This is the mail archive of the mailing list for the GDB project.

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: Cause of the ?? in backtrace

On Mon, 2007-03-12 at 10:47 -0400, Rich Rattanni wrote:
> Why would one get the following when trying to do a backtrace in GDB...
> (gdb) bt
> #0  0x403cdcb4 in _int_malloc () from /lib/
> #1  0x403cedfc in malloc () from /lib/
> #2  0x401c4418 in sqlite3MallocRaw () from /usr/lib/
> #3  0x401c450c in sqlite3StrNDup () from /usr/lib/
> #4  0x401cc070 in sqlite3VdbeChangeP3 () from /usr/lib/
> #5  0x401cc0ac in sqlite3VdbeOp3 () from /usr/lib/
> #6  0x401ac010 in sqlite3CodeSubselect () from /usr/lib/
> #7  0x401ab4b0 in sqlite3ExprCode () from /usr/lib/
> #8  0x401abd00 in sqlite3ExprIfFalse () from /usr/lib/
> #9  0x401d02cc in sqlite3WhereBegin () from /usr/lib/
> #10 0x401bf13c in sqlite3Select () from /usr/lib/
> #11 0x401b6978 in sqlite3Parser () from /usr/lib/
> #12 0x401c12e0 in sqlite3RunParser () from /usr/lib/
> #13 0x47de97e0 in ?? ()        <------------------------------- This
> is my problem

Specifically, the ?? means that gdb could not find a symbol to 
correspond with the instruction address 0x47de97e0.  This might
mean any number of things.

If the address is legitimate (ie. the return address of sqlite3RunParser
really does point back to a caller at 0x47de97e0), then this caller 
may be from a library for which gdb has no symbols.  It might be 
self-generating code, in which case it may never have had any

Or the address may NOT be legitimate, and may have come about 
as a result of a corrupted stack or something.

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]