Re: [PATCH 2/2] linux: Make profil_counter a compat_symbol (BZ#17726)

[Carlos O'Donell <carlos at redhat dot com>]

On 8/5/19 3:41 PM, Florian Weimer wrote:
> * Joseph Myers:
>
> > On Mon, 5 Aug 2019, Adhemerval Zanella wrote:
> >
> > > Also that this symbol export was not meant in first place, so it is unlikely
> >
> > Like all other exports, it's listed in a Versions file.  So it must have
> > been deliberate (even if mistaken) at some point.
>
> libc.map used to have this:
>
>      # all functions and variables in the normal name space
>      a*; b*; c*; d*; e*; f*; g*; h*; i*; j*; k*; l*; m*;
>      n*; o*; p*; q*; r*; s*; t*; u*; v*; w*; x*; y*; z*;
>
> So the missing static likely triggered the unwanted export, and that
> mistake was carried over when libc.map was switched over to explicit
> function names.  I do not see evidence of a deliberate decision here.
 
This is why we say "strong presumption" :-)

We want to err on the side of being cautious unless we have evidence
otherwise.

If there is no evidence that a deliberate and conscious decision was
made, then perhaps simplifying the situation may be fine e.g. no compat
symbols.

--
Cheers,
Carlos.