[Ltrace-devel] [PATCH 4/8] Add LS_TOPLT_GOTONLY

[Edgar E. Iglesias]

On Thu, Sep 27, 2012 at 01:30:08AM +0200, Petr Machata wrote:
> edgar.iglesias at gmail.com writes:
> 
> > From: "Edgar E. Iglesias" <edgar at axis.com>
> >
> > to describe symbols with a GOT entry but without PLT
> > entry.
> >
> > Signed-off-by: Edgar E. Iglesias <edgar at axis.com>
> > ---
> >  library.h |    1 +
> >  1 files changed, 1 insertions(+), 0 deletions(-)
> >
> > diff --git a/library.h b/library.h
> > index f207502..d764da9 100644
> > --- a/library.h
> > +++ b/library.h
> > @@ -31,6 +31,7 @@ struct library;
> >  
> >  enum toplt {
> >  	LS_TOPLT_NONE = 0,	/* PLT not used for this symbol. */
> > +	LS_TOPLT_GOTONLY,	/* Has a GOT entry but no PLT.  */
> >  	LS_TOPLT_EXEC,		/* PLT for this symbol is executable. */
> >  };
> 
> This is fine for now, but consider the following.
> 


Thanks for the review, I'll go through everything and spinn a v2 of the
series.

> I see you use that value to decide whether to enable the PLT entry right
> away, or wait for a bit.  I have a patch sketched, for support of -l.
> For -l, we need to keep around "latent" PLT entries: those that nobody
> requested directly (via -e), but that we keep around (disabled) in case
> a library is mapped matching the -l criterion.  If that happens, some of
> those latent entries may be enabled.
> 
> This seems to fit your bill.  In arch_library_symbol_init, you would
> mark those symbols as latent (and sym->arch.gotonly = 1 or some such, so
> that you can tell them from the rest).  Later, in arch_dynlink_done, you
> loop through libraries like you do now, looking for gotonly symbols, and
> enabling them.

Sounds like it would work, once you have code I can take a closer look
and see if it fits nicely.

Cheers,
Edgar