Excerpts from Segher Boessenkool's message of May 18, 2020 10:19 pm:

Hi!

On Mon, May 18, 2020 at 04:35:22PM +1000, Michael Ellerman wrote:

quoted

Nicholas Piggin [off-list ref] writes:

quoted

Provide an option to build big-endian kernels using the ELF V2 ABI. This works
on GCC and clang (since about 2014). it is is not officially supported by the
GNU toolchain, but it can give big-endian kernels  some useful advantages of
the V2 ABI (e.g., less stack usage).

quoted

This doesn't build with clang:

  /tmp/aesp8-ppc-dad624.s: Assembler messages:
  /tmp/aesp8-ppc-dad624.s: Error: .size expression for aes_p8_set_encrypt_key does not evaluate to a constant

What does this assembler code that clang doesn't swallow look like?  Is
that valid code?  Etc.

The .size directive calculation is .text - .opd because the preprocessor 
isn't passing -mabi=elfv2 which makes our _GLOBAL function entry macro 
use the v1 convention. I guess I got the 64-bit vdso wrong as well, it 
should remain in ELFv1.

Thanks,
Nick