[EXT] Re: gdb does not stop at printf for ppc

[Peter Bergner]

On 10/2/25 11:58 AM, Florian Weimer wrote:
> * Peter Bergner via Libc-help:
> 
>> Ok, it's an even bigger problem than we thought.  I'm surprised no one
>> else has hit this before us.
> 
> We've encountered it with fortification and IFUNC resolvers.  It used to
> be considered a user error.

Yeah, I don't think we can consider this a user error, since the user
called printf() and so should validly expect that "break printf" in gdb
should work.  It was only the shifty compiler that silently replaced
printf with __printfieee128 that broke everything! :-)



>> Ok, this is promising and yeah, is what Carl and Uli suggested.
>> That said, their comment from the bugzilla:
>>
>>     The new redirected symbols need to be dynamic symbols in case only
>>     the stripped binary is available.
> 
> I'd recommend distributions do not strip .symtab on libc.so.6.  I don't
> think making this a dynamic symbol is worth it.  It would have to be a
> compatibility symbol under a separate symbol version, one for each
> variant alias (eight for POWER?).  This is quite a bit of complexity.

I'd be fine with that, if that is what everyone else thinks is best.
Worst case, a distro strips libc.so.6 and we're just back with the
current state of behavior.  Do we know what Debian/Ubuntu and Gentoo
do wrt strpping or not stripping libc.so.6?

I definitely don't like the idea of all of those compatibility symbols!


Peter