Re: [PATCH v2] powerpc/64: BE option to use ELFv2 ABI for big endian kernels

[Segher Boessenkool <segher@kernel.crashing.org>]

Hi!

On Mon, May 03, 2021 at 10:51:41AM +1000, Nicholas Piggin wrote:
> Excerpts from Segher Boessenkool's message of May 3, 2021 3:55 am:
> > On Wed, Apr 29, 2020 at 10:57:16AM +1000, Nicholas Piggin wrote:
> >> Excerpts from Segher Boessenkool's message of April 29, 2020 9:40 am:
> >> I blame toolchain for -mabi=elfv2 ! And also some blame on ABI document 
> >> which is called ELF V2 ABI rather than ELF ABI V2 which would have been 
> >> unambiguous.
> > 
> > At least ELFv2 ABI is correct.  "ELF ABI v2" is not.
> > 
> >> I can go through and change all my stuff and config options to ELF_ABI_v2.
> > 
> > Please don't.  It is wrong.
> 
> Then I'm not sure what the point of your previous mail was, what did I 
> miss?

I asked if you could make it clearer to people who do not know what this
is whether they want to use it.  Or that was my intention, anyhow :-/

> > Both the original PowerPC ELF ABI and the
> > ELFv2 one have versions themselves.  Also, the base ELF standard has a
> > version, and is set up so there can be incompatible versions even!  Of
> > course it still is version 1 to this day, but :-)
> 
> The point was for people who don't know ELFv2 has a specific meaning for 
> powerpc,

It does not have *any* meaning outside of Power.  But people who do not
know what it is can assume the wrong things about it.  It isn't a great
name because of that :-(

(It's not as bad as the MIPS ABIs -- an older one is called "new" :-) )

> then ELF ABIv2 is more explanatory about it being an abi change
> rather than base elf change, even if it's not the "correct" name.

I very much disagree.  "ELF ABIv2" is completely meaningless.

> If you don't want that then good, I also prefer to just use ELFv2. I 

Good :-)

> think people who change this option can easily look up the name in 
> toolchain and other docs.

Yeah.  As long as the defaults are good, whoever blows themselves up has
only themselves to blame :-P


Segher