On Thu, 17 Jan 2008, Joey Hess wrote:
> I'm unsure about older versions of dpkg-shlibdeps. The current, insanely
> smart version, doesn't get too upset when run on split debugging symbol
> files:
>
> [EMAIL PROTECTED]:~package/aalib>dpkg-shlibdeps
> /usr/lib/debug/usr/lib/libaa.so.1.0.4
> objdump: /usr/lib/debug/usr/lib/libaa.so.1.0.4: Invalid operation
>
> (The return code is zero.)
>
> Raphael, is the objbump message above passed through intentionally?
It can be debated...
open(my $objdump, "-|", "objdump", "-w", "-f", "-p", "-T", "-R", $file)
|| syserr(sprintf(_g("Can't execute objdump: %s"), $!));
my $ret = $self->_parse($objdump);
close($objdump);
Thus it's not checking the return code of objdump and it's not redirecting its
stderr either. Since this is deep in a module used by dpkg-shlibdeps, it's not
a good idea to fail directly. In that condition hiding the errors is not a good
idea.
dpkg-shlibdeps generally acts on the assumption that its input is sane.
That said, if you know of a simple way to identify stuff that can be safely
excluded, I'll consider it.
> If dpkg-shlibdeps didn't print that message at all and silently skipped
> separated debug symbol files, I'd be inclined to make dh_shlibdeps
> not exclude anything in usr/lib/debug. If the message is intentional or
> cannot be gotten rid of, it seems that dh_shlibdeps should be changed to
> use a tighter exclude pattern, maybe including usr/lib/debug/*.so* while
> excluding anything else under usr/lib/debug ..
This will probably not work as expected:
$ objdump -w -f -p -T -R /usr/lib/debug/usr/bin/gnome-panel >/dev/null
objdump: /usr/lib/debug/usr/bin/gnome-panel: not a dynamic object
objdump: /usr/lib/debug/usr/bin/gnome-panel: Invalid operation
$ objdump -w -f -p -T -R /usr/bin/gnome-panel >/dev/null
$
And those files really look like normal ELF objects at first look (with file or
with objdump -a). If we want to relibaly detect those, we apparently have to
call
"objdump -p" on them and check if there's something in the "Dynamic Section:"
or not. If yes, then it should be safe to be analyzed.
Cheers,
--
Raphaël Hertzog
Le best-seller français mis à jour pour Debian Etch :
http://www.ouaza.com/livre/admin-debian/
