Re: Extending GDB: Python: Wrong handling of 64-bit pointers

[Andrew Pinski <pinskia at gmail dot com>]

On Tue, Oct 9, 2012 at 10:30 AM, chandan r <chandanrmail@gmail.com> wrote:
> Hi all,
>
> As the following CLI interactions show, GDB's python support code seems to be
> mishandling 64-bit pointers (GNU/Linux on x86-64):
>
> NOTE: "p" is a pointer of type "struct task_struct *"
>
> (gdb) python print gdb.parse_and_eval("p")
> 0xffff88001f5f7600
> (gdb) python print long(gdb.parse_and_eval("p"))
> -131940868983296
> (gdb) show version
> show version
> GNU gdb (GDB) 7.5
> Copyright (C) 2012 Free Software Foundation, Inc.
> License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
> This is free software: you are free to change and redistribute it.
> There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
> and "show warranty" for details.
> This GDB was configured as "x86_64-unknown-linux-gnu".
> For bug reporting instructions, please see:
> <http://www.gnu.org/software/gdb/bugs/>.
>
> Is it GDB or am I messing up something here?

Nothing looks wrong as -131940868983296 is the same as
0xffff88001f5f7600 in signed integer.
(gdb) p/x -131940868983296
$1 = 0xffff88001f5f7600

Thanks,
Andrew Pinski

>
> --
> Chandan