Fixing namespace issues for variables

[Joseph Myers]

On Fri, 23 Oct 2015, Florian Weimer wrote:

> On 10/23/2015 02:13 PM, Joseph Myers wrote:
> > On Fri, 23 Oct 2015, Florian Weimer wrote:
> > 
> >> For real global variables, this isn't pretty, but I think it is
> >> acceptable (if the ELF specifics work out, including size changes, which
> > 
> > signgam is an int; there's no reason for its size to change.
> 
> I was worried about a conflicting size for an interposed definition in
> the main program.  This concern applies to an alias-based solution as

Well, with my solution for signgam new programs won't get their signgam 
symbol bound to glibc's at all, because glibc's will be a compat symbol, 
so the two will be completely independent.

With aliases, the symbol might end up pointing at runtime to the 
wrong-size symbol in the user's program, but if it was valid for the 
user's program to define that symbol then libc will never use that 
wrong-size copy (as the internal name used internally in libc will always 
point to libc's own copy).

-- 
Joseph S. Myers
joseph@codesourcery.com