RE: Is it possible to overflow baton->size in dwarf_mark_symbols_computed() in dwarf2read.c?

["Cuthbertson, Reva D." <reva_cuthbertson at hp dot com>]

Yes, I ran into the problem.  I tried changing the declaration of the
"size" field in dwarf2_loclist_baton and dwarf2_locexpr_baton in
dwarf2loc.h to be an unsigned integer instead and that seemed to fix the
problem I encountered.  Do you think this a reasonable solution?

Thanks!

Reva Cuthbertson
reva.cuthbertson@hp.com

-----Original Message-----
From: Daniel Jacobowitz [mailto:drow@false.org] 
Sent: Friday, May 13, 2005 8:26 AM
To: Cuthbertson, Reva D.
Cc: gdb@sources.redhat.com
Subject: Re: Is it possible to overflow baton->size in
dwarf_mark_symbols_computed() in dwarf2read.c?

On Fri, May 13, 2005 at 08:18:47AM -0700, Cuthbertson, Reva D. wrote:
> Hello,
> 
> I had a question regarding the following assignment in
> dwarf2_mark_symbol_computed() in dwarf2read.c:
> 
> baton->size = dwarf2_per_objfile->loc_size - DW_UNSND (attr);
> 
> The field "loc_size" in dwarf2_per_objfile is declared to be an
unsigned
> integer and attr.u.unsnd (expansion of DW_UNSND (attr)) is declared to
> be an unsigned long but the "size" field in dwarf2_loclist_baton and
> dwarf2_locexpr_baton defined in dwarf2loc.h is defined to be an
unsigned
> short.  Is it possible to overflow baton->size with the above
> calculation?

Yes, this seems possible.  Size is used for overflow checking only at
this point; saturating at USHORT_MAX seems reasonable.

Have you encountered this problem?

-- 
Daniel Jacobowitz
CodeSourcery, LLC