how should approach debugging this?

any appreciated! thanks!

you buffer char buffer. if case, should initialize string this

nsstring *truncated = [[nsstring alloc] initwithbytes:buffer length:len nsutf8stringencoding];

where len length of characters in buffer.