Re: [PATCH v10 02/15] livepatch: avoid position-based search if `-z unique-symbol` is available

[Miroslav Benes]

On Wed, 16 Feb 2022, Josh Poimboeuf wrote:

> On Wed, Feb 16, 2022 at 04:06:24PM +0100, Miroslav Benes wrote:
> > > > +	/*
> > > > +	 * If the LD's `-z unique-symbol` flag is available and enabled,
> > > > +	 * sympos checks are not relevant.
> > > > +	 */
> > > > +	if (IS_ENABLED(CONFIG_LD_HAS_Z_UNIQUE_SYMBOL))
> > > > +		sympos = 0;
> > > > +
> > > 
> > > Similarly, I don't see a need for this.  If the patch is legit then
> > > sympos should already be zero.  If not, an error gets reported and the
> > > patch fails to load.
> > 
> > My concern was that if the patch is not legit (that is, sympos is > 0 for 
> > some reason), the error would be really cryptic and would not help the 
> > user at all. So zeroing sympos seems to be a good idea to me. There is no 
> > harm and the change is very small and compact.
> 
> But wouldn't a cryptic error be better than no error at all?  A bad
> sympos might be indicative of some larger issue, like the wrong symbol
> getting patched.

Maybe you are right. I do not feel confident enough to decide it. So 
either way would be fine, I guess.

Miroslav