Re: [PATCH v4 0/8] Validate binary before use

[Eli Zaretskii <eliz@gnu.org>]

> Date: Sun, 9 Mar 2014 19:58:03 +0100
> From: Jan Kratochvil <jan.kratochvil@redhat.com>
> Cc: gdb-patches@sourceware.org, ARistovski@qnx.com
> 
> > > +@smallexample
> > > +  Shared object "libfoo.so.1" could not be validated and will be ignored;
> > > +  or use 'set solib-build-id-force'.
> > > +@end smallexample
> > 
> > Hmm... the text says that GDB will ignore symbol files, but the error
> > message you cite complains about the shared library,
> 
> "Shared object" is terminology in GDB, it is in fact the symbol file because
> GDB never modifies the inferior itself where the real target shared object
> exists.
> 
> Just with the build-id comparisons I used "shared library" (as the target
> in-memory data) vs. "symbol file" to highlight this difference.

Sorry, I don't follow: libfoo.so.1 is a shared library, isn't it?
There's no reference in the message to any symbol file, right?

> > and doesn't even mention the fact that the problem is a mismatch of the
> > 2 build-ids.  Why not say explicitly that the build-id of the symbol file
> > doesn't match that of the shared library?
> 
> This comes from the API, I can rework the patch.  The API currently uses
> method "validate" which can validate it in arbitary way.  The current only
> implmentation in solib-svr4 implements the validation using build-ids but the
> error/warning message is currently handled by the caller, not the
> build-id-specific implementation in solib-svr4.

I think it's fine to leave the validation details unspecified, if you
want.  But then we shouldn't reveal that its actual implementation is
comparing the build-ids.  If we want to leave it opaque, let's do it
consistently, i.e. both in the warnings printed by GDB and in the
manual.  OTOH, if we do want to tell that build-ids should be
identical, then let's say that in the warning/error messages as well,
again for consistency.