Re: Filter design for nsmux

[olafBuddenhagen]

Hi,

On Mon, May 11, 2009 at 10:18:59PM +0300, Sergiu Ivanov wrote:

> antrik told me to try to step into the dir_lookup call, but gdb does
> not want to comply with my desires... I installed hurd-dbg package (as
> antrik had recommended), but it didn't help.

Eh, right... You obviously need libc0.3-dbg for that rather than
hurd-dbg -- glibc is where most of the client side stuff resides. Sorry.

However, using libc-dbg is tricky: The symbols are not loaded
automatically, unlike with other -dbg packages. IIRC you have to set
LD_LIBRARY_PATH to /lib/debug/lib or something... Except that it doesn't
seem to work anymore :-( So I can't really help here.

Also note that for single-stepping, you need to get the source code as
well, and point gdb to the right location. (I used a trick in the past:
Create a symlink to make the source code appear at the same location as
it was on the build host, so gdb picks it up automatically...)

> However, everything looks to be very much like our supposition:
> dir_lookup does not even try to invoke the corresponding RPC and
> decides what to do on its own.

Again, guessing is not helpful. Single-stepping would be nice, but it
you can't do that, you can at least look up the code of the dir_lookup()
stub in the glibc tree, and try to understand what is actually going
on...

(Note that the stubs are generated files, i.e. you have to build glibc
to look at them.)

-antrik-