Cause of the ?? in backtrace

[Bin Chen]

Rich Rattanni 写道:
> Why would one get the following when trying to do a backtrace in GDB...
> (gdb) bt
> #0 0x403cdcb4 in _int_malloc () from /lib/libc.so.6
> #1 0x403cedfc in malloc () from /lib/libc.so.6
> #2 0x401c4418 in sqlite3MallocRaw () from /usr/lib/libsqlite3.so.0
> #3 0x401c450c in sqlite3StrNDup () from /usr/lib/libsqlite3.so.0
> #4 0x401cc070 in sqlite3VdbeChangeP3 () from /usr/lib/libsqlite3.so.0
> #5 0x401cc0ac in sqlite3VdbeOp3 () from /usr/lib/libsqlite3.so.0
> #6 0x401ac010 in sqlite3CodeSubselect () from /usr/lib/libsqlite3.so.0
> #7 0x401ab4b0 in sqlite3ExprCode () from /usr/lib/libsqlite3.so.0
> #8 0x401abd00 in sqlite3ExprIfFalse () from /usr/lib/libsqlite3.so.0
> #9 0x401d02cc in sqlite3WhereBegin () from /usr/lib/libsqlite3.so.0
> #10 0x401bf13c in sqlite3Select () from /usr/lib/libsqlite3.so.0
> #11 0x401b6978 in sqlite3Parser () from /usr/lib/libsqlite3.so.0
> #12 0x401c12e0 in sqlite3RunParser () from /usr/lib/libsqlite3.so.0
> #13 0x47de97e0 in ?? () <------------------------------- This
> is my problem
> Cannot access memory at address 0x30 <------------|
> (gdb)
>
Just FYI. Last time I encounter such problem and I found that it is not 
caused with your private code didn't compile with -g, but is caused by 
your common libc related library didn't contain the debug info.